1/*
2 * dhcpcd - DHCP client daemon
3 * Copyright (c) 2006-2015 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#ifndef DHCP_H
29#define DHCP_H
30
31#include <arpa/inet.h>
32#include <netinet/in.h>
33
34#include <limits.h>
35#include <stdint.h>
36
37#include "arp.h"
38#include "auth.h"
39#include "dhcp-common.h"
40
41/* UDP port numbers for DHCP */
42#define DHCP_SERVER_PORT    67
43#define DHCP_CLIENT_PORT    68
44
45#define MAGIC_COOKIE        0x63825363
46#define BROADCAST_FLAG      0x8000
47
48/* DHCP message OP code */
49#define DHCP_BOOTREQUEST    1
50#define DHCP_BOOTREPLY      2
51
52/* DHCP message type */
53#define DHCP_DISCOVER       1
54#define DHCP_OFFER          2
55#define DHCP_REQUEST        3
56#define DHCP_DECLINE        4
57#define DHCP_ACK            5
58#define DHCP_NAK            6
59#define DHCP_RELEASE        7
60#define DHCP_INFORM         8
61#define DHCP_FORCERENEW     9
62
63/* Constants taken from RFC 2131. */
64#define T1			0.5
65#define T2			0.875
66#define DHCP_BASE		4
67#define DHCP_MAX		64
68#define DHCP_RAND_MIN		-1
69#define DHCP_RAND_MAX		1
70
71#ifdef RFC2131_STRICT
72/* Be strictly conformant for section 4.1.1 */
73#  define DHCP_MIN_DELAY	1
74#  define DHCP_MAX_DELAY	10
75#else
76/* or mirror the more modern IPv6RS and DHCPv6 delays */
77#  define DHCP_MIN_DELAY	0
78#  define DHCP_MAX_DELAY	1
79#endif
80
81/* DHCP options */
82enum DHO {
83	DHO_PAD                    = 0,
84	DHO_SUBNETMASK             = 1,
85	DHO_ROUTER                 = 3,
86	DHO_DNSSERVER              = 6,
87	DHO_HOSTNAME               = 12,
88	DHO_DNSDOMAIN              = 15,
89	DHO_MTU                    = 26,
90	DHO_BROADCAST              = 28,
91	DHO_STATICROUTE            = 33,
92	DHO_NISDOMAIN              = 40,
93	DHO_NISSERVER              = 41,
94	DHO_NTPSERVER              = 42,
95	DHO_VENDOR                 = 43,
96	DHO_IPADDRESS              = 50,
97	DHO_LEASETIME              = 51,
98	DHO_OPTIONSOVERLOADED      = 52,
99	DHO_MESSAGETYPE            = 53,
100	DHO_SERVERID               = 54,
101	DHO_PARAMETERREQUESTLIST   = 55,
102	DHO_MESSAGE                = 56,
103	DHO_MAXMESSAGESIZE         = 57,
104	DHO_RENEWALTIME            = 58,
105	DHO_REBINDTIME             = 59,
106	DHO_VENDORCLASSID          = 60,
107	DHO_CLIENTID               = 61,
108	DHO_USERCLASS              = 77,  /* RFC 3004 */
109	DHO_RAPIDCOMMIT            = 80,  /* RFC 4039 */
110	DHO_FQDN                   = 81,
111	DHO_AUTHENTICATION         = 90,  /* RFC 3118 */
112	DHO_AUTOCONFIGURE          = 116, /* RFC 2563 */
113	DHO_DNSSEARCH              = 119, /* RFC 3397 */
114	DHO_CSR                    = 121, /* RFC 3442 */
115	DHO_VIVCO                  = 124, /* RFC 3925 */
116	DHO_VIVSO                  = 125, /* RFC 3925 */
117	DHO_FORCERENEW_NONCE       = 145, /* RFC 6704 */
118	DHO_SIXRD                  = 212, /* RFC 5969 */
119	DHO_MSCSR                  = 249, /* MS code for RFC 3442 */
120	DHO_END                    = 255
121};
122
123/* FQDN values - lsnybble used in flags
124 * hsnybble to create order
125 * and to allow 0x00 to mean disable
126 */
127enum FQDN {
128	FQDN_DISABLE    = 0x00,
129	FQDN_NONE       = 0x18,
130	FQDN_PTR        = 0x20,
131	FQDN_BOTH       = 0x31
132};
133
134/* Sizes for DHCP options */
135#define DHCP_CHADDR_LEN         16
136#define SERVERNAME_LEN          64
137#define BOOTFILE_LEN            128
138#define DHCP_UDP_LEN            (14 + 20 + 8)
139#define DHCP_FIXED_LEN          (DHCP_UDP_LEN + 226)
140#define DHCP_OPTION_LEN         (MTU_MAX - DHCP_FIXED_LEN)
141
142/* Some crappy DHCP servers require the BOOTP minimum length */
143#define BOOTP_MESSAGE_LENTH_MIN 300
144
145/* Flags for the OPTIONSOVERLOADED field. */
146#define OPTION_OVERLOADED_BOOT_FILE 1
147#define OPTION_OVERLOADED_SERVER_NAME 2
148
149/* Don't import common.h as that defines __unused which causes problems
150 * on some Linux systems which define it as part of a structure */
151#if __GNUC__ > 2 || defined(__INTEL_COMPILER)
152# ifndef __packed
153#  define __packed   __attribute__((__packed__))
154# endif
155#else
156# ifndef __packed
157#  define __packed
158# endif
159#endif
160
161struct dhcp_message {
162	uint8_t op;           /* message type */
163	uint8_t hwtype;       /* hardware address type */
164	uint8_t hwlen;        /* hardware address length */
165	uint8_t hwopcount;    /* should be zero in client message */
166	uint32_t xid;            /* transaction id */
167	uint16_t secs;           /* elapsed time in sec. from boot */
168	uint16_t flags;
169	uint32_t ciaddr;         /* (previously allocated) client IP */
170	uint32_t yiaddr;         /* 'your' client IP address */
171	uint32_t siaddr;         /* should be zero in client's messages */
172	uint32_t giaddr;         /* should be zero in client's messages */
173	uint8_t chaddr[DHCP_CHADDR_LEN];  /* client's hardware address */
174	uint8_t servername[SERVERNAME_LEN];    /* server host name */
175	uint8_t bootfile[BOOTFILE_LEN];    /* boot file name */
176	uint32_t cookie;
177	uint8_t options[DHCP_OPTION_LEN]; /* message options - cookie */
178} __packed;
179
180struct dhcp_option_iterator {
181	const struct dhcp_message *message;
182	const uint8_t *ptr;
183	const uint8_t *end;
184	uint8_t extra_option_locations;
185	uint8_t extra_option_locations_set;
186};
187
188struct dhcp_lease {
189	struct in_addr addr;
190	struct in_addr net;
191	struct in_addr brd;
192	uint32_t leasetime;
193	uint32_t renewaltime;
194	uint32_t rebindtime;
195	struct in_addr server;
196	uint8_t frominfo;
197	uint32_t cookie;
198};
199
200/* Extra data about servers stored in the lease file after the dhcp_message */
201struct dhcp_server_info {
202	uint8_t gw_hwlen;
203	unsigned char gw_hwaddr[HWADDR_LEN];
204};
205
206enum DHS {
207	DHS_INIT,
208	DHS_DISCOVER,
209	DHS_REQUEST,
210	DHS_BOUND,
211	DHS_RENEW,
212	DHS_REBIND,
213	DHS_REBOOT,
214	DHS_INFORM,
215	DHS_RENEW_REQUESTED,
216	DHS_IPV4LL_BOUND,
217	DHS_PROBE
218};
219
220struct dhcp_state {
221	enum DHS state;
222	struct dhcp_message *sent;
223	struct dhcp_message *offer;
224	struct dhcp_message *new;
225	struct dhcp_message *old;
226	struct dhcp_lease lease;
227	const char *reason;
228	time_t interval;
229	time_t nakoff;
230	uint32_t xid;
231	int socket;
232
233	int raw_fd;
234	int arp_fd;
235	size_t buffer_size, buffer_len, buffer_pos;
236	unsigned char *buffer;
237
238	struct in_addr addr;
239	struct in_addr net;
240	struct in_addr dst;
241	uint8_t added;
242
243	char leasefile[PATH_MAX];
244	time_t start_uptime;
245
246	unsigned char *clientid;
247
248	struct authstate auth;
249	struct arp_statehead arp_states;
250
251	size_t arping_index;
252
253	struct arp_state *arp_ipv4ll;
254	unsigned int conflicts;
255	int nak_receive_count;
256	int failed_address_offer_count;
257	struct in_addr failed;
258	time_t defend;
259	char randomstate[128];
260	struct dhcp_server_info server_info;
261};
262
263#define D_STATE(ifp)							       \
264	((struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
265#define D_CSTATE(ifp)							       \
266	((const struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
267#define D_STATE_RUNNING(ifp)						       \
268	(D_CSTATE((ifp)) && D_CSTATE((ifp))->new && D_CSTATE((ifp))->reason)
269
270#include "dhcpcd.h"
271#include "if-options.h"
272
273#ifdef INET
274char *decode_rfc3361(const uint8_t *, size_t);
275ssize_t decode_rfc3442(char *, size_t, const uint8_t *p, size_t);
276ssize_t decode_rfc5969(char *, size_t, const uint8_t *p, size_t);
277
278void dhcp_printoptions(const struct dhcpcd_ctx *,
279    const struct dhcp_opt *, size_t);
280int get_option_addr(struct dhcpcd_ctx *,struct in_addr *,
281    const struct dhcp_message *, uint8_t);
282#define IS_BOOTP(i, m) ((m) &&						    \
283	    !IN_LINKLOCAL(htonl((m)->yiaddr)) &&			    \
284	    get_option_uint8((i)->ctx, NULL, (m), DHO_MESSAGETYPE) == -1)
285struct rt_head *get_option_routes(struct interface *,
286    const struct dhcp_message *);
287ssize_t dhcp_env(char **, const char *, const struct dhcp_message *,
288    const struct interface *);
289
290uint32_t dhcp_xid(const struct interface *);
291struct dhcp_message *dhcp_message_new(const struct in_addr *addr,
292    const struct in_addr *mask);
293int dhcp_message_add_addr(struct dhcp_message *, uint8_t, struct in_addr);
294ssize_t make_message(struct dhcp_message **, const struct interface *,
295    uint8_t);
296int valid_dhcp_packet(unsigned char *);
297
298void dhcp_handleifa(int, struct interface *,
299    const struct in_addr *, const struct in_addr *, const struct in_addr *,
300    int);
301
302void dhcp_drop(struct interface *, const char *);
303void dhcp_start(struct interface *);
304void dhcp_stop(struct interface *);
305void dhcp_discover(void *);
306void dhcp_inform(struct interface *);
307void dhcp_bind(struct interface *, struct arp_state *);
308void dhcp_reboot_newopts(struct interface *, unsigned long long);
309void dhcp_close(struct interface *);
310void dhcp_free(struct interface *);
311int dhcp_dump(struct interface *);
312#else
313#define dhcp_drop(a, b) {}
314#define dhcp_start(a) {}
315#define dhcp_reboot(a, b) (b = b)
316#define dhcp_reboot_newopts(a, b) (b = b)
317#define dhcp_close(a) {}
318#define dhcp_free(a) {}
319#define dhcp_dump(a) (-1)
320#endif
321
322#endif
323