mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-08 20:55:01 +00:00
250 lines
7.9 KiB
Go
250 lines
7.9 KiB
Go
// Copyright 2010 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
|
|
|
|
package net
|
|
|
|
import (
|
|
"syscall"
|
|
"time"
|
|
)
|
|
|
|
// BUG(mikio): On every POSIX platform, reads from the "ip4" network
|
|
// using the ReadFrom or ReadFromIP method might not return a complete
|
|
// IPv4 packet, including its header, even if there is space
|
|
// available. This can occur even in cases where Read or ReadMsgIP
|
|
// could return a complete packet. For this reason, it is recommended
|
|
// that you do not uses these methods if it is important to receive a
|
|
// full packet.
|
|
//
|
|
// The Go 1 compatibility guidelines make it impossible for us to
|
|
// change the behavior of these methods; use Read or ReadMsgIP
|
|
// instead.
|
|
|
|
func sockaddrToIP(sa syscall.Sockaddr) Addr {
|
|
switch sa := sa.(type) {
|
|
case *syscall.SockaddrInet4:
|
|
return &IPAddr{IP: sa.Addr[0:]}
|
|
case *syscall.SockaddrInet6:
|
|
return &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (a *IPAddr) family() int {
|
|
if a == nil || len(a.IP) <= IPv4len {
|
|
return syscall.AF_INET
|
|
}
|
|
if a.IP.To4() != nil {
|
|
return syscall.AF_INET
|
|
}
|
|
return syscall.AF_INET6
|
|
}
|
|
|
|
func (a *IPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
|
|
if a == nil {
|
|
return nil, nil
|
|
}
|
|
return ipToSockaddr(family, a.IP, 0, a.Zone)
|
|
}
|
|
|
|
// IPConn is the implementation of the Conn and PacketConn interfaces
|
|
// for IP network connections.
|
|
type IPConn struct {
|
|
conn
|
|
}
|
|
|
|
func newIPConn(fd *netFD) *IPConn { return &IPConn{conn{fd}} }
|
|
|
|
// ReadFromIP reads an IP packet from c, copying the payload into b.
|
|
// It returns the number of bytes copied into b and the return address
|
|
// that was on the packet.
|
|
//
|
|
// ReadFromIP can be made to time out and return an error with
|
|
// Timeout() == true after a fixed time limit; see SetDeadline and
|
|
// SetReadDeadline.
|
|
func (c *IPConn) ReadFromIP(b []byte) (int, *IPAddr, error) {
|
|
if !c.ok() {
|
|
return 0, nil, syscall.EINVAL
|
|
}
|
|
// TODO(cw,rsc): consider using readv if we know the family
|
|
// type to avoid the header trim/copy
|
|
var addr *IPAddr
|
|
n, sa, err := c.fd.readFrom(b)
|
|
switch sa := sa.(type) {
|
|
case *syscall.SockaddrInet4:
|
|
addr = &IPAddr{IP: sa.Addr[0:]}
|
|
n = stripIPv4Header(n, b)
|
|
case *syscall.SockaddrInet6:
|
|
addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))}
|
|
}
|
|
if err != nil {
|
|
err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
|
|
}
|
|
return n, addr, err
|
|
}
|
|
|
|
func stripIPv4Header(n int, b []byte) int {
|
|
if len(b) < 20 {
|
|
return n
|
|
}
|
|
l := int(b[0]&0x0f) << 2
|
|
if 20 > l || l > len(b) {
|
|
return n
|
|
}
|
|
if b[0]>>4 != 4 {
|
|
return n
|
|
}
|
|
copy(b, b[l:])
|
|
return n - l
|
|
}
|
|
|
|
// ReadFrom implements the PacketConn ReadFrom method.
|
|
func (c *IPConn) ReadFrom(b []byte) (int, Addr, error) {
|
|
if !c.ok() {
|
|
return 0, nil, syscall.EINVAL
|
|
}
|
|
n, addr, err := c.ReadFromIP(b)
|
|
if addr == nil {
|
|
return n, nil, err
|
|
}
|
|
return n, addr, err
|
|
}
|
|
|
|
// ReadMsgIP reads a packet from c, copying the payload into b and the
|
|
// associated out-of-band data into oob. It returns the number of
|
|
// bytes copied into b, the number of bytes copied into oob, the flags
|
|
// that were set on the packet and the source address of the packet.
|
|
func (c *IPConn) ReadMsgIP(b, oob []byte) (n, oobn, flags int, addr *IPAddr, err error) {
|
|
if !c.ok() {
|
|
return 0, 0, 0, nil, syscall.EINVAL
|
|
}
|
|
var sa syscall.Sockaddr
|
|
n, oobn, flags, sa, err = c.fd.readMsg(b, oob)
|
|
switch sa := sa.(type) {
|
|
case *syscall.SockaddrInet4:
|
|
addr = &IPAddr{IP: sa.Addr[0:]}
|
|
case *syscall.SockaddrInet6:
|
|
addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))}
|
|
}
|
|
if err != nil {
|
|
err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
|
|
}
|
|
return
|
|
}
|
|
|
|
// WriteToIP writes an IP packet to addr via c, copying the payload
|
|
// from b.
|
|
//
|
|
// WriteToIP can be made to time out and return an error with
|
|
// Timeout() == true after a fixed time limit; see SetDeadline and
|
|
// SetWriteDeadline. On packet-oriented connections, write timeouts
|
|
// are rare.
|
|
func (c *IPConn) WriteToIP(b []byte, addr *IPAddr) (int, error) {
|
|
if !c.ok() {
|
|
return 0, syscall.EINVAL
|
|
}
|
|
if c.fd.isConnected {
|
|
return 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: ErrWriteToConnected}
|
|
}
|
|
if addr == nil {
|
|
return 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: nil, Err: errMissingAddress}
|
|
}
|
|
sa, err := addr.sockaddr(c.fd.family)
|
|
if err != nil {
|
|
return 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
|
|
}
|
|
n, err := c.fd.writeTo(b, sa)
|
|
if err != nil {
|
|
err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
|
|
}
|
|
return n, err
|
|
}
|
|
|
|
// WriteTo implements the PacketConn WriteTo method.
|
|
func (c *IPConn) WriteTo(b []byte, addr Addr) (int, error) {
|
|
if !c.ok() {
|
|
return 0, syscall.EINVAL
|
|
}
|
|
a, ok := addr.(*IPAddr)
|
|
if !ok {
|
|
return 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr, Err: syscall.EINVAL}
|
|
}
|
|
return c.WriteToIP(b, a)
|
|
}
|
|
|
|
// WriteMsgIP writes a packet to addr via c, copying the payload from
|
|
// b and the associated out-of-band data from oob. It returns the
|
|
// number of payload and out-of-band bytes written.
|
|
func (c *IPConn) WriteMsgIP(b, oob []byte, addr *IPAddr) (n, oobn int, err error) {
|
|
if !c.ok() {
|
|
return 0, 0, syscall.EINVAL
|
|
}
|
|
if c.fd.isConnected {
|
|
return 0, 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: ErrWriteToConnected}
|
|
}
|
|
if addr == nil {
|
|
return 0, 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: nil, Err: errMissingAddress}
|
|
}
|
|
var sa syscall.Sockaddr
|
|
sa, err = addr.sockaddr(c.fd.family)
|
|
if err != nil {
|
|
return 0, 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
|
|
}
|
|
n, oobn, err = c.fd.writeMsg(b, oob, sa)
|
|
if err != nil {
|
|
err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
|
|
}
|
|
return
|
|
}
|
|
|
|
// DialIP connects to the remote address raddr on the network protocol
|
|
// netProto, which must be "ip", "ip4", or "ip6" followed by a colon
|
|
// and a protocol number or name.
|
|
func DialIP(netProto string, laddr, raddr *IPAddr) (*IPConn, error) {
|
|
return dialIP(netProto, laddr, raddr, noDeadline)
|
|
}
|
|
|
|
func dialIP(netProto string, laddr, raddr *IPAddr, deadline time.Time) (*IPConn, error) {
|
|
net, proto, err := parseNetwork(netProto)
|
|
if err != nil {
|
|
return nil, &OpError{Op: "dial", Net: netProto, Source: laddr.opAddr(), Addr: raddr.opAddr(), Err: err}
|
|
}
|
|
switch net {
|
|
case "ip", "ip4", "ip6":
|
|
default:
|
|
return nil, &OpError{Op: "dial", Net: netProto, Source: laddr.opAddr(), Addr: raddr.opAddr(), Err: UnknownNetworkError(netProto)}
|
|
}
|
|
if raddr == nil {
|
|
return nil, &OpError{Op: "dial", Net: netProto, Source: laddr.opAddr(), Addr: nil, Err: errMissingAddress}
|
|
}
|
|
fd, err := internetSocket(net, laddr, raddr, deadline, syscall.SOCK_RAW, proto, "dial", noCancel)
|
|
if err != nil {
|
|
return nil, &OpError{Op: "dial", Net: netProto, Source: laddr.opAddr(), Addr: raddr.opAddr(), Err: err}
|
|
}
|
|
return newIPConn(fd), nil
|
|
}
|
|
|
|
// ListenIP listens for incoming IP packets addressed to the local
|
|
// address laddr. The returned connection's ReadFrom and WriteTo
|
|
// methods can be used to receive and send IP packets with per-packet
|
|
// addressing.
|
|
func ListenIP(netProto string, laddr *IPAddr) (*IPConn, error) {
|
|
net, proto, err := parseNetwork(netProto)
|
|
if err != nil {
|
|
return nil, &OpError{Op: "listen", Net: netProto, Source: nil, Addr: laddr.opAddr(), Err: err}
|
|
}
|
|
switch net {
|
|
case "ip", "ip4", "ip6":
|
|
default:
|
|
return nil, &OpError{Op: "listen", Net: netProto, Source: nil, Addr: laddr.opAddr(), Err: UnknownNetworkError(netProto)}
|
|
}
|
|
fd, err := internetSocket(net, laddr, nil, noDeadline, syscall.SOCK_RAW, proto, "listen", noCancel)
|
|
if err != nil {
|
|
return nil, &OpError{Op: "listen", Net: netProto, Source: nil, Addr: laddr.opAddr(), Err: err}
|
|
}
|
|
return newIPConn(fd), nil
|
|
}
|