xref: /freebsd/contrib/sendmail/include/libmilter/mfapi.h (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
1 /*
2  * Copyright (c) 1999-2000 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 8.13.4.12 2000/09/09 02:11:48 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 # define LIBMILTER_API		extern
21 
22 
23 # include <sys/types.h>
24 
25 #ifndef _SOCK_ADDR
26 # include <sys/socket.h>
27 # define _SOCK_ADDR	struct sockaddr
28 #endif /* ! _SOCK_ADDR */
29 
30 /*
31 **  libmilter functions return one of the following to indicate
32 **  success/failure:
33 */
34 
35 #define MI_SUCCESS	0
36 #define MI_FAILURE	(-1)
37 
38 /* "forward" declarations */
39 typedef struct smfi_str SMFICTX;
40 typedef struct smfi_str *SMFICTX_PTR;
41 
42 typedef struct smfiDesc smfiDesc_str;
43 typedef struct smfiDesc	*smfiDesc_ptr;
44 
45 #define SMFI_VERSION	2		/* version number */
46 
47 /*
48 **  What the filter might do -- values to be ORed together for
49 **  smfiDesc.xxfi_flags.
50 */
51 
52 #define SMFIF_ADDHDRS	0x00000001L	/* filter may add headers */
53 #define SMFIF_CHGBODY	0x00000002L	/* filter may replace body */
54 #define SMFIF_MODBODY	SMFIF_CHGBODY	/* backwards compatible */
55 #define SMFIF_ADDRCPT	0x00000004L	/* filter may add recipients */
56 #define SMFIF_DELRCPT	0x00000008L	/* filter may delete recipients */
57 #define SMFIF_CHGHDRS	0x00000010L	/* filter may change/delete headers */
58 
59 #define SMFI_V1_ACTS	0x0000000FL	/* The actions of V1 filter */
60 #define SMFI_V2_ACTS	0x0000001FL	/* The actions of V2 filter */
61 #define SMFI_CURR_ACTS	SMFI_V2_ACTS	/* The current version */
62 
63 /*
64 **  Type which callbacks should return to indicate message status.
65 **  This may take on one of the SMFIS_* values listed below.
66 */
67 
68 typedef int	sfsistat;
69 
70 /*
71 **  structure describing one milter
72 */
73 
74 #if defined(__linux__) && defined(__GNUC__) && defined(__cplusplus) && __GNUC_MINOR__ >= 8
75 # define SM__P(X)	__PMT(X)
76 #else /* __linux__ && __GNUC__ && __cplusplus && _GNUC_MINOR__ >= 8 */
77 # define SM__P(X)	__P(X)
78 #endif /* __linux__ && __GNUC__ && __cplusplus && _GNUC_MINOR__ >= 8 */
79 
80 /* Some platforms don't define __P -- do it for them here: */
81 #ifndef __P
82 # ifdef __STDC__
83 #  define __P(X) X
84 # else /* __STDC__ */
85 #  define __P(X) ()
86 # endif /* __STDC__ */
87 #endif /* __P */
88 
89 struct smfiDesc
90 {
91 	char		*xxfi_name;	/* filter name */
92 	int		xxfi_version;	/* version code -- do not change */
93 	u_long		xxfi_flags;	/* flags */
94 
95 	/* connection info filter */
96 	sfsistat	(*xxfi_connect) SM__P((SMFICTX *, char *, _SOCK_ADDR *));
97 
98 	/* SMTP HELO command filter */
99 	sfsistat	(*xxfi_helo) SM__P((SMFICTX *, char *));
100 
101 	/* envelope sender filter */
102 	sfsistat	(*xxfi_envfrom) SM__P((SMFICTX *, char **));
103 
104 	/* envelope recipient filter */
105 	sfsistat	(*xxfi_envrcpt) SM__P((SMFICTX *, char **));
106 
107 	/* header filter */
108 	sfsistat	(*xxfi_header) SM__P((SMFICTX *, char *, char *));
109 
110 	/* end of header */
111 	sfsistat	(*xxfi_eoh) SM__P((SMFICTX *));
112 
113 	/* body block */
114 	sfsistat	(*xxfi_body) SM__P((SMFICTX *, u_char *, size_t));
115 
116 	/* end of message */
117 	sfsistat	(*xxfi_eom) SM__P((SMFICTX *));
118 
119 	/* message aborted */
120 	sfsistat	(*xxfi_abort) SM__P((SMFICTX *));
121 
122 	/* connection cleanup */
123 	sfsistat	(*xxfi_close) SM__P((SMFICTX *));
124 };
125 
126 LIBMILTER_API int smfi_register __P((struct smfiDesc));
127 LIBMILTER_API int smfi_main __P((void));
128 LIBMILTER_API int smfi_setdbg __P((int));
129 LIBMILTER_API int smfi_settimeout __P((int));
130 LIBMILTER_API int smfi_setconn __P((char *));
131 LIBMILTER_API int smfi_stop __P((void));
132 
133 /*
134 **  Continue processing message/connection.
135 */
136 
137 #define SMFIS_CONTINUE	0
138 
139 /*
140 **  Reject the message/connection.
141 **  No further routines will be called for this message
142 **  (or connection, if returned from a connection-oriented routine).
143 */
144 
145 #define SMFIS_REJECT	1
146 
147 /*
148 **  Accept the message,
149 **  but silently discard the message.
150 **  No further routines will be called for this message.
151 **  This is only meaningful from message-oriented routines.
152 */
153 
154 #define SMFIS_DISCARD	2
155 
156 /*
157 **  Accept the message/connection.
158 **  No further routines will be called for this message
159 **  (or connection, if returned from a connection-oriented routine;
160 **  in this case, it causes all messages on this connection
161 **  to be accepted without filtering).
162 */
163 
164 #define SMFIS_ACCEPT	3
165 
166 /*
167 **  Return a temporary failure, i.e.,
168 **  the corresponding SMTP command will return a 4xx status code.
169 **  In some cases this may prevent further routines from
170 **  being called on this message or connection,
171 **  although in other cases (e.g., when processing an envelope
172 **  recipient) processing of the message will continue.
173 */
174 
175 #define SMFIS_TEMPFAIL	4
176 
177 #if 0
178 /*
179 **  Filter Routine Details
180 */
181 
182 /* connection info filter */
183 extern sfsistat	xxfi_connect __P((SMFICTX *, char *, _SOCK_ADDR *));
184 
185 /*
186 **  xxfi_connect(ctx, hostname, hostaddr) Invoked on each connection
187 **
188 **	char *hostname; Host domain name, as determined by a reverse lookup
189 **		on the host address.
190 **	_SOCK_ADDR *hostaddr; Host address, as determined by a getpeername
191 **		call on the SMTP socket.
192 */
193 
194 /* SMTP HELO command filter */
195 extern sfsistat	xxfi_helo __P((SMFICTX *, char *));
196 
197 /*
198 **  xxfi_helo(ctx, helohost) Invoked on SMTP HELO/EHLO command
199 **
200 **	char *helohost; Value passed to HELO/EHLO command, which should be
201 **		the domain name of the sending host (but is, in practice,
202 **		anything the sending host wants to send).
203 */
204 
205 /* envelope sender filter */
206 extern sfsistat	xxfi_envfrom __P((SMFICTX *, char **));
207 
208 /*
209 **  xxfi_envfrom(ctx, argv) Invoked on envelope from
210 **
211 **	char **argv; Null-terminated SMTP command arguments;
212 **		argv[0] is guaranteed to be the sender address.
213 **		Later arguments are the ESMTP arguments.
214 */
215 
216 /* envelope recipient filter */
217 extern sfsistat	xxfi_envrcpt __P((SMFICTX *, char **));
218 
219 /*
220 **  xxfi_envrcpt(ctx, argv) Invoked on each envelope recipient
221 **
222 **	char **argv; Null-terminated SMTP command arguments;
223 **		argv[0] is guaranteed to be the recipient address.
224 **		Later arguments are the ESMTP arguments.
225 */
226 
227 /* header filter */
228 extern sfsistat	xxfi_header __P((SMFICTX *, char *, char *));
229 
230 /*
231 **  xxfi_header(ctx, headerf, headerv) Invoked on each message header. The
232 **  content of the header may have folded white space (that is, multiple
233 **  lines with following white space) included.
234 **
235 **	char *headerf; Header field name
236 **	char *headerv; Header field value
237 */
238 
239 /* end of header */
240 extern sfsistat	xxfi_eoh __P((SMFICTX *));
241 
242 /*
243 **  xxfi_eoh(ctx) Invoked at end of header
244 */
245 
246 /* body block */
247 extern sfsistat	xxfi_body __P((SMFICTX *, u_char *, size_t));
248 
249 /*
250 **  xxfi_body(ctx, bodyp, bodylen) Invoked for each body chunk. There may
251 **  be multiple body chunks passed to the filter. End-of-lines are
252 **  represented as received from SMTP (normally Carriage-Return/Line-Feed).
253 **
254 **	u_char *bodyp; Pointer to body data
255 **	size_t bodylen; Length of body data
256 */
257 
258 /* end of message */
259 extern sfsistat	xxfi_eom __P((SMFICTX *));
260 
261 /*
262 **  xxfi_eom(ctx) Invoked at end of message. This routine can perform
263 **  special operations such as modifying the message header, body, or
264 **  envelope.
265 */
266 
267 /* message aborted */
268 extern sfsistat	xxfi_abort __P((SMFICTX *));
269 
270 /*
271 **  xxfi_abort(ctx) Invoked if message is aborted outside of the control of
272 **  the filter, for example, if the SMTP sender issues an RSET command. If
273 **  xxfi_abort is called, xxfi_eom will not be called and vice versa.
274 */
275 
276 /* connection cleanup */
277 extern sfsistat	xxfi_close __P((SMFICTX *));
278 
279 /*
280 **  xxfi_close(ctx) Invoked at end of the connection. This is called on
281 **  close even if the previous mail transaction was aborted.
282 */
283 #endif /* 0 */
284 
285 /*
286 **  Additional information is passed in to the vendor filter routines using
287 **  symbols. Symbols correspond closely to sendmail macros. The symbols
288 **  defined depend on the context. The value of a symbol is accessed using:
289 */
290 
291 /* Return the value of a symbol. */
292 LIBMILTER_API char * smfi_getsymval __P((SMFICTX *, char *));
293 
294 /*
295 **  Return the value of a symbol.
296 **
297 **	SMFICTX *ctx; Opaque context structure
298 **	char *symname; The name of the symbol to access.
299 */
300 
301 /*
302 **  Vendor filter routines that want to pass additional information back to
303 **  the MTA for use in SMTP replies may call smfi_setreply before returning.
304 */
305 
306 LIBMILTER_API int smfi_setreply __P((SMFICTX *, char *, char *, char *));
307 
308 /*
309 **  Set the specific reply code to be used in response to the active
310 **  command. If not specified, a generic reply code is used.
311 **
312 **	SMFICTX *ctx; Opaque context structure
313 **	char *rcode; The three-digit (RFC 821) SMTP reply code to be
314 **		returned, e.g., ``551''.
315 **	char *xcode; The extended (RFC 2034) reply code, e.g., ``5.7.6''.
316 **	char *message; The text part of the SMTP reply.
317 */
318 
319 /*
320 **  The xxfi_eom routine is called at the end of a message (essentially,
321 **  after the final DATA dot). This routine can call some special routines
322 **  to modify the envelope, header, or body of the message before the
323 **  message is enqueued. These routines must not be called from any vendor
324 **  routine other than xxfi_eom.
325 */
326 
327 LIBMILTER_API int smfi_addheader __P((SMFICTX *, char *, char *));
328 
329 /*
330 **  Add a header to the message. This header is not passed to other
331 **  filters. It is not checked for standards compliance; the mail filter
332 **  must ensure that no protocols are violated as a result of adding this
333 **  header.
334 **
335 **	SMFICTX *ctx; Opaque context structure
336 **	char *headerf; Header field name
337 **	char *headerv; Header field value
338 */
339 
340 LIBMILTER_API int smfi_chgheader __P((SMFICTX *, char *, int, char *));
341 
342 /*
343 **  Change/delete a header in the message.  It is not checked for standards
344 **  compliance; the mail filter must ensure that no protocols are violated
345 **  as a result of adding this header.
346 **
347 **	SMFICTX *ctx; Opaque context structure
348 **	char *headerf; Header field name
349 **	int index; The Nth occurence of header field name
350 **	char *headerv; New header field value (empty for delete header)
351 */
352 
353 LIBMILTER_API int smfi_addrcpt __P((SMFICTX *, char *));
354 
355 /*
356 **  Add a recipient to the envelope
357 **
358 **	SMFICTX *ctx; Opaque context structure
359 **	char *rcpt; Recipient to be added
360 */
361 
362 LIBMILTER_API int smfi_delrcpt __P((SMFICTX *, char *));
363 
364 /*
365 **  Delete a recipient from the envelope
366 **
367 **	SMFICTX *ctx; Opaque context structure
368 **	char *rcpt; Envelope recipient to be deleted. This should be in
369 **		exactly the form passed to xxfi_envrcpt or the address may
370 **		not be deleted.
371 */
372 
373 LIBMILTER_API int smfi_replacebody __P((SMFICTX *, u_char *, int));
374 
375 /*
376 **  Replace the body of the message. This routine may be called multiple
377 **  times if the body is longer than convenient to send in one call. End of
378 **  line should be represented as Carriage-Return/Line Feed.
379 **
380 **	char *bodyp; Pointer to block of body information to insert
381 **	int bodylen; Length of data pointed at by bodyp
382 */
383 
384 /*
385 **  If the message is aborted (for example, if the SMTP sender sends the
386 **  envelope but then does a QUIT or RSET before the data is sent),
387 **  xxfi_abort is called. This can be used to reset state.
388 */
389 
390 
391 /*
392 **  Connection-private data (specific to an SMTP connection) can be
393 **  allocated using the smfi_setpriv routine; routines can access private
394 **  data using smfi_getpriv.
395 */
396 
397 LIBMILTER_API int smfi_setpriv __P((SMFICTX *, void *));
398 
399 /*
400 **  Set the private data pointer
401 **
402 **	SMFICTX *ctx; Opaque context structure
403 **	void *privatedata; Pointer to private data area
404 */
405 
406 LIBMILTER_API void *smfi_getpriv __P((SMFICTX *));
407 
408 
409 #endif /* !_LIBMILTER_MFAPI_H */
410