ctdb/tcp/tcp_connect.c

   1 /*
   2    ctdb over TCP
   3
   4    Copyright (C) Andrew Tridgell  2006
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "lib/events/events.h"
  22 #include "lib/tdb/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  */
  51 void ctdb_tcp_tnode_cb(uint8_t *data, size_t cnt, void *private_data)
  52 {
  53         struct ctdb_node *node = talloc_get_type(private_data, struct ctdb_node);
  54         struct ctdb_tcp_node *tnode = talloc_get_type(
  55                 node->private_data, struct ctdb_tcp_node);
  56
  57         if (data == NULL) {
  58                 node->ctdb->upcalls->node_dead(node);
  59         }
  60
  61         ctdb_tcp_stop_connection(node);
  62         tnode->connect_te = event_add_timed(node->ctdb->ev, tnode, timeval_zero(),
  63                                             ctdb_tcp_node_connect, node);
  64 }
  65
  66 /*
  67   called when socket becomes writeable on connect
  68 */
  69 static void ctdb_node_connect_write(struct event_context *ev, struct fd_event *fde,
  70                                     uint16_t flags, void *private_data)
  71 {
  72         struct ctdb_node *node = talloc_get_type(private_data,
  73                                                  struct ctdb_node);
  74         struct ctdb_tcp_node *tnode = talloc_get_type(node->private_data,
  75                                                       struct ctdb_tcp_node);
  76         struct ctdb_context *ctdb = node->ctdb;
  77         int error = 0;
  78         socklen_t len = sizeof(error);
  79         int one = 1;
  80
  81         talloc_free(tnode->connect_te);
  82         tnode->connect_te = NULL;
  83
  84         if (getsockopt(tnode->fd, SOL_SOCKET, SO_ERROR, &error, &len) != 0 ||
  85             error != 0) {
  86                 ctdb_tcp_stop_connection(node);
  87                 tnode->connect_te = event_add_timed(ctdb->ev, tnode,
  88                                                     timeval_current_ofs(1, 0),
  89                                                     ctdb_tcp_node_connect, node);
  90                 return;
  91         }
  92
  93         talloc_free(tnode->connect_fde);
  94         tnode->connect_fde = NULL;
  95
  96         setsockopt(tnode->fd,IPPROTO_TCP,TCP_NODELAY,(char *)&one,sizeof(one));
  97         setsockopt(tnode->fd,SOL_SOCKET,SO_KEEPALIVE,(char *)&one,sizeof(one));
  98
  99         ctdb_queue_set_fd(tnode->out_queue, tnode->fd);
 100
 101         /* the queue subsystem now owns this fd */
 102         tnode->fd = -1;
 103 }
 104
 105
 106 static int ctdb_tcp_get_address(struct ctdb_context *ctdb,
 107                                 const char *address, ctdb_sock_addr *addr)
 108 {
 109         if (parse_ip(address, addr) == 0) {
 110                 DEBUG(DEBUG_CRIT, (__location__ " Unparsable address : %s.\n", address));
 111                 return -1;
 112         }
 113         return 0;
 114 }
 115
 116 /*
 117   called when we should try and establish a tcp connection to a node
 118 */
 119 void ctdb_tcp_node_connect(struct event_context *ev, struct timed_event *te,
 120                            struct timeval t, void *private_data)
 121 {
 122         struct ctdb_node *node = talloc_get_type(private_data,
 123                                                  struct ctdb_node);
 124         struct ctdb_tcp_node *tnode = talloc_get_type(node->private_data,
 125                                                       struct ctdb_tcp_node);
 126         struct ctdb_context *ctdb = node->ctdb;
 127         ctdb_sock_addr sock_in;
 128         ctdb_sock_addr sock_out;
 129
 130         ctdb_tcp_stop_connection(node);
 131
 132         ZERO_STRUCT(sock_out);
 133 #ifdef HAVE_SOCK_SIN_LEN
 134         sock_out.ip.sin_len = sizeof(sock_out);
 135 #endif
 136         if (ctdb_tcp_get_address(ctdb, node->address.address, &sock_out) != 0) {
 137                 return;
 138         }
 139         switch (sock_out.sa.sa_family) {
 140         case AF_INET:
 141                 sock_out.ip.sin_port = htons(node->address.port);
 142                 break;
 143         case AF_INET6:
 144                 sock_out.ip6.sin6_port = htons(node->address.port);
 145                 break;
 146         default:
 147                 DEBUG(DEBUG_ERR, (__location__ " unknown family %u\n",
 148                         sock_out.sa.sa_family));
 149                 return;
 150         }
 151
 152         tnode->fd = socket(sock_out.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 153         set_nonblocking(tnode->fd);
 154         set_close_on_exec(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         ZERO_STRUCT(sock_in);
 163 #ifdef HAVE_SOCK_SIN_LEN
 164         sock_in.ip.sin_len = sizeof(sock_in);
 165 #endif
 166         if (ctdb_tcp_get_address(ctdb, ctdb->address.address, &sock_in) != 0) {
 167                 return;
 168         }
 169         bind(tnode->fd, (struct sockaddr *)&sock_in, sizeof(sock_in));
 170
 171         if (connect(tnode->fd, (struct sockaddr *)&sock_out, sizeof(sock_out)) != 0 &&
 172             errno != EINPROGRESS) {
 173                 ctdb_tcp_stop_connection(node);
 174                 tnode->connect_te = event_add_timed(ctdb->ev, tnode,
 175                                                     timeval_current_ofs(1, 0),
 176                                                     ctdb_tcp_node_connect, node);
 177                 return;
 178         }
 179
 180         /* non-blocking connect - wait for write event */
 181         tnode->connect_fde = event_add_fd(node->ctdb->ev, tnode, tnode->fd,
 182                                           EVENT_FD_WRITE|EVENT_FD_READ,
 183                                           ctdb_node_connect_write, node);
 184
 185         /* don't give it long to connect - retry in one second. This ensures
 186            that we find a node is up quickly (tcp normally backs off a syn reply
 187            delay by quite a lot) */
 188         tnode->connect_te = event_add_timed(ctdb->ev, tnode, timeval_current_ofs(1, 0),
 189                                             ctdb_tcp_node_connect, node);
 190 }
 191
 192 /*
 193   called when we get contacted by another node
 194   currently makes no attempt to check if the connection is really from a ctdb
 195   node in our cluster
 196 */
 197 static void ctdb_listen_event(struct event_context *ev, struct fd_event *fde,
 198                               uint16_t flags, void *private_data)
 199 {
 200         struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
 201         struct ctdb_tcp *ctcp = talloc_get_type(ctdb->private_data, struct ctdb_tcp);
 202         ctdb_sock_addr addr;
 203         socklen_t len;
 204         int fd, nodeid;
 205         struct ctdb_incoming *in;
 206         int one = 1;
 207         const char *incoming_node;
 208
 209         memset(&addr, 0, sizeof(addr));
 210         len = sizeof(addr);
 211         fd = accept(ctcp->listen_fd, (struct sockaddr *)&addr, &len);
 212         if (fd == -1) return;
 213
 214         incoming_node = ctdb_addr_to_str(&addr);
 215         nodeid = ctdb_ip_to_nodeid(ctdb, incoming_node);
 216
 217         if (nodeid == -1) {
 218                 DEBUG(DEBUG_ERR, ("Refused connection from unknown node %s\n", incoming_node));
 219                 close(fd);
 220                 return;
 221         }
 222
 223         in = talloc_zero(ctcp, struct ctdb_incoming);
 224         in->fd = fd;
 225         in->ctdb = ctdb;
 226
 227         set_nonblocking(in->fd);
 228         set_close_on_exec(in->fd);
 229
 230         setsockopt(in->fd,SOL_SOCKET,SO_KEEPALIVE,(char *)&one,sizeof(one));
 231
 232         in->queue = ctdb_queue_setup(ctdb, in, in->fd, CTDB_TCP_ALIGNMENT,
 233                                      ctdb_tcp_read_cb, in);
 234 }
 235
 236
 237 /*
 238   automatically find which address to listen on
 239 */
 240 static int ctdb_tcp_listen_automatic(struct ctdb_context *ctdb)
 241 {
 242         struct ctdb_tcp *ctcp = talloc_get_type(ctdb->private_data,
 243                                                 struct ctdb_tcp);
 244         ctdb_sock_addr sock;
 245         int lock_fd, i;
 246         const char *lock_path = "/tmp/.ctdb_socket_lock";
 247         struct flock lock;
 248         int one = 1;
 249
 250         /* in order to ensure that we don't get two nodes with the
 251            same adddress, we must make the bind() and listen() calls
 252            atomic. The SO_REUSEADDR setsockopt only prevents double
 253            binds if the first socket is in LISTEN state  */
 254         lock_fd = open(lock_path, O_RDWR|O_CREAT, 0666);
 255         if (lock_fd == -1) {
 256                 DEBUG(DEBUG_CRIT,("Unable to open %s\n", lock_path));
 257                 return -1;
 258         }
 259
 260         lock.l_type = F_WRLCK;
 261         lock.l_whence = SEEK_SET;
 262         lock.l_start = 0;
 263         lock.l_len = 1;
 264         lock.l_pid = 0;
 265
 266         if (fcntl(lock_fd, F_SETLKW, &lock) != 0) {
 267                 DEBUG(DEBUG_CRIT,("Unable to lock %s\n", lock_path));
 268                 close(lock_fd);
 269                 return -1;
 270         }
 271
 272         for (i=0;i<ctdb->num_nodes;i++) {
 273                 /* if node_ip is specified we will only try to bind to that
 274                    ip.
 275                 */
 276                 if (ctdb->node_ip != NULL) {
 277                         if (strcmp(ctdb->node_ip, ctdb->nodes[i]->address.address)) {
 278                                 continue;
 279                         }
 280                 }
 281
 282                 ZERO_STRUCT(sock);
 283 #ifdef HAVE_SOCK_SIN_LEN
 284                 sock.ip.sin_len = sizeof(sock);
 285 #endif
 286                 if (ctdb_tcp_get_address(ctdb,
 287                                 ctdb->nodes[i]->address.address,
 288                                 &sock) != 0) {
 289                         continue;
 290                 }
 291
 292                 switch (sock.sa.sa_family) {
 293                 case AF_INET:
 294                         sock.ip.sin_port = htons(ctdb->nodes[i]->address.port);
 295                         break;
 296                 case AF_INET6:
 297                         sock.ip6.sin6_port = htons(ctdb->nodes[i]->address.port);
 298                         break;
 299                 default:
 300                         DEBUG(DEBUG_ERR, (__location__ " unknown family %u\n",
 301                                 sock.sa.sa_family));
 302                         continue;
 303                 }
 304
 305                 ctcp->listen_fd = socket(sock.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 306                 if (ctcp->listen_fd == -1) {
 307                         ctdb_set_error(ctdb, "socket failed\n");
 308                         continue;
 309                 }
 310
 311                 set_close_on_exec(ctcp->listen_fd);
 312
 313                 setsockopt(ctcp->listen_fd,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one));
 314
 315                 if (bind(ctcp->listen_fd, (struct sockaddr * )&sock,
 316                          sizeof(sock)) == 0) {
 317                         break;
 318                 }
 319         }
 320
 321         if (i == ctdb->num_nodes) {
 322                 DEBUG(DEBUG_CRIT,("Unable to bind to any of the node addresses - giving up\n"));
 323                 goto failed;
 324         }
 325         ctdb->address.address = talloc_strdup(ctdb, ctdb->nodes[i]->address.address);
 326         ctdb->address.port    = ctdb->nodes[i]->address.port;
 327         ctdb->name = talloc_asprintf(ctdb, "%s:%u",
 328                                      ctdb->address.address,
 329                                      ctdb->address.port);
 330         ctdb->pnn = ctdb->nodes[i]->pnn;
 331         ctdb->nodes[i]->flags &= ~NODE_FLAGS_DISCONNECTED;
 332         DEBUG(DEBUG_INFO,("ctdb chose network address %s:%u pnn %u\n",
 333                  ctdb->address.address,
 334                  ctdb->address.port,
 335                  ctdb->pnn));
 336         /* do we start out in DISABLED mode? */
 337         if (ctdb->start_as_disabled != 0) {
 338                 DEBUG(DEBUG_INFO, ("This node is configured to start in DISABLED state\n"));
 339                 ctdb->nodes[i]->flags |= NODE_FLAGS_DISABLED;
 340         }
 341
 342         if (listen(ctcp->listen_fd, 10) == -1) {
 343                 goto failed;
 344         }
 345
 346         event_add_fd(ctdb->ev, ctcp, ctcp->listen_fd, EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
 347                      ctdb_listen_event, ctdb);
 348
 349         close(lock_fd);
 350         return 0;
 351
 352 failed:
 353         close(lock_fd);
 354         close(ctcp->listen_fd);
 355         ctcp->listen_fd = -1;
 356         return -1;
 357 }
 358
 359
 360 /*
 361   listen on our own address
 362 */
 363 int ctdb_tcp_listen(struct ctdb_context *ctdb)
 364 {
 365         struct ctdb_tcp *ctcp = talloc_get_type(ctdb->private_data,
 366                                                 struct ctdb_tcp);
 367         ctdb_sock_addr sock;
 368         int one = 1;
 369
 370         /* we can either auto-bind to the first available address, or we can
 371            use a specified address */
 372         if (!ctdb->address.address) {
 373                 return ctdb_tcp_listen_automatic(ctdb);
 374         }
 375
 376         ZERO_STRUCT(sock);
 377 #ifdef HAVE_SOCK_SIN_LEN
 378         sock.ip.sin_len = sizeof(sock);
 379 #endif
 380         if (ctdb_tcp_get_address(ctdb, ctdb->address.address,
 381                                  &sock) != 0) {
 382                 goto failed;
 383         }
 384
 385         switch (sock.sa.sa_family) {
 386         case AF_INET:
 387                 sock.ip.sin_port = htons(ctdb->address.port);
 388                 break;
 389         case AF_INET6:
 390                 sock.ip6.sin6_port = htons(ctdb->address.port);
 391                 break;
 392         default:
 393                 DEBUG(DEBUG_ERR, (__location__ " unknown family %u\n",
 394                         sock.sa.sa_family));
 395                 goto failed;
 396         }
 397
 398         ctcp->listen_fd = socket(sock.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
 399         if (ctcp->listen_fd == -1) {
 400                 ctdb_set_error(ctdb, "socket failed\n");
 401                 return -1;
 402         }
 403
 404         set_close_on_exec(ctcp->listen_fd);
 405
 406         setsockopt(ctcp->listen_fd,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one));
 407
 408         if (bind(ctcp->listen_fd, (struct sockaddr * )&sock, sizeof(sock)) != 0) {
 409                 goto failed;
 410         }
 411
 412         if (listen(ctcp->listen_fd, 10) == -1) {
 413                 goto failed;
 414         }
 415
 416         event_add_fd(ctdb->ev, ctcp, ctcp->listen_fd, EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
 417                      ctdb_listen_event, ctdb);
 418
 419         return 0;
 420
 421 failed:
 422         if (ctcp->listen_fd != -1) {
 423                 close(ctcp->listen_fd);
 424         }
 425         ctcp->listen_fd = -1;
 426         return -1;
 427 }
 428