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 * Modifications made to accommodate the new SunOS4.0 NIT facility by 22 * Micky Liu, micky@cunixc.cc.columbia.edu, Columbia University in May, 1989. 23 * This module now handles the STREAMS based NIT. 24 */ 25 26 #ifdef HAVE_CONFIG_H 27 #include <config.h> 28 #endif 29 30 #include <sys/types.h> 31 #include <sys/time.h> 32 #include <sys/timeb.h> 33 #include <sys/dir.h> 34 #include <sys/fcntlcom.h> 35 #include <sys/file.h> 36 #include <sys/ioctl.h> 37 #include <sys/socket.h> 38 #include <sys/stropts.h> 39 40 #include <net/if.h> 41 #include <net/nit.h> 42 #include <net/nit_if.h> 43 #include <net/nit_pf.h> 44 #include <net/nit_buf.h> 45 46 #include <netinet/in.h> 47 #include <netinet/in_systm.h> 48 #include <netinet/ip.h> 49 #include <netinet/if_ether.h> 50 #include <netinet/ip_var.h> 51 #include <netinet/udp.h> 52 #include <netinet/udp_var.h> 53 #include <netinet/tcp.h> 54 #include <netinet/tcpip.h> 55 56 #include <errno.h> 57 #include <stdio.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 #include "pcap-int.h" 62 63 #ifdef HAVE_OS_PROTO_H 64 #include "os-proto.h" 65 #endif 66 67 /* 68 * The chunk size for NIT. This is the amount of buffering 69 * done for read calls. 70 */ 71 #define CHUNKSIZE (2*1024) 72 73 /* 74 * The total buffer space used by NIT. 75 */ 76 #define BUFSPACE (4*CHUNKSIZE) 77 78 /* Forwards */ 79 static int nit_setflags(int, int, int, char *); 80 81 /* 82 * Private data for capturing on STREAMS NIT devices. 83 */ 84 struct pcap_snit { 85 struct pcap_stat stat; 86 }; 87 88 static int 89 pcap_stats_snit(pcap_t *p, struct pcap_stat *ps) 90 { 91 struct pcap_snit *psn = p->priv; 92 93 /* 94 * "ps_recv" counts packets handed to the filter, not packets 95 * that passed the filter. As filtering is done in userland, 96 * this does not include packets dropped because we ran out 97 * of buffer space. 98 * 99 * "ps_drop" counts packets dropped inside the "/dev/nit" 100 * device because of flow control requirements or resource 101 * exhaustion; it doesn't count packets dropped by the 102 * interface driver, or packets dropped upstream. As filtering 103 * is done in userland, it counts packets regardless of whether 104 * they would've passed the filter. 105 * 106 * These statistics don't include packets not yet read from the 107 * kernel by libpcap or packets not yet read from libpcap by the 108 * application. 109 */ 110 *ps = psn->stat; 111 return (0); 112 } 113 114 static int 115 pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 116 { 117 struct pcap_snit *psn = p->priv; 118 register int cc, n; 119 register u_char *bp, *cp, *ep; 120 register struct nit_bufhdr *hdrp; 121 register struct nit_iftime *ntp; 122 register struct nit_iflen *nlp; 123 register struct nit_ifdrops *ndp; 124 register int caplen; 125 126 cc = p->cc; 127 if (cc == 0) { 128 cc = read(p->fd, (char *)p->buffer, p->bufsize); 129 if (cc < 0) { 130 if (errno == EWOULDBLOCK) 131 return (0); 132 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf), 133 errno, "pcap_read"); 134 return (-1); 135 } 136 bp = (u_char *)p->buffer; 137 } else 138 bp = p->bp; 139 140 /* 141 * loop through each snapshot in the chunk 142 * 143 * This assumes that a single buffer of packets will have 144 * <= INT_MAX packets, so the packet count doesn't overflow. 145 */ 146 n = 0; 147 ep = bp + cc; 148 while (bp < ep) { 149 /* 150 * Has "pcap_breakloop()" been called? 151 * If so, return immediately - if we haven't read any 152 * packets, clear the flag and return -2 to indicate 153 * that we were told to break out of the loop, otherwise 154 * leave the flag set, so that the *next* call will break 155 * out of the loop without having read any packets, and 156 * return the number of packets we've processed so far. 157 */ 158 if (p->break_loop) { 159 if (n == 0) { 160 p->break_loop = 0; 161 return (-2); 162 } else { 163 p->bp = bp; 164 p->cc = ep - bp; 165 return (n); 166 } 167 } 168 169 ++psn->stat.ps_recv; 170 cp = bp; 171 172 /* get past NIT buffer */ 173 hdrp = (struct nit_bufhdr *)cp; 174 cp += sizeof(*hdrp); 175 176 /* get past NIT timer */ 177 ntp = (struct nit_iftime *)cp; 178 cp += sizeof(*ntp); 179 180 ndp = (struct nit_ifdrops *)cp; 181 psn->stat.ps_drop = ndp->nh_drops; 182 cp += sizeof *ndp; 183 184 /* get past packet len */ 185 nlp = (struct nit_iflen *)cp; 186 cp += sizeof(*nlp); 187 188 /* next snapshot */ 189 bp += hdrp->nhb_totlen; 190 191 caplen = nlp->nh_pktlen; 192 if (caplen > p->snapshot) 193 caplen = p->snapshot; 194 195 if (pcap_filter(p->fcode.bf_insns, cp, nlp->nh_pktlen, caplen)) { 196 struct pcap_pkthdr h; 197 h.ts = ntp->nh_timestamp; 198 h.len = nlp->nh_pktlen; 199 h.caplen = caplen; 200 (*callback)(user, &h, cp); 201 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) { 202 p->cc = ep - bp; 203 p->bp = bp; 204 return (n); 205 } 206 } 207 } 208 p->cc = 0; 209 return (n); 210 } 211 212 static int 213 pcap_inject_snit(pcap_t *p, const void *buf, int size) 214 { 215 struct strbuf ctl, data; 216 217 /* 218 * XXX - can we just do 219 * 220 ret = write(pd->f, buf, size); 221 */ 222 ctl.len = sizeof(*sa); /* XXX - what was this? */ 223 ctl.buf = (char *)sa; 224 data.buf = buf; 225 data.len = size; 226 ret = putmsg(p->fd, &ctl, &data); 227 if (ret == -1) { 228 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 229 errno, "send"); 230 return (-1); 231 } 232 return (ret); 233 } 234 235 static int 236 nit_setflags(pcap_t *p) 237 { 238 bpf_u_int32 flags; 239 struct strioctl si; 240 u_int zero = 0; 241 struct timeval timeout; 242 243 if (p->opt.immediate) { 244 /* 245 * Set the chunk size to zero, so that chunks get sent 246 * up immediately. 247 */ 248 si.ic_cmd = NIOCSCHUNK; 249 si.ic_len = sizeof(zero); 250 si.ic_dp = (char *)&zero; 251 if (ioctl(p->fd, I_STR, (char *)&si) < 0) { 252 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 253 errno, "NIOCSCHUNK"); 254 return (-1); 255 } 256 } 257 si.ic_timout = INFTIM; 258 if (p->opt.timeout != 0) { 259 timeout.tv_sec = p->opt.timeout / 1000; 260 timeout.tv_usec = (p->opt.timeout * 1000) % 1000000; 261 si.ic_cmd = NIOCSTIME; 262 si.ic_len = sizeof(timeout); 263 si.ic_dp = (char *)&timeout; 264 if (ioctl(p->fd, I_STR, (char *)&si) < 0) { 265 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 266 errno, "NIOCSTIME"); 267 return (-1); 268 } 269 } 270 flags = NI_TIMESTAMP | NI_LEN | NI_DROPS; 271 if (p->opt.promisc) 272 flags |= NI_PROMISC; 273 si.ic_cmd = NIOCSFLAGS; 274 si.ic_len = sizeof(flags); 275 si.ic_dp = (char *)&flags; 276 if (ioctl(p->fd, I_STR, (char *)&si) < 0) { 277 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 278 errno, "NIOCSFLAGS"); 279 return (-1); 280 } 281 return (0); 282 } 283 284 static int 285 pcap_activate_snit(pcap_t *p) 286 { 287 struct strioctl si; /* struct for ioctl() */ 288 struct ifreq ifr; /* interface request struct */ 289 int chunksize = CHUNKSIZE; 290 int fd; 291 static const char dev[] = "/dev/nit"; 292 int err; 293 294 if (p->opt.rfmon) { 295 /* 296 * No monitor mode on SunOS 4.x (no Wi-Fi devices on 297 * hardware supported by SunOS 4.x). 298 */ 299 return (PCAP_ERROR_RFMON_NOTSUP); 300 } 301 302 /* 303 * Turn a negative snapshot value (invalid), a snapshot value of 304 * 0 (unspecified), or a value bigger than the normal maximum 305 * value, into the maximum allowed value. 306 * 307 * If some application really *needs* a bigger snapshot 308 * length, we should just increase MAXIMUM_SNAPLEN. 309 */ 310 if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN) 311 p->snapshot = MAXIMUM_SNAPLEN; 312 313 if (p->snapshot < 96) 314 /* 315 * NIT requires a snapshot length of at least 96. 316 */ 317 p->snapshot = 96; 318 319 /* 320 * Initially try a read/write open (to allow the inject 321 * method to work). If that fails due to permission 322 * issues, fall back to read-only. This allows a 323 * non-root user to be granted specific access to pcap 324 * capabilities via file permissions. 325 * 326 * XXX - we should have an API that has a flag that 327 * controls whether to open read-only or read-write, 328 * so that denial of permission to send (or inability 329 * to send, if sending packets isn't supported on 330 * the device in question) can be indicated at open 331 * time. 332 */ 333 p->fd = fd = open(dev, O_RDWR); 334 if (fd < 0 && errno == EACCES) 335 p->fd = fd = open(dev, O_RDONLY); 336 if (fd < 0) { 337 if (errno == EACCES) { 338 err = PCAP_ERROR_PERM_DENIED; 339 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 340 "Attempt to open %s failed with EACCES - root privileges may be required", 341 dev); 342 } else { 343 err = PCAP_ERROR; 344 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 345 errno, "%s", dev); 346 } 347 goto bad; 348 } 349 350 /* arrange to get discrete messages from the STREAM and use NIT_BUF */ 351 if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) { 352 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 353 errno, "I_SRDOPT"); 354 err = PCAP_ERROR; 355 goto bad; 356 } 357 if (ioctl(fd, I_PUSH, "nbuf") < 0) { 358 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 359 errno, "push nbuf"); 360 err = PCAP_ERROR; 361 goto bad; 362 } 363 /* set the chunksize */ 364 si.ic_cmd = NIOCSCHUNK; 365 si.ic_timout = INFTIM; 366 si.ic_len = sizeof(chunksize); 367 si.ic_dp = (char *)&chunksize; 368 if (ioctl(fd, I_STR, (char *)&si) < 0) { 369 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 370 errno, "NIOCSCHUNK"); 371 err = PCAP_ERROR; 372 goto bad; 373 } 374 375 /* request the interface */ 376 strncpy(ifr.ifr_name, p->opt.device, sizeof(ifr.ifr_name)); 377 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0'; 378 si.ic_cmd = NIOCBIND; 379 si.ic_len = sizeof(ifr); 380 si.ic_dp = (char *)𝔦 381 if (ioctl(fd, I_STR, (char *)&si) < 0) { 382 /* 383 * XXX - is there an error that means "no such device"? 384 * Is there one that means "that device doesn't support 385 * STREAMS NIT"? 386 */ 387 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 388 errno, "NIOCBIND: %s", ifr.ifr_name); 389 err = PCAP_ERROR; 390 goto bad; 391 } 392 393 /* set the snapshot length */ 394 si.ic_cmd = NIOCSSNAP; 395 si.ic_len = sizeof(p->snapshot); 396 si.ic_dp = (char *)&p->snapshot; 397 if (ioctl(fd, I_STR, (char *)&si) < 0) { 398 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 399 errno, "NIOCSSNAP"); 400 err = PCAP_ERROR; 401 goto bad; 402 } 403 if (nit_setflags(p) < 0) { 404 err = PCAP_ERROR; 405 goto bad; 406 } 407 408 (void)ioctl(fd, I_FLUSH, (char *)FLUSHR); 409 /* 410 * NIT supports only ethernets. 411 */ 412 p->linktype = DLT_EN10MB; 413 414 p->bufsize = BUFSPACE; 415 p->buffer = malloc(p->bufsize); 416 if (p->buffer == NULL) { 417 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, 418 errno, "malloc"); 419 err = PCAP_ERROR; 420 goto bad; 421 } 422 423 /* 424 * "p->fd" is an FD for a STREAMS device, so "select()" and 425 * "poll()" should work on it. 426 */ 427 p->selectable_fd = p->fd; 428 429 /* 430 * This is (presumably) a real Ethernet capture; give it a 431 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 432 * that an application can let you choose it, in case you're 433 * capturing DOCSIS traffic that a Cisco Cable Modem 434 * Termination System is putting out onto an Ethernet (it 435 * doesn't put an Ethernet header onto the wire, it puts raw 436 * DOCSIS frames out on the wire inside the low-level 437 * Ethernet framing). 438 */ 439 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 440 /* 441 * If that fails, just leave the list empty. 442 */ 443 if (p->dlt_list != NULL) { 444 p->dlt_list[0] = DLT_EN10MB; 445 p->dlt_list[1] = DLT_DOCSIS; 446 p->dlt_count = 2; 447 } 448 449 p->read_op = pcap_read_snit; 450 p->inject_op = pcap_inject_snit; 451 p->setfilter_op = install_bpf_program; /* no kernel filtering */ 452 p->setdirection_op = NULL; /* Not implemented. */ 453 p->set_datalink_op = NULL; /* can't change data link type */ 454 p->getnonblock_op = pcap_getnonblock_fd; 455 p->setnonblock_op = pcap_setnonblock_fd; 456 p->stats_op = pcap_stats_snit; 457 458 return (0); 459 bad: 460 pcap_cleanup_live_common(p); 461 return (err); 462 } 463 464 pcap_t * 465 pcap_create_interface(const char *device _U_, char *ebuf) 466 { 467 pcap_t *p; 468 469 p = PCAP_CREATE_COMMON(ebuf, struct pcap_snit); 470 if (p == NULL) 471 return (NULL); 472 473 p->activate_op = pcap_activate_snit; 474 return (p); 475 } 476 477 /* 478 * XXX - there's probably a NIOCBIND error that means "that device 479 * doesn't support NIT"; if so, we should try an NIOCBIND and use that. 480 */ 481 static int 482 can_be_bound(const char *name _U_) 483 { 484 return (1); 485 } 486 487 static int 488 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_) 489 { 490 /* 491 * Nothing we can do. 492 * XXX - is there a way to find out whether an adapter has 493 * something plugged into it? 494 */ 495 return (0); 496 } 497 498 int 499 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf) 500 { 501 return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound, 502 get_if_flags)); 503 } 504 505 /* 506 * Libpcap version string. 507 */ 508 const char * 509 pcap_lib_version(void) 510 { 511 return (PCAP_VERSION_STRING); 512 } 513