Handle HTTP/3 SETTINGS on 0-RTT client connection.
In IETF QUIC, if 0-RTT is enabled, the client will receive 2 SETTINGS, one from cache and one from the fresh server sent SETTINGS.
If 0-RTT is accepted, the server shouldn't change dynamic table capacity according to https://quicwg.org/base-drafts/draft-ietf-quic-qpack.html#name-maximum-dynamic-table-capac. For other settings, https://www.google.com/url?sa=D&q=https%3A%2F%2Fquicwg.org%2Fbase-drafts%2Fdraft-ietf-quic-http.html%23name-initialization specifies they shouldn't be decreased.
When 0-RTT is rejected, our current approach is to retransmit 0-RTT packets. If the server changes SETTINGS, our implementation doesn't have an easy way to comply with the new SETTINGS, thus we close the connection too.
Protected by quic_enable_zero_rtt_for_tls
PiperOrigin-RevId: 316128955
Change-Id: I84b277b3c57d6a8009aec5a547c6416542122ec6
diff --git a/quic/core/qpack/qpack_header_table.cc b/quic/core/qpack/qpack_header_table.cc
index 472db89..29e7148 100644
--- a/quic/core/qpack/qpack_header_table.cc
+++ b/quic/core/qpack/qpack_header_table.cc
@@ -186,16 +186,15 @@
return true;
}
-void QpackHeaderTable::SetMaximumDynamicTableCapacity(
+bool QpackHeaderTable::SetMaximumDynamicTableCapacity(
uint64_t maximum_dynamic_table_capacity) {
- // This method can only be called once: in the decoding context, shortly after
- // construction; in the encoding context, upon receiving the SETTINGS frame.
- DCHECK_EQ(0u, dynamic_table_capacity_);
- DCHECK_EQ(0u, maximum_dynamic_table_capacity_);
- DCHECK_EQ(0u, max_entries_);
-
- maximum_dynamic_table_capacity_ = maximum_dynamic_table_capacity;
- max_entries_ = maximum_dynamic_table_capacity / 32;
+ if (maximum_dynamic_table_capacity_ == 0) {
+ maximum_dynamic_table_capacity_ = maximum_dynamic_table_capacity;
+ max_entries_ = maximum_dynamic_table_capacity / 32;
+ return true;
+ }
+ // If the value is already set, it should not be changed.
+ return maximum_dynamic_table_capacity == maximum_dynamic_table_capacity_;
}
void QpackHeaderTable::RegisterObserver(uint64_t required_insert_count,
