wifidog-1.1.1/src/ping_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.              *
 *                                                                  *
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of   *
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 * along with this program; if not, contact:                        *
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/* $Header: /cvsroot/wifidog/wifidog/src/ping_thread.c,v 1.27 2005/03/07 04:50:25 minaguib Exp $ */
#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 <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <syslog.h>
#include <signal.h>
#include <errno.h>

#include "../config.h"
#include "safe.h"
#include "common.h"
#include "conf.h"
#include "debug.h"
#include "ping_thread.h"
#include "util.h"

static void ping(void);

time_t started_time = 0;

void
thread_ping(void *arg)
{
        pthread_cond_t          cond = PTHREAD_COND_INITIALIZER;
        pthread_mutex_t         cond_mutex = PTHREAD_MUTEX_INITIALIZER;
        struct  timespec        timeout;
        
        if (!started_time) {
                debug(LOG_INFO, "Setting started_time");
                started_time = time(NULL);
        }
        else if (started_time < MINIMUM_STARTED_TIME) {
                debug(LOG_WARNING, "Detected possible clock skew - re-setting started_time");
                started_time = time(NULL);
        }

        while (1) {
                /* Make sure we check the servers at the very begining */
                debug(LOG_DEBUG, "Running ping()");
                ping();
                
                /* Sleep for config.checkinterval seconds... */
                timeout.tv_sec = time(NULL) + config_get_config()->checkinterval;
                timeout.tv_nsec = 0;

                /* Mutex must be locked for pthread_cond_timedwait... */
                pthread_mutex_lock(&cond_mutex);
                
                /* Thread safe "sleep" */
                pthread_cond_timedwait(&cond, &cond_mutex, &timeout);

                /* No longer needs to be locked */
                pthread_mutex_unlock(&cond_mutex);
        }
}

static void
ping(void)
{
        size_t                  numbytes,
                                totalbytes;
        int                     sockfd, nfds, done;
        char                    request[MAX_BUF];
        fd_set                  readfds;
        struct timeval          timeout;
        FILE * fh;
        unsigned long int sys_uptime  = 0;
        unsigned int      sys_memfree = 0;
        float             sys_load    = 0;


        debug(LOG_DEBUG, "Entering ping()");
        
        sockfd = connect_auth_server();
        if (sockfd == -1) {
                /*
                 * No auth servers for me to talk to
                 */
                return;
        }

        /*
         * Populate uptime, memfree and load
         */
        if ((fh = fopen("/proc/uptime", "r"))) {
                fscanf(fh, "%lu", &sys_uptime);
                fclose(fh);
        }
        if ((fh = fopen("/proc/meminfo", "r"))) {
                while (!feof(fh)) {
                        if (fscanf(fh, "MemFree: %u", &sys_memfree) == 0) {
                                /* Not on this line */
                                while (!feof(fh) && fgetc(fh) != '\n');
                        }
                        else {
                                /* Found it */
                                break;
                        }
                }
                fclose(fh);
        }
        if ((fh = fopen("/proc/loadavg", "r"))) {
                fscanf(fh, "%f", &sys_load);
                fclose(fh);
        }

        /*
         * Prep & send request
         */
        snprintf(request, sizeof(request) - 1, "GET %sping/?gw_id=%s&sys_uptime=%lu&sys_memfree=%u&sys_load=%.2f&wifidog_uptime=%lu HTTP/1.0\n"
                        "User-Agent: WiFiDog %s\n"
                        "Host: %s\n"
                        "\n",
                        config_get_config()->auth_servers->authserv_path,
                        config_get_config()->gw_id,
                        sys_uptime,
                        sys_memfree,
                        sys_load,
                        (long unsigned int)((long unsigned int)time(NULL) - (long unsigned int)started_time),
                        VERSION,
                        config_get_config()->auth_servers->authserv_hostname);

        debug(LOG_DEBUG, "HTTP Request to Server: [%s]", request);
        
        send(sockfd, request, strlen(request), 0);

        debug(LOG_DEBUG, "Reading response");
        
        numbytes = totalbytes = 0;
        done = 0;
        do {
                FD_ZERO(&readfds);
                FD_SET(sockfd, &readfds);
                timeout.tv_sec = 30; /* XXX magic... 30 second */
                timeout.tv_usec = 0;
                nfds = sockfd + 1;

                nfds = select(nfds, &readfds, NULL, NULL, &timeout);

                if (nfds > 0) {
                        numbytes = read(sockfd, request + totalbytes,
                                        MAX_BUF - (totalbytes + 1));
                        if (numbytes < 0) {
                                debug(LOG_ERR, "An error occurred while reading from auth server: %s", strerror(errno));
                                /* FIXME */
                                close(sockfd);
                                return;
                        }
                        else if (numbytes == 0) {
                                done = 1;
                        }
                        else {
                                totalbytes += numbytes;
                                debug(LOG_DEBUG, "Read %d bytes, total now %d", numbytes, totalbytes);
                        }
                }
                else if (nfds == 0) {
                        debug(LOG_ERR, "Timed out reading data via select() from auth server");
                        /* FIXME */
                        close(sockfd);
                        return;
                }
                else if (nfds < 0) {
                        debug(LOG_ERR, "Error reading data via select() from auth server: %s", strerror(errno));
                        /* FIXME */
                        close(sockfd);
                        return;
                }
        } while (!done);
        close(sockfd);

        debug(LOG_DEBUG, "Done reading reply, total %d bytes", totalbytes);

        request[totalbytes] = '\0';

        debug(LOG_DEBUG, "HTTP Response from Server: [%s]", request);
        
        if (strstr(request, "Pong") == 0) {
                debug(LOG_WARNING, "Auth server did NOT say pong!");
                /* FIXME */
        }
        else {
                debug(LOG_DEBUG, "Auth Server Says: Pong");
        }

        return; 
}

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