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

   1 #include "common.h"
   2 #include <netdb.h>
   3 #include <poll.h>
   4 #include <sys/time.h>
   5
   6 static memcached_return_t set_hostinfo(memcached_server_st *server)
   7 {
   8   struct addrinfo *ai;
   9   struct addrinfo hints;
  10   int e;
  11   char str_port[NI_MAXSERV];
  12
  13   snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
  14
  15   memset(&hints, 0, sizeof(hints));
  16
  17  // hints.ai_family= AF_INET;
  18   if (server->type == MEMCACHED_CONNECTION_UDP)
  19   {
  20     hints.ai_protocol= IPPROTO_UDP;
  21     hints.ai_socktype= SOCK_DGRAM;
  22   }
  23   else
  24   {
  25     hints.ai_socktype= SOCK_STREAM;
  26     hints.ai_protocol= IPPROTO_TCP;
  27   }
  28
  29   e= getaddrinfo(server->hostname, str_port, &hints, &ai);
  30   if (e != 0)
  31   {
  32     WATCHPOINT_STRING(server->hostname);
  33     WATCHPOINT_STRING(gai_strerror(e));
  34     return MEMCACHED_HOST_LOOKUP_FAILURE;
  35   }
  36
  37   if (server->address_info)
  38   {
  39     freeaddrinfo(server->address_info);
  40     server->address_info= NULL;
  41   }
  42   server->address_info= ai;
  43
  44   return MEMCACHED_SUCCESS;
  45 }
  46
  47 static memcached_return_t set_socket_options(memcached_server_st *ptr)
  48 {
  49   WATCHPOINT_ASSERT(ptr->fd != -1);
  50
  51   if (ptr->type == MEMCACHED_CONNECTION_UDP)
  52     return MEMCACHED_SUCCESS;
  53
  54 #ifdef HAVE_SNDTIMEO
  55   if (ptr->root->snd_timeout)
  56   {
  57     int error;
  58     struct timeval waittime;
  59
  60     waittime.tv_sec= 0;
  61     waittime.tv_usec= ptr->root->snd_timeout;
  62
  63     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDTIMEO,
  64                       &waittime, (socklen_t)sizeof(struct timeval));
  65     WATCHPOINT_ASSERT(error == 0);
  66     if (error)
  67       return MEMCACHED_FAILURE;
  68   }
  69 #endif
  70
  71 #ifdef HAVE_RCVTIMEO
  72   if (ptr->root->rcv_timeout)
  73   {
  74     int error;
  75     struct timeval waittime;
  76
  77     waittime.tv_sec= 0;
  78     waittime.tv_usec= ptr->root->rcv_timeout;
  79
  80     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
  81                       &waittime, (socklen_t)sizeof(struct timeval));
  82     WATCHPOINT_ASSERT(error == 0);
  83     if (error)
  84       return MEMCACHED_FAILURE;
  85   }
  86 #endif
  87
  88   if (ptr->root->flags.no_block)
  89   {
  90     int error;
  91     struct linger linger;
  92
  93     linger.l_onoff= 1;
  94     linger.l_linger= 0; /* By default on close() just drop the socket */
  95     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
  96                       &linger, (socklen_t)sizeof(struct linger));
  97     WATCHPOINT_ASSERT(error == 0);
  98     if (error)
  99       return MEMCACHED_FAILURE;
 100   }
 101
 102   if (ptr->root->flags.tcp_nodelay)
 103   {
 104     int flag= 1;
 105     int error;
 106
 107     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 108                       &flag, (socklen_t)sizeof(int));
 109     WATCHPOINT_ASSERT(error == 0);
 110     if (error)
 111       return MEMCACHED_FAILURE;
 112   }
 113
 114   if (ptr->root->send_size > 0)
 115   {
 116     int error;
 117
 118     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 119                       &ptr->root->send_size, (socklen_t)sizeof(int));
 120     WATCHPOINT_ASSERT(error == 0);
 121     if (error)
 122       return MEMCACHED_FAILURE;
 123   }
 124
 125   if (ptr->root->recv_size > 0)
 126   {
 127     int error;
 128
 129     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 130                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 131     WATCHPOINT_ASSERT(error == 0);
 132     if (error)
 133       return MEMCACHED_FAILURE;
 134   }
 135
 136   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 137   int flags;
 138
 139   do
 140     flags= fcntl(ptr->fd, F_GETFL, 0);
 141   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 142
 143   unlikely (flags == -1)
 144   {
 145     return MEMCACHED_CONNECTION_FAILURE;
 146   }
 147   else if ((flags & O_NONBLOCK) == 0)
 148   {
 149     int rval;
 150
 151     do
 152       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 153     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 154
 155     unlikely (rval == -1)
 156     {
 157       return MEMCACHED_CONNECTION_FAILURE;
 158     }
 159   }
 160
 161   return MEMCACHED_SUCCESS;
 162 }
 163
 164 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 165 {
 166   struct sockaddr_un servAddr;
 167
 168   if (ptr->fd == -1)
 169   {
 170     if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 171     {
 172       ptr->cached_errno= errno;
 173       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 174     }
 175
 176     memset(&servAddr, 0, sizeof (struct sockaddr_un));
 177     servAddr.sun_family= AF_UNIX;
 178     strcpy(servAddr.sun_path, ptr->hostname); /* Copy filename */
 179
 180 test_connect:
 181     if (connect(ptr->fd,
 182                 (struct sockaddr *)&servAddr,
 183                 sizeof(servAddr)) < 0)
 184     {
 185       switch (errno)
 186       {
 187       case EINPROGRESS:
 188       case EALREADY:
 189       case EINTR:
 190         goto test_connect;
 191       case EISCONN: /* We were spinning waiting on connect */
 192         break;
 193       default:
 194         WATCHPOINT_ERRNO(errno);
 195         ptr->cached_errno= errno;
 196         return MEMCACHED_ERRNO;
 197       }
 198     }
 199   }
 200
 201   WATCHPOINT_ASSERT(ptr->fd != -1);
 202   return MEMCACHED_SUCCESS;
 203 }
 204
 205 static memcached_return_t network_connect(memcached_server_st *ptr)
 206 {
 207   if (ptr->fd == -1)
 208   {
 209     struct addrinfo *use;
 210
 211     WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 212
 213     if (! ptr->options.sockaddr_inited ||
 214         (!(ptr->root->flags.use_cache_lookups)))
 215     {
 216       memcached_return_t rc;
 217
 218       rc= set_hostinfo(ptr);
 219       if (rc != MEMCACHED_SUCCESS)
 220         return rc;
 221       ptr->options.sockaddr_inited= true;
 222     }
 223
 224     use= ptr->address_info;
 225     /* Create the socket */
 226     while (use != NULL)
 227     {
 228       /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 229       if (ptr->type == MEMCACHED_CONNECTION_UDP && use->ai_family != AF_INET)
 230       {
 231         use= use->ai_next;
 232         continue;
 233       }
 234
 235       if ((ptr->fd= socket(use->ai_family,
 236                            use->ai_socktype,
 237                            use->ai_protocol)) < 0)
 238       {
 239         ptr->cached_errno= errno;
 240         WATCHPOINT_ERRNO(errno);
 241         return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 242       }
 243
 244       (void)set_socket_options(ptr);
 245
 246       /* connect to server */
 247       while (ptr->fd != -1 &&
 248              connect(ptr->fd, use->ai_addr, use->ai_addrlen) < 0)
 249       {
 250         ptr->cached_errno= errno;
 251         if (errno == EINPROGRESS || /* nonblocking mode - first return, */
 252             errno == EALREADY) /* nonblocking mode - subsequent returns */
 253         {
 254           struct pollfd fds[1];
 255           fds[0].fd = ptr->fd;
 256           fds[0].events = POLLOUT;
 257           int error= poll(fds, 1, ptr->root->connect_timeout);
 258
 259           if (error != 1 || fds[0].revents & POLLERR)
 260           {
 261             if (fds[0].revents & POLLERR)
 262             {
 263               int err;
 264               socklen_t len = sizeof (err);
 265               (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
 266               ptr->cached_errno= (err == 0) ? errno : err;
 267             }
 268
 269             (void)close(ptr->fd);
 270             ptr->fd= -1;
 271           }
 272         }
 273         else if (errno == EISCONN) /* we are connected :-) */
 274         {
 275           break;
 276         }
 277         else if (errno != EINTR)
 278         {
 279           (void)close(ptr->fd);
 280           ptr->fd= -1;
 281           break;
 282         }
 283       }
 284
 285       if (ptr->fd != -1)
 286       {
 287         ptr->server_failure_counter= 0;
 288         return MEMCACHED_SUCCESS;
 289       }
 290       use = use->ai_next;
 291     }
 292   }
 293
 294   if (ptr->fd == -1)
 295   {
 296     /* Failed to connect. schedule next retry */
 297     if (ptr->root->retry_timeout)
 298     {
 299       struct timeval next_time;
 300
 301       if (gettimeofday(&next_time, NULL) == 0)
 302         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 303     }
 304     ptr->server_failure_counter++;
 305     if (ptr->cached_errno == 0)
 306       return MEMCACHED_TIMEOUT;
 307
 308     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 309   }
 310
 311   ptr->server_failure_counter= 0;
 312   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 313 }
 314
 315
 316 memcached_return_t memcached_connect(memcached_server_st *ptr)
 317 {
 318   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 319   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 320
 321   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 322   WATCHPOINT_ASSERT(ptr->root);
 323   if (ptr->root->retry_timeout && ptr->root->server_failure_limit)
 324   {
 325     struct timeval curr_time;
 326
 327     gettimeofday(&curr_time, NULL);
 328
 329     /* if we've had too many consecutive errors on this server, mark it dead. */
 330     if (ptr->server_failure_counter >= ptr->root->server_failure_limit)
 331     {
 332       ptr->next_retry= curr_time.tv_sec + ptr->root->retry_timeout;
 333       ptr->server_failure_counter= 0;
 334     }
 335
 336     if (curr_time.tv_sec < ptr->next_retry)
 337     {
 338       memcached_st *root= (memcached_st *)ptr->root;
 339       // @todo fix this by fixing behavior to no longer make use of
 340       // memcached_st
 341       if (memcached_behavior_get(root, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS))
 342       {
 343         run_distribution(root);
 344       }
 345
 346       root->last_disconnected_server = ptr;
 347
 348       return MEMCACHED_SERVER_MARKED_DEAD;
 349     }
 350   }
 351
 352   /* We need to clean up the multi startup piece */
 353   switch (ptr->type)
 354   {
 355   case MEMCACHED_CONNECTION_UNKNOWN:
 356     WATCHPOINT_ASSERT(0);
 357     rc= MEMCACHED_NOT_SUPPORTED;
 358     break;
 359   case MEMCACHED_CONNECTION_UDP:
 360   case MEMCACHED_CONNECTION_TCP:
 361     rc= network_connect(ptr);
 362     break;
 363   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 364     rc= unix_socket_connect(ptr);
 365     break;
 366   case MEMCACHED_CONNECTION_MAX:
 367   default:
 368     WATCHPOINT_ASSERT(0);
 369   }
 370
 371   unlikely ( rc != MEMCACHED_SUCCESS)
 372   {
 373     //@todo create interface around last_discontected_server
 374     memcached_st *root= (memcached_st *)ptr->root;
 375     root->last_disconnected_server = ptr;
 376   }
 377
 378   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 379
 380   return rc;
 381 }