source3/lib/server_prefork.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Common server globals
   4
   5    Copyright (C) Simo Sorce <idra@samba.org> 2011
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "system/time.h"
  23 #include "system/shmem.h"
  24 #include "system/filesys.h"
  25 #include "server_prefork.h"
  26 #include "../lib/util/util.h"
  27 #include "../lib/util/tevent_unix.h"
  28
  29 struct prefork_pool {
  30
  31         int listen_fd;
  32         int lock_fd;
  33
  34         prefork_main_fn_t *main_fn;
  35         void *private_data;
  36
  37         int pool_size;
  38         struct pf_worker_data *pool;
  39
  40         int allowed_clients;
  41 };
  42
  43 int prefork_pool_destructor(struct prefork_pool *pfp)
  44 {
  45         munmap(pfp->pool, pfp->pool_size * sizeof(struct pf_worker_data));
  46         return 0;
  47 }
  48
  49 bool prefork_create_pool(struct tevent_context *ev_ctx,
  50                          TALLOC_CTX *mem_ctx, int listen_fd,
  51                          int min_children, int max_children,
  52                          prefork_main_fn_t *main_fn, void *private_data,
  53                          struct prefork_pool **pf_pool)
  54 {
  55         struct prefork_pool *pfp;
  56         pid_t pid;
  57         time_t now = time(NULL);
  58         size_t data_size;
  59         int ret;
  60         int i;
  61
  62         pfp = talloc(mem_ctx, struct prefork_pool);
  63         if (!pfp) {
  64                 DEBUG(1, ("Out of memory!\n"));
  65                 return false;
  66         }
  67         pfp->listen_fd = listen_fd;
  68         pfp->main_fn = main_fn;
  69         pfp->private_data = private_data;
  70
  71         pfp->lock_fd = create_unlink_tmp(NULL);
  72         if (pfp->lock_fd == -1) {
  73                 DEBUG(1, ("Failed to create prefork lock fd!\n"));
  74                 talloc_free(pfp);
  75                 return false;
  76         }
  77
  78         pfp->pool_size = max_children;
  79         data_size = sizeof(struct pf_worker_data) * max_children;
  80
  81         pfp->pool = mmap(NULL, data_size, PROT_READ|PROT_WRITE,
  82                          MAP_SHARED|MAP_ANONYMOUS, -1, 0);
  83         if (pfp->pool == MAP_FAILED) {
  84                 DEBUG(1, ("Failed to mmap memory for prefork pool!\n"));
  85                 talloc_free(pfp);
  86                 return false;
  87         }
  88         talloc_set_destructor(pfp, prefork_pool_destructor);
  89
  90         for (i = 0; i < min_children; i++) {
  91
  92                 pfp->pool[i].allowed_clients = 1;
  93                 pfp->pool[i].started = now;
  94
  95                 pid = sys_fork();
  96                 switch (pid) {
  97                 case -1:
  98                         DEBUG(1, ("Failed to prefork child n. %d !\n", i));
  99                         break;
 100
 101                 case 0: /* THE CHILD */
 102
 103                         pfp->pool[i].status = PF_WORKER_IDLE;
 104                         ret = pfp->main_fn(ev_ctx, &pfp->pool[i],
 105                                            pfp->listen_fd, pfp->lock_fd,
 106                                            pfp->private_data);
 107                         exit(ret);
 108
 109                 default: /* THE PARENT */
 110                         pfp->pool[i].pid = pid;
 111                         break;
 112                 }
 113         }
 114
 115         *pf_pool = pfp;
 116         return true;
 117 }
 118
 119 /* Provide the new max children number in new_max
 120  * (must be larger than current max).
 121  * Returns: 0 if all fine
 122  *          ENOSPC if mremap fails to expand
 123  *          EINVAL if new_max is invalid
 124  */
 125 int prefork_expand_pool(struct prefork_pool *pfp, int new_max)
 126 {
 127         struct pf_worker_data *pool;
 128         size_t old_size;
 129         size_t new_size;
 130
 131         if (new_max <= pfp->pool_size) {
 132                 return EINVAL;
 133         }
 134
 135         old_size = sizeof(struct pf_worker_data) * pfp->pool_size;
 136         new_size = sizeof(struct pf_worker_data) * new_max;
 137
 138         pool = mremap(pfp->pool, old_size, new_size, 0);
 139         if (pool == MAP_FAILED) {
 140                 DEBUG(3, ("Failed to mremap memory for prefork pool!\n"));
 141                 return ENOSPC;
 142         }
 143
 144         memset(&pool[pfp->pool_size], 0, new_size - old_size);
 145
 146         pfp->pool_size = new_max;
 147
 148         return 0;
 149 }
 150
 151 int prefork_add_children(struct tevent_context *ev_ctx,
 152                          struct prefork_pool *pfp,
 153                          int num_children)
 154 {
 155         pid_t pid;
 156         time_t now = time(NULL);
 157         int ret;
 158         int i, j;
 159
 160         for (i = 0, j = 0; i < pfp->pool_size && j < num_children; i++) {
 161
 162                 if (pfp->pool[i].status != PF_WORKER_NONE) {
 163                         continue;
 164                 }
 165
 166                 pfp->pool[i].allowed_clients = 1;
 167                 pfp->pool[i].started = now;
 168
 169                 pid = sys_fork();
 170                 switch (pid) {
 171                 case -1:
 172                         DEBUG(1, ("Failed to prefork child n. %d !\n", j));
 173                         break;
 174
 175                 case 0: /* THE CHILD */
 176
 177                         pfp->pool[i].status = PF_WORKER_IDLE;
 178                         ret = pfp->main_fn(ev_ctx, &pfp->pool[i],
 179                                            pfp->listen_fd, pfp->lock_fd,
 180                                            pfp->private_data);
 181
 182                         pfp->pool[i].status = PF_WORKER_EXITING;
 183                         exit(ret);
 184
 185                 default: /* THE PARENT */
 186                         pfp->pool[i].pid = pid;
 187                         j++;
 188                         break;
 189                 }
 190         }
 191
 192         DEBUG(5, ("Added %d children!\n", j));
 193
 194         return j;
 195 }
 196
 197 struct prefork_oldest {
 198         int num;
 199         time_t started;
 200 };
 201
 202 /* sort in inverse order */
 203 static int prefork_sort_oldest(const void *ap, const void *bp)
 204 {
 205         struct prefork_oldest *a = (struct prefork_oldest *)ap;
 206         struct prefork_oldest *b = (struct prefork_oldest *)bp;
 207
 208         if (a->started == b->started) {
 209                 return 0;
 210         }
 211         if (a->started < b->started) {
 212                 return 1;
 213         }
 214         return -1;
 215 }
 216
 217 int prefork_retire_children(struct prefork_pool *pfp,
 218                             int num_children, time_t age_limit)
 219 {
 220         time_t now = time(NULL);
 221         struct prefork_oldest *oldest;
 222         int i, j;
 223
 224         oldest = talloc_array(pfp, struct prefork_oldest, pfp->pool_size);
 225         if (!oldest) {
 226                 return -1;
 227         }
 228
 229         for (i = 0; i < pfp->pool_size; i++) {
 230                 oldest[i].num = i;
 231                 if (pfp->pool[i].status == PF_WORKER_IDLE) {
 232                         oldest[i].started = pfp->pool[i].started;
 233                 } else {
 234                         oldest[i].started = now;
 235                 }
 236         }
 237
 238         qsort(oldest, pfp->pool_size,
 239                 sizeof(struct prefork_oldest),
 240                 prefork_sort_oldest);
 241
 242         for (i = 0, j = 0; i < pfp->pool_size && j < num_children; i++) {
 243                 if (pfp->pool[i].status == PF_WORKER_IDLE &&
 244                     pfp->pool[i].started <= age_limit) {
 245                         /* tell the child it's time to give up */
 246                         DEBUG(5, ("Retiring pid %d!\n", pfp->pool[i].pid));
 247                         pfp->pool[i].cmds = PF_SRV_MSG_EXIT;
 248                         kill(pfp->pool[i].pid, SIGHUP);
 249                         j++;
 250                 }
 251         }
 252
 253         return j;
 254 }
 255
 256 int prefork_count_active_children(struct prefork_pool *pfp, int *total)
 257 {
 258         int i, a, t;
 259
 260         a = 0;
 261         t = 0;
 262         for (i = 0; i < pfp->pool_size; i++) {
 263                 if (pfp->pool[i].status == PF_WORKER_NONE) {
 264                         continue;
 265                 }
 266
 267                 t++;
 268
 269                 if (pfp->pool[i].num_clients == 0) {
 270                         continue;
 271                 }
 272
 273                 a++;
 274         }
 275
 276         *total = t;
 277         return a;
 278 }
 279
 280 /* to be used to finally mark a children as dead, so that it's slot can
 281  * be reused */
 282 bool prefork_mark_pid_dead(struct prefork_pool *pfp, pid_t pid)
 283 {
 284         int i;
 285
 286         for (i = 0; i < pfp->pool_size; i++) {
 287                 if (pfp->pool[i].pid == pid) {
 288                         if (pfp->pool[i].status != PF_WORKER_EXITING) {
 289                                 DEBUG(2, ("pid %d terminated abnormally!\n",
 290                                           (int)pid));
 291                         }
 292
 293                         /* reset all fields,
 294                          * this makes status = PF_WORK_NONE */
 295                         memset(&pfp->pool[i], 0,
 296                                 sizeof(struct pf_worker_data));
 297
 298                         return true;
 299                 }
 300         }
 301
 302         return false;
 303 }
 304
 305 void prefork_increase_allowed_clients(struct prefork_pool *pfp, int max)
 306 {
 307         int i;
 308
 309         for (i = 0; i < pfp->pool_size; i++) {
 310                 if (pfp->pool[i].status == PF_WORKER_NONE) {
 311                         continue;
 312                 }
 313
 314                 if (pfp->pool[i].allowed_clients < max) {
 315                         pfp->pool[i].allowed_clients++;
 316                 }
 317         }
 318 }
 319
 320 void prefork_reset_allowed_clients(struct prefork_pool *pfp)
 321 {
 322         int i;
 323
 324         for (i = 0; i < pfp->pool_size; i++) {
 325                 pfp->pool[i].allowed_clients = 1;
 326         }
 327 }
 328
 329 /* ==== Functions used by children ==== */
 330
 331 static SIG_ATOMIC_T pf_alarm;
 332
 333 static void pf_alarm_cb(int signum)
 334 {
 335         pf_alarm = 1;
 336 }
 337
 338
 339 /*
 340  * Parameters:
 341  * pf - the worker shared data structure
 342  * lock_fd - the file descriptor used for locking
 343  * timeout - expressed in seconds:
 344  *              -1 never timeouts,
 345  *              0 timeouts immediately
 346  *              N seconds before timing out
 347  *
 348  * Returns values:
 349  * negative errno on fatal error
 350  * 0 on success to acquire lock
 351  * -1 on timeout/lock held by other
 352  * -2 on server msg to terminate
 353  * ERRNO on other errors
 354  */
 355
 356 static int prefork_grab_lock(struct pf_worker_data *pf,
 357                              int lock_fd, int timeout)
 358 {
 359         struct flock lock;
 360         int op;
 361         int ret;
 362
 363         if (pf->cmds == PF_SRV_MSG_EXIT) {
 364                 return -2;
 365         }
 366
 367         pf_alarm = 0;
 368
 369         if (timeout > 0) {
 370                 CatchSignal(SIGALRM, pf_alarm_cb);
 371                 alarm(timeout);
 372         }
 373
 374         if (timeout == 0) {
 375                 op = F_SETLK;
 376         } else {
 377                 op = F_SETLKW;
 378         }
 379
 380         ret = 0;
 381         do {
 382                 ZERO_STRUCT(lock);
 383                 lock.l_type = F_WRLCK;
 384                 lock.l_whence = SEEK_SET;
 385
 386                 ret = fcntl(lock_fd, op, &lock);
 387                 if (ret == 0) break;
 388
 389                 ret = errno;
 390
 391                 if (pf->cmds == PF_SRV_MSG_EXIT) {
 392                         ret = -2;
 393                         goto done;
 394                 }
 395
 396                 switch (ret) {
 397                 case EINTR:
 398                         break;
 399
 400                 case EACCES:
 401                 case EAGAIN:
 402                         /* lock held by other proc */
 403                         ret = -1;
 404                         goto done;
 405                 default:
 406                         goto done;
 407                 }
 408
 409                 if (pf_alarm == 1) {
 410                         /* timed out */
 411                         ret = -1;
 412                         goto done;
 413                 }
 414         } while (timeout != 0);
 415
 416         if (ret != 0) {
 417                 /* We have the Lock */
 418                 pf->status = PF_WORKER_ACCEPTING;
 419         }
 420
 421 done:
 422         if (timeout > 0) {
 423                 alarm(0);
 424                 CatchSignal(SIGALRM, SIG_IGN);
 425         }
 426
 427         if (ret > 0) {
 428                 DEBUG(1, ("Failed to get lock (%d, %s)!\n",
 429                           ret, strerror(ret)));
 430         }
 431         return ret;
 432 }
 433
 434 /*
 435  * Parameters:
 436  * pf - the worker shared data structure
 437  * lock_fd - the file descriptor used for locking
 438  * timeout - expressed in seconds:
 439  *              -1 never timeouts,
 440  *              0 timeouts immediately
 441  *              N seconds before timing out
 442  *
 443  * Returns values:
 444  * negative errno on fatal error
 445  * 0 on success to release lock
 446  * -1 on timeout
 447  * ERRNO on error
 448  */
 449
 450 static int prefork_release_lock(struct pf_worker_data *pf,
 451                                 int lock_fd, int timeout)
 452 {
 453         struct flock lock;
 454         int op;
 455         int ret;
 456
 457         pf_alarm = 0;
 458
 459         if (timeout > 0) {
 460                 CatchSignal(SIGALRM, pf_alarm_cb);
 461                 alarm(timeout);
 462         }
 463
 464         if (timeout == 0) {
 465                 op = F_SETLK;
 466         } else {
 467                 op = F_SETLKW;
 468         }
 469
 470         do {
 471                 ZERO_STRUCT(lock);
 472                 lock.l_type = F_UNLCK;
 473                 lock.l_whence = SEEK_SET;
 474
 475                 ret = fcntl(lock_fd, op, &lock);
 476                 if (ret == 0) break;
 477
 478                 ret = errno;
 479
 480                 if (ret != EINTR) {
 481                         goto done;
 482                 }
 483
 484                 if (pf_alarm == 1) {
 485                         /* timed out */
 486                         ret = -1;
 487                         goto done;
 488                 }
 489         } while (timeout != 0);
 490
 491 done:
 492         if (timeout > 0) {
 493                 alarm(0);
 494                 CatchSignal(SIGALRM, SIG_IGN);
 495         }
 496
 497         if (ret > 0) {
 498                 DEBUG(1, ("Failed to release lock (%d, %s)!\n",
 499                           ret, strerror(ret)));
 500         }
 501         return ret;
 502 }
 503
 504 /* returns:
 505  * negative errno on error
 506  * -2 if server commands to terminate
 507  * 0 if all ok
 508  * ERRNO on other errors
 509  */
 510
 511 int prefork_wait_for_client(struct pf_worker_data *pf,
 512                             int lock_fd, int listen_fd,
 513                             struct sockaddr *addr,
 514                             socklen_t *addrlen, int *fd)
 515 {
 516         int ret;
 517         int sd = -1;
 518         int err;
 519
 520         ret = prefork_grab_lock(pf, lock_fd, -1);
 521         if (ret != 0) {
 522                 return ret;
 523         }
 524
 525         err = 0;
 526         do {
 527                 sd = accept(listen_fd, addr, addrlen);
 528
 529                 if (sd != -1) break;
 530
 531                 if (errno == EINTR) {
 532                         if (pf->cmds == PF_SRV_MSG_EXIT) {
 533                                 err = -2;
 534                         }
 535                 } else {
 536                         err = errno;
 537                 }
 538
 539         } while ((sd == -1) && (err == 0));
 540
 541         /* return lock now, even if the accept failed.
 542          * if it takes more than 10 seconds we are in deep trouble */
 543         ret = prefork_release_lock(pf, lock_fd, 2);
 544         if (ret != 0) {
 545                 /* we were unable to release the lock!! */
 546                 DEBUG(0, ("Terminating due to fatal failure!\n"));
 547
 548                 /* Just exit we cannot hold the whole server, better to error
 549                  * on this one client and hope it was a transiet problem */
 550                 err = -2;
 551         }
 552
 553         if (err != 0) {
 554                 if (sd != -1) {
 555                         close(sd);
 556                         sd = -1;
 557                 }
 558                 return err;
 559         }
 560
 561         pf->status = PF_WORKER_BUSY;
 562         pf->num_clients++;
 563         *fd = sd;
 564         return 0;
 565 }
 566
 567 /* ==== async code ==== */
 568
 569 #define PF_ASYNC_LOCK_GRAB      0x01
 570 #define PF_ASYNC_LOCK_RELEASE   0x02
 571 #define PF_ASYNC_ACTION_MASK    0x03
 572 #define PF_ASYNC_LOCK_DONE      0x04
 573
 574 struct pf_lock_state {
 575         struct pf_worker_data *pf;
 576         int lock_fd;
 577         int flags;
 578 };
 579
 580 static void prefork_lock_handler(struct tevent_context *ev,
 581                                         struct tevent_timer *te,
 582                                         struct timeval curtime, void *pvt);
 583
 584 static struct tevent_req *prefork_lock_send(TALLOC_CTX *mem_ctx,
 585                                                 struct tevent_context *ev,
 586                                                 struct pf_worker_data *pf,
 587                                                 int lock_fd, int action)
 588 {
 589         struct tevent_req *req;
 590         struct pf_lock_state *state;
 591
 592         req = tevent_req_create(mem_ctx, &state, struct pf_lock_state);
 593         if (!req) {
 594                 return NULL;
 595         }
 596
 597         state->pf = pf;
 598         state->lock_fd = lock_fd;
 599         state->flags = action;
 600
 601         /* try once immediately */
 602         prefork_lock_handler(ev, NULL, tevent_timeval_zero(), req);
 603         if (state->flags & PF_ASYNC_LOCK_DONE) {
 604                 tevent_req_post(req, ev);
 605         }
 606
 607         return req;
 608 }
 609
 610 static void prefork_lock_handler(struct tevent_context *ev,
 611                                  struct tevent_timer *te,
 612                                  struct timeval curtime, void *pvt)
 613 {
 614         struct tevent_req *req;
 615         struct pf_lock_state *state;
 616         int ret;
 617
 618         req = talloc_get_type_abort(pvt, struct tevent_req);
 619         state = tevent_req_data(req, struct pf_lock_state);
 620
 621         switch (state->flags & PF_ASYNC_ACTION_MASK) {
 622         case PF_ASYNC_LOCK_GRAB:
 623                 ret = prefork_grab_lock(state->pf, state->lock_fd, 0);
 624                 break;
 625         case PF_ASYNC_LOCK_RELEASE:
 626                 ret = prefork_release_lock(state->pf, state->lock_fd, 0);
 627                 break;
 628         default:
 629                 ret = EINVAL;
 630                 break;
 631         }
 632
 633         switch (ret) {
 634         case 0:
 635                 state->flags |= PF_ASYNC_LOCK_DONE;
 636                 tevent_req_done(req);
 637                 return;
 638         case -1:
 639                 te = tevent_add_timer(ev, state,
 640                                         tevent_timeval_current_ofs(1, 0),
 641                                         prefork_lock_handler, req);
 642                 tevent_req_nomem(te, req);
 643                 return;
 644         case -2:
 645                 /* server tells us to stop */
 646                 state->flags |= PF_ASYNC_LOCK_DONE;
 647                 tevent_req_error(req, -2);
 648                 return;
 649         default:
 650                 state->flags |= PF_ASYNC_LOCK_DONE;
 651                 tevent_req_error(req, ret);
 652                 return;
 653         }
 654 }
 655
 656 static int prefork_lock_recv(struct tevent_req *req)
 657 {
 658         int ret;
 659
 660         if (!tevent_req_is_unix_error(req, &ret)) {
 661                 ret = 0;
 662         }
 663
 664         tevent_req_received(req);
 665         return ret;
 666 }
 667
 668 struct pf_listen_state {
 669         struct tevent_context *ev;
 670         struct pf_worker_data *pf;
 671
 672         int lock_fd;
 673         int listen_fd;
 674
 675         struct sockaddr *addr;
 676         socklen_t *addrlen;
 677
 678         int accept_fd;
 679
 680         int error;
 681 };
 682
 683 static void prefork_listen_lock_done(struct tevent_req *subreq);
 684 static void prefork_listen_accept_handler(struct tevent_context *ev,
 685                                           struct tevent_fd *fde,
 686                                           uint16_t flags, void *pvt);
 687 static void prefork_listen_release_done(struct tevent_req *subreq);
 688
 689 struct tevent_req *prefork_listen_send(TALLOC_CTX *mem_ctx,
 690                                         struct tevent_context *ev,
 691                                         struct pf_worker_data *pf,
 692                                         int lock_fd, int listen_fd,
 693                                         struct sockaddr *addr,
 694                                         socklen_t *addrlen)
 695 {
 696         struct tevent_req *req, *subreq;
 697         struct pf_listen_state *state;
 698
 699         req = tevent_req_create(mem_ctx, &state, struct pf_listen_state);
 700         if (!req) {
 701                 return NULL;
 702         }
 703
 704         state->ev = ev;
 705         state->pf = pf;
 706         state->lock_fd = lock_fd;
 707         state->listen_fd = listen_fd;
 708         state->addr = addr;
 709         state->addrlen = addrlen;
 710         state->accept_fd = -1;
 711         state->error = 0;
 712
 713         subreq = prefork_lock_send(state, state->ev, state->pf,
 714                                    state->lock_fd, PF_ASYNC_LOCK_GRAB);
 715         if (tevent_req_nomem(subreq, req)) {
 716                 return tevent_req_post(req, ev);
 717         }
 718
 719         tevent_req_set_callback(subreq, prefork_listen_lock_done, req);
 720         return req;
 721 }
 722
 723 static void prefork_listen_lock_done(struct tevent_req *subreq)
 724 {
 725         struct tevent_req *req;
 726         struct pf_listen_state *state;
 727         struct tevent_fd *fde;
 728         int ret;
 729
 730         req = tevent_req_callback_data(subreq, struct tevent_req);
 731         state = tevent_req_data(req, struct pf_listen_state);
 732
 733         ret = prefork_lock_recv(subreq);
 734         if (ret != 0) {
 735                 tevent_req_error(req, ret);
 736                 return;
 737         }
 738
 739         /* next step, accept */
 740         fde = tevent_add_fd(state->ev, state,
 741                             state->listen_fd, TEVENT_FD_READ,
 742                             prefork_listen_accept_handler, req);
 743         tevent_req_nomem(fde, req);
 744 }
 745
 746 static void prefork_listen_accept_handler(struct tevent_context *ev,
 747                                           struct tevent_fd *fde,
 748                                           uint16_t flags, void *pvt)
 749 {
 750         struct pf_listen_state *state;
 751         struct tevent_req *req, *subreq;
 752         int err = 0;
 753         int sd = -1;
 754
 755         req = talloc_get_type_abort(pvt, struct tevent_req);
 756         state = tevent_req_data(req, struct pf_listen_state);
 757
 758         sd = accept(state->listen_fd, state->addr, state->addrlen);
 759         if (sd == -1) {
 760                 if (errno == EINTR) {
 761                         /* keep trying */
 762                         return;
 763                 }
 764                 err = errno;
 765                 DEBUG(6, ("Accept failed! (%d, %s)\n", err, strerror(err)));
 766
 767         }
 768
 769         /* do not track the listen fd anymore */
 770         talloc_free(fde);
 771         if (err) {
 772                 tevent_req_error(req, err);
 773                 return;
 774         }
 775
 776         state->accept_fd = sd;
 777
 778         /* release lock now */
 779         subreq = prefork_lock_send(state, state->ev, state->pf,
 780                                    state->lock_fd, PF_ASYNC_LOCK_RELEASE);
 781         if (tevent_req_nomem(subreq, req)) {
 782                 return;
 783         }
 784         tevent_req_set_callback(subreq, prefork_listen_release_done, req);
 785 }
 786
 787 static void prefork_listen_release_done(struct tevent_req *subreq)
 788 {
 789         struct tevent_req *req;
 790         int ret;
 791
 792         req = tevent_req_callback_data(subreq, struct tevent_req);
 793
 794         ret = prefork_lock_recv(subreq);
 795         if (ret != 0) {
 796                 tevent_req_error(req, ret);
 797                 return;
 798         }
 799
 800         tevent_req_done(req);
 801 }
 802
 803 int prefork_listen_recv(struct tevent_req *req, int *fd)
 804 {
 805         struct pf_listen_state *state;
 806         int ret;
 807
 808         state = tevent_req_data(req, struct pf_listen_state);
 809
 810         if (tevent_req_is_unix_error(req, &ret)) {
 811                 if (state->accept_fd != -1) {
 812                         close(state->accept_fd);
 813                 }
 814         } else {
 815                 *fd = state->accept_fd;
 816                 ret = 0;
 817                 state->pf->status = PF_WORKER_BUSY;
 818                 state->pf->num_clients++;
 819         }
 820
 821         tevent_req_received(req);
 822         return ret;
 823 }