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1.1 root 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.
1.1.1.4 root 13: * 3. Neither the name of the University nor the names of its contributors
1.1 root 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 */
1.1.1.3 root 37: /* Be nice and tell them it's just a pseudo-ping packet */
1.1.1.4 root 38: static const char icmp_ping_msg[] = "This is a pseudo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n";
1.1 root 39:
40: /* list of actions for icmp_error() on RX of an icmp message */
1.1.1.3 root 41: static const int icmp_flush[19] = {
1.1 root 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,
1.1.1.3 root 60: /* ADDR MASK REPLY (18) */ 0
1.1 root 61: };
62:
1.1.1.7 root 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:
1.1.1.8 ! root 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:
1.1.1.7 root 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:
1.1 root 116: /*
117: * Process a received ICMP message.
118: */
119: void
1.1.1.5 root 120: icmp_input(struct mbuf *m, int hlen)
1.1 root 121: {
122: register struct icmp *icp;
123: register struct ip *ip=mtod(m, struct ip *);
124: int icmplen=ip->ip_len;
1.1.1.5 root 125: Slirp *slirp = m->slirp;
1.1.1.3 root 126:
1.1 root 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:
1.1.1.7 root 137: m_free(m);
1.1 root 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;
1.1.1.3 root 149:
1.1 root 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 */
1.1.1.5 root 154: if (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) {
1.1 root 155: icmp_reflect(m);
1.1.1.7 root 156: } else if (slirp->restricted) {
157: goto freeit;
1.1 root 158: } else {
159: struct socket *so;
160: struct sockaddr_in addr;
1.1.1.5 root 161: if ((so = socreate(slirp)) == NULL) goto freeit;
1.1.1.7 root 162: if (icmp_send(so, m, hlen) == 0) {
163: return;
164: }
1.1 root 165: if(udp_attach(so) == -1) {
1.1.1.3 root 166: DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n",
1.1 root 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;
1.1.1.3 root 180:
1.1 root 181: /* Send the packet */
182: addr.sin_family = AF_INET;
1.1.1.5 root 183: if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
184: slirp->vnetwork_addr.s_addr) {
1.1 root 185: /* It's an alias */
1.1.1.5 root 186: if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) {
1.1.1.6 root 187: if (get_dns_addr(&addr.sin_addr) < 0)
188: addr.sin_addr = loopback_addr;
1.1.1.5 root 189: } else {
1.1 root 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)));
1.1.1.3 root 200: icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
1.1 root 201: udp_detach(so);
202: }
1.1.1.2 root 203: } /* if ip->ip_dst.s_addr == alias_addr.s_addr */
1.1 root 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:
1.1.1.7 root 213: m_free(m);
1.1 root 214: break;
1.1.1.3 root 215:
1.1 root 216: default:
1.1.1.7 root 217: m_free(m);
1.1 root 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.
1.1.1.3 root 240: * ICMP fragmentation is illegal. All machines must accept 576 bytes in one
1.1 root 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
1.1.1.4 root 246: icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
247: const char *message)
1.1 root 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 *);
1.1.1.4 root 263: #ifdef DEBUG
1.1 root 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:
1.1.1.8 ! root 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:
1.1 root 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 */
1.1.1.5 root 289: m = m_get(msrc->slirp);
290: if (!m) {
291: goto end_error;
292: }
293:
1.1 root 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 */
1.1.1.3 root 304:
1.1 root 305: /* fill in icmp */
1.1.1.3 root 306: m->m_data += hlen;
1.1 root 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:
1.1.1.3 root 315: m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */
1.1 root 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:
1.1.1.4 root 329: #ifdef DEBUG
1.1 root 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;
1.1.1.3 root 350:
1.1 root 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 adresses */
1.1.1.5 root 356: ip->ip_src = m->slirp->vhost_addr;
1.1 root 357:
358: (void ) ip_output((struct socket *)NULL, m);
1.1.1.3 root 359:
1.1 root 360: end_error:
361: return;
362: }
363: #undef ICMP_MAXDATALEN
364:
365: /*
366: * Reflect the ip packet back to the source
367: */
368: void
1.1.1.5 root 369: icmp_reflect(struct mbuf *m)
1.1 root 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:
1.1.1.7 root 384: icp->icmp_type = ICMP_ECHOREPLY;
1.1 root 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: }
1.1.1.7 root 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: }
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