lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* dnsmasq is Copyright (c) 2000-2021 Simon Kelley |
| 2 | |
| 3 | This program is free software; you can redistribute it and/or modify |
| 4 | it under the terms of the GNU General Public License as published by |
| 5 | the Free Software Foundation; version 2 dated June, 1991, or |
| 6 | (at your option) version 3 dated 29 June, 2007. |
| 7 | |
| 8 | This program is distributed in the hope that it will be useful, |
| 9 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | GNU General Public License for more details. |
| 12 | |
| 13 | You should have received a copy of the GNU General Public License |
| 14 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 15 | */ |
| 16 | |
| 17 | #define FTABSIZ 150 /* max number of outstanding requests (default) */ |
| 18 | #define MAX_PROCS 2 /* max no children for TCP requests */ |
| 19 | #define CHILD_LIFETIME 150 /* secs 'till terminated (RFC1035 suggests > 120s) */ |
| 20 | #define TCP_MAX_QUERIES 100 /* Maximum number of queries per incoming TCP connection */ |
| 21 | #define TCP_BACKLOG 32 /* kernel backlog limit for TCP connections */ |
| 22 | //#define EDNS_PKTSZ 4096 CVE-2023-28450/* default max EDNS.0 UDP packet from RFC5625 */ |
| 23 | #define EDNS_PKTSZ 1232 /* default max EDNS.0 UDP packet from from /dnsflagday.net/2020 */ |
| 24 | #define SAFE_PKTSZ 1280 /* "go anywhere" UDP packet size */ |
| 25 | #define KEYBLOCK_LEN 40 /* choose to minimise fragmentation when storing DNSSEC keys */ |
| 26 | #define DNSSEC_WORK 50 /* Max number of queries to validate one question */ |
| 27 | #define TIMEOUT 10 /* drop UDP queries after TIMEOUT seconds */ |
| 28 | #define FORWARD_TEST 50 /* try all servers every 50 queries */ |
| 29 | #define FORWARD_TIME 20 /* or 20 seconds */ |
| 30 | #define UDP_TEST_TIME 60 /* How often to reset our idea of max packet size. */ |
| 31 | #define SERVERS_LOGGED 30 /* Only log this many servers when logging state */ |
| 32 | #define LOCALS_LOGGED 8 /* Only log this many local addresses when logging state */ |
| 33 | #define LEASE_RETRY 60 /* on error, retry writing leasefile after LEASE_RETRY seconds */ |
| 34 | #define CACHESIZ 150 /* default cache size */ |
| 35 | #define TTL_FLOOR_LIMIT 3600 /* don't allow --min-cache-ttl to raise TTL above this under any circumstances */ |
| 36 | #define MAXLEASES 1000 /* maximum number of DHCP leases */ |
| 37 | #define PING_WAIT 3 /* wait for ping address-in-use test */ |
| 38 | #define PING_CACHE_TIME 30 /* Ping test assumed to be valid this long. */ |
| 39 | #define DECLINE_BACKOFF 600 /* disable DECLINEd static addresses for this long */ |
| 40 | #define DHCP_PACKET_MAX 16384 /* hard limit on DHCP packet size */ |
| 41 | #define SMALLDNAME 50 /* most domain names are smaller than this */ |
| 42 | #define CNAME_CHAIN 10 /* chains longer than this atr dropped for loop protection */ |
| 43 | #define DNSSEC_MIN_TTL 60 /* DNSKEY and DS records in cache last at least this long */ |
| 44 | #define HOSTSFILE "/etc/hosts" |
| 45 | #define ETHERSFILE "/etc/ethers" |
| 46 | #define DEFLEASE 3600 /* default DHCPv4 lease time, one hour */ |
| 47 | #define DEFLEASE6 (3600*24) /* default lease time for DHCPv6. One day. */ |
| 48 | #define CHUSER "nobody" |
| 49 | #define CHGRP "dip" |
| 50 | #define TFTP_MAX_CONNECTIONS 50 /* max simultaneous connections */ |
| 51 | #define LOG_MAX 5 /* log-queue length */ |
| 52 | #define RANDFILE "/dev/urandom" |
| 53 | #define DNSMASQ_SERVICE "uk.org.thekelleys.dnsmasq" /* Default - may be overridden by config */ |
| 54 | #define DNSMASQ_PATH "/uk/org/thekelleys/dnsmasq" |
| 55 | #define DNSMASQ_UBUS_NAME "dnsmasq" /* Default - may be overridden by config */ |
| 56 | #define AUTH_TTL 600 /* default TTL for auth DNS */ |
| 57 | #define SOA_REFRESH 1200 /* SOA refresh default */ |
| 58 | #define SOA_RETRY 180 /* SOA retry default */ |
| 59 | #define SOA_EXPIRY 1209600 /* SOA expiry default */ |
| 60 | #define LOOP_TEST_DOMAIN "test" /* domain for loop testing, "test" is reserved by RFC 2606 and won't therefore clash */ |
| 61 | #define LOOP_TEST_TYPE T_TXT |
| 62 | |
| 63 | /* compile-time options: uncomment below to enable or do eg. |
| 64 | make COPTS=-DHAVE_BROKEN_RTC |
| 65 | |
| 66 | HAVE_BROKEN_RTC |
| 67 | define this on embedded systems which don't have an RTC |
| 68 | which keeps time over reboots. Causes dnsmasq to use uptime |
| 69 | for timing, and keep lease lengths rather than expiry times |
| 70 | in its leases file. This also make dnsmasq "flash disk friendly". |
| 71 | Normally, dnsmasq tries very hard to keep the on-disk leases file |
| 72 | up-to-date: rewriting it after every renewal. When HAVE_BROKEN_RTC |
| 73 | is in effect, the lease file is only written when a new lease is |
| 74 | created, or an old one destroyed. (Because those are the only times |
| 75 | it changes.) This vastly reduces the number of file writes, and makes |
| 76 | it viable to keep the lease file on a flash filesystem. |
| 77 | NOTE: when enabling or disabling this, be sure to delete any old |
| 78 | leases file, otherwise dnsmasq may get very confused. |
| 79 | |
| 80 | HAVE_TFTP |
| 81 | define this to get dnsmasq's built-in TFTP server. |
| 82 | |
| 83 | HAVE_DHCP |
| 84 | define this to get dnsmasq's DHCPv4 server. |
| 85 | |
| 86 | HAVE_DHCP6 |
| 87 | define this to get dnsmasq's DHCPv6 server. (implies HAVE_DHCP). |
| 88 | |
| 89 | HAVE_SCRIPT |
| 90 | define this to get the ability to call scripts on lease-change. |
| 91 | |
| 92 | HAVE_LUASCRIPT |
| 93 | define this to get the ability to call Lua script on lease-change. (implies HAVE_SCRIPT) |
| 94 | |
| 95 | HAVE_DBUS |
| 96 | define this if you want to link against libdbus, and have dnsmasq |
| 97 | support some methods to allow (re)configuration of the upstream DNS |
| 98 | servers via DBus. |
| 99 | |
| 100 | HAVE_UBUS |
| 101 | define this if you want to link against libubus |
| 102 | |
| 103 | HAVE_IDN |
| 104 | define this if you want international domain name 2003 support. |
| 105 | |
| 106 | HAVE_LIBIDN2 |
| 107 | define this if you want international domain name 2008 support. |
| 108 | |
| 109 | HAVE_CONNTRACK |
| 110 | define this to include code which propagates conntrack marks from |
| 111 | incoming DNS queries to the corresponding upstream queries. This adds |
| 112 | a build-dependency on libnetfilter_conntrack, but the resulting binary will |
| 113 | still run happily on a kernel without conntrack support. |
| 114 | |
| 115 | HAVE_IPSET |
| 116 | define this to include the ability to selectively add resolved ip addresses |
| 117 | to given ipsets. |
| 118 | |
| 119 | HAVE_AUTH |
| 120 | define this to include the facility to act as an authoritative DNS |
| 121 | server for one or more zones. |
| 122 | |
| 123 | HAVE_CRYPTOHASH |
| 124 | include just hash function from crypto library, but no DNSSEC. |
| 125 | |
| 126 | HAVE_DNSSEC |
| 127 | include DNSSEC validator. |
| 128 | |
| 129 | HAVE_DUMPFILE |
| 130 | include code to dump packets to a libpcap-format file for debugging. |
| 131 | |
| 132 | HAVE_LOOP |
| 133 | include functionality to probe for and remove DNS forwarding loops. |
| 134 | |
| 135 | HAVE_INOTIFY |
| 136 | use the Linux inotify facility to efficiently re-read configuration files. |
| 137 | |
| 138 | NO_ID |
| 139 | Don't report *.bind CHAOS info to clients, forward such requests upstream instead. |
| 140 | NO_TFTP |
| 141 | NO_DHCP |
| 142 | NO_DHCP6 |
| 143 | NO_SCRIPT |
| 144 | NO_LARGEFILE |
| 145 | NO_AUTH |
| 146 | NO_DUMPFILE |
| 147 | NO_LOOP |
| 148 | NO_INOTIFY |
| 149 | these are available to explicitly disable compile time options which would |
| 150 | otherwise be enabled automatically or which are enabled by default |
| 151 | in the distributed source tree. Building dnsmasq |
| 152 | with something like "make COPTS=-DNO_SCRIPT" will do the trick. |
| 153 | NO_GMP |
| 154 | Don't use and link against libgmp, Useful if nettle is built with --enable-mini-gmp. |
| 155 | |
| 156 | LEASEFILE |
| 157 | CONFFILE |
| 158 | RESOLVFILE |
| 159 | the default locations of these files are determined below, but may be overridden |
| 160 | in a build command line using COPTS. |
| 161 | |
| 162 | */ |
| 163 | |
| 164 | /* Defining this builds a binary which handles time differently and works better on a system without a |
| 165 | stable RTC (it uses uptime, not epoch time) and writes the DHCP leases file less often to avoid flash wear. |
| 166 | */ |
| 167 | |
| 168 | /* #define HAVE_BROKEN_RTC */ |
| 169 | |
| 170 | /* The default set of options to build. Built with these options, dnsmasq |
| 171 | has no library dependencies other than libc */ |
| 172 | |
| 173 | #define HAVE_DHCP |
| 174 | #define HAVE_DHCP6 |
| 175 | #define HAVE_TFTP |
| 176 | #define HAVE_SCRIPT |
| 177 | #define HAVE_AUTH |
| 178 | #define HAVE_IPSET |
| 179 | #define HAVE_LOOP |
| 180 | #define HAVE_DUMPFILE |
| 181 | |
| 182 | /* Build options which require external libraries. |
| 183 | |
| 184 | Defining HAVE_<opt>_STATIC as _well_ as HAVE_<opt> will link the library statically. |
| 185 | |
| 186 | You can use "make COPTS=-DHAVE_<opt>" instead of editing these. |
| 187 | */ |
| 188 | |
| 189 | /* #define HAVE_LUASCRIPT */ |
| 190 | /* #define HAVE_DBUS */ |
| 191 | /* #define HAVE_IDN */ |
| 192 | /* #define HAVE_LIBIDN2 */ |
| 193 | /* #define HAVE_CONNTRACK */ |
| 194 | /* #define HAVE_CRYPTOHASH */ |
| 195 | /* #define HAVE_DNSSEC */ |
| 196 | |
| 197 | |
| 198 | /* Default locations for important system files. */ |
| 199 | |
| 200 | #ifndef LEASEFILE |
| 201 | # if defined(__FreeBSD__) || defined (__OpenBSD__) || defined(__DragonFly__) || defined(__NetBSD__) |
| 202 | # define LEASEFILE "/var/db/dnsmasq.leases" |
| 203 | # elif defined(__sun__) || defined (__sun) |
| 204 | # define LEASEFILE "/var/cache/dnsmasq.leases" |
| 205 | # elif defined(__ANDROID__) |
| 206 | # define LEASEFILE "/data/misc/dhcp/dnsmasq.leases" |
| 207 | # else |
| 208 | # define LEASEFILE "/var/lib/misc/dnsmasq.leases" |
| 209 | # endif |
| 210 | #endif |
| 211 | |
| 212 | #ifndef CONFFILE |
| 213 | # if defined(__FreeBSD__) |
| 214 | # define CONFFILE "/usr/local/etc/dnsmasq.conf" |
| 215 | # else |
| 216 | # define CONFFILE "/etc/dnsmasq.conf" |
| 217 | # endif |
| 218 | #endif |
| 219 | |
| 220 | #ifndef RESOLVFILE |
| 221 | # if defined(__uClinux__) |
| 222 | # define RESOLVFILE "/etc/config/resolv.conf" |
| 223 | # else |
| 224 | # define RESOLVFILE "/etc/resolv.conf" |
| 225 | # endif |
| 226 | #endif |
| 227 | |
| 228 | #ifndef RUNFILE |
| 229 | # if defined(__ANDROID__) |
| 230 | # define RUNFILE "/data/dnsmasq.pid" |
| 231 | # else |
| 232 | # define RUNFILE "/var/run/dnsmasq.pid" |
| 233 | # endif |
| 234 | #endif |
| 235 | |
| 236 | /* platform dependent options: these are determined automatically below |
| 237 | |
| 238 | HAVE_LINUX_NETWORK |
| 239 | HAVE_BSD_NETWORK |
| 240 | HAVE_SOLARIS_NETWORK |
| 241 | define exactly one of these to alter interaction with kernel networking. |
| 242 | |
| 243 | HAVE_GETOPT_LONG |
| 244 | defined when GNU-style getopt_long available. |
| 245 | |
| 246 | HAVE_SOCKADDR_SA_LEN |
| 247 | defined if struct sockaddr has sa_len field (*BSD) |
| 248 | */ |
| 249 | |
| 250 | #if defined(__UCLIBC__) |
| 251 | #define HAVE_LINUX_NETWORK |
| 252 | #if defined(__UCLIBC_HAS_GNU_GETOPT__) || \ |
| 253 | ((__UCLIBC_MAJOR__==0) && (__UCLIBC_MINOR__==9) && (__UCLIBC_SUBLEVEL__<21)) |
| 254 | # define HAVE_GETOPT_LONG |
| 255 | #endif |
| 256 | #undef HAVE_SOCKADDR_SA_LEN |
| 257 | #if defined(__UCLIBC_HAS_IPV6__) |
| 258 | # ifndef IPV6_V6ONLY |
| 259 | # define IPV6_V6ONLY 26 |
| 260 | # endif |
| 261 | #endif |
| 262 | |
| 263 | /* This is for glibc 2.x */ |
| 264 | #elif defined(__linux__) |
| 265 | #define HAVE_LINUX_NETWORK |
| 266 | #define HAVE_GETOPT_LONG |
| 267 | #undef HAVE_SOCKADDR_SA_LEN |
| 268 | |
| 269 | #elif defined(__FreeBSD__) || \ |
| 270 | defined(__OpenBSD__) || \ |
| 271 | defined(__DragonFly__) || \ |
| 272 | defined(__FreeBSD_kernel__) |
| 273 | #define HAVE_BSD_NETWORK |
| 274 | /* Later versions of FreeBSD have getopt_long() */ |
| 275 | #if defined(optional_argument) && defined(required_argument) |
| 276 | # define HAVE_GETOPT_LONG |
| 277 | #endif |
| 278 | #define HAVE_SOCKADDR_SA_LEN |
| 279 | |
| 280 | #elif defined(__APPLE__) |
| 281 | #define HAVE_BSD_NETWORK |
| 282 | #define HAVE_GETOPT_LONG |
| 283 | #define HAVE_SOCKADDR_SA_LEN |
| 284 | #define NO_IPSET |
| 285 | /* Define before sys/socket.h is included so we get socklen_t */ |
| 286 | #define _BSD_SOCKLEN_T_ |
| 287 | /* Select the RFC_3542 version of the IPv6 socket API. |
| 288 | Define before netinet6/in6.h is included. */ |
| 289 | #define __APPLE_USE_RFC_3542 |
| 290 | /* Required for Mojave. */ |
| 291 | #ifndef SOL_TCP |
| 292 | # define SOL_TCP IPPROTO_TCP |
| 293 | #endif |
| 294 | #define NO_IPSET |
| 295 | |
| 296 | #elif defined(__NetBSD__) |
| 297 | #define HAVE_BSD_NETWORK |
| 298 | #define HAVE_GETOPT_LONG |
| 299 | #define HAVE_SOCKADDR_SA_LEN |
| 300 | |
| 301 | #elif defined(__sun) || defined(__sun__) |
| 302 | #define HAVE_SOLARIS_NETWORK |
| 303 | #define HAVE_GETOPT_LONG |
| 304 | #undef HAVE_SOCKADDR_SA_LEN |
| 305 | #define ETHER_ADDR_LEN 6 |
| 306 | |
| 307 | #endif |
| 308 | |
| 309 | /* rules to implement compile-time option dependencies and |
| 310 | the NO_XXX flags */ |
| 311 | |
| 312 | #ifdef NO_TFTP |
| 313 | #undef HAVE_TFTP |
| 314 | #endif |
| 315 | |
| 316 | #ifdef NO_DHCP |
| 317 | #undef HAVE_DHCP |
| 318 | #undef HAVE_DHCP6 |
| 319 | #endif |
| 320 | |
| 321 | #if defined(NO_DHCP6) |
| 322 | #undef HAVE_DHCP6 |
| 323 | #endif |
| 324 | |
| 325 | /* DHCP6 needs DHCP too */ |
| 326 | #ifdef HAVE_DHCP6 |
| 327 | #define HAVE_DHCP |
| 328 | #endif |
| 329 | |
| 330 | #if defined(NO_SCRIPT) |
| 331 | #undef HAVE_SCRIPT |
| 332 | #undef HAVE_LUASCRIPT |
| 333 | #endif |
| 334 | |
| 335 | /* Must HAVE_SCRIPT to HAVE_LUASCRIPT */ |
| 336 | #ifdef HAVE_LUASCRIPT |
| 337 | #define HAVE_SCRIPT |
| 338 | #endif |
| 339 | |
| 340 | #ifdef NO_AUTH |
| 341 | #undef HAVE_AUTH |
| 342 | #endif |
| 343 | |
| 344 | #if defined(NO_IPSET) |
| 345 | #undef HAVE_IPSET |
| 346 | #endif |
| 347 | |
| 348 | #ifdef NO_LOOP |
| 349 | #undef HAVE_LOOP |
| 350 | #endif |
| 351 | |
| 352 | #ifdef NO_DUMPFILE |
| 353 | #undef HAVE_DUMPFILE |
| 354 | #endif |
| 355 | |
| 356 | #if defined (HAVE_LINUX_NETWORK) && !defined(NO_INOTIFY) |
| 357 | #define HAVE_INOTIFY |
| 358 | #endif |
| 359 | |
| 360 | /* Define a string indicating which options are in use. |
| 361 | DNSMASQ_COMPILE_OPTS is only defined in dnsmasq.c */ |
| 362 | |
| 363 | #ifdef DNSMASQ_COMPILE_OPTS |
| 364 | |
| 365 | static char *compile_opts = |
| 366 | "IPv6 " |
| 367 | #ifndef HAVE_GETOPT_LONG |
| 368 | "no-" |
| 369 | #endif |
| 370 | "GNU-getopt " |
| 371 | #ifdef HAVE_BROKEN_RTC |
| 372 | "no-RTC " |
| 373 | #endif |
| 374 | #ifndef HAVE_DBUS |
| 375 | "no-" |
| 376 | #endif |
| 377 | "DBus " |
| 378 | #ifndef HAVE_UBUS |
| 379 | "no-" |
| 380 | #endif |
| 381 | "UBus " |
| 382 | #ifndef LOCALEDIR |
| 383 | "no-" |
| 384 | #endif |
| 385 | "i18n " |
| 386 | #if defined(HAVE_LIBIDN2) |
| 387 | "IDN2 " |
| 388 | #else |
| 389 | #if !defined(HAVE_IDN) |
| 390 | "no-" |
| 391 | #endif |
| 392 | "IDN " |
| 393 | #endif |
| 394 | #ifndef HAVE_DHCP |
| 395 | "no-" |
| 396 | #endif |
| 397 | "DHCP " |
| 398 | #if defined(HAVE_DHCP) |
| 399 | # if !defined (HAVE_DHCP6) |
| 400 | "no-" |
| 401 | # endif |
| 402 | "DHCPv6 " |
| 403 | #endif |
| 404 | #if !defined(HAVE_SCRIPT) |
| 405 | "no-scripts " |
| 406 | #else |
| 407 | # if !defined(HAVE_LUASCRIPT) |
| 408 | "no-" |
| 409 | # endif |
| 410 | "Lua " |
| 411 | #endif |
| 412 | #ifndef HAVE_TFTP |
| 413 | "no-" |
| 414 | #endif |
| 415 | "TFTP " |
| 416 | #ifndef HAVE_CONNTRACK |
| 417 | "no-" |
| 418 | #endif |
| 419 | "conntrack " |
| 420 | #ifndef HAVE_IPSET |
| 421 | "no-" |
| 422 | #endif |
| 423 | "ipset " |
| 424 | #ifndef HAVE_AUTH |
| 425 | "no-" |
| 426 | #endif |
| 427 | "auth " |
| 428 | #if !defined(HAVE_CRYPTOHASH) && !defined(HAVE_DNSSEC) |
| 429 | "no-" |
| 430 | #endif |
| 431 | "cryptohash " |
| 432 | #ifndef HAVE_DNSSEC |
| 433 | "no-" |
| 434 | #endif |
| 435 | "DNSSEC " |
| 436 | #ifdef NO_ID |
| 437 | "no-ID " |
| 438 | #endif |
| 439 | #ifndef HAVE_LOOP |
| 440 | "no-" |
| 441 | #endif |
| 442 | "loop-detect " |
| 443 | #ifndef HAVE_INOTIFY |
| 444 | "no-" |
| 445 | #endif |
| 446 | "inotify " |
| 447 | #ifndef HAVE_DUMPFILE |
| 448 | "no-" |
| 449 | #endif |
| 450 | "dumpfile"; |
| 451 | |
| 452 | #endif /* defined(HAVE_DHCP) */ |