commit 4cc348e896f74a4e02ef15a77d22fc636b08afae Author: Nick Mathewson nickm@torproject.org Date: Mon Nov 8 14:21:32 2010 -0500
Code to make clients fetch and use microdescriptors for circuit building
To turn this on, set UseMicrodescriptors to "1" (or "auto" if you want it on-if-you're-a-client). It should go auto-by-default once 0.2.3.1-alpha is released.
Because of our node logic, directory caches will never use microdescriptors when they have the right routerinfo available. --- changes/microdesc_use | 10 +++++++++ src/or/config.c | 6 +++- src/or/directory.c | 11 +++++---- src/or/directory.h | 1 - src/or/microdesc.c | 53 ++++++++++++++++++++++++++++++++++++++++++++--- src/or/microdesc.h | 5 ++++ src/or/networkstatus.c | 18 +++++++++------- src/or/or.h | 22 +++++++++++++++---- src/or/router.c | 3 +- src/or/routerlist.c | 41 +++++++++++++++++++------------------ src/or/routerlist.h | 1 - src/or/routerparse.c | 3 ++ 12 files changed, 127 insertions(+), 47 deletions(-)
diff --git a/changes/microdesc_use b/changes/microdesc_use new file mode 100644 index 0000000..89faf7c --- /dev/null +++ b/changes/microdesc_use @@ -0,0 +1,10 @@ + o Major features + - Clients can now use microdescriptors instead of regular descriptors + to build circuits. Microdescriptors are authority-generated and + -authenticated summaries of regular descriptors' contents, designed + to change very rarely. This feature is designed to save bandwidth, + especially for clients on slow internet connections. It's off + by default for now, since nearly no caches support it, but it will + be on-by-default for clients in a future version. You can use the + UseMicrodescriptors option to turn it on. + diff --git a/src/or/config.c b/src/or/config.c index c936991..09ad51f 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -381,6 +381,7 @@ static config_var_t _option_vars[] = { V(UpdateBridgesFromAuthority, BOOL, "0"), V(UseBridges, BOOL, "0"), V(UseEntryGuards, BOOL, "1"), + V(UseMicrodescriptors, AUTOBOOL, "0"), V(User, STRING, NULL), VAR("V1AuthoritativeDirectory",BOOL, V1AuthoritativeDir, "0"), VAR("V2AuthoritativeDirectory",BOOL, V2AuthoritativeDir, "0"), @@ -919,7 +920,8 @@ consider_adding_dir_authorities(or_options_t *options, if (!options->AlternateBridgeAuthority) type |= BRIDGE_DIRINFO; if (!options->AlternateDirAuthority) - type |= V1_DIRINFO | V2_DIRINFO | V3_DIRINFO; + type |= V1_DIRINFO | V2_DIRINFO | V3_DIRINFO | EXTRAINFO_DIRINFO | + MICRODESC_DIRINFO; if (!options->AlternateHSAuthority) type |= HIDSERV_DIRINFO; add_default_trusted_dir_authorities(type); @@ -4605,7 +4607,7 @@ parse_dir_server_line(const char *line, dirinfo_type_t required_type, log_warn(LD_CONFIG, "Bad v3 identity digest '%s' on DirServer line", flag); } else { - type |= V3_DIRINFO; + type |= V3_DIRINFO|EXTRAINFO_DIRINFO|MICRODESC_DIRINFO; } } else { log_warn(LD_CONFIG, "Unrecognized flag '%s' on DirServer line", diff --git a/src/or/directory.c b/src/or/directory.c index f21dc85..184a6b4 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -147,9 +147,10 @@ purpose_needs_anonymity(uint8_t dir_purpose, uint8_t router_purpose) return 1; }
-/** Return a newly allocated string describing <b>auth</b>. */ -char * -dirinfo_type_to_string(dirinfo_type_t auth) +/** Return a newly allocated string describing <b>auth</b>. Only describes + * authority features. */ +static char * +authdir_type_to_string(dirinfo_type_t auth) { char *result; smartlist_t *lst = smartlist_create(); @@ -328,7 +329,7 @@ directory_post_to_dirservers(uint8_t dir_purpose, uint8_t router_purpose, NULL, payload, upload_len, 0); } SMARTLIST_FOREACH_END(ds); if (!found) { - char *s = dirinfo_type_to_string(type); + char *s = authdir_type_to_string(type); log_warn(LD_DIR, "Publishing server descriptor to directory authorities " "of type '%s', but no authorities of that type listed!", s); tor_free(s); @@ -379,7 +380,7 @@ directory_get_from_dirserver(uint8_t dir_purpose, uint8_t router_purpose, type = V3_DIRINFO; break; case DIR_PURPOSE_FETCH_MICRODESC: - type = V3_DIRINFO; + type = MICRODESC_DIRINFO; break; default: log_warn(LD_BUG, "Unexpected purpose %d", (int)dir_purpose); diff --git a/src/or/directory.h b/src/or/directory.h index 9f4c31d..caff938 100644 --- a/src/or/directory.h +++ b/src/or/directory.h @@ -13,7 +13,6 @@ #define _TOR_DIRECTORY_H
int directories_have_accepted_server_descriptor(void); -char *dirinfo_type_to_string(dirinfo_type_t auth); void directory_post_to_dirservers(uint8_t dir_purpose, uint8_t router_purpose, dirinfo_type_t type, const char *payload, size_t payload_len, size_t extrainfo_len); diff --git a/src/or/microdesc.c b/src/or/microdesc.c index 6209bbf..0e8aa83 100644 --- a/src/or/microdesc.c +++ b/src/or/microdesc.c @@ -9,6 +9,7 @@ #include "networkstatus.h" #include "nodelist.h" #include "policies.h" +#include "router.h" #include "routerlist.h" #include "routerparse.h"
@@ -251,6 +252,9 @@ microdescs_add_list_to_cache(microdesc_cache_t *cache, SMARTLIST_FOREACH(added, microdesc_t *, md, nodelist_add_microdesc(md)); }
+ if (smartlist_len(added)) + router_dir_info_changed(); + return added; }
@@ -570,6 +574,8 @@ microdesc_list_missing_digest256(networkstatus_t *ns, microdesc_cache_t *cache, continue; if (skip && digestmap_get(skip, rs->descriptor_digest)) continue; + if (tor_mem_is_zero(rs->descriptor_digest, DIGEST256_LEN)) + continue; /* This indicates a bug somewhere XXXX023*/ /* XXXX Also skip if we're a noncache and wouldn't use this router. * XXXX NM Microdesc */ @@ -602,11 +608,8 @@ update_microdesc_downloads(time_t now) if (!consensus) return;
- if (!directory_caches_dir_info(options)) { - /* Right now, only caches fetch microdescriptors. - * XXXX NM Microdescs */ + if (!we_fetch_microdescriptors(options)) return; - }
pending = digestmap_new(); list_pending_microdesc_downloads(pending); @@ -647,3 +650,45 @@ update_microdescs_from_networkstatus(time_t now) } SMARTLIST_FOREACH_END(rs); }
+/** Return true iff we should prefer to use microdescriptors rather than + * routerdescs for building circuits. */ +int +we_use_microdescriptors_for_circuits(or_options_t *options) +{ + int ret = options->UseMicrodescriptors; + if (ret == -1) { + /* UseMicrodescriptors is "auto"; we need to decide: */ + /* So we decide that we'll use microdescriptors iff we are not a server */ + ret = ! server_mode(options); + } + return ret; +} + +/** Return true iff we should try to download microdescriptors at all. */ +int +we_fetch_microdescriptors(or_options_t *options) +{ + if (directory_caches_dir_info(options)) + return 1; + return we_use_microdescriptors_for_circuits(options); +} + +/** Return true iff we should try to download router descriptors at all. */ +int +we_fetch_router_descriptors(or_options_t *options) +{ + if (directory_caches_dir_info(options)) + return 1; + return ! we_use_microdescriptors_for_circuits(options); +} + +/** Return the consensus flavor we actually want to use to build circuits. */ +int +usable_consensus_flavor(void) +{ + if (we_use_microdescriptors_for_circuits(get_options())) { + return FLAV_MICRODESC; + } else { + return FLAV_NS; + } +} diff --git a/src/or/microdesc.h b/src/or/microdesc.h index c967742..94b1ff6 100644 --- a/src/or/microdesc.h +++ b/src/or/microdesc.h @@ -43,5 +43,10 @@ void microdesc_free_all(void); void update_microdesc_downloads(time_t now); void update_microdescs_from_networkstatus(time_t now);
+int usable_consensus_flavor(void); +int we_fetch_microdescriptors(or_options_t *options); +int we_fetch_router_descriptors(or_options_t *options); +int we_use_microdescriptors_for_circuits(or_options_t *options); + #endif
diff --git a/src/or/networkstatus.c b/src/or/networkstatus.c index b191f57..663d1ad 100644 --- a/src/or/networkstatus.c +++ b/src/or/networkstatus.c @@ -50,7 +50,9 @@ static strmap_t *unnamed_server_map = NULL; * of whichever type we are using for our own circuits. This will be the same * as one of current_ns_consensus or current_md_consensus. */ -#define current_consensus current_ns_consensus +#define current_consensus \ + (we_use_microdescriptors_for_circuits(get_options()) ? \ + current_md_consensus : current_ns_consensus)
/** Most recently received and validated v3 "ns"-flavored consensus network * status. */ @@ -1187,7 +1189,7 @@ we_want_to_fetch_flavor(or_options_t *options, int flavor) } /* Otherwise, we want the flavor only if we want to use it to build * circuits. */ - return (flavor == USABLE_CONSENSUS_FLAVOR); + return flavor == usable_consensus_flavor(); }
/** How many times will we try to fetch a consensus before we give up? */ @@ -1392,7 +1394,7 @@ update_certificate_downloads(time_t now) int consensus_is_waiting_for_certs(void) { - return consensus_waiting_for_certs[USABLE_CONSENSUS_FLAVOR].consensus + return consensus_waiting_for_certs[usable_consensus_flavor()].consensus ? 1 : 0; }
@@ -1621,7 +1623,7 @@ networkstatus_set_current_consensus(const char *consensus, flavor = networkstatus_get_flavor_name(flav); }
- if (flav != USABLE_CONSENSUS_FLAVOR && + if (flav != usable_consensus_flavor() && !directory_caches_dir_info(options)) { /* This consensus is totally boring to us: we won't use it, and we won't * serve it. Drop it. */ @@ -1726,14 +1728,14 @@ networkstatus_set_current_consensus(const char *consensus, } }
- if (!from_cache && flav == USABLE_CONSENSUS_FLAVOR) + if (!from_cache && flav == usable_consensus_flavor()) control_event_client_status(LOG_NOTICE, "CONSENSUS_ARRIVED");
/* Are we missing any certificates at all? */ if (r != 1 && dl_certs) authority_certs_fetch_missing(c, now);
- if (flav == USABLE_CONSENSUS_FLAVOR) { + if (flav == usable_consensus_flavor()) { notify_control_networkstatus_changed(current_consensus, c); } if (flav == FLAV_NS) { @@ -1780,8 +1782,8 @@ networkstatus_set_current_consensus(const char *consensus, download_status_failed(&consensus_dl_status[flav], 0); }
- if (flav == USABLE_CONSENSUS_FLAVOR) { - /* XXXXNM Microdescs: needs a non-ns variant. */ + if (flav == usable_consensus_flavor()) { + /* XXXXNM Microdescs: needs a non-ns variant. ???? NM*/ update_consensus_networkstatus_fetch_time(now);
nodelist_set_consensus(current_consensus); diff --git a/src/or/or.h b/src/or/or.h index a976916..f45ccb7 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -1641,6 +1641,9 @@ typedef struct routerstatus_t { /** True iff this router is a version that, if it caches directory info, * we can get v3 downloads from. */ unsigned int version_supports_v3_dir:1; + /** True iff this router is a version that, if it caches directory info, + * we can get microdescriptors from. */ + unsigned int version_supports_microdesc_cache:1;
unsigned int has_bandwidth:1; /**< The vote/consensus had bw info */ unsigned int has_exitsummary:1; /**< The vote/consensus had exit summaries */ @@ -1918,9 +1921,6 @@ typedef enum { FLAV_MICRODESC = 1, } consensus_flavor_t;
-/** Which consensus flavor do we actually want to use to build circuits? */ -#define USABLE_CONSENSUS_FLAVOR FLAV_NS - /** How many different consensus flavors are there? */ #define N_CONSENSUS_FLAVORS ((int)(FLAV_MICRODESC)+1)
@@ -2092,6 +2092,12 @@ typedef struct authority_cert_t {
/** Bitfield enum type listing types of information that directory authorities * can be authoritative about, and that directory caches may or may not cache. + * + * Note that the granularity here is based on authority granularity and on + * cache capabilities. Thus, one particular bit may correspond in practice to + * a few types of directory info, so long as every authority that pronounces + * officially about one of the types prounounces officially about all of them, + * and so long as every cache that caches one of them caches all of them. */ typedef enum { NO_DIRINFO = 0, @@ -2107,7 +2113,9 @@ typedef enum { /** Serves bridge descriptors. */ BRIDGE_DIRINFO = 1 << 4, /** Serves extrainfo documents. */ - EXTRAINFO_DIRINFO = 1 << 5, + EXTRAINFO_DIRINFO=1 << 5, + /** Serves microdescriptors. */ + MICRODESC_DIRINFO=1 << 6, } dirinfo_type_t;
#define CRYPT_PATH_MAGIC 0x70127012u @@ -2642,7 +2650,7 @@ typedef struct { /** To what authority types do we publish our descriptor? Choices are * "v1", "v2", "v3", "bridge", or "". */ smartlist_t *PublishServerDescriptor; - /** An authority type, derived from PublishServerDescriptor. */ + /** A bitfield of authority types, derived from PublishServerDescriptor. */ dirinfo_type_t _PublishServerDescriptor; /** Boolean: do we publish hidden service descriptors to the HS auths? */ int PublishHidServDescriptors; @@ -3043,6 +3051,10 @@ typedef struct { * the defaults have changed. */ int _UsingTestNetworkDefaults;
+ /** If 1, we try to use microdescriptors to build circuits. If 0, we don't. + * If -1, Tor decides. */ + int UseMicrodescriptors; + } or_options_t;
/** Persistent state for an onion router, as saved to disk. */ diff --git a/src/or/router.c b/src/or/router.c index e4dab0e..6de069f 100644 --- a/src/or/router.c +++ b/src/or/router.c @@ -699,7 +699,8 @@ init_keys(void) crypto_pk_get_digest(get_server_identity_key(), digest); type = ((options->V1AuthoritativeDir ? V1_DIRINFO : NO_DIRINFO) | (options->V2AuthoritativeDir ? V2_DIRINFO : NO_DIRINFO) | - (options->V3AuthoritativeDir ? V3_DIRINFO : NO_DIRINFO) | + (options->V3AuthoritativeDir ? + (V3_DIRINFO|MICRODESC_DIRINFO|EXTRAINFO_DIRINFO) : NO_DIRINFO) | (options->BridgeAuthoritativeDir ? BRIDGE_DIRINFO : NO_DIRINFO) | (options->HSAuthoritativeDir ? HIDSERV_DIRINFO : NO_DIRINFO));
diff --git a/src/or/routerlist.c b/src/or/routerlist.c index 8bcfa05..6f90a8b 100644 --- a/src/or/routerlist.c +++ b/src/or/routerlist.c @@ -1127,6 +1127,9 @@ router_pick_directory_server_impl(dirinfo_type_t type, int flags) if ((type & EXTRAINFO_DIRINFO) && !router_supports_extrainfo(node->identity, 0)) continue; + if ((type & MICRODESC_DIRINFO) && !is_trusted && + !node->rs->version_supports_microdesc_cache) + continue; if (try_excluding && options->ExcludeNodes && routerset_contains_routerstatus(options->ExcludeNodes, status, country)) { @@ -2443,18 +2446,6 @@ router_get_by_nickname(const char *nickname, int warn_if_unnamed) #endif }
-/** Try to find a routerinfo for <b>digest</b>. If we don't have one, - * return 1. If we do, ask tor_version_as_new_as() for the answer. - */ -int -router_digest_version_as_new_as(const char *digest, const char *cutoff) -{ - const routerinfo_t *router = router_get_by_id_digest(digest); - if (!router) - return 1; - return tor_version_as_new_as(router->platform, cutoff); -} - /** Return true iff <b>digest</b> is the digest of the identity key of a * trusted directory matching at least one bit of <b>type</b>. If <b>type</b> * is zero, any authority is okay. */ @@ -4726,6 +4717,8 @@ update_router_descriptor_downloads(time_t now) static time_t last_dummy_download = 0; if (should_delay_dir_fetches(options)) return; + if (!we_fetch_router_descriptors(options)) + return; if (directory_fetches_dir_info_early(options)) { update_router_descriptor_cache_downloads_v2(now); } @@ -4879,20 +4872,28 @@ count_usable_descriptors(int *num_present, int *num_usable, or_options_t *options, time_t now, routerset_t *in_set) { + const int md = (consensus->flavor == FLAV_MICRODESC); *num_present = 0, *num_usable=0;
- SMARTLIST_FOREACH(consensus->routerstatus_list, routerstatus_t *, rs, - { + SMARTLIST_FOREACH_BEGIN(consensus->routerstatus_list, routerstatus_t *, rs) + { if (in_set && ! routerset_contains_routerstatus(in_set, rs, -1)) continue; if (client_would_use_router(rs, now, options)) { + const char * const digest = rs->descriptor_digest; + int present; ++*num_usable; /* the consensus says we want it. */ - if (router_get_by_descriptor_digest(rs->descriptor_digest)) { + if (md) + present = NULL != (microdesc_cache_lookup_by_digest256(NULL, digest)); + else + present = NULL != router_get_by_descriptor_digest(digest); + if (present) { /* we have the descriptor listed in the consensus. */ ++*num_present; } } - }); + } + SMARTLIST_FOREACH_END(rs);
log_debug(LD_DIR, "%d usable, %d present.", *num_usable, *num_present); } @@ -4906,7 +4907,7 @@ count_loading_descriptors_progress(void) int num_present = 0, num_usable=0; time_t now = time(NULL); const networkstatus_t *consensus = - networkstatus_get_reasonably_live_consensus(now, FLAV_NS); + networkstatus_get_reasonably_live_consensus(now, usable_consensus_flavor()); double fraction;
if (!consensus) @@ -4936,14 +4937,14 @@ update_router_have_minimum_dir_info(void) int res; or_options_t *options = get_options(); const networkstatus_t *consensus = - networkstatus_get_reasonably_live_consensus(now, FLAV_NS); + networkstatus_get_reasonably_live_consensus(now, usable_consensus_flavor());
if (!consensus) { if (!networkstatus_get_latest_consensus()) - strlcpy(dir_info_status, "We have no network-status consensus.", + strlcpy(dir_info_status, "We have no usable consensus.", sizeof(dir_info_status)); else - strlcpy(dir_info_status, "We have no recent network-status consensus.", + strlcpy(dir_info_status, "We have no recent usable consensus.", sizeof(dir_info_status)); res = 0; goto done; diff --git a/src/or/routerlist.h b/src/or/routerlist.h index 41a4c90..940e206 100644 --- a/src/or/routerlist.h +++ b/src/or/routerlist.h @@ -56,7 +56,6 @@ const node_t *router_choose_random_node(smartlist_t *excludedsmartlist,
const routerinfo_t *router_get_by_nickname(const char *nickname, int warn_if_unnamed); -int router_digest_version_as_new_as(const char *digest, const char *cutoff); int router_digest_is_trusted_dir_type(const char *digest, dirinfo_type_t type); #define router_digest_is_trusted_dir(d) \ diff --git a/src/or/routerparse.c b/src/or/routerparse.c index 80214b3..163cc37 100644 --- a/src/or/routerparse.c +++ b/src/or/routerparse.c @@ -2085,6 +2085,7 @@ routerstatus_parse_entry_from_string(memarea_t *area, rs->version_supports_begindir = 1; rs->version_supports_extrainfo_upload = 1; rs->version_supports_conditional_consensus = 1; + rs->version_supports_microdesc_cache = 1; } else { rs->version_supports_begindir = tor_version_as_new_as(tok->args[0], "0.2.0.1-alpha"); @@ -2094,6 +2095,8 @@ routerstatus_parse_entry_from_string(memarea_t *area, tor_version_as_new_as(tok->args[0], "0.2.0.8-alpha"); rs->version_supports_conditional_consensus = tor_version_as_new_as(tok->args[0], "0.2.1.1-alpha"); + rs->version_supports_microdesc_cache = + tor_version_as_new_as(tok->args[0], "0.2.3.0-alpha"); } if (vote_rs) { vote_rs->version = tor_strdup(tok->args[0]);