server.c File Reference

This program acts like a server in the LAN Messenger. More...

#include "server.h"

Go to the source code of this file.

Functions

void Close (int fd)

This function is used for closing a file.

void close_properly (int signal)

This function is called when we press Ctrl+C key or on any error condition.

ssize_t Write (int fd, const void *buf, size_t count)

This function is used for writing into the file/socket.

int Socket (int domain, int type, int protocol)

This function creates an unbound socket in a communications domain, and return a file descriptor that can be used in later function calls that operate on sockets.

void Bind (int sockfd, const struct sockaddr *my_addr, socklen_t addrlen)

This function shall assign a local socket address address to a socket identified by descriptor socket that has no local socket address assigned.

void Listen (int sockfd, int backlog)

This function shall mark a connection-mode socket, specified by the socket argument, as accepting connections.

int Accept (int sockfd, struct sockaddr *addr, socklen_t *addrlen)

This function hall extract the first connection on the queue of pending connections, create a new socket with the same socket type protocol and address family as the specified socket, and allocate a new file descriptor for that socket.

ssize_t Read (int fd, void *buf, size_t count)

This function reads the data from file/socket into a buffer.

int isNickExists (char *nick)

This function checks if the client who is attempting to connect with a nick name already exists or not.

void insert_row (char *query)

This function inserts a row into a mysql database.

void write_all (char *data)

This function sends the message send by one client to all other connected clients.

void add_widget_with_label (GtkContainer *box, gchar *caption, GtkWidget *widget)

This function adds the widget to the Box with corresponding label passed.

void end_program (GtkWidget *widget1, gpointer data)

This function calls when we close the window.

void onExit (GtkWidget *widget1, gpointer data)

This function calls when we close the window.

void mysql_connect_create_table ()

This function connects to the database and creates a table (if not present) for logging the chats of clients.

void connect_server (GtkWidget *widget1, gpointer data)

This function stars the server with the given port for listening.It is called when we press "Connect" button Widget.

void * start_server (void *arg)

This function starts the server.

int main (int argc, char *argv[])

This is where program execution starts.

Detailed Description

This program acts like a server in the LAN Messenger.

It listens to the user specified port and accepts all client connections and then it would list all the messages being sent by the clients, log them into a database and list of all connected clients.

Author:: Ratna Kumar K.V.R

Definition in file server.c.

Function Documentation

int Accept	(	int	sockfd,
		struct sockaddr *	addr,
		socklen_t *	addrlen
	)

This function hall extract the first connection on the queue of pending connections, create a new socket with the same socket type protocol and address family as the specified socket, and allocate a new file descriptor for that socket.

Parameters:

	sockfd	Specifies a socket that was created with socket(), has been bound to an address with bind(), and has issued a successful call to listen().
	addr	Either a null pointer, or a pointer to a sockaddr structure where the address of the connecting socket shall be returned.
	addrlen	Points to a socklen_t structure which specifies the length of the supplied sockaddr structure.

Returns:: the non-negative file descriptor of the accepted socket. Otherwise, -1 shall be returned and errno set to indicate the error.

Definition at line 126 of file server.c.

Referenced by start_server().

void add_widget_with_label	(	GtkContainer *	box,
		gchar *	caption,
		GtkWidget *	widget
	)

This function adds the widget to the Box with corresponding label passed.

Parameters:

	box	Box into which widget has to be packed
	caption	label to be given.
	widget	widget to be packed.

Definition at line 242 of file server.c.

Referenced by main().

void Bind	(	int	sockfd,
		const struct sockaddr *	my_addr,
		socklen_t	addrlen
	)

This function shall assign a local socket address address to a socket identified by descriptor socket that has no local socket address assigned.

Parameters:

	sockfd	Specifies the file descriptor of the socket to be bound.
	my_addr	Points to a sockaddr structure containing the address to be bound to the socket.
	addrlen	Specifies the length of the sockaddr structure pointed to by the address argument.

Definition at line 92 of file server.c.

References err_msg, and success.

Referenced by connect_server().

void Close ( int fd )

This function is used for closing a file.

It returns an error message if it cannot close the file/socket.

Parameters:

fd

file descriptor of the file/socket to be closed.

Definition at line 16 of file server.c.

Referenced by close_properly(), end_program(), and start_server().

void close_properly ( int signal )

This function is called when we press Ctrl+C key or on any error condition.

It does proper closing of all file descriptors and database connections.

Parameters:

signal

(SIGINT)

Definition at line 30 of file server.c.

References client, Close(), connection1, listen_file_descriptor, and maxi.

Referenced by insert_row(), and start_server().

void connect_server	(	GtkWidget *	widget1,
		gpointer	data
	)

This function stars the server with the given port for listening.It is called when we press "Connect" button Widget.

It gives appropriate message if it cannot listen to the port.

Parameters:

	widget1	Connect button
	data	pointer

Definition at line 318 of file server.c.

References Bind(), entry_port, err_msg, Listen(), listen_file_descriptor, Socket(), and success.

Referenced by main().

void end_program	(	GtkWidget *	widget1,
		gpointer	data
	)

This function calls when we close the window.

. which quits the window and exits the program. It shutdowns and closes all the connections.

Parameters:

	widget1	Widget to be closed
	data	pointer

Definition at line 257 of file server.c.

References client, Close(), connection1, listen_file_descriptor, and maxi.

Referenced by main().

void insert_row ( char * query )

This function inserts a row into a mysql database.

The row contains information like ID, timestamp, message of client, nickname of client, IP address of client. basically logging the chat into database.

Parameters:

query

insert query.

Definition at line 184 of file server.c.

References close_properly(), and connection1.

Referenced by write_all().

int isNickExists ( char * nick )

This function checks if the client who is attempting to connect with a nick name already exists or not.

Parameters:

nick

nickname of client attempting to connect

Returns:: 1 if nick already exists, 0 if not exists.

Definition at line 161 of file server.c.

References client, and maxi.

Referenced by start_server().

void Listen	(	int	sockfd,
		int	backlog
	)

This function shall mark a connection-mode socket, specified by the socket argument, as accepting connections.

Parameters:

	sockfd	file descriptor on which it has to listen.
	backlog	used to limit the number of outstanding connections in the socket's listen queue.

Definition at line 107 of file server.c.

References err_msg, and success.

Referenced by connect_server().

int main	(	int	argc,
		char *	argv[]
	)

This is where program execution starts.

All arguments are passed to gtk for processing, which removes any arguments relevant to it. All other arguments are ignored. This function first gets a window for user to enter listening port. If it can listen succesfully then it displays the chat room, else it displays the dialog box with approriate message.

Parameters:

	argc	Number of arguments passed.
	argv	NULL terminated array of command line arguments.

Returns:: EXIT_SUCCESS on success, EXIT_FAILURE on failure

Definition at line 568 of file server.c.

References add_widget_with_label(), buffer, connect_server(), end_program(), entry_port, iter, list_store, mysql_connect_create_table(), onExit(), and start_server().

void mysql_connect_create_table ( )

This function connects to the database and creates a table (if not present) for logging the chats of clients.

Definition at line 290 of file server.c.

References connection1.

Referenced by main().

void onExit	(	GtkWidget *	widget1,
		gpointer	data
	)

This function calls when we close the window.

. which quits the window and exits the program. so it shutdowns and closes all the connections.

Parameters:

	widget1	Widget to be closed
	data	pointer

Definition at line 282 of file server.c.

Referenced by main().

ssize_t Read	(	int	fd,
		void *	buf,
		size_t	count
	)

This function reads the data from file/socket into a buffer.

Parameters:

	fd	file descriptor used for reading data
	buf	buffer into which the data read from file is stored
	count	Maximum number of bytes to be read

Returns:: number of bytes read ( < 0 indicates error)

Definition at line 145 of file server.c.

Referenced by start_server().

int Socket	(	int	domain,
		int	type,
		int	protocol
	)

This function creates an unbound socket in a communications domain, and return a file descriptor that can be used in later function calls that operate on sockets.

Parameters:

	domain	Specifies the communications domain in which a socket is to be created.
	type	Specifies the type of socket to be created.
	protocol	Specifies a particular protocol to be used with the socket.

Returns:: non-negative integer, the socket file descriptor. Otherwise, a value of -1 shall be returned and errno set to indicate the error.

Definition at line 74 of file server.c.

References err_msg, and success.

Referenced by connect_server().

void* start_server ( void * arg )

This function starts the server.

It accepts the client connections and sends the client messages to all other connected clients, logs the chat into database and lists the connected clients.

Parameters:

arg

arguments to be sent

Definition at line 354 of file server.c.

References Accept(), buffer, BUFFER, client, Close(), close_properly(), client_data::fd, client_data::ip, ip, isNickExists(), iter, list_store, listen_file_descriptor, maxi, client_data::nick, nick, Read(), t_iter, Write(), and write_all().

Referenced by main().

ssize_t Write	(	int	fd,
		const void *	buf,
		size_t	count
	)

This function is used for writing into the file/socket.

It prints error message and returns the status if it fails to write.

Parameters:

	fd	file descriptor of the file into which we write.
	buf	pointer to the buffer which stores the data to be written.
	count	number of bytes to be written.

Returns:: number of bytes written ( < 0 indicates failure)

Definition at line 55 of file server.c.

Referenced by start_server(), and write_all().

void write_all ( char * data )

This function sends the message send by one client to all other connected clients.

Parameters:

data

message to be sent.

Definition at line 201 of file server.c.

References buffer, BUFFER, client, insert_row(), ip, transmit_unit::ip, iter, maxi, transmit_unit::msg, nick, transmit_unit::nick, transmit_unit::time, and Write().

Referenced by start_server().


Functions
void	Close (int fd)
	This function is used for closing a file.
void	close_properly (int signal)
	This function is called when we press Ctrl+C key or on any error condition.
ssize_t	Write (int fd, const void *buf, size_t count)
	This function is used for writing into the file/socket.
int	Socket (int domain, int type, int protocol)
	This function creates an unbound socket in a communications domain, and return a file descriptor that can be used in later function calls that operate on sockets.
void	Bind (int sockfd, const struct sockaddr *my_addr, socklen_t addrlen)
	This function shall assign a local socket address address to a socket identified by descriptor socket that has no local socket address assigned.
void	Listen (int sockfd, int backlog)
	This function shall mark a connection-mode socket, specified by the socket argument, as accepting connections.
int	Accept (int sockfd, struct sockaddr addr, socklen_t addrlen)
	This function hall extract the first connection on the queue of pending connections, create a new socket with the same socket type protocol and address family as the specified socket, and allocate a new file descriptor for that socket.
ssize_t	Read (int fd, void *buf, size_t count)
	This function reads the data from file/socket into a buffer.
int	isNickExists (char *nick)
	This function checks if the client who is attempting to connect with a nick name already exists or not.
void	insert_row (char *query)
	This function inserts a row into a mysql database.
void	write_all (char *data)
	This function sends the message send by one client to all other connected clients.
void	add_widget_with_label (GtkContainer box, gchar caption, GtkWidget *widget)
	This function adds the widget to the Box with corresponding label passed.
void	end_program (GtkWidget *widget1, gpointer data)
	This function calls when we close the window.
void	onExit (GtkWidget *widget1, gpointer data)
	This function calls when we close the window.
void	mysql_connect_create_table ()
	This function connects to the database and creates a table (if not present) for logging the chats of clients.
void	connect_server (GtkWidget *widget1, gpointer data)
	This function stars the server with the given port for listening.It is called when we press "Connect" button Widget.
void *	start_server (void *arg)
	This function starts the server.
int	main (int argc, char *argv[])
	This is where program execution starts.