1 /* $NetBSD: qmgr_active.c,v 1.1.1.1 2009/06/23 10:08:52 tron Exp $ */ 2 3 /*++ 4 /* NAME 5 /* qmgr_active 3 6 /* SUMMARY 7 /* active queue management 8 /* SYNOPSIS 9 /* #include "qmgr.h" 10 /* 11 /* void qmgr_active_feed(scan_info, queue_id) 12 /* QMGR_SCAN *scan_info; 13 /* const char *queue_id; 14 /* 15 /* void qmgr_active_drain() 16 /* 17 /* int qmgr_active_done(message) 18 /* QMGR_MESSAGE *message; 19 /* DESCRIPTION 20 /* These functions maintain the active message queue: the set 21 /* of messages that the queue manager is actually working on. 22 /* The active queue is limited in size. Messages are drained 23 /* from the active queue by allocating a delivery process and 24 /* by delivering mail via that process. Messages leak into the 25 /* active queue only when the active queue is small enough. 26 /* Damaged message files are saved to the "corrupt" directory. 27 /* 28 /* qmgr_active_feed() inserts the named message file into 29 /* the active queue. Message files with the wrong name or 30 /* with other wrong properties are skipped but not removed. 31 /* The following queue flags are recognized, other flags being 32 /* ignored: 33 /* .IP QMGR_SCAN_ALL 34 /* Examine all queue files. Normally, deferred queue files with 35 /* future time stamps are ignored, and incoming queue files with 36 /* future time stamps are frowned upon. 37 /* .PP 38 /* qmgr_active_drain() allocates one delivery process. 39 /* Process allocation is asynchronous. Once the delivery 40 /* process is available, an attempt is made to deliver 41 /* a message via it. Message delivery is asynchronous, too. 42 /* 43 /* qmgr_active_done() deals with a message after delivery 44 /* has been tried for all in-core recipients. If the message 45 /* was bounced, a bounce message is sent to the sender, or 46 /* to the Errors-To: address if one was specified. 47 /* If there are more on-file recipients, a new batch of 48 /* in-core recipients is read from the queue file. Otherwise, 49 /* if a delivery agent marked the queue file as corrupt, 50 /* the queue file is moved to the "corrupt" queue (surprise); 51 /* if at least one delivery failed, the message is moved 52 /* to the deferred queue. The time stamps of a deferred queue 53 /* file are set to the nearest wakeup time of its recipient 54 /* sites (if delivery failed due to a problem with a next-hop 55 /* host), are set into the future by the amount of time the 56 /* message was queued (per-message exponential backoff), or are set 57 /* into the future by a minimal backoff time, whichever is more. 58 /* The minimal_backoff_time parameter specifies the minimal 59 /* amount of time between delivery attempts; maximal_backoff_time 60 /* specifies an upper limit. 61 /* DIAGNOSTICS 62 /* Fatal: queue file access failures, out of memory. 63 /* Panic: interface violations, internal consistency errors. 64 /* Warnings: corrupt message file. A corrupt message is saved 65 /* to the "corrupt" queue for further inspection. 66 /* LICENSE 67 /* .ad 68 /* .fi 69 /* The Secure Mailer license must be distributed with this software. 70 /* AUTHOR(S) 71 /* Wietse Venema 72 /* IBM T.J. Watson Research 73 /* P.O. Box 704 74 /* Yorktown Heights, NY 10598, USA 75 /*--*/ 76 77 /* System library. */ 78 79 #include <sys_defs.h> 80 #include <sys/stat.h> 81 #include <dirent.h> 82 #include <stdlib.h> 83 #include <unistd.h> 84 #include <string.h> 85 #include <utime.h> 86 #include <errno.h> 87 88 #ifndef S_IRWXU /* What? no POSIX system? */ 89 #define S_IRWXU 0700 90 #endif 91 92 /* Utility library. */ 93 94 #include <msg.h> 95 #include <events.h> 96 #include <mymalloc.h> 97 #include <vstream.h> 98 99 /* Global library. */ 100 101 #include <mail_params.h> 102 #include <mail_open_ok.h> 103 #include <mail_queue.h> 104 #include <recipient_list.h> 105 #include <bounce.h> 106 #include <defer.h> 107 #include <trace.h> 108 #include <abounce.h> 109 #include <rec_type.h> 110 #include <qmgr_user.h> 111 112 /* Application-specific. */ 113 114 #include "qmgr.h" 115 116 /* 117 * A bunch of call-back routines. 118 */ 119 static void qmgr_active_done_2_bounce_flush(int, char *); 120 static void qmgr_active_done_2_generic(QMGR_MESSAGE *); 121 static void qmgr_active_done_3_defer_flush(int, char *); 122 static void qmgr_active_done_3_defer_warn(int, char *); 123 static void qmgr_active_done_3_generic(QMGR_MESSAGE *); 124 125 /* qmgr_active_corrupt - move corrupted file out of the way */ 126 127 static void qmgr_active_corrupt(const char *queue_id) 128 { 129 const char *myname = "qmgr_active_corrupt"; 130 131 if (mail_queue_rename(queue_id, MAIL_QUEUE_ACTIVE, MAIL_QUEUE_CORRUPT)) { 132 if (errno != ENOENT) 133 msg_fatal("%s: save corrupt file queue %s id %s: %m", 134 myname, MAIL_QUEUE_ACTIVE, queue_id); 135 } else { 136 msg_warn("saving corrupt file \"%s\" from queue \"%s\" to queue \"%s\"", 137 queue_id, MAIL_QUEUE_ACTIVE, MAIL_QUEUE_CORRUPT); 138 } 139 } 140 141 /* qmgr_active_defer - defer queue file */ 142 143 static void qmgr_active_defer(const char *queue_name, const char *queue_id, 144 const char *dest_queue, int delay) 145 { 146 const char *myname = "qmgr_active_defer"; 147 const char *path; 148 struct utimbuf tbuf; 149 150 if (msg_verbose) 151 msg_info("wakeup %s after %ld secs", queue_id, (long) delay); 152 153 tbuf.actime = tbuf.modtime = event_time() + delay; 154 path = mail_queue_path((VSTRING *) 0, queue_name, queue_id); 155 if (utime(path, &tbuf) < 0 && errno != ENOENT) 156 msg_fatal("%s: update %s time stamps: %m", myname, path); 157 if (mail_queue_rename(queue_id, queue_name, dest_queue)) { 158 if (errno != ENOENT) 159 msg_fatal("%s: rename %s from %s to %s: %m", myname, 160 queue_id, queue_name, dest_queue); 161 msg_warn("%s: rename %s from %s to %s: %m", myname, 162 queue_id, queue_name, dest_queue); 163 } else if (msg_verbose) { 164 msg_info("%s: defer %s", myname, queue_id); 165 } 166 } 167 168 /* qmgr_active_feed - feed one message into active queue */ 169 170 int qmgr_active_feed(QMGR_SCAN *scan_info, const char *queue_id) 171 { 172 const char *myname = "qmgr_active_feed"; 173 QMGR_MESSAGE *message; 174 struct stat st; 175 const char *path; 176 177 if (strcmp(scan_info->queue, MAIL_QUEUE_ACTIVE) == 0) 178 msg_panic("%s: bad queue %s", myname, scan_info->queue); 179 if (msg_verbose) 180 msg_info("%s: queue %s", myname, scan_info->queue); 181 182 /* 183 * Make sure this is something we are willing to open. 184 */ 185 if (mail_open_ok(scan_info->queue, queue_id, &st, &path) == MAIL_OPEN_NO) 186 return (0); 187 188 if (msg_verbose) 189 msg_info("%s: %s", myname, path); 190 191 /* 192 * Skip files that have time stamps into the future. They need to cool 193 * down. Incoming and deferred files can have future time stamps. 194 */ 195 if ((scan_info->flags & QMGR_SCAN_ALL) == 0 196 && st.st_mtime > time((time_t *) 0) + 1) { 197 if (msg_verbose) 198 msg_info("%s: skip %s (%ld seconds)", myname, queue_id, 199 (long) (st.st_mtime - event_time())); 200 return (0); 201 } 202 203 /* 204 * Move the message to the active queue. File access errors are fatal. 205 */ 206 if (mail_queue_rename(queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE)) { 207 if (errno != ENOENT) 208 msg_fatal("%s: %s: rename from %s to %s: %m", myname, 209 queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE); 210 msg_warn("%s: %s: rename from %s to %s: %m", myname, 211 queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE); 212 return (0); 213 } 214 215 /* 216 * Extract envelope information: sender and recipients. At this point, 217 * mail addresses have been processed by the cleanup service so they 218 * should be in canonical form. Generate requests to deliver this 219 * message. 220 * 221 * Throwing away queue files seems bad, especially when they made it this 222 * far into the mail system. Therefore we save bad files to a separate 223 * directory for further inspection. 224 * 225 * After queue manager restart it is possible that a queue file is still 226 * being delivered. In that case (the file is locked), defer delivery by 227 * a minimal amount of time. 228 */ 229 #define QMGR_FLUSH_AFTER (QMGR_FLUSH_EACH | QMGR_FLUSH_DFXP) 230 231 if ((message = qmgr_message_alloc(MAIL_QUEUE_ACTIVE, queue_id, 232 (st.st_mode & MAIL_QUEUE_STAT_UNTHROTTLE) ? 233 scan_info->flags | QMGR_FLUSH_AFTER : 234 scan_info->flags, 235 (st.st_mode & MAIL_QUEUE_STAT_UNTHROTTLE) ? 236 st.st_mode & ~MAIL_QUEUE_STAT_UNTHROTTLE : 237 0)) == 0) { 238 qmgr_active_corrupt(queue_id); 239 return (0); 240 } else if (message == QMGR_MESSAGE_LOCKED) { 241 qmgr_active_defer(MAIL_QUEUE_ACTIVE, queue_id, MAIL_QUEUE_INCOMING, 60); 242 return (0); 243 } else { 244 245 /* 246 * Special case if all recipients were already delivered. Send any 247 * bounces and clean up. 248 */ 249 if (message->refcount == 0) 250 qmgr_active_done(message); 251 return (1); 252 } 253 } 254 255 /* qmgr_active_done - dispose of message after recipients have been tried */ 256 257 void qmgr_active_done(QMGR_MESSAGE *message) 258 { 259 const char *myname = "qmgr_active_done"; 260 struct stat st; 261 262 if (msg_verbose) 263 msg_info("%s: %s", myname, message->queue_id); 264 265 /* 266 * During a previous iteration, an attempt to bounce this message may 267 * have failed, so there may still be a bounce log lying around. XXX By 268 * groping around in the bounce queue, we're trespassing on the bounce 269 * service's territory. But doing so is more robust than depending on the 270 * bounce daemon to do the lookup for us, and for us to do the deleting 271 * after we have received a successful status from the bounce service. 272 * The bounce queue directory blocks are most likely in memory anyway. If 273 * these lookups become a performance problem we will have to build an 274 * in-core cache into the bounce daemon. 275 * 276 * Don't bounce when the bounce log is empty. The bounce process obviously 277 * failed, and the delivery agent will have requested that the message be 278 * deferred. 279 * 280 * Bounces are sent asynchronously to avoid stalling while the cleanup 281 * daemon waits for the qmgr to accept the "new mail" trigger. 282 * 283 * See also code in cleanup_bounce.c. 284 */ 285 if (stat(mail_queue_path((VSTRING *) 0, MAIL_QUEUE_BOUNCE, message->queue_id), &st) == 0) { 286 if (st.st_size == 0) { 287 if (mail_queue_remove(MAIL_QUEUE_BOUNCE, message->queue_id)) 288 msg_fatal("remove %s %s: %m", 289 MAIL_QUEUE_BOUNCE, message->queue_id); 290 } else { 291 if (msg_verbose) 292 msg_info("%s: bounce %s", myname, message->queue_id); 293 if (message->verp_delims == 0 || var_verp_bounce_off) 294 abounce_flush(BOUNCE_FLAG_KEEP, 295 message->queue_name, 296 message->queue_id, 297 message->encoding, 298 message->sender, 299 message->dsn_envid, 300 message->dsn_ret, 301 qmgr_active_done_2_bounce_flush, 302 (char *) message); 303 else 304 abounce_flush_verp(BOUNCE_FLAG_KEEP, 305 message->queue_name, 306 message->queue_id, 307 message->encoding, 308 message->sender, 309 message->dsn_envid, 310 message->dsn_ret, 311 message->verp_delims, 312 qmgr_active_done_2_bounce_flush, 313 (char *) message); 314 return; 315 } 316 } 317 318 /* 319 * Asynchronous processing does not reach this point. 320 */ 321 qmgr_active_done_2_generic(message); 322 } 323 324 /* qmgr_active_done_2_bounce_flush - process abounce_flush() status */ 325 326 static void qmgr_active_done_2_bounce_flush(int status, char *context) 327 { 328 QMGR_MESSAGE *message = (QMGR_MESSAGE *) context; 329 330 /* 331 * Process abounce_flush() status and continue processing. 332 */ 333 message->flags |= status; 334 qmgr_active_done_2_generic(message); 335 } 336 337 /* qmgr_active_done_2_generic - continue processing */ 338 339 static void qmgr_active_done_2_generic(QMGR_MESSAGE *message) 340 { 341 const char *myname = "qmgr_active_done_2_generic"; 342 const char *path; 343 struct stat st; 344 int status; 345 346 /* 347 * A delivery agent marks a queue file as corrupt by changing its 348 * attributes, and by pretending that delivery was deferred. 349 */ 350 if (message->flags 351 && mail_open_ok(MAIL_QUEUE_ACTIVE, message->queue_id, &st, &path) == MAIL_OPEN_NO) { 352 qmgr_active_corrupt(message->queue_id); 353 qmgr_message_free(message); 354 return; 355 } 356 357 /* 358 * If we did not read all recipients from this file, go read some more, 359 * but remember whether some recipients have to be tried again. 360 * 361 * Throwing away queue files seems bad, especially when they made it this 362 * far into the mail system. Therefore we save bad files to a separate 363 * directory for further inspection by a human being. 364 */ 365 if (message->rcpt_offset > 0) { 366 if (qmgr_message_realloc(message) == 0) { 367 qmgr_active_corrupt(message->queue_id); 368 qmgr_message_free(message); 369 } else { 370 if (message->refcount == 0) 371 qmgr_active_done(message); /* recurse for consistency */ 372 } 373 return; 374 } 375 376 /* 377 * As a temporary implementation, synchronously inform the sender of 378 * trace information. This will block for 10 seconds when the qmgr FIFO 379 * is full. 380 * 381 * XXX With multi-recipient mail, some recipients may have NOTIFY=SUCCESS 382 * and others not. Depending on what subset of recipients are delivered, 383 * a trace file may or may not be created. Even when the last partial 384 * delivery attempt had no NOTIFY=SUCCESS recipients, a trace file may 385 * still exist from a previous partial delivery attempt. So as long as 386 * any recipient has NOTIFY=SUCCESS we have to always look for the trace 387 * file and be prepared for the file not to exist. 388 * 389 * See also comments in bounce/bounce_notify_util.c. 390 */ 391 if ((message->tflags & (DEL_REQ_FLAG_USR_VRFY | DEL_REQ_FLAG_RECORD)) 392 || (message->rflags & QMGR_READ_FLAG_NOTIFY_SUCCESS)) { 393 status = trace_flush(message->tflags, 394 message->queue_name, 395 message->queue_id, 396 message->encoding, 397 message->sender, 398 message->dsn_envid, 399 message->dsn_ret); 400 if (status == 0 && message->tflags_offset) 401 qmgr_message_kill_record(message, message->tflags_offset); 402 message->flags |= status; 403 } 404 405 /* 406 * If we get to this point we have tried all recipients for this message. 407 * If the message is too old, try to bounce it. 408 * 409 * Bounces are sent asynchronously to avoid stalling while the cleanup 410 * daemon waits for the qmgr to accept the "new mail" trigger. 411 */ 412 if (message->flags) { 413 if (event_time() >= message->create_time + 414 (*message->sender ? var_max_queue_time : var_dsn_queue_time)) { 415 msg_info("%s: from=<%s>, status=expired, returned to sender", 416 message->queue_id, message->sender); 417 if (message->verp_delims == 0 || var_verp_bounce_off) 418 adefer_flush(BOUNCE_FLAG_KEEP, 419 message->queue_name, 420 message->queue_id, 421 message->encoding, 422 message->sender, 423 message->dsn_envid, 424 message->dsn_ret, 425 qmgr_active_done_3_defer_flush, 426 (char *) message); 427 else 428 adefer_flush_verp(BOUNCE_FLAG_KEEP, 429 message->queue_name, 430 message->queue_id, 431 message->encoding, 432 message->sender, 433 message->dsn_envid, 434 message->dsn_ret, 435 message->verp_delims, 436 qmgr_active_done_3_defer_flush, 437 (char *) message); 438 return; 439 } else if (message->warn_time > 0 440 && event_time() >= message->warn_time - 1) { 441 if (msg_verbose) 442 msg_info("%s: sending defer warning for %s", myname, message->queue_id); 443 adefer_warn(BOUNCE_FLAG_KEEP, 444 message->queue_name, 445 message->queue_id, 446 message->encoding, 447 message->sender, 448 message->dsn_envid, 449 message->dsn_ret, 450 qmgr_active_done_3_defer_warn, 451 (char *) message); 452 return; 453 } 454 } 455 456 /* 457 * Asynchronous processing does not reach this point. 458 */ 459 qmgr_active_done_3_generic(message); 460 } 461 462 /* qmgr_active_done_3_defer_warn - continue after adefer_warn() completion */ 463 464 static void qmgr_active_done_3_defer_warn(int status, char *context) 465 { 466 QMGR_MESSAGE *message = (QMGR_MESSAGE *) context; 467 468 /* 469 * Process adefer_warn() completion status and continue processing. 470 */ 471 if (status == 0) 472 qmgr_message_update_warn(message); 473 qmgr_active_done_3_generic(message); 474 } 475 476 /* qmgr_active_done_3_defer_flush - continue after adefer_flush() completion */ 477 478 static void qmgr_active_done_3_defer_flush(int status, char *context) 479 { 480 QMGR_MESSAGE *message = (QMGR_MESSAGE *) context; 481 482 /* 483 * Process adefer_flush() status and continue processing. 484 */ 485 message->flags = status; 486 qmgr_active_done_3_generic(message); 487 } 488 489 /* qmgr_active_done_3_generic - continue processing */ 490 491 static void qmgr_active_done_3_generic(QMGR_MESSAGE *message) 492 { 493 const char *myname = "qmgr_active_done_3_generic"; 494 int delay; 495 496 /* 497 * Some recipients need to be tried again. Move the queue file time 498 * stamps into the future by the amount of time that the message is 499 * delayed, and move the message to the deferred queue. Impose minimal 500 * and maximal backoff times. 501 * 502 * Since we look at actual time in queue, not time since last delivery 503 * attempt, backoff times will be distributed. However, we can still see 504 * spikes in delivery activity because the interval between deferred 505 * queue scans is finite. 506 */ 507 if (message->flags) { 508 if (message->create_time > 0) { 509 delay = event_time() - message->create_time; 510 if (delay > var_max_backoff_time) 511 delay = var_max_backoff_time; 512 if (delay < var_min_backoff_time) 513 delay = var_min_backoff_time; 514 } else { 515 delay = var_min_backoff_time; 516 } 517 qmgr_active_defer(message->queue_name, message->queue_id, 518 MAIL_QUEUE_DEFERRED, delay); 519 } 520 521 /* 522 * All recipients done. Remove the queue file. 523 */ 524 else { 525 if (mail_queue_remove(message->queue_name, message->queue_id)) { 526 if (errno != ENOENT) 527 msg_fatal("%s: remove %s from %s: %m", myname, 528 message->queue_id, message->queue_name); 529 msg_warn("%s: remove %s from %s: %m", myname, 530 message->queue_id, message->queue_name); 531 } else { 532 /* Same format as logged by postsuper. */ 533 msg_info("%s: removed", message->queue_id); 534 } 535 } 536 537 /* 538 * Finally, delete the in-core message structure. 539 */ 540 qmgr_message_free(message); 541 } 542 543 /* qmgr_active_drain - drain active queue by allocating a delivery process */ 544 545 void qmgr_active_drain(void) 546 { 547 QMGR_TRANSPORT *transport; 548 549 /* 550 * Allocate one delivery process for every transport with pending mail. 551 * The process allocation completes asynchronously. 552 */ 553 while ((transport = qmgr_transport_select()) != 0) { 554 if (msg_verbose) 555 msg_info("qmgr_active_drain: allocate %s", transport->name); 556 qmgr_transport_alloc(transport, qmgr_deliver); 557 } 558 } 559