/****************************************************************************
* 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 <sys/time.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
****************************************************************************/
#ifdef CONFIG_NET_ICMP_SOCKET
/****************************************************************************
* Private Types
****************************************************************************/
struct icmp_deliver_s
{
FAR struct net_driver_s *dev; /* Current network device */
uint16_t iphdrlen; /* The size of the IPv4 header */
bool delivered; /* Whether the message is delivered */
};
/****************************************************************************
* Private Functions
****************************************************************************/
static bool icmp_filter(uint32_t filter, uint8_t type)
{
if (type < 32)
{
return ((1u << type) & filter) != 0;
}
/* Do not block unknown ICMP types */
return 0;
}
/****************************************************************************
* 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
* iphdrlen - The size of the IPv4 header
*
* Returned Value:
* The number of bytes actually buffered is returned. This will be either
* zero or equal to buflen; partial packets are not buffered.
*
****************************************************************************/
static uint16_t icmp_datahandler(FAR struct net_driver_s *dev,
FAR struct icmp_conn_s *conn,
uint16_t iphdrlen)
{
FAR struct ipv4_hdr_s *ipv4;
struct sockaddr_in inaddr;
FAR struct iob_s *iob;
uint16_t buflen;
int ret;
iob = iob_tryalloc(false);
if (iob == NULL)
{
return -ENOMEM;
}
/* 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 front of I/O buffer chain which
* overwrites the contents of the packet header field.
*/
memcpy(iob->io_data, &inaddr, sizeof(struct sockaddr_in));
iob_reserve(iob, sizeof(struct sockaddr_in));
/* Copy the ICMP message into the I/O buffer chain (without waiting) */
ret = iob_clone_partial(dev->d_iob, dev->d_iob->io_pktlen,
0, iob, 0, true, false);
if (ret < 0)
{
iob_free_chain(iob);
return ret;
}
buflen = dev->d_len;
/* 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);
iob_free_chain(iob);
}
else
{
ninfo("Buffered %d bytes\n", buflen);
}
return buflen;
}
/****************************************************************************
* Name: icmp_delivery_callback
*
* Description:
* Copy the icmp package to the application according to the filter
* conditions, but ICMP_ECHO_REPLY is a special message type, if there
* is an application waiting, it will also copy.
*
* Input Parameters:
* conn - A pointer to the ICMP connection structure.
* arg - The context information
*
****************************************************************************/
static int icmp_delivery_callback(FAR struct icmp_conn_s *conn,
FAR void *arg)
{
FAR struct icmp_deliver_s *info = arg;
FAR struct net_driver_s *dev = info->dev;
FAR struct icmp_hdr_s *icmp = IPBUF(info->iphdrlen);
if (icmp_filter(conn->filter, icmp->type) &&
(icmp->type != ICMP_ECHO_REPLY || conn->id != icmp->id ||
conn->dev != dev))
{
return 0;
}
info->delivered = true;
if (devif_conn_event(dev, ICMP_NEWDATA, conn->sconn.list) == ICMP_NEWDATA)
{
icmp_datahandler(dev, conn, info->iphdrlen);
}
return 0;
}
/****************************************************************************
* Name: icmp_deliver
*
* Description:
* Copy the icmp package to the application according to the filter
* conditions, but ICMP_ECHO_REPLY is a special message type, if there
* is an application waiting, it will also copy.
*
* Input Parameters:
* dev - Reference to a device driver structure.
* iphdrlen - The size of the IP header. This may be larger than
* IPv4_HDRLEN if IP option are present.
*
****************************************************************************/
static bool icmp_deliver(FAR struct net_driver_s *dev, uint16_t iphdrlen)
{
struct icmp_deliver_s info;
info.dev = dev;
info.iphdrlen = iphdrlen;
info.delivered = false;
icmp_foreach(icmp_delivery_callback, &info);
return info.delivered;
}
#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;
/* Get the IP header length (accounting for possible options). */
uint16_t iphdrlen = (ipv4->vhl & IPv4_HLMASK) << 2;
#ifdef CONFIG_NET_ICMP_SOCKET
bool delivered = icmp_deliver(dev, iphdrlen);
#endif
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.recv++;
#endif
/* The ICMP header immediately follows the IP header */
icmp = IPBUF(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
}
#if CONFIG_NET_ICMP_PMTU_ENTRIES > 0
else if (icmp->type == ICMP_DEST_UNREACHABLE)
{
if (icmp->icode == ICMP_FRAG_NEEDED)
{
FAR struct icmp_pmtu_entry *entry;
FAR struct ipv4_hdr_s *inner;
int mtu;
mtu = ntohs(icmp->data[0]) << 16 | ntohs(icmp->data[1]);
if (mtu <= 0)
{
goto typeerr;
}
inner = (FAR struct ipv4_hdr_s *)(icmp + 1);
entry = icmpv4_find_pmtu_entry(
net_ip4addr_conv32(inner->destipaddr));
if (entry == NULL)
{
icmpv4_add_pmtu_entry(
net_ip4addr_conv32(inner->destipaddr), mtu);
}
else
{
entry->pmtu = mtu;
}
goto icmp_send_nothing;
}
}
#endif
/* Otherwise the ICMP input was not processed */
else
{
#ifdef CONFIG_NET_ICMP_SOCKET
if (delivered)
{
goto icmp_send_nothing;
}
else if (icmp->type == ICMP_ECHO_REQUEST)
{
goto drop;
}
#endif
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:
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.drop++;
#endif
#endif
#if defined(CONFIG_NET_ICMP_SOCKET) || CONFIG_NET_ICMP_PMTU_ENTRIES > 0
icmp_send_nothing:
#endif
dev->d_len = 0;
}
#endif /* CONFIG_NET_ICMP */
#endif /* CONFIG_NET */