statefile.c File Reference

Handles parsing and encoding the persistent 'state' file that carries miscellaneous persistent state between Tor invocations. More...

#include "or.h"
#include "circuitstats.h"
#include "config.h"
#include "confparse.h"
#include "connection.h"
#include "control.h"
#include "entrynodes.h"
#include "hibernate.h"
#include "main.h"
#include "rephist.h"
#include "router.h"
#include "sandbox.h"
#include "statefile.h"

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Macros
#define	STATEFILE_PRIVATE
#define	VAR(name, conftype, member, initvalue)
#define	V(member, conftype, initvalue)   VAR(#member, conftype, member, initvalue)
#define	OR_STATE_MAGIC   0x57A73f57
#define	STATE_WRITE_RETRY_INTERVAL   3600
#define	STATE_RELAY_CHECKPOINT_INTERVAL   (12*60*60)

Functions
	DUMMY_TYPECHECK_INSTANCE (or_state_t)
	MOCK_IMPL (or_state_t *, get_or_state,(void))
int	or_state_loaded (void)
STATIC or_state_t *	or_state_new (void)
int	or_state_load (void)
int	did_last_state_file_write_fail (void)
int	or_state_save (time_t now)
STATIC config_line_t *	get_transport_in_state_by_name (const char *transport)
char *	get_stored_bindaddr_for_server_transport (const char *transport)
void	save_transport_to_state (const char *transport, const tor_addr_t *addr, uint16_t port)
void	or_state_mark_dirty (or_state_t *state, time_t when)
STATIC void	or_state_free_ (or_state_t *state)
void	or_state_free_all (void)

Detailed Description

Handles parsing and encoding the persistent 'state' file that carries miscellaneous persistent state between Tor invocations.

This 'state' file is a typed key-value store that allows multiple entries for the same key. It follows the same metaformat as described in confparse.c, and uses the same code to read and write itself.

The state file is most suitable for small values that don't change too frequently. For values that become very large, we typically use a separate file – for example, see how we handle microdescriptors, by storing them in a separate file with a journal.

The current state is accessed via get_or_state(), which returns a singleton or_state_t object. Functions that change it should call or_state_mark_dirty() to ensure that it will get written to disk.

The or_state_save() function additionally calls various functioens throughout Tor that might want to flush more state to the the disk, including some in rephist.c, entrynodes.c, circuitstats.c, hibernate.c.

Macro Definition Documentation

OR_STATE_MAGIC

#define OR_STATE_MAGIC   0x57A73f57

Magic value for or_state_t.

STATE_RELAY_CHECKPOINT_INTERVAL

#define STATE_RELAY_CHECKPOINT_INTERVAL   (12*60*60)

If we're a relay, how often should we checkpoint our state file even if nothing else dirties it? This will checkpoint ongoing stats like bandwidth used, per-country user stats, etc.

STATE_WRITE_RETRY_INTERVAL

#define STATE_WRITE_RETRY_INTERVAL   3600

If writing the state to disk fails, try again after this many seconds.

V

#define V	(		member,
			conftype,
			initvalue
	)		VAR(#member, conftype, member, initvalue)

As VAR, but the option name and member name are the same.

VAR

#define VAR	(		name,
			conftype,
			member,
			initvalue
	)

Value:

{ name, CONFIG_TYPE_ ## conftype, offsetof(or_state_t, member),       \
      initvalue CONF_TEST_MEMBERS(or_state_t, conftype, member) }

Function Documentation

did_last_state_file_write_fail()

int did_last_state_file_write_fail

(

void

)

Return whether the state file failed to write last time we tried.

DUMMY_TYPECHECK_INSTANCE()

DUMMY_TYPECHECK_INSTANCE

(

or_state_t

)

dummy instance of or_state_t, used for type-checking its members with CONF_CHECK_VAR_TYPE.

get_stored_bindaddr_for_server_transport()

char* get_stored_bindaddr_for_server_transport

(

const char *

transport

)

Return a string containing the address:port that a proxy transport should bind on. The string is stored on the heap and must be freed by the caller of this function.

If we didn't find references for this pluggable transport in the state file, we should instruct the pluggable transport proxy to listen on INADDR_ANY on a random ephemeral port.

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get_transport_in_state_by_name()

STATIC config_line_t* get_transport_in_state_by_name

(

const char *

transport

)

Return the config line for transport transport in the current state. Return NULL if there is no config line for transport.

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MOCK_IMPL()

MOCK_IMPL	(	or_state_t *	,
		get_or_state	,
		(void)
	)

Return the persistent state struct for this Tor.

or_state_load()

int or_state_load

(

void

)

Reload the persistent state from disk, generating a new state as needed. Return 0 on success, less than 0 on failure.

or_state_loaded()

int or_state_loaded

(

void

)

Return true iff we have loaded the global state for this Tor

or_state_mark_dirty()

void or_state_mark_dirty	(	or_state_t *	state,
		time_t	when
	)

Change the next_write time of state to when, unless the state is already scheduled to be written to disk earlier than when.

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or_state_save()

int or_state_save

(

time_t

now

)

Write the persistent state to disk. Return 0 for success, <0 on failure.

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save_transport_to_state()

void save_transport_to_state	(	const char *	transport,
		const tor_addr_t *	addr,
		uint16_t	port
	)

Save transport listening on addr:port to state

find where to write on the state

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