mirror of
https://github.com/autc04/Retro68.git
synced 2024-08-31 09:29:37 +00:00
229 lines
7.5 KiB
Go
229 lines
7.5 KiB
Go
// Copyright 2009 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.
|
|
|
|
//go:build aix || darwin || dragonfly || freebsd || hurd || (js && wasm) || linux || netbsd || openbsd || solaris || windows
|
|
|
|
package net
|
|
|
|
import (
|
|
"context"
|
|
"internal/poll"
|
|
"net/netip"
|
|
"runtime"
|
|
"syscall"
|
|
)
|
|
|
|
// probe probes IPv4, IPv6 and IPv4-mapped IPv6 communication
|
|
// capabilities which are controlled by the IPV6_V6ONLY socket option
|
|
// and kernel configuration.
|
|
//
|
|
// Should we try to use the IPv4 socket interface if we're only
|
|
// dealing with IPv4 sockets? As long as the host system understands
|
|
// IPv4-mapped IPv6, it's okay to pass IPv4-mapped IPv6 addresses to
|
|
// the IPv6 interface. That simplifies our code and is most
|
|
// general. Unfortunately, we need to run on kernels built without
|
|
// IPv6 support too. So probe the kernel to figure it out.
|
|
func (p *ipStackCapabilities) probe() {
|
|
s, err := sysSocket(syscall.AF_INET, syscall.SOCK_STREAM, syscall.IPPROTO_TCP)
|
|
switch err {
|
|
case syscall.EAFNOSUPPORT, syscall.EPROTONOSUPPORT:
|
|
case nil:
|
|
poll.CloseFunc(s)
|
|
p.ipv4Enabled = true
|
|
}
|
|
var probes = []struct {
|
|
laddr TCPAddr
|
|
value int
|
|
}{
|
|
// IPv6 communication capability
|
|
{laddr: TCPAddr{IP: ParseIP("::1")}, value: 1},
|
|
// IPv4-mapped IPv6 address communication capability
|
|
{laddr: TCPAddr{IP: IPv4(127, 0, 0, 1)}, value: 0},
|
|
}
|
|
switch runtime.GOOS {
|
|
case "dragonfly", "openbsd":
|
|
// The latest DragonFly BSD and OpenBSD kernels don't
|
|
// support IPV6_V6ONLY=0. They always return an error
|
|
// and we don't need to probe the capability.
|
|
probes = probes[:1]
|
|
}
|
|
for i := range probes {
|
|
s, err := sysSocket(syscall.AF_INET6, syscall.SOCK_STREAM, syscall.IPPROTO_TCP)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
defer poll.CloseFunc(s)
|
|
syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, probes[i].value)
|
|
sa, err := probes[i].laddr.sockaddr(syscall.AF_INET6)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
if err := syscall.Bind(s, sa); err != nil {
|
|
continue
|
|
}
|
|
if i == 0 {
|
|
p.ipv6Enabled = true
|
|
} else {
|
|
p.ipv4MappedIPv6Enabled = true
|
|
}
|
|
}
|
|
}
|
|
|
|
// favoriteAddrFamily returns the appropriate address family for the
|
|
// given network, laddr, raddr and mode.
|
|
//
|
|
// If mode indicates "listen" and laddr is a wildcard, we assume that
|
|
// the user wants to make a passive-open connection with a wildcard
|
|
// address family, both AF_INET and AF_INET6, and a wildcard address
|
|
// like the following:
|
|
//
|
|
// - A listen for a wildcard communication domain, "tcp" or
|
|
// "udp", with a wildcard address: If the platform supports
|
|
// both IPv6 and IPv4-mapped IPv6 communication capabilities,
|
|
// or does not support IPv4, we use a dual stack, AF_INET6 and
|
|
// IPV6_V6ONLY=0, wildcard address listen. The dual stack
|
|
// wildcard address listen may fall back to an IPv6-only,
|
|
// AF_INET6 and IPV6_V6ONLY=1, wildcard address listen.
|
|
// Otherwise we prefer an IPv4-only, AF_INET, wildcard address
|
|
// listen.
|
|
//
|
|
// - A listen for a wildcard communication domain, "tcp" or
|
|
// "udp", with an IPv4 wildcard address: same as above.
|
|
//
|
|
// - A listen for a wildcard communication domain, "tcp" or
|
|
// "udp", with an IPv6 wildcard address: same as above.
|
|
//
|
|
// - A listen for an IPv4 communication domain, "tcp4" or "udp4",
|
|
// with an IPv4 wildcard address: We use an IPv4-only, AF_INET,
|
|
// wildcard address listen.
|
|
//
|
|
// - A listen for an IPv6 communication domain, "tcp6" or "udp6",
|
|
// with an IPv6 wildcard address: We use an IPv6-only, AF_INET6
|
|
// and IPV6_V6ONLY=1, wildcard address listen.
|
|
//
|
|
// Otherwise guess: If the addresses are IPv4 then returns AF_INET,
|
|
// or else returns AF_INET6. It also returns a boolean value what
|
|
// designates IPV6_V6ONLY option.
|
|
//
|
|
// Note that the latest DragonFly BSD and OpenBSD kernels allow
|
|
// neither "net.inet6.ip6.v6only=1" change nor IPPROTO_IPV6 level
|
|
// IPV6_V6ONLY socket option setting.
|
|
func favoriteAddrFamily(network string, laddr, raddr sockaddr, mode string) (family int, ipv6only bool) {
|
|
switch network[len(network)-1] {
|
|
case '4':
|
|
return syscall.AF_INET, false
|
|
case '6':
|
|
return syscall.AF_INET6, true
|
|
}
|
|
|
|
if mode == "listen" && (laddr == nil || laddr.isWildcard()) {
|
|
if supportsIPv4map() || !supportsIPv4() {
|
|
return syscall.AF_INET6, false
|
|
}
|
|
if laddr == nil {
|
|
return syscall.AF_INET, false
|
|
}
|
|
return laddr.family(), false
|
|
}
|
|
|
|
if (laddr == nil || laddr.family() == syscall.AF_INET) &&
|
|
(raddr == nil || raddr.family() == syscall.AF_INET) {
|
|
return syscall.AF_INET, false
|
|
}
|
|
return syscall.AF_INET6, false
|
|
}
|
|
|
|
func internetSocket(ctx context.Context, net string, laddr, raddr sockaddr, sotype, proto int, mode string, ctrlFn func(string, string, syscall.RawConn) error) (fd *netFD, err error) {
|
|
if (runtime.GOOS == "aix" || runtime.GOOS == "windows" || runtime.GOOS == "openbsd") && mode == "dial" && raddr.isWildcard() {
|
|
raddr = raddr.toLocal(net)
|
|
}
|
|
family, ipv6only := favoriteAddrFamily(net, laddr, raddr, mode)
|
|
return socket(ctx, net, family, sotype, proto, ipv6only, laddr, raddr, ctrlFn)
|
|
}
|
|
|
|
func ipToSockaddrInet4(ip IP, port int) (syscall.SockaddrInet4, error) {
|
|
if len(ip) == 0 {
|
|
ip = IPv4zero
|
|
}
|
|
ip4 := ip.To4()
|
|
if ip4 == nil {
|
|
return syscall.SockaddrInet4{}, &AddrError{Err: "non-IPv4 address", Addr: ip.String()}
|
|
}
|
|
sa := syscall.SockaddrInet4{Port: port}
|
|
copy(sa.Addr[:], ip4)
|
|
return sa, nil
|
|
}
|
|
|
|
func ipToSockaddrInet6(ip IP, port int, zone string) (syscall.SockaddrInet6, error) {
|
|
// In general, an IP wildcard address, which is either
|
|
// "0.0.0.0" or "::", means the entire IP addressing
|
|
// space. For some historical reason, it is used to
|
|
// specify "any available address" on some operations
|
|
// of IP node.
|
|
//
|
|
// When the IP node supports IPv4-mapped IPv6 address,
|
|
// we allow a listener to listen to the wildcard
|
|
// address of both IP addressing spaces by specifying
|
|
// IPv6 wildcard address.
|
|
if len(ip) == 0 || ip.Equal(IPv4zero) {
|
|
ip = IPv6zero
|
|
}
|
|
// We accept any IPv6 address including IPv4-mapped
|
|
// IPv6 address.
|
|
ip6 := ip.To16()
|
|
if ip6 == nil {
|
|
return syscall.SockaddrInet6{}, &AddrError{Err: "non-IPv6 address", Addr: ip.String()}
|
|
}
|
|
sa := syscall.SockaddrInet6{Port: port, ZoneId: uint32(zoneCache.index(zone))}
|
|
copy(sa.Addr[:], ip6)
|
|
return sa, nil
|
|
}
|
|
|
|
func ipToSockaddr(family int, ip IP, port int, zone string) (syscall.Sockaddr, error) {
|
|
switch family {
|
|
case syscall.AF_INET:
|
|
sa, err := ipToSockaddrInet4(ip, port)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &sa, nil
|
|
case syscall.AF_INET6:
|
|
sa, err := ipToSockaddrInet6(ip, port, zone)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &sa, nil
|
|
}
|
|
return nil, &AddrError{Err: "invalid address family", Addr: ip.String()}
|
|
}
|
|
|
|
func addrPortToSockaddrInet4(ap netip.AddrPort) (syscall.SockaddrInet4, error) {
|
|
// ipToSockaddrInet4 has special handling here for zero length slices.
|
|
// We do not, because netip has no concept of a generic zero IP address.
|
|
addr := ap.Addr()
|
|
if !addr.Is4() {
|
|
return syscall.SockaddrInet4{}, &AddrError{Err: "non-IPv4 address", Addr: addr.String()}
|
|
}
|
|
sa := syscall.SockaddrInet4{
|
|
Addr: addr.As4(),
|
|
Port: int(ap.Port()),
|
|
}
|
|
return sa, nil
|
|
}
|
|
|
|
func addrPortToSockaddrInet6(ap netip.AddrPort) (syscall.SockaddrInet6, error) {
|
|
// ipToSockaddrInet6 has special handling here for zero length slices.
|
|
// We do not, because netip has no concept of a generic zero IP address.
|
|
addr := ap.Addr()
|
|
if !addr.Is6() {
|
|
return syscall.SockaddrInet6{}, &AddrError{Err: "non-IPv6 address", Addr: addr.String()}
|
|
}
|
|
sa := syscall.SockaddrInet6{
|
|
Addr: addr.As16(),
|
|
Port: int(ap.Port()),
|
|
ZoneId: uint32(zoneCache.index(addr.Zone())),
|
|
}
|
|
return sa, nil
|
|
}
|