From e7ae557b9111edd5667cfdb44574da30db8dfe17 Mon Sep 17 00:00:00 2001
From: hahafool <75717694+hahahrfool@users.noreply.github.com>
Date: Thu, 21 Apr 2022 21:34:56 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E8=AE=A2=E6=96=87=E6=A1=A3,=20sockopt?=
 =?UTF-8?q?=20=E5=92=8C=20utils=E5=8C=85=E7=9A=84=E4=BB=A3=E7=A0=81.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md                       | 15 ++++----
 apiServer.go                    |  4 +--
 docs/install.md                 |  4 ++-
 netLayer/addr.go                |  4 +++
 netLayer/dial.go                |  2 +-
 netLayer/listen.go              |  4 +--
 netLayer/sockopt.go             |  4 +--
 netLayer/sockopt_linux.go       | 11 +++---
 netLayer/sockopt_other.go       |  3 +-
 netLayer/tproxy/tproxy_linux.go | 56 +++++++++++++++++++++++++++++
 netLayer/tproxy/udp_linux.go    |  2 ++
 proxy/simplesocks/server.go     |  2 +-
 proxy/socks5/server.go          |  2 +-
 proxy/trojan/server.go          |  2 +-
 proxy/vless/server.go           |  2 +-
 utils/buffers.go                |  2 +-
 utils/log.go                    |  5 +--
 utils/pool.go                   | 64 +++++++++++++++++----------------
 utils/time.go                   |  4 +--
 utils/utils.go                  |  3 +-
 utils/uuid.go                   |  5 ++-
 21 files changed, 133 insertions(+), 67 deletions(-)

diff --git a/README.md b/README.md
index c41ee53..2d73afb 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-[![GoDoc][1]][2] [![MIT licensed][3]][4] [![Go Report Card][5]][6] 
+[![GoDoc][1]][2] [![MIT licensed][3]][4] [![Go Report Card][5]][6] [![Downloads][7]][8] [![release][9]][8] ![GoVersion][10]
 
 [1]: https://godoc.org/github.com/hahahrfool/v2ray_simple?status.svg
 [2]: https://godoc.org/github.com/hahahrfool/v2ray_simple
@@ -6,6 +6,11 @@
 [4]: LICENSE
 [5]: https://goreportcard.com/badge/github.com/hahahrfool/v2ray_simple
 [6]: https://goreportcard.com/report/github.com/hahahrfool/v2ray_simple
+[7]: https://img.shields.io/github/downloads/hahahrfool/v2ray_simple/total.svg
+[8]: https://github.com/hahahrfool/v2ray_simple/releases/latest
+[9]: https://img.shields.io/github/release/hahahrfool/v2ray_simple/all.svg?style=flat-square
+[10]: https://img.shields.io/github/go-mod/go-version/hahahrfool/v2ray_simple?style=flat-square
+
 
 # verysimple
 
@@ -25,13 +30,13 @@ vs的一些亮点是 全协议readv加速，lazy技术，vless v1，hysteria 阻
 
 支持的功能有:
 
-ws(以及earlydata)/grpc/quic(以及hy阻控)/smux, 
+socks5/http/dokodemo/tproxy(透明代理)/trojan/simplesocks/vless/vless_v1, 
 
-tproxy(即透明代理)/trojan/simplesocks/vless/vless_v1/socks5/http/dokodemo, 
+ws(以及earlydata)/grpc/quic(以及hy阻控)/smux, 
 
 dns(udp/tls)/route(geoip/geosite)/fallback(path/sni/alpn), 
 
-tcp/udp/unix domain socket, uTls, lazy, http伪装头, cli/apiServer
+tcp/udp/unix domain socket, uTls, lazy, http伪装头, cli(交互模式)/apiServer
 
 
 为了不吓跑小白，目前 本 README 把安装、使用方式 放在了前面，如果你要直接阅读本作的技术介绍部分，点击跳转 -> [创新点](#创新点)
@@ -296,8 +301,6 @@ api服务器；tproxy 透明代理； http伪装头
 
 这里的v1是 verysimple 自己制定的，总是要摸着石头过河嘛。标准的讨论详见 [vless_v1](docs/vless_v1.md)
 
-在客户端的 配置url中，添加 `?version=1` 即可生效。
-
 总之，强制tls，简单修订了一下协议格式，然后重点完善了fullcone。
 
 verysimple 实现了 一种独创的 非mux型“分离信道”方法的 udp over tcp 的fullcone
diff --git a/apiServer.go b/apiServer.go
index c21e98e..a6e99d9 100644
--- a/apiServer.go
+++ b/apiServer.go
@@ -38,9 +38,7 @@ func checkConfigAndTryRunApiServer() {
 //阻塞
 func runApiServer(adminUUID string) {
 
-	if ce := utils.CanLogInfo("Start Api Server"); ce != nil {
-		ce.Write()
-	}
+	utils.Info("Start Api Server")
 
 	ser := newApiServer("admin", adminUUID)
 
diff --git a/docs/install.md b/docs/install.md
index 90f0f26..bf55a10 100644
--- a/docs/install.md
+++ b/docs/install.md
@@ -7,7 +7,7 @@
 
 下面的命令也不要整个一大段拷贝，而要分条拷贝到vps并运行。
 
-## 第〇步，准备阶段
+## 第〇步，准备
 
 首先确保自己服务器相应端口都是打开状态，防火墙要处理一下。然后安装一些BBR之类的加速组件。
 
@@ -20,6 +20,8 @@
 注意，如果你以前用过verysimple，则最好在运行前将自己配置文件先拷贝到其它地方，防止下面代码将你原来配置误删除。
 或者你可以先解压 新版verysimple可执行文件 到其他位置，然后再用 mv 覆盖掉老版本 的可执行文件 和 examples 目录。
 
+### 命令
+
 ```sh
 sudo rm -rf /usr/local/etc/verysimple
 sudo mkdir -p /usr/local/etc/verysimple
diff --git a/netLayer/addr.go b/netLayer/addr.go
index e2adb63..0e88498 100644
--- a/netLayer/addr.go
+++ b/netLayer/addr.go
@@ -292,6 +292,10 @@ func (a *Addr) IsEmpty() bool {
 	return a.Name == "" && len(a.IP) == 0 && a.Network == "" && a.Port == 0
 }
 
+func (a *Addr) IsIpv6() bool {
+	return a.IP.To4() == nil
+}
+
 func (a *Addr) GetNetIPAddr() (na netip.Addr) {
 	if len(a.IP) < 1 {
 		return
diff --git a/netLayer/dial.go b/netLayer/dial.go
index 6e81f81..3353b56 100644
--- a/netLayer/dial.go
+++ b/netLayer/dial.go
@@ -100,7 +100,7 @@ func (addr Addr) DialWithOpt(sockopt *Sockopt) (net.Conn, error) {
 	}
 	dialer.Control = func(network, address string, c syscall.RawConn) error {
 		return c.Control(func(fd uintptr) {
-			SetSockOpt(int(fd), sockopt, addr.IsUDP())
+			SetSockOpt(int(fd), sockopt, addr.IsUDP(), addr.IsIpv6())
 
 		})
 	}
diff --git a/netLayer/listen.go b/netLayer/listen.go
index e5fb9dd..679bf85 100644
--- a/netLayer/listen.go
+++ b/netLayer/listen.go
@@ -77,7 +77,7 @@ func ListenAndAccept(network, addr string, sockopt *Sockopt, acceptFunc func(net
 		}
 
 		if sockopt != nil {
-			SetSockOptForListener(tcplistener, sockopt, false)
+			SetSockOptForListener(tcplistener, sockopt, false, ta.IP.To4() == nil)
 		}
 
 		go loopAccept(tcplistener, acceptFunc)
@@ -138,7 +138,7 @@ func (addr Addr) ListenUDP_withOpt(sockopt *Sockopt) (net.PacketConn, error) {
 	var lc net.ListenConfig
 	lc.Control = func(network, address string, c syscall.RawConn) error {
 		return c.Control(func(fd uintptr) {
-			SetSockOpt(int(fd), sockopt, true)
+			SetSockOpt(int(fd), sockopt, true, addr.IsIpv6())
 		})
 	}
 	return lc.ListenPacket(context.Background(), "udp", addr.String())
diff --git a/netLayer/sockopt.go b/netLayer/sockopt.go
index 435df62..2613f25 100644
--- a/netLayer/sockopt.go
+++ b/netLayer/sockopt.go
@@ -23,13 +23,13 @@ type ConnWithFile interface {
 	File() (f *os.File, err error)
 }
 
-func SetSockOptForListener(tcplistener ListenerWithFile, sockopt *Sockopt, isudp bool) {
+func SetSockOptForListener(tcplistener ListenerWithFile, sockopt *Sockopt, isudp bool, isipv6 bool) {
 	fileDescriptorSource, err := tcplistener.File()
 	if err != nil {
 		return
 	}
 	defer fileDescriptorSource.Close()
-	SetSockOpt(int(fileDescriptorSource.Fd()), sockopt, isudp)
+	SetSockOpt(int(fileDescriptorSource.Fd()), sockopt, isudp, isipv6)
 }
 
 //SetSockOpt 是平台相关的.
diff --git a/netLayer/sockopt_linux.go b/netLayer/sockopt_linux.go
index c6555be..0fa6134 100644
--- a/netLayer/sockopt_linux.go
+++ b/netLayer/sockopt_linux.go
@@ -5,7 +5,7 @@ import (
 	"syscall"
 )
 
-func SetSockOpt(fd int, sockopt *Sockopt, isudp bool) {
+func SetSockOpt(fd int, sockopt *Sockopt, isudp bool, isipv6 bool) {
 	if sockopt == nil {
 		return
 	}
@@ -18,7 +18,7 @@ func SetSockOpt(fd int, sockopt *Sockopt, isudp bool) {
 		setTproxy(int(fd))
 
 		if isudp {
-			setTproxy_udp(int(fd))
+			setTproxy_udp(int(fd), isipv6)
 		}
 	}
 
@@ -28,12 +28,15 @@ func setTproxy(fd int) error {
 	return syscall.SetsockoptInt(fd, syscall.SOL_IP, syscall.IP_TRANSPARENT, 1)
 }
 
-func setTproxy_udp(fd int) error {
+func setTproxy_udp(fd int, isipv6 bool) error {
 	err1 := syscall.SetsockoptInt(fd, syscall.SOL_IP, syscall.IP_RECVORIGDSTADDR, 1)
 	if err1 != nil {
 		return err1
 	}
-	return syscall.SetsockoptInt(int(fd), syscall.SOL_IPV6, unix.IPV6_RECVORIGDSTADDR, 1)
+	if isipv6 {
+		return syscall.SetsockoptInt(int(fd), syscall.SOL_IPV6, unix.IPV6_RECVORIGDSTADDR, 1)
+	}
+	return nil
 }
 
 func setSomark(fd int, somark int) error {
diff --git a/netLayer/sockopt_other.go b/netLayer/sockopt_other.go
index f8fbcf2..a34b6b8 100644
--- a/netLayer/sockopt_other.go
+++ b/netLayer/sockopt_other.go
@@ -3,6 +3,5 @@
 
 package netLayer
 
-func SetSockOpt(fd int, sockopt *Sockopt, isudp bool) {
-
+func SetSockOpt(fd int, sockopt *Sockopt, isudp bool, isipv6 bool) {
 }
diff --git a/netLayer/tproxy/tproxy_linux.go b/netLayer/tproxy/tproxy_linux.go
index a549d01..710049c 100644
--- a/netLayer/tproxy/tproxy_linux.go
+++ b/netLayer/tproxy/tproxy_linux.go
@@ -35,6 +35,62 @@ https://github.com/FarFetchd/simple_tproxy_example/blob/master/tproxy_captive_po
 同时，trojan-go还使用了
 https://github.com/cybozu-go/transocks/blob/master/original_dst_linux.go
 
+Iptables
+
+iptables配置教程：
+https://toutyrater.github.io/app/tproxy.html
+
+下面把该教程的重要部分搬过来。
+
+
+	ip rule add fwmark 1 table 100
+	ip route add local 0.0.0.0/0 dev lo table 100
+
+	iptables -t mangle -N V2RAY
+	iptables -t mangle -A V2RAY -d 127.0.0.1/32 -j RETURN
+	iptables -t mangle -A V2RAY -d 224.0.0.0/4 -j RETURN
+	iptables -t mangle -A V2RAY -d 255.255.255.255/32 -j RETURN
+	iptables -t mangle -A V2RAY -d 192.168.0.0/16 -p tcp -j RETURN
+	iptables -t mangle -A V2RAY -d 192.168.0.0/16 -p udp ! --dport 53 -j RETURN
+	iptables -t mangle -A V2RAY -p udp -j TPROXY --on-port 12345 --tproxy-mark 1
+	iptables -t mangle -A V2RAY -p tcp -j TPROXY --on-port 12345 --tproxy-mark 1
+	iptables -t mangle -A PREROUTING -j V2RAY
+
+	iptables -t mangle -N V2RAY_MASK
+	iptables -t mangle -A V2RAY_MASK -d 224.0.0.0/4 -j RETURN
+	iptables -t mangle -A V2RAY_MASK -d 255.255.255.255/32 -j RETURN
+	iptables -t mangle -A V2RAY_MASK -d 192.168.0.0/16 -p tcp -j RETURN
+	iptables -t mangle -A V2RAY_MASK -d 192.168.0.0/16 -p udp ! --dport 53 -j RETURN
+	iptables -t mangle -A V2RAY_MASK -j RETURN -m mark --mark 0xff
+	iptables -t mangle -A V2RAY_MASK -p udp -j MARK --set-mark 1
+	iptables -t mangle -A V2RAY_MASK -p tcp -j MARK --set-mark 1
+	iptables -t mangle -A OUTPUT -j V2RAY_MASK # 应用规则
+
+
+Persistant iptables
+
+单独设置iptables，重启后会消失. 下面是持久化方法
+
+	mkdir -p /etc/iptables && iptables-save > /etc/iptables/rules.v4
+
+	vi /etc/systemd/system/tproxyrule.service
+
+	[Unit]
+	Description=Tproxy rule
+	After=network.target
+	Wants=network.target
+
+	[Service]
+
+	Type=oneshot
+	ExecStart=/sbin/ip rule add fwmark 1 table 100 ; /sbin/ip route add local 0.0.0.0/0 dev lo table 100 ; /sbin/iptables-restore /etc/iptables/rules.v4
+
+	[Install]
+	WantedBy=multi-user.target
+
+
+	systemctl enable tproxyrule
+
 */
 package tproxy
 
diff --git a/netLayer/tproxy/udp_linux.go b/netLayer/tproxy/udp_linux.go
index a0e8f08..fe4a88f 100644
--- a/netLayer/tproxy/udp_linux.go
+++ b/netLayer/tproxy/udp_linux.go
@@ -11,6 +11,8 @@ import (
 	"unsafe"
 )
 
+//credit: https://github.com/LiamHaworth/go-tproxy/blob/master/tproxy_udp.go ,  which is under MIT License
+
 // ListenUDP will construct a new UDP listener
 // socket with the Linux IP_TRANSPARENT option
 // set on the underlying socket
diff --git a/proxy/simplesocks/server.go b/proxy/simplesocks/server.go
index 5477aa6..bf0cf52 100644
--- a/proxy/simplesocks/server.go
+++ b/proxy/simplesocks/server.go
@@ -45,7 +45,7 @@ func (s *Server) Handshake(underlay net.Conn) (result net.Conn, msgConn netLayer
 	}
 	defer underlay.SetReadDeadline(time.Time{})
 
-	readbs := utils.GetBytes(utils.StandardBytesLength)
+	readbs := utils.GetBytes(utils.MTU)
 
 	wholeReadLen, err := underlay.Read(readbs)
 	if err != nil {
diff --git a/proxy/socks5/server.go b/proxy/socks5/server.go
index 13311dd..b69032a 100644
--- a/proxy/socks5/server.go
+++ b/proxy/socks5/server.go
@@ -276,7 +276,7 @@ func (u *ServerUDPConn) ReadMsgFrom() ([]byte, netLayer.Addr, error) {
 		if !addr.IP.Equal(u.clientSupposedAddr.IP) || addr.Port != u.clientSupposedAddr.Port {
 
 			//just random attack message.
-			return nil, netLayer.Addr{}, utils.ErrInErr{ErrDesc: "socks5 UDPConn ReadMsg failed, addr not comming from supposed client addr", ErrDetail: utils.ErrInvalidData, Data: addr.String()}
+			return nil, netLayer.Addr{}, utils.ErrInErr{ErrDesc: "socks5 UDPConn ReadMsg failed, addr not coming from supposed client addr", ErrDetail: utils.ErrInvalidData, Data: addr.String()}
 
 		}
 	}
diff --git a/proxy/trojan/server.go b/proxy/trojan/server.go
index 479448e..bcf6fb2 100644
--- a/proxy/trojan/server.go
+++ b/proxy/trojan/server.go
@@ -66,7 +66,7 @@ func (s *Server) Handshake(underlay net.Conn) (result net.Conn, msgConn netLayer
 	}
 	defer underlay.SetReadDeadline(time.Time{})
 
-	readbs := utils.GetBytes(utils.StandardBytesLength)
+	readbs := utils.GetBytes(utils.MTU)
 
 	wholeReadLen, err := underlay.Read(readbs)
 	if err != nil {
diff --git a/proxy/vless/server.go b/proxy/vless/server.go
index db7c99c..9c1456f 100644
--- a/proxy/vless/server.go
+++ b/proxy/vless/server.go
@@ -142,7 +142,7 @@ func (s *Server) Handshake(underlay net.Conn) (result net.Conn, msgConn netLayer
 	// 因此v1.0.3以及更老版本都是直接一段一段read的。
 	//但是，因为需要支持fallback技术，所以还是要 进行缓存
 
-	readbs := utils.GetBytes(utils.StandardBytesLength)
+	readbs := utils.GetBytes(utils.MTU)
 
 	wholeReadLen, err := underlay.Read(readbs)
 	if err != nil {
diff --git a/utils/buffers.go b/utils/buffers.go
index 55ab627..c82970a 100644
--- a/utils/buffers.go
+++ b/utils/buffers.go
@@ -133,7 +133,7 @@ func MergeBuffers(bs [][]byte) (result []byte, duplicate bool) {
 		return b0, false
 	}
 
-	if allLen <= MaxBufLen {
+	if allLen <= MaxPacketLen {
 		result = GetPacket()
 
 	} else {
diff --git a/utils/log.go b/utils/log.go
index f7b890e..f846151 100644
--- a/utils/log.go
+++ b/utils/log.go
@@ -25,8 +25,6 @@ const (
 
 // LogLevel 值越小越唠叨, 废话越多，值越大打印的越少，见log_开头的常量;
 //
-// 默认是 info级别.因为还在开发中，所以默认级别高一些有好处，方便排错
-//
 //我们的loglevel具体值 与 zap的 loglevel+1 的含义等价
 var (
 	LogLevel  int
@@ -109,7 +107,7 @@ func InitLog() {
 
 	if ShouldLogToFile && LogOutFileName != "" {
 		jsonConf := zap.NewProductionEncoderConfig()
-		jsonConf.EncodeTime = zapcore.TimeEncoderOfLayout("060102 150405.000") //用一种比较简短的方式输出时间,年月日 时分秒.毫秒。 年分只需输出后两位数字即可, 不管Y2K问题, 80年后要是还没实现网络自由那这个世界完蛋了.
+		jsonConf.EncodeTime = zapcore.TimeEncoderOfLayout("060102 150405.000") //用一种比较简短的方式输出时间,年月日 时分秒.毫秒。 年只需输出后两位数字即可, 不管Y2K问题, 80年后要是还没实现网络自由那这个世界完蛋了.
 		jsonConf.LevelKey = "L"
 		jsonConf.TimeKey = "T"
 		jsonConf.MessageKey = "M"
@@ -123,7 +121,6 @@ func InitLog() {
 
 	}
 
-	//zap.NewDevelopmentEncoderConfig()
 	ZapLogger.Info("zap log init complete.")
 }
 
diff --git a/utils/pool.go b/utils/pool.go
index 8dee7e6..b404ca7 100644
--- a/utils/pool.go
+++ b/utils/pool.go
@@ -6,43 +6,47 @@ import (
 )
 
 var (
-	standardBytesPool sync.Pool //专门储存 长度为 StandardBytesLength 的 []byte
+	mtuPool sync.Pool //专门储存 长度为 MTU 的 []byte
 
-	// 作为参考对比，tcp默认是 16384, 16k，实际上范围是1k～128k之间
-	// 而 udp则最大还不到 64k。(65535－20－8)
-	// io.Copy 内部默认buffer大小为 32k
+	// packetPool 专门储存 长度为 MaxPacketLen 的 []byte
+	//
+	// 参考对比: tcp默认是 16k，范围是1k～128k;
+	// 而 udp则最大还不到 64k (65535－20－8);
+	// io.Copy 内部默认buffer大小为 32k;
 	// 总之 我们64k已经够了
-	standardPacketPool sync.Pool // 专门储存 长度为 MaxBufLen 的 []byte
+	packetPool sync.Pool
 
 	bufPool sync.Pool //储存 *bytes.Buffer
 )
 
-//即MTU, Maximum transmission unit, 参照的是 Ethernet v2 的MTU;
-const StandardBytesLength int = 1500
+const (
+	//即 Maximum transmission unit, 参照的是 Ethernet v2 的MTU;
+	MTU int = 1500
 
-//注意wifi信号MTU是 2304，我们并未考虑wifi,主要是因为就算用wifi传, 早晚还是要经过以太网,除非两个wifi设备互传
-// https://en.wikipedia.org/wiki/Maximum_transmission_unit
+	//注意wifi信号MTU是 2304，我们并未考虑wifi,主要是因为就算用wifi传, 早晚还是要经过以太网,除非两个wifi设备互传
+	// https://en.wikipedia.org/wiki/Maximum_transmission_unit
 
-//本作设定的最大buf大小，64k
-const MaxBufLen = 64 * 1024
+	//本作设定的最大包 长度大小，64k
+	MaxPacketLen = 64 * 1024
+)
 
 func init() {
 
-	standardBytesPool = sync.Pool{
+	mtuPool = sync.Pool{
 		New: func() interface{} {
-			return make([]byte, StandardBytesLength)
+			return make([]byte, MTU)
 		},
 	}
 
-	standardPacketPool = sync.Pool{
+	packetPool = sync.Pool{
 		New: func() interface{} {
-			return make([]byte, MaxBufLen)
+			return make([]byte, MaxPacketLen)
 		},
 	}
 
 	bufPool = sync.Pool{
 		New: func() interface{} {
-			return &bytes.Buffer{}
+			return new(bytes.Buffer)
 		},
 	}
 }
@@ -60,31 +64,31 @@ func PutBuf(buf *bytes.Buffer) {
 
 //建议在 Read net.Conn 时, 使用 GetPacket函数 获取到足够大的 []byte（MaxBufLen）
 func GetPacket() []byte {
-	return standardPacketPool.Get().([]byte)
+	return packetPool.Get().([]byte)
 }
 
 // 放回用 GetPacket 获取的 []byte
 func PutPacket(bs []byte) {
 	c := cap(bs)
-	if c < MaxBufLen {
-		if c >= StandardBytesLength {
-			standardBytesPool.Put(bs[:StandardBytesLength])
+	if c < MaxPacketLen {
+		if c >= MTU {
+			mtuPool.Put(bs[:MTU])
 		}
 		return
 	}
 
-	standardPacketPool.Put(bs[:MaxBufLen])
+	packetPool.Put(bs[:MaxPacketLen])
 }
 
-// 从Pool中获取一个 StandardBytesLength 长度的 []byte
+// 从Pool中获取一个 MTU 长度的 []byte
 func GetMTU() []byte {
-	return standardBytesPool.Get().([]byte)
+	return mtuPool.Get().([]byte)
 }
 
 // 从pool中获取 []byte, 根据给出长度不同，来源于的Pool会不同.
 func GetBytes(size int) []byte {
-	if size <= StandardBytesLength {
-		bs := standardBytesPool.Get().([]byte)
+	if size <= MTU {
+		bs := mtuPool.Get().([]byte)
 		return bs[:size]
 	}
 
@@ -95,12 +99,12 @@ func GetBytes(size int) []byte {
 // 根据bs长度 选择放入各种pool中, 只有 cap(bs)>=1500 才会被处理
 func PutBytes(bs []byte) {
 	c := cap(bs)
-	if c < StandardBytesLength {
+	if c < MTU {
 
 		return
-	} else if c >= StandardBytesLength && c < MaxBufLen {
-		standardBytesPool.Put(bs[:StandardBytesLength])
-	} else if c >= MaxBufLen {
-		standardPacketPool.Put(bs[:MaxBufLen])
+	} else if c >= MTU && c < MaxPacketLen {
+		mtuPool.Put(bs[:MTU])
+	} else if c >= MaxPacketLen {
+		packetPool.Put(bs[:MaxPacketLen])
 	}
 }
diff --git a/utils/time.go b/utils/time.go
index f19ad31..a626144 100644
--- a/utils/time.go
+++ b/utils/time.go
@@ -12,12 +12,12 @@ import (
 func fixAndroidTimezone() {
 	out, err := exec.Command("/system/bin/getprop", "persist.sys.timezone").Output()
 	if err != nil {
-		log.Println("fixAndroidTimezone failed", err)
+		log.Println("fixAndroidTimezone failed when calling /system/bin/getprop,", err)
 		return
 	}
 	z, err := time.LoadLocation(strings.TrimSpace(string(out)))
 	if err != nil {
-		log.Println("fixAndroidTimezone failed", err)
+		log.Println("fixAndroidTimezone failed,", err)
 		return
 	}
 	time.Local = z
diff --git a/utils/utils.go b/utils/utils.go
index d1e59fa..0484dea 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -2,7 +2,6 @@
 package utils
 
 import (
-	"errors"
 	"flag"
 	"math/rand"
 	"strings"
@@ -78,6 +77,6 @@ func WrapFuncForPromptUI(f func(string) bool) func(string) error {
 		if f(s) {
 			return nil
 		}
-		return errors.New("not valid")
+		return ErrInvalidData
 	}
 }
diff --git a/utils/uuid.go b/utils/uuid.go
index 5c5c36c..b827e93 100644
--- a/utils/uuid.go
+++ b/utils/uuid.go
@@ -3,17 +3,16 @@ package utils
 import (
 	"crypto/rand"
 	"encoding/hex"
-	"errors"
 	"strings"
 )
 
 func StrToUUID(s string) (uuid [16]byte, err error) {
 	if len(s) != 36 {
-		return uuid, errors.New("invalid UUID Str: " + s)
+		return uuid, ErrInErr{ErrDesc: "invalid UUID Str", ErrDetail: ErrInvalidData, Data: s}
 	}
 	b := []byte(strings.Replace(s, "-", "", -1))
 	if len(b) != 32 {
-		return uuid, errors.New("invalid UUID Str: " + s)
+		return uuid, ErrInErr{ErrDesc: "invalid UUID Str", ErrDetail: ErrInvalidData, Data: s}
 	}
 	_, err = hex.Decode(uuid[:], b)
 	return