diff options
Diffstat (limited to 'src/feature/hs_common/shared_random_client.c')
-rw-r--r-- | src/feature/hs_common/shared_random_client.c | 95 |
1 files changed, 55 insertions, 40 deletions
diff --git a/src/feature/hs_common/shared_random_client.c b/src/feature/hs_common/shared_random_client.c index ead5d681a9..4e8a2942fc 100644 --- a/src/feature/hs_common/shared_random_client.c +++ b/src/feature/hs_common/shared_random_client.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* Copyright (c) 2018-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -8,18 +8,18 @@ * as part of the dirauth module. **/ -#define SHARED_RANDOM_CLIENT_PRIVATE #include "feature/hs_common/shared_random_client.h" #include "app/config/config.h" -#include "feature/dircommon/voting_schedule.h" +#include "feature/dirauth/authmode.h" +#include "feature/dirauth/voting_schedule.h" #include "feature/nodelist/microdesc.h" #include "feature/nodelist/networkstatus.h" #include "lib/encoding/binascii.h" #include "feature/nodelist/networkstatus_st.h" -/* Convert a given srv object to a string for the control port. This doesn't +/** Convert a given srv object to a string for the control port. This doesn't * fail and the srv object MUST be valid. */ static char * srv_to_control_string(const sr_srv_t *srv) @@ -33,7 +33,25 @@ srv_to_control_string(const sr_srv_t *srv) return srv_str; } -/* Return the voting interval of the tor vote subsystem. */ +/** + * If we have no consensus and we are not an authority, assume that this is + * the voting interval. We should never actually use this: only authorities + * should be trying to figure out the schedule when they don't have a + * consensus. + **/ +#define DEFAULT_NETWORK_VOTING_INTERVAL (3600) + +/* This is an unpleasing workaround for tests. Our unit tests assume that we + * are scheduling all of our shared random stuff as if we were a directory + * authority, but they do not always set V3AuthoritativeDir. + */ +#ifdef TOR_UNIT_TESTS +#define ASSUME_AUTHORITY_SCHEDULING 1 +#else +#define ASSUME_AUTHORITY_SCHEDULING 0 +#endif + +/** Return the voting interval of the tor vote subsystem. */ int get_voting_interval(void) { @@ -43,45 +61,32 @@ get_voting_interval(void) usable_consensus_flavor()); if (consensus) { + /* Ideally we have a live consensus and we can just use that. */ + interval = (int)(consensus->fresh_until - consensus->valid_after); + } else if (authdir_mode(get_options()) || ASSUME_AUTHORITY_SCHEDULING) { + /* If we don't have a live consensus and we're an authority, + * we should believe our own view of what the schedule ought to be. */ + interval = dirauth_sched_get_configured_interval(); + } else if ((consensus = networkstatus_get_latest_consensus())) { + /* If we're a client, then maybe a latest consensus is good enough? + * It's better than falling back to the non-consensus case. */ interval = (int)(consensus->fresh_until - consensus->valid_after); } else { - /* Same for both a testing and real network. We voluntarily ignore the - * InitialVotingInterval since it complexifies things and it doesn't - * affect the SR protocol. */ - interval = get_options()->V3AuthVotingInterval; + /* We should never be reaching this point, since a client should never + * call this code unless they have some kind of a consensus. All we can + * do is hope that this network is using the default voting interval. */ + tor_assert_nonfatal_unreached_once(); + interval = DEFAULT_NETWORK_VOTING_INTERVAL; } tor_assert(interval > 0); return interval; } -/* Given the current consensus, return the start time of the current round of - * the SR protocol. For example, if it's 23:47:08, the current round thus - * started at 23:47:00 for a voting interval of 10 seconds. - * - * This function uses the consensus voting schedule to derive its results, - * instead of the actual consensus we are currently using, so it should be used - * for voting purposes. */ -time_t -get_start_time_of_current_round(void) -{ - const or_options_t *options = get_options(); - int voting_interval = get_voting_interval(); - /* First, get the start time of the next round */ - time_t next_start = voting_schedule_get_next_valid_after_time(); - /* Now roll back next_start by a voting interval to find the start time of - the current round. */ - time_t curr_start = voting_schedule_get_start_of_next_interval( - next_start - voting_interval - 1, - voting_interval, - options->TestingV3AuthVotingStartOffset); - return curr_start; -} - /* * Public API */ -/* Encode the given shared random value and put it in dst. Destination +/** Encode the given shared random value and put it in dst. Destination * buffer must be at least SR_SRV_VALUE_BASE64_LEN plus the NULL byte. */ void sr_srv_encode(char *dst, size_t dst_len, const sr_srv_t *srv) @@ -102,7 +107,7 @@ sr_srv_encode(char *dst, size_t dst_len, const sr_srv_t *srv) strlcpy(dst, buf, dst_len); } -/* Return the current SRV string representation for the control port. Return a +/** Return the current SRV string representation for the control port. Return a * newly allocated string on success containing the value else "" if not found * or if we don't have a valid consensus yet. */ char * @@ -118,7 +123,7 @@ sr_get_current_for_control(void) return srv_str; } -/* Return the previous SRV string representation for the control port. Return +/** Return the previous SRV string representation for the control port. Return * a newly allocated string on success containing the value else "" if not * found or if we don't have a valid consensus yet. */ char * @@ -134,7 +139,7 @@ sr_get_previous_for_control(void) return srv_str; } -/* Return current shared random value from the latest consensus. Caller can +/** Return current shared random value from the latest consensus. Caller can * NOT keep a reference to the returned pointer. Return NULL if none. */ const sr_srv_t * sr_get_current(const networkstatus_t *ns) @@ -158,7 +163,7 @@ sr_get_current(const networkstatus_t *ns) return NULL; } -/* Return previous shared random value from the latest consensus. Caller can +/** Return previous shared random value from the latest consensus. Caller can * NOT keep a reference to the returned pointer. Return NULL if none. */ const sr_srv_t * sr_get_previous(const networkstatus_t *ns) @@ -182,7 +187,7 @@ sr_get_previous(const networkstatus_t *ns) return NULL; } -/* Parse a list of arguments from a SRV value either from a vote, consensus +/** Parse a list of arguments from a SRV value either from a vote, consensus * or from our disk state and return a newly allocated srv object. NULL is * returned on error. * @@ -252,8 +257,19 @@ sr_state_get_start_time_of_current_protocol_run(void) usable_consensus_flavor()); if (ns) { beginning_of_curr_round = ns->valid_after; + } else if (authdir_mode(get_options()) || ASSUME_AUTHORITY_SCHEDULING) { + beginning_of_curr_round = dirauth_sched_get_cur_valid_after_time(); } else { - beginning_of_curr_round = get_start_time_of_current_round(); + /* voting_interval comes from get_voting_interval(), so if we're in + * this case as a client, we already tried to get the voting interval + * from the latest_consensus and gave a bug warning if we couldn't. + * + * We wouldn't want to look at the latest consensus's valid_after time, + * since that would be out of date. */ + beginning_of_curr_round = voting_sched_get_start_of_interval_after( + approx_time() - voting_interval, + voting_interval, + 0); } /* Get current SR protocol round */ @@ -295,4 +311,3 @@ sr_state_get_protocol_run_duration(void) int total_protocol_rounds = SHARED_RANDOM_N_ROUNDS * SHARED_RANDOM_N_PHASES; return total_protocol_rounds * get_voting_interval(); } - |