Add support for fragmentation in RtcpPacket.

webrtc/modules/rtp_rtcp/source/rtcp_packet.h

 /*
  *  Copyright (c) 2014 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.
  *
  */
 
 #ifndef WEBRTC_MODULES_RTP_RTCP_RTCP_PACKET_H_
 #define WEBRTC_MODULES_RTP_RTCP_RTCP_PACKET_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
+#include "webrtc/base/scoped_ptr.h"
 #include "webrtc/modules/rtp_rtcp/source/rtcp_utility.h"
 #include "webrtc/modules/rtp_rtcp/interface/rtp_rtcp_defines.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 namespace rtcp {
 
-enum { kCommonFbFmtLength = 12 };
-enum { kReportBlockLength = 24 };
+static const int kCommonFbFmtLength = 12;
+static const int kReportBlockLength = 24;
 
 class Dlrr;
 class RawPacket;
 class Rrtr;
 class VoipMetric;
 
 // Class for building RTCP packets.
 //
 //  Example:
 //  ReportBlock report_block;
@@ skipping 19 matching lines @@
 //  rr.Append(&fir)                        // Builds a compound RTCP packet with
 //  RawPacket packet = rr.Build();         // a receiver report, report block
 //                                         // and fir message.
 
 class RtcpPacket {
  public:
   virtual ~RtcpPacket() {}
 
   void Append(RtcpPacket* packet);
 
-  RawPacket Build() const;
+  // Callback used to signal that an RTCP packet is ready. Note that this may
+  // not contain all data in this RtcpPacket; if a packet cannot fit in
+  // max_length bytes, it will be fragmented and multiple calls to this
+  // callback will be made.
+  class PacketReadyCallback {
+   public:
+    PacketReadyCallback() {}
+    virtual ~PacketReadyCallback() {}
 
-  void Build(uint8_t* packet, size_t* length, size_t max_length) const;
+    virtual void OnPacketReady(uint8_t* data, size_t length) = 0;
+  };
+
+  // Convenience method mostly used for test. Max length of IP_PACKET_SIZE is
+  // used, will cause assertion error if fragmentation occurs.
+  rtc::scoped_ptr<RawPacket> Build() const;
+
+  // Returns true if all calls to Create succeeded. A buffer of size
+  // IP_PACKET_SIZE will be allocated and reused between calls to callback.
+  bool Build(PacketReadyCallback* callback) const;
+
+  // Returns true if all calls to Create succeeded. Provided buffer reference
+  // will be used for all calls to callback.
+  bool BuildExternalBuffer(uint8_t* buffer,
+                           size_t max_length,
+                           PacketReadyCallback* callback) const;
 
  protected:
   RtcpPacket() : kHeaderLength(4) {}
 
-  virtual void Create(
-      uint8_t* packet, size_t* length, size_t max_length) const = 0;
+  virtual bool Create(uint8_t* packet,
+                      size_t* index,
+                      size_t max_length,
+                      PacketReadyCallback* callback) const = 0;
+
+  bool OnBufferFull(uint8_t* packet,
+                    size_t* index,
+                    RtcpPacket::PacketReadyCallback* callback) const;
 
   const size_t kHeaderLength;
 
  private:
-  void CreateAndAddAppended(
-      uint8_t* packet, size_t* length, size_t max_length) const;
+  bool CreateAndAddAppended(uint8_t* packet,
+                            size_t* index,
+                            size_t max_length,
+                            PacketReadyCallback* callback) const;
 
   std::vector<RtcpPacket*> appended_packets_;
 };
 
 class Empty : public RtcpPacket {
  public:
   Empty() : RtcpPacket() {}
 
   virtual ~Empty() {}
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Empty);
 };
 
 // From RFC 3550, RTP: A Transport Protocol for Real-Time Applications.
 //
 // RTCP report block (RFC 3550).
 //
 //   0                   1                   2                   3
@@ skipping 89 matching lines @@
   }
   void WithRtpTimestamp(uint32_t rtp_timestamp) {
     sr_.RTPTimestamp = rtp_timestamp;
   }
   void WithPacketCount(uint32_t packet_count) {
     sr_.SenderPacketCount = packet_count;
   }
   void WithOctetCount(uint32_t octet_count) {
     sr_.SenderOctetCount = octet_count;
   }
-  void WithReportBlock(ReportBlock* block);
+  bool WithReportBlock(ReportBlock* block);
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  enum { kMaxNumberOfReportBlocks = 0x1f };
+  static const int kMaxNumberOfReportBlocks = 0x1f;
 
   size_t BlockLength() const {
     const size_t kSrHeaderLength = 8;
     const size_t kSenderInfoLength = 20;
     return kSrHeaderLength + kSenderInfoLength +
            report_blocks_.size() * kReportBlockLength;
   }
 
   RTCPUtility::RTCPPacketSR sr_;
   std::vector<RTCPUtility::RTCPPacketReportBlockItem> report_blocks_;
@@ skipping 18 matching lines @@
  public:
   ReceiverReport() : RtcpPacket() {
     memset(&rr_, 0, sizeof(rr_));
   }
 
   virtual ~ReceiverReport() {}
 
   void From(uint32_t ssrc) {
     rr_.SenderSSRC = ssrc;
   }
-  void WithReportBlock(ReportBlock* block);
+  bool WithReportBlock(ReportBlock* block);
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  enum { kMaxNumberOfReportBlocks = 0x1f };
+  static const int kMaxNumberOfReportBlocks = 0x1F;
 
   size_t BlockLength() const {
     const size_t kRrHeaderLength = 8;
     return kRrHeaderLength + report_blocks_.size() * kReportBlockLength;
   }
 
   RTCPUtility::RTCPPacketRR rr_;
   std::vector<RTCPUtility::RTCPPacketReportBlockItem> report_blocks_;
 
   DISALLOW_COPY_AND_ASSIGN(ReceiverReport);
@@ skipping 17 matching lines @@
 //  If present, this RTCP packet must be placed after a receiver report
 //  (inside a compound RTCP packet), and MUST have the same value for RC
 //  (reception report count) as the receiver report.
 
 class Ij : public RtcpPacket {
  public:
   Ij() : RtcpPacket() {}
 
   virtual ~Ij() {}
 
-  void WithJitterItem(uint32_t jitter);
+  bool WithJitterItem(uint32_t jitter);
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  enum { kMaxNumberOfIjItems = 0x1f };
+  static const int kMaxNumberOfIjItems = 0x1f;
 
   size_t BlockLength() const {
     return kHeaderLength + 4 * ij_items_.size();
   }
 
   std::vector<uint32_t> ij_items_;
 
   DISALLOW_COPY_AND_ASSIGN(Ij);
 };
 
@@ skipping 22 matching lines @@
 //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //   |    CNAME=1    |     length    | user and domain name        ...
 //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 
 class Sdes : public RtcpPacket {
  public:
   Sdes() : RtcpPacket() {}
 
   virtual ~Sdes() {}
 
-  void WithCName(uint32_t ssrc, std::string cname);
+  bool WithCName(uint32_t ssrc, const std::string& cname);
 
   struct Chunk {
     uint32_t ssrc;
     std::string name;
     int null_octets;
   };
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  enum { kMaxNumberOfChunks = 0x1f };
+  static const int kMaxNumberOfChunks = 0x1f;
 
   size_t BlockLength() const;
 
   std::vector<Chunk> chunks_;
 
   DISALLOW_COPY_AND_ASSIGN(Sdes);
 };
 
 //
 // Bye packet (BYE) (RFC 3550).
@@ skipping 13 matching lines @@
  public:
   Bye() : RtcpPacket() {
     memset(&bye_, 0, sizeof(bye_));
   }
 
   virtual ~Bye() {}
 
   void From(uint32_t ssrc) {
     bye_.SenderSSRC = ssrc;
   }
-  void WithCsrc(uint32_t csrc);
+
+  bool WithCsrc(uint32_t csrc);
+
+  // TODO(sprang): Add support for reason field?
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  enum { kMaxNumberOfCsrcs = 0x1f - 1 };
+  static const int kMaxNumberOfCsrcs = 0x1f - 1;  // First item is sender SSRC.
 
   size_t BlockLength() const {
     size_t source_count = 1 + csrcs_.size();
     return kHeaderLength + 4 * source_count;
   }
 
   RTCPUtility::RTCPPacketBYE bye_;
   std::vector<uint32_t> csrcs_;
 
   DISALLOW_COPY_AND_ASSIGN(Bye);
@@ skipping 35 matching lines @@
   }
   void WithData(const uint8_t* data, uint16_t data_length) {
     assert(data);
     assert(data_length <= kRtcpAppCode_DATA_SIZE);
     assert(data_length % 4 == 0);
     memcpy(app_.Data, data, data_length);
     app_.Size = data_length;
   }
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
   size_t BlockLength() const {
     return 12 + app_.Size;
   }
 
   uint32_t ssrc_;
   RTCPUtility::RTCPPacketAPP app_;
 
   DISALLOW_COPY_AND_ASSIGN(App);
@@ skipping 28 matching lines @@
   virtual ~Pli() {}
 
   void From(uint32_t ssrc) {
     pli_.SenderSSRC = ssrc;
   }
   void To(uint32_t ssrc) {
     pli_.MediaSSRC = ssrc;
   }
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
   size_t BlockLength() const {
     return kCommonFbFmtLength;
   }
 
   RTCPUtility::RTCPPacketPSFBPLI pli_;
 
   DISALLOW_COPY_AND_ASSIGN(Pli);
 };
@@ skipping 29 matching lines @@
   void WithNumberOfMb(uint16_t number_mb) {
     assert(number_mb <= 0x1fff);
     sli_item_.NumberOfMB = number_mb;
   }
   void WithPictureId(uint8_t picture_id) {
     assert(picture_id <= 0x3f);
     sli_item_.PictureId = picture_id;
   }
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
   size_t BlockLength() const {
     const size_t kFciLength = 4;
     return kCommonFbFmtLength + kFciLength;
   }
 
   RTCPUtility::RTCPPacketPSFBSLI sli_;
   RTCPUtility::RTCPPacketPSFBSLIItem sli_item_;
 
@@ skipping 19 matching lines @@
 
   void From(uint32_t ssrc) {
     nack_.SenderSSRC = ssrc;
   }
   void To(uint32_t ssrc) {
     nack_.MediaSSRC = ssrc;
   }
   void WithList(const uint16_t* nack_list, int length);
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  size_t BlockLength() const {
-    size_t fci_length = 4 * nack_fields_.size();
-    return kCommonFbFmtLength + fci_length;
-  }
 
   RTCPUtility::RTCPPacketRTPFBNACK nack_;
   std::vector<RTCPUtility::RTCPPacketRTPFBNACKItem> nack_fields_;
 
   DISALLOW_COPY_AND_ASSIGN(Nack);
 };
 
 // Reference picture selection indication (RPSI) (RFC 4585).
 //
 // FCI:
@@ skipping 22 matching lines @@
   void To(uint32_t ssrc) {
     rpsi_.MediaSSRC = ssrc;
   }
   void WithPayloadType(uint8_t payload) {
     assert(payload <= 0x7f);
     rpsi_.PayloadType = payload;
   }
   void WithPictureId(uint64_t picture_id);
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
   size_t BlockLength() const {
     size_t fci_length = 2 + (rpsi_.NumberOfValidBits / 8) + padding_bytes_;
     return kCommonFbFmtLength + fci_length;
   }
 
   uint8_t padding_bytes_;
   RTCPUtility::RTCPPacketPSFBRPSI rpsi_;
 
@@ skipping 25 matching lines @@
     fir_.SenderSSRC = ssrc;
   }
   void To(uint32_t ssrc) {
     fir_item_.SSRC = ssrc;
   }
   void WithCommandSeqNum(uint8_t seq_num) {
     fir_item_.CommandSequenceNumber = seq_num;
   }
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
   size_t BlockLength() const {
     const size_t kFciLength = 8;
     return kCommonFbFmtLength + kFciLength;
   }
 
   RTCPUtility::RTCPPacketPSFBFIR fir_;
   RTCPUtility::RTCPPacketPSFBFIRItem fir_item_;
 };
@@ skipping 27 matching lines @@
   }
   void WithBitrateKbps(uint32_t bitrate_kbps) {
     tmmbr_item_.MaxTotalMediaBitRate = bitrate_kbps;
   }
   void WithOverhead(uint16_t overhead) {
     assert(overhead <= 0x1ff);
     tmmbr_item_.MeasuredOverhead = overhead;
   }
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
   size_t BlockLength() const {
     const size_t kFciLen = 8;
     return kCommonFbFmtLength + kFciLen;
   }
 
   RTCPUtility::RTCPPacketRTPFBTMMBR tmmbr_;
   RTCPUtility::RTCPPacketRTPFBTMMBRItem tmmbr_item_;
 
@@ skipping 16 matching lines @@
  public:
   Tmmbn() : RtcpPacket() {
     memset(&tmmbn_, 0, sizeof(tmmbn_));
   }
 
   virtual ~Tmmbn() {}
 
   void From(uint32_t ssrc) {
     tmmbn_.SenderSSRC = ssrc;
   }
-  void WithTmmbr(uint32_t ssrc, uint32_t bitrate_kbps, uint16_t overhead);
+  // Max 50 TMMBR can be added per TMMBN.
+  bool WithTmmbr(uint32_t ssrc, uint32_t bitrate_kbps, uint16_t overhead);
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  enum { kMaxNumberOfTmmbrs = 50 };
+  static const int kMaxNumberOfTmmbrs = 50;
 
   size_t BlockLength() const {
     const size_t kFciLen = 8;
     return kCommonFbFmtLength + kFciLen * tmmbn_items_.size();
   }
 
   RTCPUtility::RTCPPacketRTPFBTMMBN tmmbn_;
   std::vector<RTCPUtility::RTCPPacketRTPFBTMMBRItem> tmmbn_items_;
 
   DISALLOW_COPY_AND_ASSIGN(Tmmbn);
@@ skipping 30 matching lines @@
   void From(uint32_t ssrc) {
     remb_.SenderSSRC = ssrc;
   }
   void AppliesTo(uint32_t ssrc);
 
   void WithBitrateBps(uint32_t bitrate_bps) {
     remb_item_.BitRate = bitrate_bps;
   }
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  enum { kMaxNumberOfSsrcs = 0xff };
+  static const int kMaxNumberOfSsrcs = 0xff;
 
   size_t BlockLength() const {
     return (remb_item_.NumberOfSSRCs + 5) * 4;
   }
 
   RTCPUtility::RTCPPacketPSFBAPP remb_;
   RTCPUtility::RTCPPacketPSFBREMBItem remb_item_;
 
   DISALLOW_COPY_AND_ASSIGN(Remb);
 };
@@ skipping 17 matching lines @@
   typedef std::vector<RTCPUtility::RTCPPacketXRDLRRReportBlockItem> DlrrBlock;
   Xr() : RtcpPacket() {
     memset(&xr_header_, 0, sizeof(xr_header_));
   }
 
   virtual ~Xr() {}
 
   void From(uint32_t ssrc) {
     xr_header_.OriginatorSSRC = ssrc;
   }
-  void WithRrtr(Rrtr* rrtr);
-  void WithDlrr(Dlrr* dlrr);
-  void WithVoipMetric(VoipMetric* voip_metric);
+
+  // Max 50 items of each of {Rrtr, Dlrr, VoipMetric} allowed per Xr.
+  bool WithRrtr(Rrtr* rrtr);
+  bool WithDlrr(Dlrr* dlrr);
+  bool WithVoipMetric(VoipMetric* voip_metric);
 
  protected:
-  void Create(uint8_t* packet,
-              size_t* length,
-              size_t max_length) const override;
+  bool Create(uint8_t* packet,
+              size_t* index,
+              size_t max_length,
+              RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  enum { kMaxNumberOfRrtrBlocks = 50 };
-  enum { kMaxNumberOfDlrrBlocks = 50 };
-  enum { kMaxNumberOfVoipMetricBlocks = 50 };
+  static const int kMaxNumberOfRrtrBlocks = 50;
+  static const int kMaxNumberOfDlrrBlocks = 50;
+  static const int kMaxNumberOfVoipMetricBlocks = 50;
 
   size_t BlockLength() const {
     const size_t kXrHeaderLength = 8;
     return kXrHeaderLength + RrtrLength() + DlrrLength() + VoipMetricLength();
   }
 
   size_t RrtrLength() const {
     const size_t kRrtrBlockLength = 12;
     return kRrtrBlockLength * rrtr_blocks_.size();
   }
@@ skipping 61 matching lines @@
 //  +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
 //  |                 SSRC_2 (SSRC of second receiver)              | sub-
 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ block
 //  :                               ...                             :   2
 
 class Dlrr {
  public:
   Dlrr() {}
   ~Dlrr() {}
 
-  void WithDlrrItem(uint32_t ssrc, uint32_t last_rr, uint32_t delay_last_rr);
+  // Max 100 DLRR Items can be added per DLRR report block.
+  bool WithDlrrItem(uint32_t ssrc, uint32_t last_rr, uint32_t delay_last_rr);
 
  private:
   friend class Xr;
-  enum { kMaxNumberOfDlrrItems = 100 };
+  static const int kMaxNumberOfDlrrItems = 100;
 
   std::vector<RTCPUtility::RTCPPacketXRDLRRReportBlockItem> dlrr_block_;
 
   DISALLOW_COPY_AND_ASSIGN(Dlrr);
 };
 
 // VoIP Metrics Report Block (RFC 3611).
 //
 //   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
@@ skipping 62 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(VoipMetric);
 };
 
 // Class holding a RTCP packet.
 //
 // Takes a built rtcp packet.
 //  RawPacket raw_packet(buffer, length);
 //
 // To access the raw packet:
-//  raw_packet.buffer();         - pointer to the raw packet
-//  raw_packet.buffer_length();  - the length of the raw packet
+//  raw_packet.Buffer();         - pointer to the raw packet
+//  raw_packet.BufferLength();   - the length of the raw packet
 
 class RawPacket {
  public:
-  RawPacket(const uint8_t* packet, size_t length) {
-    assert(length <= IP_PACKET_SIZE);
-    memcpy(buffer_, packet, length);
-    buffer_length_ = length;
-  }
+  explicit RawPacket(size_t buffer_length);
+  RawPacket(const uint8_t* packet, size_t packet_length);
 
-  const uint8_t* buffer() {
-    return buffer_;
-  }
-  size_t buffer_length() const {
-    return buffer_length_;
-  }
+  const uint8_t* Buffer() const;
+  uint8_t* MutableBuffer();
+  size_t BufferLength() const;
+  size_t Length() const;
+  void SetLength(size_t length);
 
  private:
-  size_t buffer_length_;
-  uint8_t buffer_[IP_PACKET_SIZE];
+  const size_t buffer_length_;
+  size_t length_;
+  rtc::scoped_ptr<uint8_t[]> buffer_;
 };
 
 }  // namespace rtcp
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_RTP_RTCP_RTCP_PACKET_H_