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)
 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)
 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     if (!ptr->sockaddr_inited ||
 212         (!(ptr->root->flags.use_cache_lookups)))
 213     {
 214       memcached_return_t rc;
 215
 216       rc= set_hostinfo(ptr);
 217       if (rc != MEMCACHED_SUCCESS)
 218         return rc;
 219       ptr->sockaddr_inited= true;
 220     }
 221
 222     use= ptr->address_info;
 223     /* Create the socket */
 224     while (use != NULL)
 225     {
 226       /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 227       if (ptr->type == MEMCACHED_CONNECTION_UDP && use->ai_family != AF_INET)
 228       {
 229         use= use->ai_next;
 230         continue;
 231       }
 232
 233       if ((ptr->fd= socket(use->ai_family,
 234                            use->ai_socktype,
 235                            use->ai_protocol)) < 0)
 236       {
 237         ptr->cached_errno= errno;
 238         WATCHPOINT_ERRNO(errno);
 239         return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 240       }
 241
 242       (void)set_socket_options(ptr);
 243
 244       /* connect to server */
 245       while (ptr->fd != -1 &&
 246              connect(ptr->fd, use->ai_addr, use->ai_addrlen) < 0)
 247       {
 248         ptr->cached_errno= errno;
 249         if (errno == EINPROGRESS || /* nonblocking mode - first return, */
 250             errno == EALREADY) /* nonblocking mode - subsequent returns */
 251         {
 252           struct pollfd fds[1];
 253           fds[0].fd = ptr->fd;
 254           fds[0].events = POLLOUT;
 255           int error= poll(fds, 1, ptr->root->connect_timeout);
 256
 257           if (error != 1 || fds[0].revents & POLLERR)
 258           {
 259             if (fds[0].revents & POLLERR)
 260             {
 261               int err;
 262               socklen_t len = sizeof (err);
 263               (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
 264               ptr->cached_errno= (err == 0) ? errno : err;
 265             }
 266
 267             (void)close(ptr->fd);
 268             ptr->fd= -1;
 269           }
 270         }
 271         else if (errno == EISCONN) /* we are connected :-) */
 272         {
 273           break;
 274         }
 275         else if (errno != EINTR)
 276         {
 277           (void)close(ptr->fd);
 278           ptr->fd= -1;
 279           break;
 280         }
 281       }
 282
 283       if (ptr->fd != -1)
 284       {
 285         WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 286         ptr->server_failure_counter= 0;
 287         return MEMCACHED_SUCCESS;
 288       }
 289       use = use->ai_next;
 290     }
 291   }
 292
 293   if (ptr->fd == -1)
 294   {
 295     /* Failed to connect. schedule next retry */
 296     if (ptr->root->retry_timeout)
 297     {
 298       struct timeval next_time;
 299
 300       if (gettimeofday(&next_time, NULL) == 0)
 301         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 302     }
 303     ptr->server_failure_counter++;
 304     if (ptr->cached_errno == 0)
 305       return MEMCACHED_TIMEOUT;
 306
 307     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 308   }
 309
 310   ptr->server_failure_counter= 0;
 311   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 312 }
 313
 314
 315 memcached_return_t memcached_connect(memcached_server_st *ptr)
 316 {
 317   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 318   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 319
 320   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 321   WATCHPOINT_ASSERT(ptr->root);
 322   if (ptr->root->retry_timeout && ptr->root->server_failure_limit)
 323   {
 324     struct timeval curr_time;
 325
 326     gettimeofday(&curr_time, NULL);
 327
 328     /* if we've had too many consecutive errors on this server, mark it dead. */
 329     if (ptr->server_failure_counter >= ptr->root->server_failure_limit)
 330     {
 331       ptr->next_retry= curr_time.tv_sec + ptr->root->retry_timeout;
 332       ptr->server_failure_counter= 0;
 333     }
 334
 335     if (curr_time.tv_sec < ptr->next_retry)
 336     {
 337       if (memcached_behavior_get(ptr->root, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS))
 338       {
 339         run_distribution(ptr->root);
 340       }
 341
 342       ptr->root->last_disconnected_server = ptr;
 343       return MEMCACHED_SERVER_MARKED_DEAD;
 344     }
 345   }
 346
 347   /* We need to clean up the multi startup piece */
 348   switch (ptr->type)
 349   {
 350   case MEMCACHED_CONNECTION_UNKNOWN:
 351     WATCHPOINT_ASSERT(0);
 352     rc= MEMCACHED_NOT_SUPPORTED;
 353     break;
 354   case MEMCACHED_CONNECTION_UDP:
 355   case MEMCACHED_CONNECTION_TCP:
 356     rc= network_connect(ptr);
 357     break;
 358   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 359     rc= unix_socket_connect(ptr);
 360     break;
 361   case MEMCACHED_CONNECTION_MAX:
 362   default:
 363     WATCHPOINT_ASSERT(0);
 364   }
 365
 366   unlikely ( rc != MEMCACHED_SUCCESS) ptr->root->last_disconnected_server = ptr;
 367
 368   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 369
 370   return rc;
 371 }