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>
23 #include <linux/if_arp.h>
33 #include "ip_common.h"
35 static const char drv_name
[] = "tun";
37 #define TUNDEV "/dev/net/tun"
39 static void usage(void) __attribute__((noreturn
));
41 static void usage(void)
43 fprintf(stderr
, "Usage: ip tuntap { add | del | show | list | lst | help } [ dev PHYS_DEV ]\n");
44 fprintf(stderr
, " [ mode { tun | tap } ] [ user USER ] [ group GROUP ]\n");
45 fprintf(stderr
, " [ one_queue ] [ pi ] [ vnet_hdr ] [ multi_queue ] [ name NAME ]\n");
46 fprintf(stderr
, "\n");
47 fprintf(stderr
, "Where: USER := { STRING | NUMBER }\n");
48 fprintf(stderr
, " GROUP := { STRING | NUMBER }\n");
52 static int tap_add_ioctl(struct ifreq
*ifr
, uid_t uid
, gid_t gid
)
58 ifr
->ifr_flags
|= IFF_TUN_EXCL
;
61 fd
= open(TUNDEV
, O_RDWR
);
66 if (ioctl(fd
, TUNSETIFF
, ifr
)) {
67 perror("ioctl(TUNSETIFF)");
70 if (uid
!= -1 && ioctl(fd
, TUNSETOWNER
, uid
)) {
71 perror("ioctl(TUNSETOWNER)");
74 if (gid
!= -1 && ioctl(fd
, TUNSETGROUP
, gid
)) {
75 perror("ioctl(TUNSETGROUP)");
78 if (ioctl(fd
, TUNSETPERSIST
, 1)) {
79 perror("ioctl(TUNSETPERSIST)");
88 static int tap_del_ioctl(struct ifreq
*ifr
)
90 int fd
= open(TUNDEV
, O_RDWR
);
97 if (ioctl(fd
, TUNSETIFF
, ifr
)) {
98 perror("ioctl(TUNSETIFF)");
101 if (ioctl(fd
, TUNSETPERSIST
, 0)) {
102 perror("ioctl(TUNSETPERSIST)");
111 static int parse_args(int argc
, char **argv
,
112 struct ifreq
*ifr
, uid_t
*uid
, gid_t
*gid
)
116 memset(ifr
, 0, sizeof(*ifr
));
118 ifr
->ifr_flags
|= IFF_NO_PI
;
121 if (matches(*argv
, "mode") == 0) {
123 if (matches(*argv
, "tun") == 0) {
124 if (ifr
->ifr_flags
& IFF_TAP
) {
125 fprintf(stderr
, "You managed to ask for more than one tunnel mode.\n");
128 ifr
->ifr_flags
|= IFF_TUN
;
129 } else if (matches(*argv
, "tap") == 0) {
130 if (ifr
->ifr_flags
& IFF_TUN
) {
131 fprintf(stderr
, "You managed to ask for more than one tunnel mode.\n");
134 ifr
->ifr_flags
|= IFF_TAP
;
136 fprintf(stderr
, "Unknown tunnel mode \"%s\"\n", *argv
);
139 } else if (uid
&& matches(*argv
, "user") == 0) {
144 if (**argv
&& ((user
= strtol(*argv
, &end
, 10)), !*end
))
147 struct passwd
*pw
= getpwnam(*argv
);
150 fprintf(stderr
, "invalid user \"%s\"\n", *argv
);
155 } else if (gid
&& matches(*argv
, "group") == 0) {
161 if (**argv
&& ((group
= strtol(*argv
, &end
, 10)), !*end
))
164 struct group
*gr
= getgrnam(*argv
);
167 fprintf(stderr
, "invalid group \"%s\"\n", *argv
);
172 } else if (matches(*argv
, "pi") == 0) {
173 ifr
->ifr_flags
&= ~IFF_NO_PI
;
174 } else if (matches(*argv
, "one_queue") == 0) {
175 ifr
->ifr_flags
|= IFF_ONE_QUEUE
;
176 } else if (matches(*argv
, "vnet_hdr") == 0) {
177 ifr
->ifr_flags
|= IFF_VNET_HDR
;
178 } else if (matches(*argv
, "multi_queue") == 0) {
179 ifr
->ifr_flags
|= IFF_MULTI_QUEUE
;
180 } else if (matches(*argv
, "dev") == 0) {
182 if (get_ifname(ifr
->ifr_name
, *argv
))
183 invarg("\"dev\" not a valid ifname", *argv
);
185 if (matches(*argv
, "name") == 0) {
187 } else if (matches(*argv
, "help") == 0)
189 if (ifr
->ifr_name
[0])
190 duparg2("name", *argv
);
191 if (get_ifname(ifr
->ifr_name
, *argv
))
192 invarg("\"name\" not a valid ifname", *argv
);
198 if (!(ifr
->ifr_flags
& TUN_TYPE_MASK
)) {
199 fprintf(stderr
, "You failed to specify a tunnel mode\n");
207 static int do_add(int argc
, char **argv
)
213 if (parse_args(argc
, argv
, &ifr
, &uid
, &gid
) < 0)
216 return tap_add_ioctl(&ifr
, uid
, gid
);
219 static int do_del(int argc
, char **argv
)
223 if (parse_args(argc
, argv
, &ifr
, NULL
, NULL
) < 0)
226 return tap_del_ioctl(&ifr
);
229 static void print_flags(long flags
)
237 if (!(flags
& IFF_NO_PI
))
240 if (flags
& IFF_ONE_QUEUE
)
241 printf(" one_queue");
243 if (flags
& IFF_VNET_HDR
)
246 flags
&= ~(IFF_TUN
|IFF_TAP
|IFF_NO_PI
|IFF_ONE_QUEUE
|IFF_VNET_HDR
);
248 printf(" UNKNOWN_FLAGS:%lx", flags
);
251 static char *pid_name(pid_t pid
)
257 err
= asprintf(&comm
, "/proc/%d/comm", pid
);
261 f
= fopen(comm
, "r");
268 if (fscanf(f
, "%ms\n", &comm
) != 1) {
280 static void show_processes(const char *name
)
282 glob_t globbuf
= { };
286 err
= glob("/proc/[0-9]*/fd/[0-9]*", GLOB_NOSORT
,
291 fd_path
= globbuf
.gl_pathv
;
293 const char *dev_net_tun
= "/dev/net/tun";
294 const size_t linkbuf_len
= strlen(dev_net_tun
) + 2;
295 char linkbuf
[linkbuf_len
], *fdinfo
;
299 if (sscanf(*fd_path
, "/proc/%d/fd/%d", &pid
, &fd
) != 2)
305 err
= readlink(*fd_path
, linkbuf
, linkbuf_len
- 1);
311 if (strcmp(dev_net_tun
, linkbuf
))
314 if (asprintf(&fdinfo
, "/proc/%d/fdinfo/%d", pid
, fd
) < 0)
317 f
= fopen(fdinfo
, "r");
325 char *key
= NULL
, *value
= NULL
;
327 err
= fscanf(f
, "%m[^:]: %ms\n", &key
, &value
);
332 } else if (err
== 2 &&
333 !strcmp("iff", key
) &&
334 !strcmp(name
, value
)) {
335 char *pname
= pid_name(pid
);
337 printf(" %s(%d)", pname
? : "<NULL>", pid
);
354 static int tuntap_filter_req(struct nlmsghdr
*nlh
, int reqlen
)
356 struct rtattr
*linkinfo
;
359 linkinfo
= addattr_nest(nlh
, reqlen
, IFLA_LINKINFO
);
361 err
= addattr_l(nlh
, reqlen
, IFLA_INFO_KIND
,
362 drv_name
, sizeof(drv_name
) - 1);
366 addattr_nest_end(nlh
, linkinfo
);
371 static int print_tuntap(const struct sockaddr_nl
*who
,
372 struct nlmsghdr
*n
, void *arg
)
374 struct ifinfomsg
*ifi
= NLMSG_DATA(n
);
375 struct rtattr
*tb
[IFLA_MAX
+1];
376 struct rtattr
*linkinfo
[IFLA_INFO_MAX
+1];
377 const char *name
, *kind
;
378 long flags
, owner
= -1, group
= -1;
380 if (n
->nlmsg_type
!= RTM_NEWLINK
&& n
->nlmsg_type
!= RTM_DELLINK
)
383 if (n
->nlmsg_len
< NLMSG_LENGTH(sizeof(*ifi
)))
386 switch (ifi
->ifi_type
) {
394 parse_rtattr(tb
, IFLA_MAX
, IFLA_RTA(ifi
), IFLA_PAYLOAD(n
));
396 if (!tb
[IFLA_IFNAME
])
399 if (!tb
[IFLA_LINKINFO
])
402 parse_rtattr_nested(linkinfo
, IFLA_INFO_MAX
, tb
[IFLA_LINKINFO
]);
404 if (!linkinfo
[IFLA_INFO_KIND
])
407 kind
= rta_getattr_str(linkinfo
[IFLA_INFO_KIND
]);
408 if (strcmp(kind
, drv_name
))
411 name
= rta_getattr_str(tb
[IFLA_IFNAME
]);
413 if (read_prop(name
, "tun_flags", &flags
))
415 if (read_prop(name
, "owner", &owner
))
417 if (read_prop(name
, "group", &group
))
423 printf(" user %ld", owner
);
425 printf(" group %ld", group
);
428 printf("\tAttached to processes:");
429 show_processes(name
);
436 static int do_show(int argc
, char **argv
)
438 if (rtnl_wilddump_req_filter_fn(&rth
, AF_UNSPEC
, RTM_GETLINK
,
439 tuntap_filter_req
) < 0) {
440 perror("Cannot send dump request\n");
444 if (rtnl_dump_filter(&rth
, print_tuntap
, NULL
) < 0) {
445 fprintf(stderr
, "Dump terminated\n");
452 int do_iptuntap(int argc
, char **argv
)
455 if (matches(*argv
, "add") == 0)
456 return do_add(argc
-1, argv
+1);
457 if (matches(*argv
, "delete") == 0)
458 return do_del(argc
-1, argv
+1);
459 if (matches(*argv
, "show") == 0 ||
460 matches(*argv
, "lst") == 0 ||
461 matches(*argv
, "list") == 0)
462 return do_show(argc
-1, argv
+1);
463 if (matches(*argv
, "help") == 0)
466 return do_show(0, NULL
);
468 fprintf(stderr
, "Command \"%s\" is unknown, try \"ip tuntap help\".\n",
473 static void print_owner(FILE *f
, uid_t uid
)
475 struct passwd
*pw
= getpwuid(uid
);
478 fprintf(f
, "user %s ", pw
->pw_name
);
480 fprintf(f
, "user %u ", uid
);
483 static void print_group(FILE *f
, gid_t gid
)
485 struct group
*group
= getgrgid(gid
);
488 fprintf(f
, "group %s ", group
->gr_name
);
490 fprintf(f
, "group %u ", gid
);
493 static void print_mq(FILE *f
, struct rtattr
*tb
[])
495 if (!tb
[IFLA_TUN_MULTI_QUEUE
] ||
496 !rta_getattr_u8(tb
[IFLA_TUN_MULTI_QUEUE
]))
499 fprintf(f
, "multi_queue ");
501 if (tb
[IFLA_TUN_NUM_QUEUES
]) {
502 fprintf(f
, "numqueues %u ",
503 rta_getattr_u32(tb
[IFLA_TUN_NUM_QUEUES
]));
506 if (tb
[IFLA_TUN_NUM_DISABLED_QUEUES
]) {
507 fprintf(f
, "numdisabled %u ",
508 rta_getattr_u32(tb
[IFLA_TUN_NUM_DISABLED_QUEUES
]));
512 static void print_onoff(FILE *f
, const char *flag
, __u8 val
)
514 fprintf(f
, "%s %s ", flag
, val
? "on" : "off");
517 static void tun_print_opt(struct link_util
*lu
, FILE *f
, struct rtattr
*tb
[])
522 if (tb
[IFLA_TUN_TYPE
]) {
523 __u8 type
= rta_getattr_u8(tb
[IFLA_TUN_TYPE
]);
526 fprintf(f
, "type tun ");
527 else if (type
== IFF_TAP
)
528 fprintf(f
, "type tap ");
530 fprintf(f
, "type UNKNOWN:%hhu ", type
);
534 print_onoff(f
, "pi", rta_getattr_u8(tb
[IFLA_TUN_PI
]));
536 if (tb
[IFLA_TUN_VNET_HDR
]) {
537 print_onoff(f
, "vnet_hdr",
538 rta_getattr_u8(tb
[IFLA_TUN_VNET_HDR
]));
543 if (tb
[IFLA_TUN_PERSIST
])
544 print_onoff(f
, "persist", rta_getattr_u8(tb
[IFLA_TUN_PERSIST
]));
546 if (tb
[IFLA_TUN_OWNER
])
547 print_owner(f
, rta_getattr_u32(tb
[IFLA_TUN_OWNER
]));
549 if (tb
[IFLA_TUN_GROUP
])
550 print_group(f
, rta_getattr_u32(tb
[IFLA_TUN_GROUP
]));
553 struct link_util tun_link_util
= {
555 .maxattr
= IFLA_TUN_MAX
,
556 .print_opt
= tun_print_opt
,