2 * iptunnel.c "ip tuntap"
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: David Woodhouse <David.Woodhouse@intel.com>
17 #include <sys/types.h>
18 #include <sys/socket.h>
19 #include <arpa/inet.h>
20 #include <sys/ioctl.h>
22 #include <linux/if_tun.h>
31 #include "ip_common.h"
33 #define TUNDEV "/dev/net/tun"
35 static void usage(void) __attribute__((noreturn));
37 static void usage(void)
39 fprintf(stderr, "Usage: ip tuntap { add | del } [ dev PHYS_DEV ] \n");
40 fprintf(stderr, " [ mode { tun | tap } ] [ user USER ] [ group GROUP ]\n");
41 fprintf(stderr, " [ one_queue ] [ pi ] [ vnet_hdr ]\n");
42 fprintf(stderr, "\n");
43 fprintf(stderr, "Where: USER := { STRING | NUMBER }\n");
44 fprintf(stderr, " GROUP := { STRING | NUMBER }\n");
48 static int tap_add_ioctl(struct ifreq *ifr, uid_t uid, gid_t gid)
54 ifr->ifr_flags |= IFF_TUN_EXCL;
57 fd = open(TUNDEV, O_RDWR);
62 if (ioctl(fd, TUNSETIFF, ifr)) {
63 perror("ioctl(TUNSETIFF)");
66 if (uid != -1 && ioctl(fd, TUNSETOWNER, uid)) {
67 perror("ioctl(TUNSETOWNER)");
70 if (gid != -1 && ioctl(fd, TUNSETGROUP, gid)) {
71 perror("ioctl(TUNSETGROUP)");
74 if (ioctl(fd, TUNSETPERSIST, 1)) {
75 perror("ioctl(TUNSETPERSIST)");
84 static int tap_del_ioctl(struct ifreq *ifr)
86 int fd = open(TUNDEV, O_RDWR);
93 if (ioctl(fd, TUNSETIFF, ifr)) {
94 perror("ioctl(TUNSETIFF)");
97 if (ioctl(fd, TUNSETPERSIST, 0)) {
98 perror("ioctl(TUNSETPERSIST)");
107 static int parse_args(int argc, char **argv, struct ifreq *ifr, uid_t *uid, gid_t *gid)
111 memset(ifr, 0, sizeof(*ifr));
113 ifr->ifr_flags |= IFF_NO_PI;
116 if (matches(*argv, "mode") == 0) {
118 if (matches(*argv, "tun") == 0) {
119 if (ifr->ifr_flags & IFF_TAP) {
120 fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
123 ifr->ifr_flags |= IFF_TUN;
124 } else if (matches(*argv, "tap") == 0) {
125 if (ifr->ifr_flags & IFF_TUN) {
126 fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
129 ifr->ifr_flags |= IFF_TAP;
131 fprintf(stderr,"Cannot guess tunnel mode.\n");
134 } else if (uid && matches(*argv, "user") == 0) {
139 if (**argv && ((user = strtol(*argv, &end, 10)), !*end))
142 struct passwd *pw = getpwnam(*argv);
144 fprintf(stderr, "invalid user \"%s\"\n", *argv);
149 } else if (gid && matches(*argv, "group") == 0) {
155 if (**argv && ((group = strtol(*argv, &end, 10)), !*end))
158 struct group *gr = getgrnam(*argv);
160 fprintf(stderr, "invalid group \"%s\"\n", *argv);
165 } else if (matches(*argv, "pi") == 0) {
166 ifr->ifr_flags &= ~IFF_NO_PI;
167 } else if (matches(*argv, "one_queue") == 0) {
168 ifr->ifr_flags |= IFF_ONE_QUEUE;
169 } else if (matches(*argv, "vnet_hdr") == 0) {
170 ifr->ifr_flags |= IFF_VNET_HDR;
171 } else if (matches(*argv, "dev") == 0) {
173 strncpy(ifr->ifr_name, *argv, IFNAMSIZ-1);
175 if (matches(*argv, "name") == 0) {
177 } else if (matches(*argv, "help") == 0)
179 if (ifr->ifr_name[0])
180 duparg2("name", *argv);
181 strncpy(ifr->ifr_name, *argv, IFNAMSIZ);
191 static int do_add(int argc, char **argv)
197 if (parse_args(argc, argv, &ifr, &uid, &gid) < 0)
200 if (!(ifr.ifr_flags & TUN_TYPE_MASK)) {
201 fprintf(stderr, "You failed to specify a tunnel mode\n");
204 return tap_add_ioctl(&ifr, uid, gid);
207 static int do_del(int argc, char **argv)
211 if (parse_args(argc, argv, &ifr, NULL, NULL) < 0)
214 return tap_del_ioctl(&ifr);
217 static int read_prop(char *dev, char *prop, long *value)
219 char fname[IFNAMSIZ+25], buf[80], *endp;
224 sprintf(fname, "/sys/class/net/%s/%s", dev, prop);
225 fd = open(fname, O_RDONLY);
227 if (strcmp(prop, "tun_flags"))
228 fprintf(stderr, "open %s: %s\n", fname,
232 len = read(fd, buf, sizeof(buf)-1);
235 fprintf(stderr, "read %s: %s", fname, strerror(errno));
240 result = strtol(buf, &endp, 0);
242 fprintf(stderr, "Failed to parse %s\n", fname);
249 static void print_flags(long flags)
257 if (!(flags & IFF_NO_PI))
260 if (flags & IFF_ONE_QUEUE)
261 printf(" one_queue");
263 if (flags & IFF_VNET_HDR)
266 flags &= ~(IFF_TUN|IFF_TAP|IFF_NO_PI|IFF_ONE_QUEUE|IFF_VNET_HDR);
268 printf(" UNKNOWN_FLAGS:%lx", flags);
271 static int do_show(int argc, char **argv)
275 long flags, owner = -1, group = -1;
277 dir = opendir("/sys/class/net");
282 while ((d = readdir(dir))) {
283 if (d->d_name[0] == '.' &&
284 (d->d_name[1] == 0 || d->d_name[1] == '.'))
287 if (read_prop(d->d_name, "tun_flags", &flags))
290 read_prop(d->d_name, "owner", &owner);
291 read_prop(d->d_name, "group", &group);
293 printf("%s:", d->d_name);
296 printf(" user %ld", owner);
298 printf(" group %ld", group);
305 int do_iptuntap(int argc, char **argv)
308 if (matches(*argv, "add") == 0)
309 return do_add(argc-1, argv+1);
310 if (matches(*argv, "del") == 0)
311 return do_del(argc-1, argv+1);
312 if (matches(*argv, "show") == 0 ||
313 matches(*argv, "lst") == 0 ||
314 matches(*argv, "list") == 0)
315 return do_show(argc-1, argv+1);
316 if (matches(*argv, "help") == 0)
319 return do_show(0, NULL);
321 fprintf(stderr, "Command \"%s\" is unknown, try \"ip tuntap help\".\n",