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 <errno.h> 47 #include <stdio.h> 48 49 #include "pcap-int.h" 50 51 #ifdef HAVE_OS_PROTO_H 52 #include "os-proto.h" 53 #endif 54 55 /* 56 * The chunk size for NIT. This is the amount of buffering 57 * done for read calls. 58 */ 59 #define CHUNKSIZE (2*1024) 60 61 /* 62 * The total buffer space used by NIT. 63 */ 64 #define BUFSPACE (4*CHUNKSIZE) 65 66 /* Forwards */ 67 static int nit_setflags(int, int, int, char *); 68 69 /* 70 * Private data for capturing on NIT devices. 71 */ 72 struct pcap_nit { 73 struct pcap_stat stat; 74 }; 75 76 static int 77 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps) 78 { 79 struct pcap_nit *pn = p->priv; 80 81 /* 82 * "ps_recv" counts packets handed to the filter, not packets 83 * that passed the filter. As filtering is done in userland, 84 * this does not include packets dropped because we ran out 85 * of buffer space. 86 * 87 * "ps_drop" presumably counts packets dropped by the socket 88 * because of flow control requirements or resource exhaustion; 89 * it doesn't count packets dropped by the interface driver. 90 * As filtering is done in userland, it counts packets regardless 91 * of whether they would've passed the filter. 92 * 93 * These statistics don't include packets not yet read from the 94 * kernel by libpcap or packets not yet read from libpcap by the 95 * application. 96 */ 97 *ps = pn->stat; 98 return (0); 99 } 100 101 static int 102 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 103 { 104 struct pcap_nit *pn = p->priv; 105 register int cc, n; 106 register u_char *bp, *cp, *ep; 107 register struct nit_hdr *nh; 108 register int caplen; 109 110 cc = p->cc; 111 if (cc == 0) { 112 cc = read(p->fd, (char *)p->buffer, p->bufsize); 113 if (cc < 0) { 114 if (errno == EWOULDBLOCK) 115 return (0); 116 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf), 117 errno, "pcap_read"); 118 return (-1); 119 } 120 bp = (u_char *)p->buffer; 121 } else 122 bp = p->bp; 123 124 /* 125 * Loop through each packet. The increment expression 126 * rounds up to the next int boundary past the end of 127 * the previous packet. 128 * 129 * This assumes that a single buffer of packets will have 130 * <= INT_MAX packets, so the packet count doesn't overflow. 131 */ 132 n = 0; 133 ep = bp + cc; 134 while (bp < ep) { 135 /* 136 * Has "pcap_breakloop()" been called? 137 * If so, return immediately - if we haven't read any 138 * packets, clear the flag and return -2 to indicate 139 * that we were told to break out of the loop, otherwise 140 * leave the flag set, so that the *next* call will break 141 * out of the loop without having read any packets, and 142 * return the number of packets we've processed so far. 143 */ 144 if (p->break_loop) { 145 if (n == 0) { 146 p->break_loop = 0; 147 return (-2); 148 } else { 149 p->cc = ep - bp; 150 p->bp = bp; 151 return (n); 152 } 153 } 154 155 nh = (struct nit_hdr *)bp; 156 cp = bp + sizeof(*nh); 157 158 switch (nh->nh_state) { 159 160 case NIT_CATCH: 161 break; 162 163 case NIT_NOMBUF: 164 case NIT_NOCLUSTER: 165 case NIT_NOSPACE: 166 pn->stat.ps_drop = nh->nh_dropped; 167 continue; 168 169 case NIT_SEQNO: 170 continue; 171 172 default: 173 snprintf(p->errbuf, sizeof(p->errbuf), 174 "bad nit state %d", nh->nh_state); 175 return (-1); 176 } 177 ++pn->stat.ps_recv; 178 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen + 179 sizeof(int) - 1) & ~(sizeof(int) - 1)); 180 181 caplen = nh->nh_wirelen; 182 if (caplen > p->snapshot) 183 caplen = p->snapshot; 184 if (pcap_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) { 185 struct pcap_pkthdr h; 186 h.ts = nh->nh_timestamp; 187 h.len = nh->nh_wirelen; 188 h.caplen = caplen; 189 (*callback)(user, &h, cp); 190 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) { 191 p->cc = ep - bp; 192 p->bp = bp; 193 return (n); 194 } 195 } 196 } 197 p->cc = 0; 198 return (n); 199 } 200 201 static int 202 pcap_inject_nit(pcap_t *p, const void *buf, int size) 203 { 204 struct sockaddr sa; 205 int ret; 206 207 memset(&sa, 0, sizeof(sa)); 208 strncpy(sa.sa_data, device, sizeof(sa.sa_data)); 209 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa)); 210 if (ret == -1) { 211 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 212 errno, "send"); 213 return (-1); 214 } 215 return (ret); 216 } 217 218 static int 219 nit_setflags(pcap_t *p) 220 { 221 struct nit_ioc nioc; 222 223 memset(&nioc, 0, sizeof(nioc)); 224 nioc.nioc_typetomatch = NT_ALLTYPES; 225 nioc.nioc_snaplen = p->snapshot; 226 nioc.nioc_bufalign = sizeof(int); 227 nioc.nioc_bufoffset = 0; 228 229 if (p->opt.buffer_size != 0) 230 nioc.nioc_bufspace = p->opt.buffer_size; 231 else { 232 /* Default buffer size */ 233 nioc.nioc_bufspace = BUFSPACE; 234 } 235 236 if (p->opt.immediate) { 237 /* 238 * XXX - will this cause packets to be delivered immediately? 239 * XXX - given that this is for SunOS prior to 4.0, do 240 * we care? 241 */ 242 nioc.nioc_chunksize = 0; 243 } else 244 nioc.nioc_chunksize = CHUNKSIZE; 245 if (p->opt.timeout != 0) { 246 nioc.nioc_flags |= NF_TIMEOUT; 247 nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000; 248 nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000; 249 } 250 if (p->opt.promisc) 251 nioc.nioc_flags |= NF_PROMISC; 252 253 if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) { 254 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 255 errno, "SIOCSNIT"); 256 return (-1); 257 } 258 return (0); 259 } 260 261 static int 262 pcap_activate_nit(pcap_t *p) 263 { 264 int fd; 265 struct sockaddr_nit snit; 266 267 if (p->opt.rfmon) { 268 /* 269 * No monitor mode on SunOS 3.x or earlier (no 270 * Wi-Fi *devices* for the hardware that supported 271 * them!). 272 */ 273 return (PCAP_ERROR_RFMON_NOTSUP); 274 } 275 276 /* 277 * Turn a negative snapshot value (invalid), a snapshot value of 278 * 0 (unspecified), or a value bigger than the normal maximum 279 * value, into the maximum allowed value. 280 * 281 * If some application really *needs* a bigger snapshot 282 * length, we should just increase MAXIMUM_SNAPLEN. 283 */ 284 if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN) 285 p->snapshot = MAXIMUM_SNAPLEN; 286 287 if (p->snapshot < 96) 288 /* 289 * NIT requires a snapshot length of at least 96. 290 */ 291 p->snapshot = 96; 292 293 memset(p, 0, sizeof(*p)); 294 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW); 295 if (fd < 0) { 296 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 297 errno, "socket"); 298 goto bad; 299 } 300 snit.snit_family = AF_NIT; 301 (void)strncpy(snit.snit_ifname, p->opt.device, NITIFSIZ); 302 303 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) { 304 /* 305 * XXX - there's probably a particular bind error that 306 * means "there's no such device" and a particular bind 307 * error that means "that device doesn't support NIT"; 308 * they might be the same error, if they both end up 309 * meaning "NIT doesn't know about that device". 310 */ 311 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 312 errno, "bind: %s", snit.snit_ifname); 313 goto bad; 314 } 315 if (nit_setflags(p) < 0) 316 goto bad; 317 318 /* 319 * NIT supports only ethernets. 320 */ 321 p->linktype = DLT_EN10MB; 322 323 p->bufsize = BUFSPACE; 324 p->buffer = malloc(p->bufsize); 325 if (p->buffer == NULL) { 326 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 327 errno, "malloc"); 328 goto bad; 329 } 330 331 /* 332 * "p->fd" is a socket, so "select()" should work on it. 333 */ 334 p->selectable_fd = p->fd; 335 336 /* 337 * This is (presumably) a real Ethernet capture; give it a 338 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 339 * that an application can let you choose it, in case you're 340 * capturing DOCSIS traffic that a Cisco Cable Modem 341 * Termination System is putting out onto an Ethernet (it 342 * doesn't put an Ethernet header onto the wire, it puts raw 343 * DOCSIS frames out on the wire inside the low-level 344 * Ethernet framing). 345 */ 346 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 347 /* 348 * If that fails, just leave the list empty. 349 */ 350 if (p->dlt_list != NULL) { 351 p->dlt_list[0] = DLT_EN10MB; 352 p->dlt_list[1] = DLT_DOCSIS; 353 p->dlt_count = 2; 354 } 355 356 p->read_op = pcap_read_nit; 357 p->inject_op = pcap_inject_nit; 358 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 359 p->setdirection_op = NULL; /* Not implemented. */ 360 p->set_datalink_op = NULL; /* can't change data link type */ 361 p->getnonblock_op = pcap_getnonblock_fd; 362 p->setnonblock_op = pcap_setnonblock_fd; 363 p->stats_op = pcap_stats_nit; 364 365 return (0); 366 bad: 367 pcap_cleanup_live_common(p); 368 return (PCAP_ERROR); 369 } 370 371 pcap_t * 372 pcap_create_interface(const char *device _U_, char *ebuf) 373 { 374 pcap_t *p; 375 376 p = PCAP_CREATE_COMMON(ebuf, struct pcap_nit); 377 if (p == NULL) 378 return (NULL); 379 380 p->activate_op = pcap_activate_nit; 381 return (p); 382 } 383 384 /* 385 * XXX - there's probably a particular bind error that means "that device 386 * doesn't support NIT"; if so, we should try a bind and use that. 387 */ 388 static int 389 can_be_bound(const char *name _U_) 390 { 391 return (1); 392 } 393 394 static int 395 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_) 396 { 397 /* 398 * Nothing we can do. 399 * XXX - is there a way to find out whether an adapter has 400 * something plugged into it? 401 */ 402 return (0); 403 } 404 405 int 406 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf) 407 { 408 return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound, 409 get_if_flags)); 410 } 411 412 /* 413 * Libpcap version string. 414 */ 415 const char * 416 pcap_lib_version(void) 417 { 418 return (PCAP_VERSION_STRING); 419 } 420