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
 109   {
 110     int set = 1;
 111     int error= setsockopt(ptr->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 112
 113     // This is not considered a fatal error
 114     if (error == -1)
 115     {
 116       WATCHPOINT_ERRNO(errno);
 117       perror("setsockopt(SO_NOSIGPIPE)");
 118     }
 119   }
 120
 121   if (ptr->root->flags.no_block)
 122   {
 123     int error;
 124     struct linger linger;
 125
 126     linger.l_onoff= 1;
 127     linger.l_linger= 0; /* By default on close() just drop the socket */
 128     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
 129                       &linger, (socklen_t)sizeof(struct linger));
 130     WATCHPOINT_ASSERT(error == 0);
 131     if (error)
 132       return MEMCACHED_FAILURE;
 133   }
 134
 135   if (ptr->root->flags.tcp_nodelay)
 136   {
 137     int flag= 1;
 138     int error;
 139
 140     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 141                       &flag, (socklen_t)sizeof(int));
 142     WATCHPOINT_ASSERT(error == 0);
 143     if (error)
 144       return MEMCACHED_FAILURE;
 145   }
 146
 147   if (ptr->root->flags.tcp_keepalive)
 148   {
 149     int flag= 1;
 150     int error;
 151
 152     error= setsockopt(ptr->fd, SOL_SOCKET, SO_KEEPALIVE,
 153                       &flag, (socklen_t)sizeof(int));
 154     WATCHPOINT_ASSERT(error == 0);
 155     if (error)
 156       return MEMCACHED_FAILURE;
 157   }
 158
 159 #ifdef TCP_KEEPIDLE
 160   if (ptr->root->tcp_keepidle > 0)
 161   {
 162     int error;
 163
 164     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_KEEPIDLE,
 165                       &ptr->root->tcp_keepidle, (socklen_t)sizeof(int));
 166     WATCHPOINT_ASSERT(error == 0);
 167     if (error)
 168       return MEMCACHED_FAILURE;
 169   }
 170 #endif
 171
 172   if (ptr->root->send_size > 0)
 173   {
 174     int error;
 175
 176     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 177                       &ptr->root->send_size, (socklen_t)sizeof(int));
 178     WATCHPOINT_ASSERT(error == 0);
 179     if (error)
 180       return MEMCACHED_FAILURE;
 181   }
 182
 183   if (ptr->root->recv_size > 0)
 184   {
 185     int error;
 186
 187     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 188                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 189     WATCHPOINT_ASSERT(error == 0);
 190     if (error)
 191       return MEMCACHED_FAILURE;
 192   }
 193
 194   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 195   int flags;
 196
 197   do
 198     flags= fcntl(ptr->fd, F_GETFL, 0);
 199   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 200
 201   unlikely (flags == -1)
 202   {
 203     return MEMCACHED_CONNECTION_FAILURE;
 204   }
 205   else if ((flags & O_NONBLOCK) == 0)
 206   {
 207     int rval;
 208
 209     do
 210       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 211     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 212
 213     unlikely (rval == -1)
 214     {
 215       return MEMCACHED_CONNECTION_FAILURE;
 216     }
 217   }
 218
 219   return MEMCACHED_SUCCESS;
 220 }
 221
 222 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 223 {
 224   struct sockaddr_un servAddr;
 225
 226   if (ptr->fd == -1)
 227   {
 228     if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 229     {
 230       ptr->cached_errno= errno;
 231       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 232     }
 233
 234     memset(&servAddr, 0, sizeof (struct sockaddr_un));
 235     servAddr.sun_family= AF_UNIX;
 236     strcpy(servAddr.sun_path, ptr->hostname); /* Copy filename */
 237
 238 test_connect:
 239     if (connect(ptr->fd,
 240                 (struct sockaddr *)&servAddr,
 241                 sizeof(servAddr)) < 0)
 242     {
 243       switch (errno)
 244       {
 245       case EINPROGRESS:
 246       case EALREADY:
 247       case EINTR:
 248         goto test_connect;
 249       case EISCONN: /* We were spinning waiting on connect */
 250         break;
 251       default:
 252         WATCHPOINT_ERRNO(errno);
 253         ptr->cached_errno= errno;
 254         return MEMCACHED_ERRNO;
 255       }
 256     }
 257   }
 258
 259   WATCHPOINT_ASSERT(ptr->fd != -1);
 260
 261   return MEMCACHED_SUCCESS;
 262 }
 263
 264 static memcached_return_t network_connect(memcached_server_st *ptr)
 265 {
 266   if (ptr->fd == -1)
 267   {
 268     struct addrinfo *use;
 269
 270     WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 271
 272     if (! ptr->options.sockaddr_inited ||
 273         (!(ptr->root->flags.use_cache_lookups)))
 274     {
 275       memcached_return_t rc;
 276
 277       rc= set_hostinfo(ptr);
 278       if (rc != MEMCACHED_SUCCESS)
 279         return rc;
 280       ptr->options.sockaddr_inited= true;
 281     }
 282
 283     use= ptr->address_info;
 284     /* Create the socket */
 285     while (use != NULL)
 286     {
 287       /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 288       if (ptr->type == MEMCACHED_CONNECTION_UDP && use->ai_family != AF_INET)
 289       {
 290         use= use->ai_next;
 291         continue;
 292       }
 293
 294       if ((ptr->fd= socket(use->ai_family,
 295                            use->ai_socktype,
 296                            use->ai_protocol)) < 0)
 297       {
 298         ptr->cached_errno= errno;
 299         WATCHPOINT_ERRNO(errno);
 300         return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 301       }
 302
 303       (void)set_socket_options(ptr);
 304
 305       /* connect to server */
 306       if ((connect(ptr->fd, use->ai_addr, use->ai_addrlen) == -1))
 307       {
 308         ptr->cached_errno= errno;
 309         if (errno == EINPROGRESS || /* nonblocking mode - first return, */
 310             errno == EALREADY) /* nonblocking mode - subsequent returns */
 311         {
 312           struct pollfd fds[1];
 313           fds[0].fd = ptr->fd;
 314           fds[0].events = POLLOUT;
 315
 316           int timeout= ptr->root->connect_timeout;
 317           if (ptr->root->flags.no_block == false)
 318             timeout= -1;
 319
 320           size_t loop_max= 5;
 321           while (--loop_max)
 322           {
 323             int error= poll(fds, 1, timeout);
 324
 325             switch (error)
 326             {
 327             case 1:
 328               loop_max= 1;
 329               break;
 330             case 0:
 331               continue;
 332               // A real error occurred and we need to completely bail
 333             default:
 334               WATCHPOINT_ERRNO(errno);
 335               switch (errno)
 336               {
 337 #ifdef TARGET_OS_LINUX
 338               case ERESTART:
 339 #endif
 340               case EINTR:
 341                 continue;
 342               default:
 343                 if (fds[0].revents & POLLERR)
 344                 {
 345                   int err;
 346                   socklen_t len= sizeof (err);
 347                   (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
 348                   ptr->cached_errno= (err == 0) ? errno : err;
 349                 }
 350
 351                 (void)close(ptr->fd);
 352                 ptr->fd= -1;
 353
 354                 break;
 355               }
 356             }
 357           }
 358         }
 359         else if (errno == EISCONN) /* we are connected :-) */
 360         {
 361           break;
 362         }
 363         else if (errno != EINTR)
 364         {
 365           (void)close(ptr->fd);
 366           ptr->fd= -1;
 367           break;
 368         }
 369       }
 370
 371 #ifdef LIBMEMCACHED_WITH_SASL_SUPPORT
 372       if (ptr->fd != -1 && ptr->root->sasl.callbacks != NULL)
 373       {
 374         memcached_return rc= memcached_sasl_authenticate_connection(ptr);
 375         if (rc != MEMCACHED_SUCCESS)
 376         {
 377           (void)close(ptr->fd);
 378           ptr->fd= -1;
 379
 380           return rc;
 381         }
 382       }
 383 #endif
 384
 385
 386       if (ptr->fd != -1)
 387       {
 388         return MEMCACHED_SUCCESS;
 389       }
 390       use = use->ai_next;
 391     }
 392   }
 393
 394   if (ptr->fd == -1)
 395   {
 396     WATCHPOINT_STRING("Never got a good file descriptor");
 397
 398     /* Failed to connect. schedule next retry */
 399     if (ptr->root->retry_timeout)
 400     {
 401       struct timeval next_time;
 402
 403       if (gettimeofday(&next_time, NULL) == 0)
 404         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 405     }
 406
 407     if (ptr->cached_errno == 0)
 408       return MEMCACHED_TIMEOUT;
 409
 410     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 411   }
 412
 413   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 414 }
 415
 416 void set_last_disconnected_host(memcached_server_write_instance_st ptr)
 417 {
 418   // const_cast
 419   memcached_st *root= (memcached_st *)ptr->root;
 420
 421 #if 0
 422   WATCHPOINT_STRING(ptr->hostname);
 423   WATCHPOINT_NUMBER(ptr->port);
 424   WATCHPOINT_ERRNO(ptr->cached_errno);
 425 #endif
 426   if (root->last_disconnected_server)
 427     memcached_server_free(root->last_disconnected_server);
 428   root->last_disconnected_server= memcached_server_clone(NULL, ptr);
 429 }
 430
 431 memcached_return_t memcached_connect(memcached_server_write_instance_st ptr)
 432 {
 433   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 434   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 435
 436   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 437   WATCHPOINT_ASSERT(ptr->root);
 438   if (ptr->root->retry_timeout && ptr->next_retry)
 439   {
 440     struct timeval curr_time;
 441
 442     gettimeofday(&curr_time, NULL);
 443
 444     // We should optimize this to remove the allocation if the server was
 445     // the last server to die
 446     if (ptr->next_retry > curr_time.tv_sec)
 447     {
 448       set_last_disconnected_host(ptr);
 449
 450       return MEMCACHED_SERVER_MARKED_DEAD;
 451     }
 452   }
 453
 454   // If we are over the counter failure, we just fail. Reject host only
 455   // works if you have a set number of failures.
 456   if (ptr->root->server_failure_limit && ptr->server_failure_counter >= ptr->root->server_failure_limit)
 457   {
 458     set_last_disconnected_host(ptr);
 459
 460     // @todo fix this by fixing behavior to no longer make use of
 461     // memcached_st
 462     if (_is_auto_eject_host(ptr->root))
 463     {
 464       run_distribution((memcached_st *)ptr->root);
 465     }
 466
 467     return MEMCACHED_SERVER_MARKED_DEAD;
 468   }
 469
 470   /* We need to clean up the multi startup piece */
 471   switch (ptr->type)
 472   {
 473   case MEMCACHED_CONNECTION_UNKNOWN:
 474     WATCHPOINT_ASSERT(0);
 475     rc= MEMCACHED_NOT_SUPPORTED;
 476     break;
 477   case MEMCACHED_CONNECTION_UDP:
 478   case MEMCACHED_CONNECTION_TCP:
 479     rc= network_connect(ptr);
 480     break;
 481   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 482     rc= unix_socket_connect(ptr);
 483     break;
 484   case MEMCACHED_CONNECTION_MAX:
 485   default:
 486     WATCHPOINT_ASSERT(0);
 487   }
 488
 489   if (rc == MEMCACHED_SUCCESS)
 490   {
 491     ptr->server_failure_counter= 0;
 492     ptr->next_retry= 0;
 493   }
 494   else
 495   {
 496     ptr->server_failure_counter++;
 497
 498     set_last_disconnected_host(ptr);
 499   }
 500
 501   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 502
 503   return rc;
 504 }