// +build linux,!386
// Copyright 2019 Wataru Ishida. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
// implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package sctp
import (
"io"
"net"
"sync/atomic"
"syscall"
"unsafe"
"runtime"
)
func setsockopt(fd int, optname, optval, optlen uintptr) (uintptr, uintptr, error) {
// FIXME: syscall.SYS_SETSOCKOPT is undefined on 386
r0, r1, errno := syscall.Syscall6(syscall.SYS_SETSOCKOPT,
uintptr(fd),
SOL_SCTP,
optname,
optval,
optlen,
0)
if errno != 0 {
return r0, r1, errno
}
return r0, r1, nil
}
func getsockopt(fd int, optname, optval, optlen uintptr) (uintptr, uintptr, error) {
if runtime.GOARCH == "s390x" {
optlen = uintptr(unsafe.Pointer(&optlen))
}
// FIXME: syscall.SYS_GETSOCKOPT is undefined on 386
r0, r1, errno := syscall.Syscall6(syscall.SYS_GETSOCKOPT,
uintptr(fd),
SOL_SCTP,
optname,
optval,
optlen,
0)
if errno != 0 {
return r0, r1, errno
}
return r0, r1, nil
}
type rawConn struct {
sockfd int
}
func (r rawConn) Control(f func(fd uintptr)) error {
f(uintptr(r.sockfd))
return nil
}
func (r rawConn) Read(f func(fd uintptr) (done bool)) error {
panic("not implemented")
}
func (r rawConn) Write(f func(fd uintptr) (done bool)) error {
panic("not implemented")
}
func (c *SCTPConn) SCTPWrite(b []byte, info *SndRcvInfo) (int, error) {
var cbuf []byte
if info != nil {
cmsgBuf := toBuf(info)
hdr := &syscall.Cmsghdr{
Level: syscall.IPPROTO_SCTP,
Type: SCTP_CMSG_SNDRCV,
}
// bitwidth of hdr.Len is platform-specific,
// so we use hdr.SetLen() rather than directly setting hdr.Len
hdr.SetLen(syscall.CmsgSpace(len(cmsgBuf)))
cbuf = append(toBuf(hdr), cmsgBuf...)
}
return syscall.SendmsgN(c.fd(), b, cbuf, nil, 0)
}
func parseSndRcvInfo(b []byte) (*SndRcvInfo, error) {
msgs, err := syscall.ParseSocketControlMessage(b)
if err != nil {
return nil, err
}
for _, m := range msgs {
if m.Header.Level == syscall.IPPROTO_SCTP {
switch m.Header.Type {
case SCTP_CMSG_SNDRCV:
return (*SndRcvInfo)(unsafe.Pointer(&m.Data[0])), nil
}
}
}
return nil, nil
}
func (c *SCTPConn) SCTPRead(b []byte) (int, *SndRcvInfo, error) {
oob := make([]byte, 254)
for {
n, oobn, recvflags, _, err := syscall.Recvmsg(c.fd(), b, oob, 0)
if err != nil {
return n, nil, err
}
if n == 0 && oobn == 0 {
return 0, nil, io.EOF
}
if recvflags&MSG_NOTIFICATION > 0 && c.notificationHandler != nil {
if err := c.notificationHandler(b[:n]); err != nil {
return 0, nil, err
}
} else {
var info *SndRcvInfo
if oobn > 0 {
info, err = parseSndRcvInfo(oob[:oobn])
}
return n, info, err
}
}
}
func (c *SCTPConn) Close() error {
if c != nil {
fd := atomic.SwapInt32(&c._fd, -1)
if fd > 0 {
info := &SndRcvInfo{
Flags: SCTP_EOF,
}
c.SCTPWrite(nil, info)
syscall.Shutdown(int(fd), syscall.SHUT_RDWR)
return syscall.Close(int(fd))
}
}
return syscall.EBADF
}
func (c *SCTPConn) SetWriteBuffer(bytes int) error {
return syscall.SetsockoptInt(c.fd(), syscall.SOL_SOCKET, syscall.SO_SNDBUF, bytes)
}
func (c *SCTPConn) GetWriteBuffer() (int, error) {
return syscall.GetsockoptInt(c.fd(), syscall.SOL_SOCKET, syscall.SO_SNDBUF)
}
func (c *SCTPConn) SetReadBuffer(bytes int) error {
return syscall.SetsockoptInt(c.fd(), syscall.SOL_SOCKET, syscall.SO_RCVBUF, bytes)
}
func (c *SCTPConn) GetReadBuffer() (int, error) {
return syscall.GetsockoptInt(c.fd(), syscall.SOL_SOCKET, syscall.SO_RCVBUF)
}
// ListenSCTP - start listener on specified address/port
func ListenSCTP(net string, laddr *SCTPAddr) (*SCTPListener, error) {
return ListenSCTPExt(net, laddr, InitMsg{NumOstreams: SCTP_MAX_STREAM})
}
// ListenSCTPExt - start listener on specified address/port with given SCTP options
func ListenSCTPExt(network string, laddr *SCTPAddr, options InitMsg) (*SCTPListener, error) {
return listenSCTPExtConfig(network, laddr, options, nil)
}
// listenSCTPExtConfig - start listener on specified address/port with given SCTP options and socket configuration
func listenSCTPExtConfig(network string, laddr *SCTPAddr, options InitMsg, control func(network, address string, c syscall.RawConn) error) (*SCTPListener, error) {
af, ipv6only := favoriteAddrFamily(network, laddr, nil, "listen")
sock, err := syscall.Socket(
af,
syscall.SOCK_STREAM,
syscall.IPPROTO_SCTP,
)
if err != nil {
return nil, err
}
// close socket on error
defer func() {
if err != nil {
syscall.Close(sock)
}
}()
if err = setDefaultSockopts(sock, af, ipv6only); err != nil {
return nil, err
}
if control != nil {
rc := rawConn{sockfd: sock}
if err = control(network, laddr.String(), rc); err != nil {
return nil, err
}
}
err = setInitOpts(sock, options)
if err != nil {
return nil, err
}
if laddr != nil {
// If IP address and/or port was not provided so far, let's use the unspecified IPv4 or IPv6 address
if len(laddr.IPAddrs) == 0 {
if af == syscall.AF_INET {
laddr.IPAddrs = append(laddr.IPAddrs, net.IPAddr{IP: net.IPv4zero})
} else if af == syscall.AF_INET6 {
laddr.IPAddrs = append(laddr.IPAddrs, net.IPAddr{IP: net.IPv6zero})
}
}
err = SCTPBind(sock, laddr, SCTP_BINDX_ADD_ADDR)
if err != nil {
return nil, err
}
}
err = syscall.Listen(sock, syscall.SOMAXCONN)
if err != nil {
return nil, err
}
return &SCTPListener{
fd: sock,
}, nil
}
// AcceptSCTP waits for and returns the next SCTP connection to the listener.
func (ln *SCTPListener) AcceptSCTP() (*SCTPConn, error) {
fd, _, err := syscall.Accept4(ln.fd, 0)
return NewSCTPConn(fd, nil), err
}
// Accept waits for and returns the next connection connection to the listener.
func (ln *SCTPListener) Accept() (net.Conn, error) {
return ln.AcceptSCTP()
}
func (ln *SCTPListener) Close() error {
syscall.Shutdown(ln.fd, syscall.SHUT_RDWR)
return syscall.Close(ln.fd)
}
// DialSCTP - bind socket to laddr (if given) and connect to raddr
func DialSCTP(net string, laddr, raddr *SCTPAddr) (*SCTPConn, error) {
return DialSCTPExt(net, laddr, raddr, InitMsg{NumOstreams: SCTP_MAX_STREAM})
}
// DialSCTPExt - same as DialSCTP but with given SCTP options
func DialSCTPExt(network string, laddr, raddr *SCTPAddr, options InitMsg) (*SCTPConn, error) {
return dialSCTPExtConfig(network, laddr, raddr, options, nil)
}
// dialSCTPExtConfig - same as DialSCTP but with given SCTP options and socket configuration
func dialSCTPExtConfig(network string, laddr, raddr *SCTPAddr, options InitMsg, control func(network, address string, c syscall.RawConn) error) (*SCTPConn, error) {
af, ipv6only := favoriteAddrFamily(network, laddr, raddr, "dial")
sock, err := syscall.Socket(
af,
syscall.SOCK_STREAM,
syscall.IPPROTO_SCTP,
)
if err != nil {
return nil, err
}
// close socket on error
defer func() {
if err != nil {
syscall.Close(sock)
}
}()
if err = setDefaultSockopts(sock, af, ipv6only); err != nil {
return nil, err
}
if control != nil {
rc := rawConn{sockfd: sock}
if err = control(network, laddr.String(), rc); err != nil {
return nil, err
}
}
err = setInitOpts(sock, options)
if err != nil {
return nil, err
}
if laddr != nil {
// If IP address and/or port was not provided so far, let's use the unspecified IPv4 or IPv6 address
if len(laddr.IPAddrs) == 0 {
if af == syscall.AF_INET {
laddr.IPAddrs = append(laddr.IPAddrs, net.IPAddr{IP: net.IPv4zero})
} else if af == syscall.AF_INET6 {
laddr.IPAddrs = append(laddr.IPAddrs, net.IPAddr{IP: net.IPv6zero})
}
}
err = SCTPBind(sock, laddr, SCTP_BINDX_ADD_ADDR)
if err != nil {
return nil, err
}
}
_, err = SCTPConnect(sock, raddr)
if err != nil {
return nil, err
}
return NewSCTPConn(sock, nil), nil
}
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