dist/libpcap/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: /pub/NetBSD/misc/repositories/cvsroot/src/dist/libpcap/pcap-nit.c,v 1.1.1.1 2006/02/27 15:45:48 drochner 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 static int
  75 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps)
  76 {
  77
  78         /*
  79          * "ps_recv" counts packets handed to the filter, not packets
  80          * that passed the filter.  As filtering is done in userland,
  81          * this does not include packets dropped because we ran out
  82          * of buffer space.
  83          *
  84          * "ps_drop" presumably counts packets dropped by the socket
  85          * because of flow control requirements or resource exhaustion;
  86          * it doesn't count packets dropped by the interface driver.
  87          * As filtering is done in userland, it counts packets regardless
  88          * of whether they would've passed the filter.
  89          *
  90          * These statistics don't include packets not yet read from the
  91          * kernel by libpcap or packets not yet read from libpcap by the
  92          * application.
  93          */
  94         *ps = p->md.stat;
  95         return (0);
  96 }
  97
  98 static int
  99 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
 100 {
 101         register int cc, n;
 102         register struct bpf_insn *fcode = p->fcode.bf_insns;
 103         register u_char *bp, *cp, *ep;
 104         register struct nit_hdr *nh;
 105         register int caplen;
 106
 107         cc = p->cc;
 108         if (cc == 0) {
 109                 cc = read(p->fd, (char *)p->buffer, p->bufsize);
 110                 if (cc < 0) {
 111                         if (errno == EWOULDBLOCK)
 112                                 return (0);
 113                         snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
 114                                 pcap_strerror(errno));
 115                         return (-1);
 116                 }
 117                 bp = p->buffer;
 118         } else
 119                 bp = p->bp;
 120
 121         /*
 122          * Loop through each packet.  The increment expression
 123          * rounds up to the next int boundary past the end of
 124          * the previous packet.
 125          */
 126         n = 0;
 127         ep = bp + cc;
 128         while (bp < ep) {
 129                 /*
 130                  * Has "pcap_breakloop()" been called?
 131                  * If so, return immediately - if we haven't read any
 132                  * packets, clear the flag and return -2 to indicate
 133                  * that we were told to break out of the loop, otherwise
 134                  * leave the flag set, so that the *next* call will break
 135                  * out of the loop without having read any packets, and
 136                  * return the number of packets we've processed so far.
 137                  */
 138                 if (p->break_loop) {
 139                         if (n == 0) {
 140                                 p->break_loop = 0;
 141                                 return (-2);
 142                         } else {
 143                                 p->cc = ep - bp;
 144                                 p->bp = bp;
 145                                 return (n);
 146                         }
 147                 }
 148
 149                 nh = (struct nit_hdr *)bp;
 150                 cp = bp + sizeof(*nh);
 151
 152                 switch (nh->nh_state) {
 153
 154                 case NIT_CATCH:
 155                         break;
 156
 157                 case NIT_NOMBUF:
 158                 case NIT_NOCLUSTER:
 159                 case NIT_NOSPACE:
 160                         p->md.stat.ps_drop = nh->nh_dropped;
 161                         continue;
 162
 163                 case NIT_SEQNO:
 164                         continue;
 165
 166                 default:
 167                         snprintf(p->errbuf, sizeof(p->errbuf),
 168                             "bad nit state %d", nh->nh_state);
 169                         return (-1);
 170                 }
 171                 ++p->md.stat.ps_recv;
 172                 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
 173                     sizeof(int) - 1) & ~(sizeof(int) - 1));
 174
 175                 caplen = nh->nh_wirelen;
 176                 if (caplen > p->snapshot)
 177                         caplen = p->snapshot;
 178                 if (bpf_filter(fcode, cp, nh->nh_wirelen, caplen)) {
 179                         struct pcap_pkthdr h;
 180                         h.ts = nh->nh_timestamp;
 181                         h.len = nh->nh_wirelen;
 182                         h.caplen = caplen;
 183                         (*callback)(user, &h, cp);
 184                         if (++n >= cnt && cnt >= 0) {
 185                                 p->cc = ep - bp;
 186                                 p->bp = bp;
 187                                 return (n);
 188                         }
 189                 }
 190         }
 191         p->cc = 0;
 192         return (n);
 193 }
 194
 195 static int
 196 pcap_inject_nit(pcap_t *p, const void *buf, size_t size)
 197 {
 198         struct sockaddr sa;
 199         int ret;
 200
 201         memset(&sa, 0, sizeof(sa));
 202         strncpy(sa.sa_data, device, sizeof(sa.sa_data));
 203         ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
 204         if (ret == -1) {
 205                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
 206                     pcap_strerror(errno));
 207                 return (-1);
 208         }
 209         return (ret);
 210 }
 211
 212 static int
 213 nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
 214 {
 215         struct nit_ioc nioc;
 216
 217         memset(&nioc, 0, sizeof(nioc));
 218         nioc.nioc_bufspace = BUFSPACE;
 219         nioc.nioc_chunksize = CHUNKSIZE;
 220         nioc.nioc_typetomatch = NT_ALLTYPES;
 221         nioc.nioc_snaplen = p->snapshot;
 222         nioc.nioc_bufalign = sizeof(int);
 223         nioc.nioc_bufoffset = 0;
 224
 225         if (to_ms != 0) {
 226                 nioc.nioc_flags |= NF_TIMEOUT;
 227                 nioc.nioc_timeout.tv_sec = to_ms / 1000;
 228                 nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000;
 229         }
 230         if (promisc)
 231                 nioc.nioc_flags |= NF_PROMISC;
 232
 233         if (ioctl(fd, SIOCSNIT, &nioc) < 0) {
 234                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
 235                     pcap_strerror(errno));
 236                 return (-1);
 237         }
 238         return (0);
 239 }
 240
 241 static void
 242 pcap_close_nit(pcap_t *p)
 243 {
 244         pcap_close_common(p);
 245         if (p->device != NULL)
 246                 free(p->device);
 247 }
 248
 249 pcap_t *
 250 pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 251     char *ebuf)
 252 {
 253         int fd;
 254         struct sockaddr_nit snit;
 255         register pcap_t *p;
 256
 257         p = (pcap_t *)malloc(sizeof(*p));
 258         if (p == NULL) {
 259                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 260                 return (NULL);
 261         }
 262
 263         if (snaplen < 96)
 264                 /*
 265                  * NIT requires a snapshot length of at least 96.
 266                  */
 267                 snaplen = 96;
 268
 269         memset(p, 0, sizeof(*p));
 270         p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
 271         if (fd < 0) {
 272                 snprintf(ebuf, PCAP_ERRBUF_SIZE,
 273                     "socket: %s", pcap_strerror(errno));
 274                 goto bad;
 275         }
 276         snit.snit_family = AF_NIT;
 277         (void)strncpy(snit.snit_ifname, device, NITIFSIZ);
 278
 279         if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
 280                 snprintf(ebuf, PCAP_ERRBUF_SIZE,
 281                     "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
 282                 goto bad;
 283         }
 284         p->snapshot = snaplen;
 285         nit_setflags(p->fd, promisc, to_ms, ebuf);
 286
 287         /*
 288          * NIT supports only ethernets.
 289          */
 290         p->linktype = DLT_EN10MB;
 291
 292         p->bufsize = BUFSPACE;
 293         p->buffer = (u_char *)malloc(p->bufsize);
 294         if (p->buffer == NULL) {
 295                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 296                 goto bad;
 297         }
 298
 299         /*
 300          * We need the device name in order to send packets.
 301          */
 302         p->device = strdup(device);
 303         if (p->device == NULL) {
 304                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 305                 free(p->buffer);
 306                 goto bad;
 307         }
 308
 309         /*
 310          * "p->fd" is a socket, so "select()" should work on it.
 311          */
 312         p->selectable_fd = p->fd;
 313
 314         /*
 315          * This is (presumably) a real Ethernet capture; give it a
 316          * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
 317          * that an application can let you choose it, in case you're
 318          * capturing DOCSIS traffic that a Cisco Cable Modem
 319          * Termination System is putting out onto an Ethernet (it
 320          * doesn't put an Ethernet header onto the wire, it puts raw
 321          * DOCSIS frames out on the wire inside the low-level
 322          * Ethernet framing).
 323          */
 324         p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
 325         /*
 326          * If that fails, just leave the list empty.
 327          */
 328         if (p->dlt_list != NULL) {
 329                 p->dlt_list[0] = DLT_EN10MB;
 330                 p->dlt_list[1] = DLT_DOCSIS;
 331                 p->dlt_count = 2;
 332         }
 333
 334         p->read_op = pcap_read_nit;
 335         p->inject_op = pcap_inject_nit;
 336         p->setfilter_op = install_bpf_program;  /* no kernel filtering */
 337         p->setdirection_op = NULL;      /* Not implemented. */
 338         p->set_datalink_op = NULL;      /* can't change data link type */
 339         p->getnonblock_op = pcap_getnonblock_fd;
 340         p->setnonblock_op = pcap_setnonblock_fd;
 341         p->stats_op = pcap_stats_nit;
 342         p->close_op = pcap_close_nit;
 343
 344         return (p);
 345  bad:
 346         if (fd >= 0)
 347                 close(fd);
 348         free(p);
 349         return (NULL);
 350 }
 351
 352 int
 353 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
 354 {
 355         return (0);
 356 }