send.h File Reference

Sender-related defines and structures. More...

Data Structures
struct	sender
	Describes one supported sender of para_server. More...
struct	sender_client
	Describes one client, connected to a paraslash sender. More...
struct	fec_client_parms
	Each paraslash sender may register arbitrary many clients to the virtual streaming system, possibly with varying fec parameters. More...
struct	sender_status
	Describes the current status of one paraslash sender. More...

Macros
#define	SENDER_SUBCOMMANDS
	A little preprocessor fu helps to create the sender_subcommand enumeration below and the list of sender name strings without duplicating the commands. More...
#define	SENDER_SUBCOMMAND(_name)   SENDER_ ## _name,
	Concatenate "SENDER_" and the given arg and append a comma. More...
#define	SENDER_SUBCOMMAND(_name)   #_name,
	Concatenate "SENDER_" and the given arg and append a comma. More...
#define	FOR_EACH_SENDER(_i)   for ((_i) = 0; senders[(_i)]; (_i)++)
	Iterate over all senders. More...
#define	FOR_EACH_LISTEN_FD(_n, _ss)   for (_n = 0; _n < (_ss)->num_listen_fds; _n++)
	Iterate over all listening addresses of the http/dccp sender. More...

Enumerations
enum	sender_subcommand {   SENDER_add, SENDER_delete, SENDER_allow, SENDER_deny,   SENDER_on, SENDER_off, NUM_SENDER_CMDS }
	Each sender subcommand gets an SENDER_xxx identifier. More...

Functions
void	shutdown_client (struct sender_client *sc, struct sender_status *ss)
	Shut down a client connected to a paraslash sender. More...
void	shutdown_clients (struct sender_status *ss)
	Shut down all clients connected to a paraslash sender. More...
void	init_sender_status (struct sender_status *ss, const struct lls_opt_result *acl_opt_result, const struct lls_opt_result *listen_address_opt_result, int default_port, int max_clients, int default_deny)
	Initialize a struct sender status. More...
void	free_sender_status (const struct sender_status *ss)
	Deallocate all resources allocated in init_sender_status(). More...
__malloc char *	generic_sender_status (struct sender_status *ss, const char *name)
	Return a string containing the current status of a sender. More...
void	generic_com_allow (struct sender_command_data *scd, struct sender_status *ss)
	Allow connections from the given range of IP addresses. More...
void	generic_com_deny (struct sender_command_data *scd, struct sender_status *ss)
	Deny connections from the given range of IP addresses. More...
void	generic_com_on (struct sender_status *ss, unsigned protocol)
	Activate a paraslash sender. More...
void	generic_acl_deplete (struct list_head *acl)
	Empty the access control list of a sender. More...
void	generic_com_off (struct sender_status *ss)
	Deactivate a paraslash sender. More...
__malloc char *	generic_sender_help (void)
	Get the generic help text. More...
struct sender_client *	accept_sender_client (struct sender_status *ss)
	Accept a connection on the socket(s) this server is listening on. More...
int	send_queued_chunks (int fd, struct chunk_queue *cq)
	Try to empty the chunk queue for this fd. More...
int	parse_fec_url (const char *arg, struct sender_command_data *scd)
	Parse a FEC URL string. More...

Variables
const struct sender *const	senders []
	NULL-terminated list, defined in vss.c. More...

Detailed Description

Sender-related defines and structures.

Macro Definition Documentation

SENDER_SUBCOMMANDS

#define SENDER_SUBCOMMANDS

Value:

        SENDER_SUBCOMMAND(add)  \
        SENDER_SUBCOMMAND(delete)  \
        SENDER_SUBCOMMAND(allow)  \
        SENDER_SUBCOMMAND(deny)  \
        SENDER_SUBCOMMAND(on)  \
        SENDER_SUBCOMMAND(off)

A little preprocessor fu helps to create the sender_subcommand enumeration below and the list of sender name strings without duplicating the commands.

Deactivate the sender.

SENDER_SUBCOMMAND [1/2]

#define SENDER_SUBCOMMAND

(

_name

)

SENDER_ ## _name,

Concatenate "SENDER_" and the given arg and append a comma.

Redefine it to expand to the stringified name of the sender so that SENDER_SUBCOMMANDS above now expands to the comma-separated list of sender name strings.

This is used in command.c to define and initialize an array of char pointers.

SENDER_SUBCOMMAND [2/2]

#define SENDER_SUBCOMMAND

(

_name

)

#_name,

Concatenate "SENDER_" and the given arg and append a comma.

Redefine it to expand to the stringified name of the sender so that SENDER_SUBCOMMANDS above now expands to the comma-separated list of sender name strings.

This is used in command.c to define and initialize an array of char pointers.

FOR_EACH_SENDER

#define FOR_EACH_SENDER

(

_i

)

for ((_i) = 0; senders[(_i)]; (_i)++)

Iterate over all senders.

FOR_EACH_LISTEN_FD

#define FOR_EACH_LISTEN_FD	(		_n,
			_ss
	)		for (_n = 0; _n < (_ss)->num_listen_fds; _n++)

Iterate over all listening addresses of the http/dccp sender.

Enumeration Type Documentation

sender_subcommand

enum sender_subcommand

Each sender subcommand gets an SENDER_xxx identifier.

The identifier is passed from the sender command handler to the server process via shared memory.

Enumerator
SENDER_add	Add a target (udp only).
SENDER_delete	Delete a target (udp only).
SENDER_allow	Allow connections from given IP address(es).
SENDER_deny	Deny connections from given IP address(es).
SENDER_on	Activate the sender.
SENDER_off	Deactivate the sender. List of SENDER_xxx identifiers.
NUM_SENDER_CMDS	Used as array size in struct sender.

Function Documentation

shutdown_client()

void shutdown_client	(	struct sender_client *	sc,
		struct sender_status *	ss
	)

Shut down a client connected to a paraslash sender.

Parameters

sc	The client to shut down.
ss	The sender whose clients are to be shut down.

Close the file descriptor given by sc, remove it from the close-on-fork list, destroy the chunk queue of this client, delete the client from the list of connected clients and free the sender_client struct.

See also

shutdown_clients().

References sender_client::cq, cq_destroy(), del_close_on_fork_list(), sender_client::fd, sender_client::name, PARA_INFO_LOG, and process_is_command_handler().

Referenced by shutdown_clients().

shutdown_clients()

void shutdown_clients

(

struct sender_status *

ss

)

Shut down all clients connected to a paraslash sender.

Parameters

ss	The sender whose clients are to be shut down.

This just loops over all connected clients and calls shutdown_client() for each client.

References sender_status::client_list, list_for_each_entry_safe, sender_client::node, and shutdown_client().

Referenced by generic_com_off().

init_sender_status()

void init_sender_status	(	struct sender_status *	ss,
		const struct lls_opt_result *	acl_opt_result,
		const struct lls_opt_result *	listen_address_opt_result,
		int	default_port,
		int	max_clients,
		int	default_deny
	)

Initialize a struct sender status.

Parameters

ss	The struct to initialize.
acl_opt_result	Contains array of –{http|dccp}-access arguments.
listen_address_opt_result	Where to listen on.
default_port	Used for addresses with no specified port.
max_clients	The maximal number of simultaneous connections.
default_deny	Whether a blacklist should be used for access control.

References alloc(), sender_status::default_port, FOR_EACH_LISTEN_FD, sender_status::listen_addresses, sender_status::listen_fds, sender_status::num_listen_fds, and para_strdup().

free_sender_status()

void free_sender_status

(

const struct sender_status *

ss

)

Deallocate all resources allocated in init_sender_status().

Parameters

ss	The structure whose components should be freed.

This frees the dynamically allocated parts of the structure which was initialized by an earlier call to init_sender_status(). It does not call free(ss), though.

References FOR_EACH_LISTEN_FD, sender_status::listen_addresses, and sender_status::listen_fds.

generic_sender_status()

__malloc char* generic_sender_status	(	struct sender_status *	ss,
		const char *	name
	)

Return a string containing the current status of a sender.

Parameters

ss	The sender.
name	Used for printing the header line.

Returns

The string printed in the "si" command.

References sender_status::acl, acl_get_contents(), sender_status::client_list, sender_status::default_deny, sender_status::default_port, FOR_EACH_LISTEN_FD, format_url(), list_for_each_entry_safe, sender_status::listen_addresses, sender_status::listen_fds, make_message(), sender_status::max_clients, sender_client::name, sender_client::node, sender_status::num_clients, and stringify_port().

generic_com_allow()

void generic_com_allow	(	struct sender_command_data *	scd,
		struct sender_status *	ss
	)

Allow connections from the given range of IP addresses.

Parameters

scd	Contains the IP and the netmask.
ss	The sender.

See also

generic_com_deny().

References sender_status::acl, acl_allow(), sender_status::default_deny, sender_command_data::host, and sender_command_data::netmask.

generic_com_deny()

void generic_com_deny	(	struct sender_command_data *	scd,
		struct sender_status *	ss
	)

Deny connections from the given range of IP addresses.

Parameters

scd	see generic_com_allow().
ss	see generic_com_allow().

See also

generic_com_allow().

References sender_status::acl, acl_deny(), sender_status::default_deny, sender_command_data::host, and sender_command_data::netmask.

generic_com_on()

void generic_com_on	(	struct sender_status *	ss,
		unsigned	protocol
	)

Activate a paraslash sender.

Parameters

ss	The sender to activate.
protocol	layer4 type (IPPROTO_TCP or IPPROTO_DCCP).

This opens a passive socket of given layer4 type, sets the resulting file descriptor to nonblocking mode and adds it to the close on fork list.

Errors are logged but otherwise ignored.

References add_close_on_fork_list(), sender_status::default_port, FOR_EACH_LISTEN_FD, format_url(), sender_status::listen_addresses, sender_status::listen_fds, mark_fd_nonblocking(), PARA_ERROR_LOG, para_listen(), and para_strerror().

generic_acl_deplete()

void generic_acl_deplete

(

struct list_head *

acl

)

Empty the access control list of a sender.

Parameters

acl	The access control list of the sender.

This is called from the ->shutdown methods of the http and the dccp sender.

References acl_allow().

generic_com_off()

void generic_com_off

(

struct sender_status *

ss

)

Deactivate a paraslash sender.

Shutdown all connected clients and stop listening on the TCP/DCCP socket.

Parameters

ss	The sender to deactivate.

See also

del_close_on_fork_list(), shutdown_clients().

References del_close_on_fork_list(), FOR_EACH_LISTEN_FD, sender_status::listen_fds, and shutdown_clients().

generic_sender_help()

__malloc char* generic_sender_help

(

void

)

Get the generic help text.

Returns

A dynamically allocated string containing the help text for a paraslash sender.

References make_message().

accept_sender_client()

struct sender_client* accept_sender_client

(

struct sender_status *

ss

)

Accept a connection on the socket(s) this server is listening on.

Parameters

ss	The sender whose listening fd is ready for reading.

This accepts incoming connections on any of the listening sockets of the server. If there is a connection pending, the function

 - Checks whether the maximal number of connections are exceeded.
 - Sets \a fd to nonblocking mode.
 - Checks the acl of the sender to find out whether connections
   are allowed from the IP of the connecting peer.
    - Increases the number of connections for this sender.
 - Creates and initializes a new chunk queue for queuing network
   packets that can not be sent immediately.
 - Allocates a new struct sender_client and fills in its \a fd, \a cq
   and \a name members.
 - Adds \a fd to the list of connected clients for this sender.
 - Adds \a fd to the list of file descriptors that should be closed
   in the child process when the server calls fork().

Returns

A pointer to the allocated sender_client structure on success, NULL on errors.

See also

para_accept(), mark_fd_nonblocking(), acl_check_access(), cq_new(), add_close_on_fork_list().

References sender_status::acl, acl_check_access(), sender_client::cq, cq_new(), sender_status::default_deny, sender_client::fd, FOR_EACH_LISTEN_FD, sender_status::listen_fds, mark_fd_nonblocking(), sender_status::max_clients, MAX_CQ_BYTES, sender_client::name, sender_status::num_clients, para_accept(), para_strdup(), remote_name(), and zalloc().

send_queued_chunks()

int send_queued_chunks	(	int	fd,
		struct chunk_queue *	cq
	)

Try to empty the chunk queue for this fd.

Parameters

fd	The file descriptor.
cq	The list of queued chunks.

Returns

Negative on errors, zero if not everything was sent, one otherwise.

References cq_dequeue(), cq_get(), cq_peek(), cq_update(), and xwrite().

parse_fec_url()

int parse_fec_url	(	const char *	arg,
		struct sender_command_data *	scd
	)

Parse a FEC URL string.

Parameters

arg	the URL string to parse.
scd	The structure containing host, port and the FEC parameters.

Returns

Standard.

A FEC URL consists of an ordinary URL string according to RFC 3986, optionally followed by a slash and the three FEC parameters slice_size, data_slices_per_group and slices_per_group. The three FEC parameters are separated by colons.

See also

parse_url().

References sender_command_data::data_slices_per_group, sender_command_data::max_slice_bytes, para_strdup(), and sender_command_data::slices_per_group.

Variable Documentation

senders

const struct sender* const senders[]

extern

NULL-terminated list, defined in vss.c.

Referenced by vss_shutdown().