d03b48c66abaa52b6f2ea366dbb62f0d00589b10
[exim.git] / src / src / exim.h
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
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 #ifndef EXIM_H
15 #define EXIM_H
16
17 /* Assume most systems have statfs() unless os.h undefines this macro */
18
19 #define HAVE_STATFS
20
21 /* Similarly, assume most systems have srandom() unless os.h undefines it.
22 This call dates back at least as far as SUSv2. */
23
24 #define HAVE_SRANDOM
25
26 /* This is primarily for the Gnu C library; we define it before os.h so that
27 os.h has a chance to hurriedly undef it, Just In Case. We need C99 for some
28 64-bit math support, and defining _ISOC99_SOURCE breaks <resolv.h> and friends.
29 */
30
31 #define _GNU_SOURCE 1
32
33 /* First of all include the os-specific header, which might set things that
34 are needed by any of the other headers, including system headers. */
35
36 #include "os.h"
37
38 /* If it didn't define os_find_running_interfaces, use the common function. */
39
40 #ifndef os_find_running_interfaces
41 # define os_find_running_interfaces os_common_find_running_interfaces
42 #endif
43
44 /* If it didn't define the base for "base 62" numbers, we really do use 62.
45 This is the case for all real Unix and Unix-like OS. It's only Cygwin and
46 Darwin, with their case-insensitive file systems, that can't use base 62 for
47 making unique names. */
48
49 #ifndef BASE_62
50 # define BASE_62 62
51 #endif
52
53 /* The maximum value of localhost_number depends on the base being used */
54
55 #if BASE_62 == 62
56 # define LOCALHOST_MAX 16
57 #else
58 # define LOCALHOST_MAX 10
59 #endif
60
61 /* If not overridden by os.h, dynamic libraries have filenames ending .so */
62 #ifndef DYNLIB_FN_EXT
63 # define DYNLIB_FN_EXT "so"
64 #endif
65
66 /* ANSI C standard includes */
67
68 #include <ctype.h>
69 #include <locale.h>
70 #include <math.h>
71 #include <signal.h>
72 #include <stdarg.h>
73 #include <stddef.h>
74 #include <stdio.h>
75 #include <stdlib.h>
76 #include <string.h>
77 #include <time.h>
78
79 /* Unix includes */
80
81 #include <errno.h>
82 #if defined(__svr4__) && defined(__sparc) && ! defined(__EXTENSIONS__)
83 # define __EXTENSIONS__ /* so that SunOS 5 gets NGROUPS_MAX */
84 # include <limits.h>
85 # undef __EXTENSIONS__
86 #else
87 # include <limits.h>
88 #endif
89
90 /* C99 integer types, figure out how to undo this if needed for older systems */
91
92 #include <inttypes.h>
93
94 /* Just in case some aged system doesn't define them... */
95
96 #ifndef INT_MAX
97 # define INT_MAX 2147483647
98 #endif
99
100 #ifndef INT_MIN
101 # define INT_MIN (-INT_MAX - 1)
102 #endif
103
104 #ifndef SHRT_MAX
105 # define SHRT_MAX 32767
106 #endif
107
108 #ifndef UCHAR_MAX
109 # define UCHAR_MAX 255
110 #endif
111
112
113 /* To match int_eximarith_t. Define in OS/os.h-<your-system> to override. */
114 #ifndef EXIM_ARITH_MAX
115 # define EXIM_ARITH_MAX ((int_eximarith_t)9223372036854775807LL)
116 #endif
117 #ifndef EXIM_ARITH_MIN
118 # define EXIM_ARITH_MIN (-EXIM_ARITH_MAX - 1)
119 #endif
120
121 /* Some systems have PATH_MAX and some have MAX_PATH_LEN. */
122
123 #ifndef PATH_MAX
124 # ifdef MAX_PATH_LEN
125 # define PATH_MAX MAX_PATH_LEN
126 # else
127 # define PATH_MAX 1024
128 # endif
129 #endif
130
131 #include <sys/types.h>
132 #include <sys/file.h>
133 #include <dirent.h>
134 #include <netdb.h>
135 #ifndef NO_POLL_H
136 # include <poll.h>
137 #endif
138 #include <pwd.h>
139 #include <grp.h>
140 #include <syslog.h>
141
142 /* Not all systems have flock() available. Those that do must define LOCK_SH
143 in sys/file.h. */
144
145 #ifndef LOCK_SH
146 # define NO_FLOCK
147 #endif
148
149 #ifndef NO_SYSEXITS /* some OS don't have this */
150 # include <sysexits.h>
151 #endif
152
153 /* A few OS don't have socklen_t; their os.h files define EXIM_SOCKLEN_T to
154 be size_t or whatever. We used to use SOCKLEN_T, but then it was discovered
155 that this is used by the AIX include files. */
156
157 #ifndef EXIM_SOCKLEN_T
158 # define EXIM_SOCKLEN_T socklen_t
159 #endif
160
161 /* Ensure that the sysexits we reference are defined */
162
163 #ifndef EX_UNAVAILABLE
164 # define EX_UNAVAILABLE 69 /* service unavailable; used for execv fail */
165 #endif
166 #ifndef EX_CANTCREAT
167 # define EX_CANTCREAT 73 /* can't create file: treat as temporary */
168 #endif
169 #ifndef EX_TEMPFAIL
170 # define EX_TEMPFAIL 75 /* temp failure; user is invited to retry */
171 #endif
172 #ifndef EX_CONFIG
173 # define EX_CONFIG 78 /* configuration error */
174 #endif
175
176 /* This one is not in any sysexits file that I've come across */
177
178 #define EX_EXECFAILED 127 /* execve() failed */
179
180
181 #include <sys/time.h>
182 #include <sys/param.h>
183
184 #ifndef NO_SYS_RESOURCE_H /* QNX doesn't have this */
185 # include <sys/resource.h>
186 #endif
187
188 #include <sys/socket.h>
189
190 /* If we are on an IPv6 system, the macro AF_INET6 will have been defined in
191 the sys/socket.h header. It is helpful to have this defined on an IPv4 system
192 so that it can appear in the code, even if it is never actually used when
193 the code is run. It saves some #ifdef occurrences. */
194
195 #ifndef AF_INET6
196 # define AF_INET6 24
197 #endif
198
199 #include <sys/ioctl.h>
200
201 /* The new standard is statvfs; some OS have statfs. For statvfs the block
202 counts must be multiplied by the "fragment size" f_frsize to get the actual
203 size. In other cases the value seems to be f_bsize (which is sometimes the only
204 block size), so we use a macro to get that instead.
205
206 Also arrange to be able to cut it out altogether for way-out OS that don't have
207 anything. I've indented a bit here to try to make the mess a bit more
208 intelligible. Note that simply defining one name to be another when
209 HAVE_SYS_STATVFS_H is not set will not work if the system has a statvfs macro
210 or a macro with entries f_frsize and f_bsize. */
211
212 #ifdef HAVE_STATFS
213 #ifdef HAVE_SYS_STATVFS_H
214 #include <sys/statvfs.h>
215 #define STATVFS statvfs
216 #define F_FRSIZE f_frsize
217 #else
218 #define STATVFS statfs
219 #define F_FRSIZE f_bsize
220 #ifdef HAVE_SYS_VFS_H
221 #include <sys/vfs.h>
222 #ifdef HAVE_SYS_STATFS_H
223 #include <sys/statfs.h>
224 #endif
225 #endif
226 #ifdef HAVE_SYS_MOUNT_H
227 #include <sys/mount.h>
228 #endif
229 #endif
230
231 /* Macros for the fields for the available space for non-superusers; define
232 these only if the OS header has not. Not all OS have f_favail; those that
233 are known to have it define F_FAVAIL as f_favail. The default is to use
234 f_free. */
235
236 #ifndef F_BAVAIL
237 # define F_BAVAIL f_bavail
238 #endif
239
240 #ifndef F_FAVAIL
241 # define F_FAVAIL f_ffree
242 #endif
243
244 /* All the systems I've been able to look at seem to have F_FILES */
245
246 #ifndef F_FILES
247 # define F_FILES f_files
248 #endif
249
250 #endif
251
252
253 #ifndef SIOCGIFCONF /* HACK for SunOS 5 */
254 # include <sys/sockio.h>
255 #endif
256
257 #include <sys/stat.h>
258 #include <sys/wait.h>
259 #include <sys/utsname.h>
260 #include <fcntl.h>
261
262 /* There's a shambles in IRIX6 - it defines EX_OK in unistd.h which conflicts
263 with the definition in sysexits.h. Exim does not actually use this macro, so we
264 just undefine it. It would be nice to be able to re-instate the definition from
265 sysexits.h if there is no definition in unistd.h, but I do not think there is a
266 way to do this in C because macro definitions are not scanned for other macros
267 at definition time. [The code here used to assume they were, until I was
268 disabused of the notion. Luckily, since EX_OK is not used, it didn't matter.] */
269
270 #ifdef EX_OK
271 # undef EX_OK
272 #endif
273
274 #include <unistd.h>
275
276 #include <utime.h>
277 #ifndef NO_NET_IF_H
278 # include <net/if.h>
279 #endif
280 #include <sys/un.h>
281 #include <netinet/in.h>
282 #include <netinet/tcp.h>
283 #include <arpa/inet.h>
284 #include <arpa/nameser.h>
285
286
287 /* If arpa/nameser.h defines a maximum name server packet size, use it,
288 provided it is greater than 2048. Otherwise go for a default. PACKETSZ was used
289 for this, but it seems that NS_PACKETSZ is coming into use. */
290
291 #if defined(NS_PACKETSZ) && NS_PACKETSZ >= 2048
292 #define MAXPACKET NS_PACKETSZ
293 #elif defined(PACKETSZ) && PACKETSZ >= 2048
294 #define MAXPACKET PACKETSZ
295 #else
296 #define MAXPACKET 2048
297 #endif
298
299 /* While IPv6 is still young the definitions of T_AAAA and T_A6 may not be
300 included in arpa/nameser.h. Fudge them here. */
301
302 #ifndef T_AAAA
303 #define T_AAAA 28
304 #endif
305
306 #ifndef T_A6
307 #define T_A6 38
308 #endif
309
310 /* Ancient systems (e.g. SunOS4) don't appear to have T_TXT defined in their
311 header files. I don't suppose they have T_SRV either. */
312
313 #ifndef T_TXT
314 # define T_TXT 16
315 #endif
316
317 #ifndef T_SRV
318 # define T_SRV 33
319 #endif
320
321 /* Many systems do not have T_SPF. */
322
323 #ifndef T_SPF
324 # define T_SPF 99
325 #endif
326
327 /* New TLSA record for DANE */
328 #ifndef T_TLSA
329 # define T_TLSA 52
330 #endif
331 #define MAX_TLSA_EXPANDED_SIZE 8192
332
333 /* It seems that some versions of arpa/nameser.h don't define *any* of the
334 T_xxx macros, which seem to be non-standard nowadays. Just to be on the safe
335 side, put in definitions for all the ones that Exim uses. */
336
337 #ifndef T_A
338 # define T_A 1
339 #endif
340
341 #ifndef T_CNAME
342 # define T_CNAME 5
343 #endif
344
345 #ifndef T_SOA
346 # define T_SOA 6
347 #endif
348
349 #ifndef T_MX
350 # define T_MX 15
351 #endif
352
353 #ifndef T_NS
354 # define T_NS 2
355 #endif
356
357 #ifndef T_PTR
358 # define T_PTR 12
359 #endif
360
361
362 /* We define a few private types for special DNS lookups:
363
364 . T_ZNS gets the nameservers of the enclosing zone of a domain
365
366 . T_MXH gets the MX hostnames only (without their priorities)
367
368 . T_CSA gets the domain's Client SMTP Authorization SRV record
369
370 . T_ADDRESSES looks up both AAAA (or A6) and A records
371
372 If any of these names appear in the RRtype list at:
373 <http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml>
374 then we should rename Exim's private type away from the conflict.
375 */
376
377 #define T_ZNS (-1)
378 #define T_MXH (-2)
379 #define T_CSA (-3)
380 #define T_ADDRESSES (-4)
381
382 /* The resolv.h header defines __P(x) on some Solaris 2.5.1 systems (without
383 checking that it is already defined, in fact). This conflicts with other
384 headers that behave likewise (see below), leading to compiler warnings. Arrange
385 to undefine it if resolv.h defines it. */
386
387 #if defined(__P)
388 # define __P_WAS_DEFINED_BEFORE_RESOLV
389 #endif
390
391 #include <resolv.h>
392
393 #if defined(__P) && ! defined (__P_WAS_DEFINED_BEFORE_RESOLV)
394 # undef __P
395 #endif
396
397 /* If not defined by os.h, we do nothing special to push DNS resolver state
398 back to be available by the classic resolver routines. Also, provide
399 prototype for our get routine, unless defined away. */
400
401 #ifndef os_put_dns_resolver_res
402 # define os_put_dns_resolver_res(R) do {/**/} while(0)
403 #endif
404 #ifndef os_get_dns_resolver_res
405 res_state os_get_dns_resolver_res(void);
406 #endif
407
408 /* These three are to support the IP option logging code. Linux is
409 different to everyone else and there are also other systems which don't
410 have netinet/ip_var.h, so there's a general macro to control its inclusion. */
411
412 #include <netinet/in_systm.h>
413 #include <netinet/ip.h>
414
415 #ifndef NO_IP_VAR_H
416 # include <netinet/ip_var.h>
417 #endif
418
419 /* Linux (and some others) uses a different type for the 2nd argument of
420 iconv(). It's os.h file defines ICONV_ARG2_TYPE. For the rest, define a default
421 here. */
422
423 #ifndef ICONV_ARG2_TYPE
424 # define ICONV_ARG2_TYPE char **
425 #endif
426
427 /* One OS uses a different type for the 5th argument of getsockopt */
428
429 #ifndef GETSOCKOPT_ARG5_TYPE
430 # define GETSOCKOPT_ARG5_TYPE socklen_t *
431 #endif
432
433 /* One operating system uses a different type for the 2nd argument of select().
434 Its os.h file defines SELECT_ARG2_TYPE. For the rest, define a default here. */
435
436 #ifndef SELECT_ARG2_TYPE
437 # define SELECT_ARG2_TYPE fd_set
438 #endif
439
440 /* One operating system uses a different type for the 4th argument of
441 dn_expand(). Its os.h file defines DN_EXPAND_ARG4_TYPE. For the rest, define a
442 default here. */
443
444 #ifndef DN_EXPAND_ARG4_TYPE
445 # define DN_EXPAND_ARG4_TYPE char *
446 #endif
447
448 /* One operating system defines a different type for the yield of inet_addr().
449 In Exim code, its value is always assigned to the s_addr members of address
450 structures. Casting the yield to the type of s_addr should fix the problem,
451 since the size of the data is correct. Just in case this ever has to be
452 changed, use a macro for the type, and define it here so that it is possible to
453 use different values for specific OS if ever necessary. */
454
455 #ifndef S_ADDR_TYPE
456 # define S_ADDR_TYPE u_long
457 #endif
458
459 /* (At least) one operating system (Solaris) defines a different type for the
460 second argument of pam_converse() - the difference is the absence of "const".
461 Its os.h file defines PAM_CONVERSE_ARG2_TYPE. For the rest, define a default
462 here. */
463
464 #ifndef PAM_CONVERSE_ARG2_TYPE
465 # define PAM_CONVERSE_ARG2_TYPE const struct pam_message
466 #endif
467
468 /* One operating system (SunOS4) defines getc, ungetc, feof, and ferror as
469 macros and not as functions. Exim needs them to be assignable functions. This
470 flag gets set to cause this to be sorted out here. */
471
472 #ifdef FUDGE_GETC_AND_FRIENDS
473 # undef getc
474 extern int getc(FILE *);
475 # undef ungetc
476 extern int ungetc(int, FILE *);
477 # undef feof
478 extern int feof(FILE *);
479 # undef ferror
480 extern int ferror(FILE *);
481 #endif
482
483 /* The header from the PCRE regex package */
484
485 #include <pcre.h>
486
487 /* Exim includes are in several files. Note that local_scan.h #includes
488 config.h, mytypes.h, and store.h, so we don't need to mention them explicitly.
489 */
490
491 #include "local_scan.h"
492 #include "macros.h"
493 #include "dbstuff.h"
494 #include "structs.h"
495 #include "globals.h"
496 #include "hash.h"
497 #include "functions.h"
498 #include "dbfunctions.h"
499 #include "osfunctions.h"
500
501 #ifdef EXPERIMENTAL_BRIGHTMAIL
502 # include "bmi_spam.h"
503 #endif
504 #ifdef EXPERIMENTAL_SPF
505 # include "spf.h"
506 #endif
507 #ifdef EXPERIMENTAL_SRS
508 # include "srs.h"
509 #endif
510 #ifndef DISABLE_DKIM
511 # include "dkim.h"
512 #endif
513 #ifdef EXPERIMENTAL_DMARC
514 # include "dmarc.h"
515 # include <opendmarc/dmarc.h>
516 #endif
517
518 /* The following stuff must follow the inclusion of config.h because it
519 requires various things that are set therein. */
520
521 #if HAVE_ICONV /* Not all OS have this */
522 # include <iconv.h>
523 #endif
524
525 #if defined(USE_READLINE) || defined(EXPAND_DLFUNC) || defined (LOOKUP_MODULE_DIR)
526 # include <dlfcn.h>
527 #endif
528
529 #ifdef ENABLE_DISABLE_FSYNC
530 # define EXIMfsync(f) (disable_fsync? 0 : fsync(f))
531 #else
532 # define EXIMfsync(f) fsync(f)
533 #endif
534
535 /* Backward compatibility; LOOKUP_LSEARCH now includes all three */
536
537 #if (!defined LOOKUP_LSEARCH) && (defined LOOKUP_WILDLSEARCH || defined LOOKUP_NWILDLSEARCH)
538 # define LOOKUP_LSEARCH yes
539 #endif
540
541 /* Define a union to hold either an IPv4 or an IPv6 sockaddr structure; this
542 simplifies some of the coding. We include the sockaddr to reduce type-punning
543 issues in C99. */
544
545 union sockaddr_46 {
546 struct sockaddr_in v4;
547 #if HAVE_IPV6
548 struct sockaddr_in6 v6;
549 #endif
550 struct sockaddr v0;
551 };
552
553 /* If SUPPORT_TLS is not defined, ensure that USE_GNUTLS is also not defined
554 so that if USE_GNUTLS *is* set, we can assume SUPPORT_TLS is also set.
555 Likewise, OSCP, AUTH_TLS and CERTNAMES cannot be supported. */
556
557 #ifndef SUPPORT_TLS
558 # undef USE_GNUTLS
559 # ifndef DISABLE_OCSP
560 # define DISABLE_OCSP
561 # endif
562 # undef EXPERIMENTAL_CERTNAMES
563 # undef AUTH_TLS
564 #endif
565
566 /* If SPOOL_DIRECTORY, LOG_FILE_PATH or PID_FILE_PATH have not been defined,
567 set them to the null string. */
568
569 #ifndef SPOOL_DIRECTORY
570 #define SPOOL_DIRECTORY ""
571 #endif
572 #ifndef LOG_FILE_PATH
573 #define LOG_FILE_PATH ""
574 #endif
575 #ifndef PID_FILE_PATH
576 #define PID_FILE_PATH ""
577 #endif
578
579 /* The EDQUOT error code isn't universally available, though it is widespread.
580 There is a particular shambles in SunOS5, where it did not exist originally,
581 but got installed with a particular patch for Solaris 2.4. There is a
582 configuration variable for specifying what the system's "over quota" error is,
583 which will end up in config.h if supplied in OS/Makefile-xxx. If it is not set,
584 default to EDQUOT if it exists, otherwise ENOSPC. */
585
586 #ifndef ERRNO_QUOTA
587 # ifdef EDQUOT
588 # define ERRNO_QUOTA EDQUOT
589 # else
590 # define ERRNO_QUOTA ENOSPC
591 # endif
592 #endif
593
594 /* DANE w/o DNSSEC is useless */
595 #if defined(EXPERIMENTAL_DANE) && defined(DISABLE_DNSSEC)
596 # undef DISABLE_DNSSEC
597 #endif
598
599 #endif
600 /* End of exim.h */