syscall_linux.go raw
1 // Copyright 2009 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 // Linux system calls.
6 // This file is compiled as ordinary Go code,
7 // but it is also input to mksyscall,
8 // which parses the //sys lines and generates system call stubs.
9 // Note that sometimes we use a lowercase //sys name and
10 // wrap it in our own nicer implementation.
11
12 package unix
13
14 import (
15 "encoding/binary"
16 "slices"
17 "strconv"
18 "syscall"
19 "time"
20 "unsafe"
21 )
22
23 /*
24 * Wrapped
25 */
26
27 func Access(path string, mode uint32) (err error) {
28 return Faccessat(AT_FDCWD, path, mode, 0)
29 }
30
31 func Chmod(path string, mode uint32) (err error) {
32 return Fchmodat(AT_FDCWD, path, mode, 0)
33 }
34
35 func Chown(path string, uid int, gid int) (err error) {
36 return Fchownat(AT_FDCWD, path, uid, gid, 0)
37 }
38
39 func Creat(path string, mode uint32) (fd int, err error) {
40 return Open(path, O_CREAT|O_WRONLY|O_TRUNC, mode)
41 }
42
43 func EpollCreate(size int) (fd int, err error) {
44 if size <= 0 {
45 return -1, EINVAL
46 }
47 return EpollCreate1(0)
48 }
49
50 //sys FanotifyInit(flags uint, event_f_flags uint) (fd int, err error)
51 //sys fanotifyMark(fd int, flags uint, mask uint64, dirFd int, pathname *byte) (err error)
52
53 func FanotifyMark(fd int, flags uint, mask uint64, dirFd int, pathname string) (err error) {
54 if pathname == "" {
55 return fanotifyMark(fd, flags, mask, dirFd, nil)
56 }
57 p, err := BytePtrFromString(pathname)
58 if err != nil {
59 return err
60 }
61 return fanotifyMark(fd, flags, mask, dirFd, p)
62 }
63
64 //sys fchmodat(dirfd int, path string, mode uint32) (err error)
65 //sys fchmodat2(dirfd int, path string, mode uint32, flags int) (err error)
66
67 func Fchmodat(dirfd int, path string, mode uint32, flags int) error {
68 // Linux fchmodat doesn't support the flags parameter, but fchmodat2 does.
69 // Try fchmodat2 if flags are specified.
70 if flags != 0 {
71 err := fchmodat2(dirfd, path, mode, flags)
72 if err == ENOSYS {
73 // fchmodat2 isn't available. If the flags are known to be valid,
74 // return EOPNOTSUPP to indicate that fchmodat doesn't support them.
75 if flags&^(AT_SYMLINK_NOFOLLOW|AT_EMPTY_PATH) != 0 {
76 return EINVAL
77 } else if flags&(AT_SYMLINK_NOFOLLOW|AT_EMPTY_PATH) != 0 {
78 return EOPNOTSUPP
79 }
80 }
81 return err
82 }
83 return fchmodat(dirfd, path, mode)
84 }
85
86 func InotifyInit() (fd int, err error) {
87 return InotifyInit1(0)
88 }
89
90 //sys ioctl(fd int, req uint, arg uintptr) (err error) = SYS_IOCTL
91 //sys ioctlPtr(fd int, req uint, arg unsafe.Pointer) (err error) = SYS_IOCTL
92
93 // ioctl itself should not be exposed directly, but additional get/set functions
94 // for specific types are permissible. These are defined in ioctl.go and
95 // ioctl_linux.go.
96 //
97 // The third argument to ioctl is often a pointer but sometimes an integer.
98 // Callers should use ioctlPtr when the third argument is a pointer and ioctl
99 // when the third argument is an integer.
100 //
101 // TODO: some existing code incorrectly uses ioctl when it should use ioctlPtr.
102
103 //sys Linkat(olddirfd int, oldpath string, newdirfd int, newpath string, flags int) (err error)
104
105 func Link(oldpath string, newpath string) (err error) {
106 return Linkat(AT_FDCWD, oldpath, AT_FDCWD, newpath, 0)
107 }
108
109 func Mkdir(path string, mode uint32) (err error) {
110 return Mkdirat(AT_FDCWD, path, mode)
111 }
112
113 func Mknod(path string, mode uint32, dev int) (err error) {
114 return Mknodat(AT_FDCWD, path, mode, dev)
115 }
116
117 func Open(path string, mode int, perm uint32) (fd int, err error) {
118 return openat(AT_FDCWD, path, mode|O_LARGEFILE, perm)
119 }
120
121 //sys openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
122
123 func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) {
124 return openat(dirfd, path, flags|O_LARGEFILE, mode)
125 }
126
127 //sys openat2(dirfd int, path string, open_how *OpenHow, size int) (fd int, err error)
128
129 func Openat2(dirfd int, path string, how *OpenHow) (fd int, err error) {
130 return openat2(dirfd, path, how, SizeofOpenHow)
131 }
132
133 func Pipe(p []int) error {
134 return Pipe2(p, 0)
135 }
136
137 //sysnb pipe2(p *[2]_C_int, flags int) (err error)
138
139 func Pipe2(p []int, flags int) error {
140 if len(p) != 2 {
141 return EINVAL
142 }
143 var pp [2]_C_int
144 err := pipe2(&pp, flags)
145 if err == nil {
146 p[0] = int(pp[0])
147 p[1] = int(pp[1])
148 }
149 return err
150 }
151
152 //sys ppoll(fds *PollFd, nfds int, timeout *Timespec, sigmask *Sigset_t) (n int, err error)
153
154 func Ppoll(fds []PollFd, timeout *Timespec, sigmask *Sigset_t) (n int, err error) {
155 if len(fds) == 0 {
156 return ppoll(nil, 0, timeout, sigmask)
157 }
158 return ppoll(&fds[0], len(fds), timeout, sigmask)
159 }
160
161 func Poll(fds []PollFd, timeout int) (n int, err error) {
162 var ts *Timespec
163 if timeout >= 0 {
164 ts = new(Timespec)
165 *ts = NsecToTimespec(int64(timeout) * 1e6)
166 }
167 return Ppoll(fds, ts, nil)
168 }
169
170 //sys Readlinkat(dirfd int, path string, buf []byte) (n int, err error)
171
172 func Readlink(path string, buf []byte) (n int, err error) {
173 return Readlinkat(AT_FDCWD, path, buf)
174 }
175
176 func Rename(oldpath string, newpath string) (err error) {
177 return Renameat(AT_FDCWD, oldpath, AT_FDCWD, newpath)
178 }
179
180 func Rmdir(path string) error {
181 return Unlinkat(AT_FDCWD, path, AT_REMOVEDIR)
182 }
183
184 //sys Symlinkat(oldpath string, newdirfd int, newpath string) (err error)
185
186 func Symlink(oldpath string, newpath string) (err error) {
187 return Symlinkat(oldpath, AT_FDCWD, newpath)
188 }
189
190 func Unlink(path string) error {
191 return Unlinkat(AT_FDCWD, path, 0)
192 }
193
194 //sys Unlinkat(dirfd int, path string, flags int) (err error)
195
196 func Utimes(path string, tv []Timeval) error {
197 if tv == nil {
198 err := utimensat(AT_FDCWD, path, nil, 0)
199 if err != ENOSYS {
200 return err
201 }
202 return utimes(path, nil)
203 }
204 if len(tv) != 2 {
205 return EINVAL
206 }
207 var ts [2]Timespec
208 ts[0] = NsecToTimespec(TimevalToNsec(tv[0]))
209 ts[1] = NsecToTimespec(TimevalToNsec(tv[1]))
210 err := utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
211 if err != ENOSYS {
212 return err
213 }
214 return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
215 }
216
217 //sys utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error)
218
219 func UtimesNano(path string, ts []Timespec) error {
220 return UtimesNanoAt(AT_FDCWD, path, ts, 0)
221 }
222
223 func UtimesNanoAt(dirfd int, path string, ts []Timespec, flags int) error {
224 if ts == nil {
225 return utimensat(dirfd, path, nil, flags)
226 }
227 if len(ts) != 2 {
228 return EINVAL
229 }
230 return utimensat(dirfd, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), flags)
231 }
232
233 func Futimesat(dirfd int, path string, tv []Timeval) error {
234 if tv == nil {
235 return futimesat(dirfd, path, nil)
236 }
237 if len(tv) != 2 {
238 return EINVAL
239 }
240 return futimesat(dirfd, path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
241 }
242
243 func Futimes(fd int, tv []Timeval) (err error) {
244 // Believe it or not, this is the best we can do on Linux
245 // (and is what glibc does).
246 return Utimes("/proc/self/fd/"+strconv.Itoa(fd), tv)
247 }
248
249 const ImplementsGetwd = true
250
251 //sys Getcwd(buf []byte) (n int, err error)
252
253 func Getwd() (wd string, err error) {
254 var buf [PathMax]byte
255 n, err := Getcwd(buf[0:])
256 if err != nil {
257 return "", err
258 }
259 // Getcwd returns the number of bytes written to buf, including the NUL.
260 if n < 1 || n > len(buf) || buf[n-1] != 0 {
261 return "", EINVAL
262 }
263 // In some cases, Linux can return a path that starts with the
264 // "(unreachable)" prefix, which can potentially be a valid relative
265 // path. To work around that, return ENOENT if path is not absolute.
266 if buf[0] != '/' {
267 return "", ENOENT
268 }
269
270 return string(buf[0 : n-1]), nil
271 }
272
273 func Getgroups() (gids []int, err error) {
274 n, err := getgroups(0, nil)
275 if err != nil {
276 return nil, err
277 }
278 if n == 0 {
279 return nil, nil
280 }
281
282 // Sanity check group count. Max is 1<<16 on Linux.
283 if n < 0 || n > 1<<20 {
284 return nil, EINVAL
285 }
286
287 a := make([]_Gid_t, n)
288 n, err = getgroups(n, &a[0])
289 if err != nil {
290 return nil, err
291 }
292 gids = make([]int, n)
293 for i, v := range a[0:n] {
294 gids[i] = int(v)
295 }
296 return
297 }
298
299 func Setgroups(gids []int) (err error) {
300 if len(gids) == 0 {
301 return setgroups(0, nil)
302 }
303
304 a := make([]_Gid_t, len(gids))
305 for i, v := range gids {
306 a[i] = _Gid_t(v)
307 }
308 return setgroups(len(a), &a[0])
309 }
310
311 type WaitStatus uint32
312
313 // Wait status is 7 bits at bottom, either 0 (exited),
314 // 0x7F (stopped), or a signal number that caused an exit.
315 // The 0x80 bit is whether there was a core dump.
316 // An extra number (exit code, signal causing a stop)
317 // is in the high bits. At least that's the idea.
318 // There are various irregularities. For example, the
319 // "continued" status is 0xFFFF, distinguishing itself
320 // from stopped via the core dump bit.
321
322 const (
323 mask = 0x7F
324 core = 0x80
325 exited = 0x00
326 stopped = 0x7F
327 shift = 8
328 )
329
330 func (w WaitStatus) Exited() bool { return w&mask == exited }
331
332 func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != exited }
333
334 func (w WaitStatus) Stopped() bool { return w&0xFF == stopped }
335
336 func (w WaitStatus) Continued() bool { return w == 0xFFFF }
337
338 func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
339
340 func (w WaitStatus) ExitStatus() int {
341 if !w.Exited() {
342 return -1
343 }
344 return int(w>>shift) & 0xFF
345 }
346
347 func (w WaitStatus) Signal() syscall.Signal {
348 if !w.Signaled() {
349 return -1
350 }
351 return syscall.Signal(w & mask)
352 }
353
354 func (w WaitStatus) StopSignal() syscall.Signal {
355 if !w.Stopped() {
356 return -1
357 }
358 return syscall.Signal(w>>shift) & 0xFF
359 }
360
361 func (w WaitStatus) TrapCause() int {
362 if w.StopSignal() != SIGTRAP {
363 return -1
364 }
365 return int(w>>shift) >> 8
366 }
367
368 //sys wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)
369
370 func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
371 var status _C_int
372 wpid, err = wait4(pid, &status, options, rusage)
373 if wstatus != nil {
374 *wstatus = WaitStatus(status)
375 }
376 return
377 }
378
379 //sys Waitid(idType int, id int, info *Siginfo, options int, rusage *Rusage) (err error)
380
381 func Mkfifo(path string, mode uint32) error {
382 return Mknod(path, mode|S_IFIFO, 0)
383 }
384
385 func Mkfifoat(dirfd int, path string, mode uint32) error {
386 return Mknodat(dirfd, path, mode|S_IFIFO, 0)
387 }
388
389 func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
390 if sa.Port < 0 || sa.Port > 0xFFFF {
391 return nil, 0, EINVAL
392 }
393 sa.raw.Family = AF_INET
394 p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
395 p[0] = byte(sa.Port >> 8)
396 p[1] = byte(sa.Port)
397 sa.raw.Addr = sa.Addr
398 return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil
399 }
400
401 func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
402 if sa.Port < 0 || sa.Port > 0xFFFF {
403 return nil, 0, EINVAL
404 }
405 sa.raw.Family = AF_INET6
406 p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
407 p[0] = byte(sa.Port >> 8)
408 p[1] = byte(sa.Port)
409 sa.raw.Scope_id = sa.ZoneId
410 sa.raw.Addr = sa.Addr
411 return unsafe.Pointer(&sa.raw), SizeofSockaddrInet6, nil
412 }
413
414 func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
415 name := sa.Name
416 n := len(name)
417 if n >= len(sa.raw.Path) {
418 return nil, 0, EINVAL
419 }
420 sa.raw.Family = AF_UNIX
421 for i := range n {
422 sa.raw.Path[i] = int8(name[i])
423 }
424 // length is family (uint16), name, NUL.
425 sl := _Socklen(2)
426 if n > 0 {
427 sl += _Socklen(n) + 1
428 }
429 if sa.raw.Path[0] == '@' || (sa.raw.Path[0] == 0 && sl > 3) {
430 // Check sl > 3 so we don't change unnamed socket behavior.
431 sa.raw.Path[0] = 0
432 // Don't count trailing NUL for abstract address.
433 sl--
434 }
435
436 return unsafe.Pointer(&sa.raw), sl, nil
437 }
438
439 // SockaddrLinklayer implements the Sockaddr interface for AF_PACKET type sockets.
440 type SockaddrLinklayer struct {
441 Protocol uint16
442 Ifindex int
443 Hatype uint16
444 Pkttype uint8
445 Halen uint8
446 Addr [8]byte
447 raw RawSockaddrLinklayer
448 }
449
450 func (sa *SockaddrLinklayer) sockaddr() (unsafe.Pointer, _Socklen, error) {
451 if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {
452 return nil, 0, EINVAL
453 }
454 sa.raw.Family = AF_PACKET
455 sa.raw.Protocol = sa.Protocol
456 sa.raw.Ifindex = int32(sa.Ifindex)
457 sa.raw.Hatype = sa.Hatype
458 sa.raw.Pkttype = sa.Pkttype
459 sa.raw.Halen = sa.Halen
460 sa.raw.Addr = sa.Addr
461 return unsafe.Pointer(&sa.raw), SizeofSockaddrLinklayer, nil
462 }
463
464 // SockaddrNetlink implements the Sockaddr interface for AF_NETLINK type sockets.
465 type SockaddrNetlink struct {
466 Family uint16
467 Pad uint16
468 Pid uint32
469 Groups uint32
470 raw RawSockaddrNetlink
471 }
472
473 func (sa *SockaddrNetlink) sockaddr() (unsafe.Pointer, _Socklen, error) {
474 sa.raw.Family = AF_NETLINK
475 sa.raw.Pad = sa.Pad
476 sa.raw.Pid = sa.Pid
477 sa.raw.Groups = sa.Groups
478 return unsafe.Pointer(&sa.raw), SizeofSockaddrNetlink, nil
479 }
480
481 // SockaddrHCI implements the Sockaddr interface for AF_BLUETOOTH type sockets
482 // using the HCI protocol.
483 type SockaddrHCI struct {
484 Dev uint16
485 Channel uint16
486 raw RawSockaddrHCI
487 }
488
489 func (sa *SockaddrHCI) sockaddr() (unsafe.Pointer, _Socklen, error) {
490 sa.raw.Family = AF_BLUETOOTH
491 sa.raw.Dev = sa.Dev
492 sa.raw.Channel = sa.Channel
493 return unsafe.Pointer(&sa.raw), SizeofSockaddrHCI, nil
494 }
495
496 // SockaddrL2 implements the Sockaddr interface for AF_BLUETOOTH type sockets
497 // using the L2CAP protocol.
498 type SockaddrL2 struct {
499 PSM uint16
500 CID uint16
501 Addr [6]uint8
502 AddrType uint8
503 raw RawSockaddrL2
504 }
505
506 func (sa *SockaddrL2) sockaddr() (unsafe.Pointer, _Socklen, error) {
507 sa.raw.Family = AF_BLUETOOTH
508 psm := (*[2]byte)(unsafe.Pointer(&sa.raw.Psm))
509 psm[0] = byte(sa.PSM)
510 psm[1] = byte(sa.PSM >> 8)
511 for i := range len(sa.Addr) {
512 sa.raw.Bdaddr[i] = sa.Addr[len(sa.Addr)-1-i]
513 }
514 cid := (*[2]byte)(unsafe.Pointer(&sa.raw.Cid))
515 cid[0] = byte(sa.CID)
516 cid[1] = byte(sa.CID >> 8)
517 sa.raw.Bdaddr_type = sa.AddrType
518 return unsafe.Pointer(&sa.raw), SizeofSockaddrL2, nil
519 }
520
521 // SockaddrRFCOMM implements the Sockaddr interface for AF_BLUETOOTH type sockets
522 // using the RFCOMM protocol.
523 //
524 // Server example:
525 //
526 // fd, _ := Socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM)
527 // _ = unix.Bind(fd, &unix.SockaddrRFCOMM{
528 // Channel: 1,
529 // Addr: [6]uint8{0, 0, 0, 0, 0, 0}, // BDADDR_ANY or 00:00:00:00:00:00
530 // })
531 // _ = Listen(fd, 1)
532 // nfd, sa, _ := Accept(fd)
533 // fmt.Printf("conn addr=%v fd=%d", sa.(*unix.SockaddrRFCOMM).Addr, nfd)
534 // Read(nfd, buf)
535 //
536 // Client example:
537 //
538 // fd, _ := Socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM)
539 // _ = Connect(fd, &SockaddrRFCOMM{
540 // Channel: 1,
541 // Addr: [6]byte{0x11, 0x22, 0x33, 0xaa, 0xbb, 0xcc}, // CC:BB:AA:33:22:11
542 // })
543 // Write(fd, []byte(`hello`))
544 type SockaddrRFCOMM struct {
545 // Addr represents a bluetooth address, byte ordering is little-endian.
546 Addr [6]uint8
547
548 // Channel is a designated bluetooth channel, only 1-30 are available for use.
549 // Since Linux 2.6.7 and further zero value is the first available channel.
550 Channel uint8
551
552 raw RawSockaddrRFCOMM
553 }
554
555 func (sa *SockaddrRFCOMM) sockaddr() (unsafe.Pointer, _Socklen, error) {
556 sa.raw.Family = AF_BLUETOOTH
557 sa.raw.Channel = sa.Channel
558 sa.raw.Bdaddr = sa.Addr
559 return unsafe.Pointer(&sa.raw), SizeofSockaddrRFCOMM, nil
560 }
561
562 // SockaddrCAN implements the Sockaddr interface for AF_CAN type sockets.
563 // The RxID and TxID fields are used for transport protocol addressing in
564 // (CAN_TP16, CAN_TP20, CAN_MCNET, and CAN_ISOTP), they can be left with
565 // zero values for CAN_RAW and CAN_BCM sockets as they have no meaning.
566 //
567 // The SockaddrCAN struct must be bound to the socket file descriptor
568 // using Bind before the CAN socket can be used.
569 //
570 // // Read one raw CAN frame
571 // fd, _ := Socket(AF_CAN, SOCK_RAW, CAN_RAW)
572 // addr := &SockaddrCAN{Ifindex: index}
573 // Bind(fd, addr)
574 // frame := make([]byte, 16)
575 // Read(fd, frame)
576 //
577 // The full SocketCAN documentation can be found in the linux kernel
578 // archives at: https://www.kernel.org/doc/Documentation/networking/can.txt
579 type SockaddrCAN struct {
580 Ifindex int
581 RxID uint32
582 TxID uint32
583 raw RawSockaddrCAN
584 }
585
586 func (sa *SockaddrCAN) sockaddr() (unsafe.Pointer, _Socklen, error) {
587 if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {
588 return nil, 0, EINVAL
589 }
590 sa.raw.Family = AF_CAN
591 sa.raw.Ifindex = int32(sa.Ifindex)
592 rx := (*[4]byte)(unsafe.Pointer(&sa.RxID))
593 for i := range 4 {
594 sa.raw.Addr[i] = rx[i]
595 }
596 tx := (*[4]byte)(unsafe.Pointer(&sa.TxID))
597 for i := range 4 {
598 sa.raw.Addr[i+4] = tx[i]
599 }
600 return unsafe.Pointer(&sa.raw), SizeofSockaddrCAN, nil
601 }
602
603 // SockaddrCANJ1939 implements the Sockaddr interface for AF_CAN using J1939
604 // protocol (https://en.wikipedia.org/wiki/SAE_J1939). For more information
605 // on the purposes of the fields, check the official linux kernel documentation
606 // available here: https://www.kernel.org/doc/Documentation/networking/j1939.rst
607 type SockaddrCANJ1939 struct {
608 Ifindex int
609 Name uint64
610 PGN uint32
611 Addr uint8
612 raw RawSockaddrCAN
613 }
614
615 func (sa *SockaddrCANJ1939) sockaddr() (unsafe.Pointer, _Socklen, error) {
616 if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {
617 return nil, 0, EINVAL
618 }
619 sa.raw.Family = AF_CAN
620 sa.raw.Ifindex = int32(sa.Ifindex)
621 n := (*[8]byte)(unsafe.Pointer(&sa.Name))
622 for i := range 8 {
623 sa.raw.Addr[i] = n[i]
624 }
625 p := (*[4]byte)(unsafe.Pointer(&sa.PGN))
626 for i := range 4 {
627 sa.raw.Addr[i+8] = p[i]
628 }
629 sa.raw.Addr[12] = sa.Addr
630 return unsafe.Pointer(&sa.raw), SizeofSockaddrCAN, nil
631 }
632
633 // SockaddrALG implements the Sockaddr interface for AF_ALG type sockets.
634 // SockaddrALG enables userspace access to the Linux kernel's cryptography
635 // subsystem. The Type and Name fields specify which type of hash or cipher
636 // should be used with a given socket.
637 //
638 // To create a file descriptor that provides access to a hash or cipher, both
639 // Bind and Accept must be used. Once the setup process is complete, input
640 // data can be written to the socket, processed by the kernel, and then read
641 // back as hash output or ciphertext.
642 //
643 // Here is an example of using an AF_ALG socket with SHA1 hashing.
644 // The initial socket setup process is as follows:
645 //
646 // // Open a socket to perform SHA1 hashing.
647 // fd, _ := unix.Socket(unix.AF_ALG, unix.SOCK_SEQPACKET, 0)
648 // addr := &unix.SockaddrALG{Type: "hash", Name: "sha1"}
649 // unix.Bind(fd, addr)
650 // // Note: unix.Accept does not work at this time; must invoke accept()
651 // // manually using unix.Syscall.
652 // hashfd, _, _ := unix.Syscall(unix.SYS_ACCEPT, uintptr(fd), 0, 0)
653 //
654 // Once a file descriptor has been returned from Accept, it may be used to
655 // perform SHA1 hashing. The descriptor is not safe for concurrent use, but
656 // may be re-used repeatedly with subsequent Write and Read operations.
657 //
658 // When hashing a small byte slice or string, a single Write and Read may
659 // be used:
660 //
661 // // Assume hashfd is already configured using the setup process.
662 // hash := os.NewFile(hashfd, "sha1")
663 // // Hash an input string and read the results. Each Write discards
664 // // previous hash state. Read always reads the current state.
665 // b := make([]byte, 20)
666 // for i := 0; i < 2; i++ {
667 // io.WriteString(hash, "Hello, world.")
668 // hash.Read(b)
669 // fmt.Println(hex.EncodeToString(b))
670 // }
671 // // Output:
672 // // 2ae01472317d1935a84797ec1983ae243fc6aa28
673 // // 2ae01472317d1935a84797ec1983ae243fc6aa28
674 //
675 // For hashing larger byte slices, or byte streams such as those read from
676 // a file or socket, use Sendto with MSG_MORE to instruct the kernel to update
677 // the hash digest instead of creating a new one for a given chunk and finalizing it.
678 //
679 // // Assume hashfd and addr are already configured using the setup process.
680 // hash := os.NewFile(hashfd, "sha1")
681 // // Hash the contents of a file.
682 // f, _ := os.Open("/tmp/linux-4.10-rc7.tar.xz")
683 // b := make([]byte, 4096)
684 // for {
685 // n, err := f.Read(b)
686 // if err == io.EOF {
687 // break
688 // }
689 // unix.Sendto(hashfd, b[:n], unix.MSG_MORE, addr)
690 // }
691 // hash.Read(b)
692 // fmt.Println(hex.EncodeToString(b))
693 // // Output: 85cdcad0c06eef66f805ecce353bec9accbeecc5
694 //
695 // For more information, see: http://www.chronox.de/crypto-API/crypto/userspace-if.html.
696 type SockaddrALG struct {
697 Type string
698 Name string
699 Feature uint32
700 Mask uint32
701 raw RawSockaddrALG
702 }
703
704 func (sa *SockaddrALG) sockaddr() (unsafe.Pointer, _Socklen, error) {
705 // Leave room for NUL byte terminator.
706 if len(sa.Type) > len(sa.raw.Type)-1 {
707 return nil, 0, EINVAL
708 }
709 if len(sa.Name) > len(sa.raw.Name)-1 {
710 return nil, 0, EINVAL
711 }
712
713 sa.raw.Family = AF_ALG
714 sa.raw.Feat = sa.Feature
715 sa.raw.Mask = sa.Mask
716
717 copy(sa.raw.Type[:], sa.Type)
718 copy(sa.raw.Name[:], sa.Name)
719
720 return unsafe.Pointer(&sa.raw), SizeofSockaddrALG, nil
721 }
722
723 // SockaddrVM implements the Sockaddr interface for AF_VSOCK type sockets.
724 // SockaddrVM provides access to Linux VM sockets: a mechanism that enables
725 // bidirectional communication between a hypervisor and its guest virtual
726 // machines.
727 type SockaddrVM struct {
728 // CID and Port specify a context ID and port address for a VM socket.
729 // Guests have a unique CID, and hosts may have a well-known CID of:
730 // - VMADDR_CID_HYPERVISOR: refers to the hypervisor process.
731 // - VMADDR_CID_LOCAL: refers to local communication (loopback).
732 // - VMADDR_CID_HOST: refers to other processes on the host.
733 CID uint32
734 Port uint32
735 Flags uint8
736 raw RawSockaddrVM
737 }
738
739 func (sa *SockaddrVM) sockaddr() (unsafe.Pointer, _Socklen, error) {
740 sa.raw.Family = AF_VSOCK
741 sa.raw.Port = sa.Port
742 sa.raw.Cid = sa.CID
743 sa.raw.Flags = sa.Flags
744
745 return unsafe.Pointer(&sa.raw), SizeofSockaddrVM, nil
746 }
747
748 type SockaddrXDP struct {
749 Flags uint16
750 Ifindex uint32
751 QueueID uint32
752 SharedUmemFD uint32
753 raw RawSockaddrXDP
754 }
755
756 func (sa *SockaddrXDP) sockaddr() (unsafe.Pointer, _Socklen, error) {
757 sa.raw.Family = AF_XDP
758 sa.raw.Flags = sa.Flags
759 sa.raw.Ifindex = sa.Ifindex
760 sa.raw.Queue_id = sa.QueueID
761 sa.raw.Shared_umem_fd = sa.SharedUmemFD
762
763 return unsafe.Pointer(&sa.raw), SizeofSockaddrXDP, nil
764 }
765
766 // This constant mirrors the #define of PX_PROTO_OE in
767 // linux/if_pppox.h. We're defining this by hand here instead of
768 // autogenerating through mkerrors.sh because including
769 // linux/if_pppox.h causes some declaration conflicts with other
770 // includes (linux/if_pppox.h includes linux/in.h, which conflicts
771 // with netinet/in.h). Given that we only need a single zero constant
772 // out of that file, it's cleaner to just define it by hand here.
773 const px_proto_oe = 0
774
775 type SockaddrPPPoE struct {
776 SID uint16
777 Remote []byte
778 Dev string
779 raw RawSockaddrPPPoX
780 }
781
782 func (sa *SockaddrPPPoE) sockaddr() (unsafe.Pointer, _Socklen, error) {
783 if len(sa.Remote) != 6 {
784 return nil, 0, EINVAL
785 }
786 if len(sa.Dev) > IFNAMSIZ-1 {
787 return nil, 0, EINVAL
788 }
789
790 *(*uint16)(unsafe.Pointer(&sa.raw[0])) = AF_PPPOX
791 // This next field is in host-endian byte order. We can't use the
792 // same unsafe pointer cast as above, because this value is not
793 // 32-bit aligned and some architectures don't allow unaligned
794 // access.
795 //
796 // However, the value of px_proto_oe is 0, so we can use
797 // encoding/binary helpers to write the bytes without worrying
798 // about the ordering.
799 binary.BigEndian.PutUint32(sa.raw[2:6], px_proto_oe)
800 // This field is deliberately big-endian, unlike the previous
801 // one. The kernel expects SID to be in network byte order.
802 binary.BigEndian.PutUint16(sa.raw[6:8], sa.SID)
803 copy(sa.raw[8:14], sa.Remote)
804 clear(sa.raw[14 : 14+IFNAMSIZ])
805 copy(sa.raw[14:], sa.Dev)
806 return unsafe.Pointer(&sa.raw), SizeofSockaddrPPPoX, nil
807 }
808
809 // SockaddrTIPC implements the Sockaddr interface for AF_TIPC type sockets.
810 // For more information on TIPC, see: http://tipc.sourceforge.net/.
811 type SockaddrTIPC struct {
812 // Scope is the publication scopes when binding service/service range.
813 // Should be set to TIPC_CLUSTER_SCOPE or TIPC_NODE_SCOPE.
814 Scope int
815
816 // Addr is the type of address used to manipulate a socket. Addr must be
817 // one of:
818 // - *TIPCSocketAddr: "id" variant in the C addr union
819 // - *TIPCServiceRange: "nameseq" variant in the C addr union
820 // - *TIPCServiceName: "name" variant in the C addr union
821 //
822 // If nil, EINVAL will be returned when the structure is used.
823 Addr TIPCAddr
824
825 raw RawSockaddrTIPC
826 }
827
828 // TIPCAddr is implemented by types that can be used as an address for
829 // SockaddrTIPC. It is only implemented by *TIPCSocketAddr, *TIPCServiceRange,
830 // and *TIPCServiceName.
831 type TIPCAddr interface {
832 tipcAddrtype() uint8
833 tipcAddr() [12]byte
834 }
835
836 func (sa *TIPCSocketAddr) tipcAddr() [12]byte {
837 var out [12]byte
838 copy(out[:], (*(*[unsafe.Sizeof(TIPCSocketAddr{})]byte)(unsafe.Pointer(sa)))[:])
839 return out
840 }
841
842 func (sa *TIPCSocketAddr) tipcAddrtype() uint8 { return TIPC_SOCKET_ADDR }
843
844 func (sa *TIPCServiceRange) tipcAddr() [12]byte {
845 var out [12]byte
846 copy(out[:], (*(*[unsafe.Sizeof(TIPCServiceRange{})]byte)(unsafe.Pointer(sa)))[:])
847 return out
848 }
849
850 func (sa *TIPCServiceRange) tipcAddrtype() uint8 { return TIPC_SERVICE_RANGE }
851
852 func (sa *TIPCServiceName) tipcAddr() [12]byte {
853 var out [12]byte
854 copy(out[:], (*(*[unsafe.Sizeof(TIPCServiceName{})]byte)(unsafe.Pointer(sa)))[:])
855 return out
856 }
857
858 func (sa *TIPCServiceName) tipcAddrtype() uint8 { return TIPC_SERVICE_ADDR }
859
860 func (sa *SockaddrTIPC) sockaddr() (unsafe.Pointer, _Socklen, error) {
861 if sa.Addr == nil {
862 return nil, 0, EINVAL
863 }
864 sa.raw.Family = AF_TIPC
865 sa.raw.Scope = int8(sa.Scope)
866 sa.raw.Addrtype = sa.Addr.tipcAddrtype()
867 sa.raw.Addr = sa.Addr.tipcAddr()
868 return unsafe.Pointer(&sa.raw), SizeofSockaddrTIPC, nil
869 }
870
871 // SockaddrL2TPIP implements the Sockaddr interface for IPPROTO_L2TP/AF_INET sockets.
872 type SockaddrL2TPIP struct {
873 Addr [4]byte
874 ConnId uint32
875 raw RawSockaddrL2TPIP
876 }
877
878 func (sa *SockaddrL2TPIP) sockaddr() (unsafe.Pointer, _Socklen, error) {
879 sa.raw.Family = AF_INET
880 sa.raw.Conn_id = sa.ConnId
881 sa.raw.Addr = sa.Addr
882 return unsafe.Pointer(&sa.raw), SizeofSockaddrL2TPIP, nil
883 }
884
885 // SockaddrL2TPIP6 implements the Sockaddr interface for IPPROTO_L2TP/AF_INET6 sockets.
886 type SockaddrL2TPIP6 struct {
887 Addr [16]byte
888 ZoneId uint32
889 ConnId uint32
890 raw RawSockaddrL2TPIP6
891 }
892
893 func (sa *SockaddrL2TPIP6) sockaddr() (unsafe.Pointer, _Socklen, error) {
894 sa.raw.Family = AF_INET6
895 sa.raw.Conn_id = sa.ConnId
896 sa.raw.Scope_id = sa.ZoneId
897 sa.raw.Addr = sa.Addr
898 return unsafe.Pointer(&sa.raw), SizeofSockaddrL2TPIP6, nil
899 }
900
901 // SockaddrIUCV implements the Sockaddr interface for AF_IUCV sockets.
902 type SockaddrIUCV struct {
903 UserID string
904 Name string
905 raw RawSockaddrIUCV
906 }
907
908 func (sa *SockaddrIUCV) sockaddr() (unsafe.Pointer, _Socklen, error) {
909 sa.raw.Family = AF_IUCV
910 // These are EBCDIC encoded by the kernel, but we still need to pad them
911 // with blanks. Initializing with blanks allows the caller to feed in either
912 // a padded or an unpadded string.
913 for i := range 8 {
914 sa.raw.Nodeid[i] = ' '
915 sa.raw.User_id[i] = ' '
916 sa.raw.Name[i] = ' '
917 }
918 if len(sa.UserID) > 8 || len(sa.Name) > 8 {
919 return nil, 0, EINVAL
920 }
921 for i, b := range []byte(sa.UserID[:]) {
922 sa.raw.User_id[i] = int8(b)
923 }
924 for i, b := range []byte(sa.Name[:]) {
925 sa.raw.Name[i] = int8(b)
926 }
927 return unsafe.Pointer(&sa.raw), SizeofSockaddrIUCV, nil
928 }
929
930 type SockaddrNFC struct {
931 DeviceIdx uint32
932 TargetIdx uint32
933 NFCProtocol uint32
934 raw RawSockaddrNFC
935 }
936
937 func (sa *SockaddrNFC) sockaddr() (unsafe.Pointer, _Socklen, error) {
938 sa.raw.Sa_family = AF_NFC
939 sa.raw.Dev_idx = sa.DeviceIdx
940 sa.raw.Target_idx = sa.TargetIdx
941 sa.raw.Nfc_protocol = sa.NFCProtocol
942 return unsafe.Pointer(&sa.raw), SizeofSockaddrNFC, nil
943 }
944
945 type SockaddrNFCLLCP struct {
946 DeviceIdx uint32
947 TargetIdx uint32
948 NFCProtocol uint32
949 DestinationSAP uint8
950 SourceSAP uint8
951 ServiceName string
952 raw RawSockaddrNFCLLCP
953 }
954
955 func (sa *SockaddrNFCLLCP) sockaddr() (unsafe.Pointer, _Socklen, error) {
956 sa.raw.Sa_family = AF_NFC
957 sa.raw.Dev_idx = sa.DeviceIdx
958 sa.raw.Target_idx = sa.TargetIdx
959 sa.raw.Nfc_protocol = sa.NFCProtocol
960 sa.raw.Dsap = sa.DestinationSAP
961 sa.raw.Ssap = sa.SourceSAP
962 if len(sa.ServiceName) > len(sa.raw.Service_name) {
963 return nil, 0, EINVAL
964 }
965 copy(sa.raw.Service_name[:], sa.ServiceName)
966 sa.raw.SetServiceNameLen(len(sa.ServiceName))
967 return unsafe.Pointer(&sa.raw), SizeofSockaddrNFCLLCP, nil
968 }
969
970 var socketProtocol = func(fd int) (int, error) {
971 return GetsockoptInt(fd, SOL_SOCKET, SO_PROTOCOL)
972 }
973
974 func anyToSockaddr(fd int, rsa *RawSockaddrAny) (Sockaddr, error) {
975 switch rsa.Addr.Family {
976 case AF_NETLINK:
977 pp := (*RawSockaddrNetlink)(unsafe.Pointer(rsa))
978 sa := new(SockaddrNetlink)
979 sa.Family = pp.Family
980 sa.Pad = pp.Pad
981 sa.Pid = pp.Pid
982 sa.Groups = pp.Groups
983 return sa, nil
984
985 case AF_PACKET:
986 pp := (*RawSockaddrLinklayer)(unsafe.Pointer(rsa))
987 sa := new(SockaddrLinklayer)
988 sa.Protocol = pp.Protocol
989 sa.Ifindex = int(pp.Ifindex)
990 sa.Hatype = pp.Hatype
991 sa.Pkttype = pp.Pkttype
992 sa.Halen = pp.Halen
993 sa.Addr = pp.Addr
994 return sa, nil
995
996 case AF_UNIX:
997 pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
998 sa := new(SockaddrUnix)
999 if pp.Path[0] == 0 {
1000 // "Abstract" Unix domain socket.
1001 // Rewrite leading NUL as @ for textual display.
1002 // (This is the standard convention.)
1003 // Not friendly to overwrite in place,
1004 // but the callers below don't care.
1005 pp.Path[0] = '@'
1006 }
1007
1008 // Assume path ends at NUL.
1009 // This is not technically the Linux semantics for
1010 // abstract Unix domain sockets--they are supposed
1011 // to be uninterpreted fixed-size binary blobs--but
1012 // everyone uses this convention.
1013 n := 0
1014 for n < len(pp.Path) && pp.Path[n] != 0 {
1015 n++
1016 }
1017 sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n))
1018 return sa, nil
1019
1020 case AF_INET:
1021 proto, err := socketProtocol(fd)
1022 if err != nil {
1023 return nil, err
1024 }
1025
1026 switch proto {
1027 case IPPROTO_L2TP:
1028 pp := (*RawSockaddrL2TPIP)(unsafe.Pointer(rsa))
1029 sa := new(SockaddrL2TPIP)
1030 sa.ConnId = pp.Conn_id
1031 sa.Addr = pp.Addr
1032 return sa, nil
1033 default:
1034 pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
1035 sa := new(SockaddrInet4)
1036 p := (*[2]byte)(unsafe.Pointer(&pp.Port))
1037 sa.Port = int(p[0])<<8 + int(p[1])
1038 sa.Addr = pp.Addr
1039 return sa, nil
1040 }
1041
1042 case AF_INET6:
1043 proto, err := socketProtocol(fd)
1044 if err != nil {
1045 return nil, err
1046 }
1047
1048 switch proto {
1049 case IPPROTO_L2TP:
1050 pp := (*RawSockaddrL2TPIP6)(unsafe.Pointer(rsa))
1051 sa := new(SockaddrL2TPIP6)
1052 sa.ConnId = pp.Conn_id
1053 sa.ZoneId = pp.Scope_id
1054 sa.Addr = pp.Addr
1055 return sa, nil
1056 default:
1057 pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
1058 sa := new(SockaddrInet6)
1059 p := (*[2]byte)(unsafe.Pointer(&pp.Port))
1060 sa.Port = int(p[0])<<8 + int(p[1])
1061 sa.ZoneId = pp.Scope_id
1062 sa.Addr = pp.Addr
1063 return sa, nil
1064 }
1065
1066 case AF_VSOCK:
1067 pp := (*RawSockaddrVM)(unsafe.Pointer(rsa))
1068 sa := &SockaddrVM{
1069 CID: pp.Cid,
1070 Port: pp.Port,
1071 Flags: pp.Flags,
1072 }
1073 return sa, nil
1074 case AF_BLUETOOTH:
1075 proto, err := socketProtocol(fd)
1076 if err != nil {
1077 return nil, err
1078 }
1079 // only BTPROTO_L2CAP and BTPROTO_RFCOMM can accept connections
1080 switch proto {
1081 case BTPROTO_L2CAP:
1082 pp := (*RawSockaddrL2)(unsafe.Pointer(rsa))
1083 sa := &SockaddrL2{
1084 PSM: pp.Psm,
1085 CID: pp.Cid,
1086 Addr: pp.Bdaddr,
1087 AddrType: pp.Bdaddr_type,
1088 }
1089 return sa, nil
1090 case BTPROTO_RFCOMM:
1091 pp := (*RawSockaddrRFCOMM)(unsafe.Pointer(rsa))
1092 sa := &SockaddrRFCOMM{
1093 Channel: pp.Channel,
1094 Addr: pp.Bdaddr,
1095 }
1096 return sa, nil
1097 }
1098 case AF_XDP:
1099 pp := (*RawSockaddrXDP)(unsafe.Pointer(rsa))
1100 sa := &SockaddrXDP{
1101 Flags: pp.Flags,
1102 Ifindex: pp.Ifindex,
1103 QueueID: pp.Queue_id,
1104 SharedUmemFD: pp.Shared_umem_fd,
1105 }
1106 return sa, nil
1107 case AF_PPPOX:
1108 pp := (*RawSockaddrPPPoX)(unsafe.Pointer(rsa))
1109 if binary.BigEndian.Uint32(pp[2:6]) != px_proto_oe {
1110 return nil, EINVAL
1111 }
1112 sa := &SockaddrPPPoE{
1113 SID: binary.BigEndian.Uint16(pp[6:8]),
1114 Remote: pp[8:14],
1115 }
1116 for i := 14; i < 14+IFNAMSIZ; i++ {
1117 if pp[i] == 0 {
1118 sa.Dev = string(pp[14:i])
1119 break
1120 }
1121 }
1122 return sa, nil
1123 case AF_TIPC:
1124 pp := (*RawSockaddrTIPC)(unsafe.Pointer(rsa))
1125
1126 sa := &SockaddrTIPC{
1127 Scope: int(pp.Scope),
1128 }
1129
1130 // Determine which union variant is present in pp.Addr by checking
1131 // pp.Addrtype.
1132 switch pp.Addrtype {
1133 case TIPC_SERVICE_RANGE:
1134 sa.Addr = (*TIPCServiceRange)(unsafe.Pointer(&pp.Addr))
1135 case TIPC_SERVICE_ADDR:
1136 sa.Addr = (*TIPCServiceName)(unsafe.Pointer(&pp.Addr))
1137 case TIPC_SOCKET_ADDR:
1138 sa.Addr = (*TIPCSocketAddr)(unsafe.Pointer(&pp.Addr))
1139 default:
1140 return nil, EINVAL
1141 }
1142
1143 return sa, nil
1144 case AF_IUCV:
1145 pp := (*RawSockaddrIUCV)(unsafe.Pointer(rsa))
1146
1147 var user [8]byte
1148 var name [8]byte
1149
1150 for i := range 8 {
1151 user[i] = byte(pp.User_id[i])
1152 name[i] = byte(pp.Name[i])
1153 }
1154
1155 sa := &SockaddrIUCV{
1156 UserID: string(user[:]),
1157 Name: string(name[:]),
1158 }
1159 return sa, nil
1160
1161 case AF_CAN:
1162 proto, err := socketProtocol(fd)
1163 if err != nil {
1164 return nil, err
1165 }
1166
1167 pp := (*RawSockaddrCAN)(unsafe.Pointer(rsa))
1168
1169 switch proto {
1170 case CAN_J1939:
1171 sa := &SockaddrCANJ1939{
1172 Ifindex: int(pp.Ifindex),
1173 }
1174 name := (*[8]byte)(unsafe.Pointer(&sa.Name))
1175 for i := range 8 {
1176 name[i] = pp.Addr[i]
1177 }
1178 pgn := (*[4]byte)(unsafe.Pointer(&sa.PGN))
1179 for i := range 4 {
1180 pgn[i] = pp.Addr[i+8]
1181 }
1182 addr := (*[1]byte)(unsafe.Pointer(&sa.Addr))
1183 addr[0] = pp.Addr[12]
1184 return sa, nil
1185 default:
1186 sa := &SockaddrCAN{
1187 Ifindex: int(pp.Ifindex),
1188 }
1189 rx := (*[4]byte)(unsafe.Pointer(&sa.RxID))
1190 for i := range 4 {
1191 rx[i] = pp.Addr[i]
1192 }
1193 tx := (*[4]byte)(unsafe.Pointer(&sa.TxID))
1194 for i := range 4 {
1195 tx[i] = pp.Addr[i+4]
1196 }
1197 return sa, nil
1198 }
1199 case AF_NFC:
1200 proto, err := socketProtocol(fd)
1201 if err != nil {
1202 return nil, err
1203 }
1204 switch proto {
1205 case NFC_SOCKPROTO_RAW:
1206 pp := (*RawSockaddrNFC)(unsafe.Pointer(rsa))
1207 sa := &SockaddrNFC{
1208 DeviceIdx: pp.Dev_idx,
1209 TargetIdx: pp.Target_idx,
1210 NFCProtocol: pp.Nfc_protocol,
1211 }
1212 return sa, nil
1213 case NFC_SOCKPROTO_LLCP:
1214 pp := (*RawSockaddrNFCLLCP)(unsafe.Pointer(rsa))
1215 if uint64(pp.Service_name_len) > uint64(len(pp.Service_name)) {
1216 return nil, EINVAL
1217 }
1218 sa := &SockaddrNFCLLCP{
1219 DeviceIdx: pp.Dev_idx,
1220 TargetIdx: pp.Target_idx,
1221 NFCProtocol: pp.Nfc_protocol,
1222 DestinationSAP: pp.Dsap,
1223 SourceSAP: pp.Ssap,
1224 ServiceName: string(pp.Service_name[:pp.Service_name_len]),
1225 }
1226 return sa, nil
1227 default:
1228 return nil, EINVAL
1229 }
1230 }
1231 return nil, EAFNOSUPPORT
1232 }
1233
1234 func Accept(fd int) (nfd int, sa Sockaddr, err error) {
1235 var rsa RawSockaddrAny
1236 var len _Socklen = SizeofSockaddrAny
1237 nfd, err = accept4(fd, &rsa, &len, 0)
1238 if err != nil {
1239 return
1240 }
1241 sa, err = anyToSockaddr(fd, &rsa)
1242 if err != nil {
1243 Close(nfd)
1244 nfd = 0
1245 }
1246 return
1247 }
1248
1249 func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) {
1250 var rsa RawSockaddrAny
1251 var len _Socklen = SizeofSockaddrAny
1252 nfd, err = accept4(fd, &rsa, &len, flags)
1253 if err != nil {
1254 return
1255 }
1256 if len > SizeofSockaddrAny {
1257 panic("RawSockaddrAny too small")
1258 }
1259 sa, err = anyToSockaddr(fd, &rsa)
1260 if err != nil {
1261 Close(nfd)
1262 nfd = 0
1263 }
1264 return
1265 }
1266
1267 func Getsockname(fd int) (sa Sockaddr, err error) {
1268 var rsa RawSockaddrAny
1269 var len _Socklen = SizeofSockaddrAny
1270 if err = getsockname(fd, &rsa, &len); err != nil {
1271 return
1272 }
1273 return anyToSockaddr(fd, &rsa)
1274 }
1275
1276 func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {
1277 var value IPMreqn
1278 vallen := _Socklen(SizeofIPMreqn)
1279 err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
1280 return &value, err
1281 }
1282
1283 func GetsockoptUcred(fd, level, opt int) (*Ucred, error) {
1284 var value Ucred
1285 vallen := _Socklen(SizeofUcred)
1286 err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
1287 return &value, err
1288 }
1289
1290 func GetsockoptTCPInfo(fd, level, opt int) (*TCPInfo, error) {
1291 var value TCPInfo
1292 vallen := _Socklen(SizeofTCPInfo)
1293 err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
1294 return &value, err
1295 }
1296
1297 // GetsockoptTCPCCVegasInfo returns algorithm specific congestion control information for a socket using the "vegas"
1298 // algorithm.
1299 //
1300 // The socket's congestion control algorighm can be retrieved via [GetsockoptString] with the [TCP_CONGESTION] option:
1301 //
1302 // algo, err := unix.GetsockoptString(fd, unix.IPPROTO_TCP, unix.TCP_CONGESTION)
1303 func GetsockoptTCPCCVegasInfo(fd, level, opt int) (*TCPVegasInfo, error) {
1304 var value [SizeofTCPCCInfo / 4]uint32 // ensure proper alignment
1305 vallen := _Socklen(SizeofTCPCCInfo)
1306 err := getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
1307 out := (*TCPVegasInfo)(unsafe.Pointer(&value[0]))
1308 return out, err
1309 }
1310
1311 // GetsockoptTCPCCDCTCPInfo returns algorithm specific congestion control information for a socket using the "dctp"
1312 // algorithm.
1313 //
1314 // The socket's congestion control algorighm can be retrieved via [GetsockoptString] with the [TCP_CONGESTION] option:
1315 //
1316 // algo, err := unix.GetsockoptString(fd, unix.IPPROTO_TCP, unix.TCP_CONGESTION)
1317 func GetsockoptTCPCCDCTCPInfo(fd, level, opt int) (*TCPDCTCPInfo, error) {
1318 var value [SizeofTCPCCInfo / 4]uint32 // ensure proper alignment
1319 vallen := _Socklen(SizeofTCPCCInfo)
1320 err := getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
1321 out := (*TCPDCTCPInfo)(unsafe.Pointer(&value[0]))
1322 return out, err
1323 }
1324
1325 // GetsockoptTCPCCBBRInfo returns algorithm specific congestion control information for a socket using the "bbr"
1326 // algorithm.
1327 //
1328 // The socket's congestion control algorighm can be retrieved via [GetsockoptString] with the [TCP_CONGESTION] option:
1329 //
1330 // algo, err := unix.GetsockoptString(fd, unix.IPPROTO_TCP, unix.TCP_CONGESTION)
1331 func GetsockoptTCPCCBBRInfo(fd, level, opt int) (*TCPBBRInfo, error) {
1332 var value [SizeofTCPCCInfo / 4]uint32 // ensure proper alignment
1333 vallen := _Socklen(SizeofTCPCCInfo)
1334 err := getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
1335 out := (*TCPBBRInfo)(unsafe.Pointer(&value[0]))
1336 return out, err
1337 }
1338
1339 // GetsockoptString returns the string value of the socket option opt for the
1340 // socket associated with fd at the given socket level.
1341 func GetsockoptString(fd, level, opt int) (string, error) {
1342 buf := make([]byte, 256)
1343 vallen := _Socklen(len(buf))
1344 err := getsockopt(fd, level, opt, unsafe.Pointer(&buf[0]), &vallen)
1345 if err != nil {
1346 if err == ERANGE {
1347 buf = make([]byte, vallen)
1348 err = getsockopt(fd, level, opt, unsafe.Pointer(&buf[0]), &vallen)
1349 }
1350 if err != nil {
1351 return "", err
1352 }
1353 }
1354 return ByteSliceToString(buf[:vallen]), nil
1355 }
1356
1357 func GetsockoptTpacketStats(fd, level, opt int) (*TpacketStats, error) {
1358 var value TpacketStats
1359 vallen := _Socklen(SizeofTpacketStats)
1360 err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
1361 return &value, err
1362 }
1363
1364 func GetsockoptTpacketStatsV3(fd, level, opt int) (*TpacketStatsV3, error) {
1365 var value TpacketStatsV3
1366 vallen := _Socklen(SizeofTpacketStatsV3)
1367 err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
1368 return &value, err
1369 }
1370
1371 func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {
1372 return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq))
1373 }
1374
1375 func SetsockoptPacketMreq(fd, level, opt int, mreq *PacketMreq) error {
1376 return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq))
1377 }
1378
1379 // SetsockoptSockFprog attaches a classic BPF or an extended BPF program to a
1380 // socket to filter incoming packets. See 'man 7 socket' for usage information.
1381 func SetsockoptSockFprog(fd, level, opt int, fprog *SockFprog) error {
1382 return setsockopt(fd, level, opt, unsafe.Pointer(fprog), unsafe.Sizeof(*fprog))
1383 }
1384
1385 func SetsockoptCanRawFilter(fd, level, opt int, filter []CanFilter) error {
1386 var p unsafe.Pointer
1387 if len(filter) > 0 {
1388 p = unsafe.Pointer(&filter[0])
1389 }
1390 return setsockopt(fd, level, opt, p, uintptr(len(filter)*SizeofCanFilter))
1391 }
1392
1393 func SetsockoptTpacketReq(fd, level, opt int, tp *TpacketReq) error {
1394 return setsockopt(fd, level, opt, unsafe.Pointer(tp), unsafe.Sizeof(*tp))
1395 }
1396
1397 func SetsockoptTpacketReq3(fd, level, opt int, tp *TpacketReq3) error {
1398 return setsockopt(fd, level, opt, unsafe.Pointer(tp), unsafe.Sizeof(*tp))
1399 }
1400
1401 func SetsockoptTCPRepairOpt(fd, level, opt int, o []TCPRepairOpt) (err error) {
1402 if len(o) == 0 {
1403 return EINVAL
1404 }
1405 return setsockopt(fd, level, opt, unsafe.Pointer(&o[0]), uintptr(SizeofTCPRepairOpt*len(o)))
1406 }
1407
1408 func SetsockoptTCPMD5Sig(fd, level, opt int, s *TCPMD5Sig) error {
1409 return setsockopt(fd, level, opt, unsafe.Pointer(s), unsafe.Sizeof(*s))
1410 }
1411
1412 // Keyctl Commands (http://man7.org/linux/man-pages/man2/keyctl.2.html)
1413
1414 // KeyctlInt calls keyctl commands in which each argument is an int.
1415 // These commands are KEYCTL_REVOKE, KEYCTL_CHOWN, KEYCTL_CLEAR, KEYCTL_LINK,
1416 // KEYCTL_UNLINK, KEYCTL_NEGATE, KEYCTL_SET_REQKEY_KEYRING, KEYCTL_SET_TIMEOUT,
1417 // KEYCTL_ASSUME_AUTHORITY, KEYCTL_SESSION_TO_PARENT, KEYCTL_REJECT,
1418 // KEYCTL_INVALIDATE, and KEYCTL_GET_PERSISTENT.
1419 //sys KeyctlInt(cmd int, arg2 int, arg3 int, arg4 int, arg5 int) (ret int, err error) = SYS_KEYCTL
1420
1421 // KeyctlBuffer calls keyctl commands in which the third and fourth
1422 // arguments are a buffer and its length, respectively.
1423 // These commands are KEYCTL_UPDATE, KEYCTL_READ, and KEYCTL_INSTANTIATE.
1424 //sys KeyctlBuffer(cmd int, arg2 int, buf []byte, arg5 int) (ret int, err error) = SYS_KEYCTL
1425
1426 // KeyctlString calls keyctl commands which return a string.
1427 // These commands are KEYCTL_DESCRIBE and KEYCTL_GET_SECURITY.
1428 func KeyctlString(cmd int, id int) (string, error) {
1429 // We must loop as the string data may change in between the syscalls.
1430 // We could allocate a large buffer here to reduce the chance that the
1431 // syscall needs to be called twice; however, this is unnecessary as
1432 // the performance loss is negligible.
1433 var buffer []byte
1434 for {
1435 // Try to fill the buffer with data
1436 length, err := KeyctlBuffer(cmd, id, buffer, 0)
1437 if err != nil {
1438 return "", err
1439 }
1440
1441 // Check if the data was written
1442 if length <= len(buffer) {
1443 // Exclude the null terminator
1444 return string(buffer[:length-1]), nil
1445 }
1446
1447 // Make a bigger buffer if needed
1448 buffer = make([]byte, length)
1449 }
1450 }
1451
1452 // Keyctl commands with special signatures.
1453
1454 // KeyctlGetKeyringID implements the KEYCTL_GET_KEYRING_ID command.
1455 // See the full documentation at:
1456 // http://man7.org/linux/man-pages/man3/keyctl_get_keyring_ID.3.html
1457 func KeyctlGetKeyringID(id int, create bool) (ringid int, err error) {
1458 createInt := 0
1459 if create {
1460 createInt = 1
1461 }
1462 return KeyctlInt(KEYCTL_GET_KEYRING_ID, id, createInt, 0, 0)
1463 }
1464
1465 // KeyctlSetperm implements the KEYCTL_SETPERM command. The perm value is the
1466 // key handle permission mask as described in the "keyctl setperm" section of
1467 // http://man7.org/linux/man-pages/man1/keyctl.1.html.
1468 // See the full documentation at:
1469 // http://man7.org/linux/man-pages/man3/keyctl_setperm.3.html
1470 func KeyctlSetperm(id int, perm uint32) error {
1471 _, err := KeyctlInt(KEYCTL_SETPERM, id, int(perm), 0, 0)
1472 return err
1473 }
1474
1475 //sys keyctlJoin(cmd int, arg2 string) (ret int, err error) = SYS_KEYCTL
1476
1477 // KeyctlJoinSessionKeyring implements the KEYCTL_JOIN_SESSION_KEYRING command.
1478 // See the full documentation at:
1479 // http://man7.org/linux/man-pages/man3/keyctl_join_session_keyring.3.html
1480 func KeyctlJoinSessionKeyring(name string) (ringid int, err error) {
1481 return keyctlJoin(KEYCTL_JOIN_SESSION_KEYRING, name)
1482 }
1483
1484 //sys keyctlSearch(cmd int, arg2 int, arg3 string, arg4 string, arg5 int) (ret int, err error) = SYS_KEYCTL
1485
1486 // KeyctlSearch implements the KEYCTL_SEARCH command.
1487 // See the full documentation at:
1488 // http://man7.org/linux/man-pages/man3/keyctl_search.3.html
1489 func KeyctlSearch(ringid int, keyType, description string, destRingid int) (id int, err error) {
1490 return keyctlSearch(KEYCTL_SEARCH, ringid, keyType, description, destRingid)
1491 }
1492
1493 //sys keyctlIOV(cmd int, arg2 int, payload []Iovec, arg5 int) (err error) = SYS_KEYCTL
1494
1495 // KeyctlInstantiateIOV implements the KEYCTL_INSTANTIATE_IOV command. This
1496 // command is similar to KEYCTL_INSTANTIATE, except that the payload is a slice
1497 // of Iovec (each of which represents a buffer) instead of a single buffer.
1498 // See the full documentation at:
1499 // http://man7.org/linux/man-pages/man3/keyctl_instantiate_iov.3.html
1500 func KeyctlInstantiateIOV(id int, payload []Iovec, ringid int) error {
1501 return keyctlIOV(KEYCTL_INSTANTIATE_IOV, id, payload, ringid)
1502 }
1503
1504 //sys keyctlDH(cmd int, arg2 *KeyctlDHParams, buf []byte) (ret int, err error) = SYS_KEYCTL
1505
1506 // KeyctlDHCompute implements the KEYCTL_DH_COMPUTE command. This command
1507 // computes a Diffie-Hellman shared secret based on the provide params. The
1508 // secret is written to the provided buffer and the returned size is the number
1509 // of bytes written (returning an error if there is insufficient space in the
1510 // buffer). If a nil buffer is passed in, this function returns the minimum
1511 // buffer length needed to store the appropriate data. Note that this differs
1512 // from KEYCTL_READ's behavior which always returns the requested payload size.
1513 // See the full documentation at:
1514 // http://man7.org/linux/man-pages/man3/keyctl_dh_compute.3.html
1515 func KeyctlDHCompute(params *KeyctlDHParams, buffer []byte) (size int, err error) {
1516 return keyctlDH(KEYCTL_DH_COMPUTE, params, buffer)
1517 }
1518
1519 // KeyctlRestrictKeyring implements the KEYCTL_RESTRICT_KEYRING command. This
1520 // command limits the set of keys that can be linked to the keyring, regardless
1521 // of keyring permissions. The command requires the "setattr" permission.
1522 //
1523 // When called with an empty keyType the command locks the keyring, preventing
1524 // any further keys from being linked to the keyring.
1525 //
1526 // The "asymmetric" keyType defines restrictions requiring key payloads to be
1527 // DER encoded X.509 certificates signed by keys in another keyring. Restrictions
1528 // for "asymmetric" include "builtin_trusted", "builtin_and_secondary_trusted",
1529 // "key_or_keyring:<key>", and "key_or_keyring:<key>:chain".
1530 //
1531 // As of Linux 4.12, only the "asymmetric" keyType defines type-specific
1532 // restrictions.
1533 //
1534 // See the full documentation at:
1535 // http://man7.org/linux/man-pages/man3/keyctl_restrict_keyring.3.html
1536 // http://man7.org/linux/man-pages/man2/keyctl.2.html
1537 func KeyctlRestrictKeyring(ringid int, keyType string, restriction string) error {
1538 if keyType == "" {
1539 return keyctlRestrictKeyring(KEYCTL_RESTRICT_KEYRING, ringid)
1540 }
1541 return keyctlRestrictKeyringByType(KEYCTL_RESTRICT_KEYRING, ringid, keyType, restriction)
1542 }
1543
1544 //sys keyctlRestrictKeyringByType(cmd int, arg2 int, keyType string, restriction string) (err error) = SYS_KEYCTL
1545 //sys keyctlRestrictKeyring(cmd int, arg2 int) (err error) = SYS_KEYCTL
1546
1547 func recvmsgRaw(fd int, iov []Iovec, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {
1548 var msg Msghdr
1549 msg.Name = (*byte)(unsafe.Pointer(rsa))
1550 msg.Namelen = uint32(SizeofSockaddrAny)
1551 var dummy byte
1552 if len(oob) > 0 {
1553 if emptyIovecs(iov) {
1554 var sockType int
1555 sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
1556 if err != nil {
1557 return
1558 }
1559 // receive at least one normal byte
1560 if sockType != SOCK_DGRAM {
1561 var iova [1]Iovec
1562 iova[0].Base = &dummy
1563 iova[0].SetLen(1)
1564 iov = iova[:]
1565 }
1566 }
1567 msg.Control = &oob[0]
1568 msg.SetControllen(len(oob))
1569 }
1570 if len(iov) > 0 {
1571 msg.Iov = &iov[0]
1572 msg.SetIovlen(len(iov))
1573 }
1574 if n, err = recvmsg(fd, &msg, flags); err != nil {
1575 return
1576 }
1577 oobn = int(msg.Controllen)
1578 recvflags = int(msg.Flags)
1579 return
1580 }
1581
1582 func sendmsgN(fd int, iov []Iovec, oob []byte, ptr unsafe.Pointer, salen _Socklen, flags int) (n int, err error) {
1583 var msg Msghdr
1584 msg.Name = (*byte)(ptr)
1585 msg.Namelen = uint32(salen)
1586 var dummy byte
1587 var empty bool
1588 if len(oob) > 0 {
1589 empty = emptyIovecs(iov)
1590 if empty {
1591 var sockType int
1592 sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
1593 if err != nil {
1594 return 0, err
1595 }
1596 // send at least one normal byte
1597 if sockType != SOCK_DGRAM {
1598 var iova [1]Iovec
1599 iova[0].Base = &dummy
1600 iova[0].SetLen(1)
1601 iov = iova[:]
1602 }
1603 }
1604 msg.Control = &oob[0]
1605 msg.SetControllen(len(oob))
1606 }
1607 if len(iov) > 0 {
1608 msg.Iov = &iov[0]
1609 msg.SetIovlen(len(iov))
1610 }
1611 if n, err = sendmsg(fd, &msg, flags); err != nil {
1612 return 0, err
1613 }
1614 if len(oob) > 0 && empty {
1615 n = 0
1616 }
1617 return n, nil
1618 }
1619
1620 // BindToDevice binds the socket associated with fd to device.
1621 func BindToDevice(fd int, device string) (err error) {
1622 return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device)
1623 }
1624
1625 //sys ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
1626 //sys ptracePtr(request int, pid int, addr uintptr, data unsafe.Pointer) (err error) = SYS_PTRACE
1627
1628 func ptracePeek(req int, pid int, addr uintptr, out []byte) (count int, err error) {
1629 // The peek requests are machine-size oriented, so we wrap it
1630 // to retrieve arbitrary-length data.
1631
1632 // The ptrace syscall differs from glibc's ptrace.
1633 // Peeks returns the word in *data, not as the return value.
1634
1635 var buf [SizeofPtr]byte
1636
1637 // Leading edge. PEEKTEXT/PEEKDATA don't require aligned
1638 // access (PEEKUSER warns that it might), but if we don't
1639 // align our reads, we might straddle an unmapped page
1640 // boundary and not get the bytes leading up to the page
1641 // boundary.
1642 n := 0
1643 if addr%SizeofPtr != 0 {
1644 err = ptracePtr(req, pid, addr-addr%SizeofPtr, unsafe.Pointer(&buf[0]))
1645 if err != nil {
1646 return 0, err
1647 }
1648 n += copy(out, buf[addr%SizeofPtr:])
1649 out = out[n:]
1650 }
1651
1652 // Remainder.
1653 for len(out) > 0 {
1654 // We use an internal buffer to guarantee alignment.
1655 // It's not documented if this is necessary, but we're paranoid.
1656 err = ptracePtr(req, pid, addr+uintptr(n), unsafe.Pointer(&buf[0]))
1657 if err != nil {
1658 return n, err
1659 }
1660 copied := copy(out, buf[0:])
1661 n += copied
1662 out = out[copied:]
1663 }
1664
1665 return n, nil
1666 }
1667
1668 func PtracePeekText(pid int, addr uintptr, out []byte) (count int, err error) {
1669 return ptracePeek(PTRACE_PEEKTEXT, pid, addr, out)
1670 }
1671
1672 func PtracePeekData(pid int, addr uintptr, out []byte) (count int, err error) {
1673 return ptracePeek(PTRACE_PEEKDATA, pid, addr, out)
1674 }
1675
1676 func PtracePeekUser(pid int, addr uintptr, out []byte) (count int, err error) {
1677 return ptracePeek(PTRACE_PEEKUSR, pid, addr, out)
1678 }
1679
1680 func ptracePoke(pokeReq int, peekReq int, pid int, addr uintptr, data []byte) (count int, err error) {
1681 // As for ptracePeek, we need to align our accesses to deal
1682 // with the possibility of straddling an invalid page.
1683
1684 // Leading edge.
1685 n := 0
1686 if addr%SizeofPtr != 0 {
1687 var buf [SizeofPtr]byte
1688 err = ptracePtr(peekReq, pid, addr-addr%SizeofPtr, unsafe.Pointer(&buf[0]))
1689 if err != nil {
1690 return 0, err
1691 }
1692 n += copy(buf[addr%SizeofPtr:], data)
1693 word := *((*uintptr)(unsafe.Pointer(&buf[0])))
1694 err = ptrace(pokeReq, pid, addr-addr%SizeofPtr, word)
1695 if err != nil {
1696 return 0, err
1697 }
1698 data = data[n:]
1699 }
1700
1701 // Interior.
1702 for len(data) > SizeofPtr {
1703 word := *((*uintptr)(unsafe.Pointer(&data[0])))
1704 err = ptrace(pokeReq, pid, addr+uintptr(n), word)
1705 if err != nil {
1706 return n, err
1707 }
1708 n += SizeofPtr
1709 data = data[SizeofPtr:]
1710 }
1711
1712 // Trailing edge.
1713 if len(data) > 0 {
1714 var buf [SizeofPtr]byte
1715 err = ptracePtr(peekReq, pid, addr+uintptr(n), unsafe.Pointer(&buf[0]))
1716 if err != nil {
1717 return n, err
1718 }
1719 copy(buf[0:], data)
1720 word := *((*uintptr)(unsafe.Pointer(&buf[0])))
1721 err = ptrace(pokeReq, pid, addr+uintptr(n), word)
1722 if err != nil {
1723 return n, err
1724 }
1725 n += len(data)
1726 }
1727
1728 return n, nil
1729 }
1730
1731 func PtracePokeText(pid int, addr uintptr, data []byte) (count int, err error) {
1732 return ptracePoke(PTRACE_POKETEXT, PTRACE_PEEKTEXT, pid, addr, data)
1733 }
1734
1735 func PtracePokeData(pid int, addr uintptr, data []byte) (count int, err error) {
1736 return ptracePoke(PTRACE_POKEDATA, PTRACE_PEEKDATA, pid, addr, data)
1737 }
1738
1739 func PtracePokeUser(pid int, addr uintptr, data []byte) (count int, err error) {
1740 return ptracePoke(PTRACE_POKEUSR, PTRACE_PEEKUSR, pid, addr, data)
1741 }
1742
1743 // elfNT_PRSTATUS is a copy of the debug/elf.NT_PRSTATUS constant so
1744 // x/sys/unix doesn't need to depend on debug/elf and thus
1745 // compress/zlib, debug/dwarf, and other packages.
1746 const elfNT_PRSTATUS = 1
1747
1748 func PtraceGetRegs(pid int, regsout *PtraceRegs) (err error) {
1749 var iov Iovec
1750 iov.Base = (*byte)(unsafe.Pointer(regsout))
1751 iov.SetLen(int(unsafe.Sizeof(*regsout)))
1752 return ptracePtr(PTRACE_GETREGSET, pid, uintptr(elfNT_PRSTATUS), unsafe.Pointer(&iov))
1753 }
1754
1755 func PtraceSetRegs(pid int, regs *PtraceRegs) (err error) {
1756 var iov Iovec
1757 iov.Base = (*byte)(unsafe.Pointer(regs))
1758 iov.SetLen(int(unsafe.Sizeof(*regs)))
1759 return ptracePtr(PTRACE_SETREGSET, pid, uintptr(elfNT_PRSTATUS), unsafe.Pointer(&iov))
1760 }
1761
1762 func PtraceSetOptions(pid int, options int) (err error) {
1763 return ptrace(PTRACE_SETOPTIONS, pid, 0, uintptr(options))
1764 }
1765
1766 func PtraceGetEventMsg(pid int) (msg uint, err error) {
1767 var data _C_long
1768 err = ptracePtr(PTRACE_GETEVENTMSG, pid, 0, unsafe.Pointer(&data))
1769 msg = uint(data)
1770 return
1771 }
1772
1773 func PtraceCont(pid int, signal int) (err error) {
1774 return ptrace(PTRACE_CONT, pid, 0, uintptr(signal))
1775 }
1776
1777 func PtraceSyscall(pid int, signal int) (err error) {
1778 return ptrace(PTRACE_SYSCALL, pid, 0, uintptr(signal))
1779 }
1780
1781 func PtraceSingleStep(pid int) (err error) { return ptrace(PTRACE_SINGLESTEP, pid, 0, 0) }
1782
1783 func PtraceInterrupt(pid int) (err error) { return ptrace(PTRACE_INTERRUPT, pid, 0, 0) }
1784
1785 func PtraceAttach(pid int) (err error) { return ptrace(PTRACE_ATTACH, pid, 0, 0) }
1786
1787 func PtraceSeize(pid int) (err error) { return ptrace(PTRACE_SEIZE, pid, 0, 0) }
1788
1789 func PtraceDetach(pid int) (err error) { return ptrace(PTRACE_DETACH, pid, 0, 0) }
1790
1791 //sys reboot(magic1 uint, magic2 uint, cmd int, arg string) (err error)
1792
1793 func Reboot(cmd int) (err error) {
1794 return reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, "")
1795 }
1796
1797 func direntIno(buf []byte) (uint64, bool) {
1798 return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
1799 }
1800
1801 func direntReclen(buf []byte) (uint64, bool) {
1802 return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
1803 }
1804
1805 func direntNamlen(buf []byte) (uint64, bool) {
1806 reclen, ok := direntReclen(buf)
1807 if !ok {
1808 return 0, false
1809 }
1810 return reclen - uint64(unsafe.Offsetof(Dirent{}.Name)), true
1811 }
1812
1813 //sys mount(source string, target string, fstype string, flags uintptr, data *byte) (err error)
1814
1815 func Mount(source string, target string, fstype string, flags uintptr, data string) (err error) {
1816 // Certain file systems get rather angry and EINVAL if you give
1817 // them an empty string of data, rather than NULL.
1818 if data == "" {
1819 return mount(source, target, fstype, flags, nil)
1820 }
1821 datap, err := BytePtrFromString(data)
1822 if err != nil {
1823 return err
1824 }
1825 return mount(source, target, fstype, flags, datap)
1826 }
1827
1828 //sys mountSetattr(dirfd int, pathname string, flags uint, attr *MountAttr, size uintptr) (err error) = SYS_MOUNT_SETATTR
1829
1830 // MountSetattr is a wrapper for mount_setattr(2).
1831 // https://man7.org/linux/man-pages/man2/mount_setattr.2.html
1832 //
1833 // Requires kernel >= 5.12.
1834 func MountSetattr(dirfd int, pathname string, flags uint, attr *MountAttr) error {
1835 return mountSetattr(dirfd, pathname, flags, attr, unsafe.Sizeof(*attr))
1836 }
1837
1838 func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
1839 if raceenabled {
1840 raceReleaseMerge(unsafe.Pointer(&ioSync))
1841 }
1842 return sendfile(outfd, infd, offset, count)
1843 }
1844
1845 // Sendto
1846 // Recvfrom
1847 // Socketpair
1848
1849 /*
1850 * Direct access
1851 */
1852 //sys Acct(path string) (err error)
1853 //sys AddKey(keyType string, description string, payload []byte, ringid int) (id int, err error)
1854 //sys Adjtimex(buf *Timex) (state int, err error)
1855 //sysnb Capget(hdr *CapUserHeader, data *CapUserData) (err error)
1856 //sysnb Capset(hdr *CapUserHeader, data *CapUserData) (err error)
1857 //sys Chdir(path string) (err error)
1858 //sys Chroot(path string) (err error)
1859 //sys ClockAdjtime(clockid int32, buf *Timex) (state int, err error)
1860 //sys ClockGetres(clockid int32, res *Timespec) (err error)
1861 //sys ClockGettime(clockid int32, time *Timespec) (err error)
1862 //sys ClockSettime(clockid int32, time *Timespec) (err error)
1863 //sys ClockNanosleep(clockid int32, flags int, request *Timespec, remain *Timespec) (err error)
1864 //sys Close(fd int) (err error)
1865 //sys CloseRange(first uint, last uint, flags uint) (err error)
1866 //sys CopyFileRange(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int, err error)
1867 //sys DeleteModule(name string, flags int) (err error)
1868 //sys Dup(oldfd int) (fd int, err error)
1869
1870 func Dup2(oldfd, newfd int) error {
1871 return Dup3(oldfd, newfd, 0)
1872 }
1873
1874 //sys Dup3(oldfd int, newfd int, flags int) (err error)
1875 //sysnb EpollCreate1(flag int) (fd int, err error)
1876 //sysnb EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
1877 //sys Eventfd(initval uint, flags int) (fd int, err error) = SYS_EVENTFD2
1878 //sys Exit(code int) = SYS_EXIT_GROUP
1879 //sys Fallocate(fd int, mode uint32, off int64, len int64) (err error)
1880 //sys Fchdir(fd int) (err error)
1881 //sys Fchmod(fd int, mode uint32) (err error)
1882 //sys Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
1883 //sys Fdatasync(fd int) (err error)
1884 //sys Fgetxattr(fd int, attr string, dest []byte) (sz int, err error)
1885 //sys FinitModule(fd int, params string, flags int) (err error)
1886 //sys Flistxattr(fd int, dest []byte) (sz int, err error)
1887 //sys Flock(fd int, how int) (err error)
1888 //sys Fremovexattr(fd int, attr string) (err error)
1889 //sys Fsetxattr(fd int, attr string, dest []byte, flags int) (err error)
1890 //sys Fsync(fd int) (err error)
1891 //sys Fsmount(fd int, flags int, mountAttrs int) (fsfd int, err error)
1892 //sys Fsopen(fsName string, flags int) (fd int, err error)
1893 //sys Fspick(dirfd int, pathName string, flags int) (fd int, err error)
1894
1895 //sys fsconfig(fd int, cmd uint, key *byte, value *byte, aux int) (err error)
1896
1897 func fsconfigCommon(fd int, cmd uint, key string, value *byte, aux int) (err error) {
1898 var keyp *byte
1899 if keyp, err = BytePtrFromString(key); err != nil {
1900 return
1901 }
1902 return fsconfig(fd, cmd, keyp, value, aux)
1903 }
1904
1905 // FsconfigSetFlag is equivalent to fsconfig(2) called
1906 // with cmd == FSCONFIG_SET_FLAG.
1907 //
1908 // fd is the filesystem context to act upon.
1909 // key the parameter key to set.
1910 func FsconfigSetFlag(fd int, key string) (err error) {
1911 return fsconfigCommon(fd, FSCONFIG_SET_FLAG, key, nil, 0)
1912 }
1913
1914 // FsconfigSetString is equivalent to fsconfig(2) called
1915 // with cmd == FSCONFIG_SET_STRING.
1916 //
1917 // fd is the filesystem context to act upon.
1918 // key the parameter key to set.
1919 // value is the parameter value to set.
1920 func FsconfigSetString(fd int, key string, value string) (err error) {
1921 var valuep *byte
1922 if valuep, err = BytePtrFromString(value); err != nil {
1923 return
1924 }
1925 return fsconfigCommon(fd, FSCONFIG_SET_STRING, key, valuep, 0)
1926 }
1927
1928 // FsconfigSetBinary is equivalent to fsconfig(2) called
1929 // with cmd == FSCONFIG_SET_BINARY.
1930 //
1931 // fd is the filesystem context to act upon.
1932 // key the parameter key to set.
1933 // value is the parameter value to set.
1934 func FsconfigSetBinary(fd int, key string, value []byte) (err error) {
1935 if len(value) == 0 {
1936 return EINVAL
1937 }
1938 return fsconfigCommon(fd, FSCONFIG_SET_BINARY, key, &value[0], len(value))
1939 }
1940
1941 // FsconfigSetPath is equivalent to fsconfig(2) called
1942 // with cmd == FSCONFIG_SET_PATH.
1943 //
1944 // fd is the filesystem context to act upon.
1945 // key the parameter key to set.
1946 // path is a non-empty path for specified key.
1947 // atfd is a file descriptor at which to start lookup from or AT_FDCWD.
1948 func FsconfigSetPath(fd int, key string, path string, atfd int) (err error) {
1949 var valuep *byte
1950 if valuep, err = BytePtrFromString(path); err != nil {
1951 return
1952 }
1953 return fsconfigCommon(fd, FSCONFIG_SET_PATH, key, valuep, atfd)
1954 }
1955
1956 // FsconfigSetPathEmpty is equivalent to fsconfig(2) called
1957 // with cmd == FSCONFIG_SET_PATH_EMPTY. The same as
1958 // FconfigSetPath but with AT_PATH_EMPTY implied.
1959 func FsconfigSetPathEmpty(fd int, key string, path string, atfd int) (err error) {
1960 var valuep *byte
1961 if valuep, err = BytePtrFromString(path); err != nil {
1962 return
1963 }
1964 return fsconfigCommon(fd, FSCONFIG_SET_PATH_EMPTY, key, valuep, atfd)
1965 }
1966
1967 // FsconfigSetFd is equivalent to fsconfig(2) called
1968 // with cmd == FSCONFIG_SET_FD.
1969 //
1970 // fd is the filesystem context to act upon.
1971 // key the parameter key to set.
1972 // value is a file descriptor to be assigned to specified key.
1973 func FsconfigSetFd(fd int, key string, value int) (err error) {
1974 return fsconfigCommon(fd, FSCONFIG_SET_FD, key, nil, value)
1975 }
1976
1977 // FsconfigCreate is equivalent to fsconfig(2) called
1978 // with cmd == FSCONFIG_CMD_CREATE.
1979 //
1980 // fd is the filesystem context to act upon.
1981 func FsconfigCreate(fd int) (err error) {
1982 return fsconfig(fd, FSCONFIG_CMD_CREATE, nil, nil, 0)
1983 }
1984
1985 // FsconfigReconfigure is equivalent to fsconfig(2) called
1986 // with cmd == FSCONFIG_CMD_RECONFIGURE.
1987 //
1988 // fd is the filesystem context to act upon.
1989 func FsconfigReconfigure(fd int) (err error) {
1990 return fsconfig(fd, FSCONFIG_CMD_RECONFIGURE, nil, nil, 0)
1991 }
1992
1993 //sys Getdents(fd int, buf []byte) (n int, err error) = SYS_GETDENTS64
1994 //sysnb Getpgid(pid int) (pgid int, err error)
1995
1996 func Getpgrp() (pid int) {
1997 pid, _ = Getpgid(0)
1998 return
1999 }
2000
2001 //sysnb Getpid() (pid int)
2002 //sysnb Getppid() (ppid int)
2003 //sys Getpriority(which int, who int) (prio int, err error)
2004
2005 func Getrandom(buf []byte, flags int) (n int, err error) {
2006 vdsoRet, supported := vgetrandom(buf, uint32(flags))
2007 if supported {
2008 if vdsoRet < 0 {
2009 return 0, errnoErr(syscall.Errno(-vdsoRet))
2010 }
2011 return vdsoRet, nil
2012 }
2013 var p *byte
2014 if len(buf) > 0 {
2015 p = &buf[0]
2016 }
2017 r, _, e := Syscall(SYS_GETRANDOM, uintptr(unsafe.Pointer(p)), uintptr(len(buf)), uintptr(flags))
2018 if e != 0 {
2019 return 0, errnoErr(e)
2020 }
2021 return int(r), nil
2022 }
2023
2024 //sysnb Getrusage(who int, rusage *Rusage) (err error)
2025 //sysnb Getsid(pid int) (sid int, err error)
2026 //sysnb Gettid() (tid int)
2027 //sys Getxattr(path string, attr string, dest []byte) (sz int, err error)
2028 //sys InitModule(moduleImage []byte, params string) (err error)
2029 //sys InotifyAddWatch(fd int, pathname string, mask uint32) (watchdesc int, err error)
2030 //sysnb InotifyInit1(flags int) (fd int, err error)
2031 //sysnb InotifyRmWatch(fd int, watchdesc uint32) (success int, err error)
2032 //sysnb Kill(pid int, sig syscall.Signal) (err error)
2033 //sys Klogctl(typ int, buf []byte) (n int, err error) = SYS_SYSLOG
2034 //sys Lgetxattr(path string, attr string, dest []byte) (sz int, err error)
2035 //sys Listxattr(path string, dest []byte) (sz int, err error)
2036 //sys Llistxattr(path string, dest []byte) (sz int, err error)
2037 //sys Lremovexattr(path string, attr string) (err error)
2038 //sys Lsetxattr(path string, attr string, data []byte, flags int) (err error)
2039 //sys MemfdCreate(name string, flags int) (fd int, err error)
2040 //sys Mkdirat(dirfd int, path string, mode uint32) (err error)
2041 //sys Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
2042 //sys MoveMount(fromDirfd int, fromPathName string, toDirfd int, toPathName string, flags int) (err error)
2043 //sys Nanosleep(time *Timespec, leftover *Timespec) (err error)
2044 //sys OpenTree(dfd int, fileName string, flags uint) (r int, err error)
2045 //sys PerfEventOpen(attr *PerfEventAttr, pid int, cpu int, groupFd int, flags int) (fd int, err error)
2046 //sys PivotRoot(newroot string, putold string) (err error) = SYS_PIVOT_ROOT
2047 //sys Prctl(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (err error)
2048 //sys pselect6(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timespec, sigmask *sigset_argpack) (n int, err error)
2049 //sys read(fd int, p []byte) (n int, err error)
2050 //sys Removexattr(path string, attr string) (err error)
2051 //sys Renameat2(olddirfd int, oldpath string, newdirfd int, newpath string, flags uint) (err error)
2052 //sys RequestKey(keyType string, description string, callback string, destRingid int) (id int, err error)
2053 //sys Setdomainname(p []byte) (err error)
2054 //sys Sethostname(p []byte) (err error)
2055 //sysnb Setpgid(pid int, pgid int) (err error)
2056 //sysnb Setsid() (pid int, err error)
2057 //sysnb Settimeofday(tv *Timeval) (err error)
2058 //sys Setns(fd int, nstype int) (err error)
2059
2060 //go:linkname syscall_prlimit syscall.prlimit
2061 func syscall_prlimit(pid, resource int, newlimit, old *syscall.Rlimit) error
2062
2063 func Prlimit(pid, resource int, newlimit, old *Rlimit) error {
2064 // Just call the syscall version, because as of Go 1.21
2065 // it will affect starting a new process.
2066 return syscall_prlimit(pid, resource, (*syscall.Rlimit)(newlimit), (*syscall.Rlimit)(old))
2067 }
2068
2069 // PrctlRetInt performs a prctl operation specified by option and further
2070 // optional arguments arg2 through arg5 depending on option. It returns a
2071 // non-negative integer that is returned by the prctl syscall.
2072 func PrctlRetInt(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (int, error) {
2073 ret, _, err := Syscall6(SYS_PRCTL, uintptr(option), uintptr(arg2), uintptr(arg3), uintptr(arg4), uintptr(arg5), 0)
2074 if err != 0 {
2075 return 0, err
2076 }
2077 return int(ret), nil
2078 }
2079
2080 func Setuid(uid int) (err error) {
2081 return syscall.Setuid(uid)
2082 }
2083
2084 func Setgid(gid int) (err error) {
2085 return syscall.Setgid(gid)
2086 }
2087
2088 func Setreuid(ruid, euid int) (err error) {
2089 return syscall.Setreuid(ruid, euid)
2090 }
2091
2092 func Setregid(rgid, egid int) (err error) {
2093 return syscall.Setregid(rgid, egid)
2094 }
2095
2096 func Setresuid(ruid, euid, suid int) (err error) {
2097 return syscall.Setresuid(ruid, euid, suid)
2098 }
2099
2100 func Setresgid(rgid, egid, sgid int) (err error) {
2101 return syscall.Setresgid(rgid, egid, sgid)
2102 }
2103
2104 // SetfsgidRetGid sets fsgid for current thread and returns previous fsgid set.
2105 // setfsgid(2) will return a non-nil error only if its caller lacks CAP_SETUID capability.
2106 // If the call fails due to other reasons, current fsgid will be returned.
2107 func SetfsgidRetGid(gid int) (int, error) {
2108 return setfsgid(gid)
2109 }
2110
2111 // SetfsuidRetUid sets fsuid for current thread and returns previous fsuid set.
2112 // setfsgid(2) will return a non-nil error only if its caller lacks CAP_SETUID capability
2113 // If the call fails due to other reasons, current fsuid will be returned.
2114 func SetfsuidRetUid(uid int) (int, error) {
2115 return setfsuid(uid)
2116 }
2117
2118 func Setfsgid(gid int) error {
2119 _, err := setfsgid(gid)
2120 return err
2121 }
2122
2123 func Setfsuid(uid int) error {
2124 _, err := setfsuid(uid)
2125 return err
2126 }
2127
2128 func Signalfd(fd int, sigmask *Sigset_t, flags int) (newfd int, err error) {
2129 return signalfd(fd, sigmask, _C__NSIG/8, flags)
2130 }
2131
2132 //sys Setpriority(which int, who int, prio int) (err error)
2133 //sys Setxattr(path string, attr string, data []byte, flags int) (err error)
2134 //sys signalfd(fd int, sigmask *Sigset_t, maskSize uintptr, flags int) (newfd int, err error) = SYS_SIGNALFD4
2135 //sys Statx(dirfd int, path string, flags int, mask int, stat *Statx_t) (err error)
2136 //sys Sync()
2137 //sys Syncfs(fd int) (err error)
2138 //sysnb Sysinfo(info *Sysinfo_t) (err error)
2139 //sys Tee(rfd int, wfd int, len int, flags int) (n int64, err error)
2140 //sysnb TimerfdCreate(clockid int, flags int) (fd int, err error)
2141 //sysnb TimerfdGettime(fd int, currValue *ItimerSpec) (err error)
2142 //sysnb TimerfdSettime(fd int, flags int, newValue *ItimerSpec, oldValue *ItimerSpec) (err error)
2143 //sysnb Tgkill(tgid int, tid int, sig syscall.Signal) (err error)
2144 //sysnb Times(tms *Tms) (ticks uintptr, err error)
2145 //sysnb Umask(mask int) (oldmask int)
2146 //sysnb Uname(buf *Utsname) (err error)
2147 //sys Unmount(target string, flags int) (err error) = SYS_UMOUNT2
2148 //sys Unshare(flags int) (err error)
2149 //sys write(fd int, p []byte) (n int, err error)
2150 //sys exitThread(code int) (err error) = SYS_EXIT
2151 //sys readv(fd int, iovs []Iovec) (n int, err error) = SYS_READV
2152 //sys writev(fd int, iovs []Iovec) (n int, err error) = SYS_WRITEV
2153 //sys preadv(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PREADV
2154 //sys pwritev(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PWRITEV
2155 //sys preadv2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PREADV2
2156 //sys pwritev2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PWRITEV2
2157
2158 // minIovec is the size of the small initial allocation used by
2159 // Readv, Writev, etc.
2160 //
2161 // This small allocation gets stack allocated, which lets the
2162 // common use case of len(iovs) <= minIovs avoid more expensive
2163 // heap allocations.
2164 const minIovec = 8
2165
2166 // appendBytes converts bs to Iovecs and appends them to vecs.
2167 func appendBytes(vecs []Iovec, bs [][]byte) []Iovec {
2168 for _, b := range bs {
2169 var v Iovec
2170 v.SetLen(len(b))
2171 if len(b) > 0 {
2172 v.Base = &b[0]
2173 } else {
2174 v.Base = (*byte)(unsafe.Pointer(&_zero))
2175 }
2176 vecs = append(vecs, v)
2177 }
2178 return vecs
2179 }
2180
2181 // offs2lohi splits offs into its low and high order bits.
2182 func offs2lohi(offs int64) (lo, hi uintptr) {
2183 const longBits = SizeofLong * 8
2184 return uintptr(offs), uintptr(uint64(offs) >> (longBits - 1) >> 1) // two shifts to avoid false positive in vet
2185 }
2186
2187 func Readv(fd int, iovs [][]byte) (n int, err error) {
2188 iovecs := make([]Iovec, 0, minIovec)
2189 iovecs = appendBytes(iovecs, iovs)
2190 n, err = readv(fd, iovecs)
2191 readvRacedetect(iovecs, n, err)
2192 return n, err
2193 }
2194
2195 func Preadv(fd int, iovs [][]byte, offset int64) (n int, err error) {
2196 iovecs := make([]Iovec, 0, minIovec)
2197 iovecs = appendBytes(iovecs, iovs)
2198 lo, hi := offs2lohi(offset)
2199 n, err = preadv(fd, iovecs, lo, hi)
2200 readvRacedetect(iovecs, n, err)
2201 return n, err
2202 }
2203
2204 func Preadv2(fd int, iovs [][]byte, offset int64, flags int) (n int, err error) {
2205 iovecs := make([]Iovec, 0, minIovec)
2206 iovecs = appendBytes(iovecs, iovs)
2207 lo, hi := offs2lohi(offset)
2208 n, err = preadv2(fd, iovecs, lo, hi, flags)
2209 readvRacedetect(iovecs, n, err)
2210 return n, err
2211 }
2212
2213 func readvRacedetect(iovecs []Iovec, n int, err error) {
2214 if !raceenabled {
2215 return
2216 }
2217 for i := 0; n > 0 && i < len(iovecs); i++ {
2218 m := min(int(iovecs[i].Len), n)
2219 n -= m
2220 if m > 0 {
2221 raceWriteRange(unsafe.Pointer(iovecs[i].Base), m)
2222 }
2223 }
2224 if err == nil {
2225 raceAcquire(unsafe.Pointer(&ioSync))
2226 }
2227 }
2228
2229 func Writev(fd int, iovs [][]byte) (n int, err error) {
2230 iovecs := make([]Iovec, 0, minIovec)
2231 iovecs = appendBytes(iovecs, iovs)
2232 if raceenabled {
2233 raceReleaseMerge(unsafe.Pointer(&ioSync))
2234 }
2235 n, err = writev(fd, iovecs)
2236 writevRacedetect(iovecs, n)
2237 return n, err
2238 }
2239
2240 func Pwritev(fd int, iovs [][]byte, offset int64) (n int, err error) {
2241 iovecs := make([]Iovec, 0, minIovec)
2242 iovecs = appendBytes(iovecs, iovs)
2243 if raceenabled {
2244 raceReleaseMerge(unsafe.Pointer(&ioSync))
2245 }
2246 lo, hi := offs2lohi(offset)
2247 n, err = pwritev(fd, iovecs, lo, hi)
2248 writevRacedetect(iovecs, n)
2249 return n, err
2250 }
2251
2252 func Pwritev2(fd int, iovs [][]byte, offset int64, flags int) (n int, err error) {
2253 iovecs := make([]Iovec, 0, minIovec)
2254 iovecs = appendBytes(iovecs, iovs)
2255 if raceenabled {
2256 raceReleaseMerge(unsafe.Pointer(&ioSync))
2257 }
2258 lo, hi := offs2lohi(offset)
2259 n, err = pwritev2(fd, iovecs, lo, hi, flags)
2260 writevRacedetect(iovecs, n)
2261 return n, err
2262 }
2263
2264 func writevRacedetect(iovecs []Iovec, n int) {
2265 if !raceenabled {
2266 return
2267 }
2268 for i := 0; n > 0 && i < len(iovecs); i++ {
2269 m := min(int(iovecs[i].Len), n)
2270 n -= m
2271 if m > 0 {
2272 raceReadRange(unsafe.Pointer(iovecs[i].Base), m)
2273 }
2274 }
2275 }
2276
2277 // mmap varies by architecture; see syscall_linux_*.go.
2278 //sys munmap(addr uintptr, length uintptr) (err error)
2279 //sys mremap(oldaddr uintptr, oldlength uintptr, newlength uintptr, flags int, newaddr uintptr) (xaddr uintptr, err error)
2280 //sys Madvise(b []byte, advice int) (err error)
2281 //sys Mprotect(b []byte, prot int) (err error)
2282 //sys Mlock(b []byte) (err error)
2283 //sys Mlockall(flags int) (err error)
2284 //sys Msync(b []byte, flags int) (err error)
2285 //sys Munlock(b []byte) (err error)
2286 //sys Munlockall() (err error)
2287
2288 const (
2289 mremapFixed = MREMAP_FIXED
2290 mremapDontunmap = MREMAP_DONTUNMAP
2291 mremapMaymove = MREMAP_MAYMOVE
2292 )
2293
2294 // Vmsplice splices user pages from a slice of Iovecs into a pipe specified by fd,
2295 // using the specified flags.
2296 func Vmsplice(fd int, iovs []Iovec, flags int) (int, error) {
2297 var p unsafe.Pointer
2298 if len(iovs) > 0 {
2299 p = unsafe.Pointer(&iovs[0])
2300 }
2301
2302 n, _, errno := Syscall6(SYS_VMSPLICE, uintptr(fd), uintptr(p), uintptr(len(iovs)), uintptr(flags), 0, 0)
2303 if errno != 0 {
2304 return 0, syscall.Errno(errno)
2305 }
2306
2307 return int(n), nil
2308 }
2309
2310 func isGroupMember(gid int) bool {
2311 groups, err := Getgroups()
2312 if err != nil {
2313 return false
2314 }
2315
2316 return slices.Contains(groups, gid)
2317 }
2318
2319 func isCapDacOverrideSet() bool {
2320 hdr := CapUserHeader{Version: LINUX_CAPABILITY_VERSION_3}
2321 data := [2]CapUserData{}
2322 err := Capget(&hdr, &data[0])
2323
2324 return err == nil && data[0].Effective&(1<<CAP_DAC_OVERRIDE) != 0
2325 }
2326
2327 //sys faccessat(dirfd int, path string, mode uint32) (err error)
2328 //sys Faccessat2(dirfd int, path string, mode uint32, flags int) (err error)
2329
2330 func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
2331 if flags == 0 {
2332 return faccessat(dirfd, path, mode)
2333 }
2334
2335 if err := Faccessat2(dirfd, path, mode, flags); err != ENOSYS && err != EPERM {
2336 return err
2337 }
2338
2339 // The Linux kernel faccessat system call does not take any flags.
2340 // The glibc faccessat implements the flags itself; see
2341 // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/faccessat.c;hb=HEAD
2342 // Because people naturally expect syscall.Faccessat to act
2343 // like C faccessat, we do the same.
2344
2345 if flags & ^(AT_SYMLINK_NOFOLLOW|AT_EACCESS) != 0 {
2346 return EINVAL
2347 }
2348
2349 var st Stat_t
2350 if err := Fstatat(dirfd, path, &st, flags&AT_SYMLINK_NOFOLLOW); err != nil {
2351 return err
2352 }
2353
2354 mode &= 7
2355 if mode == 0 {
2356 return nil
2357 }
2358
2359 var uid int
2360 if flags&AT_EACCESS != 0 {
2361 uid = Geteuid()
2362 if uid != 0 && isCapDacOverrideSet() {
2363 // If CAP_DAC_OVERRIDE is set, file access check is
2364 // done by the kernel in the same way as for root
2365 // (see generic_permission() in the Linux sources).
2366 uid = 0
2367 }
2368 } else {
2369 uid = Getuid()
2370 }
2371
2372 if uid == 0 {
2373 if mode&1 == 0 {
2374 // Root can read and write any file.
2375 return nil
2376 }
2377 if st.Mode&0111 != 0 {
2378 // Root can execute any file that anybody can execute.
2379 return nil
2380 }
2381 return EACCES
2382 }
2383
2384 var fmode uint32
2385 if uint32(uid) == st.Uid {
2386 fmode = (st.Mode >> 6) & 7
2387 } else {
2388 var gid int
2389 if flags&AT_EACCESS != 0 {
2390 gid = Getegid()
2391 } else {
2392 gid = Getgid()
2393 }
2394
2395 if uint32(gid) == st.Gid || isGroupMember(int(st.Gid)) {
2396 fmode = (st.Mode >> 3) & 7
2397 } else {
2398 fmode = st.Mode & 7
2399 }
2400 }
2401
2402 if fmode&mode == mode {
2403 return nil
2404 }
2405
2406 return EACCES
2407 }
2408
2409 //sys nameToHandleAt(dirFD int, pathname string, fh *fileHandle, mountID *_C_int, flags int) (err error) = SYS_NAME_TO_HANDLE_AT
2410 //sys openByHandleAt(mountFD int, fh *fileHandle, flags int) (fd int, err error) = SYS_OPEN_BY_HANDLE_AT
2411
2412 // fileHandle is the argument to nameToHandleAt and openByHandleAt. We
2413 // originally tried to generate it via unix/linux/types.go with "type
2414 // fileHandle C.struct_file_handle" but that generated empty structs
2415 // for mips64 and mips64le. Instead, hard code it for now (it's the
2416 // same everywhere else) until the mips64 generator issue is fixed.
2417 type fileHandle struct {
2418 Bytes uint32
2419 Type int32
2420 }
2421
2422 // FileHandle represents the C struct file_handle used by
2423 // name_to_handle_at (see NameToHandleAt) and open_by_handle_at (see
2424 // OpenByHandleAt).
2425 type FileHandle struct {
2426 *fileHandle
2427 }
2428
2429 // NewFileHandle constructs a FileHandle.
2430 func NewFileHandle(handleType int32, handle []byte) FileHandle {
2431 const hdrSize = unsafe.Sizeof(fileHandle{})
2432 buf := make([]byte, hdrSize+uintptr(len(handle)))
2433 copy(buf[hdrSize:], handle)
2434 fh := (*fileHandle)(unsafe.Pointer(&buf[0]))
2435 fh.Type = handleType
2436 fh.Bytes = uint32(len(handle))
2437 return FileHandle{fh}
2438 }
2439
2440 func (fh *FileHandle) Size() int { return int(fh.fileHandle.Bytes) }
2441 func (fh *FileHandle) Type() int32 { return fh.fileHandle.Type }
2442 func (fh *FileHandle) Bytes() []byte {
2443 n := fh.Size()
2444 if n == 0 {
2445 return nil
2446 }
2447 return unsafe.Slice((*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&fh.fileHandle.Type))+4)), n)
2448 }
2449
2450 // NameToHandleAt wraps the name_to_handle_at system call; it obtains
2451 // a handle for a path name.
2452 func NameToHandleAt(dirfd int, path string, flags int) (handle FileHandle, mountID int, err error) {
2453 var mid _C_int
2454 // Try first with a small buffer, assuming the handle will
2455 // only be 32 bytes.
2456 size := uint32(32 + unsafe.Sizeof(fileHandle{}))
2457 didResize := false
2458 for {
2459 buf := make([]byte, size)
2460 fh := (*fileHandle)(unsafe.Pointer(&buf[0]))
2461 fh.Bytes = size - uint32(unsafe.Sizeof(fileHandle{}))
2462 err = nameToHandleAt(dirfd, path, fh, &mid, flags)
2463 if err == EOVERFLOW {
2464 if didResize {
2465 // We shouldn't need to resize more than once
2466 return
2467 }
2468 didResize = true
2469 size = fh.Bytes + uint32(unsafe.Sizeof(fileHandle{}))
2470 continue
2471 }
2472 if err != nil {
2473 return
2474 }
2475 return FileHandle{fh}, int(mid), nil
2476 }
2477 }
2478
2479 // OpenByHandleAt wraps the open_by_handle_at system call; it opens a
2480 // file via a handle as previously returned by NameToHandleAt.
2481 func OpenByHandleAt(mountFD int, handle FileHandle, flags int) (fd int, err error) {
2482 return openByHandleAt(mountFD, handle.fileHandle, flags)
2483 }
2484
2485 // Klogset wraps the sys_syslog system call; it sets console_loglevel to
2486 // the value specified by arg and passes a dummy pointer to bufp.
2487 func Klogset(typ int, arg int) (err error) {
2488 var p unsafe.Pointer
2489 _, _, errno := Syscall(SYS_SYSLOG, uintptr(typ), uintptr(p), uintptr(arg))
2490 if errno != 0 {
2491 return errnoErr(errno)
2492 }
2493 return nil
2494 }
2495
2496 // RemoteIovec is Iovec with the pointer replaced with an integer.
2497 // It is used for ProcessVMReadv and ProcessVMWritev, where the pointer
2498 // refers to a location in a different process' address space, which
2499 // would confuse the Go garbage collector.
2500 type RemoteIovec struct {
2501 Base uintptr
2502 Len int
2503 }
2504
2505 //sys ProcessVMReadv(pid int, localIov []Iovec, remoteIov []RemoteIovec, flags uint) (n int, err error) = SYS_PROCESS_VM_READV
2506 //sys ProcessVMWritev(pid int, localIov []Iovec, remoteIov []RemoteIovec, flags uint) (n int, err error) = SYS_PROCESS_VM_WRITEV
2507
2508 //sys PidfdOpen(pid int, flags int) (fd int, err error) = SYS_PIDFD_OPEN
2509 //sys PidfdGetfd(pidfd int, targetfd int, flags int) (fd int, err error) = SYS_PIDFD_GETFD
2510 //sys PidfdSendSignal(pidfd int, sig Signal, info *Siginfo, flags int) (err error) = SYS_PIDFD_SEND_SIGNAL
2511
2512 //sys shmat(id int, addr uintptr, flag int) (ret uintptr, err error)
2513 //sys shmctl(id int, cmd int, buf *SysvShmDesc) (result int, err error)
2514 //sys shmdt(addr uintptr) (err error)
2515 //sys shmget(key int, size int, flag int) (id int, err error)
2516
2517 //sys getitimer(which int, currValue *Itimerval) (err error)
2518 //sys setitimer(which int, newValue *Itimerval, oldValue *Itimerval) (err error)
2519
2520 // MakeItimerval creates an Itimerval from interval and value durations.
2521 func MakeItimerval(interval, value time.Duration) Itimerval {
2522 return Itimerval{
2523 Interval: NsecToTimeval(interval.Nanoseconds()),
2524 Value: NsecToTimeval(value.Nanoseconds()),
2525 }
2526 }
2527
2528 // A value which may be passed to the which parameter for Getitimer and
2529 // Setitimer.
2530 type ItimerWhich int
2531
2532 // Possible which values for Getitimer and Setitimer.
2533 const (
2534 ItimerReal ItimerWhich = ITIMER_REAL
2535 ItimerVirtual ItimerWhich = ITIMER_VIRTUAL
2536 ItimerProf ItimerWhich = ITIMER_PROF
2537 )
2538
2539 // Getitimer wraps getitimer(2) to return the current value of the timer
2540 // specified by which.
2541 func Getitimer(which ItimerWhich) (Itimerval, error) {
2542 var it Itimerval
2543 if err := getitimer(int(which), &it); err != nil {
2544 return Itimerval{}, err
2545 }
2546
2547 return it, nil
2548 }
2549
2550 // Setitimer wraps setitimer(2) to arm or disarm the timer specified by which.
2551 // It returns the previous value of the timer.
2552 //
2553 // If the Itimerval argument is the zero value, the timer will be disarmed.
2554 func Setitimer(which ItimerWhich, it Itimerval) (Itimerval, error) {
2555 var prev Itimerval
2556 if err := setitimer(int(which), &it, &prev); err != nil {
2557 return Itimerval{}, err
2558 }
2559
2560 return prev, nil
2561 }
2562
2563 //sysnb rtSigprocmask(how int, set *Sigset_t, oldset *Sigset_t, sigsetsize uintptr) (err error) = SYS_RT_SIGPROCMASK
2564
2565 func PthreadSigmask(how int, set, oldset *Sigset_t) error {
2566 if oldset != nil {
2567 // Explicitly clear in case Sigset_t is larger than _C__NSIG.
2568 *oldset = Sigset_t{}
2569 }
2570 return rtSigprocmask(how, set, oldset, _C__NSIG/8)
2571 }
2572
2573 //sysnb getresuid(ruid *_C_int, euid *_C_int, suid *_C_int)
2574 //sysnb getresgid(rgid *_C_int, egid *_C_int, sgid *_C_int)
2575
2576 func Getresuid() (ruid, euid, suid int) {
2577 var r, e, s _C_int
2578 getresuid(&r, &e, &s)
2579 return int(r), int(e), int(s)
2580 }
2581
2582 func Getresgid() (rgid, egid, sgid int) {
2583 var r, e, s _C_int
2584 getresgid(&r, &e, &s)
2585 return int(r), int(e), int(s)
2586 }
2587
2588 // Pselect is a wrapper around the Linux pselect6 system call.
2589 // This version does not modify the timeout argument.
2590 func Pselect(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timespec, sigmask *Sigset_t) (n int, err error) {
2591 // Per https://man7.org/linux/man-pages/man2/select.2.html#NOTES,
2592 // The Linux pselect6() system call modifies its timeout argument.
2593 // [Not modifying the argument] is the behavior required by POSIX.1-2001.
2594 var mutableTimeout *Timespec
2595 if timeout != nil {
2596 mutableTimeout = new(Timespec)
2597 *mutableTimeout = *timeout
2598 }
2599
2600 // The final argument of the pselect6() system call is not a
2601 // sigset_t * pointer, but is instead a structure
2602 var kernelMask *sigset_argpack
2603 if sigmask != nil {
2604 wordBits := 32 << (^uintptr(0) >> 63) // see math.intSize
2605
2606 // A sigset stores one bit per signal,
2607 // offset by 1 (because signal 0 does not exist).
2608 // So the number of words needed is ⌈__C_NSIG - 1 / wordBits⌉.
2609 sigsetWords := (_C__NSIG - 1 + wordBits - 1) / (wordBits)
2610
2611 sigsetBytes := uintptr(sigsetWords * (wordBits / 8))
2612 kernelMask = &sigset_argpack{
2613 ss: sigmask,
2614 ssLen: sigsetBytes,
2615 }
2616 }
2617
2618 return pselect6(nfd, r, w, e, mutableTimeout, kernelMask)
2619 }
2620
2621 //sys schedSetattr(pid int, attr *SchedAttr, flags uint) (err error)
2622 //sys schedGetattr(pid int, attr *SchedAttr, size uint, flags uint) (err error)
2623
2624 // SchedSetAttr is a wrapper for sched_setattr(2) syscall.
2625 // https://man7.org/linux/man-pages/man2/sched_setattr.2.html
2626 func SchedSetAttr(pid int, attr *SchedAttr, flags uint) error {
2627 if attr == nil {
2628 return EINVAL
2629 }
2630 attr.Size = SizeofSchedAttr
2631 return schedSetattr(pid, attr, flags)
2632 }
2633
2634 // SchedGetAttr is a wrapper for sched_getattr(2) syscall.
2635 // https://man7.org/linux/man-pages/man2/sched_getattr.2.html
2636 func SchedGetAttr(pid int, flags uint) (*SchedAttr, error) {
2637 attr := &SchedAttr{}
2638 if err := schedGetattr(pid, attr, SizeofSchedAttr, flags); err != nil {
2639 return nil, err
2640 }
2641 return attr, nil
2642 }
2643
2644 //sys Cachestat(fd uint, crange *CachestatRange, cstat *Cachestat_t, flags uint) (err error)
2645 //sys Mseal(b []byte, flags uint) (err error)
2646
2647 //sys setMemPolicy(mode int, mask *CPUSet, size int) (err error) = SYS_SET_MEMPOLICY
2648
2649 func SetMemPolicy(mode int, mask *CPUSet) error {
2650 return setMemPolicy(mode, mask, _CPU_SETSIZE)
2651 }
2652