Improve packet-layer buffering and parsing logic

SendRicochetPacket now has error handling, correctly encodes channel
ids, accepts any io.Writer, and ensures that all data is written. All
callers should be changed at some point to handle errors also.

RecvRicochetPackets is refactored to return only one packet per call and
avoid reading more data than it will consume, which simplifies the logic
and fixes a number of problems with short reads or large packets. Also
fixed an error in bounds checking that caused a remote panic for invalid
packet sizes. It also now accepts any io.Reader.

Tests are updated and expanded, and now pass.

Changes to Ricochet.processConnection are whitespace-only, because of
the removal of the inner packets loop.

ricochet.go

@@ -109,147 +109,175 @@ func (r *Ricochet) processConnection(oc *OpenConnection, service RicochetService
 			return
 		}
 
-		packets, err := r.rni.RecvRicochetPackets(oc.conn)
+		packet, err := r.rni.RecvRicochetPacket(oc.conn)
-
 		if err != nil {
+			oc.Close()
 			return
 		}
 
-		for _, packet := range packets {
+		if len(packet.Data) == 0 {
+			service.OnChannelClosed(oc, packet.Channel)
+			continue
+		}
 
-			if len(packet.Data) == 0 {
+		if packet.Channel == 0 {
-				service.OnChannelClosed(oc, packet.Channel)
+
+			res := new(Protocol_Data_Control.Packet)
+			err := proto.Unmarshal(packet.Data[:], res)
+
+			if err != nil {
+				service.OnGenericError(oc, packet.Channel)
 				continue
 			}
 
-			if packet.Channel == 0 {
+			if res.GetOpenChannel() != nil {
+				opm := res.GetOpenChannel()
 
-				res := new(Protocol_Data_Control.Packet)
+				if oc.GetChannelType(opm.GetChannelIdentifier()) != "none" {
-				err := proto.Unmarshal(packet.Data[:], res)
+					// Channel is already in use.
-
+					service.OnBadUsageError(oc, opm.GetChannelIdentifier())
-				if err != nil {
-					service.OnGenericError(oc, packet.Channel)
 					continue
 				}
 
-				if res.GetOpenChannel() != nil {
+				// If I am a Client, the server can only open even numbered channels
-					opm := res.GetOpenChannel()
+				if oc.Client && opm.GetChannelIdentifier()%2 != 0 {
+					service.OnBadUsageError(oc, opm.GetChannelIdentifier())
+					continue
+				}
 
-					if oc.GetChannelType(opm.GetChannelIdentifier()) != "none" {
+				// If I am a Server, the client can only open odd numbered channels
-						// Channel is already in use.
+				if !oc.Client && opm.GetChannelIdentifier()%2 != 1 {
+					service.OnBadUsageError(oc, opm.GetChannelIdentifier())
+					continue
+				}
+
+				switch opm.GetChannelType() {
+				case "im.ricochet.auth.hidden-service":
+					if oc.Client {
+						// Servers are authed by default and can't auth with hidden-service
 						service.OnBadUsageError(oc, opm.GetChannelIdentifier())
-						continue
+					} else if oc.IsAuthed {
-					}
+						// Can't auth if already authed
-
-					// If I am a Client, the server can only open even numbered channels
-					if oc.Client && opm.GetChannelIdentifier()%2 != 0 {
 						service.OnBadUsageError(oc, opm.GetChannelIdentifier())
-						continue
+					} else if oc.HasChannel("im.ricochet.auth.hidden-service") {
-					}
+						// Can't open more than 1 auth channel
-
-					// If I am a Server, the client can only open odd numbered channels
-					if !oc.Client && opm.GetChannelIdentifier()%2 != 1 {
 						service.OnBadUsageError(oc, opm.GetChannelIdentifier())
-						continue
+					} else {
-					}
+						clientCookie, err := proto.GetExtension(opm, Protocol_Data_AuthHiddenService.E_ClientCookie)
-
+						if err == nil {
-					switch opm.GetChannelType() {
+							clientCookieB := [16]byte{}
-					case "im.ricochet.auth.hidden-service":
+							copy(clientCookieB[:], clientCookie.([]byte)[:])
-						if oc.Client {
+							service.OnAuthenticationRequest(oc, opm.GetChannelIdentifier(), clientCookieB)
-							// Servers are authed by default and can't auth with hidden-service
-							service.OnBadUsageError(oc, opm.GetChannelIdentifier())
-						} else if oc.IsAuthed {
-							// Can't auth if already authed
-							service.OnBadUsageError(oc, opm.GetChannelIdentifier())
-						} else if oc.HasChannel("im.ricochet.auth.hidden-service") {
-							// Can't open more than 1 auth channel
-							service.OnBadUsageError(oc, opm.GetChannelIdentifier())
 						} else {
-							clientCookie, err := proto.GetExtension(opm, Protocol_Data_AuthHiddenService.E_ClientCookie)
+							// Must include Client Cookie
-							if err == nil {
+							service.OnBadUsageError(oc, opm.GetChannelIdentifier())
-								clientCookieB := [16]byte{}
+						}
-								copy(clientCookieB[:], clientCookie.([]byte)[:])
+					}
-								service.OnAuthenticationRequest(oc, opm.GetChannelIdentifier(), clientCookieB)
+				case "im.ricochet.chat":
-							} else {
+					if !oc.IsAuthed {
-								// Must include Client Cookie
+						// Can't open chat channel if not authorized
-								service.OnBadUsageError(oc, opm.GetChannelIdentifier())
+						service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
+					} else if !service.IsKnownContact(oc.OtherHostname) {
+						// Can't open chat channel if not a known contact
+						service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
+					} else {
+						service.OnOpenChannelRequest(oc, opm.GetChannelIdentifier(), "im.ricochet.chat")
+					}
+				case "im.ricochet.contact.request":
+					if oc.Client {
+						// Servers are not allowed to send contact requests
+						service.OnBadUsageError(oc, opm.GetChannelIdentifier())
+					} else if !oc.IsAuthed {
+						// Can't open a contact channel if not authed
+						service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
+					} else if oc.HasChannel("im.ricochet.contact.request") {
+						// Only 1 contact channel is allowed to be open at a time
+						service.OnBadUsageError(oc, opm.GetChannelIdentifier())
+					} else {
+						contactRequestI, err := proto.GetExtension(opm, Protocol_Data_ContactRequest.E_ContactRequest)
+						if err == nil {
+							contactRequest, check := contactRequestI.(*Protocol_Data_ContactRequest.ContactRequest)
+							if check {
+								service.OnContactRequest(oc, opm.GetChannelIdentifier(), contactRequest.GetNickname(), contactRequest.GetMessageText())
+								break
 							}
 						}
+						service.OnBadUsageError(oc, opm.GetChannelIdentifier())
+					}
+				default:
+					service.OnUnknownTypeError(oc, opm.GetChannelIdentifier())
+				}
+			} else if res.GetChannelResult() != nil {
+				crm := res.GetChannelResult()
+				if crm.GetOpened() {
+					switch oc.GetChannelType(crm.GetChannelIdentifier()) {
+					case "im.ricochet.auth.hidden-service":
+						serverCookie, err := proto.GetExtension(crm, Protocol_Data_AuthHiddenService.E_ServerCookie)
+						if err == nil {
+							serverCookieB := [16]byte{}
+							copy(serverCookieB[:], serverCookie.([]byte)[:])
+							service.OnAuthenticationChallenge(oc, crm.GetChannelIdentifier(), serverCookieB)
+						} else {
+							service.OnBadUsageError(oc, crm.GetChannelIdentifier())
+						}
 					case "im.ricochet.chat":
-						if !oc.IsAuthed {
+						service.OnOpenChannelRequestSuccess(oc, crm.GetChannelIdentifier())
-							// Can't open chat channel if not authorized
-							service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
-						} else if !service.IsKnownContact(oc.OtherHostname) {
-							// Can't open chat channel if not a known contact
-							service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
-						} else {
-							service.OnOpenChannelRequest(oc, opm.GetChannelIdentifier(), "im.ricochet.chat")
-						}
 					case "im.ricochet.contact.request":
-						if oc.Client {
+						responseI, err := proto.GetExtension(res.GetChannelResult(), Protocol_Data_ContactRequest.E_Response)
-							// Servers are not allowed to send contact requests
+						if err == nil {
-							service.OnBadUsageError(oc, opm.GetChannelIdentifier())
+							response, check := responseI.(*Protocol_Data_ContactRequest.Response)
-						} else if !oc.IsAuthed {
+							if check {
-							// Can't open a contact channel if not authed
+								service.OnContactRequestAck(oc, crm.GetChannelIdentifier(), response.GetStatus().String())
-							service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
+								break
-						} else if oc.HasChannel("im.ricochet.contact.request") {
-							// Only 1 contact channel is allowed to be open at a time
-							service.OnBadUsageError(oc, opm.GetChannelIdentifier())
-						} else {
-							contactRequestI, err := proto.GetExtension(opm, Protocol_Data_ContactRequest.E_ContactRequest)
-							if err == nil {
-								contactRequest, check := contactRequestI.(*Protocol_Data_ContactRequest.ContactRequest)
-								if check {
-									service.OnContactRequest(oc, opm.GetChannelIdentifier(), contactRequest.GetNickname(), contactRequest.GetMessageText())
-									break
-								}
 							}
-							service.OnBadUsageError(oc, opm.GetChannelIdentifier())
 						}
+						service.OnBadUsageError(oc, crm.GetChannelIdentifier())
 					default:
-						service.OnUnknownTypeError(oc, opm.GetChannelIdentifier())
+						service.OnBadUsageError(oc, crm.GetChannelIdentifier())
-					}
-				} else if res.GetChannelResult() != nil {
-					crm := res.GetChannelResult()
-					if crm.GetOpened() {
-						switch oc.GetChannelType(crm.GetChannelIdentifier()) {
-						case "im.ricochet.auth.hidden-service":
-							serverCookie, err := proto.GetExtension(crm, Protocol_Data_AuthHiddenService.E_ServerCookie)
-							if err == nil {
-								serverCookieB := [16]byte{}
-								copy(serverCookieB[:], serverCookie.([]byte)[:])
-								service.OnAuthenticationChallenge(oc, crm.GetChannelIdentifier(), serverCookieB)
-							} else {
-								service.OnBadUsageError(oc, crm.GetChannelIdentifier())
-							}
-						case "im.ricochet.chat":
-							service.OnOpenChannelRequestSuccess(oc, crm.GetChannelIdentifier())
-						case "im.ricochet.contact.request":
-							responseI, err := proto.GetExtension(res.GetChannelResult(), Protocol_Data_ContactRequest.E_Response)
-							if err == nil {
-								response, check := responseI.(*Protocol_Data_ContactRequest.Response)
-								if check {
-									service.OnContactRequestAck(oc, crm.GetChannelIdentifier(), response.GetStatus().String())
-									break
-								}
-							}
-							service.OnBadUsageError(oc, crm.GetChannelIdentifier())
-						default:
-							service.OnBadUsageError(oc, crm.GetChannelIdentifier())
-						}
-					} else {
-						if oc.GetChannelType(crm.GetChannelIdentifier()) != "none" {
-							service.OnFailedChannelOpen(oc, crm.GetChannelIdentifier(), crm.GetCommonError().String())
-						} else {
-							oc.CloseChannel(crm.GetChannelIdentifier())
-						}
 					}
 				} else {
-					// Unknown Message
+					if oc.GetChannelType(crm.GetChannelIdentifier()) != "none" {
-					oc.CloseChannel(packet.Channel)
+						service.OnFailedChannelOpen(oc, crm.GetChannelIdentifier(), crm.GetCommonError().String())
+					} else {
+						oc.CloseChannel(crm.GetChannelIdentifier())
+					}
 				}
-			} else if oc.GetChannelType(packet.Channel) == "im.ricochet.auth.hidden-service" {
+			} else {
-				res := new(Protocol_Data_AuthHiddenService.Packet)
+				// Unknown Message
+				oc.CloseChannel(packet.Channel)
+			}
+		} else if oc.GetChannelType(packet.Channel) == "im.ricochet.auth.hidden-service" {
+			res := new(Protocol_Data_AuthHiddenService.Packet)
+			err := proto.Unmarshal(packet.Data[:], res)
+
+			if err != nil {
+				oc.CloseChannel(packet.Channel)
+				continue
+			}
+
+			if res.GetProof() != nil && !oc.Client { // Only Clients Send Proofs
+				service.OnAuthenticationProof(oc, packet.Channel, res.GetProof().GetPublicKey(), res.GetProof().GetSignature(), service.IsKnownContact(oc.OtherHostname))
+			} else if res.GetResult() != nil && oc.Client { // Only Servers Send Results
+				service.OnAuthenticationResult(oc, packet.Channel, res.GetResult().GetAccepted(), res.GetResult().GetIsKnownContact())
+			} else {
+				// If neither of the above are satisfied we just close the connection
+				oc.Close()
+			}
+
+		} else if oc.GetChannelType(packet.Channel) == "im.ricochet.chat" {
+
+			// NOTE: These auth checks should be redundant, however they
+			// are included here for defense-in-depth if for some reason
+			// a previously authed connection becomes untrusted / not known and
+			// the state is not cleaned up.
+			if !oc.IsAuthed {
+				// Can't send chat messages if not authorized
+				service.OnUnauthorizedError(oc, packet.Channel)
+			} else if !service.IsKnownContact(oc.OtherHostname) {
+				// Can't send chat message if not a known contact
+				service.OnUnauthorizedError(oc, packet.Channel)
+			} else {
+				res := new(Protocol_Data_Chat.Packet)
 				err := proto.Unmarshal(packet.Data[:], res)
 
 				if err != nil {
@@ -257,73 +285,42 @@ func (r *Ricochet) processConnection(oc *OpenConnection, service RicochetService
 					continue
 				}
 
-				if res.GetProof() != nil && !oc.Client { // Only Clients Send Proofs
+				if res.GetChatMessage() != nil {
-					service.OnAuthenticationProof(oc, packet.Channel, res.GetProof().GetPublicKey(), res.GetProof().GetSignature(), service.IsKnownContact(oc.OtherHostname))
+					service.OnChatMessage(oc, packet.Channel, int32(res.GetChatMessage().GetMessageId()), res.GetChatMessage().GetMessageText())
-				} else if res.GetResult() != nil && oc.Client { // Only Servers Send Results
+				} else if res.GetChatAcknowledge() != nil {
-					service.OnAuthenticationResult(oc, packet.Channel, res.GetResult().GetAccepted(), res.GetResult().GetIsKnownContact())
+					service.OnChatMessageAck(oc, packet.Channel, int32(res.GetChatMessage().GetMessageId()))
 				} else {
 					// If neither of the above are satisfied we just close the connection
 					oc.Close()
 				}
-
-			} else if oc.GetChannelType(packet.Channel) == "im.ricochet.chat" {
-
-				// NOTE: These auth checks should be redundant, however they
-				// are included here for defense-in-depth if for some reason
-				// a previously authed connection becomes untrusted / not known and
-				// the state is not cleaned up.
-				if !oc.IsAuthed {
-					// Can't send chat messages if not authorized
-					service.OnUnauthorizedError(oc, packet.Channel)
-				} else if !service.IsKnownContact(oc.OtherHostname) {
-					// Can't send chat message if not a known contact
-					service.OnUnauthorizedError(oc, packet.Channel)
-				} else {
-					res := new(Protocol_Data_Chat.Packet)
-					err := proto.Unmarshal(packet.Data[:], res)
-
-					if err != nil {
-						oc.CloseChannel(packet.Channel)
-						continue
-					}
-
-					if res.GetChatMessage() != nil {
-						service.OnChatMessage(oc, packet.Channel, int32(res.GetChatMessage().GetMessageId()), res.GetChatMessage().GetMessageText())
-					} else if res.GetChatAcknowledge() != nil {
-						service.OnChatMessageAck(oc, packet.Channel, int32(res.GetChatMessage().GetMessageId()))
-					} else {
-						// If neither of the above are satisfied we just close the connection
-						oc.Close()
-					}
-				}
-			} else if oc.GetChannelType(packet.Channel) == "im.ricochet.contact.request" {
-
-				// NOTE: These auth checks should be redundant, however they
-				// are included here for defense-in-depth if for some reason
-				// a previously authed connection becomes untrusted / not known and
-				// the state is not cleaned up.
-				if !oc.Client {
-					// Clients are not allowed to send contact request responses
-					service.OnBadUsageError(oc, packet.Channel)
-				} else if !oc.IsAuthed {
-					// Can't send a contact request if not authed
-					service.OnBadUsageError(oc, packet.Channel)
-				} else {
-					res := new(Protocol_Data_ContactRequest.Response)
-					err := proto.Unmarshal(packet.Data[:], res)
-					log.Printf("%v", res)
-					if err != nil {
-						oc.CloseChannel(packet.Channel)
-						continue
-					}
-					service.OnContactRequestAck(oc, packet.Channel, res.GetStatus().String())
-				}
-			} else if oc.GetChannelType(packet.Channel) == "none" {
-				// Invalid Channel Assignment
-				oc.CloseChannel(packet.Channel)
-			} else {
-				oc.Close()
 			}
+		} else if oc.GetChannelType(packet.Channel) == "im.ricochet.contact.request" {
+
+			// NOTE: These auth checks should be redundant, however they
+			// are included here for defense-in-depth if for some reason
+			// a previously authed connection becomes untrusted / not known and
+			// the state is not cleaned up.
+			if !oc.Client {
+				// Clients are not allowed to send contact request responses
+				service.OnBadUsageError(oc, packet.Channel)
+			} else if !oc.IsAuthed {
+				// Can't send a contact request if not authed
+				service.OnBadUsageError(oc, packet.Channel)
+			} else {
+				res := new(Protocol_Data_ContactRequest.Response)
+				err := proto.Unmarshal(packet.Data[:], res)
+				log.Printf("%v", res)
+				if err != nil {
+					oc.CloseChannel(packet.Channel)
+					continue
+				}
+				service.OnContactRequestAck(oc, packet.Channel, res.GetStatus().String())
+			}
+		} else if oc.GetChannelType(packet.Channel) == "none" {
+			// Invalid Channel Assignment
+			oc.CloseChannel(packet.Channel)
+		} else {
+			oc.Close()
 		}
 	}
 }

utils/networking.go

@@ -1,10 +1,10 @@
 package utils
 
 import (
+	"bytes"
 	"encoding/binary"
 	"errors"
-	"net"
+	"io"
-	"strconv"
 )
 
 // RicochetData is a structure containing the raw data and the channel it the
@@ -14,79 +14,67 @@ type RicochetData struct {
 	Data    []byte
 }
 
+func (rd RicochetData) Equals(other RicochetData) bool {
+	return rd.Channel == other.Channel && bytes.Equal(rd.Data, other.Data)
+}
+
 // RicochetNetworkInterface abstract operations that interact with ricochet's
 // packet layer.
 type RicochetNetworkInterface interface {
-	Recv(conn net.Conn) ([]byte, error)
+	SendRicochetPacket(dst io.Writer, channel int32, data []byte) error
-	SendRicochetPacket(conn net.Conn, channel int32, data []byte)
+	RecvRicochetPacket(reader io.Reader) (RicochetData, error)
-	RecvRicochetPackets(conn net.Conn) ([]RicochetData, error)
 }
 
 // RicochetNetwork is a concrete implementation of the RicochetNetworkInterface
 type RicochetNetwork struct {
 }
 
-// Recv reads data from the client, and returns the raw byte array, else error.
-func (rn *RicochetNetwork) Recv(conn net.Conn) ([]byte, error) {
-	buf := make([]byte, 4096)
-	n, err := conn.Read(buf)
-	if err != nil {
-		return nil, err
-	}
-	ret := make([]byte, n)
-	copy(ret[:], buf[:])
-	return ret, nil
-}
-
 // SendRicochetPacket places the data into a structure needed for the client to
 // decode the packet and writes the packet to the network.
-func (rn *RicochetNetwork) SendRicochetPacket(conn net.Conn, channel int32, data []byte) {
+func (rn *RicochetNetwork) SendRicochetPacket(dst io.Writer, channel int32, data []byte) error {
-	header := make([]byte, 4+len(data))
+	packet := make([]byte, 4+len(data))
-	header[0] = byte(len(header) >> 8)
+	if len(packet) > 65535 {
-	header[1] = byte(len(header) & 0x00FF)
+		return errors.New("packet too large")
-	header[2] = 0x00
+	}
-	header[3] = byte(channel)
+	binary.BigEndian.PutUint16(packet[0:2], uint16(len(packet)))
-	copy(header[4:], data[:])
+	if channel < 0 || channel > 65535 {
-	conn.Write(header)
+		return errors.New("invalid channel ID")
+	}
+	binary.BigEndian.PutUint16(packet[2:4], uint16(channel))
+	copy(packet[4:], data[:])
+
+	for pos := 0; pos < len(packet); {
+		n, err := dst.Write(packet[pos:])
+		if err != nil {
+			return err
+		}
+		pos += n
+	}
+	return nil
 }
 
-// RecvRicochetPackets returns an array of new messages received from the ricochet client
+// RecvRicochetPacket returns the next packet from reader as a RicochetData
-func (rn *RicochetNetwork) RecvRicochetPackets(conn net.Conn) ([]RicochetData, error) {
+// structure, or an error.
-	buf, err := rn.Recv(conn)
+func (rn *RicochetNetwork) RecvRicochetPacket(reader io.Reader) (RicochetData, error) {
-	if err != nil && len(buf) < 4 {
+	packet := RicochetData{}
-		return nil, errors.New("failed to retrieve new messages from the client")
+
+	// Read the four-byte header to get packet length
+	header := make([]byte, 4)
+	if _, err := io.ReadAtLeast(reader, header, len(header)); err != nil {
+		return packet, err
 	}
 
-	pos := 0
+	size := int(binary.BigEndian.Uint16(header[0:2]))
-	finished := false
+	if size < 4 {
-	var datas []RicochetData
+		return packet, errors.New("invalid packet length")
-
-	for !finished {
-		size := int(binary.BigEndian.Uint16(buf[pos+0 : pos+2]))
-		channel := int(binary.BigEndian.Uint16(buf[pos+2 : pos+4]))
-
-		if size < 4 {
-			return datas, errors.New("invalid ricochet packet received (size=" + strconv.Itoa(size) + ")")
-		}
-
-		if pos+size > len(buf) {
-			return datas, errors.New("partial data packet received")
-		}
-
-		data := RicochetData{}
-		data.Channel = int32(channel)
-
-		if pos+4 >= len(buf) {
-			data.Data = make([]byte, 0)
-		} else {
-			data.Data = buf[pos+4 : pos+size]
-		}
-
-		datas = append(datas, data)
-		pos += size
-		if pos >= len(buf) {
-			finished = true
-		}
 	}
-	return datas, nil
+
+	packet.Channel = int32(binary.BigEndian.Uint16(header[2:4]))
+	packet.Data = make([]byte, size-4)
+
+	if _, err := io.ReadAtLeast(reader, packet.Data, len(packet.Data)); err != nil {
+		return packet, err
+	}
+
+	return packet, nil
 }

utils/networking_test.go

@@ -1,171 +1,105 @@
 package utils
 
-import "testing"
+import (
-import "net"
+	"bytes"
-import "time"
+	"io"
+	"testing"
+	"testing/iotest"
+)
 
-type MockConn struct {
+// Valid packets and their encoded forms
-	Written    []byte
+var packetTests = []struct {
-	MockOutput []byte
+	packet  RicochetData
+	encoded []byte
+}{
+	{RicochetData{1, []byte{}}, []byte{0x00, 0x04, 0x00, 0x01}},
+	{RicochetData{65535, []byte{0xDE, 0xAD, 0xBE, 0xEF}}, []byte{0x00, 0x08, 0xFF, 0xFF, 0xDE, 0xAD, 0xBE, 0xEF}},
+	{RicochetData{2, make([]byte, 65531)}, append([]byte{0xFF, 0xFF, 0x00, 0x02}, make([]byte, 65531)...)},
 }
 
-func (mc *MockConn) Read(b []byte) (int, error) {
+// Test sending valid packets
-	copy(b[:], mc.MockOutput[:])
+func TestSendRicochetPacket(t *testing.T) {
-	return len(mc.MockOutput), nil
-}
-
-func (mc *MockConn) Write(written []byte) (int, error) {
-	mc.Written = written
-	return 0, nil
-}
-
-func (mc *MockConn) LocalAddr() net.Addr {
-	return nil
-}
-
-func (mc *MockConn) RemoteAddr() net.Addr {
-	return nil
-}
-
-func (mc *MockConn) Close() error {
-	return nil
-}
-
-func (mc *MockConn) SetDeadline(t time.Time) error {
-	return nil
-}
-
-func (mc *MockConn) SetReadDeadline(t time.Time) error {
-	return nil
-}
-
-func (mc *MockConn) SetWriteDeadline(t time.Time) error {
-	return nil
-}
-
-func TestSentRicochetPacket(t *testing.T) {
-	conn := new(MockConn)
 	rni := RicochetNetwork{}
-	rni.SendRicochetPacket(conn, 1, []byte{})
+	for _, td := range packetTests {
-	if len(conn.Written) != 4 && conn.Written[0] != 0x00 && conn.Written[1] != 0x00 && conn.Written[2] != 0x01 && conn.Written[3] != 0x00 {
+		var buf bytes.Buffer
-		t.Errorf("Output of SentRicochetPacket was Unexpected: %x", conn.Written)
+		err := rni.SendRicochetPacket(&buf, td.packet.Channel, td.packet.Data)
+		if err != nil {
+			t.Errorf("Error sending packet %v: %v", td.packet, err)
+		} else if !bytes.Equal(buf.Bytes(), td.encoded) {
+			t.Errorf("Expected serialized packet %x but got %x", td.encoded, buf.Bytes())
+		}
 	}
 }
 
-func TestRecv(t *testing.T) {
+// Test sending invalid packets
-	conn := new(MockConn)
+func TestSendRicochetPacket_Invalid(t *testing.T) {
-	conn.MockOutput = []byte{0xDE, 0xAD, 0xBE, 0xEF}
 	rni := RicochetNetwork{}
-	buf, err := rni.Recv(conn)
+	invalidPackets := []RicochetData{
-	if err != nil || len(buf) != 4 || buf[0] != 0xDE || buf[1] != 0xAD || buf[2] != 0xBE || buf[3] != 0xEF {
+		RicochetData{-1, []byte{}},
-		t.Errorf("Output of Recv was Unexpected: %x", buf)
+		RicochetData{65536, []byte{}},
+		RicochetData{0, make([]byte, 65532)},
+	}
+
+	for _, td := range invalidPackets {
+		var buf bytes.Buffer
+		err := rni.SendRicochetPacket(&buf, td.Channel, td.Data)
+		// Expect error
+		if err == nil {
+			t.Errorf("Expected error when sending invalid packet %v", td)
+		}
 	}
 }
 
+// Test receiving valid packets
 func TestRecvRicochetPacket(t *testing.T) {
-	conn := new(MockConn)
+	var buf bytes.Buffer
-	conn.MockOutput = []byte{00, 0x04, 0x00, 0x01}
+	for _, td := range packetTests {
+		if _, err := buf.Write(td.encoded); err != nil {
+			t.Error(err)
+			return
+		}
+	}
 
+	// Use a HalfReader to test behavior on short socket reads also
+	reader := iotest.HalfReader(&buf)
 	rni := RicochetNetwork{}
-	rp, err := rni.RecvRicochetPackets(conn)
 
-	if err != nil {
+	for _, td := range packetTests {
-		t.Errorf("error extracting ricochet packets: %v", err)
+		packet, err := rni.RecvRicochetPacket(reader)
-		return
+		if err != nil {
-	}
+			t.Errorf("Error receiving packet %v: %v", td.packet, err)
-
+			return
-	if len(rp) != 1 {
+		} else if !packet.Equals(td.packet) {
-		t.Errorf("unexpected number of ricochet packets: %d", len(rp))
+			t.Errorf("Expected unserialized packet %v but got %v", td.packet, packet)
-	} else {
-		if rp[0].Channel != 1 {
-			t.Errorf("channel number is Unexpected expected 1: %d", rp[0].Channel)
-		}
-
-		if len(rp[0].Data) != 0 {
-			t.Errorf("expected emptry packet, instead got %x", rp[0].Data)
 		}
 	}
 
+	if packet, err := rni.RecvRicochetPacket(reader); err != io.EOF {
+		if err != nil {
+			t.Errorf("Expected EOF on packet stream but received error: %v", err)
+		} else {
+			t.Errorf("Expected EOF but received packet: %v", packet)
+		}
+	}
 }
 
-func TestRecvRicochetPacketInvalid(t *testing.T) {
+// Test receiving invalid packets
-	conn := new(MockConn)
+func TestRecvRicochetPacket_Invalid(t *testing.T) {
-	conn.MockOutput = []byte{00, 0x01, 0x00, 0x01}
-
 	rni := RicochetNetwork{}
-	_, err := rni.RecvRicochetPackets(conn)
+	invalidPackets := [][]byte{
-
+		[]byte{0x00, 0x00, 0x00, 0x00},
-	if err == nil {
+		[]byte{0x00, 0x03, 0x00, 0x00},
-		t.Errorf("recv should have errored due to invalid packets %v", err)
+		[]byte{0xff},
+		[]byte{0x00, 0x06, 0x00, 0x00, 0x00},
+		[]byte{},
 	}
 
-	conn.MockOutput = []byte{00, 0x0A, 0x00, 0x01}
+	for _, td := range invalidPackets {
-
+		buf := bytes.NewBuffer(td)
-	_, err = rni.RecvRicochetPackets(conn)
+		packet, err := rni.RecvRicochetPacket(buf)
-
+		// Expect error
-	if err == nil {
+		if err == nil {
-		t.Errorf("recv should have errored due to invalid packets %v", err)
+			t.Errorf("Expected error when sending invalid packet %x, got packet %v", td, packet)
+		}
 	}
-
-}
-
-func TestRecvRicochetPacketLong(t *testing.T) {
-	conn := new(MockConn)
-	conn.MockOutput = []byte{0x00, 0x08, 0x00, 0xFF, 0xDE, 0xAD, 0xBE, 0xEF}
-
-	rni := RicochetNetwork{}
-	rp, err := rni.RecvRicochetPackets(conn)
-
-	if err != nil {
-		t.Errorf("error extracting ricochet packets: %v", err)
-		return
-	}
-
-	if len(rp) != 1 {
-		t.Errorf("unexpected number of ricochet packets: %d", len(rp))
-	} else {
-		if rp[0].Channel != 255 {
-			t.Errorf("channel number is Unexpected expected 255 got: %d", rp[0].Channel)
-		}
-
-		if len(rp[0].Data) != 4 || rp[0].Data[0] != 0xDE || rp[0].Data[1] != 0xAD || rp[0].Data[2] != 0xBE || rp[0].Data[3] != 0xEF {
-			t.Errorf("expected 0xDEADBEEF packet, instead got %x", rp[0].Data)
-		}
-	}
-
-}
-
-func TestRecvRicochetPacketMultiplex(t *testing.T) {
-	conn := new(MockConn)
-	conn.MockOutput = []byte{0x00, 0x04, 0x00, 0x01, 0x00, 0x08, 0x00, 0xFF, 0xDE, 0xAD, 0xBE, 0xEF}
-
-	rni := RicochetNetwork{}
-	rp, err := rni.RecvRicochetPackets(conn)
-
-	if err != nil {
-		t.Errorf("error extracting ricochet packets: %v", err)
-		return
-	}
-
-	if len(rp) != 2 {
-		t.Errorf("unexpected number of ricochet packets, expected 2 gt: %d", len(rp))
-	} else {
-
-		if rp[0].Channel != 1 {
-			t.Errorf("channel number is Unexpected expected 1: %d", rp[0].Channel)
-		}
-
-		if len(rp[0].Data) != 0 {
-			t.Errorf("expected empty packet, instead got %x", rp[0].Data)
-		}
-
-		if rp[1].Channel != 255 {
-			t.Errorf("channel number is Unexpected expected 255 got: %d", rp[0].Channel)
-		}
-
-		if len(rp[1].Data) != 4 || rp[1].Data[0] != 0xDE || rp[1].Data[1] != 0xAD || rp[1].Data[2] != 0xBE || rp[1].Data[3] != 0xEF {
-			t.Errorf("expected 0xDEADBEEF packet, instead got %x", rp[0].Data)
-		}
-	}
-
 }