/usr/share/gocode/src/github.com/linuxkit/virtsock/pkg/vsock/vsock_linux.go is in golang-github-linuxkit-virtsock-dev 0.0~git20170720.0.0416e3d-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 | // Bindings to the Linux hues interface to VM sockets.
package vsock
import (
"errors"
"fmt"
"net"
"os"
"syscall"
"time"
"golang.org/x/sys/unix"
)
// SocketMode is a NOOP on Linux
func SocketMode(m string) {
}
// Convert a generic unix.Sockaddr to a VsockAddr
func sockaddrToVsock(sa unix.Sockaddr) *VsockAddr {
switch sa := sa.(type) {
case *unix.SockaddrVM:
return &VsockAddr{CID: sa.CID, Port: sa.Port}
}
return nil
}
// Dial connects to the CID.Port via virtio sockets
func Dial(cid, port uint32) (Conn, error) {
fd, err := syscall.Socket(unix.AF_VSOCK, syscall.SOCK_STREAM|syscall.SOCK_CLOEXEC, 0)
if err != nil {
return nil, err
}
sa := &unix.SockaddrVM{CID: cid, Port: port}
// Retry connect in a loop if EINTR is encountered.
for {
if err := unix.Connect(fd, sa); err != nil {
if errno, ok := err.(syscall.Errno); ok && errno == syscall.EINTR {
continue
}
return nil, errors.New(fmt.Sprintf(
"failed connect() to %08x.%08x: %s", cid, port, err))
}
break
}
return newVsockConn(uintptr(fd), nil, &VsockAddr{cid, port}), nil
}
// Listen returns a net.Listener which can accept connections on the given port
func Listen(cid, port uint32) (net.Listener, error) {
fd, err := syscall.Socket(unix.AF_VSOCK, syscall.SOCK_STREAM|syscall.SOCK_CLOEXEC, 0)
if err != nil {
return nil, err
}
sa := &unix.SockaddrVM{CID: cid, Port: port}
if err = unix.Bind(fd, sa); err != nil {
return nil, errors.New(fmt.Sprintf(
"failed bind() to %08x.%08x: %s", cid, port, err))
}
err = syscall.Listen(fd, syscall.SOMAXCONN)
if err != nil {
return nil, err
}
return &vsockListener{fd, VsockAddr{cid, port}}, nil
}
type vsockListener struct {
fd int
local VsockAddr
}
// Accept accepts an incoming call and returns the new connection.
func (v *vsockListener) Accept() (net.Conn, error) {
fd, sa, err := unix.Accept(v.fd)
if err != nil {
return nil, err
}
return newVsockConn(uintptr(fd), &v.local, sockaddrToVsock(sa)), nil
}
// Close closes the listening connection
func (v *vsockListener) Close() error {
// Note this won't cause the Accept to unblock.
return unix.Close(v.fd)
}
// Addr returns the address the Listener is listening on
func (v *vsockListener) Addr() net.Addr {
return v.local
}
// a wrapper around FileConn which supports CloseRead and CloseWrite
type vsockConn struct {
vsock *os.File
fd uintptr
local *VsockAddr
remote *VsockAddr
}
// VsockConn represents a connection over a vsock
type VsockConn struct {
vsockConn
}
func newVsockConn(fd uintptr, local, remote *VsockAddr) *VsockConn {
vsock := os.NewFile(fd, fmt.Sprintf("vsock:%d", fd))
return &VsockConn{vsockConn{vsock: vsock, fd: fd, local: local, remote: remote}}
}
// LocalAddr returns the local address of a connection
func (v *VsockConn) LocalAddr() net.Addr {
return v.local
}
// RemoteAddr returns the remote address of a connection
func (v *VsockConn) RemoteAddr() net.Addr {
return v.remote
}
// Close closes the connection
func (v *VsockConn) Close() error {
return v.vsock.Close()
}
// CloseRead shuts down the reading side of a vsock connection
func (v *VsockConn) CloseRead() error {
return syscall.Shutdown(int(v.fd), syscall.SHUT_RD)
}
// CloseWrite shuts down the writing side of a vsock connection
func (v *VsockConn) CloseWrite() error {
return syscall.Shutdown(int(v.fd), syscall.SHUT_WR)
}
// Read reads data from the connection
func (v *VsockConn) Read(buf []byte) (int, error) {
return v.vsock.Read(buf)
}
// Write writes data over the connection
func (v *VsockConn) Write(buf []byte) (int, error) {
return v.vsock.Write(buf)
}
// SetDeadline sets the read and write deadlines associated with the connection
func (v *VsockConn) SetDeadline(t time.Time) error {
return nil // FIXME
}
// SetReadDeadline sets the deadline for future Read calls.
func (v *VsockConn) SetReadDeadline(t time.Time) error {
return nil // FIXME
}
// SetWriteDeadline sets the deadline for future Write calls
func (v *VsockConn) SetWriteDeadline(t time.Time) error {
return nil // FIXME
}
// File duplicates the underlying socket descriptor and returns it.
func (v *VsockConn) File() (*os.File, error) {
// This is equivalent to dup(2) but creates the new fd with CLOEXEC already set.
r0, _, e1 := syscall.Syscall(syscall.SYS_FCNTL, uintptr(v.vsock.Fd()), syscall.F_DUPFD_CLOEXEC, 0)
if e1 != 0 {
return nil, os.NewSyscallError("fcntl", e1)
}
return os.NewFile(r0, v.vsock.Name()), nil
}
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