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Diffstat (limited to '')
-rw-r--r-- | dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/sockcmsg_unix.go | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/sockcmsg_unix.go b/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/sockcmsg_unix.go new file mode 100644 index 0000000..453a942 --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/sockcmsg_unix.go @@ -0,0 +1,93 @@ +// 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 +} |