xref: /freebsd/contrib/sendmail/include/libmilter/mfapi.h (revision 2fb4f839f3fc72ce2bab12f9ba4760f97f73e97f)
1 /*
2  * Copyright (c) 1999-2004, 2006, 2008, 2012 Proofpoint, 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 8.83 2013-11-22 20:51:27 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
47 
48 #ifndef _SOCK_ADDR
49 # define _SOCK_ADDR	struct sockaddr
50 #endif
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
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
80 # define SM__P(X)	__P(X)
81 #endif
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
88 #  define __P(X) ()
89 # endif
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_NOMACROS	(-1)	/* Do NOT use, internal only */
210 #define SMFIM_FIRST	0	/* Do NOT use, internal marker only */
211 #define SMFIM_CONNECT	0	/* connect */
212 #define SMFIM_HELO	1	/* HELO/EHLO */
213 #define SMFIM_ENVFROM	2	/* MAIL From */
214 #define SMFIM_ENVRCPT	3	/* RCPT To */
215 #define SMFIM_DATA	4	/* DATA */
216 #define SMFIM_EOM	5	/* end of message (final dot) */
217 #define SMFIM_EOH	6	/* end of header */
218 #define SMFIM_LAST	6	/* Do NOT use, internal marker only */
219 
220 /*
221 **  Continue processing message/connection.
222 */
223 
224 #define SMFIS_CONTINUE	0
225 
226 /*
227 **  Reject the message/connection.
228 **  No further routines will be called for this message
229 **  (or connection, if returned from a connection-oriented routine).
230 */
231 
232 #define SMFIS_REJECT	1
233 
234 /*
235 **  Accept the message,
236 **  but silently discard the message.
237 **  No further routines will be called for this message.
238 **  This is only meaningful from message-oriented routines.
239 */
240 
241 #define SMFIS_DISCARD	2
242 
243 /*
244 **  Accept the message/connection.
245 **  No further routines will be called for this message
246 **  (or connection, if returned from a connection-oriented routine;
247 **  in this case, it causes all messages on this connection
248 **  to be accepted without filtering).
249 */
250 
251 #define SMFIS_ACCEPT	3
252 
253 /*
254 **  Return a temporary failure, i.e.,
255 **  the corresponding SMTP command will return a 4xx status code.
256 **  In some cases this may prevent further routines from
257 **  being called on this message or connection,
258 **  although in other cases (e.g., when processing an envelope
259 **  recipient) processing of the message will continue.
260 */
261 
262 #define SMFIS_TEMPFAIL	4
263 
264 /*
265 **  Do not send a reply to the MTA
266 */
267 
268 #define SMFIS_NOREPLY	7
269 
270 /*
271 **  Skip over rest of same callbacks, e.g., body.
272 */
273 
274 #define SMFIS_SKIP	8
275 
276 /* xxfi_negotiate: use all existing protocol options/actions */
277 #define SMFIS_ALL_OPTS	10
278 
279 #if 0
280 /*
281 **  Filter Routine Details
282 */
283 
284 /* connection info filter */
285 extern sfsistat	xxfi_connect __P((SMFICTX *, char *, _SOCK_ADDR *));
286 
287 /*
288 **  xxfi_connect(ctx, hostname, hostaddr) Invoked on each connection
289 **
290 **	char *hostname; Host domain name, as determined by a reverse lookup
291 **		on the host address.
292 **	_SOCK_ADDR *hostaddr; Host address, as determined by a getpeername
293 **		call on the SMTP socket.
294 */
295 
296 /* SMTP HELO command filter */
297 extern sfsistat	xxfi_helo __P((SMFICTX *, char *));
298 
299 /*
300 **  xxfi_helo(ctx, helohost) Invoked on SMTP HELO/EHLO command
301 **
302 **	char *helohost; Value passed to HELO/EHLO command, which should be
303 **		the domain name of the sending host (but is, in practice,
304 **		anything the sending host wants to send).
305 */
306 
307 /* envelope sender filter */
308 extern sfsistat	xxfi_envfrom __P((SMFICTX *, char **));
309 
310 /*
311 **  xxfi_envfrom(ctx, argv) Invoked on envelope from
312 **
313 **	char **argv; Null-terminated SMTP command arguments;
314 **		argv[0] is guaranteed to be the sender address.
315 **		Later arguments are the ESMTP arguments.
316 */
317 
318 /* envelope recipient filter */
319 extern sfsistat	xxfi_envrcpt __P((SMFICTX *, char **));
320 
321 /*
322 **  xxfi_envrcpt(ctx, argv) Invoked on each envelope recipient
323 **
324 **	char **argv; Null-terminated SMTP command arguments;
325 **		argv[0] is guaranteed to be the recipient address.
326 **		Later arguments are the ESMTP arguments.
327 */
328 
329 /* unknown command filter */
330 
331 extern sfsistat	*xxfi_unknown __P((SMFICTX *, const char *));
332 
333 /*
334 **  xxfi_unknown(ctx, arg) Invoked when SMTP command is not recognized or not
335 **  implemented.
336 **	const char *arg; Null-terminated SMTP command
337 */
338 
339 /* header filter */
340 extern sfsistat	xxfi_header __P((SMFICTX *, char *, char *));
341 
342 /*
343 **  xxfi_header(ctx, headerf, headerv) Invoked on each message header. The
344 **  content of the header may have folded white space (that is, multiple
345 **  lines with following white space) included.
346 **
347 **	char *headerf; Header field name
348 **	char *headerv; Header field value
349 */
350 
351 /* end of header */
352 extern sfsistat	xxfi_eoh __P((SMFICTX *));
353 
354 /*
355 **  xxfi_eoh(ctx) Invoked at end of header
356 */
357 
358 /* body block */
359 extern sfsistat	xxfi_body __P((SMFICTX *, unsigned char *, size_t));
360 
361 /*
362 **  xxfi_body(ctx, bodyp, bodylen) Invoked for each body chunk. There may
363 **  be multiple body chunks passed to the filter. End-of-lines are
364 **  represented as received from SMTP (normally Carriage-Return/Line-Feed).
365 **
366 **	unsigned char *bodyp; Pointer to body data
367 **	size_t bodylen; Length of body data
368 */
369 
370 /* end of message */
371 extern sfsistat	xxfi_eom __P((SMFICTX *));
372 
373 /*
374 **  xxfi_eom(ctx) Invoked at end of message. This routine can perform
375 **  special operations such as modifying the message header, body, or
376 **  envelope.
377 */
378 
379 /* message aborted */
380 extern sfsistat	xxfi_abort __P((SMFICTX *));
381 
382 /*
383 **  xxfi_abort(ctx) Invoked if message is aborted outside of the control of
384 **  the filter, for example, if the SMTP sender issues an RSET command. If
385 **  xxfi_abort is called, xxfi_eom will not be called and vice versa.
386 */
387 
388 /* connection cleanup */
389 extern sfsistat	xxfi_close __P((SMFICTX *));
390 
391 /*
392 **  xxfi_close(ctx) Invoked at end of the connection. This is called on
393 **  close even if the previous mail transaction was aborted.
394 */
395 #endif /* 0 */
396 
397 /*
398 **  Additional information is passed in to the vendor filter routines using
399 **  symbols. Symbols correspond closely to sendmail macros. The symbols
400 **  defined depend on the context. The value of a symbol is accessed using:
401 */
402 
403 /* Return the value of a symbol. */
404 LIBMILTER_API char * smfi_getsymval __P((SMFICTX *, char *));
405 
406 /*
407 **  Return the value of a symbol.
408 **
409 **	SMFICTX *ctx; Opaque context structure
410 **	char *symname; The name of the symbol to access.
411 */
412 
413 /*
414 **  Vendor filter routines that want to pass additional information back to
415 **  the MTA for use in SMTP replies may call smfi_setreply before returning.
416 */
417 
418 LIBMILTER_API int smfi_setreply __P((SMFICTX *, char *, char *, char *));
419 
420 /*
421 **  Alternatively, smfi_setmlreply can be called if a multi-line SMTP reply
422 **  is needed.
423 */
424 
425 LIBMILTER_API int smfi_setmlreply __P((SMFICTX *, const char *, const char *, ...));
426 
427 /*
428 **  Set the specific reply code to be used in response to the active
429 **  command. If not specified, a generic reply code is used.
430 **
431 **	SMFICTX *ctx; Opaque context structure
432 **	char *rcode; The three-digit (RFC 821) SMTP reply code to be
433 **		returned, e.g., ``551''.
434 **	char *xcode; The extended (RFC 2034) reply code, e.g., ``5.7.6''.
435 **	char *message; The text part of the SMTP reply.
436 */
437 
438 /*
439 **  The xxfi_eom routine is called at the end of a message (essentially,
440 **  after the final DATA dot). This routine can call some special routines
441 **  to modify the envelope, header, or body of the message before the
442 **  message is enqueued. These routines must not be called from any vendor
443 **  routine other than xxfi_eom.
444 */
445 
446 LIBMILTER_API int smfi_addheader __P((SMFICTX *, char *, char *));
447 
448 /*
449 **  Add a header to the message. It is not checked for standards
450 **  compliance; the mail filter must ensure that no protocols are violated
451 **  as a result of adding this header.
452 **
453 **	SMFICTX *ctx; Opaque context structure
454 **	char *headerf; Header field name
455 **	char *headerv; Header field value
456 */
457 
458 LIBMILTER_API int smfi_chgheader __P((SMFICTX *, char *, int, char *));
459 
460 /*
461 **  Change/delete a header in the message.  It is not checked for standards
462 **  compliance; the mail filter must ensure that no protocols are violated
463 **  as a result of adding this header.
464 **
465 **	SMFICTX *ctx; Opaque context structure
466 **	char *headerf; Header field name
467 **	int index; The Nth occurrence of header field name
468 **	char *headerv; New header field value (empty for delete header)
469 */
470 
471 LIBMILTER_API int smfi_insheader __P((SMFICTX *, int, char *, char *));
472 
473 /*
474 **  Insert a header into the message.  It is not checked for standards
475 **  compliance; the mail filter must ensure that no protocols are violated
476 **  as a result of adding this header.
477 **
478 **	SMFICTX *ctx; Opaque context structure
479 **	int idx; index into the header list where the insertion should happen
480 **	char *headerh; Header field name
481 **	char *headerv; Header field value
482 */
483 
484 LIBMILTER_API int smfi_chgfrom __P((SMFICTX *, char *, char *));
485 
486 /*
487 **  Modify envelope sender address
488 **
489 **	SMFICTX *ctx; Opaque context structure
490 **	char *mail; New envelope sender address
491 **	char *args; ESMTP arguments
492 */
493 
494 
495 LIBMILTER_API int smfi_addrcpt __P((SMFICTX *, char *));
496 
497 /*
498 **  Add a recipient to the envelope
499 **
500 **	SMFICTX *ctx; Opaque context structure
501 **	char *rcpt; Recipient to be added
502 */
503 
504 LIBMILTER_API int smfi_addrcpt_par __P((SMFICTX *, char *, char *));
505 
506 /*
507 **  Add a recipient to the envelope
508 **
509 **	SMFICTX *ctx; Opaque context structure
510 **	char *rcpt; Recipient to be added
511 **	char *args; ESMTP arguments
512 */
513 
514 
515 LIBMILTER_API int smfi_delrcpt __P((SMFICTX *, char *));
516 
517 /*
518 **  Send a "no-op" up to the MTA to tell it we're still alive, so long
519 **  milter-side operations don't time out.
520 **
521 **	SMFICTX *ctx; Opaque context structure
522 */
523 
524 LIBMILTER_API int smfi_progress __P((SMFICTX *));
525 
526 /*
527 **  Delete a recipient from the envelope
528 **
529 **	SMFICTX *ctx; Opaque context structure
530 **	char *rcpt; Envelope recipient to be deleted. This should be in
531 **		exactly the form passed to xxfi_envrcpt or the address may
532 **		not be deleted.
533 */
534 
535 LIBMILTER_API int smfi_replacebody __P((SMFICTX *, unsigned char *, int));
536 
537 /*
538 **  Replace the body of the message. This routine may be called multiple
539 **  times if the body is longer than convenient to send in one call. End of
540 **  line should be represented as Carriage-Return/Line Feed.
541 **
542 **	char *bodyp; Pointer to block of body information to insert
543 **	int bodylen; Length of data pointed at by bodyp
544 */
545 
546 /*
547 **  If the message is aborted (for example, if the SMTP sender sends the
548 **  envelope but then does a QUIT or RSET before the data is sent),
549 **  xxfi_abort is called. This can be used to reset state.
550 */
551 
552 /*
553 **  Quarantine an envelope
554 **
555 **	SMFICTX *ctx; Opaque context structure
556 **	char *reason: explanation
557 */
558 
559 LIBMILTER_API int smfi_quarantine __P((SMFICTX *ctx, char *reason));
560 
561 /*
562 **  Connection-private data (specific to an SMTP connection) can be
563 **  allocated using the smfi_setpriv routine; routines can access private
564 **  data using smfi_getpriv.
565 */
566 
567 LIBMILTER_API int smfi_setpriv __P((SMFICTX *, void *));
568 
569 /*
570 **  Set the private data pointer
571 **
572 **	SMFICTX *ctx; Opaque context structure
573 **	void *privatedata; Pointer to private data area
574 */
575 
576 LIBMILTER_API void *smfi_getpriv __P((SMFICTX *));
577 
578 /*
579 **  Get the private data pointer
580 **
581 **	SMFICTX *ctx; Opaque context structure
582 **	void *privatedata; Pointer to private data area
583 */
584 
585 LIBMILTER_API int smfi_setsymlist __P((SMFICTX *, int, char *));
586 
587 /*
588 **  Set list of symbols (macros) to receive
589 **
590 **	SMFICTX *ctx; Opaque context structure
591 **	int where; where in the SMTP dialogue should the macros be sent
592 **	char *macros; list of macros (space separated)
593 */
594 
595 #if _FFR_THREAD_MONITOR
596 LIBMILTER_API int smfi_set_max_exec_time __P((unsigned int));
597 #endif
598 
599 #ifdef __cplusplus
600 }
601 #endif
602 
603 #endif /* ! _LIBMILTER_MFAPI_H */
604