diff options
Diffstat (limited to 'src/feature/dirauth/dirvote.c')
| -rw-r--r-- | src/feature/dirauth/dirvote.c | 180 |
1 files changed, 120 insertions, 60 deletions
diff --git a/src/feature/dirauth/dirvote.c b/src/feature/dirauth/dirvote.c index f2032d71f6..1bb4fd7de1 100644 --- a/src/feature/dirauth/dirvote.c +++ b/src/feature/dirauth/dirvote.c @@ -1,6 +1,6 @@ /* Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2020, The Tor Project, Inc. */ + * Copyright (c) 2007-2021, The Tor Project, Inc. */ /* See LICENSE for licensing information */ #define DIRVOTE_PRIVATE @@ -1479,6 +1479,21 @@ compute_nth_protocol_set(int n, int n_voters, const smartlist_t *votes) return result; } +/** Helper: Takes a smartlist of `const char *` flags, and a flag to remove. + * + * Removes that flag if it is present in the list. Doesn't free it. + */ +static void +remove_flag(smartlist_t *sl, const char *flag) +{ + /* We can't use smartlist_string_remove() here, since that doesn't preserve + * order, and since it frees elements from the string. */ + + int idx = smartlist_string_pos(sl, flag); + if (idx >= 0) + smartlist_del_keeporder(sl, idx); +} + /** Given a list of vote networkstatus_t in <b>votes</b>, our public * authority <b>identity_key</b>, our private authority <b>signing_key</b>, * and the number of <b>total_authorities</b> that we believe exist in our @@ -1633,6 +1648,9 @@ networkstatus_compute_consensus(smartlist_t *votes, tor_free(votesec_list); tor_free(distsec_list); } + // True if anybody is voting on the BadExit flag. + const bool badexit_flag_is_listed = + smartlist_contains_string(flags, "BadExit"); chunks = smartlist_new(); @@ -1757,26 +1775,14 @@ networkstatus_compute_consensus(smartlist_t *votes, } { - char *max_unmeasured_param = NULL; - /* XXXX Extract this code into a common function. Or don't! see #19011 */ - if (params) { - if (strcmpstart(params, "maxunmeasuredbw=") == 0) - max_unmeasured_param = params; - else - max_unmeasured_param = strstr(params, " maxunmeasuredbw="); - } - if (max_unmeasured_param) { - int ok = 0; - char *eq = strchr(max_unmeasured_param, '='); - if (eq) { - max_unmeasured_bw_kb = (uint32_t) - tor_parse_ulong(eq+1, 10, 1, UINT32_MAX, &ok, NULL); - if (!ok) { - log_warn(LD_DIR, "Bad element '%s' in max unmeasured bw param", - escaped(max_unmeasured_param)); - max_unmeasured_bw_kb = DEFAULT_MAX_UNMEASURED_BW_KB; - } - } + if (consensus_method < MIN_METHOD_FOR_CORRECT_BWWEIGHTSCALE) { + max_unmeasured_bw_kb = (int32_t) extract_param_buggy( + params, "maxunmeasuredbw", DEFAULT_MAX_UNMEASURED_BW_KB); + } else { + max_unmeasured_bw_kb = dirvote_get_intermediate_param_value( + param_list, "maxunmeasurdbw", DEFAULT_MAX_UNMEASURED_BW_KB); + if (max_unmeasured_bw_kb < 1) + max_unmeasured_bw_kb = 1; } } @@ -1936,7 +1942,7 @@ networkstatus_compute_consensus(smartlist_t *votes, const char *chosen_name = NULL; int exitsummary_disagreement = 0; int is_named = 0, is_unnamed = 0, is_running = 0, is_valid = 0; - int is_guard = 0, is_exit = 0, is_bad_exit = 0; + int is_guard = 0, is_exit = 0, is_bad_exit = 0, is_middle_only = 0; int naming_conflict = 0; int n_listing = 0; char microdesc_digest[DIGEST256_LEN]; @@ -2067,7 +2073,6 @@ networkstatus_compute_consensus(smartlist_t *votes, } /* Set the flags. */ - smartlist_add(chosen_flags, (char*)"s"); /* for the start of the line. */ SMARTLIST_FOREACH_BEGIN(flags, const char *, fl) { if (!strcmp(fl, "Named")) { if (is_named) @@ -2089,6 +2094,8 @@ networkstatus_compute_consensus(smartlist_t *votes, is_running = 1; else if (!strcmp(fl, "BadExit")) is_bad_exit = 1; + else if (!strcmp(fl, "MiddleOnly")) + is_middle_only = 1; else if (!strcmp(fl, "Valid")) is_valid = 1; } @@ -2105,6 +2112,22 @@ networkstatus_compute_consensus(smartlist_t *votes, if (!is_valid) continue; + /* Starting with consensus method 32, we handle the middle-only + * flag specially: when it is present, we clear some flags, and + * set others. */ + if (is_middle_only && consensus_method >= MIN_METHOD_FOR_MIDDLEONLY) { + remove_flag(chosen_flags, "Exit"); + remove_flag(chosen_flags, "V2Dir"); + remove_flag(chosen_flags, "Guard"); + remove_flag(chosen_flags, "HSDir"); + is_exit = is_guard = 0; + if (! is_bad_exit && badexit_flag_is_listed) { + is_bad_exit = 1; + smartlist_add(chosen_flags, (char *)"BadExit"); + smartlist_sort_strings(chosen_flags); // restore order. + } + } + /* Pick the version. */ if (smartlist_len(versions)) { sort_version_list(versions, 0); @@ -2265,6 +2288,8 @@ networkstatus_compute_consensus(smartlist_t *votes, smartlist_add_asprintf(chunks, "m %s\n", m); } /* Next line is all flags. The "\n" is missing. */ + smartlist_add_asprintf(chunks, "s%s", + smartlist_len(chosen_flags)?" ":""); smartlist_add(chunks, smartlist_join_strings(chosen_flags, " ", 0, NULL)); /* Now the version line. */ @@ -2326,38 +2351,16 @@ networkstatus_compute_consensus(smartlist_t *votes, smartlist_add_strdup(chunks, "directory-footer\n"); { - int64_t weight_scale = BW_WEIGHT_SCALE; - char *bw_weight_param = NULL; - - // Parse params, extract BW_WEIGHT_SCALE if present - // DO NOT use consensus_param_bw_weight_scale() in this code! - // The consensus is not formed yet! - /* XXXX Extract this code into a common function. Or not: #19011. */ - if (params) { - if (strcmpstart(params, "bwweightscale=") == 0) - bw_weight_param = params; - else - bw_weight_param = strstr(params, " bwweightscale="); - } - - if (bw_weight_param) { - int ok=0; - char *eq = strchr(bw_weight_param, '='); - if (eq) { - weight_scale = tor_parse_long(eq+1, 10, 1, INT32_MAX, &ok, - NULL); - if (!ok) { - log_warn(LD_DIR, "Bad element '%s' in bw weight param", - escaped(bw_weight_param)); - weight_scale = BW_WEIGHT_SCALE; - } - } else { - log_warn(LD_DIR, "Bad element '%s' in bw weight param", - escaped(bw_weight_param)); - weight_scale = BW_WEIGHT_SCALE; - } + int64_t weight_scale; + if (consensus_method < MIN_METHOD_FOR_CORRECT_BWWEIGHTSCALE) { + weight_scale = extract_param_buggy(params, "bwweightscale", + BW_WEIGHT_SCALE); + } else { + weight_scale = dirvote_get_intermediate_param_value( + param_list, "bwweightscale", BW_WEIGHT_SCALE); + if (weight_scale < 1) + weight_scale = 1; } - added_weights = networkstatus_compute_bw_weights_v10(chunks, G, M, E, D, T, weight_scale); } @@ -2459,6 +2462,53 @@ networkstatus_compute_consensus(smartlist_t *votes, return result; } +/** Extract the value of a parameter from a string encoding a list of + * parameters, badly. + * + * This is a deliberately buggy implementation, for backward compatibility + * with versions of Tor affected by #19011. Once all authorities have + * upgraded to consensus method 31 or later, then we can throw away this + * function. */ +STATIC int64_t +extract_param_buggy(const char *params, + const char *param_name, + int64_t default_value) +{ + int64_t value = default_value; + const char *param_str = NULL; + + if (params) { + char *prefix1 = NULL, *prefix2=NULL; + tor_asprintf(&prefix1, "%s=", param_name); + tor_asprintf(&prefix2, " %s=", param_name); + if (strcmpstart(params, prefix1) == 0) + param_str = params; + else + param_str = strstr(params, prefix2); + tor_free(prefix1); + tor_free(prefix2); + } + + if (param_str) { + int ok=0; + char *eq = strchr(param_str, '='); + if (eq) { + value = tor_parse_long(eq+1, 10, 1, INT32_MAX, &ok, NULL); + if (!ok) { + log_warn(LD_DIR, "Bad element '%s' in %s", + escaped(param_str), param_name); + value = default_value; + } + } else { + log_warn(LD_DIR, "Bad element '%s' in %s", + escaped(param_str), param_name); + value = default_value; + } + } + + return value; +} + /** Given a list of networkstatus_t for each vote, return a newly allocated * string containing the "package" lines for the vote. */ STATIC char * @@ -4411,6 +4461,7 @@ get_all_possible_sybil(const smartlist_t *routers) // Return the digestmap: it now contains all the possible sybils return omit_as_sybil; } + /** Given a platform string as in a routerinfo_t (possibly null), return a * newly allocated version string for a networkstatus document, or NULL if the * platform doesn't give a Tor version. */ @@ -4528,13 +4579,16 @@ routers_make_ed_keys_unique(smartlist_t *routers) } SMARTLIST_FOREACH_END(ri); } -/** Routerstatus <b>rs</b> is part of a group of routers that are on - * too narrow an IP-space. Clear out its flags since we don't want it be used +/** Routerstatus <b>rs</b> is part of a group of routers that are on too + * narrow an IP-space. Clear out its flags since we don't want it be used * because of its Sybil-like appearance. * * Leave its BadExit flag alone though, since if we think it's a bad exit, * we want to vote that way in case all the other authorities are voting * Running and Exit. + * + * Also set the Sybil flag in order to let a relay operator know that's + * why their relay hasn't been voted on. */ static void clear_status_flags_on_sybil(routerstatus_t *rs) @@ -4542,6 +4596,7 @@ clear_status_flags_on_sybil(routerstatus_t *rs) rs->is_authority = rs->is_exit = rs->is_stable = rs->is_fast = rs->is_flagged_running = rs->is_named = rs->is_valid = rs->is_hs_dir = rs->is_v2_dir = rs->is_possible_guard = 0; + rs->is_sybil = 1; /* FFFF we might want some mechanism to check later on if we * missed zeroing any flags: it's easy to add a new flag but * forget to add it to this clause. */ @@ -4556,12 +4611,14 @@ const char DIRVOTE_UNIVERSAL_FLAGS[] = "HSDir " "Stable " "StaleDesc " + "Sybil " "V2Dir " "Valid"; /** Space-separated list of all flags that we may or may not vote on, * depending on our configuration. */ const char DIRVOTE_OPTIONAL_FLAGS[] = "BadExit " + "MiddleOnly " "Running"; /** Return a new networkstatus_t* containing our current opinion. (For v3 @@ -4579,7 +4636,8 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, smartlist_t *routers, *routerstatuses; char identity_digest[DIGEST_LEN]; char signing_key_digest[DIGEST_LEN]; - const int listbadexits = d_options->AuthDirListBadExits; + const int list_bad_exits = d_options->AuthDirListBadExits; + const int list_middle_only = d_options->AuthDirListMiddleOnly; routerlist_t *rl = router_get_routerlist(); time_t now = time(NULL); time_t cutoff = now - ROUTER_MAX_AGE_TO_PUBLISH; @@ -4684,7 +4742,8 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, vrs = tor_malloc_zero(sizeof(vote_routerstatus_t)); rs = &vrs->status; dirauth_set_routerstatus_from_routerinfo(rs, node, ri, now, - listbadexits); + list_bad_exits, + list_middle_only); if (ri->cache_info.signing_key_cert) { memcpy(vrs->ed25519_id, @@ -4735,7 +4794,6 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, dirserv_read_measured_bandwidths(options->V3BandwidthsFile, routerstatuses, bw_file_headers, bw_file_digest256); - } else { /* * No bandwidths file; clear the measured bandwidth cache in case we had @@ -4807,8 +4865,10 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_t *private_key, 0, SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0); if (vote_on_reachability) smartlist_add_strdup(v3_out->known_flags, "Running"); - if (listbadexits) + if (list_bad_exits) smartlist_add_strdup(v3_out->known_flags, "BadExit"); + if (list_middle_only) + smartlist_add_strdup(v3_out->known_flags, "MiddleOnly"); smartlist_sort_strings(v3_out->known_flags); if (d_options->ConsensusParams) { |