1 files changed, 94 insertions, 0 deletions
diff --git a/src/core/lib/surface/validate_metadata.cc b/src/core/lib/surface/validate_metadata.cc
new file mode 100644
index 0000000000..81d07fae44
--- /dev/null
+++ b/src/core/lib/surface/validate_metadata.cc
@@ -0,0 +1,94 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/slice/slice_internal.h"
+#include "src/core/lib/slice/slice_string_helpers.h"
+#include "src/core/lib/surface/validate_metadata.h"
+
+static grpc_error *conforms_to(grpc_slice slice, const uint8_t *legal_bits,
+                               const char *err_desc) {
+  const uint8_t *p = GRPC_SLICE_START_PTR(slice);
+  const uint8_t *e = GRPC_SLICE_END_PTR(slice);
+  for (; p != e; p++) {
+    int idx = *p;
+    int byte = idx / 8;
+    int bit = idx % 8;
+    if ((legal_bits[byte] & (1 << bit)) == 0) {
+      char *dump = grpc_dump_slice(slice, GPR_DUMP_HEX | GPR_DUMP_ASCII);
+      grpc_error *error = grpc_error_set_str(
+          grpc_error_set_int(GRPC_ERROR_CREATE_FROM_COPIED_STRING(err_desc),
+                             GRPC_ERROR_INT_OFFSET,
+                             p - GRPC_SLICE_START_PTR(slice)),
+          GRPC_ERROR_STR_RAW_BYTES, grpc_slice_from_copied_string(dump));
+      gpr_free(dump);
+      return error;
+    }
+  }
+  return GRPC_ERROR_NONE;
+}
+
+static int error2int(grpc_error *error) {
+  int r = (error == GRPC_ERROR_NONE);
+  GRPC_ERROR_UNREF(error);
+  return r;
+}
+
+grpc_error *grpc_validate_header_key_is_legal(grpc_slice slice) {
+  static const uint8_t legal_header_bits[256 / 8] = {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0xff, 0x03, 0x00, 0x00, 0x00,
+      0x80, 0xfe, 0xff, 0xff, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  if (GRPC_SLICE_LENGTH(slice) == 0) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Metadata keys cannot be zero length");
+  }
+  if (GRPC_SLICE_START_PTR(slice)[0] == ':') {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Metadata keys cannot start with :");
+  }
+  return conforms_to(slice, legal_header_bits, "Illegal header key");
+}
+
+int grpc_header_key_is_legal(grpc_slice slice) {
+  return error2int(grpc_validate_header_key_is_legal(slice));
+}
+
+grpc_error *grpc_validate_header_nonbin_value_is_legal(grpc_slice slice) {
+  static const uint8_t legal_header_bits[256 / 8] = {
+      0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+      0xff, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  return conforms_to(slice, legal_header_bits, "Illegal header value");
+}
+
+int grpc_header_nonbin_value_is_legal(grpc_slice slice) {
+  return error2int(grpc_validate_header_nonbin_value_is_legal(slice));
+}
+
+int grpc_is_binary_header(grpc_slice slice) {
+  if (GRPC_SLICE_LENGTH(slice) < 5) return 0;
+  return 0 == memcmp(GRPC_SLICE_END_PTR(slice) - 4, "-bin", 4);
+}