1 /* 2 * dhcpcd - DHCP client daemon 3 * SPDX-License-Identifier: BSD-2-Clause 4 * Copyright (c) 2006-2025 Roy Marples <roy (at) 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 <netinet/in.h> 33 #include <netinet/ip.h> 34 35 #include <arpa/inet.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 "bpf.h" 46 #include "dhcp-common.h" 47 48 /* UDP port numbers for BOOTP */ 49 #define BOOTPS 67 50 #define BOOTPC 68 51 52 #define MAGIC_COOKIE 0x63825363 53 #define BROADCAST_FLAG 0x8000 54 55 /* BOOTP message OP code */ 56 #define BOOTREQUEST 1 57 #define BOOTREPLY 2 58 59 /* DHCP message type */ 60 #define DHCP_DISCOVER 1 61 #define DHCP_OFFER 2 62 #define DHCP_REQUEST 3 63 #define DHCP_DECLINE 4 64 #define DHCP_ACK 5 65 #define DHCP_NAK 6 66 #define DHCP_RELEASE 7 67 #define DHCP_INFORM 8 68 #define DHCP_FORCERENEW 9 69 70 /* Constants taken from RFC 2131. */ 71 #define T1 0.5 72 #define T2 0.875 73 #define DHCP_BASE 4 74 #define DHCP_MAX 64 75 #define DHCP_RAND_MIN -1 76 #define DHCP_RAND_MAX 1 77 78 #ifdef RFC2131_STRICT 79 /* Be strictly conformant for section 4.1.1 */ 80 #define DHCP_MIN_DELAY 1 81 #define DHCP_MAX_DELAY 10 82 #else 83 /* or mirror the more modern IPv6RS and DHCPv6 delays */ 84 #define DHCP_MIN_DELAY 0 85 #define DHCP_MAX_DELAY 1 86 #endif 87 88 /* DHCP options */ 89 enum DHO { 90 DHO_PAD = 0, 91 DHO_SUBNETMASK = 1, 92 DHO_ROUTER = 3, 93 DHO_DNSSERVER = 6, 94 DHO_HOSTNAME = 12, 95 DHO_DNSDOMAIN = 15, 96 DHO_MTU = 26, 97 DHO_BROADCAST = 28, 98 DHO_STATICROUTE = 33, 99 DHO_NISDOMAIN = 40, 100 DHO_NISSERVER = 41, 101 DHO_NTPSERVER = 42, 102 DHO_VENDOR = 43, 103 DHO_IPADDRESS = 50, 104 DHO_LEASETIME = 51, 105 DHO_OPTSOVERLOADED = 52, 106 DHO_MESSAGETYPE = 53, 107 DHO_SERVERID = 54, 108 DHO_PARAMETERREQUESTLIST = 55, 109 DHO_MESSAGE = 56, 110 DHO_MAXMESSAGESIZE = 57, 111 DHO_RENEWALTIME = 58, 112 DHO_REBINDTIME = 59, 113 DHO_VENDORCLASSID = 60, 114 DHO_CLIENTID = 61, 115 DHO_USERCLASS = 77, /* RFC 3004 */ 116 DHO_RAPIDCOMMIT = 80, /* RFC 4039 */ 117 DHO_FQDN = 81, 118 DHO_AUTHENTICATION = 90, /* RFC 3118 */ 119 DHO_IPV6_PREFERRED_ONLY = 108, /* RFC 8925 */ 120 DHO_AUTOCONFIGURE = 116, /* RFC 2563 */ 121 DHO_DNSSEARCH = 119, /* RFC 3397 */ 122 DHO_CSR = 121, /* RFC 3442 */ 123 DHO_VIVCO = 124, /* RFC 3925 */ 124 DHO_VIVSO = 125, /* RFC 3925 */ 125 DHO_FORCERENEW_NONCE = 145, /* RFC 6704 */ 126 DHO_MUDURL = 161, /* draft-ietf-opsawg-mud */ 127 DHO_SIXRD = 212, /* RFC 5969 */ 128 DHO_MSCSR = 249, /* MS code for RFC 3442 */ 129 DHO_END = 255 130 }; 131 132 /* FQDN values - lsnybble used in flags 133 * hsnybble to create order 134 * and to allow 0x00 to mean disable 135 */ 136 enum FQDN { 137 FQDN_DISABLE = 0x00, 138 FQDN_NONE = 0x18, 139 FQDN_PTR = 0x20, 140 FQDN_BOTH = 0x31 141 }; 142 143 #define MIN_V6ONLY_WAIT 300 /* seconds, RFC 8925 */ 144 145 /* Sizes for BOOTP options */ 146 #define BOOTP_CHADDR_LEN 16 147 #define BOOTP_SNAME_LEN 64 148 #define BOOTP_FILE_LEN 128 149 #define BOOTP_VEND_LEN 64 150 151 /* DHCP is basically an extension to BOOTP */ 152 struct bootp { 153 uint8_t op; /* message type */ 154 uint8_t htype; /* hardware address type */ 155 uint8_t hlen; /* hardware address length */ 156 uint8_t hops; /* should be zero in client message */ 157 uint32_t xid; /* transaction id */ 158 uint16_t secs; /* elapsed time in sec. from boot */ 159 uint16_t flags; /* such as broadcast flag */ 160 uint32_t ciaddr; /* (previously allocated) client IP */ 161 uint32_t yiaddr; /* 'your' client IP address */ 162 uint32_t siaddr; /* should be zero in client's messages */ 163 uint32_t giaddr; /* should be zero in client's messages */ 164 uint8_t chaddr[BOOTP_CHADDR_LEN]; /* client's hardware address */ 165 uint8_t sname[BOOTP_SNAME_LEN]; /* server host name */ 166 uint8_t file[BOOTP_FILE_LEN]; /* boot file name */ 167 uint8_t vend[BOOTP_VEND_LEN]; /* vendor specific area */ 168 /* DHCP allows a variable length vendor area */ 169 }; 170 171 #define DHCP_MIN_LEN (offsetof(struct bootp, vend) + 4) 172 173 struct bootp_pkt { 174 struct ip ip; 175 struct udphdr udp; 176 struct bootp bootp; 177 }; 178 179 struct dhcp_lease { 180 struct in_addr addr; 181 struct in_addr mask; 182 struct in_addr brd; 183 uint32_t leasetime; 184 uint32_t renewaltime; 185 uint32_t rebindtime; 186 struct in_addr server; 187 uint8_t frominfo; 188 uint32_t cookie; 189 }; 190 191 #ifndef DHCP_INFINITE_LIFETIME 192 #define DHCP_INFINITE_LIFETIME (~0U) 193 #endif 194 195 enum DHS { 196 DHS_NONE, 197 DHS_INIT, 198 DHS_DISCOVER, 199 DHS_REQUEST, 200 DHS_PROBE, 201 DHS_BOUND, 202 DHS_RENEW, 203 DHS_REBIND, 204 DHS_REBOOT, 205 DHS_INFORM, 206 DHS_RENEW_REQUESTED, 207 DHS_RELEASE 208 }; 209 210 struct dhcp_state { 211 enum DHS state; 212 struct bootp *sent; 213 size_t sent_len; 214 struct bootp *offer; 215 size_t offer_len; 216 struct bootp *new; 217 size_t new_len; 218 struct bootp *old; 219 size_t old_len; 220 struct dhcp_lease lease; 221 const char *reason; 222 unsigned int interval; 223 unsigned int nakoff; 224 uint32_t xid; 225 int socket; 226 227 struct bpf *bpf; 228 int udp_rfd; 229 struct ipv4_addr *addr; 230 uint8_t added; 231 232 char leasefile[sizeof(LEASEFILE) + IF_NAMESIZE + (IF_SSIDLEN * 4)]; 233 struct timespec started; 234 unsigned char *clientid; 235 struct authstate auth; 236 #ifdef ARPING 237 ssize_t arping_index; 238 #endif 239 }; 240 241 #ifdef INET 242 #define D_STATE(ifp) ((struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP]) 243 #define D_CSTATE(ifp) ((const struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP]) 244 #define D_STATE_RUNNING(ifp) \ 245 (D_CSTATE((ifp)) && D_CSTATE((ifp))->new && D_CSTATE((ifp))->reason) 246 247 #define IS_DHCP(b) \ 248 ((b)->vend[0] == 0x63 && (b)->vend[1] == 0x82 && \ 249 (b)->vend[2] == 0x53 && (b)->vend[3] == 0x63) 250 251 #include "dhcpcd.h" 252 #include "if-options.h" 253 254 ssize_t print_rfc3361(FILE *, const uint8_t *, size_t); 255 ssize_t print_rfc3442(FILE *, const uint8_t *, size_t); 256 257 int dhcp_openudp(struct in_addr *); 258 void dhcp_packet(struct interface *, uint8_t *, size_t, unsigned int); 259 void dhcp_recvmsg(struct dhcpcd_ctx *, struct msghdr *); 260 void dhcp_printoptions(const struct dhcpcd_ctx *, const struct dhcp_opt *, 261 size_t); 262 uint16_t dhcp_get_mtu(const struct interface *); 263 int dhcp_get_routes(rb_tree_t *, struct interface *); 264 ssize_t dhcp_env(FILE *, const char *, const struct interface *, 265 const struct bootp *, size_t); 266 267 struct ipv4_addr *dhcp_handleifa(int, struct ipv4_addr *, pid_t pid); 268 void dhcp_drop(struct interface *, const char *); 269 void dhcp_start(struct interface *); 270 void dhcp_abort(struct interface *); 271 void dhcp_discover(void *); 272 void dhcp_inform(struct interface *); 273 void dhcp_renew(struct interface *); 274 void dhcp_bind(struct interface *); 275 void dhcp_reboot_newopts(struct interface *, unsigned long long); 276 void dhcp_close(struct interface *); 277 void dhcp_free(struct interface *); 278 int dhcp_dump(struct interface *); 279 #endif /* INET */ 280 281 #endif /* DHCP_H */ 282
Indexes created Tue Sep 01 00:24:37 UTC 2026