ctdb/tcp/tcp_connect.c

   1 /*
   2    ctdb over TCP
   3
   4    Copyright (C) Andrew Tridgell  2006
   5    Copyright (C) Ronnie Sahlberg  2008
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "tdb.h"
  23 #include "system/network.h"
  24 #include "system/filesys.h"
  25 #include "../include/ctdb_private.h"
  26 #include "ctdb_tcp.h"
  27
  28 /*
  29   stop any connecting (established or pending) to a node
  30  */
  31 void ctdb_tcp_stop_connection(struct ctdb_node *node)
  32 {
  33         struct ctdb_tcp_node *tnode = talloc_get_type(
  34                 node->private_data, struct ctdb_tcp_node);
  35
  36         ctdb_queue_set_fd(tnode->out_queue, -1);
  37         talloc_free(tnode->connect_te);
  38         talloc_free(tnode->connect_fde);
  39         tnode->connect_fde = NULL;
  40         tnode->connect_te = NULL;
  41         if (tnode->fd != -1) {
  42                 close(tnode->fd);
  43                 tnode->fd = -1;
  44         }
  45 }
  46
  47
  48 /*
  49   called when a complete packet has come in - should not happen on this socket
  50   unless the other side closes the connection with RST or FIN
  51  */
  52 void ctdb_tcp_tnode_cb(uint8_t *data, size_t cnt, void *private_data)
  53 {
  54         struct ctdb_node *node = talloc_get_type(private_data, struct ctdb_node);
  55         struct ctdb_tcp_node *tnode = talloc_get_type(
  56                 node->private_data, struct ctdb_tcp_node);
  57
  58         if (data == NULL) {
  59                 node->ctdb->upcalls->node_dead(node);
  60         }
  61
  62         ctdb_tcp_stop_connection(node);
  63         tnode->connect_te = event_add_timed(node->ctdb->ev, tnode,
  64                                             timeval_current_ofs(3, 0),
  65                                             ctdb_tcp_node_connect, node);
  66 }
  67
  68 /*
  69   called when socket becomes writeable on connect
  70 */
  71 static void ctdb_node_connect_write(struct event_context *ev, struct fd_event *fde,
  72                                     uint16_t flags, void *private_data)
  73 {
  74         struct ctdb_node *node = talloc_get_type(private_data,
  75                                                  struct ctdb_node);
  76         struct ctdb_tcp_node *tnode = talloc_get_type(node->private_data,
  77                                                       struct ctdb_tcp_node);
  78         struct ctdb_context *ctdb = node->ctdb;
  79         int error = 0;
  80         socklen_t len = sizeof(error);
  81         int one = 1;
  82
  83         talloc_free(tnode->connect_te);
  84         tnode->connect_te = NULL;
  85
  86         if (getsockopt(tnode->fd, SOL_SOCKET, SO_ERROR, &error, &len) != 0 ||
  87             error != 0) {
  88                 ctdb_tcp_stop_connection(node);
  89                 tnode->connect_te = event_add_timed(ctdb->ev, tnode,
  90                                                     timeval_current_ofs(1, 0),
  91                                                     ctdb_tcp_node_connect, node);
  92                 return;
  93         }
  94
  95         talloc_free(tnode->connect_fde);
  96         tnode->connect_fde = NULL;
  97
  98         if (setsockopt(tnode->fd,IPPROTO_TCP,TCP_NODELAY,(char *)&one,sizeof(one)) == -1) {
  99                 DEBUG(DEBUG_WARNING, ("Failed to set TCP_NODELAY on fd - %s\n",
 100                                       strerror(errno)));
 101         }
 102         if (setsockopt(tnode->fd,SOL_SOCKET,SO_KEEPALIVE,(char *)&one,sizeof(one)) == -1) {
 103                 DEBUG(DEBUG_WARNING, ("Failed to set KEEPALIVE on fd - %s\n",
 104                                       strerror(errno)));
 105         }
 106
 107         ctdb_queue_set_fd(tnode->out_queue, tnode->fd);
 108
 109         /* the queue subsystem now owns this fd */
 110         tnode->fd = -1;
 111 }
 112
 113
 114 static int ctdb_tcp_get_address(struct ctdb_context *ctdb,
 115                                 const char *address, ctdb_sock_addr *addr)
 116 {
 117         if (parse_ip(address, NULL, 0, addr) == 0) {
 118                 DEBUG(DEBUG_CRIT, (__location__ " Unparsable address : %s.\n", address));
 119                 return -1;
 120         }
 121         return 0;
 122 }
 123
 124 /*
 125   called when we should try and establish a tcp connection to a node
 126 */
 127 void ctdb_tcp_node_connect(struct event_context *ev, struct timed_event *te,
 128                            struct timeval t, void *private_data)
 129 {
 130         struct ctdb_node *node = talloc_get_type(private_data,
 131                                                  struct ctdb_node);
 132         struct ctdb_tcp_node *tnode = talloc_get_type(node->private_data,
 133                                                       struct ctdb_tcp_node);
 134         struct ctdb_context *ctdb = node->ctdb;
 135         ctdb_sock_addr sock_in;
 136         int sockin_size;
 137         int sockout_size;
 138         ctdb_sock_addr sock_out;
 139
 140         ctdb_tcp_stop_connection(node);
 141
 142         ZERO_STRUCT(sock_out);
 143 #ifdef HAVE_SOCK_SIN_LEN
 144         sock_out.ip.sin_len = sizeof(sock_out);
 145 #endif
 146         if (ctdb_tcp_get_address(ctdb, node->address.address, &sock_out) != 0) {
 147                 return;
 148         }
 149         switch (sock_out.sa.sa_family) {
 150         case AF_INET:
 151                 sock_out.ip.sin_port = htons(node->address.port);
 152                 break;
 153         case AF_INET6:
 154                 sock_out.ip6.sin6_port = htons(node->address.port);
 155                 break;
 156         default:
 157                 DEBUG(DEBUG_ERR, (__location__ " unknown family %u\n",
 158                         sock_out.sa.sa_family));
 159                 return;
 160         }
 161
 162         tnode->fd = socket(sock_out.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 163         if (tnode->fd == -1) {
 164                 DEBUG(DEBUG_ERR, (__location__ "Failed to create socket\n"));
 165                 return;
 166         }
 167         set_nonblocking(tnode->fd);
 168         set_close_on_exec(tnode->fd);
 169
 170         DEBUG(DEBUG_DEBUG, (__location__ " Created TCP SOCKET FD:%d\n", tnode->fd));
 171
 172         /* Bind our side of the socketpair to the same address we use to listen
 173          * on incoming CTDB traffic.
 174          * We must specify this address to make sure that the address we expose to
 175          * the remote side is actually routable in case CTDB traffic will run on
 176          * a dedicated non-routeable network.
 177          */
 178         ZERO_STRUCT(sock_in);
 179         if (ctdb_tcp_get_address(ctdb, ctdb->address.address, &sock_in) != 0) {
 180                 DEBUG(DEBUG_ERR, (__location__ " Failed to find our address. Failing bind.\n"));
 181                 close(tnode->fd);
 182                 return;
 183         }
 184
 185         /* AIX libs check to see if the socket address and length
 186            arguments are consistent with each other on calls like
 187            connect().   Can not get by with just sizeof(sock_in),
 188            need sizeof(sock_in.ip).
 189         */
 190         switch (sock_in.sa.sa_family) {
 191         case AF_INET:
 192                 sockin_size = sizeof(sock_in.ip);
 193                 sockout_size = sizeof(sock_out.ip);
 194                 break;
 195         case AF_INET6:
 196                 sockin_size = sizeof(sock_in.ip6);
 197                 sockout_size = sizeof(sock_out.ip6);
 198                 break;
 199         default:
 200                 DEBUG(DEBUG_ERR, (__location__ " unknown family %u\n",
 201                         sock_in.sa.sa_family));
 202                 close(tnode->fd);
 203                 return;
 204         }
 205 #ifdef HAVE_SOCK_SIN_LEN
 206         sock_in.ip.sin_len = sockin_size;
 207         sock_out.ip.sin_len = sockout_size;
 208 #endif
 209         if (bind(tnode->fd, (struct sockaddr *)&sock_in, sockin_size) == -1) {
 210                 DEBUG(DEBUG_ERR, (__location__ "Failed to bind socket %s(%d)\n",
 211                                   strerror(errno), errno));
 212                 close(tnode->fd);
 213                 return;
 214         }
 215
 216         if (connect(tnode->fd, (struct sockaddr *)&sock_out, sockout_size) != 0 &&
 217             errno != EINPROGRESS) {
 218                 ctdb_tcp_stop_connection(node);
 219                 tnode->connect_te = event_add_timed(ctdb->ev, tnode,
 220                                                     timeval_current_ofs(1, 0),
 221                                                     ctdb_tcp_node_connect, node);
 222                 return;
 223         }
 224
 225         /* non-blocking connect - wait for write event */
 226         tnode->connect_fde = event_add_fd(node->ctdb->ev, tnode, tnode->fd,
 227                                           EVENT_FD_WRITE|EVENT_FD_READ,
 228                                           ctdb_node_connect_write, node);
 229
 230         /* don't give it long to connect - retry in one second. This ensures
 231            that we find a node is up quickly (tcp normally backs off a syn reply
 232            delay by quite a lot) */
 233         tnode->connect_te = event_add_timed(ctdb->ev, tnode, timeval_current_ofs(1, 0),
 234                                             ctdb_tcp_node_connect, node);
 235 }
 236
 237 /*
 238   called when we get contacted by another node
 239   currently makes no attempt to check if the connection is really from a ctdb
 240   node in our cluster
 241 */
 242 static void ctdb_listen_event(struct event_context *ev, struct fd_event *fde,
 243                               uint16_t flags, void *private_data)
 244 {
 245         struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
 246         struct ctdb_tcp *ctcp = talloc_get_type(ctdb->private_data, struct ctdb_tcp);
 247         ctdb_sock_addr addr;
 248         socklen_t len;
 249         int fd, nodeid;
 250         struct ctdb_incoming *in;
 251         int one = 1;
 252         const char *incoming_node;
 253
 254         memset(&addr, 0, sizeof(addr));
 255         len = sizeof(addr);
 256         fd = accept(ctcp->listen_fd, (struct sockaddr *)&addr, &len);
 257         if (fd == -1) return;
 258
 259         incoming_node = ctdb_addr_to_str(&addr);
 260         nodeid = ctdb_ip_to_nodeid(ctdb, incoming_node);
 261
 262         if (nodeid == -1) {
 263                 DEBUG(DEBUG_ERR, ("Refused connection from unknown node %s\n", incoming_node));
 264                 close(fd);
 265                 return;
 266         }
 267
 268         in = talloc_zero(ctcp, struct ctdb_incoming);
 269         in->fd = fd;
 270         in->ctdb = ctdb;
 271
 272         set_nonblocking(in->fd);
 273         set_close_on_exec(in->fd);
 274
 275         DEBUG(DEBUG_DEBUG, (__location__ " Created SOCKET FD:%d to incoming ctdb connection\n", fd));
 276
 277         if (setsockopt(in->fd,SOL_SOCKET,SO_KEEPALIVE,(char *)&one,sizeof(one)) == -1) {
 278                 DEBUG(DEBUG_WARNING, ("Failed to set KEEPALIVE on fd - %s\n",
 279                                       strerror(errno)));
 280         }
 281
 282         in->queue = ctdb_queue_setup(ctdb, in, in->fd, CTDB_TCP_ALIGNMENT,
 283                                      ctdb_tcp_read_cb, in, "ctdbd-%s", incoming_node);
 284 }
 285
 286
 287 /*
 288   automatically find which address to listen on
 289 */
 290 static int ctdb_tcp_listen_automatic(struct ctdb_context *ctdb)
 291 {
 292         struct ctdb_tcp *ctcp = talloc_get_type(ctdb->private_data,
 293                                                 struct ctdb_tcp);
 294         ctdb_sock_addr sock;
 295         int lock_fd, i;
 296         const char *lock_path = VARDIR "/run/ctdb/.socket_lock";
 297         struct flock lock;
 298         int one = 1;
 299         int sock_size;
 300         struct tevent_fd *fde;
 301
 302         /* If there are no nodes, then it won't be possible to find
 303          * the first one.  Log a failure and short circuit the whole
 304          * process.
 305          */
 306         if (ctdb->num_nodes == 0) {
 307                 DEBUG(DEBUG_CRIT,("No nodes available to attempt bind to - is the nodes file empty?\n"));
 308                 return -1;
 309         }
 310
 311         /* in order to ensure that we don't get two nodes with the
 312            same adddress, we must make the bind() and listen() calls
 313            atomic. The SO_REUSEADDR setsockopt only prevents double
 314            binds if the first socket is in LISTEN state  */
 315         lock_fd = open(lock_path, O_RDWR|O_CREAT, 0666);
 316         if (lock_fd == -1) {
 317                 DEBUG(DEBUG_CRIT,("Unable to open %s\n", lock_path));
 318                 return -1;
 319         }
 320
 321         lock.l_type = F_WRLCK;
 322         lock.l_whence = SEEK_SET;
 323         lock.l_start = 0;
 324         lock.l_len = 1;
 325         lock.l_pid = 0;
 326
 327         if (fcntl(lock_fd, F_SETLKW, &lock) != 0) {
 328                 DEBUG(DEBUG_CRIT,("Unable to lock %s\n", lock_path));
 329                 close(lock_fd);
 330                 return -1;
 331         }
 332
 333         for (i=0; i < ctdb->num_nodes; i++) {
 334                 if (ctdb->nodes[i]->flags & NODE_FLAGS_DELETED) {
 335                         continue;
 336                 }
 337                 ZERO_STRUCT(sock);
 338                 if (ctdb_tcp_get_address(ctdb,
 339                                 ctdb->nodes[i]->address.address,
 340                                 &sock) != 0) {
 341                         continue;
 342                 }
 343
 344                 switch (sock.sa.sa_family) {
 345                 case AF_INET:
 346                         sock.ip.sin_port = htons(ctdb->nodes[i]->address.port);
 347                         sock_size = sizeof(sock.ip);
 348                         break;
 349                 case AF_INET6:
 350                         sock.ip6.sin6_port = htons(ctdb->nodes[i]->address.port);
 351                         sock_size = sizeof(sock.ip6);
 352                         break;
 353                 default:
 354                         DEBUG(DEBUG_ERR, (__location__ " unknown family %u\n",
 355                                 sock.sa.sa_family));
 356                         continue;
 357                 }
 358 #ifdef HAVE_SOCK_SIN_LEN
 359                 sock.ip.sin_len = sock_size;
 360 #endif
 361
 362                 ctcp->listen_fd = socket(sock.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 363                 if (ctcp->listen_fd == -1) {
 364                         ctdb_set_error(ctdb, "socket failed\n");
 365                         continue;
 366                 }
 367
 368                 set_close_on_exec(ctcp->listen_fd);
 369
 370                 if (setsockopt(ctcp->listen_fd,SOL_SOCKET,SO_REUSEADDR,
 371                                (char *)&one,sizeof(one)) == -1) {
 372                         DEBUG(DEBUG_WARNING, ("Failed to set REUSEADDR on fd - %s\n",
 373                                               strerror(errno)));
 374                 }
 375
 376                 if (bind(ctcp->listen_fd, (struct sockaddr * )&sock, sock_size) == 0) {
 377                         break;
 378                 }
 379
 380                 if (errno == EADDRNOTAVAIL) {
 381                         DEBUG(DEBUG_DEBUG,(__location__ " Failed to bind() to socket. %s(%d)\n",
 382                                         strerror(errno), errno));
 383                 } else {
 384                         DEBUG(DEBUG_ERR,(__location__ " Failed to bind() to socket. %s(%d)\n",
 385                                         strerror(errno), errno));
 386                 }
 387         }
 388
 389         if (i == ctdb->num_nodes) {
 390                 DEBUG(DEBUG_CRIT,("Unable to bind to any of the node addresses - giving up\n"));
 391                 goto failed;
 392         }
 393         ctdb->address.address = talloc_strdup(ctdb, ctdb->nodes[i]->address.address);
 394         ctdb->address.port    = ctdb->nodes[i]->address.port;
 395         ctdb->name = talloc_asprintf(ctdb, "%s:%u",
 396                                      ctdb->address.address,
 397                                      ctdb->address.port);
 398         ctdb->pnn = ctdb->nodes[i]->pnn;
 399         DEBUG(DEBUG_INFO,("ctdb chose network address %s:%u pnn %u\n",
 400                  ctdb->address.address,
 401                  ctdb->address.port,
 402                  ctdb->pnn));
 403
 404         if (listen(ctcp->listen_fd, 10) == -1) {
 405                 goto failed;
 406         }
 407
 408         fde = event_add_fd(ctdb->ev, ctcp, ctcp->listen_fd, EVENT_FD_READ,
 409                            ctdb_listen_event, ctdb);
 410         tevent_fd_set_auto_close(fde);
 411
 412         close(lock_fd);
 413
 414         return 0;
 415
 416 failed:
 417         close(lock_fd);
 418         if (ctcp->listen_fd != -1) {
 419                 close(ctcp->listen_fd);
 420                 ctcp->listen_fd = -1;
 421         }
 422         return -1;
 423 }
 424
 425
 426 /*
 427   listen on our own address
 428 */
 429 int ctdb_tcp_listen(struct ctdb_context *ctdb)
 430 {
 431         struct ctdb_tcp *ctcp = talloc_get_type(ctdb->private_data,
 432                                                 struct ctdb_tcp);
 433         ctdb_sock_addr sock;
 434         int sock_size;
 435         int one = 1;
 436         struct tevent_fd *fde;
 437
 438         /* we can either auto-bind to the first available address, or we can
 439            use a specified address */
 440         if (!ctdb->address.address) {
 441                 return ctdb_tcp_listen_automatic(ctdb);
 442         }
 443
 444         ZERO_STRUCT(sock);
 445         if (ctdb_tcp_get_address(ctdb, ctdb->address.address,
 446                                  &sock) != 0) {
 447                 goto failed;
 448         }
 449
 450         switch (sock.sa.sa_family) {
 451         case AF_INET:
 452                 sock.ip.sin_port = htons(ctdb->address.port);
 453                 sock_size = sizeof(sock.ip);
 454                 break;
 455         case AF_INET6:
 456                 sock.ip6.sin6_port = htons(ctdb->address.port);
 457                 sock_size = sizeof(sock.ip6);
 458                 break;
 459         default:
 460                 DEBUG(DEBUG_ERR, (__location__ " unknown family %u\n",
 461                         sock.sa.sa_family));
 462                 goto failed;
 463         }
 464 #ifdef HAVE_SOCK_SIN_LEN
 465         sock.ip.sin_len = sock_size;
 466 #endif
 467
 468         ctcp->listen_fd = socket(sock.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 469         if (ctcp->listen_fd == -1) {
 470                 ctdb_set_error(ctdb, "socket failed\n");
 471                 return -1;
 472         }
 473
 474         set_close_on_exec(ctcp->listen_fd);
 475
 476         if (setsockopt(ctcp->listen_fd,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)) == -1) {
 477                 DEBUG(DEBUG_WARNING, ("Failed to set REUSEADDR on fd - %s\n",
 478                                       strerror(errno)));
 479         }
 480
 481         if (bind(ctcp->listen_fd, (struct sockaddr * )&sock, sock_size) != 0) {
 482                 DEBUG(DEBUG_ERR,(__location__ " Failed to bind() to socket. %s(%d)\n", strerror(errno), errno));
 483                 goto failed;
 484         }
 485
 486         if (listen(ctcp->listen_fd, 10) == -1) {
 487                 goto failed;
 488         }
 489
 490         fde = event_add_fd(ctdb->ev, ctcp, ctcp->listen_fd, EVENT_FD_READ,
 491                      ctdb_listen_event, ctdb);
 492         tevent_fd_set_auto_close(fde);
 493
 494         return 0;
 495
 496 failed:
 497         if (ctcp->listen_fd != -1) {
 498                 close(ctcp->listen_fd);
 499         }
 500         ctcp->listen_fd = -1;
 501         return -1;
 502 }
 503