Include -Wunreachable-code when building.
[sysvinit.git] / src / ifdown.c
1 /*
2 * ifdown.c Find all network interfaces on the system and
3 * shut them down.
4 *
5 * Copyright (C) 1998 Miquel van Smoorenburg.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 *
21 */
22 char *v_ifdown = "@(#)ifdown.c 1.11 02-Jun-1998 miquels@cistron.nl";
23
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <unistd.h>
27 #include <time.h>
28 #include <string.h>
29 #include <errno.h>
30
31 #include <sys/ioctl.h>
32 #include <sys/socket.h>
33 #include <sys/time.h>
34
35 #include <net/if.h>
36 #include <netinet/in.h>
37
38 #define MAX_IFS 64
39
40 /* XXX: Ideally this would get detected at configure time... */
41 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || \
42 defined(__NetBSD__) || defined(__OpenBSD__)
43 #define HAVE_SOCKADDR_SA_LEN 1
44 #endif
45
46 #ifndef _SIZEOF_ADDR_IFREQ
47 #ifdef HAVE_SOCKADDR_SA_LEN
48 #define _SIZEOF_ADDR_IFREQ(ifr) \
49 ((ifr).ifr_addr.sa_len > sizeof(struct sockaddr) ? \
50 (sizeof((ifr).ifr_name) + (ifr).ifr_addr.sa_len) : \
51 sizeof(struct ifreq))
52 #else
53 #define _SIZEOF_ADDR_IFREQ(ifr) sizeof(struct ifreq)
54 #endif
55 #endif
56
57 /*
58 * First, we find all shaper devices and down them. Then we
59 * down all real interfaces. This is because the comment in the
60 * shaper driver says "if you down the shaper device before the
61 * attached inerface your computer will follow".
62 */
63 int ifdown(void)
64 {
65 char ifr_buf[sizeof(struct ifreq) * MAX_IFS];
66 char *ifr_end;
67 struct ifconf ifc;
68 int fd;
69 int shaper;
70
71 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
72 fprintf(stderr, "ifdown: ");
73 perror("socket");
74 return -1;
75 }
76 ifc.ifc_len = sizeof(ifr_buf);
77 ifc.ifc_buf = ifr_buf;
78
79 if (ioctl(fd, SIOCGIFCONF, &ifc) < 0) {
80 fprintf(stderr, "ifdown: ");
81 perror("SIOCGIFCONF");
82 close(fd);
83 return -1;
84 }
85 ifr_end = ifr_buf + ifc.ifc_len;
86
87 for (shaper = 1; shaper >= 0; shaper--) {
88 char *ifr_next = ifr_buf;
89
90 while (ifr_next < ifr_end) {
91 struct ifreq *ifr;
92 int flags;
93
94 ifr = (struct ifreq *)ifr_next;
95 ifr_next += _SIZEOF_ADDR_IFREQ(*ifr);
96
97 if ((strncmp(ifr->ifr_name, "shaper", 6) == 0)
98 != shaper) continue;
99
100 if (strncmp(ifr->ifr_name, "lo", 2) == 0)
101 continue;
102 if (strchr(ifr->ifr_name, ':') != NULL)
103 continue;
104
105 /* Read interface flags */
106 if (ioctl(fd, SIOCGIFFLAGS, ifr) < 0) {
107 fprintf(stderr, "ifdown: shutdown ");
108 perror(ifr->ifr_name);
109 continue;
110 }
111 /*
112 * Expected in <net/if.h> according to
113 * "UNIX Network Programming".
114 */
115 #ifdef ifr_flagshigh
116 flags = (ifr->ifr_flags & 0xffff) |
117 (ifr->ifr_flagshigh << 16);
118 #else
119 flags = ifr->ifr_flags;
120 #endif
121 if (flags & IFF_UP) {
122 flags &= ~(IFF_UP);
123 #ifdef ifr_flagshigh
124 ifr->ifr_flags = flags & 0xffff;
125 ifr->ifr_flagshigh = flags >> 16;
126 #else
127 ifr->ifr_flags = flags;
128 #endif
129 if (ioctl(fd, SIOCSIFFLAGS, ifr) < 0) {
130 fprintf(stderr, "ifdown: shutdown ");
131 perror(ifr->ifr_name);
132 }
133 }
134 }
135 }
136 close(fd);
137
138 return 0;
139 }