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

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)
+}