blob: 54a4a9940c64c4850017cdf4857c8dea3acba28e [file] [log] [blame]
// socket.go -- Socket handling.
// 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.
// Low-level socket interface.
// Only for implementing net package.
// DO NOT USE DIRECTLY.
package syscall
import "unsafe"
// These functions are called from the internal/syscall/unix package.
// Use go:linkname to export them.
//
//go:linkname recvfromInet4
//go:linkname recvfromInet6
//go:linkname sendtoInet4
//go:linkname sendtoInet6
//go:linkname sendmsgNInet4
//go:linkname sendmsgNInet6
//go:linkname recvmsgInet4
//go:linkname recvmsgInet6
// For testing: clients can set this flag to force
// creation of IPv6 sockets to return EAFNOSUPPORT.
var SocketDisableIPv6 bool
type Sockaddr interface {
sockaddr() (ptr *RawSockaddrAny, len Socklen_t, err error) // lowercase; only we can define Sockaddrs
}
type RawSockaddrAny struct {
Addr RawSockaddr
Pad [96]int8
}
const SizeofSockaddrAny = 0x6c
type SockaddrInet4 struct {
Port int
Addr [4]byte
raw RawSockaddrInet4
}
func (sa *SockaddrInet4) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
if sa.Port < 0 || sa.Port > 0xFFFF {
return nil, 0, EINVAL
}
sa.raw.Family = AF_INET
n := sa.raw.setLen()
p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
p[0] = byte(sa.Port >> 8)
p[1] = byte(sa.Port)
for i := 0; i < len(sa.Addr); i++ {
sa.raw.Addr[i] = sa.Addr[i]
}
return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), n, nil
}
type SockaddrInet6 struct {
Port int
ZoneId uint32
Addr [16]byte
raw RawSockaddrInet6
}
func (sa *SockaddrInet6) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
if sa.Port < 0 || sa.Port > 0xFFFF {
return nil, 0, EINVAL
}
sa.raw.Family = AF_INET6
n := sa.raw.setLen()
p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
p[0] = byte(sa.Port >> 8)
p[1] = byte(sa.Port)
sa.raw.Scope_id = sa.ZoneId
for i := 0; i < len(sa.Addr); i++ {
sa.raw.Addr[i] = sa.Addr[i]
}
return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), n, nil
}
type SockaddrUnix struct {
Name string
raw RawSockaddrUnix
}
func (sa *SockaddrUnix) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
name := sa.Name
n := len(name)
if n > len(sa.raw.Path) {
return nil, 0, EINVAL
}
sa.raw.Family = AF_UNIX
sa.raw.setLen(n)
for i := 0; i < n; i++ {
sa.raw.Path[i] = int8(name[i])
}
// length is family (uint16), name, NUL.
sl := Socklen_t(2)
if n > 0 {
sl += Socklen_t(n) + 1
}
sl = sa.raw.adjustAbstract(sl)
// Check again after adjustAbstract adjusts the length.
// This is testing whether the +1 for NUL puts us out of range.
if sl-2 > Socklen_t(len(sa.raw.Path)) {
return nil, 0, EINVAL
}
// length is family (uint16), name, NUL.
return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), sl, nil
}
func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
switch rsa.Addr.Family {
case AF_UNIX:
pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
sa := new(SockaddrUnix)
n, err := pp.getLen()
if err != nil {
return nil, err
}
bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]))
sa.Name = string(bytes[0:n])
return sa, nil
case AF_INET:
pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
sa := new(SockaddrInet4)
p := (*[2]byte)(unsafe.Pointer(&pp.Port))
sa.Port = int(p[0])<<8 + int(p[1])
for i := 0; i < len(sa.Addr); i++ {
sa.Addr[i] = pp.Addr[i]
}
return sa, nil
case AF_INET6:
pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
sa := new(SockaddrInet6)
p := (*[2]byte)(unsafe.Pointer(&pp.Port))
sa.Port = int(p[0])<<8 + int(p[1])
for i := 0; i < len(sa.Addr); i++ {
sa.Addr[i] = pp.Addr[i]
}
return sa, nil
}
return anyToSockaddrOS(rsa)
}
//sys accept(fd int, sa *RawSockaddrAny, len *Socklen_t) (nfd int, err error)
//accept(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
func Accept(fd int) (nfd int, sa Sockaddr, err error) {
var rsa RawSockaddrAny
var len Socklen_t = SizeofSockaddrAny
nfd, err = accept(fd, &rsa, &len)
if err != nil {
return
}
sa, err = anyToSockaddr(&rsa)
if err != nil {
Close(nfd)
nfd = 0
}
return
}
//sysnb getsockname(fd int, sa *RawSockaddrAny, len *Socklen_t) (err error)
//getsockname(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
func Getsockname(fd int) (sa Sockaddr, err error) {
var rsa RawSockaddrAny
var len Socklen_t = SizeofSockaddrAny
if err = getsockname(fd, &rsa, &len); err != nil {
return
}
return anyToSockaddr(&rsa)
}
//sysnb getpeername(fd int, sa *RawSockaddrAny, len *Socklen_t) (err error)
//getpeername(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
func Getpeername(fd int) (sa Sockaddr, err error) {
var rsa RawSockaddrAny
var len Socklen_t = SizeofSockaddrAny
if err = getpeername(fd, &rsa, &len); err != nil {
return
}
return anyToSockaddr(&rsa)
}
func Bind(fd int, sa Sockaddr) (err error) {
ptr, n, err := sa.sockaddr()
if err != nil {
return err
}
return bind(fd, ptr, n)
}
func Connect(fd int, sa Sockaddr) (err error) {
ptr, n, err := sa.sockaddr()
if err != nil {
return err
}
return connect(fd, ptr, n)
}
func Socket(domain, typ, proto int) (fd int, err error) {
if domain == AF_INET6 && SocketDisableIPv6 {
return -1, EAFNOSUPPORT
}
fd, err = socket(domain, typ, proto)
return
}
func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
var fdx [2]_C_int
err = socketpair(domain, typ, proto, &fdx)
if err == nil {
fd[0] = int(fdx[0])
fd[1] = int(fdx[1])
}
return
}
func GetsockoptByte(fd, level, opt int) (value byte, err error) {
var n byte
vallen := Socklen_t(1)
err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
return n, err
}
func GetsockoptInt(fd, level, opt int) (value int, err error) {
var n int32
vallen := Socklen_t(4)
err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
return int(n), err
}
func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
vallen := Socklen_t(4)
err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
return value, err
}
func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
var value IPMreq
vallen := Socklen_t(SizeofIPMreq)
err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
return &value, err
}
func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {
var value IPMreqn
vallen := Socklen_t(SizeofIPMreqn)
err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
return &value, err
}
func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
var value IPv6Mreq
vallen := Socklen_t(SizeofIPv6Mreq)
err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
return &value, err
}
func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
var value ICMPv6Filter
vallen := Socklen_t(SizeofICMPv6Filter)
err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
return &value, err
}
//sys setsockopt(s int, level int, name int, val unsafe.Pointer, vallen Socklen_t) (err error)
//setsockopt(s _C_int, level _C_int, optname _C_int, val *byte, vallen Socklen_t) _C_int
func SetsockoptByte(fd, level, opt int, value byte) (err error) {
var n = byte(value)
return setsockopt(fd, level, opt, unsafe.Pointer(&n), 1)
}
func SetsockoptInt(fd, level, opt int, value int) (err error) {
var n = int32(value)
return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
}
func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
}
func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
return setsockopt(fd, level, opt, unsafe.Pointer(tv), Socklen_t(unsafe.Sizeof(*tv)))
}
func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
}
type Linger struct {
Onoff int32
Linger int32
}
func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
return setsockopt(fd, level, opt, unsafe.Pointer(l), Socklen_t(unsafe.Sizeof(*l)))
}
func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
}
func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {
return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
}
func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
}
func SetsockoptString(fd, level, opt int, s string) (err error) {
var p unsafe.Pointer
if len(s) > 0 {
p = unsafe.Pointer(&[]byte(s)[0])
}
return setsockopt(fd, level, opt, p, Socklen_t(len(s)))
}
//sys recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *Socklen_t) (n int, err error)
//recvfrom(fd _C_int, buf *byte, len Size_t, flags _C_int, from *RawSockaddrAny, fromlen *Socklen_t) Ssize_t
func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
var rsa RawSockaddrAny
var len Socklen_t = SizeofSockaddrAny
if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
return
}
if rsa.Addr.Family != AF_UNSPEC {
from, err = anyToSockaddr(&rsa)
}
return
}
func recvfromInet4(fd int, p []byte, flags int, from *SockaddrInet4) (n int, err error) {
var rsa RawSockaddrAny
var socklen Socklen_t = SizeofSockaddrAny
if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil {
return
}
pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa))
port := (*[2]byte)(unsafe.Pointer(&pp.Port))
from.Port = int(port[0])<<8 + int(port[1])
from.Addr = pp.Addr
return
}
func recvfromInet6(fd int, p []byte, flags int, from *SockaddrInet6) (n int, err error) {
var rsa RawSockaddrAny
var socklen Socklen_t = SizeofSockaddrAny
if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil {
return
}
pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa))
port := (*[2]byte)(unsafe.Pointer(&pp.Port))
from.Port = int(port[0])<<8 + int(port[1])
from.ZoneId = pp.Scope_id
from.Addr = pp.Addr
return
}
func recvmsgInet4(fd int, p, oob []byte, flags int, from *SockaddrInet4) (n, oobn int, recvflags int, err error) {
var rsa RawSockaddrAny
n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
if err != nil {
return
}
pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa))
port := (*[2]byte)(unsafe.Pointer(&pp.Port))
from.Port = int(port[0])<<8 + int(port[1])
from.Addr = pp.Addr
return
}
func recvmsgInet6(fd int, p, oob []byte, flags int, from *SockaddrInet6) (n, oobn int, recvflags int, err error) {
var rsa RawSockaddrAny
n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
if err != nil {
return
}
pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa))
port := (*[2]byte)(unsafe.Pointer(&pp.Port))
from.Port = int(port[0])<<8 + int(port[1])
from.ZoneId = pp.Scope_id
from.Addr = pp.Addr
return
}
func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
var rsa RawSockaddrAny
n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
// source address is only specified if the socket is unconnected
if rsa.Addr.Family != AF_UNSPEC {
from, err = anyToSockaddr(&rsa)
}
return
}
func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
_, err = SendmsgN(fd, p, oob, to, flags)
return
}
func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
var ptr *RawSockaddrAny
var salen Socklen_t
if to != nil {
ptr, salen, err = to.sockaddr()
if err != nil {
return 0, err
}
}
return sendmsgN(fd, p, oob, ptr, salen, flags)
}
func sendmsgNInet4(fd int, p, oob []byte, to *SockaddrInet4, flags int) (n int, err error) {
ptr, salen, err := to.sockaddr()
if err != nil {
return 0, err
}
return sendmsgN(fd, p, oob, ptr, salen, flags)
}
func sendmsgNInet6(fd int, p, oob []byte, to *SockaddrInet6, flags int) (n int, err error) {
ptr, salen, err := to.sockaddr()
if err != nil {
return 0, err
}
return sendmsgN(fd, p, oob, ptr, salen, flags)
}
func sendtoInet4(fd int, p []byte, flags int, to *SockaddrInet4) (err error) {
ptr, n, err := to.sockaddr()
if err != nil {
return err
}
return sendto(fd, p, flags, ptr, n)
}
func sendtoInet6(fd int, p []byte, flags int, to *SockaddrInet6) (err error) {
ptr, n, err := to.sockaddr()
if err != nil {
return err
}
return sendto(fd, p, flags, ptr, n)
}
func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
ptr, n, err := to.sockaddr()
if err != nil {
return err
}
return sendto(fd, p, flags, ptr, n)
}
func recvmsgRaw(fd int, p, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {
var msg Msghdr
msg.Name = (*byte)(unsafe.Pointer(&rsa))
msg.Namelen = uint32(SizeofSockaddrAny)
var iov Iovec
if len(p) > 0 {
iov.Base = (*byte)(unsafe.Pointer(&p[0]))
iov.SetLen(len(p))
}
var dummy byte
if len(oob) > 0 {
var sockType int
sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
if err != nil {
return
}
// receive at least one normal byte
if sockType != SOCK_DGRAM && len(p) == 0 {
iov.Base = &dummy
iov.SetLen(1)
}
msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
msg.SetControllen(len(oob))
}
msg.Iov = &iov
msg.Iovlen = 1
if n, err = recvmsg(fd, &msg, flags); err != nil {
return
}
oobn = int(msg.Controllen)
recvflags = int(msg.Flags)
return
}
func sendmsgN(fd int, p, oob []byte, to *RawSockaddrAny, salen Socklen_t, flags int) (n int, err error) {
var msg Msghdr
msg.Name = (*byte)(unsafe.Pointer(to))
msg.Namelen = uint32(salen)
var iov Iovec
if len(p) > 0 {
iov.Base = (*byte)(unsafe.Pointer(&p[0]))
iov.SetLen(len(p))
}
var dummy byte
if len(oob) > 0 {
var sockType int
sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
if err != nil {
return 0, err
}
// send at least one normal byte
if sockType != SOCK_DGRAM && len(p) == 0 {
iov.Base = &dummy
iov.SetLen(1)
}
msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
msg.SetControllen(len(oob))
}
msg.Iov = &iov
msg.Iovlen = 1
if n, err = sendmsg(fd, &msg, flags); err != nil {
return 0, err
}
if len(oob) > 0 && len(p) == 0 {
n = 0
}
return n, nil
}
//sys Listen(fd int, n int) (err error)
//listen(fd _C_int, n _C_int) _C_int
//sys Shutdown(fd int, how int) (err error)
//shutdown(fd _C_int, how _C_int) _C_int
func (iov *Iovec) SetLen(length int) {
iov.Len = Iovec_len_t(length)
}
func (msghdr *Msghdr) SetControllen(length int) {
msghdr.Controllen = Msghdr_controllen_t(length)
}
func (cmsg *Cmsghdr) SetLen(length int) {
cmsg.Len = Cmsghdr_len_t(length)
}