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   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  Libmemcached library
   4  *
   5  *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
   6  *  Copyright (C) 2006-2010 Brian Aker All rights reserved.
   7  *
   8  *  Redistribution and use in source and binary forms, with or without
   9  *  modification, are permitted provided that the following conditions are
  10  *  met:
  11  *
  12  *      * Redistributions of source code must retain the above copyright
  13  *  notice, this list of conditions and the following disclaimer.
  14  *
  15  *      * Redistributions in binary form must reproduce the above
  16  *  copyright notice, this list of conditions and the following disclaimer
  17  *  in the documentation and/or other materials provided with the
  18  *  distribution.
  19  *
  20  *      * The names of its contributors may not be used to endorse or
  21  *  promote products derived from this software without specific prior
  22  *  written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  26  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  27  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  28  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  30  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  34  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  */
  37
  38
  39 #include <libmemcached/common.h>
  40 #include <assert.h>
  41 #include <sys/time.h>
  42 #include <time.h>
  43
  44 static memcached_return_t connect_poll(memcached_server_st *ptr)
  45 {
  46   struct pollfd fds[1];
  47   fds[0].fd = ptr->fd;
  48   fds[0].events = POLLOUT;
  49
  50   int error;
  51   size_t loop_max= 5;
  52
  53   while (--loop_max) // Should only loop on cases of ERESTART or EINTR
  54   {
  55     error= poll(fds, 1, ptr->root->connect_timeout);
  56
  57     switch (error)
  58     {
  59     case 1:
  60       {
  61         int err;
  62         socklen_t len= sizeof (err);
  63         (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  64
  65         // We check the value to see what happened wth the socket.
  66         if (err == 0)
  67         {
  68           return MEMCACHED_SUCCESS;
  69         }
  70         else
  71         {
  72           ptr->cached_errno= errno;
  73
  74           return MEMCACHED_ERRNO;
  75         }
  76       }
  77     case 0:
  78       return MEMCACHED_TIMEOUT;
  79     default: // A real error occurred and we need to completely bail
  80       WATCHPOINT_ERRNO(get_socket_errno());
  81       switch (get_socket_errno())
  82       {
  83 #ifdef TARGET_OS_LINUX
  84       case ERESTART:
  85 #endif
  86       case EINTR:
  87         continue;
  88       default:
  89         if (fds[0].revents & POLLERR)
  90         {
  91           int err;
  92           socklen_t len= sizeof (err);
  93           (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
  94           ptr->cached_errno= (err == 0) ? get_socket_errno() : err;
  95         }
  96         else
  97         {
  98           ptr->cached_errno= get_socket_errno();
  99         }
 100
 101         (void)closesocket(ptr->fd);
 102         ptr->fd= INVALID_SOCKET;
 103
 104         return MEMCACHED_ERRNO;
 105       }
 106     }
 107   }
 108
 109   // This should only be possible from ERESTART or EINTR;
 110   ptr->cached_errno= get_socket_errno();
 111
 112   return MEMCACHED_ERRNO;
 113 }
 114
 115 static memcached_return_t set_hostinfo(memcached_server_st *server)
 116 {
 117   char str_port[NI_MAXSERV];
 118
 119   assert(! server->address_info); // We cover the case where a programming mistake has been made.
 120   if (server->address_info)
 121   {
 122     freeaddrinfo(server->address_info);
 123     server->address_info= NULL;
 124     server->address_info_next= NULL;
 125   }
 126
 127   int length= snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
 128   if (length >= NI_MAXSERV || length < 0)
 129     return MEMCACHED_FAILURE;
 130
 131   struct addrinfo hints;
 132   memset(&hints, 0, sizeof(struct addrinfo));
 133
 134 #if 0
 135   hints.ai_family= AF_INET;
 136 #endif
 137   if (server->type == MEMCACHED_CONNECTION_UDP)
 138   {
 139     hints.ai_protocol= IPPROTO_UDP;
 140     hints.ai_socktype= SOCK_DGRAM;
 141   }
 142   else
 143   {
 144     hints.ai_socktype= SOCK_STREAM;
 145     hints.ai_protocol= IPPROTO_TCP;
 146   }
 147
 148   uint32_t counter= 5;
 149   while (--counter)
 150   {
 151     int errcode;
 152     switch(errcode= getaddrinfo(server->hostname, str_port, &hints, &server->address_info))
 153     {
 154     case 0:
 155       break;
 156     case EAI_AGAIN:
 157       if (counter > 1)
 158       {
 159 #ifndef WIN32
 160         struct timespec dream, rem;
 161
 162         dream.tv_nsec= 1000;
 163         dream.tv_sec= 0;
 164
 165         nanosleep(&dream, &rem);
 166 #endif
 167         continue;
 168       }
 169       else
 170       {
 171         return memcached_set_error_string(*server, MEMCACHED_HOST_LOOKUP_FAILURE, gai_strerror(errcode), strlen(gai_strerror(errcode)));
 172       }
 173
 174     case EAI_SYSTEM:
 175       {
 176         static memcached_string_t mesg= { memcached_string_make("getaddrinfo") };
 177         return memcached_set_errno(*server, errno, &mesg);
 178       }
 179     case EAI_BADFLAGS:
 180       return memcached_set_error_string(*server, MEMCACHED_HOST_LOOKUP_FAILURE,  memcached_literal_param("getaddrinfo(EAI_BADFLAGS)"));
 181
 182     case EAI_MEMORY:
 183       return memcached_set_error_string(*server, MEMCACHED_ERRNO,  memcached_literal_param("getaddrinfo(EAI_MEMORY)"));
 184
 185     default:
 186       {
 187         WATCHPOINT_STRING(server->hostname);
 188         WATCHPOINT_STRING(gai_strerror(e));
 189         return memcached_set_error_string(*server, MEMCACHED_HOST_LOOKUP_FAILURE, gai_strerror(errcode), strlen(gai_strerror(errcode)));
 190       }
 191     }
 192   }
 193
 194   server->address_info_next= server->address_info;
 195
 196   return MEMCACHED_SUCCESS;
 197 }
 198
 199 static inline memcached_return_t set_socket_nonblocking(memcached_server_st *ptr)
 200 {
 201 #ifdef WIN32
 202   u_long arg = 1;
 203   if (ioctlsocket(ptr->fd, FIONBIO, &arg) == SOCKET_ERROR)
 204   {
 205     return memcached_set_errno(*ptr, get_socket_errno(), NULL);
 206   }
 207 #else
 208   int flags;
 209
 210   do
 211   {
 212     flags= fcntl(ptr->fd, F_GETFL, 0);
 213   }
 214   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 215
 216   unlikely (flags == -1)
 217   {
 218     return memcached_set_errno(*ptr, errno, NULL);
 219   }
 220   else if ((flags & O_NONBLOCK) == 0)
 221   {
 222     int rval;
 223
 224     do
 225     {
 226       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 227     }
 228     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 229
 230     unlikely (rval == -1)
 231     {
 232       return memcached_set_errno(*ptr, errno, NULL);
 233     }
 234   }
 235 #endif
 236   return MEMCACHED_SUCCESS;
 237 }
 238
 239 static memcached_return_t set_socket_options(memcached_server_st *ptr)
 240 {
 241   WATCHPOINT_ASSERT(ptr->fd != -1);
 242
 243   if (ptr->type == MEMCACHED_CONNECTION_UDP)
 244     return MEMCACHED_SUCCESS;
 245
 246 #ifdef HAVE_SNDTIMEO
 247   if (ptr->root->snd_timeout)
 248   {
 249     int error;
 250     struct timeval waittime;
 251
 252     waittime.tv_sec= 0;
 253     waittime.tv_usec= ptr->root->snd_timeout;
 254
 255     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
 256                       &waittime, (socklen_t)sizeof(struct timeval));
 257     WATCHPOINT_ASSERT(error == 0);
 258     if (error)
 259       return MEMCACHED_FAILURE;
 260   }
 261 #endif
 262
 263 #ifdef HAVE_RCVTIMEO
 264   if (ptr->root->rcv_timeout)
 265   {
 266     int error;
 267     struct timeval waittime;
 268
 269     waittime.tv_sec= 0;
 270     waittime.tv_usec= ptr->root->rcv_timeout;
 271
 272     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
 273                       &waittime, (socklen_t)sizeof(struct timeval));
 274     WATCHPOINT_ASSERT(error == 0);
 275     if (error)
 276       return MEMCACHED_FAILURE;
 277   }
 278 #endif
 279
 280
 281 #if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
 282   {
 283     int set = 1;
 284     int error= setsockopt(ptr->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 285
 286     // This is not considered a fatal error
 287     if (error == -1)
 288     {
 289       WATCHPOINT_ERRNO(get_socket_errno());
 290       perror("setsockopt(SO_NOSIGPIPE)");
 291     }
 292   }
 293 #endif
 294
 295   if (ptr->root->flags.no_block)
 296   {
 297     int error;
 298     struct linger linger;
 299
 300     linger.l_onoff= 1;
 301     linger.l_linger= 0; /* By default on close() just drop the socket */
 302     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 303                       &linger, (socklen_t)sizeof(struct linger));
 304     WATCHPOINT_ASSERT(error == 0);
 305     if (error)
 306       return MEMCACHED_FAILURE;
 307   }
 308
 309   if (ptr->root->flags.tcp_nodelay)
 310   {
 311     int flag= 1;
 312     int error;
 313
 314     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 315                       &flag, (socklen_t)sizeof(int));
 316     WATCHPOINT_ASSERT(error == 0);
 317     if (error)
 318       return MEMCACHED_FAILURE;
 319   }
 320
 321   if (ptr->root->flags.tcp_keepalive)
 322   {
 323     int flag= 1;
 324     int error;
 325
 326     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 327                       &flag, (socklen_t)sizeof(int));
 328     WATCHPOINT_ASSERT(error == 0);
 329     if (error)
 330       return MEMCACHED_FAILURE;
 331   }
 332
 333 #ifdef TCP_KEEPIDLE
 334   if (ptr->root->tcp_keepidle > 0)
 335   {
 336     int error;
 337
 338     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 339                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 340     WATCHPOINT_ASSERT(error == 0);
 341     if (error)
 342       return MEMCACHED_FAILURE;
 343   }
 344 #endif
 345
 346   if (ptr->root->send_size > 0)
 347   {
 348     int error;
 349
 350     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 351                       &ptr->root->send_size, (socklen_t)sizeof(int));
 352     WATCHPOINT_ASSERT(error == 0);
 353     if (error)
 354       return MEMCACHED_FAILURE;
 355   }
 356
 357   if (ptr->root->recv_size > 0)
 358   {
 359     int error;
 360
 361     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 362                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 363     WATCHPOINT_ASSERT(error == 0);
 364     if (error)
 365       return MEMCACHED_FAILURE;
 366   }
 367
 368
 369   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 370   return set_socket_nonblocking(ptr);
 371 }
 372
 373 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 374 {
 375 #ifndef WIN32
 376   WATCHPOINT_ASSERT(ptr->fd == -1);
 377
 378   if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 379   {
 380     ptr->cached_errno= errno;
 381     return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 382   }
 383
 384   struct sockaddr_un servAddr;
 385
 386   memset(&servAddr, 0, sizeof (struct sockaddr_un));
 387   servAddr.sun_family= AF_UNIX;
 388   strncpy(servAddr.sun_path, ptr->hostname, sizeof(servAddr.sun_path)); /* Copy filename */
 389
 390 test_connect:
 391   if (connect(ptr->fd,
 392               (struct sockaddr *)&servAddr,
 393               sizeof(servAddr)) < 0)
 394   {
 395     switch (errno)
 396     {
 397     case EINPROGRESS:
 398     case EALREADY:
 399     case EINTR:
 400       goto test_connect;
 401     case EISCONN: /* We were spinning waiting on connect */
 402       break;
 403     default:
 404       WATCHPOINT_ERRNO(errno);
 405       ptr->cached_errno= errno;
 406       return MEMCACHED_ERRNO;
 407     }
 408   }
 409
 410   WATCHPOINT_ASSERT(ptr->fd != -1);
 411
 412   return MEMCACHED_SUCCESS;
 413 #else
 414   (void)ptr;
 415   return MEMCACHED_NOT_SUPPORTED;
 416 #endif
 417 }
 418
 419 static memcached_return_t network_connect(memcached_server_st *ptr)
 420 {
 421   bool timeout_error_occured= false;
 422
 423   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 424   WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 425
 426   if (! ptr->address_info)
 427   {
 428     memcached_return_t rc= set_hostinfo(ptr);
 429     if (rc != MEMCACHED_SUCCESS)
 430       return rc;
 431   }
 432
 433   /* Create the socket */
 434   while (ptr->address_info_next && ptr->fd == INVALID_SOCKET)
 435   {
 436     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 437     if (ptr->type == MEMCACHED_CONNECTION_UDP && ptr->address_info_next->ai_family != AF_INET)
 438     {
 439       ptr->address_info_next= ptr->address_info_next->ai_next;
 440       continue;
 441     }
 442
 443     if ((ptr->fd= socket(ptr->address_info_next->ai_family,
 444                          ptr->address_info_next->ai_socktype,
 445                          ptr->address_info_next->ai_protocol)) < 0)
 446     {
 447       ptr->cached_errno= get_socket_errno();
 448       WATCHPOINT_ERRNO(get_socket_errno());
 449       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 450     }
 451
 452     (void)set_socket_options(ptr);
 453
 454     /* connect to server */
 455     if ((connect(ptr->fd, ptr->address_info_next->ai_addr, ptr->address_info_next->ai_addrlen) != SOCKET_ERROR))
 456     {
 457       break; // Success
 458     }
 459
 460     /* An error occurred */
 461     ptr->cached_errno= get_socket_errno();
 462     switch (ptr->cached_errno)
 463     {
 464     case EWOULDBLOCK:
 465     case EINPROGRESS: // nonblocking mode - first return
 466     case EALREADY: // nonblocking mode - subsequent returns
 467       {
 468         memcached_return_t rc;
 469         rc= connect_poll(ptr);
 470
 471         if (rc == MEMCACHED_TIMEOUT)
 472           timeout_error_occured= true;
 473
 474         if (rc == MEMCACHED_SUCCESS)
 475           break;
 476       }
 477
 478     case EISCONN: // we are connected :-)
 479       break;
 480
 481     case EINTR: // Special case, we retry ai_addr
 482       (void)closesocket(ptr->fd);
 483       ptr->fd= INVALID_SOCKET;
 484       continue;
 485
 486     default:
 487       (void)closesocket(ptr->fd);
 488       ptr->fd= INVALID_SOCKET;
 489       ptr->address_info_next= ptr->address_info_next->ai_next;
 490       break;
 491     }
 492   }
 493
 494   if (ptr->fd == INVALID_SOCKET)
 495   {
 496     WATCHPOINT_STRING("Never got a good file descriptor");
 497
 498     /* Failed to connect. schedule next retry */
 499     if (ptr->root->retry_timeout)
 500     {
 501       struct timeval next_time;
 502
 503       if (gettimeofday(&next_time, NULL) == 0)
 504         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 505     }
 506
 507     if (timeout_error_occured)
 508       return MEMCACHED_TIMEOUT;
 509
 510     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 511   }
 512
 513   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 514 }
 515
 516 void set_last_disconnected_host(memcached_server_write_instance_st ptr)
 517 {
 518   // const_cast
 519   memcached_st *root= (memcached_st *)ptr->root;
 520
 521 #if 0
 522   WATCHPOINT_STRING(ptr->hostname);
 523   WATCHPOINT_NUMBER(ptr->port);
 524   WATCHPOINT_ERRNO(ptr->cached_errno);
 525 #endif
 526   if (root->last_disconnected_server)
 527     memcached_server_free(root->last_disconnected_server);
 528   root->last_disconnected_server= memcached_server_clone(NULL, ptr);
 529 }
 530
 531 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 532 {
 533   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 534
 535   if (ptr->fd != INVALID_SOCKET)
 536     return MEMCACHED_SUCCESS;
 537
 538   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 539
 540   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 541   WATCHPOINT_ASSERT(ptr->root);
 542   if (ptr->root->retry_timeout && ptr->next_retry)
 543   {
 544     struct timeval curr_time;
 545
 546     gettimeofday(&curr_time, NULL);
 547
 548     // We should optimize this to remove the allocation if the server was
 549     // the last server to die
 550     if (ptr->next_retry > curr_time.tv_sec)
 551     {
 552       set_last_disconnected_host(ptr);
 553
 554       return MEMCACHED_SERVER_MARKED_DEAD;
 555     }
 556   }
 557
 558   // If we are over the counter failure, we just fail. Reject host only
 559   // works if you have a set number of failures.
 560   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 561   {
 562     set_last_disconnected_host(ptr);
 563
 564     // @todo fix this by fixing behavior to no longer make use of
 565     // memcached_st
 566     if (_is_auto_eject_host(ptr->root))
 567     {
 568       run_distribution((memcached_st *)ptr->root);
 569     }
 570
 571     return MEMCACHED_SERVER_MARKED_DEAD;
 572   }
 573
 574   /* We need to clean up the multi startup piece */
 575   switch (ptr->type)
 576   {
 577   case MEMCACHED_CONNECTION_UNKNOWN:
 578     WATCHPOINT_ASSERT(0);
 579     rc= MEMCACHED_NOT_SUPPORTED;
 580     break;
 581   case MEMCACHED_CONNECTION_UDP:
 582   case MEMCACHED_CONNECTION_TCP:
 583     rc= network_connect(ptr);
 584 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 585     if (ptr->fd != INVALID_SOCKET && ptr->root->sasl.callbacks)
 586     {
 587       rc= memcached_sasl_authenticate_connection(ptr);
 588       if (rc != MEMCACHED_SUCCESS)
 589       {
 590         (void)closesocket(ptr->fd);
 591         ptr->fd= INVALID_SOCKET;
 592       }
 593     }
 594 #endif
 595     break;
 596   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 597     rc= unix_socket_connect(ptr);
 598     break;
 599   case MEMCACHED_CONNECTION_MAX:
 600   default:
 601     WATCHPOINT_ASSERT(0);
 602   }
 603
 604   if (rc == MEMCACHED_SUCCESS)
 605   {
 606     ptr->server_failure_counter= 0;
 607     ptr->next_retry= 0;
 608   }
 609   else
 610   {
 611     ptr->server_failure_counter++;
 612
 613     set_last_disconnected_host(ptr);
 614   }
 615
 616   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 617
 618   return rc;
 619 }