// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Plan 9 system calls.
// This file is compiled as ordinary Go code,
// but it is also input to mksyscall,
// which parses the //sys lines and generates system call stubs.
// Note that sometimes we use a lowercase //sys name and
// wrap it in our own nicer implementation.
package plan9
import (
"bytes"
"syscall"
"unsafe"
)
// A Note is a string describing a process note.
// It implements the os.Signal interface.
type Note string
func (n Note) Signal() {}
func (n Note) String() string {
return string(n)
}
var (
Stdin = 0
Stdout = 1
Stderr = 2
)
// For testing: clients can set this flag to force
// creation of IPv6 sockets to return EAFNOSUPPORT.
var SocketDisableIPv6 bool
func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err syscall.ErrorString)
func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.ErrorString)
func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr)
func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr)
func atoi(b []byte) (n uint) {
n = 0
for i := 0; i < len(b); i++ {
n = n*10 + uint(b[i]-'0')
}
return
}
func cstring(s []byte) string {
i := bytes.IndexByte(s, 0)
if i == -1 {
i = len(s)
}
return string(s[:i])
}
func errstr() string {
var buf [ERRMAX]byte
RawSyscall(SYS_ERRSTR, uintptr(unsafe.Pointer(&buf[0])), uintptr(len(buf)), 0)
buf[len(buf)-1] = 0
return cstring(buf[:])
}
// Implemented in assembly to import from runtime.
func exit(code int)
func Exit(code int) { exit(code) }
func readnum(path string) (uint, error) {
var b [12]byte
fd, e := Open(path, O_RDONLY)
if e != nil {
return 0, e
}
defer Close(fd)
n, e := Pread(fd, b[:], 0)
if e != nil {
return 0, e
}
m := 0
for ; m < n && b[m] == ' '; m++ {
}
return atoi(b[m : n-1]), nil
}
func Getpid() (pid int) {
n, _ := readnum("#c/pid")
return int(n)
}
func Getppid() (ppid int) {
n, _ := readnum("#c/ppid")
return int(n)
}
func Read(fd int, p []byte) (n int, err error) {
return Pread(fd, p, -1)
}
func Write(fd int, p []byte) (n int, err error) {
return Pwrite(fd, p, -1)
}
var ioSync int64
//sys fd2path(fd int, buf []byte) (err error)
func Fd2path(fd int) (path string, err error) {
var buf [512]byte
e := fd2path(fd, buf[:])
if e != nil {
return "", e
}
return cstring(buf[:]), nil
}
//sys pipe(p *[2]int32) (err error)
func Pipe(p []int) (err error) {
if len(p) != 2 {
return syscall.ErrorString("bad arg in system call")
}
var pp [2]int32
err = pipe(&pp)
if err == nil {
p[0] = int(pp[0])
p[1] = int(pp[1])
}
return
}
// Underlying system call writes to newoffset via pointer.
// Implemented in assembly to avoid allocation.
func seek(placeholder uintptr, fd int, offset int64, whence int) (newoffset int64, err string)
func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
newoffset, e := seek(0, fd, offset, whence)
if newoffset == -1 {
err = syscall.ErrorString(e)
}
return
}
func Mkdir(path string, mode uint32) (err error) {
fd, err := Create(path, O_RDONLY, DMDIR|mode)
if fd != -1 {
Close(fd)
}
return
}
type Waitmsg struct {
Pid int
Time [3]uint32
Msg string
}
func (w Waitmsg) Exited() bool { return true }
func (w Waitmsg) Signaled() bool { return false }
func (w Waitmsg) ExitStatus() int {
if len(w.Msg) == 0 {
// a normal exit returns no message
return 0
}
return 1
}
//sys await(s []byte) (n int, err error)
func Await(w *Waitmsg) (err error) {
var buf [512]byte
var f [5][]byte
n, err := await(buf[:])
if err != nil || w == nil {
return
}
nf := 0
p := 0
for i := 0; i < n && nf < len(f)-1; i++ {
if buf[i] == ' ' {
f[nf] = buf[p:i]
p = i + 1
nf++
}
}
f[nf] = buf[p:]
nf++
if nf != len(f) {
return syscall.ErrorString("invalid wait message")
}
w.Pid = int(atoi(f[0]))
w.Time[0] = uint32(atoi(f[1]))
w.Time[1] = uint32(atoi(f[2]))
w.Time[2] = uint32(atoi(f[3]))
w.Msg = cstring(f[4])
if w.Msg == "''" {
// await() returns '' for no error
w.Msg = ""
}
return
}
func Unmount(name, old string) (err error) {
fixwd()
oldp, err := BytePtrFromString(old)
if err != nil {
return err
}
oldptr := uintptr(unsafe.Pointer(oldp))
var r0 uintptr
var e syscall.ErrorString
// bind(2) man page: If name is zero, everything bound or mounted upon old is unbound or unmounted.
if name == "" {
r0, _, e = Syscall(SYS_UNMOUNT, _zero, oldptr, 0)
} else {
namep, err := BytePtrFromString(name)
if err != nil {
return err
}
r0, _, e = Syscall(SYS_UNMOUNT, uintptr(unsafe.Pointer(namep)), oldptr, 0)
}
if int32(r0) == -1 {
err = e
}
return
}
func Fchdir(fd int) (err error) {
path, err := Fd2path(fd)
if err != nil {
return
}
return Chdir(path)
}
type Timespec struct {
Sec int32
Nsec int32
}
type Timeval struct {
Sec int32
Usec int32
}
func NsecToTimeval(nsec int64) (tv Timeval) {
nsec += 999 // round up to microsecond
tv.Usec = int32(nsec % 1e9 / 1e3)
tv.Sec = int32(nsec / 1e9)
return
}
func nsec() int64 {
var scratch int64
r0, _, _ := Syscall(SYS_NSEC, uintptr(unsafe.Pointer(&scratch)), 0, 0)
// TODO(aram): remove hack after I fix _nsec in the pc64 kernel.
if r0 == 0 {
return scratch
}
return int64(r0)
}
func Gettimeofday(tv *Timeval) error {
nsec := nsec()
*tv = NsecToTimeval(nsec)
return nil
}
func Getpagesize() int { return 0x1000 }
func Getegid() (egid int) { return -1 }
func Geteuid() (euid int) { return -1 }
func Getgid() (gid int) { return -1 }
func Getuid() (uid int) { return -1 }
func Getgroups() (gids []int, err error) {
return make([]int, 0), nil
}
//sys open(path string, mode int) (fd int, err error)
func Open(path string, mode int) (fd int, err error) {
fixwd()
return open(path, mode)
}
//sys create(path string, mode int, perm uint32) (fd int, err error)
func Create(path string, mode int, perm uint32) (fd int, err error) {
fixwd()
return create(path, mode, perm)
}
//sys remove(path string) (err error)
func Remove(path string) error {
fixwd()
return remove(path)
}
//sys stat(path string, edir []byte) (n int, err error)
func Stat(path string, edir []byte) (n int, err error) {
fixwd()
return stat(path, edir)
}
//sys bind(name string, old string, flag int) (err error)
func Bind(name string, old string, flag int) (err error) {
fixwd()
return bind(name, old, flag)
}
//sys mount(fd int, afd int, old string, flag int, aname string) (err error)
func Mount(fd int, afd int, old string, flag int, aname string) (err error) {
fixwd()
return mount(fd, afd, old, flag, aname)
}
//sys wstat(path string, edir []byte) (err error)
func Wstat(path string, edir []byte) (err error) {
fixwd()
return wstat(path, edir)
}
//sys chdir(path string) (err error)
//sys Dup(oldfd int, newfd int) (fd int, err error)
//sys Pread(fd int, p []byte, offset int64) (n int, err error)
//sys Pwrite(fd int, p []byte, offset int64) (n int, err error)
//sys Close(fd int) (err error)
//sys Fstat(fd int, edir []byte) (n int, err error)
//sys Fwstat(fd int, edir []byte) (err error)
