173 lines
5.2 KiB
C
173 lines
5.2 KiB
C
/****************************************************************************
|
|
* net/icmp/icmp_reply.c
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/socket.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
#include <debug.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <net/if.h>
|
|
#include <arpa/inet.h>
|
|
|
|
#include <nuttx/net/net.h>
|
|
#include <nuttx/net/netdev.h>
|
|
#include <nuttx/net/ip.h>
|
|
#include <nuttx/net/icmp.h>
|
|
|
|
#include "utils/utils.h"
|
|
#include "netdev/netdev.h"
|
|
#include "devif/devif.h"
|
|
#include "inet/inet.h"
|
|
#include "icmp/icmp.h"
|
|
|
|
#ifdef CONFIG_NET_ICMP
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/* RFC 1812:
|
|
* 4.3.2.3, Original Message Header
|
|
* ...
|
|
* The ICMP datagram SHOULD contain as much of the original datagram as
|
|
* possible without the length of the ICMP datagram exceeding 576 bytes.
|
|
* ...
|
|
*/
|
|
|
|
#define ICMP_MAXMSGLEN 576
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: icmp_reply
|
|
*
|
|
* Description:
|
|
* Send an ICMP message in response to a situation
|
|
* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header.
|
|
* MAY send more (we do).
|
|
* MUST NOT change this header information.
|
|
* MUST NOT reply to a multicast/broadcast IP address.
|
|
* MUST NOT reply to a multicast/broadcast MAC address.
|
|
* MUST reply to only the first fragment.
|
|
*
|
|
* Input Parameters:
|
|
* dev - The device driver structure containing the received packet
|
|
* type - ICMP Message Type, eg. ICMP_DEST_UNREACHABLE
|
|
* code - ICMP Message Code, eg. ICMP_PORT_UNREACH
|
|
*
|
|
* Returned Value:
|
|
* None
|
|
*
|
|
****************************************************************************/
|
|
|
|
void icmp_reply(FAR struct net_driver_s *dev, int type, int code)
|
|
{
|
|
int ipicmplen = IPv4_HDRLEN + sizeof(struct icmp_hdr_s);
|
|
FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
|
|
FAR struct icmp_hdr_s *icmp = (FAR struct icmp_hdr_s *)(ipv4 + 1);
|
|
uint16_t datalen;
|
|
#ifdef CONFIG_NET_BROADCAST
|
|
const in_addr_t bcast = INADDR_BROADCAST;
|
|
#endif /* CONFIG_NET_BROADCAST */
|
|
const in_addr_t any = INADDR_ANY;
|
|
|
|
if (net_ipv4addr_hdrcmp(ipv4->destipaddr, &any)
|
|
# ifdef CONFIG_NET_BROADCAST
|
|
|| net_ipv4addr_hdrcmp(ipv4->destipaddr, &bcast)
|
|
|| net_ipv4addr_broadcast(net_ip4addr_conv32(ipv4->destipaddr),
|
|
dev->d_netmask)
|
|
# endif /* CONFIG_NET_BROADCAST */
|
|
)
|
|
{
|
|
dev->d_len = 0;
|
|
return;
|
|
}
|
|
|
|
/* Get the data size of the packet. */
|
|
|
|
datalen = (ipv4->len[0] << 8) + ipv4->len[1];
|
|
|
|
/* RFC says return as much as we can without exceeding 576 bytes. */
|
|
|
|
if (datalen > ICMP_MAXMSGLEN - ipicmplen)
|
|
{
|
|
datalen = ICMP_MAXMSGLEN - ipicmplen;
|
|
}
|
|
|
|
dev->d_len = ipicmplen + datalen;
|
|
|
|
/* Copy fields from original packet */
|
|
|
|
memmove(icmp + 1, ipv4, datalen);
|
|
|
|
/* Initialize the IP header. */
|
|
|
|
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;
|
|
ipv4->ipoffset[0] = IP_FLAG_DONTFRAG >> 8;
|
|
ipv4->ipoffset[1] = IP_FLAG_DONTFRAG & 0xff;
|
|
ipv4->ttl = IP_TTL_DEFAULT;
|
|
ipv4->proto = IP_PROTO_ICMP;
|
|
|
|
/* Calculate IP checksum. */
|
|
|
|
ipv4->ipchksum = 0;
|
|
ipv4->ipchksum = ~ipv4_chksum(dev);
|
|
|
|
net_ipv4addr_hdrcopy(ipv4->destipaddr, ipv4->srcipaddr);
|
|
net_ipv4addr_hdrcopy(ipv4->srcipaddr, &dev->d_ipaddr);
|
|
|
|
/* Initialize the ICMP header */
|
|
|
|
icmp->type = type;
|
|
icmp->icode = code;
|
|
icmp->data[0] = 0;
|
|
icmp->data[1] = 0;
|
|
|
|
/* Calculate the ICMP checksum. */
|
|
|
|
icmp->icmpchksum = 0;
|
|
icmp->icmpchksum = ~icmp_chksum(dev, datalen + sizeof(*icmp));
|
|
if (icmp->icmpchksum == 0)
|
|
{
|
|
icmp->icmpchksum = 0xffff;
|
|
}
|
|
|
|
ninfo("Outgoing ICMP packet length: %d (%d)\n",
|
|
dev->d_len, (ipv4->len[0] << 8) | ipv4->len[1]);
|
|
}
|
|
|
|
#endif /* CONFIG_NET_ICMP */
|