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[ETH_ALEN] __attribute__((aligned(2))) = {
  51         0xff, 0xff, 0xff, 0xff, 0xff, 0xff
  52 };
  53
  54 static const uint8_t MAC_ANY_ADDR[ETH_ALEN] __attribute__((aligned(2))) = {
  55         0x00, 0x00, 0x00, 0x00, 0x00, 0x00
  56 };
  57
  58 /* DHCP packet */
  59 #define DHCP_MAGIC              0x63825363
  60 #define DHCP_OPTIONS_BUFSIZE    308
  61 #define BOOTREQUEST             1
  62 #define BOOTREPLY               2
  63
  64 #define BROADCAST_FLAG          0x8000
  65
  66 /* See RFC 2131 */
  67 struct dhcp_packet {
  68         uint8_t op;
  69         uint8_t htype;
  70         uint8_t hlen;
  71         uint8_t hops;
  72         uint32_t xid;
  73         uint16_t secs;
  74         uint16_t flags;
  75         uint32_t ciaddr;
  76         uint32_t yiaddr;
  77         uint32_t siaddr_nip;
  78         uint32_t gateway_nip;
  79         uint8_t chaddr[16];
  80         uint8_t sname[64];
  81         uint8_t file[128];
  82         uint32_t cookie;
  83         uint8_t options[DHCP_OPTIONS_BUFSIZE + EXTEND_FOR_BUGGY_SERVERS];
  84 } __attribute__((packed));
  85
  86 struct ip_udp_dhcp_packet {
  87         struct iphdr ip;
  88         struct udphdr udp;
  89         struct dhcp_packet data;
  90 } __attribute__((packed));
  91
  92 /* See RFC 2132 */
  93 #define DHCP_PADDING            0x00
  94 #define DHCP_SUBNET             0x01
  95 #define DHCP_ROUTER             0x03
  96 #define DHCP_TIME_SERVER        0x04
  97 #define DHCP_NAME_SERVER        0x05
  98 #define DHCP_DNS_SERVER         0x06
  99 #define DHCP_HOST_NAME          0x0c
 100 #define DHCP_DOMAIN_NAME        0x0f
 101 #define DHCP_NTP_SERVER         0x2a
 102 #define DHCP_REQUESTED_IP       0x32
 103 #define DHCP_LEASE_TIME         0x33
 104 #define DHCP_OPTION_OVERLOAD    0x34
 105 #define DHCP_MESSAGE_TYPE       0x35
 106 #define DHCP_SERVER_ID          0x36
 107 #define DHCP_PARAM_REQ          0x37
 108 #define DHCP_ERR_MESSAGE        0x38
 109 #define DHCP_MAX_SIZE           0x39
 110 #define DHCP_VENDOR             0x3c
 111 #define DHCP_CLIENT_ID          0x3d
 112 #define DHCP_END                0xff
 113
 114 #define OPT_CODE                0
 115 #define OPT_LEN                 1
 116 #define OPT_DATA                2
 117 #define OPTION_FIELD            0
 118 #define FILE_FIELD              1
 119 #define SNAME_FIELD             2
 120
 121 /* DHCP_MESSAGE_TYPE values */
 122 #define DHCPDISCOVER            1
 123 #define DHCPOFFER               2
 124 #define DHCPREQUEST             3
 125 #define DHCPDECLINE             4
 126 #define DHCPACK                 5
 127 #define DHCPNAK                 6
 128 #define DHCPRELEASE             7
 129 #define DHCPINFORM              8
 130 #define DHCP_MINTYPE DHCPDISCOVER
 131 #define DHCP_MAXTYPE DHCPINFORM
 132
 133 typedef enum {
 134         OPTION_UNKNOWN,
 135         OPTION_IP,
 136         OPTION_STRING,
 137         OPTION_U8,
 138         OPTION_U16,
 139         OPTION_U32,
 140         OPTION_TYPE_MASK = 0x0f,
 141         OPTION_LIST = 0x10,
 142 } GDHCPOptionType;
 143
 144 typedef struct dhcp_option {
 145         GDHCPOptionType type;
 146         uint8_t code;
 147 } DHCPOption;
 148
 149 /* Length of the option types in binary form */
 150 static const uint8_t dhcp_option_lengths[] = {
 151         [OPTION_IP]     = 4,
 152         [OPTION_STRING] = 1,
 153         [OPTION_U8]     = 1,
 154         [OPTION_U16]    = 2,
 155         [OPTION_U32]    = 4,
 156 };
 157
 158 uint8_t *dhcp_get_option(struct dhcp_packet *packet, int code);
 159 int dhcp_end_option(uint8_t *optionptr);
 160 void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt);
 161 void dhcp_add_simple_option(struct dhcp_packet *packet,
 162                                 uint8_t code, uint32_t data);
 163 GDHCPOptionType dhcp_get_code_type(uint8_t code);
 164
 165 uint16_t dhcp_checksum(void *addr, int count);
 166
 167 void dhcp_init_header(struct dhcp_packet *packet, char type);
 168
 169 int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
 170                         uint32_t source_ip, int source_port,
 171                         uint32_t dest_ip, int dest_port,
 172                         const uint8_t *dest_arp, int ifindex);
 173 int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
 174                         uint32_t source_ip, int source_port,
 175                         uint32_t dest_ip, int dest_port);
 176 int dhcp_l3_socket(int port, const char *interface);
 177 int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd);
 178 char *get_interface_name(int index);
 179 gboolean interface_is_up(int index);