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