release/src/router/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
  40 int FAST_FUNC udhcp_read_interface(const char *interface, int *ifindex, uint32_t *addr, uint8_t *arp)
  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 (addr) {
  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                 *addr = our_ip->sin_addr.s_addr;
  60                 DEBUG("ip of %s = %s", interface, 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                 DEBUG("adapter index %d", ifr.ifr_ifindex);
  69                 *ifindex = ifr.ifr_ifindex;
  70         }
  71
  72         if (arp) {
  73                 if (ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr) != 0) {
  74                         close(fd);
  75                         return -1;
  76                 }
  77                 memcpy(arp, ifr.ifr_hwaddr.sa_data, 6);
  78                 DEBUG("adapter hardware address %02x:%02x:%02x:%02x:%02x:%02x",
  79                         arp[0], arp[1], arp[2], arp[3], arp[4], arp[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 */
  88 int FAST_FUNC udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf)
  89 {
  90         int fd;
  91         struct sockaddr_in addr;
  92
  93         DEBUG("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 }