blob: a42106960801d160a2f25b88976a368ba66dcebd
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * 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 | #include "common.h" |
26 | #include <net/if.h> |
27 | |
28 | int FAST_FUNC udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) |
29 | { |
30 | /* char buffer instead of bona-fide struct avoids aliasing warning */ |
31 | char ifr_buf[sizeof(struct ifreq)]; |
32 | struct ifreq *const ifr = (void *)ifr_buf; |
33 | |
34 | int fd; |
35 | struct sockaddr_in *our_ip; |
36 | |
37 | memset(ifr, 0, sizeof(*ifr)); |
38 | fd = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW); |
39 | |
40 | ifr->ifr_addr.sa_family = AF_INET; |
41 | strncpy_IFNAMSIZ(ifr->ifr_name, interface); |
42 | if (nip) { |
43 | if (ioctl_or_perror(fd, SIOCGIFADDR, ifr, |
44 | "is interface %s up and configured?", interface) |
45 | ) { |
46 | close(fd); |
47 | return -1; |
48 | } |
49 | our_ip = (struct sockaddr_in *) &ifr->ifr_addr; |
50 | *nip = our_ip->sin_addr.s_addr; |
51 | log1("IP %s", inet_ntoa(our_ip->sin_addr)); |
52 | } |
53 | |
54 | if (ifindex) { |
55 | if (ioctl_or_warn(fd, SIOCGIFINDEX, ifr) != 0) { |
56 | close(fd); |
57 | return -1; |
58 | } |
59 | log1("Adapter index %d", ifr->ifr_ifindex); |
60 | *ifindex = ifr->ifr_ifindex; |
61 | } |
62 | |
63 | if (mac) { |
64 | if (ioctl_or_warn(fd, SIOCGIFHWADDR, ifr) != 0) { |
65 | close(fd); |
66 | return -1; |
67 | } |
68 | memcpy(mac, ifr->ifr_hwaddr.sa_data, 6); |
69 | log1("MAC %02x:%02x:%02x:%02x:%02x:%02x", |
70 | mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]); |
71 | } |
72 | |
73 | close(fd); |
74 | return 0; |
75 | } |
76 | |
77 | /* 1. None of the callers expects it to ever fail */ |
78 | /* 2. ip was always INADDR_ANY */ |
79 | int FAST_FUNC udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) |
80 | { |
81 | int fd; |
82 | struct sockaddr_in addr; |
83 | char *colon; |
84 | |
85 | log1("Opening listen socket on *:%d %s", port, inf); |
86 | fd = xsocket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); |
87 | |
88 | setsockopt_reuseaddr(fd); |
89 | if (setsockopt_broadcast(fd) == -1) |
90 | bb_perror_msg_and_die("SO_BROADCAST"); |
91 | |
92 | /* SO_BINDTODEVICE doesn't work on ethernet aliases (ethN:M) */ |
93 | colon = strrchr(inf, ':'); |
94 | if (colon) |
95 | *colon = '\0'; |
96 | |
97 | if (setsockopt_bindtodevice(fd, inf)) |
98 | xfunc_die(); /* warning is already printed */ |
99 | |
100 | if (colon) |
101 | *colon = ':'; |
102 | |
103 | memset(&addr, 0, sizeof(addr)); |
104 | addr.sin_family = AF_INET; |
105 | addr.sin_port = htons(port); |
106 | /* addr.sin_addr.s_addr = ip; - all-zeros is INADDR_ANY */ |
107 | xbind(fd, (struct sockaddr *)&addr, sizeof(addr)); |
108 | |
109 | return fd; |
110 | } |
111 |