gdhcp/common.h

   1 /*
   2  *
   3  *  DHCP client library with GLib integration
   4  *
   5  *  Copyright (C) 2009-2010  Intel Corporation. All rights reserved.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21
  22 #include <netinet/udp.h>
  23 #include <netinet/ip.h>
  24
  25 #include <glib.h>
  26
  27 #include "gdhcp.h"
  28
  29 #define dhcp_get_unaligned(ptr)                 \
  30 ({                                              \
  31         struct __attribute__((packed)) {        \
  32                 typeof(*(ptr)) __v;             \
  33         } *__p = (void *) (ptr);                \
  34         __p->__v;                               \
  35 })
  36
  37 #define dhcp_put_unaligned(val, ptr)            \
  38 do {                                            \
  39         struct __attribute__((packed)) {        \
  40                 typeof(*(ptr)) __v;             \
  41         } *__p = (void *) (ptr);                \
  42         __p->__v = (val);                       \
  43 } while (0)
  44
  45 #define CLIENT_PORT 68
  46 #define SERVER_PORT 67
  47
  48 #define EXTEND_FOR_BUGGY_SERVERS 80
  49
  50 static const uint8_t MAC_BCAST_ADDR[6] __attribute__((aligned(2))) = {
  51         0xff, 0xff, 0xff, 0xff, 0xff, 0xff
  52 };
  53
  54 /* DHCP packet */
  55 #define DHCP_MAGIC              0x63825363
  56 #define DHCP_OPTIONS_BUFSIZE    308
  57 #define BOOTREQUEST             1
  58 #define BOOTREPLY               2
  59
  60 #define BROADCAST_FLAG          0x8000
  61
  62 /* See RFC 2131 */
  63 struct dhcp_packet {
  64         uint8_t op;
  65         uint8_t htype;
  66         uint8_t hlen;
  67         uint8_t hops;
  68         uint32_t xid;
  69         uint16_t secs;
  70         uint16_t flags;
  71         uint32_t ciaddr;
  72         uint32_t yiaddr;
  73         uint32_t siaddr_nip;
  74         uint32_t gateway_nip;
  75         uint8_t chaddr[16];
  76         uint8_t sname[64];
  77         uint8_t file[128];
  78         uint32_t cookie;
  79         uint8_t options[DHCP_OPTIONS_BUFSIZE + EXTEND_FOR_BUGGY_SERVERS];
  80 } __attribute__((packed));
  81
  82 struct ip_udp_dhcp_packet {
  83         struct iphdr ip;
  84         struct udphdr udp;
  85         struct dhcp_packet data;
  86 } __attribute__((packed));
  87
  88 /* See RFC 2132 */
  89 #define DHCP_PADDING            0x00
  90 #define DHCP_SUBNET             0x01
  91 #define DHCP_ROUTER             0x03
  92 #define DHCP_TIME_SERVER        0x04
  93 #define DHCP_NAME_SERVER        0x05
  94 #define DHCP_DNS_SERVER         0x06
  95 #define DHCP_HOST_NAME          0x0c
  96 #define DHCP_DOMAIN_NAME        0x0f
  97 #define DHCP_NTP_SERVER         0x2a
  98 #define DHCP_REQUESTED_IP       0x32
  99 #define DHCP_LEASE_TIME         0x33
 100 #define DHCP_OPTION_OVERLOAD    0x34
 101 #define DHCP_MESSAGE_TYPE       0x35
 102 #define DHCP_SERVER_ID          0x36
 103 #define DHCP_PARAM_REQ          0x37
 104 #define DHCP_ERR_MESSAGE        0x38
 105 #define DHCP_MAX_SIZE           0x39
 106 #define DHCP_VENDOR             0x3c
 107 #define DHCP_CLIENT_ID          0x3d
 108 #define DHCP_END                0xff
 109
 110 #define OPT_CODE                0
 111 #define OPT_LEN                 1
 112 #define OPT_DATA                2
 113 #define OPTION_FIELD            0
 114 #define FILE_FIELD              1
 115 #define SNAME_FIELD             2
 116
 117 /* DHCP_MESSAGE_TYPE values */
 118 #define DHCPDISCOVER            1
 119 #define DHCPOFFER               2
 120 #define DHCPREQUEST             3
 121 #define DHCPDECLINE             4
 122 #define DHCPACK                 5
 123 #define DHCPNAK                 6
 124 #define DHCPRELEASE             7
 125 #define DHCPINFORM              8
 126 #define DHCP_MINTYPE DHCPDISCOVER
 127 #define DHCP_MAXTYPE DHCPINFORM
 128
 129 typedef enum {
 130         OPTION_UNKNOWN,
 131         OPTION_IP,
 132         OPTION_STRING,
 133         OPTION_U8,
 134         OPTION_U16,
 135         OPTION_U32,
 136         OPTION_TYPE_MASK = 0x0f,
 137         OPTION_LIST = 0x10,
 138 } GDHCPOptionType;
 139
 140 typedef struct dhcp_option {
 141         GDHCPOptionType type;
 142         uint8_t code;
 143 } DHCPOption;
 144
 145 /* Length of the option types in binary form */
 146 static const uint8_t dhcp_option_lengths[] = {
 147         [OPTION_IP]     = 4,
 148         [OPTION_STRING] = 1,
 149         [OPTION_U8]     = 1,
 150         [OPTION_U16]    = 2,
 151         [OPTION_U32]    = 4,
 152 };
 153
 154 uint8_t *dhcp_get_option(struct dhcp_packet *packet, int code);
 155 int dhcp_end_option(uint8_t *optionptr);
 156 void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt);
 157 void dhcp_add_simple_option(struct dhcp_packet *packet,
 158                                 uint8_t code, uint32_t data);
 159 GDHCPOptionType dhcp_get_code_type(uint8_t code);
 160
 161 uint16_t dhcp_checksum(void *addr, int count);
 162
 163 void dhcp_init_header(struct dhcp_packet *packet, char type);
 164
 165 int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
 166                         uint32_t source_ip, int source_port,
 167                         uint32_t dest_ip, int dest_port,
 168                         const uint8_t *dest_arp, int ifindex);
 169 int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
 170                         uint32_t source_ip, int source_port,
 171                         uint32_t dest_ip, int dest_port);
 172 int dhcp_l3_socket(int port, const char *interface);
 173 int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd);