-
Notifications
You must be signed in to change notification settings - Fork 0
/
dhcp.h
201 lines (178 loc) · 6.91 KB
/
dhcp.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/*
* dhcpcd - DHCP client daemon
* Copyright (c) 2006-2008 Roy Marples <[email protected]>
* All rights reserved
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef DHCP_H
#define DHCP_H
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdint.h>
#include "common.h"
/* Max MTU - defines dhcp option length */
#define MTU_MAX 1500
#define MTU_MIN 576
/* UDP port numbers for DHCP */
#define DHCP_SERVER_PORT 67
#define DHCP_CLIENT_PORT 68
#define MAGIC_COOKIE 0x63825363
#define BROADCAST_FLAG 0x8000
/* DHCP message OP code */
#define DHCP_BOOTREQUEST 1
#define DHCP_BOOTREPLY 2
/* DHCP message type */
#define DHCP_DISCOVER 1
#define DHCP_OFFER 2
#define DHCP_REQUEST 3
#define DHCP_DECLINE 4
#define DHCP_ACK 5
#define DHCP_NAK 6
#define DHCP_RELEASE 7
#define DHCP_INFORM 8
/* Constants taken from RFC 2131. */
#define T1 0.5
#define T2 0.875
#define DHCP_BASE 4
#define DHCP_MAX 64
#define DHCP_RAND_MIN -1
#define DHCP_RAND_MAX 1
#define DHCP_ARP_FAIL 10
/* number of usecs in a second. */
#define USECS_SECOND 1000000
/* As we use timevals, we should use the usec part for
* greater randomisation. */
#define DHCP_RAND_MIN_U DHCP_RAND_MIN * USECS_SECOND
#define DHCP_RAND_MAX_U DHCP_RAND_MAX * USECS_SECOND
#define PROBE_MIN_U PROBE_MIN * USECS_SECOND
#define PROBE_MAX_U PROBE_MAX * USECS_SECOND
/* DHCP options */
enum DHO {
DHO_PAD = 0,
DHO_SUBNETMASK = 1,
DHO_ROUTER = 3,
DHO_DNSSERVER = 6,
DHO_HOSTNAME = 12,
DHO_DNSDOMAIN = 15,
DHO_MTU = 26,
DHO_BROADCAST = 28,
DHO_STATICROUTE = 33,
DHO_NISDOMAIN = 40,
DHO_NISSERVER = 41,
DHO_NTPSERVER = 42,
DHO_VENDOR = 43,
DHO_IPADDRESS = 50,
DHO_LEASETIME = 51,
DHO_OPTIONSOVERLOADED = 52,
DHO_MESSAGETYPE = 53,
DHO_SERVERID = 54,
DHO_PARAMETERREQUESTLIST = 55,
DHO_MESSAGE = 56,
DHO_MAXMESSAGESIZE = 57,
DHO_RENEWALTIME = 58,
DHO_REBINDTIME = 59,
DHO_VENDORCLASSID = 60,
DHO_CLIENTID = 61,
DHO_USERCLASS = 77, /* RFC 3004 */
DHO_FQDN = 81,
DHO_DNSSEARCH = 119, /* RFC 3397 */
DHO_CSR = 121, /* RFC 3442 */
DHO_MSCSR = 249, /* MS code for RFC 3442 */
DHO_END = 255
};
/* FQDN values - lsnybble used in flags
* hsnybble to create order
* and to allow 0x00 to mean disable
*/
enum FQDN {
FQDN_DISABLE = 0x00,
FQDN_NONE = 0x18,
FQDN_PTR = 0x20,
FQDN_BOTH = 0x31
};
/* Sizes for DHCP options */
#define DHCP_CHADDR_LEN 16
#define SERVERNAME_LEN 64
#define BOOTFILE_LEN 128
#define DHCP_UDP_LEN (14 + 20 + 8)
#define DHCP_FIXED_LEN (DHCP_UDP_LEN + 226)
#define DHCP_OPTION_LEN (MTU_MAX - DHCP_FIXED_LEN)
/* Some crappy DHCP servers require the BOOTP minimum length */
#define BOOTP_MESSAGE_LENTH_MIN 300
struct dhcp_message {
uint8_t op; /* message type */
uint8_t hwtype; /* hardware address type */
uint8_t hwlen; /* hardware address length */
uint8_t hwopcount; /* should be zero in client message */
uint32_t xid; /* transaction id */
uint16_t secs; /* elapsed time in sec. from boot */
uint16_t flags;
uint32_t ciaddr; /* (previously allocated) client IP */
uint32_t yiaddr; /* 'your' client IP address */
uint32_t siaddr; /* should be zero in client's messages */
uint32_t giaddr; /* should be zero in client's messages */
uint8_t chaddr[DHCP_CHADDR_LEN]; /* client's hardware address */
uint8_t servername[SERVERNAME_LEN]; /* server host name */
uint8_t bootfile[BOOTFILE_LEN]; /* boot file name */
uint32_t cookie;
uint8_t options[DHCP_OPTION_LEN]; /* message options - cookie */
} _packed;
struct dhcp_lease {
struct in_addr addr;
struct in_addr net;
struct in_addr brd;
uint32_t leasetime;
uint32_t renewaltime;
uint32_t rebindtime;
struct in_addr server;
time_t leasedfrom;
struct timeval boundtime;
uint8_t frominfo;
uint32_t cookie;
};
#include "dhcpcd.h"
#include "if-options.h"
#include "net.h"
#define add_option_mask(var, val) (var[val >> 3] |= 1 << (val & 7))
#define del_option_mask(var, val) (var[val >> 3] &= ~(1 << (val & 7)))
#define has_option_mask(var, val) (var[val >> 3] & (1 << (val & 7)))
int make_option_mask(uint8_t *, const char *, int);
void print_options(void);
char *get_option_string(const struct dhcp_message *, uint8_t);
int get_option_addr(struct in_addr *, const struct dhcp_message *, uint8_t);
int get_option_uint32(uint32_t *, const struct dhcp_message *, uint8_t);
int get_option_uint16(uint16_t *, const struct dhcp_message *, uint8_t);
int get_option_uint8(uint8_t *, const struct dhcp_message *, uint8_t);
#define is_bootp(m) (m && \
!IN_LINKLOCAL(htonl((m)->yiaddr)) && \
get_option_uint8(NULL, m, DHO_MESSAGETYPE) == -1)
struct rt *get_option_routes(const struct dhcp_message *, const char *, int *);
ssize_t configure_env(char **, const char *, const struct dhcp_message *,
const struct if_options *);
int dhcp_message_add_addr(struct dhcp_message *, uint8_t, struct in_addr);
ssize_t make_message(struct dhcp_message **, const struct interface *,
uint8_t);
int valid_dhcp_packet(unsigned char *);
ssize_t write_lease(const struct interface *, const struct dhcp_message *);
struct dhcp_message *read_lease(const struct interface *);
void get_lease(struct dhcp_lease *, const struct dhcp_message *);
#endif