diff options
Diffstat (limited to 'src/or/nodelist.c')
| -rw-r--r-- | src/or/nodelist.c | 152 |
1 files changed, 104 insertions, 48 deletions
diff --git a/src/or/nodelist.c b/src/or/nodelist.c index e444c73247..4d7395b047 100644 --- a/src/or/nodelist.c +++ b/src/or/nodelist.c @@ -1213,7 +1213,7 @@ static int have_min_dir_info = 0; static int need_to_update_have_min_dir_info = 1; /** String describing what we're missing before we have enough directory * info. */ -static char dir_info_status[128] = ""; +static char dir_info_status[256] = ""; /** Return true iff we have enough networkstatus and router information to * start building circuits. Right now, this means "more than half the @@ -1253,10 +1253,12 @@ get_dir_info_status_string(void) * descriptors for. Store the former in *<b>num_usable</b> and the latter in * *<b>num_present</b>. If <b>in_set</b> is non-NULL, only consider those * routers in <b>in_set</b>. If <b>exit_only</b> is true, only consider nodes - * with the Exit flag. + * with the Exit flag. If *descs_out is present, add a node_t for each + * usable descriptor to it. */ static void count_usable_descriptors(int *num_present, int *num_usable, + smartlist_t *descs_out, const networkstatus_t *consensus, const or_options_t *options, time_t now, routerset_t *in_set, int exit_only) @@ -1266,6 +1268,10 @@ count_usable_descriptors(int *num_present, int *num_usable, SMARTLIST_FOREACH_BEGIN(consensus->routerstatus_list, routerstatus_t *, rs) { + const node_t *node = node_get_by_id(rs->identity_digest); + if (!node) + continue; /* This would be a bug: every entry in the consensus is + * supposed to have a node. */ if (exit_only && ! rs->is_exit) continue; if (in_set && ! routerset_contains_routerstatus(in_set, rs, -1)) @@ -1282,6 +1288,8 @@ count_usable_descriptors(int *num_present, int *num_usable, /* we have the descriptor listed in the consensus. */ ++*num_present; } + if (descs_out) + smartlist_add(descs_out, (node_t*)node); } } SMARTLIST_FOREACH_END(rs); @@ -1291,6 +1299,66 @@ count_usable_descriptors(int *num_present, int *num_usable, md ? "microdesc" : "desc", exit_only ? " exits" : "s"); } +/** Return an extimate of which fraction of usable paths through the Tor + * network we have available for use. */ +static double +compute_frac_paths_available(const networkstatus_t *consensus, + const or_options_t *options, time_t now, + int *num_present_out, int *num_usable_out, + char **status_out) +{ + smartlist_t *guards = smartlist_new(); + smartlist_t *mid = smartlist_new(); + smartlist_t *exits = smartlist_new(); + smartlist_t *myexits= smartlist_new(); + double f_guard, f_mid, f_exit, f_myexit; + int np, nu; /* Ignored */ + + count_usable_descriptors(num_present_out, num_usable_out, + mid, consensus, options, now, NULL, 0); + if (options->EntryNodes) { + count_usable_descriptors(&np, &nu, guards, consensus, options, now, + options->EntryNodes, 0); + } else { + SMARTLIST_FOREACH(mid, const node_t *, node, { + if (node->is_possible_guard) + smartlist_add(guards, (node_t*)node); + }); + } + + count_usable_descriptors(&np, &nu, exits, consensus, options, now, + NULL, 1); + count_usable_descriptors(&np, &nu, myexits, consensus, options, now, + options->ExitNodes, 1); + + f_guard = frac_nodes_with_descriptors(guards, WEIGHT_FOR_GUARD); + f_mid = frac_nodes_with_descriptors(mid, WEIGHT_FOR_MID); + f_exit = frac_nodes_with_descriptors(exits, WEIGHT_FOR_EXIT); + f_myexit= frac_nodes_with_descriptors(myexits,WEIGHT_FOR_EXIT); + + smartlist_free(guards); + smartlist_free(mid); + smartlist_free(exits); + smartlist_free(myexits); + + /* This is a tricky point here: we don't want to make it easy for a + * directory to trickle exits to us until it learns which exits we have + * configured, so require that we have a threshold both of total exits + * and usable exits. */ + if (f_myexit < f_exit) + f_exit = f_myexit; + + tor_asprintf(status_out, + "%02d%% of guards bw, " + "%02d%% of midpoint bw, and " + "%02d%% of exit bw", + (int)(f_guard*100), + (int)(f_mid*100), + (int)(f_exit*100)); + + return f_guard * f_mid * f_exit; +} + /** We just fetched a new set of descriptors. Compute how far through * the "loading descriptors" bootstrapping phase we are, so we can inform * the controller of our progress. */ @@ -1306,7 +1374,7 @@ count_loading_descriptors_progress(void) if (!consensus) return 0; /* can't count descriptors if we have no list of them */ - count_usable_descriptors(&num_present, &num_usable, + count_usable_descriptors(&num_present, &num_usable, NULL, consensus, get_options(), now, NULL, 0); if (num_usable == 0) @@ -1319,14 +1387,28 @@ count_loading_descriptors_progress(void) BOOTSTRAP_STATUS_LOADING_DESCRIPTORS)); } +/** Return the fraction of paths needed before we're willing to build + * circuits, as configured in <b>options</b>, or in the consensus <b>ns</b>. */ +static double +get_frac_paths_needed_for_circs(const or_options_t *options, + const networkstatus_t *ns) +{ +#define DFLT_PCT_USABLE_NEEDED 60 + if (options->PathsNeededToBuildCircuits >= 1.0) { + return options->PathsNeededToBuildCircuits; + } else { + return networkstatus_get_param(ns, "min_paths_for_circs_pct", + DFLT_PCT_USABLE_NEEDED, + 25, 95)/100.0; + } +} + /** Change the value of have_min_dir_info, setting it true iff we have enough * network and router information to build circuits. Clear the value of * need_to_update_have_min_dir_info. */ static void update_router_have_minimum_dir_info(void) { - int num_present = 0, num_usable=0; - int num_exit_present = 0, num_exit_usable = 0; time_t now = time(NULL); int res; const or_options_t *options = get_options(); @@ -1355,55 +1437,29 @@ update_router_have_minimum_dir_info(void) using_md = consensus->flavor == FLAV_MICRODESC; - count_usable_descriptors(&num_present, &num_usable, consensus, options, now, - NULL, 0); - count_usable_descriptors(&num_exit_present, &num_exit_usable, - consensus, options, now, options->ExitNodes, 1); - -/* What fraction of desired server descriptors do we need before we will - * build circuits? */ -#define FRAC_USABLE_NEEDED .75 -/* What fraction of desired _exit_ server descriptors do we need before we - * will build circuits? */ -#define FRAC_EXIT_USABLE_NEEDED .5 - - if (num_present < num_usable * FRAC_USABLE_NEEDED) { - tor_snprintf(dir_info_status, sizeof(dir_info_status), - "We have only %d/%d usable %sdescriptors.", - num_present, num_usable, using_md ? "micro" : ""); - res = 0; - control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_DESCRIPTORS, 0); - goto done; - } else if (num_present < 2) { - tor_snprintf(dir_info_status, sizeof(dir_info_status), - "Only %d %sdescriptor%s here and believed reachable!", - num_present, using_md ? "micro" : "", num_present ? "" : "s"); - res = 0; - goto done; - } else if (num_exit_present < num_exit_usable * FRAC_EXIT_USABLE_NEEDED) { - tor_snprintf(dir_info_status, sizeof(dir_info_status), - "We have only %d/%d usable exit node descriptors.", - num_exit_present, num_exit_usable); - res = 0; - control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_DESCRIPTORS, 0); - goto done; - } - - /* Check for entry nodes. */ - if (options->EntryNodes) { - count_usable_descriptors(&num_present, &num_usable, consensus, options, - now, options->EntryNodes, 0); + { + char *status = NULL; + int num_present=0, num_usable=0; + double paths = compute_frac_paths_available(consensus, options, now, + &num_present, &num_usable, + &status); - if (!num_usable || !num_present) { + if (paths < get_frac_paths_needed_for_circs(options,consensus)) { tor_snprintf(dir_info_status, sizeof(dir_info_status), - "We have only %d/%d usable entry node %sdescriptors.", - num_present, num_usable, using_md?"micro":""); + "We need more %sdescriptors: we have %d/%d, and " + "can only build %02d%% of likely paths. (We have %s.)", + using_md?"micro":"", num_present, num_usable, + (int)(paths*100), status); + /* log_notice(LD_NET, "%s", dir_info_status); */ + tor_free(status); res = 0; + control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_DESCRIPTORS, 0); goto done; } - } - res = 1; + tor_free(status); + res = 1; + } done: if (res && !have_min_dir_info) { |