Code to read and apply bandwidth authority data. More...

#include "core/or/or.h"
#include "feature/dirauth/bwauth.h"
#include "app/config/config.h"
#include "feature/dirauth/dirauth_sys.h"
#include "feature/nodelist/networkstatus.h"
#include "feature/nodelist/routerlist.h"
#include "feature/dirparse/ns_parse.h"
#include "feature/dirauth/dirauth_options_st.h"
#include "feature/nodelist/routerinfo_st.h"
#include "feature/nodelist/vote_routerstatus_st.h"
#include "lib/crypt_ops/crypto_format.h"
#include "lib/encoding/keyval.h"

Data Structures
struct	mbw_cache_entry_t

Functions
void	dirserv_count_measured_bws (const smartlist_t *routers)

int	dirserv_get_last_n_measured_bws (void)

STATIC void	dirserv_cache_measured_bw (const measured_bw_line_t *parsed_line, time_t as_of)

void	dirserv_clear_measured_bw_cache (void)

STATIC void	dirserv_expire_measured_bw_cache (time_t now)

int	dirserv_query_measured_bw_cache_kb (const char node_id, long bw_kb_out, time_t *as_of_out)

int	dirserv_has_measured_bw (const char *node_id)

int	dirserv_get_measured_bw_cache_size (void)

uint32_t	dirserv_get_credible_bandwidth_kb (const routerinfo_t *ri)

int	dirserv_read_measured_bandwidths (const char from_file, smartlist_t routerstatuses, smartlist_t bw_file_headers, uint8_t digest_out)

STATIC int	measured_bw_line_parse (measured_bw_line_t out, const char orig_line, int line_is_after_headers)

STATIC int	measured_bw_line_apply (measured_bw_line_t parsed_line, smartlist_t routerstatuses)

Variables
static int	routers_with_measured_bw = 0

static digestmap_t *	mbw_cache = NULL

Detailed Description

Code to read and apply bandwidth authority data.

Code to read and apply guard fraction data.

Definition in file bwauth.c.

Function Documentation

◆ dirserv_cache_measured_bw()

STATIC void dirserv_cache_measured_bw	(	const measured_bw_line_t *	parsed_line,
		time_t	as_of
	)

Store a measured bandwidth cache entry when reading the measured bandwidths file.

Definition at line 73 of file bwauth.c.

◆ dirserv_clear_measured_bw_cache()

void dirserv_clear_measured_bw_cache ( void )

Clear and free the measured bandwidth cache

Definition at line 103 of file bwauth.c.

◆ dirserv_count_measured_bws()

void dirserv_count_measured_bws ( const smartlist_t * routers )

Look through the routerlist, and using the measured bandwidth cache count how many measured bandwidths we know. This is used to decide whether we ever trust advertised bandwidths for purposes of assigning flags.

Definition at line 39 of file bwauth.c.

◆ dirserv_expire_measured_bw_cache()

STATIC void dirserv_expire_measured_bw_cache ( time_t now )

Scan the measured bandwidth cache and remove expired entries

Definition at line 114 of file bwauth.c.

◆ dirserv_get_credible_bandwidth_kb()

uint32_t dirserv_get_credible_bandwidth_kb ( const routerinfo_t * ri )

Return the bandwidth we believe for assigning flags; prefer measured over advertised, and if we have above a threshold quantity of measured bandwidths, we don't want to ever give flags to unmeasured routers, so return 0.

Definition at line 177 of file bwauth.c.

Referenced by dirauth_set_routerstatus_from_routerinfo(), and dirserv_thinks_router_is_unreliable().

◆ dirserv_get_last_n_measured_bws()

int dirserv_get_last_n_measured_bws ( void )

Return the last-computed result from dirserv_count_mesured_bws().

Definition at line 55 of file bwauth.c.

◆ dirserv_get_measured_bw_cache_size()

int dirserv_get_measured_bw_cache_size ( void )

Get the current size of the measured bandwidth cache

Definition at line 166 of file bwauth.c.

◆ dirserv_has_measured_bw()

int dirserv_has_measured_bw ( const char * node_id )

Predicate wrapper for dirserv_query_measured_bw_cache()

Definition at line 159 of file bwauth.c.

Referenced by dirserv_count_measured_bws(), and router_counts_toward_thresholds().

◆ dirserv_query_measured_bw_cache_kb()

int dirserv_query_measured_bw_cache_kb	(	const char *	node_id,
		long *	bw_kb_out,
		time_t *	as_of_out
	)

Query the cache by identity digest, return value indicates whether we found it. The bw_out and as_of_out pointers receive the cached bandwidth value and the time it was cached if not NULL.

Definition at line 138 of file bwauth.c.

Referenced by dirserv_get_bandwidth_for_router_kb(), dirserv_get_credible_bandwidth_kb(), and dirserv_has_measured_bw().

◆ dirserv_read_measured_bandwidths()

int dirserv_read_measured_bandwidths	(	const char *	from_file,
		smartlist_t *	routerstatuses,
		smartlist_t *	bw_file_headers,
		uint8_t *	digest_out
	)

Read the measured bandwidth list from_file:

store all the headers in bw_file_headers,
apply bandwidth lines to the list of vote_routerstatus_t in routerstatuses,
cache bandwidth lines for dirserv_get_bandwidth_for_router(),
expire old entries in the measured bandwidth cache, and
store the DIGEST_SHA256 of the contents of the file in digest_out.

Returns -1 on error, 0 otherwise.

If the file can't be read, or is empty:

bw_file_headers is empty,
routerstatuses is not modified,
the measured bandwidth cache is not modified, and
digest_out is the zero-byte digest.

Otherwise, if there is an error later in the file:

bw_file_headers contains all the headers up to the error,
routerstatuses is updated with all the relay lines up to the error,
the measured bandwidth cache is updated with all the relay lines up to the error,
if the timestamp is valid and recent, old entries in the measured bandwidth cache are expired, and
digest_out is the digest up to the first read error (if any). The digest is taken over all the readable file contents, even if the file is outdated or unparseable.

Definition at line 232 of file bwauth.c.

◆ measured_bw_line_apply()

STATIC int measured_bw_line_apply	(	measured_bw_line_t *	parsed_line,
		smartlist_t *	routerstatuses
	)

Helper function to apply a parsed measurement line to a list of bandwidth statuses. Returns true if a line is found, false otherwise.

Definition at line 483 of file bwauth.c.

◆ measured_bw_line_parse()

STATIC int measured_bw_line_parse	(	measured_bw_line_t *	out,
		const char *	orig_line,
		int	line_is_after_headers
	)

Helper function to parse out a line in the measured bandwidth file into a measured_bw_line_t output structure.

If line_is_after_headers is true, then if we encounter an incomplete bw line, return -1 and warn, since we are after the headers and we should only parse bw lines. Return 0 otherwise.

If line_is_after_headers is false then it means that we are not past the header block yet. If we encounter an incomplete bw line, return -1 but don't warn since there could be additional header lines coming. If we encounter a proper bw line, return 0 (and we got past the headers).

If the line contains "vote=0", stop parsing it, and return -1, so that the line is ignored during voting.

Definition at line 375 of file bwauth.c.

Variable Documentation

◆ mbw_cache

digestmap_t* mbw_cache = NULL

static

Measured bandwidth cache - keys are identity_digests, values are mbw_cache_entry_t *.

Definition at line 68 of file bwauth.c.

Referenced by dirserv_cache_measured_bw(), dirserv_clear_measured_bw_cache(), dirserv_expire_measured_bw_cache(), and dirserv_get_measured_bw_cache_size().

◆ routers_with_measured_bw

int routers_with_measured_bw = 0