source: admin/WebConsole/rest/ogagent.php

<?php
/**
 * @file    ogagent.php
 * @brief   OpenGnsys REST routes for OGAgent communications.
 * @warning All input and output messages are formatted in JSON.
 * @note    Some ideas are based on article "How to create REST API for Android app using PHP, Slim and MySQL" by Ravi Tamada, thanx.
 * @license GNU GPLv3+
 * @author  Ramón M. Gómez, ETSII Univ. Sevilla
 * @version 1.1.0 - First version
 * @date    2016-10-03
 */


// OGAgent sessions log file.
define('LOG_FILE', '/opt/opengnsys/log/ogagent.log');

// Function to write a line into log file.
function writeLog($message = "") {
        file_put_contents(LOG_FILE, date(DATE_ISO8601).": $message\n", FILE_APPEND);
}

/**
 * @brief    OGAgent notifies that its service is started on a client.
 * @note     Route: /ogagent/started, Method: POST, Format: JSON
 * @param    string ip         IP address
 * @param    string mac        MAC (Ethernet) address
 * @param    string ostype     OS type (Linux, Windows, macOS)
 * @param    string osversion  OS version
 * @param    string secret     random secret key to access client's REST API
 * @return   Null string if OK, else error message.
 */
$app->post('/ogagent/started',
    function() use ($app) {
        global $cmd;
        $secret = "";
        $osType = $osVersion = "none";
        try {
                // Reading POST parameters in JSON format.
                $input = json_decode($app->request()->getBody());
                $ip = htmlspecialchars($input->ip);
                $mac = htmlspecialchars($input->mac);
                if (isset($input->ostype))  $osType = htmlspecialchars($input->ostype);
                if (isset($input->osversion))  $osVersion = str_replace(",", ";", htmlspecialchars($input->osversion));
                // Check sender agent type and IP address consistency (same as parameter value).
                if (empty(preg_match('/^python-requests\//', $_SERVER['HTTP_USER_AGENT'])) or $ip !== $_SERVER['REMOTE_ADDR']) {
                    throw new Exception("Bad OGAgent: ip=$ip, sender=".$_SERVER['REMOTE_ADDR'].", agent=".$_SERVER['HTTP_USER_AGENT']);
                }
                // Client secret key for secure communications.
                if (isset($input->secret)) {
                    // Check if secret key is valid (32 alphanumeric characters).
                    if (! ctype_alnum($input->secret) or strlen($input->secret) !== 32) {
                        throw new Exception("Bad secret key: ip=$ip, mac=$mac, os=$osType:$osVersion.");
                    }
                    // Store secret key in DB.
                    if (isset($input->secret))  $secret = htmlspecialchars($input->secret);
                    $cmd->texto = <<<EOD
UPDATE ordenadores
   SET agentkey='$secret'
 WHERE ip='$ip' AND mac=UPPER(REPLACE('$mac', ':', ''))
 LIMIT 1;
EOD;
                    if ($cmd->Ejecutar() !== true or mysqli_affected_rows($cmd->Conexion->controlador) !== 1) {
                        // DB access error or not updated.
                        throw new Exception("Cannot store new secret key: ip=$ip, mac=$mac, os=$osType:$osVersion.");
                    }
                } else {
                    // Insecure agent exception.
                    throw new Exception("Insecure OGAgent started: ip=$ip, mac=$mac, os=$osType:$osVersion.");
                }
                // Default processing: log activity.
                writeLog("OGAgent started: ip=$ip, mac=$mac, os=$osType:$osVersion.");
                // Response. 
                $response = "";
                jsonResponse(200, $response);
        } catch (Exception $e) {
                // Communication error.
                $response["message"] = $e->getMessage();
                writeLog($app->request()->getResourceUri().": ERROR: ".$response["message"]);
                jsonResponse(400, $response);
        }
    }
);

/**
 * @brief    OGAgent notifies that its service is stopped on client.
 * @note     Route: /ogagent/stopped, Method: POST, Format: JSON
 * @param    string ip         IP address
 * @param    string mac        MAC (Ethernet) address
 * @param    string ostype     OS type (Linux, Windows, macOS)
 * @param    string osversion  OS version
 * @return   Null string if OK, else error message.
 */
$app->post('/ogagent/stopped',
    function() use ($app) {
        $osType = $osVersion = "none";
        try {
                // Reading POST parameters in JSON format.
                $input = json_decode($app->request()->getBody());
                $ip = htmlspecialchars($input->ip);
                $mac = htmlspecialchars($input->mac);
                if (isset($input->ostype))  $osType = htmlspecialchars($input->ostype);
                if (isset($input->osversion))  $osVersion = str_replace(",", ";", htmlspecialchars($input->osversion));
                // Check sender agent type and IP address consistency (same as parameter value).
                if (empty(preg_match('/^python-requests\//', $_SERVER['HTTP_USER_AGENT'])) or $ip !== $_SERVER['REMOTE_ADDR']) {
                    throw new Exception("Bad OGAgent: ip=$ip, sender=".$_SERVER['REMOTE_ADDR'].", agent=".$_SERVER['HTTP_USER_AGENT']);
                }
                // May check if client is included in the server database?
                // Default processing: log activity.
                writeLog("OGAgent stopped: ip=$ip, mac=$mac, os=$osType:$osVersion.");
                // Response. 
                $response = "";
                jsonResponse(200, $response);
        } catch (Exception $e) {
                // Communication error.
                $response["message"] = $e->getMessage();
                writeLog($app->request()->getResourceUri().": ERROR: ".$response["message"]);
                jsonResponse(400, $response);
        }
    }
);

/**
 * @brief    OGAgent notifies that an user logs in.
 * @note     Route: /ogagent/loggedin, Method: POST, Format: JSON
 * @param    string ip         IP address
 * @param    string user       username
 * @param    string language   session language
 * @param    string ostype     OS type (Linux, Windows, macOS)
 * @param    string osversion  OS version
 * @return   Null string if OK, else error message.
 */
$app->post('/ogagent/loggedin',
    function() use ($app) {
        global $cmd;
        $osType = $osVersion = "none";
        $redirto = Array();
        $result = Array();

        try {
                // Reading POST parameters in JSON format.
                $input = json_decode($app->request()->getBody());
                $ip = htmlspecialchars($input->ip);
                $user = htmlspecialchars($input->user);
                $language = isset($input->language) ? substr($input->language, 0, strpos($input->language, "_")) : "";
                if (isset($input->ostype))  $osType = htmlspecialchars($input->ostype);
                if (isset($input->osversion))  $osVersion = str_replace(",", ";", htmlspecialchars($input->osversion));
                // Check sender IP address consistency (same as parameter value).
                if (empty(preg_match('/^python-requests\//', $_SERVER['HTTP_USER_AGENT'])) or $ip !== $_SERVER['REMOTE_ADDR']) {
                    throw new Exception("Bad OGAgent: ip=$ip, sender=".$_SERVER['REMOTE_ADDR'].", agent=".$_SERVER['HTTP_USER_AGENT']);
                }
                // Check if client is included in the server database.
                $cmd->CreaParametro("@ip", $ip, 0);
                $cmd->texto = <<<EOD
SELECT ordenadores.idordenador, ordenadores.nombreordenador, remotepc.urllogin,
       remotepc.reserved > NOW() AS reserved
  FROM remotepc
 RIGHT JOIN ordenadores ON remotepc.id=ordenadores.idordenador
 WHERE ordenadores.ip=@ip
 LIMIT 1;
EOD;
                $rs=new Recordset;
                $rs->Comando=&$cmd;
                if ($rs->Abrir()) {
                        // Read query data.
                        $rs->Primero();
                        $id = $rs->campos['idordenador'];
                        $redirto[0]['url'] = $rs->campos['urllogin'];
                        $reserved = $rs->campos['reserved'];
                        $rs->Cerrar();
                        if (!is_null($id)) {
                                // Log activity, respond to client and continue processing.
                                writeLog("User logged in: ip=$ip, user=$user, lang=$language, os=$osType:$osVersion.");
                                $response = "";
                                jsonResponseNow(200, $response);
                        } else {
                                throw new Exception("Client is not in the database: ip=$ip, user=$user");
                        }
                        // Redirect notification to UDS server, if needed.
                        if ($reserved == 1 and !is_null($redirto[0]['url'])) {
                                $redirto[0]['get'] = $app->request()->getBody();
                                $result = multiRequest($redirto);
                                // ... (check response)
                                //if ($result[0]['code'] != 200) {
                                // ...
                                // Updating user's session language for messages.
                                $cmd->texto = <<<EOD
UPDATE remotepc
   SET language = '$language'
 WHERE id = '$id';
EOD;
                                $cmd->Ejecutar();
                        }
                } else {
                        throw new Exception("Database error");
                }
        } catch (Exception $e) {
                // Communication error.
                $response["message"] = $e->getMessage();
                writeLog($app->request()->getResourceUri().": ERROR: ".$response["message"]);
                jsonResponse(400, $response);
        }
    }
);

/**
 * @brief    OGAgent notifies that an user logs out.
 * @note     Route: /ogagent/loggedout, Method: POST, Format: JSON
 * @param    string ip         IP address
 * @param    string user       username
 * @return   Null string if OK, else error message.
 */
$app->post('/ogagent/loggedout',
    function() use ($app) {
        global $cmd;
        $redirto = Array();
        $result = Array();

        try {
                // Reading POST parameters in JSON format.
                $input = json_decode($app->request()->getBody());
                $ip = htmlspecialchars($input->ip);
                $user = htmlspecialchars($input->user);
                // Check sender agent type and IP address consistency (same as parameter value).
                if (empty(preg_match('/^python-requests\//', $_SERVER['HTTP_USER_AGENT'])) or $ip !== $_SERVER['REMOTE_ADDR']) {
                    throw new Exception("Bad OGAgent: ip=$ip, sender=".$_SERVER['REMOTE_ADDR'].", agent=".$_SERVER['HTTP_USER_AGENT']);
                }
                // Check if client is included in the server database.
                $cmd->CreaParametro("@ip", $ip, 0);
                $cmd->texto = <<<EOD
SELECT ordenadores.idordenador, ordenadores.nombreordenador, remotepc.urllogout,
       remotepc.reserved > NOW() AS reserved
  FROM remotepc
 RIGHT JOIN ordenadores ON remotepc.id=ordenadores.idordenador
 WHERE ordenadores.ip=@ip
 LIMIT 1;
EOD;
                $rs=new Recordset;
                $rs->Comando=&$cmd;
                if ($rs->Abrir()) {
                        // Read query data.
                        $rs->Primero();
                        $id = $rs->campos['idordenador'];
                        $url = $rs->campos['urllogout'];
                        $reserved = $rs->campos['reserved'];
                        $rs->Cerrar();
                        if (!is_null($id)) {
                                // Log activity, respond to client and continue processing.
                                writeLog("User logged out: ip=$ip, user=$user.");
                        } else {
                                throw new Exception("Client is not in the database: ip=$ip, user=$user");
                        }
                        // Redirect notification to UDS server, if needed.
                        if ($reserved == 1 and !is_null($url)) {
                                $redirto[0]['url'] = $url;
                                $redirto[0]['get'] = $app->request()->getBody();
                                $result = multiRequest($redirto);
                                // ... (check response)
                                //if ($result[0]['code'] != 200) {
                                // ...
                        }
                } else {
                        throw new Exception("Database error");
                }
        } catch (Exception $e) {
                // Communication error.
                $response["message"] = $e->getMessage();
                writeLog($app->request()->getResourceUri().": ERROR: ".$response["message"]);
                jsonResponse(400, $response);
        }
        $response = "";
        jsonResponse(200, $response);
    }
);