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, " [ iif STRING ] [ oif STRING ] [ pref NUMBER ] [ uidrange UID1-UID2 ]\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 = rta_getattr_u32(tb[FRA_FWMARK]);
135
136 if (tb[FRA_FWMASK] &&
137 (mask = rta_getattr_u32(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 ", rta_getattr_str(tb[FRA_IFNAME]));
145 if (r->rtm_flags & FIB_RULE_IIF_DETACHED)
146 fprintf(fp, "[detached] ");
147 }
148
149 if (tb[FRA_OIFNAME]) {
150 fprintf(fp, "oif %s ", rta_getattr_str(tb[FRA_OIFNAME]));
151 if (r->rtm_flags & FIB_RULE_OIF_DETACHED)
152 fprintf(fp, "[detached] ");
153 }
154
155 if (tb[FRA_UID_START] || tb[FRA_UID_END]) {
156 fprintf(fp, "uidrange ");
157 if (tb[FRA_UID_START])
158 fprintf(fp, "%u", rta_getattr_u32(tb[FRA_UID_START]));
159 else
160 fprintf(fp, "???");
161
162 if (tb[FRA_UID_END])
163 fprintf(fp, "-%u ", rta_getattr_u32(tb[FRA_UID_END]));
164 else
165 fprintf(fp, "-??? ");
166 }
167
168 table = rtm_get_table(r, tb);
169 if (table)
170 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
171
172 if (tb[FRA_FLOW]) {
173 __u32 to = rta_getattr_u32(tb[FRA_FLOW]);
174 __u32 from = to>>16;
175 to &= 0xFFFF;
176 if (from) {
177 fprintf(fp, "realms %s/",
178 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
179 }
180 fprintf(fp, "%s ",
181 rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
182 }
183
184 if (r->rtm_type == RTN_NAT) {
185 if (tb[RTA_GATEWAY]) {
186 fprintf(fp, "map-to %s ",
187 format_host(r->rtm_family,
188 RTA_PAYLOAD(tb[RTA_GATEWAY]),
189 RTA_DATA(tb[RTA_GATEWAY]),
190 abuf, sizeof(abuf)));
191 } else
192 fprintf(fp, "masquerade");
193 } else if (r->rtm_type == FR_ACT_GOTO) {
194 fprintf(fp, "goto ");
195 if (tb[FRA_GOTO])
196 fprintf(fp, "%u", rta_getattr_u32(tb[FRA_GOTO]));
197 else
198 fprintf(fp, "none");
199 if (r->rtm_flags & FIB_RULE_UNRESOLVED)
200 fprintf(fp, " [unresolved]");
201 } else if (r->rtm_type == FR_ACT_NOP)
202 fprintf(fp, "nop");
203 else if (r->rtm_type != RTN_UNICAST)
204 fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
205
206 fprintf(fp, "\n");
207 fflush(fp);
208 return 0;
209 }
210
iprule_list(int argc,char ** argv)211 static int iprule_list(int argc, char **argv)
212 {
213 int af = preferred_family;
214
215 if (af == AF_UNSPEC)
216 af = AF_INET;
217
218 if (argc > 0) {
219 fprintf(stderr, "\"ip rule show\" does not take any arguments.\n");
220 return -1;
221 }
222
223 if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
224 perror("Cannot send dump request");
225 return 1;
226 }
227
228 if (rtnl_dump_filter(&rth, print_rule, stdout) < 0) {
229 fprintf(stderr, "Dump terminated\n");
230 return 1;
231 }
232
233 return 0;
234 }
235
236
iprule_modify(int cmd,int argc,char ** argv)237 static int iprule_modify(int cmd, int argc, char **argv)
238 {
239 int table_ok = 0;
240 struct {
241 struct nlmsghdr n;
242 struct rtmsg r;
243 char buf[1024];
244 } req;
245
246 memset(&req, 0, sizeof(req));
247
248 req.n.nlmsg_type = cmd;
249 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
250 req.n.nlmsg_flags = NLM_F_REQUEST;
251 req.r.rtm_family = preferred_family;
252 req.r.rtm_protocol = RTPROT_BOOT;
253 req.r.rtm_scope = RT_SCOPE_UNIVERSE;
254 req.r.rtm_table = 0;
255 req.r.rtm_type = RTN_UNSPEC;
256 req.r.rtm_flags = 0;
257
258 if (cmd == RTM_NEWRULE) {
259 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
260 req.r.rtm_type = RTN_UNICAST;
261 }
262
263 while (argc > 0) {
264 if (strcmp(*argv, "not") == 0) {
265 req.r.rtm_flags |= FIB_RULE_INVERT;
266 } else if (strcmp(*argv, "from") == 0) {
267 inet_prefix dst;
268 NEXT_ARG();
269 get_prefix(&dst, *argv, req.r.rtm_family);
270 req.r.rtm_src_len = dst.bitlen;
271 addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen);
272 } else if (strcmp(*argv, "to") == 0) {
273 inet_prefix dst;
274 NEXT_ARG();
275 get_prefix(&dst, *argv, req.r.rtm_family);
276 req.r.rtm_dst_len = dst.bitlen;
277 addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen);
278 } else if (matches(*argv, "preference") == 0 ||
279 matches(*argv, "order") == 0 ||
280 matches(*argv, "priority") == 0) {
281 __u32 pref;
282 NEXT_ARG();
283 if (get_u32(&pref, *argv, 0))
284 invarg("preference value is invalid\n", *argv);
285 addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref);
286 } else if (strcmp(*argv, "tos") == 0 ||
287 matches(*argv, "dsfield") == 0) {
288 __u32 tos;
289 NEXT_ARG();
290 if (rtnl_dsfield_a2n(&tos, *argv))
291 invarg("TOS value is invalid\n", *argv);
292 req.r.rtm_tos = tos;
293 } else if (strcmp(*argv, "fwmark") == 0) {
294 char *slash;
295 __u32 fwmark, fwmask;
296 NEXT_ARG();
297 if ((slash = strchr(*argv, '/')) != NULL)
298 *slash = '\0';
299 if (get_u32(&fwmark, *argv, 0))
300 invarg("fwmark value is invalid\n", *argv);
301 addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
302 if (slash) {
303 if (get_u32(&fwmask, slash+1, 0))
304 invarg("fwmask value is invalid\n", slash+1);
305 addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
306 }
307 } else if (matches(*argv, "realms") == 0) {
308 __u32 realm;
309 NEXT_ARG();
310 if (get_rt_realms(&realm, *argv))
311 invarg("invalid realms\n", *argv);
312 addattr32(&req.n, sizeof(req), FRA_FLOW, realm);
313 } else if (matches(*argv, "table") == 0 ||
314 strcmp(*argv, "lookup") == 0) {
315 __u32 tid;
316 NEXT_ARG();
317 if (rtnl_rttable_a2n(&tid, *argv))
318 invarg("invalid table ID\n", *argv);
319 if (tid < 256)
320 req.r.rtm_table = tid;
321 else {
322 req.r.rtm_table = RT_TABLE_UNSPEC;
323 addattr32(&req.n, sizeof(req), FRA_TABLE, tid);
324 }
325 table_ok = 1;
326 } else if (strcmp(*argv, "dev") == 0 ||
327 strcmp(*argv, "iif") == 0) {
328 NEXT_ARG();
329 addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1);
330 } else if (strcmp(*argv, "oif") == 0) {
331 NEXT_ARG();
332 addattr_l(&req.n, sizeof(req), FRA_OIFNAME, *argv, strlen(*argv)+1);
333 } else if (strcmp(*argv, "nat") == 0 ||
334 matches(*argv, "map-to") == 0) {
335 NEXT_ARG();
336 fprintf(stderr, "Warning: route NAT is deprecated\n");
337 addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
338 req.r.rtm_type = RTN_NAT;
339 } else if (strcmp(*argv, "uidrange") == 0) {
340 __u32 uid_start, uid_end;
341 NEXT_ARG();
342 if (sscanf(*argv, "%u-%u", &uid_start, &uid_end) != 2)
343 invarg("UID range is invalid\n", *argv);
344 addattr32(&req.n, sizeof(req), FRA_UID_START, uid_start);
345 addattr32(&req.n, sizeof(req), FRA_UID_END, uid_end);
346 } else {
347 int type;
348
349 if (strcmp(*argv, "type") == 0) {
350 NEXT_ARG();
351 }
352 if (matches(*argv, "help") == 0)
353 usage();
354 else if (matches(*argv, "goto") == 0) {
355 __u32 target;
356 type = FR_ACT_GOTO;
357 NEXT_ARG();
358 if (get_u32(&target, *argv, 0))
359 invarg("invalid target\n", *argv);
360 addattr32(&req.n, sizeof(req), FRA_GOTO, target);
361 } else if (matches(*argv, "nop") == 0)
362 type = FR_ACT_NOP;
363 else if (rtnl_rtntype_a2n(&type, *argv))
364 invarg("Failed to parse rule type", *argv);
365 req.r.rtm_type = type;
366 table_ok = 1;
367 }
368 argc--;
369 argv++;
370 }
371
372 if (req.r.rtm_family == AF_UNSPEC)
373 req.r.rtm_family = AF_INET;
374
375 if (!table_ok && cmd == RTM_NEWRULE)
376 req.r.rtm_table = RT_TABLE_MAIN;
377
378 if (rtnl_talk(&rth, &req.n, 0, 0, NULL) < 0)
379 return 2;
380
381 return 0;
382 }
383
384
flush_rule(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)385 static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
386 {
387 struct rtnl_handle rth2;
388 struct rtmsg *r = NLMSG_DATA(n);
389 int len = n->nlmsg_len;
390 struct rtattr * tb[FRA_MAX+1];
391
392 len -= NLMSG_LENGTH(sizeof(*r));
393 if (len < 0)
394 return -1;
395
396 parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
397
398 if (tb[FRA_PRIORITY]) {
399 n->nlmsg_type = RTM_DELRULE;
400 n->nlmsg_flags = NLM_F_REQUEST;
401
402 if (rtnl_open(&rth2, 0) < 0)
403 return -1;
404
405 if (rtnl_talk(&rth2, n, 0, 0, NULL) < 0)
406 return -2;
407
408 rtnl_close(&rth2);
409 }
410
411 return 0;
412 }
413
iprule_flush(int argc,char ** argv)414 static int iprule_flush(int argc, char **argv)
415 {
416 int af = preferred_family;
417
418 if (af == AF_UNSPEC)
419 af = AF_INET;
420
421 if (argc > 0) {
422 fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
423 return -1;
424 }
425
426 if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
427 perror("Cannot send dump request");
428 return 1;
429 }
430
431 if (rtnl_dump_filter(&rth, flush_rule, NULL) < 0) {
432 fprintf(stderr, "Flush terminated\n");
433 return 1;
434 }
435
436 return 0;
437 }
438
do_iprule(int argc,char ** argv)439 int do_iprule(int argc, char **argv)
440 {
441 if (argc < 1) {
442 return iprule_list(0, NULL);
443 } else if (matches(argv[0], "list") == 0 ||
444 matches(argv[0], "lst") == 0 ||
445 matches(argv[0], "show") == 0) {
446 return iprule_list(argc-1, argv+1);
447 } else if (matches(argv[0], "add") == 0) {
448 return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
449 } else if (matches(argv[0], "delete") == 0) {
450 return iprule_modify(RTM_DELRULE, argc-1, argv+1);
451 } else if (matches(argv[0], "flush") == 0) {
452 return iprule_flush(argc-1, argv+1);
453 } else if (matches(argv[0], "help") == 0)
454 usage();
455
456 fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
457 exit(-1);
458 }
459
do_multirule(int argc,char ** argv)460 int do_multirule(int argc, char **argv)
461 {
462 switch (preferred_family) {
463 case AF_UNSPEC:
464 case AF_INET:
465 preferred_family = RTNL_FAMILY_IPMR;
466 break;
467 case AF_INET6:
468 preferred_family = RTNL_FAMILY_IP6MR;
469 break;
470 case RTNL_FAMILY_IPMR:
471 case RTNL_FAMILY_IP6MR:
472 break;
473 default:
474 fprintf(stderr, "Multicast rules are only supported for IPv4/IPv6, was: %i\n",
475 preferred_family);
476 exit(-1);
477 }
478
479 return do_iprule(argc, argv);
480 }
481