flexnbd-c/src/flexnbd.c

/*  FlexNBD server (C) Bytemark Hosting 2012

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/** main() function for parsing and dispatching commands.  Each mode has
 *  a corresponding structure which is filled in and passed to a do_ function
 *  elsewhere in the program.
 */

#include "flexnbd.h"
#include "serve.h"
#include "util.h"
#include "control.h"
#include "status.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/signalfd.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>

#include <getopt.h>

#include "acl.h"


int flexnbd_build_signal_fd(void)
{
	sigset_t mask;
	int sfd;

	sigemptyset( &mask );
	sigaddset( &mask, SIGTERM );
	sigaddset( &mask, SIGQUIT );
	sigaddset( &mask, SIGINT );

	FATAL_UNLESS( 0 == pthread_sigmask( SIG_BLOCK, &mask, NULL ),
			"Signal blocking failed" );

	sfd = signalfd( -1, &mask, 0 );
	FATAL_IF( -1 == sfd, "Failed to get a signal fd" );

	return sfd;
}


void flexnbd_create_shared(
	struct flexnbd * flexnbd,
	const char * s_ctrl_sock)
{
	NULLCHECK( flexnbd );
	if ( s_ctrl_sock ){
		flexnbd->control =
			control_create( flexnbd, s_ctrl_sock );
	}
	else {
		flexnbd->control = NULL;
	}

	flexnbd->signal_fd = flexnbd_build_signal_fd();
}


struct flexnbd * flexnbd_create_serving(
	char* s_ip_address,
	char* s_port,
	char* s_file,
	char* s_ctrl_sock,
	int default_deny,
	int acl_entries,
	char** s_acl_entries,
	int max_nbd_clients)
{
	struct flexnbd * flexnbd = xmalloc( sizeof( struct flexnbd ) );
	flexnbd->serve = server_create(
			flexnbd,
			s_ip_address,
			s_port,
			s_file,
			default_deny,
			acl_entries,
			s_acl_entries,
			max_nbd_clients,
			1);
	flexnbd_create_shared( flexnbd,
			s_ctrl_sock );
	return flexnbd;
}


struct flexnbd * flexnbd_create_listening(
		char* s_ip_address,
		char* s_port,
		char* s_file,
		char* s_ctrl_sock,
		int default_deny,
		int acl_entries,
		char** s_acl_entries )
{
	struct flexnbd * flexnbd = xmalloc( sizeof( struct flexnbd ) );
	flexnbd->serve = server_create(
			flexnbd,
			s_ip_address,
			s_port,
			s_file,
			default_deny,
			acl_entries,
			s_acl_entries,
			1, 0);
	flexnbd_create_shared( flexnbd, s_ctrl_sock );
	return flexnbd;
}


struct flexnbd * flexnbd_create_proxying(
	char* s_downstream_address,
	char* s_downstream_port,
	char* s_upstream_address,
	char* s_upstream_port,
	char* s_upstream_bind
)
{
	struct flexnbd * flexnbd = xmalloc( sizeof( struct flexnbd ) );
	flexnbd->proxy = proxy_create(
			flexnbd,
			s_downstream_address,
			s_downstream_port,
			s_upstream_address,
			s_upstream_port,
			s_upstream_bind);
	flexnbd_create_shared( flexnbd, NULL );
	return flexnbd;
}

void flexnbd_spawn_control(struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	NULLCHECK( flexnbd->control );

	pthread_t * control_thread = &flexnbd->control->thread;

	FATAL_UNLESS( 0 == pthread_create(
				control_thread,
				NULL,
				control_runner,
				flexnbd->control ),
			"Couldn't create the control thread" );
}

void flexnbd_stop_control( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	NULLCHECK( flexnbd->control );

	control_signal_close( flexnbd->control );
	pthread_t tid = flexnbd->control->thread;
	FATAL_UNLESS( 0 == pthread_join( tid, NULL ),
		      "Failed joining the control thread" );
	debug( "Control thread %p pthread_join returned", tid );
}


int flexnbd_signal_fd( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	return flexnbd->signal_fd;
}

void flexnbd_destroy( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	if ( flexnbd->control ) {
		control_destroy( flexnbd->control );
	}

	close( flexnbd->signal_fd );
	free( flexnbd );
}


struct server * flexnbd_server( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	return flexnbd->serve;
}

void flexnbd_replace_acl( struct flexnbd * flexnbd, struct acl * acl )
{
	NULLCHECK( flexnbd );
	server_replace_acl( flexnbd_server(flexnbd), acl );
}


struct status * flexnbd_status_create( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	struct status * status;

	status = status_create( flexnbd_server( flexnbd ) );
	return status;
}

void flexnbd_set_server( struct flexnbd * flexnbd, struct server * serve )
{
	NULLCHECK( flexnbd );
	flexnbd->serve = serve;
}


/* Get the default_deny of the current server object. */
int flexnbd_default_deny( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	return server_default_deny( flexnbd->serve );
}


char * flexnbd_incomplete_filename( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	struct server * serve = flexnbd_server( flexnbd );

	return serve->filename_incomplete;
}

void make_writable( const char * filename )
{
	NULLCHECK( filename );
	FATAL_IF_NEGATIVE( chmod( filename, S_IWUSR ),
			"Couldn't chmod %s: %s",
			filename,
			strerror( errno ) );
}


int flexnbd_serve( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	int success;
	struct self_pipe * open_signal = NULL;

	if ( flexnbd->control ){
		debug( "Spawning control thread" );
		flexnbd_spawn_control( flexnbd );
		open_signal = flexnbd->control->open_signal;
	}

	success = do_serve( flexnbd->serve, open_signal );
	debug("do_serve success is %d", success );

	if ( flexnbd->control ) {
		debug( "Stopping control thread" );
		flexnbd_stop_control( flexnbd );
		debug("Control thread stopped");
	}

	return success;
}

int flexnbd_proxy( struct flexnbd * flexnbd )
{
	NULLCHECK( flexnbd );
	int success;

	success = do_proxy( flexnbd->proxy );
	debug("do_proxy success is %d", success );

	return success;
}