commit 080ae03ee4c5c5e06f9f813cec4f66c5ab801a19 Author: teor (Tim Wilson-Brown) <teor2345@gmail.com> Date: Wed Nov 25 08:53:29 2015 +1100 Add UseDefaultFallbackDirs for hard-coded directory mirrors UseDefaultFallbackDirs enables any hard-coded fallback directory mirrors. Default is 1, set it to 0 to disable fallbacks. Implements ticket 17576. Patch by "teor". --- changes/feature17576-UseDefaultFallbackDirs | 4 ++ doc/tor.1.txt | 8 ++- src/or/config.c | 13 ++++- src/or/or.h | 2 + src/test/test_config.c | 70 ++++++++++++++++++++------- 5 files changed, 77 insertions(+), 20 deletions(-) diff --git a/changes/feature17576-UseDefaultFallbackDirs b/changes/feature17576-UseDefaultFallbackDirs new file mode 100644 index 0000000..68843c4 --- /dev/null +++ b/changes/feature17576-UseDefaultFallbackDirs @@ -0,0 +1,4 @@ + o Minor feature (fallback directories): + - Add UseDefaultFallbackDirs, which enables any hard-coded fallback + directory mirrors. Default is 1, set it to 0 to disable fallbacks. + Implements ticket 17576. Patch by "teor". diff --git a/doc/tor.1.txt b/doc/tor.1.txt index aba0c1c..5dcfb45 100644 --- a/doc/tor.1.txt +++ b/doc/tor.1.txt @@ -356,7 +356,13 @@ GENERAL OPTIONS [[FallbackDir]] **FallbackDir** __address__:__port__ orport=__port__ id=__fingerprint__ [weight=__num__]:: When we're unable to connect to any directory cache for directory info (usually because we don't know about any yet) we try a FallbackDir. - By default, the directory authorities are also FallbackDirs. + By default, the directory authorities are also FallbackDirs. Specifying a + FallbackDir replaces Tor's default hard-coded FallbackDirs (if any). + +[[UseDefaultFallbackDirs]] **UseDefaultFallbackDirs** **0**|**1**:: + Use Tor's default hard-coded FallbackDirs (if any). (When a + FallbackDir line is present, it replaces the hard-coded FallbackDirs, + regardless of the value of UseDefaultFallbackDirs.) (Default: 1) [[DirAuthority]] **DirAuthority** [__nickname__] [**flags**] __address__:__port__ __fingerprint__:: Use a nonstandard authoritative directory server at the provided address diff --git a/src/or/config.c b/src/or/config.c index 9028414..1cd99e5 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -251,6 +251,7 @@ static config_var_t option_vars_[] = { V(ExtORPortCookieAuthFileGroupReadable, BOOL, "0"), V(ExtraInfoStatistics, BOOL, "1"), V(FallbackDir, LINELIST, NULL), + V(UseDefaultFallbackDirs, BOOL, "1"), OBSOLETE("FallbackNetworkstatusFile"), V(FascistFirewall, BOOL, "0"), @@ -990,6 +991,7 @@ consider_adding_dir_servers(const or_options_t *options, !smartlist_len(router_get_fallback_dir_servers()) || !old_options || !config_lines_eq(options->DirAuthorities, old_options->DirAuthorities) || !config_lines_eq(options->FallbackDir, old_options->FallbackDir) || + (options->UseDefaultFallbackDirs != old_options->UseDefaultFallbackDirs) || !config_lines_eq(options->AlternateBridgeAuthority, old_options->AlternateBridgeAuthority) || !config_lines_eq(options->AlternateDirAuthority, @@ -1018,8 +1020,8 @@ consider_adding_dir_servers(const or_options_t *options, type |= V3_DIRINFO | EXTRAINFO_DIRINFO | MICRODESC_DIRINFO; /* Only add the default fallback directories when the DirAuthorities, * AlternateDirAuthority, and FallbackDir directory config options - * are set to their defaults. */ - if (!options->FallbackDir) { + * are set to their defaults, and when UseDefaultFallbackDirs is 1. */ + if (!options->FallbackDir && options->UseDefaultFallbackDirs) { add_default_fallback_dir_servers(); } } @@ -3532,6 +3534,13 @@ options_validate(or_options_t *old_options, or_options_t *options, if (validate_addr_policies(options, msg) < 0) return -1; + /* If FallbackDir is set, we don't UseDefaultFallbackDirs */ + if (options->UseDefaultFallbackDirs && options->FallbackDir) { + log_info(LD_CONFIG, "You have set UseDefaultFallbackDirs 1 and " + "FallbackDir(s). Ignoring UseDefaultFallbackDirs, and " + "using the FallbackDir(s) you have set."); + } + if (validate_dir_servers(options, old_options) < 0) REJECT("Directory authority/fallback line did not parse. See logs " "for details."); diff --git a/src/or/or.h b/src/or/or.h index 97fa9dc..c5e1b9c 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -3757,6 +3757,8 @@ typedef struct { /** List of fallback directory servers */ config_line_t *FallbackDir; + /** Whether to use the default hard-coded FallbackDirs */ + int UseDefaultFallbackDirs; /** Weight to apply to all directory authority rates if considering them * along with fallbackdirs */ diff --git a/src/test/test_config.c b/src/test/test_config.c index 28e9fa0..4ecd514 100644 --- a/src/test/test_config.c +++ b/src/test/test_config.c @@ -1471,6 +1471,7 @@ add_default_fallback_dir_servers_known_default(void) n_add_default_fallback_dir_servers_known_default++; } +/* Test all the different combinations of adding dir servers */ static void test_config_adding_dir_servers(void *arg) { @@ -1529,7 +1530,7 @@ test_config_adding_dir_servers(void *arg) /* There are 16 different cases, covering each combination of set/NULL for: * DirAuthorities, AlternateBridgeAuthority, AlternateDirAuthority & - * FallbackDir. + * FallbackDir. (We always set UseDefaultFallbackDirs to 1.) * But validate_dir_servers() ensures that: * "You cannot set both DirAuthority and Alternate*Authority." * This reduces the number of cases to 10. @@ -1543,8 +1544,6 @@ test_config_adding_dir_servers(void *arg) * The valid cases are cases 0-9 counting using this method, as every case * greater than or equal to 10 = 1010 is invalid. * - * After #15642 - Disable default fallback dirs when any custom dirs set - * * 1. Outcome: Use Set Directory Authorities * - No Default Authorities * - Use AlternateBridgeAuthority, AlternateDirAuthority, and FallbackDir @@ -1581,20 +1580,6 @@ test_config_adding_dir_servers(void *arg) * Cases expected to yield this outcome: * 0 (DirAuthorities, AlternateBridgeAuthority, AlternateDirAuthority * and FallbackDir are all NULL) - * - * Before #15642 but after #13163 - Stop using default authorities when both - * Alternate Dir and Bridge Authority are set - * (#13163 was committed in 0.2.6 as c1dd43d823c7) - * - * The behaviour is different in the following cases - * where FallbackDir is NULL: - * 2, 6, 8 - * - * In these cases, the Default Fallback Directories are applied, even when - * DirAuthorities or AlternateDirAuthority are set. - * - * However, as the list of default fallback directories is currently empty, - * this change doesn't modify any user-visible behaviour. */ /* @@ -1628,6 +1613,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = NULL; options->AlternateDirAuthority = NULL; options->FallbackDir = NULL; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -1703,6 +1689,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = NULL; options->AlternateDirAuthority = NULL; options->FallbackDir = test_fallback_directory; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -1840,6 +1827,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = NULL; options->AlternateDirAuthority = NULL; options->FallbackDir = NULL; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -1977,6 +1965,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = test_alt_bridge_authority; options->AlternateDirAuthority = test_alt_dir_authority; options->FallbackDir = test_fallback_directory; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -2115,6 +2104,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = test_alt_bridge_authority; options->AlternateDirAuthority = test_alt_dir_authority; options->FallbackDir = NULL; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -2263,6 +2253,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = test_alt_bridge_authority; options->AlternateDirAuthority = NULL; options->FallbackDir = test_fallback_directory; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -2413,6 +2404,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = test_alt_bridge_authority; options->AlternateDirAuthority = NULL; options->FallbackDir = NULL; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -2572,6 +2564,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = NULL; options->AlternateDirAuthority = test_alt_dir_authority; options->FallbackDir = test_fallback_directory; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -2725,6 +2718,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = NULL; options->AlternateDirAuthority = test_alt_dir_authority; options->FallbackDir = NULL; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -2887,6 +2881,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = NULL; options->AlternateDirAuthority = NULL; options->FallbackDir = test_fallback_directory; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -3046,6 +3041,7 @@ test_config_adding_dir_servers(void *arg) options->AlternateBridgeAuthority = NULL; options->AlternateDirAuthority = NULL; options->FallbackDir = NULL; + options->UseDefaultFallbackDirs = 1; /* parse options - ensure we always update by passing NULL old_options */ consider_adding_dir_servers(options, NULL); @@ -3209,11 +3205,51 @@ test_config_adding_dir_servers(void *arg) UNMOCK(add_default_fallback_dir_servers); } +static void +test_config_default_dir_servers(void *arg) +{ + or_options_t *opts = NULL; + (void)arg; + int trusted_count = 0; + int fallback_count = 0; + + opts = tor_malloc_zero(sizeof(or_options_t)); + opts->UseDefaultFallbackDirs = 0; + consider_adding_dir_servers(opts, opts); + trusted_count = smartlist_len(router_get_trusted_dir_servers()); + fallback_count = smartlist_len(router_get_fallback_dir_servers()); + or_options_free(opts); + opts = NULL; + + /* assume a release will never go out with less than 7 authorities */ + tt_assert(trusted_count >= 7); + /* if we disable the default fallbacks, there must not be any extra */ + tt_assert(fallback_count == trusted_count); + + opts = tor_malloc_zero(sizeof(or_options_t)); + opts->UseDefaultFallbackDirs = 1; + consider_adding_dir_servers(opts, opts); + trusted_count = smartlist_len(router_get_trusted_dir_servers()); + fallback_count = smartlist_len(router_get_fallback_dir_servers()); + or_options_free(opts); + opts = NULL; + + /* assume a release will never go out with less than 7 authorities */ + tt_assert(trusted_count >= 7); + /* XX/teor - allow for default fallbacks to be added without breaking + * the unit tests. Set a minimum fallback count once the list is stable. */ + tt_assert(fallback_count >= trusted_count); + + done: + or_options_free(opts); +} + #define CONFIG_TEST(name, flags) \ { #name, test_config_ ## name, flags, NULL, NULL } struct testcase_t config_tests[] = { CONFIG_TEST(adding_dir_servers, TT_FORK), + CONFIG_TEST(default_dir_servers, TT_FORK), CONFIG_TEST(resolve_my_address, TT_FORK), CONFIG_TEST(addressmap, 0), CONFIG_TEST(parse_bridge_line, 0),