/****************************************************************************
* net/icmp/icmp_input.c
* Handling incoming ICMP input
*
* Copyright (C) 2007-2009, 2012, 2014-2015, 2017, 2019 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>
#ifdef CONFIG_NET
#include <stdint.h>
#include <string.h>
#include <debug.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/netstats.h>
#include <nuttx/net/ip.h>
#include "devif/devif.h"
#include "icmp/icmp.h"
#include "utils/utils.h"
#ifdef CONFIG_NET_ICMP
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define IPv4BUF ((FAR struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define ICMPBUF(hl) ((FAR struct icmp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + (hl)])
#define ICMPSIZE(hl) ((dev)->d_len - (hl))
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: icmp_datahandler
*
* Description:
* Handle ICMP 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 ICMP 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_ICMP_SOCKET
static uint16_t icmp_datahandler(FAR struct net_driver_s *dev,
FAR struct icmp_conn_s *conn)
{
FAR struct ipv4_hdr_s *ipv4;
struct sockaddr_in inaddr;
FAR struct iob_s *iob;
uint16_t offset;
uint16_t buflen;
uint16_t iphdrlen;
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, IOBUSER_NET_SOCK_ICMP);
if (iob == NULL)
{
nerr("ERROR: Failed to create new I/O buffer chain\n");
goto drop;
}
/* Put the IPv4 address at the beginning of the read-ahead buffer */
ipv4 = IPv4BUF;
inaddr.sin_family = AF_INET;
inaddr.sin_port = 0;
net_ipv4addr_copy(inaddr.sin_addr.s_addr,
net_ip4addr_conv32(ipv4->srcipaddr));
memset(inaddr.sin_zero, 0, sizeof(inaddr.sin_zero));
/* 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_in);
ret = iob_trycopyin(iob, &addrsize, sizeof(uint8_t), 0, true,
IOBUSER_NET_SOCK_ICMP);
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_in), offset, true,
IOBUSER_NET_SOCK_ICMP);
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_in);
/* Get the IP header length (accounting for possible options). */
iphdrlen = (ipv4->vhl & IPv4_HLMASK) << 2;
/* Copy the new ICMP reply into the I/O buffer chain (without waiting) */
buflen = ICMPSIZE(iphdrlen);
ret = iob_trycopyin(iob, (FAR uint8_t *)ICMPBUF(iphdrlen), buflen, offset,
true, IOBUSER_NET_SOCK_ICMP);
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:
iob_free_chain(iob, IOBUSER_NET_SOCK_ICMP);
drop:
dev->d_len = 0;
return 0;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmp_input
*
* Description:
* Handle incoming ICMP input
*
* Input Parameters:
* dev - The device driver structure containing the received ICMP
* packet
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
void icmp_input(FAR struct net_driver_s *dev)
{
FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
FAR struct icmp_hdr_s *icmp;
uint16_t iphdrlen;
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.recv++;
#endif
/* Get the IP header length (accounting for possible options). */
iphdrlen = (ipv4->vhl & IPv4_HLMASK) << 2;
/* The ICMP header immediately follows the IP header */
icmp = ICMPBUF(iphdrlen);
/* 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 (icmp->type == ICMP_ECHO_REQUEST)
{
/* Change the ICMP type */
icmp->type = ICMP_ECHO_REPLY;
/* Swap IP addresses. */
net_ipv4addr_hdrcopy(ipv4->destipaddr, ipv4->srcipaddr);
net_ipv4addr_hdrcopy(ipv4->srcipaddr, &dev->d_ipaddr);
/* Recalculate the ICMP checksum */
#if 0
/* Get the IP header length (accounting for possible options). */
iphdrlen = (ipv4->vhl & IPv4_HLMASK) << 2;
/* The slow way... sum over the ICMP message */
icmp->icmpchksum = 0;
icmp->icmpchksum = ~icmp_chksum(dev,
(((uint16_t)ipv4->len[0] << 8) |
(uint16_t)ipv4->len[1]) - iphdrlen);
if (icmp->icmpchksum == 0)
{
icmp->icmpchksum = 0xffff;
}
#else
/* The quick way -- Since only the type has changed, just adjust the
* checksum for the change of type
*/
if (icmp->icmpchksum >= HTONS(0xffff - (ICMP_ECHO_REQUEST << 8)))
{
icmp->icmpchksum += HTONS(ICMP_ECHO_REQUEST << 8) + 1;
}
else
{
icmp->icmpchksum += HTONS(ICMP_ECHO_REQUEST << 8);
}
#endif
ninfo("Outgoing ICMP packet length: %d (%d)\n",
dev->d_len, (ipv4->len[0] << 8) | ipv4->len[1]);
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.sent++;
g_netstats.ipv4.sent++;
#endif
}
#ifdef CONFIG_NET_ICMP_SOCKET
/* If an ICMP echo reply is received then there should also be
* a thread waiting to received the echo response.
*/
else if (icmp->type == ICMP_ECHO_REPLY)
{
FAR struct icmp_conn_s *conn;
uint16_t flags;
/* 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? */
conn = icmp_findconn(dev, icmp->id);
if (conn == NULL)
{
/* No.. drop the packet */
goto drop;
}
flags = devif_conn_event(dev, conn, ICMP_NEWDATA, conn->list);
if ((flags & ICMP_NEWDATA) != 0)
{
uint16_t nbuffered;
/* Add the ICMP echo reply to the IPPROTO_ICMP socket read-ahead
* buffer.
*/
nbuffered = icmp_datahandler(dev, conn);
if (nbuffered == 0)
{
/* Could not buffer the data.. drop the packet */
goto drop;
}
}
}
#endif
/* Otherwise the ICMP input was not processed */
else
{
nwarn("WARNING: Unknown ICMP cmd: %d\n", icmp->type);
goto typeerr;
}
return;
typeerr:
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.typeerr++;
#endif
#ifdef CONFIG_NET_ICMP_SOCKET
drop:
#endif
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.drop++;
#endif
dev->d_len = 0;
}
#endif /* CONFIG_NET_ICMP */
#endif /* CONFIG_NET */