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