Fix logging again.

On second thought instead of using log.Panicf(), panic() and do the
logging with recover().  This somewhat centralizes logging in
obfs4proxy, which will be easier to change when I invariably decide to
do logging differently in the future.

6 files changed, 31 insertions, 24 deletions

diff --git a/framing/framing.go b/framing/framing.go
index 75b9a73..62170ae 100644
--- a/framing/framing.go
+++ b/framing/framing.go
@@ -61,7 +61,6 @@ import (
 	"errors"
 	"fmt"
 	"hash"
-	"log"
 
 	"code.google.com/p/go.crypto/nacl/secretbox"
 
@@ -127,7 +126,7 @@ type boxNonce struct {
 
 func (nonce *boxNonce) init(prefix []byte) {
 	if noncePrefixLength != len(prefix) {
-		log.Panicf("BUG: Nonce prefix length invalid: %d", len(prefix))
+		panic(fmt.Sprintf("BUG: Nonce prefix length invalid: %d", len(prefix)))
 	}
 
 	copy(nonce.prefix[:], prefix)
@@ -161,7 +160,7 @@ type Encoder struct {
 // containing exactly KeyLength bytes of keying material.
 func NewEncoder(key []byte) *Encoder {
 	if len(key) != KeyLength {
-		log.Panicf("BUG: Invalid encoder key length: %d", len(key))
+		panic(fmt.Sprintf("BUG: Invalid encoder key length: %d", len(key)))
 	}
 
 	encoder := new(Encoder)
@@ -223,7 +222,7 @@ type Decoder struct {
 // containing exactly KeyLength bytes of keying material.
 func NewDecoder(key []byte) *Decoder {
 	if len(key) != KeyLength {
-		log.Panicf("BUG: Invalid decoder key length: %d", len(key))
+		panic(fmt.Sprintf("BUG: Invalid decoder key length: %d", len(key)))
 	}
 
 	decoder := new(Decoder)
@@ -253,7 +252,7 @@ func (decoder *Decoder) Decode(data *bytes.Buffer) (int, []byte, error) {
 			return 0, nil, err
 		} else if n != lengthLength {
 			// Should *NEVER* happen, since at least 2 bytes exist.
-			log.Panicf("BUG: Failed to read obfuscated length: %d", n)
+			panic(fmt.Sprintf("BUG: Failed to read obfuscated length: %d", n))
 		}
 
 		// Derive the nonce the peer used.
@@ -285,8 +284,8 @@ func (decoder *Decoder) Decode(data *bytes.Buffer) (int, []byte, error) {
 		return 0, nil, err
 	} else if n != int(decoder.nextLength) {
 		// Should *NEVER* happen, since at least 2 bytes exist.
-		log.Panicf("BUG: Failed to read secretbox, got %d, should have %d", n,
-			decoder.nextLength)
+		panic(fmt.Sprintf("BUG: Failed to read secretbox, got %d, should have %d",
+						  n, decoder.nextLength))
 	}
 	out, ok := secretbox.Open(nil, box, &decoder.nextNonce, &decoder.key)
 	if !ok {
diff --git a/ntor/ntor.go b/ntor/ntor.go
index b19c4a1..9dbed7f 100644
--- a/ntor/ntor.go
+++ b/ntor/ntor.go
@@ -45,7 +45,6 @@ import (
 	"encoding/base64"
 	"fmt"
 	"io"
-	"log"
 
 	"code.google.com/p/go.crypto/curve25519"
 	"code.google.com/p/go.crypto/hkdf"
@@ -422,9 +421,9 @@ func Kdf(keySeed []byte, okmLen int) []byte {
 	okm := make([]byte, okmLen)
 	n, err := io.ReadFull(kdf, okm)
 	if err != nil {
-		log.Panicf("BUG: Failed HKDF: %s", err.Error())
+		panic(fmt.Sprintf("BUG: Failed HKDF: %s", err.Error()))
 	} else if n != len(okm) {
-		log.Panicf("BUG: Got truncated HKDF output: %d", n)
+		panic(fmt.Sprintf("BUG: Got truncated HKDF output: %d", n))
 	}
 
 	return okm
diff --git a/obfs4.go b/obfs4.go
index dae40bd..e69c7b7 100644
--- a/obfs4.go
+++ b/obfs4.go
@@ -30,7 +30,7 @@ package obfs4
 
 import (
 	"bytes"
-	"log"
+	"fmt"
 	"net"
 	"syscall"
 	"time"
@@ -98,7 +98,7 @@ func (c *Obfs4Conn) closeAfterDelay() {
 
 func (c *Obfs4Conn) clientHandshake(nodeID *ntor.NodeID, publicKey *ntor.PublicKey) error {
 	if c.isServer {
-		log.Panicf("BUG: clientHandshake() called for server connection")
+		panic(fmt.Sprintf("BUG: clientHandshake() called for server connection"))
 	}
 
 	// Generate/send the client handshake.
@@ -156,7 +156,7 @@ func (c *Obfs4Conn) clientHandshake(nodeID *ntor.NodeID, publicKey *ntor.PublicK
 
 func (c *Obfs4Conn) serverHandshake(nodeID *ntor.NodeID, keypair *ntor.Keypair) error {
 	if !c.isServer {
-		log.Panicf("BUG: serverHandshake() called for client connection")
+		panic(fmt.Sprintf("BUG: serverHandshake() called for client connection"))
 	}
 
 	hs := newServerHandshake(nodeID, keypair)
@@ -220,7 +220,7 @@ func (c *Obfs4Conn) ServerHandshake() error {
 
 	// Clients handshake as part of Dial.
 	if !c.isServer {
-		log.Panicf("BUG: ServerHandshake() called for client connection")
+		panic(fmt.Sprintf("BUG: ServerHandshake() called for client connection"))
 	}
 
 	// Regardless of what happens, don't need the listener past returning from
@@ -297,7 +297,7 @@ func (c *Obfs4Conn) Write(b []byte) (int, error) {
 			c.isOk = false
 			return nSent, err
 		} else if n == 0 {
-			log.Panicf("BUG: Write(), chopping length was 0")
+			panic(fmt.Sprintf("BUG: Write(), chopping length was 0"))
 		}
 		nSent += n
 
diff --git a/obfs4proxy/obfs4proxy.go b/obfs4proxy/obfs4proxy.go
index 34027fc..42a6740 100644
--- a/obfs4proxy/obfs4proxy.go
+++ b/obfs4proxy/obfs4proxy.go
@@ -75,28 +75,37 @@ var ptListeners []net.Listener
 // ends, -1 is written.
 var handlerChan = make(chan int)
 
+func logAndRecover() {
+	if err := recover(); err != nil {
+		log.Println("[ERROR] Panic:", err)
+	}
+}
+
 func copyLoop(a, b net.Conn) {
 	var wg sync.WaitGroup
 	wg.Add(2)
 
-	// XXX: Log/propagate errors.
 	go func() {
+		defer logAndRecover()
+		defer wg.Done()
+
 		_, err := io.Copy(b, a)
 		if err != nil {
 			b.Close()
 			a.Close()
 			log.Printf("[WARN] Connection closed: %s", err)
 		}
-		wg.Done()
 	}()
 	go func() {
+		defer logAndRecover()
+		defer wg.Done()
+
 		_, err := io.Copy(a, b)
 		if err != nil {
 			a.Close()
 			b.Close()
 			log.Printf("[WARN] Connection closed: %s", err)
 		}
-		wg.Done()
 	}()
 
 	wg.Wait()
@@ -104,6 +113,7 @@ func copyLoop(a, b net.Conn) {
 
 func serverHandler(conn net.Conn, info *pt.ServerInfo) error {
 	defer conn.Close()
+	defer logAndRecover()
 
 	handlerChan <- 1
 	defer func() {
@@ -216,6 +226,7 @@ func clientHandler(conn *pt.SocksConn) error {
 		handlerChan <- -1
 	}()
 
+	defer logAndRecover()
 	remote, err := obfs4.Dial("tcp", conn.Req.Target, nodeID, publicKey)
 	if err != nil {
 		log.Printf("[ERROR] client: Handshake failed: %s", err)
diff --git a/packet.go b/packet.go
index 98ce426..afccc47 100644
--- a/packet.go
+++ b/packet.go
@@ -30,7 +30,6 @@ package obfs4
 import (
 	"encoding/binary"
 	"fmt"
-	"log"
 
 	"github.com/yawning/obfs4/framing"
 )
@@ -68,8 +67,8 @@ func makePacket(pkt []byte, pktType uint8, data []byte, padLen uint16) int {
 	pktLen := packetOverhead + len(data) + int(padLen)
 
 	if len(data)+int(padLen) > maxPacketPayloadLength {
-		log.Panicf("BUG: makePacket() len(data) + padLen > maxPacketPayloadLength: %d + %d > %d",
-			len(data), padLen, maxPacketPayloadLength)
+		panic(fmt.Sprintf("BUG: makePacket() len(data) + padLen > maxPacketPayloadLength: %d + %d > %d",
+			len(data), padLen, maxPacketPayloadLength))
 	}
 
 	// Packets are:
@@ -104,7 +103,6 @@ func (c *Obfs4Conn) decodePacket(pkt []byte) error {
 		c.receiveDecodedBuffer.Write(payload)
 	default:
 		// Ignore unrecognised packet types.
-		log.Printf("[INFO] - Ignoring packet type: %d", pktType)
 	}
 
 	return nil
diff --git a/utils.go b/utils.go
index f8a394a..ae7bc41 100644
--- a/utils.go
+++ b/utils.go
@@ -29,13 +29,13 @@ package obfs4
 
 import (
 	"crypto/rand"
-	"log"
+	"fmt"
 	"math/big"
 )
 
 func randRange(min, max int64) (int64, error) {
 	if max < min {
-		log.Panicf("randRange: min > max (%d, %d)", min, max)
+		panic(fmt.Sprintf("randRange: min > max (%d, %d)", min, max))
 	}
 
 	r := (max + 1) - min