contrib/libpcap-0.8.3/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 1.50.2.4 2004/03/21 08:33:23 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 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 nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
 197 {
 198         struct nit_ioc nioc;
 199
 200         memset(&nioc, 0, sizeof(nioc));
 201         nioc.nioc_bufspace = BUFSPACE;
 202         nioc.nioc_chunksize = CHUNKSIZE;
 203         nioc.nioc_typetomatch = NT_ALLTYPES;
 204         nioc.nioc_snaplen = p->snapshot;
 205         nioc.nioc_bufalign = sizeof(int);
 206         nioc.nioc_bufoffset = 0;
 207
 208         if (to_ms != 0) {
 209                 nioc.nioc_flags |= NF_TIMEOUT;
 210                 nioc.nioc_timeout.tv_sec = to_ms / 1000;
 211                 nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000;
 212         }
 213         if (promisc)
 214                 nioc.nioc_flags |= NF_PROMISC;
 215
 216         if (ioctl(fd, SIOCSNIT, &nioc) < 0) {
 217                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
 218                     pcap_strerror(errno));
 219                 return (-1);
 220         }
 221         return (0);
 222 }
 223
 224 static void
 225 pcap_close_nit(pcap_t *p)
 226 {
 227         if (p->buffer != NULL)
 228                 free(p->buffer);
 229         if (p->fd >= 0)
 230                 close(p->fd);
 231 }
 232
 233 pcap_t *
 234 pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 235     char *ebuf)
 236 {
 237         int fd;
 238         struct sockaddr_nit snit;
 239         register pcap_t *p;
 240
 241         p = (pcap_t *)malloc(sizeof(*p));
 242         if (p == NULL) {
 243                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 244                 return (NULL);
 245         }
 246
 247         if (snaplen < 96)
 248                 /*
 249                  * NIT requires a snapshot length of at least 96.
 250                  */
 251                 snaplen = 96;
 252
 253         memset(p, 0, sizeof(*p));
 254         p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
 255         if (fd < 0) {
 256                 snprintf(ebuf, PCAP_ERRBUF_SIZE,
 257                     "socket: %s", pcap_strerror(errno));
 258                 goto bad;
 259         }
 260         snit.snit_family = AF_NIT;
 261         (void)strncpy(snit.snit_ifname, device, NITIFSIZ);
 262
 263         if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
 264                 snprintf(ebuf, PCAP_ERRBUF_SIZE,
 265                     "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
 266                 goto bad;
 267         }
 268         p->snapshot = snaplen;
 269         nit_setflags(p->fd, promisc, to_ms, ebuf);
 270
 271         /*
 272          * NIT supports only ethernets.
 273          */
 274         p->linktype = DLT_EN10MB;
 275
 276         p->bufsize = BUFSPACE;
 277         p->buffer = (u_char *)malloc(p->bufsize);
 278         if (p->buffer == NULL) {
 279                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 280                 goto bad;
 281         }
 282
 283         /*
 284          * "p->fd" is a socket, so "select()" should work on it.
 285          */
 286         p->selectable_fd = p->fd;
 287
 288         p->read_op = pcap_read_nit;
 289         p->setfilter_op = install_bpf_program;  /* no kernel filtering */
 290         p->set_datalink_op = NULL;      /* can't change data link type */
 291         p->getnonblock_op = pcap_getnonblock_fd;
 292         p->setnonblock_op = pcap_setnonblock_fd;
 293         p->stats_op = pcap_stats_nit;
 294         p->close_op = pcap_close_nit;
 295
 296         return (p);
 297  bad:
 298         if (fd >= 0)
 299                 close(fd);
 300         free(p);
 301         return (NULL);
 302 }
 303
 304 int
 305 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
 306 {
 307         return (0);
 308 }