relay.h File Reference

Header file for relay.c. More...

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Macros
#define	CONTROL_CELL_ID   0
#define	relay_send_command_from_edge(stream_id, circ, relay_command, payload, payload_len, cpath_layer)
#define	packed_cell_free(cell)    FREE_AND_NULL(packed_cell_t, packed_cell_free_, (cell))
#define	update_circuit_on_cmux(circ, direction)    update_circuit_on_cmux_((circ), (direction), SHORT_FILE__, __LINE__)

Functions
void	relay_consensus_has_changed (const networkstatus_t *ns)
int	circuit_receive_relay_cell (cell_t *cell, circuit_t *circ, cell_direction_t cell_direction)
size_t	cell_queues_get_total_allocation (void)
void	relay_header_pack (uint8_t *dest, const relay_header_t *src)
void	relay_header_unpack (relay_header_t *dest, const uint8_t *src)
int	relay_send_command_from_edge_ (streamid_t stream_id, circuit_t *circ, uint8_t relay_command, const char *payload, size_t payload_len, crypt_path_t *cpath_layer, const char *filename, int lineno)
int	connection_edge_send_command (edge_connection_t *fromconn, uint8_t relay_command, const char *payload, size_t payload_len)
int	connection_edge_package_raw_inbuf (edge_connection_t *conn, int package_partial, int *max_cells)
void	connection_edge_consider_sending_sendme (edge_connection_t *conn)
void	circuit_reset_sendme_randomness (circuit_t *circ)
void	dump_cell_pool_usage (int severity)
size_t	packed_cell_mem_cost (void)
int	have_been_under_memory_pressure (void)
void	packed_cell_free_ (packed_cell_t *cell)
void	cell_queue_init (cell_queue_t *queue)
void	cell_queue_clear (cell_queue_t *queue)
void	cell_queue_append (cell_queue_t *queue, packed_cell_t *cell)
void	cell_queue_append_packed_copy (circuit_t *circ, cell_queue_t *queue, int exitward, const cell_t *cell, int wide_circ_ids, int use_stats)
void	append_cell_to_circuit_queue (circuit_t *circ, channel_t *chan, cell_t *cell, cell_direction_t direction, streamid_t fromstream)
void	destroy_cell_queue_init (destroy_cell_queue_t *queue)
void	destroy_cell_queue_clear (destroy_cell_queue_t *queue)
void	destroy_cell_queue_append (destroy_cell_queue_t *queue, circid_t circid, uint8_t reason)
void	channel_unlink_all_circuits (channel_t *chan, smartlist_t *detached_out)
int	channel_flush_from_first_active_circuit (channel_t *chan, int max)
int	circuit_package_relay_cell (cell_t *cell, circuit_t *circ, cell_direction_t cell_direction, crypt_path_t *layer_hint, streamid_t on_stream, const char *filename, int lineno)
void	update_circuit_on_cmux_ (circuit_t *circ, cell_direction_t direction, const char *file, int lineno)
int	append_address_to_payload (uint8_t *payload_out, const tor_addr_t *addr)
const uint8_t *	decode_address_from_payload (tor_addr_t *addr_out, const uint8_t *payload, int payload_len)
void	circuit_clear_cell_queue (circuit_t *circ, channel_t *chan)
circid_t	packed_cell_get_circid (const packed_cell_t *cell, int wide_circ_ids)
uint8_t	packed_cell_get_command (const packed_cell_t *cell, int wide_circ_ids)

Variables
uint64_t	stats_n_relay_cells_relayed
uint64_t	stats_n_relay_cells_delivered
uint64_t	stats_n_circ_max_cell_reached
uint64_t	stats_n_data_cells_packaged
uint64_t	stats_n_data_bytes_packaged
uint64_t	stats_n_data_cells_received
uint64_t	stats_n_data_bytes_received
uint64_t	oom_stats_n_bytes_removed_dns
uint64_t	oom_stats_n_bytes_removed_cell
uint64_t	oom_stats_n_bytes_removed_geoip
uint64_t	oom_stats_n_bytes_removed_hsdir

Detailed Description

Header file for relay.c.

Definition in file relay.h.

Macro Definition Documentation

relay_send_command_from_edge

#define relay_send_command_from_edge	(		stream_id,
			circ,
			relay_command,
			payload,
			payload_len,
			cpath_layer
	)

Value:

  relay_send_command_from_edge_((stream_id), (circ), (relay_command),   \
                                (payload), (payload_len), (cpath_layer), \
                                __FILE__, __LINE__)

Definition at line 33 of file relay.h.

Function Documentation

append_address_to_payload()

int append_address_to_payload	(	uint8_t *	payload_out,
		const tor_addr_t *	addr
	)

Append an encoded value of addr to payload_out, which must have at least 18 bytes of free space. The encoding is, as specified in tor-spec.txt: RESOLVED_TYPE_IPV4 or RESOLVED_TYPE_IPV6 [1 byte] LENGTH [1 byte] ADDRESS [length bytes] Return the number of bytes added, or -1 on error

Definition at line 3203 of file relay.c.

append_cell_to_circuit_queue()

void append_cell_to_circuit_queue	(	circuit_t *	circ,
		channel_t *	chan,
		cell_t *	cell,
		cell_direction_t	direction,
		streamid_t	fromstream
	)

Add cell to the queue of circ writing to chan transmitting in direction.

The given cell is copied onto the circuit queue so the caller must cleanup the memory.

This function is part of the fast path.

Definition at line 3130 of file relay.c.

cell_queue_append()

void cell_queue_append	(	cell_queue_t *	queue,
		packed_cell_t *	cell
	)

Append cell to the end of queue.

Definition at line 2558 of file relay.c.

Referenced by cell_queue_append_packed_copy().

cell_queue_append_packed_copy()

void cell_queue_append_packed_copy	(	circuit_t *	circ,
		cell_queue_t *	queue,
		int	exitward,
		const cell_t *	cell,
		int	wide_circ_ids,
		int	use_stats
	)

Append a newly allocated copy of cell to the end of the exitward (or app-ward) queue of circ. If use_stats is true, record statistics about the cell.

Definition at line 2569 of file relay.c.

cell_queue_clear()

void cell_queue_clear

(

cell_queue_t *

queue

)

Remove and free every cell in queue.

Definition at line 2593 of file relay.c.

Referenced by circuit_clear_cell_queue().

cell_queue_init()

void cell_queue_init

(

cell_queue_t *

queue

)

Initialize queue as an empty cell queue.

Definition at line 2585 of file relay.c.

Referenced by init_circuit_base().

channel_flush_from_first_active_circuit()

int channel_flush_from_first_active_circuit	(	channel_t *	chan,
		int	max
	)

Pull as many cells as possible (but no more than max) from the queue of the first active circuit on chan, and write them to chan->outbuf. Return the number of cells written. Advance the active circuit pointer to the next active circuit in the ring.

Definition at line 2917 of file relay.c.

channel_unlink_all_circuits()

void channel_unlink_all_circuits	(	channel_t *	chan,
		smartlist_t *	circuits_out
	)

Remove all circuits from the cmux on chan.

If circuits_out is non-NULL, add all detached circuits to circuits_out.

Definition at line 2826 of file relay.c.

Referenced by circuit_unlink_all_from_channel().

circuit_clear_cell_queue()

void circuit_clear_cell_queue	(	circuit_t *	circ,
		channel_t *	chan
	)

Remove all the cells queued on circ for chan.

Definition at line 3257 of file relay.c.

Referenced by circuit_about_to_free_atexit().

circuit_package_relay_cell()

int circuit_package_relay_cell	(	cell_t *	cell,
		circuit_t *	circ,
		cell_direction_t	cell_direction,
		crypt_path_t *	layer_hint,
		streamid_t	on_stream,
		const char *	filename,
		int	lineno
	)

Package a relay cell from an edge:

• Encrypt it to the right layer
• Append it to the appropriate cell_queue on circ.

Definition at line 364 of file relay.c.

circuit_receive_relay_cell()

int circuit_receive_relay_cell	(	cell_t *	cell,
		circuit_t *	circ,
		cell_direction_t	cell_direction
	)

Receive a relay cell:

• Crypt it (encrypt if headed toward the origin or if we are the origin; decrypt if we're headed toward the exit).
• Check if recognized (if exitward).
• If recognized and the digest checks out, then find if there's a stream that the cell is intended for, and deliver it to the right connection_edge.
• If not recognized, then we need to relay it: append it to the appropriate cell_queue on circ.

Return -reason on failure.

Definition at line 226 of file relay.c.

circuit_reset_sendme_randomness()

void circuit_reset_sendme_randomness

(

circuit_t *

circ

)

Called when initializing a circuit, or when we have reached the end of the window in which we need to send some randomness so that incoming sendme cells will be unpredictable. Resets the flags and picks a new window.

Definition at line 2070 of file relay.c.

Referenced by init_circuit_base().

connection_edge_package_raw_inbuf()

int connection_edge_package_raw_inbuf	(	edge_connection_t *	conn,
		int	package_partial,
		int *	max_cells
	)

If conn has an entire relay payload of bytes on its inbuf (or package_partial is true), and the appropriate package windows aren't empty, grab a cell and send it down the circuit.

If *max_cells is given, package no more than max_cells. Decrement *max_cells by the number of cells packaged.

Return -1 (and send a RELAY_COMMAND_END cell if necessary) if conn should be marked for close, else return 0.

Definition at line 2153 of file relay.c.

connection_edge_send_command()

int connection_edge_send_command	(	edge_connection_t *	fromconn,
		uint8_t	relay_command,
		const char *	payload,
		size_t	payload_len
	)

Make a relay cell out of relay_command and payload, and send it onto the open circuit circ. fromconn is the stream that's sending the relay cell, or NULL if it's a control cell. cpath_layer is NULL for OR->OP cells, or the destination hop for OP->OR cells.

If you can't send the cell, mark the circuit for close and return -1. Else return 0.

Definition at line 732 of file relay.c.

decode_address_from_payload()

const uint8_t* decode_address_from_payload	(	tor_addr_t *	addr_out,
		const uint8_t *	payload,
		int	payload_len
	)

Given payload_len bytes at payload, starting with an address encoded as by append_address_to_payload(), try to decode the address into *addr_out. Return the next byte in the payload after the address on success, or NULL on failure.

Definition at line 3229 of file relay.c.

destroy_cell_queue_append()

void destroy_cell_queue_append	(	destroy_cell_queue_t *	queue,
		circid_t	circid,
		uint8_t	reason
	)

Append a destroy cell for circid to queue.

Definition at line 2653 of file relay.c.

destroy_cell_queue_clear()

void destroy_cell_queue_clear

(

destroy_cell_queue_t *

queue

)

Remove and free every cell in queue.

Definition at line 2627 of file relay.c.

destroy_cell_queue_init()

void destroy_cell_queue_init

(

destroy_cell_queue_t *

queue

)

Initialize queue as an empty cell queue.

Definition at line 2619 of file relay.c.

dump_cell_pool_usage()

void dump_cell_pool_usage

(

int

severity

)

Log current statistics for cell pool allocation at log level severity.

Definition at line 2531 of file relay.c.

Referenced by dumpmemusage().

have_been_under_memory_pressure()

int have_been_under_memory_pressure

(

void

)

Return true if we've been under memory pressure in the last MEMORY_PRESSURE_INTERVAL seconds.

Definition at line 2770 of file relay.c.

packed_cell_free_()

void packed_cell_free_

(

packed_cell_t *

cell

)

Return a packed cell used outside by channel_t lower layer

Definition at line 2521 of file relay.c.

packed_cell_get_circid()

circid_t packed_cell_get_circid	(	const packed_cell_t *	cell,
		int	wide_circ_ids
	)

Extract the circuit ID from a packed cell.

Definition at line 2903 of file relay.c.

packed_cell_get_command()

uint8_t packed_cell_get_command	(	const packed_cell_t *	cell,
		int	wide_circ_ids
	)

Extract the command from a packed cell.

Definition at line 2892 of file relay.c.

Referenced by write_packed_cell().

packed_cell_mem_cost()

size_t packed_cell_mem_cost

(

void

)

Return the total number of bytes used for each packed_cell in a queue. Approximate.

Definition at line 2686 of file relay.c.

relay_header_pack()

void relay_header_pack	(	uint8_t *	dest,
		const relay_header_t *	src
	)

Pack the relay_header_t host-order structure src into network-order in the buffer dest. See tor-spec.txt for details about the wire format.

Definition at line 478 of file relay.c.

Referenced by relay_set_digest().

relay_header_unpack()

void relay_header_unpack	(	relay_header_t *	dest,
		const uint8_t *	src
	)

Unpack the network-order buffer src into a host-order relay_header_t structure dest.

Definition at line 491 of file relay.c.

Referenced by connection_exit_begin_conn(), connection_exit_begin_resolve(), pathbias_check_probe_response(), pathbias_count_valid_cells(), relay_lookup_conn(), and relay_set_digest().

relay_send_command_from_edge_()

int relay_send_command_from_edge_	(	streamid_t	stream_id,
		circuit_t *	circ,
		uint8_t	relay_command,
		const char *	payload,
		size_t	payload_len,
		crypt_path_t *	cpath_layer,
		const char *	filename,
		int	lineno
	)

Make a relay cell out of relay_command and payload, and send it onto the open circuit circ. stream_id is the ID on circ for the stream that's sending the relay cell, or 0 if it's a control cell. cpath_layer is NULL for OR->OP cells, or the destination hop for OP->OR cells.

If you can't send the cell, mark the circuit for close and return -1. Else return 0.

Definition at line 611 of file relay.c.

update_circuit_on_cmux_()

void update_circuit_on_cmux_	(	circuit_t *	circ,
		cell_direction_t	direction,
		const char *	file,
		int	lineno
	)

Update the number of cells available on the circuit's n_chan or p_chan's circuit mux.

Definition at line 2781 of file relay.c.

Variable Documentation

oom_stats_n_bytes_removed_dns

uint64_t oom_stats_n_bytes_removed_dns

extern

Statistics on how many bytes were removed by the OOM per type.

Definition at line 2705 of file relay.c.

stats_n_circ_max_cell_reached

uint64_t stats_n_circ_max_cell_reached

extern

Stats: how many circuits have we closed due to the cell queue limit being reached (see append_cell_to_circuit_queue())

Definition at line 135 of file relay.c.

stats_n_data_bytes_packaged

uint64_t stats_n_data_bytes_packaged

extern

How many bytes of data have we put in relay_data cells have we built, ever? This would be RELAY_PAYLOAD_SIZE*stats_n_data_cells_packaged if every relay cell we ever sent were completely full of data.

Definition at line 2056 of file relay.c.

stats_n_data_bytes_received

uint64_t stats_n_data_bytes_received

extern

How many bytes of data have we received relay_data cells, ever? This would be RELAY_PAYLOAD_SIZE*stats_n_data_cells_packaged if every relay cell we ever received were completely full of data.

Definition at line 2062 of file relay.c.

stats_n_data_cells_packaged

uint64_t stats_n_data_cells_packaged

extern

How many relay_data cells have we built, ever?

Definition at line 2052 of file relay.c.

stats_n_data_cells_received

uint64_t stats_n_data_cells_received

extern

How many relay_data cells have we received, ever?

Definition at line 2058 of file relay.c.

stats_n_relay_cells_delivered

uint64_t stats_n_relay_cells_delivered

extern

Stats: how many relay cells have been delivered to streams at this hop?

Definition at line 132 of file relay.c.

stats_n_relay_cells_relayed

uint64_t stats_n_relay_cells_relayed

extern

Stats: how many relay cells have originated at this hop, or have been relayed onward (not recognized at this hop)?

Definition at line 128 of file relay.c.