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