git.m6w6.name Git - m6w6/libmemcached/blob - libmemcached/memcached_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   sprintf(str_port, "%u", 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   }
  67 #endif
  68
  69 #ifdef HAVE_RCVTIMEO
  70   if (ptr->root->rcv_timeout)
  71   {
  72     int error;
  73     struct timeval waittime;
  74
  75     waittime.tv_sec= 0;
  76     waittime.tv_usec= ptr->root->rcv_timeout;
  77
  78     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVTIMEO,
  79                       &waittime, (socklen_t)sizeof(struct timeval));
  80     WATCHPOINT_ASSERT(error == 0);
  81   }
  82 #endif
  83
  84   if (ptr->root->flags.no_block)
  85   {
  86     int error;
  87     struct linger linger;
  88
  89     linger.l_onoff= 1;
  90     linger.l_linger= 0; /* By default on close() just drop the socket */
  91     error= setsockopt(ptr->fd, SOL_SOCKET, SO_LINGER,
  92                       &linger, (socklen_t)sizeof(struct linger));
  93     WATCHPOINT_ASSERT(error == 0);
  94   }
  95
  96   if (ptr->root->flags.tcp_nodelay)
  97   {
  98     int flag= 1;
  99     int error;
 100
 101     error= setsockopt(ptr->fd, IPPROTO_TCP, TCP_NODELAY,
 102                       &flag, (socklen_t)sizeof(int));
 103     WATCHPOINT_ASSERT(error == 0);
 104   }
 105
 106   if (ptr->root->send_size)
 107   {
 108     int error;
 109
 110     error= setsockopt(ptr->fd, SOL_SOCKET, SO_SNDBUF,
 111                       &ptr->root->send_size, (socklen_t)sizeof(int));
 112     WATCHPOINT_ASSERT(error == 0);
 113   }
 114
 115   if (ptr->root->recv_size)
 116   {
 117     int error;
 118
 119     error= setsockopt(ptr->fd, SOL_SOCKET, SO_RCVBUF,
 120                       &ptr->root->recv_size, (socklen_t)sizeof(int));
 121     WATCHPOINT_ASSERT(error == 0);
 122   }
 123
 124   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
 125   int flags;
 126
 127   do
 128     flags= fcntl(ptr->fd, F_GETFL, 0);
 129   while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 130
 131   unlikely (flags == -1)
 132     return MEMCACHED_CONNECTION_FAILURE;
 133   else if ((flags & O_NONBLOCK) == 0)
 134   {
 135     int rval;
 136
 137     do
 138       rval= fcntl(ptr->fd, F_SETFL, flags | O_NONBLOCK);
 139     while (rval == -1 && (errno == EINTR || errno == EAGAIN));
 140
 141     unlikely (rval == -1)
 142       return MEMCACHED_CONNECTION_FAILURE;
 143   }
 144
 145   return MEMCACHED_SUCCESS;
 146 }
 147
 148 static memcached_return_t unix_socket_connect(memcached_server_st *ptr)
 149 {
 150   struct sockaddr_un servAddr;
 151   socklen_t addrlen;
 152
 153   if (ptr->fd == -1)
 154   {
 155     if ((ptr->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 156     {
 157       ptr->cached_errno= errno;
 158       return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 159     }
 160
 161     memset(&servAddr, 0, sizeof (struct sockaddr_un));
 162     servAddr.sun_family= AF_UNIX;
 163     strcpy(servAddr.sun_path, ptr->hostname); /* Copy filename */
 164
 165     addrlen= (socklen_t) (strlen(servAddr.sun_path) + sizeof(servAddr.sun_family));
 166
 167 test_connect:
 168     if (connect(ptr->fd,
 169                 (struct sockaddr *)&servAddr,
 170                 sizeof(servAddr)) < 0)
 171     {
 172       switch (errno)
 173       {
 174       case EINPROGRESS:
 175       case EALREADY:
 176       case EINTR:
 177         goto test_connect;
 178       case EISCONN: /* We were spinning waiting on connect */
 179         break;
 180       default:
 181         WATCHPOINT_ERRNO(errno);
 182         ptr->cached_errno= errno;
 183         return MEMCACHED_ERRNO;
 184       }
 185     }
 186   }
 187
 188   WATCHPOINT_ASSERT(ptr->fd != -1);
 189   return MEMCACHED_SUCCESS;
 190 }
 191
 192 static memcached_return_t network_connect(memcached_server_st *ptr)
 193 {
 194   if (ptr->fd == -1)
 195   {
 196     struct addrinfo *use;
 197
 198     if (!ptr->sockaddr_inited ||
 199         (!(ptr->root->flags.use_cache_lookups)))
 200     {
 201       memcached_return_t rc;
 202
 203       rc= set_hostinfo(ptr);
 204       if (rc != MEMCACHED_SUCCESS)
 205         return rc;
 206       ptr->sockaddr_inited= true;
 207     }
 208
 209     use= ptr->address_info;
 210     /* Create the socket */
 211     while (use != NULL)
 212     {
 213       /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
 214       if (ptr->type == MEMCACHED_CONNECTION_UDP && use->ai_family != AF_INET)
 215       {
 216         use= use->ai_next;
 217         continue;
 218       }
 219
 220       if ((ptr->fd= socket(use->ai_family,
 221                            use->ai_socktype,
 222                            use->ai_protocol)) < 0)
 223       {
 224         ptr->cached_errno= errno;
 225         WATCHPOINT_ERRNO(errno);
 226         return MEMCACHED_CONNECTION_SOCKET_CREATE_FAILURE;
 227       }
 228
 229       (void)set_socket_options(ptr);
 230
 231       /* connect to server */
 232       while (ptr->fd != -1 &&
 233              connect(ptr->fd, use->ai_addr, use->ai_addrlen) < 0)
 234       {
 235         ptr->cached_errno= errno;
 236         if (errno == EINPROGRESS || /* nonblocking mode - first return, */
 237             errno == EALREADY) /* nonblocking mode - subsequent returns */
 238         {
 239           struct pollfd fds[1];
 240           fds[0].fd = ptr->fd;
 241           fds[0].events = POLLOUT;
 242           int error= poll(fds, 1, ptr->root->connect_timeout);
 243
 244           if (error != 1 || fds[0].revents & POLLERR)
 245           {
 246             if (fds[0].revents & POLLERR)
 247             {
 248               int err;
 249               socklen_t len = sizeof (err);
 250               (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
 251               ptr->cached_errno= (err == 0) ? errno : err;
 252             }
 253
 254             (void)close(ptr->fd);
 255             ptr->fd= -1;
 256           }
 257         }
 258         else if (errno == EISCONN) /* we are connected :-) */
 259         {
 260           break;
 261         }
 262         else if (errno != EINTR)
 263         {
 264           (void)close(ptr->fd);
 265           ptr->fd= -1;
 266           break;
 267         }
 268       }
 269
 270       if (ptr->fd != -1)
 271       {
 272         WATCHPOINT_ASSERT(ptr->cursor_active == 0);
 273         ptr->server_failure_counter= 0;
 274         return MEMCACHED_SUCCESS;
 275       }
 276       use = use->ai_next;
 277     }
 278   }
 279
 280   if (ptr->fd == -1)
 281   {
 282     /* Failed to connect. schedule next retry */
 283     if (ptr->root->retry_timeout)
 284     {
 285       struct timeval next_time;
 286
 287       if (gettimeofday(&next_time, NULL) == 0)
 288         ptr->next_retry= next_time.tv_sec + ptr->root->retry_timeout;
 289     }
 290     ptr->server_failure_counter++;
 291     if (ptr->cached_errno == 0)
 292       return MEMCACHED_TIMEOUT;
 293
 294     return MEMCACHED_ERRNO; /* The last error should be from connect() */
 295   }
 296
 297   ptr->server_failure_counter= 0;
 298   return MEMCACHED_SUCCESS; /* The last error should be from connect() */
 299 }
 300
 301
 302 memcached_return_t memcached_connect(memcached_server_st *ptr)
 303 {
 304   memcached_return_t rc= MEMCACHED_NO_SERVERS;
 305   LIBMEMCACHED_MEMCACHED_CONNECT_START();
 306
 307   /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
 308   WATCHPOINT_ASSERT(ptr->root);
 309   if (ptr->root->retry_timeout && ptr->root->server_failure_limit)
 310   {
 311     struct timeval curr_time;
 312
 313     gettimeofday(&curr_time, NULL);
 314
 315     /* if we've had too many consecutive errors on this server, mark it dead. */
 316     if (ptr->server_failure_counter >= ptr->root->server_failure_limit)
 317     {
 318       ptr->next_retry= curr_time.tv_sec + ptr->root->retry_timeout;
 319       ptr->server_failure_counter= 0;
 320     }
 321
 322     if (curr_time.tv_sec < ptr->next_retry)
 323     {
 324       if (memcached_behavior_get(ptr->root, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS))
 325         run_distribution(ptr->root);
 326
 327       ptr->root->last_disconnected_server = ptr;
 328       return MEMCACHED_SERVER_MARKED_DEAD;
 329     }
 330   }
 331
 332   /* We need to clean up the multi startup piece */
 333   switch (ptr->type)
 334   {
 335   case MEMCACHED_CONNECTION_UNKNOWN:
 336     WATCHPOINT_ASSERT(0);
 337     rc= MEMCACHED_NOT_SUPPORTED;
 338     break;
 339   case MEMCACHED_CONNECTION_UDP:
 340   case MEMCACHED_CONNECTION_TCP:
 341     rc= network_connect(ptr);
 342     break;
 343   case MEMCACHED_CONNECTION_UNIX_SOCKET:
 344     rc= unix_socket_connect(ptr);
 345     break;
 346   default:
 347     WATCHPOINT_ASSERT(0);
 348   }
 349
 350   unlikely ( rc != MEMCACHED_SUCCESS) ptr->root->last_disconnected_server = ptr;
 351
 352   LIBMEMCACHED_MEMCACHED_CONNECT_END();
 353
 354   return rc;
 355 }