source: MondoRescue/branches/3.3/mindi-busybox/networking/udhcp/socket.c@ 3621

/* vi: set sw=4 ts=4: */
/*
 * DHCP server client/server socket creation
 *
 * udhcp client/server
 * Copyright (C) 1999 Matthew Ramsay <matthewr@moreton.com.au>
 *          Chris Trew <ctrew@moreton.com.au>
 *
 * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include "common.h"
#include <net/if.h>

int FAST_FUNC udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac)
{
    /* char buffer instead of bona-fide struct avoids aliasing warning */
    char ifr_buf[sizeof(struct ifreq)];
    struct ifreq *const ifr = (void *)ifr_buf;

    int fd;
    struct sockaddr_in *our_ip;

    memset(ifr, 0, sizeof(*ifr));
    fd = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);

    ifr->ifr_addr.sa_family = AF_INET;
    strncpy_IFNAMSIZ(ifr->ifr_name, interface);
    if (nip) {
        if (ioctl_or_perror(fd, SIOCGIFADDR, ifr,
            "is interface %s up and configured?", interface)
        ) {
            close(fd);
            return -1;
        }
        our_ip = (struct sockaddr_in *) &ifr->ifr_addr;
        *nip = our_ip->sin_addr.s_addr;
        log1("IP %s", inet_ntoa(our_ip->sin_addr));
    }

    if (ifindex) {
        if (ioctl_or_warn(fd, SIOCGIFINDEX, ifr) != 0) {
            close(fd);
            return -1;
        }
        log1("adapter index %d", ifr->ifr_ifindex);
        *ifindex = ifr->ifr_ifindex;
    }

    if (mac) {
        if (ioctl_or_warn(fd, SIOCGIFHWADDR, ifr) != 0) {
            close(fd);
            return -1;
        }
        memcpy(mac, ifr->ifr_hwaddr.sa_data, 6);
        log1("MAC %02x:%02x:%02x:%02x:%02x:%02x",
            mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
    }

    close(fd);
    return 0;
}

/* 1. None of the callers expects it to ever fail */
/* 2. ip was always INADDR_ANY */
int FAST_FUNC udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf)
{
    int fd;
    struct sockaddr_in addr;
    char *colon;

    log1("opening listen socket on *:%d %s", port, inf);
    fd = xsocket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);

    setsockopt_reuseaddr(fd);
    if (setsockopt_broadcast(fd) == -1)
        bb_perror_msg_and_die("SO_BROADCAST");

    /* SO_BINDTODEVICE doesn't work on ethernet aliases (ethN:M) */
    colon = strrchr(inf, ':');
    if (colon)
        *colon = '\0';

    if (setsockopt_bindtodevice(fd, inf))
        xfunc_die(); /* warning is already printed */

    if (colon)
        *colon = ':';

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    /* addr.sin_addr.s_addr = ip; - all-zeros is INADDR_ANY */
    xbind(fd, (struct sockaddr *)&addr, sizeof(addr));

    return fd;
}