UbixOS V2 2.0

icmp.c
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1
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 "net/opt.h"
43
44 #if LWIP_IPV4 && LWIP_ICMP /* don't build if not configured for use in lwipopts.h */
45
46 #include "net/icmp.h"
47 #include "net/inet_chksum.h"
48 #include "net/ip.h"
49 #include "net/def.h"
50 #include "net/stats.h"
51
52 #include <string.h>
53
54 #ifdef LWIP_HOOK_FILENAME
55 #include LWIP_HOOK_FILENAME
56 #endif
57
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
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(iphdr_in) * 4;
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 #endif /* LWIP_DEBUG */
109 switch (type) {
110 case ICMP_ER:
111 /* This is OK, echo reply might have been parsed by a raw PCB
112 (as obviously, an echo request has been sent, too). */
113 MIB2_STATS_INC(mib2.icmpinechoreps);
114 break;
115 case ICMP_ECHO:
116 MIB2_STATS_INC(mib2.icmpinechos);
117 src = ip4_current_dest_addr();
118 /* multicast destination address? */
119 if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
120 #if LWIP_MULTICAST_PING
121 /* For multicast, use address of receiving interface as source address */
122 src = netif_ip4_addr(inp);
123 #else /* LWIP_MULTICAST_PING */
124 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast pings\n"));
125 goto icmperr;
126 #endif /* LWIP_MULTICAST_PING */
127 }
128 /* broadcast destination address? */
129 if (ip4_addr_isbroadcast(ip4_current_dest_addr(), ip_current_netif())) {
130 #if LWIP_BROADCAST_PING
131 /* For broadcast, use address of receiving interface as source address */
132 src = netif_ip4_addr(inp);
133 #else /* LWIP_BROADCAST_PING */
134 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to broadcast pings\n"));
135 goto icmperr;
136 #endif /* LWIP_BROADCAST_PING */
137 }
138 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
139 if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
140 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
141 goto lenerr;
142 }
143 #if CHECKSUM_CHECK_ICMP
144 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP) {
145 if (inet_chksum_pbuf(p) != 0) {
146 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
147 pbuf_free(p);
148 ICMP_STATS_INC(icmp.chkerr);
149 MIB2_STATS_INC(mib2.icmpinerrors);
150 return;
151 }
152 }
153 #endif
154 #if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
155 if (pbuf_header(p, (s16_t)(hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
156 /* p is not big enough to contain link headers
157 * allocate a new one and copy p into it
158 */
159 struct pbuf *r;
160 /* allocate new packet buffer with space for link headers */
161 r = pbuf_alloc(PBUF_LINK, p->tot_len + hlen, PBUF_RAM);
162 if (r == NULL) {
163 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
164 goto icmperr;
165 }
166 if (r->len < hlen + sizeof(struct icmp_echo_hdr)) {
167 LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("first pbuf cannot hold the ICMP header"));
168 pbuf_free(r);
169 goto icmperr;
170 }
171 /* copy the ip header */
172 MEMCPY(r->payload, iphdr_in, hlen);
173 /* switch r->payload back to icmp header (cannot fail) */
174 if (pbuf_header(r, (s16_t)-hlen)) {
175 LWIP_ASSERT("icmp_input: moving r->payload to icmp header failed\n", 0);
176 pbuf_free(r);
177 goto icmperr;
178 }
179 /* copy the rest of the packet without ip header */
180 if (pbuf_copy(r, p) != ERR_OK) {
181 LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("icmp_input: copying to new pbuf failed"));
182 pbuf_free(r);
183 goto icmperr;
184 }
185 /* free the original p */
186 pbuf_free(p);
187 /* we now have an identical copy of p that has room for link headers */
188 p = r;
189 } else {
190 /* restore p->payload to point to icmp header (cannot fail) */
191 if (pbuf_header(p, -(s16_t)(hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
192 LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
193 goto icmperr;
194 }
195 }
196 #endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
197 /* At this point, all checks are OK. */
198 /* We generate an answer by switching the dest and src ip addresses,
199 * setting the icmp type to ECHO_RESPONSE and updating the checksum. */
200 iecho = (struct icmp_echo_hdr *)p->payload;
201 if (pbuf_header(p, (s16_t)hlen)) {
202 LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Can't move over header in packet"));
203 } else {
204 err_t ret;
205 struct ip_hdr *iphdr = (struct ip_hdr*)p->payload;
206 ip4_addr_copy(iphdr->src, *src);
207 ip4_addr_copy(iphdr->dest, *ip4_current_src_addr());
208 ICMPH_TYPE_SET(iecho, ICMP_ER);
209 #if CHECKSUM_GEN_ICMP
210 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP) {
211 /* adjust the checksum */
212 if (iecho->chksum > PP_HTONS(0xffffU - (ICMP_ECHO << 8))) {
213 iecho->chksum += PP_HTONS(ICMP_ECHO << 8) + 1;
214 } else {
215 iecho->chksum += PP_HTONS(ICMP_ECHO << 8);
216 }
217 }
218 #if LWIP_CHECKSUM_CTRL_PER_NETIF
219 else {
220 iecho->chksum = 0;
221 }
222 #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
223 #else /* CHECKSUM_GEN_ICMP */
224 iecho->chksum = 0;
225 #endif /* CHECKSUM_GEN_ICMP */
226
227 /* Set the correct TTL and recalculate the header checksum. */
228 IPH_TTL_SET(iphdr, ICMP_TTL);
229 IPH_CHKSUM_SET(iphdr, 0);
230 #if CHECKSUM_GEN_IP
231 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP) {
232 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, hlen));
233 }
234 #endif /* CHECKSUM_GEN_IP */
235
236 ICMP_STATS_INC(icmp.xmit);
237 /* increase number of messages attempted to send */
238 MIB2_STATS_INC(mib2.icmpoutmsgs);
239 /* increase number of echo replies attempted to send */
240 MIB2_STATS_INC(mib2.icmpoutechoreps);
241
242 /* send an ICMP packet */
243 ret = ip4_output_if(p, src, LWIP_IP_HDRINCL,
244 ICMP_TTL, 0, IP_PROTO_ICMP, inp);
245 if (ret != ERR_OK) {
246 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %s\n", lwip_strerr(ret)));
247 }
248 }
249 break;
250 default:
251 if (type == ICMP_DUR) {
252 MIB2_STATS_INC(mib2.icmpindestunreachs);
253 } else if (type == ICMP_TE) {
254 MIB2_STATS_INC(mib2.icmpintimeexcds);
255 } else if (type == ICMP_PP) {
256 MIB2_STATS_INC(mib2.icmpinparmprobs);
257 } else if (type == ICMP_SQ) {
258 MIB2_STATS_INC(mib2.icmpinsrcquenchs);
259 } else if (type == ICMP_RD) {
260 MIB2_STATS_INC(mib2.icmpinredirects);
261 } else if (type == ICMP_TS) {
262 MIB2_STATS_INC(mib2.icmpintimestamps);
263 } else if (type == ICMP_TSR) {
264 MIB2_STATS_INC(mib2.icmpintimestampreps);
265 } else if (type == ICMP_AM) {
266 MIB2_STATS_INC(mib2.icmpinaddrmasks);
267 } else if (type == ICMP_AMR) {
268 MIB2_STATS_INC(mib2.icmpinaddrmaskreps);
269 }
270 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n",
271 (s16_t)type, (s16_t)code));
272 ICMP_STATS_INC(icmp.proterr);
273 ICMP_STATS_INC(icmp.drop);
274 }
275 pbuf_free(p);
276 return;
277 lenerr:
278 pbuf_free(p);
279 ICMP_STATS_INC(icmp.lenerr);
280 MIB2_STATS_INC(mib2.icmpinerrors);
281 return;
282 #if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING
283 icmperr:
284 pbuf_free(p);
285 ICMP_STATS_INC(icmp.err);
286 MIB2_STATS_INC(mib2.icmpinerrors);
287 return;
288 #endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */
289 }
290
300 void
301 icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t)
302 {
303 MIB2_STATS_INC(mib2.icmpoutdestunreachs);
304 icmp_send_response(p, ICMP_DUR, t);
305 }
306
307 #if IP_FORWARD || IP_REASSEMBLY
308
315 void
316 icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t)
317 {
318 MIB2_STATS_INC(mib2.icmpouttimeexcds);
319 icmp_send_response(p, ICMP_TE, t);
320 }
321
322 #endif /* IP_FORWARD || IP_REASSEMBLY */
323
332 static void
333 icmp_send_response(struct pbuf *p, u8_t type, u8_t code)
334 {
335 struct pbuf *q;
336 struct ip_hdr *iphdr;
337 /* we can use the echo header here */
338 struct icmp_echo_hdr *icmphdr;
339 ip4_addr_t iphdr_src;
340 struct netif *netif;
341
342 /* increase number of messages attempted to send */
343 MIB2_STATS_INC(mib2.icmpoutmsgs);
344
345 /* ICMP header + IP header + 8 bytes of data */
346 q = pbuf_alloc(PBUF_IP, sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE,
347 PBUF_RAM);
348 if (q == NULL) {
349 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMP packet.\n"));
350 MIB2_STATS_INC(mib2.icmpouterrors);
351 return;
352 }
353 LWIP_ASSERT("check that first pbuf can hold icmp message",
354 (q->len >= (sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE)));
355
356 iphdr = (struct ip_hdr *)p->payload;
357 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded from "));
358 ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->src);
359 LWIP_DEBUGF(ICMP_DEBUG, (" to "));
360 ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->dest);
361 LWIP_DEBUGF(ICMP_DEBUG, ("\n"));
362
363 icmphdr = (struct icmp_echo_hdr *)q->payload;
364 icmphdr->type = type;
365 icmphdr->code = code;
366 icmphdr->id = 0;
367 icmphdr->seqno = 0;
368
369 /* copy fields from original packet */
370 SMEMCPY((u8_t *)q->payload + sizeof(struct icmp_echo_hdr), (u8_t *)p->payload,
371 IP_HLEN + ICMP_DEST_UNREACH_DATASIZE);
372
373 ip4_addr_copy(iphdr_src, iphdr->src);
374 #ifdef LWIP_HOOK_IP4_ROUTE_SRC
375 {
376 ip4_addr_t iphdr_dst;
377 ip4_addr_copy(iphdr_dst, iphdr->dest);
378 netif = ip4_route_src(&iphdr_src, &iphdr_dst);
379 }
380 #else
381 netif = ip4_route(&iphdr_src);
382 #endif
383 if (netif != NULL) {
384 /* calculate checksum */
385 icmphdr->chksum = 0;
386 #if CHECKSUM_GEN_ICMP
387 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP) {
388 icmphdr->chksum = inet_chksum(icmphdr, q->len);
389 }
390 #endif
391 ICMP_STATS_INC(icmp.xmit);
392 ip4_output_if(q, NULL, &iphdr_src, ICMP_TTL, 0, IP_PROTO_ICMP, netif);
393 }
394 pbuf_free(q);
395 }
396
397 #endif /* LWIP_IPV4 && LWIP_ICMP */
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#define IPH_TTL_SET(hdr, ttl)
Definition: ip4.h:118
S16_F
#define S16_F
Definition: arch.h:151
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Definition: icmp.h:57
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Definition: pbuf.h:156
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Definition: icmp.h:52
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Definition: stats.h:344
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Definition: icmp.h:55
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Definition: ip4.h:64
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Definition: ip4.h:103
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Definition: ip.h:42
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Definition: lwipopts.h:209
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Definition: icmp.h:53
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Definition: icmp.h:54
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Definition: netif.h:233
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Definition: lwipopts.h:443
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Definition: icmp.h:46
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Definition: pbuf.c:949
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Definition: stats.h:467
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Definition: icmp.h:49
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Definition: icmp.h:58
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Definition: pbuf.h:108
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Definition: icmp.h:48
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Definition: icmp.h:84
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Definition: lwipopts.h:135
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Definition: icmp.h:71
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Definition: inet_chksum.c:555
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Definition: lwipopts.h:43
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Definition: icmp.h:51
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Definition: inet_chksum.c:568
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Definition: ip.h:58
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Definition: lwipopts.h:44
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Definition: icmp.h:50
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Definition: def.h:79
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