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