path: root/src/server/server.c

/*
 * This file is part of the Distributed Network Block Device 3
 *
 * Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
 *
 * This file may be licensed under the terms of of the
 * GNU General Public License Version 2 (the ``GPL'').
 *
 * Software distributed under the License is distributed
 * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
 * express or implied. See the GPL for the specific language
 * governing rights and limitations.
 *
 * You should have received a copy of the GPL along with this
 * program. If not, go to http://www.gnu.org/licenses/gpl.html
 * or write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <signal.h>
#include <getopt.h>
#include <pthread.h>
#include <string.h>
#include <fcntl.h>

#include "../types.h"
#include "../version.h"

#include "server.h"
#include "utils.h"
#include "net.h"
#include "ipc.h"
#include "memlog.h"

static int sock;
#ifdef _DEBUG
int _fake_delay = 0;
#endif
pthread_spinlock_t _spinlock;

GSList *_dnbd3_clients = NULL;
char *_config_file_name = DEFAULT_SERVER_CONFIG_FILE;
char *_local_namespace = NULL;
char *_ipc_password = NULL;
GSList *_dnbd3_images = NULL; // of dnbd3_image_t

void dnbd3_print_help(char* argv_0)
{
    printf("Usage: %s [OPTIONS]...\n", argv_0);
    printf("Start the DNBD3 server\n");
    printf("-f or --file        Configuration file (default /etc/dnbd3-server.conf)\n");
#ifdef _DEBUG
    printf("-d or --delay       Add a fake network delay of X µs\n");
#endif
    printf("-n or --nodaemon    Start server in foreground\n");
    printf("-r or --reload      Reload configuration file\n");
    printf("-s or --stop        Stop running dnbd3-server\n");
    printf("-i or --info        Print connected clients and used images\n");
    printf("-H or --help        Show this help text and quit\n");
    printf("-V or --version     Show version and quit\n");
    exit(0);
}

void dnbd3_print_version()
{
    printf("Version: %s\n", VERSION_STRING);
    exit(0);
}

void dnbd3_cleanup()
{
    int fd;
    memlogf("INFO: Cleanup...\n");

    close(sock);
    sock = -1;

    dnbd3_ipc_shutdown();

    pthread_spin_lock(&_spinlock);
    GSList *iterator = NULL;
    for (iterator = _dnbd3_clients; iterator; iterator = iterator->next)
    {
        dnbd3_client_t *client = iterator->data;
        shutdown(client->sock, SHUT_RDWR);
        pthread_join(client->thread, NULL);
        g_free(client);
    }
    g_slist_free(_dnbd3_clients);


    for (iterator = _dnbd3_images; iterator; iterator = iterator->next)
    {
    	// save cache maps to files
    	dnbd3_image_t *image = iterator->data;
        if (image->cache_file)
        {
            char tmp[strlen(image->cache_file)+4];
            strcpy(tmp, image->cache_file);
            strcat(tmp, ".map");
            fd = open(tmp, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);

            if (fd > 0)
                write(fd, image->cache_map,  ((image->filesize + (1 << 15) - 1) >> 15) * sizeof(char));

            close(fd);
        }

     	free(image->cache_map);
     	free(image->config_group);
     	free(image->low_name);
     	free(image->file);
     	free(image->cache_file);
     	g_free(image);
    }
    g_slist_free(_dnbd3_images);

    pthread_spin_unlock(&_spinlock);
#ifndef IPC_TCP
    unlink(UNIX_SOCKET);
#endif
    exit(EXIT_SUCCESS);
}

int main(int argc, char* argv[])
{
    int demonize = 1;
    int opt = 0;
    int longIndex = 0;
    static const char *optString = "f:d:nrsiHV?";
    static const struct option longOpts[] =
    {
    { "file", required_argument, NULL, 'f' },
    { "delay", required_argument, NULL, 'd' },
    { "nodaemon", no_argument, NULL, 'n' },
    { "reload", no_argument, NULL, 'r' },
    { "stop", no_argument, NULL, 's' },
    { "info", no_argument, NULL, 'i' },
    { "help", no_argument, NULL, 'H' },
    { "version", no_argument, NULL, 'V' } };

    opt = getopt_long(argc, argv, optString, longOpts, &longIndex);

    while (opt != -1)
    {
        switch (opt)
        {
        case 'f':
            _config_file_name = strdup(optarg);
            break;
        case 'd':
#ifdef _DEBUG
        	_fake_delay = atoi(optarg);
        	break;
#else
        	printf("This option is only available in debug builds.\n\n");
        	return EXIT_FAILURE;
#endif
        case 'n':
            demonize = 0;
            break;
        case 'r':
             printf("INFO: Reloading configuration file...\n\n");
             dnbd3_ipc_send(IPC_RELOAD);
            return EXIT_SUCCESS;
        case 's':
            printf("INFO: Stopping running server...\n\n");
            dnbd3_ipc_send(IPC_EXIT);
            return EXIT_SUCCESS;
        case 'i':
            printf("INFO: Requesting information...\n\n");
            dnbd3_ipc_send(IPC_INFO);
            return EXIT_SUCCESS;
        case 'H':
            dnbd3_print_help(argv[0]);
            break;
        case 'V':
            dnbd3_print_version();
            break;
        case '?':
            dnbd3_print_help(argv[0]);
            break;
        }
        opt = getopt_long(argc, argv, optString, longOpts, &longIndex);
    }

    if (demonize)
        daemon(1, 0);

    pthread_spin_init(&_spinlock, PTHREAD_PROCESS_PRIVATE);

    initmemlog();
    memlogf("DNBD3 server starting.... Machine type: " ENDIAN_MODE);

    // load config file
    dnbd3_load_config();

    // setup signal handler
    signal(SIGPIPE, dnbd3_handle_sigpipe);
    signal(SIGTERM, dnbd3_handle_sigterm);
    signal(SIGINT, dnbd3_handle_sigterm);

    // setup network
    sock = dnbd3_setup_socket();
    if (sock < 0)
        exit(EXIT_FAILURE);
    struct sockaddr_in client;
    unsigned int len = sizeof(client);
    int fd;
    time_t next_delete_invocation = 0;
    struct timeval timeout;
    timeout.tv_sec = SOCKET_TIMEOUT_SERVER;
    timeout.tv_usec = 0;

    // setup ipc
    pthread_t thread_ipc;
    pthread_create(&(thread_ipc), NULL, &dnbd3_ipc_mainloop, NULL);

    memlogf("[INFO] Server is ready...");

    // main loop
    while (1)
    {
        fd = accept(sock, (struct sockaddr*) &client, &len);
        if (fd < 0)
        {
        	memlogf("[ERROR] Accept failure");
            continue;
        }
        //memlogf("INFO: Client %s connected\n", inet_ntoa(client.sin_addr));

        setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *) &timeout, sizeof(timeout));
        setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, (char *) &timeout, sizeof(timeout));

        dnbd3_client_t *dnbd3_client = g_new0(dnbd3_client_t, 1);
        if (dnbd3_client == NULL)
        {
        	memlogf("[ERROR] Could not alloc dnbd3_client_t for new client.");
        	close(fd);
        	continue;
        }
        // TODO: Extend this if you ever want to add IPv6 (something like:)
        // dnbd3_client->addrtype = AF_INET6;
        // memcpy(dnbd3_client->ipaddr, &(client.sin6_addr), 16);
        dnbd3_client->addrtype = AF_INET;
        memcpy(dnbd3_client->ipaddr, &(client.sin_addr), 4);
        dnbd3_client->sock = fd;
        dnbd3_client->image = NULL;

        // This has to be done before creating the thread, otherwise a race condition might occur when the new thread dies faster than this thread adds the client to the list after creating the thread
        pthread_spin_lock(&_spinlock);
        _dnbd3_clients = g_slist_prepend(_dnbd3_clients, dnbd3_client);
        pthread_spin_unlock(&_spinlock);

        if (0 != pthread_create(&(dnbd3_client->thread), NULL, dnbd3_handle_query, (void *) (uintptr_t) dnbd3_client))
        {
        	memlogf("[ERROR] Could not start thread for new client.");
            pthread_spin_lock(&_spinlock);
            _dnbd3_clients = g_slist_remove(_dnbd3_clients, dnbd3_client);
            pthread_spin_unlock(&_spinlock);
            g_free(dnbd3_client);
        	close(fd);
        	continue;
        }
        pthread_detach(dnbd3_client->thread);
        // Call image deletion function if last call is more than 5 minutes ago
        const time_t now = time(NULL);
        if (now < next_delete_invocation)
        {
      	  next_delete_invocation = now + 300;
      	  dnbd3_exec_delete(TRUE);
        }
    }

    dnbd3_cleanup();
}