xref: /netbsd-src/external/ibm-public/postfix/dist/src/qmgr/qmgr_deliver.c (revision c505c4429840c353a86d4eb53b5e2bfc0092264e)
1 /*	$NetBSD: qmgr_deliver.c,v 1.1.1.1 2009/06/23 10:08:52 tron Exp $	*/
2 
3 /*++
4 /* NAME
5 /*	qmgr_deliver 3
6 /* SUMMARY
7 /*	deliver one per-site queue entry to that site
8 /* SYNOPSIS
9 /*	#include "qmgr.h"
10 /*
11 /*	int	qmgr_deliver_concurrency;
12 /*
13 /*	int	qmgr_deliver(transport, fp)
14 /*	QMGR_TRANSPORT *transport;
15 /*	VSTREAM	*fp;
16 /* DESCRIPTION
17 /*	This module implements the client side of the `queue manager
18 /*	to delivery agent' protocol. The queue manager uses
19 /*	asynchronous I/O so that it can drive multiple delivery
20 /*	agents in parallel. Depending on the outcome of a delivery
21 /*	attempt, the status of messages, queues and transports is
22 /*	updated.
23 /*
24 /*	qmgr_deliver_concurrency is a global counter that says how
25 /*	many delivery processes are in use. This can be used, for
26 /*	example, to control the size of the `active' message queue.
27 /*
28 /*	qmgr_deliver() executes when a delivery process announces its
29 /*	availability for the named transport. It arranges for delivery
30 /*	of a suitable queue entry.  The \fIfp\fR argument specifies a
31 /*	stream that is connected to a delivery process, or a null
32 /*	pointer if the transport accepts no connection. Upon completion
33 /*	of delivery (successful or not), the stream is closed, so that the
34 /*	delivery process is released.
35 /* DIAGNOSTICS
36 /* LICENSE
37 /* .ad
38 /* .fi
39 /*	The Secure Mailer license must be distributed with this software.
40 /* AUTHOR(S)
41 /*	Wietse Venema
42 /*	IBM T.J. Watson Research
43 /*	P.O. Box 704
44 /*	Yorktown Heights, NY 10598, USA
45 /*
46 /*	Preemptive scheduler enhancements:
47 /*	Patrik Rak
48 /*	Modra 6
49 /*	155 00, Prague, Czech Republic
50 /*--*/
51 
52 /* System library. */
53 
54 #include <sys_defs.h>
55 #include <time.h>
56 #include <string.h>
57 
58 /* Utility library. */
59 
60 #include <msg.h>
61 #include <vstring.h>
62 #include <vstream.h>
63 #include <vstring_vstream.h>
64 #include <events.h>
65 #include <iostuff.h>
66 #include <stringops.h>
67 #include <mymalloc.h>
68 
69 /* Global library. */
70 
71 #include <mail_queue.h>
72 #include <mail_proto.h>
73 #include <recipient_list.h>
74 #include <mail_params.h>
75 #include <deliver_request.h>
76 #include <verp_sender.h>
77 #include <dsn_util.h>
78 #include <dsn_buf.h>
79 #include <dsb_scan.h>
80 #include <rcpt_print.h>
81 
82 /* Application-specific. */
83 
84 #include "qmgr.h"
85 
86 int     qmgr_deliver_concurrency;
87 
88  /*
89   * Message delivery status codes.
90   */
91 #define DELIVER_STAT_OK		0	/* all recipients delivered */
92 #define DELIVER_STAT_DEFER	1	/* try some recipients later */
93 #define DELIVER_STAT_CRASH	2	/* mailer internal problem */
94 
95 /* qmgr_deliver_initial_reply - retrieve initial delivery process response */
96 
97 static int qmgr_deliver_initial_reply(VSTREAM *stream)
98 {
99     int     stat;
100 
101     if (peekfd(vstream_fileno(stream)) < 0) {
102 	msg_warn("%s: premature disconnect", VSTREAM_PATH(stream));
103 	return (DELIVER_STAT_CRASH);
104     } else if (attr_scan(stream, ATTR_FLAG_STRICT,
105 			 ATTR_TYPE_INT, MAIL_ATTR_STATUS, &stat,
106 			 ATTR_TYPE_END) != 1) {
107 	msg_warn("%s: malformed response", VSTREAM_PATH(stream));
108 	return (DELIVER_STAT_CRASH);
109     } else {
110 	return (stat ? DELIVER_STAT_DEFER : 0);
111     }
112 }
113 
114 /* qmgr_deliver_final_reply - retrieve final delivery process response */
115 
116 static int qmgr_deliver_final_reply(VSTREAM *stream, DSN_BUF *dsb)
117 {
118     int     stat;
119 
120     if (peekfd(vstream_fileno(stream)) < 0) {
121 	msg_warn("%s: premature disconnect", VSTREAM_PATH(stream));
122 	return (DELIVER_STAT_CRASH);
123     } else if (attr_scan(stream, ATTR_FLAG_STRICT,
124 			 ATTR_TYPE_FUNC, dsb_scan, (void *) dsb,
125 			 ATTR_TYPE_INT, MAIL_ATTR_STATUS, &stat,
126 			 ATTR_TYPE_END) != 2) {
127 	msg_warn("%s: malformed response", VSTREAM_PATH(stream));
128 	return (DELIVER_STAT_CRASH);
129     } else {
130 	return (stat ? DELIVER_STAT_DEFER : 0);
131     }
132 }
133 
134 /* qmgr_deliver_send_request - send delivery request to delivery process */
135 
136 static int qmgr_deliver_send_request(QMGR_ENTRY *entry, VSTREAM *stream)
137 {
138     RECIPIENT_LIST list = entry->rcpt_list;
139     RECIPIENT *recipient;
140     QMGR_MESSAGE *message = entry->message;
141     VSTRING *sender_buf = 0;
142     MSG_STATS stats;
143     char   *sender;
144     int     flags;
145 
146     /*
147      * If variable envelope return path is requested, change prefix+@origin
148      * into prefix+user=domain@origin. Note that with VERP there is only one
149      * recipient per delivery.
150      */
151     if (message->verp_delims == 0) {
152 	sender = message->sender;
153     } else {
154 	sender_buf = vstring_alloc(100);
155 	verp_sender(sender_buf, message->verp_delims,
156 		    message->sender, list.info);
157 	sender = vstring_str(sender_buf);
158     }
159 
160     flags = message->tflags
161 	| entry->queue->dflags
162 	| (message->inspect_xport ? DEL_REQ_FLAG_BOUNCE : DEL_REQ_FLAG_DEFLT);
163     (void) QMGR_MSG_STATS(&stats, message);
164     attr_print(stream, ATTR_FLAG_NONE,
165 	       ATTR_TYPE_INT, MAIL_ATTR_FLAGS, flags,
166 	       ATTR_TYPE_STR, MAIL_ATTR_QUEUE, message->queue_name,
167 	       ATTR_TYPE_STR, MAIL_ATTR_QUEUEID, message->queue_id,
168 	       ATTR_TYPE_LONG, MAIL_ATTR_OFFSET, message->data_offset,
169 	       ATTR_TYPE_LONG, MAIL_ATTR_SIZE, message->cont_length,
170 	       ATTR_TYPE_STR, MAIL_ATTR_NEXTHOP, entry->queue->nexthop,
171 	       ATTR_TYPE_STR, MAIL_ATTR_ENCODING, message->encoding,
172 	       ATTR_TYPE_STR, MAIL_ATTR_SENDER, sender,
173 	       ATTR_TYPE_STR, MAIL_ATTR_DSN_ENVID, message->dsn_envid,
174 	       ATTR_TYPE_INT, MAIL_ATTR_DSN_RET, message->dsn_ret,
175 	       ATTR_TYPE_FUNC, msg_stats_print, (void *) &stats,
176     /* XXX Should be encapsulated with ATTR_TYPE_FUNC. */
177 	     ATTR_TYPE_STR, MAIL_ATTR_LOG_CLIENT_NAME, message->client_name,
178 	     ATTR_TYPE_STR, MAIL_ATTR_LOG_CLIENT_ADDR, message->client_addr,
179 	     ATTR_TYPE_STR, MAIL_ATTR_LOG_CLIENT_PORT, message->client_port,
180 	     ATTR_TYPE_STR, MAIL_ATTR_LOG_PROTO_NAME, message->client_proto,
181 	       ATTR_TYPE_STR, MAIL_ATTR_LOG_HELO_NAME, message->client_helo,
182     /* XXX Should be encapsulated with ATTR_TYPE_FUNC. */
183 	       ATTR_TYPE_STR, MAIL_ATTR_SASL_METHOD, message->sasl_method,
184 	     ATTR_TYPE_STR, MAIL_ATTR_SASL_USERNAME, message->sasl_username,
185 	       ATTR_TYPE_STR, MAIL_ATTR_SASL_SENDER, message->sasl_sender,
186     /* XXX Ditto if we want to pass TLS certificate info. */
187 	     ATTR_TYPE_STR, MAIL_ATTR_RWR_CONTEXT, message->rewrite_context,
188 	       ATTR_TYPE_INT, MAIL_ATTR_RCPT_COUNT, list.len,
189 	       ATTR_TYPE_END);
190     if (sender_buf != 0)
191 	vstring_free(sender_buf);
192     for (recipient = list.info; recipient < list.info + list.len; recipient++)
193 	attr_print(stream, ATTR_FLAG_NONE,
194 		   ATTR_TYPE_FUNC, rcpt_print, (void *) recipient,
195 		   ATTR_TYPE_END);
196     if (vstream_fflush(stream) != 0) {
197 	msg_warn("write to process (%s): %m", entry->queue->transport->name);
198 	return (-1);
199     } else {
200 	if (msg_verbose)
201 	    msg_info("qmgr_deliver: site `%s'", entry->queue->name);
202 	return (0);
203     }
204 }
205 
206 /* qmgr_deliver_abort - transport response watchdog */
207 
208 static void qmgr_deliver_abort(int unused_event, char *context)
209 {
210     QMGR_ENTRY *entry = (QMGR_ENTRY *) context;
211     QMGR_QUEUE *queue = entry->queue;
212     QMGR_TRANSPORT *transport = queue->transport;
213     QMGR_MESSAGE *message = entry->message;
214 
215     msg_fatal("%s: timeout receiving delivery status from transport: %s",
216 	      message->queue_id, transport->name);
217 }
218 
219 /* qmgr_deliver_update - process delivery status report */
220 
221 static void qmgr_deliver_update(int unused_event, char *context)
222 {
223     QMGR_ENTRY *entry = (QMGR_ENTRY *) context;
224     QMGR_QUEUE *queue = entry->queue;
225     QMGR_TRANSPORT *transport = queue->transport;
226     QMGR_MESSAGE *message = entry->message;
227     static DSN_BUF *dsb;
228     int     status;
229 
230     /*
231      * Release the delivery agent from a "hot" queue entry.
232      */
233 #define QMGR_DELIVER_RELEASE_AGENT(entry) do { \
234 	event_disable_readwrite(vstream_fileno(entry->stream)); \
235 	(void) vstream_fclose(entry->stream); \
236 	entry->stream = 0; \
237 	qmgr_deliver_concurrency--; \
238     } while (0)
239 
240     if (dsb == 0)
241 	dsb = dsb_create();
242 
243     /*
244      * The message transport has responded. Stop the watchdog timer.
245      */
246     event_cancel_timer(qmgr_deliver_abort, context);
247 
248     /*
249      * Retrieve the delivery agent status report. The numerical status code
250      * indicates if delivery should be tried again. The reason text is sent
251      * only when a site should be avoided for a while, so that the queue
252      * manager can log why it does not even try to schedule delivery to the
253      * affected recipients.
254      */
255     status = qmgr_deliver_final_reply(entry->stream, dsb);
256 
257     /*
258      * The mail delivery process failed for some reason (although delivery
259      * may have been successful). Back off with this transport type for a
260      * while. Dispose of queue entries for this transport that await
261      * selection (the todo lists). Stay away from queue entries that have
262      * been selected (the busy lists), or we would have dangling pointers.
263      * The queue itself won't go away before we dispose of the current queue
264      * entry.
265      */
266     if (status == DELIVER_STAT_CRASH) {
267 	message->flags |= DELIVER_STAT_DEFER;
268 #if 0
269 	whatsup = concatenate("unknown ", transport->name,
270 			      " mail transport error", (char *) 0);
271 	qmgr_transport_throttle(transport,
272 				DSN_SIMPLE(&dsb->dsn, "4.3.0", whatsup));
273 	myfree(whatsup);
274 #else
275 	qmgr_transport_throttle(transport,
276 				DSN_SIMPLE(&dsb->dsn, "4.3.0",
277 					   "unknown mail transport error"));
278 #endif
279 	msg_warn("transport %s failure -- see a previous warning/fatal/panic logfile record for the problem description",
280 		 transport->name);
281 
282 	/*
283 	 * Assume the worst and write a defer logfile record for each
284 	 * recipient. This omission was already present in the first queue
285 	 * manager implementation of 199703, and was fixed 200511.
286 	 *
287 	 * To avoid the synchronous qmgr_defer_recipient() operation for each
288 	 * recipient of this queue entry, release the delivery process and
289 	 * move the entry back to the todo queue. Let qmgr_defer_transport()
290 	 * log the recipient asynchronously if possible, and get out of here.
291 	 * Note: if asynchronous logging is not possible,
292 	 * qmgr_defer_transport() eventually invokes qmgr_entry_done() and
293 	 * the entry becomes a dangling pointer.
294 	 */
295 	QMGR_DELIVER_RELEASE_AGENT(entry);
296 	qmgr_entry_unselect(entry);
297 	qmgr_defer_transport(transport, &dsb->dsn);
298 	return;
299     }
300 
301     /*
302      * This message must be tried again.
303      *
304      * If we have a problem talking to this site, back off with this site for a
305      * while; dispose of queue entries for this site that await selection
306      * (the todo list); stay away from queue entries that have been selected
307      * (the busy list), or we would have dangling pointers. The queue itself
308      * won't go away before we dispose of the current queue entry.
309      *
310      * XXX Caution: DSN_COPY() will panic on empty status or reason.
311      */
312 #define SUSPENDED	"delivery temporarily suspended: "
313 
314     if (status == DELIVER_STAT_DEFER) {
315 	message->flags |= DELIVER_STAT_DEFER;
316 	if (VSTRING_LEN(dsb->status)) {
317 	    /* Sanitize the DSN status/reason from the delivery agent. */
318 	    if (!dsn_valid(vstring_str(dsb->status)))
319 		vstring_strcpy(dsb->status, "4.0.0");
320 	    if (VSTRING_LEN(dsb->reason) == 0)
321 		vstring_strcpy(dsb->reason, "unknown error");
322 	    vstring_prepend(dsb->reason, SUSPENDED, sizeof(SUSPENDED) - 1);
323 	    if (QMGR_QUEUE_READY(queue)) {
324 		qmgr_queue_throttle(queue, DSN_FROM_DSN_BUF(dsb));
325 		if (QMGR_QUEUE_THROTTLED(queue))
326 		    qmgr_defer_todo(queue, &dsb->dsn);
327 	    }
328 	}
329     }
330 
331     /*
332      * No problems detected. Mark the transport and queue as alive. The queue
333      * itself won't go away before we dispose of the current queue entry.
334      */
335     if (status != DELIVER_STAT_CRASH && VSTRING_LEN(dsb->reason) == 0) {
336 	qmgr_transport_unthrottle(transport);
337 	qmgr_queue_unthrottle(queue);
338     }
339 
340     /*
341      * Release the delivery process, and give some other queue entry a chance
342      * to be delivered. When all recipients for a message have been tried,
343      * decide what to do next with this message: defer, bounce, delete.
344      */
345     QMGR_DELIVER_RELEASE_AGENT(entry);
346     qmgr_entry_done(entry, QMGR_QUEUE_BUSY);
347 }
348 
349 /* qmgr_deliver - deliver one per-site queue entry */
350 
351 void    qmgr_deliver(QMGR_TRANSPORT *transport, VSTREAM *stream)
352 {
353     QMGR_ENTRY *entry;
354     DSN     dsn;
355 
356     /*
357      * Find out if this delivery process is really available. Once elected,
358      * the delivery process is supposed to express its happiness. If there is
359      * a problem, wipe the pending deliveries for this transport. This
360      * routine runs in response to an external event, so it does not run
361      * while some other queue manipulation is happening.
362      */
363     if (stream == 0 || qmgr_deliver_initial_reply(stream) != 0) {
364 #if 0
365 	whatsup = concatenate(transport->name,
366 			      " mail transport unavailable", (char *) 0);
367 	qmgr_transport_throttle(transport,
368 				DSN_SIMPLE(&dsn, "4.3.0", whatsup));
369 	myfree(whatsup);
370 #else
371 	qmgr_transport_throttle(transport,
372 				DSN_SIMPLE(&dsn, "4.3.0",
373 					   "mail transport unavailable"));
374 #endif
375 	qmgr_defer_transport(transport, &dsn);
376 	if (stream)
377 	    (void) vstream_fclose(stream);
378 	return;
379     }
380 
381     /*
382      * Find a suitable queue entry. Things may have changed since this
383      * transport was allocated. If no suitable entry is found,
384      * unceremoniously disconnect from the delivery process. The delivery
385      * agent request reading routine is prepared for the queue manager to
386      * change its mind for no apparent reason.
387      */
388     if ((entry = qmgr_job_entry_select(transport)) == 0) {
389 	(void) vstream_fclose(stream);
390 	return;
391     }
392 
393     /*
394      * Send the queue file info and recipient info to the delivery process.
395      * If there is a problem, wipe the pending deliveries for this transport.
396      * This routine runs in response to an external event, so it does not run
397      * while some other queue manipulation is happening.
398      */
399     if (qmgr_deliver_send_request(entry, stream) < 0) {
400 	qmgr_entry_unselect(entry);
401 #if 0
402 	whatsup = concatenate(transport->name,
403 			      " mail transport unavailable", (char *) 0);
404 	qmgr_transport_throttle(transport,
405 				DSN_SIMPLE(&dsn, "4.3.0", whatsup));
406 	myfree(whatsup);
407 #else
408 	qmgr_transport_throttle(transport,
409 				DSN_SIMPLE(&dsn, "4.3.0",
410 					   "mail transport unavailable"));
411 #endif
412 	qmgr_defer_transport(transport, &dsn);
413 	/* warning: entry may be a dangling pointer here */
414 	(void) vstream_fclose(stream);
415 	return;
416     }
417 
418     /*
419      * If we get this far, go wait for the delivery status report.
420      */
421     qmgr_deliver_concurrency++;
422     entry->stream = stream;
423     event_enable_read(vstream_fileno(stream),
424 		      qmgr_deliver_update, (char *) entry);
425 
426     /*
427      * Guard against broken systems.
428      */
429     event_request_timer(qmgr_deliver_abort, (char *) entry, var_daemon_timeout);
430 }
431