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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 <cassert>
  41 #include <ctime>
  42 #include <sys/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   int errcode;
 149   switch(errcode= getaddrinfo(server->hostname, str_port, &hints, &server->address_info))
 150   {
 151   case 0:
 152     break;
 153
 154   case EAI_AGAIN:
 155     return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT, memcached_string_make_from_cstr(gai_strerror(errcode)));
 156
 157   case EAI_SYSTEM:
 158       return memcached_set_errno(*server, errno, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_SYSTEM)"));
 159
 160   case EAI_BADFLAGS:
 161     return memcached_set_error(*server, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_BADFLAGS)"));
 162
 163   case EAI_MEMORY:
 164     return memcached_set_error(*server, MEMCACHED_ERRNO, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_MEMORY)"));
 165
 166   default:
 167     {
 168       WATCHPOINT_STRING(server->hostname);
 169       WATCHPOINT_STRING(gai_strerror(e));
 170       return memcached_set_error(*server, MEMCACHED_HOST_LOOKUP_FAILURE, MEMCACHED_AT, memcached_string_make_from_cstr(gai_strerror(errcode)));
 171     }
 172   }
 173   server->address_info_next= server->address_info;
 174
 175   return MEMCACHED_SUCCESS;
 176 }
 177
 178 static inline memcached_return_t set_socket_nonblocking(memcached_server_st *ptr)
 179 {
 180 #ifdef WIN32
 181   u_long arg = 1;
 182   if (ioctlsocket(ptr->fd, FIONBIO, &arg) == SOCKET_ERROR)
 183   {
 184     return memcached_set_errno(*ptr, get_socket_errno(), NULL);
 185   }
 186 #else
 187   int flags;
 188
 189   do
 190   {
 191     flags= fcntl(ptr->fd, F_GETFL, 0);
 192   }
 193   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 194
 195   unlikely (flags == -1)
 196   {
 197     return memcached_set_errno(*ptr, errno, NULL);
 198   }
 199   else if ((flags & O_NONBLOCK) == 0)
 200   {
 201     int rval;
 202
 203     do
 204     {
 205       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 206     }
 207     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 208
 209     unlikely (rval == -1)
 210     {
 211       return memcached_set_errno(*ptr, errno, NULL);
 212     }
 213   }
 214 #endif
 215   return MEMCACHED_SUCCESS;
 216 }
 217
 218 static memcached_return_t set_socket_options(memcached_server_st *ptr)
 219 {
 220   WATCHPOINT_ASSERT(ptr->fd != -1);
 221
 222   if (ptr->type == MEMCACHED_CONNECTION_UDP)
 223     return MEMCACHED_SUCCESS;
 224
 225 #ifdef HAVE_SNDTIMEO
 226   if (ptr->root->snd_timeout)
 227   {
 228     int error;
 229     struct timeval waittime;
 230
 231     waittime.tv_sec= 0;
 232     waittime.tv_usec= ptr->root->snd_timeout;
 233
 234     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
 235                       &waittime, (socklen_t)sizeof(struct timeval));
 236     WATCHPOINT_ASSERT(error == 0);
 237     if (error)
 238       return MEMCACHED_FAILURE;
 239   }
 240 #endif
 241
 242 #ifdef HAVE_RCVTIMEO
 243   if (ptr->root->rcv_timeout)
 244   {
 245     int error;
 246     struct timeval waittime;
 247
 248     waittime.tv_sec= 0;
 249     waittime.tv_usec= ptr->root->rcv_timeout;
 250
 251     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
 252                       &waittime, (socklen_t)sizeof(struct timeval));
 253     WATCHPOINT_ASSERT(error == 0);
 254     if (error)
 255       return MEMCACHED_FAILURE;
 256   }
 257 #endif
 258
 259
 260 #if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
 261   {
 262     int set = 1;
 263     int error= setsockopt(ptr->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 264
 265     // This is not considered a fatal error
 266     if (error == -1)
 267     {
 268       WATCHPOINT_ERRNO(get_socket_errno());
 269       perror("setsockopt(SO_NOSIGPIPE)");
 270     }
 271   }
 272 #endif
 273
 274   if (ptr->root->flags.no_block)
 275   {
 276     int error;
 277     struct linger linger;
 278
 279     linger.l_onoff= 1;
 280     linger.l_linger= 0; /* By default on close() just drop the socket */
 281     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 282                       &linger, (socklen_t)sizeof(struct linger));
 283     WATCHPOINT_ASSERT(error == 0);
 284     if (error)
 285       return MEMCACHED_FAILURE;
 286   }
 287
 288   if (ptr->root->flags.tcp_nodelay)
 289   {
 290     int flag= 1;
 291     int error;
 292
 293     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 294                       &flag, (socklen_t)sizeof(int));
 295     WATCHPOINT_ASSERT(error == 0);
 296     if (error)
 297       return MEMCACHED_FAILURE;
 298   }
 299
 300   if (ptr->root->flags.tcp_keepalive)
 301   {
 302     int flag= 1;
 303     int error;
 304
 305     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 306                       &flag, (socklen_t)sizeof(int));
 307     WATCHPOINT_ASSERT(error == 0);
 308     if (error)
 309       return MEMCACHED_FAILURE;
 310   }
 311
 312 #ifdef TCP_KEEPIDLE
 313   if (ptr->root->tcp_keepidle > 0)
 314   {
 315     int error;
 316
 317     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 318                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 319     WATCHPOINT_ASSERT(error == 0);
 320     if (error)
 321       return MEMCACHED_FAILURE;
 322   }
 323 #endif
 324
 325   if (ptr->root->send_size > 0)
 326   {
 327     int error;
 328
 329     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 330                       &ptr->root->send_size, (socklen_t)sizeof(int));
 331     WATCHPOINT_ASSERT(error == 0);
 332     if (error)
 333       return MEMCACHED_FAILURE;
 334   }
 335
 336   if (ptr->root->recv_size > 0)
 337   {
 338     int error;
 339
 340     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 341                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 342     WATCHPOINT_ASSERT(error == 0);
 343     if (error)
 344       return MEMCACHED_FAILURE;
 345   }
 346
 347
 348   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 349   return set_socket_nonblocking(ptr);
 350 }
 351
 352 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 353 {
 354 #ifndef WIN32
 355   WATCHPOINT_ASSERT(ptr->fd == -1);
 356
 357   if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 358   {
 359     return memcached_set_errno(*ptr, errno, NULL);
 360   }
 361
 362   struct sockaddr_un servAddr;
 363
 364   memset(&servAddr, 0, sizeof (struct sockaddr_un));
 365   servAddr.sun_family= AF_UNIX;
 366   strncpy(servAddr.sun_path, ptr->hostname, sizeof(servAddr.sun_path)); /* Copy filename */
 367
 368 test_connect:
 369   if (connect(ptr->fd,
 370               (struct sockaddr *)&servAddr,
 371               sizeof(servAddr)) < 0)
 372   {
 373     switch (errno)
 374     {
 375     case EINPROGRESS:
 376     case EALREADY:
 377     case EINTR:
 378       goto test_connect;
 379     case EISCONN: /* We were spinning waiting on connect */
 380       break;
 381     default:
 382       WATCHPOINT_ERRNO(errno);
 383       ptr->cached_errno= errno;
 384       return MEMCACHED_ERRNO;
 385     }
 386   }
 387
 388   WATCHPOINT_ASSERT(ptr->fd != INVALID_SOCKET);
 389
 390   return MEMCACHED_SUCCESS;
 391 #else
 392   (void)ptr;
 393   return MEMCACHED_NOT_SUPPORTED;
 394 #endif
 395 }
 396
 397 static memcached_return_t network_connect(memcached_server_st *ptr)
 398 {
 399   bool timeout_error_occured= false;
 400
 401   WATCHPOINT_ASSERT(ptr->fd == INVALID_SOCKET);
 402   WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 403
 404   if (not ptr->address_info)
 405   {
 406     memcached_return_t rc;
 407     uint32_t counter= 5;
 408     while (--counter)
 409     {
 410       if ((rc= set_hostinfo(ptr)) != MEMCACHED_TIMEOUT)
 411         break;
 412
 413 #ifndef WIN32
 414       struct timespec dream, rem;
 415
 416       dream.tv_nsec= 1000;
 417       dream.tv_sec= 0;
 418
 419       nanosleep(&dream, &rem);
 420 #endif
 421     }
 422
 423     if (memcached_failed(rc))
 424       return rc;
 425   }
 426
 427   /* Create the socket */
 428   while (ptr->address_info_next && ptr->fd == INVALID_SOCKET)
 429   {
 430     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 431     if (ptr->type == MEMCACHED_CONNECTION_UDP && ptr->address_info_next->ai_family != AF_INET)
 432     {
 433       ptr->address_info_next= ptr->address_info_next->ai_next;
 434       continue;
 435     }
 436
 437     if ((ptr->fd= socket(ptr->address_info_next->ai_family,
 438                          ptr->address_info_next->ai_socktype,
 439                          ptr->address_info_next->ai_protocol)) < 0)
 440     {
 441       return memcached_set_errno(*ptr, get_socket_errno(), NULL);
 442     }
 443
 444     (void)set_socket_options(ptr);
 445
 446     /* connect to server */
 447     if ((connect(ptr->fd, ptr->address_info_next->ai_addr, ptr->address_info_next->ai_addrlen) != SOCKET_ERROR))
 448     {
 449       break; // Success
 450     }
 451
 452     /* An error occurred */
 453     ptr->cached_errno= get_socket_errno();
 454     switch (ptr->cached_errno)
 455     {
 456     case EWOULDBLOCK:
 457     case EINPROGRESS: // nonblocking mode - first return
 458     case EALREADY: // nonblocking mode - subsequent returns
 459       {
 460         memcached_return_t rc;
 461         rc= connect_poll(ptr);
 462
 463         if (rc == MEMCACHED_TIMEOUT)
 464           timeout_error_occured= true;
 465
 466         if (rc == MEMCACHED_SUCCESS)
 467           break;
 468       }
 469
 470     case EISCONN: // we are connected :-)
 471       break;
 472
 473     case EINTR: // Special case, we retry ai_addr
 474       (void)closesocket(ptr->fd);
 475       ptr->fd= INVALID_SOCKET;
 476       continue;
 477
 478     default:
 479       (void)closesocket(ptr->fd);
 480       ptr->fd= INVALID_SOCKET;
 481       ptr->address_info_next= ptr->address_info_next->ai_next;
 482       break;
 483     }
 484   }
 485
 486   if (ptr->fd == INVALID_SOCKET)
 487   {
 488     WATCHPOINT_STRING("Never got a good file descriptor");
 489
 490     /* Failed to connect. schedule next retry */
 491     if (ptr->root->retry_timeout)
 492     {
 493       struct timeval next_time;
 494
 495       if (gettimeofday(&next_time, NULL) == 0)
 496         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 497     }
 498
 499     if (timeout_error_occured)
 500       return MEMCACHED_TIMEOUT;
 501
 502     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 503   }
 504
 505   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 506 }
 507
 508 void set_last_disconnected_host(memcached_server_write_instance_st self)
 509 {
 510   // const_cast
 511   memcached_st *root= (memcached_st *)self->root;
 512
 513 #if 0
 514   WATCHPOINT_STRING(self->hostname);
 515   WATCHPOINT_NUMBER(self->port);
 516   WATCHPOINT_ERRNO(self->cached_errno);
 517 #endif
 518   memcached_server_free(root->last_disconnected_server);
 519   root->last_disconnected_server= memcached_server_clone(NULL, self);
 520 }
 521
 522 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 523 {
 524   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 525
 526   if (ptr->fd != INVALID_SOCKET)
 527     return MEMCACHED_SUCCESS;
 528
 529   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 530
 531   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 532   WATCHPOINT_ASSERT(ptr->root);
 533   if (ptr->root->retry_timeout && ptr->next_retry)
 534   {
 535     struct timeval curr_time;
 536
 537     gettimeofday(&curr_time, NULL);
 538
 539     // We should optimize this to remove the allocation if the server was
 540     // the last server to die
 541     if (ptr->next_retry > curr_time.tv_sec)
 542     {
 543       set_last_disconnected_host(ptr);
 544
 545       return memcached_set_error(*ptr, MEMCACHED_SERVER_MARKED_DEAD, MEMCACHED_AT);
 546     }
 547   }
 548
 549   // If we are over the counter failure, we just fail. Reject host only
 550   // works if you have a set number of failures.
 551   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 552   {
 553     set_last_disconnected_host(ptr);
 554
 555     // @todo fix this by fixing behavior to no longer make use of
 556     // memcached_st
 557     if (_is_auto_eject_host(ptr->root))
 558     {
 559       run_distribution((memcached_st *)ptr->root);
 560     }
 561
 562     return memcached_set_error(*ptr, MEMCACHED_SERVER_MARKED_DEAD, MEMCACHED_AT);
 563   }
 564
 565   /* We need to clean up the multi startup piece */
 566   switch (ptr->type)
 567   {
 568   case MEMCACHED_CONNECTION_UNKNOWN:
 569     WATCHPOINT_ASSERT(0);
 570     rc= MEMCACHED_NOT_SUPPORTED;
 571     break;
 572
 573   case MEMCACHED_CONNECTION_UDP:
 574   case MEMCACHED_CONNECTION_TCP:
 575     rc= network_connect(ptr);
 576 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 577     if (ptr->fd != INVALID_SOCKET && ptr->root->sasl.callbacks)
 578     {
 579       rc= memcached_sasl_authenticate_connection(ptr);
 580       if (memcached_failed(rc))
 581       {
 582         (void)closesocket(ptr->fd);
 583         ptr->fd= INVALID_SOCKET;
 584       }
 585     }
 586 #endif
 587     break;
 588
 589   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 590     rc= unix_socket_connect(ptr);
 591     break;
 592
 593   case MEMCACHED_CONNECTION_MAX:
 594   default:
 595     WATCHPOINT_ASSERT(0);
 596   }
 597
 598   if (memcached_success(rc))
 599   {
 600     ptr->server_failure_counter= 0;
 601     ptr->next_retry= 0;
 602   }
 603   else
 604   {
 605     memcached_set_error(*ptr, rc, MEMCACHED_AT);
 606     ptr->server_failure_counter++;
 607     set_last_disconnected_host(ptr);
 608   }
 609
 610   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 611
 612   return rc;
 613 }