2 This file is part of systemd.
4 Copyright (C) 2014 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/ip6.h>
24 #include <netinet/in.h>
25 #include <sys/ioctl.h>
27 #include "socket-util.h"
31 #include "dhcp6-internal.h"
32 #include "sd-icmp6-nd.h"
34 #define ICMP6_ROUTER_SOLICITATION_INTERVAL 4 * USEC_PER_SEC
35 #define ICMP6_MAX_ROUTER_SOLICITATIONS 3
38 ICMP6_NEIGHBOR_DISCOVERY_IDLE = 0,
39 ICMP6_ROUTER_SOLICITATION_SENT = 10,
40 ICMP6_ROUTER_ADVERTISMENT_LISTEN = 11,
43 #define IP6_MIN_MTU (unsigned)1280
44 #define ICMP6_ND_RECV_SIZE (IP6_MIN_MTU - sizeof(struct ip6_hdr))
45 #define ICMP6_OPT_LEN_UNITS 8
47 typedef struct ICMP6Prefix ICMP6Prefix;
52 LIST_FIELDS(ICMP6Prefix, prefixes);
55 sd_event_source *timeout_valid;
62 enum icmp6_nd_state state;
66 struct ether_addr mac_addr;
68 LIST_HEAD(ICMP6Prefix, prefixes);
70 sd_event_source *recv;
71 sd_event_source *timeout;
73 sd_icmp6_nd_callback_t callback;
77 #define log_icmp6_nd(p, fmt, ...) log_internal(LOG_DEBUG, 0, __FILE__, __LINE__, __func__, "ICMPv6 CLIENT: " fmt, ##__VA_ARGS__)
79 static ICMP6Prefix *icmp6_prefix_unref(ICMP6Prefix *prefix) {
80 if (prefix && REFCNT_DEC(prefix->n_ref) <= 0) {
81 prefix->timeout_valid =
82 sd_event_source_unref(prefix->timeout_valid);
90 static int icmp6_prefix_new(ICMP6Prefix **ret) {
91 _cleanup_free_ ICMP6Prefix *prefix = NULL;
95 prefix = new0(ICMP6Prefix, 1);
99 prefix->n_ref = REFCNT_INIT;
100 LIST_INIT(prefixes, prefix);
108 static void icmp6_nd_notify(sd_icmp6_nd *nd, int event)
111 nd->callback(nd, event, nd->userdata);
114 int sd_icmp6_nd_set_callback(sd_icmp6_nd *nd, sd_icmp6_nd_callback_t callback,
118 nd->callback = callback;
119 nd->userdata = userdata;
124 int sd_icmp6_nd_set_index(sd_icmp6_nd *nd, int interface_index) {
126 assert(interface_index >= -1);
128 nd->index = interface_index;
133 int sd_icmp6_nd_set_mac(sd_icmp6_nd *nd, const struct ether_addr *mac_addr) {
137 memcpy(&nd->mac_addr, mac_addr, sizeof(nd->mac_addr));
145 int sd_icmp6_nd_attach_event(sd_icmp6_nd *nd, sd_event *event, int priority) {
148 assert_return(nd, -EINVAL);
149 assert_return(!nd->event, -EBUSY);
152 nd->event = sd_event_ref(event);
154 r = sd_event_default(&nd->event);
159 nd->event_priority = priority;
164 int sd_icmp6_nd_detach_event(sd_icmp6_nd *nd) {
165 assert_return(nd, -EINVAL);
167 nd->event = sd_event_unref(nd->event);
172 sd_event *sd_icmp6_nd_get_event(sd_icmp6_nd *nd) {
178 sd_icmp6_nd *sd_icmp6_nd_ref(sd_icmp6_nd *nd) {
181 assert_se(REFCNT_INC(nd->n_ref) >= 2);
186 static int icmp6_nd_init(sd_icmp6_nd *nd) {
189 nd->recv = sd_event_source_unref(nd->recv);
190 nd->fd = asynchronous_close(nd->fd);
191 nd->timeout = sd_event_source_unref(nd->timeout);
196 sd_icmp6_nd *sd_icmp6_nd_unref(sd_icmp6_nd *nd) {
197 if (nd && REFCNT_DEC(nd->n_ref) == 0) {
198 ICMP6Prefix *prefix, *p;
201 sd_icmp6_nd_detach_event(nd);
203 LIST_FOREACH_SAFE(prefixes, prefix, p, nd->prefixes) {
204 LIST_REMOVE(prefixes, nd->prefixes, prefix);
206 prefix = icmp6_prefix_unref(prefix);
215 DEFINE_TRIVIAL_CLEANUP_FUNC(sd_icmp6_nd*, sd_icmp6_nd_unref);
216 #define _cleanup_sd_icmp6_nd_free_ _cleanup_(sd_icmp6_nd_unrefp)
218 int sd_icmp6_nd_new(sd_icmp6_nd **ret) {
219 _cleanup_sd_icmp6_nd_free_ sd_icmp6_nd *nd = NULL;
223 nd = new0(sd_icmp6_nd, 1);
227 nd->n_ref = REFCNT_INIT;
232 LIST_HEAD_INIT(nd->prefixes);
240 int sd_icmp6_ra_get_mtu(sd_icmp6_nd *nd, uint32_t *mtu) {
241 assert_return(nd, -EINVAL);
242 assert_return(mtu, -EINVAL);
252 static int icmp6_ra_prefix_timeout(sd_event_source *s, uint64_t usec,
254 sd_icmp6_nd *nd = userdata;
255 ICMP6Prefix *prefix, *p;
259 LIST_FOREACH_SAFE(prefixes, prefix, p, nd->prefixes) {
260 if (prefix->timeout_valid != s)
263 log_icmp6_nd(nd, "Prefix expired "SD_ICMP6_ADDRESS_FORMAT_STR"/%d",
264 SD_ICMP6_ADDRESS_FORMAT_VAL(prefix->addr),
267 LIST_REMOVE(prefixes, nd->prefixes, prefix);
270 ICMP6_EVENT_ROUTER_ADVERTISMENT_PREFIX_EXPIRED);
271 prefix = icmp6_prefix_unref(prefix);
279 static int icmp6_ra_prefix_set_timeout(sd_icmp6_nd *nd,
285 assert_return(prefix, -EINVAL);
287 r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now);
291 prefix->timeout_valid = sd_event_source_unref(prefix->timeout_valid);
293 r = sd_event_add_time(nd->event, &prefix->timeout_valid,
294 clock_boottime_or_monotonic(), time_now + valid,
295 USEC_PER_SEC, icmp6_ra_prefix_timeout, nd);
299 r = sd_event_source_set_priority(prefix->timeout_valid,
304 r = sd_event_source_set_description(prefix->timeout_valid,
305 "icmp6-prefix-timeout");
309 prefix->timeout_valid =
310 sd_event_source_unref(prefix->timeout_valid);
315 static int icmp6_prefix_match(const struct in6_addr *prefix, uint8_t prefixlen,
316 const struct in6_addr *addr,
317 uint8_t addr_prefixlen) {
318 uint8_t bytes, mask, len;
320 assert_return(prefix, -EINVAL);
321 assert_return(addr, -EINVAL);
323 len = MIN(prefixlen, addr_prefixlen);
326 mask = 0xff << (8 - len % 8);
328 if (memcmp(prefix, addr, bytes) != 0 ||
329 (prefix->s6_addr[bytes] & mask) != (addr->s6_addr[bytes] & mask))
330 return -EADDRNOTAVAIL;
335 static int icmp6_ra_prefix_match(ICMP6Prefix *head, const struct in6_addr *addr,
336 uint8_t addr_len, ICMP6Prefix **result) {
339 LIST_FOREACH(prefixes, prefix, head) {
340 if (icmp6_prefix_match(&prefix->addr, prefix->len, addr,
347 return -EADDRNOTAVAIL;
350 int sd_icmp6_prefix_match(struct in6_addr *prefix, uint8_t prefixlen,
351 struct in6_addr *addr) {
352 return icmp6_prefix_match(prefix, prefixlen, addr,
353 sizeof(addr->s6_addr) * 8);
356 int sd_icmp6_ra_get_prefixlen(sd_icmp6_nd *nd, const struct in6_addr *addr,
357 uint8_t *prefixlen) {
361 assert_return(nd, -EINVAL);
362 assert_return(addr, -EINVAL);
363 assert_return(prefixlen, -EINVAL);
365 r = icmp6_ra_prefix_match(nd->prefixes, addr,
366 sizeof(addr->s6_addr) * 8, &prefix);
370 *prefixlen = prefix->len;
375 static int icmp6_ra_prefix_update(sd_icmp6_nd *nd, ssize_t len,
376 const struct nd_opt_prefix_info *prefix_opt) {
380 char time_string[FORMAT_TIMESPAN_MAX];
382 assert_return(nd, -EINVAL);
383 assert_return(prefix_opt, -EINVAL);
385 if (len < prefix_opt->nd_opt_pi_len)
388 if (!(prefix_opt->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK))
391 lifetime = be32toh(prefix_opt->nd_opt_pi_valid_time);
393 r = icmp6_ra_prefix_match(nd->prefixes,
394 &prefix_opt->nd_opt_pi_prefix,
395 prefix_opt->nd_opt_pi_prefix_len, &prefix);
397 if (r < 0 && r != -EADDRNOTAVAIL)
400 /* if router advertisment prefix valid timeout is zero, the timeout
401 callback will be called immediately to clean up the prefix */
403 if (r == -EADDRNOTAVAIL) {
404 r = icmp6_prefix_new(&prefix);
408 prefix->len = prefix_opt->nd_opt_pi_prefix_len;
410 memcpy(&prefix->addr, &prefix_opt->nd_opt_pi_prefix,
411 sizeof(prefix->addr));
413 log_icmp6_nd(nd, "New prefix "SD_ICMP6_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s",
414 SD_ICMP6_ADDRESS_FORMAT_VAL(prefix->addr),
415 prefix->len, lifetime,
416 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
417 lifetime * USEC_PER_SEC, 0));
419 LIST_PREPEND(prefixes, nd->prefixes, prefix);
422 if (prefix->len != prefix_opt->nd_opt_pi_prefix_len) {
425 prefixlen = MIN(prefix->len, prefix_opt->nd_opt_pi_prefix_len);
427 log_icmp6_nd(nd, "Prefix length mismatch %d/%d using %d",
429 prefix_opt->nd_opt_pi_prefix_len,
432 prefix->len = prefixlen;
435 log_icmp6_nd(nd, "Update prefix "SD_ICMP6_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s",
436 SD_ICMP6_ADDRESS_FORMAT_VAL(prefix->addr),
437 prefix->len, lifetime,
438 format_timespan(time_string, FORMAT_TIMESPAN_MAX,
439 lifetime * USEC_PER_SEC, 0));
442 r = icmp6_ra_prefix_set_timeout(nd, prefix, lifetime * USEC_PER_SEC);
447 static int icmp6_ra_parse(sd_icmp6_nd *nd, struct nd_router_advert *ra,
450 struct nd_opt_hdr *opt_hdr;
452 assert_return(nd, -EINVAL);
453 assert_return(ra, -EINVAL);
456 if (len < ICMP6_OPT_LEN_UNITS) {
457 log_icmp6_nd(nd, "Router Advertisement below minimum length");
465 while (len != 0 && len >= opt_hdr->nd_opt_len * ICMP6_OPT_LEN_UNITS) {
466 struct nd_opt_mtu *opt_mtu;
468 struct nd_opt_prefix_info *opt_prefix;
470 if (opt_hdr->nd_opt_len == 0)
473 switch (opt_hdr->nd_opt_type) {
477 mtu = be32toh(opt_mtu->nd_opt_mtu_mtu);
479 if (mtu != nd->mtu) {
480 nd->mtu = MAX(mtu, IP6_MIN_MTU);
482 log_icmp6_nd(nd, "Router Advertisement link MTU %d using %d",
488 case ND_OPT_PREFIX_INFORMATION:
491 icmp6_ra_prefix_update(nd, len, opt_prefix);
496 len -= opt_hdr->nd_opt_len * ICMP6_OPT_LEN_UNITS;
497 opt = (void *)((char *)opt +
498 opt_hdr->nd_opt_len * ICMP6_OPT_LEN_UNITS);
503 log_icmp6_nd(nd, "Router Advertisement contains %zd bytes of trailing garbage", len);
508 static int icmp6_router_advertisment_recv(sd_event_source *s, int fd,
509 uint32_t revents, void *userdata)
511 sd_icmp6_nd *nd = userdata;
514 _cleanup_free_ struct nd_router_advert *ra = NULL;
515 int event = ICMP6_EVENT_ROUTER_ADVERTISMENT_NONE;
521 r = ioctl(fd, FIONREAD, &buflen);
522 if (r < 0 || buflen <= 0)
523 buflen = ICMP6_ND_RECV_SIZE;
529 len = read(fd, ra, buflen);
531 log_icmp6_nd(nd, "Could not receive message from UDP socket: %m");
535 if (ra->nd_ra_type != ND_ROUTER_ADVERT)
538 if (ra->nd_ra_code != 0)
541 nd->timeout = sd_event_source_unref(nd->timeout);
543 nd->state = ICMP6_ROUTER_ADVERTISMENT_LISTEN;
545 if (ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER )
546 event = ICMP6_EVENT_ROUTER_ADVERTISMENT_OTHER;
548 if (ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED)
549 event = ICMP6_EVENT_ROUTER_ADVERTISMENT_MANAGED;
551 log_icmp6_nd(nd, "Received Router Advertisement flags %s/%s",
552 ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED? "MANAGED": "none",
553 ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER? "OTHER": "none");
555 if (event != ICMP6_EVENT_ROUTER_ADVERTISMENT_NONE) {
556 r = icmp6_ra_parse(nd, ra, len);
558 log_icmp6_nd(nd, "Could not parse Router Advertisement: %s",
564 icmp6_nd_notify(nd, event);
569 static int icmp6_router_solicitation_timeout(sd_event_source *s, uint64_t usec,
572 sd_icmp6_nd *nd = userdata;
573 uint64_t time_now, next_timeout;
574 struct ether_addr unset = { };
575 struct ether_addr *addr = NULL;
582 nd->timeout = sd_event_source_unref(nd->timeout);
584 if (nd->nd_sent >= ICMP6_MAX_ROUTER_SOLICITATIONS) {
585 icmp6_nd_notify(nd, ICMP6_EVENT_ROUTER_ADVERTISMENT_TIMEOUT);
586 nd->state = ICMP6_ROUTER_ADVERTISMENT_LISTEN;
588 if (memcmp(&nd->mac_addr, &unset, sizeof(struct ether_addr)))
589 addr = &nd->mac_addr;
591 r = dhcp_network_icmp6_send_router_solicitation(nd->fd, addr);
593 log_icmp6_nd(nd, "Error sending Router Solicitation");
595 nd->state = ICMP6_ROUTER_SOLICITATION_SENT;
596 log_icmp6_nd(nd, "Sent Router Solicitation");
601 r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now);
603 icmp6_nd_notify(nd, r);
607 next_timeout = time_now + ICMP6_ROUTER_SOLICITATION_INTERVAL;
609 r = sd_event_add_time(nd->event, &nd->timeout, clock_boottime_or_monotonic(),
611 icmp6_router_solicitation_timeout, nd);
613 icmp6_nd_notify(nd, r);
617 r = sd_event_source_set_priority(nd->timeout,
620 icmp6_nd_notify(nd, r);
624 r = sd_event_source_set_description(nd->timeout, "icmp6-timeout");
626 icmp6_nd_notify(nd, r);
634 int sd_icmp6_nd_stop(sd_icmp6_nd *nd) {
635 assert_return(nd, -EINVAL);
636 assert_return(nd->event, -EINVAL);
638 log_icmp6_nd(client, "Stop ICMPv6");
642 nd->state = ICMP6_NEIGHBOR_DISCOVERY_IDLE;
647 int sd_icmp6_router_solicitation_start(sd_icmp6_nd *nd) {
653 if (nd->state != ICMP6_NEIGHBOR_DISCOVERY_IDLE)
659 r = dhcp_network_icmp6_bind_router_solicitation(nd->index);
665 r = sd_event_add_io(nd->event, &nd->recv, nd->fd, EPOLLIN,
666 icmp6_router_advertisment_recv, nd);
670 r = sd_event_source_set_priority(nd->recv, nd->event_priority);
674 r = sd_event_source_set_description(nd->recv, "icmp6-receive-message");
678 r = sd_event_add_time(nd->event, &nd->timeout, clock_boottime_or_monotonic(),
679 0, 0, icmp6_router_solicitation_timeout, nd);
683 r = sd_event_source_set_priority(nd->timeout, nd->event_priority);
687 r = sd_event_source_set_description(nd->timeout, "icmp6-timeout");
692 log_icmp6_nd(client, "Start Router Solicitation");