capturetest.c

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/*
 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
 *  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.
 */
 
#include "varattrs.h"
 
#ifndef lint
static const char copyright[] _U_ =
    "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
The Regents of the University of California.  All rights reserved.\n";
#endif
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <limits.h>
#ifdef _WIN32
  #include "getopt.h"
#else
  #include <unistd.h>
#endif
#include <errno.h>
#ifndef _WIN32
  #include <signal.h>
#endif
#include <sys/types.h>
 
#include <pcap.h>
 
#include "pcap/funcattrs.h"
 
#ifdef _WIN32
  #include "portability.h"
#endif
 
static char *program_name;
 
/* Forwards */
static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
static void PCAP_NORETURN usage(void);
static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
static char *copy_argv(char **);
 
static pcap_t *pd;
#ifndef _WIN32
static int breaksigint = 0;
#endif
 
#ifndef _WIN32
static void
sigint_handler(int signum _U_)
{
    if (breaksigint)
        pcap_breakloop(pd);
}
#endif
 
#ifdef _WIN32
/*
 * We don't have UN*X-style signals, so we don't have anything to test.
 */
#define B_OPTION    ""
#define R_OPTION    ""
#define S_OPTION    ""
#else
/*
 * We do have UN*X-style signals (we assume that "not Windows" means "UN*X").
 */
#define B_OPTION    "b"
#define R_OPTION    "r"
#define S_OPTION    "s"
#endif
 
#define COMMAND_OPTIONS B_OPTION "i:mn" R_OPTION S_OPTION "t:"
#define USAGE_OPTIONS   "-" B_OPTION "mn" R_OPTION S_OPTION
 
int
main(int argc, char **argv)
{
    register int op;
    register char *cp, *cmdbuf, *device;
    long longarg;
    char *p;
    int timeout = 1000;
    int immediate = 0;
    int nonblock = 0;
#ifndef _WIN32
    int sigrestart = 0;
    int catchsigint = 0;
#endif
    pcap_if_t *devlist;
    bpf_u_int32 localnet, netmask;
    struct bpf_program fcode;
    char ebuf[PCAP_ERRBUF_SIZE];
    int status;
    int packet_count;
 
    device = NULL;
    if ((cp = strrchr(argv[0], '/')) != NULL)
        program_name = cp + 1;
    else
        program_name = argv[0];
 
    opterr = 0;
    while ((op = getopt(argc, argv, COMMAND_OPTIONS)) != -1) {
        switch (op) {
 
#ifndef _WIN32
        case 'b':
            breaksigint = 1;
            break;
#endif
 
        case 'i':
            device = optarg;
            break;
 
        case 'm':
            immediate = 1;
            break;
 
        case 'n':
            nonblock = 1;
            break;
 
#ifndef _WIN32
        case 'r':
            sigrestart = 1;
            break;
 
        case 's':
            catchsigint = 1;
            break;
#endif
 
        case 't':
            longarg = strtol(optarg, &p, 10);
            if (p == optarg || *p != '\0') {
                error("Timeout value \"%s\" is not a number",
                    optarg);
                /* NOTREACHED */
            }
            if (longarg < 0) {
                error("Timeout value %ld is negative", longarg);
                /* NOTREACHED */
            }
            if (longarg > INT_MAX) {
                error("Timeout value %ld is too large (> %d)",
                    longarg, INT_MAX);
                /* NOTREACHED */
            }
            timeout = (int)longarg;
            break;
 
        default:
            usage();
            /* NOTREACHED */
        }
    }
 
    if (device == NULL) {
        if (pcap_findalldevs(&devlist, ebuf) == -1)
            error("%s", ebuf);
        if (devlist == NULL)
            error("no interfaces available for capture");
        device = strdup(devlist->name);
        pcap_freealldevs(devlist);
    }
    *ebuf = '\0';
 
#ifndef _WIN32
    /*
     * If we were told to catch SIGINT, do so.
     */
    if (catchsigint) {
        struct sigaction action;
 
        action.sa_handler = sigint_handler;
        sigemptyset(&action.sa_mask);
 
        /*
         * Should SIGINT interrupt, or restart, system calls?
         */
        action.sa_flags = sigrestart ? SA_RESTART : 0;
 
        if (sigaction(SIGINT, &action, NULL) == -1)
            error("Can't catch SIGINT: %s\n",
                strerror(errno));
    }
#endif
 
    pd = pcap_create(device, ebuf);
    if (pd == NULL)
        error("%s", ebuf);
    status = pcap_set_snaplen(pd, 65535);
    if (status != 0)
        error("%s: pcap_set_snaplen failed: %s",
                device, pcap_statustostr(status));
    if (immediate) {
        status = pcap_set_immediate_mode(pd, 1);
        if (status != 0)
            error("%s: pcap_set_immediate_mode failed: %s",
                device, pcap_statustostr(status));
    }
    status = pcap_set_timeout(pd, timeout);
    if (status != 0)
        error("%s: pcap_set_timeout failed: %s",
            device, pcap_statustostr(status));
    status = pcap_activate(pd);
    if (status < 0) {
        /*
         * pcap_activate() failed.
         */
        error("%s: %s\n(%s)", device,
            pcap_statustostr(status), pcap_geterr(pd));
    } else if (status > 0) {
        /*
         * pcap_activate() succeeded, but it's warning us
         * of a problem it had.
         */
        warning("%s: %s\n(%s)", device,
            pcap_statustostr(status), pcap_geterr(pd));
    }
    if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
        localnet = 0;
        netmask = 0;
        warning("%s", ebuf);
    }
    cmdbuf = copy_argv(&argv[optind]);
 
    if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
        error("%s", pcap_geterr(pd));
 
    if (pcap_setfilter(pd, &fcode) < 0)
        error("%s", pcap_geterr(pd));
    if (pcap_setnonblock(pd, nonblock, ebuf) == -1)
        error("pcap_setnonblock failed: %s", ebuf);
    printf("Listening on %s\n", device);
    for (;;) {
        packet_count = 0;
        status = pcap_dispatch(pd, -1, countme,
            (u_char *)&packet_count);
        if (status < 0)
            break;
        if (status != 0) {
            printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
                status, packet_count);
            struct pcap_stat ps;
            pcap_stats(pd, &ps);
            printf("%d ps_recv, %d ps_drop, %d ps_ifdrop\n",
                ps.ps_recv, ps.ps_drop, ps.ps_ifdrop);
        }
    }
    if (status == -2) {
        /*
         * We got interrupted, so perhaps we didn't
         * manage to finish a line we were printing.
         * Print an extra newline, just in case.
         */
        putchar('\n');
        printf("Broken out of loop from SIGINT handler\n");
    }
    (void)fflush(stdout);
    if (status == -1) {
        /*
         * Error.  Report it.
         */
        (void)fprintf(stderr, "%s: pcap_dispatch: %s\n",
            program_name, pcap_geterr(pd));
    }
    pcap_close(pd);
    pcap_freecode(&fcode);
    free(cmdbuf);
    exit(status == -1 ? 1 : 0);
}
 
static void
countme(u_char *user, const struct pcap_pkthdr *h _U_, const u_char *sp _U_)
{
    int *counterp = (int *)user;
 
    (*counterp)++;
}
 
static void
usage(void)
{
    (void)fprintf(stderr, "Usage: %s [ " USAGE_OPTIONS " ] [ -i interface ] [ -t timeout] [expression]\n",
        program_name);
    exit(1);
}
 
/* VARARGS */
static void
error(const char *fmt, ...)
{
    va_list ap;
 
    (void)fprintf(stderr, "%s: ", program_name);
    va_start(ap, fmt);
    (void)vfprintf(stderr, fmt, ap);
    va_end(ap);
    if (*fmt) {
        fmt += strlen(fmt);
        if (fmt[-1] != '\n')
            (void)fputc('\n', stderr);
    }
    exit(1);
    /* NOTREACHED */
}
 
/* VARARGS */
static void
warning(const char *fmt, ...)
{
    va_list ap;
 
    (void)fprintf(stderr, "%s: WARNING: ", program_name);
    va_start(ap, fmt);
    (void)vfprintf(stderr, fmt, ap);
    va_end(ap);
    if (*fmt) {
        fmt += strlen(fmt);
        if (fmt[-1] != '\n')
            (void)fputc('\n', stderr);
    }
}
 
/*
 * Copy arg vector into a new buffer, concatenating arguments with spaces.
 */
static char *
copy_argv(register char **argv)
{
    register char **p;
    register size_t len = 0;
    char *buf;
    char *src, *dst;
 
    p = argv;
    if (*p == 0)
        return 0;
 
    while (*p)
        len += strlen(*p++) + 1;
 
    buf = (char *)malloc(len);
    if (buf == NULL)
        error("copy_argv: malloc");
 
    p = argv;
    dst = buf;
    while ((src = *p++) != NULL) {
        while ((*dst++ = *src++) != '\0')
            ;
        dst[-1] = ' ';
    }
    dst[-1] = '\0';
 
    return buf;
}