statefile.c File Reference

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

#include "core/or/or.h"
#include "core/or/circuitstats.h"
#include "app/config/config.h"
#include "feature/relay/transport_config.h"
#include "lib/confmgt/confmgt.h"
#include "core/mainloop/mainloop.h"
#include "core/mainloop/netstatus.h"
#include "core/mainloop/connection.h"
#include "feature/control/control_events.h"
#include "feature/client/entrynodes.h"
#include "feature/hibernate/hibernate.h"
#include "feature/stats/bwhist.h"
#include "feature/relay/router.h"
#include "feature/relay/routermode.h"
#include "lib/sandbox/sandbox.h"
#include "app/config/statefile.h"
#include "app/main/subsysmgr.h"
#include "lib/encoding/confline.h"
#include "lib/net/resolve.h"
#include "lib/version/torversion.h"
#include "app/config/or_state_st.h"

Go to the source code of this file.

Macros
#define	STATEFILE_PRIVATE
#define	VAR(varname, conftype, member, initvalue)    CONFIG_VAR_ETYPE(or_state_t, varname, conftype, member, 0, initvalue)
#define	V(member, conftype, initvalue)    VAR(#member, conftype, member, initvalue)
#define	OR_STATE_MAGIC   0x57A73f57
#define	CHECK_STATE_MAGIC(s)
#define	STATE_WRITE_RETRY_INTERVAL   3600
#define	STATE_RELAY_CHECKPOINT_INTERVAL   (12*60*60)

Functions
	DUMMY_TYPECHECK_INSTANCE (or_state_t)
static int	or_state_validate (or_state_t *state, char **msg)
static int	or_state_validate_cb (const void *old_options, void *options, char **msg)
STATIC const config_mgr_t *	get_state_mgr (void)
or_state_t *	get_or_state (void)
int	or_state_loaded (void)
static int	state_transport_line_is_valid (const char *line)
static int	validate_transports_in_state (or_state_t *state)
static int	or_state_set (or_state_t *new_state)
static void	or_state_save_broken (char *fname)
STATIC or_state_t *	or_state_new (void)
int	or_state_load (void)
STATIC void	or_state_remove_obsolete_lines (config_line_t **extra_lines)
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)
static const char *	get_transport_bindaddr (const char *line, 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)

Variables
static config_abbrev_t	state_abbrevs_ []
static const char *	obsolete_state_keys []
static const config_var_t	state_vars_ []
static struct_member_t	state_extra_var
static const config_format_t	state_format
static config_mgr_t *	state_mgr = NULL
static or_state_t *	global_state = NULL
static int	last_state_file_write_failed = 0

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 confmgt.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.

Definition in file statefile.c.

Macro Definition Documentation

CHECK_STATE_MAGIC

#define CHECK_STATE_MAGIC

(

s

)

Value:

    STMT_BEGIN                        \
    config_check_toplevel_magic(get_state_mgr(), (s));         \
  STMT_END

Definition at line 211 of file statefile.c.

OR_STATE_MAGIC

#define OR_STATE_MAGIC   0x57A73f57

Magic value for or_state_t.

Definition at line 169 of file statefile.c.

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.

Definition at line 558 of file statefile.c.

STATE_WRITE_RETRY_INTERVAL

#define STATE_WRITE_RETRY_INTERVAL   3600

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

Definition at line 553 of file statefile.c.

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.

Definition at line 547 of file statefile.c.

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_or_state()

or_state_t* get_or_state

(

void

)

Return the persistent state struct for this Tor.

Definition at line 220 of file statefile.c.

Referenced by accounting_run_housekeeping(), entry_guards_changed_for_guard_selection(), entry_guards_update_state(), get_transport_in_state_by_name(), read_bandwidth_usage(), rotate_onion_key(), save_state_callback(), save_transport_to_state(), and tor_cleanup().

get_state_mgr()

STATIC const config_mgr_t* get_state_mgr

(

void

)

Return the configuration manager for state-file objects.

Definition at line 200 of file statefile.c.

Referenced by or_state_validate().

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.

Definition at line 689 of file statefile.c.

Referenced by get_bindaddr_for_server_proxy().

get_transport_bindaddr()

static const char* get_transport_bindaddr ( const char *  line, const char *  transport  )

static

Return string containing the address:port part of the TransportProxy line for transport transport. If the line is corrupted, return NULL.

Definition at line 663 of file statefile.c.

Referenced by get_stored_bindaddr_for_server_transport(), and save_transport_to_state().

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.

Definition at line 625 of file statefile.c.

Referenced by get_stored_bindaddr_for_server_transport(), and save_transport_to_state().

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.

Definition at line 412 of file statefile.c.

or_state_loaded()

int or_state_loaded

(

void

)

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

Definition at line 228 of file statefile.c.

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.

Definition at line 784 of file statefile.c.

Referenced by entry_guards_changed_for_guard_selection(), entry_guards_update_state(), and tor_cleanup().

or_state_remove_obsolete_lines()

STATIC void or_state_remove_obsolete_lines

(

config_line_t **

extra_lines

)

Remove from extra_lines every element whose key appears in obsolete_state_keys.

Definition at line 513 of file statefile.c.

or_state_save()

int or_state_save

(

time_t

now

)

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

Definition at line 562 of file statefile.c.

Referenced by save_state_callback(), and tor_cleanup().

or_state_save_broken()

static void or_state_save_broken ( char *  fname )

static

Save a broken state file to a backup location.

Definition at line 364 of file statefile.c.

or_state_set()

static int or_state_set ( or_state_t *  new_state )

static

Replace the current persistent state with new_state

Definition at line 332 of file statefile.c.

or_state_validate()

static int or_state_validate ( or_state_t *  state, char **  msg  )

static

Return 0 if every setting in state is reasonable, and a permissible transition from old_state. Else warn and return -1. Should have no side effects, except for normalizing the contents of state.

Definition at line 302 of file statefile.c.

or_state_validate_cb()

static int or_state_validate_cb ( const void *  old_state, void *  state_, char **  msg  )

static

Legacy validation/normalization callback for or_state_t. See legacy_validate_fn_t for more information.

Definition at line 312 of file statefile.c.

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

Definition at line 722 of file statefile.c.

Referenced by register_server_proxy().

state_transport_line_is_valid()

static int state_transport_line_is_valid ( const char *  line )

static

Return true if line is a valid state TransportProxy line. Return false otherwise.

Definition at line 236 of file statefile.c.

Referenced by validate_transports_in_state().

validate_transports_in_state()

static int validate_transports_in_state ( or_state_t *  state )

static

Return 0 if all TransportProxy lines in state are well formed. Otherwise, return -1.

Definition at line 279 of file statefile.c.

Variable Documentation

global_state

or_state_t* global_state = NULL

static

Persistent serialized state.

Definition at line 216 of file statefile.c.

Referenced by get_or_state(), and or_state_loaded().

last_state_file_write_failed

int last_state_file_write_failed = 0

static

Did the last time we tried to write the state file fail? If so, we should consider disabling such features as preemptive circuit generation to compute circuit-build-time.

Definition at line 543 of file statefile.c.

Referenced by did_last_state_file_write_fail().

obsolete_state_keys

const char* obsolete_state_keys[]

static

Initial value:

= {
  
  "AccountingBytesReadInterval",
  "HelperNode",
  "HelperNodeDownSince",
  "HelperNodeUnlistedSince",
  "EntryNode",
  "HelperNodeDownSince",
  "EntryNodeUnlistedSince",
  
  "EntryGuard",
  "EntryGuardDownSince",
  "EntryGuardUnlistedSince",
  "EntryGuardAddedBy",
  "EntryGuardPathBias",
  "EntryGuardPathUseBias",
  
  "HidServRevCounter",
 
  NULL,
}

A list of obsolete keys that we do not and should not preserve.

We could just let these live in ExtraLines indefinitely, but they're never going to be used again, and every version that used them has been obsolete for a long time.

Definition at line 70 of file statefile.c.

Referenced by or_state_remove_obsolete_lines().

state_abbrevs_

config_abbrev_t state_abbrevs_[]

static

Initial value:

= {
  { NULL, NULL, 0, 0},
}

A list of state-file "abbreviations," for compatibility.

Definition at line 60 of file statefile.c.

state_extra_var

struct_member_t state_extra_var

static

Initial value:

= {
  .name = "__extra",
  .type = CONFIG_TYPE_LINELIST,
  .offset = offsetof(or_state_t, ExtraLines),
}

"Extra" variable in the state that receives lines we can't parse. This lets us preserve options from versions of Tor newer than us.

Definition at line 173 of file statefile.c.

state_format

const config_format_t state_format

static

Initial value:

= {
  .size = sizeof(or_state_t),
  .magic = {
   "or_state_t",
   OR_STATE_MAGIC,
   offsetof(or_state_t, magic_),
  },
  .abbrevs = state_abbrevs_,
  .vars = state_vars_,
  .legacy_validate_fn = or_state_validate_cb,
  .extra = &state_extra_var,
  .has_config_suite = true,
  .config_suite_offset = offsetof(or_state_t, substates_),
}

Configuration format for or_state_t.

Definition at line 180 of file statefile.c.

state_vars_

const config_var_t state_vars_[]

static

Array of "state" variables saved to the ~/.tor/state file.

Definition at line 104 of file statefile.c.