1 files changed, 155 insertions, 0 deletions
diff --git a/third_party/libwebrtc/p2p/base/async_stun_tcp_socket.cc b/third_party/libwebrtc/p2p/base/async_stun_tcp_socket.cc
new file mode 100644
index 0000000000..4a35903dfe
--- /dev/null
+++ b/third_party/libwebrtc/p2p/base/async_stun_tcp_socket.cc
@@ -0,0 +1,155 @@
+/*
+ *  Copyright 2013 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 "p2p/base/async_stun_tcp_socket.h"
+
+#include <errno.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "api/transport/stun.h"
+#include "rtc_base/byte_order.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/network/sent_packet.h"
+#include "rtc_base/time_utils.h"
+
+namespace cricket {
+
+static const size_t kMaxPacketSize = 64 * 1024;
+
+typedef uint16_t PacketLength;
+static const size_t kPacketLenSize = sizeof(PacketLength);
+static const size_t kPacketLenOffset = 2;
+static const size_t kBufSize = kMaxPacketSize + kStunHeaderSize;
+static const size_t kTurnChannelDataHdrSize = 4;
+
+inline bool IsStunMessage(uint16_t msg_type) {
+  // The first two bits of a channel data message are 0b01.
+  return (msg_type & 0xC000) ? false : true;
+}
+
+// AsyncStunTCPSocket
+// Binds and connects `socket` and creates AsyncTCPSocket for
+// it. Takes ownership of `socket`. Returns NULL if bind() or
+// connect() fail (`socket` is destroyed in that case).
+AsyncStunTCPSocket* AsyncStunTCPSocket::Create(
+    rtc::Socket* socket,
+    const rtc::SocketAddress& bind_address,
+    const rtc::SocketAddress& remote_address) {
+  return new AsyncStunTCPSocket(
+      AsyncTCPSocketBase::ConnectSocket(socket, bind_address, remote_address));
+}
+
+AsyncStunTCPSocket::AsyncStunTCPSocket(rtc::Socket* socket)
+    : rtc::AsyncTCPSocketBase(socket, kBufSize) {}
+
+int AsyncStunTCPSocket::Send(const void* pv,
+                             size_t cb,
+                             const rtc::PacketOptions& options) {
+  if (cb > kBufSize || cb < kPacketLenSize + kPacketLenOffset) {
+    SetError(EMSGSIZE);
+    return -1;
+  }
+
+  // If we are blocking on send, then silently drop this packet
+  if (!IsOutBufferEmpty())
+    return static_cast<int>(cb);
+
+  int pad_bytes;
+  size_t expected_pkt_len = GetExpectedLength(pv, cb, &pad_bytes);
+
+  // Accepts only complete STUN/ChannelData packets.
+  if (cb != expected_pkt_len)
+    return -1;
+
+  AppendToOutBuffer(pv, cb);
+
+  RTC_DCHECK(pad_bytes < 4);
+  char padding[4] = {0};
+  AppendToOutBuffer(padding, pad_bytes);
+
+  int res = FlushOutBuffer();
+  if (res <= 0) {
+    // drop packet if we made no progress
+    ClearOutBuffer();
+    return res;
+  }
+
+  rtc::SentPacket sent_packet(options.packet_id, rtc::TimeMillis());
+  SignalSentPacket(this, sent_packet);
+
+  // We claim to have sent the whole thing, even if we only sent partial
+  return static_cast<int>(cb);
+}
+
+void AsyncStunTCPSocket::ProcessInput(char* data, size_t* len) {
+  rtc::SocketAddress remote_addr(GetRemoteAddress());
+  // STUN packet - First 4 bytes. Total header size is 20 bytes.
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |0 0|     STUN Message Type     |         Message Length        |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+  // TURN ChannelData
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |         Channel Number        |            Length             |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+  while (true) {
+    // We need at least 4 bytes to read the STUN or ChannelData packet length.
+    if (*len < kPacketLenOffset + kPacketLenSize)
+      return;
+
+    int pad_bytes;
+    size_t expected_pkt_len = GetExpectedLength(data, *len, &pad_bytes);
+    size_t actual_length = expected_pkt_len + pad_bytes;
+
+    if (*len < actual_length) {
+      return;
+    }
+
+    SignalReadPacket(this, data, expected_pkt_len, remote_addr,
+                     rtc::TimeMicros());
+
+    *len -= actual_length;
+    if (*len > 0) {
+      memmove(data, data + actual_length, *len);
+    }
+  }
+}
+
+size_t AsyncStunTCPSocket::GetExpectedLength(const void* data,
+                                             size_t len,
+                                             int* pad_bytes) {
+  *pad_bytes = 0;
+  PacketLength pkt_len =
+      rtc::GetBE16(static_cast<const char*>(data) + kPacketLenOffset);
+  size_t expected_pkt_len;
+  uint16_t msg_type = rtc::GetBE16(data);
+  if (IsStunMessage(msg_type)) {
+    // STUN message.
+    expected_pkt_len = kStunHeaderSize + pkt_len;
+  } else {
+    // TURN ChannelData message.
+    expected_pkt_len = kTurnChannelDataHdrSize + pkt_len;
+    // From RFC 5766 section 11.5
+    // Over TCP and TLS-over-TCP, the ChannelData message MUST be padded to
+    // a multiple of four bytes in order to ensure the alignment of
+    // subsequent messages.  The padding is not reflected in the length
+    // field of the ChannelData message, so the actual size of a ChannelData
+    // message (including padding) is (4 + Length) rounded up to the nearest
+    // multiple of 4.  Over UDP, the padding is not required but MAY be
+    // included.
+    if (expected_pkt_len % 4)
+      *pad_bytes = 4 - (expected_pkt_len % 4);
+  }
+  return expected_pkt_len;
+}
+
+}  // namespace cricket