Linux Cubed Series 7: Sunsite/Linux Cubed Series 7 - Sunsite Vol 1.iso/system/network/manageme/tcpdump-.001/tcpdump-~/tcpdump-3.0.2-linux/libpcap-0.0.6/pcap-snoop.c

C/C++ Source or Header | 1994-01-31 | 5.0 KB | 196 lines

/*
 * Copyright (c) 1993, 1994
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
#ifndef lint
static  char rcsid[] =
    "@(#)$Header: pcap-snoop.c,v 1.6 94/01/31 05:26:09 leres Exp $ (LBL)";
#endif

#include <sys/param.h>
#include <stdio.h>
#include <netdb.h>
#include <ctype.h>
#include <signal.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/ioctl.h>

#include <net/raw.h>

#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>
#include <net/bpf.h>

#include "pcap-int.h"

static int hdrpad;                    /* XXX */

int
pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
    int cc;
    register struct snoopheader *sh;
    register int datalen;
    register int caplen;
    register u_char *cp;
 again:
    cc = read(p->fd, (char *)p->buffer, p->bufsize);
    if (cc < 0) {
        switch (errno) {
        case EWOULDBLOCK:
            return (0);            /* XXX */
        }
        sprintf(p->errbuf, "read: %s", pcap_strerror(errno));
        return (-1);
    }
    sh = (struct snoopheader *)p->buffer;
    datalen = sh->snoop_packetlen;
    caplen = (datalen < p->snapshot) ? datalen : p->snapshot;
    cp = (u_char *)(sh + 1) + hdrpad;        /* XXX */

    if (p->fcode.bf_insns == NULL ||
        bpf_filter(p->fcode.bf_insns, cp, datalen, caplen)) {
        struct pcap_pkthdr h;
        ++p->md.stat.ps_recv;
        h.ts = sh->snoop_timestamp;
        h.len = datalen;
        h.caplen = caplen;
        (*callback)(user, &h, cp);
        return (1);
    }
    return (0);
}

int
pcap_stats(pcap_t *p, struct pcap_stat *ps)
{
    register struct rawstats *rs;
    struct rawstats rawstats;

    rs = &rawstats;
    bzero((char *)rs, sizeof(*rs));
    if (ioctl(p->fd, SIOCRAWSTATS, (char *)rs) < 0) {
        sprintf(p->errbuf, "SIOCRAWSTATS: %s", pcap_strerror(errno));
        return (-1);
    }

    p->md.stat.ps_drop =
        rs->rs_snoop.ss_ifdrops + rs->rs_snoop.ss_sbdrops +
        rs->rs_drain.ds_ifdrops + rs->rs_drain.ds_sbdrops;

    *ps = p->md.stat;
    return (0);
}

/* XXX can't disable promiscuous */
pcap_t *
pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
{
    pcap_t *p;
    struct sockaddr_raw sr;
    int fd;
    int v;
    struct snoopfilter sf;

    p = (pcap_t *)malloc(sizeof(*p));
    if (p == NULL) {
        strcpy(ebuf, "no swap");
        return (0);
    }
    bzero(p, sizeof(*p));
    p->fd = -1;
    p->bufsize = 4096;                /* XXX */
    p->buffer = (u_char *)malloc(p->bufsize);
    if (p->buffer == NULL) {
        strcpy(ebuf, "no swap");
        goto bad;
    }
    fd = p->fd = socket(PF_RAW, SOCK_RAW, RAWPROTO_SNOOP);
    if (fd < 0) {
        sprintf(ebuf, "snoop socket: %s", pcap_strerror(errno));
        goto bad;
    }
    sr.sr_family = AF_RAW;
    sr.sr_port = 0;
    (void)strncpy(sr.sr_ifname, device, sizeof(sr.sr_ifname));
    if (bind(fd, (struct sockaddr *)&sr, sizeof(sr))) {
        sprintf(ebuf, "snoop bind: %s", pcap_strerror(errno));
        goto bad;
    }
    bzero((char *)&sf, sizeof(sf));
    if (ioctl(fd, SIOCADDSNOOP, &sf) < 0) {
        sprintf(ebuf, "SIOCADDSNOOP: %s", pcap_strerror(errno));
        goto bad;
    }
    v = 64 * 1024;
    (void)setsockopt(fd, SOL_SOCKET, SO_RCVBUF, (char *)&v, sizeof(v));
    if (ioctl(fd, SIOCSNOOPLEN, &snaplen) < 0) {
        sprintf(ebuf, "SIOCSNOOPLEN: %s", pcap_strerror(errno));
        goto bad;
    }
    p->snapshot = snaplen;
    v = 1;
    if (ioctl(fd, SIOCSNOOPING, &v) < 0) {
        sprintf(ebuf, "SIOCSNOOPING: %s", pcap_strerror(errno));
        goto bad;
    }
    /*
     * XXX hack - map device name to link later type
     */
    if (strncmp("et", device, 2) == 0 ||
        strncmp("ec", device, 2) == 0) {
        p->linktype = DLT_EN10MB;
        hdrpad = RAW_HDRPAD(sizeof(struct ether_header));
    } else if (strncmp("ipg", device, 3) == 0 ||
           strncmp("xpi", device, 3) == 0) {
        p->linktype = DLT_FDDI;
        hdrpad = 3;                /* XXX yeah? */
    } else {
        sprintf(ebuf, "snoop: unknown physical layer type");
        goto bad;
    }
    return (p);
 bad:
    if (fd >= 0)
        close(fd);
    if (p->buffer != NULL)
        free(p->buffer);
    free(p);
    return (0);
}

int
pcap_setfilter(pcap_t *p, struct bpf_program *fp)
{

    p->fcode = *fp;
    return (0);
}