samba-mirror/ctdb/tcp/tcp_connect.c

/* 
   ctdb over TCP

   Copyright (C) Andrew Tridgell  2006

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "includes.h"
#include "lib/events/events.h"
#include "lib/tdb/include/tdb.h"
#include "system/network.h"
#include "system/filesys.h"
#include "../include/ctdb_private.h"
#include "ctdb_tcp.h"

static void set_nonblocking(int fd)
{
	unsigned v;
	v = fcntl(fd, F_GETFL, 0);
        fcntl(fd, F_SETFL, v | O_NONBLOCK);
}


/*
  called when a complete packet has come in - should not happen on this socket
 */
static void ctdb_tcp_tnode_cb(uint8_t *data, size_t cnt, void *private)
{
	struct ctdb_node *node = talloc_get_type(private, struct ctdb_node);
	struct ctdb_tcp_node *tnode = talloc_get_type(node->private, 
						      struct ctdb_tcp_node);

	/* start a new connect cycle to try to re-establish the
	   link */
	close(tnode->fd);
	ctdb_queue_set_fd(tnode->queue, -1);
	tnode->fd = -1;
	event_add_timed(node->ctdb->ev, node, timeval_zero(), 
			ctdb_tcp_node_connect, node);
}

/*
  called when socket becomes writeable on connect
*/
static void ctdb_node_connect_write(struct event_context *ev, struct fd_event *fde, 
				    uint16_t flags, void *private)
{
	struct ctdb_node *node = talloc_get_type(private, struct ctdb_node);
	struct ctdb_tcp_node *tnode = talloc_get_type(node->private, 
						      struct ctdb_tcp_node);
	struct ctdb_context *ctdb = node->ctdb;
	int error = 0;
	socklen_t len = sizeof(error);
	int one = 1;

	if (getsockopt(tnode->fd, SOL_SOCKET, SO_ERROR, &error, &len) != 0 ||
	    error != 0) {
		talloc_free(fde);
		close(tnode->fd);
		tnode->fd = -1;
		event_add_timed(ctdb->ev, node, timeval_current_ofs(1, 0), 
				ctdb_tcp_node_connect, node);
		return;
	}

	talloc_free(fde);
	
        setsockopt(tnode->fd,IPPROTO_TCP,TCP_NODELAY,(char *)&one,sizeof(one));

	tnode->queue = ctdb_queue_setup(node->ctdb, node, tnode->fd, CTDB_TCP_ALIGNMENT,
					ctdb_tcp_tnode_cb, node);

	/* tell the ctdb layer we are connected */
	node->ctdb->upcalls->node_connected(node);
}


static int ctdb_tcp_get_address(struct ctdb_context *ctdb,
				const char *address, struct in_addr *addr)
{
	if (inet_pton(AF_INET, address, addr) <= 0) {
		struct hostent *he = gethostbyname(address);
		if (he == NULL || he->h_length > sizeof(*addr)) {
			ctdb_set_error(ctdb, "invalid nework address '%s'\n", 
				       address);
			return -1;
		}
		memcpy(addr, he->h_addr, he->h_length);
	}
	return 0;
}

/*
  called when we should try and establish a tcp connection to a node
*/
void ctdb_tcp_node_connect(struct event_context *ev, struct timed_event *te, 
			   struct timeval t, void *private)
{
	struct ctdb_node *node = talloc_get_type(private, struct ctdb_node);
	struct ctdb_tcp_node *tnode = talloc_get_type(node->private, 
						      struct ctdb_tcp_node);
	struct ctdb_context *ctdb = node->ctdb;
        struct sockaddr_in sock_in;
        struct sockaddr_in sock_out;

	tnode->fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);

	set_nonblocking(tnode->fd);

	if (ctdb_tcp_get_address(ctdb, node->address.address, &sock_out.sin_addr) != 0) {
		return;
	}
	sock_out.sin_port = htons(node->address.port);
	sock_out.sin_family = PF_INET;


	/* Bind our side of the socketpair to the same address we use to listen
	 * on incoming CTDB traffic.
	 * We must specify this address to make sure that the address we expose to
	 * the remote side is actually routable in case CTDB traffic will run on
	 * a dedicated non-routeable network.
	 */
	if (ctdb_tcp_get_address(ctdb, ctdb->address.address, &sock_in.sin_addr) != 0) {
		return;
	}
	sock_in.sin_port = htons(0); /* INPORT_ANY is not always available */
	sock_in.sin_family = PF_INET;
	bind(tnode->fd, (struct sockaddr *)&sock_in, sizeof(sock_in));

	if (connect(tnode->fd, (struct sockaddr *)&sock_out, sizeof(sock_out)) != 0 &&
	    errno != EINPROGRESS) {
		/* try again once a second */
		close(tnode->fd);
		event_add_timed(ctdb->ev, node, timeval_current_ofs(1, 0), 
				ctdb_tcp_node_connect, node);
		return;
	}

	/* non-blocking connect - wait for write event */
	event_add_fd(node->ctdb->ev, node, tnode->fd, EVENT_FD_WRITE|EVENT_FD_READ, 
		     ctdb_node_connect_write, node);
}

/*
  destroy a ctdb_incoming structure 
*/
static int ctdb_incoming_destructor(struct ctdb_incoming *in)
{
	close(in->fd);
	in->fd = -1;
	return 0;
}

/*
  called when we get contacted by another node
  currently makes no attempt to check if the connection is really from a ctdb
  node in our cluster
*/
static void ctdb_listen_event(struct event_context *ev, struct fd_event *fde, 
			      uint16_t flags, void *private)
{
	struct ctdb_context *ctdb;
	struct ctdb_tcp *ctcp;
	struct sockaddr_in addr;
	socklen_t len;
	int fd;
	struct ctdb_incoming *in;

	ctdb = talloc_get_type(private, struct ctdb_context);
	ctcp = talloc_get_type(ctdb->private, struct ctdb_tcp);
	memset(&addr, 0, sizeof(addr));
	len = sizeof(addr);
	fd = accept(ctcp->listen_fd, (struct sockaddr *)&addr, &len);
	if (fd == -1) return;

	in = talloc_zero(ctdb, struct ctdb_incoming);
	in->fd = fd;
	in->ctdb = ctdb;

	set_nonblocking(in->fd);

	in->queue = ctdb_queue_setup(ctdb, in, in->fd, CTDB_TCP_ALIGNMENT, 
				     ctdb_tcp_read_cb, in);

	talloc_set_destructor(in, ctdb_incoming_destructor);
}


/*
  listen on our own address
*/
int ctdb_tcp_listen(struct ctdb_context *ctdb)
{
	struct ctdb_tcp *ctcp = talloc_get_type(ctdb->private, struct ctdb_tcp);
        struct sockaddr_in sock;
	int one = 1;

        sock.sin_port = htons(ctdb->address.port);
        sock.sin_family = PF_INET;
	if (ctdb_tcp_get_address(ctdb, ctdb->address.address, &sock.sin_addr) != 0) {
		return -1;
	}

        ctcp->listen_fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
        if (ctcp->listen_fd == -1) {
		ctdb_set_error(ctdb, "socket failed\n");
		return -1;
        }

        setsockopt(ctcp->listen_fd,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one));

        if (bind(ctcp->listen_fd, (struct sockaddr * )&sock, sizeof(sock)) != 0) {
		ctdb_set_error(ctdb, "bind failed\n");
		close(ctcp->listen_fd);
		ctcp->listen_fd = -1;
                return -1;
        }

	if (listen(ctcp->listen_fd, 10) == -1) {
		ctdb_set_error(ctdb, "listen failed\n");
		close(ctcp->listen_fd);
		ctcp->listen_fd = -1;
		return -1;
	}

	event_add_fd(ctdb->ev, ctdb, ctcp->listen_fd, EVENT_FD_READ, 
		     ctdb_listen_event, ctdb);	

	return 0;
}