Files
mesh-controller/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
T
jochen be92762969 Give every test a bus of its own, at the release the mesh runs (hq ADR 0237)
The live tests reached one shared bus and assert, read and remove the mesh's own objects by
their fixed names, so packages run in parallel deleted what each other read and the suite
passed only one package at a time; a red suite read as noise. internal/testbus starts a server
per test, linked in at the nats-server release go.mod pins, and a test holds that pin to the
catalogue's bus image and to the facts snapshot's bus when there is one, so the tests never run
a bus the mesh does not. The waiter test read a timing (the most connections held at one look)
and now reads the state it means (the fewest held across the wait). make check runs the packages
in parallel under the race detector, with a timeout.
2026-10-06 21:17:02 +02:00

107 lines
3.1 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
// 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
}
// ParseOneSocketControlMessage parses a single socket control message from b, returning the message header,
// message data (a slice of b), and the remainder of b after that single message.
// When there are no remaining messages, len(remainder) == 0.
func ParseOneSocketControlMessage(b []byte) (hdr Cmsghdr, data []byte, remainder []byte, err error) {
h, dbuf, err := socketControlMessageHeaderAndData(b)
if err != nil {
return Cmsghdr{}, nil, nil, err
}
if i := cmsgAlignOf(int(h.Len)); i < len(b) {
remainder = b[i:]
}
return *h, dbuf, remainder, 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
}