link_iptnl.c revision 1ce2de97386e38c258ee2048a80ee28d0e8bad01 
1/*
2 * link_iptnl.c	ipip and sit 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:	Nicolas Dichtel <nicolas.dichtel@6wind.com>
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 usage(int sit) __attribute__((noreturn));
27static void usage(int sit)
28{
29	fprintf(stderr, "Usage: ip link { add | set | change | replace | del } NAME\n");
30	fprintf(stderr, "          type { ipip | sit } [ remote ADDR ] [ local ADDR ]\n");
31	fprintf(stderr, "          [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
32	fprintf(stderr, "          [ 6rd-prefix ADDR ] [ 6rd-relay_prefix ADDR ] [ 6rd-reset ]\n");
33	if (sit)
34		fprintf(stderr, "          [ isatap ]\n");
35	fprintf(stderr, "\n");
36	fprintf(stderr, "Where: NAME := STRING\n");
37	fprintf(stderr, "       ADDR := { IP_ADDRESS | any }\n");
38	fprintf(stderr, "       TOS  := { NUMBER | inherit }\n");
39	fprintf(stderr, "       TTL  := { 1..255 | inherit }\n");
40	exit(-1);
41}
42
43static int iptunnel_parse_opt(struct link_util *lu, int argc, char **argv,
44			      struct nlmsghdr *n)
45{
46	struct {
47		struct nlmsghdr n;
48		struct ifinfomsg i;
49		char buf[2048];
50	} req;
51	struct ifinfomsg *ifi = (struct ifinfomsg *)(n + 1);
52	struct rtattr *tb[IFLA_MAX + 1];
53	struct rtattr *linkinfo[IFLA_INFO_MAX+1];
54	struct rtattr *iptuninfo[IFLA_IPTUN_MAX + 1];
55	int len;
56	__u32 link = 0;
57	__u32 laddr = 0;
58	__u32 raddr = 0;
59	__u8 ttl = 0;
60	__u8 tos = 0;
61	__u8 pmtudisc = 1;
62	__u16 iflags = 0;
63	struct in6_addr ip6rdprefix;
64	__u16 ip6rdprefixlen = 0;
65	__u32 ip6rdrelayprefix = 0;
66	__u16 ip6rdrelayprefixlen = 0;
67
68	memset(&ip6rdprefix, 0, sizeof(ip6rdprefix));
69
70	if (!(n->nlmsg_flags & NLM_F_CREATE)) {
71		memset(&req, 0, sizeof(req));
72
73		req.n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi));
74		req.n.nlmsg_flags = NLM_F_REQUEST;
75		req.n.nlmsg_type = RTM_GETLINK;
76		req.i.ifi_family = preferred_family;
77		req.i.ifi_index = ifi->ifi_index;
78
79		if (rtnl_talk(&rth, &req.n, 0, 0, &req.n) < 0) {
80get_failed:
81			fprintf(stderr,
82				"Failed to get existing tunnel info.\n");
83			return -1;
84		}
85
86		len = req.n.nlmsg_len;
87		len -= NLMSG_LENGTH(sizeof(*ifi));
88		if (len < 0)
89			goto get_failed;
90
91		parse_rtattr(tb, IFLA_MAX, IFLA_RTA(&req.i), len);
92
93		if (!tb[IFLA_LINKINFO])
94			goto get_failed;
95
96		parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);
97
98		if (!linkinfo[IFLA_INFO_DATA])
99			goto get_failed;
100
101		parse_rtattr_nested(iptuninfo, IFLA_IPTUN_MAX,
102				    linkinfo[IFLA_INFO_DATA]);
103
104		if (iptuninfo[IFLA_IPTUN_LOCAL])
105			laddr = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LOCAL]);
106
107		if (iptuninfo[IFLA_IPTUN_REMOTE])
108			raddr = rta_getattr_u32(iptuninfo[IFLA_IPTUN_REMOTE]);
109
110		if (iptuninfo[IFLA_IPTUN_TTL])
111			ttl = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TTL]);
112
113		if (iptuninfo[IFLA_IPTUN_TOS])
114			tos = rta_getattr_u8(iptuninfo[IFLA_IPTUN_TOS]);
115
116		if (iptuninfo[IFLA_IPTUN_PMTUDISC])
117			pmtudisc =
118				rta_getattr_u8(iptuninfo[IFLA_IPTUN_PMTUDISC]);
119
120		if (iptuninfo[IFLA_IPTUN_FLAGS])
121			iflags = rta_getattr_u16(iptuninfo[IFLA_IPTUN_FLAGS]);
122
123		if (iptuninfo[IFLA_IPTUN_LINK])
124			link = rta_getattr_u32(iptuninfo[IFLA_IPTUN_LINK]);
125
126		if (iptuninfo[IFLA_IPTUN_6RD_PREFIX])
127			memcpy(&ip6rdprefix,
128			       RTA_DATA(iptuninfo[IFLA_IPTUN_6RD_PREFIX]),
129			       sizeof(laddr));
130
131		if (iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN])
132			ip6rdprefixlen =
133				rta_getattr_u16(iptuninfo[IFLA_IPTUN_6RD_PREFIXLEN]);
134
135		if (iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX])
136			ip6rdrelayprefix =
137				rta_getattr_u32(iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIX]);
138
139		if (iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN])
140			ip6rdrelayprefixlen =
141				rta_getattr_u16(iptuninfo[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
142	}
143
144	while (argc > 0) {
145		if (strcmp(*argv, "remote") == 0) {
146			NEXT_ARG();
147			if (strcmp(*argv, "any"))
148				raddr = get_addr32(*argv);
149			else
150				raddr = 0;
151		} else if (strcmp(*argv, "local") == 0) {
152			NEXT_ARG();
153			if (strcmp(*argv, "any"))
154				laddr = get_addr32(*argv);
155			else
156				laddr = 0;
157		} else if (matches(*argv, "dev") == 0) {
158			NEXT_ARG();
159			link = if_nametoindex(*argv);
160			if (link == 0)
161				invarg("\"dev\" is invalid", *argv);
162		} else if (strcmp(*argv, "ttl") == 0 ||
163			   strcmp(*argv, "hoplimit") == 0) {
164			NEXT_ARG();
165			if (strcmp(*argv, "inherit") != 0) {
166				if (get_u8(&ttl, *argv, 0))
167					invarg("invalid TTL\n", *argv);
168			} else
169				ttl = 0;
170		} else if (strcmp(*argv, "tos") == 0 ||
171			   strcmp(*argv, "tclass") == 0 ||
172			   matches(*argv, "dsfield") == 0) {
173			__u32 uval;
174			NEXT_ARG();
175			if (strcmp(*argv, "inherit") != 0) {
176				if (rtnl_dsfield_a2n(&uval, *argv))
177					invarg("bad TOS value", *argv);
178				tos = uval;
179			} else
180				tos = 1;
181		} else if (strcmp(*argv, "nopmtudisc") == 0) {
182			pmtudisc = 0;
183		} else if (strcmp(*argv, "pmtudisc") == 0) {
184			pmtudisc = 1;
185		} else if (strcmp(lu->id, "sit") == 0 &&
186			   strcmp(*argv, "isatap") == 0) {
187			iflags |= SIT_ISATAP;
188		} else if (strcmp(*argv, "6rd-prefix") == 0) {
189			inet_prefix prefix;
190			NEXT_ARG();
191			if (get_prefix(&prefix, *argv, AF_INET6))
192				invarg("invalid 6rd_prefix\n", *argv);
193			memcpy(&ip6rdprefix, prefix.data, 16);
194			ip6rdprefixlen = prefix.bitlen;
195		} else if (strcmp(*argv, "6rd-relay_prefix") == 0) {
196			inet_prefix prefix;
197			NEXT_ARG();
198			if (get_prefix(&prefix, *argv, AF_INET))
199				invarg("invalid 6rd-relay_prefix\n", *argv);
200			memcpy(&ip6rdrelayprefix, prefix.data, 4);
201			ip6rdrelayprefixlen = prefix.bitlen;
202		} else if (strcmp(*argv, "6rd-reset") == 0) {
203			inet_prefix prefix;
204			get_prefix(&prefix, "2002::", AF_INET6);
205			memcpy(&ip6rdprefix, prefix.data, 16);
206			ip6rdprefixlen = 16;
207			ip6rdrelayprefix = 0;
208			ip6rdrelayprefixlen = 0;
209		} else
210			usage(strcmp(lu->id, "sit") == 0);
211		argc--, argv++;
212	}
213
214	if (ttl && pmtudisc == 0) {
215		fprintf(stderr, "ttl != 0 and noptmudisc are incompatible\n");
216		exit(-1);
217	}
218
219	addattr32(n, 1024, IFLA_IPTUN_LINK, link);
220	addattr32(n, 1024, IFLA_IPTUN_LOCAL, laddr);
221	addattr32(n, 1024, IFLA_IPTUN_REMOTE, raddr);
222	addattr8(n, 1024, IFLA_IPTUN_TTL, ttl);
223	addattr8(n, 1024, IFLA_IPTUN_TOS, tos);
224	addattr8(n, 1024, IFLA_IPTUN_PMTUDISC, pmtudisc);
225	if (strcmp(lu->id, "sit") == 0) {
226		addattr16(n, 1024, IFLA_IPTUN_FLAGS, iflags);
227		if (ip6rdprefixlen) {
228			addattr_l(n, 1024, IFLA_IPTUN_6RD_PREFIX,
229				  &ip6rdprefix, sizeof(ip6rdprefix));
230			addattr16(n, 1024, IFLA_IPTUN_6RD_PREFIXLEN,
231				  ip6rdprefixlen);
232			addattr32(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIX,
233				  ip6rdrelayprefix);
234			addattr16(n, 1024, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
235				  ip6rdrelayprefixlen);
236		}
237	}
238
239	return 0;
240}
241
242static void iptunnel_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
243{
244	char s1[1024];
245	char s2[64];
246	const char *local = "any";
247	const char *remote = "any";
248
249	if (!tb)
250		return;
251
252	if (tb[IFLA_IPTUN_REMOTE]) {
253		unsigned addr = rta_getattr_u32(tb[IFLA_IPTUN_REMOTE]);
254
255		if (addr)
256			remote = format_host(AF_INET, 4, &addr, s1, sizeof(s1));
257	}
258
259	fprintf(f, "remote %s ", remote);
260
261	if (tb[IFLA_IPTUN_LOCAL]) {
262		unsigned addr = rta_getattr_u32(tb[IFLA_IPTUN_LOCAL]);
263
264		if (addr)
265			local = format_host(AF_INET, 4, &addr, s1, sizeof(s1));
266	}
267
268	fprintf(f, "local %s ", local);
269
270	if (tb[IFLA_IPTUN_LINK] && rta_getattr_u32(tb[IFLA_IPTUN_LINK])) {
271		unsigned link = rta_getattr_u32(tb[IFLA_IPTUN_LINK]);
272		const char *n = if_indextoname(link, s2);
273
274		if (n)
275			fprintf(f, "dev %s ", n);
276		else
277			fprintf(f, "dev %u ", link);
278	}
279
280	if (tb[IFLA_IPTUN_TTL] && rta_getattr_u8(tb[IFLA_IPTUN_TTL]))
281		fprintf(f, "ttl %d ", rta_getattr_u8(tb[IFLA_IPTUN_TTL]));
282	else
283		fprintf(f, "ttl inherit ");
284
285	if (tb[IFLA_IPTUN_TOS] && rta_getattr_u8(tb[IFLA_IPTUN_TOS])) {
286		int tos = rta_getattr_u8(tb[IFLA_IPTUN_TOS]);
287
288		fputs("tos ", f);
289		if (tos == 1)
290			fputs("inherit ", f);
291		else
292			fprintf(f, "0x%x ", tos);
293	}
294
295	if (tb[IFLA_IPTUN_PMTUDISC] && rta_getattr_u8(tb[IFLA_IPTUN_PMTUDISC]))
296		fprintf(f, "pmtudisc ");
297	else
298		fprintf(f, "nopmtudisc ");
299
300	if (tb[IFLA_IPTUN_FLAGS]) {
301	       __u16 iflags = rta_getattr_u16(tb[IFLA_IPTUN_FLAGS]);
302
303	      if (iflags & SIT_ISATAP)
304		      fprintf(f, "isatap ");
305	}
306
307	if (tb[IFLA_IPTUN_6RD_PREFIXLEN] &&
308	    *(__u16 *)RTA_DATA(tb[IFLA_IPTUN_6RD_PREFIXLEN])) {
309		__u16 prefixlen = rta_getattr_u16(tb[IFLA_IPTUN_6RD_PREFIXLEN]);
310		__u16 relayprefixlen =
311			rta_getattr_u16(tb[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
312		__u32 relayprefix =
313			rta_getattr_u32(tb[IFLA_IPTUN_6RD_RELAY_PREFIX]);
314
315		printf("6rd-prefix %s/%u ",
316		       inet_ntop(AF_INET6, RTA_DATA(tb[IFLA_IPTUN_6RD_PREFIX]),
317			         s1, sizeof(s1)),
318		       prefixlen);
319		if (relayprefix) {
320			printf("6rd-relay_prefix %s/%u ",
321			       format_host(AF_INET, 4, &relayprefix, s1,
322				           sizeof(s1)),
323			       relayprefixlen);
324		}
325	}
326}
327
328struct link_util ipip_link_util = {
329	.id = "ipip",
330	.maxattr = IFLA_IPTUN_MAX,
331	.parse_opt = iptunnel_parse_opt,
332	.print_opt = iptunnel_print_opt,
333};
334
335struct link_util sit_link_util = {
336	.id = "sit",
337	.maxattr = IFLA_IPTUN_MAX,
338	.parse_opt = iptunnel_parse_opt,
339	.print_opt = iptunnel_print_opt,
340};
341