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_START] || tb[FRA_UID_END]) {
153 fprintf(fp, "uidrange ");
154 if (tb[FRA_UID_START])
155 fprintf(fp, "%u", rta_getattr_u32(tb[FRA_UID_START]));
156 else
157 fprintf(fp, "???");
158
159 if (tb[FRA_UID_END])
160 fprintf(fp, "-%u ", rta_getattr_u32(tb[FRA_UID_END]));
161 else
162 fprintf(fp, "-??? ");
163 }
164
165 table = rtm_get_table(r, tb);
166 if (table) {
167 fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
168
169 if (tb[FRA_SUPPRESS_PREFIXLEN]) {
170 int pl = rta_getattr_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
171 if (pl != -1) {
172 fprintf(fp, "suppress_prefixlength %d ", pl);
173 }
174 }
175 if (tb[FRA_SUPPRESS_IFGROUP]) {
176 int group = rta_getattr_u32(tb[FRA_SUPPRESS_IFGROUP]);
177 if (group != -1) {
178 SPRINT_BUF(b1);
179 fprintf(fp, "suppress_ifgroup %s ", rtnl_group_n2a(group, b1, sizeof(b1)));
180 }
181 }
182 }
183
184 if (tb[FRA_FLOW]) {
185 __u32 to = rta_getattr_u32(tb[FRA_FLOW]);
186 __u32 from = to>>16;
187 to &= 0xFFFF;
188 if (from) {
189 fprintf(fp, "realms %s/",
190 rtnl_rtrealm_n2a(from, b1, sizeof(b1)));
191 }
192 fprintf(fp, "%s ",
193 rtnl_rtrealm_n2a(to, b1, sizeof(b1)));
194 }
195
196 if (r->rtm_type == RTN_NAT) {
197 if (tb[RTA_GATEWAY]) {
198 fprintf(fp, "map-to %s ",
199 format_host(r->rtm_family,
200 RTA_PAYLOAD(tb[RTA_GATEWAY]),
201 RTA_DATA(tb[RTA_GATEWAY]),
202 abuf, sizeof(abuf)));
203 } else
204 fprintf(fp, "masquerade");
205 } else if (r->rtm_type == FR_ACT_GOTO) {
206 fprintf(fp, "goto ");
207 if (tb[FRA_GOTO])
208 fprintf(fp, "%u", rta_getattr_u32(tb[FRA_GOTO]));
209 else
210 fprintf(fp, "none");
211 if (r->rtm_flags & FIB_RULE_UNRESOLVED)
212 fprintf(fp, " [unresolved]");
213 } else if (r->rtm_type == FR_ACT_NOP)
214 fprintf(fp, "nop");
215 else if (r->rtm_type != RTN_UNICAST)
216 fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));
217
218 fprintf(fp, "\n");
219 fflush(fp);
220 return 0;
221 }
222
223 static __u32 rule_dump_magic = 0x71706986;
224
save_rule_prep(void)225 static int save_rule_prep(void)
226 {
227 int ret;
228
229 if (isatty(STDOUT_FILENO)) {
230 fprintf(stderr, "Not sending a binary stream to stdout\n");
231 return -1;
232 }
233
234 ret = write(STDOUT_FILENO, &rule_dump_magic, sizeof(rule_dump_magic));
235 if (ret != sizeof(rule_dump_magic)) {
236 fprintf(stderr, "Can't write magic to dump file\n");
237 return -1;
238 }
239
240 return 0;
241 }
242
save_rule(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)243 static int save_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
244 {
245 int ret;
246
247 ret = write(STDOUT_FILENO, n, n->nlmsg_len);
248 if ((ret > 0) && (ret != n->nlmsg_len)) {
249 fprintf(stderr, "Short write while saving nlmsg\n");
250 ret = -EIO;
251 }
252
253 return ret == n->nlmsg_len ? 0 : ret;
254 }
255
iprule_list_or_save(int argc,char ** argv,int save)256 static int iprule_list_or_save(int argc, char **argv, int save)
257 {
258 rtnl_filter_t filter = print_rule;
259 int af = preferred_family;
260
261 if (af == AF_UNSPEC)
262 af = AF_INET;
263
264 if (argc > 0) {
265 fprintf(stderr, "\"ip rule %s\" does not take any arguments.\n",
266 save ? "save" : "show");
267 return -1;
268 }
269
270 if (save) {
271 if (save_rule_prep())
272 return -1;
273 filter = save_rule;
274 }
275
276 if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
277 perror("Cannot send dump request");
278 return 1;
279 }
280
281 if (rtnl_dump_filter(&rth, filter, stdout) < 0) {
282 fprintf(stderr, "Dump terminated\n");
283 return 1;
284 }
285
286 return 0;
287 }
288
rule_dump_check_magic(void)289 static int rule_dump_check_magic(void)
290 {
291 int ret;
292 __u32 magic = 0;
293
294 if (isatty(STDIN_FILENO)) {
295 fprintf(stderr, "Can't restore rule dump from a terminal\n");
296 return -1;
297 }
298
299 ret = fread(&magic, sizeof(magic), 1, stdin);
300 if (magic != rule_dump_magic) {
301 fprintf(stderr, "Magic mismatch (%d elems, %x magic)\n", ret, magic);
302 return -1;
303 }
304
305 return 0;
306 }
307
restore_handler(const struct sockaddr_nl * nl,struct rtnl_ctrl_data * ctrl,struct nlmsghdr * n,void * arg)308 static int restore_handler(const struct sockaddr_nl *nl,
309 struct rtnl_ctrl_data *ctrl,
310 struct nlmsghdr *n, void *arg)
311 {
312 int ret;
313
314 n->nlmsg_flags |= NLM_F_REQUEST | NLM_F_CREATE | NLM_F_ACK;
315
316 ll_init_map(&rth);
317
318 ret = rtnl_talk(&rth, n, n, sizeof(*n));
319 if ((ret < 0) && (errno == EEXIST))
320 ret = 0;
321
322 return ret;
323 }
324
325
iprule_restore(void)326 static int iprule_restore(void)
327 {
328 if (rule_dump_check_magic())
329 exit(-1);
330
331 exit(rtnl_from_file(stdin, &restore_handler, NULL));
332 }
333
iprule_modify(int cmd,int argc,char ** argv)334 static int iprule_modify(int cmd, int argc, char **argv)
335 {
336 int table_ok = 0;
337 struct {
338 struct nlmsghdr n;
339 struct rtmsg r;
340 char buf[1024];
341 } req;
342
343 memset(&req, 0, sizeof(req));
344
345 req.n.nlmsg_type = cmd;
346 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
347 req.n.nlmsg_flags = NLM_F_REQUEST;
348 req.r.rtm_family = preferred_family;
349 req.r.rtm_protocol = RTPROT_BOOT;
350 req.r.rtm_scope = RT_SCOPE_UNIVERSE;
351 req.r.rtm_table = 0;
352 req.r.rtm_type = RTN_UNSPEC;
353 req.r.rtm_flags = 0;
354
355 if (cmd == RTM_NEWRULE) {
356 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
357 req.r.rtm_type = RTN_UNICAST;
358 }
359
360 while (argc > 0) {
361 if (strcmp(*argv, "not") == 0) {
362 req.r.rtm_flags |= FIB_RULE_INVERT;
363 } else if (strcmp(*argv, "from") == 0) {
364 inet_prefix dst;
365 NEXT_ARG();
366 get_prefix(&dst, *argv, req.r.rtm_family);
367 req.r.rtm_src_len = dst.bitlen;
368 addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen);
369 } else if (strcmp(*argv, "to") == 0) {
370 inet_prefix dst;
371 NEXT_ARG();
372 get_prefix(&dst, *argv, req.r.rtm_family);
373 req.r.rtm_dst_len = dst.bitlen;
374 addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen);
375 } else if (matches(*argv, "preference") == 0 ||
376 matches(*argv, "order") == 0 ||
377 matches(*argv, "priority") == 0) {
378 __u32 pref;
379 NEXT_ARG();
380 if (get_u32(&pref, *argv, 0))
381 invarg("preference value is invalid\n", *argv);
382 addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref);
383 } else if (strcmp(*argv, "tos") == 0 ||
384 matches(*argv, "dsfield") == 0) {
385 __u32 tos;
386 NEXT_ARG();
387 if (rtnl_dsfield_a2n(&tos, *argv))
388 invarg("TOS value is invalid\n", *argv);
389 req.r.rtm_tos = tos;
390 } else if (strcmp(*argv, "fwmark") == 0) {
391 char *slash;
392 __u32 fwmark, fwmask;
393 NEXT_ARG();
394 if ((slash = strchr(*argv, '/')) != NULL)
395 *slash = '\0';
396 if (get_u32(&fwmark, *argv, 0))
397 invarg("fwmark value is invalid\n", *argv);
398 addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark);
399 if (slash) {
400 if (get_u32(&fwmask, slash+1, 0))
401 invarg("fwmask value is invalid\n", slash+1);
402 addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask);
403 }
404 } else if (matches(*argv, "realms") == 0) {
405 __u32 realm;
406 NEXT_ARG();
407 if (get_rt_realms_or_raw(&realm, *argv))
408 invarg("invalid realms\n", *argv);
409 addattr32(&req.n, sizeof(req), FRA_FLOW, realm);
410 } else if (matches(*argv, "table") == 0 ||
411 strcmp(*argv, "lookup") == 0) {
412 __u32 tid;
413 NEXT_ARG();
414 if (rtnl_rttable_a2n(&tid, *argv))
415 invarg("invalid table ID\n", *argv);
416 if (tid < 256)
417 req.r.rtm_table = tid;
418 else {
419 req.r.rtm_table = RT_TABLE_UNSPEC;
420 addattr32(&req.n, sizeof(req), FRA_TABLE, tid);
421 }
422 table_ok = 1;
423 } else if (matches(*argv, "suppress_prefixlength") == 0 ||
424 strcmp(*argv, "sup_pl") == 0) {
425 int pl;
426 NEXT_ARG();
427 if (get_s32(&pl, *argv, 0) || pl < 0)
428 invarg("suppress_prefixlength value is invalid\n", *argv);
429 addattr32(&req.n, sizeof(req), FRA_SUPPRESS_PREFIXLEN, pl);
430 } else if (matches(*argv, "suppress_ifgroup") == 0 ||
431 strcmp(*argv, "sup_group") == 0) {
432 NEXT_ARG();
433 int group;
434 if (rtnl_group_a2n(&group, *argv))
435 invarg("Invalid \"suppress_ifgroup\" value\n", *argv);
436 addattr32(&req.n, sizeof(req), FRA_SUPPRESS_IFGROUP, group);
437 } else if (strcmp(*argv, "dev") == 0 ||
438 strcmp(*argv, "iif") == 0) {
439 NEXT_ARG();
440 addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1);
441 } else if (strcmp(*argv, "oif") == 0) {
442 NEXT_ARG();
443 addattr_l(&req.n, sizeof(req), FRA_OIFNAME, *argv, strlen(*argv)+1);
444 } else if (strcmp(*argv, "nat") == 0 ||
445 matches(*argv, "map-to") == 0) {
446 NEXT_ARG();
447 fprintf(stderr, "Warning: route NAT is deprecated\n");
448 addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv));
449 req.r.rtm_type = RTN_NAT;
450 } else if (strcmp(*argv, "uidrange") == 0) {
451 __u32 uid_start, uid_end;
452 NEXT_ARG();
453 if (sscanf(*argv, "%u-%u", &uid_start, &uid_end) != 2)
454 invarg("UID range is invalid\n", *argv);
455 addattr32(&req.n, sizeof(req), FRA_UID_START, uid_start);
456 addattr32(&req.n, sizeof(req), FRA_UID_END, uid_end);
457 } else {
458 int type;
459
460 if (strcmp(*argv, "type") == 0) {
461 NEXT_ARG();
462 }
463 if (matches(*argv, "help") == 0)
464 usage();
465 else if (matches(*argv, "goto") == 0) {
466 __u32 target;
467 type = FR_ACT_GOTO;
468 NEXT_ARG();
469 if (get_u32(&target, *argv, 0))
470 invarg("invalid target\n", *argv);
471 addattr32(&req.n, sizeof(req), FRA_GOTO, target);
472 } else if (matches(*argv, "nop") == 0)
473 type = FR_ACT_NOP;
474 else if (rtnl_rtntype_a2n(&type, *argv))
475 invarg("Failed to parse rule type", *argv);
476 req.r.rtm_type = type;
477 table_ok = 1;
478 }
479 argc--;
480 argv++;
481 }
482
483 if (req.r.rtm_family == AF_UNSPEC)
484 req.r.rtm_family = AF_INET;
485
486 if (!table_ok && cmd == RTM_NEWRULE)
487 req.r.rtm_table = RT_TABLE_MAIN;
488
489 if (rtnl_talk(&rth, &req.n, NULL, 0) < 0)
490 return -2;
491
492 return 0;
493 }
494
495
flush_rule(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)496 static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
497 {
498 struct rtnl_handle rth2;
499 struct rtmsg *r = NLMSG_DATA(n);
500 int len = n->nlmsg_len;
501 struct rtattr * tb[FRA_MAX+1];
502
503 len -= NLMSG_LENGTH(sizeof(*r));
504 if (len < 0)
505 return -1;
506
507 parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);
508
509 if (tb[FRA_PRIORITY]) {
510 n->nlmsg_type = RTM_DELRULE;
511 n->nlmsg_flags = NLM_F_REQUEST;
512
513 if (rtnl_open(&rth2, 0) < 0)
514 return -1;
515
516 if (rtnl_talk(&rth2, n, NULL, 0) < 0)
517 return -2;
518
519 rtnl_close(&rth2);
520 }
521
522 return 0;
523 }
524
iprule_flush(int argc,char ** argv)525 static int iprule_flush(int argc, char **argv)
526 {
527 int af = preferred_family;
528
529 if (af == AF_UNSPEC)
530 af = AF_INET;
531
532 if (argc > 0) {
533 fprintf(stderr, "\"ip rule flush\" does not allow arguments\n");
534 return -1;
535 }
536
537 if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) {
538 perror("Cannot send dump request");
539 return 1;
540 }
541
542 if (rtnl_dump_filter(&rth, flush_rule, NULL) < 0) {
543 fprintf(stderr, "Flush terminated\n");
544 return 1;
545 }
546
547 return 0;
548 }
549
do_iprule(int argc,char ** argv)550 int do_iprule(int argc, char **argv)
551 {
552 if (argc < 1) {
553 return iprule_list_or_save(0, NULL, 0);
554 } else if (matches(argv[0], "list") == 0 ||
555 matches(argv[0], "lst") == 0 ||
556 matches(argv[0], "show") == 0) {
557 return iprule_list_or_save(argc-1, argv+1, 0);
558 } else if (matches(argv[0], "save") == 0) {
559 return iprule_list_or_save(argc-1, argv+1, 1);
560 } else if (matches(argv[0], "restore") == 0) {
561 return iprule_restore();
562 } else if (matches(argv[0], "add") == 0) {
563 return iprule_modify(RTM_NEWRULE, argc-1, argv+1);
564 } else if (matches(argv[0], "delete") == 0) {
565 return iprule_modify(RTM_DELRULE, argc-1, argv+1);
566 } else if (matches(argv[0], "flush") == 0) {
567 return iprule_flush(argc-1, argv+1);
568 } else if (matches(argv[0], "help") == 0)
569 usage();
570
571 fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv);
572 exit(-1);
573 }
574
do_multirule(int argc,char ** argv)575 int do_multirule(int argc, char **argv)
576 {
577 switch (preferred_family) {
578 case AF_UNSPEC:
579 case AF_INET:
580 preferred_family = RTNL_FAMILY_IPMR;
581 break;
582 case AF_INET6:
583 preferred_family = RTNL_FAMILY_IP6MR;
584 break;
585 case RTNL_FAMILY_IPMR:
586 case RTNL_FAMILY_IP6MR:
587 break;
588 default:
589 fprintf(stderr, "Multicast rules are only supported for IPv4/IPv6, was: %i\n",
590 preferred_family);
591 exit(-1);
592 }
593
594 return do_iprule(argc, argv);
595 }
596