acl: fix memory leak
[qemu.git] / slirp / ip_icmp.c
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.
13 * 3. Neither the name of the University nor the names of its contributors
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
36 /* The message sent when emulating PING */
37 /* Be nice and tell them it's just a pseudo-ping packet */
38 static const char icmp_ping_msg[] = "This is a pseudo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n";
39
40 /* list of actions for icmp_error() on RX of an icmp message */
41 static const int icmp_flush[19] = {
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,
60 /* ADDR MASK REPLY (18) */ 0
61 };
62
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 void icmp_cleanup(Slirp *slirp)
70 {
71 while (slirp->icmp.so_next != &slirp->icmp) {
72 icmp_detach(slirp->icmp.so_next);
73 }
74 }
75
76 static int icmp_send(struct socket *so, struct mbuf *m, int hlen)
77 {
78 struct ip *ip = mtod(m, struct ip *);
79 struct sockaddr_in addr;
80
81 so->s = qemu_socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
82 if (so->s == -1) {
83 return -1;
84 }
85
86 so->so_m = m;
87 so->so_faddr = ip->ip_dst;
88 so->so_laddr = ip->ip_src;
89 so->so_iptos = ip->ip_tos;
90 so->so_type = IPPROTO_ICMP;
91 so->so_state = SS_ISFCONNECTED;
92 so->so_expire = curtime + SO_EXPIRE;
93
94 addr.sin_family = AF_INET;
95 addr.sin_addr = so->so_faddr;
96
97 insque(so, &so->slirp->icmp);
98
99 if (sendto(so->s, m->m_data + hlen, m->m_len - hlen, 0,
100 (struct sockaddr *)&addr, sizeof(addr)) == -1) {
101 DEBUG_MISC((dfd, "icmp_input icmp sendto tx errno = %d-%s\n",
102 errno, strerror(errno)));
103 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
104 icmp_detach(so);
105 }
106
107 return 0;
108 }
109
110 void icmp_detach(struct socket *so)
111 {
112 closesocket(so->s);
113 sofree(so);
114 }
115
116 /*
117 * Process a received ICMP message.
118 */
119 void
120 icmp_input(struct mbuf *m, int hlen)
121 {
122 register struct icmp *icp;
123 register struct ip *ip=mtod(m, struct ip *);
124 int icmplen=ip->ip_len;
125 Slirp *slirp = m->slirp;
126
127 DEBUG_CALL("icmp_input");
128 DEBUG_ARG("m = %lx", (long )m);
129 DEBUG_ARG("m_len = %d", m->m_len);
130
131 /*
132 * Locate icmp structure in mbuf, and check
133 * that its not corrupted and of at least minimum length.
134 */
135 if (icmplen < ICMP_MINLEN) { /* min 8 bytes payload */
136 freeit:
137 m_free(m);
138 goto end_error;
139 }
140
141 m->m_len -= hlen;
142 m->m_data += hlen;
143 icp = mtod(m, struct icmp *);
144 if (cksum(m, icmplen)) {
145 goto freeit;
146 }
147 m->m_len += hlen;
148 m->m_data -= hlen;
149
150 DEBUG_ARG("icmp_type = %d", icp->icmp_type);
151 switch (icp->icmp_type) {
152 case ICMP_ECHO:
153 ip->ip_len += hlen; /* since ip_input subtracts this */
154 if (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) {
155 icmp_reflect(m);
156 } else if (slirp->restricted) {
157 goto freeit;
158 } else {
159 struct socket *so;
160 struct sockaddr_in addr;
161 if ((so = socreate(slirp)) == NULL) goto freeit;
162 if (icmp_send(so, m, hlen) == 0) {
163 return;
164 }
165 if(udp_attach(so) == -1) {
166 DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n",
167 errno,strerror(errno)));
168 sofree(so);
169 m_free(m);
170 goto end_error;
171 }
172 so->so_m = m;
173 so->so_faddr = ip->ip_dst;
174 so->so_fport = htons(7);
175 so->so_laddr = ip->ip_src;
176 so->so_lport = htons(9);
177 so->so_iptos = ip->ip_tos;
178 so->so_type = IPPROTO_ICMP;
179 so->so_state = SS_ISFCONNECTED;
180
181 /* Send the packet */
182 addr.sin_family = AF_INET;
183 if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
184 slirp->vnetwork_addr.s_addr) {
185 /* It's an alias */
186 if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) {
187 if (get_dns_addr(&addr.sin_addr) < 0)
188 addr.sin_addr = loopback_addr;
189 } else {
190 addr.sin_addr = loopback_addr;
191 }
192 } else {
193 addr.sin_addr = so->so_faddr;
194 }
195 addr.sin_port = so->so_fport;
196 if(sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0,
197 (struct sockaddr *)&addr, sizeof(addr)) == -1) {
198 DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
199 errno,strerror(errno)));
200 icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
201 udp_detach(so);
202 }
203 } /* if ip->ip_dst.s_addr == alias_addr.s_addr */
204 break;
205 case ICMP_UNREACH:
206 /* XXX? report error? close socket? */
207 case ICMP_TIMXCEED:
208 case ICMP_PARAMPROB:
209 case ICMP_SOURCEQUENCH:
210 case ICMP_TSTAMP:
211 case ICMP_MASKREQ:
212 case ICMP_REDIRECT:
213 m_free(m);
214 break;
215
216 default:
217 m_free(m);
218 } /* swith */
219
220 end_error:
221 /* m is m_free()'d xor put in a socket xor or given to ip_send */
222 return;
223 }
224
225
226 /*
227 * Send an ICMP message in response to a situation
228 *
229 * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
230 * MUST NOT change this header information.
231 * MUST NOT reply to a multicast/broadcast IP address.
232 * MUST NOT reply to a multicast/broadcast MAC address.
233 * MUST reply to only the first fragment.
234 */
235 /*
236 * Send ICMP_UNREACH back to the source regarding msrc.
237 * mbuf *msrc is used as a template, but is NOT m_free()'d.
238 * It is reported as the bad ip packet. The header should
239 * be fully correct and in host byte order.
240 * ICMP fragmentation is illegal. All machines must accept 576 bytes in one
241 * packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
242 */
243
244 #define ICMP_MAXDATALEN (IP_MSS-28)
245 void
246 icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
247 const char *message)
248 {
249 unsigned hlen, shlen, s_ip_len;
250 register struct ip *ip;
251 register struct icmp *icp;
252 register struct mbuf *m;
253
254 DEBUG_CALL("icmp_error");
255 DEBUG_ARG("msrc = %lx", (long )msrc);
256 DEBUG_ARG("msrc_len = %d", msrc->m_len);
257
258 if(type!=ICMP_UNREACH && type!=ICMP_TIMXCEED) goto end_error;
259
260 /* check msrc */
261 if(!msrc) goto end_error;
262 ip = mtod(msrc, struct ip *);
263 #ifdef DEBUG
264 { char bufa[20], bufb[20];
265 strcpy(bufa, inet_ntoa(ip->ip_src));
266 strcpy(bufb, inet_ntoa(ip->ip_dst));
267 DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
268 }
269 #endif
270 if(ip->ip_off & IP_OFFMASK) goto end_error; /* Only reply to fragment 0 */
271
272 /* Do not reply to source-only IPs */
273 if ((ip->ip_src.s_addr & htonl(~(0xf << 28))) == 0) {
274 goto end_error;
275 }
276
277 shlen=ip->ip_hl << 2;
278 s_ip_len=ip->ip_len;
279 if(ip->ip_p == IPPROTO_ICMP) {
280 icp = (struct icmp *)((char *)ip + shlen);
281 /*
282 * Assume any unknown ICMP type is an error. This isn't
283 * specified by the RFC, but think about it..
284 */
285 if(icp->icmp_type>18 || icmp_flush[icp->icmp_type]) goto end_error;
286 }
287
288 /* make a copy */
289 m = m_get(msrc->slirp);
290 if (!m) {
291 goto end_error;
292 }
293
294 { int new_m_size;
295 new_m_size=sizeof(struct ip )+ICMP_MINLEN+msrc->m_len+ICMP_MAXDATALEN;
296 if(new_m_size>m->m_size) m_inc(m, new_m_size);
297 }
298 memcpy(m->m_data, msrc->m_data, msrc->m_len);
299 m->m_len = msrc->m_len; /* copy msrc to m */
300
301 /* make the header of the reply packet */
302 ip = mtod(m, struct ip *);
303 hlen= sizeof(struct ip ); /* no options in reply */
304
305 /* fill in icmp */
306 m->m_data += hlen;
307 m->m_len -= hlen;
308
309 icp = mtod(m, struct icmp *);
310
311 if(minsize) s_ip_len=shlen+ICMP_MINLEN; /* return header+8b only */
312 else if(s_ip_len>ICMP_MAXDATALEN) /* maximum size */
313 s_ip_len=ICMP_MAXDATALEN;
314
315 m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */
316
317 /* min. size = 8+sizeof(struct ip)+8 */
318
319 icp->icmp_type = type;
320 icp->icmp_code = code;
321 icp->icmp_id = 0;
322 icp->icmp_seq = 0;
323
324 memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
325 HTONS(icp->icmp_ip.ip_len);
326 HTONS(icp->icmp_ip.ip_id);
327 HTONS(icp->icmp_ip.ip_off);
328
329 #ifdef DEBUG
330 if(message) { /* DEBUG : append message to ICMP packet */
331 int message_len;
332 char *cpnt;
333 message_len=strlen(message);
334 if(message_len>ICMP_MAXDATALEN) message_len=ICMP_MAXDATALEN;
335 cpnt=(char *)m->m_data+m->m_len;
336 memcpy(cpnt, message, message_len);
337 m->m_len+=message_len;
338 }
339 #endif
340
341 icp->icmp_cksum = 0;
342 icp->icmp_cksum = cksum(m, m->m_len);
343
344 m->m_data -= hlen;
345 m->m_len += hlen;
346
347 /* fill in ip */
348 ip->ip_hl = hlen >> 2;
349 ip->ip_len = m->m_len;
350
351 ip->ip_tos=((ip->ip_tos & 0x1E) | 0xC0); /* high priority for errors */
352
353 ip->ip_ttl = MAXTTL;
354 ip->ip_p = IPPROTO_ICMP;
355 ip->ip_dst = ip->ip_src; /* ip addresses */
356 ip->ip_src = m->slirp->vhost_addr;
357
358 (void ) ip_output((struct socket *)NULL, m);
359
360 end_error:
361 return;
362 }
363 #undef ICMP_MAXDATALEN
364
365 /*
366 * Reflect the ip packet back to the source
367 */
368 void
369 icmp_reflect(struct mbuf *m)
370 {
371 register struct ip *ip = mtod(m, struct ip *);
372 int hlen = ip->ip_hl << 2;
373 int optlen = hlen - sizeof(struct ip );
374 register struct icmp *icp;
375
376 /*
377 * Send an icmp packet back to the ip level,
378 * after supplying a checksum.
379 */
380 m->m_data += hlen;
381 m->m_len -= hlen;
382 icp = mtod(m, struct icmp *);
383
384 icp->icmp_type = ICMP_ECHOREPLY;
385 icp->icmp_cksum = 0;
386 icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
387
388 m->m_data -= hlen;
389 m->m_len += hlen;
390
391 /* fill in ip */
392 if (optlen > 0) {
393 /*
394 * Strip out original options by copying rest of first
395 * mbuf's data back, and adjust the IP length.
396 */
397 memmove((caddr_t)(ip + 1), (caddr_t)ip + hlen,
398 (unsigned )(m->m_len - hlen));
399 hlen -= optlen;
400 ip->ip_hl = hlen >> 2;
401 ip->ip_len -= optlen;
402 m->m_len -= optlen;
403 }
404
405 ip->ip_ttl = MAXTTL;
406 { /* swap */
407 struct in_addr icmp_dst;
408 icmp_dst = ip->ip_dst;
409 ip->ip_dst = ip->ip_src;
410 ip->ip_src = icmp_dst;
411 }
412
413 (void ) ip_output((struct socket *)NULL, m);
414 }
415
416 void icmp_receive(struct socket *so)
417 {
418 struct mbuf *m = so->so_m;
419 struct ip *ip = mtod(m, struct ip *);
420 int hlen = ip->ip_hl << 2;
421 u_char error_code;
422 struct icmp *icp;
423 int id, len;
424
425 m->m_data += hlen;
426 m->m_len -= hlen;
427 icp = mtod(m, struct icmp *);
428
429 id = icp->icmp_id;
430 len = qemu_recv(so->s, icp, m->m_len, 0);
431 icp->icmp_id = id;
432
433 m->m_data -= hlen;
434 m->m_len += hlen;
435
436 if (len == -1 || len == 0) {
437 if (errno == ENETUNREACH) {
438 error_code = ICMP_UNREACH_NET;
439 } else {
440 error_code = ICMP_UNREACH_HOST;
441 }
442 DEBUG_MISC((dfd, " udp icmp rx errno = %d-%s\n", errno,
443 strerror(errno)));
444 icmp_error(so->so_m, ICMP_UNREACH, error_code, 0, strerror(errno));
445 } else {
446 icmp_reflect(so->so_m);
447 so->so_m = NULL; /* Don't m_free() it again! */
448 }
449 icmp_detach(so);
450 }