1 /* 2 * Copyright (c) 1993, 1994, 1995, 1996, 1997 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: (1) source code distributions 7 * retain the above copyright notice and this paragraph in its entirety, (2) 8 * distributions including binary code include the above copyright notice and 9 * this paragraph in its entirety in the documentation or other materials 10 * provided with the distribution, and (3) all advertising materials mentioning 11 * features or use of this software display the following acknowledgement: 12 * ``This product includes software developed by the University of California, 13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14 * the University nor the names of its contributors may be used to endorse 15 * or promote products derived from this software without specific prior 16 * written permission. 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20 */ 21 22 #ifdef HAVE_CONFIG_H 23 #include "config.h" 24 #endif 25 26 #include <sys/param.h> 27 #include <sys/file.h> 28 #include <sys/ioctl.h> 29 #include <sys/socket.h> 30 #include <sys/time.h> 31 32 #include <net/raw.h> 33 #include <net/if.h> 34 35 #include <netinet/in.h> 36 #include <netinet/in_systm.h> 37 #include <netinet/ip.h> 38 #include <netinet/if_ether.h> 39 #include <netinet/ip_var.h> 40 #include <netinet/udp.h> 41 #include <netinet/udp_var.h> 42 #include <netinet/tcp.h> 43 #include <netinet/tcpip.h> 44 45 #include <errno.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 51 #include "pcap-int.h" 52 53 #ifdef HAVE_OS_PROTO_H 54 #include "os-proto.h" 55 #endif 56 57 /* 58 * Private data for capturing on snoop devices. 59 */ 60 struct pcap_snoop { 61 struct pcap_stat stat; 62 }; 63 64 static int 65 pcap_read_snoop(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 66 { 67 struct pcap_snoop *psn = p->priv; 68 int cc; 69 register struct snoopheader *sh; 70 register u_int datalen; 71 register u_int caplen; 72 register u_char *cp; 73 74 again: 75 /* 76 * Has "pcap_breakloop()" been called? 77 */ 78 if (p->break_loop) { 79 /* 80 * Yes - clear the flag that indicates that it 81 * has, and return -2 to indicate that we were 82 * told to break out of the loop. 83 */ 84 p->break_loop = 0; 85 return (-2); 86 } 87 cc = read(p->fd, (char *)p->buffer, p->bufsize); 88 if (cc < 0) { 89 /* Don't choke when we get ptraced */ 90 switch (errno) { 91 92 case EINTR: 93 goto again; 94 95 case EWOULDBLOCK: 96 return (0); /* XXX */ 97 } 98 snprintf(p->errbuf, sizeof(p->errbuf), 99 "read: %s", pcap_strerror(errno)); 100 return (-1); 101 } 102 sh = (struct snoopheader *)p->buffer; 103 datalen = sh->snoop_packetlen; 104 105 /* 106 * XXX - Sigh, snoop_packetlen is a 16 bit quantity. If we 107 * got a short length, but read a full sized snoop pakcet, 108 * assume we overflowed and add back the 64K... 109 */ 110 if (cc == (p->snapshot + sizeof(struct snoopheader)) && 111 (datalen < p->snapshot)) 112 datalen += (64 * 1024); 113 114 caplen = (datalen < p->snapshot) ? datalen : p->snapshot; 115 cp = (u_char *)(sh + 1) + p->offset; /* XXX */ 116 117 /* 118 * XXX unfortunately snoop loopback isn't exactly like 119 * BSD's. The address family is encoded in the first 2 120 * bytes rather than the first 4 bytes! Luckily the last 121 * two snoop loopback bytes are zeroed. 122 */ 123 if (p->linktype == DLT_NULL && *((short *)(cp + 2)) == 0) { 124 u_int *uip = (u_int *)cp; 125 *uip >>= 16; 126 } 127 128 if (p->fcode.bf_insns == NULL || 129 bpf_filter(p->fcode.bf_insns, cp, datalen, caplen)) { 130 struct pcap_pkthdr h; 131 ++psn->stat.ps_recv; 132 h.ts.tv_sec = sh->snoop_timestamp.tv_sec; 133 h.ts.tv_usec = sh->snoop_timestamp.tv_usec; 134 h.len = datalen; 135 h.caplen = caplen; 136 (*callback)(user, &h, cp); 137 return (1); 138 } 139 return (0); 140 } 141 142 static int 143 pcap_inject_snoop(pcap_t *p, const void *buf, size_t size) 144 { 145 int ret; 146 147 /* 148 * XXX - libnet overwrites the source address with what I 149 * presume is the interface's address; is that required? 150 */ 151 ret = write(p->fd, buf, size); 152 if (ret == -1) { 153 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 154 pcap_strerror(errno)); 155 return (-1); 156 } 157 return (ret); 158 } 159 160 static int 161 pcap_stats_snoop(pcap_t *p, struct pcap_stat *ps) 162 { 163 struct pcap_snoop *psn = p->priv; 164 register struct rawstats *rs; 165 struct rawstats rawstats; 166 167 rs = &rawstats; 168 memset(rs, 0, sizeof(*rs)); 169 if (ioctl(p->fd, SIOCRAWSTATS, (char *)rs) < 0) { 170 snprintf(p->errbuf, sizeof(p->errbuf), 171 "SIOCRAWSTATS: %s", pcap_strerror(errno)); 172 return (-1); 173 } 174 175 /* 176 * "ifdrops" are those dropped by the network interface 177 * due to resource shortages or hardware errors. 178 * 179 * "sbdrops" are those dropped due to socket buffer limits. 180 * 181 * As filter is done in userland, "sbdrops" counts packets 182 * regardless of whether they would've passed the filter. 183 * 184 * XXX - does this count *all* Snoop or Drain sockets, 185 * rather than just this socket? If not, why does it have 186 * both Snoop and Drain statistics? 187 */ 188 psn->stat.ps_drop = 189 rs->rs_snoop.ss_ifdrops + rs->rs_snoop.ss_sbdrops + 190 rs->rs_drain.ds_ifdrops + rs->rs_drain.ds_sbdrops; 191 192 /* 193 * "ps_recv" counts only packets that passed the filter. 194 * As filtering is done in userland, this does not include 195 * packets dropped because we ran out of buffer space. 196 */ 197 *ps = psn->stat; 198 return (0); 199 } 200 201 /* XXX can't disable promiscuous */ 202 static int 203 pcap_activate_snoop(pcap_t *p) 204 { 205 int fd; 206 struct sockaddr_raw sr; 207 struct snoopfilter sf; 208 u_int v; 209 int ll_hdrlen; 210 int snooplen; 211 struct ifreq ifr; 212 213 fd = socket(PF_RAW, SOCK_RAW, RAWPROTO_SNOOP); 214 if (fd < 0) { 215 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "snoop socket: %s", 216 pcap_strerror(errno)); 217 goto bad; 218 } 219 p->fd = fd; 220 memset(&sr, 0, sizeof(sr)); 221 sr.sr_family = AF_RAW; 222 (void)strncpy(sr.sr_ifname, p->opt.source, sizeof(sr.sr_ifname)); 223 if (bind(fd, (struct sockaddr *)&sr, sizeof(sr))) { 224 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "snoop bind: %s", 225 pcap_strerror(errno)); 226 goto bad; 227 } 228 memset(&sf, 0, sizeof(sf)); 229 if (ioctl(fd, SIOCADDSNOOP, &sf) < 0) { 230 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCADDSNOOP: %s", 231 pcap_strerror(errno)); 232 goto bad; 233 } 234 if (p->opt.buffer_size != 0) 235 v = p->opt.buffer_size; 236 else 237 v = 64 * 1024; /* default to 64K buffer size */ 238 (void)setsockopt(fd, SOL_SOCKET, SO_RCVBUF, (char *)&v, sizeof(v)); 239 /* 240 * XXX hack - map device name to link layer type 241 */ 242 if (strncmp("et", p->opt.source, 2) == 0 || /* Challenge 10 Mbit */ 243 strncmp("ec", p->opt.source, 2) == 0 || /* Indigo/Indy 10 Mbit, 244 O2 10/100 */ 245 strncmp("ef", p->opt.source, 2) == 0 || /* O200/2000 10/100 Mbit */ 246 strncmp("eg", p->opt.source, 2) == 0 || /* Octane/O2xxx/O3xxx Gigabit */ 247 strncmp("gfe", p->opt.source, 3) == 0 || /* GIO 100 Mbit */ 248 strncmp("fxp", p->opt.source, 3) == 0 || /* Challenge VME Enet */ 249 strncmp("ep", p->opt.source, 2) == 0 || /* Challenge 8x10 Mbit EPLEX */ 250 strncmp("vfe", p->opt.source, 3) == 0 || /* Challenge VME 100Mbit */ 251 strncmp("fa", p->opt.source, 2) == 0 || 252 strncmp("qaa", p->opt.source, 3) == 0 || 253 strncmp("cip", p->opt.source, 3) == 0 || 254 strncmp("el", p->opt.source, 2) == 0) { 255 p->linktype = DLT_EN10MB; 256 p->offset = RAW_HDRPAD(sizeof(struct ether_header)); 257 ll_hdrlen = sizeof(struct ether_header); 258 /* 259 * This is (presumably) a real Ethernet capture; give it a 260 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 261 * that an application can let you choose it, in case you're 262 * capturing DOCSIS traffic that a Cisco Cable Modem 263 * Termination System is putting out onto an Ethernet (it 264 * doesn't put an Ethernet header onto the wire, it puts raw 265 * DOCSIS frames out on the wire inside the low-level 266 * Ethernet framing). 267 * 268 * XXX - are there any sorts of "fake Ethernet" that have 269 * Ethernet link-layer headers but that *shouldn't offer 270 * DLT_DOCSIS as a Cisco CMTS won't put traffic onto it 271 * or get traffic bridged onto it? "el" is for ATM LANE 272 * Ethernet devices, so that might be the case for them; 273 * the same applies for "qaa" classical IP devices. If 274 * "fa" devices are for FORE SPANS, that'd apply to them 275 * as well; what are "cip" devices - some other ATM 276 * Classical IP devices? 277 */ 278 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 279 /* 280 * If that fails, just leave the list empty. 281 */ 282 if (p->dlt_list != NULL) { 283 p->dlt_list[0] = DLT_EN10MB; 284 p->dlt_list[1] = DLT_DOCSIS; 285 p->dlt_count = 2; 286 } 287 } else if (strncmp("ipg", p->opt.source, 3) == 0 || 288 strncmp("rns", p->opt.source, 3) == 0 || /* O2/200/2000 FDDI */ 289 strncmp("xpi", p->opt.source, 3) == 0) { 290 p->linktype = DLT_FDDI; 291 p->offset = 3; /* XXX yeah? */ 292 ll_hdrlen = 13; 293 } else if (strncmp("ppp", p->opt.source, 3) == 0) { 294 p->linktype = DLT_RAW; 295 ll_hdrlen = 0; /* DLT_RAW meaning "no PPP header, just the IP packet"? */ 296 } else if (strncmp("qfa", p->opt.source, 3) == 0) { 297 p->linktype = DLT_IP_OVER_FC; 298 ll_hdrlen = 24; 299 } else if (strncmp("pl", p->opt.source, 2) == 0) { 300 p->linktype = DLT_RAW; 301 ll_hdrlen = 0; /* Cray UNICOS/mp pseudo link */ 302 } else if (strncmp("lo", p->opt.source, 2) == 0) { 303 p->linktype = DLT_NULL; 304 ll_hdrlen = 4; 305 } else { 306 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 307 "snoop: unknown physical layer type"); 308 goto bad; 309 } 310 311 if (p->opt.rfmon) { 312 /* 313 * No monitor mode on Irix (no Wi-Fi devices on 314 * hardware supported by Irix). 315 */ 316 return (PCAP_ERROR_RFMON_NOTSUP); 317 } 318 319 #ifdef SIOCGIFMTU 320 /* 321 * XXX - IRIX appears to give you an error if you try to set the 322 * capture length to be greater than the MTU, so let's try to get 323 * the MTU first and, if that succeeds, trim the snap length 324 * to be no greater than the MTU. 325 */ 326 (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name)); 327 if (ioctl(fd, SIOCGIFMTU, (char *)&ifr) < 0) { 328 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMTU: %s", 329 pcap_strerror(errno)); 330 goto bad; 331 } 332 /* 333 * OK, we got it. 334 * 335 * XXX - some versions of IRIX 6.5 define "ifr_mtu" and have an 336 * "ifru_metric" member of the "ifr_ifru" union in an "ifreq" 337 * structure, others don't. 338 * 339 * I've no idea what's going on, so, if "ifr_mtu" isn't defined, 340 * we define it as "ifr_metric", as using that field appears to 341 * work on the versions that lack "ifr_mtu" (and, on those that 342 * don't lack it, "ifru_metric" and "ifru_mtu" are both "int" 343 * members of the "ifr_ifru" union, which suggests that they 344 * may be interchangeable in this case). 345 */ 346 #ifndef ifr_mtu 347 #define ifr_mtu ifr_metric 348 #endif 349 if (p->snapshot > ifr.ifr_mtu + ll_hdrlen) 350 p->snapshot = ifr.ifr_mtu + ll_hdrlen; 351 #endif 352 353 /* 354 * The argument to SIOCSNOOPLEN is the number of link-layer 355 * payload bytes to capture - it doesn't count link-layer 356 * header bytes. 357 */ 358 snooplen = p->snapshot - ll_hdrlen; 359 if (snooplen < 0) 360 snooplen = 0; 361 if (ioctl(fd, SIOCSNOOPLEN, &snooplen) < 0) { 362 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCSNOOPLEN: %s", 363 pcap_strerror(errno)); 364 goto bad; 365 } 366 v = 1; 367 if (ioctl(fd, SIOCSNOOPING, &v) < 0) { 368 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCSNOOPING: %s", 369 pcap_strerror(errno)); 370 goto bad; 371 } 372 373 p->bufsize = 4096; /* XXX */ 374 p->buffer = (u_char *)malloc(p->bufsize); 375 if (p->buffer == NULL) { 376 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", 377 pcap_strerror(errno)); 378 goto bad; 379 } 380 381 /* 382 * "p->fd" is a socket, so "select()" should work on it. 383 */ 384 p->selectable_fd = p->fd; 385 386 p->read_op = pcap_read_snoop; 387 p->inject_op = pcap_inject_snoop; 388 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 389 p->setdirection_op = NULL; /* Not implemented. */ 390 p->set_datalink_op = NULL; /* can't change data link type */ 391 p->getnonblock_op = pcap_getnonblock_fd; 392 p->setnonblock_op = pcap_setnonblock_fd; 393 p->stats_op = pcap_stats_snoop; 394 395 return (0); 396 bad: 397 pcap_cleanup_live_common(p); 398 return (PCAP_ERROR); 399 } 400 401 pcap_t * 402 pcap_create_interface(const char *device, char *ebuf) 403 { 404 pcap_t *p; 405 406 p = pcap_create_common(device, ebuf, sizeof (struct pcap_snoop)); 407 if (p == NULL) 408 return (NULL); 409 410 p->activate_op = pcap_activate_snoop; 411 return (p); 412 } 413 414 int 415 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 416 { 417 return (0); 418 } 419
