/*
   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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

   (c) 2012 Timothy Pearson
   (c) 2012 Raptor Engineering
*/

#define _GNU_SOURCE

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

#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <pwd.h>
#include <grp.h>
#include <time.h>

#define list_delete mysql_list_delete
#include <mysql/mysql.h>
#undef list_delete

#include "list.h"
#include "libraptorsmiface.h"

#define STATISTICS_SERVER_START_EVENT		0
#define STATISTICS_SERVER_STOP_EVENT		1
#define STATISTICS_NEW_CONNECTION_EVENT		2
#define STATISTICS_CONNECTION_STATUS_EVENT	3
#define STATISTICS_DISCONNECTION_EVENT		4

#define RAPTORSMIFACE_CFG_DATABASE		"Database"
#define RAPTORSMIFACE_CFG_DATABASE_SERVER	"Server"
#define RAPTORSMIFACE_CFG_DATABASE_NAME		"Database"
#define RAPTORSMIFACE_CFG_DATABASE_USER		"User"
#define RAPTORSMIFACE_CFG_DATABASE_PASSWORD	"Password"

char *server = "localhost";
char *user = "remotelab";
char *password = "";
char *database = "remotelab_sm";

void dprint(const char *fmt, ...)
{
	va_list argp;
	va_start(argp, fmt);

#if 0
	vprintf(fmt, argp);
#else
	char debug[512];
	vsprintf(debug, fmt, argp);
	FILE *fp = fopen("/raptorsmiface.debug", "a");
	if (fp != NULL)
	{
		fputs(debug, fp);
		fclose(fp);
	}
#endif

	va_end(argp);
}

void raptorsmiface_config_read_database(int file, struct list* param_n, struct list* param_v) {
	int i;
	char* buf;
	char* temp_buf;
	
	list_clear(param_v);
	list_clear(param_n);
	
	file_read_section(file, RAPTORSMIFACE_CFG_DATABASE, param_n, param_v);
	for (i = 0; i < param_n->count; i++) {
		buf = (char*)list_get_item(param_n, i);
		if (0 == g_strcasecmp(buf, RAPTORSMIFACE_CFG_DATABASE_SERVER)) {
			server = g_strdup((char*)list_get_item(param_v, i));
		}
		if (0 == g_strcasecmp(buf, RAPTORSMIFACE_CFG_DATABASE_NAME)) {
			database = g_strdup((char*)list_get_item(param_v, i));
		}
		if (0 == g_strcasecmp(buf, RAPTORSMIFACE_CFG_DATABASE_USER)) {
			user = g_strdup((char*)list_get_item(param_v, i));
		}
		if (0 == g_strcasecmp(buf, RAPTORSMIFACE_CFG_DATABASE_PASSWORD)) {
			password = g_strdup((char*)list_get_item(param_v, i));
		}
	}

	g_printf("raptorsmiface configuration:\r\n");
	g_printf("\tServer:        %s\r\n", server);
	g_printf("\tDatabase:      %s\r\n", database);
	g_printf("\tUser:          %s\r\n", user);
}

void read_ini_configuration() {
	int fd;
	struct list* sec;
	struct list* param_n;
	struct list* param_v;

	char cfg_file[256];
	g_snprintf(cfg_file, 255, "%s/xrdp.ini", XRDP_CFG_PATH);

	fd = g_file_open(cfg_file);
	if (-1 == fd) {
		dprint("[ERROR] Unable to open configuration file [%s]", cfg_file);
		return;
	}
	
	sec = list_create();
	sec->auto_free = 1;
	file_read_sections(fd, sec);
	param_n = list_create();
	param_n->auto_free = 1;
	param_v = list_create();
	param_v->auto_free = 1;
	
	/* read database config */
	raptorsmiface_config_read_database(fd, param_n, param_v);

	/* cleanup */
	list_delete(sec);
	list_delete(param_v);
	list_delete(param_n);
	g_file_close(fd);
}

MYSQL * connect_if_needed() {
	MYSQL *conn = mysql_init(NULL);
	read_ini_configuration();
	if (!mysql_real_connect(conn, server, user, password, database, 0, NULL, 0)) {
		dprint("[ERROR] MySQL connection FAILED [%s]\n\r", mysql_error(conn));
		conn = 0;
	}
	return conn;
}

char* get_mysql_escaped_string(MYSQL *sqlcn, char* rawstr) {
	unsigned int minlen = strlen(rawstr);
	unsigned int maxlen = ((minlen*2)+1);
	char* escstr = malloc(maxlen*sizeof(char));
	mysql_real_escape_string(sqlcn, escstr, rawstr, minlen);
	return escstr;
}

char mutex;
int mysql_query_internal(MYSQL *conn, const char * query) {
	// For some reason this can hang rather badly
	// It might be related to concurrent access to the same conn object though
	return mysql_query(conn, query);
}

char* get_group_for_user(char* username) {
	struct passwd* pwd;
	pwd = getpwnam(username);
	if (!pwd) {
		return true;
	}
	gid_t groupid = pwd->pw_gid;
	struct group* primarygroup;
	primarygroup = getgrgid(groupid);
	if (!primarygroup) {
		return true;
	}

	return strdup(primarygroup->gr_name);
}

char raptor_sm_deallocate_session(char* username) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	MYSQL_RES *svr_res;
	MYSQL_ROW svr_row;
	MYSQL_RES *cnt_res;
	MYSQL_ROW cnt_row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return 1;
	}

	int display = raptor_sm_get_display_for_username(username);
	char* hostname = raptor_sm_get_hostname_for_username(username, false);
	pid_t serverpid = raptor_sm_get_pid_for_username(username, RAPTOR_SM_SERVER_PID_FIELD);
	if (serverpid >= 0) {
		// Verify non-existence of PID on remote server before removing session information from the database
		char* ip = raptor_sm_get_ip_for_hostname(hostname, 0);
		char* command_string;
		asprintf(&command_string, "ssh root@%s \'ps -p %d | grep %d\'", ip, serverpid, serverpid);
		FILE *fp;
		char output[1024];
		// Open the command for reading
		fp = popen(command_string, "r");
		if (fp == NULL) {
			mysql_close(conn);
			return -1;
		}
		// Read the output a line at a time
		fgets(output, sizeof(output)-1, fp);
		// Close output
		pclose(fp);
		free(command_string);
		free(ip);
		if (strcmp(output, "") != 0) {
			mysql_free_result(res);
			mysql_close(conn);
			return 0;
		}
	}

	// Remove the user from the system
	char* safe_username = get_mysql_escaped_string(conn, username);
	asprintf(&query, "DELETE FROM sessions WHERE username='%s'", safe_username);
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(hostname);
		free(query);
		mysql_close(conn);
		return 2;
	}
	else {
		free(query);

		// Insert connection information into the statistics database
		char* safe_servername = get_mysql_escaped_string(conn, hostname);
		char* safe_username = get_mysql_escaped_string(conn, username);
		long long timestamp = time(NULL);
		asprintf(&query, "INSERT INTO statistics (timestamp, eventtypeid, servername, display, typeid, username) VALUES ('%lld', '%d', '%s', '%d', '%d', '%s')", timestamp, STATISTICS_DISCONNECTION_EVENT, safe_servername, display, -1, safe_username);
		free(safe_servername);
		free(safe_username);
		free(hostname);
		if (mysql_query_internal(conn, query)) {
			// Server error
			dprint("Unable to insert data into statistics database! [%s]\n\r", mysql_error(conn));
		}
		free(query);

		mysql_close(conn);
		return 0;
	}
}

char* raptor_sm_allocate_session(char* username) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	MYSQL_RES *svr_res;
	MYSQL_ROW svr_row;
	MYSQL_RES *per_res;
	MYSQL_ROW per_row;
	MYSQL_RES *cnt_res;
	MYSQL_ROW cnt_row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return strdup("ERROR");
	}

	// Verify that this user is not already on the system
	char* safe_username = get_mysql_escaped_string(conn, username);
	asprintf(&query, "SELECT servername FROM sessions WHERE username='%s'", safe_username);
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return strdup("ERROR");
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		if ((row = mysql_fetch_row(res)) == NULL) {
			// User is not on a system
			// Find the least utilized node
			if (mysql_query_internal(conn, "SELECT name FROM servers WHERE online='1'")) {
				// Server error
				mysql_free_result(res);
				mysql_close(conn);
				return strdup("ERROR");
			}
			else {
				svr_res = mysql_store_result(conn);

				// Get group for user
				char* groupname = get_group_for_user(username);
				char* safe_groupname = get_mysql_escaped_string(conn, groupname);
				free(groupname);
				// Get the list of allowed nodes for this group
				asprintf(&query, "SELECT server FROM allowed_servers WHERE groupname='%s'", safe_groupname);
				free(safe_groupname);
				if (mysql_query_internal(conn, query)) {
					// Server error
					mysql_free_result(res);
					mysql_free_result(svr_res);
					mysql_close(conn);
					return strdup("ERROR");
				}
				else {
					per_res = mysql_store_result(conn);
					char* bestserver = strdup("");
					int bestusage = INT_MAX;
					while ((svr_row = mysql_fetch_row(svr_res)) != NULL) {
						// Am I allowed to use this server?
						bool can_use_server = false;
						while ((per_row = mysql_fetch_row(per_res)) != NULL) {
							if (strcmp(per_row[0], svr_row[0]) == 0) {
								can_use_server = true;
							}
						}
						mysql_data_seek(per_res, 0);
						if (can_use_server) {
							char* safe_servername = get_mysql_escaped_string(conn, svr_row[0]);
							asprintf(&query, "SELECT username FROM sessions WHERE servername='%s'", safe_servername);
							free(safe_servername);
							if (mysql_query_internal(conn, query)) {
								// Server error
								free(query);
								free(bestserver);
								mysql_free_result(res);
								mysql_free_result(svr_res);
								mysql_close(conn);
								return strdup("ERROR");
							}
							else {
								free(query);
								cnt_res = mysql_store_result(conn);
								int usagecount = 0;
								while ((cnt_row = mysql_fetch_row(cnt_res)) != NULL) {
									usagecount++;
								}
								mysql_free_result(cnt_res);
								if (usagecount < bestusage) {
									free(bestserver);
									bestserver = strdup(svr_row[0]);
									bestusage = usagecount;
								}
							}
						}
					}
					mysql_free_result(res);
					mysql_free_result(svr_res);
					mysql_free_result(per_res);
	
					if (strcmp(bestserver, "") != 0) {
						// Insert new information into the sessions database and set status to ALLOCATED
						char* safe_servername = get_mysql_escaped_string(conn, bestserver);
						char* safe_username = get_mysql_escaped_string(conn, username);
						asprintf(&query, "INSERT INTO sessions (username, servername, state) VALUES ('%s', '%s', '%d')", safe_username, safe_servername, SM_STATUS_ALLOCATED);
						free(safe_servername);
						free(safe_username);
						if (mysql_query_internal(conn, query)) {
							// Server error
							free(query);
							mysql_close(conn);
							return strdup("ERROR");
						}
						else {
							free(query);

							// Insert connection information into the statistics database
							char* safe_servername = get_mysql_escaped_string(conn, bestserver);
							char* safe_username = get_mysql_escaped_string(conn, username);
							long long timestamp = time(NULL);
							asprintf(&query, "INSERT INTO statistics (timestamp, eventtypeid, servername, display, typeid, username) VALUES ('%lld', '%d', '%s', '%d', '%d', '%s')", timestamp, STATISTICS_NEW_CONNECTION_EVENT, safe_servername, -1, SM_STATUS_ALLOCATED, safe_username);
							free(safe_servername);
							free(safe_username);
							if (mysql_query_internal(conn, query)) {
								// Server error
								dprint("Unable to insert data into statistics database! [%s]\n\r", mysql_error(conn));
							}
							free(query);

							mysql_close(conn);
							return strdup(bestserver);
						}
					}
					else {
						// No usable server found!
						mysql_close(conn);
						return strdup("ERROR");
					}
				}
			}
		}
		else {
			char* ret = strdup(row[0]);
			mysql_free_result(res);
			mysql_close(conn);
			return ret;
		}
	}
}

char* raptor_sm_get_ip_for_hostname(char* hostname, char* error) {
	struct addrinfo hints, *res;
	struct in_addr addr;
	int err;
	
	memset(&hints, 0, sizeof(hints));
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_family = AF_INET;
	
	if ((err = getaddrinfo(hostname, NULL, &hints, &res)) != 0) {
		if (error) *error = 1;
		return strdup("");
	}
	
	addr.s_addr = ((struct sockaddr_in *)(res->ai_addr))->sin_addr.s_addr;
	
	char* ret = strdup(inet_ntoa(addr));
	freeaddrinfo(res);
	if (error) *error = 0;
	return ret;
}

char* raptor_sm_get_hostname_for_username(char* username, bool create) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return strdup("SQLERR100");
	}

	char* safe_username = get_mysql_escaped_string(conn, username);
	asprintf(&query, "SELECT servername FROM sessions WHERE username='%s'", safe_username);
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return strdup("SQLERR101");
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		while ((row = mysql_fetch_row(res)) != NULL) {
			char* ret = strdup(row[0]);
			mysql_free_result(res);
			mysql_close(conn);
			return ret;
		}
		// Nothing in the DB
		mysql_free_result(res);
		if (create) {
			// Try to allocate a new session on a node
			mysql_close(conn);
			return raptor_sm_allocate_session(username);
		}
		else {
			mysql_close(conn);
			return strdup("");
		}
	}
}

char* raptor_sm_get_hostname_for_display(int display) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return strdup("SQLERR100");
	}

	asprintf(&query, "SELECT servername FROM sessions WHERE display='%d'", display);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return strdup("SQLERR101");
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		while ((row = mysql_fetch_row(res)) != NULL) {
			char* ret = strdup(row[0]);
			mysql_free_result(res);
			mysql_close(conn);
			return ret;
		}
		// Nothing in the DB
		mysql_free_result(res);
		mysql_close(conn);
		return strdup("");
	}
}

char* raptor_sm_get_ip_for_username(char* username, bool create) {
	char* hostname = raptor_sm_get_hostname_for_username(username, create);
	char err;
	char* ip = raptor_sm_get_ip_for_hostname(hostname, &err);
	free(hostname);
	if (err) {
		raptor_sm_deallocate_session(username);
		return strdup("ERROR");
	}
	return ip;
}

bool raptor_sm_sesslimit_reached(char* username) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return true;
	}

	// Respect maximum session number for the group for this user
	int sesslimit = 0;	// Default to denying all sessions

	// Get group for user
	char* groupname = get_group_for_user(username);
	char* safe_groupname = get_mysql_escaped_string(conn, groupname);
	free(groupname);
	asprintf(&query, "SELECT sesslimit FROM groups WHERE groupname='%s'", safe_groupname);
	free(safe_groupname);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return true;
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		row = mysql_fetch_row(res);
		if (row[0]) {
			sesslimit = atoi(row[0]);
		}
		mysql_free_result(res);
	}

	// Figure out how many users are online from this group
	int sesscount = 0;
	asprintf(&query, "SELECT username FROM sessions WHERE state<>'%d'", SM_STATUS_ALLOCATED);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return true;
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		while ((row = mysql_fetch_row(res)) != NULL) {
			if (row[0]) {
				char* test_groupname = get_group_for_user(row[0]);
				if (strcmp(groupname, test_groupname) == 0) {
					sesscount++;
				}
				free(test_groupname);
			}
		}
		mysql_free_result(res);

		if (sesscount < sesslimit) {
			mysql_close(conn);
			return false;
		}
		mysql_close(conn);
		return true;
	}

	// We should never end up here!
	mysql_close(conn);
	return true;
}

pid_t raptor_sm_run_remote_server(char* username, char *const argv[], char* dbfield, int display) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	if (strcmp(dbfield, RAPTOR_SM_SERVER_PID_FIELD) == 0) {
		// Respect maximum session number for the group for this user
		if (raptor_sm_sesslimit_reached(username)) {
			mysql_close(conn);
			return -5;
		}
	}

	// Make sure a server is not already running for this user
	// Return the existing PID if it is
	char* safe_username = get_mysql_escaped_string(conn, username);
	if (strcmp(dbfield, RAPTOR_SM_SERVER_PID_FIELD) == 0) {
		asprintf(&query, "SELECT %s,servername FROM sessions WHERE username='%s' AND state<>'%d'", dbfield, safe_username, SM_STATUS_ALLOCATED);
	}
	else {
		asprintf(&query, "SELECT %s,servername FROM sessions WHERE username='%s'", dbfield, safe_username);
	}
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return -2;
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		while ((row = mysql_fetch_row(res)) != NULL) {
			if (row[0]) {
				int ret = atoi(row[0]);
				if (ret >= 0) {
					// Verify existence of PID on remote server
					dprint("Verifying process %d on %s...\n\r", ret, row[1]);
					char* ip = raptor_sm_get_ip_for_hostname(row[1], 0);
					char* command_string;
					asprintf(&command_string, "ssh root@%s \'ps -p %d | grep %d\'", ip, ret, ret);
					FILE *fp;
					char output[1024];
					// Open the command for reading
					fp = popen(command_string, "r");
					if (fp == NULL) {
						mysql_close(conn);
						return -1;
					}
					// Read the output a line at a time
					fgets(output, sizeof(output)-1, fp);
					// Close output
					pclose(fp);
					free(command_string);
					free(ip);
					dprint("...result was %s\n\r", output);
					if (strcmp(output, "") != 0) {
						mysql_free_result(res);
						mysql_close(conn);
						return ret;
					}
				}
			}
		}
		mysql_free_result(res);
	}

	int i;
	int n_commands;

	n_commands = 0;
	while (argv[n_commands] != NULL) {
		n_commands++;
	}

	char* ipaddr = raptor_sm_get_ip_for_username(username, true);

	// This is HORRIBLY inefficient
	char* command_string = strdup("");
	for (i=0; i<n_commands; i++) {
		char* origstr = command_string;
		asprintf(&command_string, "%s %s", origstr, argv[i]);
		free(origstr);
	}
	char* origstr = command_string;

	if (strcmp(dbfield, RAPTOR_SM_SERVER_PID_FIELD) == 0) {
		asprintf(&command_string, "ssh root@%s \'%s & echo $! &\'", ipaddr, origstr);
	}
	else {
		asprintf(&command_string, "ssh root@%s \"su %s -c \'export DISPLAY=:%d && %s\' &> /dev/null & echo \\$!\"", ipaddr, username, display, origstr);
	}
	dprint("Running command %s...\n\r", command_string);
	free(origstr);
	
	FILE *fp;
	char output[1024];
	
	// Open the command for reading
	fp = popen(command_string, "r");
	if (fp == NULL) {
		mysql_close(conn);
		return -1;
	}
	
	// Read the output a line at a time
	fgets(output, sizeof(output)-1, fp);
	
	// Close output
	pclose(fp);

	free(command_string);

	mysql_close(conn);
	return atoi(output);
}

pid_t raptor_sm_get_pid_for_username(char* username, char* dbfield) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	// Make sure a server is not already running for this user
	// Return the existing PID if it is
	char* safe_username = get_mysql_escaped_string(conn, username);
	asprintf(&query, "SELECT %s FROM sessions WHERE username='%s'", dbfield, safe_username);
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return -2;
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		while ((row = mysql_fetch_row(res)) != NULL) {
			if (row[0]) {
				int ret = atoi(row[0]);
				if (ret >= 0) {
					mysql_free_result(res);
					mysql_close(conn);
					return ret;
				}
			}
		}
		mysql_free_result(res);
	}

	mysql_close(conn);
	return -3;
}

char* raptor_sm_server_started(char* username, pid_t pid, int display, char* dbfield) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	long long timestamp = time(NULL);

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	// Update new information into the sessions database and set status to ALLOCATED
	char* safe_username = get_mysql_escaped_string(conn, username);
	asprintf(&query, "UPDATE sessions SET %s='%d', stamp_start='%lld', state='%d', display='%d', stamp_statechange='%lld' WHERE username='%s' AND state='%d'", dbfield, pid, timestamp, SM_STATUS_RUNNING, display, timestamp, safe_username, SM_STATUS_ALLOCATED);
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return -2;
	}
	else {
		free(query);

		// Insert connection information into the statistics database
		char* current_server = raptor_sm_get_hostname_for_display(display);
		char* safe_servername = get_mysql_escaped_string(conn, current_server);
		char* safe_username = get_mysql_escaped_string(conn, username);
		long long timestamp = time(NULL);
		asprintf(&query, "INSERT INTO statistics (timestamp, eventtypeid, servername, display, typeid, username) VALUES ('%lld', '%d', '%s', '%d', '%d', '%s')", timestamp, STATISTICS_CONNECTION_STATUS_EVENT, safe_servername, display, SM_STATUS_RUNNING, safe_username);
		free(safe_servername);
		free(safe_username);
		free(current_server);
		if (mysql_query_internal(conn, query)) {
			// Server error
			dprint("Unable to insert data into statistics database! [%s]\n\r", mysql_error(conn));
		}
		free(query);

		mysql_close(conn);
		return 0;
	}
}

char* raptor_sm_wm_started(char* username, pid_t pid, char* dbfield) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	// Update new information into the sessions database and set status to ALLOCATED
	char* safe_username = get_mysql_escaped_string(conn, username);
	asprintf(&query, "UPDATE sessions SET %s='%d' WHERE username='%s'", dbfield, pid, safe_username);
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return -2;
	}
	else {
		free(query);
		mysql_close(conn);
		return 0;
	}
}

int raptor_sm_get_display_for_username(char* username) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	char* safe_username = get_mysql_escaped_string(conn, username);
	asprintf(&query, "SELECT display FROM sessions WHERE username='%s'", safe_username);
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return -2;
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		while ((row = mysql_fetch_row(res)) != NULL) {
			if (row[0]) {
				int ret = atoi(row[0]);
				mysql_free_result(res);
				mysql_close(conn);
				return ret;
			}
			else {
				mysql_free_result(res);
				mysql_close(conn);
				return -3;
			}
		}
		// Nothing in the DB
		mysql_free_result(res);
		mysql_close(conn);
		return -4;
	}
}

char* raptor_sm_get_username_for_display_and_hostname(int display, char* hostname) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	char* safe_hostname = get_mysql_escaped_string(conn, hostname);
	asprintf(&query, "SELECT username FROM sessions WHERE display='%d' AND servername='%s'", display, safe_hostname);
	free(safe_hostname);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return strdup("");
	}
	else {
		free(query);
		res = mysql_store_result(conn);
		while ((row = mysql_fetch_row(res)) != NULL) {
			if (row[0]) {
				char* ret = strdup(row[0]);
				mysql_free_result(res);
				mysql_close(conn);
				return ret;
			}
			else {
				mysql_free_result(res);
				mysql_close(conn);
				return strdup("");
			}
		}
		// Nothing in the DB
		mysql_free_result(res);
		mysql_close(conn);
		return strdup("");
	}
}

void raptor_sm_wait_for_pid_exit(char* username, pid_t pid) {
	char* ipaddr = raptor_sm_get_ip_for_username(username, false);

	char* command_string;
	asprintf(&command_string, "ssh root@%s \'while [[ `ps -p %d | grep %d` != \"\" ]]; do sleep 1; done\'", ipaddr, pid, pid);
	system(command_string);
	free(command_string);
}

void raptor_sm_session_terminated(char* username) {
	raptor_sm_deallocate_session(username);
}

void raptor_sm_wm_terminated(char* username) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	long long timestamp = time(NULL);

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	// Update new information into the sessions database
	char* safe_username = get_mysql_escaped_string(conn, username);
	asprintf(&query, "UPDATE sessions SET %s=NULL WHERE username='%s'", RAPTOR_SM_WM_PID_FIELD, safe_username);
	free(safe_username);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return -2;
	}
	else {
		free(query);
		mysql_close(conn);
		return 0;
	}
}

int raptor_sm_get_new_unique_display(int mindisplay, int maxdisplay) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	asprintf(&query, "SELECT display FROM sessions");
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		dprint("[ERROR] MySQL connection FAILED [%s]\n\r", mysql_error(conn));
		mysql_close(conn);
		return -2;
	}
	else {
		res = mysql_store_result(conn);
		int freedisp;
		bool dispinuse;
		for (freedisp=mindisplay; freedisp<maxdisplay; freedisp++) {
			dispinuse = false;
			mysql_data_seek(res, 0);
			while ((row = mysql_fetch_row(res)) != NULL) {
				if (row[0]) {
					if (atoi(row[0]) == freedisp) {
						dispinuse = true;
					}
				}
			}
			if (dispinuse == false) {
				break;
			}
		}
		mysql_free_result(res);
		mysql_close(conn);
		return freedisp;
	}
}

char raptor_sm_set_session_state(int display, int state) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	long long timestamp = time(NULL);

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	// Update new state into the sessions database
	asprintf(&query, "UPDATE sessions SET state='%d', stamp_statechange='%lld' WHERE display='%d'", state, timestamp, display);
	if (mysql_query_internal(conn, query)) {
		// Server error
		free(query);
		mysql_close(conn);
		return -2;
	}
	else {
		free(query);

		// Insert connection information into the statistics database
		char* hostname = raptor_sm_get_hostname_for_display(display);
		char* username = raptor_sm_get_username_for_display_and_hostname(display, hostname);
		char* safe_servername = get_mysql_escaped_string(conn, hostname);
		char* safe_username = get_mysql_escaped_string(conn, username);
		long long timestamp = time(NULL);
		asprintf(&query, "INSERT INTO statistics (timestamp, eventtypeid, servername, display, typeid, username) VALUES ('%lld', '%d', '%s', '%d', '%d', '%s')", timestamp, STATISTICS_CONNECTION_STATUS_EVENT, safe_servername, display, state, safe_username);
		free(safe_servername);
		free(safe_username);
		free(hostname);
		free(username);
		if (mysql_query_internal(conn, query)) {
			// Server error
			dprint("Unable to insert data into statistics database! [%s]\n\r", mysql_error(conn));
		}
		free(query);

		mysql_close(conn);
		return 0;
	}
}

void raptor_sm_run_remote_desktop(char* username, int display, char* executable) {
	char* ipaddr = raptor_sm_get_ip_for_username(username, true);
	char* command_string;
	asprintf(&command_string, "ssh root@%s \"su %s -c \'export DISPLAY=:%d && %s && exit\' &> /dev/null\"", ipaddr, username, display, executable);
	system(command_string);
	free(command_string);
}

void raptor_sm_terminate_server(char* username) {
	char* ipaddr = raptor_sm_get_ip_for_username(username, true);
	char* command_string;

	// Terminate remote X server
	pid_t pid = raptor_sm_get_pid_for_username(username, RAPTOR_SM_SERVER_PID_FIELD);
	if (pid > 0) {
		asprintf(&command_string, "ssh root@%s \'kill -9 %ld\'", ipaddr, pid);
		system(command_string);
		free(command_string);
	}
}

void raptor_sm_stats_report_server_start(char* hostname) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	// Insert information into the statistics database
	char* safe_servername = get_mysql_escaped_string(conn, hostname);
	long long timestamp = time(NULL);
	asprintf(&query, "INSERT INTO statistics (timestamp, eventtypeid, servername, display, typeid) VALUES ('%lld', '%d', '%s', '%d', '%d')", timestamp, STATISTICS_SERVER_START_EVENT, safe_servername, -1, -1);
	free(safe_servername);
	if (mysql_query_internal(conn, query)) {
		// Server error
		dprint("Unable to insert data into statistics database! [%s]\n\r", mysql_error(conn));
	}
	free(query);
	mysql_close(conn);
}

void raptor_sm_stats_report_server_stop(char* hostname) {
	MYSQL_RES *res;
	MYSQL_ROW row;
	char* query;

	MYSQL *conn = connect_if_needed();
	if (!conn) {
		return -1;
	}

	// Insert information into the statistics database
	char* safe_servername = get_mysql_escaped_string(conn, hostname);
	long long timestamp = time(NULL);
	asprintf(&query, "INSERT INTO statistics (timestamp, eventtypeid, servername, display, typeid) VALUES ('%lld', '%d', '%s', '%d', '%d')", timestamp, STATISTICS_SERVER_STOP_EVENT, safe_servername, -1, -1);
	free(safe_servername);
	if (mysql_query_internal(conn, query)) {
		// Server error
		dprint("Unable to insert data into statistics database! [%s]\n\r", mysql_error(conn));
	}
	free(query);
	mysql_close(conn);
}