| 1 |
gbeauche |
1.1 |
/* |
| 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. All advertising materials mentioning features or use of this software |
| 14 |
|
|
* must display the following acknowledgement: |
| 15 |
|
|
* This product includes software developed by the University of |
| 16 |
|
|
* California, Berkeley and its contributors. |
| 17 |
|
|
* 4. Neither the name of the University nor the names of its contributors |
| 18 |
|
|
* may be used to endorse or promote products derived from this software |
| 19 |
|
|
* without specific prior written permission. |
| 20 |
|
|
* |
| 21 |
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 22 |
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 |
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 |
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 25 |
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 |
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 |
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 |
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 |
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 |
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 |
|
|
* SUCH DAMAGE. |
| 32 |
|
|
* |
| 33 |
|
|
* @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 |
| 34 |
|
|
* ip_icmp.c,v 1.7 1995/05/30 08:09:42 rgrimes Exp |
| 35 |
|
|
*/ |
| 36 |
|
|
|
| 37 |
|
|
#include "slirp.h" |
| 38 |
|
|
#include "ip_icmp.h" |
| 39 |
|
|
|
| 40 |
|
|
struct icmpstat icmpstat; |
| 41 |
|
|
|
| 42 |
|
|
/* The message sent when emulating PING */ |
| 43 |
|
|
/* Be nice and tell them it's just a psuedo-ping packet */ |
| 44 |
|
|
char icmp_ping_msg[] = "This is a psuedo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n"; |
| 45 |
|
|
|
| 46 |
|
|
/* list of actions for icmp_error() on RX of an icmp message */ |
| 47 |
|
|
static int icmp_flush[19] = { |
| 48 |
|
|
/* ECHO REPLY (0) */ 0, |
| 49 |
|
|
1, |
| 50 |
|
|
1, |
| 51 |
|
|
/* DEST UNREACH (3) */ 1, |
| 52 |
|
|
/* SOURCE QUENCH (4)*/ 1, |
| 53 |
|
|
/* REDIRECT (5) */ 1, |
| 54 |
|
|
1, |
| 55 |
|
|
1, |
| 56 |
|
|
/* ECHO (8) */ 0, |
| 57 |
|
|
/* ROUTERADVERT (9) */ 1, |
| 58 |
|
|
/* ROUTERSOLICIT (10) */ 1, |
| 59 |
|
|
/* TIME EXCEEDED (11) */ 1, |
| 60 |
|
|
/* PARAMETER PROBLEM (12) */ 1, |
| 61 |
|
|
/* TIMESTAMP (13) */ 0, |
| 62 |
|
|
/* TIMESTAMP REPLY (14) */ 0, |
| 63 |
|
|
/* INFO (15) */ 0, |
| 64 |
|
|
/* INFO REPLY (16) */ 0, |
| 65 |
|
|
/* ADDR MASK (17) */ 0, |
| 66 |
|
|
/* ADDR MASK REPLY (18) */ 0 |
| 67 |
|
|
}; |
| 68 |
|
|
|
| 69 |
|
|
/* |
| 70 |
|
|
* Process a received ICMP message. |
| 71 |
|
|
*/ |
| 72 |
|
|
void |
| 73 |
|
|
icmp_input(m, hlen) |
| 74 |
|
|
struct mbuf *m; |
| 75 |
|
|
int hlen; |
| 76 |
|
|
{ |
| 77 |
|
|
register struct icmp *icp; |
| 78 |
|
|
register struct ip *ip=mtod(m, struct ip *); |
| 79 |
|
|
int icmplen=ip->ip_len; |
| 80 |
|
|
/* int code; */ |
| 81 |
|
|
|
| 82 |
|
|
DEBUG_CALL("icmp_input"); |
| 83 |
|
|
DEBUG_ARG("m = %lx", (long )m); |
| 84 |
|
|
DEBUG_ARG("m_len = %d", m->m_len); |
| 85 |
|
|
|
| 86 |
|
|
icmpstat.icps_received++; |
| 87 |
|
|
|
| 88 |
|
|
/* |
| 89 |
|
|
* Locate icmp structure in mbuf, and check |
| 90 |
|
|
* that its not corrupted and of at least minimum length. |
| 91 |
|
|
*/ |
| 92 |
|
|
if (icmplen < ICMP_MINLEN) { /* min 8 bytes payload */ |
| 93 |
|
|
icmpstat.icps_tooshort++; |
| 94 |
|
|
freeit: |
| 95 |
|
|
m_freem(m); |
| 96 |
|
|
goto end_error; |
| 97 |
|
|
} |
| 98 |
|
|
|
| 99 |
|
|
m->m_len -= hlen; |
| 100 |
|
|
m->m_data += hlen; |
| 101 |
|
|
icp = mtod(m, struct icmp *); |
| 102 |
|
|
if (cksum(m, icmplen)) { |
| 103 |
|
|
icmpstat.icps_checksum++; |
| 104 |
|
|
goto freeit; |
| 105 |
|
|
} |
| 106 |
|
|
m->m_len += hlen; |
| 107 |
|
|
m->m_data -= hlen; |
| 108 |
|
|
|
| 109 |
|
|
/* icmpstat.icps_inhist[icp->icmp_type]++; */ |
| 110 |
|
|
/* code = icp->icmp_code; */ |
| 111 |
|
|
|
| 112 |
|
|
DEBUG_ARG("icmp_type = %d", icp->icmp_type); |
| 113 |
|
|
switch (icp->icmp_type) { |
| 114 |
|
|
case ICMP_ECHO: |
| 115 |
|
|
icp->icmp_type = ICMP_ECHOREPLY; |
| 116 |
|
|
ip->ip_len += hlen; /* since ip_input subtracts this */ |
| 117 |
|
|
if (ip->ip_dst.s_addr == our_addr.s_addr || |
| 118 |
|
|
(ip->ip_dst.s_addr == (special_addr.s_addr|htonl(CTL_ALIAS))) ) { |
| 119 |
|
|
icmp_reflect(m); |
| 120 |
|
|
} else { |
| 121 |
|
|
struct socket *so; |
| 122 |
|
|
struct sockaddr_in addr; |
| 123 |
|
|
if ((so = socreate()) == NULL) goto freeit; |
| 124 |
|
|
if(udp_attach(so) == -1) { |
| 125 |
|
|
DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n", |
| 126 |
|
|
errno,strerror(errno))); |
| 127 |
|
|
sofree(so); |
| 128 |
|
|
m_free(m); |
| 129 |
|
|
goto end_error; |
| 130 |
|
|
} |
| 131 |
|
|
so->so_m = m; |
| 132 |
|
|
so->so_faddr = ip->ip_dst; |
| 133 |
|
|
so->so_fport = htons(7); |
| 134 |
|
|
so->so_laddr = ip->ip_src; |
| 135 |
|
|
so->so_lport = htons(9); |
| 136 |
|
|
so->so_iptos = ip->ip_tos; |
| 137 |
|
|
so->so_type = IPPROTO_ICMP; |
| 138 |
|
|
so->so_state = SS_ISFCONNECTED; |
| 139 |
|
|
|
| 140 |
|
|
/* Send the packet */ |
| 141 |
|
|
addr.sin_family = AF_INET; |
| 142 |
|
|
if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) { |
| 143 |
|
|
/* It's an alias */ |
| 144 |
|
|
switch(ntohl(so->so_faddr.s_addr) & 0xff) { |
| 145 |
|
|
case CTL_DNS: |
| 146 |
|
|
addr.sin_addr = dns_addr; |
| 147 |
|
|
break; |
| 148 |
|
|
case CTL_ALIAS: |
| 149 |
|
|
default: |
| 150 |
|
|
addr.sin_addr = loopback_addr; |
| 151 |
|
|
break; |
| 152 |
|
|
} |
| 153 |
|
|
} else { |
| 154 |
|
|
addr.sin_addr = so->so_faddr; |
| 155 |
|
|
} |
| 156 |
|
|
addr.sin_port = so->so_fport; |
| 157 |
|
|
if(sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0, |
| 158 |
|
|
(struct sockaddr *)&addr, sizeof(addr)) == -1) { |
| 159 |
|
|
DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n", |
| 160 |
|
|
errno,strerror(errno))); |
| 161 |
|
|
icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno)); |
| 162 |
|
|
udp_detach(so); |
| 163 |
|
|
} |
| 164 |
|
|
} /* if ip->ip_dst.s_addr == our_addr.s_addr */ |
| 165 |
|
|
break; |
| 166 |
|
|
case ICMP_UNREACH: |
| 167 |
|
|
/* XXX? report error? close socket? */ |
| 168 |
|
|
case ICMP_TIMXCEED: |
| 169 |
|
|
case ICMP_PARAMPROB: |
| 170 |
|
|
case ICMP_SOURCEQUENCH: |
| 171 |
|
|
case ICMP_TSTAMP: |
| 172 |
|
|
case ICMP_MASKREQ: |
| 173 |
|
|
case ICMP_REDIRECT: |
| 174 |
|
|
icmpstat.icps_notsupp++; |
| 175 |
|
|
m_freem(m); |
| 176 |
|
|
break; |
| 177 |
|
|
|
| 178 |
|
|
default: |
| 179 |
|
|
icmpstat.icps_badtype++; |
| 180 |
|
|
m_freem(m); |
| 181 |
|
|
} /* swith */ |
| 182 |
|
|
|
| 183 |
|
|
end_error: |
| 184 |
|
|
/* m is m_free()'d xor put in a socket xor or given to ip_send */ |
| 185 |
|
|
return; |
| 186 |
|
|
} |
| 187 |
|
|
|
| 188 |
|
|
|
| 189 |
|
|
/* |
| 190 |
|
|
* Send an ICMP message in response to a situation |
| 191 |
|
|
* |
| 192 |
|
|
* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do). |
| 193 |
|
|
* MUST NOT change this header information. |
| 194 |
|
|
* MUST NOT reply to a multicast/broadcast IP address. |
| 195 |
|
|
* MUST NOT reply to a multicast/broadcast MAC address. |
| 196 |
|
|
* MUST reply to only the first fragment. |
| 197 |
|
|
*/ |
| 198 |
|
|
/* |
| 199 |
|
|
* Send ICMP_UNREACH back to the source regarding msrc. |
| 200 |
|
|
* mbuf *msrc is used as a template, but is NOT m_free()'d. |
| 201 |
|
|
* It is reported as the bad ip packet. The header should |
| 202 |
|
|
* be fully correct and in host byte order. |
| 203 |
|
|
* ICMP fragmentation is illegal. All machines must accept 576 bytes in one |
| 204 |
|
|
* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548 |
| 205 |
|
|
*/ |
| 206 |
|
|
|
| 207 |
|
|
#define ICMP_MAXDATALEN (IP_MSS-28) |
| 208 |
|
|
void |
| 209 |
|
|
icmp_error(msrc, type, code, minsize, message) |
| 210 |
|
|
struct mbuf *msrc; |
| 211 |
|
|
u_char type; |
| 212 |
|
|
u_char code; |
| 213 |
|
|
int minsize; |
| 214 |
|
|
char *message; |
| 215 |
|
|
{ |
| 216 |
|
|
unsigned hlen, shlen, s_ip_len; |
| 217 |
|
|
register struct ip *ip; |
| 218 |
|
|
register struct icmp *icp; |
| 219 |
|
|
register struct mbuf *m; |
| 220 |
|
|
|
| 221 |
|
|
DEBUG_CALL("icmp_error"); |
| 222 |
|
|
DEBUG_ARG("msrc = %lx", (long )msrc); |
| 223 |
|
|
DEBUG_ARG("msrc_len = %d", msrc->m_len); |
| 224 |
|
|
|
| 225 |
|
|
if(type!=ICMP_UNREACH && type!=ICMP_TIMXCEED) goto end_error; |
| 226 |
|
|
|
| 227 |
|
|
/* check msrc */ |
| 228 |
|
|
if(!msrc) goto end_error; |
| 229 |
|
|
ip = mtod(msrc, struct ip *); |
| 230 |
|
|
#if DEBUG |
| 231 |
|
|
{ char bufa[20], bufb[20]; |
| 232 |
|
|
strcpy(bufa, inet_ntoa(ip->ip_src)); |
| 233 |
|
|
strcpy(bufb, inet_ntoa(ip->ip_dst)); |
| 234 |
|
|
DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb)); |
| 235 |
|
|
} |
| 236 |
|
|
#endif |
| 237 |
|
|
if(ip->ip_off & IP_OFFMASK) goto end_error; /* Only reply to fragment 0 */ |
| 238 |
|
|
|
| 239 |
|
|
shlen=ip->ip_hl << 2; |
| 240 |
|
|
s_ip_len=ip->ip_len; |
| 241 |
|
|
if(ip->ip_p == IPPROTO_ICMP) { |
| 242 |
|
|
icp = (struct icmp *)((char *)ip + shlen); |
| 243 |
|
|
/* |
| 244 |
|
|
* Assume any unknown ICMP type is an error. This isn't |
| 245 |
|
|
* specified by the RFC, but think about it.. |
| 246 |
|
|
*/ |
| 247 |
|
|
if(icp->icmp_type>18 || icmp_flush[icp->icmp_type]) goto end_error; |
| 248 |
|
|
} |
| 249 |
|
|
|
| 250 |
|
|
/* make a copy */ |
| 251 |
|
|
if(!(m=m_get())) goto end_error; /* get mbuf */ |
| 252 |
|
|
{ int new_m_size; |
| 253 |
|
|
new_m_size=sizeof(struct ip )+ICMP_MINLEN+msrc->m_len+ICMP_MAXDATALEN; |
| 254 |
|
|
if(new_m_size>m->m_size) m_inc(m, new_m_size); |
| 255 |
|
|
} |
| 256 |
|
|
memcpy(m->m_data, msrc->m_data, msrc->m_len); |
| 257 |
|
|
m->m_len = msrc->m_len; /* copy msrc to m */ |
| 258 |
|
|
|
| 259 |
|
|
/* make the header of the reply packet */ |
| 260 |
|
|
ip = mtod(m, struct ip *); |
| 261 |
|
|
hlen= sizeof(struct ip ); /* no options in reply */ |
| 262 |
|
|
|
| 263 |
|
|
/* fill in icmp */ |
| 264 |
|
|
m->m_data += hlen; |
| 265 |
|
|
m->m_len -= hlen; |
| 266 |
|
|
|
| 267 |
|
|
icp = mtod(m, struct icmp *); |
| 268 |
|
|
|
| 269 |
|
|
if(minsize) s_ip_len=shlen+ICMP_MINLEN; /* return header+8b only */ |
| 270 |
|
|
else if(s_ip_len>ICMP_MAXDATALEN) /* maximum size */ |
| 271 |
|
|
s_ip_len=ICMP_MAXDATALEN; |
| 272 |
|
|
|
| 273 |
|
|
m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */ |
| 274 |
|
|
|
| 275 |
|
|
/* min. size = 8+sizeof(struct ip)+8 */ |
| 276 |
|
|
|
| 277 |
|
|
icp->icmp_type = type; |
| 278 |
|
|
icp->icmp_code = code; |
| 279 |
|
|
icp->icmp_id = 0; |
| 280 |
|
|
icp->icmp_seq = 0; |
| 281 |
|
|
|
| 282 |
|
|
memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */ |
| 283 |
|
|
HTONS(icp->icmp_ip.ip_len); |
| 284 |
|
|
HTONS(icp->icmp_ip.ip_id); |
| 285 |
|
|
HTONS(icp->icmp_ip.ip_off); |
| 286 |
|
|
|
| 287 |
|
|
#if DEBUG |
| 288 |
|
|
if(message) { /* DEBUG : append message to ICMP packet */ |
| 289 |
|
|
int message_len; |
| 290 |
|
|
char *cpnt; |
| 291 |
|
|
message_len=strlen(message); |
| 292 |
|
|
if(message_len>ICMP_MAXDATALEN) message_len=ICMP_MAXDATALEN; |
| 293 |
|
|
cpnt=(char *)m->m_data+m->m_len; |
| 294 |
|
|
memcpy(cpnt, message, message_len); |
| 295 |
|
|
m->m_len+=message_len; |
| 296 |
|
|
} |
| 297 |
|
|
#endif |
| 298 |
|
|
|
| 299 |
|
|
icp->icmp_cksum = 0; |
| 300 |
|
|
icp->icmp_cksum = cksum(m, m->m_len); |
| 301 |
|
|
|
| 302 |
|
|
m->m_data -= hlen; |
| 303 |
|
|
m->m_len += hlen; |
| 304 |
|
|
|
| 305 |
|
|
/* fill in ip */ |
| 306 |
|
|
ip->ip_hl = hlen >> 2; |
| 307 |
|
|
ip->ip_len = m->m_len; |
| 308 |
|
|
|
| 309 |
|
|
ip->ip_tos=((ip->ip_tos & 0x1E) | 0xC0); /* high priority for errors */ |
| 310 |
|
|
|
| 311 |
|
|
ip->ip_ttl = MAXTTL; |
| 312 |
|
|
ip->ip_p = IPPROTO_ICMP; |
| 313 |
|
|
ip->ip_dst = ip->ip_src; /* ip adresses */ |
| 314 |
|
|
ip->ip_src = our_addr; |
| 315 |
|
|
|
| 316 |
|
|
(void ) ip_output((struct socket *)NULL, m); |
| 317 |
|
|
|
| 318 |
|
|
icmpstat.icps_reflect++; |
| 319 |
|
|
|
| 320 |
|
|
end_error: |
| 321 |
|
|
return; |
| 322 |
|
|
} |
| 323 |
|
|
#undef ICMP_MAXDATALEN |
| 324 |
|
|
|
| 325 |
|
|
/* |
| 326 |
|
|
* Reflect the ip packet back to the source |
| 327 |
|
|
*/ |
| 328 |
|
|
void |
| 329 |
|
|
icmp_reflect(m) |
| 330 |
|
|
struct mbuf *m; |
| 331 |
|
|
{ |
| 332 |
|
|
register struct ip *ip = mtod(m, struct ip *); |
| 333 |
|
|
int hlen = ip->ip_hl << 2; |
| 334 |
|
|
int optlen = hlen - sizeof(struct ip ); |
| 335 |
|
|
register struct icmp *icp; |
| 336 |
|
|
|
| 337 |
|
|
/* |
| 338 |
|
|
* Send an icmp packet back to the ip level, |
| 339 |
|
|
* after supplying a checksum. |
| 340 |
|
|
*/ |
| 341 |
|
|
m->m_data += hlen; |
| 342 |
|
|
m->m_len -= hlen; |
| 343 |
|
|
icp = mtod(m, struct icmp *); |
| 344 |
|
|
|
| 345 |
|
|
icp->icmp_cksum = 0; |
| 346 |
|
|
icp->icmp_cksum = cksum(m, ip->ip_len - hlen); |
| 347 |
|
|
|
| 348 |
|
|
m->m_data -= hlen; |
| 349 |
|
|
m->m_len += hlen; |
| 350 |
|
|
|
| 351 |
|
|
/* fill in ip */ |
| 352 |
|
|
if (optlen > 0) { |
| 353 |
|
|
/* |
| 354 |
|
|
* Strip out original options by copying rest of first |
| 355 |
|
|
* mbuf's data back, and adjust the IP length. |
| 356 |
|
|
*/ |
| 357 |
|
|
memmove((caddr_t)(ip + 1), (caddr_t)ip + hlen, |
| 358 |
|
|
(unsigned )(m->m_len - hlen)); |
| 359 |
|
|
hlen -= optlen; |
| 360 |
|
|
ip->ip_hl = hlen >> 2; |
| 361 |
|
|
ip->ip_len -= optlen; |
| 362 |
|
|
m->m_len -= optlen; |
| 363 |
|
|
} |
| 364 |
|
|
|
| 365 |
|
|
ip->ip_ttl = MAXTTL; |
| 366 |
|
|
{ /* swap */ |
| 367 |
|
|
struct in_addr icmp_dst; |
| 368 |
|
|
icmp_dst = ip->ip_dst; |
| 369 |
|
|
ip->ip_dst = ip->ip_src; |
| 370 |
|
|
ip->ip_src = icmp_dst; |
| 371 |
|
|
} |
| 372 |
|
|
|
| 373 |
|
|
(void ) ip_output((struct socket *)NULL, m); |
| 374 |
|
|
|
| 375 |
|
|
icmpstat.icps_reflect++; |
| 376 |
|
|
} |
