nghttpx: Tokenize trailer field as well so that we can ditch prohibited headers in HTTP/2

src/shrpx_downstream.cc

@@ -330,7 +330,7 @@ void Downstream::crumble_request_cookie(std::vector<nghttp2_nv> &nva) {
 
 namespace {
 void add_header(bool &key_prev, size_t &sum, Headers &headers, std::string name,
-                std::string value, int16_t token = -1) {
+                std::string value, int16_t token) {
   key_prev = true;
   sum += name.size() + value.size();
   headers.emplace_back(std::move(name), std::move(value), false, token);
@@ -415,11 +415,13 @@ const Headers::value_type *FieldStore::header(const StringRef &name) const {
   return search_header_linear_backwards(headers_, name);
 }
 
-void FieldStore::add_header_lower(std::string name, std::string value) {
-  util::inp_strlower(name);
-  auto token = http2::lookup_token(name);
-  shrpx::add_header(header_key_prev_, buffer_size_, headers_, std::move(name),
-                    std::move(value), token);
+void FieldStore::add_header_lower(const StringRef &name,
+                                  const StringRef &value) {
+  auto low_name = name.str();
+  util::inp_strlower(low_name);
+  auto token = http2::lookup_token(low_name);
+  shrpx::add_header(header_key_prev_, buffer_size_, headers_,
+                    std::move(low_name), value.str(), token);
 }
 
 void FieldStore::add_header(std::string name, std::string value,
@@ -450,16 +452,19 @@ void FieldStore::clear_headers() { headers_.clear(); }
 void FieldStore::add_trailer(const uint8_t *name, size_t namelen,
                              const uint8_t *value, size_t valuelen,
                              bool no_index, int16_t token) {
-  // we never index trailer fields.  Header size limit should be
-  // applied to all header and trailer fields combined.
+  // Header size limit should be applied to all header and trailer
+  // fields combined.
   shrpx::add_header(buffer_size_, trailers_, name, namelen, value, valuelen,
-                    no_index, -1);
+                    no_index, token);
 }
 
-void FieldStore::add_trailer_lower(std::string name, std::string value) {
-  util::inp_strlower(name);
-  shrpx::add_header(trailer_key_prev_, buffer_size_, trailers_, std::move(name),
-                    std::move(value));
+void FieldStore::add_trailer_lower(const StringRef &name,
+                                   const StringRef &value) {
+  auto low_name = name.str();
+  util::inp_strlower(low_name);
+  auto token = http2::lookup_token(low_name);
+  shrpx::add_header(trailer_key_prev_, buffer_size_, trailers_,
+                    std::move(low_name), value.str(), token);
 }
 
 void FieldStore::append_last_trailer_key(const char *data, size_t len) {

src/shrpx_downstream.h

@@ -79,7 +79,7 @@ public:
   // such header is found, returns nullptr.
   const Headers::value_type *header(const StringRef &name) const;
 
-  void add_header_lower(std::string name, std::string value);
+  void add_header_lower(const StringRef &name, const StringRef &value);
   void add_header(std::string name, std::string value, int16_t token);
   void add_header(const uint8_t *name, size_t namelen, const uint8_t *value,
                   size_t valuelen, bool no_index, int16_t token);
@@ -99,7 +99,7 @@ public:
 
   void add_trailer(const uint8_t *name, size_t namelen, const uint8_t *value,
                    size_t valuelen, bool no_index, int16_t token);
-  void add_trailer_lower(std::string name, std::string value);
+  void add_trailer_lower(const StringRef &name, const StringRef &value);
 
   void append_last_trailer_key(const char *data, size_t len);
   void append_last_trailer_value(const char *data, size_t len);

src/shrpx_http2_session.cc

@@ -735,15 +735,15 @@ int on_header_callback(nghttp2_session *session, const nghttp2_frame *frame,
       return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
     }
 
+    auto token = http2::lookup_token(name, namelen);
+
     if (trailer) {
       // just store header fields for trailer part
       resp.fs.add_trailer(name, namelen, value, valuelen,
-                          flags & NGHTTP2_NV_FLAG_NO_INDEX, -1);
+                          flags & NGHTTP2_NV_FLAG_NO_INDEX, token);
       return 0;
     }
 
-    auto token = http2::lookup_token(name, namelen);
-
     resp.fs.add_header(name, namelen, value, valuelen,
                        flags & NGHTTP2_NV_FLAG_NO_INDEX, token);
     return 0;

src/shrpx_http2_upstream.cc

@@ -201,15 +201,15 @@ int on_header_callback(nghttp2_session *session, const nghttp2_frame *frame,
     return 0;
   }
 
+  auto token = http2::lookup_token(name, namelen);
+
   if (frame->headers.cat == NGHTTP2_HCAT_HEADERS) {
     // just store header fields for trailer part
     req.fs.add_trailer(name, namelen, value, valuelen,
-                       flags & NGHTTP2_NV_FLAG_NO_INDEX, -1);
+                       flags & NGHTTP2_NV_FLAG_NO_INDEX, token);
     return 0;
   }
 
-  auto token = http2::lookup_token(name, namelen);
-
   req.fs.add_header(name, namelen, value, valuelen,
                     flags & NGHTTP2_NV_FLAG_NO_INDEX, token);
   return 0;

src/shrpx_http_downstream_connection.cc

@@ -691,7 +691,7 @@ int htp_hdr_keycb(http_parser *htp, const char *data, size_t len) {
       if (ensure_max_header_fields(downstream, httpconf) != 0) {
         return -1;
       }
-      resp.fs.add_header_lower(std::string(data, len), "");
+      resp.fs.add_header_lower(StringRef{data, len}, StringRef{});
     }
   } else {
     // trailer part
@@ -704,7 +704,7 @@ int htp_hdr_keycb(http_parser *htp, const char *data, size_t len) {
         // wrong place or crash if trailer fields are currently empty.
         return -1;
       }
-      resp.fs.add_trailer_lower(std::string(data, len), "");
+      resp.fs.add_trailer_lower(StringRef(data, len), StringRef{});
     }
   }
   return 0;

src/shrpx_https_upstream.cc

@@ -142,7 +142,7 @@ int htp_hdr_keycb(http_parser *htp, const char *data, size_t len) {
             Downstream::HTTP1_REQUEST_HEADER_TOO_LARGE);
         return -1;
       }
-      req.fs.add_header_lower(std::string(data, len), "");
+      req.fs.add_header_lower(StringRef{data, len}, StringRef{});
     }
   } else {
     // trailer part
@@ -156,7 +156,7 @@ int htp_hdr_keycb(http_parser *htp, const char *data, size_t len) {
         }
         return -1;
       }
-      req.fs.add_trailer_lower(std::string(data, len), "");
+      req.fs.add_trailer_lower(StringRef{data, len}, StringRef{});
     }
   }
   return 0;