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e3169126 PF |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright (C) 2014 Intel Corporation. All rights reserved. | |
5 | ||
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. | |
10 | ||
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. | |
15 | ||
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/>. | |
18 | ***/ | |
19 | ||
20 | #include <netinet/icmp6.h> | |
07630cea | 21 | #include <netinet/in.h> |
09667885 | 22 | #include <netinet/ip6.h> |
e3169126 | 23 | #include <stdbool.h> |
07630cea | 24 | #include <string.h> |
09667885 | 25 | #include <sys/ioctl.h> |
e3169126 | 26 | |
07630cea LP |
27 | #include "sd-ndisc.h" |
28 | ||
b5efdb8a | 29 | #include "alloc-util.h" |
e3169126 | 30 | #include "async.h" |
07630cea | 31 | #include "icmp6-util.h" |
9d96e6c3 | 32 | #include "in-addr-util.h" |
940367a0 TG |
33 | #include "list.h" |
34 | #include "socket-util.h" | |
d7fa4380 | 35 | #include "string-util.h" |
e3169126 | 36 | |
9c2438b8 LP |
37 | #define NDISC_ROUTER_SOLICITATION_INTERVAL (4U * USEC_PER_SEC) |
38 | #define NDISC_MAX_ROUTER_SOLICITATIONS 3U | |
e3169126 | 39 | |
46ec6687 | 40 | enum NDiscState { |
c93578f5 TG |
41 | NDISC_STATE_IDLE, |
42 | NDISC_STATE_SOLICITATION_SENT, | |
d54b734a | 43 | NDISC_STATE_ADVERTISEMENT_LISTEN, |
c93578f5 TG |
44 | _NDISC_STATE_MAX, |
45 | _NDISC_STATE_INVALID = -1, | |
e3169126 PF |
46 | }; |
47 | ||
9c2438b8 | 48 | #define IP6_MIN_MTU 1280U |
46ec6687 | 49 | #define ICMP6_RECV_SIZE (IP6_MIN_MTU - sizeof(struct ip6_hdr)) |
9c2438b8 | 50 | #define NDISC_OPT_LEN_UNITS 8U |
09667885 | 51 | |
9d96e6c3 TG |
52 | #define ND_RA_FLAG_PREF 0x18 |
53 | #define ND_RA_FLAG_PREF_LOW 0x03 | |
54 | #define ND_RA_FLAG_PREF_MEDIUM 0x0 | |
55 | #define ND_RA_FLAG_PREF_HIGH 0x1 | |
56 | #define ND_RA_FLAG_PREF_INVALID 0x2 | |
57 | ||
46ec6687 | 58 | typedef struct NDiscPrefix NDiscPrefix; |
5624c480 | 59 | |
46ec6687 | 60 | struct NDiscPrefix { |
9c8e3101 | 61 | unsigned n_ref; |
5624c480 | 62 | |
272f5cd9 TG |
63 | sd_ndisc *nd; |
64 | ||
46ec6687 | 65 | LIST_FIELDS(NDiscPrefix, prefixes); |
5624c480 PF |
66 | |
67 | uint8_t len; | |
f6e0ce66 | 68 | usec_t valid_until; |
5624c480 PF |
69 | struct in6_addr addr; |
70 | }; | |
71 | ||
4d7b83da | 72 | struct sd_ndisc { |
9c8e3101 | 73 | unsigned n_ref; |
e3169126 | 74 | |
46ec6687 | 75 | enum NDiscState state; |
e3169126 PF |
76 | sd_event *event; |
77 | int event_priority; | |
2f8e7633 | 78 | int ifindex; |
e3169126 | 79 | struct ether_addr mac_addr; |
5624c480 | 80 | uint32_t mtu; |
46ec6687 | 81 | LIST_HEAD(NDiscPrefix, prefixes); |
e3169126 PF |
82 | int fd; |
83 | sd_event_source *recv; | |
84 | sd_event_source *timeout; | |
9c2438b8 | 85 | unsigned nd_sent; |
9d96e6c3 TG |
86 | sd_ndisc_router_callback_t router_callback; |
87 | sd_ndisc_prefix_autonomous_callback_t prefix_autonomous_callback; | |
88 | sd_ndisc_prefix_onlink_callback_t prefix_onlink_callback; | |
4d7b83da | 89 | sd_ndisc_callback_t callback; |
e3169126 PF |
90 | void *userdata; |
91 | }; | |
92 | ||
46ec6687 | 93 | #define log_ndisc(p, fmt, ...) log_internal(LOG_DEBUG, 0, __FILE__, __LINE__, __func__, "NDisc CLIENT: " fmt, ##__VA_ARGS__) |
e3169126 | 94 | |
46ec6687 | 95 | static NDiscPrefix *ndisc_prefix_unref(NDiscPrefix *prefix) { |
5624c480 | 96 | |
9c8e3101 LP |
97 | if (!prefix) |
98 | return NULL; | |
99 | ||
100 | assert(prefix->n_ref > 0); | |
101 | prefix->n_ref--; | |
102 | ||
103 | if (prefix->n_ref > 0) | |
104 | return NULL; | |
5624c480 | 105 | |
272f5cd9 TG |
106 | if (prefix->nd) |
107 | LIST_REMOVE(prefixes, prefix->nd->prefixes, prefix); | |
108 | ||
9c8e3101 | 109 | free(prefix); |
272f5cd9 | 110 | |
5624c480 PF |
111 | return NULL; |
112 | } | |
113 | ||
272f5cd9 | 114 | static int ndisc_prefix_new(sd_ndisc *nd, NDiscPrefix **ret) { |
b0e6520c | 115 | NDiscPrefix *prefix; |
5624c480 PF |
116 | |
117 | assert(ret); | |
118 | ||
46ec6687 | 119 | prefix = new0(NDiscPrefix, 1); |
5624c480 PF |
120 | if (!prefix) |
121 | return -ENOMEM; | |
122 | ||
9c8e3101 | 123 | prefix->n_ref = 1; |
5624c480 | 124 | LIST_INIT(prefixes, prefix); |
272f5cd9 | 125 | prefix->nd = nd; |
5624c480 PF |
126 | |
127 | *ret = prefix; | |
5624c480 PF |
128 | return 0; |
129 | } | |
130 | ||
a1140666 LP |
131 | int sd_ndisc_set_callback( |
132 | sd_ndisc *nd, | |
133 | sd_ndisc_router_callback_t router_callback, | |
134 | sd_ndisc_prefix_onlink_callback_t prefix_onlink_callback, | |
135 | sd_ndisc_prefix_autonomous_callback_t prefix_autonomous_callback, | |
136 | sd_ndisc_callback_t callback, | |
137 | void *userdata) { | |
138 | ||
139 | assert_return(nd, -EINVAL); | |
e3169126 | 140 | |
9d96e6c3 TG |
141 | nd->router_callback = router_callback; |
142 | nd->prefix_onlink_callback = prefix_onlink_callback; | |
143 | nd->prefix_autonomous_callback = prefix_autonomous_callback; | |
e3169126 PF |
144 | nd->callback = callback; |
145 | nd->userdata = userdata; | |
146 | ||
147 | return 0; | |
148 | } | |
149 | ||
2f8e7633 LP |
150 | int sd_ndisc_set_ifindex(sd_ndisc *nd, int ifindex) { |
151 | assert_return(nd, -EINVAL); | |
152 | assert_return(ifindex > 0, -EINVAL); | |
e3169126 | 153 | |
2f8e7633 | 154 | nd->ifindex = ifindex; |
e3169126 PF |
155 | return 0; |
156 | } | |
157 | ||
4d7b83da | 158 | int sd_ndisc_set_mac(sd_ndisc *nd, const struct ether_addr *mac_addr) { |
a1140666 | 159 | assert_return(nd, -EINVAL); |
e3169126 PF |
160 | |
161 | if (mac_addr) | |
162 | memcpy(&nd->mac_addr, mac_addr, sizeof(nd->mac_addr)); | |
163 | else | |
eccaf899 | 164 | zero(nd->mac_addr); |
e3169126 PF |
165 | |
166 | return 0; | |
167 | ||
168 | } | |
169 | ||
32d20645 | 170 | int sd_ndisc_attach_event(sd_ndisc *nd, sd_event *event, int64_t priority) { |
e3169126 PF |
171 | int r; |
172 | ||
173 | assert_return(nd, -EINVAL); | |
174 | assert_return(!nd->event, -EBUSY); | |
175 | ||
176 | if (event) | |
177 | nd->event = sd_event_ref(event); | |
178 | else { | |
179 | r = sd_event_default(&nd->event); | |
180 | if (r < 0) | |
181 | return 0; | |
182 | } | |
183 | ||
184 | nd->event_priority = priority; | |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
4d7b83da | 189 | int sd_ndisc_detach_event(sd_ndisc *nd) { |
e3169126 PF |
190 | assert_return(nd, -EINVAL); |
191 | ||
192 | nd->event = sd_event_unref(nd->event); | |
193 | ||
194 | return 0; | |
195 | } | |
196 | ||
4d7b83da | 197 | sd_event *sd_ndisc_get_event(sd_ndisc *nd) { |
a1140666 | 198 | assert_return(nd, NULL); |
e3169126 PF |
199 | |
200 | return nd->event; | |
201 | } | |
202 | ||
4d7b83da | 203 | sd_ndisc *sd_ndisc_ref(sd_ndisc *nd) { |
e3169126 | 204 | |
9c8e3101 LP |
205 | if (!nd) |
206 | return NULL; | |
207 | ||
208 | assert(nd->n_ref > 0); | |
209 | nd->n_ref++; | |
e3169126 PF |
210 | |
211 | return nd; | |
212 | } | |
213 | ||
5c4c338a | 214 | static int ndisc_reset(sd_ndisc *nd) { |
e3169126 PF |
215 | assert(nd); |
216 | ||
217 | nd->recv = sd_event_source_unref(nd->recv); | |
218 | nd->fd = asynchronous_close(nd->fd); | |
219 | nd->timeout = sd_event_source_unref(nd->timeout); | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
4d7b83da | 224 | sd_ndisc *sd_ndisc_unref(sd_ndisc *nd) { |
46ec6687 | 225 | NDiscPrefix *prefix, *p; |
e3169126 | 226 | |
9c8e3101 LP |
227 | if (!nd) |
228 | return NULL; | |
229 | ||
230 | assert(nd->n_ref > 0); | |
231 | nd->n_ref--; | |
232 | ||
233 | if (nd->n_ref > 0) | |
234 | return NULL; | |
e3169126 | 235 | |
5c4c338a | 236 | ndisc_reset(nd); |
4d7b83da | 237 | sd_ndisc_detach_event(nd); |
5624c480 | 238 | |
272f5cd9 | 239 | LIST_FOREACH_SAFE(prefixes, prefix, p, nd->prefixes) |
46ec6687 | 240 | prefix = ndisc_prefix_unref(prefix); |
e3169126 | 241 | |
9c8e3101 LP |
242 | free(nd); |
243 | ||
e3169126 PF |
244 | return NULL; |
245 | } | |
246 | ||
4d7b83da | 247 | int sd_ndisc_new(sd_ndisc **ret) { |
4afd3348 | 248 | _cleanup_(sd_ndisc_unrefp) sd_ndisc *nd = NULL; |
e3169126 | 249 | |
a1140666 | 250 | assert_return(ret, -EINVAL); |
e3169126 | 251 | |
4d7b83da | 252 | nd = new0(sd_ndisc, 1); |
e3169126 PF |
253 | if (!nd) |
254 | return -ENOMEM; | |
255 | ||
9c8e3101 | 256 | nd->n_ref = 1; |
2f8e7633 | 257 | nd->ifindex = -1; |
03de7ed9 | 258 | nd->fd = -1; |
e3169126 | 259 | |
5624c480 PF |
260 | LIST_HEAD_INIT(nd->prefixes); |
261 | ||
e3169126 PF |
262 | *ret = nd; |
263 | nd = NULL; | |
264 | ||
265 | return 0; | |
266 | } | |
267 | ||
4d7b83da | 268 | int sd_ndisc_get_mtu(sd_ndisc *nd, uint32_t *mtu) { |
d14b5bc6 PF |
269 | assert_return(nd, -EINVAL); |
270 | assert_return(mtu, -EINVAL); | |
271 | ||
272 | if (nd->mtu == 0) | |
273 | return -ENOMSG; | |
274 | ||
275 | *mtu = nd->mtu; | |
d14b5bc6 PF |
276 | return 0; |
277 | } | |
278 | ||
46ec6687 TG |
279 | static int prefix_match(const struct in6_addr *prefix, uint8_t prefixlen, |
280 | const struct in6_addr *addr, | |
281 | uint8_t addr_prefixlen) { | |
d77bde34 PF |
282 | uint8_t bytes, mask, len; |
283 | ||
a1140666 LP |
284 | assert(prefix); |
285 | assert(addr); | |
d77bde34 PF |
286 | |
287 | len = MIN(prefixlen, addr_prefixlen); | |
288 | ||
289 | bytes = len / 8; | |
290 | mask = 0xff << (8 - len % 8); | |
291 | ||
292 | if (memcmp(prefix, addr, bytes) != 0 || | |
293 | (prefix->s6_addr[bytes] & mask) != (addr->s6_addr[bytes] & mask)) | |
294 | return -EADDRNOTAVAIL; | |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
f6e0ce66 TG |
299 | static int ndisc_prefix_match(sd_ndisc *nd, const struct in6_addr *addr, |
300 | uint8_t addr_len, NDiscPrefix **result) { | |
301 | NDiscPrefix *prefix, *p; | |
302 | usec_t time_now; | |
303 | int r; | |
304 | ||
305 | assert(nd); | |
306 | ||
307 | r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now); | |
308 | if (r < 0) | |
309 | return r; | |
310 | ||
311 | LIST_FOREACH_SAFE(prefixes, prefix, p, nd->prefixes) { | |
312 | if (prefix->valid_until < time_now) { | |
313 | prefix = ndisc_prefix_unref(prefix); | |
f6e0ce66 TG |
314 | continue; |
315 | } | |
d77bde34 | 316 | |
46ec6687 | 317 | if (prefix_match(&prefix->addr, prefix->len, addr, addr_len) >= 0) { |
d77bde34 PF |
318 | *result = prefix; |
319 | return 0; | |
320 | } | |
321 | } | |
322 | ||
323 | return -EADDRNOTAVAIL; | |
324 | } | |
325 | ||
46ec6687 | 326 | static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len, |
f6e0ce66 | 327 | const struct nd_opt_prefix_info *prefix_opt) { |
46ec6687 | 328 | NDiscPrefix *prefix; |
9d96e6c3 | 329 | uint32_t lifetime_valid, lifetime_preferred; |
f6e0ce66 | 330 | usec_t time_now; |
d77bde34 | 331 | char time_string[FORMAT_TIMESPAN_MAX]; |
f6e0ce66 | 332 | int r; |
d77bde34 | 333 | |
f6e0ce66 TG |
334 | assert(nd); |
335 | assert(prefix_opt); | |
d77bde34 PF |
336 | |
337 | if (len < prefix_opt->nd_opt_pi_len) | |
338 | return -ENOMSG; | |
339 | ||
9d96e6c3 TG |
340 | if (!(prefix_opt->nd_opt_pi_flags_reserved & (ND_OPT_PI_FLAG_ONLINK | ND_OPT_PI_FLAG_AUTO))) |
341 | return 0; | |
342 | ||
343 | if (in_addr_is_link_local(AF_INET6, (const union in_addr_union *) &prefix_opt->nd_opt_pi_prefix) > 0) | |
d77bde34 PF |
344 | return 0; |
345 | ||
9d96e6c3 TG |
346 | lifetime_valid = be32toh(prefix_opt->nd_opt_pi_valid_time); |
347 | lifetime_preferred = be32toh(prefix_opt->nd_opt_pi_preferred_time); | |
348 | ||
349 | if (lifetime_valid < lifetime_preferred) | |
350 | return 0; | |
d77bde34 | 351 | |
f6e0ce66 TG |
352 | r = ndisc_prefix_match(nd, &prefix_opt->nd_opt_pi_prefix, |
353 | prefix_opt->nd_opt_pi_prefix_len, &prefix); | |
c952944e ZJS |
354 | if (r < 0) { |
355 | if (r != -EADDRNOTAVAIL) | |
356 | return r; | |
d77bde34 | 357 | |
d54b734a | 358 | /* if router advertisement prefix valid timeout is zero, the timeout |
c952944e | 359 | callback will be called immediately to clean up the prefix */ |
d77bde34 | 360 | |
272f5cd9 | 361 | r = ndisc_prefix_new(nd, &prefix); |
d77bde34 PF |
362 | if (r < 0) |
363 | return r; | |
364 | ||
365 | prefix->len = prefix_opt->nd_opt_pi_prefix_len; | |
366 | ||
367 | memcpy(&prefix->addr, &prefix_opt->nd_opt_pi_prefix, | |
368 | sizeof(prefix->addr)); | |
369 | ||
46ec6687 | 370 | log_ndisc(nd, "New prefix "SD_NDISC_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s", |
c952944e ZJS |
371 | SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr), |
372 | prefix->len, lifetime_valid, | |
373 | format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_valid * USEC_PER_SEC, USEC_PER_SEC)); | |
d77bde34 PF |
374 | |
375 | LIST_PREPEND(prefixes, nd->prefixes, prefix); | |
376 | ||
377 | } else { | |
378 | if (prefix->len != prefix_opt->nd_opt_pi_prefix_len) { | |
379 | uint8_t prefixlen; | |
380 | ||
381 | prefixlen = MIN(prefix->len, prefix_opt->nd_opt_pi_prefix_len); | |
382 | ||
46ec6687 | 383 | log_ndisc(nd, "Prefix length mismatch %d/%d using %d", |
c952944e ZJS |
384 | prefix->len, |
385 | prefix_opt->nd_opt_pi_prefix_len, | |
386 | prefixlen); | |
d77bde34 PF |
387 | |
388 | prefix->len = prefixlen; | |
389 | } | |
390 | ||
46ec6687 | 391 | log_ndisc(nd, "Update prefix "SD_NDISC_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s", |
c952944e ZJS |
392 | SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr), |
393 | prefix->len, lifetime_valid, | |
394 | format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_valid * USEC_PER_SEC, USEC_PER_SEC)); | |
d77bde34 PF |
395 | } |
396 | ||
f6e0ce66 TG |
397 | r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now); |
398 | if (r < 0) | |
399 | return r; | |
400 | ||
9d96e6c3 TG |
401 | prefix->valid_until = time_now + lifetime_valid * USEC_PER_SEC; |
402 | ||
403 | if ((prefix_opt->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK) && nd->prefix_onlink_callback) | |
404 | nd->prefix_onlink_callback(nd, &prefix->addr, prefix->len, prefix->valid_until, nd->userdata); | |
405 | ||
406 | if ((prefix_opt->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) && nd->prefix_autonomous_callback) | |
407 | nd->prefix_autonomous_callback(nd, &prefix->addr, prefix->len, lifetime_preferred, lifetime_valid, | |
408 | nd->userdata); | |
d77bde34 | 409 | |
9d96e6c3 | 410 | return 0; |
d77bde34 PF |
411 | } |
412 | ||
cddf4d81 | 413 | static int ndisc_ra_parse(sd_ndisc *nd, struct nd_router_advert *ra, ssize_t len) { |
09667885 PF |
414 | void *opt; |
415 | struct nd_opt_hdr *opt_hdr; | |
416 | ||
a1140666 LP |
417 | assert(nd); |
418 | assert(ra); | |
09667885 PF |
419 | |
420 | len -= sizeof(*ra); | |
46ec6687 TG |
421 | if (len < NDISC_OPT_LEN_UNITS) { |
422 | log_ndisc(nd, "Router Advertisement below minimum length"); | |
09667885 PF |
423 | |
424 | return -ENOMSG; | |
425 | } | |
426 | ||
427 | opt = ra + 1; | |
428 | opt_hdr = opt; | |
429 | ||
46ec6687 | 430 | while (len != 0 && len >= opt_hdr->nd_opt_len * NDISC_OPT_LEN_UNITS) { |
d14b5bc6 PF |
431 | struct nd_opt_mtu *opt_mtu; |
432 | uint32_t mtu; | |
d77bde34 | 433 | struct nd_opt_prefix_info *opt_prefix; |
09667885 PF |
434 | |
435 | if (opt_hdr->nd_opt_len == 0) | |
436 | return -ENOMSG; | |
437 | ||
438 | switch (opt_hdr->nd_opt_type) { | |
d14b5bc6 PF |
439 | case ND_OPT_MTU: |
440 | opt_mtu = opt; | |
441 | ||
442 | mtu = be32toh(opt_mtu->nd_opt_mtu_mtu); | |
443 | ||
444 | if (mtu != nd->mtu) { | |
445 | nd->mtu = MAX(mtu, IP6_MIN_MTU); | |
446 | ||
46ec6687 | 447 | log_ndisc(nd, "Router Advertisement link MTU %d using %d", |
c952944e | 448 | mtu, nd->mtu); |
d14b5bc6 PF |
449 | } |
450 | ||
451 | break; | |
09667885 | 452 | |
d77bde34 PF |
453 | case ND_OPT_PREFIX_INFORMATION: |
454 | opt_prefix = opt; | |
455 | ||
46ec6687 | 456 | ndisc_prefix_update(nd, len, opt_prefix); |
d77bde34 PF |
457 | |
458 | break; | |
09667885 PF |
459 | } |
460 | ||
46ec6687 | 461 | len -= opt_hdr->nd_opt_len * NDISC_OPT_LEN_UNITS; |
09667885 | 462 | opt = (void *)((char *)opt + |
46ec6687 | 463 | opt_hdr->nd_opt_len * NDISC_OPT_LEN_UNITS); |
09667885 PF |
464 | opt_hdr = opt; |
465 | } | |
466 | ||
467 | if (len > 0) | |
46ec6687 | 468 | log_ndisc(nd, "Router Advertisement contains %zd bytes of trailing garbage", len); |
09667885 PF |
469 | |
470 | return 0; | |
471 | } | |
472 | ||
d54b734a | 473 | static int ndisc_router_advertisement_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
9d96e6c3 | 474 | _cleanup_free_ struct nd_router_advert *ra = NULL; |
4d7b83da | 475 | sd_ndisc *nd = userdata; |
cddf4d81 TG |
476 | union { |
477 | struct cmsghdr cmsghdr; | |
478 | uint8_t buf[CMSG_LEN(sizeof(int))]; | |
479 | } control = {}; | |
480 | struct iovec iov = {}; | |
481 | union sockaddr_union sa = {}; | |
482 | struct msghdr msg = { | |
483 | .msg_name = &sa.sa, | |
484 | .msg_namelen = sizeof(sa), | |
485 | .msg_iov = &iov, | |
486 | .msg_iovlen = 1, | |
487 | .msg_control = &control, | |
488 | .msg_controllen = sizeof(control), | |
489 | }; | |
490 | struct cmsghdr *cmsg; | |
d7fa4380 | 491 | struct in6_addr *gw; |
9d96e6c3 | 492 | unsigned lifetime; |
4edc2c9b LP |
493 | ssize_t len, buflen; |
494 | int r, pref, stateful; | |
e3169126 PF |
495 | |
496 | assert(s); | |
497 | assert(nd); | |
498 | assert(nd->event); | |
499 | ||
4edc2c9b LP |
500 | buflen = next_datagram_size_fd(fd); |
501 | if (buflen < 0) | |
502 | return buflen; | |
09667885 | 503 | |
cddf4d81 TG |
504 | iov.iov_len = buflen; |
505 | ||
506 | ra = malloc(iov.iov_len); | |
09667885 PF |
507 | if (!ra) |
508 | return -ENOMEM; | |
509 | ||
cddf4d81 TG |
510 | iov.iov_base = ra; |
511 | ||
512 | len = recvmsg(fd, &msg, 0); | |
09667885 | 513 | if (len < 0) { |
0d43d2fc TG |
514 | if (errno == EAGAIN || errno == EINTR) |
515 | return 0; | |
516 | ||
9d96e6c3 | 517 | log_ndisc(nd, "Could not receive message from ICMPv6 socket: %m"); |
0d43d2fc | 518 | return -errno; |
004845d1 LP |
519 | } |
520 | if ((size_t) len < sizeof(struct nd_router_advert)) { | |
521 | log_ndisc(nd, "Too small to be a router advertisement: ignoring"); | |
cddf4d81 | 522 | return 0; |
004845d1 LP |
523 | } |
524 | ||
525 | if (msg.msg_namelen == 0) | |
d7fa4380 | 526 | gw = NULL; /* only happens when running the test-suite over a socketpair */ |
cddf4d81 TG |
527 | else if (msg.msg_namelen != sizeof(sa.in6)) { |
528 | log_ndisc(nd, "Received invalid source address size from ICMPv6 socket: %zu bytes", (size_t)msg.msg_namelen); | |
e3169126 | 529 | return 0; |
d7fa4380 | 530 | } else |
cddf4d81 TG |
531 | gw = &sa.in6.sin6_addr; |
532 | ||
533 | assert(!(msg.msg_flags & MSG_CTRUNC)); | |
534 | assert(!(msg.msg_flags & MSG_TRUNC)); | |
535 | ||
536 | CMSG_FOREACH(cmsg, &msg) { | |
537 | if (cmsg->cmsg_level == SOL_IPV6 && | |
538 | cmsg->cmsg_type == IPV6_HOPLIMIT && | |
539 | cmsg->cmsg_len == CMSG_LEN(sizeof(int))) { | |
540 | int hops = *(int*)CMSG_DATA(cmsg); | |
541 | ||
542 | if (hops != 255) { | |
543 | log_ndisc(nd, "Received RA with invalid hop limit %d. Ignoring.", hops); | |
544 | return 0; | |
545 | } | |
546 | ||
547 | break; | |
548 | } | |
549 | } | |
d7fa4380 TG |
550 | |
551 | if (gw && !in_addr_is_link_local(AF_INET6, (const union in_addr_union*) gw)) { | |
552 | _cleanup_free_ char *addr = NULL; | |
e3169126 | 553 | |
d7fa4380 TG |
554 | (void)in_addr_to_string(AF_INET6, (const union in_addr_union*) gw, &addr); |
555 | ||
556 | log_ndisc(nd, "Received RA from non-link-local address %s. Ignoring.", strna(addr)); | |
3ccd3163 | 557 | return 0; |
d7fa4380 | 558 | } |
3ccd3163 | 559 | |
09667885 | 560 | if (ra->nd_ra_type != ND_ROUTER_ADVERT) |
e3169126 PF |
561 | return 0; |
562 | ||
09667885 | 563 | if (ra->nd_ra_code != 0) |
e3169126 PF |
564 | return 0; |
565 | ||
566 | nd->timeout = sd_event_source_unref(nd->timeout); | |
567 | ||
d54b734a | 568 | nd->state = NDISC_STATE_ADVERTISEMENT_LISTEN; |
e3169126 | 569 | |
9d96e6c3 | 570 | stateful = ra->nd_ra_flags_reserved & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER); |
133dd71f | 571 | pref = (ra->nd_ra_flags_reserved & ND_RA_FLAG_PREF) >> 3; |
3b015d40 TG |
572 | |
573 | switch (pref) { | |
9d96e6c3 | 574 | case ND_RA_FLAG_PREF_LOW: |
9d96e6c3 | 575 | case ND_RA_FLAG_PREF_HIGH: |
9d96e6c3 TG |
576 | break; |
577 | default: | |
3b015d40 | 578 | pref = ND_RA_FLAG_PREF_MEDIUM; |
9d96e6c3 TG |
579 | break; |
580 | } | |
e3169126 | 581 | |
9d96e6c3 | 582 | lifetime = be16toh(ra->nd_ra_router_lifetime); |
e3169126 | 583 | |
9d96e6c3 TG |
584 | log_ndisc(nd, "Received Router Advertisement: flags %s preference %s lifetime %u sec", |
585 | stateful & ND_RA_FLAG_MANAGED ? "MANAGED" : stateful & ND_RA_FLAG_OTHER ? "OTHER" : "none", | |
3b015d40 | 586 | pref == ND_RA_FLAG_PREF_HIGH ? "high" : pref == ND_RA_FLAG_PREF_LOW ? "low" : "medium", |
9d96e6c3 | 587 | lifetime); |
09667885 | 588 | |
9d96e6c3 TG |
589 | r = ndisc_ra_parse(nd, ra, len); |
590 | if (r < 0) { | |
591 | log_ndisc(nd, "Could not parse Router Advertisement: %s", strerror(-r)); | |
592 | return 0; | |
09667885 | 593 | } |
e3169126 | 594 | |
9d96e6c3 | 595 | if (nd->router_callback) |
d7fa4380 | 596 | nd->router_callback(nd, stateful, gw, lifetime, pref, nd->userdata); |
e3169126 PF |
597 | |
598 | return 0; | |
599 | } | |
600 | ||
46ec6687 | 601 | static int ndisc_router_solicitation_timeout(sd_event_source *s, uint64_t usec, void *userdata) { |
4d7b83da | 602 | sd_ndisc *nd = userdata; |
e3169126 | 603 | uint64_t time_now, next_timeout; |
e3169126 PF |
604 | int r; |
605 | ||
606 | assert(s); | |
607 | assert(nd); | |
608 | assert(nd->event); | |
609 | ||
610 | nd->timeout = sd_event_source_unref(nd->timeout); | |
611 | ||
46ec6687 | 612 | if (nd->nd_sent >= NDISC_MAX_ROUTER_SOLICITATIONS) { |
9d96e6c3 TG |
613 | if (nd->callback) |
614 | nd->callback(nd, SD_NDISC_EVENT_TIMEOUT, nd->userdata); | |
d54b734a | 615 | nd->state = NDISC_STATE_ADVERTISEMENT_LISTEN; |
e3169126 | 616 | } else { |
6d06ac1f | 617 | r = icmp6_send_router_solicitation(nd->fd, &nd->mac_addr); |
e3169126 | 618 | if (r < 0) |
46ec6687 | 619 | log_ndisc(nd, "Error sending Router Solicitation"); |
e3169126 | 620 | else { |
46ec6687 TG |
621 | nd->state = NDISC_STATE_SOLICITATION_SENT; |
622 | log_ndisc(nd, "Sent Router Solicitation"); | |
e3169126 PF |
623 | } |
624 | ||
625 | nd->nd_sent++; | |
626 | ||
cbe91b3c | 627 | assert_se(sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now) >= 0); |
e3169126 | 628 | |
46ec6687 | 629 | next_timeout = time_now + NDISC_ROUTER_SOLICITATION_INTERVAL; |
e3169126 | 630 | |
fa94c34b | 631 | r = sd_event_add_time(nd->event, &nd->timeout, clock_boottime_or_monotonic(), |
e3169126 | 632 | next_timeout, 0, |
46ec6687 | 633 | ndisc_router_solicitation_timeout, nd); |
e3169126 | 634 | if (r < 0) { |
cb53894d TG |
635 | /* we cannot continue if we are unable to rearm the timer */ |
636 | sd_ndisc_stop(nd); | |
e3169126 PF |
637 | return 0; |
638 | } | |
639 | ||
cbe91b3c TG |
640 | r = sd_event_source_set_priority(nd->timeout, nd->event_priority); |
641 | if (r < 0) | |
e3169126 | 642 | return 0; |
9021bb9f | 643 | |
46ec6687 | 644 | r = sd_event_source_set_description(nd->timeout, "ndisc-timeout"); |
cbe91b3c | 645 | if (r < 0) |
9021bb9f | 646 | return 0; |
e3169126 PF |
647 | } |
648 | ||
649 | return 0; | |
650 | } | |
651 | ||
4d7b83da | 652 | int sd_ndisc_stop(sd_ndisc *nd) { |
836cf090 | 653 | assert_return(nd, -EINVAL); |
836cf090 | 654 | |
c1c9b211 LP |
655 | if (nd->state == NDISC_STATE_IDLE) |
656 | return 0; | |
657 | ||
b3dfcf6a | 658 | log_ndisc(nd, "Stopping IPv6 Router Solicitation client"); |
836cf090 | 659 | |
5c4c338a | 660 | ndisc_reset(nd); |
46ec6687 | 661 | nd->state = NDISC_STATE_IDLE; |
836cf090 | 662 | |
9d96e6c3 TG |
663 | if (nd->callback) |
664 | nd->callback(nd, SD_NDISC_EVENT_STOP, nd->userdata); | |
cb53894d | 665 | |
836cf090 PF |
666 | return 0; |
667 | } | |
668 | ||
4d7b83da | 669 | int sd_ndisc_router_discovery_start(sd_ndisc *nd) { |
e3169126 PF |
670 | int r; |
671 | ||
a1140666 LP |
672 | assert_return(nd, -EINVAL); |
673 | assert_return(nd->event, -EINVAL); | |
674 | assert_return(nd->ifindex > 0, -EINVAL); | |
675 | assert_return(nd->state == NDISC_STATE_IDLE, -EBUSY); | |
e3169126 | 676 | |
2f8e7633 | 677 | r = icmp6_bind_router_solicitation(nd->ifindex); |
e3169126 PF |
678 | if (r < 0) |
679 | return r; | |
680 | ||
681 | nd->fd = r; | |
682 | ||
d54b734a | 683 | r = sd_event_add_io(nd->event, &nd->recv, nd->fd, EPOLLIN, ndisc_router_advertisement_recv, nd); |
e3169126 | 684 | if (r < 0) |
5c4c338a | 685 | goto fail; |
e3169126 PF |
686 | |
687 | r = sd_event_source_set_priority(nd->recv, nd->event_priority); | |
688 | if (r < 0) | |
5c4c338a | 689 | goto fail; |
e3169126 | 690 | |
5c4c338a | 691 | (void) sd_event_source_set_description(nd->recv, "ndisc-receive-message"); |
9021bb9f | 692 | |
5c4c338a | 693 | r = sd_event_add_time(nd->event, &nd->timeout, clock_boottime_or_monotonic(), 0, 0, ndisc_router_solicitation_timeout, nd); |
e3169126 | 694 | if (r < 0) |
5c4c338a | 695 | goto fail; |
e3169126 PF |
696 | |
697 | r = sd_event_source_set_priority(nd->timeout, nd->event_priority); | |
9021bb9f | 698 | if (r < 0) |
5c4c338a | 699 | goto fail; |
e3169126 | 700 | |
5c4c338a LP |
701 | (void) sd_event_source_set_description(nd->timeout, "ndisc-timeout"); |
702 | ||
b3dfcf6a | 703 | log_ndisc(ns, "Started IPv6 Router Solicitation client"); |
5c4c338a | 704 | return 0; |
e3169126 | 705 | |
5c4c338a LP |
706 | fail: |
707 | ndisc_reset(nd); | |
e3169126 PF |
708 | return r; |
709 | } |