commit 02f4e7b42e2158039a138c9cb68211304a754a1d Author: David Goulet dgoulet@torproject.org Date: Thu Feb 3 22:43:58 2022 +0000
cc: Export sendme_inc validation into public function
This is needed for client validation of server descriptor value, before launching a rend/intro. --- src/core/or/congestion_control_common.c | 24 ++++++++++++++++++++++++ src/core/or/congestion_control_common.h | 1 + 2 files changed, 25 insertions(+)
diff --git a/src/core/or/congestion_control_common.c b/src/core/or/congestion_control_common.c index e999f435ed..6d4f34cff8 100644 --- a/src/core/or/congestion_control_common.c +++ b/src/core/or/congestion_control_common.c @@ -1312,6 +1312,30 @@ congestion_control_build_ext_response(const circuit_params_t *our_params, return (int)ret; }
+/** Return true iff the given sendme increment is within the acceptable + * margins. */ +bool +congestion_control_validate_sendme_increment(uint8_t sendme_inc) +{ + /* We will only accept this response (and this circuit) if sendme_inc + * is within a factor of 2 of our consensus value. We should not need + * to change cc_sendme_inc much, and if we do, we can spread out those + * changes over smaller increments once every 4 hours. Exits that + * violate this range should just not be used. */ +#define MAX_SENDME_INC_NEGOTIATE_FACTOR 2 + + if (sendme_inc == 0) + return false; + + if (sendme_inc > + MAX_SENDME_INC_NEGOTIATE_FACTOR * congestion_control_sendme_inc() || + sendme_inc < + congestion_control_sendme_inc() / MAX_SENDME_INC_NEGOTIATE_FACTOR) { + return false; + } + return true; +} + /** Return 1 if CC is enabled which also will set the SENDME increment into our * params_out. Return 0 if CC is disabled. Else, return -1 on error. */ int diff --git a/src/core/or/congestion_control_common.h b/src/core/or/congestion_control_common.h index 21291983e0..936cb5887c 100644 --- a/src/core/or/congestion_control_common.h +++ b/src/core/or/congestion_control_common.h @@ -59,6 +59,7 @@ int congestion_control_build_ext_response(const circuit_params_t *our_params, int congestion_control_parse_ext_response(const uint8_t *msg, const size_t msg_len, circuit_params_t *params_out); +bool congestion_control_validate_sendme_increment(uint8_t sendme_inc);
/* Ugh, C.. these are private. Use the getter instead, when * external to the congestion control code. */