1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2 /***
3 Copyright © 2017 Intel Corporation. All rights reserved.
4 ***/
5
6 #include <netinet/icmp6.h>
7 #include <netinet/in.h>
8 #include <arpa/inet.h>
9
10 #include "sd-radv.h"
11
12 #include "alloc-util.h"
13 #include "dns-domain.h"
14 #include "ether-addr-util.h"
15 #include "event-util.h"
16 #include "fd-util.h"
17 #include "icmp6-util.h"
18 #include "in-addr-util.h"
19 #include "io-util.h"
20 #include "macro.h"
21 #include "memory-util.h"
22 #include "network-common.h"
23 #include "radv-internal.h"
24 #include "random-util.h"
25 #include "socket-util.h"
26 #include "string-util.h"
27 #include "strv.h"
28
sd_radv_new(sd_radv ** ret)29 int sd_radv_new(sd_radv **ret) {
30 _cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
31
32 assert_return(ret, -EINVAL);
33
34 ra = new(sd_radv, 1);
35 if (!ra)
36 return -ENOMEM;
37
38 *ra = (sd_radv) {
39 .n_ref = 1,
40 .fd = -1,
41 .lifetime_usec = RADV_DEFAULT_ROUTER_LIFETIME_USEC,
42 };
43
44 *ret = TAKE_PTR(ra);
45
46 return 0;
47 }
48
sd_radv_attach_event(sd_radv * ra,sd_event * event,int64_t priority)49 int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
50 int r;
51
52 assert_return(ra, -EINVAL);
53 assert_return(!ra->event, -EBUSY);
54
55 if (event)
56 ra->event = sd_event_ref(event);
57 else {
58 r = sd_event_default(&ra->event);
59 if (r < 0)
60 return 0;
61 }
62
63 ra->event_priority = priority;
64
65 return 0;
66 }
67
sd_radv_detach_event(sd_radv * ra)68 int sd_radv_detach_event(sd_radv *ra) {
69
70 assert_return(ra, -EINVAL);
71
72 ra->event = sd_event_unref(ra->event);
73 return 0;
74 }
75
sd_radv_get_event(sd_radv * ra)76 sd_event *sd_radv_get_event(sd_radv *ra) {
77 assert_return(ra, NULL);
78
79 return ra->event;
80 }
81
sd_radv_is_running(sd_radv * ra)82 int sd_radv_is_running(sd_radv *ra) {
83 assert_return(ra, false);
84
85 return ra->state != RADV_STATE_IDLE;
86 }
87
radv_reset(sd_radv * ra)88 static void radv_reset(sd_radv *ra) {
89 assert(ra);
90
91 (void) event_source_disable(ra->timeout_event_source);
92
93 ra->recv_event_source = sd_event_source_disable_unref(ra->recv_event_source);
94
95 ra->ra_sent = 0;
96 }
97
radv_free(sd_radv * ra)98 static sd_radv *radv_free(sd_radv *ra) {
99 if (!ra)
100 return NULL;
101
102 while (ra->prefixes) {
103 sd_radv_prefix *p = ra->prefixes;
104
105 LIST_REMOVE(prefix, ra->prefixes, p);
106 sd_radv_prefix_unref(p);
107 }
108
109 while (ra->route_prefixes) {
110 sd_radv_route_prefix *p = ra->route_prefixes;
111
112 LIST_REMOVE(prefix, ra->route_prefixes, p);
113 sd_radv_route_prefix_unref(p);
114 }
115
116 free(ra->rdnss);
117 free(ra->dnssl);
118
119 radv_reset(ra);
120
121 sd_event_source_unref(ra->timeout_event_source);
122 sd_radv_detach_event(ra);
123
124 ra->fd = safe_close(ra->fd);
125 free(ra->ifname);
126
127 return mfree(ra);
128 }
129
130 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);
131
router_lifetime_is_valid(usec_t lifetime_usec)132 static bool router_lifetime_is_valid(usec_t lifetime_usec) {
133 return lifetime_usec == 0 ||
134 (lifetime_usec >= RADV_MIN_ROUTER_LIFETIME_USEC &&
135 lifetime_usec <= RADV_MAX_ROUTER_LIFETIME_USEC);
136 }
137
usec_to_be32_sec(usec_t usec)138 static be32_t usec_to_be32_sec(usec_t usec) {
139 if (usec == USEC_INFINITY)
140 /* UINT32_MAX is handled as infinity. */
141 return htobe32(UINT32_MAX);
142
143 if (usec >= UINT32_MAX * USEC_PER_SEC)
144 /* Finite but too large. Let's use the largest finite value. */
145 return htobe32(UINT32_MAX - 1);
146
147 return htobe32(usec / USEC_PER_SEC);
148 }
149
radv_send(sd_radv * ra,const struct in6_addr * dst,usec_t lifetime_usec)150 static int radv_send(sd_radv *ra, const struct in6_addr *dst, usec_t lifetime_usec) {
151 struct sockaddr_in6 dst_addr = {
152 .sin6_family = AF_INET6,
153 .sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
154 };
155 struct nd_router_advert adv = {};
156 struct {
157 struct nd_opt_hdr opthdr;
158 struct ether_addr slladdr;
159 } _packed_ opt_mac = {
160 .opthdr = {
161 .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
162 .nd_opt_len = (sizeof(struct nd_opt_hdr) +
163 sizeof(struct ether_addr) - 1) /8 + 1,
164 },
165 };
166 struct nd_opt_mtu opt_mtu = {
167 .nd_opt_mtu_type = ND_OPT_MTU,
168 .nd_opt_mtu_len = 1,
169 };
170 /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, N routes, RDNSS
171 and DNSSL */
172 struct iovec iov[5 + ra->n_prefixes + ra->n_route_prefixes];
173 struct msghdr msg = {
174 .msg_name = &dst_addr,
175 .msg_namelen = sizeof(dst_addr),
176 .msg_iov = iov,
177 };
178 usec_t time_now;
179 int r;
180
181 assert(ra);
182 assert(router_lifetime_is_valid(lifetime_usec));
183
184 r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
185 if (r < 0)
186 return r;
187
188 if (dst && in6_addr_is_set(dst))
189 dst_addr.sin6_addr = *dst;
190
191 adv.nd_ra_type = ND_ROUTER_ADVERT;
192 adv.nd_ra_curhoplimit = ra->hop_limit;
193 adv.nd_ra_flags_reserved = ra->flags;
194 assert_cc(RADV_MAX_ROUTER_LIFETIME_USEC <= UINT16_MAX * USEC_PER_SEC);
195 adv.nd_ra_router_lifetime = htobe16(DIV_ROUND_UP(lifetime_usec, USEC_PER_SEC));
196 iov[msg.msg_iovlen++] = IOVEC_MAKE(&adv, sizeof(adv));
197
198 /* MAC address is optional, either because the link does not use L2
199 addresses or load sharing is desired. See RFC 4861, Section 4.2 */
200 if (!ether_addr_is_null(&ra->mac_addr)) {
201 opt_mac.slladdr = ra->mac_addr;
202 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mac, sizeof(opt_mac));
203 }
204
205 if (ra->mtu > 0) {
206 opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
207 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mtu, sizeof(opt_mtu));
208 }
209
210 LIST_FOREACH(prefix, p, ra->prefixes) {
211 usec_t lifetime_valid_usec, lifetime_preferred_usec;
212
213 lifetime_valid_usec = MIN(usec_sub_unsigned(p->valid_until, time_now),
214 p->lifetime_valid_usec);
215
216 lifetime_preferred_usec = MIN3(usec_sub_unsigned(p->preferred_until, time_now),
217 p->lifetime_preferred_usec,
218 lifetime_valid_usec);
219
220 p->opt.lifetime_valid = usec_to_be32_sec(lifetime_valid_usec);
221 p->opt.lifetime_preferred = usec_to_be32_sec(lifetime_preferred_usec);
222
223 iov[msg.msg_iovlen++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
224 }
225
226 LIST_FOREACH(prefix, rt, ra->route_prefixes) {
227 rt->opt.lifetime = usec_to_be32_sec(MIN(usec_sub_unsigned(rt->valid_until, time_now),
228 rt->lifetime_usec));
229
230 iov[msg.msg_iovlen++] = IOVEC_MAKE(&rt->opt, sizeof(rt->opt));
231 }
232
233 if (ra->rdnss)
234 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->rdnss, ra->rdnss->length * 8);
235
236 if (ra->dnssl)
237 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->dnssl, ra->dnssl->length * 8);
238
239 if (sendmsg(ra->fd, &msg, 0) < 0)
240 return -errno;
241
242 return 0;
243 }
244
radv_recv(sd_event_source * s,int fd,uint32_t revents,void * userdata)245 static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
246 sd_radv *ra = userdata;
247 _cleanup_free_ char *addr = NULL;
248 struct in6_addr src;
249 triple_timestamp timestamp;
250 int r;
251 ssize_t buflen;
252 _cleanup_free_ char *buf = NULL;
253
254 assert(s);
255 assert(ra);
256 assert(ra->event);
257
258 buflen = next_datagram_size_fd(fd);
259 if (buflen < 0) {
260 if (ERRNO_IS_TRANSIENT(buflen) || ERRNO_IS_DISCONNECT(buflen))
261 return 0;
262
263 log_radv_errno(ra, buflen, "Failed to determine datagram size to read, ignoring: %m");
264 return 0;
265 }
266
267 buf = new0(char, buflen);
268 if (!buf)
269 return -ENOMEM;
270
271 r = icmp6_receive(fd, buf, buflen, &src, ×tamp);
272 if (r < 0) {
273 if (ERRNO_IS_TRANSIENT(r) || ERRNO_IS_DISCONNECT(r))
274 return 0;
275
276 switch (r) {
277 case -EADDRNOTAVAIL:
278 (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &src, &addr);
279 log_radv(ra, "Received RS from non-link-local address %s. Ignoring", addr);
280 break;
281
282 case -EMULTIHOP:
283 log_radv(ra, "Received RS with invalid hop limit. Ignoring.");
284 break;
285
286 case -EPFNOSUPPORT:
287 log_radv(ra, "Received invalid source address from ICMPv6 socket. Ignoring.");
288 break;
289
290 default:
291 log_radv_errno(ra, r, "Unexpected error receiving from ICMPv6 socket, ignoring: %m");
292 break;
293 }
294
295 return 0;
296 }
297
298 if ((size_t) buflen < sizeof(struct nd_router_solicit)) {
299 log_radv(ra, "Too short packet received, ignoring");
300 return 0;
301 }
302
303 (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &src, &addr);
304
305 r = radv_send(ra, &src, ra->lifetime_usec);
306 if (r < 0)
307 log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", strnull(addr));
308 else
309 log_radv(ra, "Sent solicited Router Advertisement to %s", strnull(addr));
310
311 return 0;
312 }
313
radv_timeout(sd_event_source * s,uint64_t usec,void * userdata)314 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
315 usec_t min_timeout, max_timeout, time_now, timeout;
316 sd_radv *ra = userdata;
317 int r;
318
319 assert(s);
320 assert(ra);
321 assert(ra->event);
322 assert(router_lifetime_is_valid(ra->lifetime_usec));
323
324 r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
325 if (r < 0)
326 goto fail;
327
328 r = radv_send(ra, NULL, ra->lifetime_usec);
329 if (r < 0)
330 log_radv_errno(ra, r, "Unable to send Router Advertisement: %m");
331
332 /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
333 if (ra->ra_sent < RADV_MAX_INITIAL_RTR_ADVERTISEMENTS)
334 max_timeout = RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
335 else
336 max_timeout = RADV_DEFAULT_MAX_TIMEOUT_USEC;
337
338 /* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
339 * so lower the interval here */
340 if (ra->lifetime_usec > 0)
341 max_timeout = MIN(max_timeout, ra->lifetime_usec);
342
343 if (max_timeout >= 9 * USEC_PER_SEC)
344 min_timeout = max_timeout / 3;
345 else
346 min_timeout = max_timeout * 3 / 4;
347
348 /* RFC 4861, Section 6.2.1.
349 * MaxRtrAdvInterval MUST be no less than 4 seconds and no greater than 1800 seconds.
350 * MinRtrAdvInterval MUST be no less than 3 seconds and no greater than .75 * MaxRtrAdvInterval. */
351 assert(max_timeout >= RADV_MIN_MAX_TIMEOUT_USEC);
352 assert(max_timeout <= RADV_MAX_MAX_TIMEOUT_USEC);
353 assert(min_timeout >= RADV_MIN_MIN_TIMEOUT_USEC);
354 assert(min_timeout <= max_timeout * 3 / 4);
355
356 timeout = min_timeout + random_u64_range(max_timeout - min_timeout);
357 log_radv(ra, "Next Router Advertisement in %s", FORMAT_TIMESPAN(timeout, USEC_PER_SEC));
358
359 r = event_reset_time(ra->event, &ra->timeout_event_source,
360 CLOCK_BOOTTIME,
361 usec_add(time_now, timeout), MSEC_PER_SEC,
362 radv_timeout, ra,
363 ra->event_priority, "radv-timeout", true);
364 if (r < 0)
365 goto fail;
366
367 ra->ra_sent++;
368
369 return 0;
370
371 fail:
372 sd_radv_stop(ra);
373
374 return 0;
375 }
376
sd_radv_stop(sd_radv * ra)377 int sd_radv_stop(sd_radv *ra) {
378 int r;
379
380 if (!ra)
381 return 0;
382
383 if (ra->state == RADV_STATE_IDLE)
384 return 0;
385
386 log_radv(ra, "Stopping IPv6 Router Advertisement daemon");
387
388 /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
389 with zero lifetime */
390 r = radv_send(ra, NULL, 0);
391 if (r < 0)
392 log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
393
394 radv_reset(ra);
395 ra->fd = safe_close(ra->fd);
396 ra->state = RADV_STATE_IDLE;
397
398 return 0;
399 }
400
sd_radv_start(sd_radv * ra)401 int sd_radv_start(sd_radv *ra) {
402 int r;
403
404 assert_return(ra, -EINVAL);
405 assert_return(ra->event, -EINVAL);
406 assert_return(ra->ifindex > 0, -EINVAL);
407
408 if (ra->state != RADV_STATE_IDLE)
409 return 0;
410
411 r = event_reset_time(ra->event, &ra->timeout_event_source,
412 CLOCK_BOOTTIME,
413 0, 0,
414 radv_timeout, ra,
415 ra->event_priority, "radv-timeout", true);
416 if (r < 0)
417 goto fail;
418
419 r = icmp6_bind_router_advertisement(ra->ifindex);
420 if (r < 0)
421 goto fail;
422
423 ra->fd = r;
424
425 r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
426 if (r < 0)
427 goto fail;
428
429 r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
430 if (r < 0)
431 goto fail;
432
433 (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
434
435 ra->state = RADV_STATE_ADVERTISING;
436
437 log_radv(ra, "Started IPv6 Router Advertisement daemon");
438
439 return 0;
440
441 fail:
442 radv_reset(ra);
443
444 return r;
445 }
446
sd_radv_set_ifindex(sd_radv * ra,int ifindex)447 int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
448 assert_return(ra, -EINVAL);
449 assert_return(ifindex > 0, -EINVAL);
450
451 if (ra->state != RADV_STATE_IDLE)
452 return -EBUSY;
453
454 ra->ifindex = ifindex;
455
456 return 0;
457 }
458
sd_radv_set_ifname(sd_radv * ra,const char * ifname)459 int sd_radv_set_ifname(sd_radv *ra, const char *ifname) {
460 assert_return(ra, -EINVAL);
461 assert_return(ifname, -EINVAL);
462
463 if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
464 return -EINVAL;
465
466 return free_and_strdup(&ra->ifname, ifname);
467 }
468
sd_radv_get_ifname(sd_radv * ra,const char ** ret)469 int sd_radv_get_ifname(sd_radv *ra, const char **ret) {
470 int r;
471
472 assert_return(ra, -EINVAL);
473
474 r = get_ifname(ra->ifindex, &ra->ifname);
475 if (r < 0)
476 return r;
477
478 if (ret)
479 *ret = ra->ifname;
480
481 return 0;
482 }
483
sd_radv_set_mac(sd_radv * ra,const struct ether_addr * mac_addr)484 int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
485 assert_return(ra, -EINVAL);
486
487 if (ra->state != RADV_STATE_IDLE)
488 return -EBUSY;
489
490 if (mac_addr)
491 ra->mac_addr = *mac_addr;
492 else
493 zero(ra->mac_addr);
494
495 return 0;
496 }
497
sd_radv_set_mtu(sd_radv * ra,uint32_t mtu)498 int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
499 assert_return(ra, -EINVAL);
500 assert_return(mtu >= 1280, -EINVAL);
501
502 ra->mtu = mtu;
503
504 return 0;
505 }
506
sd_radv_set_hop_limit(sd_radv * ra,uint8_t hop_limit)507 int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
508 assert_return(ra, -EINVAL);
509
510 if (ra->state != RADV_STATE_IDLE)
511 return -EBUSY;
512
513 ra->hop_limit = hop_limit;
514
515 return 0;
516 }
517
sd_radv_set_router_lifetime(sd_radv * ra,uint64_t lifetime_usec)518 int sd_radv_set_router_lifetime(sd_radv *ra, uint64_t lifetime_usec) {
519 assert_return(ra, -EINVAL);
520
521 if (ra->state != RADV_STATE_IDLE)
522 return -EBUSY;
523
524 if (!router_lifetime_is_valid(lifetime_usec))
525 return -EINVAL;
526
527 /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
528 * to (00) by the sender..." */
529 if (lifetime_usec == 0 &&
530 (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
531 return -EINVAL;
532
533 ra->lifetime_usec = lifetime_usec;
534
535 return 0;
536 }
537
sd_radv_set_managed_information(sd_radv * ra,int managed)538 int sd_radv_set_managed_information(sd_radv *ra, int managed) {
539 assert_return(ra, -EINVAL);
540
541 if (ra->state != RADV_STATE_IDLE)
542 return -EBUSY;
543
544 SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
545
546 return 0;
547 }
548
sd_radv_set_other_information(sd_radv * ra,int other)549 int sd_radv_set_other_information(sd_radv *ra, int other) {
550 assert_return(ra, -EINVAL);
551
552 if (ra->state != RADV_STATE_IDLE)
553 return -EBUSY;
554
555 SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
556
557 return 0;
558 }
559
sd_radv_set_preference(sd_radv * ra,unsigned preference)560 int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
561 assert_return(ra, -EINVAL);
562 assert_return(IN_SET(preference,
563 SD_NDISC_PREFERENCE_LOW,
564 SD_NDISC_PREFERENCE_MEDIUM,
565 SD_NDISC_PREFERENCE_HIGH), -EINVAL);
566
567 /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
568 * to (00) by the sender..." */
569 if (ra->lifetime_usec == 0 && preference != SD_NDISC_PREFERENCE_MEDIUM)
570 return -EINVAL;
571
572 ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
573
574 return 0;
575 }
576
sd_radv_add_prefix(sd_radv * ra,sd_radv_prefix * p)577 int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p) {
578 _cleanup_free_ char *addr_p = NULL;
579 sd_radv_prefix *found = NULL;
580 int r;
581
582 assert_return(ra, -EINVAL);
583 assert_return(p, -EINVAL);
584
585 /* Refuse prefixes that don't have a prefix set */
586 if (in6_addr_is_null(&p->opt.in6_addr))
587 return -ENOEXEC;
588
589 (void) in6_addr_prefix_to_string(&p->opt.in6_addr, p->opt.prefixlen, &addr_p);
590
591 LIST_FOREACH(prefix, cur, ra->prefixes) {
592
593 r = in_addr_prefix_intersect(AF_INET6,
594 (const union in_addr_union*) &cur->opt.in6_addr,
595 cur->opt.prefixlen,
596 (const union in_addr_union*) &p->opt.in6_addr,
597 p->opt.prefixlen);
598 if (r < 0)
599 return r;
600 if (r == 0)
601 continue;
602
603 if (cur->opt.prefixlen == p->opt.prefixlen) {
604 found = cur;
605 break;
606 }
607
608 _cleanup_free_ char *addr_cur = NULL;
609 (void) in6_addr_prefix_to_string(&cur->opt.in6_addr, cur->opt.prefixlen, &addr_cur);
610 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
611 "IPv6 prefix %s conflicts with %s, ignoring.",
612 strna(addr_p), strna(addr_cur));
613 }
614
615 if (found) {
616 /* p and cur may be equivalent. First increment the reference counter. */
617 sd_radv_prefix_ref(p);
618
619 /* Then, remove the old entry. */
620 LIST_REMOVE(prefix, ra->prefixes, found);
621 sd_radv_prefix_unref(found);
622
623 /* Finally, add the new entry. */
624 LIST_APPEND(prefix, ra->prefixes, p);
625
626 log_radv(ra, "Updated/replaced IPv6 prefix %s (preferred: %s, valid: %s)",
627 strna(addr_p),
628 FORMAT_TIMESPAN(p->lifetime_preferred_usec, USEC_PER_SEC),
629 FORMAT_TIMESPAN(p->lifetime_valid_usec, USEC_PER_SEC));
630 } else {
631 /* The prefix is new. Let's simply add it. */
632
633 sd_radv_prefix_ref(p);
634 LIST_APPEND(prefix, ra->prefixes, p);
635 ra->n_prefixes++;
636
637 log_radv(ra, "Added prefix %s", strna(addr_p));
638 }
639
640 if (ra->state == RADV_STATE_IDLE)
641 return 0;
642
643 if (ra->ra_sent == 0)
644 return 0;
645
646 /* If RAs have already been sent, send an RA immediately to announce the newly-added prefix */
647 r = radv_send(ra, NULL, ra->lifetime_usec);
648 if (r < 0)
649 log_radv_errno(ra, r, "Unable to send Router Advertisement for added prefix %s: %m",
650 strna(addr_p));
651 else
652 log_radv(ra, "Sent Router Advertisement for added/updated prefix %s.", strna(addr_p));
653
654 return 0;
655 }
656
sd_radv_remove_prefix(sd_radv * ra,const struct in6_addr * prefix,unsigned char prefixlen)657 void sd_radv_remove_prefix(
658 sd_radv *ra,
659 const struct in6_addr *prefix,
660 unsigned char prefixlen) {
661
662 if (!ra)
663 return;
664
665 if (!prefix)
666 return;
667
668 LIST_FOREACH(prefix, cur, ra->prefixes) {
669 if (prefixlen != cur->opt.prefixlen)
670 continue;
671
672 if (!in6_addr_equal(prefix, &cur->opt.in6_addr))
673 continue;
674
675 LIST_REMOVE(prefix, ra->prefixes, cur);
676 ra->n_prefixes--;
677 sd_radv_prefix_unref(cur);
678 return;
679 }
680 }
681
sd_radv_add_route_prefix(sd_radv * ra,sd_radv_route_prefix * p)682 int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p) {
683 _cleanup_free_ char *addr_p = NULL;
684 sd_radv_route_prefix *found = NULL;
685 int r;
686
687 assert_return(ra, -EINVAL);
688 assert_return(p, -EINVAL);
689
690 (void) in6_addr_prefix_to_string(&p->opt.in6_addr, p->opt.prefixlen, &addr_p);
691
692 LIST_FOREACH(prefix, cur, ra->route_prefixes) {
693
694 r = in_addr_prefix_intersect(AF_INET6,
695 (const union in_addr_union*) &cur->opt.in6_addr,
696 cur->opt.prefixlen,
697 (const union in_addr_union*) &p->opt.in6_addr,
698 p->opt.prefixlen);
699 if (r < 0)
700 return r;
701 if (r == 0)
702 continue;
703
704 if (cur->opt.prefixlen == p->opt.prefixlen) {
705 found = cur;
706 break;
707 }
708
709 _cleanup_free_ char *addr_cur = NULL;
710 (void) in6_addr_prefix_to_string(&cur->opt.in6_addr, cur->opt.prefixlen, &addr_cur);
711 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
712 "IPv6 route prefix %s conflicts with %s, ignoring.",
713 strna(addr_p), strna(addr_cur));
714 }
715
716 if (found) {
717 /* p and cur may be equivalent. First increment the reference counter. */
718 sd_radv_route_prefix_ref(p);
719
720 /* Then, remove the old entry. */
721 LIST_REMOVE(prefix, ra->route_prefixes, found);
722 sd_radv_route_prefix_unref(found);
723
724 /* Finally, add the new entry. */
725 LIST_APPEND(prefix, ra->route_prefixes, p);
726
727 log_radv(ra, "Updated/replaced IPv6 route prefix %s (lifetime: %s)",
728 strna(addr_p),
729 FORMAT_TIMESPAN(p->lifetime_usec, USEC_PER_SEC));
730 } else {
731 /* The route prefix is new. Let's simply add it. */
732
733 sd_radv_route_prefix_ref(p);
734 LIST_APPEND(prefix, ra->route_prefixes, p);
735 ra->n_route_prefixes++;
736
737 log_radv(ra, "Added route prefix %s", strna(addr_p));
738 }
739
740 if (ra->state == RADV_STATE_IDLE)
741 return 0;
742
743 if (ra->ra_sent == 0)
744 return 0;
745
746 /* If RAs have already been sent, send an RA immediately to announce the newly-added route prefix */
747 r = radv_send(ra, NULL, ra->lifetime_usec);
748 if (r < 0)
749 log_radv_errno(ra, r, "Unable to send Router Advertisement for added route prefix %s: %m",
750 strna(addr_p));
751 else
752 log_radv(ra, "Sent Router Advertisement for added route prefix %s.", strna(addr_p));
753
754 return 0;
755 }
756
sd_radv_set_rdnss(sd_radv * ra,uint32_t lifetime,const struct in6_addr * dns,size_t n_dns)757 int sd_radv_set_rdnss(
758 sd_radv *ra,
759 uint32_t lifetime,
760 const struct in6_addr *dns,
761 size_t n_dns) {
762
763 _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
764 size_t len;
765
766 assert_return(ra, -EINVAL);
767 assert_return(n_dns < 128, -EINVAL);
768
769 if (!dns || n_dns == 0) {
770 ra->rdnss = mfree(ra->rdnss);
771 ra->n_rdnss = 0;
772
773 return 0;
774 }
775
776 len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
777
778 opt_rdnss = malloc0(len);
779 if (!opt_rdnss)
780 return -ENOMEM;
781
782 opt_rdnss->type = RADV_OPT_RDNSS;
783 opt_rdnss->length = len / 8;
784 opt_rdnss->lifetime = htobe32(lifetime);
785
786 memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
787
788 free_and_replace(ra->rdnss, opt_rdnss);
789
790 ra->n_rdnss = n_dns;
791
792 return 0;
793 }
794
sd_radv_set_dnssl(sd_radv * ra,uint32_t lifetime,char ** search_list)795 int sd_radv_set_dnssl(
796 sd_radv *ra,
797 uint32_t lifetime,
798 char **search_list) {
799
800 _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
801 size_t len = 0;
802 uint8_t *p;
803
804 assert_return(ra, -EINVAL);
805
806 if (strv_isempty(search_list)) {
807 ra->dnssl = mfree(ra->dnssl);
808 return 0;
809 }
810
811 STRV_FOREACH(s, search_list)
812 len += strlen(*s) + 2;
813
814 len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
815
816 opt_dnssl = malloc0(len);
817 if (!opt_dnssl)
818 return -ENOMEM;
819
820 opt_dnssl->type = RADV_OPT_DNSSL;
821 opt_dnssl->length = len / 8;
822 opt_dnssl->lifetime = htobe32(lifetime);
823
824 p = (uint8_t *)(opt_dnssl + 1);
825 len -= sizeof(struct sd_radv_opt_dns);
826
827 STRV_FOREACH(s, search_list) {
828 int r;
829
830 r = dns_name_to_wire_format(*s, p, len, false);
831 if (r < 0)
832 return r;
833
834 if (len < (size_t)r)
835 return -ENOBUFS;
836
837 p += r;
838 len -= r;
839 }
840
841 free_and_replace(ra->dnssl, opt_dnssl);
842
843 return 0;
844 }
845
sd_radv_prefix_new(sd_radv_prefix ** ret)846 int sd_radv_prefix_new(sd_radv_prefix **ret) {
847 sd_radv_prefix *p;
848
849 assert_return(ret, -EINVAL);
850
851 p = new(sd_radv_prefix, 1);
852 if (!p)
853 return -ENOMEM;
854
855 *p = (sd_radv_prefix) {
856 .n_ref = 1,
857
858 .opt.type = ND_OPT_PREFIX_INFORMATION,
859 .opt.length = (sizeof(p->opt) - 1)/8 + 1,
860 .opt.prefixlen = 64,
861
862 /* RFC 4861, Section 6.2.1 */
863 .opt.flags = ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO,
864
865 .lifetime_valid_usec = RADV_DEFAULT_VALID_LIFETIME_USEC,
866 .lifetime_preferred_usec = RADV_DEFAULT_PREFERRED_LIFETIME_USEC,
867 .valid_until = USEC_INFINITY,
868 .preferred_until = USEC_INFINITY,
869 };
870
871 *ret = p;
872 return 0;
873 }
874
875 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);
876
sd_radv_prefix_set_prefix(sd_radv_prefix * p,const struct in6_addr * in6_addr,unsigned char prefixlen)877 int sd_radv_prefix_set_prefix(
878 sd_radv_prefix *p,
879 const struct in6_addr *in6_addr,
880 unsigned char prefixlen) {
881
882 assert_return(p, -EINVAL);
883 assert_return(in6_addr, -EINVAL);
884
885 if (prefixlen < 3 || prefixlen > 128)
886 return -EINVAL;
887
888 if (prefixlen > 64)
889 /* unusual but allowed, log it */
890 log_radv(NULL, "Unusual prefix length %d greater than 64", prefixlen);
891
892 p->opt.in6_addr = *in6_addr;
893 p->opt.prefixlen = prefixlen;
894
895 return 0;
896 }
897
sd_radv_prefix_get_prefix(sd_radv_prefix * p,struct in6_addr * ret_in6_addr,unsigned char * ret_prefixlen)898 int sd_radv_prefix_get_prefix(
899 sd_radv_prefix *p,
900 struct in6_addr *ret_in6_addr,
901 unsigned char *ret_prefixlen) {
902
903 assert_return(p, -EINVAL);
904 assert_return(ret_in6_addr, -EINVAL);
905 assert_return(ret_prefixlen, -EINVAL);
906
907 *ret_in6_addr = p->opt.in6_addr;
908 *ret_prefixlen = p->opt.prefixlen;
909
910 return 0;
911 }
912
sd_radv_prefix_set_onlink(sd_radv_prefix * p,int onlink)913 int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
914 assert_return(p, -EINVAL);
915
916 SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
917
918 return 0;
919 }
920
sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix * p,int address_autoconfiguration)921 int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p, int address_autoconfiguration) {
922 assert_return(p, -EINVAL);
923
924 SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
925
926 return 0;
927 }
928
sd_radv_prefix_set_valid_lifetime(sd_radv_prefix * p,uint64_t lifetime_usec,uint64_t valid_until)929 int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
930 assert_return(p, -EINVAL);
931
932 p->lifetime_valid_usec = lifetime_usec;
933 p->valid_until = valid_until;
934
935 return 0;
936 }
937
sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix * p,uint64_t lifetime_usec,uint64_t valid_until)938 int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
939 assert_return(p, -EINVAL);
940
941 p->lifetime_preferred_usec = lifetime_usec;
942 p->preferred_until = valid_until;
943
944 return 0;
945 }
946
sd_radv_route_prefix_new(sd_radv_route_prefix ** ret)947 int sd_radv_route_prefix_new(sd_radv_route_prefix **ret) {
948 sd_radv_route_prefix *p;
949
950 assert_return(ret, -EINVAL);
951
952 p = new(sd_radv_route_prefix, 1);
953 if (!p)
954 return -ENOMEM;
955
956 *p = (sd_radv_route_prefix) {
957 .n_ref = 1,
958
959 .opt.type = RADV_OPT_ROUTE_INFORMATION,
960 .opt.length = DIV_ROUND_UP(sizeof(p->opt), 8),
961 .opt.prefixlen = 64,
962
963 .lifetime_usec = RADV_DEFAULT_VALID_LIFETIME_USEC,
964 .valid_until = USEC_INFINITY,
965 };
966
967 *ret = p;
968 return 0;
969 }
970
971 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_route_prefix, sd_radv_route_prefix, mfree);
972
sd_radv_route_prefix_set_prefix(sd_radv_route_prefix * p,const struct in6_addr * in6_addr,unsigned char prefixlen)973 int sd_radv_route_prefix_set_prefix(
974 sd_radv_route_prefix *p,
975 const struct in6_addr *in6_addr,
976 unsigned char prefixlen) {
977
978 assert_return(p, -EINVAL);
979 assert_return(in6_addr, -EINVAL);
980
981 if (prefixlen > 128)
982 return -EINVAL;
983
984 if (prefixlen > 64)
985 /* unusual but allowed, log it */
986 log_radv(NULL, "Unusual prefix length %u greater than 64", prefixlen);
987
988 p->opt.in6_addr = *in6_addr;
989 p->opt.prefixlen = prefixlen;
990
991 return 0;
992 }
993
sd_radv_route_prefix_set_lifetime(sd_radv_route_prefix * p,uint64_t lifetime_usec,uint64_t valid_until)994 int sd_radv_route_prefix_set_lifetime(sd_radv_route_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
995 assert_return(p, -EINVAL);
996
997 p->lifetime_usec = lifetime_usec;
998 p->valid_until = valid_until;
999
1000 return 0;
1001 }
1002