[457] | 1 | /**
|
---|
| 2 | * @file
|
---|
| 3 | * ICMP - Internet Control Message Protocol
|
---|
| 4 | *
|
---|
| 5 | */
|
---|
| 6 |
|
---|
| 7 | /*
|
---|
| 8 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
|
---|
| 9 | * All rights reserved.
|
---|
| 10 | *
|
---|
| 11 | * Redistribution and use in source and binary forms, with or without modification,
|
---|
| 12 | * are permitted provided that the following conditions are met:
|
---|
| 13 | *
|
---|
| 14 | * 1. Redistributions of source code must retain the above copyright notice,
|
---|
| 15 | * this list of conditions and the following disclaimer.
|
---|
| 16 | * 2. Redistributions in binary form must reproduce the above copyright notice,
|
---|
| 17 | * this list of conditions and the following disclaimer in the documentation
|
---|
| 18 | * and/or other materials provided with the distribution.
|
---|
| 19 | * 3. The name of the author may not be used to endorse or promote products
|
---|
| 20 | * derived from this software without specific prior written permission.
|
---|
| 21 | *
|
---|
| 22 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
---|
| 23 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
---|
| 24 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
|
---|
| 25 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
---|
| 26 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
---|
| 27 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
---|
| 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
---|
| 29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
---|
| 30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
|
---|
| 31 | * OF SUCH DAMAGE.
|
---|
| 32 | *
|
---|
| 33 | * This file is part of the lwIP TCP/IP stack.
|
---|
| 34 | *
|
---|
| 35 | * Author: Adam Dunkels <adam@sics.se>
|
---|
| 36 | *
|
---|
| 37 | */
|
---|
| 38 |
|
---|
| 39 | /* Some ICMP messages should be passed to the transport protocols. This
|
---|
| 40 | is not implemented. */
|
---|
| 41 |
|
---|
| 42 | #include "lwip/opt.h"
|
---|
| 43 |
|
---|
| 44 | #if LWIP_IPV4 && LWIP_ICMP /* don't build if not configured for use in lwipopts.h */
|
---|
| 45 |
|
---|
| 46 | #include "lwip/icmp.h"
|
---|
| 47 | #include "lwip/inet_chksum.h"
|
---|
| 48 | #include "lwip/ip.h"
|
---|
| 49 | #include "lwip/def.h"
|
---|
| 50 | #include "lwip/stats.h"
|
---|
| 51 |
|
---|
| 52 | #include <string.h>
|
---|
| 53 |
|
---|
| 54 | #ifdef LWIP_HOOK_FILENAME
|
---|
| 55 | #include LWIP_HOOK_FILENAME
|
---|
| 56 | #endif
|
---|
| 57 |
|
---|
| 58 | /** Small optimization: set to 0 if incoming PBUF_POOL pbuf always can be
|
---|
| 59 | * used to modify and send a response packet (and to 1 if this is not the case,
|
---|
| 60 | * e.g. when link header is stripped off when receiving) */
|
---|
| 61 | #ifndef LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
|
---|
| 62 | #define LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN 1
|
---|
| 63 | #endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
|
---|
| 64 |
|
---|
| 65 | /* The amount of data from the original packet to return in a dest-unreachable */
|
---|
| 66 | #define ICMP_DEST_UNREACH_DATASIZE 8
|
---|
| 67 |
|
---|
| 68 | static void icmp_send_response(struct pbuf *p, u8_t type, u8_t code);
|
---|
| 69 |
|
---|
| 70 | /**
|
---|
| 71 | * Processes ICMP input packets, called from ip_input().
|
---|
| 72 | *
|
---|
| 73 | * Currently only processes icmp echo requests and sends
|
---|
| 74 | * out the echo response.
|
---|
| 75 | *
|
---|
| 76 | * @param p the icmp echo request packet, p->payload pointing to the icmp header
|
---|
| 77 | * @param inp the netif on which this packet was received
|
---|
| 78 | */
|
---|
| 79 | void
|
---|
| 80 | icmp_input(struct pbuf *p, struct netif *inp)
|
---|
| 81 | {
|
---|
| 82 | u8_t type;
|
---|
| 83 | #ifdef LWIP_DEBUG
|
---|
| 84 | u8_t code;
|
---|
| 85 | #endif /* LWIP_DEBUG */
|
---|
| 86 | struct icmp_echo_hdr *iecho;
|
---|
| 87 | const struct ip_hdr *iphdr_in;
|
---|
| 88 | u16_t hlen;
|
---|
| 89 | const ip4_addr_t *src;
|
---|
| 90 |
|
---|
| 91 | ICMP_STATS_INC(icmp.recv);
|
---|
| 92 | MIB2_STATS_INC(mib2.icmpinmsgs);
|
---|
| 93 |
|
---|
| 94 | iphdr_in = ip4_current_header();
|
---|
| 95 | hlen = IPH_HL_BYTES(iphdr_in);
|
---|
| 96 | if (hlen < IP_HLEN) {
|
---|
| 97 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short IP header (%"S16_F" bytes) received\n", hlen));
|
---|
| 98 | goto lenerr;
|
---|
| 99 | }
|
---|
| 100 | if (p->len < sizeof(u16_t) * 2) {
|
---|
| 101 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len));
|
---|
| 102 | goto lenerr;
|
---|
| 103 | }
|
---|
| 104 |
|
---|
| 105 | type = *((u8_t *)p->payload);
|
---|
| 106 | #ifdef LWIP_DEBUG
|
---|
| 107 | code = *(((u8_t *)p->payload) + 1);
|
---|
| 108 | /* if debug is enabled but debug statement below is somehow disabled: */
|
---|
| 109 | LWIP_UNUSED_ARG(code);
|
---|
| 110 | #endif /* LWIP_DEBUG */
|
---|
| 111 | switch (type) {
|
---|
| 112 | case ICMP_ER:
|
---|
| 113 | /* This is OK, echo reply might have been parsed by a raw PCB
|
---|
| 114 | (as obviously, an echo request has been sent, too). */
|
---|
| 115 | MIB2_STATS_INC(mib2.icmpinechoreps);
|
---|
| 116 | break;
|
---|
| 117 | case ICMP_ECHO:
|
---|
| 118 | MIB2_STATS_INC(mib2.icmpinechos);
|
---|
| 119 | src = ip4_current_dest_addr();
|
---|
| 120 | /* multicast destination address? */
|
---|
| 121 | if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
|
---|
| 122 | #if LWIP_MULTICAST_PING
|
---|
| 123 | /* For multicast, use address of receiving interface as source address */
|
---|
| 124 | src = netif_ip4_addr(inp);
|
---|
| 125 | #else /* LWIP_MULTICAST_PING */
|
---|
| 126 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast pings\n"));
|
---|
| 127 | goto icmperr;
|
---|
| 128 | #endif /* LWIP_MULTICAST_PING */
|
---|
| 129 | }
|
---|
| 130 | /* broadcast destination address? */
|
---|
| 131 | if (ip4_addr_isbroadcast(ip4_current_dest_addr(), ip_current_netif())) {
|
---|
| 132 | #if LWIP_BROADCAST_PING
|
---|
| 133 | /* For broadcast, use address of receiving interface as source address */
|
---|
| 134 | src = netif_ip4_addr(inp);
|
---|
| 135 | #else /* LWIP_BROADCAST_PING */
|
---|
| 136 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to broadcast pings\n"));
|
---|
| 137 | goto icmperr;
|
---|
| 138 | #endif /* LWIP_BROADCAST_PING */
|
---|
| 139 | }
|
---|
| 140 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
|
---|
| 141 | if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
|
---|
| 142 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
|
---|
| 143 | goto lenerr;
|
---|
| 144 | }
|
---|
| 145 | #if CHECKSUM_CHECK_ICMP
|
---|
| 146 | IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP) {
|
---|
| 147 | if (inet_chksum_pbuf(p) != 0) {
|
---|
| 148 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
|
---|
| 149 | pbuf_free(p);
|
---|
| 150 | ICMP_STATS_INC(icmp.chkerr);
|
---|
| 151 | MIB2_STATS_INC(mib2.icmpinerrors);
|
---|
| 152 | return;
|
---|
| 153 | }
|
---|
| 154 | }
|
---|
| 155 | #endif
|
---|
| 156 | #if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
|
---|
| 157 | if (pbuf_add_header(p, hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN)) {
|
---|
| 158 | /* p is not big enough to contain link headers
|
---|
| 159 | * allocate a new one and copy p into it
|
---|
| 160 | */
|
---|
| 161 | struct pbuf *r;
|
---|
| 162 | u16_t alloc_len = (u16_t)(p->tot_len + hlen);
|
---|
| 163 | if (alloc_len < p->tot_len) {
|
---|
| 164 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed (tot_len overflow)\n"));
|
---|
| 165 | goto icmperr;
|
---|
| 166 | }
|
---|
| 167 | /* allocate new packet buffer with space for link headers */
|
---|
| 168 | r = pbuf_alloc(PBUF_LINK, alloc_len, PBUF_RAM);
|
---|
| 169 | if (r == NULL) {
|
---|
| 170 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
|
---|
| 171 | goto icmperr;
|
---|
| 172 | }
|
---|
| 173 | if (r->len < hlen + sizeof(struct icmp_echo_hdr)) {
|
---|
| 174 | LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("first pbuf cannot hold the ICMP header"));
|
---|
| 175 | pbuf_free(r);
|
---|
| 176 | goto icmperr;
|
---|
| 177 | }
|
---|
| 178 | /* copy the ip header */
|
---|
| 179 | MEMCPY(r->payload, iphdr_in, hlen);
|
---|
| 180 | /* switch r->payload back to icmp header (cannot fail) */
|
---|
| 181 | if (pbuf_remove_header(r, hlen)) {
|
---|
| 182 | LWIP_ASSERT("icmp_input: moving r->payload to icmp header failed\n", 0);
|
---|
| 183 | pbuf_free(r);
|
---|
| 184 | goto icmperr;
|
---|
| 185 | }
|
---|
| 186 | /* copy the rest of the packet without ip header */
|
---|
| 187 | if (pbuf_copy(r, p) != ERR_OK) {
|
---|
| 188 | LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("icmp_input: copying to new pbuf failed"));
|
---|
| 189 | pbuf_free(r);
|
---|
| 190 | goto icmperr;
|
---|
| 191 | }
|
---|
| 192 | /* free the original p */
|
---|
| 193 | pbuf_free(p);
|
---|
| 194 | /* we now have an identical copy of p that has room for link headers */
|
---|
| 195 | p = r;
|
---|
| 196 | } else {
|
---|
| 197 | /* restore p->payload to point to icmp header (cannot fail) */
|
---|
| 198 | if (pbuf_remove_header(p, hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN)) {
|
---|
| 199 | LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
|
---|
| 200 | goto icmperr;
|
---|
| 201 | }
|
---|
| 202 | }
|
---|
| 203 | #endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
|
---|
| 204 | /* At this point, all checks are OK. */
|
---|
| 205 | /* We generate an answer by switching the dest and src ip addresses,
|
---|
| 206 | * setting the icmp type to ECHO_RESPONSE and updating the checksum. */
|
---|
| 207 | iecho = (struct icmp_echo_hdr *)p->payload;
|
---|
| 208 | if (pbuf_add_header(p, hlen)) {
|
---|
| 209 | LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Can't move over header in packet"));
|
---|
| 210 | } else {
|
---|
| 211 | err_t ret;
|
---|
| 212 | struct ip_hdr *iphdr = (struct ip_hdr *)p->payload;
|
---|
| 213 | ip4_addr_copy(iphdr->src, *src);
|
---|
| 214 | ip4_addr_copy(iphdr->dest, *ip4_current_src_addr());
|
---|
| 215 | ICMPH_TYPE_SET(iecho, ICMP_ER);
|
---|
| 216 | #if CHECKSUM_GEN_ICMP
|
---|
| 217 | IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP) {
|
---|
| 218 | /* adjust the checksum */
|
---|
| 219 | if (iecho->chksum > PP_HTONS(0xffffU - (ICMP_ECHO << 8))) {
|
---|
| 220 | iecho->chksum = (u16_t)(iecho->chksum + PP_HTONS((u16_t)(ICMP_ECHO << 8)) + 1);
|
---|
| 221 | } else {
|
---|
| 222 | iecho->chksum = (u16_t)(iecho->chksum + PP_HTONS(ICMP_ECHO << 8));
|
---|
| 223 | }
|
---|
| 224 | }
|
---|
| 225 | #if LWIP_CHECKSUM_CTRL_PER_NETIF
|
---|
| 226 | else {
|
---|
| 227 | iecho->chksum = 0;
|
---|
| 228 | }
|
---|
| 229 | #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
|
---|
| 230 | #else /* CHECKSUM_GEN_ICMP */
|
---|
| 231 | iecho->chksum = 0;
|
---|
| 232 | #endif /* CHECKSUM_GEN_ICMP */
|
---|
| 233 |
|
---|
| 234 | /* Set the correct TTL and recalculate the header checksum. */
|
---|
| 235 | IPH_TTL_SET(iphdr, ICMP_TTL);
|
---|
| 236 | IPH_CHKSUM_SET(iphdr, 0);
|
---|
| 237 | #if CHECKSUM_GEN_IP
|
---|
| 238 | IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP) {
|
---|
| 239 | IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, hlen));
|
---|
| 240 | }
|
---|
| 241 | #endif /* CHECKSUM_GEN_IP */
|
---|
| 242 |
|
---|
| 243 | ICMP_STATS_INC(icmp.xmit);
|
---|
| 244 | /* increase number of messages attempted to send */
|
---|
| 245 | MIB2_STATS_INC(mib2.icmpoutmsgs);
|
---|
| 246 | /* increase number of echo replies attempted to send */
|
---|
| 247 | MIB2_STATS_INC(mib2.icmpoutechoreps);
|
---|
| 248 |
|
---|
| 249 | /* send an ICMP packet */
|
---|
| 250 | ret = ip4_output_if(p, src, LWIP_IP_HDRINCL,
|
---|
| 251 | ICMP_TTL, 0, IP_PROTO_ICMP, inp);
|
---|
| 252 | if (ret != ERR_OK) {
|
---|
| 253 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %s\n", lwip_strerr(ret)));
|
---|
| 254 | }
|
---|
| 255 | }
|
---|
| 256 | break;
|
---|
| 257 | default:
|
---|
| 258 | if (type == ICMP_DUR) {
|
---|
| 259 | MIB2_STATS_INC(mib2.icmpindestunreachs);
|
---|
| 260 | } else if (type == ICMP_TE) {
|
---|
| 261 | MIB2_STATS_INC(mib2.icmpintimeexcds);
|
---|
| 262 | } else if (type == ICMP_PP) {
|
---|
| 263 | MIB2_STATS_INC(mib2.icmpinparmprobs);
|
---|
| 264 | } else if (type == ICMP_SQ) {
|
---|
| 265 | MIB2_STATS_INC(mib2.icmpinsrcquenchs);
|
---|
| 266 | } else if (type == ICMP_RD) {
|
---|
| 267 | MIB2_STATS_INC(mib2.icmpinredirects);
|
---|
| 268 | } else if (type == ICMP_TS) {
|
---|
| 269 | MIB2_STATS_INC(mib2.icmpintimestamps);
|
---|
| 270 | } else if (type == ICMP_TSR) {
|
---|
| 271 | MIB2_STATS_INC(mib2.icmpintimestampreps);
|
---|
| 272 | } else if (type == ICMP_AM) {
|
---|
| 273 | MIB2_STATS_INC(mib2.icmpinaddrmasks);
|
---|
| 274 | } else if (type == ICMP_AMR) {
|
---|
| 275 | MIB2_STATS_INC(mib2.icmpinaddrmaskreps);
|
---|
| 276 | }
|
---|
| 277 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n",
|
---|
| 278 | (s16_t)type, (s16_t)code));
|
---|
| 279 | ICMP_STATS_INC(icmp.proterr);
|
---|
| 280 | ICMP_STATS_INC(icmp.drop);
|
---|
| 281 | }
|
---|
| 282 | pbuf_free(p);
|
---|
| 283 | return;
|
---|
| 284 | lenerr:
|
---|
| 285 | pbuf_free(p);
|
---|
| 286 | ICMP_STATS_INC(icmp.lenerr);
|
---|
| 287 | MIB2_STATS_INC(mib2.icmpinerrors);
|
---|
| 288 | return;
|
---|
| 289 | #if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING
|
---|
| 290 | icmperr:
|
---|
| 291 | pbuf_free(p);
|
---|
| 292 | ICMP_STATS_INC(icmp.err);
|
---|
| 293 | MIB2_STATS_INC(mib2.icmpinerrors);
|
---|
| 294 | return;
|
---|
| 295 | #endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */
|
---|
| 296 | }
|
---|
| 297 |
|
---|
| 298 | /**
|
---|
| 299 | * Send an icmp 'destination unreachable' packet, called from ip_input() if
|
---|
| 300 | * the transport layer protocol is unknown and from udp_input() if the local
|
---|
| 301 | * port is not bound.
|
---|
| 302 | *
|
---|
| 303 | * @param p the input packet for which the 'unreachable' should be sent,
|
---|
| 304 | * p->payload pointing to the IP header
|
---|
| 305 | * @param t type of the 'unreachable' packet
|
---|
| 306 | */
|
---|
| 307 | void
|
---|
| 308 | icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t)
|
---|
| 309 | {
|
---|
| 310 | MIB2_STATS_INC(mib2.icmpoutdestunreachs);
|
---|
| 311 | icmp_send_response(p, ICMP_DUR, t);
|
---|
| 312 | }
|
---|
| 313 |
|
---|
| 314 | #if IP_FORWARD || IP_REASSEMBLY
|
---|
| 315 | /**
|
---|
| 316 | * Send a 'time exceeded' packet, called from ip_forward() if TTL is 0.
|
---|
| 317 | *
|
---|
| 318 | * @param p the input packet for which the 'time exceeded' should be sent,
|
---|
| 319 | * p->payload pointing to the IP header
|
---|
| 320 | * @param t type of the 'time exceeded' packet
|
---|
| 321 | */
|
---|
| 322 | void
|
---|
| 323 | icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t)
|
---|
| 324 | {
|
---|
| 325 | MIB2_STATS_INC(mib2.icmpouttimeexcds);
|
---|
| 326 | icmp_send_response(p, ICMP_TE, t);
|
---|
| 327 | }
|
---|
| 328 |
|
---|
| 329 | #endif /* IP_FORWARD || IP_REASSEMBLY */
|
---|
| 330 |
|
---|
| 331 | /**
|
---|
| 332 | * Send an icmp packet in response to an incoming packet.
|
---|
| 333 | *
|
---|
| 334 | * @param p the input packet for which the 'unreachable' should be sent,
|
---|
| 335 | * p->payload pointing to the IP header
|
---|
| 336 | * @param type Type of the ICMP header
|
---|
| 337 | * @param code Code of the ICMP header
|
---|
| 338 | */
|
---|
| 339 | static void
|
---|
| 340 | icmp_send_response(struct pbuf *p, u8_t type, u8_t code)
|
---|
| 341 | {
|
---|
| 342 | struct pbuf *q;
|
---|
| 343 | struct ip_hdr *iphdr;
|
---|
| 344 | /* we can use the echo header here */
|
---|
| 345 | struct icmp_echo_hdr *icmphdr;
|
---|
| 346 | ip4_addr_t iphdr_src;
|
---|
| 347 | struct netif *netif;
|
---|
| 348 |
|
---|
| 349 | /* increase number of messages attempted to send */
|
---|
| 350 | MIB2_STATS_INC(mib2.icmpoutmsgs);
|
---|
| 351 |
|
---|
| 352 | /* ICMP header + IP header + 8 bytes of data */
|
---|
| 353 | q = pbuf_alloc(PBUF_IP, sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE,
|
---|
| 354 | PBUF_RAM);
|
---|
| 355 | if (q == NULL) {
|
---|
| 356 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMP packet.\n"));
|
---|
| 357 | MIB2_STATS_INC(mib2.icmpouterrors);
|
---|
| 358 | return;
|
---|
| 359 | }
|
---|
| 360 | LWIP_ASSERT("check that first pbuf can hold icmp message",
|
---|
| 361 | (q->len >= (sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE)));
|
---|
| 362 |
|
---|
| 363 | iphdr = (struct ip_hdr *)p->payload;
|
---|
| 364 | LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded from "));
|
---|
| 365 | ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->src);
|
---|
| 366 | LWIP_DEBUGF(ICMP_DEBUG, (" to "));
|
---|
| 367 | ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->dest);
|
---|
| 368 | LWIP_DEBUGF(ICMP_DEBUG, ("\n"));
|
---|
| 369 |
|
---|
| 370 | icmphdr = (struct icmp_echo_hdr *)q->payload;
|
---|
| 371 | icmphdr->type = type;
|
---|
| 372 | icmphdr->code = code;
|
---|
| 373 | icmphdr->id = 0;
|
---|
| 374 | icmphdr->seqno = 0;
|
---|
| 375 |
|
---|
| 376 | /* copy fields from original packet */
|
---|
| 377 | SMEMCPY((u8_t *)q->payload + sizeof(struct icmp_echo_hdr), (u8_t *)p->payload,
|
---|
| 378 | IP_HLEN + ICMP_DEST_UNREACH_DATASIZE);
|
---|
| 379 |
|
---|
| 380 | ip4_addr_copy(iphdr_src, iphdr->src);
|
---|
| 381 | #ifdef LWIP_HOOK_IP4_ROUTE_SRC
|
---|
| 382 | {
|
---|
| 383 | ip4_addr_t iphdr_dst;
|
---|
| 384 | ip4_addr_copy(iphdr_dst, iphdr->dest);
|
---|
| 385 | netif = ip4_route_src(&iphdr_dst, &iphdr_src);
|
---|
| 386 | }
|
---|
| 387 | #else
|
---|
| 388 | netif = ip4_route(&iphdr_src);
|
---|
| 389 | #endif
|
---|
| 390 | if (netif != NULL) {
|
---|
| 391 | /* calculate checksum */
|
---|
| 392 | icmphdr->chksum = 0;
|
---|
| 393 | #if CHECKSUM_GEN_ICMP
|
---|
| 394 | IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP) {
|
---|
| 395 | icmphdr->chksum = inet_chksum(icmphdr, q->len);
|
---|
| 396 | }
|
---|
| 397 | #endif
|
---|
| 398 | ICMP_STATS_INC(icmp.xmit);
|
---|
| 399 | ip4_output_if(q, NULL, &iphdr_src, ICMP_TTL, 0, IP_PROTO_ICMP, netif);
|
---|
| 400 | }
|
---|
| 401 | pbuf_free(q);
|
---|
| 402 | }
|
---|
| 403 |
|
---|
| 404 | #endif /* LWIP_IPV4 && LWIP_ICMP */
|
---|