The Tcpdump Group git mirrors - libpcap/blob - dlpisubs.c

   1 /*
   2  * This code is derived from code formerly in pcap-dlpi.c, originally
   3  * contributed by Atanu Ghosh (atanu@cs.ucl.ac.uk), University College
   4  * London, and subsequently modified by Guy Harris (guy@alum.mit.edu),
   5  * Mark Pizzolato <List-tcpdump-workers@subscriptions.pizzolato.net>,
   6  * Mark C. Brown (mbrown@hp.com), and Sagun Shakya <Sagun.Shakya@Sun.COM>.
   7  */
   8
   9 /*
  10  * This file contains dlpi/libdlpi related common functions used
  11  * by pcap-[dlpi,libdlpi].c.
  12  */
  13
  14 #ifdef HAVE_CONFIG_H
  15 #include <config.h>
  16 #endif
  17
  18 #ifndef DL_IPATM
  19 #define DL_IPATM        0x12    /* ATM Classical IP interface */
  20 #endif
  21
  22 #ifdef HAVE_SYS_BUFMOD_H
  23         /*
  24          * Size of a bufmod chunk to pass upstream; that appears to be the
  25          * biggest value to which you can set it, and setting it to that value
  26          * (which is bigger than what appears to be the Solaris default of 8192)
  27          * reduces the number of packet drops.
  28          */
  29 #define CHUNKSIZE       65536
  30
  31         /*
  32          * Size of the buffer to allocate for packet data we read; it must be
  33          * large enough to hold a chunk.
  34          */
  35 #define PKTBUFSIZE      CHUNKSIZE
  36
  37 #else /* HAVE_SYS_BUFMOD_H */
  38
  39         /*
  40          * Size of the buffer to allocate for packet data we read; this is
  41          * what the value used to be - there's no particular reason why it
  42          * should be tied to MAXDLBUF, but we'll leave it as this for now.
  43          */
  44 #define MAXDLBUF        8192
  45 #define PKTBUFSIZE      (MAXDLBUF * sizeof(bpf_u_int32))
  46
  47 #endif
  48
  49 #include <sys/types.h>
  50 #include <sys/time.h>
  51 #ifdef HAVE_SYS_BUFMOD_H
  52 #include <sys/bufmod.h>
  53 #endif
  54 #include <sys/dlpi.h>
  55 #include <sys/stream.h>
  56
  57 #include <errno.h>
  58 #include <memory.h>
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <string.h>
  62 #include <stropts.h>
  63 #include <unistd.h>
  64
  65 #ifdef HAVE_LIBDLPI
  66 #include <libdlpi.h>
  67 #endif
  68
  69 #include "pcap-int.h"
  70 #include "dlpisubs.h"
  71
  72 #ifdef HAVE_SYS_BUFMOD_H
  73 static void pcap_stream_err(const char *, int, char *);
  74 #endif
  75
  76 /*
  77  * Get the packet statistics.
  78  */
  79 int
  80 pcap_stats_dlpi(pcap_t *p, struct pcap_stat *ps)
  81 {
  82         struct pcap_dlpi *pd = p->priv;
  83
  84         /*
  85          * "ps_recv" counts packets handed to the filter, not packets
  86          * that passed the filter.  As filtering is done in userland,
  87          * this would not include packets dropped because we ran out
  88          * of buffer space; in order to make this more like other
  89          * platforms (Linux 2.4 and later, BSDs with BPF), where the
  90          * "packets received" count includes packets received but dropped
  91          * due to running out of buffer space, and to keep from confusing
  92          * applications that, for example, compute packet drop percentages,
  93          * we also make it count packets dropped by "bufmod" (otherwise we
  94          * might run the risk of the packet drop count being bigger than
  95          * the received-packet count).
  96          *
  97          * "ps_drop" counts packets dropped by "bufmod" because of
  98          * flow control requirements or resource exhaustion; it doesn't
  99          * count packets dropped by the interface driver, or packets
 100          * dropped upstream.  As filtering is done in userland, it counts
 101          * packets regardless of whether they would've passed the filter.
 102          *
 103          * These statistics don't include packets not yet read from
 104          * the kernel by libpcap, but they may include packets not
 105          * yet read from libpcap by the application.
 106          */
 107         *ps = pd->stat;
 108
 109         /*
 110          * Add in the drop count, as per the above comment.
 111          */
 112         ps->ps_recv += ps->ps_drop;
 113         return (0);
 114 }
 115
 116 /*
 117  * Does the processor for which we're compiling this support aligned loads?
 118  */
 119 #if (defined(__i386__) || defined(_M_IX86) || defined(__X86__) || defined(__x86_64__) || defined(_M_X64)) || \
 120     (defined(__arm__) || defined(_M_ARM) || defined(__aarch64__)) || \
 121     (defined(__m68k__) && (!defined(__mc68000__) && !defined(__mc68010__))) || \
 122     (defined(__ppc__) || defined(__ppc64__) || defined(_M_PPC) || defined(_ARCH_PPC) || defined(_ARCH_PPC64)) || \
 123     (defined(__s390__) || defined(__s390x__) || defined(__zarch__))
 124     /* Yes, it does. */
 125 #else
 126     /* No, it doesn't. */
 127     #define REQUIRE_ALIGNMENT
 128 #endif
 129
 130 /*
 131  * Loop through the packets and call the callback for each packet.
 132  * Return the number of packets read.
 133  */
 134 int
 135 pcap_process_pkts(pcap_t *p, pcap_handler callback, u_char *user,
 136         int count, u_char *bufp, int len)
 137 {
 138         struct pcap_dlpi *pd = p->priv;
 139         int n, caplen, origlen;
 140         u_char *ep, *pk;
 141         struct pcap_pkthdr pkthdr;
 142 #ifdef HAVE_SYS_BUFMOD_H
 143         struct sb_hdr *sbp;
 144 #ifdef REQUIRE_ALIGNMENT
 145         struct sb_hdr sbhdr;
 146 #endif
 147 #endif
 148
 149         /*
 150          * Loop through packets.
 151          *
 152          * This assumes that a single buffer of packets will have
 153          * <= INT_MAX packets, so the packet count doesn't overflow.
 154          */
 155         ep = bufp + len;
 156         n = 0;
 157
 158 #ifdef HAVE_SYS_BUFMOD_H
 159         while (bufp < ep) {
 160                 /*
 161                  * Has "pcap_breakloop()" been called?
 162                  * If so, return immediately - if we haven't read any
 163                  * packets, clear the flag and return -2 to indicate
 164                  * that we were told to break out of the loop, otherwise
 165                  * leave the flag set, so that the *next* call will break
 166                  * out of the loop without having read any packets, and
 167                  * return the number of packets we've processed so far.
 168                  */
 169                 if (p->break_loop) {
 170                         if (n == 0) {
 171                                 p->break_loop = 0;
 172                                 return (-2);
 173                         } else {
 174                                 p->bp = bufp;
 175                                 p->cc = ep - bufp;
 176                                 return (n);
 177                         }
 178                 }
 179 #ifdef REQUIRE_ALIGNMENT
 180                 if ((long)bufp & 3) {
 181                         sbp = &sbhdr;
 182                         memcpy(sbp, bufp, sizeof(*sbp));
 183                 } else
 184 #endif
 185                         sbp = (struct sb_hdr *)bufp;
 186                 pd->stat.ps_drop = sbp->sbh_drops;
 187                 pk = bufp + sizeof(*sbp);
 188                 bufp += sbp->sbh_totlen;
 189                 origlen = sbp->sbh_origlen;
 190                 caplen = sbp->sbh_msglen;
 191 #else
 192                 origlen = len;
 193                 caplen = min(p->snapshot, len);
 194                 pk = bufp;
 195                 bufp += caplen;
 196 #endif
 197                 ++pd->stat.ps_recv;
 198                 if (pcap_filter(p->fcode.bf_insns, pk, origlen, caplen)) {
 199 #ifdef HAVE_SYS_BUFMOD_H
 200                         pkthdr.ts.tv_sec = sbp->sbh_timestamp.tv_sec;
 201                         pkthdr.ts.tv_usec = sbp->sbh_timestamp.tv_usec;
 202 #else
 203                         (void) gettimeofday(&pkthdr.ts, NULL);
 204 #endif
 205                         pkthdr.len = origlen;
 206                         pkthdr.caplen = caplen;
 207                         /* Insure caplen does not exceed snapshot */
 208                         if (pkthdr.caplen > (bpf_u_int32)p->snapshot)
 209                                 pkthdr.caplen = (bpf_u_int32)p->snapshot;
 210                         (*callback)(user, &pkthdr, pk);
 211                         if (++n >= count && !PACKET_COUNT_IS_UNLIMITED(count)) {
 212                                 p->cc = ep - bufp;
 213                                 p->bp = bufp;
 214                                 return (n);
 215                         }
 216                 }
 217 #ifdef HAVE_SYS_BUFMOD_H
 218         }
 219 #endif
 220         p->cc = 0;
 221         return (n);
 222 }
 223
 224 /*
 225  * Process the mac type. Returns -1 if no matching mac type found, otherwise 0.
 226  */
 227 int
 228 pcap_process_mactype(pcap_t *p, u_int mactype)
 229 {
 230         int retv = 0;
 231
 232         switch (mactype) {
 233
 234         case DL_CSMACD:
 235         case DL_ETHER:
 236                 p->linktype = DLT_EN10MB;
 237                 p->offset = 2;
 238                 /*
 239                  * This is (presumably) a real Ethernet capture; give it a
 240                  * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
 241                  * that an application can let you choose it, in case you're
 242                  * capturing DOCSIS traffic that a Cisco Cable Modem
 243                  * Termination System is putting out onto an Ethernet (it
 244                  * doesn't put an Ethernet header onto the wire, it puts raw
 245                  * DOCSIS frames out on the wire inside the low-level
 246                  * Ethernet framing).
 247                  */
 248                 p->dlt_list = (u_int *)malloc(sizeof(u_int) * 2);
 249                 /*
 250                  * If that fails, just leave the list empty.
 251                  */
 252                 if (p->dlt_list != NULL) {
 253                         p->dlt_list[0] = DLT_EN10MB;
 254                         p->dlt_list[1] = DLT_DOCSIS;
 255                         p->dlt_count = 2;
 256                 }
 257                 break;
 258
 259         case DL_FDDI:
 260                 p->linktype = DLT_FDDI;
 261                 p->offset = 3;
 262                 break;
 263
 264         case DL_TPR:
 265                 /* XXX - what about DL_TPB?  Is that Token Bus?  */
 266                 p->linktype = DLT_IEEE802;
 267                 p->offset = 2;
 268                 break;
 269
 270 #ifdef HAVE_SOLARIS
 271         case DL_IPATM:
 272                 p->linktype = DLT_SUNATM;
 273                 p->offset = 0;  /* works for LANE and LLC encapsulation */
 274                 break;
 275 #endif
 276
 277 #ifdef DL_IPV4
 278         case DL_IPV4:
 279                 p->linktype = DLT_IPV4;
 280                 p->offset = 0;
 281                 break;
 282 #endif
 283
 284 #ifdef DL_IPV6
 285         case DL_IPV6:
 286                 p->linktype = DLT_IPV6;
 287                 p->offset = 0;
 288                 break;
 289 #endif
 290
 291 #ifdef DL_IPNET
 292         case DL_IPNET:
 293                 /*
 294                  * XXX - DL_IPNET devices default to "raw IP" rather than
 295                  * "IPNET header"; see
 296                  *
 297                  *    https://seclists.org/tcpdump/2009/q1/202
 298                  *
 299                  * We'd have to do DL_IOC_IPNET_INFO to enable getting
 300                  * the IPNET header.
 301                  */
 302                 p->linktype = DLT_RAW;
 303                 p->offset = 0;
 304                 break;
 305 #endif
 306
 307         default:
 308                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown mactype 0x%x",
 309                     mactype);
 310                 retv = -1;
 311         }
 312
 313         return (retv);
 314 }
 315
 316 #ifdef HAVE_SYS_BUFMOD_H
 317 /*
 318  * Push and configure the buffer module. Returns -1 for error, otherwise 0.
 319  */
 320 int
 321 pcap_conf_bufmod(pcap_t *p, int snaplen)
 322 {
 323         struct timeval to;
 324         bpf_u_int32 ss, chunksize;
 325
 326         /* Non-standard call to get the data nicely buffered. */
 327         if (ioctl(p->fd, I_PUSH, "bufmod") != 0) {
 328                 pcap_stream_err("I_PUSH bufmod", errno, p->errbuf);
 329                 return (-1);
 330         }
 331
 332         ss = snaplen;
 333         if (ss > 0 &&
 334             strioctl(p->fd, SBIOCSSNAP, sizeof(ss), (char *)&ss) != 0) {
 335                 pcap_stream_err("SBIOCSSNAP", errno, p->errbuf);
 336                 return (-1);
 337         }
 338
 339         if (p->opt.immediate) {
 340                 /* Set the timeout to zero, for immediate delivery. */
 341                 to.tv_sec = 0;
 342                 to.tv_usec = 0;
 343                 if (strioctl(p->fd, SBIOCSTIME, sizeof(to), (char *)&to) != 0) {
 344                         pcap_stream_err("SBIOCSTIME", errno, p->errbuf);
 345                         return (-1);
 346                 }
 347         } else {
 348                 /* Set up the bufmod timeout. */
 349                 if (p->opt.timeout != 0) {
 350                         to.tv_sec = p->opt.timeout / 1000;
 351                         to.tv_usec = (p->opt.timeout * 1000) % 1000000;
 352                         if (strioctl(p->fd, SBIOCSTIME, sizeof(to), (char *)&to) != 0) {
 353                                 pcap_stream_err("SBIOCSTIME", errno, p->errbuf);
 354                                 return (-1);
 355                         }
 356                 }
 357
 358                 /* Set the chunk length. */
 359                 chunksize = CHUNKSIZE;
 360                 if (strioctl(p->fd, SBIOCSCHUNK, sizeof(chunksize), (char *)&chunksize)
 361                     != 0) {
 362                         pcap_stream_err("SBIOCSCHUNKP", errno, p->errbuf);
 363                         return (-1);
 364                 }
 365         }
 366
 367         return (0);
 368 }
 369 #endif /* HAVE_SYS_BUFMOD_H */
 370
 371 /*
 372  * Allocate data buffer. Returns -1 if memory allocation fails, else 0.
 373  */
 374 int
 375 pcap_alloc_databuf(pcap_t *p)
 376 {
 377         p->bufsize = PKTBUFSIZE;
 378         p->buffer = malloc(p->bufsize + p->offset);
 379         if (p->buffer == NULL) {
 380                 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 381                     errno, "malloc");
 382                 return (-1);
 383         }
 384
 385         return (0);
 386 }
 387
 388 /*
 389  * Issue a STREAMS I_STR ioctl. Returns -1 on error, otherwise
 390  * length of returned data on success.
 391  */
 392 int
 393 strioctl(int fd, int cmd, int len, char *dp)
 394 {
 395         struct strioctl str;
 396         int retv;
 397
 398         str.ic_cmd = cmd;
 399         str.ic_timout = -1;
 400         str.ic_len = len;
 401         str.ic_dp = dp;
 402         if ((retv = ioctl(fd, I_STR, &str)) < 0)
 403                 return (retv);
 404
 405         return (str.ic_len);
 406 }
 407
 408 #ifdef HAVE_SYS_BUFMOD_H
 409 /*
 410  * Write stream error message to errbuf.
 411  */
 412 static void
 413 pcap_stream_err(const char *func, int err, char *errbuf)
 414 {
 415         pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, err, "%s", func);
 416 }
 417 #endif