1 /* 2 * OpenVPN -- An application to securely tunnel IP networks 3 * over a single TCP/UDP port, with support for SSL/TLS-based 4 * session authentication and key exchange, 5 * packet encryption, packet authentication, and 6 * packet compression. 7 * 8 * Copyright (C) 2002-2018 OpenVPN Inc <sales@openvpn.net> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 12 * as published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License along 20 * with this program; if not, write to the Free Software Foundation, Inc., 21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 22 */ 23 24 #ifndef DHCP_H 25 #define DHCP_H 26 27 #include "common.h" 28 #include "buffer.h" 29 #include "proto.h" 30 31 #pragma pack(1) 32 33 /* DHCP Option types */ 34 #define DHCP_PAD 0 35 #define DHCP_ROUTER 3 36 #define DHCP_MSG_TYPE 53 /* message type (u8) */ 37 #define DHCP_END 255 38 39 /* DHCP Messages types */ 40 #define DHCPDISCOVER 1 41 #define DHCPOFFER 2 42 #define DHCPREQUEST 3 43 #define DHCPDECLINE 4 44 #define DHCPACK 5 45 #define DHCPNAK 6 46 #define DHCPRELEASE 7 47 #define DHCPINFORM 8 48 49 /* DHCP UDP port numbers */ 50 #define BOOTPS_PORT 67 51 #define BOOTPC_PORT 68 52 53 struct dhcp { 54 #define BOOTREQUEST 1 55 #define BOOTREPLY 2 56 uint8_t op; /* message op */ 57 58 uint8_t htype; /* hardware address type (e.g. '1' = 10Mb Ethernet) */ 59 uint8_t hlen; /* hardware address length (e.g. '6' for 10Mb Ethernet) */ 60 uint8_t hops; /* client sets to 0, may be used by relay agents */ 61 uint32_t xid; /* transaction ID, chosen by client */ 62 uint16_t secs; /* seconds since request process began, set by client */ 63 uint16_t flags; 64 uint32_t ciaddr; /* client IP address, client sets if known */ 65 uint32_t yiaddr; /* 'your' IP address -- server's response to client */ 66 uint32_t siaddr; /* server IP address */ 67 uint32_t giaddr; /* relay agent IP address */ 68 uint8_t chaddr[16]; /* client hardware address */ 69 uint8_t sname[64]; /* optional server host name */ 70 uint8_t file[128]; /* boot file name */ 71 uint32_t magic; /* must be 0x63825363 (network order) */ 72 }; 73 74 struct dhcp_full { 75 struct openvpn_iphdr ip; 76 struct openvpn_udphdr udp; 77 struct dhcp dhcp; 78 #define DHCP_OPTIONS_BUFFER_SIZE 256 79 uint8_t options[DHCP_OPTIONS_BUFFER_SIZE]; 80 }; 81 82 #pragma pack() 83 84 in_addr_t dhcp_extract_router_msg(struct buffer *ipbuf); 85 86 #endif /* ifndef DHCP_H */ 87