root/wifidog/wifidog-client/src/wdctl_thread.c

/********************************************************************\
 * 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 2 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, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 59 Temple Place - Suite 330        Fax:    +1-617-542-2652       *
 * Boston, MA  02111-1307,  USA       gnu@gnu.org                   *
 *                                                                  *
\********************************************************************/

/* $Id: wdctl_thread.c 1241 2007-06-24 04:13:13Z benoitg $ */
/** @file wdctl_thread.c
    @brief Monitoring and control of wifidog, server part
    @author Copyright (C) 2004 Alexandre Carmel-Veilleux <acv@acv.ca>
*/

#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <string.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <syslog.h>
#include <signal.h>
#include <errno.h>

#include "common.h"
#include "httpd.h"
#include "util.h"
#include "conf.h"
#include "debug.h"
#include "auth.h"
#include "centralserver.h"
#include "fw_iptables.h"
#include "firewall.h"
#include "client_list.h"
#include "wdctl_thread.h"

/* Defined in clientlist.c */
extern  pthread_mutex_t client_list_mutex;
extern  pthread_mutex_t config_mutex;

/* From commandline.c: */
extern char ** restartargv;
static void *thread_wdctl_handler(void *);
static void wdctl_status(int);
static void wdctl_stop(int);
static void wdctl_reset(int, char *);
static void wdctl_restart(int);

/** Launches a thread that monitors the control socket for request
@param arg Must contain a pointer to a string containing the Unix domain socket to open
@todo This thread loops infinitely, need a watchdog to verify that it is still running?
*/  
void
thread_wdctl(void *arg)
{
        int     fd;
        char    *sock_name;
        struct  sockaddr_un     sa_un;
        int result;
        pthread_t       tid;
       socklen_t len;

        debug(LOG_DEBUG, "Starting wdctl.");

        memset(&sa_un, 0, sizeof(sa_un));
        sock_name = (char *)arg;
        debug(LOG_DEBUG, "Socket name: %s", sock_name);

        if (strlen(sock_name) > (sizeof(sa_un.sun_path) - 1)) {
                /* TODO: Die handler with logging.... */
                debug(LOG_ERR, "WDCTL socket name too long");
                exit(1);
        }
        

        debug(LOG_DEBUG, "Creating socket");
        wdctl_socket_server = socket(PF_UNIX, SOCK_STREAM, 0);

        debug(LOG_DEBUG, "Got server socket %d", wdctl_socket_server);

        /* If it exists, delete... Not the cleanest way to deal. */
        unlink(sock_name);

        debug(LOG_DEBUG, "Filling sockaddr_un");
        strcpy(sa_un.sun_path, sock_name); /* XXX No size check because we
                                            * check a few lines before. */
        sa_un.sun_family = AF_UNIX;
        
        debug(LOG_DEBUG, "Binding socket (%s) (%d)", sa_un.sun_path,
                        strlen(sock_name));
        
        /* Which to use, AF_UNIX, PF_UNIX, AF_LOCAL, PF_LOCAL? */
        if (bind(wdctl_socket_server, (struct sockaddr *)&sa_un, strlen(sock_name)
                                + sizeof(sa_un.sun_family))) {
                debug(LOG_ERR, "Could not bind control socket: %s",
                                strerror(errno));
                pthread_exit(NULL);
        }

        if (listen(wdctl_socket_server, 5)) {
                debug(LOG_ERR, "Could not listen on control socket: %s",
                                strerror(errno));
                pthread_exit(NULL);
        }

        while (1) {
                len = sizeof(sa_un);
                memset(&sa_un, 0, len);
                if ((fd = accept(wdctl_socket_server, (struct sockaddr *)&sa_un, &len)) == -1){
                        debug(LOG_ERR, "Accept failed on control socket: %s",
                                        strerror(errno));
                } else {
                        debug(LOG_DEBUG, "Accepted connection on wdctl socket %d (%s)", fd, sa_un.sun_path);
                        result = pthread_create(&tid, NULL, &thread_wdctl_handler, (void *)fd);
                        if (result != 0) {
                                debug(LOG_ERR, "FATAL: Failed to create a new thread (wdctl handler) - exiting");
                                termination_handler(0);
                        }
                        pthread_detach(tid);
                }
        }
}


static void *
thread_wdctl_handler(void *arg)
{
        int     fd,
                done,
                i;
        char    request[MAX_BUF];
        ssize_t read_bytes,
                len;

        debug(LOG_DEBUG, "Entering thread_wdctl_handler....");

        fd = (int)arg;
        
        debug(LOG_DEBUG, "Read bytes and stuff from %d", fd);

        /* Init variables */
        read_bytes = 0;
        done = 0;
        memset(request, 0, sizeof(request));
        
        /* Read.... */
        while (!done && read_bytes < (sizeof(request) - 1)) {
                len = read(fd, request + read_bytes,
                                sizeof(request) - read_bytes);

                /* Have we gotten a command yet? */
                for (i = read_bytes; i < (read_bytes + len); i++) {
                        if (request[i] == '\r' || request[i] == '\n') {
                                request[i] = '\0';
                                done = 1;
                        }
                }
                
                /* Increment position */
                read_bytes += len;
        }

        if (strncmp(request, "status", 6) == 0) {
                wdctl_status(fd);
        } else if (strncmp(request, "stop", 4) == 0) {
                wdctl_stop(fd);
        } else if (strncmp(request, "reset", 5) == 0) {
                wdctl_reset(fd, (request + 6));
        } else if (strncmp(request, "restart", 7) == 0) {
                wdctl_restart(fd);
        }

        if (!done) {
                debug(LOG_ERR, "Invalid wdctl request.");
                shutdown(fd, 2);
                close(fd);
                pthread_exit(NULL);
        }

        debug(LOG_DEBUG, "Request received: [%s]", request);
        
        shutdown(fd, 2);
        close(fd);
        debug(LOG_DEBUG, "Exiting thread_wdctl_handler....");

        return NULL;
}

static void
wdctl_status(int fd)
{
        char * status = NULL;
        int len = 0;

        status = get_status_text(1);
        len = strlen(status);

        write(fd, status, len);

        free(status);
}

/** A bit of an hack, self kills.... */
static void
wdctl_stop(int fd)
{
        pid_t   pid;

        pid = getpid();
        kill(pid, SIGINT);
}

static void
wdctl_restart(int afd)
{
        int     sock,
                fd;
        char    *sock_name;
        struct  sockaddr_un     sa_un;
        int result;
        s_config * conf = NULL;
        t_client * client = NULL;
        char * tempstring = NULL;
        pid_t pid;
        ssize_t written;
        socklen_t len;

        conf = config_get_config();

        debug(LOG_NOTICE, "Will restart myself");

        /*
         * First, prepare the internal socket
         */
        memset(&sa_un, 0, sizeof(sa_un));
        sock_name = conf->internal_sock;
        debug(LOG_DEBUG, "Socket name: %s", sock_name);

        if (strlen(sock_name) > (sizeof(sa_un.sun_path) - 1)) {
                /* TODO: Die handler with logging.... */
                debug(LOG_ERR, "INTERNAL socket name too long");
                return;
        }

        debug(LOG_DEBUG, "Creating socket");
        sock = socket(PF_UNIX, SOCK_STREAM, 0);

        debug(LOG_DEBUG, "Got internal socket %d", sock);

        /* If it exists, delete... Not the cleanest way to deal. */
        unlink(sock_name);

        debug(LOG_DEBUG, "Filling sockaddr_un");
        strcpy(sa_un.sun_path, sock_name); /* XXX No size check because we check a few lines before. */
        sa_un.sun_family = AF_UNIX;
        
        debug(LOG_DEBUG, "Binding socket (%s) (%d)", sa_un.sun_path, strlen(sock_name));
        
        /* Which to use, AF_UNIX, PF_UNIX, AF_LOCAL, PF_LOCAL? */
        if (bind(sock, (struct sockaddr *)&sa_un, strlen(sock_name) + sizeof(sa_un.sun_family))) {
                debug(LOG_ERR, "Could not bind internal socket: %s", strerror(errno));
                return;
        }

        if (listen(sock, 5)) {
                debug(LOG_ERR, "Could not listen on internal socket: %s", strerror(errno));
                return;
        }
        
        /*
         * The internal socket is ready, fork and exec ourselves
         */
        debug(LOG_DEBUG, "Forking in preparation for exec()...");
        pid = safe_fork();
        if (pid > 0) {
                /* Parent */

                /* Wait for the child to connect to our socket :*/
                debug(LOG_DEBUG, "Waiting for child to connect on internal socket");
                len = sizeof(sa_un);
                if ((fd = accept(sock, (struct sockaddr *)&sa_un, &len)) == -1){
                        debug(LOG_ERR, "Accept failed on internal socket: %s", strerror(errno));
                        close(sock);
                        return;
                }

                close(sock);

                debug(LOG_DEBUG, "Received connection from child.  Sending them all existing clients");

                /* The child is connected. Send them over the socket the existing clients */
                LOCK_CLIENT_LIST();
                client = client_get_first_client();
                while (client) {
                        /* Send this client */
                        safe_asprintf(&tempstring, "CLIENT|ip=%s|mac=%s|token=%s|fw_connection_state=%u|fd=%d|counters_incoming=%llu|counters_outgoing=%llu|counters_last_updated=%lu\n", client->ip, client->mac, client->token, client->fw_connection_state, client->fd, client->counters.incoming, client->counters.outgoing, client->counters.last_updated);
                        debug(LOG_DEBUG, "Sending to child client data: %s", tempstring);
                        len = 0;
                        while (len != strlen(tempstring)) {
                                written = write(fd, (tempstring + len), strlen(tempstring) - len);
                                if (written == -1) {
                                        debug(LOG_ERR, "Failed to write client data to child: %s", strerror(errno));
                                        free(tempstring);
                                        break;
                                }
                                else {
                                        len += written;
                                }
                        }
                        free(tempstring);
                        client = client->next;
                }
                UNLOCK_CLIENT_LIST();

                close(fd);

                debug(LOG_INFO, "Sent all existing clients to child.  Committing suicide!");

                shutdown(afd, 2);
                close(afd);

                /* Our job in life is done. Commit suicide! */
                wdctl_stop(afd);
        }
        else {
                /* Child */
                close(wdctl_socket_server);
                close(icmp_fd);
                close(sock);
                shutdown(afd, 2);
                close(afd);
                debug(LOG_NOTICE, "Re-executing myself (%s)", restartargv[0]);
                setsid();
                execvp(restartargv[0], restartargv);
                /* If we've reached here the exec() failed - die quickly and silently */
                debug(LOG_ERR, "I failed to re-execute myself: %s", strerror(errno));
                debug(LOG_ERR, "Exiting without cleanup");
                exit(1);
        }

}

static void
wdctl_reset(int fd, char *arg)
{
        t_client        *node;

        debug(LOG_DEBUG, "Entering wdctl_reset...");
        
        LOCK_CLIENT_LIST();
        debug(LOG_DEBUG, "Argument: %s (@%x)", arg, arg);
        
        /* We get the node or return... */
        if ((node = client_list_find_by_ip(arg)) != NULL);
        else if ((node = client_list_find_by_mac(arg)) != NULL);
        else {
                debug(LOG_DEBUG, "Client not found.");
                UNLOCK_CLIENT_LIST();
                write(fd, "No", 2);
                return;
        }

        debug(LOG_DEBUG, "Got node %x.", node);
        
        /* deny.... */
        /* TODO: maybe just deleting the connection is not best... But this
         * is a manual command, I don't anticipate it'll be that useful. */
        fw_deny(node->ip, node->mac, node->fw_connection_state);
        client_list_delete(node);
        
        UNLOCK_CLIENT_LIST();
        
        write(fd, "Yes", 3);
        
        debug(LOG_DEBUG, "Exiting wdctl_reset...");
}