Merge pull request #13 from meskio/bridges

Add support bridge descriptors and consensus

consensus.go

@@ -22,6 +22,13 @@ var consensusAnnotations = map[Annotation]bool{
 	Annotation{"network-status-consensus-3", "1", "0"}: true,
 }
 
+var bridgeNetworkStatusAnnotations = map[Annotation]bool{
+	// The file format we currently (try to) support.
+	Annotation{"bridge-network-status", "1", "2"}: true,
+}
+
+var ErrNoStatusEntry = fmt.Errorf("cannot find the end of status entry: \"\\nr \" or \"directory-signature\"")
+
 type GetStatus func() *RouterStatus
 
 type RouterFlags struct {
@@ -474,7 +481,7 @@ func extractStatusEntry(data []byte, atEOF bool) (advance int, token []byte, err
 		return start + end, data[start : start+end], bufio.ErrFinalToken
 	}
 	if atEOF {
-		return start, nil, fmt.Errorf("cannot find the end of status entry: \"\\nr \" or \"directory-signature\"")
+		return len(data), data[start:], ErrNoStatusEntry
 	}
 	// Request more data.
 	return 0, nil, nil
@@ -483,9 +490,8 @@ func extractStatusEntry(data []byte, atEOF bool) (advance int, token []byte, err
 // extractMetainfo extracts meta information of the open consensus document
 // (such as its validity times) and writes it to the provided consensus struct.
 // It assumes that the type annotation has already been read.
-func extractMetaInfo(r io.Reader, c *Consensus) error {
+func extractMetaInfo(br *bufio.Reader, c *Consensus) error {
 
-	br := bufio.NewReader(r)
 	c.MetaInfo = make(map[string][]byte)
 
 	// Read the initial metadata. We'll later extract information of particular
@@ -505,11 +511,11 @@ func extractMetaInfo(r io.Reader, c *Consensus) error {
 		c.MetaInfo[key] = bytes.TrimSpace(split[1])
 
 		// Look ahead to check if we've reached the end of the unique keys.
-		nextKey, err := br.Peek(10)
+		nextKey, err := br.Peek(11)
 		if err != nil {
 			return err
 		}
-		if bytes.Equal(nextKey, []byte("dir-source")) {
+		if bytes.HasPrefix(nextKey, []byte("dir-source")) || bytes.HasPrefix(nextKey, []byte("fingerprint")) {
 			break
 		}
 	}
@@ -590,8 +596,9 @@ func (filter *ObjectFilter) MatchesRouterStatus(status *RouterStatus) bool {
 // correct type.  The function returns a network consensus if parsing was
 // successful.  If there were any errors, an error string is returned.  If the
 // lazy argument is set to true, parsing of the router statuses is delayed until
-// they are accessed.
-func parseConsensusUnchecked(r io.Reader, lazy bool) (*Consensus, error) {
+// they are accessed. If strict it will only accept valid consensus files, not
+// strict is used to parse bridge networkstatus files or when unknown what kind is.
+func parseConsensusUnchecked(r io.Reader, lazy bool, strict bool) (*Consensus, error) {
 
 	var consensus = NewConsensus()
 	var statusParser func(string) (Fingerprint, GetStatus, error)
@@ -602,19 +609,20 @@ func parseConsensusUnchecked(r io.Reader, lazy bool) (*Consensus, error) {
 		statusParser = ParseRawStatus
 	}
 
-	err := extractMetaInfo(r, consensus)
-	if err != nil {
+	br := bufio.NewReader(r)
+	err := extractMetaInfo(br, consensus)
+	if strict && err != nil {
 		return nil, err
 	}
 
 	// We will read raw router statuses from this channel.
 	queue := make(chan QueueUnit)
-	go DissectFile(r, extractStatusEntry, queue)
+	go DissectFile(br, extractStatusEntry, queue)
 
 	// Parse incoming router statuses until the channel is closed by the remote
 	// end.
 	for unit := range queue {
-		if unit.Err != nil {
+		if unit.Err != nil && (strict || !errors.Is(unit.Err, ErrNoStatusEntry)) {
 			return nil, unit.Err
 		}
 
@@ -634,12 +642,18 @@ func parseConsensusUnchecked(r io.Reader, lazy bool) (*Consensus, error) {
 // consensusAnnotations.
 func parseConsensus(r io.Reader, lazy bool) (*Consensus, error) {
 
-	r, err := readAndCheckAnnotation(r, consensusAnnotations)
+	strict := false
+	annotation, r, err := readAnnotation(r)
 	if err != nil {
 		return nil, err
 	}
+	if _, ok := consensusAnnotations[*annotation]; ok {
+		strict = true
+	} else if _, ok := bridgeNetworkStatusAnnotations[*annotation]; !ok {
+		return nil, fmt.Errorf("unexpected file annotation: %s", annotation)
+	}
 
-	return parseConsensusUnchecked(r, lazy)
+	return parseConsensusUnchecked(r, lazy, strict)
 }
 
 // parseConsensusFile is a wrapper around parseConsensus that opens the named
@@ -655,6 +669,19 @@ func parseConsensusFile(fileName string, lazy bool) (*Consensus, error) {
 	return parseConsensus(fd, lazy)
 }
 
+// parseConsensusFileUnchecked is a wrapper around parseConsensusUnchecked that opens the named
+// file for parsing.
+func parseConsensusFileUnchecked(fileName string, lazy bool) (*Consensus, error) {
+
+	fd, err := os.Open(fileName)
+	if err != nil {
+		return nil, err
+	}
+	defer fd.Close()
+
+	return parseConsensusUnchecked(fd, lazy, false)
+}
+
 // ParseRawConsensus parses a raw consensus (in string format) and
 // returns a network consensus if parsing was successful.
 func ParseRawConsensus(rawConsensus string, lazy bool) (*Consensus, error) {
@@ -682,3 +709,33 @@ func ParseConsensusFile(fileName string) (*Consensus, error) {
 
 	return parseConsensusFile(fileName, false)
 }
+
+// ParseRawUnsafeConsensus parses a raw consensus (in string format) and
+// returns a network consensus if parsing was successful.
+func ParseRawUnsafeConsensus(rawConsensus string, lazy bool) (*Consensus, error) {
+	r := strings.NewReader(rawConsensus)
+
+	return parseConsensusUnchecked(r, lazy, false)
+}
+
+// LazilyParseUnsafeConsensusFile parses the given file without checking the
+// annotations and returns a network consensus if parsing was successful. If
+// there were any errors, consensus if parsing was successful.  If there were
+// any errors, an error string is returned.  Parsing of the router statuses is
+// delayed until they are accessed using the Get method.  As a result, this
+// function is recommended as long as you won't access more than ~50% of all
+// statuses.
+func LazilyParseUnsafeConsensusFile(fileName string) (*Consensus, error) {
+
+	return parseConsensusFileUnchecked(fileName, true)
+}
+
+// ParseUnsafeConsensusFile parses the given file without checking the annotations
+// and returns a network consensus if parsing was successful. If there were any
+// errors, an error string is returned.  In contrast to LazilyParseConsensusFile,
+// parsing of router statuses is *not* delayed.  As a result, this function is
+// recommended as long as you will access most of all statuses.
+func ParseUnsafeConsensusFile(fileName string) (*Consensus, error) {
+
+	return parseConsensusFileUnchecked(fileName, false)
+}

consensus_test.go

@@ -291,7 +291,8 @@ func TestExtractMetaInfo(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = extractMetaInfo(r, consensus)
+	br := bufio.NewReader(r)
+	err = extractMetaInfo(br, consensus)
 	if err != nil {
 		t.Errorf("unable to extractMetaInfo with error: %v", err)
 	}
@@ -326,7 +327,8 @@ func TestExtractSharedRandom(t *testing.T) {
 		t.Error(err)
 	}
 
-	err = extractMetaInfo(r, c)
+	br := bufio.NewReader(r)
+	err = extractMetaInfo(br, c)
 	if err != nil {
 		t.Error(err)
 	}

descriptor.go

@@ -1,4 +1,4 @@
-// Parses files containing server descriptors.
+// Parses files containing server or bridge descriptors.
 
 package zoossh
 
@@ -20,7 +20,8 @@ const (
 
 var descriptorAnnotations = map[Annotation]bool{
 	// The file format we currently (try to) support.
-	Annotation{"server-descriptor", "1", "0"}: true,
+	Annotation{"server-descriptor", "1", "0"}:        true,
+	Annotation{"bridge-server-descriptor", "1", "2"}: true,
 }
 
 type GetDescriptor func() *RouterDescriptor
@@ -72,6 +73,10 @@ type RouterDescriptor struct {
 	// The "hidden-service-dir" line.
 	HiddenServiceDir bool
 
+	// The "bridge-distribution-request" line
+	// it only exist on the bridge-descriptors
+	BridgeDistributionRequest string
+
 	OnionKey     string
 	NTorOnionKey string
 	SigningKey   string
@@ -327,6 +332,9 @@ func ParseRawDescriptor(rawDescriptor string) (Fingerprint, GetDescriptor, error
 		case "accept":
 			descriptor.RawAccept += words[1] + " "
 			descriptor.RawExitPolicy += words[0] + " " + words[1] + "\n"
+
+		case "bridge-distribution-request":
+			descriptor.BridgeDistributionRequest = words[1]
 		}
 	}
 
@@ -452,6 +460,19 @@ func parseDescriptorFile(fileName string, lazy bool) (*RouterDescriptors, error)
 	return parseDescriptor(fd, lazy)
 }
 
+// parseDescriptorFileUnchecked is a wrapper around parseDescriptorUnchecked
+// that opens the named file for parsing.
+func parseDescriptorFileUnchecked(fileName string, lazy bool) (*RouterDescriptors, error) {
+
+	fd, err := os.Open(fileName)
+	if err != nil {
+		return nil, err
+	}
+	defer fd.Close()
+
+	return parseDescriptorUnchecked(fd, lazy)
+}
+
 // LazilyParseDescriptorFile parses the given file and returns a pointer to
 // RouterDescriptors containing the router descriptors.  If there were any
 // errors, an error string is returned.  Note that parsing is done lazily which
@@ -471,3 +492,23 @@ func ParseDescriptorFile(fileName string) (*RouterDescriptors, error) {
 
 	return parseDescriptorFile(fileName, false)
 }
+
+// LazilyParseDescriptorFile parses the given file without checking the annotations
+// and returns a pointer to RouterDescriptors containing the router descriptors.
+// If there were any errors, an error string is returned. Note that parsing is done
+// lazily which means that it is delayed until a given router descriptor is accessed.
+// That pays off when you know that you will not parse most router descriptors.
+func LazilyParseUnsafeDescriptorFile(fileName string) (*RouterDescriptors, error) {
+
+	return parseDescriptorFileUnchecked(fileName, true)
+}
+
+// ParseDescriptorFile parses the given file without checking the annotations and
+// returns a pointer to RouterDescriptors containing the router descriptors.
+// If there were any errors, an error string is returned. Note that in contrast to
+// LazilyParseDescriptorFile, parsing is *not* delayed. That pays off when you
+// know that you will parse most router descriptors.
+func ParseUnsafeDescriptorFile(fileName string) (*RouterDescriptors, error) {
+
+	return parseDescriptorFileUnchecked(fileName, false)
+}

generic.go

@@ -101,7 +101,11 @@ func parseWithAnnotation(r io.Reader, annotation *Annotation) (ObjectSet, error)
 	}
 
 	if _, ok := consensusAnnotations[*annotation]; ok {
-		return parseConsensusUnchecked(r, false)
+		return parseConsensusUnchecked(r, false, true)
+	}
+
+	if _, ok := bridgeNetworkStatusAnnotations[*annotation]; ok {
+		return parseConsensusUnchecked(r, false, false)
 	}
 
 	return nil, fmt.Errorf("could not find suitable parser")

go.mod

@@ -0,0 +1,3 @@
+module github.com/NullHypothesis/zoossh
+
+go 1.15