git.m6w6.name Git - awesomized/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 <libmemcached/common.h>
  13 #include <assert.h>
  14 #include <sys/time.h>
  15 #include <time.h>
  16
  17 static memcached_return_t connect_poll(memcached_server_st *ptr)
  18 {
  19   struct pollfd fds[1];
  20   fds[0].fd = ptr->fd;
  21   fds[0].events = POLLOUT;
  22
  23   int error;
  24   size_t loop_max= 5;
  25
  26   while (--loop_max) // Should only loop on cases of ERESTART or EINTR
  27   {
  28     error= poll(fds, 1, ptr->root->connect_timeout);
  29
  30     switch (error)
  31     {
  32     case 1:
  33       {
  34         int err;
  35         socklen_t len= sizeof (err);
  36         (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  37
  38         // We check the value to see what happened wth the socket.
  39         if (err == 0)
  40         {
  41           return MEMCACHED_SUCCESS;
  42         }
  43         else
  44         {
  45           ptr->cached_errno= errno;
  46
  47           return MEMCACHED_ERRNO;
  48         }
  49       }
  50     case 0:
  51       return MEMCACHED_TIMEOUT;
  52     default: // A real error occurred and we need to completely bail
  53       WATCHPOINT_ERRNO(get_socket_errno());
  54       switch (get_socket_errno())
  55       {
  56 #ifdef TARGET_OS_LINUX
  57       case ERESTART:
  58 #endif
  59       case EINTR:
  60         continue;
  61       default:
  62         if (fds[0].revents & POLLERR)
  63         {
  64           int err;
  65           socklen_t len= sizeof (err);
  66           (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  67           ptr->cached_errno= (err == 0) ? get_socket_errno() : err;
  68         }
  69         else
  70         {
  71           ptr->cached_errno= get_socket_errno();
  72         }
  73
  74         (void)closesocket(ptr->fd);
  75         ptr->fd= INVALID_SOCKET;
  76
  77         return MEMCACHED_ERRNO;
  78       }
  79     }
  80   }
  81
  82   // This should only be possible from ERESTART or EINTR;
  83   ptr->cached_errno= get_socket_errno();
  84
  85   return MEMCACHED_ERRNO;
  86 }
  87
  88 static memcached_return_t set_hostinfo(memcached_server_st *server)
  89 {
  90   struct addrinfo hints;
  91   char str_port[NI_MAXSERV];
  92
  93   assert(! server->address_info); // We cover the case where a programming mistake has been made.
  94   if (server->address_info)
  95   {
  96     freeaddrinfo(server->address_info);
  97     server->address_info= NULL;
  98     server->address_info_next= NULL;
  99   }
 100
 101   int length= snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
 102   if (length >= NI_MAXSERV || length < 0)
 103     return MEMCACHED_FAILURE;
 104
 105   memset(&hints, 0, sizeof(hints));
 106
 107 #if 0
 108   hints.ai_family= AF_INET;
 109 #endif
 110   if (server->type == MEMCACHED_CONNECTION_UDP)
 111   {
 112     hints.ai_protocol= IPPROTO_UDP;
 113     hints.ai_socktype= SOCK_DGRAM;
 114   }
 115   else
 116   {
 117     hints.ai_socktype= SOCK_STREAM;
 118     hints.ai_protocol= IPPROTO_TCP;
 119   }
 120
 121   uint32_t counter= 5;
 122   while (--counter)
 123   {
 124     int e= getaddrinfo(server->hostname, str_port, &hints, &server->address_info);
 125
 126     if (e == 0)
 127     {
 128       break;
 129     }
 130     else if (e == EAI_AGAIN)
 131     {
 132 #ifndef WIN32
 133       struct timespec dream, rem;
 134
 135       dream.tv_nsec= 1000;
 136       dream.tv_sec= 0;
 137
 138       nanosleep(&dream, &rem);
 139 #endif
 140       continue;
 141     }
 142     else
 143     {
 144       WATCHPOINT_STRING(server->hostname);
 145       WATCHPOINT_STRING(gai_strerror(e));
 146       return MEMCACHED_HOST_LOOKUP_FAILURE;
 147     }
 148   }
 149
 150   server->address_info_next= server->address_info;
 151
 152   return MEMCACHED_SUCCESS;
 153 }
 154
 155 static inline memcached_return_t set_socket_nonblocking(memcached_server_st *ptr)
 156 {
 157 #ifdef WIN32
 158   u_long arg = 1;
 159   if (ioctlsocket(ptr->fd, FIONBIO, &arg) == SOCKET_ERROR)
 160   {
 161     ptr->cached_errno= get_socket_errno();
 162     return MEMCACHED_CONNECTION_FAILURE;
 163   }
 164 #else
 165   int flags;
 166
 167   do
 168     flags= fcntl(ptr->fd, F_GETFL, 0);
 169   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 170
 171   unlikely (flags == -1)
 172   {
 173     ptr->cached_errno= errno;
 174     return MEMCACHED_CONNECTION_FAILURE;
 175   }
 176   else if ((flags & O_NONBLOCK) == 0)
 177   {
 178     int rval;
 179
 180     do
 181       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 182     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 183
 184     unlikely (rval == -1)
 185     {
 186       ptr->cached_errno= errno;
 187       return MEMCACHED_CONNECTION_FAILURE;
 188     }
 189   }
 190 #endif
 191   return MEMCACHED_SUCCESS;
 192 }
 193
 194 static memcached_return_t set_socket_options(memcached_server_st *ptr)
 195 {
 196   WATCHPOINT_ASSERT(ptr->fd != -1);
 197
 198   if (ptr->type == MEMCACHED_CONNECTION_UDP)
 199     return MEMCACHED_SUCCESS;
 200
 201 #ifdef HAVE_SNDTIMEO
 202   if (ptr->root->snd_timeout)
 203   {
 204     int error;
 205     struct timeval waittime;
 206
 207     waittime.tv_sec= 0;
 208     waittime.tv_usec= ptr->root->snd_timeout;
 209
 210     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
 211                       &waittime, (socklen_t)sizeof(struct timeval));
 212     WATCHPOINT_ASSERT(error == 0);
 213     if (error)
 214       return MEMCACHED_FAILURE;
 215   }
 216 #endif
 217
 218 #ifdef HAVE_RCVTIMEO
 219   if (ptr->root->rcv_timeout)
 220   {
 221     int error;
 222     struct timeval waittime;
 223
 224     waittime.tv_sec= 0;
 225     waittime.tv_usec= ptr->root->rcv_timeout;
 226
 227     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
 228                       &waittime, (socklen_t)sizeof(struct timeval));
 229     WATCHPOINT_ASSERT(error == 0);
 230     if (error)
 231       return MEMCACHED_FAILURE;
 232   }
 233 #endif
 234
 235
 236 #if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
 237   {
 238     int set = 1;
 239     int error= setsockopt(ptr->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 240
 241     // This is not considered a fatal error
 242     if (error == -1)
 243     {
 244       WATCHPOINT_ERRNO(get_socket_errno());
 245       perror("setsockopt(SO_NOSIGPIPE)");
 246     }
 247   }
 248 #endif
 249
 250   if (ptr->root->flags.no_block)
 251   {
 252     int error;
 253     struct linger linger;
 254
 255     linger.l_onoff= 1;
 256     linger.l_linger= 0; /* By default on close() just drop the socket */
 257     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 258                       &linger, (socklen_t)sizeof(struct linger));
 259     WATCHPOINT_ASSERT(error == 0);
 260     if (error)
 261       return MEMCACHED_FAILURE;
 262   }
 263
 264   if (ptr->root->flags.tcp_nodelay)
 265   {
 266     int flag= 1;
 267     int error;
 268
 269     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 270                       &flag, (socklen_t)sizeof(int));
 271     WATCHPOINT_ASSERT(error == 0);
 272     if (error)
 273       return MEMCACHED_FAILURE;
 274   }
 275
 276   if (ptr->root->flags.tcp_keepalive)
 277   {
 278     int flag= 1;
 279     int error;
 280
 281     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 282                       &flag, (socklen_t)sizeof(int));
 283     WATCHPOINT_ASSERT(error == 0);
 284     if (error)
 285       return MEMCACHED_FAILURE;
 286   }
 287
 288 #ifdef TCP_KEEPIDLE
 289   if (ptr->root->tcp_keepidle > 0)
 290   {
 291     int error;
 292
 293     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 294                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 295     WATCHPOINT_ASSERT(error == 0);
 296     if (error)
 297       return MEMCACHED_FAILURE;
 298   }
 299 #endif
 300
 301   if (ptr->root->send_size > 0)
 302   {
 303     int error;
 304
 305     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 306                       &ptr->root->send_size, (socklen_t)sizeof(int));
 307     WATCHPOINT_ASSERT(error == 0);
 308     if (error)
 309       return MEMCACHED_FAILURE;
 310   }
 311
 312   if (ptr->root->recv_size > 0)
 313   {
 314     int error;
 315
 316     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 317                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 318     WATCHPOINT_ASSERT(error == 0);
 319     if (error)
 320       return MEMCACHED_FAILURE;
 321   }
 322
 323
 324   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 325   return set_socket_nonblocking(ptr);
 326 }
 327
 328 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 329 {
 330 #ifndef WIN32
 331   struct sockaddr_un servAddr;
 332
 333   WATCHPOINT_ASSERT(ptr->fd == -1);
 334
 335   if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 336   {
 337     ptr->cached_errno= errno;
 338     return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 339   }
 340
 341   memset(&servAddr, 0, sizeof (struct sockaddr_un));
 342   servAddr.sun_family= AF_UNIX;
 343   strncpy(servAddr.sun_path, ptr->hostname, sizeof(servAddr.sun_path)); /* Copy filename */
 344
 345 test_connect:
 346   if (connect(ptr->fd,
 347               (struct sockaddr *)&servAddr,
 348               sizeof(servAddr)) < 0)
 349   {
 350     switch (errno)
 351     {
 352     case EINPROGRESS:
 353     case EALREADY:
 354     case EINTR:
 355       goto test_connect;
 356     case EISCONN: /* We were spinning waiting on connect */
 357       break;
 358     default:
 359       WATCHPOINT_ERRNO(errno);
 360       ptr->cached_errno= errno;
 361       return MEMCACHED_ERRNO;
 362     }
 363   }
 364
 365   WATCHPOINT_ASSERT(ptr->fd != -1);
 366
 367   return MEMCACHED_SUCCESS;
 368 #else
 369   (void)ptr;
 370   return MEMCACHED_NOT_SUPPORTED;
 371 #endif
 372 }
 373
 374 static memcached_return_t network_connect(memcached_server_st *ptr)
 375 {
 376   bool timeout_error_occured= false;
 377
 378   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 379   WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 380
 381   if (! ptr->address_info)
 382   {
 383     memcached_return_t rc= set_hostinfo(ptr);
 384     if (rc != MEMCACHED_SUCCESS)
 385       return rc;
 386   }
 387
 388   /* Create the socket */
 389   while (ptr->address_info_next && ptr->fd == INVALID_SOCKET)
 390   {
 391     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 392     if (ptr->type == MEMCACHED_CONNECTION_UDP && ptr->address_info_next->ai_family != AF_INET)
 393     {
 394       ptr->address_info_next= ptr->address_info_next->ai_next;
 395       continue;
 396     }
 397
 398     if ((ptr->fd= socket(ptr->address_info_next->ai_family,
 399                          ptr->address_info_next->ai_socktype,
 400                          ptr->address_info_next->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, ptr->address_info_next->ai_addr, ptr->address_info_next->ai_addrlen) != SOCKET_ERROR))
 411     {
 412       break; // Success
 413     }
 414
 415     /* An error occurred */
 416     ptr->cached_errno= get_socket_errno();
 417     switch (ptr->cached_errno)
 418     {
 419     case EWOULDBLOCK:
 420     case EINPROGRESS: // nonblocking mode - first return
 421     case EALREADY: // nonblocking mode - subsequent returns
 422       {
 423         memcached_return_t rc;
 424         rc= connect_poll(ptr);
 425
 426         if (rc == MEMCACHED_TIMEOUT)
 427           timeout_error_occured= true;
 428
 429         if (rc == MEMCACHED_SUCCESS)
 430           break;
 431       }
 432
 433     case EISCONN: // we are connected :-)
 434       break;
 435
 436     case EINTR: // Special case, we retry ai_addr
 437       (void)closesocket(ptr->fd);
 438       ptr->fd= INVALID_SOCKET;
 439       continue;
 440
 441     default:
 442       (void)closesocket(ptr->fd);
 443       ptr->fd= INVALID_SOCKET;
 444       ptr->address_info_next= ptr->address_info_next->ai_next;
 445       break;
 446     }
 447   }
 448
 449   if (ptr->fd == INVALID_SOCKET)
 450   {
 451     WATCHPOINT_STRING("Never got a good file descriptor");
 452
 453     /* Failed to connect. schedule next retry */
 454     if (ptr->root->retry_timeout)
 455     {
 456       struct timeval next_time;
 457
 458       if (gettimeofday(&next_time, NULL) == 0)
 459         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 460     }
 461
 462     if (timeout_error_occured)
 463       return MEMCACHED_TIMEOUT;
 464
 465     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 466   }
 467
 468   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 469 }
 470
 471 void set_last_disconnected_host(memcached_server_write_instance_st ptr)
 472 {
 473   // const_cast
 474   memcached_st *root= (memcached_st *)ptr->root;
 475
 476 #if 0
 477   WATCHPOINT_STRING(ptr->hostname);
 478   WATCHPOINT_NUMBER(ptr->port);
 479   WATCHPOINT_ERRNO(ptr->cached_errno);
 480 #endif
 481   if (root->last_disconnected_server)
 482     memcached_server_free(root->last_disconnected_server);
 483   root->last_disconnected_server= memcached_server_clone(NULL, ptr);
 484 }
 485
 486 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 487 {
 488   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 489
 490   if (ptr->fd != INVALID_SOCKET)
 491     return MEMCACHED_SUCCESS;
 492
 493   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 494
 495   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 496   WATCHPOINT_ASSERT(ptr->root);
 497   if (ptr->root->retry_timeout && ptr->next_retry)
 498   {
 499     struct timeval curr_time;
 500
 501     gettimeofday(&curr_time, NULL);
 502
 503     // We should optimize this to remove the allocation if the server was
 504     // the last server to die
 505     if (ptr->next_retry > curr_time.tv_sec)
 506     {
 507       set_last_disconnected_host(ptr);
 508
 509       return MEMCACHED_SERVER_MARKED_DEAD;
 510     }
 511   }
 512
 513   // If we are over the counter failure, we just fail. Reject host only
 514   // works if you have a set number of failures.
 515   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 516   {
 517     set_last_disconnected_host(ptr);
 518
 519     // @todo fix this by fixing behavior to no longer make use of
 520     // memcached_st
 521     if (_is_auto_eject_host(ptr->root))
 522     {
 523       run_distribution((memcached_st *)ptr->root);
 524     }
 525
 526     return MEMCACHED_SERVER_MARKED_DEAD;
 527   }
 528
 529   /* We need to clean up the multi startup piece */
 530   switch (ptr->type)
 531   {
 532   case MEMCACHED_CONNECTION_UNKNOWN:
 533     WATCHPOINT_ASSERT(0);
 534     rc= MEMCACHED_NOT_SUPPORTED;
 535     break;
 536   case MEMCACHED_CONNECTION_UDP:
 537   case MEMCACHED_CONNECTION_TCP:
 538     rc= network_connect(ptr);
 539 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 540     if (ptr->fd != INVALID_SOCKET && ptr->root->sasl.callbacks)
 541     {
 542       rc= memcached_sasl_authenticate_connection(ptr);
 543       if (rc != MEMCACHED_SUCCESS)
 544       {
 545         (void)closesocket(ptr->fd);
 546         ptr->fd= INVALID_SOCKET;
 547       }
 548     }
 549 #endif
 550     break;
 551   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 552     rc= unix_socket_connect(ptr);
 553     break;
 554   case MEMCACHED_CONNECTION_MAX:
 555   default:
 556     WATCHPOINT_ASSERT(0);
 557   }
 558
 559   if (rc == MEMCACHED_SUCCESS)
 560   {
 561     ptr->server_failure_counter= 0;
 562     ptr->next_retry= 0;
 563   }
 564   else
 565   {
 566     ptr->server_failure_counter++;
 567
 568     set_last_disconnected_host(ptr);
 569   }
 570
 571   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 572
 573   return rc;
 574 }