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>
13 #include "alloc-util.h"
14 #include "dns-domain.h"
16 #include "icmp6-util.h"
17 #include "in-addr-util.h"
18 #include "radv-internal.h"
19 #include "socket-util.h"
20 #include "string-util.h"
23 #include "random-util.h"
25 _public_
int sd_radv_new(sd_radv
**ret
) {
26 _cleanup_(sd_radv_unrefp
) sd_radv
*ra
= NULL
;
28 assert_return(ret
, -EINVAL
);
30 ra
= new0(sd_radv
, 1);
37 LIST_HEAD_INIT(ra
->prefixes
);
44 _public_
int sd_radv_attach_event(sd_radv
*ra
, sd_event
*event
, int64_t priority
) {
47 assert_return(ra
, -EINVAL
);
48 assert_return(!ra
->event
, -EBUSY
);
51 ra
->event
= sd_event_ref(event
);
53 r
= sd_event_default(&ra
->event
);
58 ra
->event_priority
= priority
;
63 _public_
int sd_radv_detach_event(sd_radv
*ra
) {
65 assert_return(ra
, -EINVAL
);
67 ra
->event
= sd_event_unref(ra
->event
);
71 _public_ sd_event
*sd_radv_get_event(sd_radv
*ra
) {
72 assert_return(ra
, NULL
);
77 static void radv_reset(sd_radv
*ra
) {
80 ra
->timeout_event_source
=
81 sd_event_source_unref(ra
->timeout_event_source
);
83 ra
->recv_event_source
=
84 sd_event_source_unref(ra
->recv_event_source
);
89 static sd_radv
*radv_free(sd_radv
*ra
) {
92 while (ra
->prefixes
) {
93 sd_radv_prefix
*p
= ra
->prefixes
;
95 LIST_REMOVE(prefix
, ra
->prefixes
, p
);
96 sd_radv_prefix_unref(p
);
104 sd_radv_detach_event(ra
);
106 ra
->fd
= safe_close(ra
->fd
);
111 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv
, sd_radv
, radv_free
);
113 static int radv_send(sd_radv
*ra
, const struct in6_addr
*dst
,
114 const uint32_t router_lifetime
) {
115 static const struct ether_addr mac_zero
= {};
117 struct sockaddr_in6 dst_addr
= {
118 .sin6_family
= AF_INET6
,
119 .sin6_addr
= IN6ADDR_ALL_NODES_MULTICAST_INIT
,
121 struct nd_router_advert adv
= {};
123 struct nd_opt_hdr opthdr
;
124 struct ether_addr slladdr
;
125 } _packed_ opt_mac
= {
127 .nd_opt_type
= ND_OPT_SOURCE_LINKADDR
,
128 .nd_opt_len
= (sizeof(struct nd_opt_hdr
) +
129 sizeof(struct ether_addr
) - 1) /8 + 1,
132 struct nd_opt_mtu opt_mtu
= {
133 .nd_opt_mtu_type
= ND_OPT_MTU
,
136 /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS
138 struct iovec iov
[5 + ra
->n_prefixes
];
139 struct msghdr msg
= {
140 .msg_name
= &dst_addr
,
141 .msg_namelen
= sizeof(dst_addr
),
147 r
= sd_event_now(ra
->event
, clock_boottime_or_monotonic(), &time_now
);
151 if (dst
&& !in_addr_is_null(AF_INET6
, (union in_addr_union
*) dst
))
152 dst_addr
.sin6_addr
= *dst
;
154 adv
.nd_ra_type
= ND_ROUTER_ADVERT
;
155 adv
.nd_ra_curhoplimit
= ra
->hop_limit
;
156 adv
.nd_ra_flags_reserved
= ra
->flags
;
157 adv
.nd_ra_router_lifetime
= htobe16(router_lifetime
);
158 iov
[msg
.msg_iovlen
].iov_base
= &adv
;
159 iov
[msg
.msg_iovlen
].iov_len
= sizeof(adv
);
162 /* MAC address is optional, either because the link does not use L2
163 addresses or load sharing is desired. See RFC 4861, Section 4.2 */
164 if (memcmp(&mac_zero
, &ra
->mac_addr
, sizeof(mac_zero
))) {
165 opt_mac
.slladdr
= ra
->mac_addr
;
166 iov
[msg
.msg_iovlen
].iov_base
= &opt_mac
;
167 iov
[msg
.msg_iovlen
].iov_len
= sizeof(opt_mac
);
172 opt_mtu
.nd_opt_mtu_mtu
= htobe32(ra
->mtu
);
173 iov
[msg
.msg_iovlen
].iov_base
= &opt_mtu
;
174 iov
[msg
.msg_iovlen
].iov_len
= sizeof(opt_mtu
);
178 LIST_FOREACH(prefix
, p
, ra
->prefixes
) {
179 if (p
->valid_until
) {
181 if (time_now
> p
->valid_until
)
182 p
->opt
.valid_lifetime
= 0;
184 p
->opt
.valid_lifetime
= htobe32((p
->valid_until
- time_now
) / USEC_PER_SEC
);
186 if (time_now
> p
->preferred_until
)
187 p
->opt
.preferred_lifetime
= 0;
189 p
->opt
.preferred_lifetime
= htobe32((p
->preferred_until
- time_now
) / USEC_PER_SEC
);
191 iov
[msg
.msg_iovlen
].iov_base
= &p
->opt
;
192 iov
[msg
.msg_iovlen
].iov_len
= sizeof(p
->opt
);
197 iov
[msg
.msg_iovlen
].iov_base
= ra
->rdnss
;
198 iov
[msg
.msg_iovlen
].iov_len
= ra
->rdnss
->length
* 8;
203 iov
[msg
.msg_iovlen
].iov_base
= ra
->dnssl
;
204 iov
[msg
.msg_iovlen
].iov_len
= ra
->dnssl
->length
* 8;
208 if (sendmsg(ra
->fd
, &msg
, 0) < 0)
214 static int radv_recv(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
215 sd_radv
*ra
= userdata
;
216 _cleanup_free_
char *addr
= NULL
;
218 triple_timestamp timestamp
;
221 _cleanup_free_
char *buf
= NULL
;
227 buflen
= next_datagram_size_fd(fd
);
229 if ((unsigned) buflen
< sizeof(struct nd_router_solicit
))
230 return log_radv("Too short packet received");
232 buf
= new0(char, buflen
);
236 r
= icmp6_receive(fd
, buf
, buflen
, &src
, ×tamp
);
240 (void) in_addr_to_string(AF_INET6
, (union in_addr_union
*) &src
, &addr
);
241 log_radv("Received RS from non-link-local address %s. Ignoring", addr
);
245 log_radv("Received RS with invalid hop limit. Ignoring.");
249 log_radv("Received invalid source address from ICMPv6 socket. Ignoring.");
252 case -EAGAIN
: /* ignore spurious wakeups */
256 log_radv_errno(r
, "Unexpected error receiving from ICMPv6 socket: %m");
263 (void) in_addr_to_string(AF_INET6
, (union in_addr_union
*) &src
, &addr
);
265 r
= radv_send(ra
, &src
, ra
->lifetime
);
267 log_radv_errno(r
, "Unable to send solicited Router Advertisement to %s: %m", addr
);
269 log_radv("Sent solicited Router Advertisement to %s", addr
);
274 static usec_t
radv_compute_timeout(usec_t min
, usec_t max
) {
275 assert_return(min
<= max
, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC
);
277 return min
+ (random_u32() % (max
- min
));
280 static int radv_timeout(sd_event_source
*s
, uint64_t usec
, void *userdata
) {
282 sd_radv
*ra
= userdata
;
283 usec_t min_timeout
= SD_RADV_DEFAULT_MIN_TIMEOUT_USEC
;
284 usec_t max_timeout
= SD_RADV_DEFAULT_MAX_TIMEOUT_USEC
;
285 usec_t time_now
, timeout
;
286 char time_string
[FORMAT_TIMESPAN_MAX
];
292 ra
->timeout_event_source
= sd_event_source_unref(ra
->timeout_event_source
);
294 r
= sd_event_now(ra
->event
, clock_boottime_or_monotonic(), &time_now
);
298 r
= radv_send(ra
, NULL
, ra
->lifetime
);
300 log_radv_errno(r
, "Unable to send Router Advertisement: %m");
302 /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
303 if (ra
->ra_sent
< SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS
) {
304 max_timeout
= SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC
;
305 min_timeout
= SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC
/ 3;
308 timeout
= radv_compute_timeout(min_timeout
, max_timeout
);
310 log_radv("Next Router Advertisement in %s",
311 format_timespan(time_string
, FORMAT_TIMESPAN_MAX
,
312 timeout
, USEC_PER_SEC
));
314 r
= sd_event_add_time(ra
->event
, &ra
->timeout_event_source
,
315 clock_boottime_or_monotonic(),
316 time_now
+ timeout
, MSEC_PER_SEC
,
321 r
= sd_event_source_set_priority(ra
->timeout_event_source
,
326 r
= sd_event_source_set_description(ra
->timeout_event_source
,
340 _public_
int sd_radv_stop(sd_radv
*ra
) {
343 assert_return(ra
, -EINVAL
);
345 if (ra
->state
== SD_RADV_STATE_IDLE
)
348 log_radv("Stopping IPv6 Router Advertisement daemon");
350 /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
351 with zero lifetime */
352 r
= radv_send(ra
, NULL
, 0);
354 log_radv_errno(r
, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
357 ra
->fd
= safe_close(ra
->fd
);
358 ra
->state
= SD_RADV_STATE_IDLE
;
363 _public_
int sd_radv_start(sd_radv
*ra
) {
366 assert_return(ra
, -EINVAL
);
367 assert_return(ra
->event
, -EINVAL
);
368 assert_return(ra
->ifindex
> 0, -EINVAL
);
370 if (ra
->state
!= SD_RADV_STATE_IDLE
)
373 r
= sd_event_add_time(ra
->event
, &ra
->timeout_event_source
,
374 clock_boottime_or_monotonic(), 0, 0,
379 r
= sd_event_source_set_priority(ra
->timeout_event_source
,
384 (void) sd_event_source_set_description(ra
->timeout_event_source
,
387 r
= icmp6_bind_router_advertisement(ra
->ifindex
);
393 r
= sd_event_add_io(ra
->event
, &ra
->recv_event_source
, ra
->fd
, EPOLLIN
, radv_recv
, ra
);
397 r
= sd_event_source_set_priority(ra
->recv_event_source
, ra
->event_priority
);
401 (void) sd_event_source_set_description(ra
->recv_event_source
, "radv-receive-message");
403 ra
->state
= SD_RADV_STATE_ADVERTISING
;
405 log_radv("Started IPv6 Router Advertisement daemon");
415 _public_
int sd_radv_set_ifindex(sd_radv
*ra
, int ifindex
) {
416 assert_return(ra
, -EINVAL
);
417 assert_return(ifindex
>= -1, -EINVAL
);
419 if (ra
->state
!= SD_RADV_STATE_IDLE
)
422 ra
->ifindex
= ifindex
;
427 _public_
int sd_radv_set_mac(sd_radv
*ra
, const struct ether_addr
*mac_addr
) {
428 assert_return(ra
, -EINVAL
);
430 if (ra
->state
!= SD_RADV_STATE_IDLE
)
434 ra
->mac_addr
= *mac_addr
;
441 _public_
int sd_radv_set_mtu(sd_radv
*ra
, uint32_t mtu
) {
442 assert_return(ra
, -EINVAL
);
443 assert_return(mtu
>= 1280, -EINVAL
);
450 _public_
int sd_radv_set_hop_limit(sd_radv
*ra
, uint8_t hop_limit
) {
451 assert_return(ra
, -EINVAL
);
453 if (ra
->state
!= SD_RADV_STATE_IDLE
)
456 ra
->hop_limit
= hop_limit
;
461 _public_
int sd_radv_set_router_lifetime(sd_radv
*ra
, uint32_t router_lifetime
) {
462 assert_return(ra
, -EINVAL
);
464 if (ra
->state
!= SD_RADV_STATE_IDLE
)
467 /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
468 preference value MUST be set to (00) by the sender..." */
469 if (router_lifetime
== 0 &&
470 (ra
->flags
& (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM
<< 3))
473 ra
->lifetime
= router_lifetime
;
478 _public_
int sd_radv_set_managed_information(sd_radv
*ra
, int managed
) {
479 assert_return(ra
, -EINVAL
);
481 if (ra
->state
!= SD_RADV_STATE_IDLE
)
484 SET_FLAG(ra
->flags
, ND_RA_FLAG_MANAGED
, managed
);
489 _public_
int sd_radv_set_other_information(sd_radv
*ra
, int other
) {
490 assert_return(ra
, -EINVAL
);
492 if (ra
->state
!= SD_RADV_STATE_IDLE
)
495 SET_FLAG(ra
->flags
, ND_RA_FLAG_OTHER
, other
);
500 _public_
int sd_radv_set_preference(sd_radv
*ra
, unsigned preference
) {
503 assert_return(ra
, -EINVAL
);
504 assert_return(IN_SET(preference
,
505 SD_NDISC_PREFERENCE_LOW
,
506 SD_NDISC_PREFERENCE_MEDIUM
,
507 SD_NDISC_PREFERENCE_HIGH
), -EINVAL
);
509 ra
->flags
= (ra
->flags
& ~(0x3 << 3)) | (preference
<< 3);
514 _public_
int sd_radv_add_prefix(sd_radv
*ra
, sd_radv_prefix
*p
, bool dynamic
) {
517 _cleanup_free_
char *addr_p
= NULL
;
518 char time_string_preferred
[FORMAT_TIMESPAN_MAX
];
519 char time_string_valid
[FORMAT_TIMESPAN_MAX
];
520 usec_t time_now
, valid
, preferred
, valid_until
, preferred_until
;
522 assert_return(ra
, -EINVAL
);
527 LIST_FOREACH(prefix
, cur
, ra
->prefixes
) {
529 r
= in_addr_prefix_intersect(AF_INET6
,
530 (union in_addr_union
*) &cur
->opt
.in6_addr
,
532 (union in_addr_union
*) &p
->opt
.in6_addr
,
535 _cleanup_free_
char *addr_cur
= NULL
;
537 (void) in_addr_to_string(AF_INET6
,
538 (union in_addr_union
*) &p
->opt
.in6_addr
,
541 if (dynamic
&& cur
->opt
.prefixlen
== p
->opt
.prefixlen
)
544 (void) in_addr_to_string(AF_INET6
,
545 (union in_addr_union
*) &cur
->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
);
564 log_radv("Added prefix %s/%d", addr_p
, p
->opt
.prefixlen
);
571 r
= sd_event_now(ra
->event
, clock_boottime_or_monotonic(), &time_now
);
575 valid
= be32toh(p
->opt
.valid_lifetime
) * USEC_PER_SEC
;
576 valid_until
= usec_add(valid
, time_now
);
577 if (valid_until
== USEC_INFINITY
)
580 preferred
= be32toh(p
->opt
.preferred_lifetime
) * USEC_PER_SEC
;
581 preferred_until
= usec_add(preferred
, time_now
);
582 if (preferred_until
== USEC_INFINITY
)
585 cur
->valid_until
= valid_until
;
586 cur
->preferred_until
= preferred_until
;
588 log_radv("%s prefix %s/%u preferred %s valid %s",
589 cur
? "Updated": "Added",
590 addr_p
, p
->opt
.prefixlen
,
591 format_timespan(time_string_preferred
, FORMAT_TIMESPAN_MAX
,
592 preferred
, USEC_PER_SEC
),
593 format_timespan(time_string_valid
, FORMAT_TIMESPAN_MAX
,
594 valid
, USEC_PER_SEC
));
599 _public_ sd_radv_prefix
*sd_radv_remove_prefix(sd_radv
*ra
,
600 const struct in6_addr
*prefix
,
601 unsigned char prefixlen
) {
602 sd_radv_prefix
*cur
, *next
;
604 assert_return(ra
, NULL
);
605 assert_return(prefix
, NULL
);
607 LIST_FOREACH_SAFE(prefix
, cur
, next
, ra
->prefixes
) {
608 if (prefixlen
!= cur
->opt
.prefixlen
)
611 if (!in_addr_equal(AF_INET6
,
612 (union in_addr_union
*)prefix
,
613 (union in_addr_union
*)&cur
->opt
.in6_addr
))
616 LIST_REMOVE(prefix
, ra
->prefixes
, cur
);
625 _public_
int sd_radv_set_rdnss(sd_radv
*ra
, uint32_t lifetime
,
626 const struct in6_addr
*dns
, size_t n_dns
) {
627 _cleanup_free_
struct sd_radv_opt_dns
*opt_rdnss
= NULL
;
630 assert_return(ra
, -EINVAL
);
631 assert_return(n_dns
< 128, -EINVAL
);
633 if (!dns
|| n_dns
== 0) {
634 ra
->rdnss
= mfree(ra
->rdnss
);
640 len
= sizeof(struct sd_radv_opt_dns
) + sizeof(struct in6_addr
) * n_dns
;
642 opt_rdnss
= malloc0(len
);
646 opt_rdnss
->type
= SD_RADV_OPT_RDNSS
;
647 opt_rdnss
->length
= len
/ 8;
648 opt_rdnss
->lifetime
= htobe32(lifetime
);
650 memcpy(opt_rdnss
+ 1, dns
, n_dns
* sizeof(struct in6_addr
));
652 free_and_replace(ra
->rdnss
, opt_rdnss
);
659 _public_
int sd_radv_set_dnssl(sd_radv
*ra
, uint32_t lifetime
,
660 char **search_list
) {
661 _cleanup_free_
struct sd_radv_opt_dns
*opt_dnssl
= NULL
;
666 assert_return(ra
, -EINVAL
);
668 if (strv_isempty(search_list
)) {
669 ra
->dnssl
= mfree(ra
->dnssl
);
673 STRV_FOREACH(s
, search_list
)
674 len
+= strlen(*s
) + 2;
676 len
= (sizeof(struct sd_radv_opt_dns
) + len
+ 7) & ~0x7;
678 opt_dnssl
= malloc0(len
);
682 opt_dnssl
->type
= SD_RADV_OPT_DNSSL
;
683 opt_dnssl
->length
= len
/ 8;
684 opt_dnssl
->lifetime
= htobe32(lifetime
);
686 p
= (uint8_t *)(opt_dnssl
+ 1);
687 len
-= sizeof(struct sd_radv_opt_dns
);
689 STRV_FOREACH(s
, search_list
) {
692 r
= dns_name_to_wire_format(*s
, p
, len
, false);
703 free_and_replace(ra
->dnssl
, opt_dnssl
);
708 _public_
int sd_radv_prefix_new(sd_radv_prefix
**ret
) {
709 _cleanup_(sd_radv_prefix_unrefp
) sd_radv_prefix
*p
= NULL
;
711 assert_return(ret
, -EINVAL
);
713 p
= new0(sd_radv_prefix
, 1);
719 p
->opt
.type
= ND_OPT_PREFIX_INFORMATION
;
720 p
->opt
.length
= (sizeof(p
->opt
) - 1) /8 + 1;
722 p
->opt
.prefixlen
= 64;
724 /* RFC 4861, Section 6.2.1 */
725 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_ONLINK
, true);
726 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_AUTO
, true);
727 p
->opt
.preferred_lifetime
= htobe32(604800);
728 p
->opt
.valid_lifetime
= htobe32(2592000);
730 LIST_INIT(prefix
, p
);
737 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix
, sd_radv_prefix
, mfree
);
739 _public_
int sd_radv_prefix_set_prefix(sd_radv_prefix
*p
, const struct in6_addr
*in6_addr
,
740 unsigned char prefixlen
) {
741 assert_return(p
, -EINVAL
);
742 assert_return(in6_addr
, -EINVAL
);
744 if (prefixlen
< 3 || prefixlen
> 128)
748 /* unusual but allowed, log it */
749 log_radv("Unusual prefix length %d greater than 64", prefixlen
);
751 p
->opt
.in6_addr
= *in6_addr
;
752 p
->opt
.prefixlen
= prefixlen
;
757 _public_
int sd_radv_prefix_set_onlink(sd_radv_prefix
*p
, int onlink
) {
758 assert_return(p
, -EINVAL
);
760 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_ONLINK
, onlink
);
765 _public_
int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix
*p
,
766 int address_autoconfiguration
) {
767 assert_return(p
, -EINVAL
);
769 SET_FLAG(p
->opt
.flags
, ND_OPT_PI_FLAG_AUTO
, address_autoconfiguration
);
774 _public_
int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix
*p
,
775 uint32_t valid_lifetime
) {
776 assert_return(p
, -EINVAL
);
778 p
->opt
.valid_lifetime
= htobe32(valid_lifetime
);
783 _public_
int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix
*p
,
784 uint32_t preferred_lifetime
) {
785 assert_return(p
, -EINVAL
);
787 p
->opt
.preferred_lifetime
= htobe32(preferred_lifetime
);