Prevent SetDeadline, SetReadDeadline and SetWriteDeadline from setting up unlimited deadline, and also impose our own timeout retry mechanism.

application/network/conn.go

@@ -0,0 +1,26 @@
+// Sshwifty - A Web SSH client
+//
+// Copyright (C) 2019 Rui NI <nirui@gmx.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package network
+
+import (
+	"time"
+)
+
+var (
+	emptyTime = time.Time{}
+)

application/network/conn_timeout.go

@@ -0,0 +1,221 @@
+// Sshwifty - A Web SSH client
+//
+// Copyright (C) 2019 Rui NI <nirui@gmx.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package network
+
+import (
+	"net"
+	"time"
+)
+
+// TimeoutConn read write
+type TimeoutConn struct {
+	net.Conn
+
+	readTimeout             time.Duration
+	disableNextReadTimeout  bool
+	writeTimeout            time.Duration
+	disableNextWriteTimeout bool
+}
+
+// NewTimeoutConn creates a new TimeoutConn
+func NewTimeoutConn(
+	c net.Conn,
+	rTimeout time.Duration,
+	wTimeout time.Duration,
+) TimeoutConn {
+	return TimeoutConn{
+		Conn:                    c,
+		readTimeout:             rTimeout,
+		disableNextReadTimeout:  false,
+		writeTimeout:            wTimeout,
+		disableNextWriteTimeout: false,
+	}
+}
+
+// SetReadTimeout sets read timeout
+func (c *TimeoutConn) SetReadTimeout(t time.Duration) {
+	c.readTimeout = t
+}
+
+// SetReadDeadline sets the next read deadline
+func (c *TimeoutConn) SetReadDeadline(t time.Time) error {
+	c.disableNextReadTimeout = t.Before(time.Now())
+
+	if t.Equal(emptyTime) {
+		return c.Conn.SetReadDeadline(time.Now().Add(c.readTimeout))
+	}
+
+	return c.Conn.SetReadDeadline(t)
+}
+
+// Read reads data
+func (c *TimeoutConn) Read(b []byte) (int, error) {
+	defer func() {
+		c.disableNextReadTimeout = false
+	}()
+
+	cLen, cErr := c.Conn.Read(b)
+
+	if cErr == nil {
+		return cLen, nil
+	}
+
+	netErr, isNetErr := cErr.(net.Error)
+
+	if !isNetErr ||
+		c.disableNextReadTimeout ||
+		c.readTimeout <= 0 ||
+		!netErr.Timeout() {
+		return cLen, cErr
+	}
+
+	cErr = c.Conn.SetReadDeadline(time.Now().Add(c.readTimeout))
+
+	if cErr != nil {
+		return cLen, cErr
+	}
+
+	tryCLen, cErr := c.Conn.Read(b[cLen:])
+
+	return tryCLen + cLen, cErr
+}
+
+// SetWriteTimeout sets write timeout
+func (c *TimeoutConn) SetWriteTimeout(t time.Duration) {
+	c.writeTimeout = t
+}
+
+// SetWriteDeadline sets the next read deadline
+func (c *TimeoutConn) SetWriteDeadline(t time.Time) error {
+	c.disableNextWriteTimeout = t.Before(time.Now())
+
+	if t.Equal(emptyTime) {
+		return c.Conn.SetWriteDeadline(time.Now().Add(c.writeTimeout))
+	}
+
+	return c.Conn.SetWriteDeadline(t)
+}
+
+// Write writes data
+func (c *TimeoutConn) Write(b []byte) (int, error) {
+	defer func() {
+		c.disableNextWriteTimeout = false
+	}()
+
+	cLen, cErr := c.Conn.Write(b)
+
+	if cErr == nil {
+		return cLen, nil
+	}
+
+	netErr, isNetErr := cErr.(net.Error)
+
+	if !isNetErr ||
+		c.disableNextWriteTimeout ||
+		c.writeTimeout <= 0 ||
+		!netErr.Timeout() {
+		return cLen, cErr
+	}
+
+	cErr = c.Conn.SetWriteDeadline(time.Now().Add(c.writeTimeout))
+
+	if cErr != nil {
+		return cLen, cErr
+	}
+
+	tryCLen, cErr := c.Conn.Write(b[cLen:])
+
+	return tryCLen + cLen, cErr
+}
+
+// SetDeadline sets read and write deadline
+func (c *TimeoutConn) SetDeadline(t time.Time) error {
+	c.SetReadDeadline(t)
+	c.SetWriteDeadline(t)
+
+	return nil
+}
+
+// ReadTimeoutConn is a reader that will enforce a timeout rules
+type ReadTimeoutConn struct {
+	net.Conn
+
+	reader TimeoutConn
+}
+
+// NewReadTimeoutConn creates a ReadTimeoutConn
+func NewReadTimeoutConn(c net.Conn, timeout time.Duration) ReadTimeoutConn {
+	return ReadTimeoutConn{
+		Conn: c,
+		reader: TimeoutConn{
+			Conn:         c,
+			readTimeout:  timeout,
+			writeTimeout: 0,
+		},
+	}
+}
+
+// SetReadDeadline sets read deadline
+func (c *ReadTimeoutConn) SetReadDeadline(t time.Time) error {
+	return c.reader.SetReadDeadline(t)
+}
+
+// SetReadTimeout sets write timeout
+func (c *ReadTimeoutConn) SetReadTimeout(t time.Duration) {
+	c.reader.SetReadTimeout(t)
+}
+
+// Read writes data
+func (c ReadTimeoutConn) Read(b []byte) (int, error) {
+	return c.reader.Read(b)
+}
+
+// WriteTimeoutConn is a writer that will enforce a timeout rules onto a
+// net.Conn
+type WriteTimeoutConn struct {
+	net.Conn
+
+	writer TimeoutConn
+}
+
+// NewWriteTimeoutConn creates a WriteTimeoutConnWriter
+func NewWriteTimeoutConn(c net.Conn, timeout time.Duration) WriteTimeoutConn {
+	return WriteTimeoutConn{
+		Conn: c,
+		writer: TimeoutConn{
+			Conn:         c,
+			readTimeout:  0,
+			writeTimeout: timeout,
+		},
+	}
+}
+
+// SetWriteDeadline sets write deadline
+func (c *WriteTimeoutConn) SetWriteDeadline(t time.Time) error {
+	return c.writer.SetWriteDeadline(t)
+}
+
+// SetWriteTimeout sets write timeout
+func (c *WriteTimeoutConn) SetWriteTimeout(t time.Duration) {
+	c.writer.SetWriteTimeout(t)
+}
+
+// Write writes data
+func (c WriteTimeoutConn) Write(b []byte) (int, error) {
+	return c.writer.Write(b)
+}

application/network/dial_socks5.go

@@ -25,10 +25,6 @@ import (
 	"golang.org/x/net/proxy"
 )
 
-var (
-	emptyTime = time.Time{}
-)
-
 type socks5Dial struct {
 	net.Dialer
 }

application/server/conn.go

@@ -0,0 +1,89 @@
+// Sshwifty - A Web SSH client
+//
+// Copyright (C) 2019 Rui NI <nirui@gmx.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package server
+
+import (
+	"net"
+	"time"
+
+	"github.com/niruix/sshwifty/application/network"
+)
+
+var (
+	emptyTime = time.Time{}
+)
+
+type listener struct {
+	*net.TCPListener
+
+	readTimeout  time.Duration
+	writeTimeout time.Duration
+}
+
+func (l listener) Accept() (net.Conn, error) {
+	acc, accErr := l.TCPListener.Accept()
+
+	if accErr != nil {
+		return nil, accErr
+	}
+
+	timeoutConn := network.NewTimeoutConn(acc, l.readTimeout, l.writeTimeout)
+
+	return conn{
+		TimeoutConn:  &timeoutConn,
+		readTimeout:  l.readTimeout,
+		writeTimeout: l.writeTimeout,
+	}, nil
+}
+
+// conn is a net.Conn hack, we use it prevent the upper to alter some important
+// configuration of the connection, mainly the timeouts.
+type conn struct {
+	*network.TimeoutConn
+
+	readTimeout  time.Duration
+	writeTimeout time.Duration
+}
+
+func (c conn) normalizeTimeout(t time.Time, m time.Duration) time.Time {
+	max := time.Now().Add(m)
+
+	// You cannot set timeout that is longer than the given m
+	if t.After(max) {
+		return max
+	}
+
+	return t
+}
+
+func (c conn) SetDeadline(dl time.Time) error {
+	c.SetReadDeadline(dl)
+	c.SetWriteDeadline(dl)
+
+	return nil
+}
+
+func (c conn) SetReadDeadline(dl time.Time) error {
+	return c.TimeoutConn.SetReadDeadline(
+		c.normalizeTimeout(dl, c.readTimeout))
+}
+
+func (c conn) SetWriteDeadline(dl time.Time) error {
+	return c.TimeoutConn.SetWriteDeadline(
+		c.normalizeTimeout(dl, c.writeTimeout))
+}

application/server/server.go

@@ -26,6 +26,7 @@ import (
 	"net/http"
 	"strconv"
 	"sync"
+	"time"
 
 	"github.com/niruix/sshwifty/application/configuration"
 	"github.com/niruix/sshwifty/application/log"
@@ -111,11 +112,15 @@ func (s Server) Wait() {
 }
 
 func (s *Serving) buildListener(
-	ip string, port uint16) (*net.TCPListener, error) {
+	ip string,
+	port uint16,
+	readTimeout time.Duration,
+	writeTimeout time.Duration,
+) (listener, error) {
 	ipAddr := net.ParseIP(ip)
 
 	if ipAddr == nil {
-		return nil, ErrInvalidIPAddress
+		return listener{}, ErrInvalidIPAddress
 	}
 
 	ipPort := net.JoinHostPort(
@@ -124,10 +129,20 @@ func (s *Serving) buildListener(
 	addr, addrErr := net.ResolveTCPAddr("tcp", ipPort)
 
 	if addrErr != nil {
-		return nil, addrErr
+		return listener{}, addrErr
 	}
 
-	return net.ListenTCP("tcp", addr)
+	ll, llErr := net.ListenTCP("tcp", addr)
+
+	if llErr != nil {
+		return listener{}, llErr
+	}
+
+	return listener{
+		TCPListener:  ll,
+		readTimeout:  readTimeout,
+		writeTimeout: writeTimeout,
+	}, nil
 }
 
 // run starts the server
@@ -137,7 +152,6 @@ func (s *Serving) run(
 	closeCallback CloseCallback,
 ) error {
 	var err error
-	var ls *net.TCPListener
 
 	defer func() {
 		if err == nil || err == http.ErrServerClosed {
@@ -151,7 +165,12 @@ func (s *Serving) run(
 		closeCallback(err)
 	}()
 
-	ls, err = s.buildListener(cfg.ListenInterface, cfg.ListenPort)
+	ls, err := s.buildListener(
+		cfg.ListenInterface,
+		cfg.ListenPort,
+		cfg.ReadTimeout,
+		cfg.WriteTimeout,
+	)
 
 	if err != nil {
 		return err