git.m6w6.name Git - m6w6/libmemcached/blob - libmemcached/connect.cc

   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  Libmemcached library
   4  *
   5  *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
   6  *  Copyright (C) 2006-2010 Brian Aker All rights reserved.
   7  *
   8  *  Redistribution and use in source and binary forms, with or without
   9  *  modification, are permitted provided that the following conditions are
  10  *  met:
  11  *
  12  *      * Redistributions of source code must retain the above copyright
  13  *  notice, this list of conditions and the following disclaimer.
  14  *
  15  *      * Redistributions in binary form must reproduce the above
  16  *  copyright notice, this list of conditions and the following disclaimer
  17  *  in the documentation and/or other materials provided with the
  18  *  distribution.
  19  *
  20  *      * The names of its contributors may not be used to endorse or
  21  *  promote products derived from this software without specific prior
  22  *  written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  26  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  27  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  28  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  30  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  34  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  */
  37
  38
  39 #include <libmemcached/common.h>
  40
  41 #include <cassert>
  42
  43 #ifndef SOCK_CLOEXEC
  44 #  define SOCK_CLOEXEC 0
  45 #endif
  46
  47 #ifndef SOCK_NONBLOCK
  48 # define SOCK_NONBLOCK 0
  49 #endif
  50
  51 #ifndef FD_CLOEXEC
  52 # define FD_CLOEXEC 0
  53 #endif
  54
  55 #ifndef SO_NOSIGPIPE
  56 # define SO_NOSIGPIPE 0
  57 #endif
  58
  59 #ifndef TCP_NODELAY
  60 # define TCP_NODELAY 0
  61 #endif
  62
  63 #ifndef TCP_KEEPIDLE
  64 # define TCP_KEEPIDLE 0
  65 #endif
  66
  67 static memcached_return_t connect_poll(org::libmemcached::Instance* server)
  68 {
  69   struct pollfd fds[1];
  70   fds[0].fd= server->fd;
  71   fds[0].events= POLLOUT;
  72
  73   size_t loop_max= 5;
  74
  75   if (server->root->poll_timeout == 0)
  76   {
  77     return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT);
  78   }
  79
  80   while (--loop_max) // Should only loop on cases of ERESTART or EINTR
  81   {
  82     int number_of;
  83     if ((number_of= poll(fds, 1, server->root->connect_timeout)) <= 0)
  84     {
  85       if (number_of == -1)
  86       {
  87         int local_errno= get_socket_errno(); // We cache in case closesocket() modifies errno
  88         switch (local_errno)
  89         {
  90 #ifdef TARGET_OS_LINUX
  91         case ERESTART:
  92 #endif
  93         case EINTR:
  94           continue;
  95
  96         case EFAULT:
  97         case ENOMEM:
  98           return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
  99
 100         case EINVAL:
 101           return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT, memcached_literal_param("RLIMIT_NOFILE exceeded, or if OSX the timeout value was invalid"));
 102
 103         default: // This should not happen
 104           if (fds[0].revents & POLLERR)
 105           {
 106             int err;
 107             socklen_t len= sizeof(err);
 108             if (getsockopt(server->fd, SOL_SOCKET, SO_ERROR, (char*)&err, &len) == 0)
 109             {
 110               if (err == 0)
 111               {
 112                 // This should never happen, if it does? Punt.
 113                 continue;
 114               }
 115               local_errno= err;
 116             }
 117           }
 118
 119           assert_msg(server->fd != INVALID_SOCKET, "poll() was passed an invalid file descriptor");
 120           (void)closesocket(server->fd);
 121           server->fd= INVALID_SOCKET;
 122           server->state= MEMCACHED_SERVER_STATE_NEW;
 123
 124           return memcached_set_errno(*server, local_errno, MEMCACHED_AT);
 125         }
 126       }
 127       assert(number_of == 0);
 128
 129       server->io_wait_count.timeouts++;
 130       return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT);
 131     }
 132
 133     if (fds[0].revents & POLLERR or
 134         fds[0].revents & POLLHUP or
 135         fds[0].revents & POLLNVAL)
 136     {
 137       int err;
 138       socklen_t len= sizeof (err);
 139       if (getsockopt(fds[0].fd, SOL_SOCKET, SO_ERROR, (char*)&err, &len) == 0)
 140       {
 141         // We check the value to see what happened wth the socket.
 142         if (err == 0)
 143         {
 144           return MEMCACHED_SUCCESS;
 145         }
 146         errno= err;
 147       }
 148
 149       return memcached_set_errno(*server, err, MEMCACHED_AT);
 150     }
 151     assert(fds[0].revents & POLLIN or fds[0].revents & POLLOUT);
 152
 153     return MEMCACHED_SUCCESS;
 154   }
 155
 156   // This should only be possible from ERESTART or EINTR;
 157   return memcached_set_errno(*server, get_socket_errno(), MEMCACHED_AT);
 158 }
 159
 160 static memcached_return_t set_hostinfo(org::libmemcached::Instance* server)
 161 {
 162   assert(server->type != MEMCACHED_CONNECTION_UNIX_SOCKET);
 163   if (server->address_info)
 164   {
 165     freeaddrinfo(server->address_info);
 166     server->address_info= NULL;
 167     server->address_info_next= NULL;
 168   }
 169
 170   char str_port[MEMCACHED_NI_MAXSERV];
 171   int length= snprintf(str_port, MEMCACHED_NI_MAXSERV, "%u", uint32_t(server->port()));
 172   if (length >= MEMCACHED_NI_MAXSERV or length <= 0)
 173   {
 174     return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
 175                                memcached_literal_param("snprintf(NI_MAXSERV)"));
 176   }
 177
 178   struct addrinfo hints;
 179   memset(&hints, 0, sizeof(struct addrinfo));
 180
 181 #if 0
 182   hints.ai_family= AF_INET;
 183 #endif
 184   if (memcached_is_udp(server->root))
 185   {
 186     hints.ai_protocol= IPPROTO_UDP;
 187     hints.ai_socktype= SOCK_DGRAM;
 188   }
 189   else
 190   {
 191     hints.ai_socktype= SOCK_STREAM;
 192     hints.ai_protocol= IPPROTO_TCP;
 193   }
 194
 195   assert(server->address_info == NULL);
 196   assert(server->address_info_next == NULL);
 197   int errcode;
 198   switch(errcode= getaddrinfo(server->hostname, str_port, &hints, &server->address_info))
 199   {
 200   case 0:
 201     break;
 202
 203   case EAI_AGAIN:
 204     if (server->address_info)
 205     {
 206       freeaddrinfo(server->address_info);
 207       server->address_info= NULL;
 208       server->address_info_next= NULL;
 209     }
 210     return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT, memcached_string_make_from_cstr(gai_strerror(errcode)));
 211
 212   case EAI_SYSTEM:
 213     if (server->address_info)
 214     {
 215       freeaddrinfo(server->address_info);
 216       server->address_info= NULL;
 217       server->address_info_next= NULL;
 218     }
 219     return memcached_set_errno(*server, errno, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_SYSTEM)"));
 220
 221   case EAI_BADFLAGS:
 222     if (server->address_info)
 223     {
 224       freeaddrinfo(server->address_info);
 225       server->address_info= NULL;
 226       server->address_info_next= NULL;
 227     }
 228     return memcached_set_error(*server, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_BADFLAGS)"));
 229
 230   case EAI_MEMORY:
 231     if (server->address_info)
 232     {
 233       freeaddrinfo(server->address_info);
 234       server->address_info= NULL;
 235       server->address_info_next= NULL;
 236     }
 237     return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_MEMORY)"));
 238
 239   default:
 240     {
 241       if (server->address_info)
 242       {
 243         freeaddrinfo(server->address_info);
 244         server->address_info= NULL;
 245         server->address_info_next= NULL;
 246       }
 247       return memcached_set_error(*server, MEMCACHED_HOST_LOOKUP_FAILURE, MEMCACHED_AT, memcached_string_make_from_cstr(gai_strerror(errcode)));
 248     }
 249   }
 250   server->address_info_next= server->address_info;
 251   server->state= MEMCACHED_SERVER_STATE_ADDRINFO;
 252
 253   return MEMCACHED_SUCCESS;
 254 }
 255
 256 static inline void set_socket_nonblocking(org::libmemcached::Instance* server)
 257 {
 258 #ifdef WIN32
 259   u_long arg= 1;
 260   if (ioctlsocket(server->fd, FIONBIO, &arg) == SOCKET_ERROR)
 261   {
 262     memcached_set_errno(*server, get_socket_errno(), NULL);
 263   }
 264 #else
 265   int flags;
 266
 267   if (SOCK_NONBLOCK == 0)
 268   {
 269     do
 270     {
 271       flags= fcntl(server->fd, F_GETFL, 0);
 272     } while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 273
 274     if (flags == -1)
 275     {
 276       memcached_set_errno(*server, errno, NULL);
 277     }
 278     else if ((flags & O_NONBLOCK) == 0)
 279     {
 280       int rval;
 281
 282       do
 283       {
 284         rval= fcntl(server->fd, F_SETFL, flags | O_NONBLOCK);
 285       } while (rval == -1 && (errno == EINTR or errno == EAGAIN));
 286
 287       if (rval == -1)
 288       {
 289         memcached_set_errno(*server, errno, NULL);
 290       }
 291     }
 292   }
 293 #endif
 294 }
 295
 296 static bool set_socket_options(org::libmemcached::Instance* server)
 297 {
 298   assert_msg(server->fd != INVALID_SOCKET, "invalid socket was passed to set_socket_options()");
 299
 300 #ifdef HAVE_FCNTL
 301   // If SOCK_CLOEXEC exists then we don't need to call the following
 302   if (SOCK_CLOEXEC == 0)
 303   {
 304     if (FD_CLOEXEC)
 305     {
 306       int flags;
 307       do
 308       {
 309         flags= fcntl(server->fd, F_GETFD, 0);
 310       } while (flags == -1 and (errno == EINTR or errno == EAGAIN));
 311
 312       if (flags != -1)
 313       {
 314         int rval;
 315         do
 316         {
 317           rval= fcntl (server->fd, F_SETFD, flags | FD_CLOEXEC);
 318         } while (rval == -1 && (errno == EINTR or errno == EAGAIN));
 319         // we currently ignore the case where rval is -1
 320       }
 321     }
 322   }
 323 #endif
 324
 325   if (memcached_is_udp(server->root))
 326   {
 327     return true;
 328   }
 329
 330 #ifdef HAVE_SNDTIMEO
 331   if (server->root->snd_timeout > 0)
 332   {
 333     struct timeval waittime;
 334
 335     waittime.tv_sec= server->root->snd_timeout / 1000000;
 336     waittime.tv_usec= server->root->snd_timeout % 1000000;
 337
 338     int error= setsockopt(server->fd, SOL_SOCKET, SO_SNDTIMEO,
 339                           (char*)&waittime, (socklen_t)sizeof(struct timeval));
 340     (void)error;
 341     assert(error == 0);
 342   }
 343 #endif
 344
 345 #ifdef HAVE_RCVTIMEO
 346   if (server->root->rcv_timeout > 0)
 347   {
 348     struct timeval waittime;
 349
 350     waittime.tv_sec= server->root->rcv_timeout / 1000000;
 351     waittime.tv_usec= server->root->rcv_timeout % 1000000;
 352
 353     int error= setsockopt(server->fd, SOL_SOCKET, SO_RCVTIMEO,
 354                           (char*)&waittime, (socklen_t)sizeof(struct timeval));
 355     (void)(error);
 356     assert(error == 0);
 357   }
 358 #endif
 359
 360
 361 #if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
 362   if (SO_NOSIGPIPE)
 363   {
 364     int set= 1;
 365     int error= setsockopt(server->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 366
 367     assert(error == 0);
 368
 369     // This is not considered a fatal error
 370     if (error == -1)
 371     {
 372 #if 0
 373       perror("setsockopt(SO_NOSIGPIPE)");
 374 #endif
 375     }
 376   }
 377 #endif
 378
 379   if (server->root->flags.no_block)
 380   {
 381     struct linger linger;
 382
 383     linger.l_onoff= 1;
 384     linger.l_linger= 0; /* By default on close() just drop the socket */
 385     int error= setsockopt(server->fd, SOL_SOCKET, SO_LINGER,
 386                           (char*)&linger, (socklen_t)sizeof(struct linger));
 387     (void)(error);
 388     assert(error == 0);
 389   }
 390
 391   if (TCP_NODELAY)
 392   {
 393     if (server->root->flags.tcp_nodelay)
 394     {
 395       int flag= 1;
 396
 397       int error= setsockopt(server->fd, IPPROTO_TCP, TCP_NODELAY,
 398                             (char*)&flag, (socklen_t)sizeof(int));
 399       (void)(error);
 400       assert(error == 0);
 401     }
 402   }
 403
 404   if (server->root->flags.tcp_keepalive)
 405   {
 406     int flag= 1;
 407
 408     int error= setsockopt(server->fd, SOL_SOCKET, SO_KEEPALIVE,
 409                           (char*)&flag, (socklen_t)sizeof(int));
 410     (void)(error);
 411     assert(error == 0);
 412   }
 413
 414   if (TCP_KEEPIDLE)
 415   {
 416     if (server->root->tcp_keepidle > 0)
 417     {
 418       int error= setsockopt(server->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 419                             (char*)&server->root->tcp_keepidle, (socklen_t)sizeof(int));
 420       (void)(error);
 421       assert(error == 0);
 422     }
 423   }
 424
 425   if (server->root->send_size > 0)
 426   {
 427     int error= setsockopt(server->fd, SOL_SOCKET, SO_SNDBUF,
 428                           (char*)&server->root->send_size, (socklen_t)sizeof(int));
 429     (void)(error);
 430     assert(error == 0);
 431   }
 432
 433   if (server->root->recv_size > 0)
 434   {
 435     int error= setsockopt(server->fd, SOL_SOCKET, SO_RCVBUF,
 436                           (char*)&server->root->recv_size, (socklen_t)sizeof(int));
 437     (void)(error);
 438     assert(error == 0);
 439   }
 440
 441   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 442   set_socket_nonblocking(server);
 443
 444   return true;
 445 }
 446
 447 static memcached_return_t unix_socket_connect(org::libmemcached::Instance* server)
 448 {
 449 #ifndef WIN32
 450   WATCHPOINT_ASSERT(server->fd == INVALID_SOCKET);
 451
 452   int type= SOCK_STREAM;
 453   if (SOCK_CLOEXEC)
 454   {
 455     type|= SOCK_CLOEXEC;
 456   }
 457
 458   if (SOCK_NONBLOCK)
 459   {
 460     type|= SOCK_NONBLOCK;
 461   }
 462
 463   if ((server->fd= socket(AF_UNIX, type, 0)) < 0)
 464   {
 465     memcached_set_errno(*server, errno, NULL);
 466     return MEMCACHED_CONNECTION_FAILURE;
 467   }
 468
 469   struct sockaddr_un servAddr;
 470
 471   memset(&servAddr, 0, sizeof (struct sockaddr_un));
 472   servAddr.sun_family= AF_UNIX;
 473   strncpy(servAddr.sun_path, server->hostname, sizeof(servAddr.sun_path)); /* Copy filename */
 474
 475   do {
 476     if (connect(server->fd, (struct sockaddr *)&servAddr, sizeof(servAddr)) < 0)
 477     {
 478       switch (errno)
 479       {
 480       case EINPROGRESS:
 481       case EALREADY:
 482       case EINTR:
 483         continue;
 484
 485       case EISCONN: /* We were spinning waiting on connect */
 486         {
 487           assert(0); // Programmer error
 488           break;
 489         }
 490
 491       default:
 492         WATCHPOINT_ERRNO(errno);
 493         memcached_set_errno(*server, errno, MEMCACHED_AT);
 494         return MEMCACHED_CONNECTION_FAILURE;
 495       }
 496     }
 497   } while (0);
 498   server->state= MEMCACHED_SERVER_STATE_CONNECTED;
 499
 500   WATCHPOINT_ASSERT(server->fd != INVALID_SOCKET);
 501
 502   return MEMCACHED_SUCCESS;
 503 #else
 504   (void)server;
 505   return MEMCACHED_NOT_SUPPORTED;
 506 #endif
 507 }
 508
 509 static memcached_return_t network_connect(org::libmemcached::Instance* server)
 510 {
 511   bool timeout_error_occured= false;
 512
 513   WATCHPOINT_ASSERT(server->fd == INVALID_SOCKET);
 514   WATCHPOINT_ASSERT(server->cursor_active_ == 0);
 515
 516   /*
 517     We want to check both of these because if address_info_next has been fully tried, we want to do a new lookup to make sure we have picked up on any new DNS information.
 518   */
 519   if (server->address_info == NULL or server->address_info_next == NULL)
 520   {
 521     WATCHPOINT_ASSERT(server->state == MEMCACHED_SERVER_STATE_NEW);
 522     server->address_info_next= NULL;
 523     memcached_return_t rc= set_hostinfo(server);
 524
 525     if (memcached_failed(rc))
 526     {
 527       return rc;
 528     }
 529   }
 530
 531   if (server->address_info_next == NULL)
 532   {
 533     server->address_info_next= server->address_info;
 534     server->state= MEMCACHED_SERVER_STATE_ADDRINFO;
 535   }
 536
 537   /* Create the socket */
 538   while (server->address_info_next and server->fd == INVALID_SOCKET)
 539   {
 540     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 541     if (memcached_is_udp(server->root) and server->address_info_next->ai_family != AF_INET)
 542     {
 543       server->address_info_next= server->address_info_next->ai_next;
 544       continue;
 545     }
 546
 547     int type= server->address_info_next->ai_socktype;
 548     if (SOCK_CLOEXEC)
 549     {
 550       type|= SOCK_CLOEXEC;
 551     }
 552
 553     if (SOCK_NONBLOCK)
 554     {
 555       type|= SOCK_NONBLOCK;
 556     }
 557
 558     server->fd= socket(server->address_info_next->ai_family,
 559                        type,
 560                        server->address_info_next->ai_protocol);
 561
 562     if (int(server->fd) == SOCKET_ERROR)
 563     {
 564       return memcached_set_errno(*server, get_socket_errno(), NULL);
 565     }
 566
 567     if (set_socket_options(server) == false)
 568     {
 569       (void)closesocket(server->fd);
 570       return MEMCACHED_CONNECTION_FAILURE;
 571     }
 572
 573     /* connect to server */
 574     if ((connect(server->fd, server->address_info_next->ai_addr, server->address_info_next->ai_addrlen) != SOCKET_ERROR))
 575     {
 576       server->state= MEMCACHED_SERVER_STATE_CONNECTED;
 577       return MEMCACHED_SUCCESS;
 578     }
 579
 580     /* An error occurred */
 581     switch (get_socket_errno())
 582     {
 583     case ETIMEDOUT:
 584       timeout_error_occured= true;
 585       break;
 586
 587     case EAGAIN:
 588 #if EWOULDBLOCK != EAGAIN
 589     case EWOULDBLOCK:
 590 #endif
 591     case EINPROGRESS: // nonblocking mode - first return
 592     case EALREADY: // nonblocking mode - subsequent returns
 593       {
 594         server->state= MEMCACHED_SERVER_STATE_IN_PROGRESS;
 595         memcached_return_t rc= connect_poll(server);
 596
 597         if (memcached_success(rc))
 598         {
 599           server->state= MEMCACHED_SERVER_STATE_CONNECTED;
 600           return MEMCACHED_SUCCESS;
 601         }
 602
 603         // A timeout here is treated as an error, we will not retry
 604         if (rc == MEMCACHED_TIMEOUT)
 605         {
 606           timeout_error_occured= true;
 607         }
 608       }
 609       break;
 610
 611     case EISCONN: // we are connected :-)
 612       WATCHPOINT_ASSERT(0); // This is a programmer's error
 613       break;
 614
 615     case EINTR: // Special case, we retry ai_addr
 616       WATCHPOINT_ASSERT(server->fd != INVALID_SOCKET);
 617       (void)closesocket(server->fd);
 618       server->fd= INVALID_SOCKET;
 619       continue;
 620
 621     default:
 622       break;
 623     }
 624
 625     WATCHPOINT_ASSERT(server->fd != INVALID_SOCKET);
 626     (void)closesocket(server->fd);
 627     server->fd= INVALID_SOCKET;
 628     server->address_info_next= server->address_info_next->ai_next;
 629   }
 630
 631   WATCHPOINT_ASSERT(server->fd == INVALID_SOCKET);
 632
 633   if (timeout_error_occured)
 634   {
 635     if (server->fd != INVALID_SOCKET)
 636     {
 637       (void)closesocket(server->fd);
 638       server->fd= INVALID_SOCKET;
 639     }
 640   }
 641
 642   WATCHPOINT_STRING("Never got a good file descriptor");
 643
 644   if (memcached_has_current_error(*server))
 645   {
 646     return memcached_instance_error_return(server);
 647   }
 648
 649   if (timeout_error_occured and server->state < MEMCACHED_SERVER_STATE_IN_PROGRESS)
 650   {
 651     return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT);
 652   }
 653
 654   return memcached_set_error(*server, MEMCACHED_CONNECTION_FAILURE, MEMCACHED_AT); /* The last error should be from connect() */
 655 }
 656
 657
 658 /*
 659   backoff_handling()
 660
 661   Based on time/failure count fail the connect without trying. This prevents waiting in a state where
 662   we get caught spending cycles just waiting.
 663 */
 664 static memcached_return_t backoff_handling(org::libmemcached::Instance* server, bool& in_timeout)
 665 {
 666   struct timeval curr_time;
 667   bool _gettime_success= (gettimeofday(&curr_time, NULL) == 0);
 668
 669   /*
 670     If we hit server_failure_limit then something is completely wrong about the server.
 671
 672     1) If autoeject is enabled we do that.
 673     2) If not? We go into timeout again, there is much else to do :(
 674   */
 675   if (server->server_failure_counter >= server->root->server_failure_limit)
 676   {
 677     /*
 678       We just auto_eject if we hit this point
 679     */
 680     if (_is_auto_eject_host(server->root))
 681     {
 682       set_last_disconnected_host(server);
 683
 684       // Retry dead servers if requested
 685       if (_gettime_success and server->root->dead_timeout > 0)
 686       {
 687         server->next_retry= curr_time.tv_sec +server->root->dead_timeout;
 688
 689         // We only retry dead servers once before assuming failure again
 690         server->server_failure_counter= server->root->server_failure_limit -1;
 691       }
 692
 693       memcached_return_t rc;
 694       if (memcached_failed(rc= run_distribution((memcached_st *)server->root)))
 695       {
 696         return memcached_set_error(*server, rc, MEMCACHED_AT, memcached_literal_param("Backoff handling failed during run_distribution"));
 697       }
 698
 699       return memcached_set_error(*server, MEMCACHED_SERVER_MARKED_DEAD, MEMCACHED_AT);
 700     }
 701
 702     server->state= MEMCACHED_SERVER_STATE_IN_TIMEOUT;
 703
 704     // Sanity check/setting
 705     if (server->next_retry == 0)
 706     {
 707       server->next_retry= 1;
 708     }
 709   }
 710
 711   if (server->state == MEMCACHED_SERVER_STATE_IN_TIMEOUT)
 712   {
 713     /*
 714       If next_retry is less then our current time, then we reset and try everything again.
 715     */
 716     if (_gettime_success and server->next_retry < curr_time.tv_sec)
 717     {
 718       server->state= MEMCACHED_SERVER_STATE_NEW;
 719     }
 720     else
 721     {
 722       return memcached_set_error(*server, MEMCACHED_SERVER_TEMPORARILY_DISABLED, MEMCACHED_AT);
 723     }
 724
 725     in_timeout= true;
 726   }
 727
 728   return MEMCACHED_SUCCESS;
 729 }
 730
 731 static memcached_return_t _memcached_connect(org::libmemcached::Instance* server, const bool set_last_disconnected)
 732 {
 733   assert(server);
 734   if (server->fd != INVALID_SOCKET)
 735   {
 736     return MEMCACHED_SUCCESS;
 737   }
 738
 739   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 740
 741   bool in_timeout= false;
 742   memcached_return_t rc;
 743   if (memcached_failed(rc= backoff_handling(server, in_timeout)))
 744   {
 745     set_last_disconnected_host(server);
 746     return rc;
 747   }
 748
 749   if (LIBMEMCACHED_WITH_SASL_SUPPORT and server->root->sasl.callbacks and memcached_is_udp(server->root))
 750   {
 751     return memcached_set_error(*server, MEMCACHED_INVALID_HOST_PROTOCOL, MEMCACHED_AT, memcached_literal_param("SASL is not supported for UDP connections"));
 752   }
 753
 754   if (server->hostname[0] == '/')
 755   {
 756     server->type= MEMCACHED_CONNECTION_UNIX_SOCKET;
 757   }
 758
 759   /* We need to clean up the multi startup piece */
 760   switch (server->type)
 761   {
 762   case MEMCACHED_CONNECTION_UDP:
 763   case MEMCACHED_CONNECTION_TCP:
 764     rc= network_connect(server);
 765
 766     if (LIBMEMCACHED_WITH_SASL_SUPPORT)
 767     {
 768       if (server->fd != INVALID_SOCKET and server->root->sasl.callbacks)
 769       {
 770         rc= memcached_sasl_authenticate_connection(server);
 771         fprintf(stderr, "%s:%d %s\n", __FILE__, __LINE__, memcached_strerror(NULL, rc));
 772         if (memcached_failed(rc) and server->fd != INVALID_SOCKET)
 773         {
 774           WATCHPOINT_ASSERT(server->fd != INVALID_SOCKET);
 775           (void)closesocket(server->fd);
 776           server->fd= INVALID_SOCKET;
 777         }
 778       }
 779     }
 780     break;
 781
 782   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 783     rc= unix_socket_connect(server);
 784     break;
 785   }
 786
 787   if (memcached_success(rc))
 788   {
 789     server->mark_server_as_clean();
 790     memcached_version_instance(server);
 791     return rc;
 792   }
 793   else if (set_last_disconnected)
 794   {
 795     set_last_disconnected_host(server);
 796     if (memcached_has_current_error(*server))
 797     {
 798       memcached_mark_server_for_timeout(server);
 799       assert(memcached_failed(memcached_instance_error_return(server)));
 800     }
 801     else
 802     {
 803       memcached_set_error(*server, rc, MEMCACHED_AT);
 804       memcached_mark_server_for_timeout(server);
 805     }
 806
 807     LIBMEMCACHED_MEMCACHED_CONNECT_END();
 808
 809     if (in_timeout)
 810     {
 811       char buffer[1024];
 812       int snprintf_length= snprintf(buffer, sizeof(buffer), "%s:%d", server->hostname, int(server->port()));
 813       return memcached_set_error(*server, MEMCACHED_SERVER_TEMPORARILY_DISABLED, MEMCACHED_AT, buffer, snprintf_length);
 814     }
 815   }
 816
 817   return rc;
 818 }
 819
 820 memcached_return_t memcached_connect_try(org::libmemcached::Instance* server)
 821 {
 822   if (server and server->root and server->root->state.is_parsing)
 823   {
 824     return MEMCACHED_SUCCESS;
 825   }
 826
 827   return _memcached_connect(server, false);
 828 }
 829
 830 memcached_return_t memcached_connect(org::libmemcached::Instance* server)
 831 {
 832   return _memcached_connect(server, true);
 833 }