Common server data structures. More...

Data Structures
struct	sender_command_data
	Arguments for the sender command. More...

struct	misc_meta_data
	Miscellaneous data for communication between server and command handlers. More...

Macros
#define	MMD_INFO_SIZE 16384
	Size of the selector_info and audio_file info strings of struct misc_meta_data. More...

#define	OPT_RESULT(_name)
	Get the parse result of an option to para_server. More...

#define	OPT_GIVEN(_name) (lls_opt_given(OPT_RESULT(_name)))
	How many times a server option was given. More...

#define	OPT_STRING_VAL(_name) (lls_string_val(0, OPT_RESULT(_name)))
	The (first) argument to a server option of type string. More...

#define	OPT_UINT32_VAL(_name) (lls_uint32_val(0, OPT_RESULT(_name)))
	The (first) argument to a server option of type uint32. More...

#define	OPT_INT32_VAL(_name) (lls_int32_val(0, OPT_RESULT(_name)))
	The (first) argument to a server option of type int32. More...

Functions
int	handle_connect (int fd)
	Perform user authentication and execute a command. More...

void	parse_config_or_die (bool reload)
	(Re-)read the server configuration files. More...

char *	server_get_tasks (void)
	Return the list of tasks for the server process. More...

bool	process_is_command_handler (void)
	Tell whether the executing process is a command handler. More...

void	free_lpr (void)
	Deallocate all lopsub parse results. More...

Variables
pid_t	afs_pid
	The process id of the audio file selector process. More...

struct lls_parse_result *	server_lpr
	The active value for all config options of para_server. More...

Detailed Description

Common server data structures.

Macro Definition Documentation

◆ MMD_INFO_SIZE

#define MMD_INFO_SIZE 16384

Size of the selector_info and audio_file info strings of struct misc_meta_data.

◆ OPT_RESULT

#define OPT_RESULT ( _name )

Value:

(lls_opt_result( \

LSG_SERVER_PARA_SERVER_OPT_ ## _name, server_lpr))

Get the parse result of an option to para_server.

◆ OPT_GIVEN

#define OPT_GIVEN ( _name ) (lls_opt_given(OPT_RESULT(_name)))

How many times a server option was given.

◆ OPT_STRING_VAL

#define OPT_STRING_VAL ( _name ) (lls_string_val(0, OPT_RESULT(_name)))

The (first) argument to a server option of type string.

◆ OPT_UINT32_VAL

#define OPT_UINT32_VAL ( _name ) (lls_uint32_val(0, OPT_RESULT(_name)))

The (first) argument to a server option of type uint32.

◆ OPT_INT32_VAL

#define OPT_INT32_VAL ( _name ) (lls_int32_val(0, OPT_RESULT(_name)))

The (first) argument to a server option of type int32.

Function Documentation

◆ handle_connect()

int handle_connect ( int fd )

Perform user authentication and execute a command.

Parameters

fd	The file descriptor to send output to.

Whenever para_server accepts an incoming tcp connection on the port it listens on, it forks and the resulting child calls this function.

An RSA-based challenge/response is used to authenticate the peer. If the authentication succeeds, a random session key is generated and sent back to the peer, encrypted with its RSA public key. From this point on, all transfers are encrypted with this session key using a stream cipher.

Next it is checked if the peer supplied a valid server command or a command for the audio file selector. If yes, and if the user has sufficient permissions to execute this command, the function calls the corresponding command handler which performs argument checking and further processing.

To cope with DOS attacks, a timer is set up right after the fork. If the connection was still not authenticated when the timeout expires, the child process is terminated.

Returns: Standard.

See also: alarm(2), openssl.c, crypt.h.

References APC_CHALLENGE_SIZE, stream_cipher_context::fd, HANDSHAKE_BUFSIZE, HASH2_SIZE, command_context::scc, SESSION_KEY_LEN, and command_context::u.

◆ parse_config_or_die()

void parse_config_or_die ( bool reload )

(Re-)read the server configuration files.

Parameters

reload Whether config file overrides command line.

This function also re-opens the logfile and the user list. On SIGHUP it is called from both server and afs context.

References MCF_DONT_FREE, and server_lpr.

◆ server_get_tasks()

char* server_get_tasks ( void )

Return the list of tasks for the server process.

This is called from com_tasks(). The helper is necessary since command handlers can not access the scheduler structure directly.

Returns: A dynamically allocated string that must be freed by the caller.

References get_task_list().

◆ process_is_command_handler()

bool process_is_command_handler ( void )

Tell whether the executing process is a command handler.

Cleanup on exit must be performed differently for command handlers.

Returns: True if the pid of the executing process is neither the server pid nor the afs pid.

References afs_pid.

Referenced by shutdown_client(), and vss_shutdown().

◆ free_lpr()

void free_lpr ( void )

Deallocate all lopsub parse results.

The server allocates a parse result for command line options and optionally a second parse result for the effective configuration, defined by merging the command line options with the options stored in the configuration file. This function frees both structures.

References CMD_PTR, and server_lpr.

Variable Documentation

◆ afs_pid

pid_t afs_pid

extern

The process id of the audio file selector process.

Referenced by process_is_command_handler().

◆ server_lpr

struct lls_parse_result* server_lpr