commit 818b44cc7c22696a3206229e4e15eeb9f130e2c0 Author: Nick Mathewson nickm@torproject.org Date: Thu Dec 8 12:10:06 2016 -0500

Repair the (deprecated, ugly) DROPGUARDS controller function.

This actually is much easier to write now that guard_selection_t is first-class. --- src/or/control.c | 13 ++++++++----- src/or/entrynodes.c | 36 ++++++++++++++++++++++++++++++++++++ src/or/entrynodes.h | 6 +++++- 3 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/src/or/control.c b/src/or/control.c index 364d75c..857b732 100644 --- a/src/or/control.c +++ b/src/or/control.c @@ -4064,17 +4064,20 @@ handle_control_dropguards(control_connection_t *conn, smartlist_split_string(args, body, " ", SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);

-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM + static int have_warned = 0; + if (! have_warned) { + log_warn(LD_CONTROL, "DROPGUARDS is dangerous; make sure you understand " + "the risks before using it. It may be removed in a future " + "version of Tor."); + have_warned = 1; + } + if (smartlist_len(args)) { connection_printf_to_buf(conn, "512 Too many arguments to DROPGUARDS\r\n"); } else { remove_all_entry_guards(); send_control_done(conn); } -#else - // XXXX - connection_printf_to_buf(conn, "512 not supported\r\n"); -#endif

SMARTLIST_FOREACH(args, char *, cp, tor_free(cp)); smartlist_free(args); diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c index a4021cc..63b54f4 100644 --- a/src/or/entrynodes.c +++ b/src/or/entrynodes.c @@ -3252,6 +3252,42 @@ guards_choose_guard(cpath_build_state_t *state, return r; }

+/** Remove all currently listed entry guards for a given guard selection + * context. This frees and replaces <b>gs</b>, so don't use <b>gs</b> + * after calling this function. */ +void +remove_all_entry_guards_for_guard_selection(guard_selection_t *gs) +{ + // This function shouldn't exist. XXXX + tor_assert(gs != NULL); + char *old_name = tor_strdup(gs->name); + guard_selection_type_t old_type = gs->type; + + SMARTLIST_FOREACH(gs->sampled_entry_guards, entry_guard_t *, entry, { + control_event_guard(entry->nickname, entry->identity, "DROPPED"); + }); + + if (gs == curr_guard_context) { + curr_guard_context = NULL; + } + + smartlist_remove(guard_contexts, gs); + guard_selection_free(gs); + + gs = get_guard_selection_by_name(old_name, old_type, 1); + entry_guards_changed_for_guard_selection(gs); + tor_free(old_name); +} + +/** Remove all currently listed entry guards. So new ones will be chosen. */ +void +remove_all_entry_guards(void) +{ + // XXXX prop271 this function shouldn't exist, in the new order. + // This function shouldn't exist. + remove_all_entry_guards_for_guard_selection(get_guard_selection_info()); +} + /** Helper: pick a directory guard, with whatever algorithm is used. */ const node_t * guards_choose_dirguard(circuit_guard_state_t **guard_state_out) diff --git a/src/or/entrynodes.h b/src/or/entrynodes.h index 6bbdff1..bd501d0 100644 --- a/src/or/entrynodes.h +++ b/src/or/entrynodes.h @@ -170,7 +170,8 @@ struct entry_guard_t { * we saw them in the state, even if we don't understand them. */ char *extra_state_fields;

- /** Backpointer to the guard selection that this guard belongs to. */ + /** Backpointer to the guard selection that this guard belongs to. + * The entry_guard_t must never outlive its guard_selection. */ guard_selection_t *in_selection; /**@}*/

@@ -548,6 +549,9 @@ 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); #endif

+void remove_all_entry_guards_for_guard_selection(guard_selection_t *gs); +void remove_all_entry_guards(void); + struct bridge_info_t; void entry_guard_learned_bridge_identity(const tor_addr_port_t *addrport, const uint8_t *rsa_id_digest);