Finished partitioning uip.c (now system is broken)

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@375 42af7a65-404d-4744-a932-0658087f49c3

20 files changed, 2944 insertions, 1930 deletions

diff --git a/nuttx/fs/fs_open.c b/nuttx/fs/fs_open.c
index 094710d31..71fc8d0c4 100644
--- a/nuttx/fs/fs_open.c
+++ b/nuttx/fs/fs_open.c
@@ -74,7 +74,9 @@ int open(const char *path, int oflags, ...)
   struct filelist  *list;
   FAR struct inode *inode;
   const char       *relpath = NULL;
+#ifdef CONFIG_FILE_MODE
   mode_t            mode = 0666;
+#endif
   int               ret;
   int               fd;
 
diff --git a/nuttx/include/net/uip/uip-arch.h b/nuttx/include/net/uip/uip-arch.h
index 8f1d6b41f..1d4337839 100644
--- a/nuttx/include/net/uip/uip-arch.h
+++ b/nuttx/include/net/uip/uip-arch.h
@@ -57,28 +57,20 @@
  * Definitions
  ****************************************************************************/
 
-/* The following flags are passed as an argument to the uip_interrupt()
+/* The following flags are passed as an argument to the uip_poll()
  * function. They are used to distinguish between the two cases where
- * uip_interrupt() is called. It can be called either because we have
+ * uip_poll() is called. It can be called either because we have
  * incoming data that should be processed, or because the periodic
- * timer has fired. These values are never used directly, but only in
- * the macrose defined in this file.
+ * timer has fired.
  *
- * UIP_DRV_RECEIVE - There is new incoming data from the driver in the d_buf
- *                   field of the uip_driver_s structure.  The length of the
- *                   new data is provided in the d_len field of the
- *                   uip_driver_s structure.
  * UIP_DRV_TIMER   - Called periodically from driver to service timeout-
  *                   related activities to and to get timeout-related
  *                   responses (e.g., reset)
  * UIP_DRV_POLL    - Poll TCP for data to be transmitted
- * UIP_DRV_UDPPOLL - Poll for UDP data to be transmitted.  This value is used
- *                   internally by the uip_poll logic.
  */
 
-#define UIP_DRV_RECEIVE   1
-#define UIP_DRV_TIMER     2
-#define UIP_DRV_POLL      3
+#define UIP_DRV_TIMER     1
+#define UIP_DRV_POLL      2
 
 /****************************************************************************
  * Public Types
@@ -214,7 +206,7 @@ struct uip_driver_s
  *
  *     dev->d_len = devicedriver_poll();
  *     if(dev->d_len > 0) {
- *       uip_input();
+ *       uip_input(dev);
  *       if(dev->d_len > 0) {
  *         devicedriver_send();
  *       }
@@ -230,7 +222,7 @@ struct uip_driver_s
  *     if(dev->d_len > 0) {
  *       if(BUF->type == HTONS(UIP_ETHTYPE_IP)) {
  *         uip_arp_ipin();
- *         uip_input();
+ *         uip_input(dev);
  *         if(dev->d_len > 0) {
  *           uip_arp_out();
  *           devicedriver_send();
@@ -243,12 +235,12 @@ struct uip_driver_s
  *       }
  */
 
-#define uip_input(dev) uip_interrupt(dev, UIP_DRV_RECEIVE)
+extern void uip_input(struct uip_driver_s *dev);
 
 /* Polling of connections.
  *
  * This function will traverse each active uIP connection structure and
- * perform uip_interrupt with the specified event.  After each polling each
+ * perform uip_input with the specified event.  After each polling each
  * active uIP connection structure, this function will call the provided
  * callback function if the poll resulted in new data to be send.  The poll
  * will continue until all connections have been polled or until the user-
@@ -305,37 +297,29 @@ extern int uip_poll(struct uip_driver_s *dev, uip_poll_callback_t callback, int
 
 #define uip_periodic(dev,cb) uip_poll(dev, db, UIP_DRV_TIMER);
 
-/* Architecure support
- *
- * The actual uIP function which does all the work.  Called from the
- * interrupt level by a device driver.
- */
-
-extern void uip_interrupt(struct uip_driver_s *dev, uint8 event);
-
 /* By defining UIP_ARCH_CHKSUM, the architecture can replace the following
  * functions with hardware assisted solutions.
  */
 
 /* Carry out a 32-bit addition.
  *
- * Because not all architectures for which uIP is intended has native
- * 32-bit arithmetic, uIP uses an external C function for doing the
- * required 32-bit additions in the TCP protocol processing. This
- * function should add the two arguments and place the result in the
- * global variable uip_acc32.
+ * op32 - A pointer to a 4-byte array representing a 32-bit
+ *   integer in network byte order (big endian).  This value may not
+ *   be word aligned.
  *
- * Note: The 32-bit integer pointed to by the op32 parameter and the
- * result in the uip_acc32 variable are in network byte order (big
- * endian).
+ *   For uip_incr32, the value pointed to by op32 is modified in place
+ *   For uip_add32, the value pointed to by op32 is unmodified 
+*
+ * op16 - A 16-bit integer in host byte order.
  *
- * op32 A pointer to a 4-byte array representing a 32-bit
- * integer in network byte order (big endian).
+ * sum - The location to return the result (32-bit, network byte order,
+ *   possibly unaligned).
  *
- * op16 A 16-bit integer in host byte order.
+ *   uip_add32 only.
  */
 
-extern void uip_add32(uint8 *op32, uint16 op16);
+extern void uip_add32(const uint8 *op32, uint16 op16, uint8 *sum);
+extern void uip_incr32(uint8 *op32, uint16 op16);
 
 /* Calculate the Internet checksum over a buffer.
  *
diff --git a/nuttx/include/net/uip/uip.h b/nuttx/include/net/uip/uip.h
index 283891edb..ed8d85bed 100644
--- a/nuttx/include/net/uip/uip.h
+++ b/nuttx/include/net/uip/uip.h
@@ -222,55 +222,54 @@ struct uip_stats
 {
   struct
   {
-    uip_stats_t drop;     /* Number of dropped packets at the IP layer. */
-    uip_stats_t recv;     /* Number of received packets at the IP layer. */
-    uip_stats_t sent;     /* Number of sent packets at the IP layer. */
-    uip_stats_t vhlerr;   /* Number of packets dropped due to wrong
-                             IP version or header length. */
-    uip_stats_t hblenerr; /* Number of packets dropped due to wrong
-                             IP length, high byte. */
-    uip_stats_t lblenerr; /* Number of packets dropped due to wrong
-                             IP length, low byte. */
-    uip_stats_t fragerr;  /* Number of packets dropped since they
-                             were IP fragments. */
-    uip_stats_t chkerr;   /* Number of packets dropped due to IP
-                             checksum errors. */
-    uip_stats_t protoerr; /* Number of packets dropped since they
-                             were neither ICMP, UDP nor TCP. */
-  } ip;                   /* IP statistics. */
+    uip_stats_t drop;       /* Number of dropped packets at the IP layer. */
+    uip_stats_t recv;       /* Number of received packets at the IP layer. */
+    uip_stats_t sent;       /* Number of sent packets at the IP layer. */
+    uip_stats_t vhlerr;     /* Number of packets dropped due to wrong
+                               IP version or header length. */
+    uip_stats_t hblenerr;   /* Number of packets dropped due to wrong
+                               IP length, high byte. */
+    uip_stats_t lblenerr;   /* Number of packets dropped due to wrong
+                               IP length, low byte. */
+    uip_stats_t fragerr;    /* Number of packets dropped since they
+                               were IP fragments. */
+    uip_stats_t chkerr;     /* Number of packets dropped due to IP
+                               checksum errors. */
+    uip_stats_t protoerr;   /* Number of packets dropped since they
+                               were neither ICMP, UDP nor TCP. */
+  } ip;                     /* IP statistics. */
 
   struct
   {
-    uip_stats_t drop;     /* Number of dropped ICMP packets. */
-    uip_stats_t recv;     /* Number of received ICMP packets. */
-    uip_stats_t sent;     /* Number of sent ICMP packets. */
-    uip_stats_t typeerr;  /* Number of ICMP packets with a wrong type. */
-  } icmp;                 /* ICMP statistics. */
+    uip_stats_t drop;       /* Number of dropped ICMP packets. */
+    uip_stats_t recv;       /* Number of received ICMP packets. */
+    uip_stats_t sent;       /* Number of sent ICMP packets. */
+    uip_stats_t typeerr;    /* Number of ICMP packets with a wrong type. */
+  } icmp;                   /* ICMP statistics. */
 
   struct
 
   {
-    uip_stats_t drop;     /* Number of dropped TCP segments. */
-    uip_stats_t recv;     /* Number of recived TCP segments. */
-    uip_stats_t sent;     /* Number of sent TCP segments. */
-    uip_stats_t chkerr;   /* Number of TCP segments with a bad checksum. */
-    uip_stats_t ackerr;   /* Number of TCP segments with a bad ACK number. */
-    uip_stats_t rst;      /* Number of recevied TCP RST (reset) segments. */
-    uip_stats_t rexmit;   /* Number of retransmitted TCP segments. */
-    uip_stats_t syndrop;  /* Number of dropped SYNs due to too few
-                             connections was avaliable. */
-    uip_stats_t synrst;   /* Number of SYNs for closed ports,
-                             triggering a RST. */
-  } tcp;                  /* TCP statistics. */
+    uip_stats_t drop;       /* Number of dropped TCP segments. */
+    uip_stats_t recv;       /* Number of recived TCP segments. */
+    uip_stats_t sent;       /* Number of sent TCP segments. */
+    uip_stats_t chkerr;     /* Number of TCP segments with a bad checksum. */
+    uip_stats_t ackerr;     /* Number of TCP segments with a bad ACK number. */
+    uip_stats_t rst;        /* Number of recevied TCP RST (reset) segments. */
+    uip_stats_t rexmit;     /* Number of retransmitted TCP segments. */
+    uip_stats_t syndrop;    /* Number of dropped SYNs due to too few
+                               connections was avaliable. */
+    uip_stats_t synrst;     /* Number of SYNs for closed ports, triggering a RST. */
+  } tcp;                    /* TCP statistics. */
 
 #ifdef CONFIG_NET_UDP
   struct
   {
-    uip_stats_t drop;     /* Number of dropped UDP segments. */
-    uip_stats_t recv;     /* Number of recived UDP segments. */
-    uip_stats_t sent;     /* Number of sent UDP segments. */
-    uip_stats_t chkerr;   /* Number of UDP segments with a bad checksum. */
-  } udp;                  /* UDP statistics. */
+    uip_stats_t drop;       /* Number of dropped UDP segments. */
+    uip_stats_t recv;       /* Number of recived UDP segments. */
+    uip_stats_t sent;       /* Number of sent UDP segments. */
+    uip_stats_t chkerr;     /* Number of UDP segments with a bad checksum. */
+  } udp;                    /* UDP statistics. */
 #endif  /* CONFIG_NET_UDP */
 };
 
@@ -282,28 +281,29 @@ struct uip_tcpip_hdr
 
   /* IPv6 Ip header. */
 
-  uint8  vtc;
-  uint8  tcflow;
-  uint16 flow;
-  uint8  len[2];
-  uint8  proto, ttl;
-  uip_ip6addr_t srcipaddr;
-  uip_ip6addr_t destipaddr;
+  uint8  vtc;               /* Bits 0-3: version, bits 4-7: traffic class (MS) */
+  uint8  tcf;               /* Bits 0-3: traffic class (LS), 4-bits: flow label (MS) */
+  uint16 flow;              /* 16-bit flow label (LS) */
+  uint8  len[2];            /* 16-bit Payload length */
+  uint8  proto;             /*  8-bit Next header (same as IPv4 protocol field) */
+  uint8  ttl;               /*  8-bit Hop limit (like IPv4 TTL field) */
+  uip_ip6addr_t srcipaddr;  /* 128-bit Source address */
+  uip_ip6addr_t destipaddr; /* 128-bit Destination address */
 
 #else /* CONFIG_NET_IPv6 */
 
   /* IPv4 IP header. */
 
-  uint8  vhl;           /*  8-bit Version (4) and header length (5 or 6) */
-  uint8  tos;           /*  8-bit Type of service (e.g., 6=TCP) */
-  uint8  len[2];        /* 16-bit Total length */
-  uint8  ipid[2];       /* 16-bit Identification */
-  uint8  ipoffset[2];   /* 16-bit IP flags + fragment offset */
-  uint8  ttl;           /*  8-bit Time to Live */
-  uint8  proto;         /*  8-bit Protocol */
-  uint16 ipchksum;      /* 16-bit Header checksum */
-  uint16 srcipaddr[2];  /* 32-bit Source IP address */
-  uint16 destipaddr[2]; /* 32-bit Destination IP address */
+  uint8  vhl;              /*  8-bit Version (4) and header length (5 or 6) */
+  uint8  tos;              /*  8-bit Type of service (e.g., 6=TCP) */
+  uint8  len[2];           /* 16-bit Total length */
+  uint8  ipid[2];          /* 16-bit Identification */
+  uint8  ipoffset[2];      /* 16-bit IP flags + fragment offset */
+  uint8  ttl;              /*  8-bit Time to Live */
+  uint8  proto;            /*  8-bit Protocol */
+  uint16 ipchksum;         /* 16-bit Header checksum */
+  uint16 srcipaddr[2];     /* 32-bit Source IP address */
+  uint16 destipaddr[2];    /* 32-bit Destination IP address */
 
 #endif /* CONFIG_NET_IPv6 */
 
@@ -327,31 +327,31 @@ struct uip_icmpip_hdr
 {
 #ifdef CONFIG_NET_IPv6
 
-  /* IPv6 IP header. */
+  /* IPv6 Ip header. */
 
-  uint8  vtc;
-  uint8  tcf;
-  uint16 flow;
-  uint8  len[2];
-  uint8  proto;
-  uint8  ttl;
-  uip_ip6addr_t srcipaddr;
-  uip_ip6addr_t destipaddr;
+  uint8  vtc;               /* Bits 0-3: version, bits 4-7: traffic class (MS) */
+  uint8  tcf;               /* Bits 0-3: traffic class (LS), bits 4-7: flow label (MS) */
+  uint16 flow;              /* 16-bit flow label (LS) */
+  uint8  len[2];            /* 16-bit Payload length */
+  uint8  proto;             /*  8-bit Next header (same as IPv4 protocol field) */
+  uint8  ttl;               /*  8-bit Hop limit (like IPv4 TTL field) */
+  uip_ip6addr_t srcipaddr;  /* 128-bit Source address */
+  uip_ip6addr_t destipaddr; /* 128-bit Destination address */
 
 #else /* CONFIG_NET_IPv6 */
 
   /* IPv4 IP header. */
 
-  uint8  vhl;           /*  8-bit Version (4) and header length (5 or 6) */
-  uint8  tos;           /*  8-bit Type of service (e.g., 6=TCP) */
-  uint8  len[2];        /* 16-bit Total length */
-  uint8  ipid[2];       /* 16-bit Identification */
-  uint8  ipoffset[2];   /* 16-bit IP flags + fragment offset */
-  uint8  ttl;           /*  8-bit Time to Live */
-  uint8  proto;         /*  8-bit Protocol */
-  uint16 ipchksum;      /* 16-bit Header checksum */
-  uint16 srcipaddr[2];  /* 32-bit Source IP address */
-  uint16 destipaddr[2]; /* 32-bit Destination IP address */
+  uint8  vhl;              /*  8-bit Version (4) and header length (5 or 6) */
+  uint8  tos;              /*  8-bit Type of service (e.g., 6=TCP) */
+  uint8  len[2];           /* 16-bit Total length */
+  uint8  ipid[2];          /* 16-bit Identification */
+  uint8  ipoffset[2];      /* 16-bit IP flags + fragment offset */
+  uint8  ttl;              /*  8-bit Time to Live */
+  uint8  proto;            /*  8-bit Protocol */
+  uint16 ipchksum;         /* 16-bit Header checksum */
+  uint16 srcipaddr[2];     /* 32-bit Source IP address */
+  uint16 destipaddr[2];    /* 32-bit Destination IP address */
 
 #endif /* CONFIG_NET_IPv6 */
 
@@ -384,31 +384,31 @@ struct uip_udpip_hdr
 {
 #ifdef CONFIG_NET_IPv6
 
-  /* IPv6 IP header. */
+  /* IPv6 Ip header. */
 
-  uint8  vtc;
-  uint8  tcf;
-  uint16 flow;
-  uint8  len[2];
-  uint8  proto;
-  uint8  ttl;
-  uip_ip6addr_t srcipaddr;
-  uip_ip6addr_t destipaddr;
+  uint8  vtc;               /* Bits 0-3: version, bits 4-7: traffic class (MS) */
+  uint8  tcf;               /* Bits 0-3: traffic class (LS), 4-bits: flow label (MS) */
+  uint16 flow;              /* 16-bit flow label (LS) */
+  uint8  len[2];            /* 16-bit Payload length */
+  uint8  proto;             /*  8-bit Next header (same as IPv4 protocol field) */
+  uint8  ttl;               /*  8-bit Hop limit (like IPv4 TTL field) */
+  uip_ip6addr_t srcipaddr;  /* 128-bit Source address */
+  uip_ip6addr_t destipaddr; /* 128-bit Destination address */
 
 #else /* CONFIG_NET_IPv6 */
 
   /* IPv4 header. */
 
-  uint8  vhl;           /*  8-bit Version (4) and header length (5 or 6) */
-  uint8  tos;           /*  8-bit Type of service (e.g., 6=TCP) */
-  uint8  len[2];        /* 16-bit Total length */
-  uint8  ipid[2];       /* 16-bit Identification */
-  uint8  ipoffset[2];   /* 16-bit IP flags + fragment offset */
-  uint8  ttl;           /*  8-bit Time to Live */
-  uint8  proto;         /*  8-bit Protocol */
-  uint16 ipchksum;      /* 16-bit Header checksum */
-  uint16 srcipaddr[2];  /* 32-bit Source IP address */
-  uint16 destipaddr[2]; /* 32-bit Destination IP address */
+  uint8  vhl;              /*  8-bit Version (4) and header length (5 or 6) */
+  uint8  tos;              /*  8-bit Type of service (e.g., 6=TCP) */
+  uint8  len[2];           /* 16-bit Total length */
+  uint8  ipid[2];          /* 16-bit Identification */
+  uint8  ipoffset[2];      /* 16-bit IP flags + fragment offset */
+  uint8  ttl;              /*  8-bit Time to Live */
+  uint8  proto;            /*  8-bit Protocol */
+  uint16 ipchksum;         /* 16-bit Header checksum */
+  uint16 srcipaddr[2];     /* 32-bit Source IP address */
+  uint16 destipaddr[2];    /* 32-bit Destination IP address */
 
 #endif /* CONFIG_NET_IPv6 */
 
@@ -459,10 +459,6 @@ extern uint16 uip_urglen; /* Length of (received) urgent data */
 
 extern struct uip_conn *uip_conn;
 
-/* 4-byte array used for the 32-bit sequence number calculations.*/
-
-extern uint8 uip_acc32[4];
-
 /* The current UDP connection. */
 
 #ifdef CONFIG_NET_UDP
diff --git a/nuttx/net/uip/Make.defs b/nuttx/net/uip/Make.defs
index d150e24fe..8a232ffbf 100644
--- a/nuttx/net/uip/Make.defs
+++ b/nuttx/net/uip/Make.defs
@@ -38,9 +38,21 @@ UIP_CSRCS =
 
 ifeq ($(CONFIG_NET),y)
 
-UIP_CSRCS += uip-initialize.c uip-arp.c uip.c uip-send.c uip-fw.c \
-             uip-neighbor.c uip-split.c uip-tcpconn.c uip-listen.c \
-             uip-poll.c uip-chksum.c
+# Common network source files
+
+UIP_CSRCS += uip-initialize.c uip-setipid.c uip-arp.c uip-input.c uip-send.c \
+             uip-fw.c uip-split.c uip-poll.c uip-chksum.c
+
+ifeq ($(CONFIG_NET_IPv6),y)
+UIP_CSRCS += uip-neighbor.c
+endif
+
+# TCP source files
+
+UIP_CSRCS += uip-tcpconn.c uip-tcppoll.c uip-tcptimer.c uip-tcpsend.c \
+             uip-tcpinput.c uip-tcpappsend.c uip-listen.c uip-tcpcallback.c
+
+# UDP source files
 
 ifeq ($(CONFIG_NET_UDP),y)
 
@@ -48,6 +60,11 @@ UIP_CSRCS += uip-udpconn.c uip-udppoll.c uip-udpsend.c uip-udpinput.c \
              uip-udpcallback.c
 
 endif
+
+#ICMP source files
+
+UIP_CSRCS += uip-icmpinput.c
+
 endif
 
 
diff --git a/nuttx/net/uip/uip-chksum.c b/nuttx/net/uip/uip-chksum.c
index ebf814e8b..c8c173b95 100644
--- a/nuttx/net/uip/uip-chksum.c
+++ b/nuttx/net/uip/uip-chksum.c
@@ -116,12 +116,15 @@ static uint16 upper_layer_chksum(struct uip_driver_s *dev, uint8 proto)
   /* First sum pseudoheader. */
 
   /* IP protocol and length fields. This addition cannot carry. */
+
   sum = upper_layer_len + proto;
 
   /* Sum IP source and destination addresses. */
+
   sum = chksum(sum, (uint8 *)&BUF->srcipaddr, 2 * sizeof(uip_ipaddr_t));
 
   /* Sum TCP header and data. */
+
   sum = chksum(sum, &dev->d_buf[UIP_IPH_LEN + UIP_LLH_LEN], upper_layer_len);
 
   return (sum == 0) ? 0xffff : htons(sum);
@@ -143,35 +146,49 @@ static uint16 uip_icmp6chksum(struct uip_driver_s *dev)
 /* Calculate the Internet checksum over a buffer. */
 
 #if !UIP_ARCH_ADD32
-void uip_add32(uint8 *op32, uint16 op16)
+static void uip_carry32(uint8 *sum, uint16 op16)
 {
-  uip_acc32[3] = op32[3] + (op16 & 0xff);
-  uip_acc32[2] = op32[2] + (op16 >> 8);
-  uip_acc32[1] = op32[1];
-  uip_acc32[0] = op32[0];
-
-  if (uip_acc32[2] < (op16 >> 8))
+  if (sum[2] < (op16 >> 8))
     {
-      ++uip_acc32[1];
-      if (uip_acc32[1] == 0)
+      ++sum[1];
+      if (sum[1] == 0)
         {
-          ++uip_acc32[0];
+          ++sum[0];
         }
     }
 
-  if (uip_acc32[3] < (op16 & 0xff))
+  if (sum[3] < (op16 & 0xff))
     {
-      ++uip_acc32[2];
-      if (uip_acc32[2] == 0)
+      ++sum[2];
+      if (sum[2] == 0)
         {
-          ++uip_acc32[1];
-          if (uip_acc32[1] == 0)
+          ++sum[1];
+          if (sum[1] == 0)
             {
-              ++uip_acc32[0];
+              ++sum[0];
             }
         }
     }
 }
+
+void uip_add32(const uint8 *op32, uint16 op16, uint8 *sum)
+{
+  /* op32 and the sum are in network order (big-endian); op16 is host order. */
+
+  sum[3] = op32[3] + (op16 & 0xff);
+  sum[2] = op32[2] + (op16 >> 8);
+  sum[1] = op32[1];
+  sum[0] = op32[0];
+  uip_carry32(sum, op16);
+}
+
+void uip_incr32(uint8 *op32, uint16 op16)
+{
+  op32[3] += (op16 & 0xff);
+  op32[2] += (op16 >> 8);
+  uip_carry32(op32, op16);
+}
+
 #endif /* UIP_ARCH_ADD32 */
 
 #if !UIP_ARCH_CHKSUM
diff --git a/nuttx/net/uip/uip-icmpinput.c b/nuttx/net/uip/uip-icmpinput.c
new file mode 100644
index 000000000..c3d30dd4e
--- /dev/null
+++ b/nuttx/net/uip/uip-icmpinput.c
@@ -0,0 +1,243 @@
+/****************************************************************************
+ * net/uip/uip-icmpinput.c
+ * Handling incoming ICMP/ICMP6 input
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Adapted for NuttX from logic in uIP which also has a BSD-like license:
+ *
+ *   Original author Adam Dunkels <adam@dunkels.com>
+ *   Copyright () 2001-2003, Adam Dunkels.
+ *   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <debug.h>
+
+#include <net/uip/uipopt.h>
+#include <net/uip/uip.h>
+#include <net/uip/uip-arch.h>
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+#define ICMPBUF ((struct uip_icmpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: uip_icmpinput
+ *
+ * Description:
+ *   Handle incoming ICMP/ICMP6 input
+ *
+ * Parameters:
+ *   dev - The device driver structure containing the received ICMP/ICMP6
+ *         packet
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_icmpinput(struct uip_driver_s *dev)
+{
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.icmp.recv++;
+#endif
+
+#ifndef CONFIG_NET_IPv6
+  /* ICMPv4 processing code follows. */
+
+  /* ICMP echo (i.e., ping) processing. This is simple, we only change the
+   * ICMP type from ECHO to ECHO_REPLY and adjust the ICMP checksum before
+   * we return the packet.
+   */
+
+  if (ICMPBUF->type != ICMP_ECHO)
+    {
+      uip_log("icmp: not ICMP echo.");
+      goto typeerr;
+    }
+
+  /* If we are configured to use ping IP address assignment, we use
+   * the destination IP address of this ping packet and assign it to
+   * ourself.
+   */
+
+#if UIP_PINGADDRCONF
+  if (dev->d_ipaddr == 0)
+    {
+      dev->d_ipaddr = ICMPBUF->destipaddr;
+    }
+#endif /* UIP_PINGADDRCONF */
+
+  ICMPBUF->type = ICMP_ECHO_REPLY;
+
+  if (ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8)))
+    {
+      ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
+    }
+  else
+    {
+      ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
+    }
+
+  /* Swap IP addresses. */
+
+  uiphdr_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
+  uiphdr_ipaddr_copy(ICMPBUF->srcipaddr, &dev->d_ipaddr);
+
+  vdbg("Outgoing ICMP packet length: %d (%d)\n",
+       dev->d_len, (ICMPBUF->len[0] << 8) | ICMPBUF->len[1]);
+
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.icmp.sent++;
+  uip_stat.ip.sent++;
+#endif
+  return;
+
+typeerr:
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.icmp.typeerr++;
+  uip_stat.icmp.drop++;
+#endif
+  dev->d_len = 0;
+
+#else /* !CONFIG_NET_IPv6 */
+
+  /* If we get a neighbor solicitation for our address we should send
+   * a neighbor advertisement message back.
+   */
+
+  if (ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION)
+    {
+      if (uip_ipaddr_cmp(ICMPBUF->icmp6data, dev->d_ipaddr))
+        {
+          if (ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS)
+            {
+              /* Save the sender's address in our neighbor list. */
+
+              uiphdr_neighbor_add(ICMPBUF->srcipaddr, &(ICMPBUF->options[2]));
+            }
+
+          /* We should now send a neighbor advertisement back to where the
+           * neighbor solicication came from.
+           */
+
+          ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
+          ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */
+
+          ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0;
+
+          uiphdr_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
+          uiphdr_ipaddr_copy(ICMPBUF->srcipaddr, dev->d_ipaddr);
+          ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
+          ICMPBUF->options[1] = 1;  /* Options length, 1 = 8 bytes. */
+          memcpy(&(ICMPBUF->options[2]), &dev->d_mac, IFHWADDRLEN);
+          ICMPBUF->icmpchksum = 0;
+          ICMPBUF->icmpchksum = ~uip_icmp6chksum(dev);
+        }
+      else
+        {
+          goto drop;
+        }
+    }
+  else if (ICMPBUF->type == ICMP6_ECHO)
+    {
+      /* ICMP echo (i.e., ping) processing. This is simple, we only
+       * change the ICMP type from ECHO to ECHO_REPLY and update the
+       * ICMP checksum before we return the packet.
+       */
+
+      ICMPBUF->type = ICMP6_ECHO_REPLY;
+
+      uiphdr_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
+      uiphdr_ipaddr_copy(ICMPBUF->srcipaddr, dev->d_ipaddr);
+      ICMPBUF->icmpchksum = 0;
+      ICMPBUF->icmpchksum = ~uip_icmp6chksum(dev);
+    }
+  else
+    {
+      uip_log("icmp: unknown ICMP6 message.");
+      goto typeerr;
+    }
+
+  vdbg("Outgoing ICMP6 packet length: %d (%d)\n",
+       dev->d_len, (ICMPBUF->len[0] << 8) | ICMPBUF->len[1]);
+
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.icmp.sent++;
+  uip_stat.ip.sent++;
+#endif
+  return;
+
+typeerr:
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.icmp.typeerr++;
+#endif
+
+drop:
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.icmp.drop++;
+#endif
+  dev->d_len = 0;
+
+#endif /* !CONFIG_NET_IPv6 */
+}
+
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip-initialize.c b/nuttx/net/uip/uip-initialize.c
index dabcf64cc..00a01ef6a 100644
--- a/nuttx/net/uip/uip-initialize.c
+++ b/nuttx/net/uip/uip-initialize.c
@@ -57,6 +57,51 @@
  * Public Variables
  ****************************************************************************/
 
+#if UIP_URGDATA > 0
+void *uip_urgdata;           /* urgent data (out-of-band data), if present. */
+uint16 uip_urglen;           /* Length of (received) urgent data */
+#endif
+
+/* The uip_flags variable is used for communication between the TCP/IP
+ * stack and the application program.
+ */
+
+uint8 uip_flags;
+
+/* uip_conn always points to the current connection. */
+
+struct uip_conn *uip_conn;
+
+#ifdef CONFIG_NET_UDP
+struct uip_udp_conn *uip_udp_conn;
+#endif   /* CONFIG_NET_UDP */
+
+#ifdef CONFIG_NET_STATISTICS
+struct uip_stats uip_stat;
+#endif
+
+/* Increasing number used for the IP ID field. */
+
+uint16 g_ipid;
+
+const uip_ipaddr_t all_ones_addr =
+#ifdef CONFIG_NET_IPv6
+  {0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff};
+#else /* CONFIG_NET_IPv6 */
+  {0xffffffff};
+#endif /* CONFIG_NET_IPv6 */
+
+const uip_ipaddr_t all_zeroes_addr =
+#ifdef CONFIG_NET_IPv6
+  {0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000};
+#else
+  {0x00000000};
+#endif
+
+#if UIP_REASSEMBLY && !defined(CONFIG_NET_IPv6)
+uint8 uip_reasstmr;
+#endif
+
 /****************************************************************************
  * Private Variables
  ****************************************************************************/
diff --git a/nuttx/net/uip/uip-input.c b/nuttx/net/uip/uip-input.c
new file mode 100644
index 000000000..de8223640
--- /dev/null
+++ b/nuttx/net/uip/uip-input.c
@@ -0,0 +1,509 @@
+/****************************************************************************
+ * net/uip/uip-input.c
+ * The uIP TCP/IP stack code.
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Adapted for NuttX from logic in uIP which also has a BSD-like license:
+ *
+ * uIP is an implementation of the TCP/IP protocol stack intended for
+ * small 8-bit and 16-bit microcontrollers.
+ *
+ * uIP provides the necessary protocols for Internet communication,
+ * with a very small code footprint and RAM requirements - the uIP
+ * code size is on the order of a few kilobytes and RAM usage is on
+ * the order of a few hundred bytes.
+ *
+ *   Original author Adam Dunkels <adam@dunkels.com>
+ *   Copyright () 2001-2003, Adam Dunkels.
+ *   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * uIP is a small implementation of the IP, UDP and TCP protocols (as
+ * well as some basic ICMP stuff). The implementation couples the IP,
+ * UDP, TCP and the application layers very tightly. To keep the size
+ * of the compiled code down, this code frequently uses the goto
+ * statement. While it would be possible to break the uip_input()
+ * function into many smaller functions, this would increase the code
+ * size because of the overhead of parameter passing and the fact that
+ * the optimier would not be as efficient.
+ *
+ * The principle is that we have a small buffer, called the d_buf,
+ * in which the device driver puts an incoming packet. The TCP/IP
+ * stack parses the headers in the packet, and calls the
+ * application. If the remote host has sent data to the application,
+ * this data is present in the d_buf and the application read the
+ * data from there. It is up to the application to put this data into
+ * a byte stream if needed. The application will not be fed with data
+ * that is out of sequence.
+ *
+ * If the application whishes to send data to the peer, it should put
+ * its data into the d_buf. The d_appdata pointer points to the
+ * first available byte. The TCP/IP stack will calculate the
+ * checksums, and fill in the necessary header fields and finally send
+ * the packet back to the peer.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+
+#include <debug.h>
+#include <string.h>
+
+#include <net/uip/uipopt.h>
+#include <net/uip/uip.h>
+#include <net/uip/uip-arch.h>
+
+#ifdef CONFIG_NET_IPv6
+# include "uip-neighbor.h"
+#endif /* CONFIG_NET_IPv6 */
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/* Macros. */
+
+#define BUF     ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
+#define FBUF    ((struct uip_tcpip_hdr *)&uip_reassbuf[0])
+
+/* IP fragment re-assembly */
+
+#define IP_MF                   0x20
+#define UIP_REASS_BUFSIZE       (UIP_BUFSIZE - UIP_LLH_LEN)
+#define UIP_REASS_FLAG_LASTFRAG 0x01
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+#if UIP_REASSEMBLY && !defined(CONFIG_NET_IPv6)
+static uint8 uip_reassbuf[UIP_REASS_BUFSIZE];
+static uint8 uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
+static const uint8 bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f, 0x0f, 0x07, 0x03, 0x01};
+static uint16 uip_reasslen;
+static uint8 uip_reassflags;
+#endif /* UIP_REASSEMBLY */
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: uip_reass
+ *
+ * Description:
+ *   IP fragment reassembly: not well-tested.
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+#if UIP_REASSEMBLY && !defined(CONFIG_NET_IPv6)
+static uint8 uip_reass(void)
+{
+  uint16 offset, len;
+  uint16 i;
+
+  /* If ip_reasstmr is zero, no packet is present in the buffer, so we
+   * write the IP header of the fragment into the reassembly
+   * buffer. The timer is updated with the maximum age.
+   */
+
+  if (uip_reasstmr == 0)
+    {
+      memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
+      uip_reasstmr = UIP_REASS_MAXAGE;
+      uip_reassflags = 0;
+
+      /* Clear the bitmap. */
+      memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
+    }
+
+  /* Check if the incoming fragment matches the one currently present
+   * in the reasembly buffer. If so, we proceed with copying the
+   * fragment into the buffer.
+   */
+
+  if (uiphdr_addr_cmp(BUF->srcipaddr, FBUF->srcipaddr) && 
+      uiphdr_addr_cmp(BUF->destipaddr == FBUF->destipaddr) &&
+      BUF->g_ipid[0] == FBUF->g_ipid[0] && BUF->g_ipid[1] == FBUF->g_ipid[1])
+    {
+      len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
+      offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
+
+      /* If the offset or the offset + fragment length overflows the
+       * reassembly buffer, we discard the entire packet.
+       */
+
+      if (offset > UIP_REASS_BUFSIZE || offset + len > UIP_REASS_BUFSIZE)
+        {
+          uip_reasstmr = 0;
+          goto nullreturn;
+        }
+
+      /* Copy the fragment into the reassembly buffer, at the right offset. */
+
+      memcpy(&uip_reassbuf[UIP_IPH_LEN + offset], (char *)BUF + (int)((BUF->vhl & 0x0f) * 4), len);
+
+    /* Update the bitmap. */
+
+    if (offset / (8 * 8) == (offset + len) / (8 * 8))
+      {
+        /* If the two endpoints are in the same byte, we only update that byte. */
+
+        uip_reassbitmap[offset / (8 * 8)] |=
+          bitmap_bits[(offset / 8 ) & 7] & ~bitmap_bits[((offset + len) / 8 ) & 7];
+
+      }
+    else
+      {
+        /* If the two endpoints are in different bytes, we update the bytes
+         * in the endpoints and fill the stuff inbetween with 0xff.
+         */
+
+        uip_reassbitmap[offset / (8 * 8)] |= bitmap_bits[(offset / 8 ) & 7];
+        for (i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i)
+          {
+            uip_reassbitmap[i] = 0xff;
+          }
+        uip_reassbitmap[(offset + len) / (8 * 8)] |= ~bitmap_bits[((offset + len) / 8 ) & 7];
+      }
+
+    /* If this fragment has the More Fragments flag set to zero, we know that
+     * this is the last fragment, so we can calculate the size of the entire
+     * packet. We also set the IP_REASS_FLAG_LASTFRAG flag to indicate that
+     * we have received the final fragment.
+     */
+
+    if ((BUF->ipoffset[0] & IP_MF) == 0)
+      {
+        uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
+        uip_reasslen = offset + len;
+      }
+
+    /* Finally, we check if we have a full packet in the buffer. We do this
+     * by checking if we have the last fragment and if all bits in the bitmap
+     * are set.
+     */
+
+    if (uip_reassflags & UIP_REASS_FLAG_LASTFRAG)
+      {
+        /* Check all bytes up to and including all but the last byte in
+         * the bitmap.
+         */
+
+        for (i = 0; i < uip_reasslen / (8 * 8) - 1; ++i)
+          {
+            if (uip_reassbitmap[i] != 0xff)
+              {
+                goto nullreturn;
+              }
+          }
+
+        /* Check the last byte in the bitmap. It should contain just the
+         * right amount of bits.
+         */
+
+        if (uip_reassbitmap[uip_reasslen / (8 * 8)] != (uint8)~bitmap_bits[uip_reasslen / 8 & 7])
+          {
+            goto nullreturn;
+          }
+
+        /* If we have come this far, we have a full packet in the buffer,
+         * so we allocate a pbuf and copy the packet into it. We also reset
+         * the timer.
+         */
+
+        uip_reasstmr = 0;
+        memcpy(BUF, FBUF, uip_reasslen);
+
+        /* Pretend to be a "normal" (i.e., not fragmented) IP packet from
+         * now on.
+         */
+
+        BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
+        BUF->len[0] = uip_reasslen >> 8;
+        BUF->len[1] = uip_reasslen & 0xff;
+        BUF->ipchksum = 0;
+        BUF->ipchksum = ~(uip_ipchksum(dev));
+
+        return uip_reasslen;
+      }
+  }
+
+nullreturn:
+  return 0;
+}
+#endif /* UIP_REASSEMBLY */
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: uip_input
+ *
+ * Description:
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+void uip_input(struct uip_driver_s *dev)
+{
+  dev->d_snddata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
+  dev->d_appdata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
+
+  /* This is where the input processing starts. */
+
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.ip.recv++;
+#endif
+
+  /* Start of IP input header processing code. */
+
+#ifdef CONFIG_NET_IPv6
+  /* Check validity of the IP header. */
+
+  if ((BUF->vtc & 0xf0) != 0x60) 
+    {
+      /* IP version and header length. */
+
+#ifdef CONFIG_NET_STATISTICS
+      uip_stat.ip.drop++;
+      uip_stat.ip.vhlerr++;
+#endif
+      uip_log("ipv6: invalid version.");
+      goto drop;
+    }
+#else /* CONFIG_NET_IPv6 */
+  /* Check validity of the IP header. */
+
+  if (BUF->vhl != 0x45)
+    {
+      /* IP version and header length. */
+
+#ifdef CONFIG_NET_STATISTICS
+      uip_stat.ip.drop++;
+      uip_stat.ip.vhlerr++;
+#endif
+      uip_log("ip: invalid version or header length.");
+      goto drop;
+    }
+#endif /* CONFIG_NET_IPv6 */
+
+  /* Check the size of the packet. If the size reported to us in d_len is
+   * smaller the size reported in the IP header, we assume that the packet
+   * has been corrupted in transit. If the size of d_len is larger than the
+   * size reported in the IP packet header, the packet has been padded and
+   * we set d_len to the correct value.
+   */
+
+  if ((BUF->len[0] << 8) + BUF->len[1] <= dev->d_len)
+    {
+      dev->d_len = (BUF->len[0] << 8) + BUF->len[1];
+#ifdef CONFIG_NET_IPv6
+      /* The length reported in the IPv6 header is the length of the
+       * payload that follows the header. However, uIP uses the d_len
+       * variable for holding the size of the entire packet, including the
+       * IP header. For IPv4 this is not a problem as the length field in
+       * the IPv4 header contains the length of the entire packet. But
+       * for IPv6 we need to add the size of the IPv6 header (40 bytes).
+       */
+
+      dev->d_len += 40;
+#endif /* CONFIG_NET_IPv6 */
+    }
+  else
+    {
+      uip_log("ip: packet shorter than reported in IP header.");
+      goto drop;
+    }
+
+#ifndef CONFIG_NET_IPv6
+  /* Check the fragment flag. */
+
+  if ((BUF->ipoffset[0] & 0x3f) != 0 || BUF->ipoffset[1] != 0)
+    {
+#if UIP_REASSEMBLY
+      dev->d_len = uip_reass();
+      if (dev->d_len == 0)
+        {
+          goto drop;
+        }
+#else /* UIP_REASSEMBLY */
+#ifdef CONFIG_NET_STATISTICS
+      uip_stat.ip.drop++;
+      uip_stat.ip.fragerr++;
+#endif
+      uip_log("ip: fragment dropped.");
+      goto drop;
+#endif /* UIP_REASSEMBLY */
+    }
+#endif /* CONFIG_NET_IPv6 */
+
+  if (uip_ipaddr_cmp(dev->d_ipaddr, all_zeroes_addr))
+    {
+      /* If we are configured to use ping IP address configuration and
+       * hasn't been assigned an IP address yet, we accept all ICMP
+       * packets.
+       */
+
+#if UIP_PINGADDRCONF && !CONFIG_NET_IPv6
+      if (BUF->proto == UIP_PROTO_ICMP)
+        {
+          uip_log("ip: possible ping config packet received.");
+          uip_icmpinput(dev);
+          goto done;
+        }
+      else
+#endif /* UIP_PINGADDRCONF */
+        {
+          uip_log("ip: packet dropped since no address assigned.");
+          goto drop;
+        }
+    }
+  else
+    {
+      /* If IP broadcast support is configured, we check for a broadcast
+       * UDP packet, which may be destined to us.
+       */
+
+#if UIP_BROADCAST
+      if (BUF->proto == UIP_PROTO_UDP && uip_ipaddr_cmp(BUF->destipaddr, all_ones_addr)
+        {
+          uip_udpinput(dev);
+          return;
+        }
+#endif /* UIP_BROADCAST */
+
+      /* Check if the packet is destined for our IP address. */
+#ifndef CONFIG_NET_IPv6
+      if (!uip_ipaddr_cmp(uip_ip4addr_conv(BUF->destipaddr), dev->d_ipaddr))
+        {
+#ifdef CONFIG_NET_STATISTICS
+          uip_stat.ip.drop++;
+#endif
+          goto drop;
+        }
+#else /* CONFIG_NET_IPv6 */
+      /* For IPv6, packet reception is a little trickier as we need to
+       * make sure that we listen to certain multicast addresses (all
+       * hosts multicast address, and the solicited-node multicast
+       * address) as well. However, we will cheat here and accept all
+       * multicast packets that are sent to the ff02::/16 addresses.
+       */
+
+      if (!uip_ipaddr_cmp(BUF->destipaddr, dev->d_ipaddr) &&
+           BUF->destipaddr & HTONL(0xffff0000) != HTONL(0xff020000))
+        {
+#ifdef CONFIG_NET_STATISTICS
+          uip_stat.ip.drop++;
+#endif
+          goto drop;
+        }
+#endif /* CONFIG_NET_IPv6 */
+    }
+
+#ifndef CONFIG_NET_IPv6
+  if (uip_ipchksum(dev) != 0xffff)
+    {
+      /* Compute and check the IP header checksum. */
+
+#ifdef CONFIG_NET_STATISTICS
+      uip_stat.ip.drop++;
+      uip_stat.ip.chkerr++;
+#endif
+      uip_log("ip: bad checksum.");
+      goto drop;
+    }
+#endif /* CONFIG_NET_IPv6 */
+
+  /* Everything looks good so far.  Now process the incoming packet
+   * according to the protocol.
+   */
+
+  switch (BUF->proto)
+    {
+      case UIP_PROTO_TCP:   /* TCP input */
+        uip_tcpinput(dev);
+        break;
+
+#ifdef CONFIG_NET_UDP
+      case UIP_PROTO_UDP:   /* UDP input */
+        uip_udpinput(dev);
+        break;
+#endif
+
+  /* Check for ICMP input */
+
+#ifndef CONFIG_NET_IPv6
+      case UIP_PROTO_ICMP:  /* ICMP input */
+#else
+      case UIP_PROTO_ICMP6: /* ICMP6 input */
+#endif
+        uip_icmpinput(dev);
+        break;
+
+      default:              /* Unrecognized/unsupported protocol */
+#ifdef CONFIG_NET_STATISTICS
+        uip_stat.ip.drop++;
+        uip_stat.ip.protoerr++;
+#endif
+
+        uip_log("ip: Unrecognized IP protocol.");
+        goto drop;
+    }
+
+  /* Return and let the caller do any actual transmission. */
+
+  return;
+
+drop:
+  dev->d_len = 0;
+}
+#endif /* CONFIG_NET */
+
diff --git a/nuttx/net/uip/uip-internal.h b/nuttx/net/uip/uip-internal.h
index c8d1e10c4..d1f141a30 100644
--- a/nuttx/net/uip/uip-internal.h
+++ b/nuttx/net/uip/uip-internal.h
@@ -55,6 +55,37 @@
  * Public Macro Definitions
  ****************************************************************************/
 
+/* TCP definitions */
+
+#define TCP_FIN 0x01
+#define TCP_SYN 0x02
+#define TCP_RST 0x04
+#define TCP_PSH 0x08
+#define TCP_ACK 0x10
+#define TCP_URG 0x20
+#define TCP_CTL 0x3f
+
+#define TCP_OPT_END     0   /* End of TCP options list */
+#define TCP_OPT_NOOP    1   /* "No-operation" TCP option */
+#define TCP_OPT_MSS     2   /* Maximum segment size TCP option */
+
+#define TCP_OPT_MSS_LEN 4   /* Length of TCP MSS option. */
+
+/* ICMP/ICMP6 definitions */
+
+#define ICMP_ECHO_REPLY 0
+#define ICMP_ECHO       8
+
+#define ICMP6_ECHO_REPLY             129
+#define ICMP6_ECHO                   128
+#define ICMP6_NEIGHBOR_SOLICITATION  135
+#define ICMP6_NEIGHBOR_ADVERTISEMENT 136
+
+#define ICMP6_FLAG_S (1 << 6)
+
+#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
+#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2
+
 /****************************************************************************
  * Public Type Definitions
  ****************************************************************************/
@@ -70,6 +101,10 @@ extern const uip_ipaddr_t all_zeroes_addr;
 
 extern uint16 g_ipid;
 
+#if UIP_REASSEMBLY && !defined(CONFIG_NET_IPv6)
+extern uint8 uip_reasstmr;
+#endif
+
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
@@ -90,12 +125,43 @@ EXTERN struct uip_conn *uip_tcplistener(uint16 portno);
 EXTERN struct uip_conn *uip_tcpaccept(struct uip_tcpip_hdr *buf);
 EXTERN void uip_tcpnextsequence(void);
 
+/* Defined in uip-tcppoll.c *************************************************/
+
+EXTERN void uip_tcppoll(struct uip_driver_s *dev, struct uip_conn *conn);
+
+/* Defined in uip-udptimer.c ************************************************/
+
+EXTERN void uip_udptimer(struct uip_driver_s *dev, struct uip_conn *conn);
+
 /* Defined in uip_listen.c **************************************************/
 
 EXTERN void uip_listeninit(void);
 EXTERN boolean uip_islistener(uint16 port);
 EXTERN int uip_accept(struct uip_conn *conn, uint16 portno);
 
+/* Defined in uip-tcpsend.c *************************************************/
+
+EXTERN void uip_tcpsend(struct uip_driver_s *dev, struct uip_conn *conn,
+                        uint8 flags, uint16 len);
+EXTERN void uip_tcpreset(struct uip_driver_s *dev);
+EXTERN void uip_tcpack(struct uip_driver_s *dev, struct uip_conn *conn,
+                       uint8 ack);
+
+/* Defined in uip-tcpappsend.c **********************************************/
+
+EXTERN void uip_tcpappsend(struct uip_driver_s *dev, struct uip_conn *conn,
+                           uint8 result);
+EXTERN void uip_tcprexmit(struct uip_driver_s *dev, struct uip_conn *conn,
+                          uint8 result);
+
+/* Defined in uip-tcpinput.c ************************************************/
+
+EXTERN void uip_tcpinput(struct uip_driver_s *dev);
+
+/* Defined in uip_uipcallback.c *********************************************/
+
+EXTERN void uip_tcpcallback(struct uip_driver_s *dev);
+
 #ifdef CONFIG_NET_UDP
 /* Defined in uip_udpconn.c *************************************************/
 
@@ -103,7 +169,7 @@ EXTERN void uip_udpinit(void);
 EXTERN struct uip_udp_conn *uip_udpactive(struct uip_udpip_hdr *buf);
 EXTERN struct uip_udp_conn *uip_nextudpconn(struct uip_udp_conn *conn);
 
-/* Defined in uip-udppool.c *************************************************/
+/* Defined in uip-udppoll.c *************************************************/
 
 EXTERN void uip_udppoll(struct uip_driver_s *dev, struct uip_udp_conn *conn);
 
@@ -120,6 +186,10 @@ EXTERN void uip_udpinput(struct uip_driver_s *dev);
 EXTERN void uip_udpcallback(struct uip_driver_s *dev);
 #endif /* CONFIG_NET_UDP */
 
+/* Defined in uip-icmpinput.c ***********************************************/
+
+EXTERN void uip_icmpinput(struct uip_driver_s *dev);
+
 /* UIP logging **************************************************************/
 
 /* This function must be provided by the application if CONFIG_NET_LOGGING
diff --git a/nuttx/net/uip/uip-poll.c b/nuttx/net/uip/uip-poll.c
index 19dc16a5a..0ac8fac97 100644
--- a/nuttx/net/uip/uip-poll.c
+++ b/nuttx/net/uip/uip-poll.c
@@ -107,7 +107,15 @@ int uip_poll(struct uip_driver_s *dev, uip_poll_callback_t callback, int event)
   while ((conn = uip_nexttcpconn(conn)))
     {
       uip_conn = conn;
-      uip_interrupt(dev, event);
+      if (event == UIP_DRV_POLL)
+        {
+          uip_tcppoll(dev, conn);
+        }
+      else
+        {
+          uip_tcptimer(dev, conn);
+        }
+
       if (callback(dev))
         {
           irqrestore(flags);
diff --git a/nuttx/net/uip/uip-setipid.c b/nuttx/net/uip/uip-setipid.c
new file mode 100644
index 000000000..71467b0f8
--- /dev/null
+++ b/nuttx/net/uip/uip-setipid.c
@@ -0,0 +1,78 @@
+/****************************************************************************
+ * net/uip/uip-udpcallback.c
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <debug.h>
+
+#include <net/uip/uip.h>
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: uip_setipid
+ *
+ * Description:
+ *   This function may be used at boot time to set the initial ip_id.
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+void uip_setipid(uint16 id)
+{
+  g_ipid = id;
+}
+
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip-split.c b/nuttx/net/uip/uip-split.c
index 8488bd3d1..8d75487d2 100644
--- a/nuttx/net/uip/uip-split.c
+++ b/nuttx/net/uip/uip-split.c
@@ -102,18 +102,16 @@ void uip_split_output(struct uip_driver_s *dev)
     /*    dev->d_appdata += len1;*/
     memcpy(dev->d_appdata, dev->d_appdata + len1, len2);
 
-    uip_add32(BUF->seqno, len1);
-    BUF->seqno[0] = uip_acc32[0];
-    BUF->seqno[1] = uip_acc32[1];
-    BUF->seqno[2] = uip_acc32[2];
-    BUF->seqno[3] = uip_acc32[3];
+    uip_incr32(BUF->seqno, len1);
 
     /* Recalculate the TCP checksum. */
+
     BUF->tcpchksum = 0;
     BUF->tcpchksum = ~(uip_tcpchksum(dev));
 
 #ifndef CONFIG_NET_IPv6
     /* Recalculate the IP checksum. */
+
     BUF->ipchksum = 0;
     BUF->ipchksum = ~(uip_ipchksum(dev));
 #endif /* CONFIG_NET_IPv6 */
diff --git a/nuttx/net/uip/uip-tcpappsend.c b/nuttx/net/uip/uip-tcpappsend.c
new file mode 100644
index 000000000..c0bbe8b48
--- /dev/null
+++ b/nuttx/net/uip/uip-tcpappsend.c
@@ -0,0 +1,225 @@
+/****************************************************************************
+ * net/uip/uip-tcpappsend.c
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Adapted for NuttX from logic in uIP which also has a BSD-like license:
+ *
+ *   Original author Adam Dunkels <adam@dunkels.com>
+ *   Copyright () 2001-2003, Adam Dunkels.
+ *   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <debug.h>
+
+#include <net/uip/uipopt.h>
+#include <net/uip/uip.h>
+#include <net/uip/uip-arch.h>
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+#define BUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: uip_tcpappsend
+ *
+ * Description:
+ *   Handle application response
+ *
+ * Parameters:
+ *   dev    - The device driver structure to use in the send operation
+ *   conn   - The TCP connection structure holding connection information
+ *   result - App result event sent
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcpappsend(struct uip_driver_s *dev, struct uip_conn *conn, uint8 result)
+{
+  /* Handle the result based on the application response */
+
+  if (result & UIP_ABORT)
+    {
+      dev->d_sndlen = 0;
+      conn->tcpstateflags = UIP_CLOSED;
+      vdbg("TCP state: UIP_CLOSED\n");
+
+      uip_tcpsend(dev, conn, TCP_RST | TCP_ACK, UIP_IPTCPH_LEN);
+    }
+
+  else if (result & UIP_CLOSE)
+    {
+      conn->tcpstateflags = UIP_FIN_WAIT_1;
+      conn->len = 1;
+      conn->nrtx = 0;
+      vdbg("TCP state: UIP_FIN_WAIT_1\n");
+
+      dev->d_sndlen = 0;
+      uip_tcpsend(dev, conn, TCP_FIN | TCP_ACK, UIP_IPTCPH_LEN);
+    }
+
+  /* If d_sndlen > 0, the application has data to be sent. */
+
+  else if (dev->d_sndlen > 0)
+    {
+      /* If the connection has acknowledged data, the contents of
+       * the ->len variable should be discarded.
+       */
+
+      if (result & UIP_ACKDATA)
+        {
+          conn->len = 0;
+        }
+
+      /* If the ->len variable is non-zero the connection has
+       * already data in transit and cannot send anymore right
+       * now.
+       */
+
+      if (conn->len == 0)
+        {
+          /* The application cannot send more than what is
+           * allowed by the mss (the minumum of the MSS and the
+           * available window).
+           */
+
+          if (dev->d_sndlen > conn->mss)
+            {
+              dev->d_sndlen = conn->mss;
+            }
+
+          /* Remember how much data we send out now so that we
+           * know when everything has been acknowledged.
+           */
+
+          conn->len = dev->d_sndlen;
+        }
+      else
+        {
+          /* If the application already had unacknowledged data,
+           * we make sure that the application does not send
+           * (i.e., retransmit) out more than it previously sent
+           * out.
+           */
+
+          dev->d_sndlen = conn->len;
+        }
+
+      /* Then handle the rest of the operation just as for the rexmit case */
+
+      conn->nrtx = 0;
+      uip_tcprexmit(dev, conn, result);
+    }
+}
+
+/****************************************************************************
+ * Name: uip_tcprexmit
+ *
+ * Description:
+ *   Handle application retransmission
+ *
+ * Parameters:
+ *   dev    - The device driver structure to use in the send operation
+ *   conn   - The TCP connection structure holding connection information
+ *   result - App result event sent
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcprexmit(struct uip_driver_s *dev, struct uip_conn *conn, uint8 result)
+{
+  dev->d_appdata = dev->d_snddata;
+
+  /* If the application has data to be sent, or if the incoming packet had
+   * new data in it, we must send out a packet.
+   */
+
+  if (dev->d_sndlen > 0 && conn->len > 0)
+    {
+      /* We always set the ACK flag in response packets adding the length of
+       * the IP and TCP headers.
+       */
+
+      uip_tcpsend(dev, conn, TCP_ACK | TCP_PSH, conn->len + UIP_TCPIP_HLEN);
+    }
+
+  /* If there is no data to send, just send out a pure ACK if there is newdata. */
+
+  else if (result & UIP_NEWDATA)
+    {
+      uip_tcpsend(dev, conn, TCP_ACK, UIP_TCPIP_HLEN);
+    }
+
+  /* There is nothing to do -- drop the packet */
+
+  else
+    {
+      dev->d_len = 0;
+    }
+}
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip-tcpcallback.c b/nuttx/net/uip/uip-tcpcallback.c
new file mode 100644
index 000000000..ad1822712
--- /dev/null
+++ b/nuttx/net/uip/uip-tcpcallback.c
@@ -0,0 +1,105 @@
+/****************************************************************************
+ * net/uip/uip-tcpcallback.c
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <debug.h>
+
+#include <net/uip/uipopt.h>
+#include <net/uip/uip.h>
+#include <net/uip/uip-arch.h>
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: uip_tcpcallback
+ *
+ * Description:
+ *   Inform the application holding the TCP socket of a change in state.
+ *
+ * Assumptions:
+ *   This function is called at the interrupt level with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcpcallback(struct uip_driver_s *dev)
+{
+  vdbg("uip_flags: %02x\n", uip_flags);
+
+  /* Some sanity checking */
+
+  if (uip_conn)
+    {
+      /* Check if there is a data callback */
+
+      if (uip_conn->data_event)
+      {
+        /* Perform the callback */
+
+        uip_conn->data_event(dev, uip_conn->data_private);
+      }
+
+      /* Check if there is a connection-related event and a connection
+       * callback.
+       */
+      if (((uip_flags & UIP_CONN_EVENTS) != 0) && uip_conn->connection_event)
+        {
+          /* Perform the callback */
+
+          uip_conn->connection_event(uip_conn->connection_private);
+        }
+    }
+}
+
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip-tcpinput.c b/nuttx/net/uip/uip-tcpinput.c
new file mode 100644
index 000000000..b8a225dbc
--- /dev/null
+++ b/nuttx/net/uip/uip-tcpinput.c
@@ -0,0 +1,753 @@
+/****************************************************************************
+ * net/uip/uip-tcpinput.c
+ * Handling incoming TCP input
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Adapted for NuttX from logic in uIP which also has a BSD-like license:
+ *
+ *   Original author Adam Dunkels <adam@dunkels.com>
+ *   Copyright () 2001-2003, Adam Dunkels.
+ *   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <debug.h>
+
+#include <net/uip/uipopt.h>
+#include <net/uip/uip.h>
+#include <net/uip/uip-arch.h>
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+#define BUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: uip_tcpinput
+ *
+ * Description:
+ *   Handle incoming TCP input
+ *
+ * Parameters:
+ *   dev - The device driver structure containing the received TCP packet.
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcpinput(struct uip_driver_s *dev)
+{
+  register struct uip_conn *uip_connr = uip_conn;
+  uint16 tmp16;
+  uint8  opt;
+  int    len;
+  int    i;
+
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.tcp.recv++;
+#endif
+
+  /* Start of TCP input header processing code. */
+
+  if (uip_tcpchksum(dev) != 0xffff)
+    {
+      /* Compute and check the TCP checksum. */
+
+#ifdef CONFIG_NET_STATISTICS
+      uip_stat.tcp.drop++;
+      uip_stat.tcp.chkerr++;
+#endif
+      uip_log("tcp: bad checksum.");
+      goto drop;
+    }
+
+  /* Demultiplex this segment. First check any active connections. */
+
+  uip_connr = uip_tcpactive(BUF);
+  if (uip_connr)
+    {
+      goto found;
+    }
+
+  /* If we didn't find and active connection that expected the packet,
+   * either (1) this packet is an old duplicate, or (2) this is a SYN packet
+   * destined for a connection in LISTEN. If the SYN flag isn't set,
+   * it is an old packet and we send a RST.
+   */
+
+  if ((BUF->flags & TCP_CTL) == TCP_SYN)
+    {
+        /* This is a SYN packet for a connection.  Find the connection
+         * listening on this port.
+         */
+
+        tmp16 = BUF->destport;
+        if (uip_islistener(tmp16))
+          {
+            /* We matched the incoming packet with a connection in LISTEN.
+             * We now need to create a new connection and send a SYNACK in
+             * response.
+             */
+
+          /* First allocate a new connection structure and see if there is any
+           * user application to accept it.
+           */
+
+          uip_connr = uip_tcpaccept(BUF);
+          if (uip_connr)
+            {
+              /* The connection structure was successfully allocated.  Now see
+               * there is an application waiting to accept the connection (or at
+               * least queue it it for acceptance).
+               */
+
+              if (uip_accept(uip_connr, tmp16) != OK)
+                {
+                  /* No, then we have to give the connection back */
+
+                  uip_tcpfree(uip_connr);
+                  uip_connr = NULL;
+                }
+            }
+
+          if (!uip_connr)
+            {
+              /* Either (1) all available connections are in use, or (2) there is no
+               * application in place to accept the connection.  We drop packet and hope that
+               * the remote end will retransmit the packet at a time when we
+               * have more spare connections or someone waiting to accept the connection.
+               */
+
+#ifdef CONFIG_NET_STATISTICS
+              uip_stat.tcp.syndrop++;
+#endif
+              uip_log("tcp: found no unused connections.");
+              goto drop;
+            }
+
+          uip_incr32(uip_conn->rcv_nxt, 1);
+          uip_conn = uip_connr;
+
+          /* Parse the TCP MSS option, if present. */
+
+          if ((BUF->tcpoffset & 0xf0) > 0x50)
+            {
+              for (i = 0; i < ((BUF->tcpoffset >> 4) - 5) << 2 ;)
+                {
+                  opt = dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + i];
+                  if (opt == TCP_OPT_END)
+                    {
+                      /* End of options. */
+
+                      break;
+                    }
+                  else if (opt == TCP_OPT_NOOP)
+                    {
+                      /* NOP option. */
+
+                      ++i;
+                    }
+                  else if (opt == TCP_OPT_MSS &&
+                          dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == TCP_OPT_MSS_LEN)
+                    {
+                      /* An MSS option with the right option length. */
+
+                      tmp16 = ((uint16)dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + i] << 8) |
+                               (uint16)dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + i];
+                      uip_connr->initialmss = uip_connr->mss =
+                              tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
+
+                      /* And we are done processing options. */
+
+                      break;
+                    }
+                  else
+                    {
+                      /* All other options have a length field, so that we easily
+                       * can skip past them.
+                       */
+
+                      if (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == 0)
+                        {
+                          /* If the length field is zero, the options are malformed
+                           * and we don't process them further.
+                           */
+
+                          break;
+                        }
+                      i += dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i];
+                    }
+                }
+            }
+
+          /* Our response will be a SYNACK. */
+
+          uip_tcpack(dev, uip_connr, TCP_ACK | TCP_SYN);
+          goto done;
+        }
+    }
+
+  /* This is (1) an old duplicate packet or (2) a SYN packet but with
+   * no matching listener found.  Send RST packet in either case.
+   */
+
+  /* We do not send resets in response to resets. */
+
+  if (BUF->flags & TCP_RST)
+    {
+      goto drop;
+    }
+
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.tcp.synrst++;
+#endif
+  uip_tcpreset(dev);
+  goto done;
+
+found:
+
+  uip_conn = uip_connr;
+  uip_flags = 0;
+
+  /* We do a very naive form of TCP reset processing; we just accept
+   * any RST and kill our connection. We should in fact check if the
+   * sequence number of this reset is wihtin our advertised window
+   * before we accept the reset.
+   */
+
+  if (BUF->flags & TCP_RST)
+    {
+      uip_connr->tcpstateflags = UIP_CLOSED;
+      vdbg("TCP state: UIP_CLOSED\n");
+      uip_log("tcp: got reset, aborting connection.");
+
+      uip_flags = UIP_ABORT;
+      uip_tcpcallback(dev);
+      goto drop;
+    }
+
+  /* Calculated the length of the data, if the application has sent
+   * any data to us.
+   */
+
+  len = (BUF->tcpoffset >> 4) << 2;
+
+  /* d_len will contain the length of the actual TCP data. This is
+   * calculated by subtracing the length of the TCP header (in
+   * len) and the length of the IP header (20 bytes).
+   */
+
+  dev->d_len -= (len + UIP_IPH_LEN);
+
+  /* First, check if the sequence number of the incoming packet is
+   * what we're expecting next. If not, we send out an ACK with the
+   * correct numbers in.
+   */
+
+  if (!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) &&
+      ((BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK))))
+    {
+      if ((dev->d_len > 0 || ((BUF->flags & (TCP_SYN | TCP_FIN)) != 0)) &&
+          (BUF->seqno[0] != uip_connr->rcv_nxt[0] ||
+           BUF->seqno[1] != uip_connr->rcv_nxt[1] ||
+           BUF->seqno[2] != uip_connr->rcv_nxt[2] ||
+           BUF->seqno[3] != uip_connr->rcv_nxt[3]))
+        {
+            uip_tcpsend(dev, uip_connr, TCP_ACK, UIP_IPTCPH_LEN);
+            goto done;
+        }
+    }
+
+  /* Next, check if the incoming segment acknowledges any outstanding
+   * data. If so, we update the sequence number, reset the length of
+   * the outstanding data, calculate RTT estimations, and reset the
+   * retransmission timer.
+   */
+
+  if ((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr))
+    {
+      /* Temporary variables. */
+
+      uint8 acc32[4];
+      uip_add32(uip_connr->snd_nxt, uip_connr->len, acc32);
+
+      if (BUF->ackno[0] == acc32[0] && BUF->ackno[1] == acc32[1] &&
+          BUF->ackno[2] == acc32[2] && BUF->ackno[3] == acc32[3])
+        {
+          /* Update sequence number. */
+
+          uip_connr->snd_nxt[0] = acc32[0];
+          uip_connr->snd_nxt[1] = acc32[1];
+          uip_connr->snd_nxt[2] = acc32[2];
+          uip_connr->snd_nxt[3] = acc32[3];
+
+          /* Do RTT estimation, unless we have done retransmissions. */
+
+          if (uip_connr->nrtx == 0)
+            {
+              signed char m;
+              m = uip_connr->rto - uip_connr->timer;
+
+              /* This is taken directly from VJs original code in his paper */
+
+              m = m - (uip_connr->sa >> 3);
+              uip_connr->sa += m;
+              if (m < 0)
+                {
+                  m = -m;
+                }
+
+              m = m - (uip_connr->sv >> 2);
+              uip_connr->sv += m;
+              uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;
+            }
+
+          /* Set the acknowledged flag. */
+
+          uip_flags = UIP_ACKDATA;
+
+          /* Reset the retransmission timer. */
+
+          uip_connr->timer = uip_connr->rto;
+
+          /* Reset length of outstanding data. */
+
+          uip_connr->len = 0;
+        }
+    }
+
+  /* Do different things depending on in what state the connection is. */
+
+  switch(uip_connr->tcpstateflags & UIP_TS_MASK)
+    {
+      /* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
+       * implemented, since we force the application to close when the
+       * peer sends a FIN (hence the application goes directly from
+       * ESTABLISHED to LAST_ACK).
+       */
+
+      case UIP_SYN_RCVD:
+        /* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
+         * we are waiting for an ACK that acknowledges the data we sent
+         * out the last time. Therefore, we want to have the UIP_ACKDATA
+         * flag set. If so, we enter the ESTABLISHED state.
+         */
+
+        if (uip_flags & UIP_ACKDATA)
+          {
+            uip_connr->tcpstateflags = UIP_ESTABLISHED;
+            uip_connr->len           = 0;
+            vdbg("TCP state: UIP_ESTABLISHED\n");
+
+            uip_flags                = UIP_CONNECTED;
+
+            if (dev->d_len > 0)
+              {
+                uip_flags           |= UIP_NEWDATA;
+                uip_incr32(uip_conn->rcv_nxt, dev->d_len);
+              }
+
+            dev->d_sndlen            = 0;
+            uip_tcpcallback(dev);
+            uip_tcpappsend(dev, uip_connr, uip_flags);
+            goto done;
+          }
+        goto drop;
+
+      case UIP_SYN_SENT:
+        /* In SYN_SENT, we wait for a SYNACK that is sent in response to
+         * our SYN. The rcv_nxt is set to sequence number in the SYNACK
+         * plus one, and we send an ACK. We move into the ESTABLISHED
+         * state.
+         */
+
+        if ((uip_flags & UIP_ACKDATA) &&
+            (BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK))
+          {
+            /* Parse the TCP MSS option, if present. */
+
+            if ((BUF->tcpoffset & 0xf0) > 0x50)
+              {
+                for (i = 0; i < ((BUF->tcpoffset >> 4) - 5) << 2 ;)
+                  {
+                    opt = dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + i];
+                    if (opt == TCP_OPT_END)
+                      {
+                        /* End of options. */
+
+                        break;
+                      }
+                    else if (opt == TCP_OPT_NOOP)
+                      {
+                        /* NOP option. */
+
+                        ++i;
+                      }
+                    else if (opt == TCP_OPT_MSS &&
+                              dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == TCP_OPT_MSS_LEN)
+                      {
+                        /* An MSS option with the right option length. */
+
+                        tmp16 =
+                          (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + i] << 8) |
+                          dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + i];
+                        uip_connr->initialmss =
+                          uip_connr->mss =
+                          tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
+
+                        /* And we are done processing options. */
+
+                        break;
+                      }
+                    else
+                      {
+                        /* All other options have a length field, so that we
+                         * easily can skip past them.
+                         */
+
+                        if (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == 0)
+                          {
+                            /* If the length field is zero, the options are
+                             * malformed and we don't process them further.
+                             */
+
+                            break;
+                          }
+                        i += dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i];
+                      }
+                  }
+              }
+
+            uip_connr->tcpstateflags = UIP_ESTABLISHED;
+            uip_connr->rcv_nxt[0]    = BUF->seqno[0];
+            uip_connr->rcv_nxt[1]    = BUF->seqno[1];
+            uip_connr->rcv_nxt[2]    = BUF->seqno[2];
+            uip_connr->rcv_nxt[3]    = BUF->seqno[3];
+            vdbg("TCP state: UIP_ESTABLISHED\n");
+
+            uip_incr32(uip_conn->rcv_nxt, 1);
+            uip_flags      = UIP_CONNECTED | UIP_NEWDATA;
+            uip_connr->len = 0;
+            dev->d_len     = 0;
+            dev->d_sndlen  = 0;
+            uip_tcpcallback(dev);
+            uip_tcpappsend(dev, uip_connr, uip_flags);
+            goto done;
+          }
+
+        /* Inform the application that the connection failed */
+
+        uip_flags = UIP_ABORT;
+        uip_tcpcallback(dev);
+
+        /* The connection is closed after we send the RST */
+
+        uip_conn->tcpstateflags = UIP_CLOSED;
+        vdbg("TCP state: UIP_CLOSED\n");
+
+        /* We do not send resets in response to resets. */
+
+        if (BUF->flags & TCP_RST)
+          {
+            goto drop;
+          }
+        uip_tcpreset(dev);
+        goto done;
+
+      case UIP_ESTABLISHED:
+        /* In the ESTABLISHED state, we call upon the application to feed
+         * data into the d_buf. If the UIP_ACKDATA flag is set, the
+         * application should put new data into the buffer, otherwise we are
+         * retransmitting an old segment, and the application should put that
+         * data into the buffer.
+         *
+         * If the incoming packet is a FIN, we should close the connection on
+         * this side as well, and we send out a FIN and enter the LAST_ACK
+         * state. We require that there is no outstanding data; otherwise the
+         * sequence numbers will be screwed up.
+         */
+
+        if (BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED))
+          {
+            if (uip_outstanding(uip_connr))
+              {
+                goto drop;
+              }
+
+            uip_incr32(uip_conn->rcv_nxt, dev->d_len + 1);
+            uip_flags |= UIP_CLOSE;
+
+            if (dev->d_len > 0)
+              {
+                uip_flags |= UIP_NEWDATA;
+              }
+
+            uip_tcpcallback(dev);
+
+            uip_connr->tcpstateflags = UIP_LAST_ACK;
+            uip_connr->len = 1;
+            uip_connr->nrtx = 0;
+            vdbg("TCP state: UIP_LAST_ACK\n");
+
+            uip_tcpsend(dev, uip_connr, TCP_FIN | TCP_ACK, UIP_IPTCPH_LEN);
+            goto done;
+          }
+
+        /* Check the URG flag. If this is set, the segment carries urgent
+           data that we must pass to the application. */
+        if ((BUF->flags & TCP_URG) != 0)
+          {
+#if UIP_URGDATA > 0
+            uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1];
+            if (uip_urglen > dev->d_len)
+              {
+                /* There is more urgent data in the next segment to come. */
+
+                uip_urglen = dev->d_len;
+              }
+
+            uip_incr32(uip_conn->rcv_nxt, uip_urglen);
+            dev->d_len     -= uip_urglen;
+            uip_urgdata     = dev->d_appdata;
+            dev->d_appdata += uip_urglen;
+          }
+        else
+          {
+            uip_urglen     = 0;
+#else /* UIP_URGDATA > 0 */
+            dev->d_appdata =
+              ((uint8*)dev->d_appdata) + ((BUF->urgp[0] << 8) | BUF->urgp[1]);
+            dev->d_len    -=
+              (BUF->urgp[0] << 8) | BUF->urgp[1];
+#endif /* UIP_URGDATA > 0 */
+          }
+
+        /* If d_len > 0 we have TCP data in the packet, and we flag this
+         * by setting the UIP_NEWDATA flag and update the sequence number
+         * we acknowledge. If the application has stopped the dataflow
+         * using uip_stop(), we must not accept any data packets from the
+         * remote host.
+         */
+
+        if (dev->d_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED))
+          {
+            uip_flags |= UIP_NEWDATA;
+            uip_incr32(uip_conn->rcv_nxt, dev->d_len);
+          }
+
+        /* Check if the available buffer space advertised by the other end
+         * is smaller than the initial MSS for this connection. If so, we
+         * set the current MSS to the window size to ensure that the
+         * application does not send more data than the other end can
+         * handle.
+         *
+         * If the remote host advertises a zero window, we set the MSS to
+         * the initial MSS so that the application will send an entire MSS
+         * of data. This data will not be acknowledged by the receiver,
+         * and the application will retransmit it. This is called the
+         * "persistent timer" and uses the retransmission mechanim.
+         */
+
+        tmp16 = ((uint16)BUF->wnd[0] << 8) + (uint16)BUF->wnd[1];
+        if (tmp16 > uip_connr->initialmss || tmp16 == 0)
+          {
+            tmp16 = uip_connr->initialmss;
+          }
+        uip_connr->mss = tmp16;
+
+        /* If this packet constitutes an ACK for outstanding data (flagged
+         * by the UIP_ACKDATA flag, we should call the application since it
+         * might want to send more data. If the incoming packet had data
+         * from the peer (as flagged by the UIP_NEWDATA flag), the
+         * application must also be notified.
+         *
+         * When the application is called, the d_len field
+         * contains the length of the incoming data. The application can
+         * access the incoming data through the global pointer
+         * d_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN
+         *  bytes into the d_buf array.
+         *
+         * If the application wishes to send any data, this data should be
+         * put into the d_appdata and the length of the data should be
+         * put into d_len. If the application don't have any data to
+         * send, d_len must be set to 0.
+         */
+
+        if (uip_flags & (UIP_NEWDATA | UIP_ACKDATA))
+          {
+            dev->d_sndlen = 0;
+            uip_tcpcallback(dev);
+            uip_tcpappsend(dev, uip_connr, uip_flags);
+            goto done;
+          }
+        goto drop;
+
+      case UIP_LAST_ACK:
+        /* We can close this connection if the peer has acknowledged our
+         * FIN. This is indicated by the UIP_ACKDATA flag.
+         */
+
+        if (uip_flags & UIP_ACKDATA)
+          {
+            uip_connr->tcpstateflags = UIP_CLOSED;
+            vdbg("TCP state: UIP_CLOSED\n");
+
+            uip_flags = UIP_CLOSE;
+            uip_tcpcallback(dev);
+          }
+        break;
+
+      case UIP_FIN_WAIT_1:
+        /* The application has closed the connection, but the remote host
+         * hasn't closed its end yet. Thus we do nothing but wait for a
+         * FIN from the other side.
+         */
+
+        if (dev->d_len > 0)
+          {
+            uip_incr32(uip_conn->rcv_nxt, dev->d_len);
+          }
+        if (BUF->flags & TCP_FIN)
+          {
+            if (uip_flags & UIP_ACKDATA)
+              {
+                uip_connr->tcpstateflags = UIP_TIME_WAIT;
+                uip_connr->timer = 0;
+                uip_connr->len = 0;
+                vdbg("TCP state: UIP_TIME_WAIT\n");
+              }
+            else
+              {
+                uip_connr->tcpstateflags = UIP_CLOSING;
+                vdbg("TCP state: UIP_CLOSING\n");
+              }
+
+            uip_incr32(uip_conn->rcv_nxt, 1);
+            uip_flags = UIP_CLOSE;
+            uip_tcpcallback(dev);
+            uip_tcpsend(dev, uip_connr, TCP_ACK, UIP_IPTCPH_LEN);
+            goto done;
+          }
+        else if (uip_flags & UIP_ACKDATA)
+          {
+            uip_connr->tcpstateflags = UIP_FIN_WAIT_2;
+            uip_connr->len = 0;
+            vdbg("TCP state: UIP_FIN_WAIT_2\n");
+            goto drop;
+          }
+
+        if (dev->d_len > 0)
+          {
+            uip_tcpsend(dev, uip_connr, TCP_ACK, UIP_IPTCPH_LEN);
+            goto done;
+          }
+        goto drop;
+
+      case UIP_FIN_WAIT_2:
+        if (dev->d_len > 0)
+          {
+            uip_incr32(uip_conn->rcv_nxt, dev->d_len);
+          }
+
+        if (BUF->flags & TCP_FIN)
+          {
+            uip_connr->tcpstateflags = UIP_TIME_WAIT;
+            uip_connr->timer = 0;
+            vdbg("TCP state: UIP_TIME_WAIT\n");
+
+            uip_incr32(uip_conn->rcv_nxt, 1);
+            uip_flags = UIP_CLOSE;
+            uip_tcpcallback(dev);
+            uip_tcpsend(dev, uip_connr, TCP_ACK, UIP_IPTCPH_LEN);
+            goto done;
+          }
+
+        if (dev->d_len > 0)
+          {
+            uip_tcpsend(dev, uip_connr, TCP_ACK, UIP_IPTCPH_LEN);
+            goto done;
+          }
+        goto drop;
+
+      case UIP_TIME_WAIT:
+        uip_tcpsend(dev, uip_connr, TCP_ACK, UIP_IPTCPH_LEN);
+        goto done;
+
+      case UIP_CLOSING:
+        if (uip_flags & UIP_ACKDATA)
+          {
+            uip_connr->tcpstateflags = UIP_TIME_WAIT;
+            uip_connr->timer = 0;
+            vdbg("TCP state: UIP_TIME_WAIT\n");
+          }
+    }
+  goto drop;
+
+done:
+  uip_flags = 0;
+  return;
+
+drop:
+  uip_flags  = 0;
+  dev->d_len = 0;
+}
+
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip-tcppoll.c b/nuttx/net/uip/uip-tcppoll.c
new file mode 100644
index 000000000..625b91931
--- /dev/null
+++ b/nuttx/net/uip/uip-tcppoll.c
@@ -0,0 +1,126 @@
+/****************************************************************************
+ * net/uip/uip-tcppoll.c
+ * Poll for the availability of TCP TX data
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Adapted for NuttX from logic in uIP which also has a BSD-like license:
+ *
+ *   Original author Adam Dunkels <adam@dunkels.com>
+ *   Copyright () 2001-2003, Adam Dunkels.
+ *   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <debug.h>
+
+#include <net/uip/uipopt.h>
+#include <net/uip/uip.h>
+#include <net/uip/uip-arch.h>
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: uip_tcppoll
+ *
+ * Description:
+ *   Poll a TCP connection structure for availability of TX data
+ *
+ * Parameters:
+ *   dev - The device driver structure to use in the send operation
+ *   conn - The TCP "connection" to poll for TX data
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcppoll(struct uip_driver_s *dev, struct uip_conn *conn)
+{
+  /* Verify that the connection is established and if the connection has
+   * oustanding (unacknowledged) sent data.
+   */
+
+  if ((conn->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED &&
+      !uip_outstanding(conn))
+    {
+      /* Set up for the callback */
+
+      dev->d_snddata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
+      dev->d_appdata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
+
+      /* Perfom the callback */
+
+      uip_flags = UIP_POLL;
+      uip_tcpcallback(dev);
+
+      /* Handle the callback response */
+
+      uip_tcpappsend(dev, conn, uip_flags);
+    }
+  else
+    {
+      /* Nothing to do for this connection */
+
+      dev->d_len = 0;
+    }
+}
+
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip-tcpsend.c b/nuttx/net/uip/uip-tcpsend.c
new file mode 100644
index 000000000..9c367159d
--- /dev/null
+++ b/nuttx/net/uip/uip-tcpsend.c
@@ -0,0 +1,365 @@
+/****************************************************************************
+ * net/uip/uip-tcpsend.c
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Adapted for NuttX from logic in uIP which also has a BSD-like license:
+ *
+ *   Original author Adam Dunkels <adam@dunkels.com>
+ *   Copyright () 2001-2003, Adam Dunkels.
+ *   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <debug.h>
+
+#include <net/uip/uipopt.h>
+#include <net/uip/uip.h>
+#include <net/uip/uip-arch.h>
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+#define BUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: uip_tcpsendcomplete
+ *
+ * Description:
+ *   Complete the final portions of the send operation.  This function sets
+ *   up IP header and computes the TCP checksum
+ *
+ * Parameters:
+ *   dev    - The device driver structure to use in the send operation
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+static void uip_tcpsendcomplete(struct uip_driver_s *dev)
+{
+  BUF->ttl         = UIP_TTL;
+
+#ifdef CONFIG_NET_IPv6
+
+  /* For IPv6, the IP length field does not include the IPv6 IP header
+   * length.
+   */
+
+  BUF->len[0]      = ((dev->d_len - UIP_IPH_LEN) >> 8);
+  BUF->len[1]      = ((dev->d_len - UIP_IPH_LEN) & 0xff);
+
+#else /* CONFIG_NET_IPv6 */
+
+  BUF->len[0]      = (dev->d_len >> 8);
+  BUF->len[1]      = (dev->d_len & 0xff);
+
+#endif /* CONFIG_NET_IPv6 */
+
+  BUF->urgp[0]     = BUF->urgp[1] = 0;
+
+  /* Calculate TCP checksum. */
+
+  BUF->tcpchksum   = 0;
+  BUF->tcpchksum   = ~(uip_tcpchksum(dev));
+
+#ifdef CONFIG_NET_IPv6
+
+  BUF->vtc         = 0x60;
+  BUF->tcf         = 0x00;
+  BUF->flow        = 0x00;
+
+#else /* CONFIG_NET_IPv6 */
+
+  BUF->vhl         = 0x45;
+  BUF->tos         = 0;
+  BUF->ipoffset[0] = 0;
+  BUF->ipoffset[1] = 0;
+  ++g_ipid;
+  BUF->ipid[0]     = g_ipid >> 8;
+  BUF->ipid[1]     = g_ipid & 0xff;
+
+  /* Calculate IP checksum. */
+
+  BUF->ipchksum    = 0;
+  BUF->ipchksum    = ~(uip_ipchksum(dev));
+
+#endif /* CONFIG_NET_IPv6 */
+
+  vdbg("Outgoing TCP packet length: %d (%d)\n",
+       dev->d_len, (BUF->len[0] << 8) | BUF->len[1]);
+
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.tcp.sent++;
+  uip_stat.ip.sent++;
+#endif
+}
+
+/****************************************************************************
+ * Name: uip_tcpsendcommon
+ *
+ * Description:
+ *   We're done with the input processing. We are now ready to send a reply
+ *   Our job is to fill in all the fields of the TCP and IP headers before
+ *   calculating the checksum and finally send the packet.
+ *
+ * Parameters:
+ *   dev    - The device driver structure to use in the send operation
+ *   conn   - The TCP connection structure holding connection information
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+static void uip_tcpsendcommon(struct uip_driver_s *dev, struct uip_conn *conn)
+{
+  BUF->ackno[0] = conn->rcv_nxt[0];
+  BUF->ackno[1] = conn->rcv_nxt[1];
+  BUF->ackno[2] = conn->rcv_nxt[2];
+  BUF->ackno[3] = conn->rcv_nxt[3];
+
+  BUF->seqno[0] = conn->snd_nxt[0];
+  BUF->seqno[1] = conn->snd_nxt[1];
+  BUF->seqno[2] = conn->snd_nxt[2];
+  BUF->seqno[3] = conn->snd_nxt[3];
+
+  BUF->proto    = UIP_PROTO_TCP;
+
+  BUF->srcport  = conn->lport;
+  BUF->destport = conn->rport;
+
+  uiphdr_ipaddr_copy(BUF->srcipaddr, &dev->d_ipaddr);
+  uiphdr_ipaddr_copy(BUF->destipaddr, &conn->ripaddr);
+
+  if (conn->tcpstateflags & UIP_STOPPED)
+    {
+      /* If the connection has issued uip_stop(), we advertise a zero
+       * window so that the remote host will stop sending data.
+       */
+
+      BUF->wnd[0] = 0;
+      BUF->wnd[1] = 0;
+    }
+  else
+    {
+      BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
+      BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
+    }
+
+  /* Finish the IP portion of the message, calculate checksums and send
+   * the message.
+   */
+
+  uip_tcpsendcomplete(dev);
+
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: uip_tcpsend
+ *
+ * Description:
+ *   Setup to send a TCP packet
+ *
+ * Parameters:
+ *   dev    - The device driver structure to use in the send operation
+ *   conn   - The TCP connection structure holding connection information
+ *   flags  - flags to apply to the TCP header
+ *   len    - length of the message
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcpsend(struct uip_driver_s *dev, struct uip_conn *conn, uint8 flags, uint16 len)
+{
+  BUF->flags     = flags;
+  dev->d_len     = len;
+  BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
+  uip_tcpsendcommon(dev, conn);
+}
+
+/****************************************************************************
+ * Name: uip_tcpreset
+ *
+ * Description:
+ *   Send a TCP reset (no-data) message
+ *
+ * Parameters:
+ *   dev    - The device driver structure to use in the send operation
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcpreset(struct uip_driver_s *dev)
+{
+  uint16 tmp16;
+  uint8  seqbyte;
+
+#ifdef CONFIG_NET_STATISTICS
+  uip_stat.tcp.rst++;
+#endif
+
+  BUF->flags     = TCP_RST | TCP_ACK;
+  dev->d_len     = UIP_IPTCPH_LEN;
+  BUF->tcpoffset = 5 << 4;
+
+  /* Flip the seqno and ackno fields in the TCP header. */
+
+  seqbyte        = BUF->seqno[3];
+  BUF->seqno[3]  = BUF->ackno[3];
+  BUF->ackno[3]  = seqbyte;
+
+  seqbyte        = BUF->seqno[2];
+  BUF->seqno[2]  = BUF->ackno[2];
+  BUF->ackno[2]  = seqbyte;
+
+  seqbyte        = BUF->seqno[1];
+  BUF->seqno[1]  = BUF->ackno[1];
+  BUF->ackno[1]  = seqbyte;
+
+  seqbyte        = BUF->seqno[0];
+  BUF->seqno[0]  = BUF->ackno[0];
+  BUF->ackno[0]  = seqbyte;
+
+  /* We also have to increase the sequence number we are
+   * acknowledging. If the least significant byte overflowed, we need
+   * to propagate the carry to the other bytes as well.
+   */
+
+  if (++(BUF->ackno[3]) == 0)
+    {
+      if (++(BUF->ackno[2]) == 0)
+        {
+          if (++(BUF->ackno[1]) == 0)
+            {
+              ++(BUF->ackno[0]);
+            }
+        }
+    }
+
+  /* Swap port numbers. */
+
+  tmp16         = BUF->srcport;
+  BUF->srcport  = BUF->destport;
+  BUF->destport = tmp16;
+
+  /* Swap IP addresses. */
+
+  uiphdr_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
+  uiphdr_ipaddr_copy(BUF->srcipaddr, dev->d_ipaddr);
+
+  /* And send out the RST packet */
+
+  uip_tcpsendcomplete(dev);
+}
+
+/****************************************************************************
+ * Name: uip_tcpack
+ *
+ * Description:
+ *   Send the SYN or SYNACK response.
+ *
+ * Parameters:
+ *   dev    - The device driver structure to use in the send operation
+ *   conn   - The TCP connection structure holding connection information
+ *   ack    - The ACK response to send
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcpack(struct uip_driver_s *dev, struct uip_conn *conn, uint8 ack)
+{
+  /* Save the ACK bits */
+
+  BUF->flags = ack;
+
+  /* We send out the TCP Maximum Segment Size option with our ack. */
+
+  BUF->optdata[0] = TCP_OPT_MSS;
+  BUF->optdata[1] = TCP_OPT_MSS_LEN;
+  BUF->optdata[2] = (UIP_TCP_MSS) / 256;
+  BUF->optdata[3] = (UIP_TCP_MSS) & 255;
+  dev->d_len      = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
+  BUF->tcpoffset  = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
+
+  /* Complete the common portions of the TCP message */
+
+  uip_tcpsendcommon(dev, conn);
+}
+
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip-tcptimer.c b/nuttx/net/uip/uip-tcptimer.c
new file mode 100644
index 000000000..5b248f358
--- /dev/null
+++ b/nuttx/net/uip/uip-tcptimer.c
@@ -0,0 +1,241 @@
+/****************************************************************************
+ * net/uip/uip-tcptimer.c
+ * Poll for the availability of TCP TX data
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Adapted for NuttX from logic in uIP which also has a BSD-like license:
+ *
+ *   Original author Adam Dunkels <adam@dunkels.com>
+ *   Copyright () 2001-2003, Adam Dunkels.
+ *   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#ifdef CONFIG_NET
+
+#include <sys/types.h>
+#include <debug.h>
+
+#include <net/uip/uipopt.h>
+#include <net/uip/uip.h>
+#include <net/uip/uip-arch.h>
+
+#include "uip-internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: uip_tcptimer
+ *
+ * Description:
+ *   Handle a TCP timer expiration for the provided TCP connection
+ *
+ * Parameters:
+ *   dev - The device driver structure to use in the send operation
+ *   conn - The TCP "connection" to poll for TX data
+ *
+ * Return:
+ *   None
+ *
+ * Assumptions:
+ *   Called from the interrupt level or with interrupts disabled.
+ *
+ ****************************************************************************/
+
+void uip_tcptimer(struct uip_driver_s *dev, struct uip_conn *conn)
+{
+  dev->d_snddata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
+  dev->d_appdata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
+
+  /* Increment the timer used by the reassembly logic */
+
+#if UIP_REASSEMBLY
+  if (uip_reasstmr != 0)
+    {
+      uip_reasstmr++;
+    }
+#endif /* UIP_REASSEMBLY */
+
+  /* Increase the TCP sequence number */
+
+  uip_tcpnextsequence();
+
+  /* Reset the length variables. */
+
+  dev->d_len  = 0;
+  dev->d_sndlen = 0;
+
+  /* Check if the connection is in a state in which we simply wait
+   * for the connection to time out. If so, we increase the
+   * connection's timer and remove the connection if it times
+   * out.
+   */
+
+  if (conn->tcpstateflags == UIP_TIME_WAIT || conn->tcpstateflags == UIP_FIN_WAIT_2)
+    {
+      (conn->timer)++;
+      if (conn->timer == UIP_TIME_WAIT_TIMEOUT)
+        {
+          conn->tcpstateflags = UIP_CLOSED;
+          vdbg("TCP state: UIP_CLOSED\n");
+        }
+    }
+  else if (conn->tcpstateflags != UIP_CLOSED)
+    {
+      /* If the connection has outstanding data, we increase the
+       * connection's timer and see if it has reached the RTO value
+       * in which case we retransmit.
+       */
+
+      if (uip_outstanding(conn))
+        {
+          if (conn->timer-- == 0)
+            {
+              if (conn->nrtx == UIP_MAXRTX ||
+                  ((conn->tcpstateflags == UIP_SYN_SENT ||
+                    conn->tcpstateflags == UIP_SYN_RCVD) &&
+                    conn->nrtx == UIP_MAXSYNRTX))
+                {
+                  conn->tcpstateflags = UIP_CLOSED;
+                  vdbg("TCP state: UIP_CLOSED\n");
+
+                  /* We call uip_tcpcallback() with uip_flags set to
+                   * UIP_TIMEDOUT to inform the application that the
+                   * connection has timed out.
+                   */
+
+                  uip_flags = UIP_TIMEDOUT;
+                  uip_tcpcallback(dev);
+
+                  /* We also send a reset packet to the remote host. */
+
+                  uip_tcpsend(dev, conn, TCP_RST | TCP_ACK, UIP_IPTCPH_LEN);
+                  goto done;
+                }
+
+             /* Exponential backoff. */
+
+              conn->timer = UIP_RTO << (conn->nrtx > 4 ? 4: conn->nrtx);
+              ++(conn->nrtx);
+
+              /* Ok, so we need to retransmit. We do this differently
+               * depending on which state we are in. In ESTABLISHED, we
+               * call upon the application so that it may prepare the
+               * data for the retransmit. In SYN_RCVD, we resend the
+               * SYNACK that we sent earlier and in LAST_ACK we have to
+               * retransmit our FINACK.
+               */
+
+#ifdef CONFIG_NET_STATISTICS
+              uip_stat.tcp.rexmit++;
+#endif
+              switch(conn->tcpstateflags & UIP_TS_MASK)
+                {
+                  case UIP_SYN_RCVD:
+                    /* In the SYN_RCVD state, we should retransmit our
+                     * SYNACK.
+                     */
+
+                    uip_tcpack(dev, conn, TCP_ACK | TCP_SYN);
+                    goto done;
+
+                  case UIP_SYN_SENT:
+                    /* In the SYN_SENT state, we retransmit out SYN. */
+
+                    uip_tcpack(dev, conn, TCP_SYN);
+                    goto done;
+
+                  case UIP_ESTABLISHED:
+                    /* In the ESTABLISHED state, we call upon the application
+                     * to do the actual retransmit after which we jump into
+                     * the code for sending out the packet.
+                     */
+
+                    uip_flags = UIP_REXMIT;
+                    uip_tcpcallback(dev);
+                    uip_tcprexmit(dev, conn, uip_flags);
+                    goto done;
+
+                  case UIP_FIN_WAIT_1:
+                  case UIP_CLOSING:
+                  case UIP_LAST_ACK:
+                    /* In all these states we should retransmit a FINACK. */
+
+                    uip_tcpsend(dev, conn, TCP_FIN | TCP_ACK, UIP_IPTCPH_LEN);
+                    goto done;
+                }
+            }
+        }
+      else if ((conn->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED)
+        {
+          /* If there was no need for a retransmission, we poll the
+           * application for new data.
+           */
+
+          uip_flags = UIP_POLL;
+          uip_tcpcallback(dev);
+          uip_tcpappsend(dev, conn, uip_flags);
+          goto done;
+        }
+    }
+
+  /* Nothing to be done */
+
+  dev->d_len = 0;
+
+done:
+  uip_flags = 0;
+  return;
+}
+
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip-udpsend.c b/nuttx/net/uip/uip-udpsend.c
index 207c0ea35..7a2a0547c 100644
--- a/nuttx/net/uip/uip-udpsend.c
+++ b/nuttx/net/uip/uip-udpsend.c
@@ -1,6 +1,5 @@
 /****************************************************************************
  * net/uip/uip-udpsend.c
- * Poll for the availability of UDP TX data
  *
  *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
@@ -115,8 +114,8 @@ void uip_udpsend(struct uip_driver_s *dev, struct uip_udp_conn *conn)
       UDPBUF->flow        = 0x00;
       UDPBUF->len[0]      = (dev->d_sndlen >> 8);
       UDPBUF->len[1]      = (dev->d_sndlen & 0xff);
-      UDPBUF->proto        = UIP_PROTO_UDP;
-      UDPBUF->ttl          = conn->ttl;
+      UDPBUF->nexthdr     = UIP_PROTO_UDP;
+      UDPBUF->hoplimit    = conn->ttl;
 
       uip_ipaddr_copy(UDPBUF->srcipaddr, &dev->d_ipaddr);
       uip_ipaddr_copy(UDPBUF->destipaddr, &conn->ripaddr);
diff --git a/nuttx/net/uip/uip.c b/nuttx/net/uip/uip.c
deleted file mode 100644
index 7c9a997b6..000000000
--- a/nuttx/net/uip/uip.c
+++ /dev/null
@@ -1,1767 +0,0 @@
-/****************************************************************************
- * uip.c
- * The uIP TCP/IP stack code.
- * author Adam Dunkels <adam@dunkels.com>
- *
- * uIP is an implementation of the TCP/IP protocol stack intended for
- * small 8-bit and 16-bit microcontrollers.
- *
- * uIP provides the necessary protocols for Internet communication,
- * with a very small code footprint and RAM requirements - the uIP
- * code size is on the order of a few kilobytes and RAM usage is on
- * the order of a few hundred bytes.
- *
- * Copyright () 2001-2003, Adam Dunkels.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote
- *    products derived from this software without specific prior
- *    written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
- * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
- * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- ****************************************************************************/
-
-/****************************************************************************
- * uIP is a small implementation of the IP, UDP and TCP protocols (as
- * well as some basic ICMP stuff). The implementation couples the IP,
- * UDP, TCP and the application layers very tightly. To keep the size
- * of the compiled code down, this code frequently uses the goto
- * statement. While it would be possible to break the uip_interrupt()
- * function into many smaller functions, this would increase the code
- * size because of the overhead of parameter passing and the fact that
- * the optimier would not be as efficient.
- *
- * The principle is that we have a small buffer, called the d_buf,
- * in which the device driver puts an incoming packet. The TCP/IP
- * stack parses the headers in the packet, and calls the
- * application. If the remote host has sent data to the application,
- * this data is present in the d_buf and the application read the
- * data from there. It is up to the application to put this data into
- * a byte stream if needed. The application will not be fed with data
- * that is out of sequence.
- *
- * If the application whishes to send data to the peer, it should put
- * its data into the d_buf. The d_appdata pointer points to the
- * first available byte. The TCP/IP stack will calculate the
- * checksums, and fill in the necessary header fields and finally send
- * the packet back to the peer.
- *
- ****************************************************************************/
-
-/****************************************************************************
- * Included Files
- ****************************************************************************/
-
-#include <nuttx/config.h>
-#ifdef CONFIG_NET
-
-#include <sys/types.h>
-#include <sys/ioctl.h>
-
-#include <debug.h>
-#include <string.h>
-
-#include <net/uip/uipopt.h>
-#include <net/uip/uip.h>
-#include <net/uip/uip-arch.h>
-
-#ifdef CONFIG_NET_IPv6
-# include "uip-neighbor.h"
-#endif /* CONFIG_NET_IPv6 */
-
-#include "uip-internal.h"
-
-/****************************************************************************
- * Definitions
- ****************************************************************************/
-
-#define TCP_FIN 0x01
-#define TCP_SYN 0x02
-#define TCP_RST 0x04
-#define TCP_PSH 0x08
-#define TCP_ACK 0x10
-#define TCP_URG 0x20
-#define TCP_CTL 0x3f
-
-#define TCP_OPT_END     0   /* End of TCP options list */
-#define TCP_OPT_NOOP    1   /* "No-operation" TCP option */
-#define TCP_OPT_MSS     2   /* Maximum segment size TCP option */
-
-#define TCP_OPT_MSS_LEN 4   /* Length of TCP MSS option. */
-
-#define ICMP_ECHO_REPLY 0
-#define ICMP_ECHO       8
-
-#define ICMP6_ECHO_REPLY             129
-#define ICMP6_ECHO                   128
-#define ICMP6_NEIGHBOR_SOLICITATION  135
-#define ICMP6_NEIGHBOR_ADVERTISEMENT 136
-
-#define ICMP6_FLAG_S (1 << 6)
-
-#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
-#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2
-
-/* Macros. */
-
-#define BUF     ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
-#define FBUF    ((struct uip_tcpip_hdr *)&uip_reassbuf[0])
-#define ICMPBUF ((struct uip_icmpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
-
-/****************************************************************************
- * Public Variables
- ****************************************************************************/
-
-#if UIP_URGDATA > 0
-void *uip_urgdata;           /* urgent data (out-of-band data), if present. */
-uint16 uip_urglen;           /* Length of (received) urgent data */
-#endif
-
-/* The uip_flags variable is used for communication between the TCP/IP
- * stack and the application program.
- */
-
-uint8 uip_flags;
-
-/* uip_conn always points to the current connection. */
-
-struct uip_conn *uip_conn;
-
-#ifdef CONFIG_NET_UDP
-struct uip_udp_conn *uip_udp_conn;
-#endif   /* CONFIG_NET_UDP */
-
-/* Temporary variables. */
-
-uint8 uip_acc32[4];
-
-#ifdef CONFIG_NET_STATISTICS
-struct uip_stats uip_stat;
-# define UIP_STAT(s) s
-#else
-# define UIP_STAT(s)
-#endif
-
-/* Increasing number used for the IP ID field. */
-
-uint16 g_ipid;
-
-const uip_ipaddr_t all_ones_addr =
-#ifdef CONFIG_NET_IPv6
-  {0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff};
-#else /* CONFIG_NET_IPv6 */
-  {0xffffffff};
-#endif /* CONFIG_NET_IPv6 */
-
-const uip_ipaddr_t all_zeroes_addr =
-#ifdef CONFIG_NET_IPv6
-  {0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000};
-#else /* CONFIG_NET_IPv6 */
-  {0x00000000};
-#endif /* CONFIG_NET_IPv6 */
-
-/****************************************************************************
- * Private Variables
- ****************************************************************************/
-
-/****************************************************************************
- * Private Functions
- ****************************************************************************/
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
-/* This function may be used at boot time to set the initial ip_id.*/
-
-void uip_setipid(uint16 id)
-{
-  g_ipid = id;
-}
-
-/* IP fragment reassembly: not well-tested. */
-
-#if UIP_REASSEMBLY && !defined(CONFIG_NET_IPv6)
-#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
-static uint8 uip_reassbuf[UIP_REASS_BUFSIZE];
-static uint8 uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
-static const uint8 bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f, 0x0f, 0x07, 0x03, 0x01};
-static uint16 uip_reasslen;
-static uint8 uip_reassflags;
-#define UIP_REASS_FLAG_LASTFRAG 0x01
-static uint8 uip_reasstmr;
-
-#define IP_MF   0x20
-
-static uint8 uip_reass(void)
-{
-  uint16 offset, len;
-  uint16 i;
-
-  /* If ip_reasstmr is zero, no packet is present in the buffer, so we
-   * write the IP header of the fragment into the reassembly
-   * buffer. The timer is updated with the maximum age.
-   */
-
-  if (uip_reasstmr == 0)
-    {
-      memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
-      uip_reasstmr = UIP_REASS_MAXAGE;
-      uip_reassflags = 0;
-
-      /* Clear the bitmap. */
-      memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
-    }
-
-  /* Check if the incoming fragment matches the one currently present
-   * in the reasembly buffer. If so, we proceed with copying the
-   * fragment into the buffer.
-   */
-
-  if (uiphdr_addr_cmp(BUF->srcipaddr, FBUF->srcipaddr) && 
-      uiphdr_addr_cmp(BUF->destipaddr == FBUF->destipaddr) &&
-      BUF->g_ipid[0] == FBUF->g_ipid[0] && BUF->g_ipid[1] == FBUF->g_ipid[1])
-    {
-      len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
-      offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
-
-      /* If the offset or the offset + fragment length overflows the
-       * reassembly buffer, we discard the entire packet.
-       */
-
-      if (offset > UIP_REASS_BUFSIZE || offset + len > UIP_REASS_BUFSIZE)
-        {
-          uip_reasstmr = 0;
-          goto nullreturn;
-        }
-
-      /* Copy the fragment into the reassembly buffer, at the right offset. */
-
-      memcpy(&uip_reassbuf[UIP_IPH_LEN + offset], (char *)BUF + (int)((BUF->vhl & 0x0f) * 4), len);
-
-    /* Update the bitmap. */
-
-    if (offset / (8 * 8) == (offset + len) / (8 * 8))
-      {
-        /* If the two endpoints are in the same byte, we only update that byte. */
-
-        uip_reassbitmap[offset / (8 * 8)] |=
-          bitmap_bits[(offset / 8 ) & 7] & ~bitmap_bits[((offset + len) / 8 ) & 7];
-
-      }
-    else
-      {
-        /* If the two endpoints are in different bytes, we update the bytes
-         * in the endpoints and fill the stuff inbetween with 0xff.
-         */
-
-        uip_reassbitmap[offset / (8 * 8)] |= bitmap_bits[(offset / 8 ) & 7];
-        for (i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i)
-          {
-            uip_reassbitmap[i] = 0xff;
-          }
-        uip_reassbitmap[(offset + len) / (8 * 8)] |= ~bitmap_bits[((offset + len) / 8 ) & 7];
-      }
-
-    /* If this fragment has the More Fragments flag set to zero, we know that
-     * this is the last fragment, so we can calculate the size of the entire
-     * packet. We also set the IP_REASS_FLAG_LASTFRAG flag to indicate that
-     * we have received the final fragment.
-     */
-
-    if ((BUF->ipoffset[0] & IP_MF) == 0)
-      {
-        uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
-        uip_reasslen = offset + len;
-      }
-
-    /* Finally, we check if we have a full packet in the buffer. We do this
-     * by checking if we have the last fragment and if all bits in the bitmap
-     * are set.
-     */
-
-    if (uip_reassflags & UIP_REASS_FLAG_LASTFRAG)
-      {
-        /* Check all bytes up to and including all but the last byte in
-         * the bitmap.
-         */
-
-        for (i = 0; i < uip_reasslen / (8 * 8) - 1; ++i)
-          {
-            if (uip_reassbitmap[i] != 0xff)
-              {
-                goto nullreturn;
-              }
-          }
-
-        /* Check the last byte in the bitmap. It should contain just the
-         * right amount of bits.
-         */
-
-        if (uip_reassbitmap[uip_reasslen / (8 * 8)] != (uint8)~bitmap_bits[uip_reasslen / 8 & 7])
-          {
-            goto nullreturn;
-          }
-
-        /* If we have come this far, we have a full packet in the buffer,
-         * so we allocate a pbuf and copy the packet into it. We also reset
-         * the timer.
-         */
-
-        uip_reasstmr = 0;
-        memcpy(BUF, FBUF, uip_reasslen);
-
-        /* Pretend to be a "normal" (i.e., not fragmented) IP packet from
-         * now on.
-         */
-
-        BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
-        BUF->len[0] = uip_reasslen >> 8;
-        BUF->len[1] = uip_reasslen & 0xff;
-        BUF->ipchksum = 0;
-        BUF->ipchksum = ~(uip_ipchksum(dev));
-
-        return uip_reasslen;
-      }
-  }
-
-nullreturn:
-  return 0;
-}
-#endif /* UIP_REASSEMBLY */
-
-static void uip_add_rcv_nxt(uint16 n)
-{
-  uip_add32(uip_conn->rcv_nxt, n);
-  uip_conn->rcv_nxt[0] = uip_acc32[0];
-  uip_conn->rcv_nxt[1] = uip_acc32[1];
-  uip_conn->rcv_nxt[2] = uip_acc32[2];
-  uip_conn->rcv_nxt[3] = uip_acc32[3];
-}
-
-static void uip_tcp_callback(struct uip_driver_s *dev)
-{
-  vdbg("uip_flags: %02x\n", uip_flags);
-
-  /* Some sanity checking */
-
-  if (uip_conn)
-    {
-      /* Check if there is a data callback */
-
-      if (uip_conn->data_event)
-      {
-        /* Perform the callback */
-
-        uip_conn->data_event(dev, uip_conn->data_private);
-      }
-
-      /* Check if there is a connection-related event and a connection
-       * callback.
-       */
-      if (((uip_flags & UIP_CONN_EVENTS) != 0) && uip_conn->connection_event)
-        {
-          /* Perform the callback */
-
-          uip_conn->connection_event(uip_conn->connection_private);
-        }
-    }
-}
-
-void uip_interrupt(struct uip_driver_s *dev, uint8 event)
-{
-  register struct uip_conn *uip_connr = uip_conn;
-  uint16 tmp16;
-  uint8  seqbyte;
-  uint8  opt;
-  int    len;
-  int    i;
-
-  vdbg("event: %d\n", event);
-
-  dev->d_snddata = dev->d_appdata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
-
-  /* Check if we were invoked because of a TX poll request for a
-   * particular TCP connection.
-   */
-
-  if (event == UIP_DRV_POLL)
-    {
-      if ((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED &&
-           !uip_outstanding(uip_connr))
-        {
-          uip_flags = UIP_POLL;
-          uip_tcp_callback(dev);
-          goto appsend;
-        }
-        goto drop;
-    }
-
-  /* Check if we were invoked because of the perodic timer firing. */
-
-  else if (event == UIP_DRV_TIMER)
-    {
-#if UIP_REASSEMBLY
-      if (uip_reasstmr != 0)
-        {
-          --uip_reasstmr;
-        }
-#endif /* UIP_REASSEMBLY */
-
-      /* Increase the TCP sequence number */
-
-      uip_tcpnextsequence();
-
-      /* Reset the length variables. */
-
-      dev->d_len  = 0;
-      dev->d_sndlen = 0;
-
-      /* Check if the connection is in a state in which we simply wait
-       * for the connection to time out. If so, we increase the
-       * connection's timer and remove the connection if it times
-       * out.
-       */
-
-      if (uip_connr->tcpstateflags == UIP_TIME_WAIT ||
-          uip_connr->tcpstateflags == UIP_FIN_WAIT_2)
-        {
-          ++(uip_connr->timer);
-          if (uip_connr->timer == UIP_TIME_WAIT_TIMEOUT)
-            {
-              uip_connr->tcpstateflags = UIP_CLOSED;
-              vdbg("TCP state: UIP_CLOSED\n");
-            }
-        }
-      else if (uip_connr->tcpstateflags != UIP_CLOSED)
-        {
-          /* If the connection has outstanding data, we increase the
-           * connection's timer and see if it has reached the RTO value
-           * in which case we retransmit.
-           */
-
-          if (uip_outstanding(uip_connr))
-            {
-              if (uip_connr->timer-- == 0)
-                {
-                  if (uip_connr->nrtx == UIP_MAXRTX ||
-                      ((uip_connr->tcpstateflags == UIP_SYN_SENT ||
-                      uip_connr->tcpstateflags == UIP_SYN_RCVD) &&
-                      uip_connr->nrtx == UIP_MAXSYNRTX))
-                    {
-                      uip_connr->tcpstateflags = UIP_CLOSED;
-                      vdbg("TCP state: UIP_CLOSED\n");
-
-                      /* We call uip_tcp_callback() with uip_flags set to
-                       * UIP_TIMEDOUT to inform the application that the
-                       * connection has timed out.
-                       */
-
-                      uip_flags = UIP_TIMEDOUT;
-                      uip_tcp_callback(dev);
-
-                      /* We also send a reset packet to the remote host. */
-
-                      BUF->flags = TCP_RST | TCP_ACK;
-                      goto tcp_send_nodata;
-                    }
-
-                  /* Exponential backoff. */
-
-                  uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4 ? 4: uip_connr->nrtx);
-                  ++(uip_connr->nrtx);
-
-                  /* Ok, so we need to retransmit. We do this differently
-                   * depending on which state we are in. In ESTABLISHED, we
-                   * call upon the application so that it may prepare the
-                   * data for the retransmit. In SYN_RCVD, we resend the
-                   * SYNACK that we sent earlier and in LAST_ACK we have to
-                   * retransmit our FINACK.
-                   */
-
-                  UIP_STAT(++uip_stat.tcp.rexmit);
-                  switch(uip_connr->tcpstateflags & UIP_TS_MASK)
-                    {
-                      case UIP_SYN_RCVD:
-                        /* In the SYN_RCVD state, we should retransmit our
-                         * SYNACK.
-                         */
-
-                        goto tcp_send_synack;
-
-                      case UIP_SYN_SENT:
-                        /* In the SYN_SENT state, we retransmit out SYN. */
-
-                        BUF->flags = 0;
-                        goto tcp_send_syn;
-
-                      case UIP_ESTABLISHED:
-                        /* In the ESTABLISHED state, we call upon the application
-                         * to do the actual retransmit after which we jump into
-                         * the code for sending out the packet (the apprexmit
-                         * label).
-                         */
-
-                        uip_flags = UIP_REXMIT;
-                        uip_tcp_callback(dev);
-                        goto apprexmit;
-
-                      case UIP_FIN_WAIT_1:
-                      case UIP_CLOSING:
-                      case UIP_LAST_ACK:
-                        /* In all these states we should retransmit a FINACK. */
-
-                        goto tcp_send_finack;
-                    }
-                }
-            }
-          else if ((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED)
-            {
-              /* If there was no need for a retransmission, we poll the
-               * application for new data.
-               */
-
-              uip_flags = UIP_POLL;
-              uip_tcp_callback(dev);
-              goto appsend;
-            }
-        }
-      goto drop;
-    }
-
-  /* This is where the input processing starts. */
-
-  UIP_STAT(++uip_stat.ip.recv);
-
-  /* Start of IP input header processing code. */
-
-#ifdef CONFIG_NET_IPv6
-  /* Check validity of the IP header. */
-
-  if ((BUF->vtc & 0xf0) != 0x60) 
-    {
-      /* IP version and header length. */
-
-      UIP_STAT(++uip_stat.ip.drop);
-      UIP_STAT(++uip_stat.ip.vhlerr);
-      uip_log("ipv6: invalid version.");
-      goto drop;
-    }
-#else /* CONFIG_NET_IPv6 */
-  /* Check validity of the IP header. */
-
-  if (BUF->vhl != 0x45)
-    {
-      /* IP version and header length. */
-
-      UIP_STAT(++uip_stat.ip.drop);
-      UIP_STAT(++uip_stat.ip.vhlerr);
-      uip_log("ip: invalid version or header length.");
-      goto drop;
-    }
-#endif /* CONFIG_NET_IPv6 */
-
-  /* Check the size of the packet. If the size reported to us in d_len is
-   * smaller the size reported in the IP header, we assume that the packet
-   * has been corrupted in transit. If the size of d_len is larger than the
-   * size reported in the IP packet header, the packet has been padded and
-   * we set d_len to the correct value.
-   */
-
-  if ((BUF->len[0] << 8) + BUF->len[1] <= dev->d_len)
-    {
-      dev->d_len = (BUF->len[0] << 8) + BUF->len[1];
-#ifdef CONFIG_NET_IPv6
-      /* The length reported in the IPv6 header is the length of the
-       * payload that follows the header. However, uIP uses the d_len
-       * variable for holding the size of the entire packet, including the
-       * IP header. For IPv4 this is not a problem as the length field in
-       * the IPv4 header contains the length of the entire packet. But
-       * for IPv6 we need to add the size of the IPv6 header (40 bytes).
-       */
-
-      dev->d_len += 40;
-#endif /* CONFIG_NET_IPv6 */
-    }
-  else
-    {
-      uip_log("ip: packet shorter than reported in IP header.");
-      goto drop;
-    }
-
-#ifndef CONFIG_NET_IPv6
-  /* Check the fragment flag. */
-
-  if ((BUF->ipoffset[0] & 0x3f) != 0 || BUF->ipoffset[1] != 0)
-    {
-#if UIP_REASSEMBLY
-      dev->d_len = uip_reass();
-      if (dev->d_len == 0)
-        {
-          goto drop;
-        }
-#else /* UIP_REASSEMBLY */
-      UIP_STAT(++uip_stat.ip.drop);
-      UIP_STAT(++uip_stat.ip.fragerr);
-      uip_log("ip: fragment dropped.");
-      goto drop;
-#endif /* UIP_REASSEMBLY */
-    }
-#endif /* CONFIG_NET_IPv6 */
-
-  if (uip_ipaddr_cmp(dev->d_ipaddr, all_zeroes_addr))
-    {
-      /* If we are configured to use ping IP address configuration and
-       * hasn't been assigned an IP address yet, we accept all ICMP
-       * packets.
-       */
-
-#if UIP_PINGADDRCONF && !CONFIG_NET_IPv6
-      if (BUF->proto == UIP_PROTO_ICMP)
-        {
-          uip_log("ip: possible ping config packet received.");
-          goto icmp_input;
-        }
-      else
-        {
-          uip_log("ip: packet dropped since no address assigned.");
-          goto drop;
-        }
-#endif /* UIP_PINGADDRCONF */
-    }
-  else
-    {
-      /* If IP broadcast support is configured, we check for a broadcast
-       * UDP packet, which may be destined to us.
-       */
-
-#if UIP_BROADCAST
-      if (BUF->proto == UIP_PROTO_UDP && uip_ipaddr_cmp(BUF->destipaddr, all_ones_addr)
-        {
-          goto udp_input;
-        }
-#endif /* UIP_BROADCAST */
-
-      /* Check if the packet is destined for our IP address. */
-#ifndef CONFIG_NET_IPv6
-      if (!uip_ipaddr_cmp(uip_ip4addr_conv(BUF->destipaddr), dev->d_ipaddr))
-        {
-          UIP_STAT(++uip_stat.ip.drop);
-          goto drop;
-        }
-#else /* CONFIG_NET_IPv6 */
-      /* For IPv6, packet reception is a little trickier as we need to
-       * make sure that we listen to certain multicast addresses (all
-       * hosts multicast address, and the solicited-node multicast
-       * address) as well. However, we will cheat here and accept all
-       * multicast packets that are sent to the ff02::/16 addresses.
-       */
-
-      if (!uip_ipaddr_cmp(BUF->destipaddr, dev->d_ipaddr) &&
-           BUF->destipaddr & HTONL(0xffff0000) != HTONL(0xff020000))
-        {
-          UIP_STAT(++uip_stat.ip.drop);
-          goto drop;
-        }
-#endif /* CONFIG_NET_IPv6 */
-    }
-
-#ifndef CONFIG_NET_IPv6
-  if (uip_ipchksum(dev) != 0xffff)
-    {
-      /* Compute and check the IP header checksum. */
-
-      UIP_STAT(++uip_stat.ip.drop);
-      UIP_STAT(++uip_stat.ip.chkerr);
-      uip_log("ip: bad checksum.");
-      goto drop;
-    }
-#endif /* CONFIG_NET_IPv6 */
-
-  if (BUF->proto == UIP_PROTO_TCP)
-    {
-      /* Check for TCP packet. If so, proceed with TCP input processing. */
-
-      goto tcp_input;
-    }
-
-#ifdef CONFIG_NET_UDP
-  if (BUF->proto == UIP_PROTO_UDP)
-    {
-      uip_udpinput(dev);
-      return;
-    }
-#endif
-
-#ifndef CONFIG_NET_IPv6
-  /* ICMPv4 processing code follows. */
-
-  if (BUF->proto != UIP_PROTO_ICMP)
-    {
-      /* We only allow ICMP packets from here. */
-
-      UIP_STAT(++uip_stat.ip.drop);
-      UIP_STAT(++uip_stat.ip.protoerr);
-      uip_log("ip: neither tcp nor icmp.");
-      goto drop;
-    }
-
-#if UIP_PINGADDRCONF
-icmp_input:
-#endif
-  UIP_STAT(++uip_stat.icmp.recv);
-
-  /* ICMP echo (i.e., ping) processing. This is simple, we only change
-   * the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
-   * checksum before we return the packet.
-   */
-
-  if (ICMPBUF->type != ICMP_ECHO)
-    {
-      UIP_STAT(++uip_stat.icmp.drop);
-      UIP_STAT(++uip_stat.icmp.typeerr);
-      uip_log("icmp: not icmp echo.");
-      goto drop;
-    }
-
-  /* If we are configured to use ping IP address assignment, we use
-   * the destination IP address of this ping packet and assign it to
-   * ourself.
-   */
-
-#if UIP_PINGADDRCONF
-  if (dev->d_ipaddr == 0)
-    {
-      dev->d_ipaddr = BUF->destipaddr;
-    }
-#endif /* UIP_PINGADDRCONF */
-
-  ICMPBUF->type = ICMP_ECHO_REPLY;
-
-  if (ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8)))
-    {
-      ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
-    }
-  else
-    {
-      ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
-    }
-
-  /* Swap IP addresses. */
-
-  uiphdr_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
-  uiphdr_ipaddr_copy(BUF->srcipaddr, &dev->d_ipaddr);
-
-  UIP_STAT(++uip_stat.icmp.sent);
-  goto send;
-#else /* !CONFIG_NET_IPv6 */
-
-  /* This is IPv6 ICMPv6 processing code. */
-
-  if (BUF->proto != UIP_PROTO_ICMP6)
-    {
-      /* We only allow ICMPv6 packets from here. */
-
-      UIP_STAT(++uip_stat.ip.drop);
-      UIP_STAT(++uip_stat.ip.protoerr);
-      uip_log("ip: neither tcp nor icmp6.");
-      goto drop;
-    }
-
-  UIP_STAT(++uip_stat.icmp.recv);
-
-  /* If we get a neighbor solicitation for our address we should send
-   * a neighbor advertisement message back.
-   */
-
-  if (ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION)
-    {
-      if (uip_ipaddr_cmp(ICMPBUF->icmp6data, dev->d_ipaddr))
-        {
-          if (ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS)
-            {
-              /* Save the sender's address in our neighbor list. */
-
-              uiphdr_neighbor_add(ICMPBUF->srcipaddr, &(ICMPBUF->options[2]));
-            }
-
-          /* We should now send a neighbor advertisement back to where the
-           * neighbor solicication came from.
-           */
-
-          ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
-          ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */
-
-          ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0;
-
-          uiphdr_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
-          uiphdr_ipaddr_copy(ICMPBUF->srcipaddr, dev->d_ipaddr);
-          ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
-          ICMPBUF->options[1] = 1;  /* Options length, 1 = 8 bytes. */
-          memcpy(&(ICMPBUF->options[2]), &dev->d_mac, IFHWADDRLEN);
-          ICMPBUF->icmpchksum = 0;
-          ICMPBUF->icmpchksum = ~uip_icmp6chksum(dev);
-          goto send;
-        }
-      goto drop;
-    }
-  else if (ICMPBUF->type == ICMP6_ECHO)
-    {
-      /* ICMP echo (i.e., ping) processing. This is simple, we only
-       * change the ICMP type from ECHO to ECHO_REPLY and update the
-       * ICMP checksum before we return the packet.
-       */
-
-      ICMPBUF->type = ICMP6_ECHO_REPLY;
-
-      uiphdr_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
-      uiphdr_ipaddr_copy(BUF->srcipaddr, dev->d_ipaddr);
-      ICMPBUF->icmpchksum = 0;
-      ICMPBUF->icmpchksum = ~uip_icmp6chksum(dev);
-
-      UIP_STAT(++uip_stat.icmp.sent);
-      goto send;
-    }
-  else
-    {
-      UIP_STAT(++uip_stat.icmp.drop);
-      UIP_STAT(++uip_stat.icmp.typeerr);
-      uip_log("icmp: unknown ICMP message.");
-      goto drop;
-    }
-#endif /* !CONFIG_NET_IPv6 */
-
-  /* TCP input processing. */
-
-tcp_input:
-
-  UIP_STAT(++uip_stat.tcp.recv);
-
-  /* Start of TCP input header processing code. */
-
-  if (uip_tcpchksum(dev) != 0xffff)
-    {
-      /* Compute and check the TCP checksum. */
-
-      UIP_STAT(++uip_stat.tcp.drop);
-      UIP_STAT(++uip_stat.tcp.chkerr);
-      uip_log("tcp: bad checksum.");
-      goto drop;
-    }
-
-  /* Demultiplex this segment. First check any active connections. */
-
-  uip_connr = uip_tcpactive(BUF);
-  if (uip_connr)
-    {
-      goto found;
-    }
-
-  /* If we didn't find and active connection that expected the packet,
-   * either this packet is an old duplicate, or this is a SYN packet
-   * destined for a connection in LISTEN. If the SYN flag isn't set,
-   * it is an old packet and we send a RST.
-   */
-
-  if ((BUF->flags & TCP_CTL) != TCP_SYN)
-    {
-      goto reset;
-    }
-
-  tmp16 = BUF->destport;
-
-  /* Next, check listening connections. */
-
-  if (uip_islistener(tmp16))
-    {
-        goto found_listen;
-    }
-
-  /* No matching connection found, so we send a RST packet. */
-
-  UIP_STAT(++uip_stat.tcp.synrst);
-
-reset:
-
-  /* We do not send resets in response to resets. */
-
-  if (BUF->flags & TCP_RST)
-    {
-      goto drop;
-    }
-
-  UIP_STAT(++uip_stat.tcp.rst);
-
-  BUF->flags     = TCP_RST | TCP_ACK;
-  dev->d_len     = UIP_IPTCPH_LEN;
-  BUF->tcpoffset = 5 << 4;
-
-  /* Flip the seqno and ackno fields in the TCP header. */
-
-  seqbyte        = BUF->seqno[3];
-  BUF->seqno[3]  = BUF->ackno[3];
-  BUF->ackno[3]  = seqbyte;
-
-  seqbyte        = BUF->seqno[2];
-  BUF->seqno[2]  = BUF->ackno[2];
-  BUF->ackno[2]  = seqbyte;
-
-  seqbyte        = BUF->seqno[1];
-  BUF->seqno[1]  = BUF->ackno[1];
-  BUF->ackno[1]  = seqbyte;
-
-  seqbyte        = BUF->seqno[0];
-  BUF->seqno[0]  = BUF->ackno[0];
-  BUF->ackno[0]  = seqbyte;
-
-  /* We also have to increase the sequence number we are
-   * acknowledging. If the least significant byte overflowed, we need
-   * to propagate the carry to the other bytes as well.
-   */
-
-  if (++(BUF->ackno[3]) == 0)
-    {
-      if (++(BUF->ackno[2]) == 0)
-        {
-          if (++(BUF->ackno[1]) == 0)
-            {
-              ++(BUF->ackno[0]);
-            }
-        }
-    }
-
-  /* Swap port numbers. */
-
-  tmp16         = BUF->srcport;
-  BUF->srcport  = BUF->destport;
-  BUF->destport = tmp16;
-
-  /* Swap IP addresses. */
-
-  uiphdr_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
-  uiphdr_ipaddr_copy(BUF->srcipaddr, dev->d_ipaddr);
-
-  /* And send out the RST packet! */
-
-  goto tcp_send_noconn;
-
-  /* This label will be jumped to if we matched the incoming packet
-   * with a connection in LISTEN. In that case, we should create a new
-   * connection and send a SYNACK in return.
-   */
-
-found_listen:
-
-  /* First allocate a new connection structure and see if there is any
-   * user application to accept it.
-   */
-
-  uip_connr = uip_tcpaccept(BUF);
-  if (uip_connr)
-    {
-      /* The connection structure was successfully allocated.  Now see
-       * there is an application waiting to accept the connection (or at
-       * least queue it it for acceptance).
-       */
-
-      if (uip_accept(uip_connr, tmp16) != OK)
-        {
-          /* No, then we have to give the connection back */
-
-          uip_tcpfree(uip_connr);
-          uip_connr = NULL;
-        }
-    }
-
-  if (!uip_connr)
-    {
-      /* Either (1) all available connections are in use, or (2) there is no
-       * application in place to accept the connection.  We drop packet and hope that
-       * the remote end will retransmit the packet at a time when we
-       * have more spare connections or someone waiting to accept the connection.
-       */
-
-      UIP_STAT(++uip_stat.tcp.syndrop);
-      uip_log("tcp: found no unused connections.");
-      goto drop;
-    }
-
-  uip_add_rcv_nxt(1);
-  uip_conn = uip_connr;
-
-  /* Parse the TCP MSS option, if present. */
-
-  if ((BUF->tcpoffset & 0xf0) > 0x50)
-    {
-      for (i = 0; i < ((BUF->tcpoffset >> 4) - 5) << 2 ;)
-        {
-          opt = dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + i];
-          if (opt == TCP_OPT_END)
-            {
-              /* End of options. */
-
-              break;
-            }
-          else if (opt == TCP_OPT_NOOP)
-            {
-              /* NOP option. */
-
-              ++i;
-            }
-          else if (opt == TCP_OPT_MSS &&
-                     dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == TCP_OPT_MSS_LEN)
-            {
-              /* An MSS option with the right option length. */
-
-              tmp16 = ((uint16)dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + i] << 8) |
-                       (uint16)dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + i];
-              uip_connr->initialmss = uip_connr->mss =
-                      tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
-
-              /* And we are done processing options. */
-
-              break;
-            }
-          else
-            {
-              /* All other options have a length field, so that we easily
-               * can skip past them.
-               */
-
-              if (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == 0)
-                {
-                  /* If the length field is zero, the options are malformed
-                   * and we don't process them further.
-                   */
-
-                  break;
-                }
-              i += dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i];
-            }
-        }
-    }
-
-  /* Our response will be a SYNACK. */
-
-tcp_send_synack:
-  BUF->flags = TCP_ACK;
-
-tcp_send_syn:
-  BUF->flags |= TCP_SYN;
-
-  /* We send out the TCP Maximum Segment Size option with our SYNACK. */
-
-  BUF->optdata[0] = TCP_OPT_MSS;
-  BUF->optdata[1] = TCP_OPT_MSS_LEN;
-  BUF->optdata[2] = (UIP_TCP_MSS) / 256;
-  BUF->optdata[3] = (UIP_TCP_MSS) & 255;
-  dev->d_len      = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
-  BUF->tcpoffset  = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
-  goto tcp_send;
-
-  /* This label will be jumped to if we found an active connection. */
-
-found:
-
-  uip_conn = uip_connr;
-  uip_flags = 0;
-
-  /* We do a very naive form of TCP reset processing; we just accept
-   * any RST and kill our connection. We should in fact check if the
-   * sequence number of this reset is wihtin our advertised window
-   * before we accept the reset.
-   */
-
-  if (BUF->flags & TCP_RST)
-    {
-      uip_connr->tcpstateflags = UIP_CLOSED;
-      vdbg("TCP state: UIP_CLOSED\n");
-      uip_log("tcp: got reset, aborting connection.");
-
-      uip_flags = UIP_ABORT;
-      uip_tcp_callback(dev);
-      goto drop;
-    }
-
-  /* Calculated the length of the data, if the application has sent
-   * any data to us.
-   */
-
-  len = (BUF->tcpoffset >> 4) << 2;
-
-  /* d_len will contain the length of the actual TCP data. This is
-   * calculated by subtracing the length of the TCP header (in
-   * len) and the length of the IP header (20 bytes).
-   */
-
-  dev->d_len -= (len + UIP_IPH_LEN);
-
-  /* First, check if the sequence number of the incoming packet is
-   * what we're expecting next. If not, we send out an ACK with the
-   * correct numbers in.
-   */
-
-  if (!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) &&
-      ((BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK))))
-    {
-      if ((dev->d_len > 0 || ((BUF->flags & (TCP_SYN | TCP_FIN)) != 0)) &&
-          (BUF->seqno[0] != uip_connr->rcv_nxt[0] ||
-           BUF->seqno[1] != uip_connr->rcv_nxt[1] ||
-           BUF->seqno[2] != uip_connr->rcv_nxt[2] ||
-           BUF->seqno[3] != uip_connr->rcv_nxt[3]))
-        {
-          goto tcp_send_ack;
-        }
-    }
-
-  /* Next, check if the incoming segment acknowledges any outstanding
-   * data. If so, we update the sequence number, reset the length of
-   * the outstanding data, calculate RTT estimations, and reset the
-   * retransmission timer.
-   */
-
-  if ((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr))
-    {
-      uip_add32(uip_connr->snd_nxt, uip_connr->len);
-
-      if (BUF->ackno[0] == uip_acc32[0] &&
-          BUF->ackno[1] == uip_acc32[1] &&
-          BUF->ackno[2] == uip_acc32[2] &&
-          BUF->ackno[3] == uip_acc32[3])
-        {
-          /* Update sequence number. */
-
-          uip_connr->snd_nxt[0] = uip_acc32[0];
-          uip_connr->snd_nxt[1] = uip_acc32[1];
-          uip_connr->snd_nxt[2] = uip_acc32[2];
-          uip_connr->snd_nxt[3] = uip_acc32[3];
-
-          /* Do RTT estimation, unless we have done retransmissions. */
-
-          if (uip_connr->nrtx == 0)
-            {
-              signed char m;
-              m = uip_connr->rto - uip_connr->timer;
-
-              /* This is taken directly from VJs original code in his paper */
-
-              m = m - (uip_connr->sa >> 3);
-              uip_connr->sa += m;
-              if (m < 0)
-                {
-                  m = -m;
-                }
-
-              m = m - (uip_connr->sv >> 2);
-              uip_connr->sv += m;
-              uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;
-            }
-
-          /* Set the acknowledged flag. */
-
-          uip_flags = UIP_ACKDATA;
-
-          /* Reset the retransmission timer. */
-
-          uip_connr->timer = uip_connr->rto;
-
-          /* Reset length of outstanding data. */
-
-          uip_connr->len = 0;
-        }
-    }
-
-  /* Do different things depending on in what state the connection is. */
-
-  switch(uip_connr->tcpstateflags & UIP_TS_MASK)
-    {
-      /* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
-       * implemented, since we force the application to close when the
-       * peer sends a FIN (hence the application goes directly from
-       * ESTABLISHED to LAST_ACK).
-       */
-
-      case UIP_SYN_RCVD:
-        /* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
-         * we are waiting for an ACK that acknowledges the data we sent
-         * out the last time. Therefore, we want to have the UIP_ACKDATA
-         * flag set. If so, we enter the ESTABLISHED state.
-         */
-
-        if (uip_flags & UIP_ACKDATA)
-          {
-            uip_connr->tcpstateflags = UIP_ESTABLISHED;
-            uip_connr->len           = 0;
-            vdbg("TCP state: UIP_ESTABLISHED\n");
-
-            uip_flags                = UIP_CONNECTED;
-
-            if (dev->d_len > 0)
-              {
-                uip_flags           |= UIP_NEWDATA;
-                uip_add_rcv_nxt(dev->d_len);
-              }
-
-            dev->d_sndlen            = 0;
-            uip_tcp_callback(dev);
-            goto appsend;
-          }
-        goto drop;
-
-      case UIP_SYN_SENT:
-        /* In SYN_SENT, we wait for a SYNACK that is sent in response to
-         * our SYN. The rcv_nxt is set to sequence number in the SYNACK
-         * plus one, and we send an ACK. We move into the ESTABLISHED
-         * state.
-         */
-
-        if ((uip_flags & UIP_ACKDATA) &&
-            (BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK))
-          {
-            /* Parse the TCP MSS option, if present. */
-
-            if ((BUF->tcpoffset & 0xf0) > 0x50)
-              {
-                for (i = 0; i < ((BUF->tcpoffset >> 4) - 5) << 2 ;)
-                  {
-                    opt = dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + i];
-                    if (opt == TCP_OPT_END)
-                      {
-                        /* End of options. */
-
-                        break;
-                      }
-                    else if (opt == TCP_OPT_NOOP)
-                      {
-                        /* NOP option. */
-
-                        ++i;
-                      }
-                    else if (opt == TCP_OPT_MSS &&
-                              dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == TCP_OPT_MSS_LEN)
-                      {
-                        /* An MSS option with the right option length. */
-
-                        tmp16 =
-                          (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + i] << 8) |
-                          dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + i];
-                        uip_connr->initialmss =
-                          uip_connr->mss =
-                          tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
-
-                        /* And we are done processing options. */
-
-                        break;
-                      }
-                    else
-                      {
-                        /* All other options have a length field, so that we
-                         * easily can skip past them.
-                         */
-
-                        if (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == 0)
-                          {
-                            /* If the length field is zero, the options are
-                             * malformed and we don't process them further.
-                             */
-
-                            break;
-                          }
-                        i += dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i];
-                      }
-                  }
-              }
-
-            uip_connr->tcpstateflags = UIP_ESTABLISHED;
-            uip_connr->rcv_nxt[0]    = BUF->seqno[0];
-            uip_connr->rcv_nxt[1]    = BUF->seqno[1];
-            uip_connr->rcv_nxt[2]    = BUF->seqno[2];
-            uip_connr->rcv_nxt[3]    = BUF->seqno[3];
-            vdbg("TCP state: UIP_ESTABLISHED\n");
-
-            uip_add_rcv_nxt(1);
-            uip_flags      = UIP_CONNECTED | UIP_NEWDATA;
-            uip_connr->len = 0;
-            dev->d_len     = 0;
-            dev->d_sndlen  = 0;
-            uip_tcp_callback(dev);
-            goto appsend;
-          }
-
-        /* Inform the application that the connection failed */
-
-        uip_flags = UIP_ABORT;
-        uip_tcp_callback(dev);
-
-        /* The connection is closed after we send the RST */
-
-        uip_conn->tcpstateflags = UIP_CLOSED;
-        vdbg("TCP state: UIP_CLOSED\n");
-        goto reset;
-
-      case UIP_ESTABLISHED:
-        /* In the ESTABLISHED state, we call upon the application to feed
-         * data into the d_buf. If the UIP_ACKDATA flag is set, the
-         * application should put new data into the buffer, otherwise we are
-         * retransmitting an old segment, and the application should put that
-         * data into the buffer.
-         *
-         * If the incoming packet is a FIN, we should close the connection on
-         * this side as well, and we send out a FIN and enter the LAST_ACK
-         * state. We require that there is no outstanding data; otherwise the
-         * sequence numbers will be screwed up.
-         */
-
-        if (BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED))
-          {
-            if (uip_outstanding(uip_connr))
-              {
-                goto drop;
-              }
-
-            uip_add_rcv_nxt(dev->d_len + 1);
-            uip_flags |= UIP_CLOSE;
-
-            if (dev->d_len > 0)
-              {
-                uip_flags |= UIP_NEWDATA;
-              }
-
-            uip_tcp_callback(dev);
-
-            uip_connr->tcpstateflags = UIP_LAST_ACK;
-            uip_connr->len = 1;
-            uip_connr->nrtx = 0;
-            vdbg("TCP state: UIP_LAST_ACK\n");
-
-tcp_send_finack:
-
-            BUF->flags = TCP_FIN | TCP_ACK;
-            goto tcp_send_nodata;
-          }
-
-        /* Check the URG flag. If this is set, the segment carries urgent
-           data that we must pass to the application. */
-        if ((BUF->flags & TCP_URG) != 0)
-          {
-#if UIP_URGDATA > 0
-            uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1];
-            if (uip_urglen > dev->d_len)
-              {
-                /* There is more urgent data in the next segment to come. */
-
-                uip_urglen = dev->d_len;
-              }
-
-            uip_add_rcv_nxt(uip_urglen);
-            dev->d_len     -= uip_urglen;
-            uip_urgdata     = dev->d_appdata;
-            dev->d_appdata += uip_urglen;
-          }
-        else
-          {
-            uip_urglen     = 0;
-#else /* UIP_URGDATA > 0 */
-            dev->d_appdata =
-              ((uint8*)dev->d_appdata) + ((BUF->urgp[0] << 8) | BUF->urgp[1]);
-            dev->d_len    -=
-              (BUF->urgp[0] << 8) | BUF->urgp[1];
-#endif /* UIP_URGDATA > 0 */
-          }
-
-        /* If d_len > 0 we have TCP data in the packet, and we flag this
-         * by setting the UIP_NEWDATA flag and update the sequence number
-         * we acknowledge. If the application has stopped the dataflow
-         * using uip_stop(), we must not accept any data packets from the
-         * remote host.
-         */
-
-        if (dev->d_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED))
-          {
-            uip_flags |= UIP_NEWDATA;
-            uip_add_rcv_nxt(dev->d_len);
-          }
-
-        /* Check if the available buffer space advertised by the other end
-         * is smaller than the initial MSS for this connection. If so, we
-         * set the current MSS to the window size to ensure that the
-         * application does not send more data than the other end can
-         * handle.
-         *
-         * If the remote host advertises a zero window, we set the MSS to
-         * the initial MSS so that the application will send an entire MSS
-         * of data. This data will not be acknowledged by the receiver,
-         * and the application will retransmit it. This is called the
-         * "persistent timer" and uses the retransmission mechanim.
-         */
-
-        tmp16 = ((uint16)BUF->wnd[0] << 8) + (uint16)BUF->wnd[1];
-        if (tmp16 > uip_connr->initialmss || tmp16 == 0)
-          {
-            tmp16 = uip_connr->initialmss;
-          }
-        uip_connr->mss = tmp16;
-
-        /* If this packet constitutes an ACK for outstanding data (flagged
-         * by the UIP_ACKDATA flag, we should call the application since it
-         * might want to send more data. If the incoming packet had data
-         * from the peer (as flagged by the UIP_NEWDATA flag), the
-         * application must also be notified.
-         *
-         * When the application is called, the d_len field
-         * contains the length of the incoming data. The application can
-         * access the incoming data through the global pointer
-         * d_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN
-         *  bytes into the d_buf array.
-         *
-         * If the application wishes to send any data, this data should be
-         * put into the d_appdata and the length of the data should be
-         * put into d_len. If the application don't have any data to
-         * send, d_len must be set to 0.
-         */
-
-        if (uip_flags & (UIP_NEWDATA | UIP_ACKDATA))
-          {
-            dev->d_sndlen = 0;
-            uip_tcp_callback(dev);
-
-appsend:
-
-           if (uip_flags & UIP_ABORT)
-              {
-                dev->d_sndlen = 0;
-                uip_connr->tcpstateflags = UIP_CLOSED;
-                vdbg("TCP state: UIP_CLOSED\n");
-
-                BUF->flags = TCP_RST | TCP_ACK;
-                goto tcp_send_nodata;
-              }
-
-            if (uip_flags & UIP_CLOSE)
-              {
-                uip_connr->tcpstateflags = UIP_FIN_WAIT_1;
-                uip_connr->len = 1;
-                uip_connr->nrtx = 0;
-                vdbg("TCP state: UIP_FIN_WAIT_1\n");
-
-                BUF->flags = TCP_FIN | TCP_ACK;
-                dev->d_sndlen = 0;
-                goto tcp_send_nodata;
-              }
-
-            /* If d_sndlen > 0, the application has data to be sent. */
-
-            if (dev->d_sndlen > 0)
-              {
-                /* If the connection has acknowledged data, the contents of
-                 * the ->len variable should be discarded.
-                 */
-
-                if ((uip_flags & UIP_ACKDATA) != 0)
-                  {
-                    uip_connr->len = 0;
-                  }
-
-                /* If the ->len variable is non-zero the connection has
-                 * already data in transit and cannot send anymore right
-                 * now.
-                 */
-
-                if (uip_connr->len == 0)
-                  {
-                    /* The application cannot send more than what is
-                     * allowed by the mss (the minumum of the MSS and the
-                     * available window).
-                     */
-
-                    if (dev->d_sndlen > uip_connr->mss)
-                      {
-                        dev->d_sndlen = uip_connr->mss;
-                      }
-
-                    /* Remember how much data we send out now so that we
-                     * know when everything has been acknowledged.
-                     */
-
-                    uip_connr->len = dev->d_sndlen;
-                  }
-                else
-                  {
-                    /* If the application already had unacknowledged data,
-                     * we make sure that the application does not send
-                     * (i.e., retransmit) out more than it previously sent
-                     * out.
-                     */
-
-                    dev->d_sndlen = uip_connr->len;
-                  }
-              }
-            uip_connr->nrtx = 0;
-apprexmit:
-            dev->d_appdata = dev->d_snddata;
-
-            /* If the application has data to be sent, or if the incoming
-             * packet had new data in it, we must send out a packet.
-             */
-
-            if (dev->d_sndlen > 0 && uip_connr->len > 0)
-              {
-                /* Add the length of the IP and TCP headers. */
-
-                dev->d_len = uip_connr->len + UIP_TCPIP_HLEN;
-
-                /* We always set the ACK flag in response packets. */
-
-                BUF->flags = TCP_ACK | TCP_PSH;
-
-                /* Send the packet. */
-
-                goto tcp_send_noopts;
-              }
-
-            /* If there is no data to send, just send out a pure ACK if
-             * there is newdata.
-             */
-
-            if (uip_flags & UIP_NEWDATA)
-              {
-                dev->d_len = UIP_TCPIP_HLEN;
-                BUF->flags = TCP_ACK;
-                goto tcp_send_noopts;
-              }
-          }
-        goto drop;
-
-      case UIP_LAST_ACK:
-        /* We can close this connection if the peer has acknowledged our
-         * FIN. This is indicated by the UIP_ACKDATA flag.
-         */
-
-        if (uip_flags & UIP_ACKDATA)
-          {
-            uip_connr->tcpstateflags = UIP_CLOSED;
-            vdbg("TCP state: UIP_CLOSED\n");
-
-            uip_flags = UIP_CLOSE;
-            uip_tcp_callback(dev);
-          }
-        break;
-
-      case UIP_FIN_WAIT_1:
-        /* The application has closed the connection, but the remote host
-         * hasn't closed its end yet. Thus we do nothing but wait for a
-         * FIN from the other side.
-         */
-
-        if (dev->d_len > 0)
-          {
-            uip_add_rcv_nxt(dev->d_len);
-          }
-        if (BUF->flags & TCP_FIN)
-          {
-            if (uip_flags & UIP_ACKDATA)
-              {
-                uip_connr->tcpstateflags = UIP_TIME_WAIT;
-                uip_connr->timer = 0;
-                uip_connr->len = 0;
-                vdbg("TCP state: UIP_TIME_WAIT\n");
-              }
-            else
-              {
-                uip_connr->tcpstateflags = UIP_CLOSING;
-                vdbg("TCP state: UIP_CLOSING\n");
-              }
-
-            uip_add_rcv_nxt(1);
-            uip_flags = UIP_CLOSE;
-            uip_tcp_callback(dev);
-            goto tcp_send_ack;
-          }
-        else if (uip_flags & UIP_ACKDATA)
-          {
-            uip_connr->tcpstateflags = UIP_FIN_WAIT_2;
-            uip_connr->len = 0;
-            vdbg("TCP state: UIP_FIN_WAIT_2\n");
-            goto drop;
-          }
-
-        if (dev->d_len > 0)
-          {
-            goto tcp_send_ack;
-          }
-        goto drop;
-
-      case UIP_FIN_WAIT_2:
-        if (dev->d_len > 0)
-          {
-            uip_add_rcv_nxt(dev->d_len);
-          }
-
-        if (BUF->flags & TCP_FIN)
-          {
-            uip_connr->tcpstateflags = UIP_TIME_WAIT;
-            uip_connr->timer = 0;
-            vdbg("TCP state: UIP_TIME_WAIT\n");
-
-            uip_add_rcv_nxt(1);
-            uip_flags = UIP_CLOSE;
-            uip_tcp_callback(dev);
-            goto tcp_send_ack;
-          }
-
-        if (dev->d_len > 0)
-          {
-            goto tcp_send_ack;
-          }
-        goto drop;
-
-      case UIP_TIME_WAIT:
-        goto tcp_send_ack;
-
-      case UIP_CLOSING:
-        if (uip_flags & UIP_ACKDATA)
-          {
-            uip_connr->tcpstateflags = UIP_TIME_WAIT;
-            uip_connr->timer = 0;
-            vdbg("TCP state: UIP_TIME_WAIT\n");
-          }
-    }
-  goto drop;
-
-  /* We jump here when we are ready to send the packet, and just want
-   * to set the appropriate TCP sequence numbers in the TCP header.
-   */
-
-tcp_send_ack:
-
-  BUF->flags = TCP_ACK;
-
-tcp_send_nodata:
-
-  dev->d_len = UIP_IPTCPH_LEN;
-
-tcp_send_noopts:
-
-  BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
-
-tcp_send:
-
-  /* We're done with the input processing. We are now ready to send a
-   * reply. Our job is to fill in all the fields of the TCP and IP
-   * headers before calculating the checksum and finally send the
-   * packet.
-   */
-
-  BUF->ackno[0] = uip_connr->rcv_nxt[0];
-  BUF->ackno[1] = uip_connr->rcv_nxt[1];
-  BUF->ackno[2] = uip_connr->rcv_nxt[2];
-  BUF->ackno[3] = uip_connr->rcv_nxt[3];
-
-  BUF->seqno[0] = uip_connr->snd_nxt[0];
-  BUF->seqno[1] = uip_connr->snd_nxt[1];
-  BUF->seqno[2] = uip_connr->snd_nxt[2];
-  BUF->seqno[3] = uip_connr->snd_nxt[3];
-
-  BUF->proto = UIP_PROTO_TCP;
-
-  BUF->srcport  = uip_connr->lport;
-  BUF->destport = uip_connr->rport;
-
-  uiphdr_ipaddr_copy(BUF->srcipaddr, &dev->d_ipaddr);
-  uiphdr_ipaddr_copy(BUF->destipaddr, &uip_connr->ripaddr);
-
-  if (uip_connr->tcpstateflags & UIP_STOPPED)
-    {
-      /* If the connection has issued uip_stop(), we advertise a zero
-       * window so that the remote host will stop sending data.
-       */
-
-      BUF->wnd[0] = BUF->wnd[1] = 0;
-    }
-  else
-    {
-      BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
-      BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
-    }
-
-tcp_send_noconn:
-
-  BUF->ttl       = UIP_TTL;
-#ifdef CONFIG_NET_IPv6
-  /* For IPv6, the IP length field does not include the IPv6 IP header
-   * length.
-   */
-
-  BUF->len[0]    = ((dev->d_len - UIP_IPH_LEN) >> 8);
-  BUF->len[1]    = ((dev->d_len - UIP_IPH_LEN) & 0xff);
-#else /* CONFIG_NET_IPv6 */
-  BUF->len[0]    = (dev->d_len >> 8);
-  BUF->len[1]    = (dev->d_len & 0xff);
-#endif /* CONFIG_NET_IPv6 */
-
-  BUF->urgp[0]   = BUF->urgp[1] = 0;
-
-  /* Calculate TCP checksum. */
-
-  BUF->tcpchksum = 0;
-  BUF->tcpchksum = ~(uip_tcpchksum(dev));
-
-#ifdef CONFIG_NET_IPv6
-  BUF->vtc         = 0x60;
-  BUF->tcflow      = 0x00;
-  BUF->flow        = 0x00;
-#else /* CONFIG_NET_IPv6 */
-  BUF->vhl         = 0x45;
-  BUF->tos         = 0;
-  BUF->ipoffset[0] = 0;
-  BUF->ipoffset[1] = 0;
-  ++g_ipid;
-  BUF->ipid[0]     = g_ipid >> 8;
-  BUF->ipid[1]     = g_ipid & 0xff;
-
-  /* Calculate IP checksum. */
-
-  BUF->ipchksum    = 0;
-  BUF->ipchksum    = ~(uip_ipchksum(dev));
-#endif /* CONFIG_NET_IPv6 */
-
-  UIP_STAT(++uip_stat.tcp.sent);
-
-send:
-  vdbg("Sending packet length %d (%d)\n",
-       dev->d_len, (BUF->len[0] << 8) | BUF->len[1]);
-
-  UIP_STAT(++uip_stat.ip.sent);
-
-  /* Return and let the caller do the actual transmission. */
-
-  uip_flags = 0;
-  return;
-
-drop:
-  dev->d_len = 0;
-  uip_flags = 0;
-  return;
-}
-#endif /* CONFIG_NET */
-