xref: /freebsd/contrib/sendmail/include/libmilter/mfapi.h (revision 7cd2dcf07629713e5a3d60472cfe4701b705a167)
1 /*
2  * Copyright (c) 1999-2004, 2006, 2008 Sendmail, Inc. and its suppliers.
3  *	All rights reserved.
4  *
5  * By using this file, you agree to the terms and conditions set
6  * forth in the LICENSE file which can be found at the top level of
7  * the sendmail distribution.
8  *
9  *
10  *	$Id: mfapi.h,v 8.80 2009/11/06 00:57:08 ca Exp $
11  */
12 
13 /*
14 **  MFAPI.H -- Global definitions for mail filter library and mail filters.
15 */
16 
17 #ifndef _LIBMILTER_MFAPI_H
18 # define _LIBMILTER_MFAPI_H	1
19 
20 #ifndef SMFI_VERSION
21 # if _FFR_MDS_NEGOTIATE
22 #  define SMFI_VERSION	0x01000002	/* libmilter version number */
23 
24    /* first libmilter version that has MDS support */
25 #  define SMFI_VERSION_MDS	0x01000002
26 # else /* _FFR_MDS_NEGOTIATE */
27 #  define SMFI_VERSION	0x01000001	/* libmilter version number */
28 # endif /* _FFR_MDS_NEGOTIATE */
29 #endif /* ! SMFI_VERSION */
30 
31 #define SM_LM_VRS_MAJOR(v)	(((v) & 0x7f000000) >> 24)
32 #define SM_LM_VRS_MINOR(v)	(((v) & 0x007fff00) >> 8)
33 #define SM_LM_VRS_PLVL(v)	((v) & 0x0000007f)
34 
35 # include <sys/types.h>
36 # include <sys/socket.h>
37 
38 #include "libmilter/mfdef.h"
39 
40 # define LIBMILTER_API		extern
41 
42 
43 /* Only need to export C interface if used by C++ source code */
44 #ifdef __cplusplus
45 extern "C" {
46 #endif /* __cplusplus */
47 
48 #ifndef _SOCK_ADDR
49 # define _SOCK_ADDR	struct sockaddr
50 #endif /* ! _SOCK_ADDR */
51 
52 /*
53 **  libmilter functions return one of the following to indicate
54 **  success/failure(/continue):
55 */
56 
57 #define MI_SUCCESS	0
58 #define MI_FAILURE	(-1)
59 #if _FFR_WORKERS_POOL
60 # define MI_CONTINUE	1
61 #endif /* _FFR_WORKERS_POOL */
62 
63 /* "forward" declarations */
64 typedef struct smfi_str SMFICTX;
65 typedef struct smfi_str *SMFICTX_PTR;
66 
67 typedef struct smfiDesc smfiDesc_str;
68 typedef struct smfiDesc	*smfiDesc_ptr;
69 
70 /*
71 **  Type which callbacks should return to indicate message status.
72 **  This may take on one of the SMFIS_* values listed below.
73 */
74 
75 typedef int	sfsistat;
76 
77 #if defined(__linux__) && defined(__GNUC__) && defined(__cplusplus) && __GNUC_MINOR__ >= 8
78 # define SM__P(X)	__PMT(X)
79 #else /* __linux__ && __GNUC__ && __cplusplus && _GNUC_MINOR__ >= 8 */
80 # define SM__P(X)	__P(X)
81 #endif /* __linux__ && __GNUC__ && __cplusplus && _GNUC_MINOR__ >= 8 */
82 
83 /* Some platforms don't define __P -- do it for them here: */
84 #ifndef __P
85 # ifdef __STDC__
86 #  define __P(X) X
87 # else /* __STDC__ */
88 #  define __P(X) ()
89 # endif /* __STDC__ */
90 #endif /* __P */
91 
92 #if SM_CONF_STDBOOL_H
93 # include <stdbool.h>
94 #else /* SM_CONF_STDBOOL_H */
95 # ifndef __cplusplus
96 #  ifndef bool
97 #   ifndef __bool_true_false_are_defined
98 typedef int	bool;
99 #    define false	0
100 #    define true	1
101 #    define __bool_true_false_are_defined	1
102 #   endif /* ! __bool_true_false_are_defined */
103 #  endif /* bool */
104 # endif /* ! __cplusplus */
105 #endif /* SM_CONF_STDBOOL_H */
106 
107 /*
108 **  structure describing one milter
109 */
110 
111 struct smfiDesc
112 {
113 	char		*xxfi_name;	/* filter name */
114 	int		xxfi_version;	/* version code -- do not change */
115 	unsigned long	xxfi_flags;	/* flags */
116 
117 	/* connection info filter */
118 	sfsistat	(*xxfi_connect) SM__P((SMFICTX *, char *, _SOCK_ADDR *));
119 
120 	/* SMTP HELO command filter */
121 	sfsistat	(*xxfi_helo) SM__P((SMFICTX *, char *));
122 
123 	/* envelope sender filter */
124 	sfsistat	(*xxfi_envfrom) SM__P((SMFICTX *, char **));
125 
126 	/* envelope recipient filter */
127 	sfsistat	(*xxfi_envrcpt) SM__P((SMFICTX *, char **));
128 
129 	/* header filter */
130 	sfsistat	(*xxfi_header) SM__P((SMFICTX *, char *, char *));
131 
132 	/* end of header */
133 	sfsistat	(*xxfi_eoh) SM__P((SMFICTX *));
134 
135 	/* body block */
136 	sfsistat	(*xxfi_body) SM__P((SMFICTX *, unsigned char *, size_t));
137 
138 	/* end of message */
139 	sfsistat	(*xxfi_eom) SM__P((SMFICTX *));
140 
141 	/* message aborted */
142 	sfsistat	(*xxfi_abort) SM__P((SMFICTX *));
143 
144 	/* connection cleanup */
145 	sfsistat	(*xxfi_close) SM__P((SMFICTX *));
146 
147 	/* any unrecognized or unimplemented command filter */
148 	sfsistat	(*xxfi_unknown) SM__P((SMFICTX *, const char *));
149 
150 	/* SMTP DATA command filter */
151 	sfsistat	(*xxfi_data) SM__P((SMFICTX *));
152 
153 	/* negotiation callback */
154 	sfsistat	(*xxfi_negotiate) SM__P((SMFICTX *,
155 					unsigned long, unsigned long,
156 					unsigned long, unsigned long,
157 					unsigned long *, unsigned long *,
158 					unsigned long *, unsigned long *));
159 
160 #if 0
161 	/* signal handler callback, not yet implemented. */
162 	int		(*xxfi_signal) SM__P((int));
163 #endif
164 
165 };
166 
167 LIBMILTER_API int smfi_opensocket __P((bool));
168 LIBMILTER_API int smfi_register __P((struct smfiDesc));
169 LIBMILTER_API int smfi_main __P((void));
170 LIBMILTER_API int smfi_setbacklog __P((int));
171 LIBMILTER_API int smfi_setdbg __P((int));
172 LIBMILTER_API int smfi_settimeout __P((int));
173 LIBMILTER_API int smfi_setconn __P((char *));
174 LIBMILTER_API int smfi_stop __P((void));
175 LIBMILTER_API size_t smfi_setmaxdatasize __P((size_t));
176 LIBMILTER_API int smfi_version __P((unsigned int *, unsigned int *, unsigned int *));
177 
178 /*
179 **  What the filter might do -- values to be ORed together for
180 **  smfiDesc.xxfi_flags.
181 */
182 
183 #define SMFIF_NONE	0x00000000L	/* no flags */
184 #define SMFIF_ADDHDRS	0x00000001L	/* filter may add headers */
185 #define SMFIF_CHGBODY	0x00000002L	/* filter may replace body */
186 #define SMFIF_MODBODY	SMFIF_CHGBODY	/* backwards compatible */
187 #define SMFIF_ADDRCPT	0x00000004L	/* filter may add recipients */
188 #define SMFIF_DELRCPT	0x00000008L	/* filter may delete recipients */
189 #define SMFIF_CHGHDRS	0x00000010L	/* filter may change/delete headers */
190 #define SMFIF_QUARANTINE 0x00000020L	/* filter may quarantine envelope */
191 
192 /* filter may change "from" (envelope sender) */
193 #define SMFIF_CHGFROM	0x00000040L
194 #define SMFIF_ADDRCPT_PAR	0x00000080L	/* add recipients incl. args */
195 
196 /* filter can send set of symbols (macros) that it wants */
197 #define SMFIF_SETSYMLIST	0x00000100L
198 
199 
200 /*
201 **  Macro "places";
202 **  Notes:
203 **  - must be coordinated with libmilter/engine.c and sendmail/milter.c
204 **  - the order MUST NOT be changed as it would break compatibility between
205 **	different versions. It's ok to append new entries however
206 **	(hence the list is not sorted by the SMT protocol steps).
207 */
208 
209 #define SMFIM_FIRST	0	/* Do NOT use, internal marker only */
210 #define SMFIM_CONNECT	0	/* connect */
211 #define SMFIM_HELO	1	/* HELO/EHLO */
212 #define SMFIM_ENVFROM	2	/* MAIL From */
213 #define SMFIM_ENVRCPT	3	/* RCPT To */
214 #define SMFIM_DATA	4	/* DATA */
215 #define SMFIM_EOM	5	/* end of message (final dot) */
216 #define SMFIM_EOH	6	/* end of header */
217 #define SMFIM_LAST	6	/* Do NOT use, internal marker only */
218 
219 /*
220 **  Continue processing message/connection.
221 */
222 
223 #define SMFIS_CONTINUE	0
224 
225 /*
226 **  Reject the message/connection.
227 **  No further routines will be called for this message
228 **  (or connection, if returned from a connection-oriented routine).
229 */
230 
231 #define SMFIS_REJECT	1
232 
233 /*
234 **  Accept the message,
235 **  but silently discard the message.
236 **  No further routines will be called for this message.
237 **  This is only meaningful from message-oriented routines.
238 */
239 
240 #define SMFIS_DISCARD	2
241 
242 /*
243 **  Accept the message/connection.
244 **  No further routines will be called for this message
245 **  (or connection, if returned from a connection-oriented routine;
246 **  in this case, it causes all messages on this connection
247 **  to be accepted without filtering).
248 */
249 
250 #define SMFIS_ACCEPT	3
251 
252 /*
253 **  Return a temporary failure, i.e.,
254 **  the corresponding SMTP command will return a 4xx status code.
255 **  In some cases this may prevent further routines from
256 **  being called on this message or connection,
257 **  although in other cases (e.g., when processing an envelope
258 **  recipient) processing of the message will continue.
259 */
260 
261 #define SMFIS_TEMPFAIL	4
262 
263 /*
264 **  Do not send a reply to the MTA
265 */
266 
267 #define SMFIS_NOREPLY	7
268 
269 /*
270 **  Skip over rest of same callbacks, e.g., body.
271 */
272 
273 #define SMFIS_SKIP	8
274 
275 /* xxfi_negotiate: use all existing protocol options/actions */
276 #define SMFIS_ALL_OPTS	10
277 
278 #if 0
279 /*
280 **  Filter Routine Details
281 */
282 
283 /* connection info filter */
284 extern sfsistat	xxfi_connect __P((SMFICTX *, char *, _SOCK_ADDR *));
285 
286 /*
287 **  xxfi_connect(ctx, hostname, hostaddr) Invoked on each connection
288 **
289 **	char *hostname; Host domain name, as determined by a reverse lookup
290 **		on the host address.
291 **	_SOCK_ADDR *hostaddr; Host address, as determined by a getpeername
292 **		call on the SMTP socket.
293 */
294 
295 /* SMTP HELO command filter */
296 extern sfsistat	xxfi_helo __P((SMFICTX *, char *));
297 
298 /*
299 **  xxfi_helo(ctx, helohost) Invoked on SMTP HELO/EHLO command
300 **
301 **	char *helohost; Value passed to HELO/EHLO command, which should be
302 **		the domain name of the sending host (but is, in practice,
303 **		anything the sending host wants to send).
304 */
305 
306 /* envelope sender filter */
307 extern sfsistat	xxfi_envfrom __P((SMFICTX *, char **));
308 
309 /*
310 **  xxfi_envfrom(ctx, argv) Invoked on envelope from
311 **
312 **	char **argv; Null-terminated SMTP command arguments;
313 **		argv[0] is guaranteed to be the sender address.
314 **		Later arguments are the ESMTP arguments.
315 */
316 
317 /* envelope recipient filter */
318 extern sfsistat	xxfi_envrcpt __P((SMFICTX *, char **));
319 
320 /*
321 **  xxfi_envrcpt(ctx, argv) Invoked on each envelope recipient
322 **
323 **	char **argv; Null-terminated SMTP command arguments;
324 **		argv[0] is guaranteed to be the recipient address.
325 **		Later arguments are the ESMTP arguments.
326 */
327 
328 /* unknown command filter */
329 
330 extern sfsistat	*xxfi_unknown __P((SMFICTX *, const char *));
331 
332 /*
333 **  xxfi_unknown(ctx, arg) Invoked when SMTP command is not recognized or not
334 **  implemented.
335 **	const char *arg; Null-terminated SMTP command
336 */
337 
338 /* header filter */
339 extern sfsistat	xxfi_header __P((SMFICTX *, char *, char *));
340 
341 /*
342 **  xxfi_header(ctx, headerf, headerv) Invoked on each message header. The
343 **  content of the header may have folded white space (that is, multiple
344 **  lines with following white space) included.
345 **
346 **	char *headerf; Header field name
347 **	char *headerv; Header field value
348 */
349 
350 /* end of header */
351 extern sfsistat	xxfi_eoh __P((SMFICTX *));
352 
353 /*
354 **  xxfi_eoh(ctx) Invoked at end of header
355 */
356 
357 /* body block */
358 extern sfsistat	xxfi_body __P((SMFICTX *, unsigned char *, size_t));
359 
360 /*
361 **  xxfi_body(ctx, bodyp, bodylen) Invoked for each body chunk. There may
362 **  be multiple body chunks passed to the filter. End-of-lines are
363 **  represented as received from SMTP (normally Carriage-Return/Line-Feed).
364 **
365 **	unsigned char *bodyp; Pointer to body data
366 **	size_t bodylen; Length of body data
367 */
368 
369 /* end of message */
370 extern sfsistat	xxfi_eom __P((SMFICTX *));
371 
372 /*
373 **  xxfi_eom(ctx) Invoked at end of message. This routine can perform
374 **  special operations such as modifying the message header, body, or
375 **  envelope.
376 */
377 
378 /* message aborted */
379 extern sfsistat	xxfi_abort __P((SMFICTX *));
380 
381 /*
382 **  xxfi_abort(ctx) Invoked if message is aborted outside of the control of
383 **  the filter, for example, if the SMTP sender issues an RSET command. If
384 **  xxfi_abort is called, xxfi_eom will not be called and vice versa.
385 */
386 
387 /* connection cleanup */
388 extern sfsistat	xxfi_close __P((SMFICTX *));
389 
390 /*
391 **  xxfi_close(ctx) Invoked at end of the connection. This is called on
392 **  close even if the previous mail transaction was aborted.
393 */
394 #endif /* 0 */
395 
396 /*
397 **  Additional information is passed in to the vendor filter routines using
398 **  symbols. Symbols correspond closely to sendmail macros. The symbols
399 **  defined depend on the context. The value of a symbol is accessed using:
400 */
401 
402 /* Return the value of a symbol. */
403 LIBMILTER_API char * smfi_getsymval __P((SMFICTX *, char *));
404 
405 /*
406 **  Return the value of a symbol.
407 **
408 **	SMFICTX *ctx; Opaque context structure
409 **	char *symname; The name of the symbol to access.
410 */
411 
412 /*
413 **  Vendor filter routines that want to pass additional information back to
414 **  the MTA for use in SMTP replies may call smfi_setreply before returning.
415 */
416 
417 LIBMILTER_API int smfi_setreply __P((SMFICTX *, char *, char *, char *));
418 
419 /*
420 **  Alternatively, smfi_setmlreply can be called if a multi-line SMTP reply
421 **  is needed.
422 */
423 
424 LIBMILTER_API int smfi_setmlreply __P((SMFICTX *, const char *, const char *, ...));
425 
426 /*
427 **  Set the specific reply code to be used in response to the active
428 **  command. If not specified, a generic reply code is used.
429 **
430 **	SMFICTX *ctx; Opaque context structure
431 **	char *rcode; The three-digit (RFC 821) SMTP reply code to be
432 **		returned, e.g., ``551''.
433 **	char *xcode; The extended (RFC 2034) reply code, e.g., ``5.7.6''.
434 **	char *message; The text part of the SMTP reply.
435 */
436 
437 /*
438 **  The xxfi_eom routine is called at the end of a message (essentially,
439 **  after the final DATA dot). This routine can call some special routines
440 **  to modify the envelope, header, or body of the message before the
441 **  message is enqueued. These routines must not be called from any vendor
442 **  routine other than xxfi_eom.
443 */
444 
445 LIBMILTER_API int smfi_addheader __P((SMFICTX *, char *, char *));
446 
447 /*
448 **  Add a header to the message. It is not checked for standards
449 **  compliance; the mail filter must ensure that no protocols are violated
450 **  as a result of adding this header.
451 **
452 **	SMFICTX *ctx; Opaque context structure
453 **	char *headerf; Header field name
454 **	char *headerv; Header field value
455 */
456 
457 LIBMILTER_API int smfi_chgheader __P((SMFICTX *, char *, int, char *));
458 
459 /*
460 **  Change/delete a header in the message.  It is not checked for standards
461 **  compliance; the mail filter must ensure that no protocols are violated
462 **  as a result of adding this header.
463 **
464 **	SMFICTX *ctx; Opaque context structure
465 **	char *headerf; Header field name
466 **	int index; The Nth occurence of header field name
467 **	char *headerv; New header field value (empty for delete header)
468 */
469 
470 LIBMILTER_API int smfi_insheader __P((SMFICTX *, int, char *, char *));
471 
472 /*
473 **  Insert a header into the message.  It is not checked for standards
474 **  compliance; the mail filter must ensure that no protocols are violated
475 **  as a result of adding this header.
476 **
477 **	SMFICTX *ctx; Opaque context structure
478 **  	int idx; index into the header list where the insertion should happen
479 **	char *headerh; Header field name
480 **	char *headerv; Header field value
481 */
482 
483 LIBMILTER_API int smfi_chgfrom __P((SMFICTX *, char *, char *));
484 
485 /*
486 **  Modify envelope sender address
487 **
488 **	SMFICTX *ctx; Opaque context structure
489 **	char *mail; New envelope sender address
490 **	char *args; ESMTP arguments
491 */
492 
493 
494 LIBMILTER_API int smfi_addrcpt __P((SMFICTX *, char *));
495 
496 /*
497 **  Add a recipient to the envelope
498 **
499 **	SMFICTX *ctx; Opaque context structure
500 **	char *rcpt; Recipient to be added
501 */
502 
503 LIBMILTER_API int smfi_addrcpt_par __P((SMFICTX *, char *, char *));
504 
505 /*
506 **  Add a recipient to the envelope
507 **
508 **	SMFICTX *ctx; Opaque context structure
509 **	char *rcpt; Recipient to be added
510 **	char *args; ESMTP arguments
511 */
512 
513 
514 LIBMILTER_API int smfi_delrcpt __P((SMFICTX *, char *));
515 
516 /*
517 **  Send a "no-op" up to the MTA to tell it we're still alive, so long
518 **  milter-side operations don't time out.
519 **
520 **	SMFICTX *ctx; Opaque context structure
521 */
522 
523 LIBMILTER_API int smfi_progress __P((SMFICTX *));
524 
525 /*
526 **  Delete a recipient from the envelope
527 **
528 **	SMFICTX *ctx; Opaque context structure
529 **	char *rcpt; Envelope recipient to be deleted. This should be in
530 **		exactly the form passed to xxfi_envrcpt or the address may
531 **		not be deleted.
532 */
533 
534 LIBMILTER_API int smfi_replacebody __P((SMFICTX *, unsigned char *, int));
535 
536 /*
537 **  Replace the body of the message. This routine may be called multiple
538 **  times if the body is longer than convenient to send in one call. End of
539 **  line should be represented as Carriage-Return/Line Feed.
540 **
541 **	char *bodyp; Pointer to block of body information to insert
542 **	int bodylen; Length of data pointed at by bodyp
543 */
544 
545 /*
546 **  If the message is aborted (for example, if the SMTP sender sends the
547 **  envelope but then does a QUIT or RSET before the data is sent),
548 **  xxfi_abort is called. This can be used to reset state.
549 */
550 
551 /*
552 **  Quarantine an envelope
553 **
554 **	SMFICTX *ctx; Opaque context structure
555 **	char *reason: explanation
556 */
557 
558 LIBMILTER_API int smfi_quarantine __P((SMFICTX *ctx, char *reason));
559 
560 /*
561 **  Connection-private data (specific to an SMTP connection) can be
562 **  allocated using the smfi_setpriv routine; routines can access private
563 **  data using smfi_getpriv.
564 */
565 
566 LIBMILTER_API int smfi_setpriv __P((SMFICTX *, void *));
567 
568 /*
569 **  Set the private data pointer
570 **
571 **	SMFICTX *ctx; Opaque context structure
572 **	void *privatedata; Pointer to private data area
573 */
574 
575 LIBMILTER_API void *smfi_getpriv __P((SMFICTX *));
576 
577 /*
578 **  Get the private data pointer
579 **
580 **	SMFICTX *ctx; Opaque context structure
581 **	void *privatedata; Pointer to private data area
582 */
583 
584 LIBMILTER_API int smfi_setsymlist __P((SMFICTX *, int, char *));
585 
586 /*
587 **  Set list of symbols (macros) to receive
588 **
589 **	SMFICTX *ctx; Opaque context structure
590 **	int where; where in the SMTP dialogue should the macros be sent
591 **	char *macros; list of macros (space separated)
592 */
593 
594 #if _FFR_THREAD_MONITOR
595 LIBMILTER_API int smfi_set_max_exec_time __P((unsigned int));
596 #endif /* _FFR_THREAD_MONITOR */
597 
598 #ifdef __cplusplus
599 }
600 #endif /* __cplusplus */
601 
602 #endif /* ! _LIBMILTER_MFAPI_H */
603