1 /* 2 * dhcpcd - DHCP client daemon 3 * Copyright (c) 2006-2015 Roy Marples <roy (at) 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 <limits.h> 35 #include <stdint.h> 36 37 #include "arp.h" 38 #include "auth.h" 39 #include "dhcp-common.h" 40 41 /* UDP port numbers for DHCP */ 42 #define DHCP_SERVER_PORT 67 43 #define DHCP_CLIENT_PORT 68 44 45 #define MAGIC_COOKIE 0x63825363 46 #define BROADCAST_FLAG 0x8000 47 48 /* DHCP message OP code */ 49 #define DHCP_BOOTREQUEST 1 50 #define DHCP_BOOTREPLY 2 51 52 /* DHCP message type */ 53 #define DHCP_DISCOVER 1 54 #define DHCP_OFFER 2 55 #define DHCP_REQUEST 3 56 #define DHCP_DECLINE 4 57 #define DHCP_ACK 5 58 #define DHCP_NAK 6 59 #define DHCP_RELEASE 7 60 #define DHCP_INFORM 8 61 #define DHCP_FORCERENEW 9 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 71 #ifdef RFC2131_STRICT 72 /* Be strictly conformant for section 4.1.1 */ 73 # define DHCP_MIN_DELAY 1 74 # define DHCP_MAX_DELAY 10 75 #else 76 /* or mirror the more modern IPv6RS and DHCPv6 delays */ 77 # define DHCP_MIN_DELAY 0 78 # define DHCP_MAX_DELAY 1 79 #endif 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_RAPIDCOMMIT = 80, /* RFC 4039 */ 110 DHO_FQDN = 81, 111 DHO_AUTHENTICATION = 90, /* RFC 3118 */ 112 DHO_AUTOCONFIGURE = 116, /* RFC 2563 */ 113 DHO_DNSSEARCH = 119, /* RFC 3397 */ 114 DHO_CSR = 121, /* RFC 3442 */ 115 DHO_VIVCO = 124, /* RFC 3925 */ 116 DHO_VIVSO = 125, /* RFC 3925 */ 117 DHO_FORCERENEW_NONCE = 145, /* RFC 6704 */ 118 DHO_SIXRD = 212, /* RFC 5969 */ 119 DHO_MSCSR = 249, /* MS code for RFC 3442 */ 120 DHO_END = 255 121 }; 122 123 /* FQDN values - lsnybble used in flags 124 * hsnybble to create order 125 * and to allow 0x00 to mean disable 126 */ 127 enum FQDN { 128 FQDN_DISABLE = 0x00, 129 FQDN_NONE = 0x18, 130 FQDN_PTR = 0x20, 131 FQDN_BOTH = 0x31 132 }; 133 134 /* Sizes for DHCP options */ 135 #define DHCP_CHADDR_LEN 16 136 #define SERVERNAME_LEN 64 137 #define BOOTFILE_LEN 128 138 #define DHCP_UDP_LEN (14 + 20 + 8) 139 #define DHCP_FIXED_LEN (DHCP_UDP_LEN + 226) 140 #define DHCP_OPTION_LEN (MTU_MAX - DHCP_FIXED_LEN) 141 142 /* Some crappy DHCP servers require the BOOTP minimum length */ 143 #define BOOTP_MESSAGE_LENTH_MIN 300 144 145 /* Flags for the OPTIONSOVERLOADED field. */ 146 #define OPTION_OVERLOADED_BOOT_FILE 1 147 #define OPTION_OVERLOADED_SERVER_NAME 2 148 149 /* Don't import common.h as that defines __unused which causes problems 150 * on some Linux systems which define it as part of a structure */ 151 #if __GNUC__ > 2 || defined(__INTEL_COMPILER) 152 # ifndef __packed 153 # define __packed __attribute__((__packed__)) 154 # endif 155 #else 156 # ifndef __packed 157 # define __packed 158 # endif 159 #endif 160 161 struct dhcp_message { 162 uint8_t op; /* message type */ 163 uint8_t hwtype; /* hardware address type */ 164 uint8_t hwlen; /* hardware address length */ 165 uint8_t hwopcount; /* should be zero in client message */ 166 uint32_t xid; /* transaction id */ 167 uint16_t secs; /* elapsed time in sec. from boot */ 168 uint16_t flags; 169 uint32_t ciaddr; /* (previously allocated) client IP */ 170 uint32_t yiaddr; /* 'your' client IP address */ 171 uint32_t siaddr; /* should be zero in client's messages */ 172 uint32_t giaddr; /* should be zero in client's messages */ 173 uint8_t chaddr[DHCP_CHADDR_LEN]; /* client's hardware address */ 174 uint8_t servername[SERVERNAME_LEN]; /* server host name */ 175 uint8_t bootfile[BOOTFILE_LEN]; /* boot file name */ 176 uint32_t cookie; 177 uint8_t options[DHCP_OPTION_LEN]; /* message options - cookie */ 178 } __packed; 179 180 struct dhcp_option_iterator { 181 const struct dhcp_message *message; 182 const uint8_t *ptr; 183 const uint8_t *end; 184 uint8_t extra_option_locations; 185 uint8_t extra_option_locations_set; 186 }; 187 188 struct dhcp_lease { 189 struct in_addr addr; 190 struct in_addr net; 191 struct in_addr brd; 192 uint32_t leasetime; 193 uint32_t renewaltime; 194 uint32_t rebindtime; 195 struct in_addr server; 196 uint8_t frominfo; 197 uint32_t cookie; 198 }; 199 200 /* Extra data about servers stored in the lease file after the dhcp_message */ 201 struct dhcp_server_info { 202 uint8_t gw_hwlen; 203 unsigned char gw_hwaddr[HWADDR_LEN]; 204 }; 205 206 enum DHS { 207 DHS_INIT, 208 DHS_DISCOVER, 209 DHS_REQUEST, 210 DHS_BOUND, 211 DHS_RENEW, 212 DHS_REBIND, 213 DHS_REBOOT, 214 DHS_INFORM, 215 DHS_RENEW_REQUESTED, 216 DHS_IPV4LL_BOUND, 217 DHS_PROBE 218 }; 219 220 struct dhcp_state { 221 enum DHS state; 222 struct dhcp_message *sent; 223 struct dhcp_message *offer; 224 struct dhcp_message *new; 225 struct dhcp_message *old; 226 struct dhcp_lease lease; 227 const char *reason; 228 time_t interval; 229 time_t nakoff; 230 uint32_t xid; 231 int socket; 232 233 int raw_fd; 234 int arp_fd; 235 size_t buffer_size, buffer_len, buffer_pos; 236 unsigned char *buffer; 237 238 struct in_addr addr; 239 struct in_addr net; 240 struct in_addr dst; 241 uint8_t added; 242 243 char leasefile[PATH_MAX]; 244 time_t start_uptime; 245 246 unsigned char *clientid; 247 248 struct authstate auth; 249 struct arp_statehead arp_states; 250 251 size_t arping_index; 252 253 struct arp_state *arp_ipv4ll; 254 unsigned int conflicts; 255 int nak_receive_count; 256 int failed_address_offer_count; 257 struct in_addr failed; 258 time_t defend; 259 char randomstate[128]; 260 struct dhcp_server_info server_info; 261 }; 262 263 #define D_STATE(ifp) \ 264 ((struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP]) 265 #define D_CSTATE(ifp) \ 266 ((const struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP]) 267 #define D_STATE_RUNNING(ifp) \ 268 (D_CSTATE((ifp)) && D_CSTATE((ifp))->new && D_CSTATE((ifp))->reason) 269 270 #include "dhcpcd.h" 271 #include "if-options.h" 272 273 #ifdef INET 274 char *decode_rfc3361(const uint8_t *, size_t); 275 ssize_t decode_rfc3442(char *, size_t, const uint8_t *p, size_t); 276 ssize_t decode_rfc5969(char *, size_t, const uint8_t *p, size_t); 277 278 void dhcp_printoptions(const struct dhcpcd_ctx *, 279 const struct dhcp_opt *, size_t); 280 int get_option_addr(struct dhcpcd_ctx *,struct in_addr *, 281 const struct dhcp_message *, uint8_t); 282 #define IS_BOOTP(i, m) ((m) && \ 283 !IN_LINKLOCAL(htonl((m)->yiaddr)) && \ 284 get_option_uint8((i)->ctx, NULL, (m), DHO_MESSAGETYPE) == -1) 285 struct rt_head *get_option_routes(struct interface *, 286 const struct dhcp_message *); 287 ssize_t dhcp_env(char **, const char *, const struct dhcp_message *, 288 const struct interface *); 289 290 uint32_t dhcp_xid(const struct interface *); 291 struct dhcp_message *dhcp_message_new(const struct in_addr *addr, 292 const struct in_addr *mask); 293 int dhcp_message_add_addr(struct dhcp_message *, uint8_t, struct in_addr); 294 ssize_t make_message(struct dhcp_message **, const struct interface *, 295 uint8_t); 296 int valid_dhcp_packet(unsigned char *); 297 298 void dhcp_handleifa(int, struct interface *, 299 const struct in_addr *, const struct in_addr *, const struct in_addr *, 300 int); 301 302 void dhcp_drop(struct interface *, const char *); 303 void dhcp_start(struct interface *); 304 void dhcp_stop(struct interface *); 305 void dhcp_discover(void *); 306 void dhcp_inform(struct interface *); 307 void dhcp_bind(struct interface *, struct arp_state *); 308 void dhcp_reboot_newopts(struct interface *, unsigned long long); 309 void dhcp_close(struct interface *); 310 void dhcp_free(struct interface *); 311 int dhcp_dump(struct interface *); 312 #else 313 #define dhcp_drop(a, b) {} 314 #define dhcp_start(a) {} 315 #define dhcp_reboot(a, b) (b = b) 316 #define dhcp_reboot_newopts(a, b) (b = b) 317 #define dhcp_close(a) {} 318 #define dhcp_free(a) {} 319 #define dhcp_dump(a) (-1) 320 #endif 321 322 #endif 323
