xref: /minix/external/bsd/dhcpcd/dist/dhcp.h (revision 9f20bfa6)
1 /* $NetBSD: dhcp.h,v 1.11 2015/08/21 10:39:00 roy Exp $ */
2 
3 /*
4  * dhcpcd - DHCP client daemon
5  * Copyright (c) 2006-2015 Roy Marples <roy@marples.name>
6  * All rights reserved
7 
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef DHCP_H
31 #define DHCP_H
32 
33 #include <arpa/inet.h>
34 #include <netinet/in.h>
35 
36 #include <limits.h>
37 #include <stdint.h>
38 
39 #include "arp.h"
40 #include "auth.h"
41 #include "dhcp-common.h"
42 
43 /* UDP port numbers for DHCP */
44 #define DHCP_SERVER_PORT    67
45 #define DHCP_CLIENT_PORT    68
46 
47 #define MAGIC_COOKIE        0x63825363
48 #define BROADCAST_FLAG      0x8000
49 
50 /* DHCP message OP code */
51 #define DHCP_BOOTREQUEST    1
52 #define DHCP_BOOTREPLY      2
53 
54 /* DHCP message type */
55 #define DHCP_DISCOVER       1
56 #define DHCP_OFFER          2
57 #define DHCP_REQUEST        3
58 #define DHCP_DECLINE        4
59 #define DHCP_ACK            5
60 #define DHCP_NAK            6
61 #define DHCP_RELEASE        7
62 #define DHCP_INFORM         8
63 #define DHCP_FORCERENEW     9
64 
65 /* Constants taken from RFC 2131. */
66 #define T1			0.5
67 #define T2			0.875
68 #define DHCP_BASE		4
69 #define DHCP_MAX		64
70 #define DHCP_RAND_MIN		-1
71 #define DHCP_RAND_MAX		1
72 
73 #ifdef RFC2131_STRICT
74 /* Be strictly conformant for section 4.1.1 */
75 #  define DHCP_MIN_DELAY	1
76 #  define DHCP_MAX_DELAY	10
77 #else
78 /* or mirror the more modern IPv6RS and DHCPv6 delays */
79 #  define DHCP_MIN_DELAY	0
80 #  define DHCP_MAX_DELAY	1
81 #endif
82 
83 /* DHCP options */
84 enum DHO {
85 	DHO_PAD                    = 0,
86 	DHO_SUBNETMASK             = 1,
87 	DHO_ROUTER                 = 3,
88 	DHO_DNSSERVER              = 6,
89 	DHO_HOSTNAME               = 12,
90 	DHO_DNSDOMAIN              = 15,
91 	DHO_MTU                    = 26,
92 	DHO_BROADCAST              = 28,
93 	DHO_STATICROUTE            = 33,
94 	DHO_NISDOMAIN              = 40,
95 	DHO_NISSERVER              = 41,
96 	DHO_NTPSERVER              = 42,
97 	DHO_VENDOR                 = 43,
98 	DHO_IPADDRESS              = 50,
99 	DHO_LEASETIME              = 51,
100 	DHO_OPTIONSOVERLOADED      = 52,
101 	DHO_MESSAGETYPE            = 53,
102 	DHO_SERVERID               = 54,
103 	DHO_PARAMETERREQUESTLIST   = 55,
104 	DHO_MESSAGE                = 56,
105 	DHO_MAXMESSAGESIZE         = 57,
106 	DHO_RENEWALTIME            = 58,
107 	DHO_REBINDTIME             = 59,
108 	DHO_VENDORCLASSID          = 60,
109 	DHO_CLIENTID               = 61,
110 	DHO_USERCLASS              = 77,  /* RFC 3004 */
111 	DHO_RAPIDCOMMIT            = 80,  /* RFC 4039 */
112 	DHO_FQDN                   = 81,
113 	DHO_AUTHENTICATION         = 90,  /* RFC 3118 */
114 	DHO_AUTOCONFIGURE          = 116, /* RFC 2563 */
115 	DHO_DNSSEARCH              = 119, /* RFC 3397 */
116 	DHO_CSR                    = 121, /* RFC 3442 */
117 	DHO_VIVCO                  = 124, /* RFC 3925 */
118 	DHO_VIVSO                  = 125, /* RFC 3925 */
119 	DHO_FORCERENEW_NONCE       = 145, /* RFC 6704 */
120 	DHO_SIXRD                  = 212, /* RFC 5969 */
121 	DHO_MSCSR                  = 249, /* MS code for RFC 3442 */
122 	DHO_END                    = 255
123 };
124 
125 /* FQDN values - lsnybble used in flags
126  * hsnybble to create order
127  * and to allow 0x00 to mean disable
128  */
129 enum FQDN {
130 	FQDN_DISABLE    = 0x00,
131 	FQDN_NONE       = 0x18,
132 	FQDN_PTR        = 0x20,
133 	FQDN_BOTH       = 0x31
134 };
135 
136 /* Sizes for DHCP options */
137 #define DHCP_CHADDR_LEN         16
138 #define SERVERNAME_LEN          64
139 #define BOOTFILE_LEN            128
140 #define DHCP_UDP_LEN            (14 + 20 + 8)
141 #define DHCP_FIXED_LEN          (DHCP_UDP_LEN + 226)
142 #define DHCP_OPTION_LEN         (MTU_MAX - DHCP_FIXED_LEN)
143 
144 /* Some crappy DHCP servers require the BOOTP minimum length */
145 #define BOOTP_MESSAGE_LENTH_MIN 300
146 
147 /* Don't import common.h as that defines __unused which causes problems
148  * on some Linux systems which define it as part of a structure */
149 #if __GNUC__ > 2 || defined(__INTEL_COMPILER)
150 # ifndef __packed
151 #  define __packed   __attribute__((__packed__))
152 # endif
153 #else
154 # ifndef __packed
155 #  define __packed
156 # endif
157 #endif
158 
159 struct dhcp_message {
160 	uint8_t op;           /* message type */
161 	uint8_t hwtype;       /* hardware address type */
162 	uint8_t hwlen;        /* hardware address length */
163 	uint8_t hwopcount;    /* should be zero in client message */
164 	uint32_t xid;            /* transaction id */
165 	uint16_t secs;           /* elapsed time in sec. from boot */
166 	uint16_t flags;
167 	uint32_t ciaddr;         /* (previously allocated) client IP */
168 	uint32_t yiaddr;         /* 'your' client IP address */
169 	uint32_t siaddr;         /* should be zero in client's messages */
170 	uint32_t giaddr;         /* should be zero in client's messages */
171 	uint8_t chaddr[DHCP_CHADDR_LEN];  /* client's hardware address */
172 	uint8_t servername[SERVERNAME_LEN];    /* server host name */
173 	uint8_t bootfile[BOOTFILE_LEN];    /* boot file name */
174 	uint32_t cookie;
175 	uint8_t options[DHCP_OPTION_LEN]; /* message options - cookie */
176 } __packed;
177 
178 struct dhcp_lease {
179 	struct in_addr addr;
180 	struct in_addr net;
181 	struct in_addr brd;
182 	uint32_t leasetime;
183 	uint32_t renewaltime;
184 	uint32_t rebindtime;
185 	struct in_addr server;
186 	uint8_t frominfo;
187 	uint32_t cookie;
188 };
189 
190 enum DHS {
191 	DHS_INIT,
192 	DHS_DISCOVER,
193 	DHS_REQUEST,
194 	DHS_BOUND,
195 	DHS_RENEW,
196 	DHS_REBIND,
197 	DHS_REBOOT,
198 	DHS_INFORM,
199 	DHS_RENEW_REQUESTED,
200 	DHS_RELEASE
201 };
202 
203 struct dhcp_state {
204 	enum DHS state;
205 	struct dhcp_message *sent;
206 	struct dhcp_message *offer;
207 	struct dhcp_message *new;
208 	struct dhcp_message *old;
209 	struct dhcp_lease lease;
210 	const char *reason;
211 	time_t interval;
212 	time_t nakoff;
213 	uint32_t xid;
214 	int socket;
215 
216 	int raw_fd;
217 	struct in_addr addr;
218 	struct in_addr net;
219 	struct in_addr dst;
220 	uint8_t added;
221 
222 	char leasefile[sizeof(LEASEFILE) + IF_NAMESIZE + (IF_SSIDSIZE * 4)];
223 	struct timespec started;
224 	unsigned char *clientid;
225 	struct authstate auth;
226 	size_t arping_index;
227 };
228 
229 #define D_STATE(ifp)							       \
230 	((struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
231 #define D_CSTATE(ifp)							       \
232 	((const struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
233 #define D_STATE_RUNNING(ifp)						       \
234 	(D_CSTATE((ifp)) && D_CSTATE((ifp))->new && D_CSTATE((ifp))->reason)
235 
236 #include "dhcpcd.h"
237 #include "if-options.h"
238 
239 #ifdef INET
240 char *decode_rfc3361(const uint8_t *, size_t);
241 ssize_t decode_rfc3442(char *, size_t, const uint8_t *p, size_t);
242 ssize_t decode_rfc5969(char *, size_t, const uint8_t *p, size_t);
243 
244 void dhcp_printoptions(const struct dhcpcd_ctx *,
245     const struct dhcp_opt *, size_t);
246 int get_option_addr(struct dhcpcd_ctx *,struct in_addr *,
247     const struct dhcp_message *, uint8_t);
248 #define IS_BOOTP(i, m) ((m) != NULL &&						    \
249 	    get_option_uint8((i)->ctx, NULL, (m), DHO_MESSAGETYPE) == -1)
250 uint16_t dhcp_get_mtu(const struct interface *);
251 struct rt_head *dhcp_get_routes(struct interface *);
252 ssize_t dhcp_env(char **, const char *, const struct dhcp_message *,
253     const struct interface *);
254 
255 uint32_t dhcp_xid(const struct interface *);
256 struct dhcp_message *dhcp_message_new(const struct in_addr *addr,
257     const struct in_addr *mask);
258 int dhcp_message_add_addr(struct dhcp_message *, uint8_t, struct in_addr);
259 ssize_t make_message(struct dhcp_message **, const struct interface *,
260     uint8_t);
261 int valid_dhcp_packet(unsigned char *);
262 
263 void dhcp_handleifa(int, struct interface *,
264     const struct in_addr *, const struct in_addr *, const struct in_addr *,
265     int);
266 
267 void dhcp_drop(struct interface *, const char *);
268 void dhcp_start(struct interface *);
269 void dhcp_abort(struct interface *);
270 void dhcp_discover(void *);
271 void dhcp_inform(struct interface *);
272 void dhcp_bind(struct interface *);
273 void dhcp_reboot_newopts(struct interface *, unsigned long long);
274 void dhcp_close(struct interface *);
275 void dhcp_free(struct interface *);
276 int dhcp_dump(struct interface *);
277 #else
278 #define dhcp_drop(a, b) {}
279 #define dhcp_start(a) {}
280 #define dhcp_abort(a) {}
281 #define dhcp_reboot(a, b) (b = b)
282 #define dhcp_reboot_newopts(a, b) (b = b)
283 #define dhcp_close(a) {}
284 #define dhcp_free(a) {}
285 #define dhcp_dump(a) (-1)
286 #endif
287 
288 #endif
289