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

   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 #ifndef lint
  22 static const char rcsid[] _U_ =
  23     "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.62 2008-04-14 20:40:58 guy Exp $ (LBL)";
  24 #endif
  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/file.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/socket.h>
  36
  37 #include <net/if.h>
  38 #include <net/nit.h>
  39
  40 #include <netinet/in.h>
  41 #include <netinet/in_systm.h>
  42 #include <netinet/ip.h>
  43 #include <netinet/if_ether.h>
  44 #include <netinet/ip_var.h>
  45 #include <netinet/udp.h>
  46 #include <netinet/udp_var.h>
  47 #include <netinet/tcp.h>
  48 #include <netinet/tcpip.h>
  49
  50 #include <ctype.h>
  51 #include <errno.h>
  52 #include <stdio.h>
  53
  54 #include "pcap-int.h"
  55
  56 #ifdef HAVE_OS_PROTO_H
  57 #include "os-proto.h"
  58 #endif
  59
  60 /*
  61  * The chunk size for NIT.  This is the amount of buffering
  62  * done for read calls.
  63  */
  64 #define CHUNKSIZE (2*1024)
  65
  66 /*
  67  * The total buffer space used by NIT.
  68  */
  69 #define BUFSPACE (4*CHUNKSIZE)
  70
  71 /* Forwards */
  72 static int nit_setflags(int, int, int, char *);
  73
  74 /*
  75  * Private data for capturing on NIT devices.
  76  */
  77 struct pcap_nit {
  78         struct pcap_stat stat;
  79 };
  80
  81 static int
  82 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps)
  83 {
  84         struct pcap_nit *pn = p->priv;
  85
  86         /*
  87          * "ps_recv" counts packets handed to the filter, not packets
  88          * that passed the filter.  As filtering is done in userland,
  89          * this does not include packets dropped because we ran out
  90          * of buffer space.
  91          *
  92          * "ps_drop" presumably counts packets dropped by the socket
  93          * because of flow control requirements or resource exhaustion;
  94          * it doesn't count packets dropped by the interface driver.
  95          * As filtering is done in userland, it counts packets regardless
  96          * of whether they would've passed the filter.
  97          *
  98          * These statistics don't include packets not yet read from the
  99          * kernel by libpcap or packets not yet read from libpcap by the
 100          * application.
 101          */
 102         *ps = pn->stat;
 103         return (0);
 104 }
 105
 106 static int
 107 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
 108 {
 109         struct pcap_nit *pn = p->priv;
 110         register int cc, n;
 111         register u_char *bp, *cp, *ep;
 112         register struct nit_hdr *nh;
 113         register int caplen;
 114
 115         cc = p->cc;
 116         if (cc == 0) {
 117                 cc = read(p->fd, (char *)p->buffer, p->bufsize);
 118                 if (cc < 0) {
 119                         if (errno == EWOULDBLOCK)
 120                                 return (0);
 121                         snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
 122                                 pcap_strerror(errno));
 123                         return (-1);
 124                 }
 125                 bp = p->buffer;
 126         } else
 127                 bp = p->bp;
 128
 129         /*
 130          * Loop through each packet.  The increment expression
 131          * rounds up to the next int boundary past the end of
 132          * the previous packet.
 133          */
 134         n = 0;
 135         ep = bp + cc;
 136         while (bp < ep) {
 137                 /*
 138                  * Has "pcap_breakloop()" been called?
 139                  * If so, return immediately - if we haven't read any
 140                  * packets, clear the flag and return -2 to indicate
 141                  * that we were told to break out of the loop, otherwise
 142                  * leave the flag set, so that the *next* call will break
 143                  * out of the loop without having read any packets, and
 144                  * return the number of packets we've processed so far.
 145                  */
 146                 if (p->break_loop) {
 147                         if (n == 0) {
 148                                 p->break_loop = 0;
 149                                 return (-2);
 150                         } else {
 151                                 p->cc = ep - bp;
 152                                 p->bp = bp;
 153                                 return (n);
 154                         }
 155                 }
 156
 157                 nh = (struct nit_hdr *)bp;
 158                 cp = bp + sizeof(*nh);
 159
 160                 switch (nh->nh_state) {
 161
 162                 case NIT_CATCH:
 163                         break;
 164
 165                 case NIT_NOMBUF:
 166                 case NIT_NOCLUSTER:
 167                 case NIT_NOSPACE:
 168                         pn->stat.ps_drop = nh->nh_dropped;
 169                         continue;
 170
 171                 case NIT_SEQNO:
 172                         continue;
 173
 174                 default:
 175                         snprintf(p->errbuf, sizeof(p->errbuf),
 176                             "bad nit state %d", nh->nh_state);
 177                         return (-1);
 178                 }
 179                 ++pn->stat.ps_recv;
 180                 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
 181                     sizeof(int) - 1) & ~(sizeof(int) - 1));
 182
 183                 caplen = nh->nh_wirelen;
 184                 if (caplen > p->snapshot)
 185                         caplen = p->snapshot;
 186                 if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) {
 187                         struct pcap_pkthdr h;
 188                         h.ts = nh->nh_timestamp;
 189                         h.len = nh->nh_wirelen;
 190                         h.caplen = caplen;
 191                         (*callback)(user, &h, cp);
 192                         if (++n >= cnt && cnt > 0) {
 193                                 p->cc = ep - bp;
 194                                 p->bp = bp;
 195                                 return (n);
 196                         }
 197                 }
 198         }
 199         p->cc = 0;
 200         return (n);
 201 }
 202
 203 static int
 204 pcap_inject_nit(pcap_t *p, const void *buf, size_t size)
 205 {
 206         struct sockaddr sa;
 207         int ret;
 208
 209         memset(&sa, 0, sizeof(sa));
 210         strncpy(sa.sa_data, device, sizeof(sa.sa_data));
 211         ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
 212         if (ret == -1) {
 213                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
 214                     pcap_strerror(errno));
 215                 return (-1);
 216         }
 217         return (ret);
 218 }
 219
 220 static int
 221 nit_setflags(pcap_t *p)
 222 {
 223         struct nit_ioc nioc;
 224
 225         memset(&nioc, 0, sizeof(nioc));
 226         nioc.nioc_typetomatch = NT_ALLTYPES;
 227         nioc.nioc_snaplen = p->snapshot;
 228         nioc.nioc_bufalign = sizeof(int);
 229         nioc.nioc_bufoffset = 0;
 230
 231         if (p->opt.buffer_size != 0)
 232                 nioc.nioc_bufspace = p->opt.buffer_size;
 233         else {
 234                 /* Default buffer size */
 235                 nioc.nioc_bufspace = BUFSPACE;
 236         }
 237
 238         if (p->opt.immediate) {
 239                 /*
 240                  * XXX - will this cause packets to be delivered immediately?
 241                  * XXX - given that this is for SunOS prior to 4.0, do
 242                  * we care?
 243                  */
 244                 nioc.nioc_chunksize = 0;
 245         } else
 246                 nioc.nioc_chunksize = CHUNKSIZE;
 247         if (p->opt.timeout != 0) {
 248                 nioc.nioc_flags |= NF_TIMEOUT;
 249                 nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000;
 250                 nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
 251         }
 252         if (p->opt.promisc)
 253                 nioc.nioc_flags |= NF_PROMISC;
 254
 255         if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) {
 256                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
 257                     pcap_strerror(errno));
 258                 return (-1);
 259         }
 260         return (0);
 261 }
 262
 263 static int
 264 pcap_activate_nit(pcap_t *p)
 265 {
 266         int fd;
 267         struct sockaddr_nit snit;
 268
 269         if (p->opt.rfmon) {
 270                 /*
 271                  * No monitor mode on SunOS 3.x or earlier (no
 272                  * Wi-Fi *devices* for the hardware that supported
 273                  * them!).
 274                  */
 275                 return (PCAP_ERROR_RFMON_NOTSUP);
 276         }
 277
 278         if (p->snapshot < 96)
 279                 /*
 280                  * NIT requires a snapshot length of at least 96.
 281                  */
 282                 p->snapshot = 96;
 283
 284         memset(p, 0, sizeof(*p));
 285         p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
 286         if (fd < 0) {
 287                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 288                     "socket: %s", pcap_strerror(errno));
 289                 goto bad;
 290         }
 291         snit.snit_family = AF_NIT;
 292         (void)strncpy(snit.snit_ifname, p->opt.source, NITIFSIZ);
 293
 294         if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
 295                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 296                     "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
 297                 goto bad;
 298         }
 299         if (nit_setflags(p) < 0)
 300                 goto bad;
 301
 302         /*
 303          * NIT supports only ethernets.
 304          */
 305         p->linktype = DLT_EN10MB;
 306
 307         p->bufsize = BUFSPACE;
 308         p->buffer = (u_char *)malloc(p->bufsize);
 309         if (p->buffer == NULL) {
 310                 strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 311                 goto bad;
 312         }
 313
 314         /*
 315          * "p->fd" is a socket, so "select()" should work on it.
 316          */
 317         p->selectable_fd = p->fd;
 318
 319         /*
 320          * This is (presumably) a real Ethernet capture; give it a
 321          * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
 322          * that an application can let you choose it, in case you're
 323          * capturing DOCSIS traffic that a Cisco Cable Modem
 324          * Termination System is putting out onto an Ethernet (it
 325          * doesn't put an Ethernet header onto the wire, it puts raw
 326          * DOCSIS frames out on the wire inside the low-level
 327          * Ethernet framing).
 328          */
 329         p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
 330         /*
 331          * If that fails, just leave the list empty.
 332          */
 333         if (p->dlt_list != NULL) {
 334                 p->dlt_list[0] = DLT_EN10MB;
 335                 p->dlt_list[1] = DLT_DOCSIS;
 336                 p->dlt_count = 2;
 337         }
 338
 339         p->read_op = pcap_read_nit;
 340         p->inject_op = pcap_inject_nit;
 341         p->setfilter_op = install_bpf_program;  /* no kernel filtering */
 342         p->setdirection_op = NULL;      /* Not implemented. */
 343         p->set_datalink_op = NULL;      /* can't change data link type */
 344         p->getnonblock_op = pcap_getnonblock_fd;
 345         p->setnonblock_op = pcap_setnonblock_fd;
 346         p->stats_op = pcap_stats_nit;
 347
 348         return (0);
 349  bad:
 350         pcap_cleanup_live_common(p);
 351         return (PCAP_ERROR);
 352 }
 353
 354 pcap_t *
 355 pcap_create_interface(const char *device, char *ebuf)
 356 {
 357         pcap_t *p;
 358
 359         p = pcap_create_common(device, ebuf, sizeof (struct pcap_nit));
 360         if (p == NULL)
 361                 return (NULL);
 362
 363         p->activate_op = pcap_activate_nit;
 364         return (p);
 365 }
 366
 367 int
 368 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
 369 {
 370         return (0);
 371 }