Networking: Fix issues with UDP packet length and checksum calculations when IPv6 is selected

5 files changed, 103 insertions, 44 deletions

diff --git a/nuttx/net/udp/udp_input.c b/nuttx/net/udp/udp_input.c
index 57e7d39d4..3176e7daf 100644
--- a/nuttx/net/udp/udp_input.c
+++ b/nuttx/net/udp/udp_input.c
@@ -99,6 +99,7 @@ static int udp_input(FAR struct net_driver_s *dev, unsigned int iplen)
   FAR struct udp_conn_s *conn;
   unsigned int udpiplen;
   unsigned int hdrlen;
+  uint16_t chksum;
   int ret = OK;
 
   /* Update the count of UDP packets received */
@@ -126,13 +127,34 @@ static int udp_input(FAR struct net_driver_s *dev, unsigned int iplen)
    * application sets d_sndlen, it has a packet to send.
    */
 
-  dev->d_len -= udpiplen;
-
-#ifdef CONFIG_NET_UDP_CHECKSUMS
+  dev->d_len    -= udpiplen;
   dev->d_appdata = &dev->d_buf[hdrlen];
 
-  if (udp->udpchksum != 0 && udp_chksum(dev) != 0xffff)
+#ifdef CONFIG_NET_UDP_CHECKSUMS
+  chksum = udp->udpchksum;
+  if (chksum != 0)
     {
+#ifdef CONFIG_NET_IPv6
+#ifdef CONFIG_NET_IPv4
+      if (IFF_IS_IPv6(dev->d_flags))
+#endif
+        {
+          chksum = ~udp_ipv6_chksum(dev);
+        }
+#endif /* CONFIG_NET_IPv6 */
+
+#ifdef CONFIG_NET_IPv4
+#ifdef CONFIG_NET_IPv6
+      else
+#endif
+        {
+          chksum = ~udp_ipv4_chksum(dev);
+        }
+#endif /* CONFIG_NET_IPv6 */
+     }
+
+   if (chksum != 0)
+     {
 #ifdef CONFIG_NET_STATISTICS
       g_netstats.udp.drop++;
       g_netstats.udp.chkerr++;
diff --git a/nuttx/net/udp/udp_send.c b/nuttx/net/udp/udp_send.c
index ab71fbdc3..27d5ff1c9 100644
--- a/nuttx/net/udp/udp_send.c
+++ b/nuttx/net/udp/udp_send.c
@@ -129,8 +129,6 @@ void udp_send(FAR struct net_driver_s *dev, FAR struct udp_conn_s *conn)
 
           ipv4->vhl         = 0x45;
           ipv4->tos         = 0;
-          ipv4->len[0]      = (dev->d_len >> 8);
-          ipv4->len[1]      = (dev->d_len & 0xff);
           ++g_ipid;
           ipv4->ipid[0]     = g_ipid >> 8;
           ipv4->ipid[1]     = g_ipid & 0xff;
@@ -142,17 +140,22 @@ void udp_send(FAR struct net_driver_s *dev, FAR struct udp_conn_s *conn)
           net_ipv4addr_hdrcopy(ipv4->srcipaddr, &dev->d_ipaddr);
           net_ipv4addr_hdrcopy(ipv4->destipaddr, &conn->u.ipv4.raddr);
 
-          /* Calculate IP checksum. */
-
-          ipv4->ipchksum    = 0;
-          ipv4->ipchksum    = ~ipv4_chksum(dev);
-
           /* The total length to send is the size of the application data
            * plus the IPv4 and UDP headers (and, eventually, the link layer
            * header)
            */
 
-          dev->d_len = dev->d_sndlen + IPv4UDP_HDRLEN;
+          dev->d_len        = dev->d_sndlen + IPv4UDP_HDRLEN;
+
+          /* The IPv4 length includes the size of the IPv4 header */
+
+          ipv4->len[0]      = (dev->d_len >> 8);
+          ipv4->len[1]      = (dev->d_len & 0xff);
+
+          /* Calculate IP checksum. */
+
+          ipv4->ipchksum    = 0;
+          ipv4->ipchksum    = ~ipv4_chksum(dev);
         }
 #endif /* CONFIG_NET_IPv4 */
 
@@ -175,20 +178,26 @@ void udp_send(FAR struct net_driver_s *dev, FAR struct udp_conn_s *conn)
           ipv6->vtc         = 0x60;
           ipv6->tcf         = 0x00;
           ipv6->flow        = 0x00;
-          ipv6->len[0]      = (dev->d_sndlen >> 8);
-          ipv6->len[1]      = (dev->d_sndlen & 0xff);
           ipv6->proto       = IP_PROTO_UDP;
           ipv6->ttl         = conn->ttl;
 
           net_ipv6addr_copy(ipv6->srcipaddr, dev->d_ipv6addr);
           net_ipv6addr_copy(ipv6->destipaddr, conn->u.ipv6.raddr);
 
+          /* The IPv6 length, Includes the UDP header size but not the IPv6
+           * header size
+           */
+
+          dev->d_len        = dev->d_sndlen + UDP_HDRLEN;
+          ipv6->len[0]      = (dev->d_len >> 8);
+          ipv6->len[1]      = (dev->d_len & 0xff);
+
           /* The total length to send is the size of the application data
-           * plus the IPv4 and UDP headers (and, eventually, the link layer
+           * plus the IPv6 and UDP headers (and, eventually, the link layer
            * header)
            */
 
-          dev->d_len = dev->d_sndlen + IPv6UDP_HDRLEN;
+          dev->d_len       += IPv6_HDRLEN;
         }
 #endif /* CONFIG_NET_IPv6 */
 
@@ -197,19 +206,34 @@ void udp_send(FAR struct net_driver_s *dev, FAR struct udp_conn_s *conn)
       udp->srcport     = conn->lport;
       udp->destport    = conn->rport;
       udp->udplen      = HTONS(dev->d_sndlen + UDP_HDRLEN);
+      udp->udpchksum   = 0;
 
 #ifdef CONFIG_NET_UDP_CHECKSUMS
       /* Calculate UDP checksum. */
 
-      udp->udpchksum   = 0;
-      udp->udpchksum   = ~(udp_chksum(dev));
+#ifdef CONFIG_NET_IPv4
+#ifdef CONFIG_NET_IPv5
+      if (conn->domain = PF_INET)
+#endif
+        {
+          udp->udpchksum = ~udp_ipv4_chksum(dev);
+        }
+#endif /* CONFIG_NET_IPv4 */
+
+#ifdef CONFIG_NET_IPv6
+#ifdef CONFIG_NET_IPv4
+      else
+#endif
+        {
+          udp->udpchksum = ~udp_ipv6_chksum(dev);
+        }
+#endif /* CONFIG_NET_IPv6 */
+
       if (udp->udpchksum == 0)
         {
           udp->udpchksum = 0xffff;
         }
-#else
-      udp->udpchksum   = 0;
-#endif
+#endif /* CONFIG_NET_UDP_CHECKSUMS */
 
       nllvdbg("Outgoing UDP packet length: %d\n", dev->d_len);
 
diff --git a/nuttx/net/utils/Kconfig b/nuttx/net/utils/Kconfig
index 5ba6ffe3e..c6700624b 100644
--- a/nuttx/net/utils/Kconfig
+++ b/nuttx/net/utils/Kconfig
@@ -23,4 +23,5 @@ config NET_ARCH_CHKSUM
 			uint16_t ipv4_chksum(FAR struct net_driver_s *dev)
 			uint16_t tcp_ipv4_chksum(FAR struct net_driver_s *dev);
 			uint16_t tcp_ipv6_chksum(FAR struct net_driver_s *dev);
-			uint16_t udp_chksum(FAR struct net_driver_s *dev);
+			uint16_t udp_ipv4_chksum(FAR struct net_driver_s *dev);
+			uint16_t udp_ipv6_chksum(FAR struct net_driver_s *dev);
diff --git a/nuttx/net/utils/net_chksum.c b/nuttx/net/utils/net_chksum.c
index d4179470c..98732bcc6 100644
--- a/nuttx/net/utils/net_chksum.c
+++ b/nuttx/net/utils/net_chksum.c
@@ -372,34 +372,34 @@ uint16_t tcp_chksum(FAR struct net_driver_s *dev)
 #endif
 
 /****************************************************************************
- * Name: udp_chksum
+ * Name: udp_ipv4_chksum
  *
  * Description:
- *   Calculate the UDP checksum of the packet in d_buf and d_appdata.
+ *   Calculate the UDP/IPv4 checksum of the packet in d_buf and d_appdata.
  *
  ****************************************************************************/
 
-#if defined(CONFIG_NET_UDP_CHECKSUMS) && !defined(CONFIG_NET_ARCH_CHKSUM)
-uint16_t udp_chksum(FAR struct net_driver_s *dev)
+#if defined(CONFIG_NET_UDP_CHECKSUMS) && defined(CONFIG_NET_IPv4)
+uint16_t udp_ipv4_chksum(FAR struct net_driver_s *dev)
 {
-#if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)
-  if (IFF_IS_IPv6(dev->d_flags))
-    {
-      return ipv6_upperlayer_chksum(dev, IP_PROTO_UDP);
-    }
-  else
-    {
-      return ipv4_upperlayer_chksum(dev, IP_PROTO_UDP);
-    }
-
-#elif defined(CONFIG_NET_IPv4)
   return ipv4_upperlayer_chksum(dev, IP_PROTO_UDP);
+}
+#endif
 
-#else /* if defined(CONFIG_NET_IPv6) */
+/****************************************************************************
+ * Name: udp_ipv6_chksum
+ *
+ * Description:
+ *   Calculate the UDP/IPv6 checksum of the packet in d_buf and d_appdata.
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NET_UDP_CHECKSUMS) && defined(CONFIG_NET_IPv6)
+uint16_t udp_ipv6_chksum(FAR struct net_driver_s *dev)
+{
   return ipv6_upperlayer_chksum(dev, IP_PROTO_UDP);
-#endif
 }
-#endif /* CONFIG_NET_UDP_CHECKSUMS && !CONFIG_NET_ARCH_CHKSUM */
+#endif
 
 /****************************************************************************
  * Name: icmp_chksum
diff --git a/nuttx/net/utils/utils.h b/nuttx/net/utils/utils.h
index 6eabf097e..20aeab7d7 100644
--- a/nuttx/net/utils/utils.h
+++ b/nuttx/net/utils/utils.h
@@ -176,15 +176,27 @@ uint16_t tcp_chksum(FAR struct net_driver_s *dev);
 
 
 /****************************************************************************
- * Name: udp_chksum
+ * Name: udp_ipv4_chksum
  *
  * Description:
- *   Calculate the UDP checksum of the packet in d_buf and d_appdata.
+ *   Calculate the UDP/IPv4 checksum of the packet in d_buf and d_appdata.
  *
  ****************************************************************************/
 
-#ifdef CONFIG_NET_UDP_CHECKSUMS
-uint16_t udp_chksum(FAR struct net_driver_s *dev);
+#if defined(CONFIG_NET_UDP_CHECKSUMS) && defined(CONFIG_NET_IPv4)
+uint16_t udp_ipv4_chksum(FAR struct net_driver_s *dev);
+#endif
+
+/****************************************************************************
+ * Name: udp_ipv6_chksum
+ *
+ * Description:
+ *   Calculate the UDP/IPv6 checksum of the packet in d_buf and d_appdata.
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NET_UDP_CHECKSUMS) && defined(CONFIG_NET_IPv6)
+uint16_t udp_ipv6_chksum(FAR struct net_driver_s *dev);
 #endif
 
 /****************************************************************************