summaryrefslogtreecommitdiff
path: root/gdhcp/common.h
blob: 4b7df7ef61cf90a82c8a050effa408c2d20c194a (plain)
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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 *
 *  DHCP client library with GLib integration
 *
 *  Copyright (C) 2009-2010  Intel Corporation. All rights reserved.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <netinet/udp.h>
#include <netinet/ip.h>

#include <glib.h>

#include "gdhcp.h"

#define dhcp_get_unaligned(ptr)			\
({						\
	struct __attribute__((packed)) {	\
		typeof(*(ptr)) __v;		\
	} *__p = (void *) (ptr);		\
	__p->__v;				\
})

#define dhcp_put_unaligned(val, ptr)		\
do {						\
	struct __attribute__((packed)) {	\
		typeof(*(ptr)) __v;		\
	} *__p = (void *) (ptr);		\
	__p->__v = (val);			\
} while (0)

#define CLIENT_PORT 68
#define SERVER_PORT 67

#define DHCPV6_CLIENT_PORT 546
#define DHCPV6_SERVER_PORT 547
#define MAX_DHCPV6_PKT_SIZE 1500

#define EXTEND_FOR_BUGGY_SERVERS 80

static const uint8_t MAC_BCAST_ADDR[ETH_ALEN] __attribute__((aligned(2))) = {
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff
};

static const uint8_t MAC_ANY_ADDR[ETH_ALEN] __attribute__((aligned(2))) = {
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

/* DHCP packet */
#define DHCP_MAGIC              0x63825363
#define DHCP_OPTIONS_BUFSIZE    308
#define BOOTREQUEST             1
#define BOOTREPLY               2

#define BROADCAST_FLAG		0x8000

/* See RFC 2131 */
struct dhcp_packet {
	uint8_t op;
	uint8_t htype;
	uint8_t hlen;
	uint8_t hops;
	uint32_t xid;
	uint16_t secs;
	uint16_t flags;
	uint32_t ciaddr;
	uint32_t yiaddr;
	uint32_t siaddr_nip;
	uint32_t gateway_nip;
	uint8_t chaddr[16];
	uint8_t sname[64];
	uint8_t file[128];
	uint32_t cookie;
	uint8_t options[DHCP_OPTIONS_BUFSIZE + EXTEND_FOR_BUGGY_SERVERS];
} __attribute__((packed));

struct ip_udp_dhcp_packet {
	struct iphdr ip;
	struct udphdr udp;
	struct dhcp_packet data;
} __attribute__((packed));

/* See RFC 3315 */
struct dhcpv6_packet {
	uint8_t message;
	uint8_t transaction_id[3];
	uint8_t options[];
} __attribute__((packed));


/* See RFC 2132 */
#define DHCP_PADDING		0x00
#define DHCP_SUBNET		0x01
#define DHCP_ROUTER		0x03
#define DHCP_TIME_SERVER	0x04
#define DHCP_NAME_SERVER	0x05
#define DHCP_DNS_SERVER		0x06
#define DHCP_HOST_NAME		0x0c
#define DHCP_DOMAIN_NAME	0x0f
#define DHCP_NTP_SERVER		0x2a
#define DHCP_REQUESTED_IP	0x32
#define DHCP_LEASE_TIME		0x33
#define DHCP_OPTION_OVERLOAD	0x34
#define DHCP_MESSAGE_TYPE	0x35
#define DHCP_SERVER_ID		0x36
#define DHCP_PARAM_REQ		0x37
#define DHCP_ERR_MESSAGE	0x38
#define DHCP_MAX_SIZE		0x39
#define DHCP_VENDOR		0x3c
#define DHCP_CLIENT_ID		0x3d
#define DHCP_END		0xff

#define OPT_CODE		0
#define OPT_LEN			1
#define OPT_DATA		2
#define OPTION_FIELD		0
#define FILE_FIELD		1
#define SNAME_FIELD		2

/* DHCP_MESSAGE_TYPE values */
#define DHCPDISCOVER		1
#define DHCPOFFER		2
#define DHCPREQUEST		3
#define DHCPDECLINE		4
#define DHCPACK			5
#define DHCPNAK			6
#define DHCPRELEASE		7
#define DHCPINFORM		8
#define DHCP_MINTYPE DHCPDISCOVER
#define DHCP_MAXTYPE DHCPINFORM

/* Message types for DHCPv6, RFC 3315 sec 5.3 */
#define DHCPV6_SOLICIT		1
#define DHCPV6_ADVERTISE	2
#define DHCPV6_REQUEST		3
#define DHCPV6_CONFIRM		4
#define DHCPV6_RENEW		5
#define DHCPV6_REBIND		6
#define DHCPV6_REPLY		7
#define DHCPV6_RELEASE		8
#define DHCPV6_DECLINE		9
#define DHCPV6_RECONFIGURE	10
#define DHCPV6_INFORMATION_REQ	11

/*
 * DUID time starts 2000-01-01.
 */
#define DUID_TIME_EPOCH 946684800

typedef enum {
	OPTION_UNKNOWN,
	OPTION_IP,
	OPTION_STRING,
	OPTION_U8,
	OPTION_U16,
	OPTION_U32,
	OPTION_TYPE_MASK = 0x0f,
	OPTION_LIST = 0x10,
} GDHCPOptionType;

typedef struct dhcp_option {
	GDHCPOptionType type;
	uint8_t code;
} DHCPOption;

/* Length of the option types in binary form */
static const uint8_t dhcp_option_lengths[] = {
	[OPTION_IP]	= 4,
	[OPTION_STRING]	= 1,
	[OPTION_U8]	= 1,
	[OPTION_U16]	= 2,
	[OPTION_U32]	= 4,
};

uint8_t *dhcp_get_option(struct dhcp_packet *packet, int code);
uint8_t *dhcpv6_get_option(struct dhcpv6_packet *packet, uint16_t pkt_len,
			int code, uint16_t *option_len, int *option_count);
uint8_t *dhcpv6_get_sub_option(unsigned char *option, uint16_t max_len,
			uint16_t *code, uint16_t *option_len);
int dhcp_end_option(uint8_t *optionptr);
void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt);
void dhcpv6_add_binary_option(struct dhcpv6_packet *packet, uint16_t max_len,
				uint16_t *pkt_len, uint8_t *addopt);
void dhcp_add_simple_option(struct dhcp_packet *packet,
				uint8_t code, uint32_t data);
GDHCPOptionType dhcp_get_code_type(uint8_t code);
GDHCPOptionType dhcpv6_get_code_type(uint16_t code);

uint16_t dhcp_checksum(void *addr, int count);

void dhcp_init_header(struct dhcp_packet *packet, char type);
void dhcpv6_init_header(struct dhcpv6_packet *packet, uint8_t type);

int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
			uint32_t source_ip, int source_port,
			uint32_t dest_ip, int dest_port,
			const uint8_t *dest_arp, int ifindex);
int dhcpv6_send_packet(int index, struct dhcpv6_packet *dhcp_pkt, int len);
int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
			uint32_t source_ip, int source_port,
			uint32_t dest_ip, int dest_port);
int dhcp_l3_socket(int port, const char *interface, int family);
int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd);
int dhcpv6_recv_l3_packet(struct dhcpv6_packet **packet, unsigned char *buf,
			int buf_len, int fd);
int dhcp_l3_socket_send(int index, int port, int family);

char *get_interface_name(int index);
gboolean interface_is_up(int index);