1/*
2 * dhcpcd - DHCP client daemon
3 * Copyright (c) 2006-2012 Roy Marples <roy@marples.name>
4 * All rights reserved
5
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <ctype.h>
29#include <errno.h>
30#include <fcntl.h>
31#include <stdlib.h>
32#include <string.h>
33#include <syslog.h>
34#include <unistd.h>
35
36#include "config.h"
37#include "common.h"
38#include "dhcp.h"
39
40#define REQUEST	(1 << 0)
41#define UINT8	(1 << 1)
42#define UINT16	(1 << 2)
43#define SINT16	(1 << 3)
44#define UINT32	(1 << 4)
45#define SINT32	(1 << 5)
46#define IPV4	(1 << 6)
47#define STRING	(1 << 7)
48#define PAIR	(1 << 8)
49#define ARRAY	(1 << 9)
50#define RFC3361	(1 << 10)
51#define RFC3397	(1 << 11)
52#define RFC3442 (1 << 12)
53#define RFC5969 (1 << 13)
54
55#define IPV4R	IPV4 | REQUEST
56
57#define DAD	"Duplicate address detected"
58
59/* Our aggregate option buffer.
60 * We ONLY use this when options are split, which for most purposes is
61 * practically never. See RFC3396 for details. */
62static uint8_t *opt_buffer;
63
64struct dhcp_opt {
65	uint8_t option;
66	int type;
67	const char *var;
68};
69
70static const struct dhcp_opt const dhcp_opts[] = {
71	{ 1,	IPV4 | REQUEST,	"subnet_mask" },
72		/* RFC 3442 states that the CSR has to come before all other
73		 * routes. For completeness, we also specify static routes,
74	 	 * then routers. */
75	{ 121,  RFC3442,	"classless_static_routes" },
76	{ 249,  RFC3442,	"ms_classless_static_routes" },
77	{ 33,	IPV4 | ARRAY | REQUEST,	"static_routes" },
78	{ 3,	IPV4 | ARRAY | REQUEST,	"routers" },
79	{ 2,	UINT32,		"time_offset" },
80	{ 4,	IPV4 | ARRAY,	"time_servers" },
81	{ 5,	IPV4 | ARRAY,	"ien116_name_servers" },
82        /* Explicitly include DNS in the list of parameters requested in the DNS request.
83         * Without this some DHCP servers may skip the DNS entries in the DHCP replies.*/
84	{ 6,	IPV4 | ARRAY | REQUEST, "domain_name_servers" },
85	{ 7,	IPV4 | ARRAY,	"log_servers" },
86	{ 8,	IPV4 | ARRAY,	"cookie_servers" },
87	{ 9, 	IPV4 | ARRAY,	"lpr_servers" },
88	{ 10,	IPV4 | ARRAY,	"impress_servers" },
89	{ 11,	IPV4 | ARRAY,	"resource_location_servers" },
90	{ 12,	STRING,		"host_name" },
91	{ 13,	UINT16,		"boot_size" },
92	{ 14,	STRING,		"merit_dump" },
93        /* Explicitly include DNS in the list of parameters requested in the DNS request.
94         * Without this some DHCP servers may skip the DNS entries in the DHCP replies.*/
95	{ 15,	STRING | REQUEST, "domain_name" },
96	{ 16,	IPV4,		"swap_server" },
97	{ 17,	STRING,		"root_path" },
98	{ 18,	STRING,		"extensions_path" },
99	{ 19,	UINT8,		"ip_forwarding" },
100	{ 20,	UINT8,		"non_local_source_routing" },
101	{ 21,	IPV4 | ARRAY,	"policy_filter" },
102	{ 22,	SINT16,		"max_dgram_reassembly" },
103	{ 23,	UINT16,		"default_ip_ttl" },
104	{ 24,	UINT32,		"path_mtu_aging_timeout" },
105	{ 25,	UINT16 | ARRAY,	"path_mtu_plateau_table" },
106	{ 26,	UINT16,		"interface_mtu" },
107	{ 27,	UINT8,		"all_subnets_local" },
108	{ 28,	IPV4 | REQUEST,	"broadcast_address" },
109	{ 29,	UINT8,		"perform_mask_discovery" },
110	{ 30,	UINT8,		"mask_supplier" },
111	{ 31,	UINT8,		"router_discovery" },
112	{ 32,	IPV4,		"router_solicitation_address" },
113	{ 34,	UINT8,		"trailer_encapsulation" },
114	{ 35, 	UINT32,		"arp_cache_timeout" },
115	{ 36,	UINT16,		"ieee802_3_encapsulation" },
116	{ 37,	UINT8,		"default_tcp_ttl" },
117	{ 38,	UINT32,		"tcp_keepalive_interval" },
118	{ 39,	UINT8,		"tcp_keepalive_garbage" },
119	{ 40,	STRING,		"nis_domain" },
120	{ 41,	IPV4 | ARRAY,	"nis_servers" },
121	{ 42,	IPV4 | ARRAY,	"ntp_servers" },
122	{ 43,	STRING,		"vendor_encapsulated_options" },
123	{ 44,	IPV4 | ARRAY,	"netbios_name_servers" },
124	{ 45,	IPV4,		"netbios_dd_server" },
125	{ 46,	UINT8,		"netbios_node_type" },
126	{ 47,	STRING,		"netbios_scope" },
127	{ 48,	IPV4 | ARRAY,	"font_servers" },
128	{ 49,	IPV4 | ARRAY,	"x_display_manager" },
129	{ 50, 	IPV4,		"dhcp_requested_address" },
130	{ 51,	UINT32 | REQUEST,	"dhcp_lease_time" },
131	{ 52,	UINT8,		"dhcp_option_overload" },
132	{ 53,	UINT8,		"dhcp_message_type" },
133	{ 54,	IPV4,		"dhcp_server_identifier" },
134	{ 55,	UINT8 | ARRAY,	"dhcp_parameter_request_list" },
135	{ 56,	STRING,		"dhcp_message" },
136	{ 57,	UINT16,		"dhcp_max_message_size" },
137	{ 58,	UINT32 | REQUEST,	"dhcp_renewal_time" },
138	{ 59,	UINT32 | REQUEST,	"dhcp_rebinding_time" },
139	{ 64,	STRING,		"nisplus_domain" },
140	{ 65,	IPV4 | ARRAY,	"nisplus_servers" },
141	{ 66,	STRING,		"tftp_server_name" },
142	{ 67,	STRING,		"bootfile_name" },
143	{ 68,	IPV4 | ARRAY,	"mobile_ip_home_agent" },
144	{ 69,	IPV4 | ARRAY,	"smtp_server" },
145	{ 70,	IPV4 | ARRAY,	"pop_server" },
146	{ 71,	IPV4 | ARRAY,	"nntp_server" },
147	{ 72,	IPV4 | ARRAY,	"www_server" },
148	{ 73,	IPV4 | ARRAY,	"finger_server" },
149	{ 74,	IPV4 | ARRAY,	"irc_server" },
150	{ 75,	IPV4 | ARRAY,	"streettalk_server" },
151	{ 76,	IPV4 | ARRAY,	"streettalk_directory_assistance_server" },
152	{ 77,	STRING,		"user_class" },
153	{ 81,	STRING | RFC3397,	"fqdn_name" },
154	{ 85,	IPV4 | ARRAY,	"nds_servers" },
155	{ 86,	STRING,		"nds_tree_name" },
156	{ 87,	STRING,		"nds_context" },
157	{ 88,	STRING | RFC3397,	"bcms_controller_names" },
158	{ 89,	IPV4 | ARRAY,	"bcms_controller_address" },
159	{ 91,	UINT32,		"client_last_transaction_time" },
160	{ 92,	IPV4 | ARRAY,	"associated_ip" },
161	{ 98,	STRING,		"uap_servers" },
162	{ 112,	IPV4 | ARRAY,	"netinfo_server_address" },
163	{ 113,	STRING,		"netinfo_server_tag" },
164	{ 114,	STRING,		"default_url" },
165	{ 118,	IPV4,		"subnet_selection" },
166	{ 119,	STRING | RFC3397,	"domain_search" },
167	{ 120,	STRING | RFC3361,	"sip_server" },
168	{ 212,  RFC5969,	"sixrd" },
169	{ 0, 0, NULL }
170};
171
172static const char *if_params[] = {
173	"interface",
174	"reason",
175	"pid",
176	"ifmetric",
177	"ifwireless",
178	"ifflags",
179	"profile",
180	"interface_order",
181	NULL
182};
183
184static const char *dhcp_params[] = {
185	"ip_address",
186	"subnet_cidr",
187	"network_number",
188	"ssid",
189	"filename",
190	"server_name",
191	NULL
192};
193
194void
195print_options(void)
196{
197	const struct dhcp_opt *opt;
198	const char **p;
199
200	for (p = if_params; *p; p++)
201		printf(" -  %s\n", *p);
202
203	for (p = dhcp_params; *p; p++)
204		printf("    %s\n", *p);
205
206	for (opt = dhcp_opts; opt->option; opt++)
207		if (opt->var)
208			printf("%03d %s\n", opt->option, opt->var);
209}
210
211int make_option_mask(uint8_t *mask, const char *opts, int add)
212{
213	char *token, *o, *p, *t;
214	const struct dhcp_opt *opt;
215	int match, n;
216
217	o = p = xstrdup(opts);
218	while ((token = strsep(&p, ", "))) {
219		if (*token == '\0')
220			continue;
221		for (opt = dhcp_opts; opt->option; opt++) {
222			if (!opt->var)
223				continue;
224			match = 0;
225			if (strcmp(opt->var, token) == 0)
226				match = 1;
227			else {
228				errno = 0;
229				n = strtol(token, &t, 0);
230				if (errno == 0 && !*t)
231					if (opt->option == n)
232						match = 1;
233			}
234			if (match) {
235				if (add == 2 && !(opt->type & IPV4)) {
236					free(o);
237					errno = EINVAL;
238					return -1;
239				}
240				if (add == 1 || add == 2)
241					add_option_mask(mask,
242					    opt->option);
243				else
244					del_option_mask(mask,
245					    opt->option);
246				break;
247			}
248		}
249		if (!opt->option) {
250			free(o);
251			errno = ENOENT;
252			return -1;
253		}
254	}
255	free(o);
256	return 0;
257}
258
259static int
260valid_length(uint8_t option, int dl, int *type)
261{
262	const struct dhcp_opt *opt;
263	ssize_t sz;
264
265	if (dl == 0)
266		return -1;
267
268	for (opt = dhcp_opts; opt->option; opt++) {
269		if (opt->option != option)
270			continue;
271
272		if (type)
273			*type = opt->type;
274
275		if (opt->type == 0 ||
276		    opt->type & (STRING | RFC3442 | RFC5969))
277			return 0;
278
279		sz = 0;
280		if (opt->type & (UINT32 | IPV4))
281			sz = sizeof(uint32_t);
282		if (opt->type & UINT16)
283			sz = sizeof(uint16_t);
284		if (opt->type & UINT8)
285			sz = sizeof(uint8_t);
286		if (opt->type & (IPV4 | ARRAY))
287			return dl % sz;
288		return (dl == sz ? 0 : -1);
289	}
290
291	/* unknown option, so let it pass */
292	return 0;
293}
294
295#ifdef DEBUG_MEMORY
296static void
297free_option_buffer(void)
298{
299	free(opt_buffer);
300}
301#endif
302
303#define get_option_raw(dhcp, opt) get_option(dhcp, opt, NULL, NULL)
304static const uint8_t *
305get_option(const struct dhcp_message *dhcp, uint8_t opt, int *len, int *type)
306{
307	const uint8_t *p = dhcp->options;
308	const uint8_t *e = p + sizeof(dhcp->options);
309	uint8_t l, ol = 0;
310	uint8_t o = 0;
311	uint8_t overl = 0;
312	uint8_t *bp = NULL;
313	const uint8_t *op = NULL;
314	int bl = 0;
315
316	while (p < e) {
317		o = *p++;
318		if (o == opt) {
319			if (op) {
320				if (!opt_buffer) {
321					opt_buffer = xmalloc(sizeof(*dhcp));
322#ifdef DEBUG_MEMORY
323					atexit(free_option_buffer);
324#endif
325				}
326				if (!bp)
327					bp = opt_buffer;
328				memcpy(bp, op, ol);
329				bp += ol;
330			}
331			ol = *p;
332			op = p + 1;
333			bl += ol;
334		}
335		switch (o) {
336		case DHO_PAD:
337			continue;
338		case DHO_END:
339			if (overl & 1) {
340				/* bit 1 set means parse boot file */
341				overl &= ~1;
342				p = dhcp->bootfile;
343				e = p + sizeof(dhcp->bootfile);
344			} else if (overl & 2) {
345				/* bit 2 set means parse server name */
346				overl &= ~2;
347				p = dhcp->servername;
348				e = p + sizeof(dhcp->servername);
349			} else
350				goto exit;
351			break;
352		case DHO_OPTIONSOVERLOADED:
353			/* Ensure we only get this option once */
354			if (!overl)
355				overl = p[1];
356			break;
357		}
358		l = *p++;
359		p += l;
360	}
361
362exit:
363	if (valid_length(opt, bl, type) == -1) {
364		errno = EINVAL;
365		return NULL;
366	}
367	if (len)
368		*len = bl;
369	if (bp) {
370		memcpy(bp, op, ol);
371		return (const uint8_t *)opt_buffer;
372	}
373	if (op)
374		return op;
375	errno = ENOENT;
376	return NULL;
377}
378
379int
380get_option_addr(struct in_addr *a, const struct dhcp_message *dhcp,
381    uint8_t option)
382{
383	const uint8_t *p = get_option_raw(dhcp, option);
384
385	if (!p)
386		return -1;
387	memcpy(&a->s_addr, p, sizeof(a->s_addr));
388	return 0;
389}
390
391int
392get_option_uint32(uint32_t *i, const struct dhcp_message *dhcp, uint8_t option)
393{
394	const uint8_t *p = get_option_raw(dhcp, option);
395	uint32_t d;
396
397	if (!p)
398		return -1;
399	memcpy(&d, p, sizeof(d));
400	*i = ntohl(d);
401	return 0;
402}
403
404int
405get_option_uint16(uint16_t *i, const struct dhcp_message *dhcp, uint8_t option)
406{
407	const uint8_t *p = get_option_raw(dhcp, option);
408	uint16_t d;
409
410	if (!p)
411		return -1;
412	memcpy(&d, p, sizeof(d));
413	*i = ntohs(d);
414	return 0;
415}
416
417int
418get_option_uint8(uint8_t *i, const struct dhcp_message *dhcp, uint8_t option)
419{
420	const uint8_t *p = get_option_raw(dhcp, option);
421
422	if (!p)
423		return -1;
424	if (i)
425		*i = *(p);
426	return 0;
427}
428
429/* Decode an RFC3397 DNS search order option into a space
430 * separated string. Returns length of string (including
431 * terminating zero) or zero on error. out may be NULL
432 * to just determine output length. */
433ssize_t
434decode_rfc3397(char *out, ssize_t len, int pl, const uint8_t *p)
435{
436	const uint8_t *r, *q = p;
437	int count = 0, l, hops;
438	uint8_t ltype;
439
440	while (q - p < pl) {
441		r = NULL;
442		hops = 0;
443		/* We check we are inside our length again incase
444		 * the data is NOT terminated correctly. */
445		while ((l = *q++) && q - p < pl) {
446			ltype = l & 0xc0;
447			if (ltype == 0x80 || ltype == 0x40)
448				return 0;
449			else if (ltype == 0xc0) { /* pointer */
450				l = (l & 0x3f) << 8;
451				l |= *q++;
452				/* save source of first jump. */
453				if (!r)
454					r = q;
455				hops++;
456				if (hops > 255)
457					return 0;
458				q = p + l;
459				if (q - p >= pl)
460					return 0;
461			} else {
462				/* straightforward name segment, add with '.' */
463				count += l + 1;
464				if (out) {
465					if ((ssize_t)l + 1 > len) {
466						errno = ENOBUFS;
467						return -1;
468					}
469					memcpy(out, q, l);
470					out += l;
471					*out++ = '.';
472					len -= l;
473					len--;
474				}
475				q += l;
476			}
477		}
478		/* change last dot to space */
479		if (out)
480			*(out - 1) = ' ';
481		if (r)
482			q = r;
483	}
484
485	/* change last space to zero terminator */
486	if (out)
487		*(out - 1) = 0;
488
489	return count;
490}
491
492static ssize_t
493decode_rfc3442(char *out, ssize_t len, int pl, const uint8_t *p)
494{
495	const uint8_t *e;
496	ssize_t b, bytes = 0, ocets;
497	uint8_t cidr;
498	struct in_addr addr;
499	char *o = out;
500
501	/* Minimum is 5 -first is CIDR and a router length of 4 */
502	if (pl < 5) {
503		errno = EINVAL;
504		return -1;
505	}
506
507	e = p + pl;
508	while (p < e) {
509		cidr = *p++;
510		if (cidr > 32) {
511			errno = EINVAL;
512			return -1;
513		}
514		ocets = (cidr + 7) / 8;
515		if (!out) {
516			p += 4 + ocets;
517			bytes += ((4 * 4) * 2) + 4;
518			continue;
519		}
520		if ((((4 * 4) * 2) + 4) > len) {
521			errno = ENOBUFS;
522			return -1;
523		}
524		if (o != out) {
525			*o++ = ' ';
526			len--;
527		}
528		/* If we have ocets then we have a destination and netmask */
529		if (ocets > 0) {
530			addr.s_addr = 0;
531			memcpy(&addr.s_addr, p, ocets);
532			b = snprintf(o, len, "%s/%d", inet_ntoa(addr), cidr);
533			p += ocets;
534		} else
535			b = snprintf(o, len, "0.0.0.0/0");
536		o += b;
537		len -= b;
538
539		/* Finally, snag the router */
540		memcpy(&addr.s_addr, p, 4);
541		p += 4;
542		b = snprintf(o, len, " %s", inet_ntoa(addr));
543		o += b;
544		len -= b;
545	}
546
547	if (out)
548		return o - out;
549	return bytes;
550}
551
552static struct rt *
553decode_rfc3442_rt(int dl, const uint8_t *data)
554{
555	const uint8_t *p = data;
556	const uint8_t *e;
557	uint8_t cidr;
558	size_t ocets;
559	struct rt *routes = NULL;
560	struct rt *rt = NULL;
561
562	/* Minimum is 5 -first is CIDR and a router length of 4 */
563	if (dl < 5)
564		return NULL;
565
566	e = p + dl;
567	while (p < e) {
568		cidr = *p++;
569		if (cidr > 32) {
570			free_routes(routes);
571			errno = EINVAL;
572			return NULL;
573		}
574
575		if (rt) {
576			rt->next = xzalloc(sizeof(*rt));
577			rt = rt->next;
578		} else {
579			routes = rt = xzalloc(sizeof(*routes));
580		}
581		rt->next = NULL;
582
583		ocets = (cidr + 7) / 8;
584		/* If we have ocets then we have a destination and netmask */
585		if (ocets > 0) {
586			memcpy(&rt->dest.s_addr, p, ocets);
587			p += ocets;
588			rt->net.s_addr = htonl(~0U << (32 - cidr));
589		}
590
591		/* Finally, snag the router */
592		memcpy(&rt->gate.s_addr, p, 4);
593		p += 4;
594	}
595	return routes;
596}
597
598static char *
599decode_rfc3361(int dl, const uint8_t *data)
600{
601	uint8_t enc;
602	unsigned int l;
603	char *sip = NULL;
604	struct in_addr addr;
605	char *p;
606
607	if (dl < 2) {
608		errno = EINVAL;
609		return 0;
610	}
611
612	enc = *data++;
613	dl--;
614	switch (enc) {
615	case 0:
616		if ((l = decode_rfc3397(NULL, 0, dl, data)) > 0) {
617			sip = xmalloc(l);
618			decode_rfc3397(sip, l, dl, data);
619		}
620		break;
621	case 1:
622		if (dl == 0 || dl % 4 != 0) {
623			errno = EINVAL;
624			break;
625		}
626		addr.s_addr = INADDR_BROADCAST;
627		l = ((dl / sizeof(addr.s_addr)) * ((4 * 4) + 1)) + 1;
628		sip = p = xmalloc(l);
629		while (dl != 0) {
630			memcpy(&addr.s_addr, data, sizeof(addr.s_addr));
631			data += sizeof(addr.s_addr);
632			p += snprintf(p, l - (p - sip), "%s ", inet_ntoa(addr));
633			dl -= sizeof(addr.s_addr);
634		}
635		*--p = '\0';
636		break;
637	default:
638		errno = EINVAL;
639		return 0;
640	}
641
642	return sip;
643}
644
645/* Decode an RFC5969 6rd order option into a space
646 * separated string. Returns length of string (including
647 * terminating zero) or zero on error. */
648static ssize_t
649decode_rfc5969(char *out, ssize_t len, int pl, const uint8_t *p)
650{
651	uint8_t ipv4masklen, ipv6prefixlen;
652	uint8_t ipv6prefix[16];
653	uint8_t br[4];
654	int i;
655	ssize_t b, bytes = 0;
656
657	if (pl < 22) {
658		errno = EINVAL;
659		return 0;
660	}
661
662	ipv4masklen = *p++;
663	pl--;
664	ipv6prefixlen = *p++;
665	pl--;
666
667	for (i = 0; i < 16; i++) {
668		ipv6prefix[i] = *p++;
669		pl--;
670	}
671	if (out) {
672		b= snprintf(out, len,
673		    "%d %d "
674		    "%02x%02x:%02x%02x:"
675		    "%02x%02x:%02x%02x:"
676		    "%02x%02x:%02x%02x:"
677		    "%02x%02x:%02x%02x",
678		    ipv4masklen, ipv6prefixlen,
679		    ipv6prefix[0], ipv6prefix[1], ipv6prefix[2], ipv6prefix[3],
680		    ipv6prefix[4], ipv6prefix[5], ipv6prefix[6], ipv6prefix[7],
681		    ipv6prefix[8], ipv6prefix[9], ipv6prefix[10],ipv6prefix[11],
682		    ipv6prefix[12],ipv6prefix[13],ipv6prefix[14], ipv6prefix[15]
683		);
684
685		len -= b;
686		out += b;
687		bytes += b;
688	} else {
689		bytes += 16 * 2 + 8 + 2 + 1 + 2;
690	}
691
692	while (pl >= 4) {
693		br[0] = *p++;
694		br[1] = *p++;
695		br[2] = *p++;
696		br[3] = *p++;
697		pl -= 4;
698
699		if (out) {
700			b= snprintf(out, len, " %d.%d.%d.%d",
701			    br[0], br[1], br[2], br[3]);
702			len -= b;
703			out += b;
704			bytes += b;
705		} else {
706			bytes += (4 * 4);
707		}
708	}
709
710	return bytes;
711}
712
713char *
714get_option_string(const struct dhcp_message *dhcp, uint8_t option)
715{
716	int type = 0;
717	int len;
718	const uint8_t *p;
719	char *s;
720
721	p = get_option(dhcp, option, &len, &type);
722	if (!p || *p == '\0')
723		return NULL;
724
725	if (type & RFC3397) {
726		type = decode_rfc3397(NULL, 0, len, p);
727		if (!type) {
728			errno = EINVAL;
729			return NULL;
730		}
731		s = xmalloc(sizeof(char) * type);
732		decode_rfc3397(s, type, len, p);
733		return s;
734	}
735
736	if (type & RFC3361)
737		return decode_rfc3361(len, p);
738
739	s = xmalloc(sizeof(char) * (len + 1));
740	memcpy(s, p, len);
741	s[len] = '\0';
742	return s;
743}
744
745/* This calculates the netmask that we should use for static routes.
746 * This IS different from the calculation used to calculate the netmask
747 * for an interface address. */
748static uint32_t
749route_netmask(uint32_t ip_in)
750{
751	/* used to be unsigned long - check if error */
752	uint32_t p = ntohl(ip_in);
753	uint32_t t;
754
755	if (IN_CLASSA(p))
756		t = ~IN_CLASSA_NET;
757	else {
758		if (IN_CLASSB(p))
759			t = ~IN_CLASSB_NET;
760		else {
761			if (IN_CLASSC(p))
762				t = ~IN_CLASSC_NET;
763			else
764				t = 0;
765		}
766	}
767
768	while (t & p)
769		t >>= 1;
770
771	return (htonl(~t));
772}
773
774/* We need to obey routing options.
775 * If we have a CSR then we only use that.
776 * Otherwise we add static routes and then routers. */
777struct rt *
778get_option_routes(const struct dhcp_message *dhcp,
779    const char *ifname, unsigned long long *opts)
780{
781	const uint8_t *p;
782	const uint8_t *e;
783	struct rt *routes = NULL;
784	struct rt *route = NULL;
785	int len;
786
787	/* If we have CSR's then we MUST use these only */
788	p = get_option(dhcp, DHO_CSR, &len, NULL);
789	/* Check for crappy MS option */
790	if (!p)
791		p = get_option(dhcp, DHO_MSCSR, &len, NULL);
792	if (p) {
793		routes = decode_rfc3442_rt(len, p);
794		if (routes) {
795			if (!(*opts & DHCPCD_CSR_WARNED)) {
796				syslog(LOG_DEBUG,
797				    "%s: using Classless Static Routes",
798				    ifname);
799				*opts |= DHCPCD_CSR_WARNED;
800			}
801			return routes;
802		}
803	}
804
805	/* OK, get our static routes first. */
806	p = get_option(dhcp, DHO_STATICROUTE, &len, NULL);
807	if (p) {
808		e = p + len;
809		while (p < e) {
810			if (route) {
811				route->next = xmalloc(sizeof(*route));
812				route = route->next;
813			} else
814				routes = route = xmalloc(sizeof(*routes));
815			route->next = NULL;
816			memcpy(&route->dest.s_addr, p, 4);
817			p += 4;
818			memcpy(&route->gate.s_addr, p, 4);
819			p += 4;
820			route->net.s_addr = route_netmask(route->dest.s_addr);
821		}
822	}
823
824	/* Now grab our routers */
825	p = get_option(dhcp, DHO_ROUTER, &len, NULL);
826	if (p) {
827		e = p + len;
828		while (p < e) {
829			if (route) {
830				route->next = xzalloc(sizeof(*route));
831				route = route->next;
832			} else
833				routes = route = xzalloc(sizeof(*route));
834			memcpy(&route->gate.s_addr, p, 4);
835			p += 4;
836		}
837	}
838
839	return routes;
840}
841
842static size_t
843encode_rfc1035(const char *src, uint8_t *dst)
844{
845	uint8_t *p = dst;
846	uint8_t *lp = p++;
847
848	if (*src == '\0')
849		return 0;
850	for (; *src; src++) {
851		if (*src == '\0')
852			break;
853		if (*src == '.') {
854			/* Skip the trailing . */
855			if (src[1] == '\0')
856				break;
857			*lp = p - lp - 1;
858			if (*lp == '\0')
859				return p - dst;
860			lp = p++;
861		} else
862			*p++ = (uint8_t)*src;
863	}
864	*lp = p - lp - 1;
865	*p++ = '\0';
866	return p - dst;
867}
868
869#define PUTADDR(_type, _val)						      \
870	{								      \
871		*p++ = _type;						      \
872		*p++ = 4;						      \
873		memcpy(p, &_val.s_addr, 4);				      \
874		p += 4;							      \
875	}
876
877int
878dhcp_message_add_addr(struct dhcp_message *dhcp,
879    uint8_t type, struct in_addr addr)
880{
881	uint8_t *p;
882	size_t len;
883
884	p = dhcp->options;
885	while (*p != DHO_END) {
886		p++;
887		p += *p + 1;
888	}
889
890	len = p - (uint8_t *)dhcp;
891	if (len + 6 > sizeof(*dhcp)) {
892		errno = ENOMEM;
893		return -1;
894	}
895
896	PUTADDR(type, addr);
897	*p = DHO_END;
898	return 0;
899}
900
901ssize_t
902make_message(struct dhcp_message **message,
903    const struct interface *iface,
904    uint8_t type)
905{
906	struct dhcp_message *dhcp;
907	uint8_t *m, *lp, *p;
908	uint8_t *n_params = NULL;
909	time_t up = uptime() - iface->start_uptime;
910	uint32_t ul;
911	uint16_t sz;
912	size_t len;
913	const char *hp;
914	const struct dhcp_opt *opt;
915	const struct if_options *ifo = iface->state->options;
916	const struct dhcp_lease *lease = &iface->state->lease;
917
918	dhcp = xzalloc(sizeof (*dhcp));
919	m = (uint8_t *)dhcp;
920	p = dhcp->options;
921
922	if ((type == DHCP_INFORM || type == DHCP_RELEASE ||
923		(type == DHCP_REQUEST &&
924		    iface->net.s_addr == lease->net.s_addr &&
925		    (iface->state->new == NULL ||
926			iface->state->new->cookie == htonl(MAGIC_COOKIE)))))
927	{
928		dhcp->ciaddr = iface->addr.s_addr;
929		/* In-case we haven't actually configured the address yet */
930		if (type == DHCP_INFORM && iface->addr.s_addr == 0)
931			dhcp->ciaddr = lease->addr.s_addr;
932	}
933
934	dhcp->op = DHCP_BOOTREQUEST;
935	dhcp->hwtype = iface->family;
936	switch (iface->family) {
937	case ARPHRD_ETHER:
938	case ARPHRD_IEEE802:
939		dhcp->hwlen = iface->hwlen;
940		memcpy(&dhcp->chaddr, &iface->hwaddr, iface->hwlen);
941		break;
942	}
943
944	if (ifo->options & DHCPCD_BROADCAST &&
945	    dhcp->ciaddr == 0 &&
946	    type != DHCP_DECLINE &&
947	    type != DHCP_RELEASE)
948		dhcp->flags = htons(BROADCAST_FLAG);
949
950	if (type != DHCP_DECLINE && type != DHCP_RELEASE) {
951		if (up < 0 || up > (time_t)UINT16_MAX)
952			dhcp->secs = htons((uint16_t)UINT16_MAX);
953		else
954			dhcp->secs = htons(up);
955	}
956	dhcp->xid = iface->state->xid;
957	dhcp->cookie = htonl(MAGIC_COOKIE);
958
959	*p++ = DHO_MESSAGETYPE;
960	*p++ = 1;
961	*p++ = type;
962
963	if (iface->clientid) {
964		*p++ = DHO_CLIENTID;
965		memcpy(p, iface->clientid, iface->clientid[0] + 1);
966		p += iface->clientid[0] + 1;
967	}
968
969	if (lease->addr.s_addr && lease->cookie == htonl(MAGIC_COOKIE)) {
970		if (type == DHCP_DECLINE ||
971		    (type == DHCP_REQUEST &&
972			lease->addr.s_addr != iface->addr.s_addr))
973		{
974			PUTADDR(DHO_IPADDRESS, lease->addr);
975			if (lease->server.s_addr)
976				PUTADDR(DHO_SERVERID, lease->server);
977		}
978
979		if (type == DHCP_RELEASE) {
980			if (lease->server.s_addr)
981				PUTADDR(DHO_SERVERID, lease->server);
982		}
983	}
984
985	if (type == DHCP_DECLINE) {
986		*p++ = DHO_MESSAGE;
987		len = strlen(DAD);
988		*p++ = len;
989		memcpy(p, DAD, len);
990		p += len;
991	}
992
993	if (type == DHCP_DISCOVER && ifo->options & DHCPCD_REQUEST)
994		PUTADDR(DHO_IPADDRESS, ifo->req_addr);
995
996	if (type == DHCP_DISCOVER ||
997	    type == DHCP_INFORM ||
998	    type == DHCP_REQUEST)
999	{
1000		*p++ = DHO_MAXMESSAGESIZE;
1001		*p++ = 2;
1002		sz = get_mtu(iface->name);
1003		if (sz < MTU_MIN) {
1004			if (set_mtu(iface->name, MTU_MIN) == 0)
1005				sz = MTU_MIN;
1006		} else if (sz > MTU_MAX) {
1007			/* Even though our MTU could be greater than
1008			 * MTU_MAX (1500) dhcpcd does not presently
1009			 * handle DHCP packets any bigger. */
1010			sz = MTU_MAX;
1011		}
1012		sz = htons(sz);
1013		memcpy(p, &sz, 2);
1014		p += 2;
1015
1016		if (ifo->userclass[0]) {
1017			*p++ = DHO_USERCLASS;
1018			memcpy(p, ifo->userclass, ifo->userclass[0] + 1);
1019			p += ifo->userclass[0] + 1;
1020		}
1021
1022		if (ifo->vendorclassid[0]) {
1023			*p++ = DHO_VENDORCLASSID;
1024			memcpy(p, ifo->vendorclassid,
1025			    ifo->vendorclassid[0] + 1);
1026			p += ifo->vendorclassid[0] + 1;
1027		}
1028
1029
1030		if (type != DHCP_INFORM) {
1031			if (ifo->leasetime != 0) {
1032				*p++ = DHO_LEASETIME;
1033				*p++ = 4;
1034				ul = htonl(ifo->leasetime);
1035				memcpy(p, &ul, 4);
1036				p += 4;
1037			}
1038		}
1039
1040		/* Regardless of RFC2132, we should always send a hostname
1041		 * upto the first dot (the short hostname) as otherwise
1042		 * confuses some DHCP servers when updating DNS.
1043		 * The FQDN option should be used if a FQDN is required. */
1044		if (ifo->options & DHCPCD_HOSTNAME && ifo->hostname[0]) {
1045			*p++ = DHO_HOSTNAME;
1046			hp = strchr(ifo->hostname, '.');
1047			if (hp)
1048				len = hp - ifo->hostname;
1049			else
1050				len = strlen(ifo->hostname);
1051			*p++ = len;
1052			memcpy(p, ifo->hostname, len);
1053			p += len;
1054		}
1055		if (ifo->fqdn != FQDN_DISABLE && ifo->hostname[0]) {
1056			/* IETF DHC-FQDN option (81), RFC4702 */
1057			*p++ = DHO_FQDN;
1058			lp = p;
1059			*p++ = 3;
1060			/*
1061			 * Flags: 0000NEOS
1062			 * S: 1 => Client requests Server to update
1063			 *         a RR in DNS as well as PTR
1064			 * O: 1 => Server indicates to client that
1065			 *         DNS has been updated
1066			 * E: 1 => Name data is DNS format
1067			 * N: 1 => Client requests Server to not
1068			 *         update DNS
1069			 */
1070			*p++ = (ifo->fqdn & 0x09) | 0x04;
1071			*p++ = 0; /* from server for PTR RR */
1072			*p++ = 0; /* from server for A RR if S=1 */
1073			ul = encode_rfc1035(ifo->hostname, p);
1074			*lp += ul;
1075			p += ul;
1076		}
1077
1078		/* vendor is already encoded correctly, so just add it */
1079		if (ifo->vendor[0]) {
1080			*p++ = DHO_VENDOR;
1081			memcpy(p, ifo->vendor, ifo->vendor[0] + 1);
1082			p += ifo->vendor[0] + 1;
1083		}
1084
1085		*p++ = DHO_PARAMETERREQUESTLIST;
1086		n_params = p;
1087		*p++ = 0;
1088		for (opt = dhcp_opts; opt->option; opt++) {
1089			if (!(opt->type & REQUEST ||
1090				has_option_mask(ifo->requestmask, opt->option)))
1091				continue;
1092			if (type == DHCP_INFORM &&
1093			    (opt->option == DHO_RENEWALTIME ||
1094				opt->option == DHO_REBINDTIME))
1095				continue;
1096			*p++ = opt->option;
1097		}
1098		*n_params = p - n_params - 1;
1099	}
1100	*p++ = DHO_END;
1101
1102#ifdef BOOTP_MESSAGE_LENTH_MIN
1103	/* Some crappy DHCP servers think they have to obey the BOOTP minimum
1104	 * message length.
1105	 * They are wrong, but we should still cater for them. */
1106	while (p - m < BOOTP_MESSAGE_LENTH_MIN)
1107		*p++ = DHO_PAD;
1108#endif
1109
1110	*message = dhcp;
1111	return p - m;
1112}
1113
1114ssize_t
1115write_lease(const struct interface *iface, const struct dhcp_message *dhcp)
1116{
1117	int fd;
1118	ssize_t bytes = sizeof(*dhcp);
1119	const uint8_t *p = dhcp->options;
1120	const uint8_t *e = p + sizeof(dhcp->options);
1121	uint8_t l;
1122	uint8_t o = 0;
1123
1124	/* We don't write BOOTP leases */
1125	if (is_bootp(dhcp)) {
1126		unlink(iface->leasefile);
1127		return 0;
1128	}
1129
1130	syslog(LOG_DEBUG, "%s: writing lease `%s'",
1131	    iface->name, iface->leasefile);
1132
1133	fd = open(iface->leasefile, O_WRONLY | O_CREAT | O_TRUNC, 0444);
1134#ifdef ANDROID
1135	if (fd == -1 && errno == EACCES) {
1136		/* the lease file might have been created when dhcpcd was running as root */
1137		unlink(iface->leasefile);
1138		fd = open(iface->leasefile, O_WRONLY | O_CREAT | O_TRUNC, 0444);
1139	}
1140#endif
1141	if (fd == -1) {
1142		syslog(LOG_ERR, "%s: open: %m", iface->name);
1143		return -1;
1144	}
1145
1146	/* Only write as much as we need */
1147	while (p < e) {
1148		o = *p;
1149		if (o == DHO_END) {
1150			bytes = p - (const uint8_t *)dhcp;
1151			break;
1152		}
1153		p++;
1154		if (o != DHO_PAD) {
1155			l = *p++;
1156			p += l;
1157		}
1158	}
1159	bytes = write(fd, dhcp, bytes);
1160	close(fd);
1161	return bytes;
1162}
1163
1164struct dhcp_message *
1165read_lease(const struct interface *iface)
1166{
1167	int fd;
1168	struct dhcp_message *dhcp;
1169	ssize_t bytes;
1170
1171	fd = open(iface->leasefile, O_RDONLY);
1172	if (fd == -1) {
1173		if (errno != ENOENT)
1174			syslog(LOG_ERR, "%s: open `%s': %m",
1175			    iface->name, iface->leasefile);
1176		return NULL;
1177	}
1178	syslog(LOG_DEBUG, "%s: reading lease `%s'",
1179	    iface->name, iface->leasefile);
1180	dhcp = xmalloc(sizeof(*dhcp));
1181	memset(dhcp, 0, sizeof(*dhcp));
1182	bytes = read(fd, dhcp, sizeof(*dhcp));
1183	close(fd);
1184	if (bytes < 0) {
1185		free(dhcp);
1186		dhcp = NULL;
1187	}
1188	return dhcp;
1189}
1190
1191static ssize_t
1192print_string(char *s, ssize_t len, int dl, const uint8_t *data)
1193{
1194	uint8_t c;
1195	const uint8_t *e, *p;
1196	ssize_t bytes = 0;
1197	ssize_t r;
1198
1199	e = data + dl;
1200	while (data < e) {
1201		c = *data++;
1202		if (c == '\0') {
1203			/* If rest is all NULL, skip it. */
1204			for (p = data; p < e; p++)
1205				if (*p != '\0')
1206					break;
1207			if (p == e)
1208				break;
1209		}
1210		if (!isascii(c) || !isprint(c)) {
1211			if (s) {
1212				if (len < 5) {
1213					errno = ENOBUFS;
1214					return -1;
1215				}
1216				r = snprintf(s, len, "\\%03o", c);
1217				len -= r;
1218				bytes += r;
1219				s += r;
1220			} else
1221				bytes += 4;
1222			continue;
1223		}
1224		switch (c) {
1225		case '"':  /* FALLTHROUGH */
1226		case '\'': /* FALLTHROUGH */
1227		case '$':  /* FALLTHROUGH */
1228		case '`':  /* FALLTHROUGH */
1229 		case '\\': /* FALLTHROUGH */
1230		case '|':  /* FALLTHROUGH */
1231		case '&':
1232			if (s) {
1233				if (len < 3) {
1234					errno = ENOBUFS;
1235					return -1;
1236				}
1237				*s++ = '\\';
1238				len--;
1239			}
1240			bytes++;
1241			break;
1242		}
1243		if (s) {
1244			*s++ = c;
1245			len--;
1246		}
1247		bytes++;
1248	}
1249
1250	/* NULL */
1251	if (s)
1252		*s = '\0';
1253	bytes++;
1254	return bytes;
1255}
1256
1257static ssize_t
1258print_option(char *s, ssize_t len, int type, int dl, const uint8_t *data)
1259{
1260	const uint8_t *e, *t;
1261	uint16_t u16;
1262	int16_t s16;
1263	uint32_t u32;
1264	int32_t s32;
1265	struct in_addr addr;
1266	ssize_t bytes = 0;
1267	ssize_t l;
1268	char *tmp;
1269
1270	if (type & RFC3397) {
1271		l = decode_rfc3397(NULL, 0, dl, data);
1272		if (l < 1)
1273			return l;
1274		tmp = xmalloc(l);
1275		decode_rfc3397(tmp, l, dl, data);
1276		l = print_string(s, len, l - 1, (uint8_t *)tmp);
1277		free(tmp);
1278		return l;
1279	}
1280
1281	if (type & RFC3361) {
1282		if ((tmp = decode_rfc3361(dl, data)) == NULL)
1283			return -1;
1284		l = strlen(tmp);
1285		l = print_string(s, len, l - 1, (uint8_t *)tmp);
1286		free(tmp);
1287		return l;
1288	}
1289
1290	if (type & RFC3442)
1291		return decode_rfc3442(s, len, dl, data);
1292
1293	if (type & RFC5969)
1294		return decode_rfc5969(s, len, dl, data);
1295
1296	if (type & STRING) {
1297		/* Some DHCP servers return NULL strings */
1298		if (*data == '\0')
1299			return 0;
1300		return print_string(s, len, dl, data);
1301	}
1302
1303	if (!s) {
1304		if (type & UINT8)
1305			l = 3;
1306		else if (type & UINT16) {
1307			l = 5;
1308			dl /= 2;
1309		} else if (type & SINT16) {
1310			l = 6;
1311			dl /= 2;
1312		} else if (type & UINT32) {
1313			l = 10;
1314			dl /= 4;
1315		} else if (type & SINT32) {
1316			l = 11;
1317			dl /= 4;
1318		} else if (type & IPV4) {
1319			l = 16;
1320			dl /= 4;
1321		} else {
1322			errno = EINVAL;
1323			return -1;
1324		}
1325		return (l + 1) * dl;
1326	}
1327
1328	t = data;
1329	e = data + dl;
1330	while (data < e) {
1331		if (data != t) {
1332			*s++ = ' ';
1333			bytes++;
1334			len--;
1335		}
1336		if (type & UINT8) {
1337			l = snprintf(s, len, "%d", *data);
1338			data++;
1339		} else if (type & UINT16) {
1340			memcpy(&u16, data, sizeof(u16));
1341			u16 = ntohs(u16);
1342			l = snprintf(s, len, "%d", u16);
1343			data += sizeof(u16);
1344		} else if (type & SINT16) {
1345			memcpy(&s16, data, sizeof(s16));
1346			s16 = ntohs(s16);
1347			l = snprintf(s, len, "%d", s16);
1348			data += sizeof(s16);
1349		} else if (type & UINT32) {
1350			memcpy(&u32, data, sizeof(u32));
1351			u32 = ntohl(u32);
1352			l = snprintf(s, len, "%d", u32);
1353			data += sizeof(u32);
1354		} else if (type & SINT32) {
1355			memcpy(&s32, data, sizeof(s32));
1356			s32 = ntohl(s32);
1357			l = snprintf(s, len, "%d", s32);
1358			data += sizeof(s32);
1359		} else if (type & IPV4) {
1360			memcpy(&addr.s_addr, data, sizeof(addr.s_addr));
1361			l = snprintf(s, len, "%s", inet_ntoa(addr));
1362			data += sizeof(addr.s_addr);
1363		} else
1364			l = 0;
1365		len -= l;
1366		bytes += l;
1367		s += l;
1368	}
1369
1370	return bytes;
1371}
1372
1373ssize_t
1374configure_env(char **env, const char *prefix, const struct dhcp_message *dhcp,
1375    const struct if_options *ifo)
1376{
1377	unsigned int i;
1378	const uint8_t *p;
1379	int pl;
1380	struct in_addr addr;
1381	struct in_addr net;
1382	struct in_addr brd;
1383	char *val, *v;
1384	const struct dhcp_opt *opt;
1385	ssize_t len, e = 0;
1386	char **ep;
1387	char cidr[4];
1388	uint8_t overl = 0;
1389
1390	get_option_uint8(&overl, dhcp, DHO_OPTIONSOVERLOADED);
1391
1392	if (!env) {
1393		for (opt = dhcp_opts; opt->option; opt++) {
1394			if (!opt->var)
1395				continue;
1396			if (has_option_mask(ifo->nomask, opt->option))
1397				continue;
1398			if (get_option_raw(dhcp, opt->option))
1399				e++;
1400		}
1401		if (dhcp->yiaddr || dhcp->ciaddr)
1402			e += 5;
1403		if (*dhcp->bootfile && !(overl & 1))
1404			e++;
1405		if (*dhcp->servername && !(overl & 2))
1406			e++;
1407		return e;
1408	}
1409
1410	ep = env;
1411	if (dhcp->yiaddr || dhcp->ciaddr) {
1412		/* Set some useful variables that we derive from the DHCP
1413		 * message but are not necessarily in the options */
1414		addr.s_addr = dhcp->yiaddr ? dhcp->yiaddr : dhcp->ciaddr;
1415		setvar(&ep, prefix, "ip_address", inet_ntoa(addr));
1416		if (get_option_addr(&net, dhcp, DHO_SUBNETMASK) == -1) {
1417			net.s_addr = get_netmask(addr.s_addr);
1418			setvar(&ep, prefix, "subnet_mask", inet_ntoa(net));
1419		}
1420		i = inet_ntocidr(net);
1421		snprintf(cidr, sizeof(cidr), "%d", inet_ntocidr(net));
1422		setvar(&ep, prefix, "subnet_cidr", cidr);
1423		if (get_option_addr(&brd, dhcp, DHO_BROADCAST) == -1) {
1424			brd.s_addr = addr.s_addr | ~net.s_addr;
1425			setvar(&ep, prefix, "broadcast_address", inet_ntoa(brd));
1426		}
1427		addr.s_addr = dhcp->yiaddr & net.s_addr;
1428		setvar(&ep, prefix, "network_number", inet_ntoa(addr));
1429	}
1430
1431	if (*dhcp->bootfile && !(overl & 1))
1432		setvar(&ep, prefix, "filename", (const char *)dhcp->bootfile);
1433	if (*dhcp->servername && !(overl & 2))
1434		setvar(&ep, prefix, "server_name", (const char *)dhcp->servername);
1435
1436	for (opt = dhcp_opts; opt->option; opt++) {
1437		if (!opt->var)
1438			continue;
1439		if (has_option_mask(ifo->nomask, opt->option))
1440			continue;
1441		val = NULL;
1442		p = get_option(dhcp, opt->option, &pl, NULL);
1443		if (!p)
1444			continue;
1445		/* We only want the FQDN name */
1446		if (opt->option == DHO_FQDN) {
1447			p += 3;
1448			pl -= 3;
1449		}
1450		len = print_option(NULL, 0, opt->type, pl, p);
1451		if (len < 0)
1452			return -1;
1453		e = strlen(prefix) + strlen(opt->var) + len + 4;
1454		v = val = *ep++ = xmalloc(e);
1455		v += snprintf(val, e, "%s_%s=", prefix, opt->var);
1456		if (len != 0)
1457			print_option(v, len, opt->type, pl, p);
1458	}
1459
1460	return ep - env;
1461}
1462
1463void
1464get_lease(struct dhcp_lease *lease, const struct dhcp_message *dhcp)
1465{
1466	struct timeval now;
1467
1468	lease->cookie = dhcp->cookie;
1469	/* BOOTP does not set yiaddr for replies when ciaddr is set. */
1470	if (dhcp->yiaddr)
1471		lease->addr.s_addr = dhcp->yiaddr;
1472	else
1473		lease->addr.s_addr = dhcp->ciaddr;
1474	if (get_option_addr(&lease->net, dhcp, DHO_SUBNETMASK) == -1)
1475		lease->net.s_addr = get_netmask(lease->addr.s_addr);
1476	if (get_option_addr(&lease->brd, dhcp, DHO_BROADCAST) == -1)
1477		lease->brd.s_addr = lease->addr.s_addr | ~lease->net.s_addr;
1478	if (get_option_uint32(&lease->leasetime, dhcp, DHO_LEASETIME) == 0) {
1479		/* Ensure that we can use the lease */
1480		get_monotonic(&now);
1481		if (now.tv_sec + (time_t)lease->leasetime < now.tv_sec)
1482			lease->leasetime = ~0U; /* Infinite lease */
1483	} else
1484		lease->leasetime = ~0U; /* Default to infinite lease */
1485	if (get_option_uint32(&lease->renewaltime, dhcp, DHO_RENEWALTIME) != 0)
1486		lease->renewaltime = 0;
1487	if (get_option_uint32(&lease->rebindtime, dhcp, DHO_REBINDTIME) != 0)
1488		lease->rebindtime = 0;
1489	if (get_option_addr(&lease->server, dhcp, DHO_SERVERID) != 0)
1490		lease->server.s_addr = INADDR_ANY;
1491}
1492