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Diffstat (limited to 'src/feature/client/entrynodes.h')
| -rw-r--r-- | src/feature/client/entrynodes.h | 639 |
1 files changed, 639 insertions, 0 deletions
diff --git a/src/feature/client/entrynodes.h b/src/feature/client/entrynodes.h new file mode 100644 index 0000000000..5f9b5bdcba --- /dev/null +++ b/src/feature/client/entrynodes.h @@ -0,0 +1,639 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file entrynodes.h + * \brief Header file for circuitbuild.c. + **/ + +#ifndef TOR_ENTRYNODES_H +#define TOR_ENTRYNODES_H + +#include "lib/container/handles.h" + +/* Forward declare for guard_selection_t; entrynodes.c has the real struct */ +typedef struct guard_selection_s guard_selection_t; + +/* Forward declare for entry_guard_t; the real declaration is private. */ +typedef struct entry_guard_t entry_guard_t; + +/* Forward declaration for circuit_guard_state_t; the real declaration is + private. */ +typedef struct circuit_guard_state_t circuit_guard_state_t; + +/* Forward declaration for entry_guard_restriction_t; the real declaration is + private. */ +typedef struct entry_guard_restriction_t entry_guard_restriction_t; + +/* Information about a guard's pathbias status. + * These fields are used in circpathbias.c to try to detect entry + * nodes that are failing circuits at a suspicious frequency. + */ +typedef struct guard_pathbias_t { + unsigned int path_bias_noticed : 1; /**< Did we alert the user about path + * bias for this node already? */ + unsigned int path_bias_warned : 1; /**< Did we alert the user about path bias + * for this node already? */ + unsigned int path_bias_extreme : 1; /**< Did we alert the user about path + * bias for this node already? */ + unsigned int path_bias_disabled : 1; /**< Have we disabled this node because + * of path bias issues? */ + unsigned int path_bias_use_noticed : 1; /**< Did we alert the user about path + * use bias for this node already? */ + unsigned int path_bias_use_extreme : 1; /**< Did we alert the user about path + * use bias for this node already? */ + + double circ_attempts; /**< Number of circuits this guard has "attempted" */ + double circ_successes; /**< Number of successfully built circuits using + * this guard as first hop. */ + double successful_circuits_closed; /**< Number of circuits that carried + * streams successfully. */ + double collapsed_circuits; /**< Number of fully built circuits that were + * remotely closed before any streams were + * attempted. */ + double unusable_circuits; /**< Number of circuits for which streams were + * attempted, but none succeeded. */ + double timeouts; /**< Number of 'right-censored' circuit timeouts for this + * guard. */ + double use_attempts; /**< Number of circuits we tried to use with streams */ + double use_successes; /**< Number of successfully used circuits using + * this guard as first hop. */ +} guard_pathbias_t; + +#if defined(ENTRYNODES_PRIVATE) +#include "lib/crypt_ops/crypto_ed25519.h" + +/** + * @name values for entry_guard_t.is_reachable. + * + * See entry_guard_t.is_reachable for more information. + */ +/**@{*/ +#define GUARD_REACHABLE_NO 0 +#define GUARD_REACHABLE_YES 1 +#define GUARD_REACHABLE_MAYBE 2 +/**@}*/ + +/** An entry_guard_t represents our information about a chosen long-term + * first hop, known as a "helper" node in the literature. We can't just + * use a node_t, since we want to remember these even when we + * don't have any directory info. */ +struct entry_guard_t { + HANDLE_ENTRY(entry_guard, entry_guard_t); + + char nickname[MAX_HEX_NICKNAME_LEN+1]; + char identity[DIGEST_LEN]; + ed25519_public_key_t ed_id; + + /** + * @name new guard selection algorithm fields. + * + * Only the new (prop271) algorithm uses these. For a more full + * description of the algorithm, see the module documentation for + * entrynodes.c + */ + /**@{*/ + + /* == Persistent fields, present for all sampled guards. */ + /** When was this guard added to the sample? */ + time_t sampled_on_date; + /** Since what date has this guard been "unlisted"? A guard counts as + * unlisted if we have a live consensus that does not include it, or + * if we have a live consensus that does not include it as a usable + * guard. This field is zero when the guard is listed. */ + time_t unlisted_since_date; // can be zero + /** What version of Tor added this guard to the sample? */ + char *sampled_by_version; + /** Is this guard listed right now? If this is set, then + * unlisted_since_date should be set too. */ + unsigned currently_listed : 1; + + /* == Persistent fields, for confirmed guards only */ + /** When was this guard confirmed? (That is, when did we first use it + * successfully and decide to keep it?) This field is zero if this is not a + * confirmed guard. */ + time_t confirmed_on_date; /* 0 if not confirmed */ + /** + * In what order was this guard confirmed? Guards with lower indices + * appear earlier on the confirmed list. If the confirmed list is compacted, + * this field corresponds to the index of this guard on the confirmed list. + * + * This field is set to -1 if this guard is not confirmed. + */ + int confirmed_idx; /* -1 if not confirmed; otherwise the order that this + * item should occur in the CONFIRMED_GUARDS ordered + * list */ + + /** + * Which selection does this guard belong to? + */ + char *selection_name; + + /** Bridges only: address of the bridge. */ + tor_addr_port_t *bridge_addr; + + /* ==== Non-persistent fields. */ + /* == These are used by sampled guards */ + /** When did we last decide to try using this guard for a circuit? 0 for + * "not since we started up." */ + time_t last_tried_to_connect; + /** How reachable do we consider this guard to be? One of + * GUARD_REACHABLE_NO, GUARD_REACHABLE_YES, or GUARD_REACHABLE_MAYBE. */ + unsigned is_reachable : 2; + /** Boolean: true iff this guard is pending. A pending guard is one + * that we have an in-progress circuit through, and which we do not plan + * to try again until it either succeeds or fails. Primary guards can + * never be pending. */ + unsigned is_pending : 1; + /** If true, don't write this guard to disk. (Used for bridges with unknown + * identities) */ + unsigned is_persistent : 1; + /** When did we get the earliest connection failure for this guard? + * We clear this field on a successful connect. We do _not_ clear it + * when we mark the guard as "MAYBE" reachable. + */ + time_t failing_since; + + /* == Set inclusion flags. */ + /** If true, this guard is in the filtered set. The filtered set includes + * all sampled guards that our configuration allows us to use. */ + unsigned is_filtered_guard : 1; + /** If true, this guard is in the usable filtered set. The usable filtered + * set includes all filtered guards that are not believed to be + * unreachable. (That is, those for which is_reachable is not + * GUARD_REACHABLE_NO) */ + unsigned is_usable_filtered_guard : 1; + unsigned is_primary:1; + + /** This string holds any fields that we are maintaining because + * we saw them in the state, even if we don't understand them. */ + char *extra_state_fields; + + /** Backpointer to the guard selection that this guard belongs to. + * The entry_guard_t must never outlive its guard_selection. */ + guard_selection_t *in_selection; + /**@}*/ + + /** Path bias information for this guard. */ + guard_pathbias_t pb; +}; + +/** + * Possible rules for a guard selection to follow + */ +typedef enum guard_selection_type_t { + /** Infer the type of this selection from its name. */ + GS_TYPE_INFER=0, + /** Use the normal guard selection algorithm, taking our sample from the + * complete list of guards in the consensus. */ + GS_TYPE_NORMAL=1, + /** Use the normal guard selection algorithm, taking our sample from the + * configured bridges, and allowing it to grow as large as all the configured + * bridges */ + GS_TYPE_BRIDGE, + /** Use the normal guard selection algorithm, taking our sample from the + * set of filtered nodes. */ + GS_TYPE_RESTRICTED, +} guard_selection_type_t; + +/** + * All of the the context for guard selection on a particular client. + * + * We maintain multiple guard selection contexts for a client, depending + * aspects on its current configuration -- whether an extremely + * restrictive EntryNodes is used, whether UseBridges is enabled, and so + * on.) + * + * See the module documentation for entrynodes.c for more information + * about guard selection algorithms. + */ +struct guard_selection_s { + /** + * The name for this guard-selection object. (Must not contain spaces). + */ + char *name; + + /** + * What rules does this guard-selection object follow? + */ + guard_selection_type_t type; + + /** + * A value of 1 means that primary_entry_guards is up-to-date with respect to + * the consensus and status info that we currently have; 0 means we need to + * recalculate it before using primary_entry_guards or the is_primary flag on + * any guard. + */ + int primary_guards_up_to_date; + + /** + * A list of the sampled entry guards, as entry_guard_t structures. + * Not in any particular order. When we 'sample' a guard, we are + * noting it as a possible guard to pick in the future. The use of + * sampling here prevents us from being forced by an attacker to try + * every guard on the network. This list is persistent. + */ + smartlist_t *sampled_entry_guards; + + /** + * Ordered list (from highest to lowest priority) of guards that we + * have successfully contacted and decided to use. Every member of + * this list is a member of sampled_entry_guards. Every member should + * have confirmed_on_date set, and have confirmed_idx greater than + * any earlier member of the list. + * + * This list is persistent. It is a subset of the elements in + * sampled_entry_guards, and its pointers point to elements of + * sampled_entry_guards. + */ + smartlist_t *confirmed_entry_guards; + + /** + * Ordered list (from highest to lowest priority) of guards that we + * are willing to use the most happily. These guards may or may not + * yet be confirmed yet. If we can use one of these guards, we are + * probably not on a network that is trying to restrict our guard + * choices. + * + * This list is a subset of the elements in + * sampled_entry_guards, and its pointers point to elements of + * sampled_entry_guards. + */ + smartlist_t *primary_entry_guards; + + /** When did we last successfully build a circuit or use a circuit? */ + time_t last_time_on_internet; + + /** What confirmed_idx value should the next-added member of + * confirmed_entry_guards receive? */ + int next_confirmed_idx; + +}; + +struct entry_guard_handle_t; + +/** Types of restrictions we impose when picking guard nodes */ +typedef enum guard_restriction_type_t { + /* Don't pick the same guard node as our exit node (or its family) */ + RST_EXIT_NODE = 0, + /* Don't pick dirguards that have previously shown to be outdated */ + RST_OUTDATED_MD_DIRSERVER = 1 +} guard_restriction_type_t; + +/** + * A restriction to remember which entry guards are off-limits for a given + * circuit. + * + * Note: This mechanism is NOT for recording which guards are never to be + * used: only which guards cannot be used on <em>one particular circuit</em>. + */ +struct entry_guard_restriction_t { + /* What type of restriction are we imposing? */ + guard_restriction_type_t type; + + /* In case of restriction type RST_EXIT_NODE, the guard's RSA identity + * digest must not equal this; and it must not be in the same family as any + * node with this digest. */ + uint8_t exclude_id[DIGEST_LEN]; +}; + +/** + * Per-circuit state to track whether we'll be able to use the circuit. + */ +struct circuit_guard_state_t { + /** Handle to the entry guard object for this circuit. */ + struct entry_guard_handle_t *guard; + /** The time at which <b>state</b> last changed. */ + time_t state_set_at; + /** One of GUARD_CIRC_STATE_* */ + uint8_t state; + + /** + * A set of restrictions that were placed on this guard when we selected it + * for this particular circuit. We need to remember the restrictions here, + * since any guard that breaks these restrictions will not block this + * circuit from becoming COMPLETE. + */ + entry_guard_restriction_t *restrictions; +}; +#endif /* defined(ENTRYNODES_PRIVATE) */ + +/* Common entry points for old and new guard code */ +int guards_update_all(void); +const node_t *guards_choose_guard(cpath_build_state_t *state, + uint8_t purpose, + circuit_guard_state_t **guard_state_out); +const node_t *guards_choose_dirguard(uint8_t dir_purpose, + circuit_guard_state_t **guard_state_out); + +#if 1 +/* XXXX NM I would prefer that all of this stuff be private to + * entrynodes.c. */ +entry_guard_t *entry_guard_get_by_id_digest_for_guard_selection( + guard_selection_t *gs, const char *digest); +entry_guard_t *entry_guard_get_by_id_digest(const char *digest); + +circuit_guard_state_t * +get_guard_state_for_bridge_desc_fetch(const char *digest); + +void entry_guards_changed_for_guard_selection(guard_selection_t *gs); +void entry_guards_changed(void); +guard_selection_t * get_guard_selection_info(void); +int num_live_entry_guards_for_guard_selection( + guard_selection_t *gs, + int for_directory); +int num_live_entry_guards(int for_directory); +#endif /* 1 */ + +const node_t *entry_guard_find_node(const entry_guard_t *guard); +const char *entry_guard_get_rsa_id_digest(const entry_guard_t *guard); +const char *entry_guard_describe(const entry_guard_t *guard); +guard_pathbias_t *entry_guard_get_pathbias_state(entry_guard_t *guard); + +/** Enum to specify how we're going to use a given guard, when we're picking + * one for immediate use. */ +typedef enum { + GUARD_USAGE_TRAFFIC = 0, + GUARD_USAGE_DIRGUARD = 1 +} guard_usage_t; + +#define circuit_guard_state_free(val) \ + FREE_AND_NULL(circuit_guard_state_t, circuit_guard_state_free_, (val)) + +void circuit_guard_state_free_(circuit_guard_state_t *state); +int entry_guard_pick_for_circuit(guard_selection_t *gs, + guard_usage_t usage, + entry_guard_restriction_t *rst, + const node_t **chosen_node_out, + circuit_guard_state_t **guard_state_out); + +/* We just connected to an entry guard. What should we do with the circuit? */ +typedef enum { + GUARD_USABLE_NEVER = -1, /* Never use the circuit */ + GUARD_MAYBE_USABLE_LATER = 0, /* Keep it. We might use it in the future */ + GUARD_USABLE_NOW = 1, /* Use it right now */ +} guard_usable_t; + +guard_usable_t entry_guard_succeeded(circuit_guard_state_t **guard_state_p); +void entry_guard_failed(circuit_guard_state_t **guard_state_p); +void entry_guard_cancel(circuit_guard_state_t **guard_state_p); +void entry_guard_chan_failed(channel_t *chan); +int entry_guards_update_all(guard_selection_t *gs); +int entry_guards_upgrade_waiting_circuits(guard_selection_t *gs, + const smartlist_t *all_circuits, + smartlist_t *newly_complete_out); +int entry_guard_state_should_expire(circuit_guard_state_t *guard_state); +void entry_guards_note_internet_connectivity(guard_selection_t *gs); + +int update_guard_selection_choice(const or_options_t *options); + +int entry_guard_could_succeed(const circuit_guard_state_t *guard_state); + +MOCK_DECL(int,num_bridges_usable,(int use_maybe_reachable)); + +#ifdef ENTRYNODES_PRIVATE +/** + * @name Default values for the parameters for the new (prop271) entry guard + * algorithm. + */ +/**@{*/ +/** + * We never let our sampled guard set grow larger than this percentage + * of the guards on the network. + */ +#define DFLT_MAX_SAMPLE_THRESHOLD_PERCENT 20 +/** + * We never let our sampled guard set grow larger than this number of + * guards. + */ +#define DFLT_MAX_SAMPLE_SIZE 60 +/** + * We always try to make our sample contain at least this many guards. + */ +#define DFLT_MIN_FILTERED_SAMPLE_SIZE 20 +/** + * If a guard is unlisted for this many days in a row, we remove it. + */ +#define DFLT_REMOVE_UNLISTED_GUARDS_AFTER_DAYS 20 +/** + * We remove unconfirmed guards from the sample after this many days, + * regardless of whether they are listed or unlisted. + */ +#define DFLT_GUARD_LIFETIME_DAYS 120 +/** + * We remove confirmed guards from the sample if they were sampled + * GUARD_LIFETIME_DAYS ago and confirmed this many days ago. + */ +#define DFLT_GUARD_CONFIRMED_MIN_LIFETIME_DAYS 60 +/** + * How many guards do we try to keep on our primary guard list? + */ +#define DFLT_N_PRIMARY_GUARDS 3 +/** + * Of the live guards on the primary guard list, how many do we consider when + * choosing a guard to use? + */ +#define DFLT_N_PRIMARY_GUARDS_TO_USE 1 +/** + * As DFLT_N_PRIMARY_GUARDS, but for choosing which directory guard to use. + */ +#define DFLT_N_PRIMARY_DIR_GUARDS_TO_USE 3 +/** + * If we haven't successfully built or used a circuit in this long, then + * consider that the internet is probably down. + */ +#define DFLT_INTERNET_LIKELY_DOWN_INTERVAL (10*60) +/** + * If we're trying to connect to a nonprimary guard for at least this + * many seconds, and we haven't gotten the connection to work, we will treat + * lower-priority guards as usable. + */ +#define DFLT_NONPRIMARY_GUARD_CONNECT_TIMEOUT 15 +/** + * If a circuit has been sitting around in 'waiting for better guard' state + * for at least this long, we'll expire it. + */ +#define DFLT_NONPRIMARY_GUARD_IDLE_TIMEOUT (10*60) +/** + * If our configuration retains fewer than this fraction of guards from the + * torrc, we are in a restricted setting. + */ +#define DFLT_MEANINGFUL_RESTRICTION_PERCENT 20 +/** + * If our configuration retains fewer than this fraction of guards from the + * torrc, we are in an extremely restricted setting, and should warn. + */ +#define DFLT_EXTREME_RESTRICTION_PERCENT 1 +/**@}*/ + +STATIC double get_max_sample_threshold(void); +STATIC int get_max_sample_size_absolute(void); +STATIC int get_min_filtered_sample_size(void); +STATIC int get_remove_unlisted_guards_after_days(void); +STATIC int get_guard_lifetime(void); +STATIC int get_guard_confirmed_min_lifetime(void); +STATIC int get_n_primary_guards(void); +STATIC int get_n_primary_guards_to_use(guard_usage_t usage); +STATIC int get_internet_likely_down_interval(void); +STATIC int get_nonprimary_guard_connect_timeout(void); +STATIC int get_nonprimary_guard_idle_timeout(void); +STATIC double get_meaningful_restriction_threshold(void); +STATIC double get_extreme_restriction_threshold(void); + +HANDLE_DECL(entry_guard, entry_guard_t, STATIC) +#define entry_guard_handle_free(h) \ + FREE_AND_NULL(entry_guard_handle_t, entry_guard_handle_free_, (h)) + +STATIC guard_selection_type_t guard_selection_infer_type( + guard_selection_type_t type_in, + const char *name); +STATIC guard_selection_t *guard_selection_new(const char *name, + guard_selection_type_t type); +STATIC guard_selection_t *get_guard_selection_by_name( + const char *name, guard_selection_type_t type, int create_if_absent); +STATIC void guard_selection_free_(guard_selection_t *gs); +#define guard_selection_free(gs) \ + FREE_AND_NULL(guard_selection_t, guard_selection_free_, (gs)) +MOCK_DECL(STATIC int, entry_guard_is_listed, + (guard_selection_t *gs, const entry_guard_t *guard)); +STATIC const char *choose_guard_selection(const or_options_t *options, + const networkstatus_t *ns, + const guard_selection_t *old_selection, + guard_selection_type_t *type_out); +STATIC entry_guard_t *get_sampled_guard_with_id(guard_selection_t *gs, + const uint8_t *rsa_id); + +MOCK_DECL(STATIC time_t, randomize_time, (time_t now, time_t max_backdate)); + +MOCK_DECL(STATIC circuit_guard_state_t *, + circuit_guard_state_new,(entry_guard_t *guard, unsigned state, + entry_guard_restriction_t *rst)); + +STATIC entry_guard_t *entry_guard_add_to_sample(guard_selection_t *gs, + const node_t *node); +STATIC entry_guard_t *entry_guards_expand_sample(guard_selection_t *gs); +STATIC char *entry_guard_encode_for_state(entry_guard_t *guard); +STATIC entry_guard_t *entry_guard_parse_from_state(const char *s); +#define entry_guard_free(e) \ + FREE_AND_NULL(entry_guard_t, entry_guard_free_, (e)) +STATIC void entry_guard_free_(entry_guard_t *e); +STATIC void entry_guards_update_filtered_sets(guard_selection_t *gs); +STATIC int entry_guards_all_primary_guards_are_down(guard_selection_t *gs); +/** + * @name Flags for sample_reachable_filtered_entry_guards() + */ +/**@{*/ +#define SAMPLE_EXCLUDE_CONFIRMED (1u<<0) +#define SAMPLE_EXCLUDE_PRIMARY (1u<<1) +#define SAMPLE_EXCLUDE_PENDING (1u<<2) +#define SAMPLE_NO_UPDATE_PRIMARY (1u<<3) +#define SAMPLE_EXCLUDE_NO_DESCRIPTOR (1u<<4) +/**@}*/ +STATIC entry_guard_t *sample_reachable_filtered_entry_guards( + guard_selection_t *gs, + const entry_guard_restriction_t *rst, + unsigned flags); +STATIC void entry_guard_consider_retry(entry_guard_t *guard); +STATIC void make_guard_confirmed(guard_selection_t *gs, entry_guard_t *guard); +STATIC void entry_guards_update_confirmed(guard_selection_t *gs); +STATIC void entry_guards_update_primary(guard_selection_t *gs); +STATIC int num_reachable_filtered_guards(const guard_selection_t *gs, + const entry_guard_restriction_t *rst); +STATIC void sampled_guards_update_from_consensus(guard_selection_t *gs); +/** + * @name Possible guard-states for a circuit. + */ +/**@{*/ +/** State for a circuit that can (so far as the guard subsystem is + * concerned) be used for actual traffic as soon as it is successfully + * opened. */ +#define GUARD_CIRC_STATE_USABLE_ON_COMPLETION 1 +/** State for an non-open circuit that we shouldn't use for actual + * traffic, when it completes, unless other circuits to preferable + * guards fail. */ +#define GUARD_CIRC_STATE_USABLE_IF_NO_BETTER_GUARD 2 +/** State for an open circuit that we shouldn't use for actual traffic + * unless other circuits to preferable guards fail. */ +#define GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD 3 +/** State for a circuit that can (so far as the guard subsystem is + * concerned) be used for actual traffic. */ +#define GUARD_CIRC_STATE_COMPLETE 4 +/** State for a circuit that is unusable, and will not become usable. */ +#define GUARD_CIRC_STATE_DEAD 5 +/**@}*/ +STATIC void entry_guards_note_guard_failure(guard_selection_t *gs, + entry_guard_t *guard); +STATIC entry_guard_t *select_entry_guard_for_circuit(guard_selection_t *gs, + guard_usage_t usage, + const entry_guard_restriction_t *rst, + unsigned *state_out); +STATIC void mark_primary_guards_maybe_reachable(guard_selection_t *gs); +STATIC unsigned entry_guards_note_guard_success(guard_selection_t *gs, + entry_guard_t *guard, + unsigned old_state); +STATIC int entry_guard_has_higher_priority(entry_guard_t *a, entry_guard_t *b); +STATIC char *getinfo_helper_format_single_entry_guard(const entry_guard_t *e); + +STATIC entry_guard_restriction_t *guard_create_exit_restriction( + const uint8_t *exit_id); + +STATIC entry_guard_restriction_t *guard_create_dirserver_md_restriction(void); + +STATIC void entry_guard_restriction_free_(entry_guard_restriction_t *rst); +#define entry_guard_restriction_free(rst) \ + FREE_AND_NULL(entry_guard_restriction_t, \ + entry_guard_restriction_free_, (rst)) + +#endif /* defined(ENTRYNODES_PRIVATE) */ + +void remove_all_entry_guards_for_guard_selection(guard_selection_t *gs); +void remove_all_entry_guards(void); + +struct bridge_info_t; +void entry_guard_learned_bridge_identity(const tor_addr_port_t *addrport, + const uint8_t *rsa_id_digest); + +int entry_list_is_constrained(const or_options_t *options); +int guards_retry_optimistic(const or_options_t *options); +int entry_guards_parse_state_for_guard_selection( + guard_selection_t *gs, or_state_t *state, int set, char **msg); +int entry_guards_parse_state(or_state_t *state, int set, char **msg); +void entry_guards_update_state(or_state_t *state); +int getinfo_helper_entry_guards(control_connection_t *conn, + const char *question, char **answer, + const char **errmsg); + +int entries_known_but_down(const or_options_t *options); +void entries_retry_all(const or_options_t *options); + +char *entry_guards_get_err_str_if_dir_info_missing(int using_mds, + int num_present, int num_usable); +char *guard_selection_get_err_str_if_dir_info_missing(guard_selection_t *gs, + int using_mds, + int num_present, int num_usable); + +void entry_guards_free_all(void); + +double pathbias_get_close_success_count(entry_guard_t *guard); +double pathbias_get_use_success_count(entry_guard_t *guard); + +/** Contains the bandwidth of a relay as a guard and as a non-guard + * after the guardfraction has been considered. */ +typedef struct guardfraction_bandwidth_t { + /** Bandwidth as a guard after guardfraction has been considered. */ + int guard_bw; + /** Bandwidth as a non-guard after guardfraction has been considered. */ + int non_guard_bw; +} guardfraction_bandwidth_t; + +int should_apply_guardfraction(const networkstatus_t *ns); + +void +guard_get_guardfraction_bandwidth(guardfraction_bandwidth_t *guardfraction_bw, + int orig_bandwidth, + uint32_t guardfraction_percentage); + +#endif /* !defined(TOR_ENTRYNODES_H) */ |