This CL adds methods to manipulate RTP header extension, particularly

AbsoulteSendTime extension. If there is matching extension ID present
in RTP packet, we will update with the current time.

R=solenberg@chromium.org, juberti@chromium.org, sergeyu@chromium.org

BUG=

Review URL: https://codereview.chromium.org/159353002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256580 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 795 insertions, 6 deletions

diff --git a/content/browser/renderer_host/p2p/socket_host.cc b/content/browser/renderer_host/p2p/socket_host.cc
index 4b45e99..fd1a903 100644
--- a/content/browser/renderer_host/p2p/socket_host.cc
+++ b/content/browser/renderer_host/p2p/socket_host.cc
@@ -8,13 +8,386 @@
 #include "content/browser/renderer_host/p2p/socket_host_tcp.h"
 #include "content/browser/renderer_host/p2p/socket_host_tcp_server.h"
 #include "content/browser/renderer_host/p2p/socket_host_udp.h"
+#include "crypto/hmac.h"
+#include "third_party/libjingle/source/talk/base/asyncpacketsocket.h"
+#include "third_party/libjingle/source/talk/base/byteorder.h"
+#include "third_party/libjingle/source/talk/base/messagedigest.h"
+#include "third_party/libjingle/source/talk/p2p/base/stun.h"
 
 namespace {
+
 const uint32 kStunMagicCookie = 0x2112A442;
+const int kMinRtpHdrLen = 12;
+const int kRtpExtnHdrLen = 4;
+const int kDtlsRecordHeaderLen = 13;
+const int kTurnChannelHdrLen = 4;
+const int kAbsSendTimeExtnLen = 3;
+const int kOneByteHdrLen = 1;
+
+// Fake auth tag written by the render process if external authentication is
+// enabled. HMAC in packet will be compared against this value before updating
+// packet with actual HMAC value.
+static const unsigned char kFakeAuthTag[10] = {
+    0xba, 0xdd, 0xba, 0xdd, 0xba, 0xdd, 0xba, 0xdd, 0xba, 0xdd
+};
+
+bool IsTurnChannelData(const char* data) {
+  return ((*data & 0xC0) == 0x40);
+}
+
+bool IsDtlsPacket(const char* data, int len) {
+  const uint8* u = reinterpret_cast<const uint8*>(data);
+  return (len >= kDtlsRecordHeaderLen && (u[0] > 19 && u[0] < 64));
+}
+
+bool IsRtcpPacket(const char* data) {
+  int type = (static_cast<uint8>(data[1]) & 0x7F);
+  return (type >= 64 && type < 96);
+}
+
+bool IsTurnSendIndicationPacket(const char* data) {
+  uint16 type = talk_base::GetBE16(data);
+  return (type == cricket::TURN_SEND_INDICATION);
+}
+
+bool IsRtpPacket(const char* data, int len) {
+  return ((*data & 0xC0) == 0x80);
+}
+
+// Verifies rtp header and message length.
+bool ValidateRtpHeader(char* rtp, int length) {
+  int cc_count = rtp[0] & 0x0F;
+  int rtp_hdr_len_without_extn = kMinRtpHdrLen + 4 * cc_count;
+  if (rtp_hdr_len_without_extn > length) {
+    return false;
+  }
+
+  // If extension bit is not set, we are done with header processing, as input
+  // length is verified above.
+  if (!(rtp[0] & 0x10)) {
+    return true;
+  }
+
+  rtp += rtp_hdr_len_without_extn;
+
+  // Getting extension profile length.
+  // Length is in 32 bit words.
+  uint16 extn_length = talk_base::GetBE16(rtp + 2) * 4;
+
+  // Verify input length against total header size.
+  if (rtp_hdr_len_without_extn + kRtpExtnHdrLen + extn_length > length) {
+    return false;
+  }
+  return true;
+}
+
+void UpdateAbsSendTimeExtnValue(char* extn_data, int len,
+                                uint32 abs_send_time) {
+  // Absolute send time in RTP streams.
+  //
+  // The absolute send time is signaled to the receiver in-band using the
+  // general mechanism for RTP header extensions [RFC5285]. The payload
+  // of this extension (the transmitted value) is a 24-bit unsigned integer
+  // containing the sender's current time in seconds as a fixed point number
+  // with 18 bits fractional part.
+  //
+  // The form of the absolute send time extension block:
+  //
+  //    0                   1                   2                   3
+  //    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+  //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  //   |  ID   | len=2 |              absolute send time               |
+  //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  DCHECK_EQ(len, kAbsSendTimeExtnLen);
+  // Now() has resolution ~1-15ms, using HighResNow(). But it is warned not to
+  // use it unless necessary, as it is expensive than Now().
+  uint32 now_second = abs_send_time;
+  if (!now_second) {
+    uint64 now_us =
+        (base::TimeTicks::HighResNow() - base::TimeTicks()).InMicroseconds();
+    // Convert second to 24-bit unsigned with 18 bit fractional part
+    now_second =
+        ((now_us << 18) / base::Time::kMicrosecondsPerSecond) & 0x00FFFFFF;
+  }
+  // TODO(mallinath) - Add SetBE24 to byteorder.h in libjingle.
+  extn_data[0] = static_cast<uint8>(now_second >> 16);
+  extn_data[1] = static_cast<uint8>(now_second >> 8);
+  extn_data[2] = static_cast<uint8>(now_second);
+}
+
+// Assumes |len| is actual packet length + tag length. Updates HMAC at end of
+// the RTP packet.
+void UpdateRtpAuthTag(char* rtp, int len,
+                      const talk_base::PacketOptions& options) {
+  // If there is no key, return.
+  if (options.packet_time_params.srtp_auth_key.empty())
+    return;
+
+  size_t tag_length = options.packet_time_params.srtp_auth_tag_len;
+  char* auth_tag = rtp + (len - tag_length);
+
+  // We should have a fake HMAC value @ auth_tag.
+  DCHECK_EQ(0, memcmp(auth_tag, kFakeAuthTag, tag_length));
+
+  crypto::HMAC hmac(crypto::HMAC::SHA1);
+  if (!hmac.Init(reinterpret_cast<const unsigned char*>(
+        &options.packet_time_params.srtp_auth_key[0]),
+        options.packet_time_params.srtp_auth_key.size())) {
+    NOTREACHED();
+    return;
+  }
+
+  if (hmac.DigestLength() < tag_length) {
+    NOTREACHED();
+    return;
+  }
+
+  // Copy ROC after end of rtp packet.
+  memcpy(auth_tag, &options.packet_time_params.srtp_packet_index, 4);
+  // Authentication of a RTP packet will have RTP packet + ROC size.
+  int auth_required_length = len - tag_length + 4;
+
+  unsigned char output[64];
+  if (!hmac.Sign(base::StringPiece(rtp, auth_required_length),
+                 output, sizeof(output))) {
+    NOTREACHED();
+    return;
+  }
+  // Copy HMAC from output to packet. This is required as auth tag length
+  // may not be equal to the actual HMAC length.
+  memcpy(auth_tag, output, tag_length);
+}
+
 }  // namespace
 
 namespace content {
 
+namespace packet_processing_helpers {
+
+bool ApplyPacketOptions(char* data, int length,
+                        const talk_base::PacketOptions& options,
+                        uint32 abs_send_time) {
+  DCHECK(data != NULL);
+  DCHECK(length > 0);
+  // if there is no valid |rtp_sendtime_extension_id| and |srtp_auth_key| in
+  // PacketOptions, nothing to be updated in this packet.
+  if (options.packet_time_params.rtp_sendtime_extension_id == -1 &&
+      options.packet_time_params.srtp_auth_key.empty()) {
+    return true;
+  }
+
+  DCHECK(!IsDtlsPacket(data, length));
+  DCHECK(!IsRtcpPacket(data));
+
+  // If there is a srtp auth key present then packet must be a RTP packet.
+  // RTP packet may have been wrapped in a TURN Channel Data or
+  // TURN send indication.
+  int rtp_start_pos;
+  int rtp_length;
+  if (!GetRtpPacketStartPositionAndLength(
+      data, length, &rtp_start_pos, &rtp_length)) {
+    // This method should never return false.
+    NOTREACHED();
+    return false;
+  }
+
+  // Skip to rtp packet.
+  char* start = data + rtp_start_pos;
+  // If packet option has non default value (-1) for sendtime extension id,
+  // then we should parse the rtp packet to update the timestamp. Otherwise
+  // just calculate HMAC and update packet with it.
+  if (options.packet_time_params.rtp_sendtime_extension_id != -1) {
+    UpdateRtpAbsSendTimeExtn(
+        start, rtp_length,
+        options.packet_time_params.rtp_sendtime_extension_id, abs_send_time);
+  }
+
+  UpdateRtpAuthTag(start, rtp_length, options);
+  return true;
+}
+
+bool GetRtpPacketStartPositionAndLength(
+    char* packet, int length, int* rtp_start_pos, int* rtp_packet_length) {
+  int rtp_begin, rtp_length;
+  if (IsTurnChannelData(packet)) {
+    // Turn Channel Message header format.
+    //   0                   1                   2                   3
+    //  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    // |         Channel Number        |            Length             |
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    // |                                                               |
+    // /                       Application Data                        /
+    // /                                                               /
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    if (length < kTurnChannelHdrLen) {
+      return false;
+    }
+
+    rtp_begin = kTurnChannelHdrLen;
+    rtp_length = talk_base::GetBE16(&packet[2]);
+    if (length < rtp_length + kTurnChannelHdrLen) {
+      return false;
+    }
+  } else if (IsTurnSendIndicationPacket(packet)) {
+    if (length <= P2PSocketHost::kStunHeaderSize) {
+      // Message must be greater than 20 bytes, if it's carrying any payload.
+      return false;
+    }
+    // Validate STUN message length.
+    int stun_msg_len = talk_base::GetBE16(&packet[2]);
+    if (stun_msg_len + P2PSocketHost::kStunHeaderSize != length) {
+      return false;
+    }
+
+    // First skip mandatory stun header which is of 20 bytes.
+    rtp_begin = P2PSocketHost::kStunHeaderSize;
+    // Loop through STUN attributes until we find STUN DATA attribute.
+    char* start = packet + rtp_begin;
+    bool data_attr_present = false;
+    while ((packet + rtp_begin) - start < length) {
+      // Keep reading STUN attributes until we hit DATA attribute.
+      // Attribute will be a TLV structure.
+      // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      // |         Type                  |            Length             |
+      // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      // |                         Value (variable)                ....
+      // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      // The value in the length field MUST contain the length of the Value
+      // part of the attribute, prior to padding, measured in bytes.  Since
+      // STUN aligns attributes on 32-bit boundaries, attributes whose content
+      // is not a multiple of 4 bytes are padded with 1, 2, or 3 bytes of
+      // padding so that its value contains a multiple of 4 bytes.  The
+      // padding bits are ignored, and may be any value.
+      uint16 attr_type, attr_length;
+      // Getting attribute type and length.
+      attr_type = talk_base::GetBE16(&packet[rtp_begin]);
+      attr_length = talk_base::GetBE16(
+          &packet[rtp_begin + sizeof(attr_type)]);
+      // Checking for bogus attribute length.
+      if (length < attr_length + rtp_begin) {
+        return false;
+      }
+
+      if (attr_type != cricket::STUN_ATTR_DATA) {
+        rtp_begin += sizeof(attr_type) + sizeof(attr_length) + attr_length;
+        if ((attr_length % 4) != 0) {
+          rtp_begin += (4 - (attr_length % 4));
+        }
+        continue;
+      }
+
+      data_attr_present = true;
+      rtp_begin += 4;  // Skip STUN_DATA_ATTR header.
+      rtp_length = attr_length;
+      // One final check of length before exiting.
+      if (length < rtp_length + rtp_begin) {
+        return false;
+      }
+      // We found STUN_DATA_ATTR. We can skip parsing rest of the packet.
+      break;
+    }
+
+    if (!data_attr_present) {
+      // There is no data attribute present in the message. We can't do anything
+      // with the message.
+      return false;
+    }
+
+  } else {
+    // This is a raw RTP packet.
+    rtp_begin = 0;
+    rtp_length = length;
+  }
+
+  // Making sure we have a valid RTP packet at the end.
+  if (IsRtpPacket(packet + rtp_begin, rtp_length) &&
+      ValidateRtpHeader(packet + rtp_begin, rtp_length)) {
+    *rtp_start_pos = rtp_begin;
+    *rtp_packet_length = rtp_length;
+    return true;
+  }
+  return false;
+}
+
+// ValidateRtpHeader must be called before this method to make sure, we have
+// a sane rtp packet.
+bool UpdateRtpAbsSendTimeExtn(char* rtp, int length,
+                              int extension_id, uint32 abs_send_time) {
+  //  0                   1                   2                   3
+  //  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |V=2|P|X|  CC   |M|     PT      |       sequence number         |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |                           timestamp                           |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |           synchronization source (SSRC) identifier            |
+  // +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+  // |            contributing source (CSRC) identifiers             |
+  // |                             ....                              |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+  // Return if extension bit is not set.
+  if (!(rtp[0] & 0x10)) {
+    return true;
+  }
+
+  int cc_count = rtp[0] & 0x0F;
+  int rtp_hdr_len_without_extn = kMinRtpHdrLen + 4 * cc_count;
+
+  rtp += rtp_hdr_len_without_extn;
+
+  // Getting extension profile ID and length.
+  uint16 profile_id = talk_base::GetBE16(rtp);
+  // Length is in 32 bit words.
+  uint16 extn_length = talk_base::GetBE16(rtp + 2) * 4;
+
+  rtp += kRtpExtnHdrLen;  // Moving past extn header.
+
+  bool found = false;
+  // WebRTC is using one byte header extension.
+  // TODO(mallinath) - Handle two byte header extension.
+  if (profile_id == 0xBEDE) {  // OneByte extension header
+    //  0
+    //  0 1 2 3 4 5 6 7
+    // +-+-+-+-+-+-+-+-+
+    // |  ID   |  len  |
+    // +-+-+-+-+-+-+-+-+
+
+    //  0                   1                   2                   3
+    //  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    // |       0xBE    |    0xDE       |           length=3            |
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    // |  ID   | L=0   |     data      |  ID   |  L=1  |   data...
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //       ...data   |    0 (pad)    |    0 (pad)    |  ID   | L=3   |
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    // |                          data                                 |
+    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    char* extn_start = rtp;
+    while (rtp - extn_start < extn_length) {
+      const int id = (*rtp & 0xF0) >> 4;
+      const int len = (*rtp & 0x0F) + 1;
+      // The 4-bit length is the number minus one of data bytes of this header
+      // extension element following the one-byte header.
+      if (id == extension_id) {
+        UpdateAbsSendTimeExtnValue(rtp + kOneByteHdrLen, len, abs_send_time);
+        found = true;
+        break;
+      }
+      rtp += kOneByteHdrLen + len;
+      // Counting padding bytes.
+      while ((*rtp == 0) && (rtp - extn_start < extn_length)) {
+        ++rtp;
+      }
+    }
+  }
+  return found;
+}
+
+}  // packet_processing_helpers
+
 P2PSocketHost::P2PSocketHost(IPC::Sender* message_sender,
                              int id)
     : message_sender_(message_sender),
diff --git a/content/browser/renderer_host/p2p/socket_host.h b/content/browser/renderer_host/p2p/socket_host.h
index d4ff1da..a4c82f3 100644
--- a/content/browser/renderer_host/p2p/socket_host.h
+++ b/content/browser/renderer_host/p2p/socket_host.h
@@ -25,6 +25,28 @@ struct PacketOptions;
 namespace content {
 class P2PMessageThrottler;
 
+namespace packet_processing_helpers {
+
+// This method can handle only RTP packet, otherwise this method must not be
+// called. It will try to do, 1. update absolute send time extension header
+// if present with current time and 2. update HMAC in RTP packet.
+// If abs_send_time is 0, ApplyPacketOption will get current time from system.
+CONTENT_EXPORT bool ApplyPacketOptions(char* data, int length,
+                                       const talk_base::PacketOptions& options,
+                                       uint32 abs_send_time);
+
+// Helper method which finds RTP ofset and length if the packet is encapsulated
+// in a TURN Channel Message or TURN Send Indication message.
+CONTENT_EXPORT bool GetRtpPacketStartPositionAndLength(char* data, int length,
+                                                       int* rtp_start_pos,
+                                                       int* rtp_packet_length);
+// Helper method which updates absoulute send time extension if present.
+CONTENT_EXPORT bool UpdateRtpAbsSendTimeExtn(char* rtp, int length,
+                                             int extension_id,
+                                             uint32 abs_send_time);
+
+}  // packet_processing_helpers
+
 // Base class for P2P sockets.
 class CONTENT_EXPORT P2PSocketHost {
  public:
diff --git a/content/browser/renderer_host/p2p/socket_host_tcp.cc b/content/browser/renderer_host/p2p/socket_host_tcp.cc
index 00f2e87..9b4acb7 100644
--- a/content/browser/renderer_host/p2p/socket_host_tcp.cc
+++ b/content/browser/renderer_host/p2p/socket_host_tcp.cc
@@ -18,6 +18,7 @@
 #include "net/socket/tcp_client_socket.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
+#include "third_party/libjingle/source/talk/base/asyncpacketsocket.h"
 
 namespace {
 
@@ -318,7 +319,7 @@ void P2PSocketHostTcpBase::Send(const net::IPEndPoint& to,
     }
   }
 
-  DoSend(to, data);
+  DoSend(to, data, options);
 }
 
 void P2PSocketHostTcpBase::WriteOrQueue(
@@ -450,13 +451,17 @@ int P2PSocketHostTcp::ProcessInput(char* input, int input_len) {
 }
 
 void P2PSocketHostTcp::DoSend(const net::IPEndPoint& to,
-                              const std::vector<char>& data) {
+                              const std::vector<char>& data,
+                              const talk_base::PacketOptions& options) {
   int size = kPacketHeaderSize + data.size();
   scoped_refptr<net::DrainableIOBuffer> buffer =
       new net::DrainableIOBuffer(new net::IOBuffer(size), size);
   *reinterpret_cast<uint16*>(buffer->data()) = base::HostToNet16(data.size());
   memcpy(buffer->data() + kPacketHeaderSize, &data[0], data.size());
 
+  packet_processing_helpers::ApplyPacketOptions(
+      buffer->data(), buffer->BytesRemaining(), options, 0);
+
   WriteOrQueue(buffer);
 }
 
@@ -495,7 +500,8 @@ int P2PSocketHostStunTcp::ProcessInput(char* input, int input_len) {
 }
 
 void P2PSocketHostStunTcp::DoSend(const net::IPEndPoint& to,
-                                  const std::vector<char>& data) {
+                                  const std::vector<char>& data,
+                                  const talk_base::PacketOptions& options) {
   // Each packet is expected to have header (STUN/TURN ChannelData), where
   // header contains message type and and length of message.
   if (data.size() < kPacketHeaderSize + kPacketLengthOffset) {
@@ -522,6 +528,9 @@ void P2PSocketHostStunTcp::DoSend(const net::IPEndPoint& to,
       new net::DrainableIOBuffer(new net::IOBuffer(size), size);
   memcpy(buffer->data(), &data[0], data.size());
 
+  packet_processing_helpers::ApplyPacketOptions(
+      buffer->data(), data.size(), options, 0);
+
   if (pad_bytes) {
     char padding[4] = {0};
     DCHECK_LE(pad_bytes, 4);
diff --git a/content/browser/renderer_host/p2p/socket_host_tcp.h b/content/browser/renderer_host/p2p/socket_host_tcp.h
index b7ed2bc1..fcaac2a 100644
--- a/content/browser/renderer_host/p2p/socket_host_tcp.h
+++ b/content/browser/renderer_host/p2p/socket_host_tcp.h
@@ -52,7 +52,8 @@ class CONTENT_EXPORT P2PSocketHostTcpBase : public P2PSocketHost {
   // Derived classes will provide the implementation.
   virtual int ProcessInput(char* input, int input_len) = 0;
   virtual void DoSend(const net::IPEndPoint& to,
-                      const std::vector<char>& data) = 0;
+                      const std::vector<char>& data,
+                      const talk_base::PacketOptions& options) = 0;
 
   void WriteOrQueue(scoped_refptr<net::DrainableIOBuffer>& buffer);
   void OnPacket(const std::vector<char>& data);
@@ -108,7 +109,8 @@ class CONTENT_EXPORT P2PSocketHostTcp : public P2PSocketHostTcpBase {
  protected:
   virtual int ProcessInput(char* input, int input_len) OVERRIDE;
   virtual void DoSend(const net::IPEndPoint& to,
-                      const std::vector<char>& data) OVERRIDE;
+                      const std::vector<char>& data,
+                      const talk_base::PacketOptions& options) OVERRIDE;
  private:
   DISALLOW_COPY_AND_ASSIGN(P2PSocketHostTcp);
 };
@@ -129,7 +131,8 @@ class CONTENT_EXPORT P2PSocketHostStunTcp : public P2PSocketHostTcpBase {
  protected:
   virtual int ProcessInput(char* input, int input_len) OVERRIDE;
   virtual void DoSend(const net::IPEndPoint& to,
-                      const std::vector<char>& data) OVERRIDE;
+                      const std::vector<char>& data,
+                      const talk_base::PacketOptions& options) OVERRIDE;
  private:
   int GetExpectedPacketSize(const char* data, int len, int* pad_bytes);
 
diff --git a/content/browser/renderer_host/p2p/socket_host_udp.cc b/content/browser/renderer_host/p2p/socket_host_udp.cc
index 7569bb3..db17c5f 100644
--- a/content/browser/renderer_host/p2p/socket_host_udp.cc
+++ b/content/browser/renderer_host/p2p/socket_host_udp.cc
@@ -15,6 +15,7 @@
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
+#include "third_party/libjingle/source/talk/base/asyncpacketsocket.h"
 
 namespace {
 
@@ -234,6 +235,8 @@ void P2PSocketHostUdp::DoSend(const PendingPacket& packet) {
       last_dscp_ = net::DSCP_NO_CHANGE;
     }
   }
+  packet_processing_helpers::ApplyPacketOptions(
+      packet.data->data(), packet.size, packet.packet_options, 0);
   int result = socket_->SendTo(
       packet.data.get(),
       packet.size,
diff --git a/content/browser/renderer_host/p2p/socket_host_unittest.cc b/content/browser/renderer_host/p2p/socket_host_unittest.cc
new file mode 100644
index 0000000..73dd900
--- /dev/null
+++ b/content/browser/renderer_host/p2p/socket_host_unittest.cc
@@ -0,0 +1,376 @@
+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/renderer_host/p2p/socket_host.h"
+
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "content/browser/renderer_host/p2p/socket_host_test_utils.h"
+#include "net/base/ip_endpoint.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+static unsigned char kFakeTag[4] = { 0xba, 0xdd, 0xba, 0xdd };
+static unsigned char kTestKey[] = "12345678901234567890";
+static unsigned char kTestAstValue[3] = { 0xaa, 0xbb, 0xcc };
+
+// Rtp message with invalid length.
+static unsigned char kRtpMsgWithInvalidLength[] = {
+  0x94, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0xAA, 0xBB, 0xCC, 0XDD,  // SSRC
+  0xDD, 0xCC, 0xBB, 0xAA   // Only 1 CSRC, but CC count is 4.
+};
+
+// Rtp message with single byte header extension, invalid extension length.
+static unsigned char kRtpMsgWithInvalidExtnLength[] = {
+  0x90, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0xBE, 0xDE, 0x0A, 0x00   // Extn length - 0x0A00
+};
+
+// Valid rtp Message with 2 byte header extension.
+static unsigned char kRtpMsgWith2ByteExtnHeader[] = {
+  0x90, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0xAA, 0xBB, 0xCC, 0XDD,  // SSRC
+  0x10, 0x00, 0x00, 0x01,  // 2 Byte header extension
+  0x01, 0x00, 0x00, 0x00
+};
+
+// Stun Indication message with Zero length
+static unsigned char kTurnSendIndicationMsgWithNoAttributes[] = {
+  0x00, 0x16, 0x00, 0x00,  // Zero length
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+};
+
+// Stun Send Indication message with invalid length in stun header.
+static unsigned char kTurnSendIndicationMsgWithInvalidLength[] = {
+  0x00, 0x16, 0xFF, 0x00,  // length of 0xFF00
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+};
+
+// Stun Send Indication message with no DATA attribute in message.
+static unsigned char kTurnSendIndicatinMsgWithNoDataAttribute[] = {
+  0x00, 0x16, 0x00, 0x08,  // length of
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+  0x00, 0x20, 0x00, 0x04,  // Mapped address.
+  0x00, 0x00, 0x00, 0x00
+};
+
+// A valid STUN indication message with a valid RTP header in data attribute
+// payload field and no extension bit set.
+static unsigned char kTurnSendIndicationMsgWithoutRtpExtension[] = {
+  0x00, 0x16, 0x00, 0x18,  // length of
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+  0x00, 0x20, 0x00, 0x04,  // Mapped address.
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x13, 0x00, 0x0C,  // Data attribute.
+  0x80, 0x00, 0x00, 0x00,  // RTP packet.
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+};
+
+// A valid STUN indication message with a valid RTP header and a extension
+// header.
+static unsigned char kTurnSendIndicationMsgWithAbsSendTimeExtension[] = {
+  0x00, 0x16, 0x00, 0x24,  // length of
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+  0x00, 0x20, 0x00, 0x04,  // Mapped address.
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x13, 0x00, 0x18,  // Data attribute.
+  0x90, 0x00, 0x00, 0x00,  // RTP packet.
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0xBE, 0xDE, 0x00, 0x02,
+  0x22, 0xaa, 0xbb, 0xcc,
+  0x32, 0xaa, 0xbb, 0xcc,
+};
+
+// A valid TURN channel header, but not RTP packet.
+static unsigned char kTurnChannelMsgNoRtpPacket[] = {
+  0x40, 0x00, 0x00, 0x04,
+  0xaa, 0xbb, 0xcc, 0xdd,
+};
+
+// Turn ChannelMessage with zero length of payload.
+static unsigned char kTurnChannelMsgWithZeroLength[] = {
+  0x40, 0x00, 0x00, 0x00
+};
+
+// Turn ChannelMessage, wrapping a RTP packet without extension.
+static unsigned char kTurnChannelMsgWithRtpPacket[] = {
+  0x40, 0x00, 0x00, 0x0C,
+  0x80, 0x00, 0x00, 0x00,  // RTP packet.
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+};
+
+// Turn ChannelMessage, wrapping a RTP packet with AbsSendTime Extension.
+static unsigned char kTurnChannelMsgWithAbsSendTimeExtension[] = {
+  0x40, 0x00, 0x00, 0x14,
+  0x90, 0x00, 0x00, 0x00,  // RTP packet.
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0xBE, 0xDE, 0x00, 0x01,
+  0x32, 0xaa, 0xbb, 0xcc,
+};
+
+// RTP packet with single byte extension header of length 4 bytes.
+// Extension id = 3 and length = 3
+static unsigned char kRtpMsgWithAbsSendTimeExtension[] = {
+  0x90, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00,
+  0xBE, 0xDE, 0x00, 0x02,
+  0x22, 0x00, 0x02, 0x1c,
+  0x32, 0xaa, 0xbb, 0xcc,
+};
+
+// Index of AbsSendTimeExtn data in message |kRtpMsgWithAbsSendTimeExtension|.
+static const int kAstIndexInRtpMsg = 21;
+
+namespace content {
+
+// This test verifies parsing of all invalid raw packets.
+TEST(P2PSocketHostTest, TestInvalidRawRtpMessages) {
+  int start_pos = INT_MAX, rtp_length = INT_MAX;
+  EXPECT_FALSE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kRtpMsgWithInvalidLength),
+      sizeof(kRtpMsgWithInvalidLength),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(INT_MAX, start_pos);
+  EXPECT_EQ(INT_MAX, rtp_length);
+
+  EXPECT_FALSE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kRtpMsgWithInvalidExtnLength),
+      sizeof(kRtpMsgWithInvalidExtnLength),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(INT_MAX, start_pos);
+  EXPECT_EQ(INT_MAX, rtp_length);
+}
+
+// Verify invalid TURN send indication messages. Messages are proper STUN
+// messages with incorrect values in attributes.
+TEST(P2PSocketHostTest, TestInvalidTurnSendIndicationMessages) {
+  // Initializing out params to very large value.
+  int start_pos = INT_MAX, rtp_length = INT_MAX;
+  EXPECT_FALSE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnSendIndicationMsgWithNoAttributes),
+      sizeof(kTurnSendIndicationMsgWithNoAttributes),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(INT_MAX, start_pos);
+  EXPECT_EQ(INT_MAX, rtp_length);
+
+  EXPECT_FALSE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnSendIndicationMsgWithInvalidLength),
+      sizeof(kTurnSendIndicationMsgWithInvalidLength),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(INT_MAX, start_pos);
+  EXPECT_EQ(INT_MAX, rtp_length);
+
+  EXPECT_FALSE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnSendIndicatinMsgWithNoDataAttribute),
+      sizeof(kTurnSendIndicatinMsgWithNoDataAttribute),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(INT_MAX, start_pos);
+  EXPECT_EQ(INT_MAX, rtp_length);
+}
+
+// This test verifies incorrectly formed TURN channel messages.
+TEST(P2PSocketHostTest, TestInvalidTurnChannelMessages) {
+  int start_pos = INT_MAX, rtp_length = INT_MAX;
+  EXPECT_FALSE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnChannelMsgNoRtpPacket),
+      sizeof(kTurnChannelMsgNoRtpPacket),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(INT_MAX, start_pos);
+  EXPECT_EQ(INT_MAX, rtp_length);
+
+  EXPECT_FALSE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnChannelMsgWithZeroLength),
+      sizeof(kTurnChannelMsgWithZeroLength),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(INT_MAX, start_pos);
+  EXPECT_EQ(INT_MAX, rtp_length);
+}
+
+// This test verifies parsing of a valid RTP packet which has 2byte header
+// extension instead of a 1 byte header extension.
+TEST(P2PSocketHostTest, TestValid2ByteExtnHdrRtpMessage) {
+  int start_pos = INT_MAX, rtp_length = INT_MAX;
+  EXPECT_TRUE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kRtpMsgWith2ByteExtnHeader),
+      sizeof(kRtpMsgWith2ByteExtnHeader),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(20, rtp_length);
+  EXPECT_EQ(0, start_pos);
+}
+
+// This test verifies parsing of a valid RTP packet which has 1 byte header
+// AbsSendTime extension in it.
+TEST(P2PSocketHostTest, TestValidRtpPacketWithAbsSendTimeExtension) {
+  int start_pos = INT_MAX, rtp_length = INT_MAX;
+  EXPECT_TRUE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kRtpMsgWithAbsSendTimeExtension),
+      sizeof(kRtpMsgWithAbsSendTimeExtension),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(24, rtp_length);
+  EXPECT_EQ(0, start_pos);
+}
+
+// This test verifies parsing of a valid TURN Send Indication messages.
+TEST(P2PSocketHostTest, TestValidTurnSendIndicationMessages) {
+  int start_pos = INT_MAX, rtp_length = INT_MAX;
+  EXPECT_TRUE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnSendIndicationMsgWithoutRtpExtension),
+      sizeof(kTurnSendIndicationMsgWithoutRtpExtension),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(12, rtp_length);
+  EXPECT_EQ(32, start_pos);
+
+  start_pos = INT_MAX, rtp_length = INT_MAX;
+  EXPECT_TRUE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnSendIndicationMsgWithAbsSendTimeExtension),
+      sizeof(kTurnSendIndicationMsgWithAbsSendTimeExtension),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(24, rtp_length);
+  EXPECT_EQ(32, start_pos);
+}
+
+// This test verifies parsing of valid TURN Channel Messages.
+TEST(P2PSocketHostTest, TestValidTurnChannelMessages) {
+  int start_pos = -1, rtp_length = -1;
+  EXPECT_TRUE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnChannelMsgWithRtpPacket),
+      sizeof(kTurnChannelMsgWithRtpPacket), &start_pos, &rtp_length));
+  EXPECT_EQ(12, rtp_length);
+  EXPECT_EQ(4, start_pos);
+
+  start_pos = -1, rtp_length = -1;
+  EXPECT_TRUE(packet_processing_helpers::GetRtpPacketStartPositionAndLength(
+      reinterpret_cast<char*>(kTurnChannelMsgWithAbsSendTimeExtension),
+      sizeof(kTurnChannelMsgWithAbsSendTimeExtension),
+      &start_pos, &rtp_length));
+  EXPECT_EQ(20, rtp_length);
+  EXPECT_EQ(4, start_pos);
+}
+
+// Verify handling of a 2 byte extension header RTP messsage. Currently we don't
+// handle this kind of message.
+TEST(P2PSocketHostTest, TestUpdateAbsSendTimeExtensionIn2ByteHeaderExtn) {
+  EXPECT_FALSE(packet_processing_helpers::UpdateRtpAbsSendTimeExtn(
+    reinterpret_cast<char*>(kRtpMsgWith2ByteExtnHeader),
+    sizeof(kRtpMsgWith2ByteExtnHeader), 3, 0));
+}
+
+// Verify finding an extension ID in the TURN send indication message.
+TEST(P2PSocketHostTest, TestUpdateAbsSendTimeExtensionInTurnSendIndication) {
+  EXPECT_TRUE(packet_processing_helpers::UpdateRtpAbsSendTimeExtn(
+      reinterpret_cast<char*>(kTurnSendIndicationMsgWithoutRtpExtension),
+      sizeof(kTurnSendIndicationMsgWithoutRtpExtension), 3, 0));
+
+  EXPECT_TRUE(packet_processing_helpers::UpdateRtpAbsSendTimeExtn(
+      reinterpret_cast<char*>(kTurnSendIndicationMsgWithAbsSendTimeExtension),
+      sizeof(kTurnSendIndicationMsgWithAbsSendTimeExtension), 3, 0));
+}
+
+// Verify finding an extension ID in a raw rtp message.
+TEST(P2PSocketHostTest, TestUpdateAbsSendTimeExtensionInRtpPacket) {
+  EXPECT_TRUE(packet_processing_helpers::UpdateRtpAbsSendTimeExtn(
+      reinterpret_cast<char*>(kRtpMsgWithAbsSendTimeExtension),
+      sizeof(kRtpMsgWithAbsSendTimeExtension), 3, 0));
+}
+
+// Test without any packet options variables set. This method should return
+// without HMAC value in the packet.
+TEST(P2PSocketHostTest, TestApplyPacketOptionsWithDefaultValues) {
+  unsigned char fake_tag[4] = { 0xba, 0xdd, 0xba, 0xdd };
+  talk_base::PacketOptions options;
+  std::vector<char> rtp_packet;
+  rtp_packet.resize(sizeof(kRtpMsgWithAbsSendTimeExtension) + 4);  // tag length
+  memcpy(&rtp_packet[0], kRtpMsgWithAbsSendTimeExtension,
+         sizeof(kRtpMsgWithAbsSendTimeExtension));
+  memcpy(&rtp_packet[sizeof(kRtpMsgWithAbsSendTimeExtension)], fake_tag, 4);
+  EXPECT_TRUE(
+      packet_processing_helpers::ApplyPacketOptions(
+      &rtp_packet[0], rtp_packet.size(), options, 0));
+  // Making sure we have't updated the HMAC.
+  EXPECT_EQ(0, memcmp(&rtp_packet[sizeof(kRtpMsgWithAbsSendTimeExtension)],
+                      fake_tag, 4));
+
+  // Verify AbsouluteSendTime extension field is not modified.
+  EXPECT_EQ(0, memcmp(&rtp_packet[kAstIndexInRtpMsg],
+                      kTestAstValue, sizeof(kTestAstValue)));
+}
+
+// Veirfy HMAC is updated when packet option parameters are set.
+TEST(P2PSocketHostTest, TestApplyPacketOptionsWithAuthParams) {
+  talk_base::PacketOptions options;
+  options.packet_time_params.srtp_auth_key.resize(20);
+  options.packet_time_params.srtp_auth_key.assign(
+      kTestKey, kTestKey + sizeof(kTestKey));
+  options.packet_time_params.srtp_auth_tag_len = 4;
+
+  std::vector<char> rtp_packet;
+  rtp_packet.resize(sizeof(kRtpMsgWithAbsSendTimeExtension) + 4);  // tag length
+  memcpy(&rtp_packet[0], kRtpMsgWithAbsSendTimeExtension,
+         sizeof(kRtpMsgWithAbsSendTimeExtension));
+  memcpy(&rtp_packet[sizeof(kRtpMsgWithAbsSendTimeExtension)], kFakeTag, 4);
+  EXPECT_TRUE(packet_processing_helpers::ApplyPacketOptions(
+                  &rtp_packet[0], rtp_packet.size(), options, 0));
+  // HMAC should be different from fake_tag.
+  EXPECT_NE(0, memcmp(&rtp_packet[sizeof(kRtpMsgWithAbsSendTimeExtension)],
+                      kFakeTag, sizeof(kFakeTag)));
+
+   // Verify AbsouluteSendTime extension field is not modified.
+  EXPECT_EQ(0, memcmp(&rtp_packet[kAstIndexInRtpMsg],
+                      kTestAstValue, sizeof(kTestAstValue)));
+}
+
+// Verify we update both AbsSendTime extension header and HMAC.
+TEST(P2PSocketHostTest, TestApplyPacketOptionsWithAuthParamsAndAbsSendTime) {
+  talk_base::PacketOptions options;
+  options.packet_time_params.srtp_auth_key.resize(20);
+  options.packet_time_params.srtp_auth_key.assign(
+      kTestKey, kTestKey + sizeof(kTestKey));
+  options.packet_time_params.srtp_auth_tag_len = 4;
+  options.packet_time_params.rtp_sendtime_extension_id = 3;
+  // 3 is also present in the test message.
+
+  std::vector<char> rtp_packet;
+  rtp_packet.resize(sizeof(kRtpMsgWithAbsSendTimeExtension) + 4);  // tag length
+  memcpy(&rtp_packet[0], kRtpMsgWithAbsSendTimeExtension,
+         sizeof(kRtpMsgWithAbsSendTimeExtension));
+  memcpy(&rtp_packet[sizeof(kRtpMsgWithAbsSendTimeExtension)], kFakeTag, 4);
+  EXPECT_TRUE(packet_processing_helpers::ApplyPacketOptions(
+                  &rtp_packet[0], rtp_packet.size(), options, 0xccbbaa));
+  // HMAC should be different from fake_tag.
+  EXPECT_NE(0, memcmp(&rtp_packet[sizeof(kRtpMsgWithAbsSendTimeExtension)],
+                      kFakeTag, sizeof(kFakeTag)));
+
+  // ApplyPackets should have the new timestamp passed as input.
+  unsigned char timestamp_array[3] = { 0xcc, 0xbb, 0xaa };
+  EXPECT_EQ(0, memcmp(&rtp_packet[kAstIndexInRtpMsg],
+                      timestamp_array, sizeof(timestamp_array)));
+}
+
+}  // namespace content
diff --git a/content/content_tests.gypi b/content/content_tests.gypi
index eb4b07b..ebd5f91 100644
--- a/content/content_tests.gypi
+++ b/content/content_tests.gypi
@@ -710,6 +710,7 @@
             'browser/renderer_host/p2p/socket_host_tcp_unittest.cc',
             'browser/renderer_host/p2p/socket_host_tcp_server_unittest.cc',
             'browser/renderer_host/p2p/socket_host_udp_unittest.cc',
+            'browser/renderer_host/p2p/socket_host_unittest.cc',
             'renderer/media/media_stream_audio_processor_unittest.cc',
             'renderer/media/media_stream_dependency_factory_unittest.cc',
             'renderer/media/media_stream_dispatcher_unittest.cc',
diff --git a/third_party/libjingle/libjingle.gyp b/third_party/libjingle/libjingle.gyp
index 6e8319f..c7dc2f8 100644
--- a/third_party/libjingle/libjingle.gyp
+++ b/third_party/libjingle/libjingle.gyp
@@ -435,6 +435,8 @@
             '<(libjingle_source)/talk/session/media/channelmanager.h',
             '<(libjingle_source)/talk/session/media/currentspeakermonitor.cc',
             '<(libjingle_source)/talk/session/media/currentspeakermonitor.h',
+            '<(libjingle_source)/talk/session/media/externalhmac.cc',
+            '<(libjingle_source)/talk/session/media/externalhmac.h',
             '<(libjingle_source)/talk/session/media/mediamessages.cc',
             '<(libjingle_source)/talk/session/media/mediamessages.h',
             '<(libjingle_source)/talk/session/media/mediamonitor.cc',