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 #include <cassert>
  41 #include <ctime>
  42 #include <sys/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   size_t loop_max= 5;
  51
  52   while (--loop_max) // Should only loop on cases of ERESTART or EINTR
  53   {
  54     int error;
  55     if (ptr->root->poll_timeout)
  56     {
  57       error= poll(fds, 1, ptr->root->connect_timeout);
  58     }
  59     else
  60     {
  61       error= 0;
  62     }
  63
  64     switch (error)
  65     {
  66     case 1:
  67       {
  68         int err;
  69         socklen_t len= sizeof (err);
  70         (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  71
  72         // We check the value to see what happened wth the socket.
  73         if (err == 0)
  74         {
  75           return MEMCACHED_SUCCESS;
  76         }
  77
  78         return memcached_set_errno(*ptr, err, MEMCACHED_AT);
  79       }
  80     case 0:
  81       {
  82         return memcached_set_error(*ptr, MEMCACHED_TIMEOUT, MEMCACHED_AT);
  83       }
  84
  85     default: // A real error occurred and we need to completely bail
  86       WATCHPOINT_ERRNO(get_socket_errno());
  87       switch (get_socket_errno())
  88       {
  89 #ifdef TARGET_OS_LINUX
  90       case ERESTART:
  91 #endif
  92       case EINTR:
  93         continue;
  94
  95       case EFAULT:
  96       case ENOMEM:
  97         return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
  98
  99       case EINVAL:
 100         return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT, memcached_literal_param("RLIMIT_NOFILE exceeded, or if OSX the timeout value was invalid"));
 101
 102       default: // This should not happen
 103         if (fds[0].revents & POLLERR)
 104         {
 105           int err;
 106           socklen_t len= sizeof (err);
 107           (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
 108           ptr->cached_errno= (err == 0) ? get_socket_errno() : err;
 109         }
 110         else
 111         {
 112           ptr->cached_errno= get_socket_errno();
 113         }
 114
 115         WATCHPOINT_ASSERT(ptr->fd != INVALID_SOCKET);
 116         (void)closesocket(ptr->fd);
 117         ptr->fd= INVALID_SOCKET;
 118         ptr->state= MEMCACHED_SERVER_STATE_NEW;
 119
 120         return memcached_set_errno(*ptr, get_socket_errno(), MEMCACHED_AT);
 121       }
 122     }
 123   }
 124
 125   // This should only be possible from ERESTART or EINTR;
 126   return memcached_set_errno(*ptr, get_socket_errno(), MEMCACHED_AT);
 127 }
 128
 129 static memcached_return_t set_hostinfo(memcached_server_st *server)
 130 {
 131   WATCHPOINT_ASSERT(not server->address_info); // We cover the case where a programming mistake has been made.
 132   if (server->address_info)
 133   {
 134     freeaddrinfo(server->address_info);
 135     server->address_info= NULL;
 136     server->address_info_next= NULL;
 137   }
 138
 139   char str_port[NI_MAXSERV];
 140   int length= snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
 141   if (length >= NI_MAXSERV || length < 0)
 142     return MEMCACHED_FAILURE;
 143
 144   struct addrinfo hints;
 145   memset(&hints, 0, sizeof(struct addrinfo));
 146
 147 #if 0
 148   hints.ai_family= AF_INET;
 149 #endif
 150   if (server->type == MEMCACHED_CONNECTION_UDP)
 151   {
 152     hints.ai_protocol= IPPROTO_UDP;
 153     hints.ai_socktype= SOCK_DGRAM;
 154   }
 155   else
 156   {
 157     hints.ai_socktype= SOCK_STREAM;
 158     hints.ai_protocol= IPPROTO_TCP;
 159   }
 160
 161   int errcode;
 162   switch(errcode= getaddrinfo(server->hostname, str_port, &hints, &server->address_info))
 163   {
 164   case 0:
 165     break;
 166
 167   case EAI_AGAIN:
 168     return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT, memcached_string_make_from_cstr(gai_strerror(errcode)));
 169
 170   case EAI_SYSTEM:
 171       return memcached_set_errno(*server, errno, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_SYSTEM)"));
 172
 173   case EAI_BADFLAGS:
 174     return memcached_set_error(*server, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_BADFLAGS)"));
 175
 176   case EAI_MEMORY:
 177     return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_MEMORY)"));
 178
 179   default:
 180     {
 181       WATCHPOINT_STRING(server->hostname);
 182       WATCHPOINT_STRING(gai_strerror(errcode));
 183       return memcached_set_error(*server, MEMCACHED_HOST_LOOKUP_FAILURE, MEMCACHED_AT, memcached_string_make_from_cstr(gai_strerror(errcode)));
 184     }
 185   }
 186   server->address_info_next= server->address_info;
 187   server->state= MEMCACHED_SERVER_STATE_ADDRINFO;
 188
 189   return MEMCACHED_SUCCESS;
 190 }
 191
 192 static inline void set_socket_nonblocking(memcached_server_st *ptr)
 193 {
 194 #ifdef WIN32
 195   u_long arg = 1;
 196   if (ioctlsocket(ptr->fd, FIONBIO, &arg) == SOCKET_ERROR)
 197   {
 198     memcached_set_errno(*ptr, get_socket_errno(), NULL);
 199   }
 200 #else
 201   int flags;
 202
 203   do
 204   {
 205     flags= fcntl(ptr->fd, F_GETFL, 0);
 206   } while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 207
 208   if (flags == -1)
 209   {
 210     memcached_set_errno(*ptr, errno, NULL);
 211   }
 212   else if ((flags & O_NONBLOCK) == 0)
 213   {
 214     int rval;
 215
 216     do
 217     {
 218       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 219     } while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 220
 221     unlikely (rval == -1)
 222     {
 223       memcached_set_errno(*ptr, errno, NULL);
 224     }
 225   }
 226 #endif
 227 }
 228
 229 static void set_socket_options(memcached_server_st *ptr)
 230 {
 231   WATCHPOINT_ASSERT(ptr->fd != -1);
 232
 233   if (ptr->type == MEMCACHED_CONNECTION_UDP)
 234     return;
 235
 236 #ifdef HAVE_SNDTIMEO
 237   if (ptr->root->snd_timeout)
 238   {
 239     int error;
 240     struct timeval waittime;
 241
 242     waittime.tv_sec= 0;
 243     waittime.tv_usec= ptr->root->snd_timeout;
 244
 245     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
 246                       &waittime, (socklen_t)sizeof(struct timeval));
 247     WATCHPOINT_ASSERT(error == 0);
 248   }
 249 #endif
 250
 251 #ifdef HAVE_RCVTIMEO
 252   if (ptr->root->rcv_timeout)
 253   {
 254     int error;
 255     struct timeval waittime;
 256
 257     waittime.tv_sec= 0;
 258     waittime.tv_usec= ptr->root->rcv_timeout;
 259
 260     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
 261                       &waittime, (socklen_t)sizeof(struct timeval));
 262     WATCHPOINT_ASSERT(error == 0);
 263   }
 264 #endif
 265
 266
 267 #if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
 268   {
 269     int set= 1;
 270     int error= setsockopt(ptr->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 271
 272     // This is not considered a fatal error
 273     if (error == -1)
 274     {
 275       WATCHPOINT_ERRNO(get_socket_errno());
 276       perror("setsockopt(SO_NOSIGPIPE)");
 277     }
 278   }
 279 #endif
 280
 281   if (ptr->root->flags.no_block)
 282   {
 283     int error;
 284     struct linger linger;
 285
 286     linger.l_onoff= 1;
 287     linger.l_linger= 0; /* By default on close() just drop the socket */
 288     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 289                       &linger, (socklen_t)sizeof(struct linger));
 290     WATCHPOINT_ASSERT(error == 0);
 291   }
 292
 293   if (ptr->root->flags.tcp_nodelay)
 294   {
 295     int flag= 1;
 296     int error;
 297
 298     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 299                       &flag, (socklen_t)sizeof(int));
 300     WATCHPOINT_ASSERT(error == 0);
 301   }
 302
 303   if (ptr->root->flags.tcp_keepalive)
 304   {
 305     int flag= 1;
 306     int error;
 307
 308     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 309                       &flag, (socklen_t)sizeof(int));
 310     WATCHPOINT_ASSERT(error == 0);
 311   }
 312
 313 #ifdef TCP_KEEPIDLE
 314   if (ptr->root->tcp_keepidle > 0)
 315   {
 316     int error;
 317
 318     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 319                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 320     WATCHPOINT_ASSERT(error == 0);
 321   }
 322 #endif
 323
 324   if (ptr->root->send_size > 0)
 325   {
 326     int error;
 327
 328     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 329                       &ptr->root->send_size, (socklen_t)sizeof(int));
 330     WATCHPOINT_ASSERT(error == 0);
 331   }
 332
 333   if (ptr->root->recv_size > 0)
 334   {
 335     int error;
 336
 337     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 338                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 339     WATCHPOINT_ASSERT(error == 0);
 340   }
 341
 342
 343   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 344   set_socket_nonblocking(ptr);
 345 }
 346
 347 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 348 {
 349 #ifndef WIN32
 350   WATCHPOINT_ASSERT(ptr->fd == -1);
 351
 352   if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 353   {
 354     return memcached_set_errno(*ptr, errno, NULL);
 355   }
 356
 357   struct sockaddr_un servAddr;
 358
 359   memset(&servAddr, 0, sizeof (struct sockaddr_un));
 360   servAddr.sun_family= AF_UNIX;
 361   strncpy(servAddr.sun_path, ptr->hostname, sizeof(servAddr.sun_path)); /* Copy filename */
 362
 363   do {
 364     if (connect(ptr->fd, (struct sockaddr *)&servAddr, sizeof(servAddr)) < 0)
 365     {
 366       switch (errno)
 367       {
 368       case EINPROGRESS:
 369       case EALREADY:
 370       case EINTR:
 371         continue;
 372
 373       case EISCONN: /* We were spinning waiting on connect */
 374         {
 375           WATCHPOINT_ASSERT(0); // Programmer error
 376           break;
 377         }
 378
 379       default:
 380         WATCHPOINT_ERRNO(errno);
 381         return memcached_set_errno(*ptr, errno, MEMCACHED_AT);
 382       }
 383     }
 384   } while (0);
 385   ptr->state= MEMCACHED_SERVER_STATE_CONNECTED;
 386
 387   WATCHPOINT_ASSERT(ptr->fd != INVALID_SOCKET);
 388
 389   return MEMCACHED_SUCCESS;
 390 #else
 391   (void)ptr;
 392   return MEMCACHED_NOT_SUPPORTED;
 393 #endif
 394 }
 395
 396 static memcached_return_t network_connect(memcached_server_st *ptr)
 397 {
 398   bool timeout_error_occured= false;
 399
 400   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 401   WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 402
 403   if (not ptr->address_info)
 404   {
 405     WATCHPOINT_ASSERT(ptr->state == MEMCACHED_SERVER_STATE_NEW);
 406     memcached_return_t rc;
 407     uint32_t counter= 5;
 408     while (--counter)
 409     {
 410       if ((rc= set_hostinfo(ptr)) != MEMCACHED_TIMEOUT)
 411         break;
 412
 413 #ifndef WIN32
 414       struct timespec dream, rem;
 415
 416       dream.tv_nsec= 1000;
 417       dream.tv_sec= 0;
 418
 419       nanosleep(&dream, &rem);
 420 #endif
 421     }
 422
 423     if (memcached_failed(rc))
 424       return rc;
 425   }
 426
 427   /* Create the socket */
 428   while (ptr->address_info_next && ptr->fd == INVALID_SOCKET)
 429   {
 430     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 431     if (ptr->type == MEMCACHED_CONNECTION_UDP && ptr->address_info_next->ai_family != AF_INET)
 432     {
 433       ptr->address_info_next= ptr->address_info_next->ai_next;
 434       continue;
 435     }
 436
 437     if ((ptr->fd= socket(ptr->address_info_next->ai_family,
 438                          ptr->address_info_next->ai_socktype,
 439                          ptr->address_info_next->ai_protocol)) < 0)
 440     {
 441       return memcached_set_errno(*ptr, get_socket_errno(), NULL);
 442     }
 443
 444     set_socket_options(ptr);
 445
 446     /* connect to server */
 447     if ((connect(ptr->fd, ptr->address_info_next->ai_addr, ptr->address_info_next->ai_addrlen) != SOCKET_ERROR))
 448     {
 449       ptr->state= MEMCACHED_SERVER_STATE_CONNECTED;
 450       break; // Success
 451     }
 452
 453     /* An error occurred */
 454     switch (get_socket_errno())
 455     {
 456     case ETIMEDOUT:
 457       timeout_error_occured= true;
 458       break;
 459
 460     case EWOULDBLOCK:
 461     case EINPROGRESS: // nonblocking mode - first return
 462     case EALREADY: // nonblocking mode - subsequent returns
 463       {
 464         ptr->state= MEMCACHED_SERVER_STATE_IN_PROGRESS;
 465         memcached_return_t rc= connect_poll(ptr);
 466
 467         if (memcached_success(rc))
 468         {
 469           ptr->state= MEMCACHED_SERVER_STATE_CONNECTED;
 470           return MEMCACHED_SUCCESS;
 471         }
 472
 473         // A timeout here is treated as an error, we will not retry
 474         if (rc == MEMCACHED_TIMEOUT)
 475         {
 476           timeout_error_occured= true;
 477         }
 478       }
 479       break;
 480
 481     case EISCONN: // we are connected :-)
 482       WATCHPOINT_ASSERT(0); // This is a programmer's error
 483       break;
 484
 485     case EINTR: // Special case, we retry ai_addr
 486       WATCHPOINT_ASSERT(ptr->fd != INVALID_SOCKET);
 487       (void)closesocket(ptr->fd);
 488       ptr->fd= INVALID_SOCKET;
 489       continue;
 490
 491     default:
 492       break;
 493     }
 494
 495     WATCHPOINT_ASSERT(ptr->fd != INVALID_SOCKET);
 496     (void)closesocket(ptr->fd);
 497     ptr->fd= INVALID_SOCKET;
 498     ptr->address_info_next= ptr->address_info_next->ai_next;
 499   }
 500
 501   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 502
 503   if (timeout_error_occured)
 504   {
 505     if (ptr->fd != INVALID_SOCKET)
 506     {
 507       (void)closesocket(ptr->fd);
 508       ptr->fd= INVALID_SOCKET;
 509     }
 510   }
 511
 512   WATCHPOINT_STRING("Never got a good file descriptor");
 513   /* Failed to connect. schedule next retry */
 514   if (ptr->root->retry_timeout)
 515   {
 516     struct timeval next_time;
 517
 518     if (gettimeofday(&next_time, NULL) == 0)
 519       ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 520   }
 521
 522   if (timeout_error_occured)
 523     return memcached_set_error(*ptr, MEMCACHED_TIMEOUT, MEMCACHED_AT);
 524
 525   return memcached_set_error(*ptr, MEMCACHED_CONNECTION_FAILURE, MEMCACHED_AT); /* The last error should be from connect() */
 526 }
 527
 528 void set_last_disconnected_host(memcached_server_write_instance_st self)
 529 {
 530   // const_cast
 531   memcached_st *root= (memcached_st *)self->root;
 532
 533 #if 0
 534   WATCHPOINT_STRING(self->hostname);
 535   WATCHPOINT_NUMBER(self->port);
 536   WATCHPOINT_ERRNO(self->cached_errno);
 537 #endif
 538   memcached_server_free(root->last_disconnected_server);
 539   root->last_disconnected_server= memcached_server_clone(NULL, self);
 540 }
 541
 542 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 543 {
 544   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 545
 546   if (ptr->fd != INVALID_SOCKET)
 547     return MEMCACHED_SUCCESS;
 548
 549   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 550
 551   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 552   WATCHPOINT_ASSERT(ptr->root);
 553   if (ptr->root->retry_timeout && ptr->next_retry)
 554   {
 555     struct timeval curr_time;
 556
 557     gettimeofday(&curr_time, NULL);
 558
 559     // We should optimize this to remove the allocation if the server was
 560     // the last server to die
 561     if (ptr->next_retry > curr_time.tv_sec)
 562     {
 563       set_last_disconnected_host(ptr);
 564
 565       return memcached_set_error(*ptr, MEMCACHED_SERVER_MARKED_DEAD, MEMCACHED_AT);
 566     }
 567   }
 568
 569   // If we are over the counter failure, we just fail. Reject host only
 570   // works if you have a set number of failures.
 571   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 572   {
 573     set_last_disconnected_host(ptr);
 574
 575     // @todo fix this by fixing behavior to no longer make use of
 576     // memcached_st
 577     if (_is_auto_eject_host(ptr->root))
 578     {
 579       run_distribution((memcached_st *)ptr->root);
 580     }
 581
 582     return memcached_set_error(*ptr, MEMCACHED_SERVER_MARKED_DEAD, MEMCACHED_AT);
 583   }
 584
 585   /* We need to clean up the multi startup piece */
 586   switch (ptr->type)
 587   {
 588   case MEMCACHED_CONNECTION_UNKNOWN:
 589     WATCHPOINT_ASSERT(0);
 590     rc= MEMCACHED_NOT_SUPPORTED;
 591     break;
 592
 593   case MEMCACHED_CONNECTION_UDP:
 594   case MEMCACHED_CONNECTION_TCP:
 595     rc= network_connect(ptr);
 596 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 597     if (ptr->fd != INVALID_SOCKET and ptr->root->sasl.callbacks)
 598     {
 599       rc= memcached_sasl_authenticate_connection(ptr);
 600       if (memcached_failed(rc) and ptr->fd != INVALID_SOCKET)
 601       {
 602         WATCHPOINT_ASSERT(ptr->fd != INVALID_SOCKET);
 603         (void)closesocket(ptr->fd);
 604         ptr->fd= INVALID_SOCKET;
 605       }
 606     }
 607 #endif
 608     break;
 609
 610   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 611     rc= unix_socket_connect(ptr);
 612     break;
 613
 614   case MEMCACHED_CONNECTION_MAX:
 615   default:
 616     WATCHPOINT_ASSERT(0);
 617   }
 618
 619   if (memcached_success(rc))
 620   {
 621     ptr->server_failure_counter= 0;
 622     ptr->next_retry= 0;
 623   }
 624   else
 625   {
 626     memcached_set_error(*ptr, rc, MEMCACHED_AT);
 627     ptr->server_failure_counter++;
 628     set_last_disconnected_host(ptr);
 629   }
 630
 631   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 632
 633   return rc;
 634 }