xref: /netbsd-src/external/ibm-public/postfix/dist/src/oqmgr/qmgr.h (revision 46f5119e40af2e51998f686b2fdcc76b5488f7f3)
1 /*	$NetBSD: qmgr.h,v 1.1.1.2 2011/03/02 19:32:23 tron Exp $	*/
2 
3 /*++
4 /* NAME
5 /*	qmgr 3h
6 /* SUMMARY
7 /*	queue manager data structures
8 /* SYNOPSIS
9 /*	#include "qmgr.h"
10 /* DESCRIPTION
11 /* .nf
12 
13  /*
14   * System library.
15   */
16 #include <sys/time.h>
17 #include <time.h>
18 
19  /*
20   * Utility library.
21   */
22 #include <vstream.h>
23 #include <scan_dir.h>
24 
25  /*
26   * Global library.
27   */
28 #include <recipient_list.h>
29 #include <dsn.h>
30 
31  /*
32   * The queue manager is built around lots of mutually-referring structures.
33   * These typedefs save some typing.
34   */
35 typedef struct QMGR_TRANSPORT QMGR_TRANSPORT;
36 typedef struct QMGR_QUEUE QMGR_QUEUE;
37 typedef struct QMGR_ENTRY QMGR_ENTRY;
38 typedef struct QMGR_MESSAGE QMGR_MESSAGE;
39 typedef struct QMGR_TRANSPORT_LIST QMGR_TRANSPORT_LIST;
40 typedef struct QMGR_QUEUE_LIST QMGR_QUEUE_LIST;
41 typedef struct QMGR_ENTRY_LIST QMGR_ENTRY_LIST;
42 typedef struct QMGR_SCAN QMGR_SCAN;
43 typedef struct QMGR_FEEDBACK QMGR_FEEDBACK;
44 
45  /*
46   * Hairy macros to update doubly-linked lists.
47   */
48 #define QMGR_LIST_ROTATE(head, object) { \
49     head.next->peers.prev = head.prev; \
50     head.prev->peers.next = head.next; \
51     head.next = object->peers.next; \
52     if (object->peers.next) \
53 	head.next->peers.prev = 0; \
54     head.prev = object; \
55     object->peers.next = 0; \
56 }
57 
58 #define QMGR_LIST_UNLINK(head, type, object) { \
59     type   next = object->peers.next; \
60     type   prev = object->peers.prev; \
61     if (prev) prev->peers.next = next; \
62     else head.next = next; \
63     if (next) next->peers.prev = prev; \
64     else head.prev = prev; \
65     object->peers.next = object->peers.prev = 0; \
66 }
67 
68 #define QMGR_LIST_APPEND(head, object) { \
69     object->peers.next = head.next; \
70     object->peers.prev = 0; \
71     if (head.next) { \
72 	head.next->peers.prev = object; \
73     } else { \
74 	head.prev = object; \
75     } \
76     head.next = object; \
77 }
78 
79 #define QMGR_LIST_PREPEND(head, object) { \
80     object->peers.prev = head.prev; \
81     object->peers.next = 0; \
82     if (head.prev) { \
83 	head.prev->peers.next = object; \
84     } else { \
85 	head.next = object; \
86     } \
87     head.prev = object; \
88 }
89 
90 #define QMGR_LIST_INIT(head) { \
91     head.prev = 0; \
92     head.next = 0; \
93 }
94 
95  /*
96   * Transports are looked up by name (when we have resolved a message), or
97   * round-robin wise (when we want to distribute resources fairly).
98   */
99 struct QMGR_TRANSPORT_LIST {
100     QMGR_TRANSPORT *next;
101     QMGR_TRANSPORT *prev;
102 };
103 
104 extern struct HTABLE *qmgr_transport_byname;	/* transport by name */
105 extern QMGR_TRANSPORT_LIST qmgr_transport_list;	/* transports, round robin */
106 
107  /*
108   * Delivery agents provide feedback, as hints that Postfix should expend
109   * more or fewer resources on a specific destination domain. The main.cf
110   * file specifies how feedback affects delivery concurrency: add/subtract a
111   * constant, a ratio of constants, or a constant divided by the delivery
112   * concurrency; and it specifies how much feedback must accumulate between
113   * concurrency updates.
114   */
115 struct QMGR_FEEDBACK {
116     int     hysteresis;			/* to pass, need to be this tall */
117     double  base;			/* pre-computed from main.cf */
118     int     index;			/* none, window, sqrt(window) */
119 };
120 
121 #define QMGR_FEEDBACK_IDX_NONE		0	/* no window dependence */
122 #define QMGR_FEEDBACK_IDX_WIN		1	/* 1/window dependence */
123 #if 0
124 #define QMGR_FEEDBACK_IDX_SQRT_WIN	2	/* 1/sqrt(window) dependence */
125 #endif
126 
127 #ifdef QMGR_FEEDBACK_IDX_SQRT_WIN
128 #include <math.h>
129 #endif
130 
131 extern void qmgr_feedback_init(QMGR_FEEDBACK *, const char *, const char *, const char *, const char *);
132 
133 #ifndef QMGR_FEEDBACK_IDX_SQRT_WIN
134 #define QMGR_FEEDBACK_VAL(fb, win) \
135     ((fb).index == QMGR_FEEDBACK_IDX_NONE ? (fb).base : (fb).base / (win))
136 #else
137 #define QMGR_FEEDBACK_VAL(fb, win) \
138     ((fb).index == QMGR_FEEDBACK_IDX_NONE ? (fb).base : \
139     (fb).index == QMGR_FEEDBACK_IDX_WIN ? (fb).base / (win) : \
140     (fb).base / sqrt(win))
141 #endif
142 
143  /*
144   * Each transport (local, smtp-out, bounce) can have one queue per next hop
145   * name. Queues are looked up by next hop name (when we have resolved a
146   * message destination), or round-robin wise (when we want to deliver
147   * messages fairly).
148   */
149 struct QMGR_QUEUE_LIST {
150     QMGR_QUEUE *next;
151     QMGR_QUEUE *prev;
152 };
153 
154 struct QMGR_TRANSPORT {
155     int     flags;			/* blocked, etc. */
156     int     pending;			/* incomplete DA connections */
157     char   *name;			/* transport name */
158     int     dest_concurrency_limit;	/* concurrency per domain */
159     int     init_dest_concurrency;	/* init. per-domain concurrency */
160     int     recipient_limit;		/* recipients per transaction */
161     struct HTABLE *queue_byname;	/* queues indexed by domain */
162     QMGR_QUEUE_LIST queue_list;		/* queues, round robin order */
163     QMGR_TRANSPORT_LIST peers;		/* linkage */
164     DSN    *dsn;			/* why unavailable */
165     QMGR_FEEDBACK pos_feedback;		/* positive feedback control */
166     QMGR_FEEDBACK neg_feedback;		/* negative feedback control */
167     int     fail_cohort_limit;		/* flow shutdown control */
168     int     rate_delay;			/* suspend per delivery */
169 };
170 
171 #define QMGR_TRANSPORT_STAT_DEAD	(1<<1)
172 
173 typedef void (*QMGR_TRANSPORT_ALLOC_NOTIFY) (QMGR_TRANSPORT *, VSTREAM *);
174 extern QMGR_TRANSPORT *qmgr_transport_select(void);
175 extern void qmgr_transport_alloc(QMGR_TRANSPORT *, QMGR_TRANSPORT_ALLOC_NOTIFY);
176 extern void qmgr_transport_throttle(QMGR_TRANSPORT *, DSN *);
177 extern void qmgr_transport_unthrottle(QMGR_TRANSPORT *);
178 extern QMGR_TRANSPORT *qmgr_transport_create(const char *);
179 extern QMGR_TRANSPORT *qmgr_transport_find(const char *);
180 
181 #define QMGR_TRANSPORT_THROTTLED(t)	((t)->flags & QMGR_TRANSPORT_STAT_DEAD)
182 
183  /*
184   * Each next hop (e.g., a domain name) has its own queue of pending message
185   * transactions. The "todo" queue contains messages that are to be delivered
186   * to this next hop. When a message is elected for transmission, it is moved
187   * from the "todo" queue to the "busy" queue. Messages are taken from the
188   * "todo" queue in sequence. An initial destination delivery concurrency > 1
189   * ensures that one problematic message will not block all other traffic to
190   * that next hop.
191   */
192 struct QMGR_ENTRY_LIST {
193     QMGR_ENTRY *next;
194     QMGR_ENTRY *prev;
195 };
196 
197 struct QMGR_QUEUE {
198     int     dflags;			/* delivery request options */
199     time_t  last_done;			/* last delivery completion */
200     char   *name;			/* domain name or address */
201     char   *nexthop;			/* domain name */
202     int     todo_refcount;		/* queue entries (todo list) */
203     int     busy_refcount;		/* queue entries (busy list) */
204     int     window;			/* slow open algorithm */
205     double  success;			/* accumulated positive feedback */
206     double  failure;			/* accumulated negative feedback */
207     double  fail_cohorts;		/* pseudo-cohort failure count */
208     QMGR_TRANSPORT *transport;		/* transport linkage */
209     QMGR_ENTRY_LIST todo;		/* todo queue entries */
210     QMGR_ENTRY_LIST busy;		/* messages on the wire */
211     QMGR_QUEUE_LIST peers;		/* neighbor queues */
212     DSN    *dsn;			/* why unavailable */
213     time_t  clog_time_to_warn;		/* time of next warning */
214 };
215 
216 #define	QMGR_QUEUE_TODO	1		/* waiting for service */
217 #define QMGR_QUEUE_BUSY	2		/* recipients on the wire */
218 
219 extern int qmgr_queue_count;
220 
221 extern QMGR_QUEUE *qmgr_queue_create(QMGR_TRANSPORT *, const char *, const char *);
222 extern QMGR_QUEUE *qmgr_queue_select(QMGR_TRANSPORT *);
223 extern void qmgr_queue_done(QMGR_QUEUE *);
224 extern void qmgr_queue_throttle(QMGR_QUEUE *, DSN *);
225 extern void qmgr_queue_unthrottle(QMGR_QUEUE *);
226 extern QMGR_QUEUE *qmgr_queue_find(QMGR_TRANSPORT *, const char *);
227 extern void qmgr_queue_suspend(QMGR_QUEUE *, int);
228 
229  /*
230   * Exclusive queue states. Originally there were only two: "throttled" and
231   * "not throttled". It was natural to encode these in the queue window size.
232   * After 10 years it's not practical to rip out all the working code and
233   * change representations, so we just clean up the names a little.
234   *
235   * Note: only the "ready" state can reach every state (including itself);
236   * non-ready states can reach only the "ready" state. Other transitions are
237   * forbidden, because they would result in dangling event handlers.
238   */
239 #define QMGR_QUEUE_STAT_THROTTLED	0	/* back-off timer */
240 #define QMGR_QUEUE_STAT_SUSPENDED	-1	/* voluntary delay timer */
241 #define QMGR_QUEUE_STAT_SAVED		-2	/* delayed cleanup timer */
242 #define QMGR_QUEUE_STAT_BAD		-3	/* can't happen */
243 
244 #define QMGR_QUEUE_READY(q)	((q)->window > 0)
245 #define QMGR_QUEUE_THROTTLED(q)	((q)->window == QMGR_QUEUE_STAT_THROTTLED)
246 #define QMGR_QUEUE_SUSPENDED(q)	((q)->window == QMGR_QUEUE_STAT_SUSPENDED)
247 #define QMGR_QUEUE_SAVED(q)	((q)->window == QMGR_QUEUE_STAT_SAVED)
248 #define QMGR_QUEUE_BAD(q)	((q)->window <= QMGR_QUEUE_STAT_BAD)
249 
250 #define QMGR_QUEUE_STATUS(q) ( \
251 	    QMGR_QUEUE_READY(q) ? "ready" : \
252 	    QMGR_QUEUE_THROTTLED(q) ? "throttled" : \
253 	    QMGR_QUEUE_SUSPENDED(q) ? "suspended" : \
254 	    QMGR_QUEUE_SAVED(q) ? "saved" : \
255 	    "invalid queue status" \
256 	)
257 
258  /*
259   * Structure of one next-hop queue entry. In order to save some copying
260   * effort we allow multiple recipients per transaction.
261   */
262 struct QMGR_ENTRY {
263     VSTREAM *stream;			/* delivery process */
264     QMGR_MESSAGE *message;		/* message info */
265     RECIPIENT_LIST rcpt_list;		/* as many as it takes */
266     QMGR_QUEUE *queue;			/* parent linkage */
267     QMGR_ENTRY_LIST peers;		/* neighbor entries */
268 };
269 
270 extern QMGR_ENTRY *qmgr_entry_select(QMGR_QUEUE *);
271 extern void qmgr_entry_unselect(QMGR_QUEUE *, QMGR_ENTRY *);
272 extern void qmgr_entry_move_todo(QMGR_QUEUE *, QMGR_ENTRY *);
273 extern void qmgr_entry_done(QMGR_ENTRY *, int);
274 extern QMGR_ENTRY *qmgr_entry_create(QMGR_QUEUE *, QMGR_MESSAGE *);
275 
276  /*
277   * All common in-core information about a message is kept here. When all
278   * recipients have been tried the message file is linked to the "deferred"
279   * queue (some hosts not reachable), to the "bounce" queue (some recipients
280   * were rejected), and is then removed from the "active" queue.
281   */
282 struct QMGR_MESSAGE {
283     int     flags;			/* delivery problems */
284     int     qflags;			/* queuing flags */
285     int     tflags;			/* tracing flags */
286     long    tflags_offset;		/* offset for killing */
287     int     rflags;			/* queue file read flags */
288     VSTREAM *fp;			/* open queue file or null */
289     int     refcount;			/* queue entries */
290     int     single_rcpt;		/* send one rcpt at a time */
291     struct timeval arrival_time;	/* start of receive transaction */
292     time_t  create_time;		/* queue file create time */
293     struct timeval active_time;		/* time of entry into active queue */
294     long    warn_offset;		/* warning bounce flag offset */
295     time_t  warn_time;			/* time next warning to be sent */
296     long    data_offset;		/* data seek offset */
297     char   *queue_name;			/* queue name */
298     char   *queue_id;			/* queue file */
299     char   *encoding;			/* content encoding */
300     char   *sender;			/* complete address */
301     char   *dsn_envid;			/* DSN envelope ID */
302     int     dsn_ret;			/* DSN headers/full */
303     char   *verp_delims;		/* VERP delimiters */
304     char   *filter_xport;		/* filtering transport */
305     char   *inspect_xport;		/* inspecting transport */
306     char   *redirect_addr;		/* info@spammer.tld */
307     long    data_size;			/* data segment size */
308     long    cont_length;		/* message content length */
309     long    rcpt_offset;		/* more recipients here */
310     char   *client_name;		/* client hostname */
311     char   *client_addr;		/* client address */
312     char   *client_port;		/* client port */
313     char   *client_proto;		/* client protocol */
314     char   *client_helo;		/* helo parameter */
315     char   *sasl_method;		/* SASL method */
316     char   *sasl_username;		/* SASL user name */
317     char   *sasl_sender;		/* SASL sender */
318     char   *log_ident;			/* up-stream queue ID */
319     char   *rewrite_context;		/* address qualification */
320     RECIPIENT_LIST rcpt_list;		/* complete addresses */
321 };
322 
323  /*
324   * Flags 0-15 are reserved for qmgr_user.h.
325   */
326 #define QMGR_READ_FLAG_SEEN_ALL_NON_RCPT	(1<<16)
327 
328 #define QMGR_MESSAGE_LOCKED	((QMGR_MESSAGE *) 1)
329 
330 extern int qmgr_message_count;
331 extern int qmgr_recipient_count;
332 
333 extern void qmgr_message_free(QMGR_MESSAGE *);
334 extern void qmgr_message_update_warn(QMGR_MESSAGE *);
335 extern void qmgr_message_kill_record(QMGR_MESSAGE *, long);
336 extern QMGR_MESSAGE *qmgr_message_alloc(const char *, const char *, int, mode_t);
337 extern QMGR_MESSAGE *qmgr_message_realloc(QMGR_MESSAGE *);
338 
339 #define QMGR_MSG_STATS(stats, message) \
340     MSG_STATS_INIT2(stats, \
341 		    incoming_arrival, message->arrival_time, \
342 		    active_arrival, message->active_time)
343 
344  /*
345   * qmgr_defer.c
346   */
347 extern void qmgr_defer_transport(QMGR_TRANSPORT *, DSN *);
348 extern void qmgr_defer_todo(QMGR_QUEUE *, DSN *);
349 extern void qmgr_defer_recipient(QMGR_MESSAGE *, RECIPIENT *, DSN *);
350 
351  /*
352   * qmgr_bounce.c
353   */
354 extern void qmgr_bounce_recipient(QMGR_MESSAGE *, RECIPIENT *, DSN *);
355 
356  /*
357   * qmgr_deliver.c
358   */
359 extern int qmgr_deliver_concurrency;
360 extern void qmgr_deliver(QMGR_TRANSPORT *, VSTREAM *);
361 
362  /*
363   * qmgr_active.c
364   */
365 extern int qmgr_active_feed(QMGR_SCAN *, const char *);
366 extern void qmgr_active_drain(void);
367 extern void qmgr_active_done(QMGR_MESSAGE *);
368 
369  /*
370   * qmgr_move.c
371   */
372 extern void qmgr_move(const char *, const char *, time_t);
373 
374  /*
375   * qmgr_enable.c
376   */
377 extern void qmgr_enable_all(void);
378 extern void qmgr_enable_transport(QMGR_TRANSPORT *);
379 extern void qmgr_enable_queue(QMGR_QUEUE *);
380 
381  /*
382   * Queue scan context.
383   */
384 struct QMGR_SCAN {
385     char   *queue;			/* queue name */
386     int     flags;			/* private, this run */
387     int     nflags;			/* private, next run */
388     struct SCAN_DIR *handle;		/* scan */
389 };
390 
391  /*
392   * Flags that control queue scans or destination selection. These are
393   * similar to the QMGR_REQ_XXX request codes.
394   */
395 #define QMGR_SCAN_START	(1<<0)		/* start now/restart when done */
396 #define QMGR_SCAN_ALL	(1<<1)		/* all queue file time stamps */
397 #define QMGR_FLUSH_ONCE	(1<<2)		/* unthrottle once */
398 #define QMGR_FLUSH_DFXP	(1<<3)		/* override defer_transports */
399 #define QMGR_FLUSH_EACH	(1<<4)		/* unthrottle per message */
400 
401  /*
402   * qmgr_scan.c
403   */
404 extern QMGR_SCAN *qmgr_scan_create(const char *);
405 extern void qmgr_scan_request(QMGR_SCAN *, int);
406 extern char *qmgr_scan_next(QMGR_SCAN *);
407 
408  /*
409   * qmgr_error.c
410   */
411 extern QMGR_TRANSPORT *qmgr_error_transport(const char *);
412 extern QMGR_QUEUE *qmgr_error_queue(const char *, DSN *);
413 extern char *qmgr_error_nexthop(DSN *);
414 
415 /* LICENSE
416 /* .ad
417 /* .fi
418 /*	The Secure Mailer license must be distributed with this software.
419 /* AUTHOR(S)
420 /*	Wietse Venema
421 /*	IBM T.J. Watson Research
422 /*	P.O. Box 704
423 /*	Yorktown Heights, NY 10598, USA
424 /*--*/
425