src/frontend/sock.c

   1 /*
   2  * SysDB - src/frontend/sock.c
   3  * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "sysdb.h"
  33 #include "core/object.h"
  34 #include "frontend/connection-private.h"
  35 #include "frontend/sock.h"
  36
  37 #include "utils/channel.h"
  38 #include "utils/error.h"
  39 #include "utils/llist.h"
  40 #include "utils/os.h"
  41 #include "utils/strbuf.h"
  42
  43 #include <assert.h>
  44 #include <errno.h>
  45
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49
  50 #include <unistd.h>
  51
  52 #include <sys/time.h>
  53 #include <sys/types.h>
  54 #include <sys/select.h>
  55 #include <sys/socket.h>
  56 #include <sys/param.h>
  57 #include <sys/un.h>
  58
  59 #ifdef HAVE_UCRED_H
  60 #       include <ucred.h>
  61 #endif
  62 #ifdef HAVE_SYS_UCRED_H
  63 #       include <sys/ucred.h>
  64 #endif
  65
  66 #include <pwd.h>
  67
  68 #include <fcntl.h>
  69 #include <netdb.h>
  70 #include <libgen.h>
  71 #include <pthread.h>
  72
  73 /*
  74  * private data types
  75  */
  76
  77 typedef struct {
  78         char *address;
  79         int   type;
  80
  81         int sock_fd;
  82         int (*setup)(sdb_conn_t *, void *);
  83 } listener_t;
  84
  85 typedef struct {
  86         int type;
  87         const char *prefix;
  88
  89         int (*open)(listener_t *);
  90         void (*close)(listener_t *);
  91 } fe_listener_impl_t;
  92
  93 struct sdb_fe_socket {
  94         listener_t *listeners;
  95         size_t listeners_num;
  96
  97         /* list of open, idle connections; active connections will be passed on to
  98          * the connection handler threads which place them back after handling
  99          * pending actions; the trigger pipe is used to notify the main thread
 100          * after adding a connection (back) to the list */
 101         sdb_llist_t *open_connections;
 102         int trigger[2];
 103 #define TRIGGER_READ 0
 104 #define TRIGGER_WRITE 1
 105
 106         /* channel used for communication between main
 107          * and connection handler threads */
 108         sdb_channel_t *chan;
 109 };
 110
 111 /*
 112  * connection management functions
 113  */
 114
 115 static int
 116 setup_unixsock(sdb_conn_t *conn, void __attribute__((unused)) *user_data)
 117 {
 118         uid_t uid;
 119
 120         struct passwd pw_entry;
 121         struct passwd *result = NULL;
 122         char buf[1024];
 123
 124 #ifdef SO_PEERCRED
 125         struct ucred cred;
 126         socklen_t len = sizeof(cred);
 127
 128         if (getsockopt(conn->fd, SOL_SOCKET, SO_PEERCRED, &cred, &len)
 129                         || (len != sizeof(cred))) {
 130                 char errbuf[1024];
 131                 sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
 132                                 "connection conn#%i: %s", conn->fd,
 133                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 134                 return -1;
 135         }
 136         uid = cred.uid;
 137 #else /* SO_PEERCRED */
 138         sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
 139                         "connection conn#%i: operation not supported", conn->fd);
 140         return -1;
 141 #endif
 142
 143         memset(&pw_entry, 0, sizeof(pw_entry));
 144         if (getpwuid_r(uid, &pw_entry, buf, sizeof(buf), &result) || (! result)
 145                         || (! (conn->username = strdup(result->pw_name)))) {
 146                 char errbuf[1024];
 147                 sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
 148                                 "connection conn#%i: %s", conn->fd,
 149                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 150                 return -1;
 151         }
 152         return 0;
 153 } /* setup_unixsock */
 154
 155 static int
 156 open_unixsock(listener_t *listener)
 157 {
 158         char *addr_copy;
 159         char *base_dir;
 160         struct sockaddr_un sa;
 161         int status;
 162
 163         listener->sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
 164         if (listener->sock_fd < 0) {
 165                 char buf[1024];
 166                 sdb_log(SDB_LOG_ERR, "frontend: Failed to open UNIX socket %s: %s",
 167                                 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
 168                 return -1;
 169         }
 170
 171         memset(&sa, 0, sizeof(sa));
 172         sa.sun_family = AF_UNIX;
 173         strncpy(sa.sun_path, listener->address, sizeof(sa.sun_path));
 174
 175         addr_copy = strdup(listener->address);
 176         if (! addr_copy) {
 177                 char errbuf[1024];
 178                 sdb_log(SDB_LOG_ERR, "frontend: strdup failed: %s",
 179                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 180                 return -1;
 181         }
 182         base_dir = dirname(addr_copy);
 183
 184         /* ensure that the directory exists */
 185         if (sdb_mkdir_all(base_dir, 0777)) {
 186                 char errbuf[1024];
 187                 sdb_log(SDB_LOG_ERR, "frontend: Failed to create directory '%s': %s",
 188                                 base_dir, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 189                 free(addr_copy);
 190                 return -1;
 191         }
 192         free(addr_copy);
 193
 194         if (unlink(listener->address) && (errno != ENOENT)) {
 195                 char errbuf[1024];
 196                 sdb_log(SDB_LOG_WARNING, "frontend: Failed to remove stale UNIX "
 197                                 "socket %s: %s", listener->address,
 198                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 199         }
 200
 201         status = bind(listener->sock_fd, (struct sockaddr *)&sa, sizeof(sa));
 202         if (status) {
 203                 char buf[1024];
 204                 sdb_log(SDB_LOG_ERR, "frontend: Failed to bind to UNIX socket %s: %s",
 205                                 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
 206                 return -1;
 207         }
 208
 209         listener->setup = setup_unixsock;
 210         return 0;
 211 } /* open_unixsock */
 212
 213 static void
 214 close_unixsock(listener_t *listener)
 215 {
 216         assert(listener);
 217
 218         if (! listener->address)
 219                 return;
 220
 221         if (listener->sock_fd >= 0)
 222                 close(listener->sock_fd);
 223         listener->sock_fd = -1;
 224
 225         unlink(listener->address);
 226 } /* close_unixsock */
 227
 228 static int
 229 open_tcp(listener_t *listener)
 230 {
 231         struct addrinfo *ai, *ai_list = NULL;
 232         int status;
 233
 234         assert(listener);
 235
 236         if ((status = sdb_resolve(SDB_NET_TCP, listener->address, &ai_list))) {
 237                 sdb_log(SDB_LOG_ERR, "frontend: Failed to resolve '%s': %s",
 238                                 listener->address, gai_strerror(status));
 239                 return -1;
 240         }
 241
 242         for (ai = ai_list; ai != NULL; ai = ai->ai_next) {
 243                 char errbuf[1024];
 244                 int reuse = 1;
 245
 246                 listener->sock_fd = socket(ai->ai_family,
 247                                 ai->ai_socktype, ai->ai_protocol);
 248                 if (listener->sock_fd < 0) {
 249                         sdb_log(SDB_LOG_ERR, "frontend: Failed to open socket for %s: %s",
 250                                         listener->address,
 251                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 252                         continue;
 253                 }
 254
 255                 if (setsockopt(listener->sock_fd, SOL_SOCKET, SO_REUSEADDR,
 256                                         &reuse, sizeof(reuse)) < 0) {
 257                         sdb_log(SDB_LOG_ERR, "frontend: Failed to set socket option: %s",
 258                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 259                         close(listener->sock_fd);
 260                         listener->sock_fd = -1;
 261                         continue;
 262                 }
 263
 264                 if (bind(listener->sock_fd, ai->ai_addr, ai->ai_addrlen) < 0) {
 265                         char host[1024], port[32];
 266                         getnameinfo(ai->ai_addr, ai->ai_addrlen, host, sizeof(host),
 267                                         port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV);
 268                         sdb_log(SDB_LOG_ERR, "frontend: Failed to bind to %s:%s: %s",
 269                                         host, port, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 270                         close(listener->sock_fd);
 271                         listener->sock_fd = -1;
 272                         continue;
 273                 }
 274                 break;
 275         }
 276         freeaddrinfo(ai_list);
 277
 278         if (listener->sock_fd < 0)
 279                 return -1;
 280         return 0;
 281 } /* open_tcp */
 282
 283 static void
 284 close_tcp(listener_t *listener)
 285 {
 286         assert(listener);
 287
 288         if (listener->sock_fd >= 0)
 289                 close(listener->sock_fd);
 290         listener->sock_fd = -1;
 291 } /* close_tcp */
 292
 293 /*
 294  * private variables
 295  */
 296
 297 /* the enum has to be sorted the same as the implementations array
 298  * to ensure that the type may be used as index into the array */
 299 enum {
 300         LISTENER_TCP = 0, /* this is the default */
 301         LISTENER_UNIXSOCK,
 302 };
 303 static fe_listener_impl_t listener_impls[] = {
 304         { LISTENER_TCP,      "tcp",  open_tcp,      close_tcp },
 305         { LISTENER_UNIXSOCK, "unix", open_unixsock, close_unixsock },
 306 };
 307
 308 /*
 309  * private helper functions
 310  */
 311
 312 static int
 313 listener_listen(listener_t *listener)
 314 {
 315         assert(listener);
 316
 317         /* try to reopen */
 318         if (listener->sock_fd < 0)
 319                 if (listener_impls[listener->type].open(listener))
 320                         return -1;
 321         assert(listener->sock_fd >= 0);
 322
 323         if (listen(listener->sock_fd, /* backlog = */ 32)) {
 324                 char buf[1024];
 325                 sdb_log(SDB_LOG_ERR, "frontend: Failed to listen on socket %s: %s",
 326                                 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
 327                 return -1;
 328         }
 329         return 0;
 330 } /* listener_listen */
 331
 332 static void
 333 listener_close(listener_t *listener)
 334 {
 335         assert(listener);
 336
 337         if (listener_impls[listener->type].close)
 338                 listener_impls[listener->type].close(listener);
 339
 340         if (listener->sock_fd >= 0)
 341                 close(listener->sock_fd);
 342         listener->sock_fd = -1;
 343 } /* listener_close */
 344
 345 static int
 346 get_type(const char *address)
 347 {
 348         char *sep;
 349         size_t len;
 350         size_t i;
 351
 352         if (*address == '/')
 353                 return LISTENER_UNIXSOCK;
 354         sep = strchr(address, (int)':');
 355         if (! sep)
 356                 return listener_impls[0].type;
 357
 358         assert(sep > address);
 359         len = (size_t)(sep - address);
 360
 361         for (i = 0; i < SDB_STATIC_ARRAY_LEN(listener_impls); ++i) {
 362                 fe_listener_impl_t *impl = listener_impls + i;
 363
 364                 if (!strncmp(address, impl->prefix, len)) {
 365                         assert(impl->type == (int)i);
 366                         return impl->type;
 367                 }
 368         }
 369         return -1;
 370 } /* get_type */
 371
 372 static void
 373 listener_destroy(listener_t *listener)
 374 {
 375         if (! listener)
 376                 return;
 377
 378         listener_close(listener);
 379
 380         if (listener->address)
 381                 free(listener->address);
 382         listener->address = NULL;
 383 } /* listener_destroy */
 384
 385 static listener_t *
 386 listener_create(sdb_fe_socket_t *sock, const char *address)
 387 {
 388         listener_t *listener;
 389         size_t len;
 390         int type;
 391
 392         type = get_type(address);
 393         if (type < 0) {
 394                 sdb_log(SDB_LOG_ERR, "frontend: Unsupported address type specified "
 395                                 "in listen address '%s'", address);
 396                 return NULL;
 397         }
 398
 399         listener = realloc(sock->listeners,
 400                         (sock->listeners_num + 1) * sizeof(*sock->listeners));
 401         if (! listener) {
 402                 char buf[1024];
 403                 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
 404                                 sdb_strerror(errno, buf, sizeof(buf)));
 405                 return NULL;
 406         }
 407
 408         sock->listeners = listener;
 409         listener = sock->listeners + sock->listeners_num;
 410
 411         len = strlen(listener_impls[type].prefix);
 412         if ((! strncmp(address, listener_impls[type].prefix, len))
 413                         && (address[len] == ':'))
 414                 address += strlen(listener_impls[type].prefix) + 1;
 415
 416         listener->sock_fd = -1;
 417         listener->address = strdup(address);
 418         if (! listener->address) {
 419                 char buf[1024];
 420                 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
 421                                 sdb_strerror(errno, buf, sizeof(buf)));
 422                 listener_destroy(listener);
 423                 return NULL;
 424         }
 425         listener->type = type;
 426         listener->setup = NULL;
 427
 428         if (listener_impls[type].open(listener)) {
 429                 /* prints error */
 430                 listener_destroy(listener);
 431                 return NULL;
 432         }
 433
 434         ++sock->listeners_num;
 435         return listener;
 436 } /* listener_create */
 437
 438 static void
 439 socket_clear(sdb_fe_socket_t *sock)
 440 {
 441         size_t i;
 442
 443         assert(sock);
 444         for (i = 0; i < sock->listeners_num; ++i)
 445                 listener_destroy(sock->listeners + i);
 446         if (sock->listeners)
 447                 free(sock->listeners);
 448         sock->listeners = NULL;
 449         sock->listeners_num = 0;
 450 } /* socket_clear */
 451
 452 static void
 453 socket_close(sdb_fe_socket_t *sock)
 454 {
 455         size_t i;
 456
 457         assert(sock);
 458         for (i = 0; i < sock->listeners_num; ++i)
 459                 listener_close(sock->listeners + i);
 460 } /* socket_close */
 461
 462 /*
 463  * connection handler functions
 464  */
 465
 466 static void *
 467 connection_handler(void *data)
 468 {
 469         sdb_fe_socket_t *sock = data;
 470
 471         assert(sock);
 472
 473         while (42) {
 474                 struct timespec timeout = { 0, 500000000 }; /* .5 seconds */
 475                 sdb_conn_t *conn;
 476                 int status;
 477
 478                 errno = 0;
 479                 status = sdb_channel_select(sock->chan, /* read */ NULL, &conn,
 480                                 /* write */ NULL, NULL, &timeout);
 481                 if (status) {
 482                         char buf[1024];
 483
 484                         if (errno == ETIMEDOUT)
 485                                 continue;
 486                         if (errno == EBADF) /* channel shut down */
 487                                 break;
 488
 489                         sdb_log(SDB_LOG_ERR, "frontend: Failed to read from channel: %s",
 490                                         sdb_strerror(errno, buf, sizeof(buf)));
 491                         continue;
 492                 }
 493
 494                 status = (int)sdb_connection_handle(conn);
 495                 if (status <= 0) {
 496                         /* error or EOF -> close connection */
 497                         sdb_object_deref(SDB_OBJ(conn));
 498                         continue;
 499                 }
 500
 501                 /* return the connection to the main loop */
 502                 if (sdb_llist_append(sock->open_connections, SDB_OBJ(conn))) {
 503                         sdb_log(SDB_LOG_ERR, "frontend: Failed to re-append "
 504                                         "connection %s to list of open connections",
 505                                         SDB_OBJ(conn)->name);
 506                 }
 507                 write(sock->trigger[TRIGGER_WRITE], "", 1);
 508
 509                 /* pass ownership back to list; or destroy in case of an error */
 510                 sdb_object_deref(SDB_OBJ(conn));
 511         }
 512         return NULL;
 513 } /* connection_handler */
 514
 515 static int
 516 connection_accept(sdb_fe_socket_t *sock, listener_t *listener)
 517 {
 518         sdb_object_t *obj;
 519         int status;
 520
 521         obj = SDB_OBJ(sdb_connection_accept(listener->sock_fd,
 522                                 listener->setup, NULL));
 523         if (! obj)
 524                 return -1;
 525
 526         status = sdb_llist_append(sock->open_connections, obj);
 527         if (status)
 528                 sdb_log(SDB_LOG_ERR, "frontend: Failed to append "
 529                                 "connection %s to list of open connections",
 530                                 obj->name);
 531
 532         /* hand ownership over to the list; or destroy in case of an error */
 533         sdb_object_deref(obj);
 534         return status;
 535 } /* connection_accept */
 536
 537 static int
 538 socket_handle_incoming(sdb_fe_socket_t *sock,
 539                 fd_set *ready, fd_set *exceptions)
 540 {
 541         sdb_llist_iter_t *iter;
 542         size_t i;
 543
 544         for (i = 0; i < sock->listeners_num; ++i) {
 545                 listener_t *listener = sock->listeners + i;
 546                 if (FD_ISSET(listener->sock_fd, ready))
 547                         if (connection_accept(sock, listener))
 548                                 continue;
 549         }
 550
 551         iter = sdb_llist_get_iter(sock->open_connections);
 552         if (! iter) {
 553                 sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
 554                                 "for open connections");
 555                 return -1;
 556         }
 557
 558         while (sdb_llist_iter_has_next(iter)) {
 559                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 560
 561                 if (FD_ISSET(CONN(obj)->fd, exceptions)) {
 562                         sdb_log(SDB_LOG_INFO, "Exception on fd %d",
 563                                         CONN(obj)->fd);
 564                         /* close the connection */
 565                         sdb_llist_iter_remove_current(iter);
 566                         sdb_object_deref(obj);
 567                         continue;
 568                 }
 569
 570                 if (FD_ISSET(CONN(obj)->fd, ready)) {
 571                         sdb_llist_iter_remove_current(iter);
 572                         sdb_channel_write(sock->chan, &obj);
 573                 }
 574         }
 575         sdb_llist_iter_destroy(iter);
 576         return 0;
 577 } /* socket_handle_incoming */
 578
 579 /*
 580  * public API
 581  */
 582
 583 sdb_fe_socket_t *
 584 sdb_fe_sock_create(void)
 585 {
 586         sdb_fe_socket_t *sock;
 587         int flags;
 588
 589         sock = calloc(1, sizeof(*sock));
 590         if (! sock)
 591                 return NULL;
 592         sock->trigger[TRIGGER_READ] = sock->trigger[TRIGGER_WRITE] = -1;
 593
 594         sock->open_connections = sdb_llist_create();
 595         if (! sock->open_connections) {
 596                 sdb_fe_sock_destroy(sock);
 597                 return NULL;
 598         }
 599
 600         if (pipe(sock->trigger)) {
 601                 char errbuf[1024];
 602                 sdb_log(SDB_LOG_ERR, "frontend: Failed to create pipe: %s",
 603                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 604                 sdb_fe_sock_destroy(sock);
 605                 return NULL;
 606         }
 607         /* TODO: Can we do a zero-byte write as well to trigger select()?
 608          * Linux does not seem to support the I_SWROPT ioctl on a pipe. */
 609         flags = fcntl(sock->trigger[TRIGGER_WRITE], F_GETFL);
 610         if (fcntl(sock->trigger[TRIGGER_WRITE], F_SETFL, flags | O_NONBLOCK)) {
 611                 char errbuf[1024];
 612                 sdb_log(SDB_LOG_ERR, "frontend: Failed to switch pipe to non-blocking "
 613                                 "mode: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 614                 sdb_fe_sock_destroy(sock);
 615                 return NULL;
 616         }
 617         flags = fcntl(sock->trigger[TRIGGER_READ], F_GETFL);
 618         if (fcntl(sock->trigger[TRIGGER_READ], F_SETFL, flags | O_NONBLOCK)) {
 619                 char errbuf[1024];
 620                 sdb_log(SDB_LOG_ERR, "frontend: Failed to switch pipe to non-blocking "
 621                                 "mode: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 622                 sdb_fe_sock_destroy(sock);
 623                 return NULL;
 624         }
 625         return sock;
 626 } /* sdb_fe_sock_create */
 627
 628 void
 629 sdb_fe_sock_destroy(sdb_fe_socket_t *sock)
 630 {
 631         if (! sock)
 632                 return;
 633
 634         socket_clear(sock);
 635
 636         if (sock->trigger[TRIGGER_WRITE] >= 0)
 637                 close(sock->trigger[TRIGGER_WRITE]);
 638         if (sock->trigger[TRIGGER_READ] >= 0)
 639                 close(sock->trigger[TRIGGER_READ]);
 640         sock->trigger[TRIGGER_READ] = sock->trigger[TRIGGER_WRITE] = -1;
 641
 642         sdb_llist_destroy(sock->open_connections);
 643         sock->open_connections = NULL;
 644         free(sock);
 645 } /* sdb_fe_sock_destroy */
 646
 647 int
 648 sdb_fe_sock_add_listener(sdb_fe_socket_t *sock, const char *address)
 649 {
 650         listener_t *listener;
 651
 652         if ((! sock) || (! address))
 653                 return -1;
 654
 655         listener = listener_create(sock, address);
 656         if (! listener)
 657                 return -1;
 658         return 0;
 659 } /* sdb_fe_sock_add_listener */
 660
 661 void
 662 sdb_fe_sock_clear_listeners(sdb_fe_socket_t *sock)
 663 {
 664         if (! sock)
 665                 return;
 666
 667         socket_clear(sock);
 668 } /* sdb_fe_sock_clear_listeners */
 669
 670 int
 671 sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
 672 {
 673         fd_set sockets;
 674         int max_listen_fd = 0;
 675         size_t i;
 676
 677         pthread_t handler_threads[loop->num_threads];
 678         size_t num_threads;
 679
 680         if ((! sock) || (! sock->listeners_num) || sock->chan
 681                         || (! loop) || (loop->num_threads <= 0))
 682                 return -1;
 683
 684         if (! loop->do_loop)
 685                 return 0;
 686
 687         FD_ZERO(&sockets);
 688         for (i = 0; i < sock->listeners_num; ++i) {
 689                 listener_t *listener = sock->listeners + i;
 690
 691                 if (listener_listen(listener)) {
 692                         socket_close(sock);
 693                         return -1;
 694                 }
 695
 696                 FD_SET(listener->sock_fd, &sockets);
 697                 if (listener->sock_fd > max_listen_fd)
 698                         max_listen_fd = listener->sock_fd;
 699         }
 700
 701         sock->chan = sdb_channel_create(1024, sizeof(sdb_conn_t *));
 702         if (! sock->chan) {
 703                 socket_close(sock);
 704                 return -1;
 705         }
 706
 707         sdb_log(SDB_LOG_INFO, "frontend: Starting %zu connection "
 708                         "handler thread%s managing %zu listener%s",
 709                         loop->num_threads, loop->num_threads == 1 ? "" : "s",
 710                         sock->listeners_num, sock->listeners_num == 1 ? "" : "s");
 711
 712         num_threads = loop->num_threads;
 713         memset(&handler_threads, 0, sizeof(handler_threads));
 714         for (i = 0; i < num_threads; ++i) {
 715                 errno = 0;
 716                 if (pthread_create(&handler_threads[i], /* attr = */ NULL,
 717                                         connection_handler, /* arg = */ sock)) {
 718                         char errbuf[1024];
 719                         sdb_log(SDB_LOG_ERR, "frontend: Failed to create "
 720                                         "connection handler thread: %s",
 721                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 722                         num_threads = i;
 723                         break;
 724                 }
 725         }
 726
 727         while (loop->do_loop && num_threads) {
 728                 struct timeval timeout = { 1, 0 }; /* one second */
 729                 sdb_llist_iter_t *iter;
 730
 731                 int max_fd = max_listen_fd;
 732                 fd_set ready;
 733                 fd_set exceptions;
 734                 int n;
 735
 736                 FD_ZERO(&ready);
 737                 FD_ZERO(&exceptions);
 738
 739                 ready = sockets;
 740                 FD_SET(sock->trigger[TRIGGER_READ], &ready);
 741
 742                 iter = sdb_llist_get_iter(sock->open_connections);
 743                 if (! iter) {
 744                         sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
 745                                         "for open connections");
 746                         break;
 747                 }
 748
 749                 while (sdb_llist_iter_has_next(iter)) {
 750                         sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 751
 752                         if (CONN(obj)->fd < 0) {
 753                                 sdb_llist_iter_remove_current(iter);
 754                                 sdb_object_deref(obj);
 755                                 continue;
 756                         }
 757
 758                         FD_SET(CONN(obj)->fd, &ready);
 759                         FD_SET(CONN(obj)->fd, &exceptions);
 760
 761                         if (CONN(obj)->fd > max_fd)
 762                                 max_fd = CONN(obj)->fd;
 763                 }
 764                 sdb_llist_iter_destroy(iter);
 765
 766                 errno = 0;
 767                 n = select(max_fd + 1, &ready, NULL, &exceptions, &timeout);
 768                 if (n < 0) {
 769                         char buf[1024];
 770
 771                         if (errno == EINTR)
 772                                 continue;
 773
 774                         sdb_log(SDB_LOG_ERR, "frontend: Failed to monitor sockets: %s",
 775                                         sdb_strerror(errno, buf, sizeof(buf)));
 776                         break;
 777                 }
 778                 else if (! n)
 779                         continue;
 780
 781                 if (FD_ISSET(sock->trigger[TRIGGER_READ], &ready)) {
 782                         char buf[1024];
 783                         while (read(sock->trigger[TRIGGER_READ], buf, sizeof(buf)) > 0)
 784                                 /* do nothing */;
 785                 }
 786
 787                 /* handle new and open connections */
 788                 if (socket_handle_incoming(sock, &ready, &exceptions))
 789                         break;
 790         }
 791
 792         socket_close(sock);
 793
 794         sdb_log(SDB_LOG_INFO, "frontend: Waiting for connection handler threads "
 795                         "to terminate");
 796         if (! sdb_channel_shutdown(sock->chan))
 797                 for (i = 0; i < num_threads; ++i)
 798                         pthread_join(handler_threads[i], NULL);
 799         /* else: we tried our best; let the operating system clean up */
 800
 801         sdb_channel_destroy(sock->chan);
 802         sock->chan = NULL;
 803
 804         if (! num_threads)
 805                 return -1;
 806         return 0;
 807 } /* sdb_fe_sock_listen_and_server */
 808
 809 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 810