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authorMitja Felicijan <mitja.felicijan@gmail.com>2024-10-25 00:47:47 +0200
committerMitja Felicijan <mitja.felicijan@gmail.com>2024-10-25 00:47:47 +0200
commitc6cc0108ca7738023b45e0eeac0fa2390532dd93 (patch)
tree36890e6cd3091bbab8efbe686cc56f467f645bfd /vendor/golang.org/x/sys/unix/sockcmsg_unix.go
parent0130404a1dc663d4aa68d780c9bcb23a4243e68d (diff)
downloadjbmafp-master.tar.gz
Added vendor lock on depsHEADmaster
Diffstat (limited to 'vendor/golang.org/x/sys/unix/sockcmsg_unix.go')
-rw-r--r--vendor/golang.org/x/sys/unix/sockcmsg_unix.go107
1 files changed, 107 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..3865943
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/sockcmsg_unix.go
@@ -0,0 +1,107 @@
1// Copyright 2011 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
6// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
7
8// Socket control messages
9
10package unix
11
12import (
13 "unsafe"
14)
15
16// CmsgLen returns the value to store in the Len field of the Cmsghdr
17// structure, taking into account any necessary alignment.
18func CmsgLen(datalen int) int {
19 return cmsgAlignOf(SizeofCmsghdr) + datalen
20}
21
22// CmsgSpace returns the number of bytes an ancillary element with
23// payload of the passed data length occupies.
24func CmsgSpace(datalen int) int {
25 return cmsgAlignOf(SizeofCmsghdr) + cmsgAlignOf(datalen)
26}
27
28func (h *Cmsghdr) data(offset uintptr) unsafe.Pointer {
29 return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(cmsgAlignOf(SizeofCmsghdr)) + offset)
30}
31
32// SocketControlMessage represents a socket control message.
33type SocketControlMessage struct {
34 Header Cmsghdr
35 Data []byte
36}
37
38// ParseSocketControlMessage parses b as an array of socket control
39// messages.
40func ParseSocketControlMessage(b []byte) ([]SocketControlMessage, error) {
41 var msgs []SocketControlMessage
42 i := 0
43 for i+CmsgLen(0) <= len(b) {
44 h, dbuf, err := socketControlMessageHeaderAndData(b[i:])
45 if err != nil {
46 return nil, err
47 }
48 m := SocketControlMessage{Header: *h, Data: dbuf}
49 msgs = append(msgs, m)
50 i += cmsgAlignOf(int(h.Len))
51 }
52 return msgs, nil
53}
54
55// ParseOneSocketControlMessage parses a single socket control message from b, returning the message header,
56// message data (a slice of b), and the remainder of b after that single message.
57// When there are no remaining messages, len(remainder) == 0.
58func ParseOneSocketControlMessage(b []byte) (hdr Cmsghdr, data []byte, remainder []byte, err error) {
59 h, dbuf, err := socketControlMessageHeaderAndData(b)
60 if err != nil {
61 return Cmsghdr{}, nil, nil, err
62 }
63 if i := cmsgAlignOf(int(h.Len)); i < len(b) {
64 remainder = b[i:]
65 }
66 return *h, dbuf, remainder, nil
67}
68
69func socketControlMessageHeaderAndData(b []byte) (*Cmsghdr, []byte, error) {
70 h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
71 if h.Len < SizeofCmsghdr || uint64(h.Len) > uint64(len(b)) {
72 return nil, nil, EINVAL
73 }
74 return h, b[cmsgAlignOf(SizeofCmsghdr):h.Len], nil
75}
76
77// UnixRights encodes a set of open file descriptors into a socket
78// control message for sending to another process.
79func UnixRights(fds ...int) []byte {
80 datalen := len(fds) * 4
81 b := make([]byte, CmsgSpace(datalen))
82 h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
83 h.Level = SOL_SOCKET
84 h.Type = SCM_RIGHTS
85 h.SetLen(CmsgLen(datalen))
86 for i, fd := range fds {
87 *(*int32)(h.data(4 * uintptr(i))) = int32(fd)
88 }
89 return b
90}
91
92// ParseUnixRights decodes a socket control message that contains an
93// integer array of open file descriptors from another process.
94func ParseUnixRights(m *SocketControlMessage) ([]int, error) {
95 if m.Header.Level != SOL_SOCKET {
96 return nil, EINVAL
97 }
98 if m.Header.Type != SCM_RIGHTS {
99 return nil, EINVAL
100 }
101 fds := make([]int, len(m.Data)>>2)
102 for i, j := 0, 0; i < len(m.Data); i += 4 {
103 fds[j] = int(*(*int32)(unsafe.Pointer(&m.Data[i])))
104 j++
105 }
106 return fds, nil
107}