The Tcpdump Group git mirrors - libpcap/blob - pcap-snit.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  * Modifications made to accommodate the new SunOS4.0 NIT facility by
  22  * Micky Liu, micky@cunixc.cc.columbia.edu, Columbia University in May, 1989.
  23  * This module now handles the STREAMS based NIT.
  24  */
  25
  26 #ifndef lint
  27 static const char rcsid[] =
  28     "@(#) $Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.50 2000-07-11 00:37:07 assar Exp $ (LBL)";
  29 #endif
  30
  31 #ifdef HAVE_CONFIG_H
  32 #include "config.h"
  33 #endif
  34
  35 #include <sys/types.h>
  36 #include <sys/time.h>
  37 #include <sys/timeb.h>
  38 #include <sys/dir.h>
  39 #include <sys/fcntlcom.h>
  40 #include <sys/file.h>
  41 #include <sys/ioctl.h>
  42 #include <sys/socket.h>
  43 #include <sys/stropts.h>
  44
  45 #include <net/if.h>
  46 #include <net/nit.h>
  47 #include <net/nit_if.h>
  48 #include <net/nit_pf.h>
  49 #include <net/nit_buf.h>
  50
  51 #include <netinet/in.h>
  52 #include <netinet/in_systm.h>
  53 #include <netinet/ip.h>
  54 #include <netinet/if_ether.h>
  55 #include <netinet/ip_var.h>
  56 #include <netinet/udp.h>
  57 #include <netinet/udp_var.h>
  58 #include <netinet/tcp.h>
  59 #include <netinet/tcpip.h>
  60
  61 #include <ctype.h>
  62 #include <errno.h>
  63 #include <stdio.h>
  64 #include <string.h>
  65 #include <unistd.h>
  66
  67 #include "pcap-int.h"
  68
  69 #ifdef HAVE_OS_PROTO_H
  70 #include "os-proto.h"
  71 #endif
  72
  73 /*
  74  * The chunk size for NIT.  This is the amount of buffering
  75  * done for read calls.
  76  */
  77 #define CHUNKSIZE (2*1024)
  78
  79 /*
  80  * The total buffer space used by NIT.
  81  */
  82 #define BUFSPACE (4*CHUNKSIZE)
  83
  84 /* Forwards */
  85 static int nit_setflags(int, int, int, char *);
  86
  87 int
  88 pcap_stats(pcap_t *p, struct pcap_stat *ps)
  89 {
  90
  91         *ps = p->md.stat;
  92         return (0);
  93 }
  94
  95 int
  96 pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
  97 {
  98         register int cc, n;
  99         register struct bpf_insn *fcode = p->fcode.bf_insns;
 100         register u_char *bp, *cp, *ep;
 101         register struct nit_bufhdr *hdrp;
 102         register struct nit_iftime *ntp;
 103         register struct nit_iflen *nlp;
 104         register struct nit_ifdrops *ndp;
 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 snapshot in the chunk
 123          */
 124         n = 0;
 125         ep = bp + cc;
 126         while (bp < ep) {
 127                 ++p->md.stat.ps_recv;
 128                 cp = bp;
 129
 130                 /* get past NIT buffer  */
 131                 hdrp = (struct nit_bufhdr *)cp;
 132                 cp += sizeof(*hdrp);
 133
 134                 /* get past NIT timer   */
 135                 ntp = (struct nit_iftime *)cp;
 136                 cp += sizeof(*ntp);
 137
 138                 ndp = (struct nit_ifdrops *)cp;
 139                 p->md.stat.ps_drop = ndp->nh_drops;
 140                 cp += sizeof *ndp;
 141
 142                 /* get past packet len  */
 143                 nlp = (struct nit_iflen *)cp;
 144                 cp += sizeof(*nlp);
 145
 146                 /* next snapshot        */
 147                 bp += hdrp->nhb_totlen;
 148
 149                 caplen = nlp->nh_pktlen;
 150                 if (caplen > p->snapshot)
 151                         caplen = p->snapshot;
 152
 153                 if (bpf_filter(fcode, cp, nlp->nh_pktlen, caplen)) {
 154                         struct pcap_pkthdr h;
 155                         h.ts = ntp->nh_timestamp;
 156                         h.len = nlp->nh_pktlen;
 157                         h.caplen = caplen;
 158                         (*callback)(user, &h, cp);
 159                         if (++n >= cnt && cnt >= 0) {
 160                                 p->cc = ep - bp;
 161                                 p->bp = bp;
 162                                 return (n);
 163                         }
 164                 }
 165         }
 166         p->cc = 0;
 167         return (n);
 168 }
 169
 170 static int
 171 nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
 172 {
 173         bpf_u_int32 flags;
 174         struct strioctl si;
 175         struct timeval timeout;
 176
 177         si.ic_timout = INFTIM;
 178         if (to_ms != 0) {
 179                 timeout.tv_sec = to_ms / 1000;
 180                 timeout.tv_usec = (to_ms * 1000) % 1000000;
 181                 si.ic_cmd = NIOCSTIME;
 182                 si.ic_len = sizeof(timeout);
 183                 si.ic_dp = (char *)&timeout;
 184                 if (ioctl(fd, I_STR, (char *)&si) < 0) {
 185                         snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s",
 186                             pcap_strerror(errno));
 187                         return (-1);
 188                 }
 189         }
 190         flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
 191         if (promisc)
 192                 flags |= NI_PROMISC;
 193         si.ic_cmd = NIOCSFLAGS;
 194         si.ic_len = sizeof(flags);
 195         si.ic_dp = (char *)&flags;
 196         if (ioctl(fd, I_STR, (char *)&si) < 0) {
 197                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s",
 198                     pcap_strerror(errno));
 199                 return (-1);
 200         }
 201         return (0);
 202 }
 203
 204 pcap_t *
 205 pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
 206 {
 207         struct strioctl si;             /* struct for ioctl() */
 208         struct ifreq ifr;               /* interface request struct */
 209         int chunksize = CHUNKSIZE;
 210         int fd;
 211         static char dev[] = "/dev/nit";
 212         register pcap_t *p;
 213
 214         p = (pcap_t *)malloc(sizeof(*p));
 215         if (p == NULL) {
 216                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 217                 return (NULL);
 218         }
 219
 220         if (snaplen < 96)
 221                 /*
 222                  * NIT requires a snapshot length of at least 96.
 223                  */
 224                 snaplen = 96;
 225
 226         bzero(p, sizeof(*p));
 227         p->fd = fd = open(dev, O_RDONLY);
 228         if (fd < 0) {
 229                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s", dev,
 230                     pcap_strerror(errno));
 231                 goto bad;
 232         }
 233
 234         /* arrange to get discrete messages from the STREAM and use NIT_BUF */
 235         if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
 236                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s",
 237                     pcap_strerror(errno));
 238                 goto bad;
 239         }
 240         if (ioctl(fd, I_PUSH, "nbuf") < 0) {
 241                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "push nbuf: %s",
 242                     pcap_strerror(errno));
 243                 goto bad;
 244         }
 245         /* set the chunksize */
 246         si.ic_cmd = NIOCSCHUNK;
 247         si.ic_timout = INFTIM;
 248         si.ic_len = sizeof(chunksize);
 249         si.ic_dp = (char *)&chunksize;
 250         if (ioctl(fd, I_STR, (char *)&si) < 0) {
 251                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s",
 252                     pcap_strerror(errno));
 253                 goto bad;
 254         }
 255
 256         /* request the interface */
 257         strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
 258         ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = ' ';
 259         si.ic_cmd = NIOCBIND;
 260         si.ic_len = sizeof(ifr);
 261         si.ic_dp = (char *)&ifr;
 262         if (ioctl(fd, I_STR, (char *)&si) < 0) {
 263                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s",
 264                         ifr.ifr_name, pcap_strerror(errno));
 265                 goto bad;
 266         }
 267
 268         /* set the snapshot length */
 269         si.ic_cmd = NIOCSSNAP;
 270         si.ic_len = sizeof(snaplen);
 271         si.ic_dp = (char *)&snaplen;
 272         if (ioctl(fd, I_STR, (char *)&si) < 0) {
 273                 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s",
 274                     pcap_strerror(errno));
 275                 goto bad;
 276         }
 277         p->snapshot = snaplen;
 278         if (nit_setflags(p->fd, promisc, to_ms, ebuf) < 0)
 279                 goto bad;
 280
 281         (void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
 282         /*
 283          * NIT supports only ethernets.
 284          */
 285         p->linktype = DLT_EN10MB;
 286
 287         p->bufsize = BUFSPACE;
 288         p->buffer = (u_char *)malloc(p->bufsize);
 289         if (p->buffer == NULL) {
 290                 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
 291                 goto bad;
 292         }
 293         return (p);
 294  bad:
 295         if (fd >= 0)
 296                 close(fd);
 297         free(p);
 298         return (NULL);
 299 }
 300
 301 int
 302 pcap_setfilter(pcap_t *p, struct bpf_program *fp)
 303 {
 304
 305         p->fcode = *fp;
 306         return (0);
 307 }