Move htmlfilter to its own package.

Makefile

@@ -17,6 +17,7 @@ PACKAGES = \
 	pkg/serverconf \
 	pkg/sessionpool \
 	pkg/ban \
+	pkg/htmlfilter \
 	pkg/sqlite
 
 GCFLAGS = \
@@ -27,6 +28,7 @@ GCFLAGS = \
 	-Ipkg/serverconf/_obj \
 	-Ipkg/sessionpool/_obj \
 	-Ipkg/ban/_obj \
+	-Ipkg/htmlfilter/_obj \
 	-Ipkg/sqlite/_obj
 
 LDFLAGS = \
@@ -37,6 +39,7 @@ LDFLAGS = \
 	-Lpkg/serverconf/_obj \
 	-Lpkg/sessionpool/_obj \
 	-Lpkg/ban/_obj \
+	-Lpkg/htmlfilter/_obj \
 	-Lpkg/sqlite/_obj
 
 GOFILES = \

pkg/htmlfilter/Makefile

@@ -0,0 +1,7 @@
+include $(GOROOT)/src/Make.inc
+
+TARG = grumble/htmlfilter
+GOFILES = \
+	htmlfilter.go
+
+include $(GOROOT)/src/Make.pkg

pkg/htmlfilter/htmlfilter.go

@@ -0,0 +1,157 @@
+// Copyright (c) 2011 The Grumble Authors
+// The use of this source code is goverened by a BSD-style
+// license that can be found in the LICENSE-file.
+
+package htmlfilter
+
+import (
+	"bytes"
+	"os"
+	"strings"
+	"xml"
+)
+
+type Options struct {
+	StripHTML             bool
+	MaxTextMessageLength  int
+	MaxImageMessageLength int
+}
+
+var defaultOptions Options = Options{
+	StripHTML:             true,
+	MaxTextMessageLength:  1024,
+	MaxImageMessageLength: 1024 * 1024,
+}
+
+var (
+	ErrExceedsTextMessageLength = os.NewError("Exceeds text message length")
+	ErrExceedsImageMessageLength = os.NewError("Exceeds image message length")
+)
+
+// Filter text according to options.
+func Filter(text string, options *Options) (filtered string, err os.Error) {
+	// This function filters incoming text from clients according to the three options:
+	//
+	// StripHTML:
+	//    If true, all HTML shall be stripped.
+	//    When stripping br tags, append a newline to the output stream.
+	//    When stripping p tags, append a newline after the end tag.
+	//
+	// MaxTextsageLength:
+	//    Text length for "plain" messages (messages without images)
+	//
+	// MaxImageMessageLength:
+	//    Text length for messages with images.
+
+	if options == nil {
+		options = &defaultOptions
+	}
+
+	max := options.MaxTextMessageLength
+	maximg := options.MaxImageMessageLength
+
+	if options.StripHTML {
+		// Does the message include HTML? If not, take the fast path.
+		if strings.Index(text, "<") == -1 {
+			filtered = strings.TrimSpace(text)
+		} else {
+			// Strip away all HTML
+			out := bytes.NewBuffer(nil)
+			buf := bytes.NewBufferString(text)
+			parser := xml.NewParser(buf)
+			parser.Strict = false
+			parser.AutoClose = xml.HTMLAutoClose
+			parser.Entity = xml.HTMLEntity
+			for {
+				tok, err := parser.Token()
+				if err == os.EOF {
+					break
+				} else if err != nil {
+					return "", err
+				}
+
+				switch t := tok.(type) {
+				case xml.CharData:
+					out.Write(t)
+				case xml.EndElement:
+					if t.Name.Local == "p" || t.Name.Local == "br" {
+						out.WriteString("\n")
+					}
+				}
+			}
+			filtered = strings.TrimSpace(out.String())
+		}
+		if max != 0 && len(filtered) > max {
+			return "", ErrExceedsTextMessageLength
+		}
+	} else {
+		// No limits
+		if max == 0 && maximg == 0 {
+			return text, nil
+		}
+
+		// Too big for images?
+		if maximg != 0 && len(text) > maximg {
+			return "", ErrExceedsImageMessageLength
+		}
+
+		// Under max plain length?
+		if max == 0 || len(text) <= max {
+			return text, nil
+		}
+
+		// Over max length, under image limit. If text doesn't include
+		// any HTML, this is a no-go. If there is HTML, we can attempt to
+		// strip away data URIs to see if we can get the message to fit
+		// into the plain message limit.
+		if strings.Index(text, "<") == -1 {
+			return "", ErrExceedsTextMessageLength
+		}
+
+		// Simplify the received HTML data by stripping away data URIs
+		out := bytes.NewBuffer(nil)
+		buf := bytes.NewBufferString(text)
+		parser := xml.NewParser(buf)
+		parser.Strict = false
+		parser.AutoClose = xml.HTMLAutoClose
+		parser.Entity = xml.HTMLEntity
+		for {
+			tok, err := parser.Token()
+			if err == os.EOF {
+				break
+			} else if err != nil {
+				return "", err
+			}
+
+			switch t := tok.(type) {
+			case xml.CharData:
+				out.Write(t)
+			case xml.StartElement:
+				out.WriteString("<")
+				xml.Escape(out, []byte(t.Name.Local))
+				for _, attr := range t.Attr {
+					if t.Name.Local == "img" && attr.Name.Local == "src" {
+						continue
+					}
+					out.WriteString(" ")
+					xml.Escape(out, []byte(attr.Name.Local))
+					out.WriteString(`="`)
+					out.WriteString(attr.Value)
+					out.WriteString(`"`)
+				}
+				out.WriteString(">")
+			case xml.EndElement:
+				out.WriteString("</")
+				xml.Escape(out, []byte(t.Name.Local))
+				out.WriteString(">")
+			}
+		}
+
+		filtered = strings.TrimSpace(out.String())
+		if len(filtered) > max {
+			return "", ErrExceedsTextMessageLength
+		}
+	}
+
+	return
+}

server.go

@@ -24,6 +24,7 @@ import (
 	"grumble/ban"
 	"grumble/blobstore"
 	"grumble/cryptstate"
+	"grumble/htmlfilter"
 	"grumble/serverconf"
 	"grumble/sessionpool"
 	"hash"
@@ -31,7 +32,6 @@ import (
 	"path/filepath"
 	"strings"
 	"time"
-	"xml"
 )
 
 // The default port a Murmur server listens on
@@ -172,11 +172,11 @@ func NewServer(id int64, addr string, port int) (s *Server, err os.Error) {
 
 // Get a pointer to the root channel
 func (server *Server) RootChannel() *Channel {
-	 root, exists := server.Channels[0]
+	root, exists := server.Channels[0]
-	 if !exists {
+	if !exists {
-		 server.Fatalf("Not Root channel found for server")
+		server.Fatalf("Not Root channel found for server")
-	 }
+	}
-	 return root
+	return root
 }
 
 // Set password as the new SuperUser password
@@ -1193,125 +1193,12 @@ func (server *Server) IsBanned(conn net.Conn) bool {
 
 // Filter incoming text according to the server's current rules.
 func (server *Server) FilterText(text string) (filtered string, err os.Error) {
-	// This function filters incoming text from clients according to three server settings:
+	options := &htmlfilter.Options{
-	//
+		StripHTML:             !server.cfg.BoolValue("AllowHTML"),
-	// AllowHTML:
+		MaxTextMessageLength:  server.cfg.IntValue("MaxTextMessageLength"),
-	//    If false, all HTML shall be stripped.
+		MaxImageMessageLength: server.cfg.IntValue("MaxImageMessageLength"),
-	//    When stripping br tags, append a newline to the output stream.
-	//    When stripping p tags, append a newline after the end tag.
-	//
-	// MaxTextMessageLength:
-	//    Text length for "plain" messages (messages without images)
-	//
-	// MaxImageTextMessageLength:
-	//    Text length for messages with images.
-
-	max := server.cfg.IntValue("MaxTextMessageLength")
-	maximg := server.cfg.IntValue("MaxImageMessageLength")
-
-	if !server.cfg.BoolValue("AllowHTML") {
-		if strings.Index(text, "<") == -1 {
-			filtered = strings.TrimSpace(text)
-		} else {
-			// Strip away all HTML
-			out := bytes.NewBuffer(nil)
-			buf := bytes.NewBufferString(text)
-			parser := xml.NewParser(buf)
-			parser.Strict = false
-			parser.AutoClose = xml.HTMLAutoClose
-			parser.Entity = xml.HTMLEntity
-			for {
-				tok, err := parser.Token()
-				if err == os.EOF {
-					break
-				} else if err != nil {
-					return "", err
-				}
-
-				switch t := tok.(type) {
-				case xml.CharData:
-					out.Write(t)
-				case xml.EndElement:
-					if t.Name.Local == "p" || t.Name.Local == "br" {
-						out.WriteString("\n")
-					}
-				}
-			}
-			filtered = strings.TrimSpace(out.String())
-		}
-		if max != 0 && len(filtered) > max {
-			return "", os.NewError("Message exceeds max length")
-		}
-	} else {
-		// No limits
-		if max == 0 && maximg == 0 {
-			return text, nil
-		}
-
-		// Too big for images?
-		if maximg != 0 && len(text) > maximg {
-			return "", os.NewError("Message exceeds max image message length")
-		}
-
-		// Under max plain length?
-		if max == 0 || len(text) <= max {
-			return text, nil
-		}
-
-		// Over max length, under image limit. If text doesn't include
-		// any HTML, this is a no-go. If there is XML, we can attempt to
-		// strip away data URIs to see if we can get the message to fit
-		// into the plain message limit.
-		if strings.Index(text, "<") == -1 {
-			return "", os.NewError("Over plain length")
-		}
-
-		// Simplify the received HTML data by stripping away data URIs
-		out := bytes.NewBuffer(nil)
-		buf := bytes.NewBufferString(text)
-		parser := xml.NewParser(buf)
-		parser.Strict = false
-		parser.AutoClose = xml.HTMLAutoClose
-		parser.Entity = xml.HTMLEntity
-		for {
-			tok, err := parser.Token()
-			if err == os.EOF {
-				break
-			} else if err != nil {
-				return "", err
-			}
-
-			switch t := tok.(type) {
-			case xml.CharData:
-				out.Write(t)
-			case xml.StartElement:
-				out.WriteString("<")
-				xml.Escape(out, []byte(t.Name.Local))
-				for _, attr := range t.Attr {
-					if t.Name.Local == "img" && attr.Name.Local == "src" {
-						continue
-					}
-					out.WriteString(" ")
-					xml.Escape(out, []byte(attr.Name.Local))
-					out.WriteString(`="`)
-					out.WriteString(attr.Value)
-					out.WriteString(`"`)
-				}
-				out.WriteString(">")
-			case xml.EndElement:
-				out.WriteString("</")
-				xml.Escape(out, []byte(t.Name.Local))
-				out.WriteString(">")
-			}
-		}
-
-		filtered = strings.TrimSpace(out.String())
-		if len(filtered) > max {
-			return "", os.NewError("Data URI stripped message longer than max length")
-		}
 	}
-
+	return htmlfilter.Filter(text, options)
-	return
 }
 
 // The accept loop of the server.