contrib/dhcpcd/src/dhcp.h

   1 /* SPDX-License-Identifier: BSD-2-Clause */
   2 /*
   3  * dhcpcd - DHCP client daemon
   4  * Copyright (c) 2006-2019 Roy Marples <roy@marples.name>
   5  * All rights reserved
   6
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #ifndef DHCP_H
  30 #define DHCP_H
  31
  32 #include <arpa/inet.h>
  33 #include <netinet/in.h>
  34
  35 #include <netinet/ip.h>
  36 #define __FAVOR_BSD /* Nasty glibc hack so we can use BSD semantics for UDP */
  37 #include <netinet/udp.h>
  38 #undef __FAVOR_BSD
  39
  40 #include <limits.h>
  41 #include <stdint.h>
  42
  43 #include "arp.h"
  44 #include "auth.h"
  45 #include "dhcp-common.h"
  46
  47 /* UDP port numbers for BOOTP */
  48 #define BOOTPS                  67
  49 #define BOOTPC                  68
  50
  51 #define MAGIC_COOKIE            0x63825363
  52 #define BROADCAST_FLAG          0x8000
  53
  54 /* BOOTP message OP code */
  55 #define BOOTREQUEST             1
  56 #define BOOTREPLY               2
  57
  58 /* DHCP message type */
  59 #define DHCP_DISCOVER           1
  60 #define DHCP_OFFER              2
  61 #define DHCP_REQUEST            3
  62 #define DHCP_DECLINE            4
  63 #define DHCP_ACK                5
  64 #define DHCP_NAK                6
  65 #define DHCP_RELEASE            7
  66 #define DHCP_INFORM             8
  67 #define DHCP_FORCERENEW         9
  68
  69 /* Constants taken from RFC 2131. */
  70 #define T1                      0.5
  71 #define T2                      0.875
  72 #define DHCP_BASE               4
  73 #define DHCP_MAX                64
  74 #define DHCP_RAND_MIN           -1
  75 #define DHCP_RAND_MAX           1
  76
  77 #ifdef RFC2131_STRICT
  78 /* Be strictly conformant for section 4.1.1 */
  79 #  define DHCP_MIN_DELAY        1
  80 #  define DHCP_MAX_DELAY        10
  81 #else
  82 /* or mirror the more modern IPv6RS and DHCPv6 delays */
  83 #  define DHCP_MIN_DELAY        0
  84 #  define DHCP_MAX_DELAY        1
  85 #endif
  86
  87 /* DHCP options */
  88 enum DHO {
  89         DHO_PAD                    = 0,
  90         DHO_SUBNETMASK             = 1,
  91         DHO_ROUTER                 = 3,
  92         DHO_DNSSERVER              = 6,
  93         DHO_HOSTNAME               = 12,
  94         DHO_DNSDOMAIN              = 15,
  95         DHO_MTU                    = 26,
  96         DHO_BROADCAST              = 28,
  97         DHO_STATICROUTE            = 33,
  98         DHO_NISDOMAIN              = 40,
  99         DHO_NISSERVER              = 41,
 100         DHO_NTPSERVER              = 42,
 101         DHO_VENDOR                 = 43,
 102         DHO_IPADDRESS              = 50,
 103         DHO_LEASETIME              = 51,
 104         DHO_OPTSOVERLOADED         = 52,
 105         DHO_MESSAGETYPE            = 53,
 106         DHO_SERVERID               = 54,
 107         DHO_PARAMETERREQUESTLIST   = 55,
 108         DHO_MESSAGE                = 56,
 109         DHO_MAXMESSAGESIZE         = 57,
 110         DHO_RENEWALTIME            = 58,
 111         DHO_REBINDTIME             = 59,
 112         DHO_VENDORCLASSID          = 60,
 113         DHO_CLIENTID               = 61,
 114         DHO_USERCLASS              = 77,  /* RFC 3004 */
 115         DHO_RAPIDCOMMIT            = 80,  /* RFC 4039 */
 116         DHO_FQDN                   = 81,
 117         DHO_AUTHENTICATION         = 90,  /* RFC 3118 */
 118         DHO_AUTOCONFIGURE          = 116, /* RFC 2563 */
 119         DHO_DNSSEARCH              = 119, /* RFC 3397 */
 120         DHO_CSR                    = 121, /* RFC 3442 */
 121         DHO_VIVCO                  = 124, /* RFC 3925 */
 122         DHO_VIVSO                  = 125, /* RFC 3925 */
 123         DHO_FORCERENEW_NONCE       = 145, /* RFC 6704 */
 124         DHO_MUDURL                 = 161, /* draft-ietf-opsawg-mud */
 125         DHO_SIXRD                  = 212, /* RFC 5969 */
 126         DHO_MSCSR                  = 249, /* MS code for RFC 3442 */
 127         DHO_END                    = 255
 128 };
 129
 130 /* FQDN values - lsnybble used in flags
 131  * hsnybble to create order
 132  * and to allow 0x00 to mean disable
 133  */
 134 enum FQDN {
 135         FQDN_DISABLE    = 0x00,
 136         FQDN_NONE       = 0x18,
 137         FQDN_PTR        = 0x20,
 138         FQDN_BOTH       = 0x31
 139 };
 140
 141 /* Sizes for BOOTP options */
 142 #define BOOTP_CHADDR_LEN         16
 143 #define BOOTP_SNAME_LEN          64
 144 #define BOOTP_FILE_LEN          128
 145 #define BOOTP_VEND_LEN           64
 146
 147 /* DHCP is basically an extension to BOOTP */
 148 struct bootp {
 149         uint8_t op;             /* message type */
 150         uint8_t htype;          /* hardware address type */
 151         uint8_t hlen;           /* hardware address length */
 152         uint8_t hops;           /* should be zero in client message */
 153         uint32_t xid;           /* transaction id */
 154         uint16_t secs;          /* elapsed time in sec. from boot */
 155         uint16_t flags;         /* such as broadcast flag */
 156         uint32_t ciaddr;        /* (previously allocated) client IP */
 157         uint32_t yiaddr;        /* 'your' client IP address */
 158         uint32_t siaddr;        /* should be zero in client's messages */
 159         uint32_t giaddr;        /* should be zero in client's messages */
 160         uint8_t chaddr[BOOTP_CHADDR_LEN];       /* client's hardware address */
 161         uint8_t sname[BOOTP_SNAME_LEN];         /* server host name */
 162         uint8_t file[BOOTP_FILE_LEN];           /* boot file name */
 163         uint8_t vend[BOOTP_VEND_LEN];           /* vendor specific area */
 164         /* DHCP allows a variable length vendor area */
 165 };
 166
 167 struct bootp_pkt
 168 {
 169         struct ip ip;
 170         struct udphdr udp;
 171         struct bootp bootp;
 172 };
 173
 174 struct dhcp_lease {
 175         struct in_addr addr;
 176         struct in_addr mask;
 177         struct in_addr brd;
 178         uint32_t leasetime;
 179         uint32_t renewaltime;
 180         uint32_t rebindtime;
 181         struct in_addr server;
 182         uint8_t frominfo;
 183         uint32_t cookie;
 184 };
 185
 186 #ifndef DHCP_INFINITE_LIFETIME
 187 #  define DHCP_INFINITE_LIFETIME        (~0U)
 188 #endif
 189
 190 enum DHS {
 191         DHS_NONE,
 192         DHS_INIT,
 193         DHS_DISCOVER,
 194         DHS_REQUEST,
 195         DHS_PROBE,
 196         DHS_BOUND,
 197         DHS_RENEW,
 198         DHS_REBIND,
 199         DHS_REBOOT,
 200         DHS_INFORM,
 201         DHS_RENEW_REQUESTED,
 202         DHS_RELEASE
 203 };
 204
 205 struct dhcp_state {
 206         enum DHS state;
 207         struct bootp *sent;
 208         size_t sent_len;
 209         struct bootp *offer;
 210         size_t offer_len;
 211         struct bootp *new;
 212         size_t new_len;
 213         struct bootp *old;
 214         size_t old_len;
 215         struct dhcp_lease lease;
 216         const char *reason;
 217         time_t interval;
 218         time_t nakoff;
 219         uint32_t xid;
 220         int socket;
 221
 222         int bpf_fd;
 223         unsigned int bpf_flags;
 224         int udp_fd;
 225         struct ipv4_addr *addr;
 226         uint8_t added;
 227
 228         char leasefile[sizeof(LEASEFILE) + IF_NAMESIZE + (IF_SSIDLEN * 4)];
 229         struct timespec started;
 230         unsigned char *clientid;
 231         struct authstate auth;
 232 #ifdef ARPING
 233         ssize_t arping_index;
 234 #endif
 235 };
 236
 237 #ifdef INET
 238 #define D_STATE(ifp)                                                           \
 239         ((struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
 240 #define D_CSTATE(ifp)                                                          \
 241         ((const struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP])
 242 #define D_STATE_RUNNING(ifp)                                                   \
 243         (D_CSTATE((ifp)) && D_CSTATE((ifp))->new && D_CSTATE((ifp))->reason)
 244
 245 #define IS_DHCP(b)      ((b)->vend[0] == 0x63 &&        \
 246                          (b)->vend[1] == 0x82 &&        \
 247                          (b)->vend[2] == 0x53 &&        \
 248                          (b)->vend[3] == 0x63)
 249
 250 #include "dhcpcd.h"
 251 #include "if-options.h"
 252
 253 ssize_t print_rfc3361(FILE *, const uint8_t *, size_t);
 254 ssize_t print_rfc3442(FILE *, const uint8_t *, size_t);
 255
 256 void dhcp_printoptions(const struct dhcpcd_ctx *,
 257     const struct dhcp_opt *, size_t);
 258 uint16_t dhcp_get_mtu(const struct interface *);
 259 int dhcp_get_routes(rb_tree_t *, struct interface *);
 260 ssize_t dhcp_env(FILE *, const char *, const struct interface *,
 261     const struct bootp *, size_t);
 262
 263 void dhcp_handleifa(int, struct ipv4_addr *, pid_t pid);
 264 void dhcp_drop(struct interface *, const char *);
 265 void dhcp_start(struct interface *);
 266 void dhcp_abort(struct interface *);
 267 void dhcp_discover(void *);
 268 void dhcp_inform(struct interface *);
 269 void dhcp_renew(struct interface *);
 270 void dhcp_bind(struct interface *);
 271 void dhcp_reboot_newopts(struct interface *, unsigned long long);
 272 void dhcp_close(struct interface *);
 273 void dhcp_free(struct interface *);
 274 int dhcp_dump(struct interface *);
 275 #endif /* INET */
 276
 277 #endif /* DHCP_H */