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     WATCHPOINT_ASSERT(0); // Programming error
  84   }
  85
  86   // This should only be possible from ERESTART or EINTR;
  87   ptr->cached_errno= get_socket_errno();
  88
  89   return MEMCACHED_ERRNO;
  90 }
  91
  92 static memcached_return_t set_hostinfo(memcached_server_st *server)
  93 {
  94   struct addrinfo *ai;
  95   struct addrinfo hints;
  96   char str_port[NI_MAXSERV];
  97   uint32_t counter= 5;
  98
  99   snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
 100
 101   memset(&hints, 0, sizeof(hints));
 102
 103  // hints.ai_family= AF_INET;
 104   if (server->type == MEMCACHED_CONNECTION_UDP)
 105   {
 106     hints.ai_protocol= IPPROTO_UDP;
 107     hints.ai_socktype= SOCK_DGRAM;
 108   }
 109   else
 110   {
 111     hints.ai_socktype= SOCK_STREAM;
 112     hints.ai_protocol= IPPROTO_TCP;
 113   }
 114
 115   while (--counter)
 116   {
 117     int e= getaddrinfo(server->hostname, str_port, &hints, &ai);
 118
 119     if (e == 0)
 120     {
 121       break;
 122     }
 123     else if (e == EAI_AGAIN)
 124     {
 125 #ifndef WIN32
 126       struct timespec dream, rem;
 127
 128       dream.tv_nsec= 1000;
 129       dream.tv_sec= 0;
 130
 131       nanosleep(&dream, &rem);
 132 #endif
 133       continue;
 134     }
 135     else
 136     {
 137       WATCHPOINT_STRING(server->hostname);
 138       WATCHPOINT_STRING(gai_strerror(e));
 139       return MEMCACHED_HOST_LOOKUP_FAILURE;
 140     }
 141   }
 142
 143   if (server->address_info)
 144   {
 145     freeaddrinfo(server->address_info);
 146     server->address_info= NULL;
 147   }
 148   server->address_info= ai;
 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   strcpy(servAddr.sun_path, ptr->hostname); /* 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
 377   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 378   WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 379
 380   if (! ptr->options.sockaddr_inited || (!(ptr->root->flags.use_cache_lookups)))
 381   {
 382     memcached_return_t rc;
 383
 384     rc= set_hostinfo(ptr);
 385     if (rc != MEMCACHED_SUCCESS)
 386       return rc;
 387     ptr->options.sockaddr_inited= true;
 388   }
 389
 390   struct addrinfo *use= ptr->address_info;
 391   /* Create the socket */
 392   while (use != NULL)
 393   {
 394     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 395     if (ptr->type == MEMCACHED_CONNECTION_UDP && use->ai_family != AF_INET)
 396     {
 397       use= use->ai_next;
 398       continue;
 399     }
 400
 401     if ((ptr->fd= socket(use->ai_family,
 402                          use->ai_socktype,
 403                          use->ai_protocol)) < 0)
 404     {
 405       ptr->cached_errno= get_socket_errno();
 406       WATCHPOINT_ERRNO(get_socket_errno());
 407       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 408     }
 409
 410     (void)set_socket_options(ptr);
 411
 412     /* connect to server */
 413     if ((connect(ptr->fd, use->ai_addr, use->ai_addrlen) != SOCKET_ERROR))
 414     {
 415       break; // Success
 416     }
 417
 418     /* An error occurred */
 419     ptr->cached_errno= get_socket_errno();
 420     if (ptr->cached_errno == EWOULDBLOCK ||
 421         ptr->cached_errno == EINPROGRESS || /* nonblocking mode - first return, */
 422         ptr->cached_errno == EALREADY) /* nonblocking mode - subsequent returns */
 423     {
 424       memcached_return_t rc;
 425       rc= connect_poll(ptr);
 426
 427       if (rc == MEMCACHED_TIMEOUT)
 428         timeout_error_occured= true;
 429
 430       if (rc == MEMCACHED_SUCCESS)
 431         break;
 432     }
 433     else if (get_socket_errno() == EISCONN) /* we are connected :-) */
 434     {
 435       break;
 436     }
 437     else if (get_socket_errno() == EINTR) // Special case, we retry ai_addr
 438     {
 439       (void)closesocket(ptr->fd);
 440       ptr->fd= INVALID_SOCKET;
 441       continue;
 442     }
 443
 444     (void)closesocket(ptr->fd);
 445     ptr->fd= INVALID_SOCKET;
 446     use= use->ai_next;
 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 && 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 }