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

   1 /* LibMemcached
   2  * Copyright (C) 2006-2010 Brian Aker
   3  * All rights reserved.
   4  *
   5  * Use and distribution licensed under the BSD license.  See
   6  * the COPYING file in the parent directory for full text.
   7  *
   8  * Summary: Server IO, Not public!
   9  *
  10  */
  11
  12 #include "common.h"
  13 #include <sys/time.h>
  14 #include <time.h>
  15
  16 static memcached_return_t connect_poll(memcached_server_st *ptr)
  17 {
  18   struct pollfd fds[1];
  19   fds[0].fd = ptr->fd;
  20   fds[0].events = POLLOUT;
  21
  22   int error;
  23   size_t loop_max= 5;
  24
  25   while (--loop_max) // Should only loop on cases of ERESTART or EINTR
  26   {
  27     error= poll(fds, 1, ptr->root->connect_timeout);
  28
  29     switch (error)
  30     {
  31     case 1:
  32       {
  33         int err;
  34         socklen_t len= sizeof (err);
  35         (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  36
  37         // We check the value to see what happened wth the socket.
  38         if (err == 0)
  39         {
  40           return MEMCACHED_SUCCESS;
  41         }
  42         else
  43         {
  44           ptr->cached_errno= errno;
  45
  46           return MEMCACHED_ERRNO;
  47         }
  48       }
  49     case 0:
  50       return MEMCACHED_TIMEOUT;
  51     default: // A real error occurred and we need to completely bail
  52       WATCHPOINT_ERRNO(get_socket_errno());
  53       switch (get_socket_errno())
  54       {
  55 #ifdef TARGET_OS_LINUX
  56       case ERESTART:
  57 #endif
  58       case EINTR:
  59         continue;
  60       default:
  61         if (fds[0].revents & POLLERR)
  62         {
  63           int err;
  64           socklen_t len= sizeof (err);
  65           (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  66           ptr->cached_errno= (err == 0) ? get_socket_errno() : err;
  67         }
  68         else
  69         {
  70           ptr->cached_errno= get_socket_errno();
  71         }
  72
  73         (void)closesocket(ptr->fd);
  74         ptr->fd= INVALID_SOCKET;
  75
  76         return MEMCACHED_ERRNO;
  77       }
  78     }
  79   }
  80
  81   // This should only be possible from ERESTART or EINTR;
  82   ptr->cached_errno= get_socket_errno();
  83
  84   return MEMCACHED_ERRNO;
  85 }
  86
  87 static memcached_return_t set_hostinfo(memcached_server_st *server)
  88 {
  89   struct addrinfo *ai;
  90   struct addrinfo hints;
  91   char str_port[NI_MAXSERV];
  92   uint32_t counter= 5;
  93
  94   int length= snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
  95   if (length >= NI_MAXSERV || length < 0)
  96     return MEMCACHED_FAILURE;
  97
  98   memset(&hints, 0, sizeof(hints));
  99
 100  // hints.ai_family= AF_INET;
 101   if (server->type == MEMCACHED_CONNECTION_UDP)
 102   {
 103     hints.ai_protocol= IPPROTO_UDP;
 104     hints.ai_socktype= SOCK_DGRAM;
 105   }
 106   else
 107   {
 108     hints.ai_socktype= SOCK_STREAM;
 109     hints.ai_protocol= IPPROTO_TCP;
 110   }
 111
 112   while (--counter)
 113   {
 114     int e= getaddrinfo(server->hostname, str_port, &hints, &ai);
 115
 116     if (e == 0)
 117     {
 118       break;
 119     }
 120     else if (e == EAI_AGAIN)
 121     {
 122 #ifndef WIN32
 123       struct timespec dream, rem;
 124
 125       dream.tv_nsec= 1000;
 126       dream.tv_sec= 0;
 127
 128       nanosleep(&dream, &rem);
 129 #endif
 130       continue;
 131     }
 132     else
 133     {
 134       WATCHPOINT_STRING(server->hostname);
 135       WATCHPOINT_STRING(gai_strerror(e));
 136       return MEMCACHED_HOST_LOOKUP_FAILURE;
 137     }
 138   }
 139
 140   if (server->address_info)
 141   {
 142     freeaddrinfo(server->address_info);
 143     server->address_info= NULL;
 144   }
 145   server->address_info= ai;
 146
 147   return MEMCACHED_SUCCESS;
 148 }
 149
 150 static inline memcached_return_t set_socket_nonblocking(memcached_server_st *ptr)
 151 {
 152 #ifdef WIN32
 153   u_long arg = 1;
 154   if (ioctlsocket(ptr->fd, FIONBIO, &arg) == SOCKET_ERROR)
 155   {
 156     ptr->cached_errno= get_socket_errno();
 157     return MEMCACHED_CONNECTION_FAILURE;
 158   }
 159 #else
 160   int flags;
 161
 162   do
 163     flags= fcntl(ptr->fd, F_GETFL, 0);
 164   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 165
 166   unlikely (flags == -1)
 167   {
 168     ptr->cached_errno= errno;
 169     return MEMCACHED_CONNECTION_FAILURE;
 170   }
 171   else if ((flags & O_NONBLOCK) == 0)
 172   {
 173     int rval;
 174
 175     do
 176       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 177     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 178
 179     unlikely (rval == -1)
 180     {
 181       ptr->cached_errno= errno;
 182       return MEMCACHED_CONNECTION_FAILURE;
 183     }
 184   }
 185 #endif
 186   return MEMCACHED_SUCCESS;
 187 }
 188
 189 static memcached_return_t set_socket_options(memcached_server_st *ptr)
 190 {
 191   WATCHPOINT_ASSERT(ptr->fd != -1);
 192
 193   if (ptr->type == MEMCACHED_CONNECTION_UDP)
 194     return MEMCACHED_SUCCESS;
 195
 196 #ifdef HAVE_SNDTIMEO
 197   if (ptr->root->snd_timeout)
 198   {
 199     int error;
 200     struct timeval waittime;
 201
 202     waittime.tv_sec= 0;
 203     waittime.tv_usec= ptr->root->snd_timeout;
 204
 205     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
 206                       &waittime, (socklen_t)sizeof(struct timeval));
 207     WATCHPOINT_ASSERT(error == 0);
 208     if (error)
 209       return MEMCACHED_FAILURE;
 210   }
 211 #endif
 212
 213 #ifdef HAVE_RCVTIMEO
 214   if (ptr->root->rcv_timeout)
 215   {
 216     int error;
 217     struct timeval waittime;
 218
 219     waittime.tv_sec= 0;
 220     waittime.tv_usec= ptr->root->rcv_timeout;
 221
 222     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
 223                       &waittime, (socklen_t)sizeof(struct timeval));
 224     WATCHPOINT_ASSERT(error == 0);
 225     if (error)
 226       return MEMCACHED_FAILURE;
 227   }
 228 #endif
 229
 230
 231 #if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
 232   {
 233     int set = 1;
 234     int error= setsockopt(ptr->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 235
 236     // This is not considered a fatal error
 237     if (error == -1)
 238     {
 239       WATCHPOINT_ERRNO(get_socket_errno());
 240       perror("setsockopt(SO_NOSIGPIPE)");
 241     }
 242   }
 243 #endif
 244
 245   if (ptr->root->flags.no_block)
 246   {
 247     int error;
 248     struct linger linger;
 249
 250     linger.l_onoff= 1;
 251     linger.l_linger= 0; /* By default on close() just drop the socket */
 252     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 253                       &linger, (socklen_t)sizeof(struct linger));
 254     WATCHPOINT_ASSERT(error == 0);
 255     if (error)
 256       return MEMCACHED_FAILURE;
 257   }
 258
 259   if (ptr->root->flags.tcp_nodelay)
 260   {
 261     int flag= 1;
 262     int error;
 263
 264     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 265                       &flag, (socklen_t)sizeof(int));
 266     WATCHPOINT_ASSERT(error == 0);
 267     if (error)
 268       return MEMCACHED_FAILURE;
 269   }
 270
 271   if (ptr->root->flags.tcp_keepalive)
 272   {
 273     int flag= 1;
 274     int error;
 275
 276     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 277                       &flag, (socklen_t)sizeof(int));
 278     WATCHPOINT_ASSERT(error == 0);
 279     if (error)
 280       return MEMCACHED_FAILURE;
 281   }
 282
 283 #ifdef TCP_KEEPIDLE
 284   if (ptr->root->tcp_keepidle > 0)
 285   {
 286     int error;
 287
 288     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 289                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 290     WATCHPOINT_ASSERT(error == 0);
 291     if (error)
 292       return MEMCACHED_FAILURE;
 293   }
 294 #endif
 295
 296   if (ptr->root->send_size > 0)
 297   {
 298     int error;
 299
 300     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 301                       &ptr->root->send_size, (socklen_t)sizeof(int));
 302     WATCHPOINT_ASSERT(error == 0);
 303     if (error)
 304       return MEMCACHED_FAILURE;
 305   }
 306
 307   if (ptr->root->recv_size > 0)
 308   {
 309     int error;
 310
 311     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 312                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 313     WATCHPOINT_ASSERT(error == 0);
 314     if (error)
 315       return MEMCACHED_FAILURE;
 316   }
 317
 318
 319   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 320   return set_socket_nonblocking(ptr);
 321 }
 322
 323 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 324 {
 325 #ifndef WIN32
 326   struct sockaddr_un servAddr;
 327
 328   WATCHPOINT_ASSERT(ptr->fd == -1);
 329
 330   if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 331   {
 332     ptr->cached_errno= errno;
 333     return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 334   }
 335
 336   memset(&servAddr, 0, sizeof (struct sockaddr_un));
 337   servAddr.sun_family= AF_UNIX;
 338   strncpy(servAddr.sun_path, ptr->hostname, sizeof(servAddr.sun_path)); /* Copy filename */
 339
 340 test_connect:
 341   if (connect(ptr->fd,
 342               (struct sockaddr *)&servAddr,
 343               sizeof(servAddr)) < 0)
 344   {
 345     switch (errno)
 346     {
 347     case EINPROGRESS:
 348     case EALREADY:
 349     case EINTR:
 350       goto test_connect;
 351     case EISCONN: /* We were spinning waiting on connect */
 352       break;
 353     default:
 354       WATCHPOINT_ERRNO(errno);
 355       ptr->cached_errno= errno;
 356       return MEMCACHED_ERRNO;
 357     }
 358   }
 359
 360   WATCHPOINT_ASSERT(ptr->fd != -1);
 361
 362   return MEMCACHED_SUCCESS;
 363 #else
 364   (void)ptr;
 365   return MEMCACHED_NOT_SUPPORTED;
 366 #endif
 367 }
 368
 369 static memcached_return_t network_connect(memcached_server_st *ptr)
 370 {
 371   bool timeout_error_occured= false;
 372
 373
 374   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 375   WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 376
 377   if (! ptr->options.sockaddr_inited || (!(ptr->root->flags.use_cache_lookups)))
 378   {
 379     memcached_return_t rc;
 380
 381     rc= set_hostinfo(ptr);
 382     if (rc != MEMCACHED_SUCCESS)
 383       return rc;
 384     ptr->options.sockaddr_inited= true;
 385   }
 386
 387   struct addrinfo *use= ptr->address_info;
 388   /* Create the socket */
 389   while (use != NULL)
 390   {
 391     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 392     if (ptr->type == MEMCACHED_CONNECTION_UDP && use->ai_family != AF_INET)
 393     {
 394       use= use->ai_next;
 395       continue;
 396     }
 397
 398     if ((ptr->fd= socket(use->ai_family,
 399                          use->ai_socktype,
 400                          use->ai_protocol)) < 0)
 401     {
 402       ptr->cached_errno= get_socket_errno();
 403       WATCHPOINT_ERRNO(get_socket_errno());
 404       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 405     }
 406
 407     (void)set_socket_options(ptr);
 408
 409     /* connect to server */
 410     if ((connect(ptr->fd, use->ai_addr, use->ai_addrlen) != SOCKET_ERROR))
 411     {
 412       break; // Success
 413     }
 414
 415     /* An error occurred */
 416     ptr->cached_errno= get_socket_errno();
 417     if (ptr->cached_errno == EWOULDBLOCK ||
 418         ptr->cached_errno == EINPROGRESS || /* nonblocking mode - first return, */
 419         ptr->cached_errno == EALREADY) /* nonblocking mode - subsequent returns */
 420     {
 421       memcached_return_t rc;
 422       rc= connect_poll(ptr);
 423
 424       if (rc == MEMCACHED_TIMEOUT)
 425         timeout_error_occured= true;
 426
 427       if (rc == MEMCACHED_SUCCESS)
 428         break;
 429     }
 430     else if (get_socket_errno() == EISCONN) /* we are connected :-) */
 431     {
 432       break;
 433     }
 434     else if (get_socket_errno() == EINTR) // Special case, we retry ai_addr
 435     {
 436       (void)closesocket(ptr->fd);
 437       ptr->fd= INVALID_SOCKET;
 438       continue;
 439     }
 440
 441     (void)closesocket(ptr->fd);
 442     ptr->fd= INVALID_SOCKET;
 443     use= use->ai_next;
 444   }
 445
 446   if (ptr->fd == INVALID_SOCKET)
 447   {
 448     WATCHPOINT_STRING("Never got a good file descriptor");
 449
 450     /* Failed to connect. schedule next retry */
 451     if (ptr->root->retry_timeout)
 452     {
 453       struct timeval next_time;
 454
 455       if (gettimeofday(&next_time, NULL) == 0)
 456         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 457     }
 458
 459     if (timeout_error_occured)
 460       return MEMCACHED_TIMEOUT;
 461
 462     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 463   }
 464
 465   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 466 }
 467
 468 void set_last_disconnected_host(memcached_server_write_instance_st ptr)
 469 {
 470   // const_cast
 471   memcached_st *root= (memcached_st *)ptr->root;
 472
 473 #if 0
 474   WATCHPOINT_STRING(ptr->hostname);
 475   WATCHPOINT_NUMBER(ptr->port);
 476   WATCHPOINT_ERRNO(ptr->cached_errno);
 477 #endif
 478   if (root->last_disconnected_server)
 479     memcached_server_free(root->last_disconnected_server);
 480   root->last_disconnected_server= memcached_server_clone(NULL, ptr);
 481 }
 482
 483 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 484 {
 485   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 486
 487   if (ptr->fd != INVALID_SOCKET)
 488     return MEMCACHED_SUCCESS;
 489
 490   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 491
 492   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 493   WATCHPOINT_ASSERT(ptr->root);
 494   if (ptr->root->retry_timeout && ptr->next_retry)
 495   {
 496     struct timeval curr_time;
 497
 498     gettimeofday(&curr_time, NULL);
 499
 500     // We should optimize this to remove the allocation if the server was
 501     // the last server to die
 502     if (ptr->next_retry > curr_time.tv_sec)
 503     {
 504       set_last_disconnected_host(ptr);
 505
 506       return MEMCACHED_SERVER_MARKED_DEAD;
 507     }
 508   }
 509
 510   // If we are over the counter failure, we just fail. Reject host only
 511   // works if you have a set number of failures.
 512   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 513   {
 514     set_last_disconnected_host(ptr);
 515
 516     // @todo fix this by fixing behavior to no longer make use of
 517     // memcached_st
 518     if (_is_auto_eject_host(ptr->root))
 519     {
 520       run_distribution((memcached_st *)ptr->root);
 521     }
 522
 523     return MEMCACHED_SERVER_MARKED_DEAD;
 524   }
 525
 526   /* We need to clean up the multi startup piece */
 527   switch (ptr->type)
 528   {
 529   case MEMCACHED_CONNECTION_UNKNOWN:
 530     WATCHPOINT_ASSERT(0);
 531     rc= MEMCACHED_NOT_SUPPORTED;
 532     break;
 533   case MEMCACHED_CONNECTION_UDP:
 534   case MEMCACHED_CONNECTION_TCP:
 535     rc= network_connect(ptr);
 536 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 537     if (ptr->fd != INVALID_SOCKET && ptr->root->sasl.callbacks)
 538     {
 539       rc= memcached_sasl_authenticate_connection(ptr);
 540       if (rc != MEMCACHED_SUCCESS)
 541       {
 542         (void)closesocket(ptr->fd);
 543         ptr->fd= INVALID_SOCKET;
 544       }
 545     }
 546 #endif
 547     break;
 548   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 549     rc= unix_socket_connect(ptr);
 550     break;
 551   case MEMCACHED_CONNECTION_MAX:
 552   default:
 553     WATCHPOINT_ASSERT(0);
 554   }
 555
 556   if (rc == MEMCACHED_SUCCESS)
 557   {
 558     ptr->server_failure_counter= 0;
 559     ptr->next_retry= 0;
 560   }
 561   else
 562   {
 563     ptr->server_failure_counter++;
 564
 565     set_last_disconnected_host(ptr);
 566   }
 567
 568   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 569
 570   return rc;
 571 }