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/ssl.h"
  42 #include "utils/strbuf.h"
  43
  44 #include <assert.h>
  45 #include <errno.h>
  46
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50
  51 #include <unistd.h>
  52
  53 #include <sys/time.h>
  54 #include <sys/types.h>
  55 #include <sys/select.h>
  56 #include <sys/socket.h>
  57 #include <sys/param.h>
  58 #include <sys/un.h>
  59
  60 #ifdef HAVE_UCRED_H
  61 #       include <ucred.h>
  62 #endif
  63 #ifdef HAVE_SYS_UCRED_H
  64 #       include <sys/ucred.h>
  65 #endif
  66
  67 #include <pwd.h>
  68
  69 #include <fcntl.h>
  70 #include <netdb.h>
  71 #include <libgen.h>
  72 #include <pthread.h>
  73
  74 /*
  75  * private data types
  76  */
  77
  78 typedef struct {
  79         char *address;
  80         int   type;
  81
  82         /* optional SSL settings */
  83         sdb_ssl_options_t ssl_opts;
  84         sdb_ssl_server_t *ssl;
  85
  86         /* listener configuration */
  87         int sock_fd;
  88         int (*setup)(sdb_conn_t *, void *);
  89 } listener_t;
  90
  91 typedef struct {
  92         int type;
  93         const char *prefix;
  94
  95         int (*open)(listener_t *);
  96         void (*close)(listener_t *);
  97 } fe_listener_impl_t;
  98
  99 struct sdb_fe_socket {
 100         listener_t *listeners;
 101         size_t listeners_num;
 102
 103         /* list of open, idle connections; active connections will be passed on to
 104          * the connection handler threads which place them back after handling
 105          * pending actions; the trigger pipe is used to notify the main thread
 106          * after adding a connection (back) to the list */
 107         sdb_llist_t *open_connections;
 108         int trigger[2];
 109 #define TRIGGER_READ 0
 110 #define TRIGGER_WRITE 1
 111
 112         /* channel used for communication between main
 113          * and connection handler threads */
 114         sdb_channel_t *chan;
 115 };
 116
 117 /*
 118  * SSL helper functions
 119  */
 120
 121 static ssize_t
 122 ssl_read(sdb_conn_t *conn, size_t n)
 123 {
 124         char buf[n];
 125         ssize_t ret;
 126
 127         ret = sdb_ssl_session_read(conn->ssl_session, buf, n);
 128         if (ret <= 0)
 129                 return ret;
 130
 131         sdb_strbuf_memappend(conn->buf, buf, ret);
 132         return ret;
 133 } /* ssl_read */
 134
 135 static ssize_t
 136 ssl_write(sdb_conn_t *conn, const void *buf, size_t n)
 137 {
 138         return sdb_ssl_session_write(conn->ssl_session, buf, n);
 139 } /* ssl_write */
 140
 141 /*
 142  * connection management functions
 143  */
 144
 145 static int
 146 setup_unixsock(sdb_conn_t *conn, void __attribute__((unused)) *user_data)
 147 {
 148         uid_t uid;
 149
 150         struct passwd pw_entry;
 151         struct passwd *result = NULL;
 152         char buf[1024];
 153
 154 #ifdef SO_PEERCRED
 155         struct ucred cred;
 156         socklen_t len = sizeof(cred);
 157
 158         if (getsockopt(conn->fd, SOL_SOCKET, SO_PEERCRED, &cred, &len)
 159                         || (len != sizeof(cred))) {
 160                 char errbuf[1024];
 161                 sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
 162                                 "connection conn#%i: %s", conn->fd,
 163                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 164                 return -1;
 165         }
 166         uid = cred.uid;
 167 #else /* SO_PEERCRED */
 168         sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
 169                         "connection conn#%i: operation not supported", conn->fd);
 170         return -1;
 171 #endif
 172
 173         memset(&pw_entry, 0, sizeof(pw_entry));
 174         if (getpwuid_r(uid, &pw_entry, buf, sizeof(buf), &result) || (! result)
 175                         || (! (conn->username = strdup(result->pw_name)))) {
 176                 char errbuf[1024];
 177                 sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
 178                                 "connection conn#%i: %s", conn->fd,
 179                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 180                 return -1;
 181         }
 182         return 0;
 183 } /* setup_unixsock */
 184
 185 static int
 186 open_unixsock(listener_t *listener)
 187 {
 188         char *addr_copy;
 189         char *base_dir;
 190         struct sockaddr_un sa;
 191         int status;
 192
 193         listener->sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
 194         if (listener->sock_fd < 0) {
 195                 char buf[1024];
 196                 sdb_log(SDB_LOG_ERR, "frontend: Failed to open UNIX socket %s: %s",
 197                                 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
 198                 return -1;
 199         }
 200
 201         memset(&sa, 0, sizeof(sa));
 202         sa.sun_family = AF_UNIX;
 203         strncpy(sa.sun_path, listener->address, sizeof(sa.sun_path));
 204
 205         addr_copy = strdup(listener->address);
 206         if (! addr_copy) {
 207                 char errbuf[1024];
 208                 sdb_log(SDB_LOG_ERR, "frontend: strdup failed: %s",
 209                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 210                 return -1;
 211         }
 212         base_dir = dirname(addr_copy);
 213
 214         /* ensure that the directory exists */
 215         if (sdb_mkdir_all(base_dir, 0777)) {
 216                 char errbuf[1024];
 217                 sdb_log(SDB_LOG_ERR, "frontend: Failed to create directory '%s': %s",
 218                                 base_dir, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 219                 free(addr_copy);
 220                 return -1;
 221         }
 222         free(addr_copy);
 223
 224         if (unlink(listener->address) && (errno != ENOENT)) {
 225                 char errbuf[1024];
 226                 sdb_log(SDB_LOG_WARNING, "frontend: Failed to remove stale UNIX "
 227                                 "socket %s: %s", listener->address,
 228                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 229         }
 230
 231         status = bind(listener->sock_fd, (struct sockaddr *)&sa, sizeof(sa));
 232         if (status) {
 233                 char buf[1024];
 234                 sdb_log(SDB_LOG_ERR, "frontend: Failed to bind to UNIX socket %s: %s",
 235                                 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
 236                 return -1;
 237         }
 238
 239         listener->setup = setup_unixsock;
 240         return 0;
 241 } /* open_unixsock */
 242
 243 static void
 244 close_unixsock(listener_t *listener)
 245 {
 246         assert(listener);
 247
 248         if (! listener->address)
 249                 return;
 250
 251         if (listener->sock_fd >= 0)
 252                 close(listener->sock_fd);
 253         listener->sock_fd = -1;
 254
 255         unlink(listener->address);
 256 } /* close_unixsock */
 257
 258 static int
 259 finish_tcp(sdb_conn_t *conn)
 260 {
 261         if (! conn->ssl_session)
 262                 return 0;
 263
 264         sdb_ssl_session_destroy(conn->ssl_session);
 265         conn->ssl_session = NULL;
 266         return 0;
 267 } /* finish_tcp */
 268
 269 static int
 270 setup_tcp(sdb_conn_t *conn, void *user_data)
 271 {
 272         listener_t *listener = user_data;
 273
 274         conn->ssl_session = sdb_ssl_server_accept(listener->ssl, conn->fd);
 275         if (! conn->ssl_session)
 276                 return -1;
 277
 278         conn->username = sdb_ssl_session_peer(conn->ssl_session);
 279
 280         conn->finish = finish_tcp;
 281         conn->read = ssl_read;
 282         conn->write = ssl_write;
 283         return 0;
 284 } /* setup_tcp */
 285
 286 static int
 287 open_tcp(listener_t *listener)
 288 {
 289         struct addrinfo *ai, *ai_list = NULL;
 290         int status;
 291
 292         assert(listener);
 293
 294         listener->ssl = sdb_ssl_server_create(&listener->ssl_opts);
 295         if (! listener->ssl)
 296                 return -1;
 297
 298         if ((status = sdb_resolve(SDB_NET_TCP, listener->address, &ai_list))) {
 299                 sdb_log(SDB_LOG_ERR, "frontend: Failed to resolve '%s': %s",
 300                                 listener->address, gai_strerror(status));
 301                 return -1;
 302         }
 303
 304         for (ai = ai_list; ai != NULL; ai = ai->ai_next) {
 305                 char errbuf[1024];
 306                 int reuse = 1;
 307
 308                 listener->sock_fd = socket(ai->ai_family,
 309                                 ai->ai_socktype, ai->ai_protocol);
 310                 if (listener->sock_fd < 0) {
 311                         sdb_log(SDB_LOG_ERR, "frontend: Failed to open socket for %s: %s",
 312                                         listener->address,
 313                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 314                         continue;
 315                 }
 316
 317                 if (setsockopt(listener->sock_fd, SOL_SOCKET, SO_REUSEADDR,
 318                                         &reuse, sizeof(reuse)) < 0) {
 319                         sdb_log(SDB_LOG_ERR, "frontend: Failed to set socket option: %s",
 320                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 321                         close(listener->sock_fd);
 322                         listener->sock_fd = -1;
 323                         continue;
 324                 }
 325
 326                 if (bind(listener->sock_fd, ai->ai_addr, ai->ai_addrlen) < 0) {
 327                         char host[1024], port[32];
 328                         getnameinfo(ai->ai_addr, ai->ai_addrlen, host, sizeof(host),
 329                                         port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV);
 330                         sdb_log(SDB_LOG_ERR, "frontend: Failed to bind to %s:%s: %s",
 331                                         host, port, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 332                         close(listener->sock_fd);
 333                         listener->sock_fd = -1;
 334                         continue;
 335                 }
 336                 break;
 337         }
 338         freeaddrinfo(ai_list);
 339
 340         if (listener->sock_fd < 0)
 341                 return -1;
 342
 343         listener->setup = setup_tcp;
 344         return 0;
 345 } /* open_tcp */
 346
 347 static void
 348 close_tcp(listener_t *listener)
 349 {
 350         assert(listener);
 351
 352         sdb_ssl_server_destroy(listener->ssl);
 353         listener->ssl = NULL;
 354
 355         if (listener->sock_fd >= 0)
 356                 close(listener->sock_fd);
 357         listener->sock_fd = -1;
 358 } /* close_tcp */
 359
 360 /*
 361  * private variables
 362  */
 363
 364 /* the enum has to be sorted the same as the implementations array
 365  * to ensure that the type may be used as index into the array */
 366 enum {
 367         LISTENER_TCP = 0, /* this is the default */
 368         LISTENER_UNIXSOCK,
 369 };
 370 static fe_listener_impl_t listener_impls[] = {
 371         { LISTENER_TCP,      "tcp",  open_tcp,      close_tcp },
 372         { LISTENER_UNIXSOCK, "unix", open_unixsock, close_unixsock },
 373 };
 374
 375 /*
 376  * private helper functions
 377  */
 378
 379 static int
 380 listener_listen(listener_t *listener)
 381 {
 382         assert(listener);
 383
 384         /* try to reopen */
 385         if (listener->sock_fd < 0)
 386                 if (listener_impls[listener->type].open(listener))
 387                         return -1;
 388         assert(listener->sock_fd >= 0);
 389
 390         if (listen(listener->sock_fd, /* backlog = */ 32)) {
 391                 char buf[1024];
 392                 sdb_log(SDB_LOG_ERR, "frontend: Failed to listen on socket %s: %s",
 393                                 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
 394                 return -1;
 395         }
 396         sdb_log(SDB_LOG_INFO, "frontend: Listening on %s", listener->address);
 397         return 0;
 398 } /* listener_listen */
 399
 400 static void
 401 listener_close(listener_t *listener)
 402 {
 403         assert(listener);
 404
 405         if (listener_impls[listener->type].close)
 406                 listener_impls[listener->type].close(listener);
 407
 408         if (listener->sock_fd >= 0)
 409                 close(listener->sock_fd);
 410         listener->sock_fd = -1;
 411 } /* listener_close */
 412
 413 static int
 414 get_type(const char *address)
 415 {
 416         char *sep;
 417         size_t len;
 418         size_t i;
 419
 420         if (*address == '/')
 421                 return LISTENER_UNIXSOCK;
 422         sep = strchr(address, (int)':');
 423         if (! sep)
 424                 return listener_impls[0].type;
 425
 426         assert(sep > address);
 427         len = (size_t)(sep - address);
 428
 429         for (i = 0; i < SDB_STATIC_ARRAY_LEN(listener_impls); ++i) {
 430                 fe_listener_impl_t *impl = listener_impls + i;
 431
 432                 if (!strncmp(address, impl->prefix, len)) {
 433                         assert(impl->type == (int)i);
 434                         return impl->type;
 435                 }
 436         }
 437         /* don't report an error, this could be an IPv6 address */
 438         return listener_impls[0].type;
 439 } /* get_type */
 440
 441 static void
 442 listener_destroy(listener_t *listener)
 443 {
 444         if (! listener)
 445                 return;
 446
 447         listener_close(listener);
 448         sdb_ssl_free_options(&listener->ssl_opts);
 449
 450         if (listener->address)
 451                 free(listener->address);
 452         listener->address = NULL;
 453 } /* listener_destroy */
 454
 455 static listener_t *
 456 listener_create(sdb_fe_socket_t *sock, const char *address)
 457 {
 458         listener_t *listener;
 459         size_t len;
 460         int type;
 461
 462         type = get_type(address);
 463         if (type < 0) {
 464                 sdb_log(SDB_LOG_ERR, "frontend: Unsupported address type specified "
 465                                 "in listen address '%s'", address);
 466                 return NULL;
 467         }
 468
 469         listener = realloc(sock->listeners,
 470                         (sock->listeners_num + 1) * sizeof(*sock->listeners));
 471         if (! listener) {
 472                 char buf[1024];
 473                 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
 474                                 sdb_strerror(errno, buf, sizeof(buf)));
 475                 return NULL;
 476         }
 477
 478         sock->listeners = listener;
 479         listener = sock->listeners + sock->listeners_num;
 480
 481         len = strlen(listener_impls[type].prefix);
 482         if ((! strncmp(address, listener_impls[type].prefix, len))
 483                         && (address[len] == ':'))
 484                 address += strlen(listener_impls[type].prefix) + 1;
 485         memset(listener, 0, sizeof(*listener));
 486
 487         listener->sock_fd = -1;
 488         listener->address = strdup(address);
 489         if (! listener->address) {
 490                 char buf[1024];
 491                 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
 492                                 sdb_strerror(errno, buf, sizeof(buf)));
 493                 listener_destroy(listener);
 494                 return NULL;
 495         }
 496         listener->type = type;
 497         listener->setup = NULL;
 498         listener->ssl = NULL;
 499
 500         ++sock->listeners_num;
 501         return listener;
 502 } /* listener_create */
 503
 504 static void
 505 socket_clear(sdb_fe_socket_t *sock)
 506 {
 507         size_t i;
 508
 509         assert(sock);
 510         for (i = 0; i < sock->listeners_num; ++i)
 511                 listener_destroy(sock->listeners + i);
 512         if (sock->listeners)
 513                 free(sock->listeners);
 514         sock->listeners = NULL;
 515         sock->listeners_num = 0;
 516 } /* socket_clear */
 517
 518 static void
 519 socket_close(sdb_fe_socket_t *sock)
 520 {
 521         size_t i;
 522
 523         assert(sock);
 524         for (i = 0; i < sock->listeners_num; ++i)
 525                 listener_close(sock->listeners + i);
 526 } /* socket_close */
 527
 528 /*
 529  * connection handler functions
 530  */
 531
 532 static void *
 533 connection_handler(void *data)
 534 {
 535         sdb_fe_socket_t *sock = data;
 536
 537         assert(sock);
 538
 539         while (42) {
 540                 struct timespec timeout = { 0, 500000000 }; /* .5 seconds */
 541                 sdb_conn_t *conn;
 542                 int status;
 543
 544                 errno = 0;
 545                 status = sdb_channel_select(sock->chan, /* read */ NULL, &conn,
 546                                 /* write */ NULL, NULL, &timeout);
 547                 if (status) {
 548                         char buf[1024];
 549
 550                         if (errno == ETIMEDOUT)
 551                                 continue;
 552                         if (errno == EBADF) /* channel shut down */
 553                                 break;
 554
 555                         sdb_log(SDB_LOG_ERR, "frontend: Failed to read from channel: %s",
 556                                         sdb_strerror(errno, buf, sizeof(buf)));
 557                         continue;
 558                 }
 559
 560                 status = (int)sdb_connection_handle(conn);
 561                 if (status <= 0) {
 562                         /* error or EOF -> close connection */
 563                         sdb_object_deref(SDB_OBJ(conn));
 564                         continue;
 565                 }
 566
 567                 /* return the connection to the main loop */
 568                 if (sdb_llist_append(sock->open_connections, SDB_OBJ(conn))) {
 569                         sdb_log(SDB_LOG_ERR, "frontend: Failed to re-append "
 570                                         "connection %s to list of open connections",
 571                                         SDB_OBJ(conn)->name);
 572                 }
 573                 write(sock->trigger[TRIGGER_WRITE], "", 1);
 574
 575                 /* pass ownership back to list; or destroy in case of an error */
 576                 sdb_object_deref(SDB_OBJ(conn));
 577         }
 578         return NULL;
 579 } /* connection_handler */
 580
 581 static int
 582 connection_accept(sdb_fe_socket_t *sock, listener_t *listener)
 583 {
 584         sdb_object_t *obj;
 585         int status;
 586
 587         obj = SDB_OBJ(sdb_connection_accept(listener->sock_fd,
 588                                 listener->setup, listener));
 589         if (! obj)
 590                 return -1;
 591
 592         status = sdb_llist_append(sock->open_connections, obj);
 593         if (status)
 594                 sdb_log(SDB_LOG_ERR, "frontend: Failed to append "
 595                                 "connection %s to list of open connections",
 596                                 obj->name);
 597
 598         /* hand ownership over to the list; or destroy in case of an error */
 599         sdb_object_deref(obj);
 600         return status;
 601 } /* connection_accept */
 602
 603 static int
 604 socket_handle_incoming(sdb_fe_socket_t *sock,
 605                 fd_set *ready, fd_set *exceptions)
 606 {
 607         sdb_llist_iter_t *iter;
 608         size_t i;
 609
 610         for (i = 0; i < sock->listeners_num; ++i) {
 611                 listener_t *listener = sock->listeners + i;
 612                 if (FD_ISSET(listener->sock_fd, ready))
 613                         if (connection_accept(sock, listener))
 614                                 continue;
 615         }
 616
 617         iter = sdb_llist_get_iter(sock->open_connections);
 618         if (! iter) {
 619                 sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
 620                                 "for open connections");
 621                 return -1;
 622         }
 623
 624         while (sdb_llist_iter_has_next(iter)) {
 625                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 626
 627                 if (FD_ISSET(CONN(obj)->fd, exceptions)) {
 628                         sdb_log(SDB_LOG_INFO, "Exception on fd %d",
 629                                         CONN(obj)->fd);
 630                         /* close the connection */
 631                         sdb_llist_iter_remove_current(iter);
 632                         sdb_object_deref(obj);
 633                         continue;
 634                 }
 635
 636                 if (FD_ISSET(CONN(obj)->fd, ready)) {
 637                         sdb_llist_iter_remove_current(iter);
 638                         sdb_channel_write(sock->chan, &obj);
 639                 }
 640         }
 641         sdb_llist_iter_destroy(iter);
 642         return 0;
 643 } /* socket_handle_incoming */
 644
 645 /*
 646  * public API
 647  */
 648
 649 sdb_fe_socket_t *
 650 sdb_fe_sock_create(void)
 651 {
 652         sdb_fe_socket_t *sock;
 653         int flags;
 654
 655         sock = calloc(1, sizeof(*sock));
 656         if (! sock)
 657                 return NULL;
 658         sock->trigger[TRIGGER_READ] = sock->trigger[TRIGGER_WRITE] = -1;
 659
 660         sock->open_connections = sdb_llist_create();
 661         if (! sock->open_connections) {
 662                 sdb_fe_sock_destroy(sock);
 663                 return NULL;
 664         }
 665
 666         if (pipe(sock->trigger)) {
 667                 char errbuf[1024];
 668                 sdb_log(SDB_LOG_ERR, "frontend: Failed to create pipe: %s",
 669                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 670                 sdb_fe_sock_destroy(sock);
 671                 return NULL;
 672         }
 673         /* TODO: Can we do a zero-byte write as well to trigger select()?
 674          * Linux does not seem to support the I_SWROPT ioctl on a pipe. */
 675         flags = fcntl(sock->trigger[TRIGGER_WRITE], F_GETFL);
 676         if (fcntl(sock->trigger[TRIGGER_WRITE], F_SETFL, flags | O_NONBLOCK)) {
 677                 char errbuf[1024];
 678                 sdb_log(SDB_LOG_ERR, "frontend: Failed to switch pipe to non-blocking "
 679                                 "mode: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 680                 sdb_fe_sock_destroy(sock);
 681                 return NULL;
 682         }
 683         flags = fcntl(sock->trigger[TRIGGER_READ], F_GETFL);
 684         if (fcntl(sock->trigger[TRIGGER_READ], F_SETFL, flags | O_NONBLOCK)) {
 685                 char errbuf[1024];
 686                 sdb_log(SDB_LOG_ERR, "frontend: Failed to switch pipe to non-blocking "
 687                                 "mode: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 688                 sdb_fe_sock_destroy(sock);
 689                 return NULL;
 690         }
 691         return sock;
 692 } /* sdb_fe_sock_create */
 693
 694 void
 695 sdb_fe_sock_destroy(sdb_fe_socket_t *sock)
 696 {
 697         if (! sock)
 698                 return;
 699
 700         socket_clear(sock);
 701
 702         if (sock->trigger[TRIGGER_WRITE] >= 0)
 703                 close(sock->trigger[TRIGGER_WRITE]);
 704         if (sock->trigger[TRIGGER_READ] >= 0)
 705                 close(sock->trigger[TRIGGER_READ]);
 706         sock->trigger[TRIGGER_READ] = sock->trigger[TRIGGER_WRITE] = -1;
 707
 708         sdb_llist_destroy(sock->open_connections);
 709         sock->open_connections = NULL;
 710         free(sock);
 711 } /* sdb_fe_sock_destroy */
 712
 713 int
 714 sdb_fe_sock_add_listener(sdb_fe_socket_t *sock, const char *address,
 715                 const sdb_ssl_options_t *opts)
 716 {
 717         listener_t *listener;
 718
 719         if ((! sock) || (! address))
 720                 return -1;
 721
 722         listener = listener_create(sock, address);
 723         if (! listener)
 724                 return -1;
 725
 726         if (opts) {
 727                 int ret = 0;
 728
 729                 if (opts->ca_file) {
 730                         listener->ssl_opts.ca_file = strdup(opts->ca_file);
 731                         if (! listener->ssl_opts.ca_file)
 732                                 ret = -1;
 733                 }
 734                 if (opts->key_file) {
 735                         listener->ssl_opts.key_file = strdup(opts->key_file);
 736                         if (! listener->ssl_opts.key_file)
 737                                 ret = -1;
 738                 }
 739                 if (opts->cert_file) {
 740                         listener->ssl_opts.cert_file = strdup(opts->cert_file);
 741                         if (! listener->ssl_opts.cert_file)
 742                                 ret = -1;
 743                 }
 744                 if (opts->crl_file) {
 745                         listener->ssl_opts.crl_file = strdup(opts->crl_file);
 746                         if (! listener->ssl_opts.crl_file)
 747                                 ret = -1;
 748                 }
 749
 750                 if (ret) {
 751                         listener_destroy(listener);
 752                         --sock->listeners_num;
 753                         return ret;
 754                 }
 755         }
 756
 757         if (listener_impls[listener->type].open(listener)) {
 758                 /* prints error */
 759                 listener_destroy(listener);
 760                 --sock->listeners_num;
 761                 return -1;
 762         }
 763         return 0;
 764 } /* sdb_fe_sock_add_listener */
 765
 766 void
 767 sdb_fe_sock_clear_listeners(sdb_fe_socket_t *sock)
 768 {
 769         if (! sock)
 770                 return;
 771
 772         socket_clear(sock);
 773 } /* sdb_fe_sock_clear_listeners */
 774
 775 int
 776 sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
 777 {
 778         fd_set sockets;
 779         int max_listen_fd = 0;
 780         size_t i;
 781
 782         pthread_t handler_threads[loop->num_threads];
 783         size_t num_threads;
 784
 785         if ((! sock) || (! sock->listeners_num) || sock->chan
 786                         || (! loop) || (loop->num_threads <= 0))
 787                 return -1;
 788
 789         if (! loop->do_loop)
 790                 return 0;
 791
 792         FD_ZERO(&sockets);
 793         for (i = 0; i < sock->listeners_num; ++i) {
 794                 listener_t *listener = sock->listeners + i;
 795
 796                 if (listener_listen(listener)) {
 797                         socket_close(sock);
 798                         return -1;
 799                 }
 800
 801                 FD_SET(listener->sock_fd, &sockets);
 802                 if (listener->sock_fd > max_listen_fd)
 803                         max_listen_fd = listener->sock_fd;
 804         }
 805
 806         sock->chan = sdb_channel_create(1024, sizeof(sdb_conn_t *));
 807         if (! sock->chan) {
 808                 socket_close(sock);
 809                 return -1;
 810         }
 811
 812         sdb_log(SDB_LOG_INFO, "frontend: Starting %zu connection "
 813                         "handler thread%s managing %zu listener%s",
 814                         loop->num_threads, loop->num_threads == 1 ? "" : "s",
 815                         sock->listeners_num, sock->listeners_num == 1 ? "" : "s");
 816
 817         num_threads = loop->num_threads;
 818         memset(&handler_threads, 0, sizeof(handler_threads));
 819         for (i = 0; i < num_threads; ++i) {
 820                 errno = 0;
 821                 if (pthread_create(&handler_threads[i], /* attr = */ NULL,
 822                                         connection_handler, /* arg = */ sock)) {
 823                         char errbuf[1024];
 824                         sdb_log(SDB_LOG_ERR, "frontend: Failed to create "
 825                                         "connection handler thread: %s",
 826                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 827                         num_threads = i;
 828                         break;
 829                 }
 830         }
 831
 832         while (loop->do_loop && num_threads) {
 833                 struct timeval timeout = { 1, 0 }; /* one second */
 834                 sdb_llist_iter_t *iter;
 835
 836                 int max_fd = max_listen_fd;
 837                 fd_set ready;
 838                 fd_set exceptions;
 839                 int n;
 840
 841                 FD_ZERO(&ready);
 842                 FD_ZERO(&exceptions);
 843
 844                 ready = sockets;
 845                 FD_SET(sock->trigger[TRIGGER_READ], &ready);
 846
 847                 iter = sdb_llist_get_iter(sock->open_connections);
 848                 if (! iter) {
 849                         sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
 850                                         "for open connections");
 851                         break;
 852                 }
 853
 854                 while (sdb_llist_iter_has_next(iter)) {
 855                         sdb_object_t *obj = sdb_llist_iter_get_next(iter);
 856
 857                         if (CONN(obj)->fd < 0) {
 858                                 sdb_llist_iter_remove_current(iter);
 859                                 sdb_object_deref(obj);
 860                                 continue;
 861                         }
 862
 863                         FD_SET(CONN(obj)->fd, &ready);
 864                         FD_SET(CONN(obj)->fd, &exceptions);
 865
 866                         if (CONN(obj)->fd > max_fd)
 867                                 max_fd = CONN(obj)->fd;
 868                 }
 869                 sdb_llist_iter_destroy(iter);
 870
 871                 errno = 0;
 872                 n = select(max_fd + 1, &ready, NULL, &exceptions, &timeout);
 873                 if (n < 0) {
 874                         char buf[1024];
 875
 876                         if (errno == EINTR)
 877                                 continue;
 878
 879                         sdb_log(SDB_LOG_ERR, "frontend: Failed to monitor sockets: %s",
 880                                         sdb_strerror(errno, buf, sizeof(buf)));
 881                         break;
 882                 }
 883                 else if (! n)
 884                         continue;
 885
 886                 if (FD_ISSET(sock->trigger[TRIGGER_READ], &ready)) {
 887                         char buf[1024];
 888                         while (read(sock->trigger[TRIGGER_READ], buf, sizeof(buf)) > 0)
 889                                 /* do nothing */;
 890                 }
 891
 892                 /* handle new and open connections */
 893                 if (socket_handle_incoming(sock, &ready, &exceptions))
 894                         break;
 895         }
 896
 897         socket_close(sock);
 898
 899         sdb_log(SDB_LOG_INFO, "frontend: Waiting for connection handler threads "
 900                         "to terminate");
 901         if (! sdb_channel_shutdown(sock->chan))
 902                 for (i = 0; i < num_threads; ++i)
 903                         pthread_join(handler_threads[i], NULL);
 904         /* else: we tried our best; let the operating system clean up */
 905
 906         sdb_channel_destroy(sock->chan);
 907         sock->chan = NULL;
 908
 909         if (! num_threads)
 910                 return -1;
 911         return 0;
 912 } /* sdb_fe_sock_listen_and_server */
 913
 914 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 915