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 | * |
| 10 | * Licensed under GPLv2, see file LICENSE in this tarball for details. |
| 11 | */ |
| 12 | #include <netinet/in.h> |
| 13 | #include <net/if.h> |
| 14 | #include <linux/if_tun.h> |
| 15 | #include "libbb.h" |
| 16 | |
| 17 | /* TUNSETGROUP appeared in 2.6.23 */ |
| 18 | #ifndef TUNSETGROUP |
| 19 | #define TUNSETGROUP _IOW('T', 206, int) |
| 20 | #endif |
| 21 | |
| 22 | #define IOCTL(a, b, c) ioctl_or_perror_and_die(a, b, c, NULL) |
| 23 | |
| 24 | #if 1 |
| 25 | |
| 26 | int tunctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 27 | int tunctl_main(int argc UNUSED_PARAM, char **argv) |
| 28 | { |
| 29 | struct ifreq ifr; |
| 30 | int fd; |
| 31 | const char *opt_name = "tap%d"; |
| 32 | const char *opt_device = "/dev/net/tun"; |
| 33 | #if ENABLE_FEATURE_TUNCTL_UG |
| 34 | const char *opt_user, *opt_group; |
| 35 | long user = -1, group = -1; |
| 36 | #endif |
| 37 | unsigned opts; |
| 38 | |
| 39 | enum { |
| 40 | OPT_f = 1 << 0, // control device name (/dev/net/tun) |
| 41 | OPT_t = 1 << 1, // create named interface |
| 42 | OPT_d = 1 << 2, // delete named interface |
| 43 | #if ENABLE_FEATURE_TUNCTL_UG |
| 44 | OPT_u = 1 << 3, // set new interface owner |
| 45 | OPT_g = 1 << 4, // set new interface group |
| 46 | OPT_b = 1 << 5, // brief output |
| 47 | #endif |
| 48 | }; |
| 49 | |
| 50 | opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d |
Denis Vlasenko | 5e34ff2 | 2009-04-21 11:09:40 +0000 | [diff] [blame^] | 51 | 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] | 52 | &opt_device, &opt_name, &opt_name |
Denis Vlasenko | 5e34ff2 | 2009-04-21 11:09:40 +0000 | [diff] [blame^] | 53 | IF_FEATURE_TUNCTL_UG(, &opt_user, &opt_group)); |
Denis Vlasenko | 39b6813 | 2009-01-23 02:07:14 +0000 | [diff] [blame] | 54 | |
| 55 | // select device |
| 56 | memset(&ifr, 0, sizeof(ifr)); |
| 57 | ifr.ifr_flags = IFF_TAP | IFF_NO_PI; |
| 58 | strncpy_IFNAMSIZ(ifr.ifr_name, opt_name); |
| 59 | |
| 60 | // open device |
| 61 | fd = xopen(opt_device, O_RDWR); |
| 62 | IOCTL(fd, TUNSETIFF, (void *)&ifr); |
| 63 | |
| 64 | // delete? |
| 65 | if (opts & OPT_d) { |
| 66 | IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)0); |
| 67 | bb_info_msg("Set '%s' %spersistent", ifr.ifr_name, "non"); |
| 68 | return EXIT_SUCCESS; |
| 69 | } |
| 70 | |
| 71 | // create |
| 72 | #if ENABLE_FEATURE_TUNCTL_UG |
| 73 | if (opts & OPT_g) { |
| 74 | group = xgroup2gid(opt_group); |
| 75 | IOCTL(fd, TUNSETGROUP, (void *)(uintptr_t)group); |
| 76 | } else |
| 77 | user = geteuid(); |
| 78 | if (opts & OPT_u) |
| 79 | user = xuname2uid(opt_user); |
| 80 | IOCTL(fd, TUNSETOWNER, (void *)(uintptr_t)user); |
| 81 | #endif |
| 82 | IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)1); |
| 83 | |
| 84 | // show info |
| 85 | #if ENABLE_FEATURE_TUNCTL_UG |
| 86 | if (opts & OPT_b) { |
| 87 | puts(ifr.ifr_name); |
| 88 | } else { |
| 89 | printf("Set '%s' %spersistent", ifr.ifr_name, ""); |
| 90 | printf(" and owned by uid %ld", user); |
| 91 | if (group != -1) |
| 92 | printf(" gid %ld", group); |
| 93 | bb_putchar('\n'); |
| 94 | } |
| 95 | #else |
| 96 | puts(ifr.ifr_name); |
| 97 | #endif |
| 98 | return EXIT_SUCCESS; |
| 99 | } |
| 100 | |
| 101 | #else |
| 102 | |
| 103 | /* -210 bytes: */ |
| 104 | |
| 105 | int tunctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 106 | int tunctl_main(int argc UNUSED_PARAM, char **argv) |
| 107 | { |
| 108 | struct ifreq ifr; |
| 109 | int fd; |
| 110 | const char *opt_name = "tap%d"; |
| 111 | const char *opt_device = "/dev/net/tun"; |
| 112 | unsigned opts; |
| 113 | |
| 114 | enum { |
| 115 | OPT_f = 1 << 0, // control device name (/dev/net/tun) |
| 116 | OPT_t = 1 << 1, // create named interface |
| 117 | OPT_d = 1 << 2, // delete named interface |
| 118 | }; |
| 119 | |
| 120 | opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d |
| 121 | opts = getopt32(argv, "f:t:d:u:g:b", // u, g, b accepted and ignored |
| 122 | &opt_device, &opt_name, &opt_name, NULL, NULL); |
| 123 | |
| 124 | // set interface name |
| 125 | memset(&ifr, 0, sizeof(ifr)); |
| 126 | ifr.ifr_flags = IFF_TAP | IFF_NO_PI; |
| 127 | strncpy_IFNAMSIZ(ifr.ifr_name, opt_name); |
| 128 | |
| 129 | // open device |
| 130 | fd = xopen(opt_device, O_RDWR); |
| 131 | IOCTL(fd, TUNSETIFF, (void *)&ifr); |
| 132 | |
| 133 | // create or delete interface |
| 134 | IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)(0 == (opts & OPT_d))); |
| 135 | |
| 136 | return EXIT_SUCCESS; |
| 137 | } |
| 138 | |
| 139 | #endif |