LXR busybox/networking/udhcp/socket.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * socket.c -- DHCP server client/server socket creation
   4 *
   5 * udhcp client/server
   6 * Copyright (C) 1999 Matthew Ramsay <matthewr@moreton.com.au>
   7 *                      Chris Trew <ctrew@moreton.com.au>
   8 *
   9 * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2 of the License, or
  14 * (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24 */
  25
  26#include <net/if.h>
  27//#include <features.h>
  28#if (defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1) || defined _NEWLIB_VERSION
  29#include <netpacket/packet.h>
  30#include <net/ethernet.h>
  31#else
  32#include <asm/types.h>
  33#include <linux/if_packet.h>
  34#include <linux/if_ether.h>
  35#endif
  36
  37#include "common.h"
  38
  39
  40int FAST_FUNC udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac)
  41{
  42        int fd;
  43        struct ifreq ifr;
  44        struct sockaddr_in *our_ip;
  45
  46        memset(&ifr, 0, sizeof(ifr));
  47        fd = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
  48
  49        ifr.ifr_addr.sa_family = AF_INET;
  50        strncpy_IFNAMSIZ(ifr.ifr_name, interface);
  51        if (nip) {
  52                if (ioctl_or_perror(fd, SIOCGIFADDR, &ifr,
  53                        "is interface %s up and configured?", interface)
  54                ) {
  55                        close(fd);
  56                        return -1;
  57                }
  58                our_ip = (struct sockaddr_in *) &ifr.ifr_addr;
  59                *nip = our_ip->sin_addr.s_addr;
  60                log1("IP %s", inet_ntoa(our_ip->sin_addr));
  61        }
  62
  63        if (ifindex) {
  64                if (ioctl_or_warn(fd, SIOCGIFINDEX, &ifr) != 0) {
  65                        close(fd);
  66                        return -1;
  67                }
  68                log1("Adapter index %d", ifr.ifr_ifindex);
  69                *ifindex = ifr.ifr_ifindex;
  70        }
  71
  72        if (mac) {
  73                if (ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr) != 0) {
  74                        close(fd);
  75                        return -1;
  76                }
  77                memcpy(mac, ifr.ifr_hwaddr.sa_data, 6);
  78                log1("MAC %02x:%02x:%02x:%02x:%02x:%02x",
  79                        mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
  80        }
  81
  82        close(fd);
  83        return 0;
  84}
  85
  86/* 1. None of the callers expects it to ever fail */
  87/* 2. ip was always INADDR_ANY */
  88int FAST_FUNC udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf)
  89{
  90        int fd;
  91        struct sockaddr_in addr;
  92
  93        log1("Opening listen socket on *:%d %s", port, inf);
  94        fd = xsocket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
  95
  96        setsockopt_reuseaddr(fd);
  97        if (setsockopt_broadcast(fd) == -1)
  98                bb_perror_msg_and_die("SO_BROADCAST");
  99
 100        /* NB: bug 1032 says this doesn't work on ethernet aliases (ethN:M) */
 101        if (setsockopt_bindtodevice(fd, inf))
 102                xfunc_die(); /* warning is already printed */
 103
 104        memset(&addr, 0, sizeof(addr));
 105        addr.sin_family = AF_INET;
 106        addr.sin_port = htons(port);
 107        /* addr.sin_addr.s_addr = ip; - all-zeros is INADDR_ANY */
 108        xbind(fd, (struct sockaddr *)&addr, sizeof(addr));
 109
 110        return fd;
 111}
 112