Initial import

protocol/detect_http.go

@@ -0,0 +1,94 @@
+package protocol
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"net/http"
+)
+
+func init() {
+	Register(Client, "", detectHTTPRequest)
+	Register(Server, "HTTP/?.", detectHTTPResponse)
+}
+
+func detectHTTPRequest(dir Direction, data []byte) *Protocol {
+	// A minimal request "GET / HTTP/1.0\r\n" is > 8 bytes.
+	if len(data) < 8 {
+		return nil
+	}
+
+	if Strict {
+		var (
+			b = append(data, '\r', '\n')
+			r = bufio.NewReader(bytes.NewReader(b))
+		)
+		if request, err := http.ReadRequest(r); err == nil {
+			return &Protocol{
+				Name: ProtocolHTTP,
+				Version: Version{
+					Major: request.ProtoMajor,
+					Minor: request.ProtoMinor,
+					Patch: -1,
+				},
+			}
+		}
+		r.Reset(bytes.NewReader(b))
+		if response, err := http.ReadResponse(r, nil); err == nil {
+			return &Protocol{
+				Name: ProtocolHTTP,
+				Version: Version{
+					Major: response.ProtoMajor,
+					Minor: response.ProtoMinor,
+					Patch: -1,
+				},
+			}
+		}
+		return nil
+	}
+
+	crlfIndex := bytes.IndexFunc(data, func(r rune) bool {
+		return r == '\r' || r == '\n'
+	})
+	if crlfIndex == -1 {
+		return nil
+	}
+
+	// A request has three, space-separated parts.
+	part := bytes.Split(data[:crlfIndex], []byte(" "))
+	if len(part) != 3 {
+		return nil
+	}
+
+	// The last part starts with "HTTP/".
+	if !bytes.HasPrefix(part[2], []byte("HTTP/1")) {
+		return nil
+	}
+
+	var version = Version{Patch: -1}
+	fmt.Sscanf(string(part[2]), "HTTP/%d.%d ", &version.Major, &version.Minor)
+
+	return &Protocol{
+		Name:    ProtocolHTTP,
+		Version: version,
+	}
+}
+
+func detectHTTPResponse(dir Direction, data []byte) *Protocol {
+	if !dir.Contains(Server) {
+		return nil
+	}
+
+	// A minimal response "HTTP/1.0 200 OK\r\n" is > 8 bytes.
+	if len(data) < 8 {
+		return nil
+	}
+
+	var version = Version{Patch: -1}
+	fmt.Sscanf(string(data), "HTTP/%d.%d ", &version.Major, &version.Minor)
+
+	return &Protocol{
+		Name:    ProtocolHTTP,
+		Version: version,
+	}
+}