1: /* dnsmasq is Copyright (c) 2000-2016 Simon Kelley
2:
3: This program is free software; you can redistribute it and/or modify
4: it under the terms of the GNU General Public License as published by
5: the Free Software Foundation; version 2 dated June, 1991, or
6: (at your option) version 3 dated 29 June, 2007.
7:
8: This program is distributed in the hope that it will be useful,
9: but WITHOUT ANY WARRANTY; without even the implied warranty of
10: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11: GNU General Public License for more details.
12:
13: You should have received a copy of the GNU General Public License
14: along with this program. If not, see <http://www.gnu.org/licenses/>.
15: */
16:
17:
18: /* NB. This code may be called during a DHCPv4 or transaction which is in ping-wait
19: It therefore cannot use any DHCP buffer resources except outpacket, which is
20: not used by DHCPv4 code. This code may also be called when DHCP 4 or 6 isn't
21: active, so we ensure that outpacket is allocated here too */
22:
23: #include "dnsmasq.h"
24:
25: #ifdef HAVE_DHCP6
26:
27: #include <netinet/icmp6.h>
28:
29: struct ra_param {
30: time_t now;
31: int ind, managed, other, first, adv_router;
32: char *if_name;
33: struct dhcp_netid *tags;
34: struct in6_addr link_local, link_global, ula;
35: unsigned int glob_pref_time, link_pref_time, ula_pref_time, adv_interval, prio;
36: struct dhcp_context *found_context;
37: };
38:
39: struct search_param {
40: time_t now; int iface;
41: char name[IF_NAMESIZE+1];
42: };
43:
44: struct alias_param {
45: int iface;
46: struct dhcp_bridge *bridge;
47: int num_alias_ifs;
48: int max_alias_ifs;
49: int *alias_ifs;
50: };
51:
52: static void send_ra(time_t now, int iface, char *iface_name, struct in6_addr *dest);
53: static void send_ra_alias(time_t now, int iface, char *iface_name, struct in6_addr *dest,
54: int send_iface);
55: static int send_ra_to_aliases(int index, unsigned int type, char *mac, size_t maclen, void *parm);
56: static int add_prefixes(struct in6_addr *local, int prefix,
57: int scope, int if_index, int flags,
58: unsigned int preferred, unsigned int valid, void *vparam);
59: static int iface_search(struct in6_addr *local, int prefix,
60: int scope, int if_index, int flags,
61: int prefered, int valid, void *vparam);
62: static int add_lla(int index, unsigned int type, char *mac, size_t maclen, void *parm);
63: static void new_timeout(struct dhcp_context *context, char *iface_name, time_t now);
64: static unsigned int calc_lifetime(struct ra_interface *ra);
65: static unsigned int calc_interval(struct ra_interface *ra);
66: static unsigned int calc_prio(struct ra_interface *ra);
67: static struct ra_interface *find_iface_param(char *iface);
68:
69: static int hop_limit;
70:
71: void ra_init(time_t now)
72: {
73: struct icmp6_filter filter;
74: int fd;
75: #if defined(IPV6_TCLASS) && defined(IPTOS_CLASS_CS6)
76: int class = IPTOS_CLASS_CS6;
77: #endif
78: int val = 255; /* radvd uses this value */
79: socklen_t len = sizeof(int);
80: struct dhcp_context *context;
81:
82: /* ensure this is around even if we're not doing DHCPv6 */
83: expand_buf(&daemon->outpacket, sizeof(struct dhcp_packet));
84:
85: /* See if we're guessing SLAAC addresses, if so we need to recieve ping replies */
86: for (context = daemon->dhcp6; context; context = context->next)
87: if ((context->flags & CONTEXT_RA_NAME))
88: break;
89:
90: /* Need ICMP6 socket for transmission for DHCPv6 even when not doing RA. */
91:
92: ICMP6_FILTER_SETBLOCKALL(&filter);
93: if (daemon->doing_ra)
94: {
95: ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filter);
96: if (context)
97: ICMP6_FILTER_SETPASS(ICMP6_ECHO_REPLY, &filter);
98: }
99:
100: if ((fd = socket(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) == -1 ||
101: getsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &hop_limit, &len) ||
102: #if defined(IPV6_TCLASS) && defined(IPTOS_CLASS_CS6)
103: setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, &class, sizeof(class)) == -1 ||
104: #endif
105: !fix_fd(fd) ||
106: !set_ipv6pktinfo(fd) ||
107: setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val, sizeof(val)) ||
108: setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val)) ||
109: setsockopt(fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filter, sizeof(filter)) == -1)
110: die (_("cannot create ICMPv6 socket: %s"), NULL, EC_BADNET);
111:
112: daemon->icmp6fd = fd;
113:
114: if (daemon->doing_ra)
115: ra_start_unsolicted(now, NULL);
116: }
117:
118: void ra_start_unsolicted(time_t now, struct dhcp_context *context)
119: {
120: /* init timers so that we do ra's for some/all soon. some ra_times will end up zeroed
121: if it's not appropriate to advertise those contexts.
122: This gets re-called on a netlink route-change to re-do the advertisement
123: and pick up new interfaces */
124:
125: if (context)
126: context->ra_short_period_start = context->ra_time = now;
127: else
128: for (context = daemon->dhcp6; context; context = context->next)
129: if (!(context->flags & CONTEXT_TEMPLATE))
130: {
131: context->ra_time = now + (rand16()/13000); /* range 0 - 5 */
132: /* re-do frequently for a minute or so, in case the first gets lost. */
133: context->ra_short_period_start = now;
134: }
135: }
136:
137: void icmp6_packet(time_t now)
138: {
139: char interface[IF_NAMESIZE+1];
140: ssize_t sz;
141: int if_index = 0;
142: struct cmsghdr *cmptr;
143: struct msghdr msg;
144: union {
145: struct cmsghdr align; /* this ensures alignment */
146: char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
147: } control_u;
148: struct sockaddr_in6 from;
149: unsigned char *packet;
150: struct iname *tmp;
151:
152: /* Note: use outpacket for input buffer */
153: msg.msg_control = control_u.control6;
154: msg.msg_controllen = sizeof(control_u);
155: msg.msg_flags = 0;
156: msg.msg_name = &from;
157: msg.msg_namelen = sizeof(from);
158: msg.msg_iov = &daemon->outpacket;
159: msg.msg_iovlen = 1;
160:
161: if ((sz = recv_dhcp_packet(daemon->icmp6fd, &msg)) == -1 || sz < 8)
162: return;
163:
164: packet = (unsigned char *)daemon->outpacket.iov_base;
165:
166: for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
167: if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo)
168: {
169: union {
170: unsigned char *c;
171: struct in6_pktinfo *p;
172: } p;
173: p.c = CMSG_DATA(cmptr);
174:
175: if_index = p.p->ipi6_ifindex;
176: }
177:
178: if (!indextoname(daemon->icmp6fd, if_index, interface))
179: return;
180:
181: if (!iface_check(AF_LOCAL, NULL, interface, NULL))
182: return;
183:
184: for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
185: if (tmp->name && wildcard_match(tmp->name, interface))
186: return;
187:
188: if (packet[1] != 0)
189: return;
190:
191: if (packet[0] == ICMP6_ECHO_REPLY)
192: lease_ping_reply(&from.sin6_addr, packet, interface);
193: else if (packet[0] == ND_ROUTER_SOLICIT)
194: {
195: char *mac = "";
196: struct dhcp_bridge *bridge, *alias;
197:
198: /* look for link-layer address option for logging */
199: if (sz >= 16 && packet[8] == ICMP6_OPT_SOURCE_MAC && (packet[9] * 8) + 8 <= sz)
200: {
201: print_mac(daemon->namebuff, &packet[10], (packet[9] * 8) - 2);
202: mac = daemon->namebuff;
203: }
204:
205: if (!option_bool(OPT_QUIET_RA))
206: my_syslog(MS_DHCP | LOG_INFO, "RTR-SOLICIT(%s) %s", interface, mac);
207:
208: /* If the incoming interface is an alias of some other one (as
209: specified by the --bridge-interface option), send an RA using
210: the context of the aliased interface. */
211: for (bridge = daemon->bridges; bridge; bridge = bridge->next)
212: {
213: int bridge_index = if_nametoindex(bridge->iface);
214: if (bridge_index)
215: {
216: for (alias = bridge->alias; alias; alias = alias->next)
217: if (wildcard_matchn(alias->iface, interface, IF_NAMESIZE))
218: {
219: /* Send an RA on if_index with information from
220: bridge_index. */
221: send_ra_alias(now, bridge_index, bridge->iface, NULL, if_index);
222: break;
223: }
224: if (alias)
225: break;
226: }
227: }
228:
229: /* If the incoming interface wasn't an alias, send an RA using
230: the context of the incoming interface. */
231: if (!bridge)
232: /* source address may not be valid in solicit request. */
233: send_ra(now, if_index, interface, !IN6_IS_ADDR_UNSPECIFIED(&from.sin6_addr) ? &from.sin6_addr : NULL);
234: }
235: }
236:
237: static void send_ra_alias(time_t now, int iface, char *iface_name, struct in6_addr *dest, int send_iface)
238: {
239: struct ra_packet *ra;
240: struct ra_param parm;
241: struct sockaddr_in6 addr;
242: struct dhcp_context *context, *tmp, **up;
243: struct dhcp_netid iface_id;
244: struct dhcp_opt *opt_cfg;
245: struct ra_interface *ra_param = find_iface_param(iface_name);
246: int done_dns = 0, old_prefix = 0;
247: unsigned int min_pref_time;
248: #ifdef HAVE_LINUX_NETWORK
249: FILE *f;
250: #endif
251:
252: parm.ind = iface;
253: parm.managed = 0;
254: parm.other = 0;
255: parm.found_context = NULL;
256: parm.adv_router = 0;
257: parm.if_name = iface_name;
258: parm.first = 1;
259: parm.now = now;
260: parm.glob_pref_time = parm.link_pref_time = parm.ula_pref_time = 0;
261: parm.adv_interval = calc_interval(ra_param);
262: parm.prio = calc_prio(ra_param);
263:
264: save_counter(0);
265: ra = expand(sizeof(struct ra_packet));
266:
267: ra->type = ND_ROUTER_ADVERT;
268: ra->code = 0;
269: ra->hop_limit = hop_limit;
270: ra->flags = parm.prio;
271: ra->lifetime = htons(calc_lifetime(ra_param));
272: ra->reachable_time = 0;
273: ra->retrans_time = 0;
274:
275: /* set tag with name == interface */
276: iface_id.net = iface_name;
277: iface_id.next = NULL;
278: parm.tags = &iface_id;
279:
280: for (context = daemon->dhcp6; context; context = context->next)
281: {
282: context->flags &= ~CONTEXT_RA_DONE;
283: context->netid.next = &context->netid;
284: }
285:
286: if (!iface_enumerate(AF_INET6, &parm, add_prefixes))
287: return;
288:
289: /* Find smallest preferred time within address classes,
290: to use as lifetime for options. This is a rather arbitrary choice. */
291: min_pref_time = 0xffffffff;
292: if (parm.glob_pref_time != 0 && parm.glob_pref_time < min_pref_time)
293: min_pref_time = parm.glob_pref_time;
294:
295: if (parm.ula_pref_time != 0 && parm.ula_pref_time < min_pref_time)
296: min_pref_time = parm.ula_pref_time;
297:
298: if (parm.link_pref_time != 0 && parm.link_pref_time < min_pref_time)
299: min_pref_time = parm.link_pref_time;
300:
301: /* Look for constructed contexts associated with addresses which have gone,
302: and advertise them with preferred_time == 0 RFC 6204 4.3 L-13 */
303: for (up = &daemon->dhcp6, context = daemon->dhcp6; context; context = tmp)
304: {
305: tmp = context->next;
306:
307: if (context->if_index == iface && (context->flags & CONTEXT_OLD))
308: {
309: unsigned int old = difftime(now, context->address_lost_time);
310:
311: if (old > context->saved_valid)
312: {
313: /* We've advertised this enough, time to go */
314:
315: /* If this context held the timeout, and there's another context in use
316: transfer the timeout there. */
317: if (context->ra_time != 0 && parm.found_context && parm.found_context->ra_time == 0)
318: new_timeout(parm.found_context, iface_name, now);
319:
320: *up = context->next;
321: free(context);
322: }
323: else
324: {
325: struct prefix_opt *opt;
326: struct in6_addr local = context->start6;
327: int do_slaac = 0;
328:
329: old_prefix = 1;
330:
331: /* zero net part of address */
332: setaddr6part(&local, addr6part(&local) & ~((context->prefix == 64) ? (u64)-1LL : (1LLU << (128 - context->prefix)) - 1LLU));
333:
334:
335: if (context->flags & CONTEXT_RA)
336: {
337: do_slaac = 1;
338: if (context->flags & CONTEXT_DHCP)
339: {
340: parm.other = 1;
341: if (!(context->flags & CONTEXT_RA_STATELESS))
342: parm.managed = 1;
343: }
344: }
345: else
346: {
347: /* don't do RA for non-ra-only unless --enable-ra is set */
348: if (option_bool(OPT_RA))
349: {
350: parm.managed = 1;
351: parm.other = 1;
352: }
353: }
354:
355: if ((opt = expand(sizeof(struct prefix_opt))))
356: {
357: opt->type = ICMP6_OPT_PREFIX;
358: opt->len = 4;
359: opt->prefix_len = context->prefix;
360: /* autonomous only if we're not doing dhcp, set
361: "on-link" unless "off-link" was specified */
362: opt->flags = (do_slaac ? 0x40 : 0) |
363: ((context->flags & CONTEXT_RA_OFF_LINK) ? 0 : 0x80);
364: opt->valid_lifetime = htonl(context->saved_valid - old);
365: opt->preferred_lifetime = htonl(0);
366: opt->reserved = 0;
367: opt->prefix = local;
368:
369: inet_ntop(AF_INET6, &local, daemon->addrbuff, ADDRSTRLEN);
370: if (!option_bool(OPT_QUIET_RA))
371: my_syslog(MS_DHCP | LOG_INFO, "RTR-ADVERT(%s) %s old prefix", iface_name, daemon->addrbuff);
372: }
373:
374: up = &context->next;
375: }
376: }
377: else
378: up = &context->next;
379: }
380:
381: /* If we're advertising only old prefixes, set router lifetime to zero. */
382: if (old_prefix && !parm.found_context)
383: ra->lifetime = htons(0);
384:
385: /* No prefixes to advertise. */
386: if (!old_prefix && !parm.found_context)
387: return;
388:
389: /* If we're sending router address instead of prefix in at least on prefix,
390: include the advertisement interval option. */
391: if (parm.adv_router)
392: {
393: put_opt6_char(ICMP6_OPT_ADV_INTERVAL);
394: put_opt6_char(1);
395: put_opt6_short(0);
396: /* interval value is in milliseconds */
397: put_opt6_long(1000 * calc_interval(find_iface_param(iface_name)));
398: }
399:
400: #ifdef HAVE_LINUX_NETWORK
401: /* Note that IPv6 MTU is not necessarilly the same as the IPv4 MTU
402: available from SIOCGIFMTU */
403: sprintf(daemon->namebuff, "/proc/sys/net/ipv6/conf/%s/mtu", iface_name);
404: if ((f = fopen(daemon->namebuff, "r")))
405: {
406: if (fgets(daemon->namebuff, MAXDNAME, f))
407: {
408: put_opt6_char(ICMP6_OPT_MTU);
409: put_opt6_char(1);
410: put_opt6_short(0);
411: put_opt6_long(atoi(daemon->namebuff));
412: }
413: fclose(f);
414: }
415: #endif
416:
417: iface_enumerate(AF_LOCAL, &send_iface, add_lla);
418:
419: /* RDNSS, RFC 6106, use relevant DHCP6 options */
420: (void)option_filter(parm.tags, NULL, daemon->dhcp_opts6);
421:
422: for (opt_cfg = daemon->dhcp_opts6; opt_cfg; opt_cfg = opt_cfg->next)
423: {
424: int i;
425:
426: /* netids match and not encapsulated? */
427: if (!(opt_cfg->flags & DHOPT_TAGOK))
428: continue;
429:
430: if (opt_cfg->opt == OPTION6_DNS_SERVER)
431: {
432: struct in6_addr *a;
433: int len;
434:
435: done_dns = 1;
436:
437: if (opt_cfg->len == 0)
438: continue;
439:
440: /* reduce len for any addresses we can't substitute */
441: for (a = (struct in6_addr *)opt_cfg->val, len = opt_cfg->len, i = 0;
442: i < opt_cfg->len; i += IN6ADDRSZ, a++)
443: if ((IN6_IS_ADDR_UNSPECIFIED(a) && parm.glob_pref_time == 0) ||
444: (IN6_IS_ADDR_ULA_ZERO(a) && parm.ula_pref_time == 0) ||
445: (IN6_IS_ADDR_LINK_LOCAL_ZERO(a) && parm.link_pref_time == 0))
446: len -= IN6ADDRSZ;
447:
448: if (len != 0)
449: {
450: put_opt6_char(ICMP6_OPT_RDNSS);
451: put_opt6_char((len/8) + 1);
452: put_opt6_short(0);
453: put_opt6_long(min_pref_time);
454:
455: for (a = (struct in6_addr *)opt_cfg->val, i = 0; i < opt_cfg->len; i += IN6ADDRSZ, a++)
456: if (IN6_IS_ADDR_UNSPECIFIED(a))
457: {
458: if (parm.glob_pref_time != 0)
459: put_opt6(&parm.link_global, IN6ADDRSZ);
460: }
461: else if (IN6_IS_ADDR_ULA_ZERO(a))
462: {
463: if (parm.ula_pref_time != 0)
464: put_opt6(&parm.ula, IN6ADDRSZ);
465: }
466: else if (IN6_IS_ADDR_LINK_LOCAL_ZERO(a))
467: {
468: if (parm.link_pref_time != 0)
469: put_opt6(&parm.link_local, IN6ADDRSZ);
470: }
471: else
472: put_opt6(a, IN6ADDRSZ);
473: }
474: }
475:
476: if (opt_cfg->opt == OPTION6_DOMAIN_SEARCH && opt_cfg->len != 0)
477: {
478: int len = ((opt_cfg->len+7)/8);
479:
480: put_opt6_char(ICMP6_OPT_DNSSL);
481: put_opt6_char(len + 1);
482: put_opt6_short(0);
483: put_opt6_long(min_pref_time);
484: put_opt6(opt_cfg->val, opt_cfg->len);
485:
486: /* pad */
487: for (i = opt_cfg->len; i < len * 8; i++)
488: put_opt6_char(0);
489: }
490: }
491:
492: if (daemon->port == NAMESERVER_PORT && !done_dns && parm.link_pref_time != 0)
493: {
494: /* default == us, as long as we are supplying DNS service. */
495: put_opt6_char(ICMP6_OPT_RDNSS);
496: put_opt6_char(3);
497: put_opt6_short(0);
498: put_opt6_long(min_pref_time);
499: put_opt6(&parm.link_local, IN6ADDRSZ);
500: }
501:
502: /* set managed bits unless we're providing only RA on this link */
503: if (parm.managed)
504: ra->flags |= 0x80; /* M flag, managed, */
505: if (parm.other)
506: ra->flags |= 0x40; /* O flag, other */
507:
508: /* decide where we're sending */
509: memset(&addr, 0, sizeof(addr));
510: #ifdef HAVE_SOCKADDR_SA_LEN
511: addr.sin6_len = sizeof(struct sockaddr_in6);
512: #endif
513: addr.sin6_family = AF_INET6;
514: addr.sin6_port = htons(IPPROTO_ICMPV6);
515: if (dest)
516: {
517: addr.sin6_addr = *dest;
518: if (IN6_IS_ADDR_LINKLOCAL(dest) ||
519: IN6_IS_ADDR_MC_LINKLOCAL(dest))
520: addr.sin6_scope_id = iface;
521: }
522: else
523: {
524: inet_pton(AF_INET6, ALL_NODES, &addr.sin6_addr);
525: setsockopt(daemon->icmp6fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &send_iface, sizeof(send_iface));
526: }
527:
528: while (retry_send(sendto(daemon->icmp6fd, daemon->outpacket.iov_base,
529: save_counter(0), 0, (struct sockaddr *)&addr,
530: sizeof(addr))));
531:
532: }
533:
534: static void send_ra(time_t now, int iface, char *iface_name, struct in6_addr *dest)
535: {
536: /* Send an RA on the same interface that the RA content is based
537: on. */
538: send_ra_alias(now, iface, iface_name, dest, iface);
539: }
540:
541: static int add_prefixes(struct in6_addr *local, int prefix,
542: int scope, int if_index, int flags,
543: unsigned int preferred, unsigned int valid, void *vparam)
544: {
545: struct ra_param *param = vparam;
546:
547: (void)scope; /* warning */
548:
549: if (if_index == param->ind)
550: {
551: if (IN6_IS_ADDR_LINKLOCAL(local))
552: {
553: /* Can there be more than one LL address?
554: Select the one with the longest preferred time
555: if there is. */
556: if (preferred > param->link_pref_time)
557: {
558: param->link_pref_time = preferred;
559: param->link_local = *local;
560: }
561: }
562: else if (!IN6_IS_ADDR_LOOPBACK(local) &&
563: !IN6_IS_ADDR_MULTICAST(local))
564: {
565: int real_prefix = 0;
566: int do_slaac = 0;
567: int deprecate = 0;
568: int constructed = 0;
569: int adv_router = 0;
570: int off_link = 0;
571: unsigned int time = 0xffffffff;
572: struct dhcp_context *context;
573:
574: for (context = daemon->dhcp6; context; context = context->next)
575: if (!(context->flags & (CONTEXT_TEMPLATE | CONTEXT_OLD)) &&
576: prefix <= context->prefix &&
577: is_same_net6(local, &context->start6, context->prefix) &&
578: is_same_net6(local, &context->end6, context->prefix))
579: {
580: context->saved_valid = valid;
581:
582: if (context->flags & CONTEXT_RA)
583: {
584: do_slaac = 1;
585: if (context->flags & CONTEXT_DHCP)
586: {
587: param->other = 1;
588: if (!(context->flags & CONTEXT_RA_STATELESS))
589: param->managed = 1;
590: }
591: }
592: else
593: {
594: /* don't do RA for non-ra-only unless --enable-ra is set */
595: if (!option_bool(OPT_RA))
596: continue;
597: param->managed = 1;
598: param->other = 1;
599: }
600:
601: /* Configured to advertise router address, not prefix. See RFC 3775 7.2
602: In this case we do all addresses associated with a context,
603: hence the real_prefix setting here. */
604: if (context->flags & CONTEXT_RA_ROUTER)
605: {
606: adv_router = 1;
607: param->adv_router = 1;
608: real_prefix = context->prefix;
609: }
610:
611: /* find floor time, don't reduce below 3 * RA interval. */
612: if (time > context->lease_time)
613: {
614: time = context->lease_time;
615: if (time < ((unsigned int)(3 * param->adv_interval)))
616: time = 3 * param->adv_interval;
617: }
618:
619: if (context->flags & CONTEXT_DEPRECATE)
620: deprecate = 1;
621:
622: if (context->flags & CONTEXT_CONSTRUCTED)
623: constructed = 1;
624:
625:
626: /* collect dhcp-range tags */
627: if (context->netid.next == &context->netid && context->netid.net)
628: {
629: context->netid.next = param->tags;
630: param->tags = &context->netid;
631: }
632:
633: /* subsequent prefixes on the same interface
634: and subsequent instances of this prefix don't need timers.
635: Be careful not to find the same prefix twice with different
636: addresses unless we're advertising the actual addresses. */
637: if (!(context->flags & CONTEXT_RA_DONE))
638: {
639: if (!param->first)
640: context->ra_time = 0;
641: context->flags |= CONTEXT_RA_DONE;
642: real_prefix = context->prefix;
643: off_link = (context->flags & CONTEXT_RA_OFF_LINK);
644: }
645:
646: param->first = 0;
647: /* found_context is the _last_ one we found, so if there's
648: more than one, it's not the first. */
649: param->found_context = context;
650: }
651:
652: /* configured time is ceiling */
653: if (!constructed || valid > time)
654: valid = time;
655:
656: if (flags & IFACE_DEPRECATED)
657: preferred = 0;
658:
659: if (deprecate)
660: time = 0;
661:
662: /* configured time is ceiling */
663: if (!constructed || preferred > time)
664: preferred = time;
665:
666: if (IN6_IS_ADDR_ULA(local))
667: {
668: if (preferred > param->ula_pref_time)
669: {
670: param->ula_pref_time = preferred;
671: param->ula = *local;
672: }
673: }
674: else
675: {
676: if (preferred > param->glob_pref_time)
677: {
678: param->glob_pref_time = preferred;
679: param->link_global = *local;
680: }
681: }
682:
683: if (real_prefix != 0)
684: {
685: struct prefix_opt *opt;
686:
687: if ((opt = expand(sizeof(struct prefix_opt))))
688: {
689: /* zero net part of address */
690: if (!adv_router)
691: setaddr6part(local, addr6part(local) & ~((real_prefix == 64) ? (u64)-1LL : (1LLU << (128 - real_prefix)) - 1LLU));
692:
693: opt->type = ICMP6_OPT_PREFIX;
694: opt->len = 4;
695: opt->prefix_len = real_prefix;
696: /* autonomous only if we're not doing dhcp, set
697: "on-link" unless "off-link" was specified */
698: opt->flags = (off_link ? 0 : 0x80);
699: if (do_slaac)
700: opt->flags |= 0x40;
701: if (adv_router)
702: opt->flags |= 0x20;
703: opt->valid_lifetime = htonl(valid);
704: opt->preferred_lifetime = htonl(preferred);
705: opt->reserved = 0;
706: opt->prefix = *local;
707:
708: inet_ntop(AF_INET6, local, daemon->addrbuff, ADDRSTRLEN);
709: if (!option_bool(OPT_QUIET_RA))
710: my_syslog(MS_DHCP | LOG_INFO, "RTR-ADVERT(%s) %s", param->if_name, daemon->addrbuff);
711: }
712: }
713: }
714: }
715: return 1;
716: }
717:
718: static int add_lla(int index, unsigned int type, char *mac, size_t maclen, void *parm)
719: {
720: (void)type;
721:
722: if (index == *((int *)parm))
723: {
724: /* size is in units of 8 octets and includes type and length (2 bytes)
725: add 7 to round up */
726: int len = (maclen + 9) >> 3;
727: unsigned char *p = expand(len << 3);
728: memset(p, 0, len << 3);
729: *p++ = ICMP6_OPT_SOURCE_MAC;
730: *p++ = len;
731: memcpy(p, mac, maclen);
732:
733: return 0;
734: }
735:
736: return 1;
737: }
738:
739: time_t periodic_ra(time_t now)
740: {
741: struct search_param param;
742: struct dhcp_context *context;
743: time_t next_event;
744: struct alias_param aparam;
745:
746: param.now = now;
747: param.iface = 0;
748:
749: while (1)
750: {
751: /* find overdue events, and time of first future event */
752: for (next_event = 0, context = daemon->dhcp6; context; context = context->next)
753: if (context->ra_time != 0)
754: {
755: if (difftime(context->ra_time, now) <= 0.0)
756: break; /* overdue */
757:
758: if (next_event == 0 || difftime(next_event, context->ra_time) > 0.0)
759: next_event = context->ra_time;
760: }
761:
762: /* none overdue */
763: if (!context)
764: break;
765:
766: if ((context->flags & CONTEXT_OLD) &&
767: context->if_index != 0 &&
768: indextoname(daemon->icmp6fd, context->if_index, param.name))
769: {
770: /* A context for an old address. We'll not find the interface by
771: looking for addresses, but we know it anyway, since the context is
772: constructed */
773: param.iface = context->if_index;
774: new_timeout(context, param.name, now);
775: }
776: else if (iface_enumerate(AF_INET6, ¶m, iface_search))
777: /* There's a context overdue, but we can't find an interface
778: associated with it, because it's for a subnet we dont
779: have an interface on. Probably we're doing DHCP on
780: a remote subnet via a relay. Zero the timer, since we won't
781: ever be able to send ra's and satistfy it. */
782: context->ra_time = 0;
783:
784: if (param.iface != 0 &&
785: iface_check(AF_LOCAL, NULL, param.name, NULL))
786: {
787: struct iname *tmp;
788: for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
789: if (tmp->name && wildcard_match(tmp->name, param.name))
790: break;
791: if (!tmp)
792: {
793: send_ra(now, param.iface, param.name, NULL);
794:
795: /* Also send on all interfaces that are aliases of this
796: one. */
797: for (aparam.bridge = daemon->bridges;
798: aparam.bridge;
799: aparam.bridge = aparam.bridge->next)
800: if ((int)if_nametoindex(aparam.bridge->iface) == param.iface)
801: {
802: /* Count the number of alias interfaces for this
803: 'bridge', by calling iface_enumerate with
804: send_ra_to_aliases and NULL alias_ifs. */
805: aparam.iface = param.iface;
806: aparam.alias_ifs = NULL;
807: aparam.num_alias_ifs = 0;
808: iface_enumerate(AF_LOCAL, &aparam, send_ra_to_aliases);
809: my_syslog(MS_DHCP | LOG_INFO, "RTR-ADVERT(%s) %s => %d alias(es)",
810: param.name, daemon->addrbuff, aparam.num_alias_ifs);
811:
812: /* Allocate memory to store the alias interface
813: indices. */
814: aparam.alias_ifs = (int *)whine_malloc(aparam.num_alias_ifs *
815: sizeof(int));
816: if (aparam.alias_ifs)
817: {
818: /* Use iface_enumerate again to get the alias
819: interface indices, then send on each of
820: those. */
821: aparam.max_alias_ifs = aparam.num_alias_ifs;
822: aparam.num_alias_ifs = 0;
823: iface_enumerate(AF_LOCAL, &aparam, send_ra_to_aliases);
824: for (; aparam.num_alias_ifs; aparam.num_alias_ifs--)
825: {
826: my_syslog(MS_DHCP | LOG_INFO, "RTR-ADVERT(%s) %s => i/f %d",
827: param.name, daemon->addrbuff,
828: aparam.alias_ifs[aparam.num_alias_ifs - 1]);
829: send_ra_alias(now,
830: param.iface,
831: param.name,
832: NULL,
833: aparam.alias_ifs[aparam.num_alias_ifs - 1]);
834: }
835: free(aparam.alias_ifs);
836: }
837:
838: /* The source interface can only appear in at most
839: one --bridge-interface. */
840: break;
841: }
842: }
843: }
844: }
845: return next_event;
846: }
847:
848: static int send_ra_to_aliases(int index, unsigned int type, char *mac, size_t maclen, void *parm)
849: {
850: struct alias_param *aparam = (struct alias_param *)parm;
851: char ifrn_name[IFNAMSIZ];
852: struct dhcp_bridge *alias;
853:
854: (void)type;
855: (void)mac;
856: (void)maclen;
857:
858: if (if_indextoname(index, ifrn_name))
859: for (alias = aparam->bridge->alias; alias; alias = alias->next)
860: if (wildcard_matchn(alias->iface, ifrn_name, IFNAMSIZ))
861: {
862: if (aparam->alias_ifs && (aparam->num_alias_ifs < aparam->max_alias_ifs))
863: aparam->alias_ifs[aparam->num_alias_ifs] = index;
864: aparam->num_alias_ifs++;
865: }
866:
867: return 1;
868: }
869:
870: static int iface_search(struct in6_addr *local, int prefix,
871: int scope, int if_index, int flags,
872: int preferred, int valid, void *vparam)
873: {
874: struct search_param *param = vparam;
875: struct dhcp_context *context;
876:
877: (void)scope;
878: (void)preferred;
879: (void)valid;
880:
881: for (context = daemon->dhcp6; context; context = context->next)
882: if (!(context->flags & (CONTEXT_TEMPLATE | CONTEXT_OLD)) &&
883: prefix <= context->prefix &&
884: is_same_net6(local, &context->start6, context->prefix) &&
885: is_same_net6(local, &context->end6, context->prefix) &&
886: context->ra_time != 0 &&
887: difftime(context->ra_time, param->now) <= 0.0)
888: {
889: /* found an interface that's overdue for RA determine new
890: timeout value and arrange for RA to be sent unless interface is
891: still doing DAD.*/
892:
893: if (!(flags & IFACE_TENTATIVE))
894: param->iface = if_index;
895:
896: /* should never fail */
897: if (!indextoname(daemon->icmp6fd, if_index, param->name))
898: {
899: param->iface = 0;
900: return 0;
901: }
902:
903: new_timeout(context, param->name, param->now);
904:
905: /* zero timers for other contexts on the same subnet, so they don't timeout
906: independently */
907: for (context = context->next; context; context = context->next)
908: if (prefix <= context->prefix &&
909: is_same_net6(local, &context->start6, context->prefix) &&
910: is_same_net6(local, &context->end6, context->prefix))
911: context->ra_time = 0;
912:
913: return 0; /* found, abort */
914: }
915:
916: return 1; /* keep searching */
917: }
918:
919: static void new_timeout(struct dhcp_context *context, char *iface_name, time_t now)
920: {
921: if (difftime(now, context->ra_short_period_start) < 60.0)
922: /* range 5 - 20 */
923: context->ra_time = now + 5 + (rand16()/4400);
924: else
925: {
926: /* range 3/4 - 1 times MaxRtrAdvInterval */
927: unsigned int adv_interval = calc_interval(find_iface_param(iface_name));
928: context->ra_time = now + (3 * adv_interval)/4 + ((adv_interval * (unsigned int)rand16()) >> 18);
929: }
930: }
931:
932: static struct ra_interface *find_iface_param(char *iface)
933: {
934: struct ra_interface *ra;
935:
936: for (ra = daemon->ra_interfaces; ra; ra = ra->next)
937: if (wildcard_match(ra->name, iface))
938: return ra;
939:
940: return NULL;
941: }
942:
943: static unsigned int calc_interval(struct ra_interface *ra)
944: {
945: int interval = 600;
946:
947: if (ra && ra->interval != 0)
948: {
949: interval = ra->interval;
950: if (interval > 1800)
951: interval = 1800;
952: else if (interval < 4)
953: interval = 4;
954: }
955:
956: return (unsigned int)interval;
957: }
958:
959: static unsigned int calc_lifetime(struct ra_interface *ra)
960: {
961: int lifetime, interval = (int)calc_interval(ra);
962:
963: if (!ra || ra->lifetime == -1) /* not specified */
964: lifetime = 3 * interval;
965: else
966: {
967: lifetime = ra->lifetime;
968: if (lifetime < interval && lifetime != 0)
969: lifetime = interval;
970: else if (lifetime > 9000)
971: lifetime = 9000;
972: }
973:
974: return (unsigned int)lifetime;
975: }
976:
977: static unsigned int calc_prio(struct ra_interface *ra)
978: {
979: if (ra)
980: return ra->prio;
981:
982: return 0;
983: }
984:
985: #endif
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