1 /* 2 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996 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/types.h> 27 #include <sys/time.h> 28 #include <sys/timeb.h> 29 #include <sys/file.h> 30 #include <sys/ioctl.h> 31 #include <sys/socket.h> 32 33 #include <net/if.h> 34 #include <net/nit.h> 35 36 #include <netinet/in.h> 37 #include <netinet/in_systm.h> 38 #include <netinet/ip.h> 39 #include <netinet/if_ether.h> 40 #include <netinet/ip_var.h> 41 #include <netinet/udp.h> 42 #include <netinet/udp_var.h> 43 #include <netinet/tcp.h> 44 #include <netinet/tcpip.h> 45 46 #include <ctype.h> 47 #include <errno.h> 48 #include <stdio.h> 49 50 #include "pcap-int.h" 51 52 #ifdef HAVE_OS_PROTO_H 53 #include "os-proto.h" 54 #endif 55 56 /* 57 * The chunk size for NIT. This is the amount of buffering 58 * done for read calls. 59 */ 60 #define CHUNKSIZE (2*1024) 61 62 /* 63 * The total buffer space used by NIT. 64 */ 65 #define BUFSPACE (4*CHUNKSIZE) 66 67 /* Forwards */ 68 static int nit_setflags(int, int, int, char *); 69 70 /* 71 * Private data for capturing on NIT devices. 72 */ 73 struct pcap_nit { 74 struct pcap_stat stat; 75 }; 76 77 static int 78 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps) 79 { 80 struct pcap_nit *pn = p->priv; 81 82 /* 83 * "ps_recv" counts packets handed to the filter, not packets 84 * that passed the filter. As filtering is done in userland, 85 * this does not include packets dropped because we ran out 86 * of buffer space. 87 * 88 * "ps_drop" presumably counts packets dropped by the socket 89 * because of flow control requirements or resource exhaustion; 90 * it doesn't count packets dropped by the interface driver. 91 * As filtering is done in userland, it counts packets regardless 92 * of whether they would've passed the filter. 93 * 94 * These statistics don't include packets not yet read from the 95 * kernel by libpcap or packets not yet read from libpcap by the 96 * application. 97 */ 98 *ps = pn->stat; 99 return (0); 100 } 101 102 static int 103 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 104 { 105 struct pcap_nit *pn = p->priv; 106 register int cc, n; 107 register u_char *bp, *cp, *ep; 108 register struct nit_hdr *nh; 109 register int caplen; 110 111 cc = p->cc; 112 if (cc == 0) { 113 cc = read(p->fd, (char *)p->buffer, p->bufsize); 114 if (cc < 0) { 115 if (errno == EWOULDBLOCK) 116 return (0); 117 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf), 118 errno, "pcap_read"); 119 return (-1); 120 } 121 bp = (u_char *)p->buffer; 122 } else 123 bp = p->bp; 124 125 /* 126 * Loop through each packet. The increment expression 127 * rounds up to the next int boundary past the end of 128 * the previous packet. 129 */ 130 n = 0; 131 ep = bp + cc; 132 while (bp < ep) { 133 /* 134 * Has "pcap_breakloop()" been called? 135 * If so, return immediately - if we haven't read any 136 * packets, clear the flag and return -2 to indicate 137 * that we were told to break out of the loop, otherwise 138 * leave the flag set, so that the *next* call will break 139 * out of the loop without having read any packets, and 140 * return the number of packets we've processed so far. 141 */ 142 if (p->break_loop) { 143 if (n == 0) { 144 p->break_loop = 0; 145 return (-2); 146 } else { 147 p->cc = ep - bp; 148 p->bp = bp; 149 return (n); 150 } 151 } 152 153 nh = (struct nit_hdr *)bp; 154 cp = bp + sizeof(*nh); 155 156 switch (nh->nh_state) { 157 158 case NIT_CATCH: 159 break; 160 161 case NIT_NOMBUF: 162 case NIT_NOCLUSTER: 163 case NIT_NOSPACE: 164 pn->stat.ps_drop = nh->nh_dropped; 165 continue; 166 167 case NIT_SEQNO: 168 continue; 169 170 default: 171 pcap_snprintf(p->errbuf, sizeof(p->errbuf), 172 "bad nit state %d", nh->nh_state); 173 return (-1); 174 } 175 ++pn->stat.ps_recv; 176 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen + 177 sizeof(int) - 1) & ~(sizeof(int) - 1)); 178 179 caplen = nh->nh_wirelen; 180 if (caplen > p->snapshot) 181 caplen = p->snapshot; 182 if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) { 183 struct pcap_pkthdr h; 184 h.ts = nh->nh_timestamp; 185 h.len = nh->nh_wirelen; 186 h.caplen = caplen; 187 (*callback)(user, &h, cp); 188 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) { 189 p->cc = ep - bp; 190 p->bp = bp; 191 return (n); 192 } 193 } 194 } 195 p->cc = 0; 196 return (n); 197 } 198 199 static int 200 pcap_inject_nit(pcap_t *p, const void *buf, size_t size) 201 { 202 struct sockaddr sa; 203 int ret; 204 205 memset(&sa, 0, sizeof(sa)); 206 strncpy(sa.sa_data, device, sizeof(sa.sa_data)); 207 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa)); 208 if (ret == -1) { 209 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 210 errno, "send"); 211 return (-1); 212 } 213 return (ret); 214 } 215 216 static int 217 nit_setflags(pcap_t *p) 218 { 219 struct nit_ioc nioc; 220 221 memset(&nioc, 0, sizeof(nioc)); 222 nioc.nioc_typetomatch = NT_ALLTYPES; 223 nioc.nioc_snaplen = p->snapshot; 224 nioc.nioc_bufalign = sizeof(int); 225 nioc.nioc_bufoffset = 0; 226 227 if (p->opt.buffer_size != 0) 228 nioc.nioc_bufspace = p->opt.buffer_size; 229 else { 230 /* Default buffer size */ 231 nioc.nioc_bufspace = BUFSPACE; 232 } 233 234 if (p->opt.immediate) { 235 /* 236 * XXX - will this cause packets to be delivered immediately? 237 * XXX - given that this is for SunOS prior to 4.0, do 238 * we care? 239 */ 240 nioc.nioc_chunksize = 0; 241 } else 242 nioc.nioc_chunksize = CHUNKSIZE; 243 if (p->opt.timeout != 0) { 244 nioc.nioc_flags |= NF_TIMEOUT; 245 nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000; 246 nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000; 247 } 248 if (p->opt.promisc) 249 nioc.nioc_flags |= NF_PROMISC; 250 251 if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) { 252 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 253 errno, "SIOCSNIT"); 254 return (-1); 255 } 256 return (0); 257 } 258 259 static int 260 pcap_activate_nit(pcap_t *p) 261 { 262 int fd; 263 struct sockaddr_nit snit; 264 265 if (p->opt.rfmon) { 266 /* 267 * No monitor mode on SunOS 3.x or earlier (no 268 * Wi-Fi *devices* for the hardware that supported 269 * them!). 270 */ 271 return (PCAP_ERROR_RFMON_NOTSUP); 272 } 273 274 /* 275 * Turn a negative snapshot value (invalid), a snapshot value of 276 * 0 (unspecified), or a value bigger than the normal maximum 277 * value, into the maximum allowed value. 278 * 279 * If some application really *needs* a bigger snapshot 280 * length, we should just increase MAXIMUM_SNAPLEN. 281 */ 282 if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN) 283 p->snapshot = MAXIMUM_SNAPLEN; 284 285 if (p->snapshot < 96) 286 /* 287 * NIT requires a snapshot length of at least 96. 288 */ 289 p->snapshot = 96; 290 291 memset(p, 0, sizeof(*p)); 292 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW); 293 if (fd < 0) { 294 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 295 errno, "socket"); 296 goto bad; 297 } 298 snit.snit_family = AF_NIT; 299 (void)strncpy(snit.snit_ifname, p->opt.device, NITIFSIZ); 300 301 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) { 302 /* 303 * XXX - there's probably a particular bind error that 304 * means "there's no such device" and a particular bind 305 * error that means "that device doesn't support NIT"; 306 * they might be the same error, if they both end up 307 * meaning "NIT doesn't know about that device". 308 */ 309 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 310 errno, "bind: %s", snit.snit_ifname); 311 goto bad; 312 } 313 if (nit_setflags(p) < 0) 314 goto bad; 315 316 /* 317 * NIT supports only ethernets. 318 */ 319 p->linktype = DLT_EN10MB; 320 321 p->bufsize = BUFSPACE; 322 p->buffer = malloc(p->bufsize); 323 if (p->buffer == NULL) { 324 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 325 errno, "malloc"); 326 goto bad; 327 } 328 329 /* 330 * "p->fd" is a socket, so "select()" should work on it. 331 */ 332 p->selectable_fd = p->fd; 333 334 /* 335 * This is (presumably) a real Ethernet capture; give it a 336 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 337 * that an application can let you choose it, in case you're 338 * capturing DOCSIS traffic that a Cisco Cable Modem 339 * Termination System is putting out onto an Ethernet (it 340 * doesn't put an Ethernet header onto the wire, it puts raw 341 * DOCSIS frames out on the wire inside the low-level 342 * Ethernet framing). 343 */ 344 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 345 /* 346 * If that fails, just leave the list empty. 347 */ 348 if (p->dlt_list != NULL) { 349 p->dlt_list[0] = DLT_EN10MB; 350 p->dlt_list[1] = DLT_DOCSIS; 351 p->dlt_count = 2; 352 } 353 354 p->read_op = pcap_read_nit; 355 p->inject_op = pcap_inject_nit; 356 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 357 p->setdirection_op = NULL; /* Not implemented. */ 358 p->set_datalink_op = NULL; /* can't change data link type */ 359 p->getnonblock_op = pcap_getnonblock_fd; 360 p->setnonblock_op = pcap_setnonblock_fd; 361 p->stats_op = pcap_stats_nit; 362 363 return (0); 364 bad: 365 pcap_cleanup_live_common(p); 366 return (PCAP_ERROR); 367 } 368 369 pcap_t * 370 pcap_create_interface(const char *device _U_, char *ebuf) 371 { 372 pcap_t *p; 373 374 p = pcap_create_common(ebuf, sizeof (struct pcap_nit)); 375 if (p == NULL) 376 return (NULL); 377 378 p->activate_op = pcap_activate_nit; 379 return (p); 380 } 381 382 /* 383 * XXX - there's probably a particular bind error that means "that device 384 * doesn't support NIT"; if so, we should try a bind and use that. 385 */ 386 static int 387 can_be_bound(const char *name _U_) 388 { 389 return (1); 390 } 391 392 static int 393 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_) 394 { 395 /* 396 * Nothing we can do. 397 * XXX - is there a way to find out whether an adapter has 398 * something plugged into it? 399 */ 400 return (0); 401 } 402 403 int 404 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf) 405 { 406 return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound, 407 get_if_flags)); 408 } 409 410 /* 411 * Libpcap version string. 412 */ 413 const char * 414 pcap_lib_version(void) 415 { 416 return (PCAP_VERSION_STRING); 417 } 418