summaryrefslogtreecommitdiff
path: root/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
diff options
context:
space:
mode:
authorkali kaneko (leap communications) <kali@leap.se>2021-04-14 16:54:42 +0200
committerkali kaneko (leap communications) <kali@leap.se>2021-04-14 16:54:42 +0200
commit67a0eb7111d3f89e4a0cb21e43aefe6d87d37e04 (patch)
treec9b18e0da6e06ac165a485ee957b7850adb12e86 /vendor/golang.org/x/sys/unix/sockcmsg_unix.go
parent2e8f2a2e8e83fd89f956cdde886d5d9d808132da (diff)
[pkg] go mod vendor to build debian/ubuntu packages
Diffstat (limited to 'vendor/golang.org/x/sys/unix/sockcmsg_unix.go')
-rw-r--r--vendor/golang.org/x/sys/unix/sockcmsg_unix.go92
1 files changed, 92 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/unix/sockcmsg_unix.go b/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
new file mode 100644
index 0000000..003916e
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
@@ -0,0 +1,92 @@
+// 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 aix darwin dragonfly freebsd linux netbsd openbsd solaris
+
+// 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
+}