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