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-rw-r--r--changes/bug320407
-rw-r--r--scripts/maint/practracker/exceptions.txt4
-rw-r--r--src/core/or/circuitpadding.c39
-rw-r--r--src/core/or/circuitpadding.h14
-rw-r--r--src/core/or/circuitpadding_machines.c25
-rw-r--r--src/test/test_circuitpadding.c12
6 files changed, 76 insertions, 25 deletions
diff --git a/changes/bug32040 b/changes/bug32040
new file mode 100644
index 0000000000..1cdc0bec9a
--- /dev/null
+++ b/changes/bug32040
@@ -0,0 +1,7 @@
+ o Minor bugfixes (circuitpadding):
+ - Add the abilility to keep circuit padding machines if they match a set
+ of circuit state or purposes. This allows us to have machines that start
+ up under some conditions but don't shut down under others. We now
+ use this mask to avoid starting up introduction circuit padding
+ again after the machines have already completed. Fixes bug 32040;
+ bugfix on 0.4.1.1-alpha.
diff --git a/scripts/maint/practracker/exceptions.txt b/scripts/maint/practracker/exceptions.txt
index 7c8a17001e..25568f03f0 100644
--- a/scripts/maint/practracker/exceptions.txt
+++ b/scripts/maint/practracker/exceptions.txt
@@ -108,10 +108,10 @@ problem dependency-violation /src/core/or/circuitlist.h 1
problem function-size /src/core/or/circuitmux.c:circuitmux_set_policy() 109
problem function-size /src/core/or/circuitmux.c:circuitmux_attach_circuit() 113
problem dependency-violation /src/core/or/circuitmux_ewma.c 2
-problem file-size /src/core/or/circuitpadding.c 3101
+problem file-size /src/core/or/circuitpadding.c 3183
problem function-size /src/core/or/circuitpadding.c:circpad_machine_schedule_padding() 113
problem dependency-violation /src/core/or/circuitpadding.c 6
-problem file-size /src/core/or/circuitpadding.h 813
+problem file-size /src/core/or/circuitpadding.h 832
problem function-size /src/core/or/circuitpadding_machines.c:circpad_machine_relay_hide_intro_circuits() 103
problem function-size /src/core/or/circuitpadding_machines.c:circpad_machine_client_hide_rend_circuits() 112
problem dependency-violation /src/core/or/circuitpadding_machines.c 1
diff --git a/src/core/or/circuitpadding.c b/src/core/or/circuitpadding.c
index b958fec4f9..889ffb03f1 100644
--- a/src/core/or/circuitpadding.c
+++ b/src/core/or/circuitpadding.c
@@ -2008,7 +2008,7 @@ circpad_internal_event_state_length_up(circpad_machine_runtime_t *mi)
* Returns true if the circuit matches the conditions.
*/
static inline bool
-circpad_machine_conditions_met(origin_circuit_t *circ,
+circpad_machine_conditions_apply(origin_circuit_t *circ,
const circpad_machine_spec_t *machine)
{
/* If padding is disabled, no machines should match/apply. This has
@@ -2025,7 +2025,7 @@ circpad_machine_conditions_met(origin_circuit_t *circ,
}
if (!(circpad_circ_purpose_to_mask(TO_CIRCUIT(circ)->purpose)
- & machine->conditions.purpose_mask))
+ & machine->conditions.apply_purpose_mask))
return 0;
if (machine->conditions.requires_vanguards) {
@@ -2041,7 +2041,7 @@ circpad_machine_conditions_met(origin_circuit_t *circ,
* "I want to apply to circuits with either streams or no streams"; OR
* "I only want to apply to circuits with streams"; OR
* "I only want to apply to circuits without streams". */
- if (!(circpad_circuit_state(circ) & machine->conditions.state_mask))
+ if (!(circpad_circuit_state(circ) & machine->conditions.apply_state_mask))
return 0;
if (circuit_get_cpath_opened_len(circ) < machine->conditions.min_hops)
@@ -2051,6 +2051,26 @@ circpad_machine_conditions_met(origin_circuit_t *circ,
}
/**
+ * Check to see if any of the keep conditions still apply to this circuit.
+ *
+ * These conditions keep the machines active if they match, but do not
+ * cause new machines to start up.
+ */
+static inline bool
+circpad_machine_conditions_keep(origin_circuit_t *circ,
+ const circpad_machine_spec_t *machine)
+{
+ if ((circpad_circ_purpose_to_mask(TO_CIRCUIT(circ)->purpose)
+ & machine->conditions.keep_purpose_mask))
+ return 1;
+
+ if ((circpad_circuit_state(circ) & machine->conditions.keep_state_mask))
+ return 1;
+
+ return 0;
+}
+
+/**
* Returns a minimized representation of the circuit state.
*
* The padding code only cares if the circuit is building,
@@ -2115,7 +2135,12 @@ circpad_shutdown_old_machines(origin_circuit_t *on_circ)
circuit_t *circ = TO_CIRCUIT(on_circ);
FOR_EACH_ACTIVE_CIRCUIT_MACHINE_BEGIN(i, circ) {
- if (!circpad_machine_conditions_met(on_circ,
+ /* We shut down a machine if neither the apply conditions
+ * nor the keep conditions match. If either set of conditions match,
+ * keep it around. */
+ if (!circpad_machine_conditions_apply(on_circ,
+ circ->padding_machine[i]) &&
+ !circpad_machine_conditions_keep(on_circ,
circ->padding_machine[i])) {
uint32_t machine_ctr = circ->padding_info[i]->machine_ctr;
// Clear machineinfo (frees timers)
@@ -2174,7 +2199,7 @@ circpad_add_matching_machines(origin_circuit_t *on_circ,
* machines installed on a circuit. Make sure we only
* add this machine if its target machine index is free. */
if (machine->machine_index == i &&
- circpad_machine_conditions_met(on_circ, machine)) {
+ circpad_machine_conditions_apply(on_circ, machine)) {
// We can only replace this machine if the target hopnum
// is the same, otherwise we'll get invalid data
@@ -2587,9 +2612,9 @@ circpad_circ_client_machine_init(void)
= tor_malloc_zero(sizeof(circpad_machine_spec_t));
circ_client_machine->conditions.min_hops = 2;
- circ_client_machine->conditions.state_mask =
+ circ_client_machine->conditions.apply_state_mask =
CIRCPAD_CIRC_BUILDING|CIRCPAD_CIRC_OPENED|CIRCPAD_CIRC_HAS_RELAY_EARLY;
- circ_client_machine->conditions.purpose_mask = CIRCPAD_PURPOSE_ALL;
+ circ_client_machine->conditions.apply_purpose_mask = CIRCPAD_PURPOSE_ALL;
circ_client_machine->conditions.reduced_padding_ok = 1;
circ_client_machine->target_hopnum = 2;
diff --git a/src/core/or/circuitpadding.h b/src/core/or/circuitpadding.h
index 4fadcb742a..3d2929cf74 100644
--- a/src/core/or/circuitpadding.h
+++ b/src/core/or/circuitpadding.h
@@ -173,11 +173,21 @@ typedef struct circpad_machine_conditions_t {
/** Only apply the machine *if* the circuit's state matches any of
* the bits set in this bitmask. */
- circpad_circuit_state_t state_mask;
+ circpad_circuit_state_t apply_state_mask;
/** Only apply a machine *if* the circuit's purpose matches one
* of the bits set in this bitmask */
- circpad_purpose_mask_t purpose_mask;
+ circpad_purpose_mask_t apply_purpose_mask;
+
+ /** Keep a machine if any of the circuits's state machine's match
+ * the bits set in this bitmask, but don't apply new machines if
+ * they match this mask. */
+ circpad_circuit_state_t keep_state_mask;
+
+ /** Keep a machine if any of the circuits's state machine's match
+ * the bits set in this bitmask, but don't apply new machines if
+ * they match this mask. */
+ circpad_purpose_mask_t keep_purpose_mask;
} circpad_machine_conditions_t;
diff --git a/src/core/or/circuitpadding_machines.c b/src/core/or/circuitpadding_machines.c
index 98767f9e8f..1e6b580f5b 100644
--- a/src/core/or/circuitpadding_machines.c
+++ b/src/core/or/circuitpadding_machines.c
@@ -67,7 +67,7 @@ circpad_machine_client_hide_intro_circuits(smartlist_t *machines_sl)
client_machine->name = "client_ip_circ";
- client_machine->conditions.state_mask = CIRCPAD_CIRC_OPENED;
+ client_machine->conditions.apply_state_mask = CIRCPAD_CIRC_OPENED;
client_machine->target_hopnum = 2;
/* This is a client machine */
@@ -102,9 +102,18 @@ circpad_machine_client_hide_intro_circuits(smartlist_t *machines_sl)
* INTRO_MACHINE_MAXIMUM_PADDING cells, to match the "...(inbound data cells
* continue)" portion of the trace (aka the rest of an HTTPS response body).
*/
- client_machine->conditions.purpose_mask =
- circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT)|
- circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_INTRODUCE_ACKED)|
+
+ /* Start the machine on fresh intro circs. */
+ client_machine->conditions.apply_purpose_mask =
+ circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT);
+
+ /* If the client purpose changes back to CIRCUIT_PURPOSE_C_INTRODUCING,
+ * or transitions to CIRCUIT_PURPOSE_C_INTRODUCE_ACKED, keep the machine
+ * alive, but do not launch new machines for these purposes. Also
+ * keep the machine around if it is in the CIRCUIT_PADDING purpose
+ * (but do not try to take over other machines in that purpose). */
+ client_machine->conditions.keep_purpose_mask =
+ circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_INTRODUCE_ACKED) |
circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_CIRCUIT_PADDING);
/* Keep the circuit alive even after the introduction has been finished,
@@ -152,7 +161,7 @@ circpad_machine_relay_hide_intro_circuits(smartlist_t *machines_sl)
relay_machine->name = "relay_ip_circ";
- relay_machine->conditions.state_mask = CIRCPAD_CIRC_OPENED;
+ relay_machine->conditions.apply_state_mask = CIRCPAD_CIRC_OPENED;
/* This is a relay-side machine */
relay_machine->is_origin_side = 0;
@@ -263,7 +272,7 @@ circpad_machine_client_hide_rend_circuits(smartlist_t *machines_sl)
client_machine->name = "client_rp_circ";
/* Only pad after the circuit has been built and pad to the middle */
- client_machine->conditions.state_mask = CIRCPAD_CIRC_OPENED;
+ client_machine->conditions.apply_state_mask = CIRCPAD_CIRC_OPENED;
client_machine->target_hopnum = 2;
/* This is a client machine */
@@ -299,7 +308,7 @@ circpad_machine_client_hide_rend_circuits(smartlist_t *machines_sl)
*
* Hence this way we make rendezvous circuits look like general circuits up
* till the end of the circuit setup. */
- client_machine->conditions.purpose_mask =
+ client_machine->conditions.apply_purpose_mask =
circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_REND_JOINED)|
circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_REND_READY)|
circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED);
@@ -383,7 +392,7 @@ circpad_machine_relay_hide_rend_circuits(smartlist_t *machines_sl)
/* Only pad after the circuit has been built and pad to the middle */
relay_machine->conditions.min_hops = 2;
- relay_machine->conditions.state_mask = CIRCPAD_CIRC_OPENED;
+ relay_machine->conditions.apply_state_mask = CIRCPAD_CIRC_OPENED;
/* This is a relay-side machine */
relay_machine->is_origin_side = 0;
diff --git a/src/test/test_circuitpadding.c b/src/test/test_circuitpadding.c
index cc8c63d608..c3346e2e03 100644
--- a/src/test/test_circuitpadding.c
+++ b/src/test/test_circuitpadding.c
@@ -1733,9 +1733,9 @@ helper_create_conditional_machines(void)
add->conditions.requires_vanguards = 0;
add->conditions.min_hops = 2;
- add->conditions.state_mask = CIRCPAD_CIRC_BUILDING|
+ add->conditions.apply_state_mask = CIRCPAD_CIRC_BUILDING|
CIRCPAD_CIRC_NO_STREAMS|CIRCPAD_CIRC_HAS_RELAY_EARLY;
- add->conditions.purpose_mask = CIRCPAD_PURPOSE_ALL;
+ add->conditions.apply_purpose_mask = CIRCPAD_PURPOSE_ALL;
circpad_register_padding_machine(add, origin_padding_machines);
add = helper_create_conditional_machine();
@@ -1752,9 +1752,9 @@ helper_create_conditional_machines(void)
add->conditions.requires_vanguards = 1;
add->conditions.min_hops = 3;
- add->conditions.state_mask = CIRCPAD_CIRC_OPENED|
+ add->conditions.apply_state_mask = CIRCPAD_CIRC_OPENED|
CIRCPAD_CIRC_STREAMS|CIRCPAD_CIRC_HAS_NO_RELAY_EARLY;
- add->conditions.purpose_mask = CIRCPAD_PURPOSE_ALL;
+ add->conditions.apply_purpose_mask = CIRCPAD_PURPOSE_ALL;
circpad_register_padding_machine(add, origin_padding_machines);
add = helper_create_conditional_machine();
@@ -2728,8 +2728,8 @@ helper_create_ender_machine(void)
circ_client_machine.states[CIRCPAD_STATE_START].
next_state[CIRCPAD_EVENT_NONPADDING_RECV] = CIRCPAD_STATE_END;
- circ_client_machine.conditions.state_mask = CIRCPAD_STATE_ALL;
- circ_client_machine.conditions.purpose_mask = CIRCPAD_PURPOSE_ALL;
+ circ_client_machine.conditions.apply_state_mask = CIRCPAD_STATE_ALL;
+ circ_client_machine.conditions.apply_purpose_mask = CIRCPAD_PURPOSE_ALL;
}
static time_t mocked_timeofday;
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