1 files changed, 96 insertions, 0 deletions
diff --git a/third_party/libwebrtc/net/dcsctp/packet/parameter/parameter.cc b/third_party/libwebrtc/net/dcsctp/packet/parameter/parameter.cc
new file mode 100644
index 0000000000..b3b2bffef7
--- /dev/null
+++ b/third_party/libwebrtc/net/dcsctp/packet/parameter/parameter.cc
@@ -0,0 +1,96 @@
+/*
+ *  Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "net/dcsctp/packet/parameter/parameter.h"
+
+#include <stddef.h>
+
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "absl/memory/memory.h"
+#include "absl/types/optional.h"
+#include "api/array_view.h"
+#include "net/dcsctp/common/math.h"
+#include "net/dcsctp/packet/bounded_byte_reader.h"
+#include "net/dcsctp/packet/parameter/add_incoming_streams_request_parameter.h"
+#include "net/dcsctp/packet/parameter/add_outgoing_streams_request_parameter.h"
+#include "net/dcsctp/packet/parameter/forward_tsn_supported_parameter.h"
+#include "net/dcsctp/packet/parameter/heartbeat_info_parameter.h"
+#include "net/dcsctp/packet/parameter/incoming_ssn_reset_request_parameter.h"
+#include "net/dcsctp/packet/parameter/outgoing_ssn_reset_request_parameter.h"
+#include "net/dcsctp/packet/parameter/reconfiguration_response_parameter.h"
+#include "net/dcsctp/packet/parameter/ssn_tsn_reset_request_parameter.h"
+#include "net/dcsctp/packet/parameter/state_cookie_parameter.h"
+#include "net/dcsctp/packet/parameter/supported_extensions_parameter.h"
+#include "net/dcsctp/packet/tlv_trait.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/strings/string_builder.h"
+
+namespace dcsctp {
+
+constexpr size_t kParameterHeaderSize = 4;
+
+Parameters::Builder& Parameters::Builder::Add(const Parameter& p) {
+  // https://tools.ietf.org/html/rfc4960#section-3.2.1
+  // "If the length of the parameter is not a multiple of 4 bytes, the sender
+  // pads the parameter at the end (i.e., after the Parameter Value field) with
+  // all zero bytes."
+  if (data_.size() % 4 != 0) {
+    data_.resize(RoundUpTo4(data_.size()));
+  }
+
+  p.SerializeTo(data_);
+  return *this;
+}
+
+std::vector<ParameterDescriptor> Parameters::descriptors() const {
+  rtc::ArrayView<const uint8_t> span(data_);
+  std::vector<ParameterDescriptor> result;
+  while (!span.empty()) {
+    BoundedByteReader<kParameterHeaderSize> header(span);
+    uint16_t type = header.Load16<0>();
+    uint16_t length = header.Load16<2>();
+    result.emplace_back(type, span.subview(0, length));
+    size_t length_with_padding = RoundUpTo4(length);
+    if (length_with_padding > span.size()) {
+      break;
+    }
+    span = span.subview(length_with_padding);
+  }
+  return result;
+}
+
+absl::optional<Parameters> Parameters::Parse(
+    rtc::ArrayView<const uint8_t> data) {
+  // Validate the parameter descriptors
+  rtc::ArrayView<const uint8_t> span(data);
+  while (!span.empty()) {
+    if (span.size() < kParameterHeaderSize) {
+      RTC_DLOG(LS_WARNING) << "Insufficient parameter length";
+      return absl::nullopt;
+    }
+    BoundedByteReader<kParameterHeaderSize> header(span);
+    uint16_t length = header.Load16<2>();
+    if (length < kParameterHeaderSize || length > span.size()) {
+      RTC_DLOG(LS_WARNING) << "Invalid parameter length field";
+      return absl::nullopt;
+    }
+    size_t length_with_padding = RoundUpTo4(length);
+    if (length_with_padding > span.size()) {
+      break;
+    }
+    span = span.subview(length_with_padding);
+  }
+  return Parameters(std::vector<uint8_t>(data.begin(), data.end()));
+}
+}  // namespace dcsctp