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 timeout= ptr->root->connect_timeout;
  23   if (ptr->root->flags.no_block == true)
  24     timeout= -1;
  25
  26   int error;
  27   size_t loop_max= 5;
  28
  29   while (--loop_max) // Should only loop on cases of ERESTART or EINTR
  30   {
  31     error= poll(fds, 1, timeout);
  32
  33     switch (error)
  34     {
  35     case 1:
  36       {
  37         int err;
  38         socklen_t len= sizeof (err);
  39         (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  40
  41         // We check the value to see what happened wth the socket.
  42         if (err == 0)
  43         {
  44           return MEMCACHED_SUCCESS;
  45         }
  46         else
  47         {
  48           ptr->cached_errno= errno;
  49
  50           return MEMCACHED_ERRNO;
  51         }
  52       }
  53     case 0:
  54       return MEMCACHED_TIMEOUT;
  55     default: // A real error occurred and we need to completely bail
  56       WATCHPOINT_ERRNO(get_socket_errno());
  57       switch (get_socket_errno())
  58       {
  59 #ifdef TARGET_OS_LINUX
  60       case ERESTART:
  61 #endif
  62       case EINTR:
  63         continue;
  64       default:
  65         if (fds[0].revents & POLLERR)
  66         {
  67           int err;
  68           socklen_t len= sizeof (err);
  69           (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  70           ptr->cached_errno= (err == 0) ? get_socket_errno() : err;
  71         }
  72         else
  73         {
  74           ptr->cached_errno= get_socket_errno();
  75         }
  76
  77         (void)closesocket(ptr->fd);
  78         ptr->fd= INVALID_SOCKET;
  79
  80         return MEMCACHED_ERRNO;
  81       }
  82     }
  83   }
  84
  85   // This should only be possible from ERESTART or EINTR;
  86   ptr->cached_errno= get_socket_errno();
  87
  88   return MEMCACHED_ERRNO;
  89 }
  90
  91 static memcached_return_t set_hostinfo(memcached_server_st *server)
  92 {
  93   struct addrinfo *ai;
  94   struct addrinfo hints;
  95   char str_port[NI_MAXSERV];
  96   uint32_t counter= 5;
  97
  98   snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
  99
 100   memset(&hints, 0, sizeof(hints));
 101
 102  // hints.ai_family= AF_INET;
 103   if (server->type == MEMCACHED_CONNECTION_UDP)
 104   {
 105     hints.ai_protocol= IPPROTO_UDP;
 106     hints.ai_socktype= SOCK_DGRAM;
 107   }
 108   else
 109   {
 110     hints.ai_socktype= SOCK_STREAM;
 111     hints.ai_protocol= IPPROTO_TCP;
 112   }
 113
 114   while (--counter)
 115   {
 116     int e= getaddrinfo(server->hostname, str_port, &hints, &ai);
 117
 118     if (e == 0)
 119     {
 120       break;
 121     }
 122     else if (e == EAI_AGAIN)
 123     {
 124 #ifndef WIN32
 125       struct timespec dream, rem;
 126
 127       dream.tv_nsec= 1000;
 128       dream.tv_sec= 0;
 129
 130       nanosleep(&dream, &rem);
 131 #endif
 132       continue;
 133     }
 134     else
 135     {
 136       WATCHPOINT_STRING(server->hostname);
 137       WATCHPOINT_STRING(gai_strerror(e));
 138       return MEMCACHED_HOST_LOOKUP_FAILURE;
 139     }
 140   }
 141
 142   if (server->address_info)
 143   {
 144     freeaddrinfo(server->address_info);
 145     server->address_info= NULL;
 146   }
 147   server->address_info= ai;
 148
 149   return MEMCACHED_SUCCESS;
 150 }
 151
 152 static inline memcached_return_t set_socket_nonblocking(memcached_server_st *ptr)
 153 {
 154 #ifdef WIN32
 155   u_long arg = 1;
 156   if (ioctlsocket(ptr->fd, FIONBIO, &arg) == SOCKET_ERROR)
 157   {
 158     ptr->cached_errno= get_socket_errno();
 159     return MEMCACHED_CONNECTION_FAILURE;
 160   }
 161 #else
 162   int flags;
 163
 164   do
 165     flags= fcntl(ptr->fd, F_GETFL, 0);
 166   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 167
 168   unlikely (flags == -1)
 169   {
 170     ptr->cached_errno= errno;
 171     return MEMCACHED_CONNECTION_FAILURE;
 172   }
 173   else if ((flags & O_NONBLOCK) == 0)
 174   {
 175     int rval;
 176
 177     do
 178       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 179     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 180
 181     unlikely (rval == -1)
 182     {
 183       ptr->cached_errno= errno;
 184       return MEMCACHED_CONNECTION_FAILURE;
 185     }
 186   }
 187 #endif
 188   return MEMCACHED_SUCCESS;
 189 }
 190
 191 static memcached_return_t set_socket_options(memcached_server_st *ptr)
 192 {
 193   WATCHPOINT_ASSERT(ptr->fd != -1);
 194
 195   if (ptr->type == MEMCACHED_CONNECTION_UDP)
 196     return MEMCACHED_SUCCESS;
 197
 198 #ifdef HAVE_SNDTIMEO
 199   if (ptr->root->snd_timeout)
 200   {
 201     int error;
 202     struct timeval waittime;
 203
 204     waittime.tv_sec= 0;
 205     waittime.tv_usec= ptr->root->snd_timeout;
 206
 207     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
 208                       &waittime, (socklen_t)sizeof(struct timeval));
 209     WATCHPOINT_ASSERT(error == 0);
 210     if (error)
 211       return MEMCACHED_FAILURE;
 212   }
 213 #endif
 214
 215 #ifdef HAVE_RCVTIMEO
 216   if (ptr->root->rcv_timeout)
 217   {
 218     int error;
 219     struct timeval waittime;
 220
 221     waittime.tv_sec= 0;
 222     waittime.tv_usec= ptr->root->rcv_timeout;
 223
 224     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
 225                       &waittime, (socklen_t)sizeof(struct timeval));
 226     WATCHPOINT_ASSERT(error == 0);
 227     if (error)
 228       return MEMCACHED_FAILURE;
 229   }
 230 #endif
 231
 232
 233 #if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
 234   {
 235     int set = 1;
 236     int error= setsockopt(ptr->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 237
 238     // This is not considered a fatal error
 239     if (error == -1)
 240     {
 241       WATCHPOINT_ERRNO(get_socket_errno());
 242       perror("setsockopt(SO_NOSIGPIPE)");
 243     }
 244   }
 245 #endif
 246
 247   if (ptr->root->flags.no_block)
 248   {
 249     int error;
 250     struct linger linger;
 251
 252     linger.l_onoff= 1;
 253     linger.l_linger= 0; /* By default on close() just drop the socket */
 254     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 255                       &linger, (socklen_t)sizeof(struct linger));
 256     WATCHPOINT_ASSERT(error == 0);
 257     if (error)
 258       return MEMCACHED_FAILURE;
 259   }
 260
 261   if (ptr->root->flags.tcp_nodelay)
 262   {
 263     int flag= 1;
 264     int error;
 265
 266     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 267                       &flag, (socklen_t)sizeof(int));
 268     WATCHPOINT_ASSERT(error == 0);
 269     if (error)
 270       return MEMCACHED_FAILURE;
 271   }
 272
 273   if (ptr->root->flags.tcp_keepalive)
 274   {
 275     int flag= 1;
 276     int error;
 277
 278     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 279                       &flag, (socklen_t)sizeof(int));
 280     WATCHPOINT_ASSERT(error == 0);
 281     if (error)
 282       return MEMCACHED_FAILURE;
 283   }
 284
 285 #ifdef TCP_KEEPIDLE
 286   if (ptr->root->tcp_keepidle > 0)
 287   {
 288     int error;
 289
 290     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 291                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 292     WATCHPOINT_ASSERT(error == 0);
 293     if (error)
 294       return MEMCACHED_FAILURE;
 295   }
 296 #endif
 297
 298   if (ptr->root->send_size > 0)
 299   {
 300     int error;
 301
 302     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 303                       &ptr->root->send_size, (socklen_t)sizeof(int));
 304     WATCHPOINT_ASSERT(error == 0);
 305     if (error)
 306       return MEMCACHED_FAILURE;
 307   }
 308
 309   if (ptr->root->recv_size > 0)
 310   {
 311     int error;
 312
 313     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 314                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 315     WATCHPOINT_ASSERT(error == 0);
 316     if (error)
 317       return MEMCACHED_FAILURE;
 318   }
 319
 320
 321   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 322   return set_socket_nonblocking(ptr);
 323 }
 324
 325 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 326 {
 327 #ifndef WIN32
 328   struct sockaddr_un servAddr;
 329
 330   WATCHPOINT_ASSERT(ptr->fd == -1);
 331
 332   if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 333   {
 334     ptr->cached_errno= errno;
 335     return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 336   }
 337
 338   memset(&servAddr, 0, sizeof (struct sockaddr_un));
 339   servAddr.sun_family= AF_UNIX;
 340   strcpy(servAddr.sun_path, ptr->hostname); /* Copy filename */
 341
 342 test_connect:
 343   if (connect(ptr->fd,
 344               (struct sockaddr *)&servAddr,
 345               sizeof(servAddr)) < 0)
 346   {
 347     switch (errno)
 348     {
 349     case EINPROGRESS:
 350     case EALREADY:
 351     case EINTR:
 352       goto test_connect;
 353     case EISCONN: /* We were spinning waiting on connect */
 354       break;
 355     default:
 356       WATCHPOINT_ERRNO(errno);
 357       ptr->cached_errno= errno;
 358       return MEMCACHED_ERRNO;
 359     }
 360   }
 361
 362   WATCHPOINT_ASSERT(ptr->fd != -1);
 363
 364   return MEMCACHED_SUCCESS;
 365 #else
 366   (void)ptr;
 367   return MEMCACHED_NOT_SUPPORTED;
 368 #endif
 369 }
 370
 371 static memcached_return_t network_connect(memcached_server_st *ptr)
 372 {
 373   bool timeout_error_occured= false;
 374
 375
 376   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 377   WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 378
 379   if (! ptr->options.sockaddr_inited || (!(ptr->root->flags.use_cache_lookups)))
 380   {
 381     memcached_return_t rc;
 382
 383     rc= set_hostinfo(ptr);
 384     if (rc != MEMCACHED_SUCCESS)
 385       return rc;
 386     ptr->options.sockaddr_inited= true;
 387   }
 388
 389   struct addrinfo *use= ptr->address_info;
 390   /* Create the socket */
 391   while (use != NULL)
 392   {
 393     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 394     if (ptr->type == MEMCACHED_CONNECTION_UDP && use->ai_family != AF_INET)
 395     {
 396       use= use->ai_next;
 397       continue;
 398     }
 399
 400     if ((ptr->fd= socket(use->ai_family,
 401                          use->ai_socktype,
 402                          use->ai_protocol)) < 0)
 403     {
 404       ptr->cached_errno= get_socket_errno();
 405       WATCHPOINT_ERRNO(get_socket_errno());
 406       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 407     }
 408
 409     (void)set_socket_options(ptr);
 410
 411     /* connect to server */
 412     if ((connect(ptr->fd, use->ai_addr, use->ai_addrlen) != SOCKET_ERROR))
 413     {
 414       break; // Success
 415     }
 416
 417     /* An error occurred */
 418     ptr->cached_errno= get_socket_errno();
 419     if (ptr->cached_errno == EWOULDBLOCK ||
 420         ptr->cached_errno == EINPROGRESS || /* nonblocking mode - first return, */
 421         ptr->cached_errno == 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     else if (get_socket_errno() == EISCONN) /* we are connected :-) */
 433     {
 434       break;
 435     }
 436     else if (get_socket_errno() == EINTR) // Special case, we retry ai_addr
 437     {
 438       (void)closesocket(ptr->fd);
 439       ptr->fd= INVALID_SOCKET;
 440       continue;
 441     }
 442
 443     (void)closesocket(ptr->fd);
 444     ptr->fd= INVALID_SOCKET;
 445     use= use->ai_next;
 446   }
 447
 448   if (ptr->fd == INVALID_SOCKET)
 449   {
 450     WATCHPOINT_STRING("Never got a good file descriptor");
 451
 452     /* Failed to connect. schedule next retry */
 453     if (ptr->root->retry_timeout)
 454     {
 455       struct timeval next_time;
 456
 457       if (gettimeofday(&next_time, NULL) == 0)
 458         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 459     }
 460
 461     if (timeout_error_occured)
 462       return MEMCACHED_TIMEOUT;
 463
 464     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 465   }
 466
 467   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 468 }
 469
 470 void set_last_disconnected_host(memcached_server_write_instance_st ptr)
 471 {
 472   // const_cast
 473   memcached_st *root= (memcached_st *)ptr->root;
 474
 475 #if 0
 476   WATCHPOINT_STRING(ptr->hostname);
 477   WATCHPOINT_NUMBER(ptr->port);
 478   WATCHPOINT_ERRNO(ptr->cached_errno);
 479 #endif
 480   if (root->last_disconnected_server)
 481     memcached_server_free(root->last_disconnected_server);
 482   root->last_disconnected_server= memcached_server_clone(NULL, ptr);
 483 }
 484
 485 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 486 {
 487   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 488
 489   if (ptr->fd != INVALID_SOCKET)
 490     return MEMCACHED_SUCCESS;
 491
 492   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 493
 494   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 495   WATCHPOINT_ASSERT(ptr->root);
 496   if (ptr->root->retry_timeout && ptr->next_retry)
 497   {
 498     struct timeval curr_time;
 499
 500     gettimeofday(&curr_time, NULL);
 501
 502     // We should optimize this to remove the allocation if the server was
 503     // the last server to die
 504     if (ptr->next_retry > curr_time.tv_sec)
 505     {
 506       set_last_disconnected_host(ptr);
 507
 508       return MEMCACHED_SERVER_MARKED_DEAD;
 509     }
 510   }
 511
 512   // If we are over the counter failure, we just fail. Reject host only
 513   // works if you have a set number of failures.
 514   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 515   {
 516     set_last_disconnected_host(ptr);
 517
 518     // @todo fix this by fixing behavior to no longer make use of
 519     // memcached_st
 520     if (_is_auto_eject_host(ptr->root))
 521     {
 522       run_distribution((memcached_st *)ptr->root);
 523     }
 524
 525     return MEMCACHED_SERVER_MARKED_DEAD;
 526   }
 527
 528   /* We need to clean up the multi startup piece */
 529   switch (ptr->type)
 530   {
 531   case MEMCACHED_CONNECTION_UNKNOWN:
 532     WATCHPOINT_ASSERT(0);
 533     rc= MEMCACHED_NOT_SUPPORTED;
 534     break;
 535   case MEMCACHED_CONNECTION_UDP:
 536   case MEMCACHED_CONNECTION_TCP:
 537     rc= network_connect(ptr);
 538 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 539     if (ptr->fd != INVALID_SOCKET && ptr->root->sasl && ptr->root->sasl->callbacks)
 540     {
 541       rc= memcached_sasl_authenticate_connection(ptr);
 542       if (rc != MEMCACHED_SUCCESS)
 543       {
 544         (void)closesocket(ptr->fd);
 545         ptr->fd= INVALID_SOCKET;
 546       }
 547     }
 548 #endif
 549     break;
 550   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 551     rc= unix_socket_connect(ptr);
 552     break;
 553   case MEMCACHED_CONNECTION_MAX:
 554   default:
 555     WATCHPOINT_ASSERT(0);
 556   }
 557
 558   if (rc == MEMCACHED_SUCCESS)
 559   {
 560     ptr->server_failure_counter= 0;
 561     ptr->next_retry= 0;
 562   }
 563   else
 564   {
 565     ptr->server_failure_counter++;
 566
 567     set_last_disconnected_host(ptr);
 568   }
 569
 570   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 571
 572   return rc;
 573 }