1 /* vi: set sw=4 ts=4: */
6 * WARNING: THIS CODE IS INCOMPLETE. IT IS NOWHERE NEAR
7 * TO BE READY FOR PRODUCTION USE.
9 * Copyright (C) 2011 Denys Vlasenko.
11 * Licensed under GPLv2, see file LICENSE in this source tree.
14 //config:config UDHCPC6
15 //config: bool "udhcpc6 (DHCPv6 client, NOT READY)"
16 //config: default n # not yet ready
17 //config: depends on FEATURE_IPV6
19 //config: udhcpc6 is a DHCPv6 client
21 //applet:IF_UDHCPC6(APPLET(udhcpc6, BB_DIR_USR_BIN, BB_SUID_DROP))
23 //kbuild:lib-$(CONFIG_UDHCPC6) += d6_dhcpc.o d6_packet.o d6_socket.o common.o socket.o signalpipe.o
27 /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
28 #define WANT_PIDFILE 1
32 #include "d6_common.h"
34 #include <netinet/if_ether.h>
35 #include <netpacket/packet.h>
36 #include <linux/filter.h>
38 /* "struct client_config_t client_config" is in bb_common_bufsiz1 */
42 static const char udhcpc6_longopts[] ALIGN1 =
43 "interface\0" Required_argument "i"
44 "now\0" No_argument "n"
45 "pidfile\0" Required_argument "p"
46 "quit\0" No_argument "q"
47 "release\0" No_argument "R"
48 "request\0" Required_argument "r"
49 "script\0" Required_argument "s"
50 "timeout\0" Required_argument "T"
51 "retries\0" Required_argument "t"
52 "tryagain\0" Required_argument "A"
53 "syslog\0" No_argument "S"
54 "request-option\0" Required_argument "O"
55 "no-default-options\0" No_argument "o"
56 "foreground\0" No_argument "f"
57 "background\0" No_argument "b"
58 /// IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
59 IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
62 /* Must match getopt32 option string order */
79 /* The rest has variable bit positions, need to be clever */
81 USE_FOR_MMU( OPTBIT_b,)
82 ///IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
83 IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
84 USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
85 ///IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
86 IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
90 /*** Utility functions ***/
92 static void *d6_find_option(uint8_t *option, uint8_t *option_end, unsigned code)
94 /* "length minus 4" */
95 int len_m4 = option_end - option - 4;
97 /* Next option's len is too big? */
98 if (option[3] > len_m4)
99 return NULL; /* yes. bogus packet! */
100 /* So far we treat any opts with code >255
101 * or len >255 as bogus, and stop at once.
102 * This simplifies big-endian handling.
104 if (option[0] != 0 || option[2] != 0)
106 /* Option seems to be valid */
107 /* Does its code match? */
108 if (option[1] == code)
109 return option; /* yes! */
110 option += option[3] + 4;
111 len_m4 -= option[3] + 4;
116 static void *d6_copy_option(uint8_t *option, uint8_t *option_end, unsigned code)
118 uint8_t *opt = d6_find_option(option, option_end, code);
121 return xmemdup(opt, opt[3] + 4);
124 static void *d6_store_blob(void *dst, const void *src, unsigned len)
126 memcpy(dst, src, len);
131 /*** Script execution code ***/
133 static char** new_env(void)
135 client6_data.env_ptr = xrealloc_vector(client6_data.env_ptr, 3, client6_data.env_idx);
136 return &client6_data.env_ptr[client6_data.env_idx++];
139 /* put all the parameters into the environment */
140 static void option_to_env(uint8_t *option, uint8_t *option_end)
142 /* "length minus 4" */
143 int len_m4 = option_end - option - 4;
144 while (len_m4 >= 0) {
146 char ipv6str[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff")];
148 if (option[0] != 0 || option[2] != 0)
152 //case D6_OPT_CLIENTID:
153 //case D6_OPT_SERVERID:
156 option_to_env(option + 16, option + 4 + option[3]);
161 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
162 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
163 * | OPTION_IAADDR | option-len |
164 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
170 * | preferred-lifetime |
171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
173 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
175 sprint_nip6(ipv6str, option + 4);
176 *new_env() = xasprintf("ipv6=%s", ipv6str);
178 move_from_unaligned32(v32, option + 4 + 16 + 4);
179 *new_env() = xasprintf("lease=%u", (unsigned)v32);
183 //case D6_OPT_PREFERENCE:
184 //case D6_OPT_ELAPSED_TIME:
185 //case D6_OPT_RELAY_MSG:
187 //case D6_OPT_UNICAST:
188 //case D6_OPT_STATUS_CODE:
189 //case D6_OPT_RAPID_COMMIT:
190 //case D6_OPT_USER_CLASS:
191 //case D6_OPT_VENDOR_CLASS:
192 //case D6_OPT_VENDOR_OPTS:
193 //case D6_OPT_INTERFACE_ID:
194 //case D6_OPT_RECONF_MSG:
195 //case D6_OPT_RECONF_ACCEPT:
197 case D6_OPT_IAPREFIX:
199 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
200 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
201 * | OPTION_IAPREFIX | option-length |
202 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
203 * | preferred-lifetime |
204 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
206 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
207 * | prefix-length | |
208 * +-+-+-+-+-+-+-+-+ IPv6 prefix |
211 * | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
215 //move_from_unaligned32(v32, option + 4 + 4);
216 //*new_env() = xasprintf("lease=%u", (unsigned)v32);
218 sprint_nip6(ipv6str, option + 4 + 4 + 1);
219 *new_env() = xasprintf("ipv6prefix=%s/%u", ipv6str, (unsigned)(option[4 + 4]));
221 option += 4 + option[3];
222 len_m4 -= 4 + option[3];
226 static char **fill_envp(struct d6_packet *packet)
230 client6_data.env_ptr = NULL;
231 client6_data.env_idx = 0;
233 *new_env() = xasprintf("interface=%s", client_config.interface);
236 option_to_env(packet->d6_options, packet->d6_options + sizeof(packet->d6_options));
238 envp = curr = client6_data.env_ptr;
245 /* Call a script with a par file and env vars */
246 static void d6_run_script(struct d6_packet *packet, const char *name)
251 envp = fill_envp(packet);
254 log1("executing %s %s", client_config.script, name);
255 argv[0] = (char*) client_config.script;
256 argv[1] = (char*) name;
258 spawn_and_wait(argv);
260 for (curr = envp; *curr; curr++) {
262 bb_unsetenv_and_free(*curr);
268 /*** Sending/receiving packets ***/
270 static ALWAYS_INLINE uint32_t random_xid(void)
272 uint32_t t = rand() & htonl(0x00ffffff);
276 /* Initialize the packet with the proper defaults */
277 static uint8_t *init_d6_packet(struct d6_packet *packet, char type, uint32_t xid)
279 struct d6_option *clientid;
281 memset(packet, 0, sizeof(*packet));
283 packet->d6_xid32 = xid;
284 packet->d6_msg_type = type;
286 clientid = (void*)client_config.clientid;
287 return d6_store_blob(packet->d6_options, clientid, clientid->len + 2+2);
290 static uint8_t *add_d6_client_options(uint8_t *ptr)
296 /* Add a "param req" option with the list of options we'd like to have
297 * from stubborn DHCP servers. Pull the data from the struct in common.c.
298 * No bounds checking because it goes towards the head of the packet. */
301 /* Add -x options if any */
305 static int d6_mcast_from_client_config_ifindex(struct d6_packet *packet, uint8_t *end)
307 static const uint8_t FF02__1_2[16] = {
308 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
309 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02,
312 return d6_send_raw_packet(
313 packet, (end - (uint8_t*) packet),
314 /*src*/ NULL, CLIENT_PORT6,
315 /*dst*/ (struct in6_addr*)FF02__1_2, SERVER_PORT6, MAC_BCAST_ADDR,
316 client_config.ifindex
320 /* Milticast a DHCPv6 Solicit packet to the network, with an optionally requested IP.
322 * RFC 3315 17.1.1. Creation of Solicit Messages
324 * The client MUST include a Client Identifier option to identify itself
325 * to the server. The client includes IA options for any IAs to which
326 * it wants the server to assign addresses. The client MAY include
327 * addresses in the IAs as a hint to the server about addresses for
328 * which the client has a preference. ...
330 * The client uses IA_NA options to request the assignment of non-
331 * temporary addresses and uses IA_TA options to request the assignment
332 * of temporary addresses. Either IA_NA or IA_TA options, or a
333 * combination of both, can be included in DHCP messages.
335 * The client SHOULD include an Option Request option (see section 22.7)
336 * to indicate the options the client is interested in receiving. The
337 * client MAY additionally include instances of those options that are
338 * identified in the Option Request option, with data values as hints to
339 * the server about parameter values the client would like to have
342 * The client includes a Reconfigure Accept option (see section 22.20)
343 * if the client is willing to accept Reconfigure messages from the
345 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
346 | OPTION_CLIENTID | option-len |
347 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
350 . (variable length) .
352 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
355 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
356 | OPTION_IA_NA | option-len |
357 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
359 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
361 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
363 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
367 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
370 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
371 | OPTION_IAADDR | option-len |
372 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
377 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
378 | preferred-lifetime |
379 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
381 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
385 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
388 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
389 | OPTION_ORO | option-len |
390 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
391 | requested-option-code-1 | requested-option-code-2 |
392 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
394 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
397 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
398 | OPTION_RECONF_ACCEPT | 0 |
399 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
401 /* NOINLINE: limit stack usage in caller */
402 static NOINLINE int send_d6_discover(uint32_t xid, struct in6_addr *requested_ipv6)
404 struct d6_packet packet;
408 /* Fill in: msg type, client id */
409 opt_ptr = init_d6_packet(&packet, D6_MSG_SOLICIT, xid);
411 /* Create new IA_NA, optionally with included IAADDR with requested IP */
412 free(client6_data.ia_na);
413 len = requested_ipv6 ? 2+2+4+4+4 + 2+2+16+4+4 : 2+2+4+4+4;
414 client6_data.ia_na = xzalloc(len);
415 client6_data.ia_na->code = D6_OPT_IA_NA;
416 client6_data.ia_na->len = len - 4;
417 *(uint32_t*)client6_data.ia_na->data = rand(); /* IAID */
418 if (requested_ipv6) {
419 struct d6_option *iaaddr = (void*)(client6_data.ia_na->data + 4+4+4);
420 iaaddr->code = D6_OPT_IAADDR;
421 iaaddr->len = 16+4+4;
422 memcpy(iaaddr->data, requested_ipv6, 16);
424 opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, len);
427 * "param req" option according to -O, options specified with -x
429 opt_ptr = add_d6_client_options(opt_ptr);
431 bb_error_msg("sending %s", "discover");
432 return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
435 /* Multicast a DHCPv6 request message
437 * RFC 3315 18.1.1. Creation and Transmission of Request Messages
439 * The client uses a Request message to populate IAs with addresses and
440 * obtain other configuration information. The client includes one or
441 * more IA options in the Request message. The server then returns
442 * addresses and other information about the IAs to the client in IA
443 * options in a Reply message.
445 * The client generates a transaction ID and inserts this value in the
446 * "transaction-id" field.
448 * The client places the identifier of the destination server in a
449 * Server Identifier option.
451 * The client MUST include a Client Identifier option to identify itself
452 * to the server. The client adds any other appropriate options,
453 * including one or more IA options (if the client is requesting that
454 * the server assign it some network addresses).
456 * The client MUST include an Option Request option (see section 22.7)
457 * to indicate the options the client is interested in receiving. The
458 * client MAY include options with data values as hints to the server
459 * about parameter values the client would like to have returned.
461 * The client includes a Reconfigure Accept option (see section 22.20)
462 * indicating whether or not the client is willing to accept Reconfigure
463 * messages from the server.
465 /* NOINLINE: limit stack usage in caller */
466 static NOINLINE int send_d6_select(uint32_t xid)
468 struct d6_packet packet;
471 /* Fill in: msg type, client id */
472 opt_ptr = init_d6_packet(&packet, D6_MSG_REQUEST, xid);
475 opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
476 /* IA NA (contains requested IP) */
477 opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
480 * "param req" option according to -O, options specified with -x
482 opt_ptr = add_d6_client_options(opt_ptr);
484 bb_error_msg("sending %s", "select");
485 return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
488 /* Unicast or broadcast a DHCP renew message
490 * RFC 3315 18.1.3. Creation and Transmission of Renew Messages
492 * To extend the valid and preferred lifetimes for the addresses
493 * associated with an IA, the client sends a Renew message to the server
494 * from which the client obtained the addresses in the IA containing an
495 * IA option for the IA. The client includes IA Address options in the
496 * IA option for the addresses associated with the IA. The server
497 * determines new lifetimes for the addresses in the IA according to the
498 * administrative configuration of the server. The server may also add
499 * new addresses to the IA. The server may remove addresses from the IA
500 * by setting the preferred and valid lifetimes of those addresses to
503 * The server controls the time at which the client contacts the server
504 * to extend the lifetimes on assigned addresses through the T1 and T2
505 * parameters assigned to an IA.
507 * At time T1 for an IA, the client initiates a Renew/Reply message
508 * exchange to extend the lifetimes on any addresses in the IA. The
509 * client includes an IA option with all addresses currently assigned to
510 * the IA in its Renew message.
512 * If T1 or T2 is set to 0 by the server (for an IA_NA) or there are no
513 * T1 or T2 times (for an IA_TA), the client may send a Renew or Rebind
514 * message, respectively, at the client's discretion.
516 * The client sets the "msg-type" field to RENEW. The client generates
517 * a transaction ID and inserts this value in the "transaction-id"
520 * The client places the identifier of the destination server in a
521 * Server Identifier option.
523 * The client MUST include a Client Identifier option to identify itself
524 * to the server. The client adds any appropriate options, including
525 * one or more IA options. The client MUST include the list of
526 * addresses the client currently has associated with the IAs in the
529 * The client MUST include an Option Request option (see section 22.7)
530 * to indicate the options the client is interested in receiving. The
531 * client MAY include options with data values as hints to the server
532 * about parameter values the client would like to have returned.
534 /* NOINLINE: limit stack usage in caller */
535 static NOINLINE int send_d6_renew(uint32_t xid, struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
537 struct d6_packet packet;
540 /* Fill in: msg type, client id */
541 opt_ptr = init_d6_packet(&packet, DHCPREQUEST, xid);
544 opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
545 /* IA NA (contains requested IP) */
546 opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
549 * "param req" option according to -O, options specified with -x
551 opt_ptr = add_d6_client_options(opt_ptr);
553 bb_error_msg("sending %s", "renew");
555 return d6_send_kernel_packet(
556 &packet, (opt_ptr - (uint8_t*) &packet),
557 our_cur_ipv6, CLIENT_PORT6,
558 server_ipv6, SERVER_PORT6
560 return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
563 /* Unicast a DHCP release message */
564 static int send_d6_release(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
566 struct d6_packet packet;
569 /* Fill in: msg type, client id */
570 opt_ptr = init_d6_packet(&packet, D6_MSG_RELEASE, random_xid());
572 opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
573 /* IA NA (contains our current IP) */
574 opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
576 bb_error_msg("sending %s", "release");
577 return d6_send_kernel_packet(
578 &packet, (opt_ptr - (uint8_t*) &packet),
579 our_cur_ipv6, CLIENT_PORT6,
580 server_ipv6, SERVER_PORT6
584 /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
585 /* NOINLINE: limit stack usage in caller */
586 static NOINLINE int d6_recv_raw_packet(struct in6_addr *peer_ipv6
588 , struct d6_packet *d6_pkt, int fd)
591 struct ip6_udp_d6_packet packet;
593 bytes = safe_read(fd, &packet, sizeof(packet));
595 log1("packet read error, ignoring");
596 /* NB: possible down interface, etc. Caller should pause. */
597 return bytes; /* returns -1 */
600 if (bytes < (int) (sizeof(packet.ip6) + sizeof(packet.udp))) {
601 log1("packet is too short, ignoring");
605 if (bytes < sizeof(packet.ip6) + ntohs(packet.ip6.ip6_plen)) {
606 /* packet is bigger than sizeof(packet), we did partial read */
607 log1("oversized packet, ignoring");
611 /* ignore any extra garbage bytes */
612 bytes = sizeof(packet.ip6) + ntohs(packet.ip6.ip6_plen);
614 /* make sure its the right packet for us, and that it passes sanity checks */
615 if (packet.ip6.ip6_nxt != IPPROTO_UDP
616 || (packet.ip6.ip6_vfc >> 4) != 6
617 || packet.udp.dest != htons(CLIENT_PORT6)
618 /* || bytes > (int) sizeof(packet) - can't happen */
619 || packet.udp.len != packet.ip6.ip6_plen
621 log1("unrelated/bogus packet, ignoring");
625 //How to do this for ipv6?
626 // /* verify UDP checksum. IP header has to be modified for this */
627 // memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
628 // /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
629 // packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
630 // check = packet.udp.check;
631 // packet.udp.check = 0;
632 // if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
633 // log1("packet with bad UDP checksum received, ignoring");
637 log1("received %s", "a packet");
638 d6_dump_packet(&packet.data);
640 bytes -= sizeof(packet.ip6) + sizeof(packet.udp);
641 memcpy(d6_pkt, &packet.data, bytes);
648 static int sockfd = -1;
650 #define LISTEN_NONE 0
651 #define LISTEN_KERNEL 1
653 static smallint listen_mode;
655 /* initial state: (re)start DHCP negotiation */
656 #define INIT_SELECTING 0
657 /* discover was sent, DHCPOFFER reply received */
659 /* select/renew was sent, DHCPACK reply received */
661 /* half of lease passed, want to renew it by sending unicast renew requests */
663 /* renew requests were not answered, lease is almost over, send broadcast renew */
665 /* manually requested renew (SIGUSR1) */
666 #define RENEW_REQUESTED 5
667 /* release, possibly manually requested (SIGUSR2) */
669 static smallint state;
671 static int d6_raw_socket(int ifindex)
674 struct sockaddr_ll sock;
679 * I've selected not to see LL header, so BPF doesn't see it, too.
680 * The filter may also pass non-IP and non-ARP packets, but we do
681 * a more complete check when receiving the message in userspace.
683 * and filter shamelessly stolen from:
685 * http://www.flamewarmaster.de/software/dhcpclient/
687 * There are a few other interesting ideas on that page (look under
688 * "Motivation"). Use of netlink events is most interesting. Think
689 * of various network servers listening for events and reconfiguring.
690 * That would obsolete sending HUP signals and/or make use of restarts.
692 * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
695 * TODO: make conditional?
698 static const struct sock_filter filter_instr[] = {
699 /* load 9th byte (protocol) */
700 BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
701 /* jump to L1 if it is IPPROTO_UDP, else to L4 */
702 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
703 /* L1: load halfword from offset 6 (flags and frag offset) */
704 BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
705 /* jump to L4 if any bits in frag offset field are set, else to L2 */
706 BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
707 /* L2: skip IP header (load index reg with header len) */
708 BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
709 /* load udp destination port from halfword[header_len + 2] */
710 BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
711 /* jump to L3 if udp dport is CLIENT_PORT6, else to L4 */
712 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
713 /* L3: accept packet */
714 BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
715 /* L4: discard packet */
716 BPF_STMT(BPF_RET|BPF_K, 0),
718 static const struct sock_fprog filter_prog = {
719 .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
720 /* casting const away: */
721 .filter = (struct sock_filter *) filter_instr,
725 log1("opening raw socket on ifindex %d", ifindex); //log2?
727 fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6));
728 log1("got raw socket fd %d", fd); //log2?
730 sock.sll_family = AF_PACKET;
731 sock.sll_protocol = htons(ETH_P_IPV6);
732 sock.sll_ifindex = ifindex;
733 xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
736 if (CLIENT_PORT6 == 546) {
737 /* Use only if standard port is in use */
738 /* Ignoring error (kernel may lack support for this) */
739 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
740 sizeof(filter_prog)) >= 0)
741 log1("attached filter to raw socket fd %d", fd); // log?
745 log1("created raw socket");
750 static void change_listen_mode(int new_mode)
752 log1("entering listen mode: %s",
753 new_mode != LISTEN_NONE
754 ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
758 listen_mode = new_mode;
763 if (new_mode == LISTEN_KERNEL)
764 sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT6, client_config.interface);
765 else if (new_mode != LISTEN_NONE)
766 sockfd = d6_raw_socket(client_config.ifindex);
767 /* else LISTEN_NONE: sockfd stays closed */
770 /* Called only on SIGUSR1 */
771 static void perform_renew(void)
773 bb_error_msg("performing DHCP renew");
776 change_listen_mode(LISTEN_KERNEL);
779 state = RENEW_REQUESTED;
781 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
782 d6_run_script(NULL, "deconfig");
785 change_listen_mode(LISTEN_RAW);
786 state = INIT_SELECTING;
793 static void perform_d6_release(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
795 /* send release packet */
798 || state == REBINDING
799 || state == RENEW_REQUESTED
801 bb_error_msg("unicasting a release");
802 send_d6_release(server_ipv6, our_cur_ipv6); /* unicast */
804 bb_error_msg("entering released state");
806 * We can be here on: SIGUSR2,
807 * or on exit (SIGTERM) and -R "release on quit" is specified.
808 * Users requested to be notified in all cases, even if not in one
809 * of the states above.
811 d6_run_script(NULL, "deconfig");
812 change_listen_mode(LISTEN_NONE);
816 ///static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
818 /// uint8_t *storage;
819 /// int len = strnlen(str, 255);
820 /// storage = xzalloc(len + extra + OPT_DATA);
821 /// storage[OPT_CODE] = code;
822 /// storage[OPT_LEN] = len + extra;
823 /// memcpy(storage + extra + OPT_DATA, str, len);
828 static void client_background(void)
831 logmode &= ~LOGMODE_STDIO;
832 /* rewrite pidfile, as our pid is different now */
833 write_pidfile(client_config.pidfile);
837 //usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
838 //usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
840 //usage:# define IF_UDHCP_VERBOSE(...)
842 //usage:#define udhcpc6_trivial_usage
843 //usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oR] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n"
844 //usage: " [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]")
845 //usage:#define udhcpc6_full_usage "\n"
846 //usage: IF_LONG_OPTS(
847 //usage: "\n -i,--interface IFACE Interface to use (default eth0)"
848 //usage: "\n -p,--pidfile FILE Create pidfile"
849 //usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
850 //usage: "\n -B,--broadcast Request broadcast replies"
851 //usage: "\n -t,--retries N Send up to N discover packets"
852 //usage: "\n -T,--timeout N Pause between packets (default 3 seconds)"
853 //usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)"
854 //usage: "\n -f,--foreground Run in foreground"
855 //usage: USE_FOR_MMU(
856 //usage: "\n -b,--background Background if lease is not obtained"
858 //usage: "\n -n,--now Exit if lease is not obtained"
859 //usage: "\n -q,--quit Exit after obtaining lease"
860 //usage: "\n -R,--release Release IP on exit"
861 //usage: "\n -S,--syslog Log to syslog too"
862 //usage: IF_FEATURE_UDHCP_PORT(
863 //usage: "\n -P,--client-port N Use port N (default 546)"
865 ////usage: IF_FEATURE_UDHCPC_ARPING(
866 ////usage: "\n -a,--arping Use arping to validate offered address"
868 //usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
869 //usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
870 //usage: "\n -r,--request IP Request this IP address"
871 //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
872 //usage: "\n Examples of string, numeric, and hex byte opts:"
873 //usage: "\n -x hostname:bbox - option 12"
874 //usage: "\n -x lease:3600 - option 51 (lease time)"
875 //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
876 //usage: IF_UDHCP_VERBOSE(
877 //usage: "\n -v Verbose"
880 //usage: IF_NOT_LONG_OPTS(
881 //usage: "\n -i IFACE Interface to use (default eth0)"
882 //usage: "\n -p FILE Create pidfile"
883 //usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
884 //usage: "\n -B Request broadcast replies"
885 //usage: "\n -t N Send up to N discover packets"
886 //usage: "\n -T N Pause between packets (default 3 seconds)"
887 //usage: "\n -A N Wait N seconds (default 20) after failure"
888 //usage: "\n -f Run in foreground"
889 //usage: USE_FOR_MMU(
890 //usage: "\n -b Background if lease is not obtained"
892 //usage: "\n -n Exit if lease is not obtained"
893 //usage: "\n -q Exit after obtaining lease"
894 //usage: "\n -R Release IP on exit"
895 //usage: "\n -S Log to syslog too"
896 //usage: IF_FEATURE_UDHCP_PORT(
897 //usage: "\n -P N Use port N (default 546)"
899 ////usage: IF_FEATURE_UDHCPC_ARPING(
900 ////usage: "\n -a Use arping to validate offered address"
902 //usage: "\n -O OPT Request option OPT from server (cumulative)"
903 //usage: "\n -o Don't request any options (unless -O is given)"
904 //usage: "\n -r IP Request this IP address"
905 //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
906 //usage: "\n Examples of string, numeric, and hex byte opts:"
907 //usage: "\n -x hostname:bbox - option 12"
908 //usage: "\n -x lease:3600 - option 51 (lease time)"
909 //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
910 //usage: IF_UDHCP_VERBOSE(
911 //usage: "\n -v Verbose"
914 //usage: "\nSignals:"
915 //usage: "\n USR1 Renew lease"
916 //usage: "\n USR2 Release lease"
919 int udhcpc6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
920 int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
923 IF_FEATURE_UDHCP_PORT(char *str_P;)
924 void *clientid_mac_ptr;
925 llist_t *list_O = NULL;
926 llist_t *list_x = NULL;
927 int tryagain_timeout = 20;
928 int discover_timeout = 3;
929 int discover_retries = 3;
930 struct in6_addr srv6_buf;
931 struct in6_addr ipv6_buf;
932 struct in6_addr *requested_ipv6;
935 int timeout; /* must be signed */
936 unsigned already_waited_sec;
942 setup_common_bufsiz();
944 /* Default options */
945 IF_FEATURE_UDHCP_PORT(SERVER_PORT6 = 547;)
946 IF_FEATURE_UDHCP_PORT(CLIENT_PORT6 = 546;)
947 client_config.interface = "eth0";
948 client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
950 /* Parse command line */
951 /* O,x: list; -T,-t,-A take numeric param */
952 IF_UDHCP_VERBOSE(opt_complementary = "vv";)
953 IF_LONG_OPTS(applet_long_options = udhcpc6_longopts;)
954 opt = getopt32(argv, "i:np:qRr:s:T:+t:+SA:+O:*ox:*f"
956 ///IF_FEATURE_UDHCPC_ARPING("a")
957 IF_FEATURE_UDHCP_PORT("P:")
959 , &client_config.interface, &client_config.pidfile, &str_r /* i,p */
960 , &client_config.script /* s */
961 , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
964 IF_FEATURE_UDHCP_PORT(, &str_P)
965 IF_UDHCP_VERBOSE(, &dhcp_verbose)
967 requested_ipv6 = NULL;
969 if (inet_pton(AF_INET6, str_r, &ipv6_buf) <= 0)
970 bb_error_msg_and_die("bad IPv6 address '%s'", str_r);
971 requested_ipv6 = &ipv6_buf;
973 #if ENABLE_FEATURE_UDHCP_PORT
975 CLIENT_PORT6 = xatou16(str_P);
976 SERVER_PORT6 = CLIENT_PORT6 + 1;
980 char *optstr = llist_pop(&list_O);
981 unsigned n = bb_strtou(optstr, NULL, 0);
982 if (errno || n > 254) {
983 n = udhcp_option_idx(optstr);
984 n = dhcp_optflags[n].code;
986 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
988 if (!(opt & OPT_o)) {
991 for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
992 if (dhcp_optflags[i].flags & OPTION_REQ) {
993 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
999 char *optstr = llist_pop(&list_x);
1000 char *colon = strchr(optstr, ':');
1003 /* now it looks similar to udhcpd's config file line:
1004 * "optname optval", using the common routine: */
1005 udhcp_str2optset(optstr, &client_config.options);
1008 if (udhcp_read_interface(client_config.interface,
1009 &client_config.ifindex,
1011 client_config.client_mac)
1016 /* Create client ID based on mac, set clientid_mac_ptr */
1018 struct d6_option *clientid;
1019 clientid = xzalloc(2+2+2+2+6);
1020 clientid->code = D6_OPT_CLIENTID;
1021 clientid->len = 2+2+6;
1022 clientid->data[1] = 3; /* DUID-LL */
1023 clientid->data[3] = 1; /* ethernet */
1024 clientid_mac_ptr = clientid->data + 2+2;
1025 memcpy(clientid_mac_ptr, client_config.client_mac, 6);
1026 client_config.clientid = (void*)clientid;
1030 /* on NOMMU reexec (i.e., background) early */
1031 if (!(opt & OPT_f)) {
1032 bb_daemonize_or_rexec(0 /* flags */, argv);
1033 logmode = LOGMODE_NONE;
1037 openlog(applet_name, LOG_PID, LOG_DAEMON);
1038 logmode |= LOGMODE_SYSLOG;
1041 /* Make sure fd 0,1,2 are open */
1042 bb_sanitize_stdio();
1043 /* Equivalent of doing a fflush after every \n */
1045 /* Create pidfile */
1046 write_pidfile(client_config.pidfile);
1047 /* Goes to stdout (unless NOMMU) and possibly syslog */
1048 bb_error_msg("started, v"BB_VER);
1049 /* Set up the signal pipe */
1051 /* We want random_xid to be random... */
1052 srand(monotonic_us());
1054 state = INIT_SELECTING;
1055 d6_run_script(NULL, "deconfig");
1056 change_listen_mode(LISTEN_RAW);
1059 already_waited_sec = 0;
1061 /* Main event loop. select() waits on signal pipe and possibly
1063 * "continue" statements in code below jump to the top of the loop.
1067 struct d6_packet packet;
1068 uint8_t *packet_end;
1069 /* silence "uninitialized!" warning */
1070 unsigned timestamp_before_wait = timestamp_before_wait;
1072 //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
1074 /* Was opening raw or udp socket here
1075 * if (listen_mode != LISTEN_NONE && sockfd < 0),
1076 * but on fast network renew responses return faster
1077 * than we open sockets. Thus this code is moved
1078 * to change_listen_mode(). Thus we open listen socket
1079 * BEFORE we send renew request (see "case BOUND:"). */
1081 max_fd = udhcp_sp_fd_set(&rfds, sockfd);
1083 tv.tv_sec = timeout - already_waited_sec;
1086 /* If we already timed out, fall through with retval = 0, else... */
1087 if ((int)tv.tv_sec > 0) {
1088 log1("waiting on select %u seconds", (int)tv.tv_sec);
1089 timestamp_before_wait = (unsigned)monotonic_sec();
1090 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
1092 /* EINTR? A signal was caught, don't panic */
1093 if (errno == EINTR) {
1094 already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
1097 /* Else: an error occured, panic! */
1098 bb_perror_msg_and_die("select");
1102 /* If timeout dropped to zero, time to become active:
1103 * resend discover/renew/whatever
1106 /* When running on a bridge, the ifindex may have changed
1107 * (e.g. if member interfaces were added/removed
1108 * or if the status of the bridge changed).
1109 * Refresh ifindex and client_mac:
1111 if (udhcp_read_interface(client_config.interface,
1112 &client_config.ifindex,
1114 client_config.client_mac)
1116 goto ret0; /* iface is gone? */
1118 memcpy(clientid_mac_ptr, client_config.client_mac, 6);
1120 /* We will restart the wait in any case */
1121 already_waited_sec = 0;
1124 case INIT_SELECTING:
1125 if (!discover_retries || packet_num < discover_retries) {
1126 if (packet_num == 0)
1129 send_d6_discover(xid, requested_ipv6);
1130 timeout = discover_timeout;
1135 d6_run_script(NULL, "leasefail");
1136 #if BB_MMU /* -b is not supported on NOMMU */
1137 if (opt & OPT_b) { /* background if no lease */
1138 bb_error_msg("no lease, forking to background");
1139 client_background();
1140 /* do not background again! */
1141 opt = ((opt & ~OPT_b) | OPT_f);
1144 if (opt & OPT_n) { /* abort if no lease */
1145 bb_error_msg("no lease, failing");
1149 /* wait before trying again */
1150 timeout = tryagain_timeout;
1154 if (!discover_retries || packet_num < discover_retries) {
1155 /* send multicast select packet */
1156 send_d6_select(xid);
1157 timeout = discover_timeout;
1161 /* Timed out, go back to init state.
1162 * "discover...select...discover..." loops
1163 * were seen in the wild. Treat them similarly
1164 * to "no response to discover" case */
1165 change_listen_mode(LISTEN_RAW);
1166 state = INIT_SELECTING;
1169 /* 1/2 lease passed, enter renewing state */
1171 client_config.first_secs = 0; /* make secs field count from 0 */
1172 change_listen_mode(LISTEN_KERNEL);
1173 log1("entering renew state");
1174 /* fall right through */
1175 case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
1176 case_RENEW_REQUESTED:
1179 /* send an unicast renew request */
1180 /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
1181 * a new UDP socket for sending inside send_renew.
1182 * I hazard to guess existing listening socket
1183 * is somehow conflicting with it, but why is it
1184 * not deterministic then?! Strange.
1185 * Anyway, it does recover by eventually failing through
1186 * into INIT_SELECTING state.
1188 send_d6_renew(xid, &srv6_buf, requested_ipv6);
1192 /* Timed out, enter rebinding state */
1193 log1("entering rebinding state");
1195 /* fall right through */
1197 /* Switch to bcast receive */
1198 change_listen_mode(LISTEN_RAW);
1199 /* Lease is *really* about to run out,
1200 * try to find DHCP server using broadcast */
1202 /* send a broadcast renew request */
1203 send_d6_renew(xid, /*server_ipv6:*/ NULL, requested_ipv6);
1207 /* Timed out, enter init state */
1208 bb_error_msg("lease lost, entering init state");
1209 d6_run_script(NULL, "deconfig");
1210 state = INIT_SELECTING;
1211 client_config.first_secs = 0; /* make secs field count from 0 */
1212 /*timeout = 0; - already is */
1215 /* case RELEASED: */
1217 /* yah, I know, *you* say it would never happen */
1219 continue; /* back to main loop */
1220 } /* if select timed out */
1222 /* select() didn't timeout, something happened */
1224 /* Is it a signal? */
1225 /* note: udhcp_sp_read checks FD_ISSET before reading */
1226 switch (udhcp_sp_read(&rfds)) {
1228 client_config.first_secs = 0; /* make secs field count from 0 */
1229 already_waited_sec = 0;
1231 if (state == RENEW_REQUESTED) {
1232 /* We might be either on the same network
1233 * (in which case renew might work),
1234 * or we might be on a completely different one
1235 * (in which case renew won't ever succeed).
1236 * For the second case, must make sure timeout
1237 * is not too big, or else we can send
1238 * futile renew requests for hours.
1239 * (Ab)use -A TIMEOUT value (usually 20 sec)
1240 * as a cap on the timeout.
1242 if (timeout > tryagain_timeout)
1243 timeout = tryagain_timeout;
1244 goto case_RENEW_REQUESTED;
1246 /* Start things over */
1248 /* Kill any timeouts, user wants this to hurry along */
1252 perform_d6_release(&srv6_buf, requested_ipv6);
1256 bb_error_msg("received %s", "SIGTERM");
1260 /* Is it a packet? */
1261 if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
1267 /* A packet is ready, read it */
1268 if (listen_mode == LISTEN_KERNEL)
1269 len = d6_recv_kernel_packet(&srv6_buf, &packet, sockfd);
1271 len = d6_recv_raw_packet(&srv6_buf, &packet, sockfd);
1273 /* Error is severe, reopen socket */
1274 bb_error_msg("read error: %s, reopening socket", strerror(errno));
1275 sleep(discover_timeout); /* 3 seconds by default */
1276 change_listen_mode(listen_mode); /* just close and reopen */
1278 /* If this packet will turn out to be unrelated/bogus,
1279 * we will go back and wait for next one.
1280 * Be sure timeout is properly decreased. */
1281 already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
1284 packet_end = (uint8_t*)&packet + len;
1287 if ((packet.d6_xid32 & htonl(0x00ffffff)) != xid) {
1288 log1("xid %x (our is %x), ignoring packet",
1289 (unsigned)(packet.d6_xid32 & htonl(0x00ffffff)), (unsigned)xid);
1294 case INIT_SELECTING:
1295 if (packet.d6_msg_type == D6_MSG_ADVERTISE)
1297 /* DHCPv6 has "Rapid Commit", when instead of Advertise,
1298 * server sends Reply right away.
1299 * Fall through to check for this case.
1303 case RENEW_REQUESTED:
1305 if (packet.d6_msg_type == D6_MSG_REPLY) {
1306 uint32_t lease_seconds;
1307 struct d6_option *option, *iaaddr;
1309 option = d6_find_option(packet.d6_options, packet_end, D6_OPT_STATUS_CODE);
1310 if (option && option->data[4] != 0) {
1311 /* return to init state */
1312 bb_error_msg("received DHCP NAK (%u)", option->data[4]);
1313 d6_run_script(&packet, "nak");
1314 if (state != REQUESTING)
1315 d6_run_script(NULL, "deconfig");
1316 change_listen_mode(LISTEN_RAW);
1317 sleep(3); /* avoid excessive network traffic */
1318 state = INIT_SELECTING;
1319 client_config.first_secs = 0; /* make secs field count from 0 */
1320 requested_ipv6 = NULL;
1323 already_waited_sec = 0;
1326 option = d6_copy_option(packet.d6_options, packet_end, D6_OPT_SERVERID);
1328 bb_error_msg("no server ID, ignoring packet");
1330 /* still selecting - this server looks bad */
1332 //Note: we do not bother comparing server IDs in Advertise and Reply msgs.
1333 //server_id variable is used solely for creation of proper server_id option
1334 //in outgoing packets. (why DHCPv6 even introduced it is a mystery).
1335 free(client6_data.server_id);
1336 client6_data.server_id = option;
1337 if (packet.d6_msg_type == D6_MSG_ADVERTISE) {
1338 /* enter requesting state */
1342 already_waited_sec = 0;
1345 /* It's a D6_MSG_REPLY */
1347 * RFC 3315 18.1.8. Receipt of Reply Messages
1349 * Upon the receipt of a valid Reply message in response to a Solicit
1350 * (with a Rapid Commit option), Request, Confirm, Renew, Rebind or
1351 * Information-request message, the client extracts the configuration
1352 * information contained in the Reply. The client MAY choose to report
1353 * any status code or message from the status code option in the Reply
1356 * The client SHOULD perform duplicate address detection [17] on each of
1357 * the addresses in any IAs it receives in the Reply message before
1358 * using that address for traffic. If any of the addresses are found to
1359 * be in use on the link, the client sends a Decline message to the
1360 * server as described in section 18.1.7.
1362 * If the Reply was received in response to a Solicit (with a Rapid
1363 * Commit option), Request, Renew or Rebind message, the client updates
1364 * the information it has recorded about IAs from the IA options
1365 * contained in the Reply message:
1367 * - Record T1 and T2 times.
1369 * - Add any new addresses in the IA option to the IA as recorded by
1372 * - Update lifetimes for any addresses in the IA option that the
1373 * client already has recorded in the IA.
1375 * - Discard any addresses from the IA, as recorded by the client, that
1376 * have a valid lifetime of 0 in the IA Address option.
1378 * - Leave unchanged any information about addresses the client has
1379 * recorded in the IA but that were not included in the IA from the
1382 * Management of the specific configuration information is detailed in
1383 * the definition of each option in section 22.
1385 * If the client receives a Reply message with a Status Code containing
1386 * UnspecFail, the server is indicating that it was unable to process
1387 * the message due to an unspecified failure condition. If the client
1388 * retransmits the original message to the same server to retry the
1389 * desired operation, the client MUST limit the rate at which it
1390 * retransmits the message and limit the duration of the time during
1391 * which it retransmits the message.
1393 * When the client receives a Reply message with a Status Code option
1394 * with the value UseMulticast, the client records the receipt of the
1395 * message and sends subsequent messages to the server through the
1396 * interface on which the message was received using multicast. The
1397 * client resends the original message using multicast.
1399 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1400 * | OPTION_IA_NA | option-len |
1401 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1402 * | IAID (4 octets) |
1403 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1405 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1407 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1411 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1414 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1415 * | OPTION_IAADDR | option-len |
1416 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1421 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1422 * | preferred-lifetime |
1423 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1424 * | valid-lifetime |
1425 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1427 * . IAaddr-options .
1429 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1431 free(client6_data.ia_na);
1432 client6_data.ia_na = d6_copy_option(packet.d6_options, packet_end, D6_OPT_IA_NA);
1433 if (!client6_data.ia_na) {
1434 bb_error_msg("no %s option, ignoring packet", "IA_NA");
1437 if (client6_data.ia_na->len < (4 + 4 + 4) + (2 + 2 + 16 + 4 + 4)) {
1438 bb_error_msg("IA_NA option is too short:%d bytes", client6_data.ia_na->len);
1441 iaaddr = d6_find_option(client6_data.ia_na->data + 4 + 4 + 4,
1442 client6_data.ia_na->data + client6_data.ia_na->len,
1446 bb_error_msg("no %s option, ignoring packet", "IAADDR");
1449 if (iaaddr->len < (16 + 4 + 4)) {
1450 bb_error_msg("IAADDR option is too short:%d bytes", iaaddr->len);
1453 /* Note: the address is sufficiently aligned for cast:
1454 * we _copied_ IA-NA, and copy is always well-aligned.
1456 requested_ipv6 = (struct in6_addr*) iaaddr->data;
1457 move_from_unaligned32(lease_seconds, iaaddr->data + 16 + 4);
1458 lease_seconds = ntohl(lease_seconds);
1459 /* paranoia: must not be too small and not prone to overflows */
1460 if (lease_seconds < 0x10)
1461 lease_seconds = 0x10;
1462 /// TODO: check for 0 lease time?
1463 if (lease_seconds >= 0x10000000)
1464 lease_seconds = 0x0fffffff;
1465 /* enter bound state */
1466 timeout = lease_seconds / 2;
1467 bb_error_msg("lease obtained, lease time %u",
1468 /*inet_ntoa(temp_addr),*/ (unsigned)lease_seconds);
1469 d6_run_script(&packet, state == REQUESTING ? "bound" : "renew");
1472 change_listen_mode(LISTEN_NONE);
1473 if (opt & OPT_q) { /* quit after lease */
1476 /* future renew failures should not exit (JM) */
1478 #if BB_MMU /* NOMMU case backgrounded earlier */
1479 if (!(opt & OPT_f)) {
1480 client_background();
1481 /* do not background again! */
1482 opt = ((opt & ~OPT_b) | OPT_f);
1485 already_waited_sec = 0;
1486 continue; /* back to main loop */
1489 /* case BOUND: - ignore all packets */
1490 /* case RELEASED: - ignore all packets */
1492 /* back to main loop */
1493 } /* for (;;) - main loop ends */
1496 if (opt & OPT_R) /* release on quit */
1497 perform_d6_release(&srv6_buf, requested_ipv6);
1500 /*if (client_config.pidfile) - remove_pidfile has its own check */
1501 remove_pidfile(client_config.pidfile);