git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/connect.c

   1 #include "common.h"
   2 #include <netdb.h>
   3 #include <poll.h>
   4 #include <sys/time.h>
   5 #include <time.h>
   6
   7 static memcached_return_t set_hostinfo(memcached_server_st *server)
   8 {
   9   struct addrinfo *ai;
  10   struct addrinfo hints;
  11   char str_port[NI_MAXSERV];
  12   uint32_t counter= 5;
  13
  14   snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
  15
  16   memset(&hints, 0, sizeof(hints));
  17
  18  // hints.ai_family= AF_INET;
  19   if (server->type == MEMCACHED_CONNECTION_UDP)
  20   {
  21     hints.ai_protocol= IPPROTO_UDP;
  22     hints.ai_socktype= SOCK_DGRAM;
  23   }
  24   else
  25   {
  26     hints.ai_socktype= SOCK_STREAM;
  27     hints.ai_protocol= IPPROTO_TCP;
  28   }
  29
  30   while (--counter)
  31   {
  32     int e= getaddrinfo(server->hostname, str_port, &hints, &ai);
  33
  34     if (e == 0)
  35     {
  36       break;
  37     }
  38     else if (e == EAI_AGAIN)
  39     {
  40       struct timespec dream, rem;
  41
  42       dream.tv_nsec= 1000;
  43       dream.tv_sec= 0;
  44
  45       nanosleep(&dream, &rem);
  46
  47       continue;
  48     }
  49     else
  50     {
  51       WATCHPOINT_STRING(server->hostname);
  52       WATCHPOINT_STRING(gai_strerror(e));
  53       return MEMCACHED_HOST_LOOKUP_FAILURE;
  54     }
  55   }
  56
  57   if (server->address_info)
  58   {
  59     freeaddrinfo(server->address_info);
  60     server->address_info= NULL;
  61   }
  62   server->address_info= ai;
  63
  64   return MEMCACHED_SUCCESS;
  65 }
  66
  67 static memcached_return_t set_socket_options(memcached_server_st *ptr)
  68 {
  69   WATCHPOINT_ASSERT(ptr->fd != -1);
  70
  71   if (ptr->type == MEMCACHED_CONNECTION_UDP)
  72     return MEMCACHED_SUCCESS;
  73
  74 #ifdef HAVE_SNDTIMEO
  75   if (ptr->root->snd_timeout)
  76   {
  77     int error;
  78     struct timeval waittime;
  79
  80     waittime.tv_sec= 0;
  81     waittime.tv_usec= ptr->root->snd_timeout;
  82
  83     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
  84                       &waittime, (socklen_t)sizeof(struct timeval));
  85     WATCHPOINT_ASSERT(error == 0);
  86     if (error)
  87       return MEMCACHED_FAILURE;
  88   }
  89 #endif
  90
  91 #ifdef HAVE_RCVTIMEO
  92   if (ptr->root->rcv_timeout)
  93   {
  94     int error;
  95     struct timeval waittime;
  96
  97     waittime.tv_sec= 0;
  98     waittime.tv_usec= ptr->root->rcv_timeout;
  99
 100     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
 101                       &waittime, (socklen_t)sizeof(struct timeval));
 102     WATCHPOINT_ASSERT(error == 0);
 103     if (error)
 104       return MEMCACHED_FAILURE;
 105   }
 106 #endif
 107
 108   if (ptr->root->flags.no_block)
 109   {
 110     int error;
 111     struct linger linger;
 112
 113     linger.l_onoff= 1;
 114     linger.l_linger= 0; /* By default on close() just drop the socket */
 115     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 116                       &linger, (socklen_t)sizeof(struct linger));
 117     WATCHPOINT_ASSERT(error == 0);
 118     if (error)
 119       return MEMCACHED_FAILURE;
 120   }
 121
 122   if (ptr->root->flags.tcp_nodelay)
 123   {
 124     int flag= 1;
 125     int error;
 126
 127     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 128                       &flag, (socklen_t)sizeof(int));
 129     WATCHPOINT_ASSERT(error == 0);
 130     if (error)
 131       return MEMCACHED_FAILURE;
 132   }
 133
 134   if (ptr->root->flags.tcp_keepalive)
 135   {
 136     int flag= 1;
 137     int error;
 138
 139     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 140                       &flag, (socklen_t)sizeof(int));
 141     WATCHPOINT_ASSERT(error == 0);
 142     if (error)
 143       return MEMCACHED_FAILURE;
 144   }
 145
 146 #ifdef TCP_KEEPIDLE
 147   if (ptr->root->tcp_keepidle > 0)
 148   {
 149     int error;
 150
 151     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 152                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 153     WATCHPOINT_ASSERT(error == 0);
 154     if (error)
 155       return MEMCACHED_FAILURE;
 156   }
 157 #endif
 158
 159   if (ptr->root->send_size > 0)
 160   {
 161     int error;
 162
 163     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 164                       &ptr->root->send_size, (socklen_t)sizeof(int));
 165     WATCHPOINT_ASSERT(error == 0);
 166     if (error)
 167       return MEMCACHED_FAILURE;
 168   }
 169
 170   if (ptr->root->recv_size > 0)
 171   {
 172     int error;
 173
 174     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 175                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 176     WATCHPOINT_ASSERT(error == 0);
 177     if (error)
 178       return MEMCACHED_FAILURE;
 179   }
 180
 181   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 182   int flags;
 183
 184   do
 185     flags= fcntl(ptr->fd, F_GETFL, 0);
 186   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 187
 188   unlikely (flags == -1)
 189   {
 190     return MEMCACHED_CONNECTION_FAILURE;
 191   }
 192   else if ((flags & O_NONBLOCK) == 0)
 193   {
 194     int rval;
 195
 196     do
 197       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 198     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 199
 200     unlikely (rval == -1)
 201     {
 202       return MEMCACHED_CONNECTION_FAILURE;
 203     }
 204   }
 205
 206   return MEMCACHED_SUCCESS;
 207 }
 208
 209 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 210 {
 211   struct sockaddr_un servAddr;
 212
 213   if (ptr->fd == -1)
 214   {
 215     if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 216     {
 217       ptr->cached_errno= errno;
 218       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 219     }
 220
 221     memset(&servAddr, 0, sizeof (struct sockaddr_un));
 222     servAddr.sun_family= AF_UNIX;
 223     strcpy(servAddr.sun_path, ptr->hostname); /* Copy filename */
 224
 225 test_connect:
 226     if (connect(ptr->fd,
 227                 (struct sockaddr *)&servAddr,
 228                 sizeof(servAddr)) < 0)
 229     {
 230       switch (errno)
 231       {
 232       case EINPROGRESS:
 233       case EALREADY:
 234       case EINTR:
 235         goto test_connect;
 236       case EISCONN: /* We were spinning waiting on connect */
 237         break;
 238       default:
 239         WATCHPOINT_ERRNO(errno);
 240         ptr->cached_errno= errno;
 241         return MEMCACHED_ERRNO;
 242       }
 243     }
 244   }
 245
 246   WATCHPOINT_ASSERT(ptr->fd != -1);
 247   return MEMCACHED_SUCCESS;
 248 }
 249
 250 static memcached_return_t network_connect(memcached_server_st *ptr)
 251 {
 252   if (ptr->fd == -1)
 253   {
 254     struct addrinfo *use;
 255
 256     WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 257
 258     if (! ptr->options.sockaddr_inited ||
 259         (!(ptr->root->flags.use_cache_lookups)))
 260     {
 261       memcached_return_t rc;
 262
 263       rc= set_hostinfo(ptr);
 264       if (rc != MEMCACHED_SUCCESS)
 265         return rc;
 266       ptr->options.sockaddr_inited= true;
 267     }
 268
 269     use= ptr->address_info;
 270     /* Create the socket */
 271     while (use != NULL)
 272     {
 273       /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 274       if (ptr->type == MEMCACHED_CONNECTION_UDP && use->ai_family != AF_INET)
 275       {
 276         use= use->ai_next;
 277         continue;
 278       }
 279
 280       if ((ptr->fd= socket(use->ai_family,
 281                            use->ai_socktype,
 282                            use->ai_protocol)) < 0)
 283       {
 284         ptr->cached_errno= errno;
 285         WATCHPOINT_ERRNO(errno);
 286         return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 287       }
 288
 289       (void)set_socket_options(ptr);
 290
 291       /* connect to server */
 292       if ((connect(ptr->fd, use->ai_addr, use->ai_addrlen) == -1))
 293       {
 294         ptr->cached_errno= errno;
 295         if (errno == EINPROGRESS || /* nonblocking mode - first return, */
 296             errno == EALREADY) /* nonblocking mode - subsequent returns */
 297         {
 298           struct pollfd fds[1];
 299           fds[0].fd = ptr->fd;
 300           fds[0].events = POLLOUT;
 301
 302           int timeout= ptr->root->connect_timeout;
 303           if (ptr->root->flags.no_block == false)
 304             timeout= -1;
 305
 306           size_t loop_max= 5;
 307           while (--loop_max)
 308           {
 309             int error= poll(fds, 1, timeout);
 310
 311             switch (error)
 312             {
 313             case 1:
 314               loop_max= 1;
 315               break;
 316             case 0:
 317               continue;
 318               // A real error occurred and we need to completely bail
 319             default:
 320               WATCHPOINT_ERRNO(errno);
 321               switch (errno)
 322               {
 323 #ifdef TARGET_OS_LINUX
 324               case ERESTART:
 325 #endif
 326               case EINTR:
 327                 continue;
 328               default:
 329                 if (fds[0].revents & POLLERR)
 330                 {
 331                   int err;
 332                   socklen_t len= sizeof (err);
 333                   (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
 334                   ptr->cached_errno= (err == 0) ? errno : err;
 335                 }
 336
 337                 (void)close(ptr->fd);
 338                 ptr->fd= -1;
 339
 340                 break;
 341               }
 342             }
 343           }
 344         }
 345         else if (errno == EISCONN) /* we are connected :-) */
 346         {
 347           break;
 348         }
 349         else if (errno != EINTR)
 350         {
 351           (void)close(ptr->fd);
 352           ptr->fd= -1;
 353           break;
 354         }
 355       }
 356
 357 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 358       if (ptr->fd != -1 && ptr->root->sasl.callbacks != NULL)
 359       {
 360         memcached_return rc= memcached_sasl_authenticate_connection(ptr);
 361         if (rc != MEMCACHED_SUCCESS)
 362         {
 363           (void)close(ptr->fd);
 364           ptr->fd= -1;
 365
 366           return rc;
 367         }
 368       }
 369 #endif
 370
 371
 372       if (ptr->fd != -1)
 373       {
 374         return MEMCACHED_SUCCESS;
 375       }
 376       use = use->ai_next;
 377     }
 378   }
 379
 380   if (ptr->fd == -1)
 381   {
 382     WATCHPOINT_STRING("Never got a good file descriptor");
 383
 384     /* Failed to connect. schedule next retry */
 385     if (ptr->root->retry_timeout)
 386     {
 387       struct timeval next_time;
 388
 389       if (gettimeofday(&next_time, NULL) == 0)
 390         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 391     }
 392
 393     if (ptr->cached_errno == 0)
 394       return MEMCACHED_TIMEOUT;
 395
 396     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 397   }
 398
 399   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 400 }
 401
 402 void set_last_disconnected_host(memcached_server_write_instance_st ptr)
 403 {
 404   // const_cast
 405   memcached_st *root= (memcached_st *)ptr->root;
 406
 407 #if 0
 408   WATCHPOINT_STRING(ptr->hostname);
 409   WATCHPOINT_NUMBER(ptr->port);
 410   WATCHPOINT_ERRNO(ptr->cached_errno);
 411 #endif
 412   if (root->last_disconnected_server)
 413     memcached_server_free(root->last_disconnected_server);
 414   root->last_disconnected_server= memcached_server_clone(NULL, ptr);
 415 }
 416
 417 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 418 {
 419   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 420   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 421
 422   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 423   WATCHPOINT_ASSERT(ptr->root);
 424   if (ptr->root->retry_timeout && ptr->next_retry)
 425   {
 426     struct timeval curr_time;
 427
 428     gettimeofday(&curr_time, NULL);
 429
 430     // We should optimize this to remove the allocation if the server was
 431     // the last server to die
 432     if (ptr->next_retry > curr_time.tv_sec)
 433     {
 434       set_last_disconnected_host(ptr);
 435
 436       return MEMCACHED_SERVER_MARKED_DEAD;
 437     }
 438   }
 439
 440   // If we are over the counter failure, we just fail. Reject host only
 441   // works if you have a set number of failures.
 442   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 443   {
 444     set_last_disconnected_host(ptr);
 445
 446     // @todo fix this by fixing behavior to no longer make use of
 447     // memcached_st
 448     if (_is_auto_eject_host(ptr->root))
 449     {
 450       run_distribution((memcached_st *)ptr->root);
 451     }
 452
 453     return MEMCACHED_SERVER_MARKED_DEAD;
 454   }
 455
 456   /* We need to clean up the multi startup piece */
 457   switch (ptr->type)
 458   {
 459   case MEMCACHED_CONNECTION_UNKNOWN:
 460     WATCHPOINT_ASSERT(0);
 461     rc= MEMCACHED_NOT_SUPPORTED;
 462     break;
 463   case MEMCACHED_CONNECTION_UDP:
 464   case MEMCACHED_CONNECTION_TCP:
 465     rc= network_connect(ptr);
 466     break;
 467   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 468     rc= unix_socket_connect(ptr);
 469     break;
 470   case MEMCACHED_CONNECTION_MAX:
 471   default:
 472     WATCHPOINT_ASSERT(0);
 473   }
 474
 475   if (rc == MEMCACHED_SUCCESS)
 476   {
 477     ptr->server_failure_counter= 0;
 478     ptr->next_retry= 0;
 479   }
 480   else
 481   {
 482     ptr->server_failure_counter++;
 483
 484     set_last_disconnected_host(ptr);
 485   }
 486
 487   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 488
 489   return rc;
 490 }