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 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 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 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
