tcpbridge.c

/* $Id$ */

/*
 *   Copyright (c) 2001-2010 Aaron Turner <aturner at synfin dot net>
 *   Copyright (c) 2013-2017 Fred Klassen <tcpreplay at appneta dot com> - AppNeta
 *
 *   The Tcpreplay Suite of tools is free software: you can redistribute it 
 *   and/or modify it under the terms of the GNU General Public License as 
 *   published by the Free Software Foundation, either version 3 of the 
 *   License, or with the authors permission any later version.
 *
 *   The Tcpreplay Suite is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with the Tcpreplay Suite.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Purpose: Modify packets in a pcap file based on rules provided by the
 * user to offload work from tcpreplay and provide a easier means of 
 * reproducing traffic for testing purposes.
 */


#include "config.h"
#include "defines.h"
#include "common.h"

#include <ctype.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>

#include "tcpbridge.h"
#include "tcpbridge_opts.h"
#include "bridge.h"
#include "tcpedit/tcpedit.h"

#ifdef DEBUG
int debug;
#endif


COUNTER cache_packets;
tcpreplay_stats_t stats;
tcpbridge_opt_t options;
tcpedit_t *tcpedit;

/* local functions */
void init(void);
void post_args(int argc, char *argv[]);

int 
main(int argc, char *argv[])
{
    int optct, rcode;

    init();

    /* call autoopts to process arguments */
    optct = optionProcess(&tcpbridgeOptions, argc, argv);
    argc -= optct;
    argv += optct;

    post_args(argc, argv);

    /* init tcpedit context */
    if (tcpedit_init(&tcpedit, pcap_datalink(options.pcap1)) < 0) {
        errx(-1, "Error initializing tcpedit: %s", tcpedit_geterr(tcpedit));
    }

    /* parse the tcpedit args */
    rcode = tcpedit_post_args(tcpedit);
    if (rcode < 0) {
        errx(-1, "Unable to parse args: %s", tcpedit_geterr(tcpedit));
    } else if (rcode == 1) {
        warnx("%s", tcpedit_geterr(tcpedit));
    }

    if (tcpedit_validate(tcpedit) < 0) {
        errx(-1, "Unable to edit packets given options:\n%s",
                tcpedit_geterr(tcpedit));
    }

#ifdef ENABLE_VERBOSE
    if (options.verbose) {
        options.tcpdump = (tcpdump_t*)safe_malloc(sizeof(tcpdump_t));
        tcpdump_open(options.tcpdump, options.pcap1);
    }
#endif

    if (gettimeofday(&stats.start_time, NULL) < 0)
        err(-1, "gettimeofday() failed");


    /* process packets */
    do_bridge(&options, tcpedit);

    /* clean up after ourselves */
    pcap_close(options.pcap1);

    if (options.unidir) {
        pcap_close(options.pcap2);
    }

#ifdef ENABLE_VERBOSE
    tcpdump_close(options.tcpdump);
#endif

    return 0;
}

void 
init(void)
{

    memset(&stats, 0, sizeof(stats));
    memset(&options, 0, sizeof(options));

    options.snaplen = 65535;
    options.promisc = 1;
    options.to_ms = 1;

    if (fcntl(STDERR_FILENO, F_SETFL, O_NONBLOCK) < 0)
        warnx("Unable to set STDERR to non-blocking: %s", strerror(errno));

}


void 
post_args(_U_ int argc, _U_ char *argv[])
{
    char ebuf[SENDPACKET_ERRBUF_SIZE];
    struct tcpr_ether_addr *eth_buff;
    char *intname;
    sendpacket_t *sp;
#ifdef ENABLE_PCAP_FINDALLDEVS
    interface_list_t *intlist = get_interface_list();
#else
    interface_list_t *intlist = NULL;
#endif

#ifdef DEBUG
    if (HAVE_OPT(DBUG))
        debug = OPT_VALUE_DBUG;
#else
    if (HAVE_OPT(DBUG))
        warn("not configured with --enable-debug.  Debugging disabled.");
#endif


#ifdef ENABLE_VERBOSE
    if (HAVE_OPT(VERBOSE))
        options.verbose = 1;

    if (HAVE_OPT(DECODE))
        options.tcpdump->args = safe_strdup(OPT_ARG(DECODE));
#endif

    if (HAVE_OPT(UNIDIR))
        options.unidir = 1;

    if (HAVE_OPT(LIMIT))
        options.limit_send = OPT_VALUE_LIMIT; /* default is -1 */


    if ((intname = get_interface(intlist, OPT_ARG(INTF1))) == NULL) {
        if (!strncmp(OPT_ARG(INTF1), "netmap:", 7) || !strncmp(OPT_ARG(INTF1), "vale", 4))
            errx(-1, "Unable to connect to netmap interface %s. Ensure netmap module is installed (see INSTALL).",
                    OPT_ARG(INTF1));
        else
            errx(-1, "Invalid interface name/alias: %s", OPT_ARG(INTF1));
    }

    options.intf1 = safe_strdup(intname);

    if (HAVE_OPT(INTF2)) {
        if ((intname = get_interface(intlist, OPT_ARG(INTF2))) == NULL)
            errx(-1, "Invalid interface name/alias: %s", OPT_ARG(INTF2));

        options.intf2 = safe_strdup(intname);
    }

    if (HAVE_OPT(MAC)) {
        int ct = STACKCT_OPT(MAC);
        char **list = (char**)STACKLST_OPT(MAC);
        int first = 1;
        do {
            char *p = *list++;
            if (first)
                mac2hex(p, (u_char *)options.intf1_mac, ETHER_ADDR_LEN);
            else
                mac2hex(p, (u_char *)options.intf2_mac, ETHER_ADDR_LEN);
            first = 0;
        } while (--ct > 0);
    }

    /* 
     * Figure out MAC addresses of sending interface(s)
     * if user doesn't specify MAC address on CLI, query for it 
     */
    if (memcmp(options.intf1_mac, "\00\00\00\00\00\00", ETHER_ADDR_LEN) == 0) {
        if ((sp = sendpacket_open(options.intf1, ebuf, TCPR_DIR_C2S, SP_TYPE_NONE, NULL)) == NULL)
            errx(-1, "Unable to open interface %s: %s", options.intf1, ebuf);

        if ((eth_buff = sendpacket_get_hwaddr(sp)) == NULL) {
            warnx("Unable to get MAC address: %s", sendpacket_geterr(sp));
            err(-1, "Please consult the man page for using the -M option.");
        }
        sendpacket_close(sp);
        memcpy(options.intf1_mac, eth_buff, ETHER_ADDR_LEN);
    }

    if (memcmp(options.intf2_mac, "\00\00\00\00\00\00", ETHER_ADDR_LEN) == 0) {
        if ((sp = sendpacket_open(options.intf2, ebuf, TCPR_DIR_S2C, SP_TYPE_NONE, NULL)) == NULL)
            errx(-1, "Unable to open interface %s: %s", options.intf2, ebuf);

        if ((eth_buff = sendpacket_get_hwaddr(sp)) == NULL) {
            warnx("Unable to get MAC address: %s", sendpacket_geterr(sp));
            err(-1, "Please consult the man page for using the -M option.");
        }
        sendpacket_close(sp);
        memcpy(options.intf2_mac, eth_buff, ETHER_ADDR_LEN);
    }

    /* 
     * Open interfaces for sending & receiving 
     */
    if ((options.pcap1 = pcap_open_live(options.intf1, options.snaplen, 
                                          options.promisc, options.to_ms, ebuf)) == NULL)
        errx(-1, "Unable to open interface %s: %s", options.intf1, ebuf);


    if (strcmp(options.intf1, options.intf2) == 0)
        errx(-1, "Whoa tiger!  You don't want to use %s twice!", options.intf1);


    /* we always have to open the other pcap handle to send, but we may not listen */
    if ((options.pcap2 = pcap_open_live(options.intf2, options.snaplen,
                                          options.promisc, options.to_ms, ebuf)) == NULL)
        errx(-1, "Unable to open interface %s: %s", options.intf2, ebuf);

    /* poll should be -1 to wait indefinitely */
    options.poll_timeout = -1;

    safe_free(intlist);
}