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[] =
  23     "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.39 2000-10-28 00:01:29 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 int
  75 pcap_stats(pcap_t *p, struct pcap_stat *ps)
  76 {
  77
  78         *ps = p->md.stat;
  79         return (0);
  80 }
  81
  82 int
  83 pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
  84 {
  85         register int cc, n;
  86         register struct bpf_insn *fcode = p->fcode.bf_insns;
  87         register u_char *bp, *cp, *ep;
  88         register struct nit_hdr *nh;
  89         register int caplen;
  90
  91         cc = p->cc;
  92         if (cc == 0) {
  93                 cc = read(p->fd, (char *)p->buffer, p->bufsize);
  94                 if (cc < 0) {
  95                         if (errno == EWOULDBLOCK)
  96                                 return (0);
  97                         snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
  98                                 pcap_strerror(errno));
  99                         return (-1);
 100                 }
 101                 bp = p->buffer;
 102         } else
 103                 bp = p->bp;
 104
 105         /*
 106          * Loop through each packet.  The increment expression
 107          * rounds up to the next int boundary past the end of
 108          * the previous packet.
 109          */
 110         n = 0;
 111         ep = bp + cc;
 112         while (bp < ep) {
 113                 nh = (struct nit_hdr *)bp;
 114                 cp = bp + sizeof(*nh);
 115
 116                 switch (nh->nh_state) {
 117
 118                 case NIT_CATCH:
 119                         break;
 120
 121                 case NIT_NOMBUF:
 122                 case NIT_NOCLUSTER:
 123                 case NIT_NOSPACE:
 124                         p->md.stat.ps_drop = nh->nh_dropped;
 125                         continue;
 126
 127                 case NIT_SEQNO:
 128                         continue;
 129
 130                 default:
 131                         snprintf(p->errbuf, sizeof(p->errbuf),
 132                             "bad nit state %d", nh->nh_state);
 133                         return (-1);
 134                 }
 135                 ++p->md.stat.ps_recv;
 136                 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
 137                     sizeof(int) - 1) & ~(sizeof(int) - 1));
 138
 139                 caplen = nh->nh_wirelen;
 140                 if (caplen > p->snapshot)
 141                         caplen = p->snapshot;
 142                 if (bpf_filter(fcode, cp, nh->nh_wirelen, caplen)) {
 143                         struct pcap_pkthdr h;
 144                         h.ts = nh->nh_timestamp;
 145                         h.len = nh->nh_wirelen;
 146                         h.caplen = caplen;
 147                         (*callback)(user, &h, cp);
 148                         if (++n >= cnt && cnt >= 0) {
 149                                 p->cc = ep - bp;
 150                                 p->bp = bp;
 151                                 return (n);
 152                         }
 153                 }
 154         }
 155         p->cc = 0;
 156         return (n);
 157 }
 158
 159 static int
 160 nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
 161 {
 162         struct nit_ioc nioc;
 163
 164         memset(&nioc, 0, sizeof(nioc));
 165         nioc.nioc_bufspace = BUFSPACE;
 166         nioc.nioc_chunksize = CHUNKSIZE;
 167         nioc.nioc_typetomatch = NT_ALLTYPES;
 168         nioc.nioc_snaplen = p->snapshot;
 169         nioc.nioc_bufalign = sizeof(int);
 170         nioc.nioc_bufoffset = 0;
 171
 172         if (to_ms != 0) {
 173                 nioc.nioc_flags |= NF_TIMEOUT;
 174                 nioc.nioc_timeout.tv_sec = to_ms / 1000;
 175                 nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000;
 176         }
 177         if (promisc)
 178                 nioc.nioc_flags |= NF_PROMISC;
 179
 180         if (ioctl(fd, SIOCSNIT, &nioc) < 0) {
 181                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
 182                     pcap_strerror(errno));
 183                 return (-1);
 184         }
 185         return (0);
 186 }
 187
 188 pcap_t *
 189 pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
 190 {
 191         int fd;
 192         struct sockaddr_nit snit;
 193         register pcap_t *p;
 194
 195         p = (pcap_t *)malloc(sizeof(*p));
 196         if (p == NULL) {
 197                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 198                 return (NULL);
 199         }
 200
 201         if (snaplen < 96)
 202                 /*
 203                  * NIT requires a snapshot length of at least 96.
 204                  */
 205                 snaplen = 96;
 206
 207         memset(p, 0, sizeof(*p));
 208         p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
 209         if (fd < 0) {
 210                 snprintf(ebuf, PCAP_ERRBUF_SIZE,
 211                     "socket: %s", pcap_strerror(errno));
 212                 goto bad;
 213         }
 214         snit.snit_family = AF_NIT;
 215         (void)strncpy(snit.snit_ifname, device, NITIFSIZ);
 216
 217         if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
 218                 snprintf(ebuf, PCAP_ERRBUF_SIZE,
 219                     "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
 220                 goto bad;
 221         }
 222         p->snapshot = snaplen;
 223         nit_setflags(p->fd, promisc, to_ms, ebuf);
 224
 225         /*
 226          * NIT supports only ethernets.
 227          */
 228         p->linktype = DLT_EN10MB;
 229
 230         p->bufsize = BUFSPACE;
 231         p->buffer = (u_char *)malloc(p->bufsize);
 232         if (p->buffer == NULL) {
 233                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 234                 goto bad;
 235         }
 236         return (p);
 237  bad:
 238         if (fd >= 0)
 239                 close(fd);
 240         free(p);
 241         return (NULL);
 242 }
 243
 244 int
 245 pcap_setfilter(pcap_t *p, struct bpf_program *fp)
 246 {
 247
 248         if (install_bpf_program(p, fp) < 0)
 249                 return (-1);
 250         return (0);
 251 }