Deprecate --gfe2_reloadable_flag_quic_allow_host_in_request2.

PiperOrigin-RevId: 695948280

quiche/common/quiche_feature_flags_list.h

diff --git a/quiche/common/quiche_feature_flags_list.h b/quiche/common/quiche_feature_flags_list.h
index 6bbc38d..fab0f08 100755
--- a/quiche/common/quiche_feature_flags_list.h
+++ b/quiche/common/quiche_feature_flags_list.h
@@ -12,7 +12,6 @@
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_act_upon_invalid_header, true, true, "If true, reject or send error response code upon receiving invalid request or response headers.")
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_add_stream_info_to_idle_close_detail, false, true, "If true, include stream information in idle timeout connection close detail.")
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_allow_client_enabled_bbr_v2, true, true, "If true, allow client to enable BBRv2 on server via connection option 'B2ON'.")
-QUICHE_FLAG(bool, quiche_reloadable_flag_quic_allow_host_in_request2, true, true, "If true, requests with a host header will be allowed.")
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_avoid_nested_close_connection, false, true, "If true, if QuicConnection::CloseConnection triggers a nested call to itself, make the nested call a no-op.")
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_bbr2_extra_acked_window, false, true, "When true, the BBR4 copt sets the extra_acked window to 20 RTTs and BBR5 sets it to 40 RTTs.")
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_bbr2_probe_two_rounds, true, true, "When true, the BB2U copt causes BBR2 to wait two rounds with out draining the queue before exiting PROBE_UP and BB2S has the same effect in STARTUP.")

quiche/quic/core/http/quic_spdy_server_stream_base.cc

diff --git a/quiche/quic/core/http/quic_spdy_server_stream_base.cc b/quiche/quic/core/http/quic_spdy_server_stream_base.cc
index d010bb5..bfcc565 100644
--- a/quiche/quic/core/http/quic_spdy_server_stream_base.cc
+++ b/quiche/quic/core/http/quic_spdy_server_stream_base.cc
@@ -115,23 +115,20 @@
     }
   }
 
-  if (GetQuicReloadableFlag(quic_allow_host_in_request2)) {
-    // If the :scheme pseudo-header field identifies a scheme that has a
-    // mandatory authority component (including "http" and "https"), the
-    // request MUST contain either an :authority pseudo-header field or a
-    // Host header field. If these fields are present, they MUST NOT be
-    // empty. If both fields are present, they MUST contain the same value.
-    // If the scheme does not have a mandatory authority component and none
-    // is provided in the request target, the request MUST NOT contain the
-    // :authority pseudo-header or Host header fields.
-    //
-    // https://datatracker.ietf.org/doc/html/rfc9114#section-4.3.1
-    QUICHE_RELOADABLE_FLAG_COUNT_N(quic_allow_host_in_request2, 2, 3);
-    if (host && (!authority || *authority != *host)) {
-      QUIC_CODE_COUNT(http3_host_header_does_not_match_authority);
-      set_invalid_request_details("Host header does not match authority");
-      return false;
-    }
+  // If the :scheme pseudo-header field identifies a scheme that has a
+  // mandatory authority component (including "http" and "https"), the
+  // request MUST contain either an :authority pseudo-header field or a
+  // Host header field. If these fields are present, they MUST NOT be
+  // empty. If both fields are present, they MUST contain the same value.
+  // If the scheme does not have a mandatory authority component and none
+  // is provided in the request target, the request MUST NOT contain the
+  // :authority pseudo-header or Host header fields.
+  //
+  // https://datatracker.ietf.org/doc/html/rfc9114#section-4.3.1
+  if (host && (!authority || *authority != *host)) {
+    QUIC_CODE_COUNT(http3_host_header_does_not_match_authority);
+    set_invalid_request_details("Host header does not match authority");
+    return false;
   }
 
   if (is_extended_connect) {

quiche/quic/core/http/quic_spdy_server_stream_base_test.cc

diff --git a/quiche/quic/core/http/quic_spdy_server_stream_base_test.cc b/quiche/quic/core/http/quic_spdy_server_stream_base_test.cc
index 2f1c2ff..63719f9 100644
--- a/quiche/quic/core/http/quic_spdy_server_stream_base_test.cc
+++ b/quiche/quic/core/http/quic_spdy_server_stream_base_test.cc
@@ -291,7 +291,6 @@
 
 TEST_F(QuicSpdyServerStreamBaseTest, HostHeaderWithoutAuthority) {
   SetQuicReloadableFlag(quic_act_upon_invalid_header, true);
-  SetQuicReloadableFlag(quic_allow_host_in_request2, true);
   // A request with host but without authority should be rejected.
   QuicHeaderList header_list;
   header_list.OnHeader("host", "www.google.com:4433");
@@ -311,7 +310,6 @@
 
 TEST_F(QuicSpdyServerStreamBaseTest, HostHeaderWitDifferentAuthority) {
   SetQuicReloadableFlag(quic_act_upon_invalid_header, true);
-  SetQuicReloadableFlag(quic_allow_host_in_request2, true);
   // A request with host that does not match authority should be rejected.
   QuicHeaderList header_list;
   header_list.OnHeader(":authority", "www.google.com:4433");
@@ -332,7 +330,6 @@
 
 TEST_F(QuicSpdyServerStreamBaseTest, ValidHostHeader) {
   SetQuicReloadableFlag(quic_act_upon_invalid_header, true);
-  SetQuicReloadableFlag(quic_allow_host_in_request2, true);
   // A request with host that matches authority should be accepted.
   QuicHeaderList header_list;
   header_list.OnHeader(":authority", "www.google.com:4433");

quiche/quic/core/http/quic_spdy_stream.cc

diff --git a/quiche/quic/core/http/quic_spdy_stream.cc b/quiche/quic/core/http/quic_spdy_stream.cc
index 093f4ad..2e649ab 100644
--- a/quiche/quic/core/http/quic_spdy_stream.cc
+++ b/quiche/quic/core/http/quic_spdy_stream.cc
@@ -1777,7 +1777,6 @@
     QUIC_DLOG(ERROR) << invalid_request_details_;
     return false;
   }
-  bool is_response = false;
   for (const std::pair<std::string, std::string>& pair : header_list) {
     const std::string& name = pair.first;
     if (!IsValidHeaderName(name)) {
@@ -1786,18 +1785,8 @@
       QUIC_DLOG(ERROR) << invalid_request_details_;
       return false;
     }
-    if (name == ":status") {
-      is_response = !pair.second.empty();
-    }
     if (name == "host") {
-      if (GetQuicReloadableFlag(quic_allow_host_in_request2)) {
-        QUICHE_RELOADABLE_FLAG_COUNT_N(quic_allow_host_in_request2, 1, 3);
-        continue;
-      }
-      if (is_response) {
-        // Host header is allowed in response.
-        continue;
-      }
+      continue;
     }
     if (http2::GetInvalidHttp2HeaderSet().contains(name)) {
       invalid_request_details_ = absl::StrCat(name, " header is not allowed");

quiche/quic/core/http/quic_spdy_stream_test.cc

diff --git a/quiche/quic/core/http/quic_spdy_stream_test.cc b/quiche/quic/core/http/quic_spdy_stream_test.cc
index 4028098..1ca8721 100644
--- a/quiche/quic/core/http/quic_spdy_stream_test.cc
+++ b/quiche/quic/core/http/quic_spdy_stream_test.cc
@@ -3566,12 +3566,7 @@
   Initialize(kShouldProcessData);
 
   headers_["host"] = "foo";
-  if (GetQuicReloadableFlag(quic_allow_host_in_request2)) {
-    EXPECT_TRUE(stream_->ValidateReceivedHeaders(AsHeaderList(headers_)));
-  } else {
-    EXPECT_FALSE(stream_->ValidateReceivedHeaders(AsHeaderList(headers_)));
-    EXPECT_EQ("host header is not allowed", stream_->invalid_request_details());
-  }
+  EXPECT_TRUE(stream_->ValidateReceivedHeaders(AsHeaderList(headers_)));
 }
 
 }  // namespace