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
udhcp_read_interface(const char * interface,int * ifindex,uint32_t * nip,uint8_t * mac)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 */
udhcp_listen_socket(int port,const char * inf)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