nuttx/net/icmpv6/icmpv6_input.c
2018-03-13 09:52:27 -06:00

509 lines
15 KiB
C

/****************************************************************************
* net/icmpv6/icmpv6_input.c
* Handling incoming ICMPv6 input
*
* Copyright (C) 2015, 2017 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:
*
* 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>
#include <stdint.h>
#include <string.h>
#include <debug.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/netstats.h>
#include <nuttx/net/icmpv6.h>
#include "devif/devif.h"
#include "neighbor/neighbor.h"
#include "utils/utils.h"
#include "icmpv6/icmpv6.h"
#ifdef CONFIG_NET_ICMPv6
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define ETHBUF \
((struct eth_hdr_s *)&dev->d_buf[0])
#define IPv6BUF \
((FAR struct ipv6_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define IPICMPv6 \
((struct icmpv6_iphdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define ICMPv6REPLY \
((FAR struct icmpv6_echo_reply_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN])
#define ICMPv6SIZE \
((dev)->d_len - IPv6_HDRLEN)
#define ICMPv6SOLICIT \
((struct icmpv6_neighbor_solicit_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN])
#define ICMPv6ADVERTISE \
((struct icmpv6_neighbor_advertise_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN])
#define ICMPv6RADVERTISE \
((struct icmpv6_router_advertise_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv6_HDRLEN])
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: icmpv6_datahandler
*
* Description:
* Handle ICMPv6 echo replies that are not accepted by the application.
*
* Input Parameters:
* dev - Device instance only the input packet in d_buf, length = d_len;
* conn - A pointer to the ICMPv6 connection structure
* buffer - A pointer to the buffer to be copied to the read-ahead
* buffers
* buflen - The number of bytes to copy to the read-ahead buffer.
*
* Returned Value:
* The number of bytes actually buffered is returned. This will be either
* zero or equal to buflen; partial packets are not buffered.
*
****************************************************************************/
#ifdef CONFIG_NET_ICMPv6_SOCKET
static uint16_t icmpv6_datahandler(FAR struct net_driver_s *dev,
FAR struct icmpv6_conn_s *conn)
{
FAR struct ipv6_hdr_s *ipv6;
struct sockaddr_in6 inaddr;
FAR struct iob_s *iob;
uint16_t offset;
uint16_t buflen;
uint8_t addrsize;
int ret;
/* Try to allocate on I/O buffer to start the chain without waiting (and
* throttling as necessary). If we would have to wait, then drop the
* packet.
*/
iob = iob_tryalloc(true);
if (iob == NULL)
{
nerr("ERROR: Failed to create new I/O buffer chain\n");
goto drop;
}
/* Put the IPv6 address at the beginning of the read-ahead buffer */
ipv6 = IPv6BUF;
inaddr.sin6_family = AF_INET6;
inaddr.sin6_port = 0;
net_ipv6addr_copy(inaddr.sin6_addr.s6_addr16, ipv6->srcipaddr);
/* Copy the src address info into the I/O buffer chain. We will not wait
* for an I/O buffer to become available in this context. It there is
* any failure to allocated, the entire I/O buffer chain will be discarded.
*/
addrsize = sizeof(struct sockaddr_in6);
ret = iob_trycopyin(iob, &addrsize, sizeof(uint8_t), 0, true);
if (ret < 0)
{
/* On a failure, iob_trycopyin return a negated error value but does
* not free any I/O buffers.
*/
nerr("ERROR: Failed to length to the I/O buffer chain: %d\n", ret);
goto drop_with_chain;
}
offset = sizeof(uint8_t);
ret = iob_trycopyin(iob, (FAR const uint8_t *)&inaddr,
sizeof(struct sockaddr_in6), offset, true);
if (ret < 0)
{
/* On a failure, iob_trycopyin return a negated error value but does
* not free any I/O buffers.
*/
nerr("ERROR: Failed to source address to the I/O buffer chain: %d\n", ret);
goto drop_with_chain;
}
offset += sizeof(struct sockaddr_in6);
/* Copy the new ICMPv6 reply into the I/O buffer chain (without waiting) */
buflen = ICMPv6SIZE;
ret = iob_trycopyin(iob, (FAR uint8_t *)ICMPv6REPLY, buflen, offset, true);
if (ret < 0)
{
/* On a failure, iob_copyin return a negated error value but does
* not free any I/O buffers.
*/
nerr("ERROR: Failed to add data to the I/O buffer chain: %d\n", ret);
goto drop_with_chain;
}
/* Add the new I/O buffer chain to the tail of the read-ahead queue (again
* without waiting).
*/
ret = iob_tryadd_queue(iob, &conn->readahead);
if (ret < 0)
{
nerr("ERROR: Failed to queue the I/O buffer chain: %d\n", ret);
goto drop_with_chain;
}
ninfo("Buffered %d bytes\n", buflen + addrsize + 1);
dev->d_len = 0;
return buflen;
drop_with_chain:
(void)iob_free_chain(iob);
drop:
dev->d_len = 0;
return 0;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmpv6_input
*
* Description:
* Handle incoming ICMPv6 input
*
* Input Parameters:
* dev - The device driver structure containing the received ICMPv6
* packet
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
void icmpv6_input(FAR struct net_driver_s *dev)
{
FAR struct icmpv6_iphdr_s *ipicmp = IPICMPv6;
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmpv6.recv++;
#endif
/* Handle the ICMPv6 message by its type */
switch (ipicmp->type)
{
/* If we get a neighbor solicitation for our address we should send
* a neighbor advertisement message back.
*/
case ICMPv6_NEIGHBOR_SOLICIT:
{
FAR struct icmpv6_neighbor_solicit_s *sol;
/* Check if we are the target of the solicitation */
sol = ICMPv6SOLICIT;
if (net_ipv6addr_cmp(sol->tgtaddr, dev->d_ipv6addr))
{
/* Yes.. Send a neighbor advertisement back to where the neighbor
* solicitation came from.
*/
icmpv6_advertise(dev, ipicmp->srcipaddr);
/* All statistics have been updated. Nothing to do but exit. */
return;
}
else
{
goto icmpv6_drop_packet;
}
}
break;
/* Check if we received a Neighbor Advertisement */
case ICMPv6_NEIGHBOR_ADVERTISE:
{
FAR struct icmpv6_neighbor_advertise_s *adv;
/* If the IPv6 destination address matches our address, and if so,
* add the neighbor address mapping to the list of neighbors.
*
* Missing checks:
* optlen = 1 (8 octets)
* Should only update Neighbor Table if [O]verride bit is set in flags
*/
adv = ICMPv6ADVERTISE;
if (net_ipv6addr_cmp(ipicmp->destipaddr, dev->d_ipv6addr))
{
/* This message is required to support the Target link-layer
* address option.
*/
if (adv->opttype == ICMPv6_OPT_TGTLLADDR)
{
/* Save the sender's address mapping in our Neighbor Table. */
neighbor_add(dev, ipicmp->srcipaddr, adv->tgtlladdr);
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
/* Then notify any logic waiting for the Neighbor Advertisement */
icmpv6_notify(ipicmp->srcipaddr);
#endif
/* We consumed the packet but we don't send anything in
* response.
*/
goto icmpv6_send_nothing;
}
}
goto icmpv6_drop_packet;
}
break;
#ifdef CONFIG_NET_ICMPv6_ROUTER
/* Check if we received a Router Solicitation */
case ICMPV6_ROUTER_SOLICIT:
{
/* Just give a knee-jerk Router Advertisement in respond with no
* further examination of the Router Solicitation.
*/
icmpv6_radvertise(dev);
/* All statistics have been updated. Nothing to do but exit. */
return;
}
#endif
#ifdef CONFIG_NET_ICMPv6_AUTOCONF
/* Check if we received a Router Advertisement */
case ICMPV6_ROUTER_ADVERTISE:
{
FAR struct icmpv6_router_advertise_s *adv;
FAR uint8_t *options;
uint16_t pktlen;
uint16_t optlen;
int ndx;
/* Get the length of the option data */
pktlen = (uint16_t)ipicmp->len[0] << 8 | ipicmp->len[1];
if (pktlen <= ICMPv6_RADV_MINLEN)
{
/* Too small to contain any options */
goto icmpv6_drop_packet;
}
optlen = ICMPv6_RADV_OPTLEN(pktlen);
/* We need to have a valid router advertisement with a Prefix and
* with the "A" bit set in the flags. Options immediately follow
* the ICMPv6 router advertisement.
*/
adv = ICMPv6RADVERTISE;
options = (FAR uint8_t *)adv + sizeof(struct icmpv6_router_advertise_s);
for (ndx = 0; ndx + sizeof(struct icmpv6_prefixinfo_s) <= optlen; )
{
FAR struct icmpv6_srclladdr_s *sllopt =
(FAR struct icmpv6_srclladdr_s *)&options[ndx];
if (sllopt->opttype == 1 && sllopt->optlen == 1)
{
neighbor_add(dev, ipicmp->srcipaddr, sllopt->srclladdr);
}
FAR struct icmpv6_prefixinfo_s *opt =
(FAR struct icmpv6_prefixinfo_s *)&options[ndx];
/* Is this the sought for prefix? Is it the correct size? Is
* the "A" flag set?
*/
if (opt->opttype &&
opt->optlen == 4 &&
(opt->flags & ICMPv6_PRFX_FLAG_A) != 0)
{
/* Yes.. Notify any waiting threads */
icmpv6_rnotify(dev, ipicmp->srcipaddr, opt->prefix, opt->preflen);
goto icmpv6_send_nothing;
}
/* Skip to the next option (units of octets) */
ndx += (opt->optlen << 3);
}
goto icmpv6_drop_packet;
}
break;
#endif
/* Handle the ICMPv6 Echo Request */
case ICMPv6_ECHO_REQUEST:
{
/* ICMPv6 echo (i.e., ping) processing. This is simple, we only
* change the ICMPv6 type from ECHO to ECHO_REPLY and update the
* ICMPv6 checksum before we return the packet.
*/
ipicmp->type = ICMPv6_ECHO_REPLY;
net_ipv6addr_copy(ipicmp->destipaddr, ipicmp->srcipaddr);
net_ipv6addr_copy(ipicmp->srcipaddr, dev->d_ipv6addr);
ipicmp->chksum = 0;
ipicmp->chksum = ~icmpv6_chksum(dev);
}
break;
#ifdef CONFIG_NET_ICMPv6_SOCKET
/* If an ICMPv6 echo reply is received then there should also be
* a thread waiting to received the echo response.
*/
case ICMPv6_ECHO_REPLY:
{
uint16_t flags = ICMPv6_ECHOREPLY;
/* Dispatch the ECHO reply to the waiting thread */
flags = devif_conn_event(dev, NULL, flags, dev->d_conncb);
/* Was the ECHO reply consumed by any waiting thread? */
if ((flags & ICMPv6_ECHOREPLY) != 0)
{
FAR struct icmpv6_echo_reply_s *reply;
FAR struct icmpv6_conn_s *conn;
uint16_t nbuffered;
/* Nothing consumed the ICMP reply. That might because this is
* an old, invalid reply or simply because the ping application
* has not yet put its poll or recv in place.
*/
/* Is there any connection that might expect this reply? */
reply = ICMPv6REPLY;
conn = icmpv6_findconn(dev, reply->id);
if (conn == NULL)
{
/* No.. drop the packet */
goto icmpv6_drop_packet;
}
/* Yes.. Add the ICMP echo reply to the IPPROTO_ICMP socket read
* ahead buffer.
*/
nbuffered = icmpv6_datahandler(dev, conn);
if (nbuffered == 0)
{
/* Could not buffer the data.. drop the packet */
goto icmpv6_drop_packet;
}
}
goto icmpv6_send_nothing;
}
break;
#endif
default:
{
nwarn("WARNING: Unknown ICMPv6 type: %d\n", ipicmp->type);
goto icmpv6_type_error;
}
}
ninfo("Outgoing ICMPv6 packet length: %d (%d)\n",
dev->d_len, (ipicmp->len[0] << 8) | ipicmp->len[1]);
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmpv6.sent++;
g_netstats.ipv6.sent++;
#endif
return;
icmpv6_type_error:
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmpv6.typeerr++;
#endif
icmpv6_drop_packet:
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmpv6.drop++;
#endif
icmpv6_send_nothing:
dev->d_len = 0;
}
#endif /* CONFIG_NET_ICMPv6 */