1 /*
2 * iptunnel.c "ip tunnel"
3 *
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.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 */
12
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <unistd.h>
17 #include <sys/types.h>
18 #include <sys/socket.h>
19 #include <arpa/inet.h>
20 #include <sys/ioctl.h>
21 #include <net/if.h>
22 #include <net/if_arp.h>
23 #include <linux/ip.h>
24 #include <linux/if_tunnel.h>
25
26 #include "rt_names.h"
27 #include "utils.h"
28 #include "ip_common.h"
29 #include "tunnel.h"
30
31 static void usage(void) __attribute__((noreturn));
32
usage(void)33 static void usage(void)
34 {
35 fprintf(stderr, "Usage: ip tunnel { add | change | del | show | prl | 6rd } [ NAME ]\n");
36 fprintf(stderr, " [ mode { ipip | gre | sit | isatap | vti } ] [ remote ADDR ] [ local ADDR ]\n");
37 fprintf(stderr, " [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ]\n");
38 fprintf(stderr, " [ prl-default ADDR ] [ prl-nodefault ADDR ] [ prl-delete ADDR ]\n");
39 fprintf(stderr, " [ 6rd-prefix ADDR ] [ 6rd-relay_prefix ADDR ] [ 6rd-reset ]\n");
40 fprintf(stderr, " [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
41 fprintf(stderr, "\n");
42 fprintf(stderr, "Where: NAME := STRING\n");
43 fprintf(stderr, " ADDR := { IP_ADDRESS | any }\n");
44 fprintf(stderr, " TOS := { STRING | 00..ff | inherit | inherit/STRING | inherit/00..ff }\n");
45 fprintf(stderr, " TTL := { 1..255 | inherit }\n");
46 fprintf(stderr, " KEY := { DOTTED_QUAD | NUMBER }\n");
47 exit(-1);
48 }
49
set_tunnel_proto(struct ip_tunnel_parm * p,int proto)50 static void set_tunnel_proto(struct ip_tunnel_parm *p, int proto)
51 {
52 if (p->iph.protocol && p->iph.protocol != proto) {
53 fprintf(stderr,
54 "You managed to ask for more than one tunnel mode.\n");
55 exit(-1);
56 }
57 p->iph.protocol = proto;
58 }
59
parse_args(int argc,char ** argv,int cmd,struct ip_tunnel_parm * p)60 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
61 {
62 int count = 0;
63 const char *medium = NULL;
64 int isatap = 0;
65
66 memset(p, 0, sizeof(*p));
67 p->iph.version = 4;
68 p->iph.ihl = 5;
69 #ifndef IP_DF
70 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
71 #endif
72 p->iph.frag_off = htons(IP_DF);
73
74 while (argc > 0) {
75 if (strcmp(*argv, "mode") == 0) {
76 NEXT_ARG();
77 if (strcmp(*argv, "ipip") == 0 ||
78 strcmp(*argv, "ip/ip") == 0) {
79 set_tunnel_proto(p, IPPROTO_IPIP);
80 } else if (strcmp(*argv, "gre") == 0 ||
81 strcmp(*argv, "gre/ip") == 0) {
82 set_tunnel_proto(p, IPPROTO_GRE);
83 } else if (strcmp(*argv, "sit") == 0 ||
84 strcmp(*argv, "ipv6/ip") == 0) {
85 set_tunnel_proto(p, IPPROTO_IPV6);
86 } else if (strcmp(*argv, "isatap") == 0) {
87 set_tunnel_proto(p, IPPROTO_IPV6);
88 isatap++;
89 } else if (strcmp(*argv, "vti") == 0) {
90 set_tunnel_proto(p, IPPROTO_IPIP);
91 p->i_flags |= VTI_ISVTI;
92 } else {
93 fprintf(stderr,
94 "Unknown tunnel mode \"%s\"\n", *argv);
95 exit(-1);
96 }
97 } else if (strcmp(*argv, "key") == 0) {
98 NEXT_ARG();
99 p->i_flags |= GRE_KEY;
100 p->o_flags |= GRE_KEY;
101 p->i_key = p->o_key = tnl_parse_key("key", *argv);
102 } else if (strcmp(*argv, "ikey") == 0) {
103 NEXT_ARG();
104 p->i_flags |= GRE_KEY;
105 p->i_key = tnl_parse_key("ikey", *argv);
106 } else if (strcmp(*argv, "okey") == 0) {
107 NEXT_ARG();
108 p->o_flags |= GRE_KEY;
109 p->o_key = tnl_parse_key("okey", *argv);
110 } else if (strcmp(*argv, "seq") == 0) {
111 p->i_flags |= GRE_SEQ;
112 p->o_flags |= GRE_SEQ;
113 } else if (strcmp(*argv, "iseq") == 0) {
114 p->i_flags |= GRE_SEQ;
115 } else if (strcmp(*argv, "oseq") == 0) {
116 p->o_flags |= GRE_SEQ;
117 } else if (strcmp(*argv, "csum") == 0) {
118 p->i_flags |= GRE_CSUM;
119 p->o_flags |= GRE_CSUM;
120 } else if (strcmp(*argv, "icsum") == 0) {
121 p->i_flags |= GRE_CSUM;
122 } else if (strcmp(*argv, "ocsum") == 0) {
123 p->o_flags |= GRE_CSUM;
124 } else if (strcmp(*argv, "nopmtudisc") == 0) {
125 p->iph.frag_off = 0;
126 } else if (strcmp(*argv, "pmtudisc") == 0) {
127 p->iph.frag_off = htons(IP_DF);
128 } else if (strcmp(*argv, "remote") == 0) {
129 NEXT_ARG();
130 if (strcmp(*argv, "any"))
131 p->iph.daddr = get_addr32(*argv);
132 else
133 p->iph.daddr = htonl(INADDR_ANY);
134 } else if (strcmp(*argv, "local") == 0) {
135 NEXT_ARG();
136 if (strcmp(*argv, "any"))
137 p->iph.saddr = get_addr32(*argv);
138 else
139 p->iph.saddr = htonl(INADDR_ANY);
140 } else if (strcmp(*argv, "dev") == 0) {
141 NEXT_ARG();
142 medium = *argv;
143 } else if (strcmp(*argv, "ttl") == 0 ||
144 strcmp(*argv, "hoplimit") == 0 ||
145 strcmp(*argv, "hlim") == 0) {
146 __u8 uval;
147
148 NEXT_ARG();
149 if (strcmp(*argv, "inherit") != 0) {
150 if (get_u8(&uval, *argv, 0))
151 invarg("invalid TTL\n", *argv);
152 p->iph.ttl = uval;
153 }
154 } else if (strcmp(*argv, "tos") == 0 ||
155 strcmp(*argv, "tclass") == 0 ||
156 matches(*argv, "dsfield") == 0) {
157 char *dsfield;
158 __u32 uval;
159
160 NEXT_ARG();
161 dsfield = *argv;
162 strsep(&dsfield, "/");
163 if (strcmp(*argv, "inherit") != 0) {
164 dsfield = *argv;
165 p->iph.tos = 0;
166 } else
167 p->iph.tos = 1;
168 if (dsfield) {
169 if (rtnl_dsfield_a2n(&uval, dsfield))
170 invarg("bad TOS value", *argv);
171 p->iph.tos |= uval;
172 }
173 } else {
174 if (strcmp(*argv, "name") == 0)
175 NEXT_ARG();
176 else if (matches(*argv, "help") == 0)
177 usage();
178
179 if (p->name[0])
180 duparg2("name", *argv);
181 if (get_ifname(p->name, *argv))
182 invarg("\"name\" not a valid ifname", *argv);
183 if (cmd == SIOCCHGTUNNEL && count == 0) {
184 struct ip_tunnel_parm old_p = {};
185
186 if (tnl_get_ioctl(*argv, &old_p))
187 return -1;
188 *p = old_p;
189 }
190 }
191 count++;
192 argc--; argv++;
193 }
194
195
196 if (p->iph.protocol == 0) {
197 if (memcmp(p->name, "gre", 3) == 0)
198 p->iph.protocol = IPPROTO_GRE;
199 else if (memcmp(p->name, "ipip", 4) == 0)
200 p->iph.protocol = IPPROTO_IPIP;
201 else if (memcmp(p->name, "sit", 3) == 0)
202 p->iph.protocol = IPPROTO_IPV6;
203 else if (memcmp(p->name, "isatap", 6) == 0) {
204 p->iph.protocol = IPPROTO_IPV6;
205 isatap++;
206 } else if (memcmp(p->name, "vti", 3) == 0) {
207 p->iph.protocol = IPPROTO_IPIP;
208 p->i_flags |= VTI_ISVTI;
209 }
210 }
211
212 if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
213 if (!(p->i_flags & VTI_ISVTI) &&
214 (p->iph.protocol != IPPROTO_GRE)) {
215 fprintf(stderr, "Keys are not allowed with ipip and sit tunnels\n");
216 return -1;
217 }
218 }
219
220 if (medium) {
221 p->link = ll_name_to_index(medium);
222 if (p->link == 0) {
223 fprintf(stderr, "Cannot find device \"%s\"\n", medium);
224 return -1;
225 }
226 }
227
228 if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
229 p->i_key = p->iph.daddr;
230 p->i_flags |= GRE_KEY;
231 }
232 if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
233 p->o_key = p->iph.daddr;
234 p->o_flags |= GRE_KEY;
235 }
236 if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
237 fprintf(stderr, "A broadcast tunnel requires a source address\n");
238 return -1;
239 }
240 if (isatap)
241 p->i_flags |= SIT_ISATAP;
242
243 return 0;
244 }
245
tnl_defname(const struct ip_tunnel_parm * p)246 static const char *tnl_defname(const struct ip_tunnel_parm *p)
247 {
248 switch (p->iph.protocol) {
249 case IPPROTO_IPIP:
250 if (p->i_flags & VTI_ISVTI)
251 return "ip_vti0";
252 else
253 return "tunl0";
254 case IPPROTO_GRE:
255 return "gre0";
256 case IPPROTO_IPV6:
257 return "sit0";
258 }
259 return NULL;
260 }
261
do_add(int cmd,int argc,char ** argv)262 static int do_add(int cmd, int argc, char **argv)
263 {
264 struct ip_tunnel_parm p;
265 const char *basedev;
266
267 if (parse_args(argc, argv, cmd, &p) < 0)
268 return -1;
269
270 if (p.iph.ttl && p.iph.frag_off == 0) {
271 fprintf(stderr, "ttl != 0 and nopmtudisc are incompatible\n");
272 return -1;
273 }
274
275 basedev = tnl_defname(&p);
276 if (!basedev) {
277 fprintf(stderr,
278 "cannot determine tunnel mode (ipip, gre, vti or sit)\n");
279 return -1;
280 }
281
282 return tnl_add_ioctl(cmd, basedev, p.name, &p);
283 }
284
do_del(int argc,char ** argv)285 static int do_del(int argc, char **argv)
286 {
287 struct ip_tunnel_parm p;
288
289 if (parse_args(argc, argv, SIOCDELTUNNEL, &p) < 0)
290 return -1;
291
292 return tnl_del_ioctl(tnl_defname(&p) ? : p.name, p.name, &p);
293 }
294
print_tunnel(struct ip_tunnel_parm * p)295 static void print_tunnel(struct ip_tunnel_parm *p)
296 {
297 struct ip_tunnel_6rd ip6rd = {};
298 char s1[1024];
299 char s2[1024];
300
301 /* Do not use format_host() for local addr,
302 * symbolic name will not be useful.
303 */
304 printf("%s: %s/ip remote %s local %s",
305 p->name,
306 tnl_strproto(p->iph.protocol),
307 p->iph.daddr ? format_host_r(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1)) : "any",
308 p->iph.saddr ? rt_addr_n2a_r(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2)) : "any");
309
310 if (p->iph.protocol == IPPROTO_IPV6 && (p->i_flags & SIT_ISATAP)) {
311 struct ip_tunnel_prl prl[16] = {};
312 int i;
313
314 prl[0].datalen = sizeof(prl) - sizeof(prl[0]);
315 prl[0].addr = htonl(INADDR_ANY);
316
317 if (!tnl_prl_ioctl(SIOCGETPRL, p->name, prl))
318 for (i = 1; i < ARRAY_SIZE(prl); i++) {
319 if (prl[i].addr != htonl(INADDR_ANY)) {
320 printf(" %s %s ",
321 (prl[i].flags & PRL_DEFAULT) ? "pdr" : "pr",
322 format_host(AF_INET, 4, &prl[i].addr));
323 }
324 }
325 }
326
327 if (p->link) {
328 const char *n = ll_index_to_name(p->link);
329
330 if (n)
331 printf(" dev %s", n);
332 }
333
334 if (p->iph.ttl)
335 printf(" ttl %d", p->iph.ttl);
336 else
337 printf(" ttl inherit");
338
339 if (p->iph.tos) {
340 SPRINT_BUF(b1);
341 printf(" tos");
342 if (p->iph.tos & 1)
343 printf(" inherit");
344 if (p->iph.tos & ~1)
345 printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
346 rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1)));
347 }
348
349 if (!(p->iph.frag_off & htons(IP_DF)))
350 printf(" nopmtudisc");
351
352 if (p->iph.protocol == IPPROTO_IPV6 && !tnl_ioctl_get_6rd(p->name, &ip6rd) && ip6rd.prefixlen) {
353 printf(" 6rd-prefix %s/%u",
354 inet_ntop(AF_INET6, &ip6rd.prefix, s1, sizeof(s1)),
355 ip6rd.prefixlen);
356 if (ip6rd.relay_prefix) {
357 printf(" 6rd-relay_prefix %s/%u",
358 format_host(AF_INET, 4, &ip6rd.relay_prefix),
359 ip6rd.relay_prefixlen);
360 }
361 }
362
363 if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
364 printf(" key %u", ntohl(p->i_key));
365 else if ((p->i_flags | p->o_flags) & GRE_KEY) {
366 if (p->i_flags & GRE_KEY)
367 printf(" ikey %u", ntohl(p->i_key));
368 if (p->o_flags & GRE_KEY)
369 printf(" okey %u", ntohl(p->o_key));
370 }
371
372 if (p->i_flags & GRE_SEQ)
373 printf("%s Drop packets out of sequence.", _SL_);
374 if (p->i_flags & GRE_CSUM)
375 printf("%s Checksum in received packet is required.", _SL_);
376 if (p->o_flags & GRE_SEQ)
377 printf("%s Sequence packets on output.", _SL_);
378 if (p->o_flags & GRE_CSUM)
379 printf("%s Checksum output packets.", _SL_);
380 }
381
do_tunnels_list(struct ip_tunnel_parm * p)382 static int do_tunnels_list(struct ip_tunnel_parm *p)
383 {
384 char buf[512];
385 int err = -1;
386 FILE *fp = fopen("/proc/net/dev", "r");
387
388 if (fp == NULL) {
389 perror("fopen");
390 return -1;
391 }
392
393 /* skip header lines */
394 if (!fgets(buf, sizeof(buf), fp) ||
395 !fgets(buf, sizeof(buf), fp)) {
396 fprintf(stderr, "/proc/net/dev read error\n");
397 goto end;
398 }
399
400 while (fgets(buf, sizeof(buf), fp) != NULL) {
401 char name[IFNAMSIZ];
402 int index, type;
403 struct ip_tunnel_parm p1 = {};
404 char *ptr;
405
406 buf[sizeof(buf) - 1] = 0;
407 ptr = strchr(buf, ':');
408 if (ptr == NULL ||
409 (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
410 fprintf(stderr, "Wrong format for /proc/net/dev. Giving up.\n");
411 goto end;
412 }
413 if (p->name[0] && strcmp(p->name, name))
414 continue;
415 index = ll_name_to_index(name);
416 if (index == 0)
417 continue;
418 type = ll_index_to_type(index);
419 if (type == -1) {
420 fprintf(stderr, "Failed to get type of \"%s\"\n", name);
421 continue;
422 }
423 if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
424 continue;
425 if (tnl_get_ioctl(name, &p1))
426 continue;
427 if ((p->link && p1.link != p->link) ||
428 (p->name[0] && strcmp(p1.name, p->name)) ||
429 (p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
430 (p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
431 (p->i_key && p1.i_key != p->i_key))
432 continue;
433 print_tunnel(&p1);
434 if (show_stats)
435 tnl_print_stats(ptr);
436 printf("\n");
437 }
438 err = 0;
439 end:
440 fclose(fp);
441 return err;
442 }
443
do_show(int argc,char ** argv)444 static int do_show(int argc, char **argv)
445 {
446 struct ip_tunnel_parm p;
447 const char *basedev;
448
449 ll_init_map(&rth);
450 if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
451 return -1;
452
453 basedev = tnl_defname(&p);
454 if (!basedev)
455 return do_tunnels_list(&p);
456
457 if (tnl_get_ioctl(p.name[0] ? p.name : basedev, &p))
458 return -1;
459
460 print_tunnel(&p);
461 printf("\n");
462 return 0;
463 }
464
do_prl(int argc,char ** argv)465 static int do_prl(int argc, char **argv)
466 {
467 struct ip_tunnel_prl p = {};
468 int count = 0;
469 int cmd = 0;
470 const char *medium = NULL;
471
472 while (argc > 0) {
473 if (strcmp(*argv, "prl-default") == 0) {
474 NEXT_ARG();
475 cmd = SIOCADDPRL;
476 p.addr = get_addr32(*argv);
477 p.flags |= PRL_DEFAULT;
478 count++;
479 } else if (strcmp(*argv, "prl-nodefault") == 0) {
480 NEXT_ARG();
481 cmd = SIOCADDPRL;
482 p.addr = get_addr32(*argv);
483 count++;
484 } else if (strcmp(*argv, "prl-delete") == 0) {
485 NEXT_ARG();
486 cmd = SIOCDELPRL;
487 p.addr = get_addr32(*argv);
488 count++;
489 } else if (strcmp(*argv, "dev") == 0) {
490 NEXT_ARG();
491 if (check_ifname(*argv))
492 invarg("\"dev\" not a valid ifname", *argv);
493 medium = *argv;
494 } else {
495 fprintf(stderr,
496 "Invalid PRL parameter \"%s\"\n", *argv);
497 exit(-1);
498 }
499 if (count > 1) {
500 fprintf(stderr,
501 "One PRL entry at a time\n");
502 exit(-1);
503 }
504 argc--; argv++;
505 }
506 if (!medium) {
507 fprintf(stderr, "Must specify device\n");
508 exit(-1);
509 }
510
511 return tnl_prl_ioctl(cmd, medium, &p);
512 }
513
do_6rd(int argc,char ** argv)514 static int do_6rd(int argc, char **argv)
515 {
516 struct ip_tunnel_6rd ip6rd = {};
517 int cmd = 0;
518 const char *medium = NULL;
519 inet_prefix prefix;
520
521 while (argc > 0) {
522 if (strcmp(*argv, "6rd-prefix") == 0) {
523 NEXT_ARG();
524 if (get_prefix(&prefix, *argv, AF_INET6))
525 invarg("invalid 6rd_prefix\n", *argv);
526 cmd = SIOCADD6RD;
527 memcpy(&ip6rd.prefix, prefix.data, 16);
528 ip6rd.prefixlen = prefix.bitlen;
529 } else if (strcmp(*argv, "6rd-relay_prefix") == 0) {
530 NEXT_ARG();
531 if (get_prefix(&prefix, *argv, AF_INET))
532 invarg("invalid 6rd-relay_prefix\n", *argv);
533 cmd = SIOCADD6RD;
534 memcpy(&ip6rd.relay_prefix, prefix.data, 4);
535 ip6rd.relay_prefixlen = prefix.bitlen;
536 } else if (strcmp(*argv, "6rd-reset") == 0) {
537 cmd = SIOCDEL6RD;
538 } else if (strcmp(*argv, "dev") == 0) {
539 NEXT_ARG();
540 if (check_ifname(*argv))
541 invarg("\"dev\" not a valid ifname", *argv);
542 medium = *argv;
543 } else {
544 fprintf(stderr,
545 "Invalid 6RD parameter \"%s\"\n", *argv);
546 exit(-1);
547 }
548 argc--; argv++;
549 }
550 if (!medium) {
551 fprintf(stderr, "Must specify device\n");
552 exit(-1);
553 }
554
555 return tnl_6rd_ioctl(cmd, medium, &ip6rd);
556 }
557
tunnel_mode_is_ipv6(char * tunnel_mode)558 static int tunnel_mode_is_ipv6(char *tunnel_mode)
559 {
560 static const char * const ipv6_modes[] = {
561 "ipv6/ipv6", "ip6ip6",
562 "vti6",
563 "ip/ipv6", "ipv4/ipv6", "ipip6", "ip4ip6",
564 "ip6gre", "gre/ipv6",
565 "any/ipv6", "any"
566 };
567 int i;
568
569 for (i = 0; i < ARRAY_SIZE(ipv6_modes); i++) {
570 if (strcmp(ipv6_modes[i], tunnel_mode) == 0)
571 return 1;
572 }
573 return 0;
574 }
575
do_iptunnel(int argc,char ** argv)576 int do_iptunnel(int argc, char **argv)
577 {
578 int i;
579
580 for (i = 0; i < argc - 1; i++) {
581 if (strcmp(argv[i], "mode") == 0) {
582 if (tunnel_mode_is_ipv6(argv[i + 1]))
583 preferred_family = AF_INET6;
584 break;
585 }
586 }
587 switch (preferred_family) {
588 case AF_UNSPEC:
589 preferred_family = AF_INET;
590 break;
591 case AF_INET:
592 break;
593 /*
594 * This is silly enough but we have no easy way to make it
595 * protocol-independent because of unarranged structure between
596 * IPv4 and IPv6.
597 */
598 case AF_INET6:
599 return do_ip6tunnel(argc, argv);
600 default:
601 fprintf(stderr, "Unsupported protocol family: %d\n", preferred_family);
602 exit(-1);
603 }
604
605 if (argc > 0) {
606 if (matches(*argv, "add") == 0)
607 return do_add(SIOCADDTUNNEL, argc - 1, argv + 1);
608 if (matches(*argv, "change") == 0)
609 return do_add(SIOCCHGTUNNEL, argc - 1, argv + 1);
610 if (matches(*argv, "delete") == 0)
611 return do_del(argc - 1, argv + 1);
612 if (matches(*argv, "show") == 0 ||
613 matches(*argv, "lst") == 0 ||
614 matches(*argv, "list") == 0)
615 return do_show(argc - 1, argv + 1);
616 if (matches(*argv, "prl") == 0)
617 return do_prl(argc - 1, argv + 1);
618 if (matches(*argv, "6rd") == 0)
619 return do_6rd(argc - 1, argv + 1);
620 if (matches(*argv, "help") == 0)
621 usage();
622 } else
623 return do_show(0, NULL);
624
625 fprintf(stderr, "Command \"%s\" is unknown, try \"ip tunnel help\"\n", *argv);
626 exit(-1);
627 }
628