1 /*
2 * Copyright 2008, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <stdio.h>
18 #include <stdarg.h>
19 #include <string.h>
20 #include <netinet/in.h>
21
22 #include "dhcpmsg.h"
23
init_dhcp_msg(dhcp_msg * msg,int type,void * hwaddr,uint32_t xid)24 static void *init_dhcp_msg(dhcp_msg *msg, int type, void *hwaddr, uint32_t xid)
25 {
26 uint8_t *x;
27
28 memset(msg, 0, sizeof(dhcp_msg));
29
30 msg->op = OP_BOOTREQUEST;
31 msg->htype = HTYPE_ETHER;
32 msg->hlen = 6;
33 msg->hops = 0;
34
35 msg->flags = htons(FLAGS_BROADCAST);
36
37 msg->xid = xid;
38
39 memcpy(msg->chaddr, hwaddr, 6);
40
41 x = msg->options;
42
43 *x++ = OPT_COOKIE1;
44 *x++ = OPT_COOKIE2;
45 *x++ = OPT_COOKIE3;
46 *x++ = OPT_COOKIE4;
47
48 *x++ = OPT_MESSAGE_TYPE;
49 *x++ = 1;
50 *x++ = type;
51
52 return x;
53 }
54
init_dhcp_discover_msg(dhcp_msg * msg,void * hwaddr,uint32_t xid)55 int init_dhcp_discover_msg(dhcp_msg *msg, void *hwaddr, uint32_t xid)
56 {
57 uint8_t *x;
58
59 x = init_dhcp_msg(msg, DHCPDISCOVER, hwaddr, xid);
60
61 *x++ = OPT_PARAMETER_LIST;
62 *x++ = 4;
63 *x++ = OPT_SUBNET_MASK;
64 *x++ = OPT_GATEWAY;
65 *x++ = OPT_DNS;
66 *x++ = OPT_BROADCAST_ADDR;
67
68 *x++ = OPT_END;
69
70 return DHCP_MSG_FIXED_SIZE + (x - msg->options);
71 }
72
init_dhcp_request_msg(dhcp_msg * msg,void * hwaddr,uint32_t xid,uint32_t ipaddr,uint32_t serveraddr)73 int init_dhcp_request_msg(dhcp_msg *msg, void *hwaddr, uint32_t xid,
74 uint32_t ipaddr, uint32_t serveraddr)
75 {
76 uint8_t *x;
77
78 x = init_dhcp_msg(msg, DHCPREQUEST, hwaddr, xid);
79
80 *x++ = OPT_PARAMETER_LIST;
81 *x++ = 4;
82 *x++ = OPT_SUBNET_MASK;
83 *x++ = OPT_GATEWAY;
84 *x++ = OPT_DNS;
85 *x++ = OPT_BROADCAST_ADDR;
86
87 *x++ = OPT_REQUESTED_IP;
88 *x++ = 4;
89 memcpy(x, &ipaddr, 4);
90 x += 4;
91
92 *x++ = OPT_SERVER_ID;
93 *x++ = 4;
94 memcpy(x, &serveraddr, 4);
95 x += 4;
96
97 *x++ = OPT_END;
98
99 return DHCP_MSG_FIXED_SIZE + (x - msg->options);
100 }
101