external/bsd/dhcpcd/dist/dhcp.h

   1 /*
   2  * dhcpcd - DHCP client daemon
   3  * Copyright (c) 2006-2008 Roy Marples <roy@marples.name>
   4  * All rights reserved
   5
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #ifndef DHCP_H
  29 #define DHCP_H
  30
  31 #include <arpa/inet.h>
  32 #include <netinet/in.h>
  33
  34 #include <stdint.h>
  35
  36 #include "common.h"
  37
  38 /* Max MTU - defines dhcp option length */
  39 #define MTU_MAX             1500
  40 #define MTU_MIN             576
  41
  42 /* UDP port numbers for DHCP */
  43 #define DHCP_SERVER_PORT    67
  44 #define DHCP_CLIENT_PORT    68
  45
  46 #define MAGIC_COOKIE        0x63825363
  47 #define BROADCAST_FLAG      0x8000
  48
  49 /* DHCP message OP code */
  50 #define DHCP_BOOTREQUEST    1
  51 #define DHCP_BOOTREPLY      2
  52
  53 /* DHCP message type */
  54 #define DHCP_DISCOVER       1
  55 #define DHCP_OFFER          2
  56 #define DHCP_REQUEST        3
  57 #define DHCP_DECLINE        4
  58 #define DHCP_ACK            5
  59 #define DHCP_NAK            6
  60 #define DHCP_RELEASE        7
  61 #define DHCP_INFORM         8
  62
  63 /* Constants taken from RFC 2131. */
  64 #define T1                      0.5
  65 #define T2                      0.875
  66 #define DHCP_BASE               4
  67 #define DHCP_MAX                64
  68 #define DHCP_RAND_MIN           -1
  69 #define DHCP_RAND_MAX           1
  70 #define DHCP_ARP_FAIL           10
  71
  72 /* number of usecs in a second. */
  73 #define USECS_SECOND            1000000
  74 /* As we use timevals, we should use the usec part for
  75  * greater randomisation. */
  76 #define DHCP_RAND_MIN_U         DHCP_RAND_MIN * USECS_SECOND
  77 #define DHCP_RAND_MAX_U         DHCP_RAND_MAX * USECS_SECOND
  78 #define PROBE_MIN_U             PROBE_MIN * USECS_SECOND
  79 #define PROBE_MAX_U             PROBE_MAX * USECS_SECOND
  80
  81 /* DHCP options */
  82 enum DHO {
  83         DHO_PAD                    = 0,
  84         DHO_SUBNETMASK             = 1,
  85         DHO_ROUTER                 = 3,
  86         DHO_DNSSERVER              = 6,
  87         DHO_HOSTNAME               = 12,
  88         DHO_DNSDOMAIN              = 15,
  89         DHO_MTU                    = 26,
  90         DHO_BROADCAST              = 28,
  91         DHO_STATICROUTE            = 33,
  92         DHO_NISDOMAIN              = 40,
  93         DHO_NISSERVER              = 41,
  94         DHO_NTPSERVER              = 42,
  95         DHO_VENDOR                 = 43,
  96         DHO_IPADDRESS              = 50,
  97         DHO_LEASETIME              = 51,
  98         DHO_OPTIONSOVERLOADED      = 52,
  99         DHO_MESSAGETYPE            = 53,
 100         DHO_SERVERID               = 54,
 101         DHO_PARAMETERREQUESTLIST   = 55,
 102         DHO_MESSAGE                = 56,
 103         DHO_MAXMESSAGESIZE         = 57,
 104         DHO_RENEWALTIME            = 58,
 105         DHO_REBINDTIME             = 59,
 106         DHO_VENDORCLASSID          = 60,
 107         DHO_CLIENTID               = 61,
 108         DHO_USERCLASS              = 77,  /* RFC 3004 */
 109         DHO_FQDN                   = 81,
 110         DHO_DNSSEARCH              = 119, /* RFC 3397 */
 111         DHO_CSR                    = 121, /* RFC 3442 */
 112         DHO_MSCSR                  = 249, /* MS code for RFC 3442 */
 113         DHO_END                    = 255
 114 };
 115
 116 /* FQDN values - lsnybble used in flags
 117  * hsnybble to create order
 118  * and to allow 0x00 to mean disable
 119  */
 120 enum FQDN {
 121         FQDN_DISABLE    = 0x00,
 122         FQDN_NONE       = 0x18,
 123         FQDN_PTR        = 0x20,
 124         FQDN_BOTH       = 0x31
 125 };
 126
 127 /* Sizes for DHCP options */
 128 #define DHCP_CHADDR_LEN         16
 129 #define SERVERNAME_LEN          64
 130 #define BOOTFILE_LEN            128
 131 #define DHCP_UDP_LEN            (14 + 20 + 8)
 132 #define DHCP_FIXED_LEN          (DHCP_UDP_LEN + 226)
 133 #define DHCP_OPTION_LEN         (MTU_MAX - DHCP_FIXED_LEN)
 134
 135 /* Some crappy DHCP servers require the BOOTP minimum length */
 136 #define BOOTP_MESSAGE_LENTH_MIN 300
 137
 138 struct dhcp_message {
 139         uint8_t op;           /* message type */
 140         uint8_t hwtype;       /* hardware address type */
 141         uint8_t hwlen;        /* hardware address length */
 142         uint8_t hwopcount;    /* should be zero in client message */
 143         uint32_t xid;            /* transaction id */
 144         uint16_t secs;           /* elapsed time in sec. from boot */
 145         uint16_t flags;
 146         uint32_t ciaddr;         /* (previously allocated) client IP */
 147         uint32_t yiaddr;         /* 'your' client IP address */
 148         uint32_t siaddr;         /* should be zero in client's messages */
 149         uint32_t giaddr;         /* should be zero in client's messages */
 150         uint8_t chaddr[DHCP_CHADDR_LEN];  /* client's hardware address */
 151         uint8_t servername[SERVERNAME_LEN];    /* server host name */
 152         uint8_t bootfile[BOOTFILE_LEN];    /* boot file name */
 153         uint32_t cookie;
 154         uint8_t options[DHCP_OPTION_LEN]; /* message options - cookie */
 155 } _packed;
 156
 157 struct dhcp_lease {
 158         struct in_addr addr;
 159         struct in_addr net;
 160         struct in_addr brd;
 161         uint32_t leasetime;
 162         uint32_t renewaltime;
 163         uint32_t rebindtime;
 164         struct in_addr server;
 165         time_t leasedfrom;
 166         struct timeval boundtime;
 167         uint8_t frominfo;
 168 };
 169
 170 #include "dhcpcd.h"
 171 #include "if-options.h"
 172 #include "net.h"
 173
 174 #define add_option_mask(var, val) (var[val >> 3] |= 1 << (val & 7))
 175 #define del_option_mask(var, val) (var[val >> 3] &= ~(1 << (val & 7)))
 176 #define has_option_mask(var, val) (var[val >> 3] & (1 << (val & 7)))
 177 int make_option_mask(uint8_t *, const char *, int);
 178 void print_options(void);
 179 char *get_option_string(const struct dhcp_message *, uint8_t);
 180 int get_option_addr(struct in_addr *, const struct dhcp_message *, uint8_t);
 181 int get_option_uint32(uint32_t *, const struct dhcp_message *, uint8_t);
 182 int get_option_uint16(uint16_t *, const struct dhcp_message *, uint8_t);
 183 int get_option_uint8(uint8_t *, const struct dhcp_message *, uint8_t);
 184 #define is_bootp(m) (m &&                                               \
 185             !IN_LINKLOCAL(htonl((m)->yiaddr)) &&                        \
 186             get_option_uint8(NULL, m, DHO_MESSAGETYPE) == -1)
 187 struct rt *get_option_routes(const struct dhcp_message *, const char *, int *);
 188 ssize_t configure_env(char **, const char *, const struct dhcp_message *,
 189     const struct if_options *);
 190
 191 int dhcp_message_add_addr(struct dhcp_message *, uint8_t, struct in_addr);
 192 ssize_t make_message(struct dhcp_message **, const struct interface *,
 193     uint8_t);
 194 int valid_dhcp_packet(unsigned char *);
 195
 196 ssize_t write_lease(const struct interface *, const struct dhcp_message *);
 197 struct dhcp_message *read_lease(const struct interface *);
 198 void get_lease(struct dhcp_lease *, const struct dhcp_message *);
 199
 200 #endif