1/*
2 * dhcpcd - DHCP client daemon
3 * Copyright (c) 2006-2019 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 <netinet/ip.h>
35#define __FAVOR_BSD /* Nasty glibc hack so we can use BSD semantics for UDP */
36#include <netinet/udp.h>
37#undef __FAVOR_BSD
38
39#include <limits.h>
40#include <stdint.h>
41
42#include "arp.h"
43#include "auth.h"
44#include "dhcp-common.h"
45
46/* UDP port numbers for BOOTP */
47#define BOOTPS 67
48#define BOOTPC 68
49
50#define MAGIC_COOKIE 0x63825363
51#define BROADCAST_FLAG 0x8000
52
53/* BOOTP message OP code */
54#define BOOTREQUEST 1
55#define BOOTREPLY 2
56
57/* DHCP message type */
58#define DHCP_DISCOVER 1
59#define DHCP_OFFER 2
60#define DHCP_REQUEST 3
61#define DHCP_DECLINE 4
62#define DHCP_ACK 5
63#define DHCP_NAK 6
64#define DHCP_RELEASE 7
65#define DHCP_INFORM 8
66#define DHCP_FORCERENEW 9
67
68/* Constants taken from RFC 2131. */
69#define T1 0.5
70#define T2 0.875
71#define DHCP_BASE 4
72#define DHCP_MAX 64
73#define DHCP_RAND_MIN -1
74#define DHCP_RAND_MAX 1
75
76#ifdef RFC2131_STRICT
77/* Be strictly conformant for section 4.1.1 */
78# define DHCP_MIN_DELAY 1
79# define DHCP_MAX_DELAY 10
80#else
81/* or mirror the more modern IPv6RS and DHCPv6 delays */
82# define DHCP_MIN_DELAY 0
83# define DHCP_MAX_DELAY 1
84#endif
85
86/* DHCP options */
87enum DHO {
88 DHO_PAD = 0,
89 DHO_SUBNETMASK = 1,
90 DHO_ROUTER = 3,
91 DHO_DNSSERVER = 6,
92 DHO_HOSTNAME = 12,
93 DHO_DNSDOMAIN = 15,
94 DHO_MTU = 26,
95 DHO_BROADCAST = 28,
96 DHO_STATICROUTE = 33,
97 DHO_NISDOMAIN = 40,
98 DHO_NISSERVER = 41,
99 DHO_NTPSERVER = 42,
100 DHO_VENDOR = 43,
101 DHO_IPADDRESS = 50,
102 DHO_LEASETIME = 51,
103 DHO_OPTSOVERLOADED = 52,
104 DHO_MESSAGETYPE = 53,
105 DHO_SERVERID = 54,
106 DHO_PARAMETERREQUESTLIST = 55,
107 DHO_MESSAGE = 56,
108 DHO_MAXMESSAGESIZE = 57,
109 DHO_RENEWALTIME = 58,
110 DHO_REBINDTIME = 59,
111 DHO_VENDORCLASSID = 60,
112 DHO_CLIENTID = 61,
113 DHO_USERCLASS = 77, /* RFC 3004 */
114 DHO_RAPIDCOMMIT = 80, /* RFC 4039 */
115 DHO_FQDN = 81,
116 DHO_AUTHENTICATION = 90, /* RFC 3118 */
117 DHO_AUTOCONFIGURE = 116, /* RFC 2563 */
118 DHO_DNSSEARCH = 119, /* RFC 3397 */
119 DHO_CSR = 121, /* RFC 3442 */
120 DHO_VIVCO = 124, /* RFC 3925 */
121 DHO_VIVSO = 125, /* RFC 3925 */
122 DHO_FORCERENEW_NONCE = 145, /* RFC 6704 */
123 DHO_MUDURL = 161, /* draft-ietf-opsawg-mud */
124 DHO_SIXRD = 212, /* RFC 5969 */
125 DHO_MSCSR = 249, /* MS code for RFC 3442 */
126 DHO_END = 255
127};
128
129/* FQDN values - lsnybble used in flags
130 * hsnybble to create order
131 * and to allow 0x00 to mean disable
132 */
133enum FQDN {
134 FQDN_DISABLE = 0x00,
135 FQDN_NONE = 0x18,
136 FQDN_PTR = 0x20,
137 FQDN_BOTH = 0x31
138};
139
140/* Sizes for BOOTP options */
141#define BOOTP_CHADDR_LEN 16
142#define BOOTP_SNAME_LEN 64
143#define BOOTP_FILE_LEN 128
144#define BOOTP_VEND_LEN 64
145
146/* DHCP is basically an extension to BOOTP */
147struct bootp {
148 uint8_t op; /* message type */
149 uint8_t htype; /* hardware address type */
150 uint8_t hlen; /* hardware address length */
151 uint8_t hops; /* should be zero in client message */
152 uint32_t xid; /* transaction id */
153 uint16_t secs; /* elapsed time in sec. from boot */
154 uint16_t flags; /* such as broadcast flag */
155 uint32_t ciaddr; /* (previously allocated) client IP */
156 uint32_t yiaddr; /* 'your' client IP address */
157 uint32_t siaddr; /* should be zero in client's messages */
158 uint32_t giaddr; /* should be zero in client's messages */
159 uint8_t chaddr[BOOTP_CHADDR_LEN]; /* client's hardware address */
160 uint8_t sname[BOOTP_SNAME_LEN]; /* server host name */
161 uint8_t file[BOOTP_FILE_LEN]; /* boot file name */
162 uint8_t vend[BOOTP_VEND_LEN]; /* vendor specific area */
163 /* DHCP allows a variable length vendor area */
164};
165
166struct bootp_pkt
167{
168 struct ip ip;
169 struct udphdr udp;
170 struct bootp bootp;
171};
172
173struct dhcp_lease {
174 struct in_addr addr;
175 struct in_addr mask;
176 struct in_addr brd;
177 uint32_t leasetime;
178 uint32_t renewaltime;
179 uint32_t rebindtime;
180 struct in_addr server;
181 uint8_t frominfo;
182 uint32_t cookie;
183};
184
185enum DHS {
186 DHS_NONE,
187 DHS_INIT,
188 DHS_DISCOVER,
189 DHS_REQUEST,
190 DHS_PROBE,
191 DHS_BOUND,
192 DHS_RENEW,
193 DHS_REBIND,
194 DHS_REBOOT,
195 DHS_INFORM,
196 DHS_RENEW_REQUESTED,
197 DHS_RELEASE
198};
199
200struct dhcp_state {
201 enum DHS state;
202 struct bootp *sent;
203 size_t sent_len;
204 struct bootp *offer;
205 size_t offer_len;
206 struct bootp *new;
207 size_t new_len;
208 struct bootp *old;
209 size_t old_len;
210 struct dhcp_lease lease;
211 const char *reason;
212 time_t interval;
213 time_t nakoff;
214 uint32_t xid;
215 int socket;
216
217 int bpf_fd;
218 unsigned int bpf_flags;
219 int udp_fd;
220 struct ipv4_addr *addr;
221 uint8_t added;
222
223 char leasefile[sizeof(LEASEFILE) + IF_NAMESIZE + (IF_SSIDLEN * 4)];
224 struct timespec started;
225 unsigned char *clientid;
226 struct authstate auth;
227#ifdef ARPING
228 ssize_t arping_index;
229#endif
230};
231
232#ifdef INET
233#define D_STATE(ifp) \
234 ((struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
235#define D_CSTATE(ifp) \
236 ((const struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
237#define D_STATE_RUNNING(ifp) \
238 (D_CSTATE((ifp)) && D_CSTATE((ifp))->new && D_CSTATE((ifp))->reason)
239
240#define IS_DHCP(b) ((b)->vend[0] == 0x63 && \
241 (b)->vend[1] == 0x82 && \
242 (b)->vend[2] == 0x53 && \
243 (b)->vend[3] == 0x63)
244
245#include "dhcpcd.h"
246#include "if-options.h"
247
248char *decode_rfc3361(const uint8_t *, size_t);
249ssize_t decode_rfc3442(char *, size_t, const uint8_t *p, size_t);
250
251void dhcp_printoptions(const struct dhcpcd_ctx *,
252 const struct dhcp_opt *, size_t);
253uint16_t dhcp_get_mtu(const struct interface *);
254int dhcp_get_routes(struct rt_head *, struct interface *);
255ssize_t dhcp_env(char **, const char *, const struct bootp *, size_t,
256 const struct interface *);
257
258void dhcp_handleifa(int, struct ipv4_addr *, pid_t pid);
259void dhcp_drop(struct interface *, const char *);
260void dhcp_start(struct interface *);
261void dhcp_abort(struct interface *);
262void dhcp_discover(void *);
263void dhcp_inform(struct interface *);
264void dhcp_renew(struct interface *);
265void dhcp_bind(struct interface *);
266void dhcp_reboot_newopts(struct interface *, unsigned long long);
267void dhcp_close(struct interface *);
268void dhcp_free(struct interface *);
269int dhcp_dump(struct interface *);
270#endif /* INET */
271
272#endif /* DHCP_H */
273