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 #include <errno.h>
25
26 #include "rt_names.h"
27 #include "utils.h"
28 #include "ip_common.h"
29
30 extern struct rtnl_handle rth;
31
32 static void usage(void) __attribute__((noreturn));
33
usage(void)34 static void usage(void)
35 {
36 fprintf(stderr, "Usage: ip rule [ list | add | del | flush | save ] SELECTOR ACTION\n");
37 fprintf(stderr, " ip rule restore\n");
38 fprintf(stderr, "SELECTOR := [ not ] [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK[/MASK] ]\n");
39 fprintf(stderr, " [ iif STRING ] [ oif STRING ] [ pref NUMBER ] [ uidrange UID1-UID2 ]\n");
40 fprintf(stderr, "ACTION := [ table TABLE_ID ]\n");
41 fprintf(stderr, " [ realms [SRCREALM/]DSTREALM ]\n");
42 fprintf(stderr, " [ goto NUMBER ]\n");
43 fprintf(stderr, " SUPPRESSOR\n");
44 fprintf(stderr, "SUPPRESSOR := [ suppress_prefixlength NUMBER ]\n");
45 fprintf(stderr, " [ suppress_ifgroup DEVGROUP ]\n");
46 fprintf(stderr, "TABLE_ID := [ local | main | default | NUMBER ]\n");
47 exit(-1);
48 }
49
print_rule(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)50 int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
51 {
52 FILE *fp = (FILE*)arg;
53 struct rtmsg *r = NLMSG_DATA(n);
54 int len = n->nlmsg_len;
55 int host_len = -1;
56 __u32 table;
57 struct rtattr * tb[FRA_MAX+1];
58 char abuf[256];
59 SPRINT_BUF(b1);
60
61 if (n->nlmsg_type != RTM_NEWRULE && n->nlmsg_type != RTM_DELRULE)
62 return 0;
63
64 len -= NLMSG_LENGTH(sizeof(*r));
65 if (len < 0)
66 return -1;
67
68 parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
69
70 host_len = af_bit_len(r->rtm_family);
71
72 if (n->nlmsg_type == RTM_DELRULE)
73 fprintf(fp, "Deleted ");
74
75 if (tb[FRA_PRIORITY])
76 fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[FRA_PRIORITY]));
77 else
78 fprintf(fp, "0:\t");
79
80 if (r->rtm_flags & FIB_RULE_INVERT)
81 fprintf(fp, "not ");
82
83 if (tb[FRA_SRC]) {
84 if (r->rtm_src_len != host_len) {
85 fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
86 RTA_PAYLOAD(tb[FRA_SRC]),
87 RTA_DATA(tb[FRA_SRC]),
88 abuf, sizeof(abuf)),
89 r->rtm_src_len
90 );
91 } else {
92 fprintf(fp, "from %s ", format_host(r->rtm_family,
93 RTA_PAYLOAD(tb[FRA_SRC]),
94 RTA_DATA(tb[FRA_SRC]),
95 abuf, sizeof(abuf))
96 );
97 }
98 } else if (r->rtm_src_len) {
99 fprintf(fp, "from 0/%d ", r->rtm_src_len);
100 } else {
101 fprintf(fp, "from all ");
102 }
103
104 if (tb[FRA_DST]) {
105 if (r->rtm_dst_len != host_len) {
106 fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
107 RTA_PAYLOAD(tb[FRA_DST]),
108 RTA_DATA(tb[FRA_DST]),
109 abuf, sizeof(abuf)),
110 r->rtm_dst_len
111 );
112 } else {
113 fprintf(fp, "to %s ", format_host(r->rtm_family,
114 RTA_PAYLOAD(tb[FRA_DST]),
115 RTA_DATA(tb[FRA_DST]),
116 abuf, sizeof(abuf)));
117 }
118 } else if (r->rtm_dst_len) {
119 fprintf(fp, "to 0/%d ", r->rtm_dst_len);
120 }
121
122 if (r->rtm_tos) {
123 SPRINT_BUF(b1);
124 fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
125 }
126
127 if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) {
128 __u32 mark = 0, mask = 0;
129
130 if (tb[FRA_FWMARK])
131 mark = rta_getattr_u32(tb[FRA_FWMARK]);
132
133 if (tb[FRA_FWMASK] &&
134 (mask = rta_getattr_u32(tb[FRA_FWMASK])) != 0xFFFFFFFF)
135 fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask);
136 else
137 fprintf(fp, "fwmark 0x%x ", mark);
138 }
139
140 if (tb[FRA_IFNAME]) {
141 fprintf(fp, "iif %s ", rta_getattr_str(tb[FRA_IFNAME]));
142 if (r->rtm_flags & FIB_RULE_IIF_DETACHED)
143 fprintf(fp, "[detached] ");
144 }
145
146 if (tb[FRA_OIFNAME]) {
147 fprintf(fp, "oif %s ", rta_getattr_str(tb[FRA_OIFNAME]));
148 if (r->rtm_flags & FIB_RULE_OIF_DETACHED)
149 fprintf(fp, "[detached] ");
150 }
151
152 if (tb[FRA_UID_RANGE]) {
153 struct fib_rule_uid_range *r = RTA_DATA(tb[FRA_UID_RANGE]);
154
155 fprintf(fp, "uidrange %u-%u ", r->start, r->end);
156 }
157
158 table = rtm_get_table(r, tb);
159 if (table) {
160 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
161
162 if (tb[FRA_SUPPRESS_PREFIXLEN]) {
163 int pl = rta_getattr_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
164 if (pl != -1) {
165 fprintf(fp, "suppress_prefixlength %d ", pl);
166 }
167 }
168 if (tb[FRA_SUPPRESS_IFGROUP]) {
169 int group = rta_getattr_u32(tb[FRA_SUPPRESS_IFGROUP]);
170 if (group != -1) {
171 SPRINT_BUF(b1);
172 fprintf(fp, "suppress_ifgroup %s ", rtnl_group_n2a(group, b1, sizeof(b1)));
173 }
174 }
175 }
176
177 if (tb[FRA_FLOW]) {
178 __u32 to = rta_getattr_u32(tb[FRA_FLOW]);
179 __u32 from = to>>16;
180 to &= 0xFFFF;
181 if (from) {
182 fprintf(fp, "realms %s/",
183 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
184 }
185 fprintf(fp, "%s ",
186 rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
187 }
188
189 if (r->rtm_type == RTN_NAT) {
190 if (tb[RTA_GATEWAY]) {
191 fprintf(fp, "map-to %s ",
192 format_host(r->rtm_family,
193 RTA_PAYLOAD(tb[RTA_GATEWAY]),
194 RTA_DATA(tb[RTA_GATEWAY]),
195 abuf, sizeof(abuf)));
196 } else
197 fprintf(fp, "masquerade");
198 } else if (r->rtm_type == FR_ACT_GOTO) {
199 fprintf(fp, "goto ");
200 if (tb[FRA_GOTO])
201 fprintf(fp, "%u", rta_getattr_u32(tb[FRA_GOTO]));
202 else
203 fprintf(fp, "none");
204 if (r->rtm_flags & FIB_RULE_UNRESOLVED)
205 fprintf(fp, " [unresolved]");
206 } else if (r->rtm_type == FR_ACT_NOP)
207 fprintf(fp, "nop");
208 else if (r->rtm_type != RTN_UNICAST)
209 fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
210
211 fprintf(fp, "\n");
212 fflush(fp);
213 return 0;
214 }
215
216 static __u32 rule_dump_magic = 0x71706986;
217
save_rule_prep(void)218 static int save_rule_prep(void)
219 {
220 int ret;
221
222 if (isatty(STDOUT_FILENO)) {
223 fprintf(stderr, "Not sending a binary stream to stdout\n");
224 return -1;
225 }
226
227 ret = write(STDOUT_FILENO, &rule_dump_magic, sizeof(rule_dump_magic));
228 if (ret != sizeof(rule_dump_magic)) {
229 fprintf(stderr, "Can't write magic to dump file\n");
230 return -1;
231 }
232
233 return 0;
234 }
235
save_rule(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)236 static int save_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
237 {
238 int ret;
239
240 ret = write(STDOUT_FILENO, n, n->nlmsg_len);
241 if ((ret > 0) && (ret != n->nlmsg_len)) {
242 fprintf(stderr, "Short write while saving nlmsg\n");
243 ret = -EIO;
244 }
245
246 return ret == n->nlmsg_len ? 0 : ret;
247 }
248
iprule_list_or_save(int argc,char ** argv,int save)249 static int iprule_list_or_save(int argc, char **argv, int save)
250 {
251 rtnl_filter_t filter = print_rule;
252 int af = preferred_family;
253
254 if (af == AF_UNSPEC)
255 af = AF_INET;
256
257 if (argc > 0) {
258 fprintf(stderr, "\"ip rule %s\" does not take any arguments.\n",
259 save ? "save" : "show");
260 return -1;
261 }
262
263 if (save) {
264 if (save_rule_prep())
265 return -1;
266 filter = save_rule;
267 }
268
269 if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
270 perror("Cannot send dump request");
271 return 1;
272 }
273
274 if (rtnl_dump_filter(&rth, filter, stdout) < 0) {
275 fprintf(stderr, "Dump terminated\n");
276 return 1;
277 }
278
279 return 0;
280 }
281
rule_dump_check_magic(void)282 static int rule_dump_check_magic(void)
283 {
284 int ret;
285 __u32 magic = 0;
286
287 if (isatty(STDIN_FILENO)) {
288 fprintf(stderr, "Can't restore rule dump from a terminal\n");
289 return -1;
290 }
291
292 ret = fread(&magic, sizeof(magic), 1, stdin);
293 if (magic != rule_dump_magic) {
294 fprintf(stderr, "Magic mismatch (%d elems, %x magic)\n", ret, magic);
295 return -1;
296 }
297
298 return 0;
299 }
300
restore_handler(const struct sockaddr_nl * nl,struct rtnl_ctrl_data * ctrl,struct nlmsghdr * n,void * arg)301 static int restore_handler(const struct sockaddr_nl *nl,
302 struct rtnl_ctrl_data *ctrl,
303 struct nlmsghdr *n, void *arg)
304 {
305 int ret;
306
307 n->nlmsg_flags |= NLM_F_REQUEST | NLM_F_CREATE | NLM_F_ACK;
308
309 ll_init_map(&rth);
310
311 ret = rtnl_talk(&rth, n, n, sizeof(*n));
312 if ((ret < 0) && (errno == EEXIST))
313 ret = 0;
314
315 return ret;
316 }
317
318
iprule_restore(void)319 static int iprule_restore(void)
320 {
321 if (rule_dump_check_magic())
322 exit(-1);
323
324 exit(rtnl_from_file(stdin, &restore_handler, NULL));
325 }
326
iprule_modify(int cmd,int argc,char ** argv)327 static int iprule_modify(int cmd, int argc, char **argv)
328 {
329 int table_ok = 0;
330 struct {
331 struct nlmsghdr n;
332 struct rtmsg r;
333 char buf[1024];
334 } req;
335
336 memset(&req, 0, sizeof(req));
337
338 req.n.nlmsg_type = cmd;
339 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
340 req.n.nlmsg_flags = NLM_F_REQUEST;
341 req.r.rtm_family = preferred_family;
342 req.r.rtm_protocol = RTPROT_BOOT;
343 req.r.rtm_scope = RT_SCOPE_UNIVERSE;
344 req.r.rtm_table = 0;
345 req.r.rtm_type = RTN_UNSPEC;
346 req.r.rtm_flags = 0;
347
348 if (cmd == RTM_NEWRULE) {
349 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
350 req.r.rtm_type = RTN_UNICAST;
351 }
352
353 while (argc > 0) {
354 if (strcmp(*argv, "not") == 0) {
355 req.r.rtm_flags |= FIB_RULE_INVERT;
356 } else if (strcmp(*argv, "from") == 0) {
357 inet_prefix dst;
358 NEXT_ARG();
359 get_prefix(&dst, *argv, req.r.rtm_family);
360 req.r.rtm_src_len = dst.bitlen;
361 addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen);
362 } else if (strcmp(*argv, "to") == 0) {
363 inet_prefix dst;
364 NEXT_ARG();
365 get_prefix(&dst, *argv, req.r.rtm_family);
366 req.r.rtm_dst_len = dst.bitlen;
367 addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen);
368 } else if (matches(*argv, "preference") == 0 ||
369 matches(*argv, "order") == 0 ||
370 matches(*argv, "priority") == 0) {
371 __u32 pref;
372 NEXT_ARG();
373 if (get_u32(&pref, *argv, 0))
374 invarg("preference value is invalid\n", *argv);
375 addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref);
376 } else if (strcmp(*argv, "tos") == 0 ||
377 matches(*argv, "dsfield") == 0) {
378 __u32 tos;
379 NEXT_ARG();
380 if (rtnl_dsfield_a2n(&tos, *argv))
381 invarg("TOS value is invalid\n", *argv);
382 req.r.rtm_tos = tos;
383 } else if (strcmp(*argv, "fwmark") == 0) {
384 char *slash;
385 __u32 fwmark, fwmask;
386 NEXT_ARG();
387 if ((slash = strchr(*argv, '/')) != NULL)
388 *slash = '\0';
389 if (get_u32(&fwmark, *argv, 0))
390 invarg("fwmark value is invalid\n", *argv);
391 addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
392 if (slash) {
393 if (get_u32(&fwmask, slash+1, 0))
394 invarg("fwmask value is invalid\n", slash+1);
395 addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
396 }
397 } else if (matches(*argv, "realms") == 0) {
398 __u32 realm;
399 NEXT_ARG();
400 if (get_rt_realms_or_raw(&realm, *argv))
401 invarg("invalid realms\n", *argv);
402 addattr32(&req.n, sizeof(req), FRA_FLOW, realm);
403 } else if (matches(*argv, "table") == 0 ||
404 strcmp(*argv, "lookup") == 0) {
405 __u32 tid;
406 NEXT_ARG();
407 if (rtnl_rttable_a2n(&tid, *argv))
408 invarg("invalid table ID\n", *argv);
409 if (tid < 256)
410 req.r.rtm_table = tid;
411 else {
412 req.r.rtm_table = RT_TABLE_UNSPEC;
413 addattr32(&req.n, sizeof(req), FRA_TABLE, tid);
414 }
415 table_ok = 1;
416 } else if (matches(*argv, "suppress_prefixlength") == 0 ||
417 strcmp(*argv, "sup_pl") == 0) {
418 int pl;
419 NEXT_ARG();
420 if (get_s32(&pl, *argv, 0) || pl < 0)
421 invarg("suppress_prefixlength value is invalid\n", *argv);
422 addattr32(&req.n, sizeof(req), FRA_SUPPRESS_PREFIXLEN, pl);
423 } else if (matches(*argv, "suppress_ifgroup") == 0 ||
424 strcmp(*argv, "sup_group") == 0) {
425 NEXT_ARG();
426 int group;
427 if (rtnl_group_a2n(&group, *argv))
428 invarg("Invalid \"suppress_ifgroup\" value\n", *argv);
429 addattr32(&req.n, sizeof(req), FRA_SUPPRESS_IFGROUP, group);
430 } else if (strcmp(*argv, "dev") == 0 ||
431 strcmp(*argv, "iif") == 0) {
432 NEXT_ARG();
433 addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1);
434 } else if (strcmp(*argv, "oif") == 0) {
435 NEXT_ARG();
436 addattr_l(&req.n, sizeof(req), FRA_OIFNAME, *argv, strlen(*argv)+1);
437 } else if (strcmp(*argv, "uidrange") == 0) {
438 struct fib_rule_uid_range r;
439
440 NEXT_ARG();
441 if (sscanf(*argv, "%u-%u", &r.start, &r.end) != 2)
442 invarg("invalid UID range\n", *argv);
443 addattr_l(&req.n, sizeof(req), FRA_UID_RANGE, &r,
444 sizeof(r));
445 } else if (strcmp(*argv, "nat") == 0 ||
446 matches(*argv, "map-to") == 0) {
447 NEXT_ARG();
448 fprintf(stderr, "Warning: route NAT is deprecated\n");
449 addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
450 req.r.rtm_type = RTN_NAT;
451 } else {
452 int type;
453
454 if (strcmp(*argv, "type") == 0) {
455 NEXT_ARG();
456 }
457 if (matches(*argv, "help") == 0)
458 usage();
459 else if (matches(*argv, "goto") == 0) {
460 __u32 target;
461 type = FR_ACT_GOTO;
462 NEXT_ARG();
463 if (get_u32(&target, *argv, 0))
464 invarg("invalid target\n", *argv);
465 addattr32(&req.n, sizeof(req), FRA_GOTO, target);
466 } else if (matches(*argv, "nop") == 0)
467 type = FR_ACT_NOP;
468 else if (rtnl_rtntype_a2n(&type, *argv))
469 invarg("Failed to parse rule type", *argv);
470 req.r.rtm_type = type;
471 table_ok = 1;
472 }
473 argc--;
474 argv++;
475 }
476
477 if (req.r.rtm_family == AF_UNSPEC)
478 req.r.rtm_family = AF_INET;
479
480 if (!table_ok && cmd == RTM_NEWRULE)
481 req.r.rtm_table = RT_TABLE_MAIN;
482
483 if (rtnl_talk(&rth, &req.n, NULL, 0) < 0)
484 return -2;
485
486 return 0;
487 }
488
489
flush_rule(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)490 static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
491 {
492 struct rtnl_handle rth2;
493 struct rtmsg *r = NLMSG_DATA(n);
494 int len = n->nlmsg_len;
495 struct rtattr * tb[FRA_MAX+1];
496
497 len -= NLMSG_LENGTH(sizeof(*r));
498 if (len < 0)
499 return -1;
500
501 parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
502
503 if (tb[FRA_PRIORITY]) {
504 n->nlmsg_type = RTM_DELRULE;
505 n->nlmsg_flags = NLM_F_REQUEST;
506
507 if (rtnl_open(&rth2, 0) < 0)
508 return -1;
509
510 if (rtnl_talk(&rth2, n, NULL, 0) < 0)
511 return -2;
512
513 rtnl_close(&rth2);
514 }
515
516 return 0;
517 }
518
iprule_flush(int argc,char ** argv)519 static int iprule_flush(int argc, char **argv)
520 {
521 int af = preferred_family;
522
523 if (af == AF_UNSPEC)
524 af = AF_INET;
525
526 if (argc > 0) {
527 fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
528 return -1;
529 }
530
531 if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
532 perror("Cannot send dump request");
533 return 1;
534 }
535
536 if (rtnl_dump_filter(&rth, flush_rule, NULL) < 0) {
537 fprintf(stderr, "Flush terminated\n");
538 return 1;
539 }
540
541 return 0;
542 }
543
do_iprule(int argc,char ** argv)544 int do_iprule(int argc, char **argv)
545 {
546 if (argc < 1) {
547 return iprule_list_or_save(0, NULL, 0);
548 } else if (matches(argv[0], "list") == 0 ||
549 matches(argv[0], "lst") == 0 ||
550 matches(argv[0], "show") == 0) {
551 return iprule_list_or_save(argc-1, argv+1, 0);
552 } else if (matches(argv[0], "save") == 0) {
553 return iprule_list_or_save(argc-1, argv+1, 1);
554 } else if (matches(argv[0], "restore") == 0) {
555 return iprule_restore();
556 } else if (matches(argv[0], "add") == 0) {
557 return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
558 } else if (matches(argv[0], "delete") == 0) {
559 return iprule_modify(RTM_DELRULE, argc-1, argv+1);
560 } else if (matches(argv[0], "flush") == 0) {
561 return iprule_flush(argc-1, argv+1);
562 } else if (matches(argv[0], "help") == 0)
563 usage();
564
565 fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
566 exit(-1);
567 }
568
do_multirule(int argc,char ** argv)569 int do_multirule(int argc, char **argv)
570 {
571 switch (preferred_family) {
572 case AF_UNSPEC:
573 case AF_INET:
574 preferred_family = RTNL_FAMILY_IPMR;
575 break;
576 case AF_INET6:
577 preferred_family = RTNL_FAMILY_IP6MR;
578 break;
579 case RTNL_FAMILY_IPMR:
580 case RTNL_FAMILY_IP6MR:
581 break;
582 default:
583 fprintf(stderr, "Multicast rules are only supported for IPv4/IPv6, was: %i\n",
584 preferred_family);
585 exit(-1);
586 }
587
588 return do_iprule(argc, argv);
589 }
590