/* vi: set sw=4 ts=4: */ /* * tun devices controller * * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com> * * Original code: * Jeff Dike * * Licensed under GPLv2, see file LICENSE in this source tree. */ //usage:#define tunctl_trivial_usage //usage: "[-f device] ([-t name] | -d name)" IF_FEATURE_TUNCTL_UG(" [-u owner] [-g group] [-b]") //usage:#define tunctl_full_usage "\n\n" //usage: "Create or delete tun interfaces\n" //usage: "\n -f name tun device (/dev/net/tun)" //usage: "\n -t name Create iface 'name'" //usage: "\n -d name Delete iface 'name'" //usage: IF_FEATURE_TUNCTL_UG( //usage: "\n -u owner Set iface owner" //usage: "\n -g group Set iface group" //usage: "\n -b Brief output" //usage: ) //usage: //usage:#define tunctl_example_usage //usage: "# tunctl\n" //usage: "# tunctl -d tun0\n" #include <netinet/in.h> #include <net/if.h> #include <linux/if_tun.h> #include "libbb.h" /* TUNSETGROUP appeared in 2.6.23 */ #ifndef TUNSETGROUP #define TUNSETGROUP _IOW('T', 206, int) #endif #define IOCTL(a, b, c) ioctl_or_perror_and_die(a, b, c, NULL) #if 1 int tunctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int tunctl_main(int argc UNUSED_PARAM, char **argv) { struct ifreq ifr; int fd; const char *opt_name = "tap%d"; const char *opt_device = "/dev/net/tun"; #if ENABLE_FEATURE_TUNCTL_UG const char *opt_user, *opt_group; long user = -1, group = -1; #endif unsigned opts; enum { OPT_f = 1 << 0, // control device name (/dev/net/tun) OPT_t = 1 << 1, // create named interface OPT_d = 1 << 2, // delete named interface #if ENABLE_FEATURE_TUNCTL_UG OPT_u = 1 << 3, // set new interface owner OPT_g = 1 << 4, // set new interface group OPT_b = 1 << 5, // brief output #endif }; opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d opts = getopt32(argv, "f:t:d:" IF_FEATURE_TUNCTL_UG("u:g:b"), &opt_device, &opt_name, &opt_name IF_FEATURE_TUNCTL_UG(, &opt_user, &opt_group)); // select device memset(&ifr, 0, sizeof(ifr)); ifr.ifr_flags = IFF_TAP | IFF_NO_PI; strncpy_IFNAMSIZ(ifr.ifr_name, opt_name); // open device fd = xopen(opt_device, O_RDWR); IOCTL(fd, TUNSETIFF, (void *)&ifr); // delete? if (opts & OPT_d) { IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)0); printf("Set '%s' nonpersistent\n", ifr.ifr_name); return EXIT_SUCCESS; } // create #if ENABLE_FEATURE_TUNCTL_UG if (opts & OPT_g) { group = xgroup2gid(opt_group); IOCTL(fd, TUNSETGROUP, (void *)(uintptr_t)group); } else user = geteuid(); if (opts & OPT_u) user = xuname2uid(opt_user); IOCTL(fd, TUNSETOWNER, (void *)(uintptr_t)user); #endif IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)1); // show info #if ENABLE_FEATURE_TUNCTL_UG if (opts & OPT_b) { puts(ifr.ifr_name); } else { printf("Set '%s' %spersistent", ifr.ifr_name, ""); printf(" and owned by uid %ld", user); if (group != -1) printf(" gid %ld", group); bb_putchar('\n'); } #else puts(ifr.ifr_name); #endif return EXIT_SUCCESS; } #else /* -210 bytes: */ int tunctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int tunctl_main(int argc UNUSED_PARAM, char **argv) { struct ifreq ifr; int fd; const char *opt_name = "tap%d"; const char *opt_device = "/dev/net/tun"; unsigned opts; enum { OPT_f = 1 << 0, // control device name (/dev/net/tun) OPT_t = 1 << 1, // create named interface OPT_d = 1 << 2, // delete named interface }; opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d opts = getopt32(argv, "f:t:d:u:g:b", // u, g, b accepted and ignored &opt_device, &opt_name, &opt_name, NULL, NULL); // set interface name memset(&ifr, 0, sizeof(ifr)); ifr.ifr_flags = IFF_TAP | IFF_NO_PI; strncpy_IFNAMSIZ(ifr.ifr_name, opt_name); // open device fd = xopen(opt_device, O_RDWR); IOCTL(fd, TUNSETIFF, (void *)&ifr); // create or delete interface IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)(0 == (opts & OPT_d))); return EXIT_SUCCESS; } #endif