commit b3178134859a70abaa09a2c5546ce54d9f1562dd Author: Nick Mathewson nickm@torproject.org Date: Thu Dec 8 11:51:06 2016 -0500

Make GETINFO entry-guards work again with prop271

This is not a great solution, but it's as close to backward-compatible as possible. A better GETINFO API should expose more information. --- src/or/entrynodes.c | 131 ++++++++++++++++++++++++++++++++++++---------------- src/or/entrynodes.h | 3 +- 2 files changed, 92 insertions(+), 42 deletions(-)

diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c index 8260186..ca3e57b 100644 --- a/src/or/entrynodes.c +++ b/src/or/entrynodes.c @@ -4746,6 +4746,78 @@ entry_guards_update_state(or_state_t *state) entry_guards_dirty = 0; }

+/** + * Format a single entry guard in the format expected by the controller. + * Return a newly allocated string. + */ +STATIC char * +getinfo_helper_format_single_entry_guard(const entry_guard_t *e, + int legacy_guard) +{ + const char *status = NULL; + time_t when = 0; + const node_t *node; + char tbuf[ISO_TIME_LEN+1]; + char nbuf[MAX_VERBOSE_NICKNAME_LEN+1]; + + if (legacy_guard) { +#ifdef ENABLE_LEGACY_GUARD_ALGORITHM + if (!e->made_contact) { + status = "never-connected"; + } else if (e->bad_since) { + when = e->bad_since; + status = "unusable"; + } else if (e->unreachable_since) { + when = e->unreachable_since; + status = "down"; + } else { + status = "up"; + } +#else + tor_assert_nonfatal_unreached(); + status = "BUG"; +#endif + } else { + /* modern case. This is going to be a bit tricky, since the status + * codes above weren't really intended for prop271 guards. + * + * XXXX use a more appropriate format for exporting this information + */ + if (e->confirmed_idx < 0) { + status = "never-connected"; + } else if (! e->currently_listed) { + when = e->unlisted_since_date; + status = "unusable"; + } else if (! e->is_filtered_guard) { + status = "unusable"; + } else if (e->is_reachable == GUARD_REACHABLE_NO) { + when = e->failing_since; + status = "down"; + } else { + status = "up"; + } + } + + node = entry_guard_find_node(e); + if (node) { + node_get_verbose_nickname(node, nbuf); + } else { + nbuf[0] = '$'; + base16_encode(nbuf+1, sizeof(nbuf)-1, e->identity, DIGEST_LEN); + /* e->nickname field is not very reliable if we don't know about + * this router any longer; don't include it. */ + } + + char *result = NULL; + if (when) { + format_iso_time(tbuf, when); + tor_asprintf(&result, "%s %s %s\n", nbuf, status, tbuf); + } else { + tor_asprintf(&result, "%s %s\n", nbuf, status); + } + return result; +} + /** If <b>question</b> is the string "entry-guards", then dump * to *<b>answer</b> a newly allocated string describing all of * the nodes in the global entry_guards list. See control-spec.txt @@ -4765,61 +4837,38 @@ getinfo_helper_entry_guards(control_connection_t *conn, tor_assert(gs != NULL); #ifdef ENABLE_LEGACY_GUARD_ALGORITHM tor_assert(gs->chosen_entry_guards != NULL); -#else - // XXXX - (void)question; - (void)answer; #endif

(void) conn; (void) errmsg;

-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM if (!strcmp(question,"entry-guards") || !strcmp(question,"helper-nodes")) { - smartlist_t *sl = smartlist_new(); - char tbuf[ISO_TIME_LEN+1]; - char nbuf[MAX_VERBOSE_NICKNAME_LEN+1]; - - SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, e) { - const char *status = NULL; - time_t when = 0; - const node_t *node; - - if (!e->made_contact) { - status = "never-connected"; - } else if (e->bad_since) { - when = e->bad_since; - status = "unusable"; - } else if (e->unreachable_since) { - when = e->unreachable_since; - status = "down"; - } else { - status = "up"; - } + const smartlist_t *guards; + int legacy_mode; + if (gs->type == GS_TYPE_LEGACY) { +#ifdef ENABLE_LEGACY_GUARD_ALGORITHM + guards = gs->chosen_entry_guards; + legacy_mode = 1; +#else + tor_assert_nonfatal_unreached(); + return 0; +#endif + } else { + guards = gs->sampled_entry_guards; + legacy_mode = 0; + }

- node = node_get_by_id(e->identity); - if (node) { - node_get_verbose_nickname(node, nbuf); - } else { - nbuf[0] = '$'; - base16_encode(nbuf+1, sizeof(nbuf)-1, e->identity, DIGEST_LEN); - /* e->nickname field is not very reliable if we don't know about - * this router any longer; don't include it. */ - } + smartlist_t *sl = smartlist_new();

- if (when) { - format_iso_time(tbuf, when); - smartlist_add_asprintf(sl, "%s %s %s\n", nbuf, status, tbuf); - } else { - smartlist_add_asprintf(sl, "%s %s\n", nbuf, status); - } + SMARTLIST_FOREACH_BEGIN(guards, const entry_guard_t *, e) { + char *cp = getinfo_helper_format_single_entry_guard(e, legacy_mode); + smartlist_add(sl, cp); } SMARTLIST_FOREACH_END(e); *answer = smartlist_join_strings(sl, "", 0, NULL); SMARTLIST_FOREACH(sl, char *, c, tor_free(c)); smartlist_free(sl); } -#endif return 0; }

diff --git a/src/or/entrynodes.h b/src/or/entrynodes.h index db84d59..5fa0fec 100644 --- a/src/or/entrynodes.h +++ b/src/or/entrynodes.h @@ -610,7 +610,8 @@ STATIC unsigned entry_guards_note_guard_success(guard_selection_t *gs, entry_guard_t *guard, unsigned old_state); STATIC int entry_guard_has_higher_priority(entry_guard_t *a, entry_guard_t *b); - +STATIC char *getinfo_helper_format_single_entry_guard(const entry_guard_t *e, + int is_legacy); #ifdef ENABLE_LEGACY_GUARD_ALGORITHM // ---------- XXXX this stuff is pre-prop271.