1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * dhcpcd - DHCP client daemon 4 * Copyright (c) 2006-2020 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 #define DHCP_MIN_LEN (offsetof(struct bootp, vend) + 4) 168 169 struct bootp_pkt 170 { 171 struct ip ip; 172 struct udphdr udp; 173 struct bootp bootp; 174 }; 175 176 struct dhcp_lease { 177 struct in_addr addr; 178 struct in_addr mask; 179 struct in_addr brd; 180 uint32_t leasetime; 181 uint32_t renewaltime; 182 uint32_t rebindtime; 183 struct in_addr server; 184 uint8_t frominfo; 185 uint32_t cookie; 186 }; 187 188 #ifndef DHCP_INFINITE_LIFETIME 189 # define DHCP_INFINITE_LIFETIME (~0U) 190 #endif 191 192 enum DHS { 193 DHS_NONE, 194 DHS_INIT, 195 DHS_DISCOVER, 196 DHS_REQUEST, 197 DHS_PROBE, 198 DHS_BOUND, 199 DHS_RENEW, 200 DHS_REBIND, 201 DHS_REBOOT, 202 DHS_INFORM, 203 DHS_RENEW_REQUESTED, 204 DHS_RELEASE 205 }; 206 207 struct dhcp_state { 208 enum DHS state; 209 struct bootp *sent; 210 size_t sent_len; 211 struct bootp *offer; 212 size_t offer_len; 213 struct bootp *new; 214 size_t new_len; 215 struct bootp *old; 216 size_t old_len; 217 struct dhcp_lease lease; 218 const char *reason; 219 unsigned int interval; 220 unsigned int nakoff; 221 uint32_t xid; 222 int socket; 223 224 int bpf_fd; 225 unsigned int bpf_flags; 226 int udp_fd; 227 struct ipv4_addr *addr; 228 uint8_t added; 229 230 char leasefile[sizeof(LEASEFILE) + IF_NAMESIZE + (IF_SSIDLEN * 4)]; 231 struct timespec started; 232 unsigned char *clientid; 233 struct authstate auth; 234 #ifdef ARPING 235 ssize_t arping_index; 236 #endif 237 }; 238 239 #ifdef INET 240 #define D_STATE(ifp) \ 241 ((struct dhcp_state *)(ifp)->if_data[IF_DATA_DHCP]) 242 #define D_CSTATE(ifp) \ 243 ((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) ((b)->vend[0] == 0x63 && \ 248 (b)->vend[1] == 0x82 && \ 249 (b)->vend[2] == 0x53 && \ 250 (b)->vend[3] == 0x63) 251 252 #include "dhcpcd.h" 253 #include "if-options.h" 254 255 ssize_t print_rfc3361(FILE *, const uint8_t *, size_t); 256 ssize_t print_rfc3442(FILE *, const uint8_t *, size_t); 257 258 int dhcp_openudp(struct in_addr *); 259 void dhcp_packet(struct interface *, uint8_t *, size_t); 260 void dhcp_recvmsg(struct dhcpcd_ctx *, struct msghdr *); 261 void dhcp_printoptions(const struct dhcpcd_ctx *, 262 const struct dhcp_opt *, size_t); 263 uint16_t dhcp_get_mtu(const struct interface *); 264 int dhcp_get_routes(rb_tree_t *, struct interface *); 265 ssize_t dhcp_env(FILE *, const char *, const struct interface *, 266 const struct bootp *, size_t); 267 268 struct ipv4_addr *dhcp_handleifa(int, struct ipv4_addr *, pid_t pid); 269 void dhcp_drop(struct interface *, const char *); 270 void dhcp_start(struct interface *); 271 void dhcp_abort(struct interface *); 272 void dhcp_discover(void *); 273 void dhcp_inform(struct interface *); 274 void dhcp_renew(struct interface *); 275 void dhcp_bind(struct interface *); 276 void dhcp_reboot_newopts(struct interface *, unsigned long long); 277 void dhcp_close(struct interface *); 278 void dhcp_free(struct interface *); 279 #endif /* INET */ 280 281 #endif /* DHCP_H */ 282