Daiki Kato / mbed-os-lychee

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features/FEATURE_LWIP/lwip-interface/lwip/src/core/ipv4/lwip_icmp.c@0:f782d9c66c49, 2018-02-02 (annotated)

Committer:
dkato
Date:
Fri Feb 02 05:42:23 2018 +0000
Revision:
0:f782d9c66c49
mbed-os for GR-LYCHEE

Who changed what in which revision?

UserRevisionLine numberNew contents of line
dkato 0:f782d9c66c49 1 /**
dkato 0:f782d9c66c49 2 * @file
dkato 0:f782d9c66c49 3 * ICMP - Internet Control Message Protocol
dkato 0:f782d9c66c49 4 *
dkato 0:f782d9c66c49 5 */
dkato 0:f782d9c66c49 6
dkato 0:f782d9c66c49 7 /*
dkato 0:f782d9c66c49 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
dkato 0:f782d9c66c49 9 * All rights reserved.
dkato 0:f782d9c66c49 10 *
dkato 0:f782d9c66c49 11 * Redistribution and use in source and binary forms, with or without modification,
dkato 0:f782d9c66c49 12 * are permitted provided that the following conditions are met:
dkato 0:f782d9c66c49 13 *
dkato 0:f782d9c66c49 14 * 1. Redistributions of source code must retain the above copyright notice,
dkato 0:f782d9c66c49 15 * this list of conditions and the following disclaimer.
dkato 0:f782d9c66c49 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
dkato 0:f782d9c66c49 17 * this list of conditions and the following disclaimer in the documentation
dkato 0:f782d9c66c49 18 * and/or other materials provided with the distribution.
dkato 0:f782d9c66c49 19 * 3. The name of the author may not be used to endorse or promote products
dkato 0:f782d9c66c49 20 * derived from this software without specific prior written permission.
dkato 0:f782d9c66c49 21 *
dkato 0:f782d9c66c49 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
dkato 0:f782d9c66c49 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
dkato 0:f782d9c66c49 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
dkato 0:f782d9c66c49 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
dkato 0:f782d9c66c49 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
dkato 0:f782d9c66c49 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
dkato 0:f782d9c66c49 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
dkato 0:f782d9c66c49 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
dkato 0:f782d9c66c49 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
dkato 0:f782d9c66c49 31 * OF SUCH DAMAGE.
dkato 0:f782d9c66c49 32 *
dkato 0:f782d9c66c49 33 * This file is part of the lwIP TCP/IP stack.
dkato 0:f782d9c66c49 34 *
dkato 0:f782d9c66c49 35 * Author: Adam Dunkels <adam@sics.se>
dkato 0:f782d9c66c49 36 *
dkato 0:f782d9c66c49 37 */
dkato 0:f782d9c66c49 38
dkato 0:f782d9c66c49 39 /* Some ICMP messages should be passed to the transport protocols. This
dkato 0:f782d9c66c49 40 is not implemented. */
dkato 0:f782d9c66c49 41
dkato 0:f782d9c66c49 42 #include "lwip/opt.h"
dkato 0:f782d9c66c49 43
dkato 0:f782d9c66c49 44 #if LWIP_IPV4 && LWIP_ICMP /* don't build if not configured for use in lwipopts.h */
dkato 0:f782d9c66c49 45
dkato 0:f782d9c66c49 46 #include "lwip/icmp.h"
dkato 0:f782d9c66c49 47 #include "lwip/inet_chksum.h"
dkato 0:f782d9c66c49 48 #include "lwip/ip.h"
dkato 0:f782d9c66c49 49 #include "lwip/def.h"
dkato 0:f782d9c66c49 50 #include "lwip/stats.h"
dkato 0:f782d9c66c49 51
dkato 0:f782d9c66c49 52 #include <string.h>
dkato 0:f782d9c66c49 53
dkato 0:f782d9c66c49 54 /** Small optimization: set to 0 if incoming PBUF_POOL pbuf always can be
dkato 0:f782d9c66c49 55 * used to modify and send a response packet (and to 1 if this is not the case,
dkato 0:f782d9c66c49 56 * e.g. when link header is stripped of when receiving) */
dkato 0:f782d9c66c49 57 #ifndef LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
dkato 0:f782d9c66c49 58 #define LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN 1
dkato 0:f782d9c66c49 59 #endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
dkato 0:f782d9c66c49 60
dkato 0:f782d9c66c49 61 /* The amount of data from the original packet to return in a dest-unreachable */
dkato 0:f782d9c66c49 62 #define ICMP_DEST_UNREACH_DATASIZE 8
dkato 0:f782d9c66c49 63
dkato 0:f782d9c66c49 64 static void icmp_send_response(struct pbuf *p, u8_t type, u8_t code);
dkato 0:f782d9c66c49 65
dkato 0:f782d9c66c49 66 /**
dkato 0:f782d9c66c49 67 * Processes ICMP input packets, called from ip_input().
dkato 0:f782d9c66c49 68 *
dkato 0:f782d9c66c49 69 * Currently only processes icmp echo requests and sends
dkato 0:f782d9c66c49 70 * out the echo response.
dkato 0:f782d9c66c49 71 *
dkato 0:f782d9c66c49 72 * @param p the icmp echo request packet, p->payload pointing to the icmp header
dkato 0:f782d9c66c49 73 * @param inp the netif on which this packet was received
dkato 0:f782d9c66c49 74 */
dkato 0:f782d9c66c49 75 void
dkato 0:f782d9c66c49 76 icmp_input(struct pbuf *p, struct netif *inp)
dkato 0:f782d9c66c49 77 {
dkato 0:f782d9c66c49 78 u8_t type;
dkato 0:f782d9c66c49 79 #ifdef LWIP_DEBUG
dkato 0:f782d9c66c49 80 u8_t code;
dkato 0:f782d9c66c49 81 #endif /* LWIP_DEBUG */
dkato 0:f782d9c66c49 82 struct icmp_echo_hdr *iecho;
dkato 0:f782d9c66c49 83 const struct ip_hdr *iphdr_in;
dkato 0:f782d9c66c49 84 u16_t hlen;
dkato 0:f782d9c66c49 85 const ip4_addr_t* src;
dkato 0:f782d9c66c49 86
dkato 0:f782d9c66c49 87 ICMP_STATS_INC(icmp.recv);
dkato 0:f782d9c66c49 88 MIB2_STATS_INC(mib2.icmpinmsgs);
dkato 0:f782d9c66c49 89
dkato 0:f782d9c66c49 90 iphdr_in = ip4_current_header();
dkato 0:f782d9c66c49 91 hlen = IPH_HL(iphdr_in) * 4;
dkato 0:f782d9c66c49 92 if (hlen < IP_HLEN) {
dkato 0:f782d9c66c49 93 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short IP header (%"S16_F" bytes) received\n", hlen));
dkato 0:f782d9c66c49 94 goto lenerr;
dkato 0:f782d9c66c49 95 }
dkato 0:f782d9c66c49 96 if (p->len < sizeof(u16_t)*2) {
dkato 0:f782d9c66c49 97 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len));
dkato 0:f782d9c66c49 98 goto lenerr;
dkato 0:f782d9c66c49 99 }
dkato 0:f782d9c66c49 100
dkato 0:f782d9c66c49 101 type = *((u8_t *)p->payload);
dkato 0:f782d9c66c49 102 #ifdef LWIP_DEBUG
dkato 0:f782d9c66c49 103 code = *(((u8_t *)p->payload)+1);
dkato 0:f782d9c66c49 104 #endif /* LWIP_DEBUG */
dkato 0:f782d9c66c49 105 switch (type) {
dkato 0:f782d9c66c49 106 case ICMP_ER:
dkato 0:f782d9c66c49 107 /* This is OK, echo reply might have been parsed by a raw PCB
dkato 0:f782d9c66c49 108 (as obviously, an echo request has been sent, too). */
dkato 0:f782d9c66c49 109 MIB2_STATS_INC(mib2.icmpinechoreps);
dkato 0:f782d9c66c49 110 break;
dkato 0:f782d9c66c49 111 case ICMP_ECHO:
dkato 0:f782d9c66c49 112 MIB2_STATS_INC(mib2.icmpinechos);
dkato 0:f782d9c66c49 113 src = ip4_current_dest_addr();
dkato 0:f782d9c66c49 114 /* multicast destination address? */
dkato 0:f782d9c66c49 115 if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
dkato 0:f782d9c66c49 116 #if LWIP_MULTICAST_PING
dkato 0:f782d9c66c49 117 /* For multicast, use address of receiving interface as source address */
dkato 0:f782d9c66c49 118 src = netif_ip4_addr(inp);
dkato 0:f782d9c66c49 119 #else /* LWIP_MULTICAST_PING */
dkato 0:f782d9c66c49 120 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast pings\n"));
dkato 0:f782d9c66c49 121 goto icmperr;
dkato 0:f782d9c66c49 122 #endif /* LWIP_MULTICAST_PING */
dkato 0:f782d9c66c49 123 }
dkato 0:f782d9c66c49 124 /* broadcast destination address? */
dkato 0:f782d9c66c49 125 if (ip4_addr_isbroadcast(ip4_current_dest_addr(), ip_current_netif())) {
dkato 0:f782d9c66c49 126 #if LWIP_BROADCAST_PING
dkato 0:f782d9c66c49 127 /* For broadcast, use address of receiving interface as source address */
dkato 0:f782d9c66c49 128 src = netif_ip4_addr(inp);
dkato 0:f782d9c66c49 129 #else /* LWIP_BROADCAST_PING */
dkato 0:f782d9c66c49 130 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to broadcast pings\n"));
dkato 0:f782d9c66c49 131 goto icmperr;
dkato 0:f782d9c66c49 132 #endif /* LWIP_BROADCAST_PING */
dkato 0:f782d9c66c49 133 }
dkato 0:f782d9c66c49 134 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
dkato 0:f782d9c66c49 135 if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
dkato 0:f782d9c66c49 136 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
dkato 0:f782d9c66c49 137 goto lenerr;
dkato 0:f782d9c66c49 138 }
dkato 0:f782d9c66c49 139 #if CHECKSUM_CHECK_ICMP
dkato 0:f782d9c66c49 140 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP) {
dkato 0:f782d9c66c49 141 if (inet_chksum_pbuf(p) != 0) {
dkato 0:f782d9c66c49 142 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
dkato 0:f782d9c66c49 143 pbuf_free(p);
dkato 0:f782d9c66c49 144 ICMP_STATS_INC(icmp.chkerr);
dkato 0:f782d9c66c49 145 MIB2_STATS_INC(mib2.icmpinerrors);
dkato 0:f782d9c66c49 146 return;
dkato 0:f782d9c66c49 147 }
dkato 0:f782d9c66c49 148 }
dkato 0:f782d9c66c49 149 #endif
dkato 0:f782d9c66c49 150 #if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
dkato 0:f782d9c66c49 151 if (pbuf_header(p, (s16_t)(hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
dkato 0:f782d9c66c49 152 /* p is not big enough to contain link headers
dkato 0:f782d9c66c49 153 * allocate a new one and copy p into it
dkato 0:f782d9c66c49 154 */
dkato 0:f782d9c66c49 155 struct pbuf *r;
dkato 0:f782d9c66c49 156 /* allocate new packet buffer with space for link headers */
dkato 0:f782d9c66c49 157 r = pbuf_alloc(PBUF_LINK, p->tot_len + hlen, PBUF_RAM);
dkato 0:f782d9c66c49 158 if (r == NULL) {
dkato 0:f782d9c66c49 159 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
dkato 0:f782d9c66c49 160 goto icmperr;
dkato 0:f782d9c66c49 161 }
dkato 0:f782d9c66c49 162 if (r->len < hlen + sizeof(struct icmp_echo_hdr)) {
dkato 0:f782d9c66c49 163 LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("first pbuf cannot hold the ICMP header"));
dkato 0:f782d9c66c49 164 pbuf_free(r);
dkato 0:f782d9c66c49 165 goto icmperr;
dkato 0:f782d9c66c49 166 }
dkato 0:f782d9c66c49 167 /* copy the ip header */
dkato 0:f782d9c66c49 168 MEMCPY(r->payload, iphdr_in, hlen);
dkato 0:f782d9c66c49 169 /* switch r->payload back to icmp header (cannot fail) */
dkato 0:f782d9c66c49 170 if (pbuf_header(r, (s16_t)-hlen)) {
dkato 0:f782d9c66c49 171 LWIP_ASSERT("icmp_input: moving r->payload to icmp header failed\n", 0);
dkato 0:f782d9c66c49 172 pbuf_free(r);
dkato 0:f782d9c66c49 173 goto icmperr;
dkato 0:f782d9c66c49 174 }
dkato 0:f782d9c66c49 175 /* copy the rest of the packet without ip header */
dkato 0:f782d9c66c49 176 if (pbuf_copy(r, p) != ERR_OK) {
dkato 0:f782d9c66c49 177 LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("icmp_input: copying to new pbuf failed"));
dkato 0:f782d9c66c49 178 pbuf_free(r);
dkato 0:f782d9c66c49 179 goto icmperr;
dkato 0:f782d9c66c49 180 }
dkato 0:f782d9c66c49 181 /* free the original p */
dkato 0:f782d9c66c49 182 pbuf_free(p);
dkato 0:f782d9c66c49 183 /* we now have an identical copy of p that has room for link headers */
dkato 0:f782d9c66c49 184 p = r;
dkato 0:f782d9c66c49 185 } else {
dkato 0:f782d9c66c49 186 /* restore p->payload to point to icmp header (cannot fail) */
dkato 0:f782d9c66c49 187 if (pbuf_header(p, -(s16_t)(hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
dkato 0:f782d9c66c49 188 LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
dkato 0:f782d9c66c49 189 goto icmperr;
dkato 0:f782d9c66c49 190 }
dkato 0:f782d9c66c49 191 }
dkato 0:f782d9c66c49 192 #endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
dkato 0:f782d9c66c49 193 /* At this point, all checks are OK. */
dkato 0:f782d9c66c49 194 /* We generate an answer by switching the dest and src ip addresses,
dkato 0:f782d9c66c49 195 * setting the icmp type to ECHO_RESPONSE and updating the checksum. */
dkato 0:f782d9c66c49 196 iecho = (struct icmp_echo_hdr *)p->payload;
dkato 0:f782d9c66c49 197 if (pbuf_header(p, (s16_t)hlen)) {
dkato 0:f782d9c66c49 198 LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Can't move over header in packet"));
dkato 0:f782d9c66c49 199 } else {
dkato 0:f782d9c66c49 200 err_t ret;
dkato 0:f782d9c66c49 201 struct ip_hdr *iphdr = (struct ip_hdr*)p->payload;
dkato 0:f782d9c66c49 202 ip4_addr_copy(iphdr->src, *src);
dkato 0:f782d9c66c49 203 ip4_addr_copy(iphdr->dest, *ip4_current_src_addr());
dkato 0:f782d9c66c49 204 ICMPH_TYPE_SET(iecho, ICMP_ER);
dkato 0:f782d9c66c49 205 #if CHECKSUM_GEN_ICMP
dkato 0:f782d9c66c49 206 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP) {
dkato 0:f782d9c66c49 207 /* adjust the checksum */
dkato 0:f782d9c66c49 208 if (iecho->chksum > PP_HTONS(0xffffU - (ICMP_ECHO << 8))) {
dkato 0:f782d9c66c49 209 iecho->chksum += PP_HTONS(ICMP_ECHO << 8) + 1;
dkato 0:f782d9c66c49 210 } else {
dkato 0:f782d9c66c49 211 iecho->chksum += PP_HTONS(ICMP_ECHO << 8);
dkato 0:f782d9c66c49 212 }
dkato 0:f782d9c66c49 213 }
dkato 0:f782d9c66c49 214 #if LWIP_CHECKSUM_CTRL_PER_NETIF
dkato 0:f782d9c66c49 215 else {
dkato 0:f782d9c66c49 216 iecho->chksum = 0;
dkato 0:f782d9c66c49 217 }
dkato 0:f782d9c66c49 218 #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
dkato 0:f782d9c66c49 219 #else /* CHECKSUM_GEN_ICMP */
dkato 0:f782d9c66c49 220 iecho->chksum = 0;
dkato 0:f782d9c66c49 221 #endif /* CHECKSUM_GEN_ICMP */
dkato 0:f782d9c66c49 222
dkato 0:f782d9c66c49 223 /* Set the correct TTL and recalculate the header checksum. */
dkato 0:f782d9c66c49 224 IPH_TTL_SET(iphdr, ICMP_TTL);
dkato 0:f782d9c66c49 225 IPH_CHKSUM_SET(iphdr, 0);
dkato 0:f782d9c66c49 226 #if CHECKSUM_GEN_IP
dkato 0:f782d9c66c49 227 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP) {
dkato 0:f782d9c66c49 228 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, hlen));
dkato 0:f782d9c66c49 229 }
dkato 0:f782d9c66c49 230 #endif /* CHECKSUM_GEN_IP */
dkato 0:f782d9c66c49 231
dkato 0:f782d9c66c49 232 ICMP_STATS_INC(icmp.xmit);
dkato 0:f782d9c66c49 233 /* increase number of messages attempted to send */
dkato 0:f782d9c66c49 234 MIB2_STATS_INC(mib2.icmpoutmsgs);
dkato 0:f782d9c66c49 235 /* increase number of echo replies attempted to send */
dkato 0:f782d9c66c49 236 MIB2_STATS_INC(mib2.icmpoutechoreps);
dkato 0:f782d9c66c49 237
dkato 0:f782d9c66c49 238 /* send an ICMP packet */
dkato 0:f782d9c66c49 239 ret = ip4_output_if(p, src, LWIP_IP_HDRINCL,
dkato 0:f782d9c66c49 240 ICMP_TTL, 0, IP_PROTO_ICMP, inp);
dkato 0:f782d9c66c49 241 if (ret != ERR_OK) {
dkato 0:f782d9c66c49 242 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %s\n", lwip_strerr(ret)));
dkato 0:f782d9c66c49 243 }
dkato 0:f782d9c66c49 244 }
dkato 0:f782d9c66c49 245 break;
dkato 0:f782d9c66c49 246 default:
dkato 0:f782d9c66c49 247 if (type == ICMP_DUR) {
dkato 0:f782d9c66c49 248 MIB2_STATS_INC(mib2.icmpindestunreachs);
dkato 0:f782d9c66c49 249 } else if (type == ICMP_TE) {
dkato 0:f782d9c66c49 250 MIB2_STATS_INC(mib2.icmpintimeexcds);
dkato 0:f782d9c66c49 251 } else if (type == ICMP_PP) {
dkato 0:f782d9c66c49 252 MIB2_STATS_INC(mib2.icmpinparmprobs);
dkato 0:f782d9c66c49 253 } else if (type == ICMP_SQ) {
dkato 0:f782d9c66c49 254 MIB2_STATS_INC(mib2.icmpinsrcquenchs);
dkato 0:f782d9c66c49 255 } else if (type == ICMP_RD) {
dkato 0:f782d9c66c49 256 MIB2_STATS_INC(mib2.icmpinredirects);
dkato 0:f782d9c66c49 257 } else if (type == ICMP_TS) {
dkato 0:f782d9c66c49 258 MIB2_STATS_INC(mib2.icmpintimestamps);
dkato 0:f782d9c66c49 259 } else if (type == ICMP_TSR) {
dkato 0:f782d9c66c49 260 MIB2_STATS_INC(mib2.icmpintimestampreps);
dkato 0:f782d9c66c49 261 } else if (type == ICMP_AM) {
dkato 0:f782d9c66c49 262 MIB2_STATS_INC(mib2.icmpinaddrmasks);
dkato 0:f782d9c66c49 263 } else if (type == ICMP_AMR) {
dkato 0:f782d9c66c49 264 MIB2_STATS_INC(mib2.icmpinaddrmaskreps);
dkato 0:f782d9c66c49 265 }
dkato 0:f782d9c66c49 266 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n",
dkato 0:f782d9c66c49 267 (s16_t)type, (s16_t)code));
dkato 0:f782d9c66c49 268 ICMP_STATS_INC(icmp.proterr);
dkato 0:f782d9c66c49 269 ICMP_STATS_INC(icmp.drop);
dkato 0:f782d9c66c49 270 }
dkato 0:f782d9c66c49 271 pbuf_free(p);
dkato 0:f782d9c66c49 272 return;
dkato 0:f782d9c66c49 273 lenerr:
dkato 0:f782d9c66c49 274 pbuf_free(p);
dkato 0:f782d9c66c49 275 ICMP_STATS_INC(icmp.lenerr);
dkato 0:f782d9c66c49 276 MIB2_STATS_INC(mib2.icmpinerrors);
dkato 0:f782d9c66c49 277 return;
dkato 0:f782d9c66c49 278 #if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING
dkato 0:f782d9c66c49 279 icmperr:
dkato 0:f782d9c66c49 280 pbuf_free(p);
dkato 0:f782d9c66c49 281 ICMP_STATS_INC(icmp.err);
dkato 0:f782d9c66c49 282 MIB2_STATS_INC(mib2.icmpinerrors);
dkato 0:f782d9c66c49 283 return;
dkato 0:f782d9c66c49 284 #endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */
dkato 0:f782d9c66c49 285 }
dkato 0:f782d9c66c49 286
dkato 0:f782d9c66c49 287 /**
dkato 0:f782d9c66c49 288 * Send an icmp 'destination unreachable' packet, called from ip_input() if
dkato 0:f782d9c66c49 289 * the transport layer protocol is unknown and from udp_input() if the local
dkato 0:f782d9c66c49 290 * port is not bound.
dkato 0:f782d9c66c49 291 *
dkato 0:f782d9c66c49 292 * @param p the input packet for which the 'unreachable' should be sent,
dkato 0:f782d9c66c49 293 * p->payload pointing to the IP header
dkato 0:f782d9c66c49 294 * @param t type of the 'unreachable' packet
dkato 0:f782d9c66c49 295 */
dkato 0:f782d9c66c49 296 void
dkato 0:f782d9c66c49 297 icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t)
dkato 0:f782d9c66c49 298 {
dkato 0:f782d9c66c49 299 MIB2_STATS_INC(mib2.icmpoutdestunreachs);
dkato 0:f782d9c66c49 300 icmp_send_response(p, ICMP_DUR, t);
dkato 0:f782d9c66c49 301 }
dkato 0:f782d9c66c49 302
dkato 0:f782d9c66c49 303 #if IP_FORWARD || IP_REASSEMBLY
dkato 0:f782d9c66c49 304 /**
dkato 0:f782d9c66c49 305 * Send a 'time exceeded' packet, called from ip_forward() if TTL is 0.
dkato 0:f782d9c66c49 306 *
dkato 0:f782d9c66c49 307 * @param p the input packet for which the 'time exceeded' should be sent,
dkato 0:f782d9c66c49 308 * p->payload pointing to the IP header
dkato 0:f782d9c66c49 309 * @param t type of the 'time exceeded' packet
dkato 0:f782d9c66c49 310 */
dkato 0:f782d9c66c49 311 void
dkato 0:f782d9c66c49 312 icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t)
dkato 0:f782d9c66c49 313 {
dkato 0:f782d9c66c49 314 MIB2_STATS_INC(mib2.icmpouttimeexcds);
dkato 0:f782d9c66c49 315 icmp_send_response(p, ICMP_TE, t);
dkato 0:f782d9c66c49 316 }
dkato 0:f782d9c66c49 317
dkato 0:f782d9c66c49 318 #endif /* IP_FORWARD || IP_REASSEMBLY */
dkato 0:f782d9c66c49 319
dkato 0:f782d9c66c49 320 /**
dkato 0:f782d9c66c49 321 * Send an icmp packet in response to an incoming packet.
dkato 0:f782d9c66c49 322 *
dkato 0:f782d9c66c49 323 * @param p the input packet for which the 'unreachable' should be sent,
dkato 0:f782d9c66c49 324 * p->payload pointing to the IP header
dkato 0:f782d9c66c49 325 * @param type Type of the ICMP header
dkato 0:f782d9c66c49 326 * @param code Code of the ICMP header
dkato 0:f782d9c66c49 327 */
dkato 0:f782d9c66c49 328 static void
dkato 0:f782d9c66c49 329 icmp_send_response(struct pbuf *p, u8_t type, u8_t code)
dkato 0:f782d9c66c49 330 {
dkato 0:f782d9c66c49 331 struct pbuf *q;
dkato 0:f782d9c66c49 332 struct ip_hdr *iphdr;
dkato 0:f782d9c66c49 333 /* we can use the echo header here */
dkato 0:f782d9c66c49 334 struct icmp_echo_hdr *icmphdr;
dkato 0:f782d9c66c49 335 ip4_addr_t iphdr_src;
dkato 0:f782d9c66c49 336 struct netif *netif;
dkato 0:f782d9c66c49 337
dkato 0:f782d9c66c49 338 /* increase number of messages attempted to send */
dkato 0:f782d9c66c49 339 MIB2_STATS_INC(mib2.icmpoutmsgs);
dkato 0:f782d9c66c49 340
dkato 0:f782d9c66c49 341 /* ICMP header + IP header + 8 bytes of data */
dkato 0:f782d9c66c49 342 q = pbuf_alloc(PBUF_IP, sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE,
dkato 0:f782d9c66c49 343 PBUF_RAM);
dkato 0:f782d9c66c49 344 if (q == NULL) {
dkato 0:f782d9c66c49 345 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMP packet.\n"));
dkato 0:f782d9c66c49 346 MIB2_STATS_INC(mib2.icmpouterrors);
dkato 0:f782d9c66c49 347 return;
dkato 0:f782d9c66c49 348 }
dkato 0:f782d9c66c49 349 LWIP_ASSERT("check that first pbuf can hold icmp message",
dkato 0:f782d9c66c49 350 (q->len >= (sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE)));
dkato 0:f782d9c66c49 351
dkato 0:f782d9c66c49 352 iphdr = (struct ip_hdr *)p->payload;
dkato 0:f782d9c66c49 353 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded from "));
dkato 0:f782d9c66c49 354 ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->src);
dkato 0:f782d9c66c49 355 LWIP_DEBUGF(ICMP_DEBUG, (" to "));
dkato 0:f782d9c66c49 356 ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->dest);
dkato 0:f782d9c66c49 357 LWIP_DEBUGF(ICMP_DEBUG, ("\n"));
dkato 0:f782d9c66c49 358
dkato 0:f782d9c66c49 359 icmphdr = (struct icmp_echo_hdr *)q->payload;
dkato 0:f782d9c66c49 360 icmphdr->type = type;
dkato 0:f782d9c66c49 361 icmphdr->code = code;
dkato 0:f782d9c66c49 362 icmphdr->id = 0;
dkato 0:f782d9c66c49 363 icmphdr->seqno = 0;
dkato 0:f782d9c66c49 364
dkato 0:f782d9c66c49 365 /* copy fields from original packet */
dkato 0:f782d9c66c49 366 SMEMCPY((u8_t *)q->payload + sizeof(struct icmp_echo_hdr), (u8_t *)p->payload,
dkato 0:f782d9c66c49 367 IP_HLEN + ICMP_DEST_UNREACH_DATASIZE);
dkato 0:f782d9c66c49 368
dkato 0:f782d9c66c49 369 ip4_addr_copy(iphdr_src, iphdr->src);
dkato 0:f782d9c66c49 370 #ifdef LWIP_HOOK_IP4_ROUTE_SRC
dkato 0:f782d9c66c49 371 {
dkato 0:f782d9c66c49 372 ip4_addr_t iphdr_dst;
dkato 0:f782d9c66c49 373 ip4_addr_copy(iphdr_dst, iphdr->dest);
dkato 0:f782d9c66c49 374 netif = ip4_route_src(&iphdr_src, &iphdr_dst);
dkato 0:f782d9c66c49 375 }
dkato 0:f782d9c66c49 376 #else
dkato 0:f782d9c66c49 377 netif = ip4_route(&iphdr_src);
dkato 0:f782d9c66c49 378 #endif
dkato 0:f782d9c66c49 379 if (netif != NULL) {
dkato 0:f782d9c66c49 380 /* calculate checksum */
dkato 0:f782d9c66c49 381 icmphdr->chksum = 0;
dkato 0:f782d9c66c49 382 #if CHECKSUM_GEN_ICMP
dkato 0:f782d9c66c49 383 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP) {
dkato 0:f782d9c66c49 384 icmphdr->chksum = inet_chksum(icmphdr, q->len);
dkato 0:f782d9c66c49 385 }
dkato 0:f782d9c66c49 386 #endif
dkato 0:f782d9c66c49 387 ICMP_STATS_INC(icmp.xmit);
dkato 0:f782d9c66c49 388 ip4_output_if(q, NULL, &iphdr_src, ICMP_TTL, 0, IP_PROTO_ICMP, netif);
dkato 0:f782d9c66c49 389 }
dkato 0:f782d9c66c49 390 pbuf_free(q);
dkato 0:f782d9c66c49 391 }
dkato 0:f782d9c66c49 392
dkato 0:f782d9c66c49 393 #endif /* LWIP_IPV4 && LWIP_ICMP */