1 files changed, 180 insertions, 0 deletions
diff --git a/vendor/github.com/pion/srtp/v2/session_srtcp.go b/vendor/github.com/pion/srtp/v2/session_srtcp.go
new file mode 100644
index 0000000..a5fb656
--- /dev/null
+++ b/vendor/github.com/pion/srtp/v2/session_srtcp.go
@@ -0,0 +1,180 @@
+package srtp
+
+import (
+	"net"
+	"time"
+
+	"github.com/pion/logging"
+	"github.com/pion/rtcp"
+)
+
+const defaultSessionSRTCPReplayProtectionWindow = 64
+
+// SessionSRTCP implements io.ReadWriteCloser and provides a bi-directional SRTCP session
+// SRTCP itself does not have a design like this, but it is common in most applications
+// for local/remote to each have their own keying material. This provides those patterns
+// instead of making everyone re-implement
+type SessionSRTCP struct {
+	session
+	writeStream *WriteStreamSRTCP
+}
+
+// NewSessionSRTCP creates a SRTCP session using conn as the underlying transport.
+func NewSessionSRTCP(conn net.Conn, config *Config) (*SessionSRTCP, error) { //nolint:dupl
+	if config == nil {
+		return nil, errNoConfig
+	} else if conn == nil {
+		return nil, errNoConn
+	}
+
+	loggerFactory := config.LoggerFactory
+	if loggerFactory == nil {
+		loggerFactory = logging.NewDefaultLoggerFactory()
+	}
+
+	localOpts := append(
+		[]ContextOption{},
+		config.LocalOptions...,
+	)
+	remoteOpts := append(
+		[]ContextOption{
+			// Default options
+			SRTCPReplayProtection(defaultSessionSRTCPReplayProtectionWindow),
+		},
+		config.RemoteOptions...,
+	)
+
+	s := &SessionSRTCP{
+		session: session{
+			nextConn:      conn,
+			localOptions:  localOpts,
+			remoteOptions: remoteOpts,
+			readStreams:   map[uint32]readStream{},
+			newStream:     make(chan readStream),
+			started:       make(chan interface{}),
+			closed:        make(chan interface{}),
+			bufferFactory: config.BufferFactory,
+			log:           loggerFactory.NewLogger("srtp"),
+		},
+	}
+	s.writeStream = &WriteStreamSRTCP{s}
+
+	err := s.session.start(
+		config.Keys.LocalMasterKey, config.Keys.LocalMasterSalt,
+		config.Keys.RemoteMasterKey, config.Keys.RemoteMasterSalt,
+		config.Profile,
+		s,
+	)
+	if err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+// OpenWriteStream returns the global write stream for the Session
+func (s *SessionSRTCP) OpenWriteStream() (*WriteStreamSRTCP, error) {
+	return s.writeStream, nil
+}
+
+// OpenReadStream opens a read stream for the given SSRC, it can be used
+// if you want a certain SSRC, but don't want to wait for AcceptStream
+func (s *SessionSRTCP) OpenReadStream(ssrc uint32) (*ReadStreamSRTCP, error) {
+	r, _ := s.session.getOrCreateReadStream(ssrc, s, newReadStreamSRTCP)
+
+	if readStream, ok := r.(*ReadStreamSRTCP); ok {
+		return readStream, nil
+	}
+	return nil, errFailedTypeAssertion
+}
+
+// AcceptStream returns a stream to handle RTCP for a single SSRC
+func (s *SessionSRTCP) AcceptStream() (*ReadStreamSRTCP, uint32, error) {
+	stream, ok := <-s.newStream
+	if !ok {
+		return nil, 0, errStreamAlreadyClosed
+	}
+
+	readStream, ok := stream.(*ReadStreamSRTCP)
+	if !ok {
+		return nil, 0, errFailedTypeAssertion
+	}
+
+	return readStream, stream.GetSSRC(), nil
+}
+
+// Close ends the session
+func (s *SessionSRTCP) Close() error {
+	return s.session.close()
+}
+
+// Private
+
+func (s *SessionSRTCP) write(buf []byte) (int, error) {
+	if _, ok := <-s.session.started; ok {
+		return 0, errStartedChannelUsedIncorrectly
+	}
+
+	s.session.localContextMutex.Lock()
+	encrypted, err := s.localContext.EncryptRTCP(nil, buf, nil)
+	s.session.localContextMutex.Unlock()
+
+	if err != nil {
+		return 0, err
+	}
+	return s.session.nextConn.Write(encrypted)
+}
+
+func (s *SessionSRTCP) setWriteDeadline(t time.Time) error {
+	return s.session.nextConn.SetWriteDeadline(t)
+}
+
+// create a list of Destination SSRCs
+// that's a superset of all Destinations in the slice.
+func destinationSSRC(pkts []rtcp.Packet) []uint32 {
+	ssrcSet := make(map[uint32]struct{})
+	for _, p := range pkts {
+		for _, ssrc := range p.DestinationSSRC() {
+			ssrcSet[ssrc] = struct{}{}
+		}
+	}
+
+	out := make([]uint32, 0, len(ssrcSet))
+	for ssrc := range ssrcSet {
+		out = append(out, ssrc)
+	}
+
+	return out
+}
+
+func (s *SessionSRTCP) decrypt(buf []byte) error {
+	decrypted, err := s.remoteContext.DecryptRTCP(buf, buf, nil)
+	if err != nil {
+		return err
+	}
+
+	pkt, err := rtcp.Unmarshal(decrypted)
+	if err != nil {
+		return err
+	}
+
+	for _, ssrc := range destinationSSRC(pkt) {
+		r, isNew := s.session.getOrCreateReadStream(ssrc, s, newReadStreamSRTCP)
+		if r == nil {
+			return nil // Session has been closed
+		} else if isNew {
+			s.session.newStream <- r // Notify AcceptStream
+		}
+
+		readStream, ok := r.(*ReadStreamSRTCP)
+		if !ok {
+			return errFailedTypeAssertion
+		}
+
+		_, err = readStream.write(decrypted)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}