/*  ipguard.c
 *
 * Copyright (c) 2005 SeaD <sead@deep.perm.ru>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include "ipguard.h"

void help(char *name) {
    fprintf(stdout, "%s v%s by %s <%s>\n\n", NAME, VERSION, AUTHOR, MAIL);
    fprintf(stdout, "usage: %s [-felpmunbarxiodvh] <iface>\n\n", name);
    fprintf(stdout, "available options:\n");
    fprintf(stdout, "    -f | -e <ethers>    ethers file (" ETHERSFILE ")\n");
    fprintf(stdout, "    -l <log>            log file (" LOGNAME "_<iface>." LOGEXT ")\n");
    fprintf(stdout, "    -p <pid>            pid file (" PIDNAME "_<iface>." PIDEXT ")\n");
    fprintf(stdout, "    -m <mac>            fake mac (" FAKEMAC ")\n");
    fprintf(stdout, "    -u <seconds>        update ethers interval (%d)\n", ETHERSTO);
    fprintf(stdout, "    -n <num>            fake replies number (%d)\n", FAKENUM);
    fprintf(stdout, "    -b <num>            mac/ip buffer size (%d)\n", BUFSIZE);
    fprintf(stdout, "    -a                  no address substitition\n");
    fprintf(stdout, "    -r                  read only\n");
    fprintf(stdout, "    -x                  duplex mode\n");
    fprintf(stdout, "    -i                  hidden mode\n");
    fprintf(stdout, "    -o                  promiscuous mode\n");
    fprintf(stdout, "    -d                  don't fork\n");
    fprintf(stdout, "    -v                  verbose\n");
    fprintf(stdout, "    -h                  this help\n");
}

int main(int argc, char *argv[]) {
    extern char *optarg;
    extern int optind;
    int i;

    if (verbose && (getuid() || geteuid()))
        fprintf(stderr, "warning: you must have ro|rw permission to /dev/bpf*\n");

    srand((unsigned int) getpid());

    iface[0] = fmac[0] = log_name[0] = pid_name[0] = '\0';
    strncpy(ethers_name, ETHERSFILE, PATH_MAX);
    strncpy(fmac, FAKEMAC, MAC_SIZE);
    ethers_update = ETHERSTO;
    fake_num = FAKENUM;
    buffer_num = BUFSIZE;
    addr_nosubst = read_only = hidden = duplex = promisc = dont_fork = verbose = 0;

    all = good = zmac = zip = bad = bmac = bip = bdip =
        bnew = bent = mymac = fake = nze = mis = 0;

    while ((i = getopt(argc, argv, "f:e:l:p:m:u:n:b:arxiodvh")) != EOF) {
        switch (i) {
            case 'f':
            case 'e': if (optarg) strncpy(ethers_name, optarg, PATH_MAX); break;
            case 'l': if (optarg) strncpy(log_name, optarg, PATH_MAX); break;
            case 'p': if (optarg) strncpy(pid_name, optarg, PATH_MAX); break;
            case 'm': if (optarg) strncpy(fmac, optarg, MAC_SIZE); break;
            case 'u': ethers_update = atoi(optarg); break;
            case 'n': fake_num = atoi(optarg); break;
            case 'b': buffer_num = atoi(optarg); break;
            case 'a': addr_nosubst++; break;
            case 'r': read_only++; break;
            case 'x': duplex++; break;
            case 'i': hidden++; break;
            case 'o': promisc++; break;
            case 'd': dont_fork++; break;
            case 'v': verbose++; break;
            case 'h': help(argv[0]); exit(EXIT_SUCCESS);
            default: help(argv[0]); exit(EXIT_FAILURE);
        }
    }
    if (argc > optind) { strncpy(iface, argv[optind], IFNAMSIZ); }
    else { help(argv[0]); exit(EXIT_FAILURE); }

    if (!log_name[0]) snprintf(log_name, PATH_MAX, "%s_%s.%s", LOGNAME, iface, LOGEXT);
    if (!pid_name[0]) snprintf(pid_name, PATH_MAX, "%s_%s.%s", PIDNAME, iface, PIDEXT);

    log_open();

    if (!dont_fork) {
        if ((i = fork()) == -1) {
            log_str(ERROR, "fork():", strerror(errno));
            exit(EXIT_FAILURE);
        } else if (i != 0) exit(EXIT_SUCCESS);
        if (!setsid()) {
            log_str(ERROR, "setsid():", strerror(errno));
            exit(EXIT_FAILURE);
        }
    }

    sig_init();
    pid_creat();
    pair_init(iface);
    ethers_init();
    packet_init();
    if (buffer_num) buffer_init();

    while (1) packet_recv();

    exit_ipguard(EXIT_SUCCESS);
    return 0;
}