Add support for "logLevel" to reduce log spam.

By default logging will be done at the "WARN" level.  Fatal
initialization errors will always be logged as long as logging
is enabled regardless of logLevel.

obfs4proxy/log.go

+/*
+ * Copyright (c) 2014, Yawning Angel <yawning at torproject dot org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package main
+
+import (
+	"fmt"
+	"log"
+	"strings"
+)
+
+const (
+	levelError = iota
+	levelWarn
+	levelInfo
+)
+
+var logLevel = levelInfo
+
+func errorf(format string, a ...interface{}) {
+	if enableLogging && logLevel >= levelError {
+		msg := fmt.Sprintf(format, a...)
+		log.Print("[ERROR]: " + msg)
+	}
+}
+
+func warnf(format string, a ...interface{}) {
+	if enableLogging && logLevel >= levelWarn {
+		msg := fmt.Sprintf(format, a...)
+		log.Print("[WARN]: " + msg)
+	}
+}
+
+func infof(format string, a ...interface{}) {
+	if enableLogging && logLevel >= levelInfo {
+		msg := fmt.Sprintf(format, a...)
+		log.Print("[INFO]: " + msg)
+	}
+}
+
+func setLogLevel(logLevelStr string) error {
+	switch strings.ToUpper(logLevelStr) {
+	case "ERROR":
+		logLevel = levelError
+
+	case "WARN":
+		logLevel = levelWarn
+
+	case "INFO":
+		logLevel = levelInfo
+
+	default:
+		return fmt.Errorf("invalid log level '%s'", logLevelStr)
+	}
+
+	return nil
+}

obfs4proxy/obfs4proxy.go

@@ -150,7 +150,7 @@ func clientSetup() (launched bool, listeners []net.Listener) {
 		go clientAcceptLoop(f, ln, ptClientProxy)
 		pt.Cmethod(name, ln.Version(), ln.Addr())
 
-		log.Printf("[INFO]: %s - registered listener: %s", name, ln.Addr())
+		infof("%s - registered listener: %s", name, ln.Addr())
 
 		listeners = append(listeners, ln)
 		launched = true
@@ -183,12 +183,12 @@ func clientHandler(f base.ClientFactory, conn *pt.SocksConn, proxyURI *url.URL)
 
 	name := f.Transport().Name()
 	addrStr := elideAddr(conn.Req.Target)
-	log.Printf("[INFO]: %s(%s) - new connection", name, addrStr)
+	infof("%s(%s) - new connection", name, addrStr)
 
 	// Deal with arguments.
 	args, err := f.ParseArgs(&conn.Req.Args)
 	if err != nil {
-		log.Printf("[ERROR]: %s(%s) - invalid arguments: %s", name, addrStr, err)
+		warnf("%s(%s) - invalid arguments: %s", name, addrStr, err)
 		conn.Reject()
 		return
 	}
@@ -202,7 +202,7 @@ func clientHandler(f base.ClientFactory, conn *pt.SocksConn, proxyURI *url.URL)
 		// the configuration phase.
 		dialer, err := proxy.FromURL(proxyURI, proxy.Direct)
 		if err != nil {
-			log.Printf("[ERROR]: %s(%s) - failed to obtain proxy dialer: %s", name, addrStr, elideError(err))
+			errorf("%s(%s) - failed to obtain proxy dialer: %s", name, addrStr, elideError(err))
 			conn.Reject()
 			return
 		}
@@ -210,7 +210,7 @@ func clientHandler(f base.ClientFactory, conn *pt.SocksConn, proxyURI *url.URL)
 	}
 	remoteConn, err := dialFn("tcp", conn.Req.Target) // XXX: Allow UDP?
 	if err != nil {
-		log.Printf("[ERROR]: %s(%s) - outgoing connection failed: %s", name, addrStr, elideError(err))
+		warnf("%s(%s) - outgoing connection failed: %s", name, addrStr, elideError(err))
 		conn.Reject()
 		return
 	}
@@ -220,21 +220,21 @@ func clientHandler(f base.ClientFactory, conn *pt.SocksConn, proxyURI *url.URL)
 	// bytes back and forth.
 	remote, err := f.WrapConn(remoteConn, args)
 	if err != nil {
-		log.Printf("[ERROR]: %s(%s) - handshake failed: %s", name, addrStr, elideError(err))
+		warnf("%s(%s) - handshake failed: %s", name, addrStr, elideError(err))
 		conn.Reject()
 		return
 	}
 	err = conn.Grant(remoteConn.RemoteAddr().(*net.TCPAddr))
 	if err != nil {
-		log.Printf("[ERROR]: %s(%s) - SOCKS grant failed: %s", name, addrStr, elideError(err))
+		warnf("%s(%s) - SOCKS grant failed: %s", name, addrStr, elideError(err))
 		return
 	}
 
 	err = copyLoop(conn, remote)
 	if err != nil {
-		log.Printf("[INFO]: %s(%s) - closed connection: %s", name, addrStr, elideError(err))
+		warnf("%s(%s) - closed connection: %s", name, addrStr, elideError(err))
 	} else {
-		log.Printf("[INFO]: %s(%s) - closed connection", name, addrStr)
+		infof("%s(%s) - closed connection", name, addrStr)
 	}
 
 	return
@@ -273,7 +273,7 @@ func serverSetup() (launched bool, listeners []net.Listener) {
 			pt.SmethodArgs(name, ln.Addr(), nil)
 		}
 
-		log.Printf("[INFO]: %s - registered listener: %s", name, elideAddr(ln.Addr().String()))
+		infof("%s - registered listener: %s", name, elideAddr(ln.Addr().String()))
 
 		listeners = append(listeners, ln)
 		launched = true
@@ -306,28 +306,28 @@ func serverHandler(f base.ServerFactory, conn net.Conn, info *pt.ServerInfo) {
 
 	name := f.Transport().Name()
 	addrStr := elideAddr(conn.RemoteAddr().String())
-	log.Printf("[INFO]: %s(%s) - new connection", name, addrStr)
+	infof("%s(%s) - new connection", name, addrStr)
 
 	// Instantiate the server transport method and handshake.
 	remote, err := f.WrapConn(conn)
 	if err != nil {
-		log.Printf("[ERROR]: %s(%s) - handshake failed: %s", name, addrStr, elideError(err))
+		warnf("%s(%s) - handshake failed: %s", name, addrStr, elideError(err))
 		return
 	}
 
 	// Connect to the orport.
 	orConn, err := pt.DialOr(info, conn.RemoteAddr().String(), name)
 	if err != nil {
-		log.Printf("[ERROR]: %s(%s) - failed to connect to ORPort: %s", name, addrStr, elideError(err))
+		errorf("%s(%s) - failed to connect to ORPort: %s", name, addrStr, elideError(err))
 		return
 	}
 	defer orConn.Close()
 
 	err = copyLoop(orConn, remote)
 	if err != nil {
-		log.Printf("[INFO]: %s(%s) - closed connection: %s", name, addrStr, elideError(err))
+		warnf("%s(%s) - closed connection: %s", name, addrStr, elideError(err))
 	} else {
-		log.Printf("[INFO]: %s(%s) - closed connection", name, addrStr)
+		infof("%s(%s) - closed connection", name, addrStr)
 	}
 
 	return
@@ -392,6 +392,7 @@ func main() {
 	// Handle the command line arguments.
 	_, execName := path.Split(os.Args[0])
 	showVer := flag.Bool("v", false, "Print version and exit")
+	logLevelStr := flag.String("logLevel", "WARN", "Log level (ERROR/WARN/INFO)")
 	flag.BoolVar(&enableLogging, "enableLogging", false, "Log to TOR_PT_STATE_LOCATION/"+obfs4proxyLogFile)
 	flag.BoolVar(&unsafeLogging, "unsafeLogging", false, "Disable the address scrubber")
 	flag.Parse()
@@ -399,6 +400,9 @@ func main() {
 	if *showVer {
 		version()
 	}
+	if err := setLogLevel(*logLevelStr); err != nil {
+		log.Fatalf("[ERROR]: failed to set log level: %s", err)
+	}
 
 	// Determine if this is a client or server, initialize logging, and finish
 	// the pt configuration.
@@ -416,10 +420,10 @@ func main() {
 		log.Fatalf("[ERROR]: %s - failed to initialize logging", execName)
 	}
 	if isClient {
-		log.Printf("[INFO]: %s - initializing client transport listeners", execName)
+		infof("%s - initializing client transport listeners", execName)
 		launched, ptListeners = clientSetup()
 	} else {
-		log.Printf("[INFO]: %s - initializing server transport listeners", execName)
+		infof("%s - initializing server transport listeners", execName)
 		launched, ptListeners = serverSetup()
 	}
 	if !launched {
@@ -428,9 +432,9 @@ func main() {
 		os.Exit(-1)
 	}
 
-	log.Printf("[INFO]: %s - launched and accepting connections", execName)
+	infof("%s - launched and accepting connections", execName)
 	defer func() {
-		log.Printf("[INFO]: %s - terminated", execName)
+		infof("%s - terminated", execName)
 	}()
 
 	// At this point, the pt config protocol is finished, and incoming