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Commit | Line | Data |
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f0cbd3ec FB |
1 | /* |
2 | * Copyright (c) 1982, 1986, 1988, 1993 | |
3 | * The Regents of the University of California. All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
2f5f8996 | 13 | * 3. Neither the name of the University nor the names of its contributors |
f0cbd3ec FB |
14 | * may be used to endorse or promote products derived from this software |
15 | * without specific prior written permission. | |
16 | * | |
17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
27 | * SUCH DAMAGE. | |
28 | * | |
29 | * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 | |
30 | * ip_icmp.c,v 1.7 1995/05/30 08:09:42 rgrimes Exp | |
31 | */ | |
32 | ||
33 | #include "slirp.h" | |
34 | #include "ip_icmp.h" | |
35 | ||
f0cbd3ec | 36 | /* The message sent when emulating PING */ |
7878ff6b | 37 | /* Be nice and tell them it's just a pseudo-ping packet */ |
7ca699c8 | 38 | static const char icmp_ping_msg[] = "This is a pseudo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n"; |
f0cbd3ec FB |
39 | |
40 | /* list of actions for icmp_error() on RX of an icmp message */ | |
9634d903 | 41 | static const int icmp_flush[19] = { |
f0cbd3ec FB |
42 | /* ECHO REPLY (0) */ 0, |
43 | 1, | |
44 | 1, | |
45 | /* DEST UNREACH (3) */ 1, | |
46 | /* SOURCE QUENCH (4)*/ 1, | |
47 | /* REDIRECT (5) */ 1, | |
48 | 1, | |
49 | 1, | |
50 | /* ECHO (8) */ 0, | |
51 | /* ROUTERADVERT (9) */ 1, | |
52 | /* ROUTERSOLICIT (10) */ 1, | |
53 | /* TIME EXCEEDED (11) */ 1, | |
54 | /* PARAMETER PROBLEM (12) */ 1, | |
55 | /* TIMESTAMP (13) */ 0, | |
56 | /* TIMESTAMP REPLY (14) */ 0, | |
57 | /* INFO (15) */ 0, | |
58 | /* INFO REPLY (16) */ 0, | |
59 | /* ADDR MASK (17) */ 0, | |
5fafdf24 | 60 | /* ADDR MASK REPLY (18) */ 0 |
f0cbd3ec FB |
61 | }; |
62 | ||
e6d43cfb JK |
63 | void icmp_init(Slirp *slirp) |
64 | { | |
65 | slirp->icmp.so_next = slirp->icmp.so_prev = &slirp->icmp; | |
66 | slirp->icmp_last_so = &slirp->icmp; | |
67 | } | |
68 | ||
69 | static int icmp_send(struct socket *so, struct mbuf *m, int hlen) | |
70 | { | |
71 | struct ip *ip = mtod(m, struct ip *); | |
72 | struct sockaddr_in addr; | |
73 | ||
74 | so->s = qemu_socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP); | |
75 | if (so->s == -1) { | |
76 | return -1; | |
77 | } | |
78 | ||
79 | so->so_m = m; | |
80 | so->so_faddr = ip->ip_dst; | |
81 | so->so_laddr = ip->ip_src; | |
82 | so->so_iptos = ip->ip_tos; | |
83 | so->so_type = IPPROTO_ICMP; | |
84 | so->so_state = SS_ISFCONNECTED; | |
85 | so->so_expire = curtime + SO_EXPIRE; | |
86 | ||
87 | addr.sin_family = AF_INET; | |
88 | addr.sin_addr = so->so_faddr; | |
89 | ||
90 | insque(so, &so->slirp->icmp); | |
91 | ||
92 | if (sendto(so->s, m->m_data + hlen, m->m_len - hlen, 0, | |
93 | (struct sockaddr *)&addr, sizeof(addr)) == -1) { | |
94 | DEBUG_MISC((dfd, "icmp_input icmp sendto tx errno = %d-%s\n", | |
95 | errno, strerror(errno))); | |
96 | icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno)); | |
97 | icmp_detach(so); | |
98 | } | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | void icmp_detach(struct socket *so) | |
104 | { | |
105 | closesocket(so->s); | |
106 | sofree(so); | |
107 | } | |
108 | ||
f0cbd3ec FB |
109 | /* |
110 | * Process a received ICMP message. | |
111 | */ | |
112 | void | |
511d2b14 | 113 | icmp_input(struct mbuf *m, int hlen) |
f0cbd3ec FB |
114 | { |
115 | register struct icmp *icp; | |
116 | register struct ip *ip=mtod(m, struct ip *); | |
117 | int icmplen=ip->ip_len; | |
460fec67 | 118 | Slirp *slirp = m->slirp; |
5fafdf24 | 119 | |
f0cbd3ec FB |
120 | DEBUG_CALL("icmp_input"); |
121 | DEBUG_ARG("m = %lx", (long )m); | |
122 | DEBUG_ARG("m_len = %d", m->m_len); | |
123 | ||
f0cbd3ec FB |
124 | /* |
125 | * Locate icmp structure in mbuf, and check | |
126 | * that its not corrupted and of at least minimum length. | |
127 | */ | |
128 | if (icmplen < ICMP_MINLEN) { /* min 8 bytes payload */ | |
f0cbd3ec | 129 | freeit: |
3acccfc6 | 130 | m_free(m); |
f0cbd3ec FB |
131 | goto end_error; |
132 | } | |
133 | ||
134 | m->m_len -= hlen; | |
135 | m->m_data += hlen; | |
136 | icp = mtod(m, struct icmp *); | |
137 | if (cksum(m, icmplen)) { | |
f0cbd3ec FB |
138 | goto freeit; |
139 | } | |
140 | m->m_len += hlen; | |
141 | m->m_data -= hlen; | |
3b46e624 | 142 | |
f0cbd3ec FB |
143 | DEBUG_ARG("icmp_type = %d", icp->icmp_type); |
144 | switch (icp->icmp_type) { | |
145 | case ICMP_ECHO: | |
f0cbd3ec | 146 | ip->ip_len += hlen; /* since ip_input subtracts this */ |
460fec67 | 147 | if (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) { |
f0cbd3ec | 148 | icmp_reflect(m); |
12b513d8 JK |
149 | } else if (slirp->restricted) { |
150 | goto freeit; | |
f0cbd3ec FB |
151 | } else { |
152 | struct socket *so; | |
153 | struct sockaddr_in addr; | |
460fec67 | 154 | if ((so = socreate(slirp)) == NULL) goto freeit; |
e6d43cfb JK |
155 | if (icmp_send(so, m, hlen) == 0) { |
156 | return; | |
157 | } | |
f0cbd3ec | 158 | if(udp_attach(so) == -1) { |
5fafdf24 | 159 | DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n", |
f0cbd3ec FB |
160 | errno,strerror(errno))); |
161 | sofree(so); | |
162 | m_free(m); | |
163 | goto end_error; | |
164 | } | |
165 | so->so_m = m; | |
166 | so->so_faddr = ip->ip_dst; | |
167 | so->so_fport = htons(7); | |
168 | so->so_laddr = ip->ip_src; | |
169 | so->so_lport = htons(9); | |
170 | so->so_iptos = ip->ip_tos; | |
171 | so->so_type = IPPROTO_ICMP; | |
172 | so->so_state = SS_ISFCONNECTED; | |
3b46e624 | 173 | |
f0cbd3ec FB |
174 | /* Send the packet */ |
175 | addr.sin_family = AF_INET; | |
460fec67 JK |
176 | if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) == |
177 | slirp->vnetwork_addr.s_addr) { | |
f0cbd3ec | 178 | /* It's an alias */ |
460fec67 | 179 | if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) { |
df7a86ed ES |
180 | if (get_dns_addr(&addr.sin_addr) < 0) |
181 | addr.sin_addr = loopback_addr; | |
a13a4126 | 182 | } else { |
f0cbd3ec | 183 | addr.sin_addr = loopback_addr; |
f0cbd3ec FB |
184 | } |
185 | } else { | |
186 | addr.sin_addr = so->so_faddr; | |
187 | } | |
188 | addr.sin_port = so->so_fport; | |
189 | if(sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0, | |
190 | (struct sockaddr *)&addr, sizeof(addr)) == -1) { | |
191 | DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n", | |
192 | errno,strerror(errno))); | |
5fafdf24 | 193 | icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno)); |
f0cbd3ec FB |
194 | udp_detach(so); |
195 | } | |
8dbca8dd | 196 | } /* if ip->ip_dst.s_addr == alias_addr.s_addr */ |
f0cbd3ec FB |
197 | break; |
198 | case ICMP_UNREACH: | |
199 | /* XXX? report error? close socket? */ | |
200 | case ICMP_TIMXCEED: | |
201 | case ICMP_PARAMPROB: | |
202 | case ICMP_SOURCEQUENCH: | |
203 | case ICMP_TSTAMP: | |
204 | case ICMP_MASKREQ: | |
205 | case ICMP_REDIRECT: | |
3acccfc6 | 206 | m_free(m); |
f0cbd3ec | 207 | break; |
3b46e624 | 208 | |
f0cbd3ec | 209 | default: |
3acccfc6 | 210 | m_free(m); |
f0cbd3ec FB |
211 | } /* swith */ |
212 | ||
213 | end_error: | |
214 | /* m is m_free()'d xor put in a socket xor or given to ip_send */ | |
215 | return; | |
216 | } | |
217 | ||
218 | ||
219 | /* | |
220 | * Send an ICMP message in response to a situation | |
221 | * | |
222 | * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do). | |
223 | * MUST NOT change this header information. | |
224 | * MUST NOT reply to a multicast/broadcast IP address. | |
225 | * MUST NOT reply to a multicast/broadcast MAC address. | |
226 | * MUST reply to only the first fragment. | |
227 | */ | |
228 | /* | |
229 | * Send ICMP_UNREACH back to the source regarding msrc. | |
230 | * mbuf *msrc is used as a template, but is NOT m_free()'d. | |
231 | * It is reported as the bad ip packet. The header should | |
232 | * be fully correct and in host byte order. | |
5fafdf24 | 233 | * ICMP fragmentation is illegal. All machines must accept 576 bytes in one |
f0cbd3ec FB |
234 | * packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548 |
235 | */ | |
236 | ||
237 | #define ICMP_MAXDATALEN (IP_MSS-28) | |
238 | void | |
7ccfb2eb BS |
239 | icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize, |
240 | const char *message) | |
f0cbd3ec FB |
241 | { |
242 | unsigned hlen, shlen, s_ip_len; | |
243 | register struct ip *ip; | |
244 | register struct icmp *icp; | |
245 | register struct mbuf *m; | |
246 | ||
247 | DEBUG_CALL("icmp_error"); | |
248 | DEBUG_ARG("msrc = %lx", (long )msrc); | |
249 | DEBUG_ARG("msrc_len = %d", msrc->m_len); | |
250 | ||
251 | if(type!=ICMP_UNREACH && type!=ICMP_TIMXCEED) goto end_error; | |
252 | ||
253 | /* check msrc */ | |
254 | if(!msrc) goto end_error; | |
255 | ip = mtod(msrc, struct ip *); | |
eb38c52c | 256 | #ifdef DEBUG |
f0cbd3ec FB |
257 | { char bufa[20], bufb[20]; |
258 | strcpy(bufa, inet_ntoa(ip->ip_src)); | |
259 | strcpy(bufb, inet_ntoa(ip->ip_dst)); | |
260 | DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb)); | |
261 | } | |
262 | #endif | |
263 | if(ip->ip_off & IP_OFFMASK) goto end_error; /* Only reply to fragment 0 */ | |
264 | ||
265 | shlen=ip->ip_hl << 2; | |
266 | s_ip_len=ip->ip_len; | |
267 | if(ip->ip_p == IPPROTO_ICMP) { | |
268 | icp = (struct icmp *)((char *)ip + shlen); | |
269 | /* | |
270 | * Assume any unknown ICMP type is an error. This isn't | |
271 | * specified by the RFC, but think about it.. | |
272 | */ | |
273 | if(icp->icmp_type>18 || icmp_flush[icp->icmp_type]) goto end_error; | |
274 | } | |
275 | ||
276 | /* make a copy */ | |
460fec67 JK |
277 | m = m_get(msrc->slirp); |
278 | if (!m) { | |
279 | goto end_error; | |
280 | } | |
281 | ||
f0cbd3ec FB |
282 | { int new_m_size; |
283 | new_m_size=sizeof(struct ip )+ICMP_MINLEN+msrc->m_len+ICMP_MAXDATALEN; | |
284 | if(new_m_size>m->m_size) m_inc(m, new_m_size); | |
285 | } | |
286 | memcpy(m->m_data, msrc->m_data, msrc->m_len); | |
287 | m->m_len = msrc->m_len; /* copy msrc to m */ | |
288 | ||
289 | /* make the header of the reply packet */ | |
290 | ip = mtod(m, struct ip *); | |
291 | hlen= sizeof(struct ip ); /* no options in reply */ | |
3b46e624 | 292 | |
f0cbd3ec | 293 | /* fill in icmp */ |
3b46e624 | 294 | m->m_data += hlen; |
f0cbd3ec FB |
295 | m->m_len -= hlen; |
296 | ||
297 | icp = mtod(m, struct icmp *); | |
298 | ||
299 | if(minsize) s_ip_len=shlen+ICMP_MINLEN; /* return header+8b only */ | |
300 | else if(s_ip_len>ICMP_MAXDATALEN) /* maximum size */ | |
301 | s_ip_len=ICMP_MAXDATALEN; | |
302 | ||
3b46e624 | 303 | m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */ |
f0cbd3ec FB |
304 | |
305 | /* min. size = 8+sizeof(struct ip)+8 */ | |
306 | ||
307 | icp->icmp_type = type; | |
308 | icp->icmp_code = code; | |
309 | icp->icmp_id = 0; | |
310 | icp->icmp_seq = 0; | |
311 | ||
312 | memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */ | |
313 | HTONS(icp->icmp_ip.ip_len); | |
314 | HTONS(icp->icmp_ip.ip_id); | |
315 | HTONS(icp->icmp_ip.ip_off); | |
316 | ||
eb38c52c | 317 | #ifdef DEBUG |
f0cbd3ec FB |
318 | if(message) { /* DEBUG : append message to ICMP packet */ |
319 | int message_len; | |
320 | char *cpnt; | |
321 | message_len=strlen(message); | |
322 | if(message_len>ICMP_MAXDATALEN) message_len=ICMP_MAXDATALEN; | |
323 | cpnt=(char *)m->m_data+m->m_len; | |
324 | memcpy(cpnt, message, message_len); | |
325 | m->m_len+=message_len; | |
326 | } | |
327 | #endif | |
328 | ||
329 | icp->icmp_cksum = 0; | |
330 | icp->icmp_cksum = cksum(m, m->m_len); | |
331 | ||
332 | m->m_data -= hlen; | |
333 | m->m_len += hlen; | |
334 | ||
335 | /* fill in ip */ | |
336 | ip->ip_hl = hlen >> 2; | |
337 | ip->ip_len = m->m_len; | |
3b46e624 | 338 | |
f0cbd3ec FB |
339 | ip->ip_tos=((ip->ip_tos & 0x1E) | 0xC0); /* high priority for errors */ |
340 | ||
341 | ip->ip_ttl = MAXTTL; | |
342 | ip->ip_p = IPPROTO_ICMP; | |
343 | ip->ip_dst = ip->ip_src; /* ip adresses */ | |
460fec67 | 344 | ip->ip_src = m->slirp->vhost_addr; |
f0cbd3ec FB |
345 | |
346 | (void ) ip_output((struct socket *)NULL, m); | |
3b46e624 | 347 | |
f0cbd3ec FB |
348 | end_error: |
349 | return; | |
350 | } | |
351 | #undef ICMP_MAXDATALEN | |
352 | ||
353 | /* | |
354 | * Reflect the ip packet back to the source | |
355 | */ | |
356 | void | |
511d2b14 | 357 | icmp_reflect(struct mbuf *m) |
f0cbd3ec FB |
358 | { |
359 | register struct ip *ip = mtod(m, struct ip *); | |
360 | int hlen = ip->ip_hl << 2; | |
361 | int optlen = hlen - sizeof(struct ip ); | |
362 | register struct icmp *icp; | |
363 | ||
364 | /* | |
365 | * Send an icmp packet back to the ip level, | |
366 | * after supplying a checksum. | |
367 | */ | |
368 | m->m_data += hlen; | |
369 | m->m_len -= hlen; | |
370 | icp = mtod(m, struct icmp *); | |
371 | ||
e6d43cfb | 372 | icp->icmp_type = ICMP_ECHOREPLY; |
f0cbd3ec FB |
373 | icp->icmp_cksum = 0; |
374 | icp->icmp_cksum = cksum(m, ip->ip_len - hlen); | |
375 | ||
376 | m->m_data -= hlen; | |
377 | m->m_len += hlen; | |
378 | ||
379 | /* fill in ip */ | |
380 | if (optlen > 0) { | |
381 | /* | |
382 | * Strip out original options by copying rest of first | |
383 | * mbuf's data back, and adjust the IP length. | |
384 | */ | |
385 | memmove((caddr_t)(ip + 1), (caddr_t)ip + hlen, | |
386 | (unsigned )(m->m_len - hlen)); | |
387 | hlen -= optlen; | |
388 | ip->ip_hl = hlen >> 2; | |
389 | ip->ip_len -= optlen; | |
390 | m->m_len -= optlen; | |
391 | } | |
392 | ||
393 | ip->ip_ttl = MAXTTL; | |
394 | { /* swap */ | |
395 | struct in_addr icmp_dst; | |
396 | icmp_dst = ip->ip_dst; | |
397 | ip->ip_dst = ip->ip_src; | |
398 | ip->ip_src = icmp_dst; | |
399 | } | |
400 | ||
401 | (void ) ip_output((struct socket *)NULL, m); | |
f0cbd3ec | 402 | } |
e6d43cfb JK |
403 | |
404 | void icmp_receive(struct socket *so) | |
405 | { | |
406 | struct mbuf *m = so->so_m; | |
407 | struct ip *ip = mtod(m, struct ip *); | |
408 | int hlen = ip->ip_hl << 2; | |
409 | u_char error_code; | |
410 | struct icmp *icp; | |
411 | int id, len; | |
412 | ||
413 | m->m_data += hlen; | |
414 | m->m_len -= hlen; | |
415 | icp = mtod(m, struct icmp *); | |
416 | ||
417 | id = icp->icmp_id; | |
00aa0040 | 418 | len = qemu_recv(so->s, icp, m->m_len, 0); |
e6d43cfb JK |
419 | icp->icmp_id = id; |
420 | ||
421 | m->m_data -= hlen; | |
422 | m->m_len += hlen; | |
423 | ||
424 | if (len == -1 || len == 0) { | |
425 | if (errno == ENETUNREACH) { | |
426 | error_code = ICMP_UNREACH_NET; | |
427 | } else { | |
428 | error_code = ICMP_UNREACH_HOST; | |
429 | } | |
430 | DEBUG_MISC((dfd, " udp icmp rx errno = %d-%s\n", errno, | |
431 | strerror(errno))); | |
432 | icmp_error(so->so_m, ICMP_UNREACH, error_code, 0, strerror(errno)); | |
433 | } else { | |
434 | icmp_reflect(so->so_m); | |
435 | so->so_m = NULL; /* Don't m_free() it again! */ | |
436 | } | |
437 | icmp_detach(so); | |
438 | } |