Denis Vlasenko | 39b6813 | 2009-01-23 02:07:14 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * tun devices controller |
| 4 | * |
| 5 | * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com> |
| 6 | * |
| 7 | * Original code: |
| 8 | * Jeff Dike |
| 9 | * |
Denys Vlasenko | 0ef64bd | 2010-08-16 20:14:46 +0200 | [diff] [blame] | 10 | * Licensed under GPLv2, see file LICENSE in this source tree. |
Denis Vlasenko | 39b6813 | 2009-01-23 02:07:14 +0000 | [diff] [blame] | 11 | */ |
Denys Vlasenko | 47367e1 | 2016-11-23 09:05:14 +0100 | [diff] [blame] | 12 | //config:config TUNCTL |
Denys Vlasenko | 4eed2c6 | 2017-07-18 22:01:24 +0200 | [diff] [blame^] | 13 | //config: bool "tunctl (6.4 kb)" |
Denys Vlasenko | 47367e1 | 2016-11-23 09:05:14 +0100 | [diff] [blame] | 14 | //config: default y |
| 15 | //config: select PLATFORM_LINUX |
| 16 | //config: help |
| 17 | //config: tunctl creates or deletes tun devices. |
| 18 | //config: |
| 19 | //config:config FEATURE_TUNCTL_UG |
| 20 | //config: bool "Support owner:group assignment" |
| 21 | //config: default y |
| 22 | //config: depends on TUNCTL |
| 23 | //config: help |
| 24 | //config: Allow to specify owner and group of newly created interface. |
| 25 | //config: 340 bytes of pure bloat. Say no here. |
| 26 | |
| 27 | //applet:IF_TUNCTL(APPLET(tunctl, BB_DIR_SBIN, BB_SUID_DROP)) |
| 28 | |
| 29 | //kbuild:lib-$(CONFIG_TUNCTL) += tunctl.o |
Pere Orga | 5bc8c00 | 2011-04-11 03:29:49 +0200 | [diff] [blame] | 30 | |
| 31 | //usage:#define tunctl_trivial_usage |
| 32 | //usage: "[-f device] ([-t name] | -d name)" IF_FEATURE_TUNCTL_UG(" [-u owner] [-g group] [-b]") |
| 33 | //usage:#define tunctl_full_usage "\n\n" |
| 34 | //usage: "Create or delete tun interfaces\n" |
Pere Orga | 5bc8c00 | 2011-04-11 03:29:49 +0200 | [diff] [blame] | 35 | //usage: "\n -f name tun device (/dev/net/tun)" |
| 36 | //usage: "\n -t name Create iface 'name'" |
| 37 | //usage: "\n -d name Delete iface 'name'" |
| 38 | //usage: IF_FEATURE_TUNCTL_UG( |
| 39 | //usage: "\n -u owner Set iface owner" |
| 40 | //usage: "\n -g group Set iface group" |
| 41 | //usage: "\n -b Brief output" |
| 42 | //usage: ) |
| 43 | //usage: |
| 44 | //usage:#define tunctl_example_usage |
| 45 | //usage: "# tunctl\n" |
| 46 | //usage: "# tunctl -d tun0\n" |
| 47 | |
Denis Vlasenko | 39b6813 | 2009-01-23 02:07:14 +0000 | [diff] [blame] | 48 | #include <netinet/in.h> |
| 49 | #include <net/if.h> |
| 50 | #include <linux/if_tun.h> |
| 51 | #include "libbb.h" |
| 52 | |
| 53 | /* TUNSETGROUP appeared in 2.6.23 */ |
| 54 | #ifndef TUNSETGROUP |
| 55 | #define TUNSETGROUP _IOW('T', 206, int) |
| 56 | #endif |
| 57 | |
| 58 | #define IOCTL(a, b, c) ioctl_or_perror_and_die(a, b, c, NULL) |
| 59 | |
| 60 | #if 1 |
| 61 | |
| 62 | int tunctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 63 | int tunctl_main(int argc UNUSED_PARAM, char **argv) |
| 64 | { |
| 65 | struct ifreq ifr; |
| 66 | int fd; |
| 67 | const char *opt_name = "tap%d"; |
| 68 | const char *opt_device = "/dev/net/tun"; |
| 69 | #if ENABLE_FEATURE_TUNCTL_UG |
| 70 | const char *opt_user, *opt_group; |
| 71 | long user = -1, group = -1; |
| 72 | #endif |
| 73 | unsigned opts; |
| 74 | |
| 75 | enum { |
| 76 | OPT_f = 1 << 0, // control device name (/dev/net/tun) |
| 77 | OPT_t = 1 << 1, // create named interface |
| 78 | OPT_d = 1 << 2, // delete named interface |
| 79 | #if ENABLE_FEATURE_TUNCTL_UG |
| 80 | OPT_u = 1 << 3, // set new interface owner |
| 81 | OPT_g = 1 << 4, // set new interface group |
| 82 | OPT_b = 1 << 5, // brief output |
| 83 | #endif |
| 84 | }; |
| 85 | |
| 86 | opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d |
Denis Vlasenko | 5e34ff2 | 2009-04-21 11:09:40 +0000 | [diff] [blame] | 87 | opts = getopt32(argv, "f:t:d:" IF_FEATURE_TUNCTL_UG("u:g:b"), |
Denis Vlasenko | 39b6813 | 2009-01-23 02:07:14 +0000 | [diff] [blame] | 88 | &opt_device, &opt_name, &opt_name |
Denis Vlasenko | 5e34ff2 | 2009-04-21 11:09:40 +0000 | [diff] [blame] | 89 | IF_FEATURE_TUNCTL_UG(, &opt_user, &opt_group)); |
Denis Vlasenko | 39b6813 | 2009-01-23 02:07:14 +0000 | [diff] [blame] | 90 | |
| 91 | // select device |
| 92 | memset(&ifr, 0, sizeof(ifr)); |
| 93 | ifr.ifr_flags = IFF_TAP | IFF_NO_PI; |
| 94 | strncpy_IFNAMSIZ(ifr.ifr_name, opt_name); |
| 95 | |
| 96 | // open device |
| 97 | fd = xopen(opt_device, O_RDWR); |
| 98 | IOCTL(fd, TUNSETIFF, (void *)&ifr); |
| 99 | |
| 100 | // delete? |
| 101 | if (opts & OPT_d) { |
| 102 | IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)0); |
Denys Vlasenko | 066e76b | 2016-03-30 16:20:28 +0200 | [diff] [blame] | 103 | printf("Set '%s' nonpersistent\n", ifr.ifr_name); |
Denis Vlasenko | 39b6813 | 2009-01-23 02:07:14 +0000 | [diff] [blame] | 104 | return EXIT_SUCCESS; |
| 105 | } |
| 106 | |
| 107 | // create |
| 108 | #if ENABLE_FEATURE_TUNCTL_UG |
| 109 | if (opts & OPT_g) { |
| 110 | group = xgroup2gid(opt_group); |
| 111 | IOCTL(fd, TUNSETGROUP, (void *)(uintptr_t)group); |
| 112 | } else |
| 113 | user = geteuid(); |
| 114 | if (opts & OPT_u) |
| 115 | user = xuname2uid(opt_user); |
| 116 | IOCTL(fd, TUNSETOWNER, (void *)(uintptr_t)user); |
| 117 | #endif |
| 118 | IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)1); |
| 119 | |
| 120 | // show info |
| 121 | #if ENABLE_FEATURE_TUNCTL_UG |
| 122 | if (opts & OPT_b) { |
| 123 | puts(ifr.ifr_name); |
| 124 | } else { |
| 125 | printf("Set '%s' %spersistent", ifr.ifr_name, ""); |
| 126 | printf(" and owned by uid %ld", user); |
| 127 | if (group != -1) |
| 128 | printf(" gid %ld", group); |
| 129 | bb_putchar('\n'); |
| 130 | } |
| 131 | #else |
| 132 | puts(ifr.ifr_name); |
| 133 | #endif |
| 134 | return EXIT_SUCCESS; |
| 135 | } |
| 136 | |
| 137 | #else |
| 138 | |
| 139 | /* -210 bytes: */ |
| 140 | |
| 141 | int tunctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 142 | int tunctl_main(int argc UNUSED_PARAM, char **argv) |
| 143 | { |
| 144 | struct ifreq ifr; |
| 145 | int fd; |
| 146 | const char *opt_name = "tap%d"; |
| 147 | const char *opt_device = "/dev/net/tun"; |
| 148 | unsigned opts; |
| 149 | |
| 150 | enum { |
| 151 | OPT_f = 1 << 0, // control device name (/dev/net/tun) |
| 152 | OPT_t = 1 << 1, // create named interface |
| 153 | OPT_d = 1 << 2, // delete named interface |
| 154 | }; |
| 155 | |
| 156 | opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d |
| 157 | opts = getopt32(argv, "f:t:d:u:g:b", // u, g, b accepted and ignored |
| 158 | &opt_device, &opt_name, &opt_name, NULL, NULL); |
| 159 | |
| 160 | // set interface name |
| 161 | memset(&ifr, 0, sizeof(ifr)); |
| 162 | ifr.ifr_flags = IFF_TAP | IFF_NO_PI; |
| 163 | strncpy_IFNAMSIZ(ifr.ifr_name, opt_name); |
| 164 | |
| 165 | // open device |
| 166 | fd = xopen(opt_device, O_RDWR); |
| 167 | IOCTL(fd, TUNSETIFF, (void *)&ifr); |
| 168 | |
| 169 | // create or delete interface |
| 170 | IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)(0 == (opts & OPT_d))); |
| 171 | |
| 172 | return EXIT_SUCCESS; |
| 173 | } |
| 174 | |
| 175 | #endif |