git.m6w6.name Git - awesomized/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 #include <assert.h>
  41 #include <sys/time.h>
  42 #include <time.h>
  43
  44 static memcached_return_t connect_poll(memcached_server_st *ptr)
  45 {
  46   struct pollfd fds[1];
  47   fds[0].fd = ptr->fd;
  48   fds[0].events = POLLOUT;
  49
  50   int error;
  51   size_t loop_max= 5;
  52
  53   while (--loop_max) // Should only loop on cases of ERESTART or EINTR
  54   {
  55     error= poll(fds, 1, ptr->root->connect_timeout);
  56
  57     switch (error)
  58     {
  59     case 1:
  60       {
  61         int err;
  62         socklen_t len= sizeof (err);
  63         (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  64
  65         // We check the value to see what happened wth the socket.
  66         if (err == 0)
  67         {
  68           return MEMCACHED_SUCCESS;
  69         }
  70         else
  71         {
  72           ptr->cached_errno= errno;
  73
  74           return MEMCACHED_ERRNO;
  75         }
  76       }
  77     case 0:
  78       return MEMCACHED_TIMEOUT;
  79     default: // A real error occurred and we need to completely bail
  80       WATCHPOINT_ERRNO(get_socket_errno());
  81       switch (get_socket_errno())
  82       {
  83 #ifdef TARGET_OS_LINUX
  84       case ERESTART:
  85 #endif
  86       case EINTR:
  87         continue;
  88       default:
  89         if (fds[0].revents & POLLERR)
  90         {
  91           int err;
  92           socklen_t len= sizeof (err);
  93           (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  94           ptr->cached_errno= (err == 0) ? get_socket_errno() : err;
  95         }
  96         else
  97         {
  98           ptr->cached_errno= get_socket_errno();
  99         }
 100
 101         (void)closesocket(ptr->fd);
 102         ptr->fd= INVALID_SOCKET;
 103
 104         return MEMCACHED_ERRNO;
 105       }
 106     }
 107   }
 108
 109   // This should only be possible from ERESTART or EINTR;
 110   ptr->cached_errno= get_socket_errno();
 111
 112   return MEMCACHED_ERRNO;
 113 }
 114
 115 static memcached_return_t set_hostinfo(memcached_server_st *server)
 116 {
 117   char str_port[NI_MAXSERV];
 118
 119   assert(! server->address_info); // We cover the case where a programming mistake has been made.
 120   if (server->address_info)
 121   {
 122     freeaddrinfo(server->address_info);
 123     server->address_info= NULL;
 124     server->address_info_next= NULL;
 125   }
 126
 127   int length= snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
 128   if (length >= NI_MAXSERV || length < 0)
 129     return MEMCACHED_FAILURE;
 130
 131   struct addrinfo hints;
 132   memset(&hints, 0, sizeof(struct addrinfo));
 133
 134 #if 0
 135   hints.ai_family= AF_INET;
 136 #endif
 137   if (server->type == MEMCACHED_CONNECTION_UDP)
 138   {
 139     hints.ai_protocol= IPPROTO_UDP;
 140     hints.ai_socktype= SOCK_DGRAM;
 141   }
 142   else
 143   {
 144     hints.ai_socktype= SOCK_STREAM;
 145     hints.ai_protocol= IPPROTO_TCP;
 146   }
 147
 148   uint32_t counter= 5;
 149   while (--counter)
 150   {
 151     int e= getaddrinfo(server->hostname, str_port, &hints, &server->address_info);
 152
 153     if (e == 0)
 154     {
 155       break;
 156     }
 157     else if (e == EAI_AGAIN)
 158     {
 159 #ifndef WIN32
 160       struct timespec dream, rem;
 161
 162       dream.tv_nsec= 1000;
 163       dream.tv_sec= 0;
 164
 165       nanosleep(&dream, &rem);
 166 #endif
 167       continue;
 168     }
 169     else
 170     {
 171       WATCHPOINT_STRING(server->hostname);
 172       WATCHPOINT_STRING(gai_strerror(e));
 173       return MEMCACHED_HOST_LOOKUP_FAILURE;
 174     }
 175   }
 176
 177   server->address_info_next= server->address_info;
 178
 179   return MEMCACHED_SUCCESS;
 180 }
 181
 182 static inline memcached_return_t set_socket_nonblocking(memcached_server_st *ptr)
 183 {
 184 #ifdef WIN32
 185   u_long arg = 1;
 186   if (ioctlsocket(ptr->fd, FIONBIO, &arg) == SOCKET_ERROR)
 187   {
 188     return memcached_set_errno(*ptr, get_socket_errno(), NULL);
 189   }
 190 #else
 191   int flags;
 192
 193   do
 194   {
 195     flags= fcntl(ptr->fd, F_GETFL, 0);
 196   }
 197   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 198
 199   unlikely (flags == -1)
 200   {
 201     return memcached_set_errno(*ptr, errno, NULL);
 202   }
 203   else if ((flags & O_NONBLOCK) == 0)
 204   {
 205     int rval;
 206
 207     do
 208     {
 209       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 210     }
 211     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 212
 213     unlikely (rval == -1)
 214     {
 215       return memcached_set_errno(*ptr, errno, NULL);
 216     }
 217   }
 218 #endif
 219   return MEMCACHED_SUCCESS;
 220 }
 221
 222 static memcached_return_t set_socket_options(memcached_server_st *ptr)
 223 {
 224   WATCHPOINT_ASSERT(ptr->fd != -1);
 225
 226   if (ptr->type == MEMCACHED_CONNECTION_UDP)
 227     return MEMCACHED_SUCCESS;
 228
 229 #ifdef HAVE_SNDTIMEO
 230   if (ptr->root->snd_timeout)
 231   {
 232     int error;
 233     struct timeval waittime;
 234
 235     waittime.tv_sec= 0;
 236     waittime.tv_usec= ptr->root->snd_timeout;
 237
 238     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
 239                       &waittime, (socklen_t)sizeof(struct timeval));
 240     WATCHPOINT_ASSERT(error == 0);
 241     if (error)
 242       return MEMCACHED_FAILURE;
 243   }
 244 #endif
 245
 246 #ifdef HAVE_RCVTIMEO
 247   if (ptr->root->rcv_timeout)
 248   {
 249     int error;
 250     struct timeval waittime;
 251
 252     waittime.tv_sec= 0;
 253     waittime.tv_usec= ptr->root->rcv_timeout;
 254
 255     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
 256                       &waittime, (socklen_t)sizeof(struct timeval));
 257     WATCHPOINT_ASSERT(error == 0);
 258     if (error)
 259       return MEMCACHED_FAILURE;
 260   }
 261 #endif
 262
 263
 264 #if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
 265   {
 266     int set = 1;
 267     int error= setsockopt(ptr->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 268
 269     // This is not considered a fatal error
 270     if (error == -1)
 271     {
 272       WATCHPOINT_ERRNO(get_socket_errno());
 273       perror("setsockopt(SO_NOSIGPIPE)");
 274     }
 275   }
 276 #endif
 277
 278   if (ptr->root->flags.no_block)
 279   {
 280     int error;
 281     struct linger linger;
 282
 283     linger.l_onoff= 1;
 284     linger.l_linger= 0; /* By default on close() just drop the socket */
 285     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 286                       &linger, (socklen_t)sizeof(struct linger));
 287     WATCHPOINT_ASSERT(error == 0);
 288     if (error)
 289       return MEMCACHED_FAILURE;
 290   }
 291
 292   if (ptr->root->flags.tcp_nodelay)
 293   {
 294     int flag= 1;
 295     int error;
 296
 297     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 298                       &flag, (socklen_t)sizeof(int));
 299     WATCHPOINT_ASSERT(error == 0);
 300     if (error)
 301       return MEMCACHED_FAILURE;
 302   }
 303
 304   if (ptr->root->flags.tcp_keepalive)
 305   {
 306     int flag= 1;
 307     int error;
 308
 309     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 310                       &flag, (socklen_t)sizeof(int));
 311     WATCHPOINT_ASSERT(error == 0);
 312     if (error)
 313       return MEMCACHED_FAILURE;
 314   }
 315
 316 #ifdef TCP_KEEPIDLE
 317   if (ptr->root->tcp_keepidle > 0)
 318   {
 319     int error;
 320
 321     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 322                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 323     WATCHPOINT_ASSERT(error == 0);
 324     if (error)
 325       return MEMCACHED_FAILURE;
 326   }
 327 #endif
 328
 329   if (ptr->root->send_size > 0)
 330   {
 331     int error;
 332
 333     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 334                       &ptr->root->send_size, (socklen_t)sizeof(int));
 335     WATCHPOINT_ASSERT(error == 0);
 336     if (error)
 337       return MEMCACHED_FAILURE;
 338   }
 339
 340   if (ptr->root->recv_size > 0)
 341   {
 342     int error;
 343
 344     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 345                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 346     WATCHPOINT_ASSERT(error == 0);
 347     if (error)
 348       return MEMCACHED_FAILURE;
 349   }
 350
 351
 352   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 353   return set_socket_nonblocking(ptr);
 354 }
 355
 356 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 357 {
 358 #ifndef WIN32
 359   WATCHPOINT_ASSERT(ptr->fd == -1);
 360
 361   if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 362   {
 363     ptr->cached_errno= errno;
 364     return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 365   }
 366
 367   struct sockaddr_un servAddr;
 368
 369   memset(&servAddr, 0, sizeof (struct sockaddr_un));
 370   servAddr.sun_family= AF_UNIX;
 371   strncpy(servAddr.sun_path, ptr->hostname, sizeof(servAddr.sun_path)); /* Copy filename */
 372
 373 test_connect:
 374   if (connect(ptr->fd,
 375               (struct sockaddr *)&servAddr,
 376               sizeof(servAddr)) < 0)
 377   {
 378     switch (errno)
 379     {
 380     case EINPROGRESS:
 381     case EALREADY:
 382     case EINTR:
 383       goto test_connect;
 384     case EISCONN: /* We were spinning waiting on connect */
 385       break;
 386     default:
 387       WATCHPOINT_ERRNO(errno);
 388       ptr->cached_errno= errno;
 389       return MEMCACHED_ERRNO;
 390     }
 391   }
 392
 393   WATCHPOINT_ASSERT(ptr->fd != -1);
 394
 395   return MEMCACHED_SUCCESS;
 396 #else
 397   (void)ptr;
 398   return MEMCACHED_NOT_SUPPORTED;
 399 #endif
 400 }
 401
 402 static memcached_return_t network_connect(memcached_server_st *ptr)
 403 {
 404   bool timeout_error_occured= false;
 405
 406   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 407   WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 408
 409   if (! ptr->address_info)
 410   {
 411     memcached_return_t rc= set_hostinfo(ptr);
 412     if (rc != MEMCACHED_SUCCESS)
 413       return rc;
 414   }
 415
 416   /* Create the socket */
 417   while (ptr->address_info_next && ptr->fd == INVALID_SOCKET)
 418   {
 419     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 420     if (ptr->type == MEMCACHED_CONNECTION_UDP && ptr->address_info_next->ai_family != AF_INET)
 421     {
 422       ptr->address_info_next= ptr->address_info_next->ai_next;
 423       continue;
 424     }
 425
 426     if ((ptr->fd= socket(ptr->address_info_next->ai_family,
 427                          ptr->address_info_next->ai_socktype,
 428                          ptr->address_info_next->ai_protocol)) < 0)
 429     {
 430       ptr->cached_errno= get_socket_errno();
 431       WATCHPOINT_ERRNO(get_socket_errno());
 432       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 433     }
 434
 435     (void)set_socket_options(ptr);
 436
 437     /* connect to server */
 438     if ((connect(ptr->fd, ptr->address_info_next->ai_addr, ptr->address_info_next->ai_addrlen) != SOCKET_ERROR))
 439     {
 440       break; // Success
 441     }
 442
 443     /* An error occurred */
 444     ptr->cached_errno= get_socket_errno();
 445     switch (ptr->cached_errno)
 446     {
 447     case EWOULDBLOCK:
 448     case EINPROGRESS: // nonblocking mode - first return
 449     case EALREADY: // nonblocking mode - subsequent returns
 450       {
 451         memcached_return_t rc;
 452         rc= connect_poll(ptr);
 453
 454         if (rc == MEMCACHED_TIMEOUT)
 455           timeout_error_occured= true;
 456
 457         if (rc == MEMCACHED_SUCCESS)
 458           break;
 459       }
 460
 461     case EISCONN: // we are connected :-)
 462       break;
 463
 464     case EINTR: // Special case, we retry ai_addr
 465       (void)closesocket(ptr->fd);
 466       ptr->fd= INVALID_SOCKET;
 467       continue;
 468
 469     default:
 470       (void)closesocket(ptr->fd);
 471       ptr->fd= INVALID_SOCKET;
 472       ptr->address_info_next= ptr->address_info_next->ai_next;
 473       break;
 474     }
 475   }
 476
 477   if (ptr->fd == INVALID_SOCKET)
 478   {
 479     WATCHPOINT_STRING("Never got a good file descriptor");
 480
 481     /* Failed to connect. schedule next retry */
 482     if (ptr->root->retry_timeout)
 483     {
 484       struct timeval next_time;
 485
 486       if (gettimeofday(&next_time, NULL) == 0)
 487         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 488     }
 489
 490     if (timeout_error_occured)
 491       return MEMCACHED_TIMEOUT;
 492
 493     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 494   }
 495
 496   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 497 }
 498
 499 void set_last_disconnected_host(memcached_server_write_instance_st ptr)
 500 {
 501   // const_cast
 502   memcached_st *root= (memcached_st *)ptr->root;
 503
 504 #if 0
 505   WATCHPOINT_STRING(ptr->hostname);
 506   WATCHPOINT_NUMBER(ptr->port);
 507   WATCHPOINT_ERRNO(ptr->cached_errno);
 508 #endif
 509   if (root->last_disconnected_server)
 510     memcached_server_free(root->last_disconnected_server);
 511   root->last_disconnected_server= memcached_server_clone(NULL, ptr);
 512 }
 513
 514 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 515 {
 516   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 517
 518   if (ptr->fd != INVALID_SOCKET)
 519     return MEMCACHED_SUCCESS;
 520
 521   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 522
 523   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 524   WATCHPOINT_ASSERT(ptr->root);
 525   if (ptr->root->retry_timeout && ptr->next_retry)
 526   {
 527     struct timeval curr_time;
 528
 529     gettimeofday(&curr_time, NULL);
 530
 531     // We should optimize this to remove the allocation if the server was
 532     // the last server to die
 533     if (ptr->next_retry > curr_time.tv_sec)
 534     {
 535       set_last_disconnected_host(ptr);
 536
 537       return MEMCACHED_SERVER_MARKED_DEAD;
 538     }
 539   }
 540
 541   // If we are over the counter failure, we just fail. Reject host only
 542   // works if you have a set number of failures.
 543   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 544   {
 545     set_last_disconnected_host(ptr);
 546
 547     // @todo fix this by fixing behavior to no longer make use of
 548     // memcached_st
 549     if (_is_auto_eject_host(ptr->root))
 550     {
 551       run_distribution((memcached_st *)ptr->root);
 552     }
 553
 554     return MEMCACHED_SERVER_MARKED_DEAD;
 555   }
 556
 557   /* We need to clean up the multi startup piece */
 558   switch (ptr->type)
 559   {
 560   case MEMCACHED_CONNECTION_UNKNOWN:
 561     WATCHPOINT_ASSERT(0);
 562     rc= MEMCACHED_NOT_SUPPORTED;
 563     break;
 564   case MEMCACHED_CONNECTION_UDP:
 565   case MEMCACHED_CONNECTION_TCP:
 566     rc= network_connect(ptr);
 567 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 568     if (ptr->fd != INVALID_SOCKET && ptr->root->sasl.callbacks)
 569     {
 570       rc= memcached_sasl_authenticate_connection(ptr);
 571       if (rc != MEMCACHED_SUCCESS)
 572       {
 573         (void)closesocket(ptr->fd);
 574         ptr->fd= INVALID_SOCKET;
 575       }
 576     }
 577 #endif
 578     break;
 579   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 580     rc= unix_socket_connect(ptr);
 581     break;
 582   case MEMCACHED_CONNECTION_MAX:
 583   default:
 584     WATCHPOINT_ASSERT(0);
 585   }
 586
 587   if (rc == MEMCACHED_SUCCESS)
 588   {
 589     ptr->server_failure_counter= 0;
 590     ptr->next_retry= 0;
 591   }
 592   else
 593   {
 594     ptr->server_failure_counter++;
 595
 596     set_last_disconnected_host(ptr);
 597   }
 598
 599   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 600
 601   return rc;
 602 }