status-go/vendor/github.com/marten-seemann/tcp/conn.go

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2021-10-19 13:43:41 +00:00
// Copyright 2014 Mikio Hara. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tcp
import (
"net"
"syscall"
"github.com/mikioh/tcpopt"
)
var _ net.Conn = &Conn{}
// SetOption sets a socket option.
func (c *Conn) SetOption(o tcpopt.Option) error {
if !c.ok() {
return syscall.EINVAL
}
b, err := o.Marshal()
if err != nil {
return &net.OpError{Op: "raw-control", Net: c.LocalAddr().Network(), Source: nil, Addr: c.LocalAddr(), Err: err}
}
if err := c.setOption(o.Level(), o.Name(), b); err != nil {
return &net.OpError{Op: "raw-control", Net: c.LocalAddr().Network(), Source: nil, Addr: c.LocalAddr(), Err: err}
}
return nil
}
// Option returns a socket option.
func (c *Conn) Option(level, name int, b []byte) (tcpopt.Option, error) {
if !c.ok() || len(b) == 0 {
return nil, syscall.EINVAL
}
n, err := c.option(level, name, b)
if err != nil {
return nil, &net.OpError{Op: "raw-control", Net: c.LocalAddr().Network(), Source: nil, Addr: c.LocalAddr(), Err: err}
}
o, err := tcpopt.Parse(level, name, b[:n])
if err != nil {
return nil, &net.OpError{Op: "raw-control", Net: c.LocalAddr().Network(), Source: nil, Addr: c.LocalAddr(), Err: err}
}
return o, nil
}
// Buffered returns the number of bytes that can be read from the
// underlying socket read buffer.
// It returns -1 when the platform doesn't support this feature.
func (c *Conn) Buffered() int {
if !c.ok() {
return -1
}
return c.buffered()
}
// Available returns how many bytes are unused in the underlying
// socket write buffer.
// It returns -1 when the platform doesn't support this feature.
func (c *Conn) Available() int {
if !c.ok() {
return -1
}
return c.available()
}
// OriginalDst returns an original destination address, which is an
// address not modified by intermediate entities such as network
// address and port translators inside the kernel, on the connection.
//
// Only Linux and BSD variants using PF support this feature.
func (c *Conn) OriginalDst() (net.Addr, error) {
if !c.ok() {
return nil, syscall.EINVAL
}
la := c.LocalAddr().(*net.TCPAddr)
od, err := c.originalDst(la, c.RemoteAddr().(*net.TCPAddr))
if err != nil {
return nil, &net.OpError{Op: "raw-control", Net: c.LocalAddr().Network(), Source: nil, Addr: la, Err: err}
}
return od, nil
}