1/*
2 * iprule.c		"ip rule".
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 * Changes:
13 *
14 * Rani Assaf <rani@magic.metawire.com> 980929:	resolve addresses
15 */
16
17#include <stdio.h>
18#include <stdlib.h>
19#include <unistd.h>
20#include <syslog.h>
21#include <fcntl.h>
22#include <sys/socket.h>
23#include <netinet/in.h>
24#include <netinet/ip.h>
25#include <arpa/inet.h>
26#include <string.h>
27
28#include "rt_names.h"
29#include "utils.h"
30
31extern struct rtnl_handle rth;
32
33static void usage(void) __attribute__((noreturn));
34
35static void usage(void)
36{
37	fprintf(stderr, "Usage: ip rule [ list | add | del | flush ] SELECTOR ACTION\n");
38	fprintf(stderr, "SELECTOR := [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK ]\n");
39	fprintf(stderr, "            [ dev STRING ] [ pref NUMBER ]\n");
40	fprintf(stderr, "ACTION := [ table TABLE_ID ]\n");
41	fprintf(stderr, "          [ prohibit | reject | unreachable ]\n");
42	fprintf(stderr, "          [ realms [SRCREALM/]DSTREALM ]\n");
43	fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
44	exit(-1);
45}
46
47static int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n,
48		      void *arg)
49{
50	FILE *fp = (FILE*)arg;
51	struct rtmsg *r = NLMSG_DATA(n);
52	int len = n->nlmsg_len;
53	int host_len = -1;
54	struct rtattr * tb[RTA_MAX+1];
55	char abuf[256];
56	SPRINT_BUF(b1);
57
58	if (n->nlmsg_type != RTM_NEWRULE)
59		return 0;
60
61	len -= NLMSG_LENGTH(sizeof(*r));
62	if (len < 0)
63		return -1;
64
65	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
66
67	if (r->rtm_family == AF_INET)
68		host_len = 32;
69	else if (r->rtm_family == AF_INET6)
70		host_len = 128;
71	else if (r->rtm_family == AF_DECnet)
72		host_len = 16;
73	else if (r->rtm_family == AF_IPX)
74		host_len = 80;
75
76	if (tb[RTA_PRIORITY])
77		fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[RTA_PRIORITY]));
78	else
79		fprintf(fp, "0:\t");
80
81	if (tb[RTA_SRC]) {
82		if (r->rtm_src_len != host_len) {
83			fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
84							 RTA_PAYLOAD(tb[RTA_SRC]),
85							 RTA_DATA(tb[RTA_SRC]),
86							 abuf, sizeof(abuf)),
87				r->rtm_src_len
88				);
89		} else {
90			fprintf(fp, "from %s ", format_host(r->rtm_family,
91						       RTA_PAYLOAD(tb[RTA_SRC]),
92						       RTA_DATA(tb[RTA_SRC]),
93						       abuf, sizeof(abuf))
94				);
95		}
96	} else if (r->rtm_src_len) {
97		fprintf(fp, "from 0/%d ", r->rtm_src_len);
98	} else {
99		fprintf(fp, "from all ");
100	}
101
102	if (tb[RTA_DST]) {
103		if (r->rtm_dst_len != host_len) {
104			fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
105							 RTA_PAYLOAD(tb[RTA_DST]),
106							 RTA_DATA(tb[RTA_DST]),
107							 abuf, sizeof(abuf)),
108				r->rtm_dst_len
109				);
110		} else {
111			fprintf(fp, "to %s ", format_host(r->rtm_family,
112						       RTA_PAYLOAD(tb[RTA_DST]),
113						       RTA_DATA(tb[RTA_DST]),
114						       abuf, sizeof(abuf)));
115		}
116	} else if (r->rtm_dst_len) {
117		fprintf(fp, "to 0/%d ", r->rtm_dst_len);
118	}
119
120	if (r->rtm_tos) {
121		SPRINT_BUF(b1);
122		fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
123	}
124	if (tb[RTA_PROTOINFO]) {
125		fprintf(fp, "fwmark %#x ", *(__u32*)RTA_DATA(tb[RTA_PROTOINFO]));
126	}
127
128	if (tb[RTA_IIF]) {
129		fprintf(fp, "iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
130	}
131
132	if (r->rtm_table)
133		fprintf(fp, "lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1, sizeof(b1)));
134
135	if (tb[RTA_FLOW]) {
136		__u32 to = *(__u32*)RTA_DATA(tb[RTA_FLOW]);
137		__u32 from = to>>16;
138		to &= 0xFFFF;
139		if (from) {
140			fprintf(fp, "realms %s/",
141				rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
142		}
143		fprintf(fp, "%s ",
144			rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
145	}
146
147	if (r->rtm_type == RTN_NAT) {
148		if (tb[RTA_GATEWAY]) {
149			fprintf(fp, "map-to %s ",
150				format_host(r->rtm_family,
151					    RTA_PAYLOAD(tb[RTA_GATEWAY]),
152					    RTA_DATA(tb[RTA_GATEWAY]),
153					    abuf, sizeof(abuf)));
154		} else
155			fprintf(fp, "masquerade");
156	} else if (r->rtm_type != RTN_UNICAST)
157		fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
158
159	fprintf(fp, "\n");
160	fflush(fp);
161	return 0;
162}
163
164static int iprule_list(int argc, char **argv)
165{
166	int af = preferred_family;
167
168	if (af == AF_UNSPEC)
169		af = AF_INET;
170
171	if (argc > 0) {
172		fprintf(stderr, "\"ip rule show\" does not take any arguments.\n");
173		return -1;
174	}
175
176	if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
177		perror("Cannot send dump request");
178		return 1;
179	}
180
181	if (rtnl_dump_filter(&rth, print_rule, stdout, NULL, NULL) < 0) {
182		fprintf(stderr, "Dump terminated\n");
183		return 1;
184	}
185
186	return 0;
187}
188
189
190static int iprule_modify(int cmd, int argc, char **argv)
191{
192	int table_ok = 0;
193	struct {
194		struct nlmsghdr 	n;
195		struct rtmsg 		r;
196		char   			buf[1024];
197	} req;
198
199	memset(&req, 0, sizeof(req));
200
201	req.n.nlmsg_type = cmd;
202	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
203	req.n.nlmsg_flags = NLM_F_REQUEST;
204	req.r.rtm_family = preferred_family;
205	req.r.rtm_protocol = RTPROT_BOOT;
206	req.r.rtm_scope = RT_SCOPE_UNIVERSE;
207	req.r.rtm_table = 0;
208	req.r.rtm_type = RTN_UNSPEC;
209
210	if (cmd == RTM_NEWRULE) {
211		req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
212		req.r.rtm_type = RTN_UNICAST;
213	}
214
215	while (argc > 0) {
216		if (strcmp(*argv, "from") == 0) {
217			inet_prefix dst;
218			NEXT_ARG();
219			get_prefix(&dst, *argv, req.r.rtm_family);
220			req.r.rtm_src_len = dst.bitlen;
221			addattr_l(&req.n, sizeof(req), RTA_SRC, &dst.data, dst.bytelen);
222		} else if (strcmp(*argv, "to") == 0) {
223			inet_prefix dst;
224			NEXT_ARG();
225			get_prefix(&dst, *argv, req.r.rtm_family);
226			req.r.rtm_dst_len = dst.bitlen;
227			addattr_l(&req.n, sizeof(req), RTA_DST, &dst.data, dst.bytelen);
228		} else if (matches(*argv, "preference") == 0 ||
229			   matches(*argv, "order") == 0 ||
230			   matches(*argv, "priority") == 0) {
231			__u32 pref;
232			NEXT_ARG();
233			if (get_u32(&pref, *argv, 0))
234				invarg("preference value is invalid\n", *argv);
235			addattr32(&req.n, sizeof(req), RTA_PRIORITY, pref);
236		} else if (strcmp(*argv, "tos") == 0) {
237			__u32 tos;
238			NEXT_ARG();
239			if (rtnl_dsfield_a2n(&tos, *argv))
240				invarg("TOS value is invalid\n", *argv);
241			req.r.rtm_tos = tos;
242		} else if (strcmp(*argv, "fwmark") == 0) {
243			__u32 fwmark;
244			NEXT_ARG();
245			if (get_u32(&fwmark, *argv, 0))
246				invarg("fwmark value is invalid\n", *argv);
247			addattr32(&req.n, sizeof(req), RTA_PROTOINFO, fwmark);
248		} else if (matches(*argv, "realms") == 0) {
249			__u32 realm;
250			NEXT_ARG();
251			if (get_rt_realms(&realm, *argv))
252				invarg("invalid realms\n", *argv);
253			addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
254		} else if (matches(*argv, "table") == 0 ||
255			   strcmp(*argv, "lookup") == 0) {
256			__u32 tid;
257			NEXT_ARG();
258			if (rtnl_rttable_a2n(&tid, *argv))
259				invarg("invalid table ID\n", *argv);
260			req.r.rtm_table = tid;
261			table_ok = 1;
262		} else if (strcmp(*argv, "dev") == 0 ||
263			   strcmp(*argv, "iif") == 0) {
264			NEXT_ARG();
265			addattr_l(&req.n, sizeof(req), RTA_IIF, *argv, strlen(*argv)+1);
266		} else if (strcmp(*argv, "nat") == 0 ||
267			   matches(*argv, "map-to") == 0) {
268			NEXT_ARG();
269			fprintf(stderr, "Warning: route NAT is deprecated\n");
270			addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
271			req.r.rtm_type = RTN_NAT;
272		} else {
273			int type;
274
275			if (strcmp(*argv, "type") == 0) {
276				NEXT_ARG();
277			}
278			if (matches(*argv, "help") == 0)
279				usage();
280			if (rtnl_rtntype_a2n(&type, *argv))
281				invarg("Failed to parse rule type", *argv);
282			req.r.rtm_type = type;
283		}
284		argc--;
285		argv++;
286	}
287
288	if (req.r.rtm_family == AF_UNSPEC)
289		req.r.rtm_family = AF_INET;
290
291	if (!table_ok && cmd == RTM_NEWRULE)
292		req.r.rtm_table = RT_TABLE_MAIN;
293
294	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
295		return 2;
296
297	return 0;
298}
299
300
301static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
302{
303	struct rtmsg *r = NLMSG_DATA(n);
304	int len = n->nlmsg_len;
305	struct rtattr * tb[RTA_MAX+1];
306
307	len -= NLMSG_LENGTH(sizeof(*r));
308	if (len < 0)
309		return -1;
310
311	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
312
313	if (tb[RTA_PRIORITY]) {
314		n->nlmsg_type = RTM_DELRULE;
315		n->nlmsg_flags = NLM_F_REQUEST;
316
317		if (rtnl_talk(&rth, n, 0, 0, NULL, NULL, NULL) < 0)
318			return -2;
319	}
320
321	return 0;
322}
323
324static int iprule_flush(int argc, char **argv)
325{
326	int af = preferred_family;
327
328	if (af == AF_UNSPEC)
329		af = AF_INET;
330
331	if (argc > 0) {
332		fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
333		return -1;
334	}
335
336	if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
337		perror("Cannot send dump request");
338		return 1;
339	}
340
341	if (rtnl_dump_filter(&rth, flush_rule, NULL, NULL, NULL) < 0) {
342		fprintf(stderr, "Flush terminated\n");
343		return 1;
344	}
345
346	return 0;
347}
348
349int do_iprule(int argc, char **argv)
350{
351	if (argc < 1) {
352		return iprule_list(0, NULL);
353	} else if (matches(argv[0], "list") == 0 ||
354		   matches(argv[0], "lst") == 0 ||
355		   matches(argv[0], "show") == 0) {
356		return iprule_list(argc-1, argv+1);
357	} else if (matches(argv[0], "add") == 0) {
358		return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
359	} else if (matches(argv[0], "delete") == 0) {
360		return iprule_modify(RTM_DELRULE, argc-1, argv+1);
361	} else if (matches(argv[0], "flush") == 0) {
362		return iprule_flush(argc-1, argv+1);
363	} else if (matches(argv[0], "help") == 0)
364		usage();
365
366	fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
367	exit(-1);
368}
369
370