1/*++ 2/* NAME 3/* qmgr_active 3 4/* SUMMARY 5/* active queue management 6/* SYNOPSIS 7/* #include "qmgr.h" 8/* 9/* void qmgr_active_feed(scan_info, queue_id) 10/* QMGR_SCAN *scan_info; 11/* const char *queue_id; 12/* 13/* void qmgr_active_drain() 14/* 15/* int qmgr_active_done(message) 16/* QMGR_MESSAGE *message; 17/* DESCRIPTION 18/* These functions maintain the active message queue: the set 19/* of messages that the queue manager is actually working on. 20/* The active queue is limited in size. Messages are drained 21/* from the active queue by allocating a delivery process and 22/* by delivering mail via that process. Messages leak into the 23/* active queue only when the active queue is small enough. 24/* Damaged message files are saved to the "corrupt" directory. 25/* 26/* qmgr_active_feed() inserts the named message file into 27/* the active queue. Message files with the wrong name or 28/* with other wrong properties are skipped but not removed. 29/* The following queue flags are recognized, other flags being 30/* ignored: 31/* .IP QMGR_SCAN_ALL 32/* Examine all queue files. Normally, deferred queue files with 33/* future time stamps are ignored, and incoming queue files with 34/* future time stamps are frowned upon. 35/* .PP 36/* qmgr_active_drain() allocates one delivery process. 37/* Process allocation is asynchronous. Once the delivery 38/* process is available, an attempt is made to deliver 39/* a message via it. Message delivery is asynchronous, too. 40/* 41/* qmgr_active_done() deals with a message after delivery 42/* has been tried for all in-core recipients. If the message 43/* was bounced, a bounce message is sent to the sender, or 44/* to the Errors-To: address if one was specified. 45/* If there are more on-file recipients, a new batch of 46/* in-core recipients is read from the queue file. Otherwise, 47/* if a delivery agent marked the queue file as corrupt, 48/* the queue file is moved to the "corrupt" queue (surprise); 49/* if at least one delivery failed, the message is moved 50/* to the deferred queue. The time stamps of a deferred queue 51/* file are set to the nearest wakeup time of its recipient 52/* sites (if delivery failed due to a problem with a next-hop 53/* host), are set into the future by the amount of time the 54/* message was queued (per-message exponential backoff), or are set 55/* into the future by a minimal backoff time, whichever is more. 56/* The minimal_backoff_time parameter specifies the minimal 57/* amount of time between delivery attempts; maximal_backoff_time 58/* specifies an upper limit. 59/* DIAGNOSTICS 60/* Fatal: queue file access failures, out of memory. 61/* Panic: interface violations, internal consistency errors. 62/* Warnings: corrupt message file. A corrupt message is saved 63/* to the "corrupt" queue for further inspection. 64/* LICENSE 65/* .ad 66/* .fi 67/* The Secure Mailer license must be distributed with this software. 68/* AUTHOR(S) 69/* Wietse Venema 70/* IBM T.J. Watson Research 71/* P.O. Box 704 72/* Yorktown Heights, NY 10598, USA 73/*--*/ 74 75/* System library. */ 76 77#include <sys_defs.h> 78#include <sys/stat.h> 79#include <dirent.h> 80#include <stdlib.h> 81#include <unistd.h> 82#include <string.h> 83#include <utime.h> 84#include <errno.h> 85 86#ifndef S_IRWXU /* What? no POSIX system? */ 87#define S_IRWXU 0700 88#endif 89 90/* Utility library. */ 91 92#include <msg.h> 93#include <events.h> 94#include <mymalloc.h> 95#include <vstream.h> 96#include <warn_stat.h> 97 98/* Global library. */ 99 100#include <mail_params.h> 101#include <mail_open_ok.h> 102#include <mail_queue.h> 103#include <recipient_list.h> 104#include <bounce.h> 105#include <defer.h> 106#include <trace.h> 107#include <abounce.h> 108#include <rec_type.h> 109#include <qmgr_user.h> 110 111/* Application-specific. */ 112 113#include "qmgr.h" 114 115 /* 116 * A bunch of call-back routines. 117 */ 118static void qmgr_active_done_2_bounce_flush(int, char *); 119static void qmgr_active_done_2_generic(QMGR_MESSAGE *); 120static void qmgr_active_done_25_trace_flush(int, char *); 121static void qmgr_active_done_25_generic(QMGR_MESSAGE *); 122static void qmgr_active_done_3_defer_flush(int, char *); 123static void qmgr_active_done_3_defer_warn(int, char *); 124static void qmgr_active_done_3_generic(QMGR_MESSAGE *); 125 126/* qmgr_active_corrupt - move corrupted file out of the way */ 127 128static void qmgr_active_corrupt(const char *queue_id) 129{ 130 const char *myname = "qmgr_active_corrupt"; 131 132 if (mail_queue_rename(queue_id, MAIL_QUEUE_ACTIVE, MAIL_QUEUE_CORRUPT)) { 133 if (errno != ENOENT) 134 msg_fatal("%s: save corrupt file queue %s id %s: %m", 135 myname, MAIL_QUEUE_ACTIVE, queue_id); 136 } else { 137 msg_warn("saving corrupt file \"%s\" from queue \"%s\" to queue \"%s\"", 138 queue_id, MAIL_QUEUE_ACTIVE, MAIL_QUEUE_CORRUPT); 139 } 140} 141 142/* qmgr_active_defer - defer queue file */ 143 144static void qmgr_active_defer(const char *queue_name, const char *queue_id, 145 const char *dest_queue, int delay) 146{ 147 const char *myname = "qmgr_active_defer"; 148 const char *path; 149 struct utimbuf tbuf; 150 151 if (msg_verbose) 152 msg_info("wakeup %s after %ld secs", queue_id, (long) delay); 153 154 tbuf.actime = tbuf.modtime = event_time() + delay; 155 path = mail_queue_path((VSTRING *) 0, queue_name, queue_id); 156 if (utime(path, &tbuf) < 0 && errno != ENOENT) 157 msg_fatal("%s: update %s time stamps: %m", myname, path); 158 if (mail_queue_rename(queue_id, queue_name, dest_queue)) { 159 if (errno != ENOENT) 160 msg_fatal("%s: rename %s from %s to %s: %m", myname, 161 queue_id, queue_name, dest_queue); 162 msg_warn("%s: rename %s from %s to %s: %m", myname, 163 queue_id, queue_name, dest_queue); 164 } else if (msg_verbose) { 165 msg_info("%s: defer %s", myname, queue_id); 166 } 167} 168 169/* qmgr_active_feed - feed one message into active queue */ 170 171int qmgr_active_feed(QMGR_SCAN *scan_info, const char *queue_id) 172{ 173 const char *myname = "qmgr_active_feed"; 174 QMGR_MESSAGE *message; 175 struct stat st; 176 const char *path; 177 178 if (strcmp(scan_info->queue, MAIL_QUEUE_ACTIVE) == 0) 179 msg_panic("%s: bad queue %s", myname, scan_info->queue); 180 if (msg_verbose) 181 msg_info("%s: queue %s", myname, scan_info->queue); 182 183 /* 184 * Make sure this is something we are willing to open. 185 */ 186 if (mail_open_ok(scan_info->queue, queue_id, &st, &path) == MAIL_OPEN_NO) 187 return (0); 188 189 if (msg_verbose) 190 msg_info("%s: %s", myname, path); 191 192 /* 193 * Skip files that have time stamps into the future. They need to cool 194 * down. Incoming and deferred files can have future time stamps. 195 */ 196 if ((scan_info->flags & QMGR_SCAN_ALL) == 0 197 && st.st_mtime > time((time_t *) 0) + 1) { 198 if (msg_verbose) 199 msg_info("%s: skip %s (%ld seconds)", myname, queue_id, 200 (long) (st.st_mtime - event_time())); 201 return (0); 202 } 203 204 /* 205 * Move the message to the active queue. File access errors are fatal. 206 */ 207 if (mail_queue_rename(queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE)) { 208 if (errno != ENOENT) 209 msg_fatal("%s: %s: rename from %s to %s: %m", myname, 210 queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE); 211 msg_warn("%s: %s: rename from %s to %s: %m", myname, 212 queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE); 213 return (0); 214 } 215 216 /* 217 * Extract envelope information: sender and recipients. At this point, 218 * mail addresses have been processed by the cleanup service so they 219 * should be in canonical form. Generate requests to deliver this 220 * message. 221 * 222 * Throwing away queue files seems bad, especially when they made it this 223 * far into the mail system. Therefore we save bad files to a separate 224 * directory for further inspection. 225 * 226 * After queue manager restart it is possible that a queue file is still 227 * being delivered. In that case (the file is locked), defer delivery by 228 * a minimal amount of time. 229 */ 230#define QMGR_FLUSH_AFTER (QMGR_FLUSH_EACH | QMGR_FLUSH_DFXP) 231 232 if ((message = qmgr_message_alloc(MAIL_QUEUE_ACTIVE, queue_id, 233 (st.st_mode & MAIL_QUEUE_STAT_UNTHROTTLE) ? 234 scan_info->flags | QMGR_FLUSH_AFTER : 235 scan_info->flags, 236 (st.st_mode & MAIL_QUEUE_STAT_UNTHROTTLE) ? 237 st.st_mode & ~MAIL_QUEUE_STAT_UNTHROTTLE : 238 0)) == 0) { 239 qmgr_active_corrupt(queue_id); 240 return (0); 241 } else if (message == QMGR_MESSAGE_LOCKED) { 242 qmgr_active_defer(MAIL_QUEUE_ACTIVE, queue_id, MAIL_QUEUE_INCOMING, 60); 243 return (0); 244 } else { 245 246 /* 247 * Special case if all recipients were already delivered. Send any 248 * bounces and clean up. 249 */ 250 if (message->refcount == 0) 251 qmgr_active_done(message); 252 return (1); 253 } 254} 255 256/* qmgr_active_done - dispose of message after recipients have been tried */ 257 258void qmgr_active_done(QMGR_MESSAGE *message) 259{ 260 const char *myname = "qmgr_active_done"; 261 struct stat st; 262 263 if (msg_verbose) 264 msg_info("%s: %s", myname, message->queue_id); 265 266 /* 267 * During a previous iteration, an attempt to bounce this message may 268 * have failed, so there may still be a bounce log lying around. XXX By 269 * groping around in the bounce queue, we're trespassing on the bounce 270 * service's territory. But doing so is more robust than depending on the 271 * bounce daemon to do the lookup for us, and for us to do the deleting 272 * after we have received a successful status from the bounce service. 273 * The bounce queue directory blocks are most likely in memory anyway. If 274 * these lookups become a performance problem we will have to build an 275 * in-core cache into the bounce daemon. 276 * 277 * Don't bounce when the bounce log is empty. The bounce process obviously 278 * failed, and the delivery agent will have requested that the message be 279 * deferred. 280 * 281 * Bounces are sent asynchronously to avoid stalling while the cleanup 282 * daemon waits for the qmgr to accept the "new mail" trigger. 283 * 284 * See also code in cleanup_bounce.c. 285 */ 286 if (stat(mail_queue_path((VSTRING *) 0, MAIL_QUEUE_BOUNCE, message->queue_id), &st) == 0) { 287 if (st.st_size == 0) { 288 if (mail_queue_remove(MAIL_QUEUE_BOUNCE, message->queue_id)) 289 msg_fatal("remove %s %s: %m", 290 MAIL_QUEUE_BOUNCE, message->queue_id); 291 } else { 292 if (msg_verbose) 293 msg_info("%s: bounce %s", myname, message->queue_id); 294 if (message->verp_delims == 0 || var_verp_bounce_off) 295 abounce_flush(BOUNCE_FLAG_KEEP, 296 message->queue_name, 297 message->queue_id, 298 message->encoding, 299 message->sender, 300 message->dsn_envid, 301 message->dsn_ret, 302 qmgr_active_done_2_bounce_flush, 303 (char *) message); 304 else 305 abounce_flush_verp(BOUNCE_FLAG_KEEP, 306 message->queue_name, 307 message->queue_id, 308 message->encoding, 309 message->sender, 310 message->dsn_envid, 311 message->dsn_ret, 312 message->verp_delims, 313 qmgr_active_done_2_bounce_flush, 314 (char *) message); 315 return; 316 } 317 } 318 319 /* 320 * Asynchronous processing does not reach this point. 321 */ 322 qmgr_active_done_2_generic(message); 323} 324 325/* qmgr_active_done_2_bounce_flush - process abounce_flush() status */ 326 327static void qmgr_active_done_2_bounce_flush(int status, char *context) 328{ 329 QMGR_MESSAGE *message = (QMGR_MESSAGE *) context; 330 331 /* 332 * Process abounce_flush() status and continue processing. 333 */ 334 message->flags |= status; 335 qmgr_active_done_2_generic(message); 336} 337 338/* qmgr_active_done_2_generic - continue processing */ 339 340static void qmgr_active_done_2_generic(QMGR_MESSAGE *message) 341{ 342 const char *path; 343 struct stat st; 344 345 /* 346 * A delivery agent marks a queue file as corrupt by changing its 347 * attributes, and by pretending that delivery was deferred. 348 */ 349 if (message->flags 350 && mail_open_ok(MAIL_QUEUE_ACTIVE, message->queue_id, &st, &path) == MAIL_OPEN_NO) { 351 qmgr_active_corrupt(message->queue_id); 352 qmgr_message_free(message); 353 return; 354 } 355 356 /* 357 * If we did not read all recipients from this file, go read some more, 358 * but remember whether some recipients have to be tried again. 359 * 360 * Throwing away queue files seems bad, especially when they made it this 361 * far into the mail system. Therefore we save bad files to a separate 362 * directory for further inspection by a human being. 363 */ 364 if (message->rcpt_offset > 0) { 365 if (qmgr_message_realloc(message) == 0) { 366 qmgr_active_corrupt(message->queue_id); 367 qmgr_message_free(message); 368 } else { 369 if (message->refcount == 0) 370 qmgr_active_done(message); /* recurse for consistency */ 371 } 372 return; 373 } 374 375 /* 376 * XXX With multi-recipient mail, some recipients may have NOTIFY=SUCCESS 377 * and others not. Depending on what subset of recipients are delivered, 378 * a trace file may or may not be created. Even when the last partial 379 * delivery attempt had no NOTIFY=SUCCESS recipients, a trace file may 380 * still exist from a previous partial delivery attempt. So as long as 381 * any recipient has NOTIFY=SUCCESS we have to always look for the trace 382 * file and be prepared for the file not to exist. 383 * 384 * See also comments in bounce/bounce_notify_util.c. 385 */ 386 if ((message->tflags & (DEL_REQ_FLAG_USR_VRFY | DEL_REQ_FLAG_RECORD)) 387 || (message->rflags & QMGR_READ_FLAG_NOTIFY_SUCCESS)) { 388 atrace_flush(message->tflags, 389 message->queue_name, 390 message->queue_id, 391 message->encoding, 392 message->sender, 393 message->dsn_envid, 394 message->dsn_ret, 395 qmgr_active_done_25_trace_flush, 396 (char *) message); 397 return; 398 } 399 400 /* 401 * Asynchronous processing does not reach this point. 402 */ 403 qmgr_active_done_25_generic(message); 404} 405 406/* qmgr_active_done_25_trace_flush - continue after atrace_flush() completion */ 407 408static void qmgr_active_done_25_trace_flush(int status, char *context) 409{ 410 QMGR_MESSAGE *message = (QMGR_MESSAGE *) context; 411 412 /* 413 * Process atrace_flush() status and continue processing. 414 */ 415 if (status == 0 && message->tflags_offset) 416 qmgr_message_kill_record(message, message->tflags_offset); 417 message->flags |= status; 418 qmgr_active_done_25_generic(message); 419} 420 421/* qmgr_active_done_25_generic - continue processing */ 422 423static void qmgr_active_done_25_generic(QMGR_MESSAGE *message) 424{ 425 const char *myname = "qmgr_active_done_25_generic"; 426 427 /* 428 * If we get to this point we have tried all recipients for this message. 429 * If the message is too old, try to bounce it. 430 * 431 * Bounces are sent asynchronously to avoid stalling while the cleanup 432 * daemon waits for the qmgr to accept the "new mail" trigger. 433 */ 434 if (message->flags) { 435 if (event_time() >= message->create_time + 436 (*message->sender ? var_max_queue_time : var_dsn_queue_time)) { 437 msg_info("%s: from=<%s>, status=expired, returned to sender", 438 message->queue_id, message->sender); 439 if (message->verp_delims == 0 || var_verp_bounce_off) 440 adefer_flush(BOUNCE_FLAG_KEEP, 441 message->queue_name, 442 message->queue_id, 443 message->encoding, 444 message->sender, 445 message->dsn_envid, 446 message->dsn_ret, 447 qmgr_active_done_3_defer_flush, 448 (char *) message); 449 else 450 adefer_flush_verp(BOUNCE_FLAG_KEEP, 451 message->queue_name, 452 message->queue_id, 453 message->encoding, 454 message->sender, 455 message->dsn_envid, 456 message->dsn_ret, 457 message->verp_delims, 458 qmgr_active_done_3_defer_flush, 459 (char *) message); 460 return; 461 } else if (message->warn_time > 0 462 && event_time() >= message->warn_time - 1) { 463 if (msg_verbose) 464 msg_info("%s: sending defer warning for %s", myname, message->queue_id); 465 adefer_warn(BOUNCE_FLAG_KEEP, 466 message->queue_name, 467 message->queue_id, 468 message->encoding, 469 message->sender, 470 message->dsn_envid, 471 message->dsn_ret, 472 qmgr_active_done_3_defer_warn, 473 (char *) message); 474 return; 475 } 476 } 477 478 /* 479 * Asynchronous processing does not reach this point. 480 */ 481 qmgr_active_done_3_generic(message); 482} 483 484/* qmgr_active_done_3_defer_warn - continue after adefer_warn() completion */ 485 486static void qmgr_active_done_3_defer_warn(int status, char *context) 487{ 488 QMGR_MESSAGE *message = (QMGR_MESSAGE *) context; 489 490 /* 491 * Process adefer_warn() completion status and continue processing. 492 */ 493 if (status == 0) 494 qmgr_message_update_warn(message); 495 qmgr_active_done_3_generic(message); 496} 497 498/* qmgr_active_done_3_defer_flush - continue after adefer_flush() completion */ 499 500static void qmgr_active_done_3_defer_flush(int status, char *context) 501{ 502 QMGR_MESSAGE *message = (QMGR_MESSAGE *) context; 503 504 /* 505 * Process adefer_flush() status and continue processing. 506 */ 507 message->flags = status; 508 qmgr_active_done_3_generic(message); 509} 510 511/* qmgr_active_done_3_generic - continue processing */ 512 513static void qmgr_active_done_3_generic(QMGR_MESSAGE *message) 514{ 515 const char *myname = "qmgr_active_done_3_generic"; 516 int delay; 517 518 /* 519 * Some recipients need to be tried again. Move the queue file time 520 * stamps into the future by the amount of time that the message is 521 * delayed, and move the message to the deferred queue. Impose minimal 522 * and maximal backoff times. 523 * 524 * Since we look at actual time in queue, not time since last delivery 525 * attempt, backoff times will be distributed. However, we can still see 526 * spikes in delivery activity because the interval between deferred 527 * queue scans is finite. 528 */ 529 if (message->flags) { 530 if (message->create_time > 0) { 531 delay = event_time() - message->create_time; 532 if (delay > var_max_backoff_time) 533 delay = var_max_backoff_time; 534 if (delay < var_min_backoff_time) 535 delay = var_min_backoff_time; 536 } else { 537 delay = var_min_backoff_time; 538 } 539 qmgr_active_defer(message->queue_name, message->queue_id, 540 MAIL_QUEUE_DEFERRED, delay); 541 } 542 543 /* 544 * All recipients done. Remove the queue file. 545 */ 546 else { 547 if (mail_queue_remove(message->queue_name, message->queue_id)) { 548 if (errno != ENOENT) 549 msg_fatal("%s: remove %s from %s: %m", myname, 550 message->queue_id, message->queue_name); 551 msg_warn("%s: remove %s from %s: %m", myname, 552 message->queue_id, message->queue_name); 553 } else { 554 /* Same format as logged by postsuper. */ 555 msg_info("%s: removed", message->queue_id); 556 } 557 } 558 559 /* 560 * Finally, delete the in-core message structure. 561 */ 562 qmgr_message_free(message); 563} 564 565/* qmgr_active_drain - drain active queue by allocating a delivery process */ 566 567void qmgr_active_drain(void) 568{ 569 QMGR_TRANSPORT *transport; 570 571 /* 572 * Allocate one delivery process for every transport with pending mail. 573 * The process allocation completes asynchronously. 574 */ 575 while ((transport = qmgr_transport_select()) != 0) { 576 if (msg_verbose) 577 msg_info("qmgr_active_drain: allocate %s", transport->name); 578 qmgr_transport_alloc(transport, qmgr_deliver); 579 } 580} 581