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
26static 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
43static void usage(void) __attribute__((noreturn));
44static void usage(void)
45{
46	print_usage(stderr);
47	exit(-1);
48}
49
50static 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) {
89get_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
340static 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
471static void gre_print_help(struct link_util *lu, int argc, char **argv,
472	FILE *f)
473{
474	print_usage(f);
475}
476
477struct 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
485struct 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