[tor-commits] [tor/master] Bug 32040: Add a keep_*_mask to keep circpad machines
asn at torproject.org
asn at torproject.org
Fri Jul 3 07:51:42 UTC 2020
commit f697ac58610a74c1cbffd16b39e8e90d1592290f
Author: Mike Perry <mikeperry-git at torproject.org>
Date: Tue Jun 9 02:36:45 2020 -0500
Bug 32040: Add a keep_*_mask to keep circpad machines
Allows us to program machines that stay around after creation if circuit state
or purpose changes.
---
src/core/or/circuitpadding.c | 39 ++++++++++++++++++++++++++++-------
src/core/or/circuitpadding.h | 14 +++++++++++--
src/core/or/circuitpadding_machines.c | 12 +++++------
3 files changed, 50 insertions(+), 15 deletions(-)
diff --git a/src/core/or/circuitpadding.c b/src/core/or/circuitpadding.c
index b958fec4f..889ffb03f 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)
@@ -2050,6 +2050,26 @@ circpad_machine_conditions_met(origin_circuit_t *circ,
return 1;
}
+/**
+ * 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.
*
@@ -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 4fadcb742..3d2929cf7 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 98767f9e8..405af5061 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 */
@@ -102,7 +102,7 @@ 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 =
+ client_machine->conditions.apply_purpose_mask =
circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT)|
circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_INTRODUCE_ACKED)|
circpad_circ_purpose_to_mask(CIRCUIT_PURPOSE_C_CIRCUIT_PADDING);
@@ -152,7 +152,7 @@ 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 +263,7 @@ 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 +299,7 @@ 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 +383,7 @@ 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;
More information about the tor-commits
mailing list