1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 Copyright © 2017 Intel Corporation. All rights reserved.
6 #include <netinet/icmp6.h>
7 #include <netinet/in.h>
12 #include "alloc-util.h"
13 #include "dns-domain.h"
14 #include "ether-addr-util.h"
15 #include "event-util.h"
17 #include "icmp6-util.h"
18 #include "in-addr-util.h"
21 #include "radv-internal.h"
22 #include "random-util.h"
23 #include "socket-util.h"
24 #include "string-util.h"
28 _public_
int sd_radv_new(sd_radv
**ret
) {
29 _cleanup_(sd_radv_unrefp
) sd_radv
*ra
= NULL
;
31 assert_return(ret
, -EINVAL
);
47 _public_
int sd_radv_attach_event(sd_radv
*ra
, sd_event
*event
, int64_t priority
) {
50 assert_return(ra
, -EINVAL
);
51 assert_return(!ra
->event
, -EBUSY
);
54 ra
->event
= sd_event_ref(event
);
56 r
= sd_event_default(&ra
->event
);
61 ra
->event_priority
= priority
;
66 _public_
int sd_radv_detach_event(sd_radv
*ra
) {
68 assert_return(ra
, -EINVAL
);
70 ra
->event
= sd_event_unref(ra
->event
);
74 _public_ sd_event
*sd_radv_get_event(sd_radv
*ra
) {
75 assert_return(ra
, NULL
);
80 static void radv_reset(sd_radv
*ra
) {
83 (void) event_source_disable(ra
->timeout_event_source
);
85 ra
->recv_event_source
=
86 sd_event_source_unref(ra
->recv_event_source
);
91 static sd_radv
*radv_free(sd_radv
*ra
) {
95 while (ra
->prefixes
) {
96 sd_radv_prefix
*p
= ra
->prefixes
;
98 LIST_REMOVE(prefix
, ra
->prefixes
, p
);
99 sd_radv_prefix_unref(p
);
105 ra
->timeout_event_source
= sd_event_source_unref(ra
->timeout_event_source
);
109 sd_radv_detach_event(ra
);
111 ra
->fd
= safe_close(ra
->fd
);
116 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv
, sd_radv
, radv_free
);
118 static int radv_send(sd_radv
*ra
, const struct in6_addr
*dst
, uint32_t router_lifetime
) {
120 struct sockaddr_in6 dst_addr
= {
121 .sin6_family
= AF_INET6
,
122 .sin6_addr
= IN6ADDR_ALL_NODES_MULTICAST_INIT
,
124 struct nd_router_advert adv
= {};
126 struct nd_opt_hdr opthdr
;
127 struct ether_addr slladdr
;
128 } _packed_ opt_mac
= {
130 .nd_opt_type
= ND_OPT_SOURCE_LINKADDR
,
131 .nd_opt_len
= (sizeof(struct nd_opt_hdr
) +
132 sizeof(struct ether_addr
) - 1) /8 + 1,
135 struct nd_opt_mtu opt_mtu
= {
136 .nd_opt_mtu_type
= ND_OPT_MTU
,
139 /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS
141 struct iovec iov
[5 + ra
->n_prefixes
];
142 struct msghdr msg
= {
143 .msg_name
= &dst_addr
,
144 .msg_namelen
= sizeof(dst_addr
),
152 r
= sd_event_now(ra
->event
, clock_boottime_or_monotonic(), &time_now
);
156 if (dst
&& !IN6_IS_ADDR_UNSPECIFIED(dst
))
157 dst_addr
.sin6_addr
= *dst
;
159 adv
.nd_ra_type
= ND_ROUTER_ADVERT
;
160 adv
.nd_ra_curhoplimit
= ra
->hop_limit
;
161 adv
.nd_ra_flags_reserved
= ra
->flags
;
162 adv
.nd_ra_router_lifetime
= htobe16(router_lifetime
);
163 iov
[msg
.msg_iovlen
++] = IOVEC_MAKE(&adv
, sizeof(adv
));
165 /* MAC address is optional, either because the link does not use L2
166 addresses or load sharing is desired. See RFC 4861, Section 4.2 */
167 if (!ether_addr_is_null(&ra
->mac_addr
)) {
168 opt_mac
.slladdr
= ra
->mac_addr
;
169 iov
[msg
.msg_iovlen
++] = IOVEC_MAKE(&opt_mac
, sizeof(opt_mac
));
173 opt_mtu
.nd_opt_mtu_mtu
= htobe32(ra
->mtu
);
174 iov
[msg
.msg_iovlen
++] = IOVEC_MAKE(&opt_mtu
, sizeof(opt_mtu
));
177 LIST_FOREACH(prefix
, p
, ra
->prefixes
) {
178 if (p
->valid_until
) {
180 if (time_now
> p
->valid_until
)
181 p
->opt
.valid_lifetime
= 0;
183 p
->opt
.valid_lifetime
= htobe32((p
->valid_until
- time_now
) / USEC_PER_SEC
);
185 if (time_now
> p
->preferred_until
)
186 p
->opt
.preferred_lifetime
= 0;
188 p
->opt
.preferred_lifetime
= htobe32((p
->preferred_until
- time_now
) / USEC_PER_SEC
);
190 iov
[msg
.msg_iovlen
++] = IOVEC_MAKE(&p
->opt
, sizeof(p
->opt
));
194 iov
[msg
.msg_iovlen
++] = IOVEC_MAKE(ra
->rdnss
, ra
->rdnss
->length
* 8);
197 iov
[msg
.msg_iovlen
++] = IOVEC_MAKE(ra
->dnssl
, ra
->dnssl
->length
* 8);
199 if (sendmsg(ra
->fd
, &msg
, 0) < 0)
205 static int radv_recv(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
206 sd_radv
*ra
= userdata
;
207 _cleanup_free_
char *addr
= NULL
;
209 triple_timestamp timestamp
;
212 _cleanup_free_
char *buf
= NULL
;
218 buflen
= next_datagram_size_fd(fd
);
222 buf
= new0(char, buflen
);
226 r
= icmp6_receive(fd
, buf
, buflen
, &src
, ×tamp
);
230 (void) in_addr_to_string(AF_INET6
, (union in_addr_union
*) &src
, &addr
);
231 log_radv("Received RS from non-link-local address %s. Ignoring", addr
);
235 log_radv("Received RS with invalid hop limit. Ignoring.");
239 log_radv("Received invalid source address from ICMPv6 socket. Ignoring.");
242 case -EAGAIN
: /* ignore spurious wakeups */
246 log_radv_errno(r
, "Unexpected error receiving from ICMPv6 socket: %m");
253 if ((size_t) buflen
< sizeof(struct nd_router_solicit
)) {
254 log_radv("Too short packet received");
258 (void) in_addr_to_string(AF_INET6
, (union in_addr_union
*) &src
, &addr
);
260 r
= radv_send(ra
, &src
, ra
->lifetime
);
262 log_radv_errno(r
, "Unable to send solicited Router Advertisement to %s: %m", strnull(addr
));
264 log_radv("Sent solicited Router Advertisement to %s", strnull(addr
));
269 static usec_t
radv_compute_timeout(usec_t min
, usec_t max
) {
270 assert_return(min
<= max
, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC
);
272 return min
+ (random_u32() % (max
- min
));
275 static int radv_timeout(sd_event_source
*s
, uint64_t usec
, void *userdata
) {
277 sd_radv
*ra
= userdata
;
278 usec_t min_timeout
= SD_RADV_DEFAULT_MIN_TIMEOUT_USEC
;
279 usec_t max_timeout
= SD_RADV_DEFAULT_MAX_TIMEOUT_USEC
;
280 usec_t time_now
, timeout
;
281 char time_string
[FORMAT_TIMESPAN_MAX
];
287 r
= sd_event_now(ra
->event
, clock_boottime_or_monotonic(), &time_now
);
291 r
= radv_send(ra
, NULL
, ra
->lifetime
);
293 log_radv_errno(r
, "Unable to send Router Advertisement: %m");
295 /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
296 if (ra
->ra_sent
< SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS
) {
297 max_timeout
= SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC
;
298 min_timeout
= SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC
/ 3;
301 timeout
= radv_compute_timeout(min_timeout
, max_timeout
);
303 log_radv("Next Router Advertisement in %s",
304 format_timespan(time_string
, FORMAT_TIMESPAN_MAX
,
305 timeout
, USEC_PER_SEC
));
307 r
= event_reset_time(ra
->event
, &ra
->timeout_event_source
,
308 clock_boottime_or_monotonic(),
309 time_now
+ timeout
, MSEC_PER_SEC
,
311 ra
->event_priority
, "radv-timeout", true);
325 _public_
int sd_radv_stop(sd_radv
*ra
) {
328 assert_return(ra
, -EINVAL
);
330 if (ra
->state
== SD_RADV_STATE_IDLE
)
333 log_radv("Stopping IPv6 Router Advertisement daemon");
335 /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
336 with zero lifetime */
337 r
= radv_send(ra
, NULL
, 0);
339 log_radv_errno(r
, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
342 ra
->fd
= safe_close(ra
->fd
);
343 ra
->state
= SD_RADV_STATE_IDLE
;
348 _public_
int sd_radv_start(sd_radv
*ra
) {
351 assert_return(ra
, -EINVAL
);
352 assert_return(ra
->event
, -EINVAL
);
353 assert_return(ra
->ifindex
> 0, -EINVAL
);
355 if (ra
->state
!= SD_RADV_STATE_IDLE
)
358 r
= event_reset_time(ra
->event
, &ra
->timeout_event_source
,
359 clock_boottime_or_monotonic(),
362 ra
->event_priority
, "radv-timeout", true);
366 r
= icmp6_bind_router_advertisement(ra
->ifindex
);
372 r
= sd_event_add_io(ra
->event
, &ra
->recv_event_source
, ra
->fd
, EPOLLIN
, radv_recv
, ra
);
376 r
= sd_event_source_set_priority(ra
->recv_event_source
, ra
->event_priority
);
380 (void) sd_event_source_set_description(ra
->recv_event_source
, "radv-receive-message");
382 ra
->state
= SD_RADV_STATE_ADVERTISING
;
384 log_radv("Started IPv6 Router Advertisement daemon");
394 _public_
int sd_radv_set_ifindex(sd_radv
*ra
, int ifindex
) {
395 assert_return(ra
, -EINVAL
);
396 assert_return(ifindex
>= -1, -EINVAL
);
398 if (ra
->state
!= SD_RADV_STATE_IDLE
)
401 ra
->ifindex
= ifindex
;
406 _public_
int sd_radv_set_mac(sd_radv
*ra
, const struct ether_addr
*mac_addr
) {
407 assert_return(ra
, -EINVAL
);
409 if (ra
->state
!= SD_RADV_STATE_IDLE
)
413 ra
->mac_addr
= *mac_addr
;
420 _public_
int sd_radv_set_mtu(sd_radv
*ra
, uint32_t mtu
) {
421 assert_return(ra
, -EINVAL
);
422 assert_return(mtu
>= 1280, -EINVAL
);
429 _public_
int sd_radv_set_hop_limit(sd_radv
*ra
, uint8_t hop_limit
) {
430 assert_return(ra
, -EINVAL
);
432 if (ra
->state
!= SD_RADV_STATE_IDLE
)
435 ra
->hop_limit
= hop_limit
;
440 _public_
int sd_radv_set_router_lifetime(sd_radv
*ra
, uint32_t router_lifetime
) {
441 assert_return(ra
, -EINVAL
);
443 if (ra
->state
!= SD_RADV_STATE_IDLE
)
446 /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
447 preference value MUST be set to (00) by the sender..." */
448 if (router_lifetime
== 0 &&
449 (ra
->flags
& (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM
<< 3))
452 ra
->lifetime
= router_lifetime
;
457 _public_
int sd_radv_set_managed_information(sd_radv
*ra
, int managed
) {
458 assert_return(ra
, -EINVAL
);
460 if (ra
->state
!= SD_RADV_STATE_IDLE
)
463 SET_FLAG(ra
->flags
, ND_RA_FLAG_MANAGED
, managed
);
468 _public_
int sd_radv_set_other_information(sd_radv
*ra
, int other
) {
469 assert_return(ra
, -EINVAL
);
471 if (ra
->state
!= SD_RADV_STATE_IDLE
)
474 SET_FLAG(ra
->flags
, ND_RA_FLAG_OTHER
, other
);
479 _public_
int sd_radv_set_preference(sd_radv
*ra
, unsigned preference
) {
482 assert_return(ra
, -EINVAL
);
483 assert_return(IN_SET(preference
,
484 SD_NDISC_PREFERENCE_LOW
,
485 SD_NDISC_PREFERENCE_MEDIUM
,
486 SD_NDISC_PREFERENCE_HIGH
), -EINVAL
);
488 ra
->flags
= (ra
->flags
& ~(0x3 << 3)) | (preference
<< 3);
493 _public_
int sd_radv_add_prefix(sd_radv
*ra
, sd_radv_prefix
*p
, int dynamic
) {
496 _cleanup_free_
char *addr_p
= NULL
;
497 char time_string_preferred
[FORMAT_TIMESPAN_MAX
];
498 char time_string_valid
[FORMAT_TIMESPAN_MAX
];
499 usec_t time_now
, valid
, preferred
, valid_until
, preferred_until
;
501 assert_return(ra
, -EINVAL
);
506 /* Refuse prefixes that don't have a prefix set */
507 if (IN6_IS_ADDR_UNSPECIFIED(&p
->opt
.in6_addr
))
510 LIST_FOREACH(prefix
, cur
, ra
->prefixes
) {
512 r
= in_addr_prefix_intersect(AF_INET6
,
513 (union in_addr_union
*) &cur
->opt
.in6_addr
,
515 (union in_addr_union
*) &p
->opt
.in6_addr
,
518 _cleanup_free_
char *addr_cur
= NULL
;
520 (void) in_addr_to_string(AF_INET6
,
521 (union in_addr_union
*) &p
->opt
.in6_addr
,
524 if (dynamic
&& cur
->opt
.prefixlen
== p
->opt
.prefixlen
)
527 (void) in_addr_to_string(AF_INET6
,
528 (union in_addr_union
*) &cur
->opt
.in6_addr
,
530 log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
531 addr_cur
, cur
->opt
.prefixlen
,
532 addr_p
, p
->opt
.prefixlen
);
538 p
= sd_radv_prefix_ref(p
);
540 LIST_APPEND(prefix
, ra
->prefixes
, p
);
544 (void) in_addr_to_string(AF_INET6
, (union in_addr_union
*) &p
->opt
.in6_addr
, &addr_p
);
547 log_radv("Added prefix %s/%d", addr_p
, p
->opt
.prefixlen
);
554 r
= sd_event_now(ra
->event
, clock_boottime_or_monotonic(), &time_now
);
558 valid
= be32toh(p
->opt
.valid_lifetime
) * USEC_PER_SEC
;
559 valid_until
= usec_add(valid
, time_now
);
560 if (valid_until
== USEC_INFINITY
)
563 preferred
= be32toh(p
->opt
.preferred_lifetime
) * USEC_PER_SEC
;
564 preferred_until
= usec_add(preferred
, time_now
);
565 if (preferred_until
== USEC_INFINITY
)
568 cur
->valid_until
= valid_until
;
569 cur
->preferred_until
= preferred_until
;
571 log_radv("%s prefix %s/%u preferred %s valid %s",
572 cur
? "Updated": "Added",
573 addr_p
, p
->opt
.prefixlen
,
574 format_timespan(time_string_preferred
, FORMAT_TIMESPAN_MAX
,
575 preferred
, USEC_PER_SEC
),
576 format_timespan(time_string_valid
, FORMAT_TIMESPAN_MAX
,
577 valid
, USEC_PER_SEC
));
582 _public_ sd_radv_prefix
*sd_radv_remove_prefix(sd_radv
*ra
,
583 const struct in6_addr
*prefix
,
584 unsigned char prefixlen
) {
585 sd_radv_prefix
*cur
, *next
;
587 assert_return(ra
, NULL
);
588 assert_return(prefix
, NULL
);
590 LIST_FOREACH_SAFE(prefix
, cur
, next
, ra
->prefixes
) {
591 if (prefixlen
!= cur
->opt
.prefixlen
)
594 if (!in_addr_equal(AF_INET6
,
595 (union in_addr_union
*)prefix
,
596 (union in_addr_union
*)&cur
->opt
.in6_addr
))
599 LIST_REMOVE(prefix
, ra
->prefixes
, cur
);
608 _public_
int sd_radv_set_rdnss(sd_radv
*ra
, uint32_t lifetime
,
609 const struct in6_addr
*dns
, size_t n_dns
) {
610 _cleanup_free_
struct sd_radv_opt_dns
*opt_rdnss
= NULL
;
613 assert_return(ra
, -EINVAL
);
614 assert_return(n_dns
< 128, -EINVAL
);
616 if (!dns
|| n_dns
== 0) {
617 ra
->rdnss
= mfree(ra
->rdnss
);
623 len
= sizeof(struct sd_radv_opt_dns
) + sizeof(struct in6_addr
) * n_dns
;
625 opt_rdnss
= malloc0(len
);
629 opt_rdnss
->type
= SD_RADV_OPT_RDNSS
;
630 opt_rdnss
->length
= len
/ 8;
631 opt_rdnss
->lifetime
= htobe32(lifetime
);
633 memcpy(opt_rdnss
+ 1, dns
, n_dns
* sizeof(struct in6_addr
));
635 free_and_replace(ra
->rdnss
, opt_rdnss
);
642 _public_
int sd_radv_set_dnssl(sd_radv
*ra
, uint32_t lifetime
,
643 char **search_list
) {
644 _cleanup_free_
struct sd_radv_opt_dns
*opt_dnssl
= NULL
;
649 assert_return(ra
, -EINVAL
);
651 if (strv_isempty(search_list
)) {
652 ra
->dnssl
= mfree(ra
->dnssl
);
656 STRV_FOREACH(s
, search_list
)
657 len
+= strlen(*s
) + 2;
659 len
= (sizeof(struct sd_radv_opt_dns
) + len
+ 7) & ~0x7;
661 opt_dnssl
= malloc0(len
);
665 opt_dnssl
->type
= SD_RADV_OPT_DNSSL
;
666 opt_dnssl
->length
= len
/ 8;
667 opt_dnssl
->lifetime
= htobe32(lifetime
);
669 p
= (uint8_t *)(opt_dnssl
+ 1);
670 len
-= sizeof(struct sd_radv_opt_dns
);
672 STRV_FOREACH(s
, search_list
) {
675 r
= dns_name_to_wire_format(*s
, p
, len
, false);
686 free_and_replace(ra
->dnssl
, opt_dnssl
);
691 _public_
int sd_radv_prefix_new(sd_radv_prefix
**ret
) {
694 assert_return(ret
, -EINVAL
);
696 p
= new(sd_radv_prefix
, 1);
700 *p
= (sd_radv_prefix
) {
703 .opt
.type
= ND_OPT_PREFIX_INFORMATION
,
704 .opt
.length
= (sizeof(p
->opt
) - 1)/8 + 1,
707 /* RFC 4861, Section 6.2.1 */
708 .opt
.flags
= ND_OPT_PI_FLAG_ONLINK
|ND_OPT_PI_FLAG_AUTO
,
710 .opt
.preferred_lifetime
= htobe32(604800),
711 .opt
.valid_lifetime
= htobe32(2592000),
718 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix
, sd_radv_prefix
, mfree
);
720 _public_
int sd_radv_prefix_set_prefix(sd_radv_prefix
*p
, const struct in6_addr
*in6_addr
,
721 unsigned char prefixlen
) {
722 assert_return(p
, -EINVAL
);
723 assert_return(in6_addr
, -EINVAL
);
725 if (prefixlen
< 3 || prefixlen
> 128)
729 /* unusual but allowed, log it */
730 log_radv("Unusual prefix length %d greater than 64", prefixlen
);
732 p
->opt
.in6_addr
= *in6_addr
;
733 p
->opt
.prefixlen
= prefixlen
;
738 _public_
int sd_radv_prefix_set_onlink(sd_radv_prefix
*p
, int onlink
) {
739 assert_return(p
, -EINVAL
);
741 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_ONLINK
, onlink
);
746 _public_
int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix
*p
,
747 int address_autoconfiguration
) {
748 assert_return(p
, -EINVAL
);
750 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_AUTO
, address_autoconfiguration
);
755 _public_
int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix
*p
,
756 uint32_t valid_lifetime
) {
757 assert_return(p
, -EINVAL
);
759 p
->opt
.valid_lifetime
= htobe32(valid_lifetime
);
764 _public_
int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix
*p
,
765 uint32_t preferred_lifetime
) {
766 assert_return(p
, -EINVAL
);
768 p
->opt
.preferred_lifetime
= htobe32(preferred_lifetime
);