1 /*
2 * link_gre.c gre driver module
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: Herbert Xu <herbert@gondor.apana.org.au>
10 *
11 */
12
13 #include <string.h>
14 #include <net/if.h>
15 #include <sys/types.h>
16 #include <sys/socket.h>
17 #include <arpa/inet.h>
18
19 #include <linux/ip.h>
20 #include <linux/if_tunnel.h>
21 #include "rt_names.h"
22 #include "utils.h"
23 #include "ip_common.h"
24 #include "tunnel.h"
25
print_usage(FILE * f)26 static void print_usage(FILE *f)
27 {
28 fprintf(f, "Usage: ip link { add | set | change | replace | del } NAME\n");
29 fprintf(f, " type { gre | gretap } [ remote ADDR ] [ local ADDR ]\n");
30 fprintf(f, " [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ]\n");
31 fprintf(f, " [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
32 fprintf(f, " [ noencap ] [ encap { fou | gue | none } ]\n");
33 fprintf(f, " [ encap-sport PORT ] [ encap-dport PORT ]\n");
34 fprintf(f, " [ [no]encap-csum ] [ [no]encap-csum6 ] [ [no]encap-remcsum ]\n");
35 fprintf(f, "\n");
36 fprintf(f, "Where: NAME := STRING\n");
37 fprintf(f, " ADDR := { IP_ADDRESS | any }\n");
38 fprintf(f, " TOS := { NUMBER | inherit }\n");
39 fprintf(f, " TTL := { 1..255 | inherit }\n");
40 fprintf(f, " KEY := { DOTTED_QUAD | NUMBER }\n");
41 }
42
43 static void usage(void) __attribute__((noreturn));
usage(void)44 static void usage(void)
45 {
46 print_usage(stderr);
47 exit(-1);
48 }
49
gre_parse_opt(struct link_util * lu,int argc,char ** argv,struct nlmsghdr * n)50 static int gre_parse_opt(struct link_util *lu, int argc, char **argv,
51 struct nlmsghdr *n)
52 {
53 struct {
54 struct nlmsghdr n;
55 struct ifinfomsg i;
56 char buf[16384];
57 } req;
58 struct ifinfomsg *ifi = (struct ifinfomsg *)(n + 1);
59 struct rtattr *tb[IFLA_MAX + 1];
60 struct rtattr *linkinfo[IFLA_INFO_MAX+1];
61 struct rtattr *greinfo[IFLA_GRE_MAX + 1];
62 __u16 iflags = 0;
63 __u16 oflags = 0;
64 unsigned ikey = 0;
65 unsigned okey = 0;
66 unsigned saddr = 0;
67 unsigned daddr = 0;
68 unsigned link = 0;
69 __u8 pmtudisc = 1;
70 __u8 ttl = 0;
71 __u8 tos = 0;
72 int len;
73 __u16 encaptype = 0;
74 __u16 encapflags = 0;
75 __u16 encapsport = 0;
76 __u16 encapdport = 0;
77 __u8 metadata = 0;
78
79 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
80 memset(&req, 0, sizeof(req));
81
82 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi));
83 req.n.nlmsg_flags = NLM_F_REQUEST;
84 req.n.nlmsg_type = RTM_GETLINK;
85 req.i.ifi_family = preferred_family;
86 req.i.ifi_index = ifi->ifi_index;
87
88 if (rtnl_talk(&rth, &req.n, &req.n, sizeof(req)) < 0) {
89 get_failed:
90 fprintf(stderr,
91 "Failed to get existing tunnel info.\n");
92 return -1;
93 }
94
95 len = req.n.nlmsg_len;
96 len -= NLMSG_LENGTH(sizeof(*ifi));
97 if (len < 0)
98 goto get_failed;
99
100 parse_rtattr(tb, IFLA_MAX, IFLA_RTA(&req.i), len);
101
102 if (!tb[IFLA_LINKINFO])
103 goto get_failed;
104
105 parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);
106
107 if (!linkinfo[IFLA_INFO_DATA])
108 goto get_failed;
109
110 parse_rtattr_nested(greinfo, IFLA_GRE_MAX,
111 linkinfo[IFLA_INFO_DATA]);
112
113 if (greinfo[IFLA_GRE_IKEY])
114 ikey = rta_getattr_u32(greinfo[IFLA_GRE_IKEY]);
115
116 if (greinfo[IFLA_GRE_OKEY])
117 okey = rta_getattr_u32(greinfo[IFLA_GRE_OKEY]);
118
119 if (greinfo[IFLA_GRE_IFLAGS])
120 iflags = rta_getattr_u16(greinfo[IFLA_GRE_IFLAGS]);
121
122 if (greinfo[IFLA_GRE_OFLAGS])
123 oflags = rta_getattr_u16(greinfo[IFLA_GRE_OFLAGS]);
124
125 if (greinfo[IFLA_GRE_LOCAL])
126 saddr = rta_getattr_u32(greinfo[IFLA_GRE_LOCAL]);
127
128 if (greinfo[IFLA_GRE_REMOTE])
129 daddr = rta_getattr_u32(greinfo[IFLA_GRE_REMOTE]);
130
131 if (greinfo[IFLA_GRE_PMTUDISC])
132 pmtudisc = rta_getattr_u8(
133 greinfo[IFLA_GRE_PMTUDISC]);
134
135 if (greinfo[IFLA_GRE_TTL])
136 ttl = rta_getattr_u8(greinfo[IFLA_GRE_TTL]);
137
138 if (greinfo[IFLA_GRE_TOS])
139 tos = rta_getattr_u8(greinfo[IFLA_GRE_TOS]);
140
141 if (greinfo[IFLA_GRE_LINK])
142 link = rta_getattr_u8(greinfo[IFLA_GRE_LINK]);
143
144 if (greinfo[IFLA_GRE_ENCAP_TYPE])
145 encaptype = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_TYPE]);
146 if (greinfo[IFLA_GRE_ENCAP_FLAGS])
147 encapflags = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_FLAGS]);
148 if (greinfo[IFLA_GRE_ENCAP_SPORT])
149 encapsport = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_SPORT]);
150 if (greinfo[IFLA_GRE_ENCAP_DPORT])
151 encapdport = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_DPORT]);
152
153 if (greinfo[IFLA_GRE_COLLECT_METADATA])
154 metadata = 1;
155 }
156
157 while (argc > 0) {
158 if (!matches(*argv, "key")) {
159 unsigned uval;
160
161 NEXT_ARG();
162 iflags |= GRE_KEY;
163 oflags |= GRE_KEY;
164 if (strchr(*argv, '.'))
165 uval = get_addr32(*argv);
166 else {
167 if (get_unsigned(&uval, *argv, 0) < 0) {
168 fprintf(stderr,
169 "Invalid value for \"key\": \"%s\"; it should be an unsigned integer\n", *argv);
170 exit(-1);
171 }
172 uval = htonl(uval);
173 }
174
175 ikey = okey = uval;
176 } else if (!matches(*argv, "ikey")) {
177 unsigned uval;
178
179 NEXT_ARG();
180 iflags |= GRE_KEY;
181 if (strchr(*argv, '.'))
182 uval = get_addr32(*argv);
183 else {
184 if (get_unsigned(&uval, *argv, 0)<0) {
185 fprintf(stderr, "invalid value for \"ikey\": \"%s\"; it should be an unsigned integer\n", *argv);
186 exit(-1);
187 }
188 uval = htonl(uval);
189 }
190 ikey = uval;
191 } else if (!matches(*argv, "okey")) {
192 unsigned uval;
193
194 NEXT_ARG();
195 oflags |= GRE_KEY;
196 if (strchr(*argv, '.'))
197 uval = get_addr32(*argv);
198 else {
199 if (get_unsigned(&uval, *argv, 0)<0) {
200 fprintf(stderr, "invalid value for \"okey\": \"%s\"; it should be an unsigned integer\n", *argv);
201 exit(-1);
202 }
203 uval = htonl(uval);
204 }
205 okey = uval;
206 } else if (!matches(*argv, "seq")) {
207 iflags |= GRE_SEQ;
208 oflags |= GRE_SEQ;
209 } else if (!matches(*argv, "iseq")) {
210 iflags |= GRE_SEQ;
211 } else if (!matches(*argv, "oseq")) {
212 oflags |= GRE_SEQ;
213 } else if (!matches(*argv, "csum")) {
214 iflags |= GRE_CSUM;
215 oflags |= GRE_CSUM;
216 } else if (!matches(*argv, "icsum")) {
217 iflags |= GRE_CSUM;
218 } else if (!matches(*argv, "ocsum")) {
219 oflags |= GRE_CSUM;
220 } else if (!matches(*argv, "nopmtudisc")) {
221 pmtudisc = 0;
222 } else if (!matches(*argv, "pmtudisc")) {
223 pmtudisc = 1;
224 } else if (!matches(*argv, "remote")) {
225 NEXT_ARG();
226 if (strcmp(*argv, "any"))
227 daddr = get_addr32(*argv);
228 } else if (!matches(*argv, "local")) {
229 NEXT_ARG();
230 if (strcmp(*argv, "any"))
231 saddr = get_addr32(*argv);
232 } else if (!matches(*argv, "dev")) {
233 NEXT_ARG();
234 link = if_nametoindex(*argv);
235 if (link == 0) {
236 fprintf(stderr, "Cannot find device \"%s\"\n",
237 *argv);
238 exit(-1);
239 }
240 } else if (!matches(*argv, "ttl") ||
241 !matches(*argv, "hoplimit")) {
242 unsigned uval;
243
244 NEXT_ARG();
245 if (strcmp(*argv, "inherit") != 0) {
246 if (get_unsigned(&uval, *argv, 0))
247 invarg("invalid TTL\n", *argv);
248 if (uval > 255)
249 invarg("TTL must be <= 255\n", *argv);
250 ttl = uval;
251 }
252 } else if (!matches(*argv, "tos") ||
253 !matches(*argv, "tclass") ||
254 !matches(*argv, "dsfield")) {
255 __u32 uval;
256
257 NEXT_ARG();
258 if (strcmp(*argv, "inherit") != 0) {
259 if (rtnl_dsfield_a2n(&uval, *argv))
260 invarg("bad TOS value", *argv);
261 tos = uval;
262 } else
263 tos = 1;
264 } else if (strcmp(*argv, "noencap") == 0) {
265 encaptype = TUNNEL_ENCAP_NONE;
266 } else if (strcmp(*argv, "encap") == 0) {
267 NEXT_ARG();
268 if (strcmp(*argv, "fou") == 0)
269 encaptype = TUNNEL_ENCAP_FOU;
270 else if (strcmp(*argv, "gue") == 0)
271 encaptype = TUNNEL_ENCAP_GUE;
272 else if (strcmp(*argv, "none") == 0)
273 encaptype = TUNNEL_ENCAP_NONE;
274 else
275 invarg("Invalid encap type.", *argv);
276 } else if (strcmp(*argv, "encap-sport") == 0) {
277 NEXT_ARG();
278 if (strcmp(*argv, "auto") == 0)
279 encapsport = 0;
280 else if (get_u16(&encapsport, *argv, 0))
281 invarg("Invalid source port.", *argv);
282 } else if (strcmp(*argv, "encap-dport") == 0) {
283 NEXT_ARG();
284 if (get_u16(&encapdport, *argv, 0))
285 invarg("Invalid destination port.", *argv);
286 } else if (strcmp(*argv, "encap-csum") == 0) {
287 encapflags |= TUNNEL_ENCAP_FLAG_CSUM;
288 } else if (strcmp(*argv, "noencap-csum") == 0) {
289 encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM;
290 } else if (strcmp(*argv, "encap-udp6-csum") == 0) {
291 encapflags |= TUNNEL_ENCAP_FLAG_CSUM6;
292 } else if (strcmp(*argv, "noencap-udp6-csum") == 0) {
293 encapflags |= ~TUNNEL_ENCAP_FLAG_CSUM6;
294 } else if (strcmp(*argv, "encap-remcsum") == 0) {
295 encapflags |= TUNNEL_ENCAP_FLAG_REMCSUM;
296 } else if (strcmp(*argv, "noencap-remcsum") == 0) {
297 encapflags |= ~TUNNEL_ENCAP_FLAG_REMCSUM;
298 } else if (strcmp(*argv, "external") == 0) {
299 metadata = 1;
300 } else
301 usage();
302 argc--; argv++;
303 }
304
305 if (!ikey && IN_MULTICAST(ntohl(daddr))) {
306 ikey = daddr;
307 iflags |= GRE_KEY;
308 }
309 if (!okey && IN_MULTICAST(ntohl(daddr))) {
310 okey = daddr;
311 oflags |= GRE_KEY;
312 }
313 if (IN_MULTICAST(ntohl(daddr)) && !saddr) {
314 fprintf(stderr, "A broadcast tunnel requires a source address.\n");
315 return -1;
316 }
317
318 addattr32(n, 1024, IFLA_GRE_IKEY, ikey);
319 addattr32(n, 1024, IFLA_GRE_OKEY, okey);
320 addattr_l(n, 1024, IFLA_GRE_IFLAGS, &iflags, 2);
321 addattr_l(n, 1024, IFLA_GRE_OFLAGS, &oflags, 2);
322 addattr_l(n, 1024, IFLA_GRE_LOCAL, &saddr, 4);
323 addattr_l(n, 1024, IFLA_GRE_REMOTE, &daddr, 4);
324 addattr_l(n, 1024, IFLA_GRE_PMTUDISC, &pmtudisc, 1);
325 if (link)
326 addattr32(n, 1024, IFLA_GRE_LINK, link);
327 addattr_l(n, 1024, IFLA_GRE_TTL, &ttl, 1);
328 addattr_l(n, 1024, IFLA_GRE_TOS, &tos, 1);
329
330 addattr16(n, 1024, IFLA_GRE_ENCAP_TYPE, encaptype);
331 addattr16(n, 1024, IFLA_GRE_ENCAP_FLAGS, encapflags);
332 addattr16(n, 1024, IFLA_GRE_ENCAP_SPORT, htons(encapsport));
333 addattr16(n, 1024, IFLA_GRE_ENCAP_DPORT, htons(encapdport));
334 if (metadata)
335 addattr_l(n, 1024, IFLA_GRE_COLLECT_METADATA, NULL, 0);
336
337 return 0;
338 }
339
gre_print_opt(struct link_util * lu,FILE * f,struct rtattr * tb[])340 static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
341 {
342 char s1[1024];
343 char s2[64];
344 const char *local = "any";
345 const char *remote = "any";
346 unsigned iflags = 0;
347 unsigned oflags = 0;
348
349 if (!tb)
350 return;
351
352 if (tb[IFLA_GRE_REMOTE]) {
353 unsigned addr = rta_getattr_u32(tb[IFLA_GRE_REMOTE]);
354
355 if (addr)
356 remote = format_host(AF_INET, 4, &addr, s1, sizeof(s1));
357 }
358
359 fprintf(f, "remote %s ", remote);
360
361 if (tb[IFLA_GRE_LOCAL]) {
362 unsigned addr = rta_getattr_u32(tb[IFLA_GRE_LOCAL]);
363
364 if (addr)
365 local = format_host(AF_INET, 4, &addr, s1, sizeof(s1));
366 }
367
368 fprintf(f, "local %s ", local);
369
370 if (tb[IFLA_GRE_LINK] && rta_getattr_u32(tb[IFLA_GRE_LINK])) {
371 unsigned link = rta_getattr_u32(tb[IFLA_GRE_LINK]);
372 const char *n = if_indextoname(link, s2);
373
374 if (n)
375 fprintf(f, "dev %s ", n);
376 else
377 fprintf(f, "dev %u ", link);
378 }
379
380 if (tb[IFLA_GRE_TTL] && rta_getattr_u8(tb[IFLA_GRE_TTL]))
381 fprintf(f, "ttl %d ", rta_getattr_u8(tb[IFLA_GRE_TTL]));
382 else
383 fprintf(f, "ttl inherit ");
384
385 if (tb[IFLA_GRE_TOS] && rta_getattr_u8(tb[IFLA_GRE_TOS])) {
386 int tos = rta_getattr_u8(tb[IFLA_GRE_TOS]);
387
388 fputs("tos ", f);
389 if (tos == 1)
390 fputs("inherit ", f);
391 else
392 fprintf(f, "0x%x ", tos);
393 }
394
395 if (tb[IFLA_GRE_PMTUDISC] &&
396 !rta_getattr_u8(tb[IFLA_GRE_PMTUDISC]))
397 fputs("nopmtudisc ", f);
398
399 if (tb[IFLA_GRE_IFLAGS])
400 iflags = rta_getattr_u16(tb[IFLA_GRE_IFLAGS]);
401
402 if (tb[IFLA_GRE_OFLAGS])
403 oflags = rta_getattr_u16(tb[IFLA_GRE_OFLAGS]);
404
405 if ((iflags & GRE_KEY) && tb[IFLA_GRE_IKEY]) {
406 inet_ntop(AF_INET, RTA_DATA(tb[IFLA_GRE_IKEY]), s2, sizeof(s2));
407 fprintf(f, "ikey %s ", s2);
408 }
409
410 if ((oflags & GRE_KEY) && tb[IFLA_GRE_OKEY]) {
411 inet_ntop(AF_INET, RTA_DATA(tb[IFLA_GRE_OKEY]), s2, sizeof(s2));
412 fprintf(f, "okey %s ", s2);
413 }
414
415 if (iflags & GRE_SEQ)
416 fputs("iseq ", f);
417 if (oflags & GRE_SEQ)
418 fputs("oseq ", f);
419 if (iflags & GRE_CSUM)
420 fputs("icsum ", f);
421 if (oflags & GRE_CSUM)
422 fputs("ocsum ", f);
423
424 if (tb[IFLA_GRE_COLLECT_METADATA])
425 fputs("external ", f);
426
427 if (tb[IFLA_GRE_ENCAP_TYPE] &&
428 *(__u16 *)RTA_DATA(tb[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) {
429 __u16 type = rta_getattr_u16(tb[IFLA_GRE_ENCAP_TYPE]);
430 __u16 flags = rta_getattr_u16(tb[IFLA_GRE_ENCAP_FLAGS]);
431 __u16 sport = rta_getattr_u16(tb[IFLA_GRE_ENCAP_SPORT]);
432 __u16 dport = rta_getattr_u16(tb[IFLA_GRE_ENCAP_DPORT]);
433
434 fputs("encap ", f);
435 switch (type) {
436 case TUNNEL_ENCAP_FOU:
437 fputs("fou ", f);
438 break;
439 case TUNNEL_ENCAP_GUE:
440 fputs("gue ", f);
441 break;
442 default:
443 fputs("unknown ", f);
444 break;
445 }
446
447 if (sport == 0)
448 fputs("encap-sport auto ", f);
449 else
450 fprintf(f, "encap-sport %u", ntohs(sport));
451
452 fprintf(f, "encap-dport %u ", ntohs(dport));
453
454 if (flags & TUNNEL_ENCAP_FLAG_CSUM)
455 fputs("encap-csum ", f);
456 else
457 fputs("noencap-csum ", f);
458
459 if (flags & TUNNEL_ENCAP_FLAG_CSUM6)
460 fputs("encap-csum6 ", f);
461 else
462 fputs("noencap-csum6 ", f);
463
464 if (flags & TUNNEL_ENCAP_FLAG_REMCSUM)
465 fputs("encap-remcsum ", f);
466 else
467 fputs("noencap-remcsum ", f);
468 }
469 }
470
gre_print_help(struct link_util * lu,int argc,char ** argv,FILE * f)471 static void gre_print_help(struct link_util *lu, int argc, char **argv,
472 FILE *f)
473 {
474 print_usage(f);
475 }
476
477 struct link_util gre_link_util = {
478 .id = "gre",
479 .maxattr = IFLA_GRE_MAX,
480 .parse_opt = gre_parse_opt,
481 .print_opt = gre_print_opt,
482 .print_help = gre_print_help,
483 };
484
485 struct link_util gretap_link_util = {
486 .id = "gretap",
487 .maxattr = IFLA_GRE_MAX,
488 .parse_opt = gre_parse_opt,
489 .print_opt = gre_print_opt,
490 .print_help = gre_print_help,
491 };
492