commit 7e504515b326fe2f302d2c1550e3a46bec29b9f6 Author: Nick Mathewson nickm@torproject.org Date: Wed Jan 24 13:52:51 2018 -0500

Always look at the subprotocol versions summary flags

Previously, we wouldn't do this when running with a routerinfo_t in some cases, leading to many needless calls to the protover module.

This change also cleans up the code in nodelist.c a bit.

Fixes bug 25008; bugfix on 0.2.9.4-alpha. --- changes/bug25008 | 9 ++++++ src/or/nodelist.c | 97 +++++++++++++++++++------------------------------------ 2 files changed, 43 insertions(+), 63 deletions(-)

diff --git a/changes/bug25008 b/changes/bug25008 new file mode 100644 index 000000000..5ddc06298 --- /dev/null +++ b/changes/bug25008 @@ -0,0 +1,9 @@ + o Minor bugfixes (performance): + - Avoid calling protocol_list_supports_protocol() from inside tight loops + when running with cached routerinfo_t objects. Instead, + summarize the relevant protocols as flags in the routerinfo_t, as we do + for routerstatus_t objects. This change simplifies our code a little, + and saves a large amount of short-term memory allocation operations. + Fixes bug 25008; bugfix on 0.2.9.4-alpha. + + diff --git a/src/or/nodelist.c b/src/or/nodelist.c index 7cdf28a37..c2bc0d1f7 100644 --- a/src/or/nodelist.c +++ b/src/or/nodelist.c @@ -959,6 +959,30 @@ node_ed25519_id_matches(const node_t *node, const ed25519_public_key_t *id) } }

+/** Dummy object that should be unreturnable. Used to ensure that + * node_get_protover_summary_flags() always returns non-NULL. */ +static const protover_summary_flags_t zero_protover_flags = { + 0,0,0,0,0,0,0 +}; + +/** Return the protover_summary_flags for a given node. */ +static const protover_summary_flags_t * +node_get_protover_summary_flags(const node_t *node) +{ + if (node->rs) { + return &node->rs->pv; + } else if (node->ri) { + return &node->ri->pv; + } else { + /* This should be impossible: every node should have a routerstatus or a + * router descriptor or both. But just in case we've messed up somehow, + * return a nice empty set of flags to indicate "this node supports + * nothing." */ + tor_assert_nonfatal_unreached_once(); + return &zero_protover_flags; + } +} + /** Return true iff <b>node</b> supports authenticating itself * by ed25519 ID during the link handshake. If <b>compatible_with_us</b>, * it needs to be using a link authentication method that we understand. @@ -969,23 +993,13 @@ node_supports_ed25519_link_authentication(const node_t *node, { if (! node_get_ed25519_id(node)) return 0; - if (node->ri) { - const char *protos = node->ri->protocol_list; - if (protos == NULL) - return 0; - if (compatible_with_us) - return protocol_list_supports_protocol(protos, PRT_LINKAUTH, 3); - else - return protocol_list_supports_protocol_or_later(protos, PRT_LINKAUTH, 3); - } - if (node->rs) { - if (compatible_with_us) - return node->rs->pv.supports_ed25519_link_handshake_compat; - else - return node->rs->pv.supports_ed25519_link_handshake_any; - } - tor_assert_nonfatal_unreached_once(); - return 0; + + const protover_summary_flags_t *pv = node_get_protover_summary_flags(node); + + if (compatible_with_us) + return pv->supports_ed25519_link_handshake_compat; + else + return pv->supports_ed25519_link_handshake_any; }

/** Return true iff <b>node</b> supports the hidden service directory version @@ -995,27 +1009,7 @@ node_supports_v3_hsdir(const node_t *node) { tor_assert(node);

- if (node->rs) { - return node->rs->pv.supports_v3_hsdir; - } - if (node->ri) { - if (node->ri->protocol_list == NULL) { - return 0; - } - /* Bug #22447 forces us to filter on tor version: - * If platform is a Tor version, and older than 0.3.0.8, return False. - * Else, obey the protocol list. */ - if (node->ri->platform) { - if (!strcmpstart(node->ri->platform, "Tor ") && - !tor_version_as_new_as(node->ri->platform, "0.3.0.8")) { - return 0; - } - } - return protocol_list_supports_protocol(node->ri->protocol_list, - PRT_HSDIR, PROTOVER_HSDIR_V3); - } - tor_assert_nonfatal_unreached_once(); - return 0; + return node_get_protover_summary_flags(node)->supports_v3_hsdir; }

/** Return true iff <b>node</b> supports ed25519 authentication as an hidden @@ -1025,18 +1019,7 @@ node_supports_ed25519_hs_intro(const node_t *node) { tor_assert(node);

- if (node->rs) { - return node->rs->pv.supports_ed25519_hs_intro; - } - if (node->ri) { - if (node->ri->protocol_list == NULL) { - return 0; - } - return protocol_list_supports_protocol(node->ri->protocol_list, - PRT_HSINTRO, PROTOVER_HS_INTRO_V3); - } - tor_assert_nonfatal_unreached_once(); - return 0; + return node_get_protover_summary_flags(node)->supports_ed25519_hs_intro; }

/** Return true iff <b>node</b> supports to be a rendezvous point for hidden @@ -1046,19 +1029,7 @@ node_supports_v3_rendezvous_point(const node_t *node) { tor_assert(node);

- if (node->rs) { - return node->rs->pv.supports_v3_rendezvous_point; - } - if (node->ri) { - if (node->ri->protocol_list == NULL) { - return 0; - } - return protocol_list_supports_protocol(node->ri->protocol_list, - PRT_HSREND, - PROTOVER_HS_RENDEZVOUS_POINT_V3); - } - tor_assert_nonfatal_unreached_once(); - return 0; + return node_get_protover_summary_flags(node)->supports_v3_rendezvous_point; }

/** Return the RSA ID key's SHA1 digest for the provided node. */