gitea-tea/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
6543 0d98cbd657 Update Vendors (#337)
* update & migrate gitea sdk (Fix Delete Tag Issue)
* upgraded github.com/AlecAivazis/survey v2.2.7 => v2.2.8
* upgraded github.com/adrg/xdg v0.2.3 => v0.3.1
* upgraded github.com/araddon/dateparse
* upgraded github.com/olekukonko/tablewriter v0.0.4 => v0.0.5
* upgraded gopkg.in/yaml.v2 v2.3.0 => v2.4.0

Reviewed-on: https://gitea.com/gitea/tea/pulls/337
Reviewed-by: Norwin <noerw@noreply.gitea.io>
Reviewed-by: khmarbaise <khmarbaise@noreply.gitea.io>
Co-authored-by: 6543 <6543@obermui.de>
Co-committed-by: 6543 <6543@obermui.de>
2021-03-05 18:06:25 +08:00

94 lines
2.7 KiB
Go

// 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.
//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
// Socket control messages
package unix
import (
"unsafe"
)
// 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 (h *Cmsghdr) data(offset uintptr) unsafe.Pointer {
return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(cmsgAlignOf(SizeofCmsghdr)) + offset)
}
// 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))
for i, fd := range fds {
*(*int32)(h.data(4 * uintptr(i))) = int32(fd)
}
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
}