fix commands

[bytom/shuttle.git] / vendor / github.com / bytom / vendor / golang.org / x / sys / unix / sockcmsg_unix.go

diff --git a/vendor/github.com/bytom/vendor/golang.org/x/sys/unix/sockcmsg_unix.go b/vendor/github.com/bytom/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
new file mode 100644 (file)
index 0000000..bb756ec
--- /dev/null
+++ b/vendor/github.com/bytom/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
@@ -0,0 +1,104 @@
+// Copyright 2011 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 netbsd openbsd solaris
+
+// Socket control messages
+
+package unix
+
+import "unsafe"
+
+// Round the length of a raw sockaddr up to align it properly.
+func cmsgAlignOf(salen int) int {
+       salign := sizeofPtr
+       // NOTE: It seems like 64-bit Darwin, DragonFly BSD and
+       // Solaris kernels still require 32-bit aligned access to
+       // network subsystem.
+       if darwin64Bit || dragonfly64Bit || solaris64Bit {
+               salign = 4
+       }
+       return (salen + salign - 1) & ^(salign - 1)
+}
+
+// CmsgLen returns the value to store in the Len field of the Cmsghdr
+// structure, taking into account any necessary alignment.
+func CmsgLen(datalen int) int {
+       return cmsgAlignOf(SizeofCmsghdr) + datalen
+}
+
+// CmsgSpace returns the number of bytes an ancillary element with
+// payload of the passed data length occupies.
+func CmsgSpace(datalen int) int {
+       return cmsgAlignOf(SizeofCmsghdr) + cmsgAlignOf(datalen)
+}
+
+func cmsgData(h *Cmsghdr) unsafe.Pointer {
+       return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(cmsgAlignOf(SizeofCmsghdr)))
+}
+
+// SocketControlMessage represents a socket control message.
+type SocketControlMessage struct {
+       Header Cmsghdr
+       Data   []byte
+}
+
+// ParseSocketControlMessage parses b as an array of socket control
+// messages.
+func ParseSocketControlMessage(b []byte) ([]SocketControlMessage, error) {
+       var msgs []SocketControlMessage
+       i := 0
+       for i+CmsgLen(0) <= len(b) {
+               h, dbuf, err := socketControlMessageHeaderAndData(b[i:])
+               if err != nil {
+                       return nil, err
+               }
+               m := SocketControlMessage{Header: *h, Data: dbuf}
+               msgs = append(msgs, m)
+               i += cmsgAlignOf(int(h.Len))
+       }
+       return msgs, nil
+}
+
+func socketControlMessageHeaderAndData(b []byte) (*Cmsghdr, []byte, error) {
+       h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
+       if h.Len < SizeofCmsghdr || uint64(h.Len) > uint64(len(b)) {
+               return nil, nil, EINVAL
+       }
+       return h, b[cmsgAlignOf(SizeofCmsghdr):h.Len], nil
+}
+
+// UnixRights encodes a set of open file descriptors into a socket
+// control message for sending to another process.
+func UnixRights(fds ...int) []byte {
+       datalen := len(fds) * 4
+       b := make([]byte, CmsgSpace(datalen))
+       h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
+       h.Level = SOL_SOCKET
+       h.Type = SCM_RIGHTS
+       h.SetLen(CmsgLen(datalen))
+       data := cmsgData(h)
+       for _, fd := range fds {
+               *(*int32)(data) = int32(fd)
+               data = unsafe.Pointer(uintptr(data) + 4)
+       }
+       return b
+}
+
+// ParseUnixRights decodes a socket control message that contains an
+// integer array of open file descriptors from another process.
+func ParseUnixRights(m *SocketControlMessage) ([]int, error) {
+       if m.Header.Level != SOL_SOCKET {
+               return nil, EINVAL
+       }
+       if m.Header.Type != SCM_RIGHTS {
+               return nil, EINVAL
+       }
+       fds := make([]int, len(m.Data)>>2)
+       for i, j := 0, 0; i < len(m.Data); i += 4 {
+               fds[j] = int(*(*int32)(unsafe.Pointer(&m.Data[i])))
+               j++
+       }
+       return fds, nil
+}