src_common/command.cpp File Reference

#include "../include/command.h"
#include <cstdlib>
#include <cstring>

Include dependency graph for command.cpp:

Go to the source code of this file.

Functions
int	send_command (int sock, command com, int *rep_data_size, char **rep_data)
	sends a synchronized command
int	receive_command (int sock, command *com)
	receives a synchronized command
int	reply_command (int sock, int status, int add_bytes, const char *add_data)
	sends a response message to a previously received command
int	receive_sft_reply (int sock, int *rep_data_size, char **rep_data)
	receives a response message

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Function Documentation

int receive_command	(	int	sock,
		command *	com
	)

receives a synchronized command

receive_command() is declared friend to allow use of fill_from_string() private member function

See also:

receive_command()

this function receives a singular command from a channel which must have been previously initialized. It will not return until a command is received, or an error occours. received parameters are saved in the command object pointed by com.

Parameters:

	sock	| socket from which to receive the command
	com	| command object to be filled for the caller

Returns:

0 if everything is ok, -1 otherwise

Definition at line 161 of file command.cpp.

References command::fill_from_string().

Referenced by CL_req_s_body(), FS_req_s_body(), mode_2(), and req_server().

int receive_sft_reply	(	int	sock,
		int *	rep_data_size,
		char **	rep_data
	)

receives a response message

this function SHOULD be used only by the CLs, when they ask a notification and the DFR finally signals the disponibility of the file to the client, the server sends a notify command to the client. If the client replies to this message with an OK status, the server assumes that a start_file_transfer command has been initiated by the client, this means that the DFR will reply with a start_file_transfer response message. the CL can use this function to catch that response message.

Parameters:

	sock	| socket on which the CL wants to wait for the response
	rep_data	| pointer to data to be returned to the client (allocated dynamically)
	rep_data_size	| pointer to an integer to return the size of the rep_data

Returns:

a state code from the following list

See also:

OK

ERR_FILE_NOT_REGISTERED

ERR_TOO_MANY_CLIENTS

ERR_FILE_NOT_EXISTS

ERR_NO_TRANSFER

ERR_NO_NOTIFICATION

ERR_UNKNOWN

Definition at line 213 of file command.cpp.

References ERR_UNKNOWN.

Referenced by mode_2().

int reply_command	(	int	sock,
		int	status,
		int	add_bytes,
		const char *	add_data
	)

sends a response message to a previously received command

each command needs a response message, allowing the corresponding send_command() call to return to the caller. the reply message is built as follows:

<status_integer|size_of_additional_data|additional_data>

status_integer is one of the following values:

• OK
• ERR_FILE_NOT_REGISTERED
• ERR_TOO_MANY_CLIENTS
• ERR_FILE_NOT_EXISTS
• ERR_NO_TRANSFER
• ERR_NO_NOTIFICATION
• ERR_UNKNOWN

size_of_additional_data is an integer-as-string field which is the number of bytes in the following field.

additional_data is the data the responder is sending to the commander which has previously sent a command.

Parameters:

	sock	| socket to send the response message
	status	| status of the request, as described above
	add_bytes	| number of bytes to be sent as additional data (0 if no additional data)
	add_data	| pointer to additional data to be sent (NULL if no additional data)

Returns:

0 if everything is ok, -1 otherwise

Definition at line 178 of file command.cpp.

References INT_AS_STRING_BYTES.

Referenced by FS_req_s_body(), mode_2(), req_server(), serve_end_file_transfer(), serve_reg_notification(), and serve_start_file_transfer().

int send_command	(	int	sock,
		command	com,
		int *	rep_data_size,
		char **	rep_data
	)

sends a synchronized command

send_command() is declared friend to allow use of to_string() private member function

See also:

send_command()

this function sends a command to a remote server or client, the connection must be previously established. It will not return until some data are received in response on the socket, this means a state message and eventually some data.

the response data will be one of the following, depending on the command:

• register_file -> no data (NULL)
• unregister_file -> no data (NULL)
• start_file_transfer -> information on how to contact the associated FS
• end_file_transfer -> no data (NULL)
• reg_notification -> no data (NULL)
• notify -> no data (NULL)
• get_file -> transferred file

Parameters:

	sock	| socket to contact the opposite end of the channel
	com	| command to be sent
	rep_data	| pointer to data to be returned to the caller (allocated dynamically)
	rep_data_size	| pointer to an integer to return the size of the rep_data, if any

Returns:

a state code from the following list

See also:

OK

ERR_FILE_NOT_REGISTERED

ERR_TOO_MANY_CLIENTS

ERR_FILE_NOT_EXISTS

ERR_NO_TRANSFER

ERR_NO_NOTIFICATION

ERR_UNKNOWN

Definition at line 112 of file command.cpp.

References ERR_UNKNOWN, and command::to_string().

Referenced by main(), mode_1(), mode_2(), send_end_command(), serve_reg_notification(), and transfer_file().