gdhcp/common.h

   1 /*
   2  *
   3  *  DHCP client library with GLib integration
   4  *
   5  *  Copyright (C) 2009-2012  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 DHCPV6_CLIENT_PORT 546
  49 #define DHCPV6_SERVER_PORT 547
  50 #define MAX_DHCPV6_PKT_SIZE 1500
  51
  52 #define EXTEND_FOR_BUGGY_SERVERS 80
  53
  54 static const uint8_t MAC_BCAST_ADDR[ETH_ALEN] __attribute__((aligned(2))) = {
  55         0xff, 0xff, 0xff, 0xff, 0xff, 0xff
  56 };
  57
  58 static const uint8_t MAC_ANY_ADDR[ETH_ALEN] __attribute__((aligned(2))) = {
  59         0x00, 0x00, 0x00, 0x00, 0x00, 0x00
  60 };
  61
  62 /* DHCP packet */
  63 #define DHCP_MAGIC              0x63825363
  64 #define DHCP_OPTIONS_BUFSIZE    308
  65 #define BOOTREQUEST             1
  66 #define BOOTREPLY               2
  67
  68 #define BROADCAST_FLAG          0x8000
  69
  70 /* See RFC 2131 */
  71 struct dhcp_packet {
  72         uint8_t op;
  73         uint8_t htype;
  74         uint8_t hlen;
  75         uint8_t hops;
  76         uint32_t xid;
  77         uint16_t secs;
  78         uint16_t flags;
  79         uint32_t ciaddr;
  80         uint32_t yiaddr;
  81         uint32_t siaddr_nip;
  82         uint32_t gateway_nip;
  83         uint8_t chaddr[16];
  84         uint8_t sname[64];
  85         uint8_t file[128];
  86         uint32_t cookie;
  87         uint8_t options[DHCP_OPTIONS_BUFSIZE + EXTEND_FOR_BUGGY_SERVERS];
  88 } __attribute__((packed));
  89
  90 struct ip_udp_dhcp_packet {
  91         struct iphdr ip;
  92         struct udphdr udp;
  93         struct dhcp_packet data;
  94 } __attribute__((packed));
  95
  96 /* See RFC 3315 */
  97 struct dhcpv6_packet {
  98         uint8_t message;
  99         uint8_t transaction_id[3];
 100         uint8_t options[];
 101 } __attribute__((packed));
 102
 103
 104 /* See RFC 2132 */
 105 #define DHCP_PADDING            0x00
 106 #define DHCP_SUBNET             0x01
 107 #define DHCP_ROUTER             0x03
 108 #define DHCP_TIME_SERVER        0x04
 109 #define DHCP_NAME_SERVER        0x05
 110 #define DHCP_DNS_SERVER         0x06
 111 #define DHCP_HOST_NAME          0x0c
 112 #define DHCP_DOMAIN_NAME        0x0f
 113 #define DHCP_NTP_SERVER         0x2a
 114 #define DHCP_REQUESTED_IP       0x32
 115 #define DHCP_LEASE_TIME         0x33
 116 #define DHCP_OPTION_OVERLOAD    0x34
 117 #define DHCP_MESSAGE_TYPE       0x35
 118 #define DHCP_SERVER_ID          0x36
 119 #define DHCP_PARAM_REQ          0x37
 120 #define DHCP_ERR_MESSAGE        0x38
 121 #define DHCP_MAX_SIZE           0x39
 122 #define DHCP_VENDOR             0x3c
 123 #define DHCP_CLIENT_ID          0x3d
 124 #define DHCP_END                0xff
 125
 126 #define OPT_CODE                0
 127 #define OPT_LEN                 1
 128 #define OPT_DATA                2
 129 #define OPTION_FIELD            0
 130 #define FILE_FIELD              1
 131 #define SNAME_FIELD             2
 132
 133 /* DHCP_MESSAGE_TYPE values */
 134 #define DHCPDISCOVER            1
 135 #define DHCPOFFER               2
 136 #define DHCPREQUEST             3
 137 #define DHCPDECLINE             4
 138 #define DHCPACK                 5
 139 #define DHCPNAK                 6
 140 #define DHCPRELEASE             7
 141 #define DHCPINFORM              8
 142 #define DHCP_MINTYPE DHCPDISCOVER
 143 #define DHCP_MAXTYPE DHCPINFORM
 144
 145 /* Message types for DHCPv6, RFC 3315 sec 5.3 */
 146 #define DHCPV6_SOLICIT          1
 147 #define DHCPV6_ADVERTISE        2
 148 #define DHCPV6_REQUEST          3
 149 #define DHCPV6_CONFIRM          4
 150 #define DHCPV6_RENEW            5
 151 #define DHCPV6_REBIND           6
 152 #define DHCPV6_REPLY            7
 153 #define DHCPV6_RELEASE          8
 154 #define DHCPV6_DECLINE          9
 155 #define DHCPV6_RECONFIGURE      10
 156 #define DHCPV6_INFORMATION_REQ  11
 157
 158 /*
 159  * DUID time starts 2000-01-01.
 160  */
 161 #define DUID_TIME_EPOCH 946684800
 162
 163 typedef enum {
 164         OPTION_UNKNOWN,
 165         OPTION_IP,
 166         OPTION_STRING,
 167         OPTION_U8,
 168         OPTION_U16,
 169         OPTION_U32,
 170         OPTION_TYPE_MASK = 0x0f,
 171         OPTION_LIST = 0x10,
 172 } GDHCPOptionType;
 173
 174 typedef struct dhcp_option {
 175         GDHCPOptionType type;
 176         uint8_t code;
 177 } DHCPOption;
 178
 179 /* Length of the option types in binary form */
 180 static const uint8_t dhcp_option_lengths[] = {
 181         [OPTION_IP]     = 4,
 182         [OPTION_STRING] = 1,
 183         [OPTION_U8]     = 1,
 184         [OPTION_U16]    = 2,
 185         [OPTION_U32]    = 4,
 186 };
 187
 188 uint8_t *dhcp_get_option(struct dhcp_packet *packet, int code);
 189 uint8_t *dhcpv6_get_option(struct dhcpv6_packet *packet, uint16_t pkt_len,
 190                         int code, uint16_t *option_len, int *option_count);
 191 uint8_t *dhcpv6_get_sub_option(unsigned char *option, uint16_t max_len,
 192                         uint16_t *code, uint16_t *option_len);
 193 int dhcp_end_option(uint8_t *optionptr);
 194 void dhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt);
 195 void dhcpv6_add_binary_option(struct dhcpv6_packet *packet, uint16_t max_len,
 196                                 uint16_t *pkt_len, uint8_t *addopt);
 197 void dhcp_add_simple_option(struct dhcp_packet *packet,
 198                                 uint8_t code, uint32_t data);
 199 GDHCPOptionType dhcp_get_code_type(uint8_t code);
 200 GDHCPOptionType dhcpv6_get_code_type(uint16_t code);
 201
 202 uint16_t dhcp_checksum(void *addr, int count);
 203
 204 void dhcp_init_header(struct dhcp_packet *packet, char type);
 205 void dhcpv6_init_header(struct dhcpv6_packet *packet, uint8_t type);
 206
 207 int dhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
 208                         uint32_t source_ip, int source_port,
 209                         uint32_t dest_ip, int dest_port,
 210                         const uint8_t *dest_arp, int ifindex);
 211 int dhcpv6_send_packet(int index, struct dhcpv6_packet *dhcp_pkt, int len);
 212 int dhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
 213                         uint32_t source_ip, int source_port,
 214                         uint32_t dest_ip, int dest_port);
 215 int dhcp_l3_socket(int port, const char *interface, int family);
 216 int dhcp_recv_l3_packet(struct dhcp_packet *packet, int fd);
 217 int dhcpv6_recv_l3_packet(struct dhcpv6_packet **packet, unsigned char *buf,
 218                         int buf_len, int fd);
 219 int dhcp_l3_socket_send(int index, int port, int family);
 220
 221 char *get_interface_name(int index);
 222 gboolean interface_is_up(int index);