2 This file is part of systemd.
4 Copyright (C) 2017 Intel Corporation. All rights reserved.
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
20 #include <netinet/icmp6.h>
21 #include <netinet/in.h>
22 #include <arpa/inet.h>
23 #include <linux/in6.h>
28 #include "alloc-util.h"
29 #include "dns-domain.h"
31 #include "icmp6-util.h"
32 #include "in-addr-util.h"
33 #include "radv-internal.h"
34 #include "socket-util.h"
35 #include "string-util.h"
38 #include "random-util.h"
40 _public_
int sd_radv_new(sd_radv
**ret
) {
41 _cleanup_(sd_radv_unrefp
) sd_radv
*ra
= NULL
;
43 assert_return(ret
, -EINVAL
);
45 ra
= new0(sd_radv
, 1);
52 LIST_HEAD_INIT(ra
->prefixes
);
60 _public_
int sd_radv_attach_event(sd_radv
*ra
, sd_event
*event
, int64_t priority
) {
63 assert_return(ra
, -EINVAL
);
64 assert_return(!ra
->event
, -EBUSY
);
67 ra
->event
= sd_event_ref(event
);
69 r
= sd_event_default(&ra
->event
);
74 ra
->event_priority
= priority
;
79 _public_
int sd_radv_detach_event(sd_radv
*ra
) {
81 assert_return(ra
, -EINVAL
);
83 ra
->event
= sd_event_unref(ra
->event
);
87 _public_ sd_event
*sd_radv_get_event(sd_radv
*ra
) {
88 assert_return(ra
, NULL
);
93 static void radv_reset(sd_radv
*ra
) {
95 ra
->timeout_event_source
=
96 sd_event_source_unref(ra
->timeout_event_source
);
98 ra
->recv_event_source
=
99 sd_event_source_unref(ra
->recv_event_source
);
104 _public_ sd_radv
*sd_radv_ref(sd_radv
*ra
) {
108 assert(ra
->n_ref
> 0);
114 _public_ sd_radv
*sd_radv_unref(sd_radv
*ra
) {
118 assert(ra
->n_ref
> 0);
124 while (ra
->prefixes
) {
125 sd_radv_prefix
*p
= ra
->prefixes
;
127 LIST_REMOVE(prefix
, ra
->prefixes
, p
);
128 sd_radv_prefix_unref(p
);
136 sd_radv_detach_event(ra
);
140 static int radv_send(sd_radv
*ra
, const struct in6_addr
*dst
,
141 const uint32_t router_lifetime
) {
142 static const struct ether_addr mac_zero
= {};
144 struct sockaddr_in6 dst_addr
= {
145 .sin6_family
= AF_INET6
,
146 .sin6_addr
= IN6ADDR_ALL_NODES_MULTICAST_INIT
,
148 struct nd_router_advert adv
= {};
150 struct nd_opt_hdr opthdr
;
151 struct ether_addr slladdr
;
152 } _packed_ opt_mac
= {
154 .nd_opt_type
= ND_OPT_SOURCE_LINKADDR
,
155 .nd_opt_len
= (sizeof(struct nd_opt_hdr
) +
156 sizeof(struct ether_addr
) - 1) /8 + 1,
159 struct nd_opt_mtu opt_mtu
= {
160 .nd_opt_mtu_type
= ND_OPT_MTU
,
163 /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS
165 struct iovec iov
[5 + ra
->n_prefixes
];
166 struct msghdr msg
= {
167 .msg_name
= &dst_addr
,
168 .msg_namelen
= sizeof(dst_addr
),
172 if (dst
&& !in_addr_is_null(AF_INET6
, (union in_addr_union
*) dst
))
173 dst_addr
.sin6_addr
= *dst
;
175 adv
.nd_ra_type
= ND_ROUTER_ADVERT
;
176 adv
.nd_ra_curhoplimit
= ra
->hop_limit
;
177 adv
.nd_ra_flags_reserved
= ra
->flags
;
178 adv
.nd_ra_router_lifetime
= htobe16(router_lifetime
);
179 iov
[msg
.msg_iovlen
].iov_base
= &adv
;
180 iov
[msg
.msg_iovlen
].iov_len
= sizeof(adv
);
183 /* MAC address is optional, either because the link does not use L2
184 addresses or load sharing is desired. See RFC 4861, Section 4.2 */
185 if (memcmp(&mac_zero
, &ra
->mac_addr
, sizeof(mac_zero
))) {
186 opt_mac
.slladdr
= ra
->mac_addr
;
187 iov
[msg
.msg_iovlen
].iov_base
= &opt_mac
;
188 iov
[msg
.msg_iovlen
].iov_len
= sizeof(opt_mac
);
193 opt_mtu
.nd_opt_mtu_mtu
= htobe32(ra
->mtu
);
194 iov
[msg
.msg_iovlen
].iov_base
= &opt_mtu
;
195 iov
[msg
.msg_iovlen
].iov_len
= sizeof(opt_mtu
);
199 LIST_FOREACH(prefix
, p
, ra
->prefixes
) {
200 iov
[msg
.msg_iovlen
].iov_base
= &p
->opt
;
201 iov
[msg
.msg_iovlen
].iov_len
= sizeof(p
->opt
);
206 iov
[msg
.msg_iovlen
].iov_base
= ra
->rdnss
;
207 iov
[msg
.msg_iovlen
].iov_len
= ra
->rdnss
->length
* 8;
212 iov
[msg
.msg_iovlen
].iov_base
= ra
->dnssl
;
213 iov
[msg
.msg_iovlen
].iov_len
= ra
->dnssl
->length
* 8;
217 if (sendmsg(ra
->fd
, &msg
, 0) < 0)
223 static int radv_recv(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
224 sd_radv
*ra
= userdata
;
225 _cleanup_free_
char *addr
= NULL
;
227 triple_timestamp timestamp
;
230 _cleanup_free_
char *buf
= NULL
;
236 buflen
= next_datagram_size_fd(fd
);
238 if ((unsigned) buflen
< sizeof(struct nd_router_solicit
))
239 return log_radv("Too short packet received");
241 buf
= new0(char, buflen
);
245 r
= icmp6_receive(fd
, buf
, buflen
, &src
, ×tamp
);
249 (void) in_addr_to_string(AF_INET6
, (union in_addr_union
*) &src
, &addr
);
250 log_radv("Received RS from non-link-local address %s. Ignoring", addr
);
254 log_radv("Received RS with invalid hop limit. Ignoring.");
258 log_radv("Received invalid source address from ICMPv6 socket. Ignoring.");
262 log_radv_warning_errno(r
, "Error receiving from ICMPv6 socket: %m");
269 (void) in_addr_to_string(AF_INET6
, (union in_addr_union
*) &src
, &addr
);
271 r
= radv_send(ra
, &src
, ra
->lifetime
);
273 log_radv_warning_errno(r
, "Unable to send solicited Router Advertisment to %s: %m", addr
);
275 log_radv("Sent solicited Router Advertisement to %s", addr
);
280 static usec_t
radv_compute_timeout(usec_t min
, usec_t max
) {
281 assert_return(min
<= max
, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC
);
283 return min
+ (random_u32() % (max
- min
));
286 static int radv_timeout(sd_event_source
*s
, uint64_t usec
, void *userdata
) {
288 sd_radv
*ra
= userdata
;
289 usec_t min_timeout
= SD_RADV_DEFAULT_MIN_TIMEOUT_USEC
;
290 usec_t max_timeout
= SD_RADV_DEFAULT_MAX_TIMEOUT_USEC
;
291 usec_t time_now
, timeout
;
292 char time_string
[FORMAT_TIMESPAN_MAX
];
298 ra
->timeout_event_source
= sd_event_source_unref(ra
->timeout_event_source
);
300 r
= sd_event_now(ra
->event
, clock_boottime_or_monotonic(), &time_now
);
304 r
= radv_send(ra
, NULL
, ra
->lifetime
);
306 log_radv_warning_errno(r
, "Unable to send Router Advertisement: %m");
308 /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
309 if (ra
->ra_sent
< SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS
) {
310 max_timeout
= SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC
;
311 min_timeout
= SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC
/ 3;
314 timeout
= radv_compute_timeout(min_timeout
, max_timeout
);
316 log_radv("Next Router Advertisement in %s",
317 format_timespan(time_string
, FORMAT_TIMESPAN_MAX
,
318 timeout
, USEC_PER_SEC
));
320 r
= sd_event_add_time(ra
->event
, &ra
->timeout_event_source
,
321 clock_boottime_or_monotonic(),
322 time_now
+ timeout
, MSEC_PER_SEC
,
327 r
= sd_event_source_set_priority(ra
->timeout_event_source
,
332 r
= sd_event_source_set_description(ra
->timeout_event_source
,
346 _public_
int sd_radv_stop(sd_radv
*ra
) {
349 assert_return(ra
, -EINVAL
);
351 log_radv("Stopping IPv6 Router Advertisement daemon");
353 /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
354 with zero lifetime */
355 r
= radv_send(ra
, NULL
, 0);
357 log_radv_warning_errno(r
, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
360 ra
->fd
= safe_close(ra
->fd
);
361 ra
->state
= SD_RADV_STATE_IDLE
;
366 _public_
int sd_radv_start(sd_radv
*ra
) {
369 assert_return(ra
, -EINVAL
);
370 assert_return(ra
->event
, -EINVAL
);
371 assert_return(ra
->ifindex
> 0, -EINVAL
);
373 if (ra
->state
!= SD_RADV_STATE_IDLE
)
376 r
= sd_event_add_time(ra
->event
, &ra
->timeout_event_source
,
377 clock_boottime_or_monotonic(), 0, 0,
382 r
= sd_event_source_set_priority(ra
->timeout_event_source
,
387 (void) sd_event_source_set_description(ra
->timeout_event_source
,
390 r
= icmp6_bind_router_advertisement(ra
->ifindex
);
396 r
= sd_event_add_io(ra
->event
, &ra
->recv_event_source
, ra
->fd
, EPOLLIN
, radv_recv
, ra
);
400 r
= sd_event_source_set_priority(ra
->recv_event_source
, ra
->event_priority
);
404 (void) sd_event_source_set_description(ra
->recv_event_source
, "radv-receive-message");
406 ra
->state
= SD_RADV_STATE_ADVERTISING
;
408 log_radv("Started IPv6 Router Advertisement daemon");
418 _public_
int sd_radv_set_ifindex(sd_radv
*ra
, int ifindex
) {
419 assert_return(ra
, -EINVAL
);
420 assert_return(ifindex
>= -1, -EINVAL
);
422 if (ra
->state
!= SD_RADV_STATE_IDLE
)
425 ra
->ifindex
= ifindex
;
430 _public_
int sd_radv_set_mac(sd_radv
*ra
, const struct ether_addr
*mac_addr
) {
431 assert_return(ra
, -EINVAL
);
433 if (ra
->state
!= SD_RADV_STATE_IDLE
)
437 ra
->mac_addr
= *mac_addr
;
444 _public_
int sd_radv_set_mtu(sd_radv
*ra
, uint32_t mtu
) {
445 assert_return(ra
, -EINVAL
);
446 assert_return(mtu
>= 1280, -EINVAL
);
448 if (ra
->state
!= SD_RADV_STATE_IDLE
)
456 _public_
int sd_radv_set_hop_limit(sd_radv
*ra
, uint8_t hop_limit
) {
457 assert_return(ra
, -EINVAL
);
459 if (ra
->state
!= SD_RADV_STATE_IDLE
)
462 ra
->hop_limit
= hop_limit
;
467 _public_
int sd_radv_set_router_lifetime(sd_radv
*ra
, uint32_t router_lifetime
) {
468 assert_return(ra
, -EINVAL
);
470 if (ra
->state
!= SD_RADV_STATE_IDLE
)
473 /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
474 preference value MUST be set to (00) by the sender..." */
475 if (router_lifetime
== 0 &&
476 (ra
->flags
& (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM
<< 3))
479 ra
->lifetime
= router_lifetime
;
484 _public_
int sd_radv_set_managed_information(sd_radv
*ra
, int managed
) {
485 assert_return(ra
, -EINVAL
);
487 if (ra
->state
!= SD_RADV_STATE_IDLE
)
490 SET_FLAG(ra
->flags
, ND_RA_FLAG_MANAGED
, managed
);
495 _public_
int sd_radv_set_other_information(sd_radv
*ra
, int other
) {
496 assert_return(ra
, -EINVAL
);
498 if (ra
->state
!= SD_RADV_STATE_IDLE
)
501 SET_FLAG(ra
->flags
, ND_RA_FLAG_OTHER
, other
);
506 _public_
int sd_radv_set_preference(sd_radv
*ra
, unsigned preference
) {
509 assert_return(ra
, -EINVAL
);
510 assert_return(IN_SET(preference
,
511 SD_NDISC_PREFERENCE_LOW
,
512 SD_NDISC_PREFERENCE_MEDIUM
,
513 SD_NDISC_PREFERENCE_HIGH
), -EINVAL
);
515 ra
->flags
= (ra
->flags
& ~(0x3 << 3)) | (preference
<< 3);
520 _public_
int sd_radv_add_prefix(sd_radv
*ra
, sd_radv_prefix
*p
) {
522 _cleanup_free_
char *addr_p
= NULL
;
524 assert_return(ra
, -EINVAL
);
529 LIST_FOREACH(prefix
, cur
, ra
->prefixes
) {
532 r
= in_addr_prefix_intersect(AF_INET6
,
533 (union in_addr_union
*) &cur
->opt
.in6_addr
,
535 (union in_addr_union
*) &p
->opt
.in6_addr
,
538 _cleanup_free_
char *addr_cur
= NULL
;
540 (void) in_addr_to_string(AF_INET6
,
541 (union in_addr_union
*) &cur
->opt
.in6_addr
,
543 (void) in_addr_to_string(AF_INET6
,
544 (union in_addr_union
*) &p
->opt
.in6_addr
,
547 log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
548 addr_cur
, cur
->opt
.prefixlen
,
549 addr_p
, p
->opt
.prefixlen
);
555 p
= sd_radv_prefix_ref(p
);
557 LIST_APPEND(prefix
, ra
->prefixes
, p
);
561 (void) in_addr_to_string(AF_INET6
, (union in_addr_union
*) &p
->opt
.in6_addr
, &addr_p
);
562 log_radv("Added prefix %s/%d", addr_p
, p
->opt
.prefixlen
);
567 _public_
int sd_radv_set_rdnss(sd_radv
*ra
, uint32_t lifetime
,
568 const struct in6_addr
*dns
, size_t n_dns
) {
569 _cleanup_free_
struct sd_radv_opt_dns
*opt_rdnss
= NULL
;
572 assert_return(ra
, -EINVAL
);
573 assert_return(n_dns
< 128, -EINVAL
);
575 if (!dns
|| n_dns
== 0) {
576 ra
->rdnss
= mfree(ra
->rdnss
);
582 len
= sizeof(struct sd_radv_opt_dns
) + sizeof(struct in6_addr
) * n_dns
;
584 opt_rdnss
= malloc0(len
);
588 opt_rdnss
->type
= SD_RADV_OPT_RDNSS
;
589 opt_rdnss
->length
= len
/ 8;
590 opt_rdnss
->lifetime
= htobe32(lifetime
);
592 memcpy(opt_rdnss
+ 1, dns
, n_dns
* sizeof(struct in6_addr
));
595 ra
->rdnss
= opt_rdnss
;
603 _public_
int sd_radv_set_dnssl(sd_radv
*ra
, uint32_t lifetime
,
604 char **search_list
) {
605 _cleanup_free_
struct sd_radv_opt_dns
*opt_dnssl
= NULL
;
610 assert_return(ra
, -EINVAL
);
612 if (!search_list
|| *search_list
== NULL
) {
613 ra
->dnssl
= mfree(ra
->dnssl
);
618 STRV_FOREACH(s
, search_list
)
619 len
+= strlen(*s
) + 2;
621 len
= (sizeof(struct sd_radv_opt_dns
) + len
+ 7) & ~0x7;
623 opt_dnssl
= malloc0(len
);
627 opt_dnssl
->type
= SD_RADV_OPT_DNSSL
;
628 opt_dnssl
->length
= len
/ 8;
629 opt_dnssl
->lifetime
= htobe32(lifetime
);
631 p
= (uint8_t *)(opt_dnssl
+ 1);
632 len
-= sizeof(struct sd_radv_opt_dns
);
634 STRV_FOREACH(s
, search_list
) {
637 r
= dns_name_to_wire_format(*s
, p
, len
, false);
649 ra
->dnssl
= opt_dnssl
;
655 _public_
int sd_radv_prefix_new(sd_radv_prefix
**ret
) {
656 _cleanup_(sd_radv_prefix_unrefp
) sd_radv_prefix
*p
= NULL
;
658 assert_return(ret
, -EINVAL
);
660 p
= new0(sd_radv_prefix
, 1);
666 p
->opt
.type
= ND_OPT_PREFIX_INFORMATION
;
667 p
->opt
.length
= (sizeof(p
->opt
) - 1) /8 + 1;
669 p
->opt
.prefixlen
= 64;
671 /* RFC 4861, Section 6.2.1 */
672 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_ONLINK
, true);
673 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_AUTO
, true);
674 p
->opt
.preferred_lifetime
= htobe32(604800);
675 p
->opt
.valid_lifetime
= htobe32(2592000);
677 LIST_INIT(prefix
, p
);
685 _public_ sd_radv_prefix
*sd_radv_prefix_ref(sd_radv_prefix
*p
) {
689 assert(p
->n_ref
> 0);
695 _public_ sd_radv_prefix
*sd_radv_prefix_unref(sd_radv_prefix
*p
) {
699 assert(p
->n_ref
> 0);
708 _public_
int sd_radv_prefix_set_prefix(sd_radv_prefix
*p
, struct in6_addr
*in6_addr
,
709 unsigned char prefixlen
) {
710 assert_return(p
, -EINVAL
);
711 assert_return(in6_addr
, -EINVAL
);
713 if (prefixlen
< 3 || prefixlen
> 128)
717 /* unusual but allowed, log it */
718 log_radv("Unusual prefix length %d greater than 64", prefixlen
);
720 p
->opt
.in6_addr
= *in6_addr
;
721 p
->opt
.prefixlen
= prefixlen
;
726 _public_
int sd_radv_prefix_set_onlink(sd_radv_prefix
*p
, int onlink
) {
727 assert_return(p
, -EINVAL
);
729 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_ONLINK
, onlink
);
734 _public_
int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix
*p
,
735 int address_autoconfiguration
) {
736 assert_return(p
, -EINVAL
);
738 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_AUTO
, address_autoconfiguration
);
743 _public_
int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix
*p
,
744 uint32_t valid_lifetime
) {
745 assert_return(p
, -EINVAL
);
747 p
->opt
.valid_lifetime
= htobe32(valid_lifetime
);
752 _public_
int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix
*p
,
753 uint32_t preferred_lifetime
) {
754 assert_return(p
, -EINVAL
);
756 p
->opt
.preferred_lifetime
= htobe32(preferred_lifetime
);