The Tcpdump Group git mirrors - libpcap/blob - pcap-snf.c

   1 #ifdef HAVE_CONFIG_H
   2 #include <config.h>
   3 #endif
   4
   5 #ifndef _WIN32
   6 #include <sys/param.h>
   7 #endif /* !_WIN32 */
   8
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <errno.h>
  12 #include <limits.h> /* for INT_MAX */
  13
  14 #ifndef _WIN32
  15 #include <netinet/in.h>
  16 #include <sys/mman.h>
  17 #include <sys/socket.h>
  18 #include <sys/types.h>
  19 #include <unistd.h>
  20 #endif /* !_WIN32 */
  21
  22 #include <snf.h>
  23 #if SNF_VERSION_API >= 0x0003
  24 #define SNF_HAVE_INJECT_API
  25 #endif
  26
  27 #include "pcap-int.h"
  28 #include "pcap-snf.h"
  29
  30 /*
  31  * Private data for capturing on SNF devices.
  32  */
  33 struct pcap_snf {
  34         snf_handle_t snf_handle; /* opaque device handle */
  35         snf_ring_t   snf_ring;   /* opaque device ring handle */
  36 #ifdef SNF_HAVE_INJECT_API
  37         snf_inject_t snf_inj;    /* inject handle, if inject is used */
  38 #endif
  39         int          snf_timeout;
  40         int          snf_boardnum;
  41 };
  42
  43 static int
  44 snf_set_datalink(pcap_t *p, int dlt)
  45 {
  46         p->linktype = dlt;
  47         return (0);
  48 }
  49
  50 static int
  51 snf_pcap_stats(pcap_t *p, struct pcap_stat *ps)
  52 {
  53         struct snf_ring_stats stats;
  54         struct pcap_snf *snfps = p->priv;
  55         int rc;
  56
  57         if ((rc = snf_ring_getstats(snfps->snf_ring, &stats))) {
  58                 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
  59                     rc, "snf_get_stats");
  60                 return -1;
  61         }
  62         ps->ps_recv = stats.ring_pkt_recv + stats.ring_pkt_overflow;
  63         ps->ps_drop = stats.ring_pkt_overflow;
  64         ps->ps_ifdrop = stats.nic_pkt_overflow + stats.nic_pkt_bad;
  65         return 0;
  66 }
  67
  68 static void
  69 snf_platform_cleanup(pcap_t *p)
  70 {
  71         struct pcap_snf *ps = p->priv;
  72
  73 #ifdef SNF_HAVE_INJECT_API
  74         if (ps->snf_inj)
  75                 snf_inject_close(ps->snf_inj);
  76 #endif
  77         snf_ring_close(ps->snf_ring);
  78         snf_close(ps->snf_handle);
  79         pcap_cleanup_live_common(p);
  80 }
  81
  82 static int
  83 snf_getnonblock(pcap_t *p)
  84 {
  85         struct pcap_snf *ps = p->priv;
  86
  87         return (ps->snf_timeout == 0);
  88 }
  89
  90 static int
  91 snf_setnonblock(pcap_t *p, int nonblock)
  92 {
  93         struct pcap_snf *ps = p->priv;
  94
  95         if (nonblock)
  96                 ps->snf_timeout = 0;
  97         else {
  98                 if (p->opt.timeout <= 0)
  99                         ps->snf_timeout = -1; /* forever */
 100                 else
 101                         ps->snf_timeout = p->opt.timeout;
 102         }
 103         return (0);
 104 }
 105
 106 #define _NSEC_PER_SEC 1000000000
 107
 108 static inline
 109 struct timeval
 110 snf_timestamp_to_timeval(const int64_t ts_nanosec, const int tstamp_precision)
 111 {
 112         struct timeval tv;
 113         long tv_nsec;
 114         const static struct timeval zero_timeval;
 115
 116         if (ts_nanosec == 0)
 117                 return zero_timeval;
 118
 119         tv.tv_sec = ts_nanosec / _NSEC_PER_SEC;
 120         tv_nsec = (ts_nanosec % _NSEC_PER_SEC);
 121
 122         /* libpcap expects tv_usec to be nanos if using nanosecond precision. */
 123         if (tstamp_precision == PCAP_TSTAMP_PRECISION_NANO)
 124                 tv.tv_usec = tv_nsec;
 125         else
 126                 tv.tv_usec = tv_nsec / 1000;
 127
 128         return tv;
 129 }
 130
 131 static int
 132 snf_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
 133 {
 134         struct pcap_snf *ps = p->priv;
 135         struct pcap_pkthdr hdr;
 136         int i, flags, err, caplen, n;
 137         struct snf_recv_req req;
 138         int nonblock, timeout;
 139
 140         /*
 141          * This can conceivably process more than INT_MAX packets,
 142          * which would overflow the packet count, causing it either
 143          * to look like a negative number, and thus cause us to
 144          * return a value that looks like an error, or overflow
 145          * back into positive territory, and thus cause us to
 146          * return a too-low count.
 147          *
 148          * Therefore, if the packet count is unlimited, we clip
 149          * it at INT_MAX; this routine is not expected to
 150          * process packets indefinitely, so that's not an issue.
 151          */
 152         if (PACKET_COUNT_IS_UNLIMITED(cnt))
 153                 cnt = INT_MAX;
 154
 155         n = 0;
 156         timeout = ps->snf_timeout;
 157         while (n < cnt) {
 158                 /*
 159                  * Has "pcap_breakloop()" been called?
 160                  */
 161                 if (p->break_loop) {
 162                         if (n == 0) {
 163                                 p->break_loop = 0;
 164                                 return (-2);
 165                         } else {
 166                                 return (n);
 167                         }
 168                 }
 169
 170                 err = snf_ring_recv(ps->snf_ring, timeout, &req);
 171
 172                 if (err) {
 173                         if (err == EBUSY || err == EAGAIN) {
 174                                 return (n);
 175                         }
 176                         else if (err == EINTR) {
 177                                 timeout = 0;
 178                                 continue;
 179                         }
 180                         else {
 181                                 pcap_fmt_errmsg_for_errno(p->errbuf,
 182                                     PCAP_ERRBUF_SIZE, err, "snf_read");
 183                                 return -1;
 184                         }
 185                 }
 186
 187                 caplen = req.length;
 188                 if (caplen > p->snapshot)
 189                         caplen = p->snapshot;
 190
 191                 if ((p->fcode.bf_insns == NULL) ||
 192                      pcap_filter(p->fcode.bf_insns, req.pkt_addr, req.length, caplen)) {
 193                         hdr.ts = snf_timestamp_to_timeval(req.timestamp, p->opt.tstamp_precision);
 194                         hdr.caplen = caplen;
 195                         hdr.len = req.length;
 196                         callback(user, &hdr, req.pkt_addr);
 197                         n++;
 198                 }
 199
 200                 /* After one successful packet is received, we won't block
 201                 * again for that timeout. */
 202                 if (timeout != 0)
 203                         timeout = 0;
 204         }
 205         return (n);
 206 }
 207
 208 static int
 209 snf_inject(pcap_t *p, const void *buf _U_, int size _U_)
 210 {
 211 #ifdef SNF_HAVE_INJECT_API
 212         struct pcap_snf *ps = p->priv;
 213         int rc;
 214         if (ps->snf_inj == NULL) {
 215                 rc = snf_inject_open(ps->snf_boardnum, 0, &ps->snf_inj);
 216                 if (rc) {
 217                         pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 218                             rc, "snf_inject_open");
 219                         return (-1);
 220                 }
 221         }
 222
 223         rc = snf_inject_send(ps->snf_inj, -1, 0, buf, size);
 224         if (!rc) {
 225                 return (size);
 226         }
 227         else {
 228                 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 229                     rc, "snf_inject_send");
 230                 return (-1);
 231         }
 232 #else
 233         pcap_strlcpy(p->errbuf, "Sending packets isn't supported with this snf version",
 234             PCAP_ERRBUF_SIZE);
 235         return (-1);
 236 #endif
 237 }
 238
 239 static int
 240 snf_activate(pcap_t* p)
 241 {
 242         struct pcap_snf *ps = p->priv;
 243         char *device = p->opt.device;
 244         const char *nr = NULL;
 245         int err;
 246         int flags = -1, ring_id = -1;
 247
 248         if (device == NULL) {
 249                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "device is NULL");
 250                 return -1;
 251         }
 252
 253         /* In Libpcap, we set pshared by default if NUM_RINGS is set to > 1.
 254          * Since libpcap isn't thread-safe */
 255         if ((nr = getenv("SNF_FLAGS")) && *nr)
 256                 flags = strtol(nr, NULL, 0);
 257         else if ((nr = getenv("SNF_NUM_RINGS")) && *nr && atoi(nr) > 1)
 258                 flags = SNF_F_PSHARED;
 259         else
 260                 nr = NULL;
 261
 262
 263         /* Allow pcap_set_buffer_size() to set dataring_size.
 264          * Default is zero which allows setting from env SNF_DATARING_SIZE.
 265          * pcap_set_buffer_size() is in bytes while snf_open() accepts values
 266          * between 0 and 1048576 in Megabytes. Values in this range are
 267          * mapped to 1MB.
 268          */
 269         err = snf_open(ps->snf_boardnum,
 270                         0, /* let SNF API parse SNF_NUM_RINGS, if set */
 271                         NULL, /* default RSS, or use SNF_RSS_FLAGS env */
 272                         (p->opt.buffer_size > 0 && p->opt.buffer_size < 1048576) ? 1048576 : p->opt.buffer_size, /* default to SNF_DATARING_SIZE from env */
 273                         flags, /* may want pshared */
 274                         &ps->snf_handle);
 275         if (err != 0) {
 276                 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 277                     err, "snf_open failed");
 278                 return -1;
 279         }
 280
 281         if ((nr = getenv("SNF_PCAP_RING_ID")) && *nr) {
 282                 ring_id = (int) strtol(nr, NULL, 0);
 283         }
 284         err = snf_ring_open_id(ps->snf_handle, ring_id, &ps->snf_ring);
 285         if (err != 0) {
 286                 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 287                     err, "snf_ring_open_id(ring=%d) failed", ring_id);
 288                 return -1;
 289         }
 290
 291         /*
 292          * Turn a negative snapshot value (invalid), a snapshot value of
 293          * 0 (unspecified), or a value bigger than the normal maximum
 294          * value, into the maximum allowed value.
 295          *
 296          * If some application really *needs* a bigger snapshot
 297          * length, we should just increase MAXIMUM_SNAPLEN.
 298          */
 299         if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
 300                 p->snapshot = MAXIMUM_SNAPLEN;
 301
 302         if (p->opt.timeout <= 0)
 303                 ps->snf_timeout = -1;
 304         else
 305                 ps->snf_timeout = p->opt.timeout;
 306
 307         err = snf_start(ps->snf_handle);
 308         if (err != 0) {
 309                 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 310                     err, "snf_start failed");
 311                 return -1;
 312         }
 313
 314         /*
 315          * "select()" and "poll()" don't work on snf descriptors.
 316          */
 317 #ifndef _WIN32
 318         p->selectable_fd = -1;
 319 #endif /* !_WIN32 */
 320         p->linktype = DLT_EN10MB;
 321         p->read_op = snf_read;
 322         p->inject_op = snf_inject;
 323         p->setfilter_op = pcap_install_bpf_program;
 324         p->setdirection_op = NULL; /* Not implemented.*/
 325         p->set_datalink_op = snf_set_datalink;
 326         p->getnonblock_op = snf_getnonblock;
 327         p->setnonblock_op = snf_setnonblock;
 328         p->stats_op = snf_pcap_stats;
 329         p->cleanup_op = snf_platform_cleanup;
 330 #ifdef SNF_HAVE_INJECT_API
 331         ps->snf_inj = NULL;
 332 #endif
 333         return 0;
 334 }
 335
 336 #define MAX_DESC_LENGTH 128
 337 int
 338 snf_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
 339 {
 340         pcap_if_t *dev;
 341 #ifdef _WIN32
 342         struct sockaddr_in addr;
 343 #endif
 344         struct snf_ifaddrs *ifaddrs, *ifa;
 345         char name[MAX_DESC_LENGTH];
 346         char desc[MAX_DESC_LENGTH];
 347         int ret, allports = 0, merge = 0;
 348         const char *nr = NULL;
 349
 350         if (snf_init(SNF_VERSION_API)) {
 351                 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 352                     "snf_getifaddrs: snf_init failed");
 353                 return (-1);
 354         }
 355
 356         if (snf_getifaddrs(&ifaddrs) || ifaddrs == NULL)
 357         {
 358                 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
 359                     errno, "snf_getifaddrs");
 360                 return (-1);
 361         }
 362         if ((nr = getenv("SNF_FLAGS")) && *nr) {
 363                 errno = 0;
 364                 merge = strtol(nr, NULL, 0);
 365                 if (errno) {
 366                         (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
 367                                 "snf_getifaddrs: SNF_FLAGS is not a valid number");
 368                         return (-1);
 369                 }
 370                 merge = merge & SNF_F_AGGREGATE_PORTMASK;
 371         }
 372
 373         for (ifa = ifaddrs; ifa != NULL; ifa = ifa->snf_ifa_next) {
 374                 /*
 375                  * Myricom SNF adapter ports may appear as regular
 376                  * network interfaces, which would already have been
 377                  * added to the list of adapters by pcap_platform_finddevs()
 378                  * if this isn't an SNF-only version of libpcap.
 379                  *
 380                  * Our create routine intercepts pcap_create() calls for
 381                  * those interfaces and arranges that they will be
 382                  * opened using the SNF API instead.
 383                  *
 384                  * So if we already have an entry for the device, we
 385                  * don't add an additional entry for it, we just
 386                  * update the description for it, if any, to indicate
 387                  * which snfN device it is.  Otherwise, we add an entry
 388                  * for it.
 389                  *
 390                  * In either case, if SNF_F_AGGREGATE_PORTMASK is set
 391                  * in SNF_FLAGS, we add this port to the bitmask
 392                  * of ports, which we use to generate a device
 393                  * we can use to capture on all ports.
 394                  *
 395                  * Generate the description string.  If port aggregation
 396                  * is set, use 2^{port number} as the unit number,
 397                  * rather than {port number}.
 398                  *
 399                  * XXX - do entries in this list have IP addresses for
 400                  * the port?  If so, should we add them to the
 401                  * entry for the device, if they're not already in the
 402                  * list of IP addresses for the device?
 403                  */
 404                 (void)snprintf(desc,MAX_DESC_LENGTH,"Myricom %ssnf%d",
 405                         merge ? "Merge Bitmask Port " : "",
 406                         merge ? 1 << ifa->snf_ifa_portnum : ifa->snf_ifa_portnum);
 407                 /*
 408                  * Add the port to the bitmask.
 409                  */
 410                 if (merge)
 411                         allports |= 1 << ifa->snf_ifa_portnum;
 412                 /*
 413                  * See if there's already an entry for the device
 414                  * with the name ifa->snf_ifa_name.
 415                  */
 416                 dev = pcap_find_dev(devlistp, ifa->snf_ifa_name);
 417                 if (dev != NULL) {
 418                         /*
 419                          * Yes.  Update its description.
 420                          */
 421                         char *desc_str;
 422
 423                         desc_str = strdup(desc);
 424                         if (desc_str == NULL) {
 425                                 pcap_fmt_errmsg_for_errno(errbuf,
 426                                     PCAP_ERRBUF_SIZE, errno,
 427                                     "snf_findalldevs strdup");
 428                                 return -1;
 429                         }
 430                         free(dev->description);
 431                         dev->description = desc_str;
 432                 } else {
 433                         /*
 434                          * No.  Add an entry for it.
 435                          *
 436                          * XXX - is there a notion of "up" or "running",
 437                          * and can we determine whether something's
 438                          * plugged into the adapter and set
 439                          * PCAP_IF_CONNECTION_STATUS_CONNECTED or
 440                          * PCAP_IF_CONNECTION_STATUS_DISCONNECTED?
 441                          */
 442                         dev = pcap_add_dev(devlistp, ifa->snf_ifa_name, 0, desc,
 443                             errbuf);
 444                         if (dev == NULL)
 445                                 return -1;
 446 #ifdef _WIN32
 447                         /*
 448                          * On Windows, fill in IP# from device name
 449                          */
 450                         ret = inet_pton(AF_INET, dev->name, &addr.sin_addr);
 451                         if (ret == 1) {
 452                                 /*
 453                                  * Successful conversion of device name
 454                                  * to IPv4 address.
 455                                  */
 456                                 addr.sin_family = AF_INET;
 457                                 if (pcap_add_addr_to_dev(dev, &addr, sizeof(addr),
 458                                     NULL, 0, NULL, 0, NULL, 0, errbuf) == -1)
 459                                         return -1;
 460                         } else if (ret == -1) {
 461                                 /*
 462                                  * Error.
 463                                  */
 464                                 pcap_fmt_errmsg_for_errno(errbuf,
 465                                     PCAP_ERRBUF_SIZE, errno,
 466                                     "sinf_findalldevs inet_pton");
 467                                 return -1;
 468                         }
 469 #endif _WIN32
 470                 }
 471         }
 472         snf_freeifaddrs(ifaddrs);
 473         /*
 474          * Create a snfX entry if port aggregation is enabled
 475          */
 476         if (merge) {
 477                 /*
 478                  * Add a new entry with all ports bitmask
 479                  */
 480                 (void)snprintf(name,MAX_DESC_LENGTH,"snf%d",allports);
 481                 (void)snprintf(desc,MAX_DESC_LENGTH,"Myricom Merge Bitmask All Ports snf%d",
 482                         allports);
 483                 /*
 484                  * XXX - is there any notion of "up" and "running" that
 485                  * would apply to this device, given that it handles
 486                  * multiple ports?
 487                  *
 488                  * Presumably, there's no notion of "connected" vs.
 489                  * "disconnected", as "is this plugged into a network?"
 490                  * would be a per-port property.
 491                  */
 492                 if (pcap_add_dev(devlistp, name,
 493                     PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE, desc,
 494                     errbuf) == NULL)
 495                         return (-1);
 496                 /*
 497                  * XXX - should we give it a list of addresses with all
 498                  * the addresses for all the ports?
 499                  */
 500         }
 501
 502         return 0;
 503 }
 504
 505 pcap_t *
 506 snf_create(const char *device, char *ebuf, int *is_ours)
 507 {
 508         pcap_t *p;
 509         int boardnum = -1;
 510         struct snf_ifaddrs *ifaddrs, *ifa;
 511         size_t devlen;
 512         struct pcap_snf *ps;
 513
 514         if (snf_init(SNF_VERSION_API)) {
 515                 /* Can't initialize the API, so no SNF devices */
 516                 *is_ours = 0;
 517                 return NULL;
 518         }
 519
 520         /*
 521          * Match a given interface name to our list of interface names, from
 522          * which we can obtain the intended board number
 523          */
 524         if (snf_getifaddrs(&ifaddrs) || ifaddrs == NULL) {
 525                 /* Can't get SNF addresses */
 526                 *is_ours = 0;
 527                 return NULL;
 528         }
 529         devlen = strlen(device) + 1;
 530         ifa = ifaddrs;
 531         while (ifa) {
 532                 if (strncmp(device, ifa->snf_ifa_name, devlen) == 0) {
 533                         boardnum = ifa->snf_ifa_boardnum;
 534                         break;
 535                 }
 536                 ifa = ifa->snf_ifa_next;
 537         }
 538         snf_freeifaddrs(ifaddrs);
 539
 540         if (ifa == NULL) {
 541                 /*
 542                  * If we can't find the device by name, support the name "snfX"
 543                  * and "snf10gX" where X is the board number.
 544                  */
 545                 if (sscanf(device, "snf10g%d", &boardnum) != 1 &&
 546                     sscanf(device, "snf%d", &boardnum) != 1) {
 547                         /* Nope, not a supported name */
 548                         *is_ours = 0;
 549                         return NULL;
 550                 }
 551         }
 552
 553         /* OK, it's probably ours. */
 554         *is_ours = 1;
 555
 556         p = PCAP_CREATE_COMMON(ebuf, struct pcap_snf);
 557         if (p == NULL)
 558                 return NULL;
 559         ps = p->priv;
 560
 561         /*
 562          * We support microsecond and nanosecond time stamps.
 563          */
 564         p->tstamp_precision_list = malloc(2 * sizeof(u_int));
 565         if (p->tstamp_precision_list == NULL) {
 566                 pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE, errno,
 567                     "malloc");
 568                 pcap_close(p);
 569                 return NULL;
 570         }
 571         p->tstamp_precision_list[0] = PCAP_TSTAMP_PRECISION_MICRO;
 572         p->tstamp_precision_list[1] = PCAP_TSTAMP_PRECISION_NANO;
 573         p->tstamp_precision_count = 2;
 574
 575         p->activate_op = snf_activate;
 576         ps->snf_boardnum = boardnum;
 577         return p;
 578 }
 579
 580 #ifdef SNF_ONLY
 581 /*
 582  * This libpcap build supports only SNF cards, not regular network
 583  * interfaces..
 584  */
 585
 586 /*
 587  * There are no regular interfaces, just SNF interfaces.
 588  */
 589 int
 590 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
 591 {
 592         return (0);
 593 }
 594
 595 /*
 596  * Attempts to open a regular interface fail.
 597  */
 598 pcap_t *
 599 pcap_create_interface(const char *device, char *errbuf)
 600 {
 601         snprintf(errbuf, PCAP_ERRBUF_SIZE,
 602             "This version of libpcap only supports SNF cards");
 603         return NULL;
 604 }
 605
 606 /*
 607  * Libpcap version string.
 608  */
 609 const char *
 610 pcap_lib_version(void)
 611 {
 612         return (PCAP_VERSION_STRING " (SNF-only)");
 613 }
 614 #endif