commit a8d491a8fdfafe6e56924a19b5169c2eb9d3a66a Author: Nick Mathewson <nickm@torproject.org> Date: Wed Sep 12 13:56:36 2012 -0400 Add an option to weight down authorities when choosing a fallback --- doc/tor.1.txt | 6 ++++++ src/or/config.c | 1 + src/or/or.h | 4 ++++ src/or/routerlist.c | 9 +++++++-- 4 files changed, 18 insertions(+), 2 deletions(-) diff --git a/doc/tor.1.txt b/doc/tor.1.txt index e79d21e..231ac52 100644 --- a/doc/tor.1.txt +++ b/doc/tor.1.txt @@ -322,6 +322,12 @@ GENERAL OPTIONS distinguishable from other users, because you won't believe the same authorities they do. +**DirAuthorityFallbackRate** __NUM__:: + When configured to use both directory authorities and fallback + directories, the directory authorities also work as fallbacks. They are + chosen with their regular weights, multiplied by this number, which + should be 1.0 or less. (Default: 1.0) + **DynamicDHGroups** **0**|**1**:: If this option is set to 1, when running as a server, generate our own Diffie-Hellman group instead of using the one from Apache's mod_ssl. diff --git a/src/or/config.c b/src/or/config.c index af699d9..17b5b79 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -208,6 +208,7 @@ static config_var_t option_vars_[] = { OBSOLETE("DirRecordUsageSaveInterval"), V(DirReqStatistics, BOOL, "1"), VAR("DirAuthority", LINELIST, DirAuthorities, NULL), + V(DirAuthorityFallbackRate, DOUBLE, "1.0"), V(DisableAllSwap, BOOL, "0"), V(DisableDebuggerAttachment, BOOL, "1"), V(DisableIOCP, BOOL, "1"), diff --git a/src/or/or.h b/src/or/or.h index cbb437e..9f9316b 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -3431,6 +3431,10 @@ typedef struct { /** List of fallback directory servers */ config_line_t *FallbackDir; + /** Weight to apply to all directory authority rates if considering them + * along with fallbackdirs */ + double DirAuthorityFallbackRate; + /** If set, use these main (currently v3) directory authorities and * not the default ones. */ config_line_t *AlternateDirAuthority; diff --git a/src/or/routerlist.c b/src/or/routerlist.c index a5dd9c4..5536d1c 100644 --- a/src/or/routerlist.c +++ b/src/or/routerlist.c @@ -1252,7 +1252,7 @@ router_pick_directory_server_impl(dirinfo_type_t type, int flags) /** Pick a random element from a list of dir_server_t, weighting by their * <b>weight</b> field. */ static const dir_server_t * -dirserver_choose_by_weight(const smartlist_t *servers) +dirserver_choose_by_weight(const smartlist_t *servers, double authority_weight) { int n = smartlist_len(servers); int i; @@ -1263,6 +1263,8 @@ dirserver_choose_by_weight(const smartlist_t *servers) for (i = 0; i < n; ++i) { ds = smartlist_get(servers, i); weights[i].dbl = ds->weight; + if (ds->is_authority) + weights[i].dbl *= authority_weight; } scale_array_elements_to_u64(weights, n, NULL); @@ -1290,6 +1292,8 @@ router_pick_trusteddirserver_impl(const smartlist_t *sourcelist, const int prefer_tunnel = (flags & PDS_PREFER_TUNNELED_DIR_CONNS_); const int no_serverdesc_fetching =(flags & PDS_NO_EXISTING_SERVERDESC_FETCH); const int no_microdesc_fetching =(flags & PDS_NO_EXISTING_MICRODESC_FETCH); + const double auth_weight = (sourcelist == fallback_dir_servers) ? + options->DirAuthorityFallbackRate : 1.0; smartlist_t *pick_from; int n_busy = 0; int try_excluding = 1, n_excluded = 0; @@ -1368,7 +1372,8 @@ router_pick_trusteddirserver_impl(const smartlist_t *sourcelist, } { - const dir_server_t *selection = dirserver_choose_by_weight(pick_from); + const dir_server_t *selection = + dirserver_choose_by_weight(pick_from, auth_weight); if (selection) result = &selection->fake_status;