1 /* vi: set sw=4 ts=4: */
3 * iptunnel.c "ip tunnel"
5 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
7 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
11 * Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
12 * Rani Assaf <rani@magic.metawire.com> 980930: do not allow key for ipip/sit
13 * Phil Karn <karn@ka9q.ampr.org> 990408: "pmtudisc" flag
16 #include <netinet/ip.h>
18 #include <net/if_arp.h>
19 #include <asm/types.h>
21 #ifndef __constant_htons
22 #define __constant_htons htons
25 // FYI: #define SIOCDEVPRIVATE 0x89F0
27 /* From linux/if_tunnel.h. #including it proved troublesome
28 * (redefiniton errors due to name collisions in linux/ and net[inet]/) */
29 #define SIOCGETTUNNEL (SIOCDEVPRIVATE + 0)
30 #define SIOCADDTUNNEL (SIOCDEVPRIVATE + 1)
31 #define SIOCDELTUNNEL (SIOCDEVPRIVATE + 2)
32 #define SIOCCHGTUNNEL (SIOCDEVPRIVATE + 3)
33 //#define SIOCGETPRL (SIOCDEVPRIVATE + 4)
34 //#define SIOCADDPRL (SIOCDEVPRIVATE + 5)
35 //#define SIOCDELPRL (SIOCDEVPRIVATE + 6)
36 //#define SIOCCHGPRL (SIOCDEVPRIVATE + 7)
37 #define GRE_CSUM __constant_htons(0x8000)
38 //#define GRE_ROUTING __constant_htons(0x4000)
39 #define GRE_KEY __constant_htons(0x2000)
40 #define GRE_SEQ __constant_htons(0x1000)
41 //#define GRE_STRICT __constant_htons(0x0800)
42 //#define GRE_REC __constant_htons(0x0700)
43 //#define GRE_FLAGS __constant_htons(0x00F8)
44 //#define GRE_VERSION __constant_htons(0x0007)
45 struct ip_tunnel_parm {
54 /* SIT-mode i_flags */
55 //#define SIT_ISATAP 0x0001
56 //struct ip_tunnel_prl {
59 // uint16_t __reserved;
61 // uint32_t __reserved2;
65 //#define PRL_DEFAULT 0x0001
67 #include "ip_common.h" /* #include "libbb.h" is inside */
73 static int do_ioctl_get_ifindex(char *dev)
78 strncpy_IFNAMSIZ(ifr.ifr_name, dev);
79 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
80 xioctl(fd, SIOCGIFINDEX, &ifr);
82 return ifr.ifr_ifindex;
85 static int do_ioctl_get_iftype(char *dev)
91 strncpy_IFNAMSIZ(ifr.ifr_name, dev);
92 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
93 err = ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr);
95 return err ? -1 : ifr.ifr_addr.sa_family;
98 static char *do_ioctl_get_ifname(int idx)
104 ifr.ifr_ifindex = idx;
105 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
106 err = ioctl_or_warn(fd, SIOCGIFNAME, &ifr);
108 return err ? NULL : xstrndup(ifr.ifr_name, sizeof(ifr.ifr_name));
111 static int do_get_ioctl(const char *basedev, struct ip_tunnel_parm *p)
117 strncpy_IFNAMSIZ(ifr.ifr_name, basedev);
118 ifr.ifr_ifru.ifru_data = (void*)p;
119 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
120 err = ioctl_or_warn(fd, SIOCGETTUNNEL, &ifr);
125 /* Dies on error, otherwise returns 0 */
126 static int do_add_ioctl(int cmd, const char *basedev, struct ip_tunnel_parm *p)
131 if (cmd == SIOCCHGTUNNEL && p->name[0]) {
132 strncpy_IFNAMSIZ(ifr.ifr_name, p->name);
134 strncpy_IFNAMSIZ(ifr.ifr_name, basedev);
136 ifr.ifr_ifru.ifru_data = (void*)p;
137 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
138 #if ENABLE_IOCTL_HEX2STR_ERROR
139 /* #define magic will turn ioctl# into string */
140 if (cmd == SIOCCHGTUNNEL)
141 xioctl(fd, SIOCCHGTUNNEL, &ifr);
143 xioctl(fd, SIOCADDTUNNEL, &ifr);
145 xioctl(fd, cmd, &ifr);
151 /* Dies on error, otherwise returns 0 */
152 static int do_del_ioctl(const char *basedev, struct ip_tunnel_parm *p)
158 strncpy_IFNAMSIZ(ifr.ifr_name, p->name);
160 strncpy_IFNAMSIZ(ifr.ifr_name, basedev);
162 ifr.ifr_ifru.ifru_data = (void*)p;
163 fd = xsocket(AF_INET, SOCK_DGRAM, 0);
164 xioctl(fd, SIOCDELTUNNEL, &ifr);
170 static void parse_args(char **argv, int cmd, struct ip_tunnel_parm *p)
172 static const char keywords[] ALIGN1 =
173 "mode\0""ipip\0""ip/ip\0""gre\0""gre/ip\0""sit\0""ipv6/ip\0"
174 "key\0""ikey\0""okey\0""seq\0""iseq\0""oseq\0"
175 "csum\0""icsum\0""ocsum\0""nopmtudisc\0""pmtudisc\0"
176 "remote\0""any\0""local\0""dev\0"
177 "ttl\0""inherit\0""tos\0""dsfield\0"
180 ARG_mode, ARG_ipip, ARG_ip_ip, ARG_gre, ARG_gre_ip, ARG_sit, ARG_ip6_ip,
181 ARG_key, ARG_ikey, ARG_okey, ARG_seq, ARG_iseq, ARG_oseq,
182 ARG_csum, ARG_icsum, ARG_ocsum, ARG_nopmtudisc, ARG_pmtudisc,
183 ARG_remote, ARG_any, ARG_local, ARG_dev,
184 ARG_ttl, ARG_inherit, ARG_tos, ARG_dsfield,
188 char medium[IFNAMSIZ];
191 memset(p, 0, sizeof(*p));
197 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
199 p->iph.frag_off = htons(IP_DF);
202 key = index_in_strings(keywords, *argv);
203 if (key == ARG_mode) {
205 key = index_in_strings(keywords, *argv);
206 if (key == ARG_ipip ||
208 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
209 bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
211 p->iph.protocol = IPPROTO_IPIP;
212 } else if (key == ARG_gre ||
214 if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
215 bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
217 p->iph.protocol = IPPROTO_GRE;
218 } else if (key == ARG_sit ||
220 if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
221 bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
223 p->iph.protocol = IPPROTO_IPV6;
225 bb_error_msg_and_die("%s tunnel mode", "cannot guess");
227 } else if (key == ARG_key) {
230 p->i_flags |= GRE_KEY;
231 p->o_flags |= GRE_KEY;
232 if (strchr(*argv, '.'))
233 p->i_key = p->o_key = get_addr32(*argv);
235 if (get_unsigned(&uval, *argv, 0) < 0) {
236 invarg(*argv, "key");
238 p->i_key = p->o_key = htonl(uval);
240 } else if (key == ARG_ikey) {
243 p->i_flags |= GRE_KEY;
244 if (strchr(*argv, '.'))
245 p->o_key = get_addr32(*argv);
247 if (get_unsigned(&uval, *argv, 0) < 0) {
248 invarg(*argv, "ikey");
250 p->i_key = htonl(uval);
252 } else if (key == ARG_okey) {
255 p->o_flags |= GRE_KEY;
256 if (strchr(*argv, '.'))
257 p->o_key = get_addr32(*argv);
259 if (get_unsigned(&uval, *argv, 0) < 0) {
260 invarg(*argv, "okey");
262 p->o_key = htonl(uval);
264 } else if (key == ARG_seq) {
265 p->i_flags |= GRE_SEQ;
266 p->o_flags |= GRE_SEQ;
267 } else if (key == ARG_iseq) {
268 p->i_flags |= GRE_SEQ;
269 } else if (key == ARG_oseq) {
270 p->o_flags |= GRE_SEQ;
271 } else if (key == ARG_csum) {
272 p->i_flags |= GRE_CSUM;
273 p->o_flags |= GRE_CSUM;
274 } else if (key == ARG_icsum) {
275 p->i_flags |= GRE_CSUM;
276 } else if (key == ARG_ocsum) {
277 p->o_flags |= GRE_CSUM;
278 } else if (key == ARG_nopmtudisc) {
280 } else if (key == ARG_pmtudisc) {
281 p->iph.frag_off = htons(IP_DF);
282 } else if (key == ARG_remote) {
284 key = index_in_strings(keywords, *argv);
286 p->iph.daddr = get_addr32(*argv);
287 } else if (key == ARG_local) {
289 key = index_in_strings(keywords, *argv);
291 p->iph.saddr = get_addr32(*argv);
292 } else if (key == ARG_dev) {
294 strncpy_IFNAMSIZ(medium, *argv);
295 } else if (key == ARG_ttl) {
298 key = index_in_strings(keywords, *argv);
299 if (key != ARG_inherit) {
300 if (get_unsigned(&uval, *argv, 0))
301 invarg(*argv, "TTL");
303 invarg(*argv, "TTL must be <=255");
306 } else if (key == ARG_tos ||
307 key == ARG_dsfield) {
310 key = index_in_strings(keywords, *argv);
311 if (key != ARG_inherit) {
312 if (rtnl_dsfield_a2n(&uval, *argv))
313 invarg(*argv, "TOS");
318 if (key == ARG_name) {
322 duparg2("name", *argv);
323 strncpy_IFNAMSIZ(p->name, *argv);
324 if (cmd == SIOCCHGTUNNEL && count == 0) {
325 struct ip_tunnel_parm old_p;
326 memset(&old_p, 0, sizeof(old_p));
327 if (do_get_ioctl(*argv, &old_p))
336 if (p->iph.protocol == 0) {
337 if (memcmp(p->name, "gre", 3) == 0)
338 p->iph.protocol = IPPROTO_GRE;
339 else if (memcmp(p->name, "ipip", 4) == 0)
340 p->iph.protocol = IPPROTO_IPIP;
341 else if (memcmp(p->name, "sit", 3) == 0)
342 p->iph.protocol = IPPROTO_IPV6;
345 if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) {
346 if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
347 bb_error_msg_and_die("keys are not allowed with ipip and sit");
352 p->link = do_ioctl_get_ifindex(medium);
355 if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
356 p->i_key = p->iph.daddr;
357 p->i_flags |= GRE_KEY;
359 if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
360 p->o_key = p->iph.daddr;
361 p->o_flags |= GRE_KEY;
363 if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
364 bb_error_msg_and_die("broadcast tunnel requires a source address");
368 /* Return value becomes exitcode. It's okay to not return at all */
369 static int do_add(int cmd, char **argv)
371 struct ip_tunnel_parm p;
373 parse_args(argv, cmd, &p);
375 if (p.iph.ttl && p.iph.frag_off == 0) {
376 bb_error_msg_and_die("ttl != 0 and noptmudisc are incompatible");
379 switch (p.iph.protocol) {
381 return do_add_ioctl(cmd, "tunl0", &p);
383 return do_add_ioctl(cmd, "gre0", &p);
385 return do_add_ioctl(cmd, "sit0", &p);
387 bb_error_msg_and_die("cannot determine tunnel mode (ipip, gre or sit)");
391 /* Return value becomes exitcode. It's okay to not return at all */
392 static int do_del(char **argv)
394 struct ip_tunnel_parm p;
396 parse_args(argv, SIOCDELTUNNEL, &p);
398 switch (p.iph.protocol) {
400 return do_del_ioctl("tunl0", &p);
402 return do_del_ioctl("gre0", &p);
404 return do_del_ioctl("sit0", &p);
406 return do_del_ioctl(p.name, &p);
410 static void print_tunnel(struct ip_tunnel_parm *p)
417 format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1));
418 format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2));
419 inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
420 inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
422 printf("%s: %s/ip remote %s local %s ",
424 p->iph.protocol == IPPROTO_IPIP ? "ip" :
425 (p->iph.protocol == IPPROTO_GRE ? "gre" :
426 (p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
427 p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any");
429 char *n = do_ioctl_get_ifname(p->link);
431 printf(" dev %s ", n);
436 printf(" ttl %d ", p->iph.ttl);
438 printf(" ttl inherit ");
445 printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
446 rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1)));
448 if (!(p->iph.frag_off & htons(IP_DF)))
449 printf(" nopmtudisc");
451 if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
452 printf(" key %s", s3);
453 else if ((p->i_flags | p->o_flags) & GRE_KEY) {
454 if (p->i_flags & GRE_KEY)
455 printf(" ikey %s ", s3);
456 if (p->o_flags & GRE_KEY)
457 printf(" okey %s ", s4);
460 if (p->i_flags & GRE_SEQ)
461 printf("%c Drop packets out of sequence.\n", _SL_);
462 if (p->i_flags & GRE_CSUM)
463 printf("%c Checksum in received packet is required.", _SL_);
464 if (p->o_flags & GRE_SEQ)
465 printf("%c Sequence packets on output.", _SL_);
466 if (p->o_flags & GRE_CSUM)
467 printf("%c Checksum output packets.", _SL_);
470 static void do_tunnels_list(struct ip_tunnel_parm *p)
473 unsigned long rx_bytes, rx_packets, rx_errs, rx_drops,
475 tx_bytes, tx_packets, tx_errs, tx_drops,
476 tx_fifo, tx_colls, tx_carrier, rx_multi;
478 struct ip_tunnel_parm p1;
480 FILE *fp = fopen_or_warn("/proc/net/dev", "r");
486 fgets(buf, sizeof(buf), fp);
487 fgets(buf, sizeof(buf), fp);
489 while (fgets(buf, sizeof(buf), fp) != NULL) {
492 /*buf[sizeof(buf) - 1] = 0; - fgets is safe anyway */
493 ptr = strchr(buf, ':');
495 (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
496 bb_error_msg("wrong format of /proc/net/dev");
499 if (sscanf(ptr, "%lu%lu%lu%lu%lu%lu%lu%*d%lu%lu%lu%lu%lu%lu%lu",
500 &rx_bytes, &rx_packets, &rx_errs, &rx_drops,
501 &rx_fifo, &rx_frame, &rx_multi,
502 &tx_bytes, &tx_packets, &tx_errs, &tx_drops,
503 &tx_fifo, &tx_colls, &tx_carrier) != 14)
505 if (p->name[0] && strcmp(p->name, name))
507 type = do_ioctl_get_iftype(name);
509 bb_error_msg("cannot get type of [%s]", name);
512 if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
514 memset(&p1, 0, sizeof(p1));
515 if (do_get_ioctl(name, &p1))
517 if ((p->link && p1.link != p->link) ||
518 (p->name[0] && strcmp(p1.name, p->name)) ||
519 (p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
520 (p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
521 (p->i_key && p1.i_key != p->i_key))
528 /* Return value becomes exitcode. It's okay to not return at all */
529 static int do_show(char **argv)
532 struct ip_tunnel_parm p;
534 parse_args(argv, SIOCGETTUNNEL, &p);
536 switch (p.iph.protocol) {
538 err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p);
541 err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p);
544 err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p);
558 /* Return value becomes exitcode. It's okay to not return at all */
559 int do_iptunnel(char **argv)
561 static const char keywords[] ALIGN1 =
562 "add\0""change\0""delete\0""show\0""list\0""lst\0";
563 enum { ARG_add = 0, ARG_change, ARG_del, ARG_show, ARG_list, ARG_lst };
567 key = index_in_substrings(keywords, *argv);
569 bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
572 return do_add(SIOCADDTUNNEL, argv);
573 if (key == ARG_change)
574 return do_add(SIOCCHGTUNNEL, argv);
578 return do_show(argv);