Reset stream if HTTP/2 response status is invalid.

net/spdy/spdy_stream.cc

Index: net/spdy/spdy_stream.cc
diff --git a/net/spdy/spdy_stream.cc b/net/spdy/spdy_stream.cc
index d8cbe4dcc31da3d70183dc54c84f1adcaa67ecdb..b21cf2b1d37cc395a6a2ab22343174a6f69cce16 100644
--- a/net/spdy/spdy_stream.cc
+++ b/net/spdy/spdy_stream.cc
@@ -32,38 +32,6 @@ namespace net {
 
 namespace {
 
-enum StatusHeader {
-  STATUS_HEADER_NOT_INCLUDED = 0,
-  STATUS_HEADER_DOES_NOT_START_WITH_NUMBER = 1,
-  STATUS_HEADER_IS_NUMBER = 2,
-  STATUS_HEADER_HAS_STATUS_TEXT = 3,
-  STATUS_HEADER_MAX = STATUS_HEADER_HAS_STATUS_TEXT
-};
-
-StatusHeader ParseStatusHeaderImpl(const SpdyHeaderBlock& response_headers,
-                                   int* status) {
-  SpdyHeaderBlock::const_iterator it = response_headers.find(":status");
-  if (it == response_headers.end())
-    return STATUS_HEADER_NOT_INCLUDED;
-
-  // Save status in |*status| even if some text follows the status code.
-  SpdyStringPiece status_string = it->second;
-  SpdyStringPiece::size_type end = status_string.find(' ');
-  if (!StringToInt(status_string.substr(0, end), status))
-    return STATUS_HEADER_DOES_NOT_START_WITH_NUMBER;
-
-  return end == SpdyStringPiece::npos ? STATUS_HEADER_IS_NUMBER
-                                      : STATUS_HEADER_HAS_STATUS_TEXT;
-}
-
-StatusHeader ParseStatusHeader(const SpdyHeaderBlock& response_headers,
-                               int* status) {
-  StatusHeader status_header = ParseStatusHeaderImpl(response_headers, status);
-  UMA_HISTOGRAM_ENUMERATION("Net.Http2ResponseStatusHeader", status_header,
-                            STATUS_HEADER_MAX + 1);
-  return status_header;
-}
-
 std::unique_ptr<base::Value> NetLogSpdyStreamErrorCallback(
     SpdyStreamId stream_id,
     int status,
@@ -411,34 +379,32 @@ void SpdyStream::OnHeadersReceived(const SpdyHeaderBlock& response_headers,
                                    base::Time response_time,
                                    base::TimeTicks recv_first_byte_time) {
   switch (response_state_) {
-    case READY_FOR_HEADERS: {
+    case READY_FOR_HEADERS:
       // No header block has been received yet.
       DCHECK(response_headers_.empty());
-      int status;
-      switch (ParseStatusHeader(response_headers, &status)) {
-        case STATUS_HEADER_NOT_INCLUDED: {
+
+      {
+        SpdyHeaderBlock::const_iterator it = response_headers.find(":status");
+        if (it == response_headers.end()) {
           const std::string error("Response headers do not include :status.");
           LogStreamError(ERR_SPDY_PROTOCOL_ERROR, error);
           session_->ResetStream(stream_id_, ERROR_CODE_PROTOCOL_ERROR, error);
           return;
         }
-        case STATUS_HEADER_DOES_NOT_START_WITH_NUMBER: {
+
+        int status;
+        if (!StringToInt(it->second, &status)) {
           const std::string error("Cannot parse :status.");
           LogStreamError(ERR_SPDY_PROTOCOL_ERROR, error);
           session_->ResetStream(stream_id_, ERROR_CODE_PROTOCOL_ERROR, error);
           return;
         }
-        // Intentional fallthrough for the following two cases,
-        // to maintain compatibility with broken servers that include
-        // status text in the response.
-        case STATUS_HEADER_IS_NUMBER:
-        case STATUS_HEADER_HAS_STATUS_TEXT:
-          // Ignore informational headers.
-          // TODO(bnc): Add support for 103 Early Hints,
-          // https://crbug.com/671310.
-          if (status / 100 == 1) {
-            return;
-          }
+
+        // Ignore informational headers.
+        // TODO(bnc): Add support for 103 Early Hints, https://crbug.com/671310.
+        if (status / 100 == 1) {
+          return;
+        }
       }
 
       response_state_ = READY_FOR_DATA_OR_TRAILERS;
@@ -476,7 +442,7 @@ void SpdyStream::OnHeadersReceived(const SpdyHeaderBlock& response_headers,
       SaveResponseHeaders(response_headers);
 
       break;
-    }
+
     case READY_FOR_DATA_OR_TRAILERS:
       // Second header block is trailers.
       if (type_ == SPDY_PUSH_STREAM) {