Change return value of entry_guard_succeeded to an enum.

George pointed out that (-1,0,1) for (never usable, maybe usable
later, usable right now) was a pretty rotten convention that made
the code harder to read.
This commit is contained in:
Nick Mathewson 2016-11-29 11:47:12 -05:00
parent 46619ec914
commit 84bfa895d7
4 changed files with 42 additions and 35 deletions

View File

@ -964,28 +964,29 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
memset(&ec, 0, sizeof(ec)); memset(&ec, 0, sizeof(ec));
if (!hop) { if (!hop) {
/* done building the circuit. whew. */ /* done building the circuit. whew. */
int r; guard_usable_t r;
if (get_options()->UseDeprecatedGuardAlgorithm) { if (get_options()->UseDeprecatedGuardAlgorithm) {
// The circuit is usable; we already marked the guard as okay. // The circuit is usable; we already marked the guard as okay.
r = 1; r = GUARD_USABLE_NOW;
} else if (! circ->guard_state) { } else if (! circ->guard_state) {
if (circuit_get_cpath_len(circ) != 1) { if (circuit_get_cpath_len(circ) != 1) {
log_warn(LD_BUG, "%d-hop circuit %p with purpose %d has no " log_warn(LD_BUG, "%d-hop circuit %p with purpose %d has no "
"guard state", "guard state",
circuit_get_cpath_len(circ), circ, circ->base_.purpose); circuit_get_cpath_len(circ), circ, circ->base_.purpose);
} }
r = 1; r = GUARD_USABLE_NOW;
} else { } else {
r = entry_guard_succeeded(&circ->guard_state); r = entry_guard_succeeded(&circ->guard_state);
} }
const int is_usable_for_streams = (r == 1); const int is_usable_for_streams = (r == GUARD_USABLE_NOW);
if (r == 1) { if (r == GUARD_USABLE_NOW) {
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN); circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN);
} else if (r == 0) { } else if (r == GUARD_MAYBE_USABLE_LATER) {
// XXXX prop271 we might want to probe for whether this // XXXX prop271 we might want to probe for whether this
// XXXX one is ready even before the next second rolls over. // XXXX one is ready even before the next second rolls over.
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_GUARD_WAIT); circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_GUARD_WAIT);
} else { } else {
tor_assert_nonfatal(r == GUARD_USABLE_NEVER);
return - END_CIRC_REASON_INTERNAL; return - END_CIRC_REASON_INTERNAL;
} }

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@ -1965,28 +1965,26 @@ entry_guard_pick_for_circuit(guard_selection_t *gs,
} }
/** /**
* Called by the circuit building module when a circuit has succeeded: * Called by the circuit building module when a circuit has succeeded: informs
* informs the guards code that the guard in *<b>guard_state_p</b> is * the guards code that the guard in *<b>guard_state_p</b> is working, and
* working, and advances the state of the guard module. On a -1 return * advances the state of the guard module. On a GUARD_USABLE_NEVER return
* value, the circuit is broken and should not be used. On a 1 return * value, the circuit is broken and should not be used. On a GUARD_USABLE_NOW
* value, the circuit is ready to use. On a 0 return value, the circuit * return value, the circuit is ready to use. On a GUARD_MAYBE_USABLE_LATER
* should not be used until we find out whether preferred guards will * return value, the circuit should not be used until we find out whether
* work for us. * preferred guards will work for us.
*
* XXXXX prop271 tristates are ugly; reconsider that interface.
*/ */
int guard_usable_t
entry_guard_succeeded(circuit_guard_state_t **guard_state_p) entry_guard_succeeded(circuit_guard_state_t **guard_state_p)
{ {
if (get_options()->UseDeprecatedGuardAlgorithm) if (get_options()->UseDeprecatedGuardAlgorithm)
return 1; return GUARD_USABLE_NOW;
if (BUG(*guard_state_p == NULL)) if (BUG(*guard_state_p == NULL))
return -1; return GUARD_USABLE_NEVER;
entry_guard_t *guard = entry_guard_handle_get((*guard_state_p)->guard); entry_guard_t *guard = entry_guard_handle_get((*guard_state_p)->guard);
if (! guard || BUG(guard->in_selection == NULL)) if (! guard || BUG(guard->in_selection == NULL))
return -1; return GUARD_USABLE_NEVER;
unsigned newstate = unsigned newstate =
entry_guards_note_guard_success(guard->in_selection, guard, entry_guards_note_guard_success(guard->in_selection, guard,
@ -1996,9 +1994,9 @@ entry_guard_succeeded(circuit_guard_state_t **guard_state_p)
(*guard_state_p)->state_set_at = approx_time(); (*guard_state_p)->state_set_at = approx_time();
if (newstate == GUARD_CIRC_STATE_COMPLETE) { if (newstate == GUARD_CIRC_STATE_COMPLETE) {
return 1; return GUARD_USABLE_NOW;
} else { } else {
return 0; return GUARD_MAYBE_USABLE_LATER;
} }
} }

View File

@ -359,7 +359,12 @@ void circuit_guard_state_free(circuit_guard_state_t *state);
int entry_guard_pick_for_circuit(guard_selection_t *gs, int entry_guard_pick_for_circuit(guard_selection_t *gs,
const node_t **chosen_node_out, const node_t **chosen_node_out,
circuit_guard_state_t **guard_state_out); circuit_guard_state_t **guard_state_out);
int entry_guard_succeeded(circuit_guard_state_t **guard_state_p); typedef enum {
GUARD_USABLE_NEVER = -1,
GUARD_MAYBE_USABLE_LATER = 0,
GUARD_USABLE_NOW = 1,
} guard_usable_t;
guard_usable_t entry_guard_succeeded(circuit_guard_state_t **guard_state_p);
void entry_guard_failed(circuit_guard_state_t **guard_state_p); void entry_guard_failed(circuit_guard_state_t **guard_state_p);
void entry_guard_cancel(circuit_guard_state_t **guard_state_p); void entry_guard_cancel(circuit_guard_state_t **guard_state_p);
void entry_guard_chan_failed(channel_t *chan); void entry_guard_chan_failed(channel_t *chan);

View File

@ -2324,6 +2324,7 @@ test_entry_guard_select_for_circuit_highlevel_primary(void *arg)
const node_t *node = NULL; const node_t *node = NULL;
circuit_guard_state_t *guard = NULL; circuit_guard_state_t *guard = NULL;
entry_guard_t *g; entry_guard_t *g;
guard_usable_t u;
/* /*
* Make sure that the pick-for-circuit API basically works. We'll get * Make sure that the pick-for-circuit API basically works. We'll get
* a primary guard, so it'll be usable on completion. * a primary guard, so it'll be usable on completion.
@ -2343,8 +2344,8 @@ test_entry_guard_select_for_circuit_highlevel_primary(void *arg)
/* Call that circuit successful. */ /* Call that circuit successful. */
update_approx_time(start+15); update_approx_time(start+15);
r = entry_guard_succeeded(&guard); u = entry_guard_succeeded(&guard);
tt_int_op(r, OP_EQ, 1); /* We can use it now. */ tt_int_op(u, OP_EQ, GUARD_USABLE_NOW); /* We can use it now. */
tt_assert(guard); tt_assert(guard);
tt_int_op(guard->state, OP_EQ, GUARD_CIRC_STATE_COMPLETE); tt_int_op(guard->state, OP_EQ, GUARD_CIRC_STATE_COMPLETE);
g = entry_guard_handle_get(guard->guard); g = entry_guard_handle_get(guard->guard);
@ -2411,8 +2412,8 @@ test_entry_guard_select_for_circuit_highlevel_primary(void *arg)
/* Call this one up; watch it get confirmed. */ /* Call this one up; watch it get confirmed. */
update_approx_time(start+90); update_approx_time(start+90);
r = entry_guard_succeeded(&guard); u = entry_guard_succeeded(&guard);
tt_int_op(r, OP_EQ, 1); /* We can use it now. */ tt_int_op(u, OP_EQ, GUARD_USABLE_NOW);
tt_assert(guard); tt_assert(guard);
tt_int_op(guard->state, OP_EQ, GUARD_CIRC_STATE_COMPLETE); tt_int_op(guard->state, OP_EQ, GUARD_CIRC_STATE_COMPLETE);
g = entry_guard_handle_get(guard->guard); g = entry_guard_handle_get(guard->guard);
@ -2440,6 +2441,7 @@ test_entry_guard_select_for_circuit_highlevel_confirm_other(void *arg)
circuit_guard_state_t *guard = NULL; circuit_guard_state_t *guard = NULL;
int i, r; int i, r;
const node_t *node = NULL; const node_t *node = NULL;
guard_usable_t u;
/* Declare that we're on the internet. */ /* Declare that we're on the internet. */
entry_guards_note_internet_connectivity(gs); entry_guards_note_internet_connectivity(gs);
@ -2471,13 +2473,13 @@ test_entry_guard_select_for_circuit_highlevel_confirm_other(void *arg)
tt_int_op(g->is_pending, OP_EQ, 1); tt_int_op(g->is_pending, OP_EQ, 1);
(void)start; (void)start;
r = entry_guard_succeeded(&guard); u = entry_guard_succeeded(&guard);
/* We're on the internet (by fiat), so this guard will get called "confirmed" /* We're on the internet (by fiat), so this guard will get called "confirmed"
* and should immediately become primary. * and should immediately become primary.
* XXXX prop271 -- I don't like that behavior, but it's what is specified * XXXX prop271 -- I don't like that behavior, but it's what is specified
*/ */
tt_int_op(guard->state, OP_EQ, GUARD_CIRC_STATE_COMPLETE); tt_int_op(guard->state, OP_EQ, GUARD_CIRC_STATE_COMPLETE);
tt_assert(r == 1); tt_assert(u == GUARD_USABLE_NOW);
tt_int_op(g->confirmed_idx, OP_EQ, 0); tt_int_op(g->confirmed_idx, OP_EQ, 0);
tt_int_op(g->is_primary, OP_EQ, 1); tt_int_op(g->is_primary, OP_EQ, 1);
tt_int_op(g->is_pending, OP_EQ, 0); tt_int_op(g->is_pending, OP_EQ, 0);
@ -2503,6 +2505,7 @@ test_entry_guard_select_for_circuit_highlevel_primary_retry(void *arg)
int i, r; int i, r;
const node_t *node = NULL; const node_t *node = NULL;
entry_guard_t *g; entry_guard_t *g;
guard_usable_t u;
/* Declare that we're on the internet. */ /* Declare that we're on the internet. */
entry_guards_note_internet_connectivity(gs); entry_guards_note_internet_connectivity(gs);
@ -2540,8 +2543,8 @@ test_entry_guard_select_for_circuit_highlevel_primary_retry(void *arg)
update_approx_time(start + 3600); update_approx_time(start + 3600);
/* Say that guard has succeeded! */ /* Say that guard has succeeded! */
r = entry_guard_succeeded(&guard); u = entry_guard_succeeded(&guard);
tt_int_op(r, OP_EQ, 0); // can't use it yet. tt_int_op(u, OP_EQ, GUARD_MAYBE_USABLE_LATER);
tt_int_op(guard->state, OP_EQ, GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD); tt_int_op(guard->state, OP_EQ, GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD);
g = entry_guard_handle_get(guard->guard); g = entry_guard_handle_get(guard->guard);
@ -2556,8 +2559,8 @@ test_entry_guard_select_for_circuit_highlevel_primary_retry(void *arg)
r = entry_guard_pick_for_circuit(gs, &node, &guard2); r = entry_guard_pick_for_circuit(gs, &node, &guard2);
tt_assert(r == 0); tt_assert(r == 0);
tt_int_op(guard2->state, OP_EQ, GUARD_CIRC_STATE_USABLE_ON_COMPLETION); tt_int_op(guard2->state, OP_EQ, GUARD_CIRC_STATE_USABLE_ON_COMPLETION);
r = entry_guard_succeeded(&guard2); u = entry_guard_succeeded(&guard2);
tt_assert(r == 1); tt_assert(u == GUARD_USABLE_NOW);
tt_int_op(guard2->state, OP_EQ, GUARD_CIRC_STATE_COMPLETE); tt_int_op(guard2->state, OP_EQ, GUARD_CIRC_STATE_COMPLETE);
tt_assert(! entry_guards_all_primary_guards_are_down(gs)); tt_assert(! entry_guards_all_primary_guards_are_down(gs));
@ -2689,18 +2692,18 @@ upgrade_circuits_setup(const struct testcase_t *testcase)
tor_assert(data->guard2_state->state == tor_assert(data->guard2_state->state ==
GUARD_CIRC_STATE_USABLE_IF_NO_BETTER_GUARD); GUARD_CIRC_STATE_USABLE_IF_NO_BETTER_GUARD);
int r; guard_usable_t r;
update_approx_time(data->start + 32); update_approx_time(data->start + 32);
if (make_circ1_succeed) { if (make_circ1_succeed) {
r = entry_guard_succeeded(&data->guard1_state); r = entry_guard_succeeded(&data->guard1_state);
tor_assert(r == 0); tor_assert(r == GUARD_MAYBE_USABLE_LATER);
tor_assert(data->guard1_state->state == tor_assert(data->guard1_state->state ==
GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD); GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD);
} }
update_approx_time(data->start + 33); update_approx_time(data->start + 33);
if (make_circ2_succeed) { if (make_circ2_succeed) {
r = entry_guard_succeeded(&data->guard2_state); r = entry_guard_succeeded(&data->guard2_state);
tor_assert(r == 0); tor_assert(r == GUARD_MAYBE_USABLE_LATER);
tor_assert(data->guard2_state->state == tor_assert(data->guard2_state->state ==
GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD); GUARD_CIRC_STATE_WAITING_FOR_BETTER_GUARD);
} }