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
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <unistd.h>
16 #include <syslog.h>
17 #include <fcntl.h>
18 #include <sys/socket.h>
19 #include <netinet/in.h>
20 #include <netinet/ip.h>
21 #include <arpa/inet.h>
22 #include <string.h>
23 #include <linux/fib_rules.h>
24
25 #include "rt_names.h"
26 #include "utils.h"
27 #include "ip_common.h"
28
29 extern struct rtnl_handle rth;
30
31 static void usage(void) __attribute__((noreturn));
32
usage(void)33 static void usage(void)
34 {
35 fprintf(stderr, "Usage: ip rule [ list | add | del | flush ] SELECTOR ACTION\n");
36 fprintf(stderr, "SELECTOR := [ not ] [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK[/MASK] ]\n");
37 fprintf(stderr, " [ dev STRING ] [ pref NUMBER ]\n");
38 fprintf(stderr, "ACTION := [ table TABLE_ID ]\n");
39 fprintf(stderr, " [ prohibit | reject | unreachable ]\n");
40 fprintf(stderr, " [ realms [SRCREALM/]DSTREALM ]\n");
41 fprintf(stderr, " [ goto NUMBER ]\n");
42 fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
43 exit(-1);
44 }
45
print_rule(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)46 int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
47 {
48 FILE *fp = (FILE*)arg;
49 struct rtmsg *r = NLMSG_DATA(n);
50 int len = n->nlmsg_len;
51 int host_len = -1;
52 __u32 table;
53 struct rtattr * tb[FRA_MAX+1];
54 char abuf[256];
55 SPRINT_BUF(b1);
56
57 if (n->nlmsg_type != RTM_NEWRULE && n->nlmsg_type != RTM_DELRULE)
58 return 0;
59
60 len -= NLMSG_LENGTH(sizeof(*r));
61 if (len < 0)
62 return -1;
63
64 parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
65
66 if (r->rtm_family == AF_INET)
67 host_len = 32;
68 else if (r->rtm_family == AF_INET6)
69 host_len = 128;
70 else if (r->rtm_family == AF_DECnet)
71 host_len = 16;
72 else if (r->rtm_family == AF_IPX)
73 host_len = 80;
74
75 if (n->nlmsg_type == RTM_DELRULE)
76 fprintf(fp, "Deleted ");
77
78 if (tb[FRA_PRIORITY])
79 fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[FRA_PRIORITY]));
80 else
81 fprintf(fp, "0:\t");
82
83 if (r->rtm_flags & FIB_RULE_INVERT)
84 fprintf(fp, "not ");
85
86 if (tb[FRA_SRC]) {
87 if (r->rtm_src_len != host_len) {
88 fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
89 RTA_PAYLOAD(tb[FRA_SRC]),
90 RTA_DATA(tb[FRA_SRC]),
91 abuf, sizeof(abuf)),
92 r->rtm_src_len
93 );
94 } else {
95 fprintf(fp, "from %s ", format_host(r->rtm_family,
96 RTA_PAYLOAD(tb[FRA_SRC]),
97 RTA_DATA(tb[FRA_SRC]),
98 abuf, sizeof(abuf))
99 );
100 }
101 } else if (r->rtm_src_len) {
102 fprintf(fp, "from 0/%d ", r->rtm_src_len);
103 } else {
104 fprintf(fp, "from all ");
105 }
106
107 if (tb[FRA_DST]) {
108 if (r->rtm_dst_len != host_len) {
109 fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
110 RTA_PAYLOAD(tb[FRA_DST]),
111 RTA_DATA(tb[FRA_DST]),
112 abuf, sizeof(abuf)),
113 r->rtm_dst_len
114 );
115 } else {
116 fprintf(fp, "to %s ", format_host(r->rtm_family,
117 RTA_PAYLOAD(tb[FRA_DST]),
118 RTA_DATA(tb[FRA_DST]),
119 abuf, sizeof(abuf)));
120 }
121 } else if (r->rtm_dst_len) {
122 fprintf(fp, "to 0/%d ", r->rtm_dst_len);
123 }
124
125 if (r->rtm_tos) {
126 SPRINT_BUF(b1);
127 fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
128 }
129
130 if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) {
131 __u32 mark = 0, mask = 0;
132
133 if (tb[FRA_FWMARK])
134 mark = *(__u32*)RTA_DATA(tb[FRA_FWMARK]);
135
136 if (tb[FRA_FWMASK] &&
137 (mask = *(__u32*)RTA_DATA(tb[FRA_FWMASK])) != 0xFFFFFFFF)
138 fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask);
139 else
140 fprintf(fp, "fwmark 0x%x ", mark);
141 }
142
143 if (tb[FRA_IFNAME]) {
144 fprintf(fp, "iif %s ", (char*)RTA_DATA(tb[FRA_IFNAME]));
145 if (r->rtm_flags & FIB_RULE_DEV_DETACHED)
146 fprintf(fp, "[detached] ");
147 }
148
149 table = rtm_get_table(r, tb);
150 if (table)
151 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
152
153 if (tb[FRA_FLOW]) {
154 __u32 to = *(__u32*)RTA_DATA(tb[FRA_FLOW]);
155 __u32 from = to>>16;
156 to &= 0xFFFF;
157 if (from) {
158 fprintf(fp, "realms %s/",
159 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
160 }
161 fprintf(fp, "%s ",
162 rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
163 }
164
165 if (r->rtm_type == RTN_NAT) {
166 if (tb[RTA_GATEWAY]) {
167 fprintf(fp, "map-to %s ",
168 format_host(r->rtm_family,
169 RTA_PAYLOAD(tb[RTA_GATEWAY]),
170 RTA_DATA(tb[RTA_GATEWAY]),
171 abuf, sizeof(abuf)));
172 } else
173 fprintf(fp, "masquerade");
174 } else if (r->rtm_type == FR_ACT_GOTO) {
175 fprintf(fp, "goto ");
176 if (tb[FRA_GOTO])
177 fprintf(fp, "%u", *(__u32 *) RTA_DATA(tb[FRA_GOTO]));
178 else
179 fprintf(fp, "none");
180 if (r->rtm_flags & FIB_RULE_UNRESOLVED)
181 fprintf(fp, " [unresolved]");
182 } else if (r->rtm_type == FR_ACT_NOP)
183 fprintf(fp, "nop");
184 else if (r->rtm_type != RTN_UNICAST)
185 fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
186
187 fprintf(fp, "\n");
188 fflush(fp);
189 return 0;
190 }
191
iprule_list(int argc,char ** argv)192 static int iprule_list(int argc, char **argv)
193 {
194 int af = preferred_family;
195
196 if (af == AF_UNSPEC)
197 af = AF_INET;
198
199 if (argc > 0) {
200 fprintf(stderr, "\"ip rule show\" does not take any arguments.\n");
201 return -1;
202 }
203
204 if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
205 perror("Cannot send dump request");
206 return 1;
207 }
208
209 if (rtnl_dump_filter(&rth, print_rule, stdout, NULL, NULL) < 0) {
210 fprintf(stderr, "Dump terminated\n");
211 return 1;
212 }
213
214 return 0;
215 }
216
217
iprule_modify(int cmd,int argc,char ** argv)218 static int iprule_modify(int cmd, int argc, char **argv)
219 {
220 int table_ok = 0;
221 struct {
222 struct nlmsghdr n;
223 struct rtmsg r;
224 char buf[1024];
225 } req;
226
227 memset(&req, 0, sizeof(req));
228
229 req.n.nlmsg_type = cmd;
230 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
231 req.n.nlmsg_flags = NLM_F_REQUEST;
232 req.r.rtm_family = preferred_family;
233 req.r.rtm_protocol = RTPROT_BOOT;
234 req.r.rtm_scope = RT_SCOPE_UNIVERSE;
235 req.r.rtm_table = 0;
236 req.r.rtm_type = RTN_UNSPEC;
237 req.r.rtm_flags = 0;
238
239 if (cmd == RTM_NEWRULE) {
240 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
241 req.r.rtm_type = RTN_UNICAST;
242 }
243
244 while (argc > 0) {
245 if (strcmp(*argv, "not") == 0) {
246 req.r.rtm_flags |= FIB_RULE_INVERT;
247 } else if (strcmp(*argv, "from") == 0) {
248 inet_prefix dst;
249 NEXT_ARG();
250 get_prefix(&dst, *argv, req.r.rtm_family);
251 req.r.rtm_src_len = dst.bitlen;
252 addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen);
253 } else if (strcmp(*argv, "to") == 0) {
254 inet_prefix dst;
255 NEXT_ARG();
256 get_prefix(&dst, *argv, req.r.rtm_family);
257 req.r.rtm_dst_len = dst.bitlen;
258 addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen);
259 } else if (matches(*argv, "preference") == 0 ||
260 matches(*argv, "order") == 0 ||
261 matches(*argv, "priority") == 0) {
262 __u32 pref;
263 NEXT_ARG();
264 if (get_u32(&pref, *argv, 0))
265 invarg("preference value is invalid\n", *argv);
266 addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref);
267 } else if (strcmp(*argv, "tos") == 0) {
268 __u32 tos;
269 NEXT_ARG();
270 if (rtnl_dsfield_a2n(&tos, *argv))
271 invarg("TOS value is invalid\n", *argv);
272 req.r.rtm_tos = tos;
273 } else if (strcmp(*argv, "fwmark") == 0) {
274 char *slash;
275 __u32 fwmark, fwmask;
276 NEXT_ARG();
277 if ((slash = strchr(*argv, '/')) != NULL)
278 *slash = '\0';
279 if (get_u32(&fwmark, *argv, 0))
280 invarg("fwmark value is invalid\n", *argv);
281 addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
282 if (slash) {
283 if (get_u32(&fwmask, slash+1, 0))
284 invarg("fwmask value is invalid\n", slash+1);
285 addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
286 }
287 } else if (matches(*argv, "realms") == 0) {
288 __u32 realm;
289 NEXT_ARG();
290 if (get_rt_realms(&realm, *argv))
291 invarg("invalid realms\n", *argv);
292 addattr32(&req.n, sizeof(req), FRA_FLOW, realm);
293 } else if (matches(*argv, "table") == 0 ||
294 strcmp(*argv, "lookup") == 0) {
295 __u32 tid;
296 NEXT_ARG();
297 if (rtnl_rttable_a2n(&tid, *argv))
298 invarg("invalid table ID\n", *argv);
299 if (tid < 256)
300 req.r.rtm_table = tid;
301 else {
302 req.r.rtm_table = RT_TABLE_UNSPEC;
303 addattr32(&req.n, sizeof(req), FRA_TABLE, tid);
304 }
305 table_ok = 1;
306 } else if (strcmp(*argv, "dev") == 0 ||
307 strcmp(*argv, "iif") == 0) {
308 NEXT_ARG();
309 addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1);
310 } else if (strcmp(*argv, "nat") == 0 ||
311 matches(*argv, "map-to") == 0) {
312 NEXT_ARG();
313 fprintf(stderr, "Warning: route NAT is deprecated\n");
314 addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
315 req.r.rtm_type = RTN_NAT;
316 } else {
317 int type;
318
319 if (strcmp(*argv, "type") == 0) {
320 NEXT_ARG();
321 }
322 if (matches(*argv, "help") == 0)
323 usage();
324 else if (matches(*argv, "goto") == 0) {
325 __u32 target;
326 type = FR_ACT_GOTO;
327 NEXT_ARG();
328 if (get_u32(&target, *argv, 0))
329 invarg("invalid target\n", *argv);
330 addattr32(&req.n, sizeof(req), FRA_GOTO, target);
331 } else if (matches(*argv, "nop") == 0)
332 type = FR_ACT_NOP;
333 else if (rtnl_rtntype_a2n(&type, *argv))
334 invarg("Failed to parse rule type", *argv);
335 req.r.rtm_type = type;
336 table_ok = 1;
337 }
338 argc--;
339 argv++;
340 }
341
342 if (req.r.rtm_family == AF_UNSPEC)
343 req.r.rtm_family = AF_INET;
344
345 if (!table_ok && cmd == RTM_NEWRULE)
346 req.r.rtm_table = RT_TABLE_MAIN;
347
348 if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
349 return 2;
350
351 return 0;
352 }
353
354
flush_rule(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)355 static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
356 {
357 struct rtnl_handle rth2;
358 struct rtmsg *r = NLMSG_DATA(n);
359 int len = n->nlmsg_len;
360 struct rtattr * tb[FRA_MAX+1];
361
362 len -= NLMSG_LENGTH(sizeof(*r));
363 if (len < 0)
364 return -1;
365
366 parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
367
368 if (tb[FRA_PRIORITY]) {
369 n->nlmsg_type = RTM_DELRULE;
370 n->nlmsg_flags = NLM_F_REQUEST;
371
372 if (rtnl_open(&rth2, 0) < 0)
373 return -1;
374
375 if (rtnl_talk(&rth2, n, 0, 0, NULL, NULL, NULL) < 0)
376 return -2;
377
378 rtnl_close(&rth2);
379 }
380
381 return 0;
382 }
383
iprule_flush(int argc,char ** argv)384 static int iprule_flush(int argc, char **argv)
385 {
386 int af = preferred_family;
387
388 if (af == AF_UNSPEC)
389 af = AF_INET;
390
391 if (argc > 0) {
392 fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
393 return -1;
394 }
395
396 if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
397 perror("Cannot send dump request");
398 return 1;
399 }
400
401 if (rtnl_dump_filter(&rth, flush_rule, NULL, NULL, NULL) < 0) {
402 fprintf(stderr, "Flush terminated\n");
403 return 1;
404 }
405
406 return 0;
407 }
408
do_iprule(int argc,char ** argv)409 int do_iprule(int argc, char **argv)
410 {
411 if (argc < 1) {
412 return iprule_list(0, NULL);
413 } else if (matches(argv[0], "list") == 0 ||
414 matches(argv[0], "lst") == 0 ||
415 matches(argv[0], "show") == 0) {
416 return iprule_list(argc-1, argv+1);
417 } else if (matches(argv[0], "add") == 0) {
418 return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
419 } else if (matches(argv[0], "delete") == 0) {
420 return iprule_modify(RTM_DELRULE, argc-1, argv+1);
421 } else if (matches(argv[0], "flush") == 0) {
422 return iprule_flush(argc-1, argv+1);
423 } else if (matches(argv[0], "help") == 0)
424 usage();
425
426 fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
427 exit(-1);
428 }
429
430