src/exim.h

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2014 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Source files for exim all #include this header, which drags in everything
  10 that is needed. They don't all need everything, of course, but it's far too
  11 messy to have each one importing its own list, and anyway, most of them need
  12 most of these includes. */
  13
  14 /* Assume most systems have statfs() unless os.h undefines this macro */
  15
  16 #define HAVE_STATFS
  17
  18 /* Similarly, assume most systems have srandom() unless os.h undefines it.
  19 This call dates back at least as far as SUSv2. */
  20
  21 #define HAVE_SRANDOM
  22
  23 /* This is primarily for the Gnu C library; we define it before os.h so that
  24 os.h has a chance to hurriedly undef it, Just In Case.  We need C99 for some
  25 64-bit math support, and defining _ISOC99_SOURCE breaks <resolv.h> and friends.
  26 */
  27
  28 #define _GNU_SOURCE 1
  29
  30 /* First of all include the os-specific header, which might set things that
  31 are needed by any of the other headers, including system headers. */
  32
  33 #include "os.h"
  34
  35 /* If it didn't define os_find_running_interfaces, use the common function. */
  36
  37 #ifndef os_find_running_interfaces
  38 # define os_find_running_interfaces os_common_find_running_interfaces
  39 #endif
  40
  41 /* If it didn't define the base for "base 62" numbers, we really do use 62.
  42 This is the case for all real Unix and Unix-like OS. It's only Cygwin and
  43 Darwin, with their case-insensitive file systems, that can't use base 62 for
  44 making unique names. */
  45
  46 #ifndef BASE_62
  47 # define BASE_62 62
  48 #endif
  49
  50 /* The maximum value of localhost_number depends on the base being used */
  51
  52 #if BASE_62 == 62
  53 # define LOCALHOST_MAX  16
  54 #else
  55 # define LOCALHOST_MAX  10
  56 #endif
  57
  58 /* If not overridden by os.h, dynamic libraries have filenames ending .so */
  59 #ifndef DYNLIB_FN_EXT
  60 # define DYNLIB_FN_EXT "so"
  61 #endif
  62
  63 /* ANSI C standard includes */
  64
  65 #include <ctype.h>
  66 #include <locale.h>
  67 #include <math.h>
  68 #include <signal.h>
  69 #include <stdarg.h>
  70 #include <stddef.h>
  71 #include <stdio.h>
  72 #include <stdlib.h>
  73 #include <string.h>
  74 #include <time.h>
  75
  76 /* Unix includes */
  77
  78 #include <errno.h>
  79 #if defined(__svr4__) && defined(__sparc) && ! defined(__EXTENSIONS__)
  80 # define __EXTENSIONS__  /* so that SunOS 5 gets NGROUPS_MAX */
  81 # include <limits.h>
  82 # undef  __EXTENSIONS__
  83 #else
  84 # include <limits.h>
  85 #endif
  86
  87 /* C99 integer types, figure out how to undo this if needed for older systems */
  88
  89 #include <inttypes.h>
  90
  91 /* Just in case some aged system doesn't define them... */
  92
  93 #ifndef INT_MAX
  94 # define INT_MAX 2147483647
  95 #endif
  96
  97 #ifndef INT_MIN
  98 # define INT_MIN (-INT_MAX - 1)
  99 #endif
 100
 101 #ifndef SHRT_MAX
 102 # define SHRT_MAX 32767
 103 #endif
 104
 105 #ifndef UCHAR_MAX
 106 # define UCHAR_MAX 255
 107 #endif
 108
 109
 110 /* To match int_eximarith_t.  Define in OS/os.h-<your-system> to override. */
 111 #ifndef EXIM_ARITH_MAX
 112 # define EXIM_ARITH_MAX ((int_eximarith_t)9223372036854775807LL)
 113 #endif
 114 #ifndef EXIM_ARITH_MIN
 115 # define EXIM_ARITH_MIN (-EXIM_ARITH_MAX - 1)
 116 #endif
 117
 118 /* Some systems have PATH_MAX and some have MAX_PATH_LEN. */
 119
 120 #ifndef PATH_MAX
 121 # ifdef MAX_PATH_LEN
 122 #  define PATH_MAX MAX_PATH_LEN
 123 # else
 124 #  define PATH_MAX 1024
 125 # endif
 126 #endif
 127
 128 #include <sys/types.h>
 129 #include <sys/file.h>
 130 #include <dirent.h>
 131 #include <netdb.h>
 132 #ifndef NO_POLL_H
 133 # include <poll.h>
 134 #endif
 135 #include <pwd.h>
 136 #include <grp.h>
 137 #include <syslog.h>
 138
 139 /* Not all systems have flock() available. Those that do must define LOCK_SH
 140 in sys/file.h. */
 141
 142 #ifndef LOCK_SH
 143 # define NO_FLOCK
 144 #endif
 145
 146 #ifndef NO_SYSEXITS        /* some OS don't have this */
 147 # include <sysexits.h>
 148 #endif
 149
 150 /* A few OS don't have socklen_t; their os.h files define EXIM_SOCKLEN_T to
 151 be size_t or whatever. We used to use SOCKLEN_T, but then it was discovered
 152 that this is used by the AIX include files. */
 153
 154 #ifndef EXIM_SOCKLEN_T
 155 # define EXIM_SOCKLEN_T socklen_t
 156 #endif
 157
 158 /* Ensure that the sysexits we reference are defined */
 159
 160 #ifndef EX_UNAVAILABLE
 161 # define EX_UNAVAILABLE 69        /* service unavailable; used for execv fail */
 162 #endif
 163 #ifndef EX_CANTCREAT
 164 # define EX_CANTCREAT   73        /* can't create file: treat as temporary */
 165 #endif
 166 #ifndef EX_TEMPFAIL
 167 # define EX_TEMPFAIL    75        /* temp failure; user is invited to retry */
 168 #endif
 169 #ifndef EX_CONFIG
 170 # define EX_CONFIG      78        /* configuration error */
 171 #endif
 172
 173 /* This one is not in any sysexits file that I've come across */
 174
 175 #define EX_EXECFAILED 127        /* execve() failed */
 176
 177
 178 #include <sys/time.h>
 179 #include <sys/param.h>
 180
 181 #ifndef NO_SYS_RESOURCE_H  /* QNX doesn't have this */
 182 # include <sys/resource.h>
 183 #endif
 184
 185 #include <sys/socket.h>
 186
 187 /* If we are on an IPv6 system, the macro AF_INET6 will have been defined in
 188 the sys/socket.h header. It is helpful to have this defined on an IPv4 system
 189 so that it can appear in the code, even if it is never actually used when
 190 the code is run. It saves some #ifdef occurrences. */
 191
 192 #ifndef AF_INET6
 193 # define AF_INET6 24
 194 #endif
 195
 196 #include <sys/ioctl.h>
 197
 198 /* The new standard is statvfs; some OS have statfs. For statvfs the block
 199 counts must be multiplied by the "fragment size" f_frsize to get the actual
 200 size. In other cases the value seems to be f_bsize (which is sometimes the only
 201 block size), so we use a macro to get that instead.
 202
 203 Also arrange to be able to cut it out altogether for way-out OS that don't have
 204 anything. I've indented a bit here to try to make the mess a bit more
 205 intelligible. Note that simply defining one name to be another when
 206 HAVE_SYS_STATVFS_H is not set will not work if the system has a statvfs macro
 207 or a macro with entries f_frsize and f_bsize. */
 208
 209 #ifdef HAVE_STATFS
 210   #ifdef HAVE_SYS_STATVFS_H
 211     #include <sys/statvfs.h>
 212     #define STATVFS statvfs
 213     #define F_FRSIZE f_frsize
 214   #else
 215     #define STATVFS statfs
 216     #define F_FRSIZE f_bsize
 217     #ifdef HAVE_SYS_VFS_H
 218       #include <sys/vfs.h>
 219       #ifdef HAVE_SYS_STATFS_H
 220       #include <sys/statfs.h>
 221       #endif
 222     #endif
 223     #ifdef HAVE_SYS_MOUNT_H
 224     #include <sys/mount.h>
 225     #endif
 226   #endif
 227
 228   /* Macros for the fields for the available space for non-superusers; define
 229   these only if the OS header has not. Not all OS have f_favail; those that
 230   are known to have it define F_FAVAIL as f_favail. The default is to use
 231   f_free. */
 232
 233   #ifndef F_BAVAIL
 234   # define F_BAVAIL f_bavail
 235   #endif
 236
 237   #ifndef F_FAVAIL
 238   # define F_FAVAIL f_ffree
 239   #endif
 240
 241   /* All the systems I've been able to look at seem to have F_FILES */
 242
 243   #ifndef F_FILES
 244   # define F_FILES  f_files
 245   #endif
 246
 247 #endif
 248
 249
 250 #ifndef  SIOCGIFCONF   /* HACK for SunOS 5 */
 251 # include <sys/sockio.h>
 252 #endif
 253
 254 #include <sys/stat.h>
 255 #include <sys/wait.h>
 256 #include <sys/utsname.h>
 257 #include <fcntl.h>
 258
 259 /* There's a shambles in IRIX6 - it defines EX_OK in unistd.h which conflicts
 260 with the definition in sysexits.h. Exim does not actually use this macro, so we
 261 just undefine it. It would be nice to be able to re-instate the definition from
 262 sysexits.h if there is no definition in unistd.h, but I do not think there is a
 263 way to do this in C because macro definitions are not scanned for other macros
 264 at definition time. [The code here used to assume they were, until I was
 265 disabused of the notion. Luckily, since EX_OK is not used, it didn't matter.] */
 266
 267 #ifdef EX_OK
 268 # undef EX_OK
 269 #endif
 270
 271 #include <unistd.h>
 272
 273 #include <utime.h>
 274 #ifndef NO_NET_IF_H
 275 # include <net/if.h>
 276 #endif
 277 #include <sys/un.h>
 278 #include <netinet/in.h>
 279 #include <netinet/tcp.h>
 280 #include <arpa/inet.h>
 281 #include <arpa/nameser.h>
 282
 283
 284 /* If arpa/nameser.h defines a maximum name server packet size, use it,
 285 provided it is greater than 2048. Otherwise go for a default. PACKETSZ was used
 286 for this, but it seems that NS_PACKETSZ is coming into use. */
 287
 288 #if defined(NS_PACKETSZ) && NS_PACKETSZ >= 2048
 289   #define MAXPACKET NS_PACKETSZ
 290 #elif defined(PACKETSZ) && PACKETSZ >= 2048
 291   #define MAXPACKET PACKETSZ
 292 #else
 293   #define MAXPACKET 2048
 294 #endif
 295
 296 /* While IPv6 is still young the definitions of T_AAAA and T_A6 may not be
 297 included in arpa/nameser.h. Fudge them here. */
 298
 299 #ifndef T_AAAA
 300 #define T_AAAA 28
 301 #endif
 302
 303 #ifndef T_A6
 304 #define T_A6 38
 305 #endif
 306
 307 /* Ancient systems (e.g. SunOS4) don't appear to have T_TXT defined in their
 308 header files. I don't suppose they have T_SRV either. */
 309
 310 #ifndef T_TXT
 311 # define T_TXT 16
 312 #endif
 313
 314 #ifndef T_SRV
 315 # define T_SRV 33
 316 #endif
 317
 318 /* Many systems do not have T_SPF. */
 319
 320 #ifndef T_SPF
 321 # define T_SPF 99
 322 #endif
 323
 324 /* New TLSA record for DANE */
 325 #ifndef T_TLSA
 326 # define T_TLSA 52
 327 #endif
 328 #define MAX_TLSA_EXPANDED_SIZE 8192
 329
 330 /* It seems that some versions of arpa/nameser.h don't define *any* of the
 331 T_xxx macros, which seem to be non-standard nowadays. Just to be on the safe
 332 side, put in definitions for all the ones that Exim uses. */
 333
 334 #ifndef T_A
 335 # define T_A 1
 336 #endif
 337
 338 #ifndef T_CNAME
 339 # define T_CNAME 5
 340 #endif
 341
 342 #ifndef T_SOA
 343 # define T_SOA 6
 344 #endif
 345
 346 #ifndef T_MX
 347 # define T_MX 15
 348 #endif
 349
 350 #ifndef T_NS
 351 # define T_NS 2
 352 #endif
 353
 354 #ifndef T_PTR
 355 # define T_PTR 12
 356 #endif
 357
 358
 359 /* We define a few private types for special DNS lookups:
 360
 361  . T_ZNS gets the nameservers of the enclosing zone of a domain
 362
 363  . T_MXH gets the MX hostnames only (without their priorities)
 364
 365  . T_CSA gets the domain's Client SMTP Authorization SRV record
 366
 367  . T_ADDRESSES looks up both AAAA (or A6) and A records
 368
 369 If any of these names appear in the RRtype list at:
 370   <http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml>
 371 then we should rename Exim's private type away from the conflict.
 372 */
 373
 374 #define T_ZNS (-1)
 375 #define T_MXH (-2)
 376 #define T_CSA (-3)
 377 #define T_ADDRESSES (-4)
 378
 379 /* The resolv.h header defines __P(x) on some Solaris 2.5.1 systems (without
 380 checking that it is already defined, in fact). This conflicts with other
 381 headers that behave likewise (see below), leading to compiler warnings. Arrange
 382 to undefine it if resolv.h defines it. */
 383
 384 #if defined(__P)
 385 # define __P_WAS_DEFINED_BEFORE_RESOLV
 386 #endif
 387
 388 #include <resolv.h>
 389
 390 #if defined(__P) && ! defined (__P_WAS_DEFINED_BEFORE_RESOLV)
 391 # undef __P
 392 #endif
 393
 394 /* If not defined by os.h, we do nothing special to push DNS resolver state
 395 back to be available by the classic resolver routines.  Also, provide
 396 prototype for our get routine, unless defined away. */
 397
 398 #ifndef os_put_dns_resolver_res
 399 # define os_put_dns_resolver_res(R) do {/**/} while(0)
 400 #endif
 401 #ifndef os_get_dns_resolver_res
 402 res_state os_get_dns_resolver_res(void);
 403 #endif
 404
 405 /* These three are to support the IP option logging code. Linux is
 406 different to everyone else and there are also other systems which don't
 407 have netinet/ip_var.h, so there's a general macro to control its inclusion. */
 408
 409 #include <netinet/in_systm.h>
 410 #include <netinet/ip.h>
 411
 412 #ifndef NO_IP_VAR_H
 413 # include <netinet/ip_var.h>
 414 #endif
 415
 416 /* Linux (and some others) uses a different type for the 2nd argument of
 417 iconv(). It's os.h file defines ICONV_ARG2_TYPE. For the rest, define a default
 418 here. */
 419
 420 #ifndef ICONV_ARG2_TYPE
 421 # define ICONV_ARG2_TYPE const char **
 422 #endif
 423
 424 /* One OS uses a different type for the 5th argument of getsockopt */
 425
 426 #ifndef GETSOCKOPT_ARG5_TYPE
 427 # define GETSOCKOPT_ARG5_TYPE socklen_t *
 428 #endif
 429
 430 /* One operating system uses a different type for the 2nd argument of select().
 431 Its os.h file defines SELECT_ARG2_TYPE. For the rest, define a default here. */
 432
 433 #ifndef SELECT_ARG2_TYPE
 434 # define SELECT_ARG2_TYPE fd_set
 435 #endif
 436
 437 /* One operating system uses a different type for the 4th argument of
 438 dn_expand(). Its os.h file defines DN_EXPAND_ARG4_TYPE. For the rest, define a
 439 default here. */
 440
 441 #ifndef DN_EXPAND_ARG4_TYPE
 442 # define DN_EXPAND_ARG4_TYPE char *
 443 #endif
 444
 445 /* One operating system defines a different type for the yield of inet_addr().
 446 In Exim code, its value is always assigned to the s_addr members of address
 447 structures. Casting the yield to the type of s_addr should fix the problem,
 448 since the size of the data is correct. Just in case this ever has to be
 449 changed, use a macro for the type, and define it here so that it is possible to
 450 use different values for specific OS if ever necessary. */
 451
 452 #ifndef S_ADDR_TYPE
 453 # define S_ADDR_TYPE u_long
 454 #endif
 455
 456 /* (At least) one operating system (Solaris) defines a different type for the
 457 second argument of pam_converse() - the difference is the absence of "const".
 458 Its os.h file defines PAM_CONVERSE_ARG2_TYPE. For the rest, define a default
 459 here. */
 460
 461 #ifndef PAM_CONVERSE_ARG2_TYPE
 462 # define PAM_CONVERSE_ARG2_TYPE const struct pam_message
 463 #endif
 464
 465 /* One operating system (SunOS4) defines getc, ungetc, feof, and ferror as
 466 macros and not as functions. Exim needs them to be assignable functions. This
 467 flag gets set to cause this to be sorted out here. */
 468
 469 #ifdef FUDGE_GETC_AND_FRIENDS
 470 # undef getc
 471 extern int getc(FILE *);
 472 # undef ungetc
 473 extern int ungetc(int, FILE *);
 474 # undef feof
 475 extern int feof(FILE *);
 476 # undef ferror
 477 extern int ferror(FILE *);
 478 #endif
 479
 480 /* The header from the PCRE regex package */
 481
 482 #include <pcre.h>
 483
 484 /* Exim includes are in several files. Note that local_scan.h #includes
 485 config.h, mytypes.h, and store.h, so we don't need to mention them explicitly.
 486 */
 487
 488 #include "local_scan.h"
 489 #include "macros.h"
 490 #include "dbstuff.h"
 491 #include "structs.h"
 492 #include "globals.h"
 493 #include "functions.h"
 494 #include "dbfunctions.h"
 495 #include "osfunctions.h"
 496
 497 #ifdef EXPERIMENTAL_BRIGHTMAIL
 498 # include "bmi_spam.h"
 499 #endif
 500 #ifdef EXPERIMENTAL_SPF
 501 # include "spf.h"
 502 #endif
 503 #ifdef EXPERIMENTAL_SRS
 504 # include "srs.h"
 505 #endif
 506 #ifndef DISABLE_DKIM
 507 # include "dkim.h"
 508 #endif
 509 #ifdef EXPERIMENTAL_DMARC
 510 # include "dmarc.h"
 511 # include <opendmarc/dmarc.h>
 512 #endif
 513
 514 /* The following stuff must follow the inclusion of config.h because it
 515 requires various things that are set therein. */
 516
 517 #if HAVE_ICONV             /* Not all OS have this */
 518 # include <iconv.h>
 519 #endif
 520
 521 #if defined(USE_READLINE) || defined(EXPAND_DLFUNC) || defined (LOOKUP_MODULE_DIR)
 522 # include <dlfcn.h>
 523 #endif
 524
 525 #ifdef ENABLE_DISABLE_FSYNC
 526 # define EXIMfsync(f) (disable_fsync? 0 : fsync(f))
 527 #else
 528 # define EXIMfsync(f) fsync(f)
 529 #endif
 530
 531 /* Backward compatibility; LOOKUP_LSEARCH now includes all three */
 532
 533 #if (!defined LOOKUP_LSEARCH) && (defined LOOKUP_WILDLSEARCH || defined LOOKUP_NWILDLSEARCH)
 534 # define LOOKUP_LSEARCH yes
 535 #endif
 536
 537 /* Define a union to hold either an IPv4 or an IPv6 sockaddr structure; this
 538 simplifies some of the coding.  We include the sockaddr to reduce type-punning
 539 issues in C99. */
 540
 541 union sockaddr_46 {
 542   struct sockaddr_in v4;
 543   #if HAVE_IPV6
 544   struct sockaddr_in6 v6;
 545   #endif
 546   struct sockaddr v0;
 547 };
 548
 549 /* If SUPPORT_TLS is not defined, ensure that USE_GNUTLS is also not defined
 550 so that if USE_GNUTLS *is* set, we can assume SUPPORT_TLS is also set. */
 551
 552 #ifndef SUPPORT_TLS
 553 # undef USE_GNUTLS
 554 #endif
 555
 556 /* If SPOOL_DIRECTORY, LOG_FILE_PATH or PID_FILE_PATH have not been defined,
 557 set them to the null string. */
 558
 559 #ifndef SPOOL_DIRECTORY
 560   #define SPOOL_DIRECTORY ""
 561 #endif
 562 #ifndef LOG_FILE_PATH
 563   #define LOG_FILE_PATH ""
 564 #endif
 565 #ifndef PID_FILE_PATH
 566   #define PID_FILE_PATH ""
 567 #endif
 568
 569 /* The EDQUOT error code isn't universally available, though it is widespread.
 570 There is a particular shambles in SunOS5, where it did not exist originally,
 571 but got installed with a particular patch for Solaris 2.4. There is a
 572 configuration variable for specifying what the system's "over quota" error is,
 573 which will end up in config.h if supplied in OS/Makefile-xxx. If it is not set,
 574 default to EDQUOT if it exists, otherwise ENOSPC. */
 575
 576 #ifndef ERRNO_QUOTA
 577 # ifdef  EDQUOT
 578 #  define ERRNO_QUOTA EDQUOT
 579 # else
 580 #  define ERRNO_QUOTA ENOSPC
 581 # endif
 582 #endif
 583
 584 /* Ensure PATH_MAX is defined */
 585
 586 #ifndef PATH_MAX
 587   #ifdef MAXPATHLEN
 588   # define PATH_MAX MAXPATHLEN
 589   #else
 590   # define PATH_MAX 1024
 591   #endif
 592 #endif
 593
 594 /* End of exim.h */