/****************************************************************************
* net/devif/ipv6_input.c
* Device driver IPv6 packet receipt interface
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 ipv6_input()
* function into many smaller functions, this would increase the code
* size because of the overhead of parameter passing and the fact that
* the optimizer 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 wishes 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_IPv6
#include <sys/ioctl.h>
#include <stdint.h>
#include <debug.h>
#include <string.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/netstats.h>
#include <nuttx/net/ip.h>
#include "ipv6/ipv6.h"
#include "tcp/tcp.h"
#include "udp/udp.h"
#include "pkt/pkt.h"
#include "icmpv6/icmpv6.h"
#include "devif/devif.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Macros */
#define BUF ((FAR struct net_ipv6hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: ipv6_input
*
* Description:
*
* Returned Value:
* OK The packet was processed (or dropped) and can be discarded.
* ERROR There is a matching connection, but could not dispatch the packet
* yet. Currently useful for UDP when a packet arrives before a recv
* call is in place.
*
* Assumptions:
*
****************************************************************************/
int ipv6_input(FAR struct net_driver_s *dev)
{
FAR struct net_ipv6hdr_s *pbuf = BUF;
uint16_t iplen;
/* This is where the input processing starts. */
#ifdef CONFIG_NET_STATISTICS
g_netstats.ip.recv++;
#endif
/* Start of IP input header processing code. */
/* Check validity of the IP header. */
if ((pbuf->vtc & 0xf0) != 0x60)
{
/* IP version and header length. */
#ifdef CONFIG_NET_STATISTICS
g_netstats.ip.drop++;
g_netstats.ip.vhlerr++;
#endif
nlldbg("Invalid IPv6 version: %d\n", pbuf->vtc >> 4);
goto drop;
}
/* 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.
*
* 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).
*/
iplen = (pbuf->len[0] << 8) + pbuf->len[1] + IPv6_HDRLEN;
if (iplen <= dev->d_len)
{
dev->d_len = iplen;
}
else
{
nlldbg("IP packet shorter than length in IP header\n");
goto drop;
}
/* If IP broadcast support is configured, we check for a broadcast
* UDP packet, which may be destined to us (even if there is no IP
* address yet assigned to the device as is the case when we are
* negotiating over DHCP for an address).
*/
#if defined(CONFIG_NET_BROADCAST) && defined(CONFIG_NET_UDP)
if (pbuf->proto == IP_PROTO_UDP &&
net_ipv6addr_cmp(pbuf->destipaddr, g_alloneaddr))
{
return udp_input(dev);
}
/* In most other cases, the device must be assigned a non-zero IP
* address. Another exception is when CONFIG_NET_PINGADDRCONF is
* enabled...
*/
else
#endif
#ifdef CONFIG_NET_ICMPv6
if (net_ipv6addr_cmp(dev->d_ipaddr, g_allzeroaddr))
{
/* If we are configured to use ping IP address configuration and
* hasn't been assigned an IP address yet, we accept all ICMP
* packets.
*/
nlldbg("No IP address assigned\n");
goto drop;
}
/* Check if the packet is destined for out IP address */
else
#endif
{
/* Check if the packet is destined for our IP address.
*
* 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 (!net_ipv6addr_cmp(pbuf->destipaddr, dev->d_ipaddr) &&
pbuf->destipaddr[0] != 0xff02)
{
#ifdef CONFIG_NET_STATISTICS
g_netstats.ip.drop++;
#endif
goto drop;
}
}
/* Everything looks good so far. Now process the incoming packet
* according to the protocol.
*/
switch (pbuf->proto)
{
#ifdef CONFIG_NET_TCP
case IP_PROTO_TCP: /* TCP input */
tcp_input(dev);
break;
#endif
#ifdef CONFIG_NET_UDP
case IP_PROTO_UDP: /* UDP input */
udp_input(dev);
break;
#endif
/* Check for ICMP input */
#ifdef CONFIG_NET_ICMPv6
case IP_PROTO_ICMP6: /* ICMP6 input */
icmpv6_input(dev);
break;
#endif
default: /* Unrecognized/unsupported protocol */
#ifdef CONFIG_NET_STATISTICS
g_netstats.ip.drop++;
g_netstats.ip.protoerr++;
#endif
nlldbg("Unrecognized IP protocol\n");
goto drop;
}
/* Return and let the caller do any pending transmission. */
return OK;
/* Drop the packet. NOTE that OK is returned meaning that the
* packet has been processed (although processed unsuccessfully).
*/
drop:
dev->d_len = 0;
return OK;
}
#endif /* CONFIG_NET_IPv6 */
