// Copyright 2009,2010 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.

// Darwin 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, either here or in
// syscall_bsd.go or syscall_unix.go.

package unix

import (
    "errors"
    "syscall"
    "unsafe"
)

const ImplementsGetwd = true

func Getwd() (string, error) {
    buf := make([]byte, 2048)
    attrs, err := getAttrList(".", attrList{CommonAttr: attrCmnFullpath}, buf, 0)
    if err == nil && len(attrs) == 1 && len(attrs[0]) >= 2 {
        wd := string(attrs[0])
        // Sanity check that it's an absolute path and ends
        // in a null byte, which we then strip.
        if wd[0] == '/' && wd[len(wd)-1] == 0 {
            return wd[:len(wd)-1], nil
        }
    }
    // If pkg/os/getwd.go gets ENOTSUP, it will fall back to the
    // slow algorithm.
    return "", ENOTSUP
}

// SockaddrDatalink implements the Sockaddr interface for AF_LINK type sockets.
type SockaddrDatalink struct {
    Len    uint8
    Family uint8
    Index  uint16
    Type   uint8
    Nlen   uint8
    Alen   uint8
    Slen   uint8
    Data   [12]int8
    raw    RawSockaddrDatalink
}

// Translate "kern.hostname" to []_C_int{0,1,2,3}.
func nametomib(name string) (mib []_C_int, err error) {
    const siz = unsafe.Sizeof(mib[0])

    // NOTE(rsc): It seems strange to set the buffer to have
    // size CTL_MAXNAME+2 but use only CTL_MAXNAME
    // as the size. I don't know why the +2 is here, but the
    // kernel uses +2 for its own implementation of this function.
    // I am scared that if we don't include the +2 here, the kernel
    // will silently write 2 words farther than we specify
    // and we'll get memory corruption.
    var buf [CTL_MAXNAME + 2]_C_int
    n := uintptr(CTL_MAXNAME) * siz

    p := (*byte)(unsafe.Pointer(&buf[0]))
    bytes, err := ByteSliceFromString(name)
    if err != nil {
        return nil, err
    }

    // Magic sysctl: "setting" 0.3 to a string name
    // lets you read back the array of integers form.
    if err = sysctl([]_C_int{0, 3}, p, &n, &bytes[0], uintptr(len(name))); err != nil {
        return nil, err
    }
    return buf[0 : n/siz], nil
}

//sys   ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
func PtraceAttach(pid int) (err error) { return ptrace(PT_ATTACH, pid, 0, 0) }
func PtraceDetach(pid int) (err error) { return ptrace(PT_DETACH, pid, 0, 0) }

const (
    attrBitMapCount = 5
    attrCmnFullpath = 0x08000000
)

type attrList struct {
    bitmapCount uint16
    _           uint16
    CommonAttr  uint32
    VolAttr     uint32
    DirAttr     uint32
    FileAttr    uint32
    Forkattr    uint32
}

func getAttrList(path string, attrList attrList, attrBuf []byte, options uint) (attrs [][]byte, err error) {
    if len(attrBuf) < 4 {
        return nil, errors.New("attrBuf too small")
    }
    attrList.bitmapCount = attrBitMapCount

    var _p0 *byte
    _p0, err = BytePtrFromString(path)
    if err != nil {
        return nil, err
    }

    if err := getattrlist(_p0, unsafe.Pointer(&attrList), unsafe.Pointer(&attrBuf[0]), uintptr(len(attrBuf)), int(options)); err != nil {
        return nil, err
    }
    size := *(*uint32)(unsafe.Pointer(&attrBuf[0]))

    // dat is the section of attrBuf that contains valid data,
    // without the 4 byte length header. All attribute offsets
    // are relative to dat.
    dat := attrBuf
    if int(size) < len(attrBuf) {
        dat = dat[:size]
    }
    dat = dat[4:] // remove length prefix

    for i := uint32(0); int(i) < len(dat); {
        header := dat[i:]
        if len(header) < 8 {
            return attrs, errors.New("truncated attribute header")
        }
        datOff := *(*int32)(unsafe.Pointer(&header[0]))
        attrLen := *(*uint32)(unsafe.Pointer(&header[4]))
        if datOff < 0 || uint32(datOff)+attrLen > uint32(len(dat)) {
            return attrs, errors.New("truncated results; attrBuf too small")
        }
        end := uint32(datOff) + attrLen
        attrs = append(attrs, dat[datOff:end])
        i = end
        if r := i % 4; r != 0 {
            i += (4 - r)
        }
    }
    return
}

//sys getattrlist(path *byte, list unsafe.Pointer, buf unsafe.Pointer, size uintptr, options int) (err error)

//sysnb pipe() (r int, w int, err error)

func Pipe(p []int) (err error) {
    if len(p) != 2 {
        return EINVAL
    }
    p[0], p[1], err = pipe()
    return
}

func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
    var _p0 unsafe.Pointer
    var bufsize uintptr
    if len(buf) > 0 {
        _p0 = unsafe.Pointer(&buf[0])
        bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
    }
    return getfsstat(_p0, bufsize, flags)
}

func xattrPointer(dest []byte) *byte {
    // It's only when dest is set to NULL that the OS X implementations of
    // getxattr() and listxattr() return the current sizes of the named attributes.
    // An empty byte array is not sufficient. To maintain the same behaviour as the
    // linux implementation, we wrap around the system calls and pass in NULL when
    // dest is empty.
    var destp *byte
    if len(dest) > 0 {
        destp = &dest[0]
    }
    return destp
}

//sys   getxattr(path string, attr string, dest *byte, size int, position uint32, options int) (sz int, err error)

func Getxattr(path string, attr string, dest []byte) (sz int, err error) {
    return getxattr(path, attr, xattrPointer(dest), len(dest), 0, 0)
}

func Lgetxattr(link string, attr string, dest []byte) (sz int, err error) {
    return getxattr(link, attr, xattrPointer(dest), len(dest), 0, XATTR_NOFOLLOW)
}

//sys   fgetxattr(fd int, attr string, dest *byte, size int, position uint32, options int) (sz int, err error)

func Fgetxattr(fd int, attr string, dest []byte) (sz int, err error) {
    return fgetxattr(fd, attr, xattrPointer(dest), len(dest), 0, 0)
}

//sys   setxattr(path string, attr string, data *byte, size int, position uint32, options int) (err error)

func Setxattr(path string, attr string, data []byte, flags int) (err error) {
    // The parameters for the OS X implementation vary slightly compared to the
    // linux system call, specifically the position parameter:
    //
    //  linux:
    //      int setxattr(
    //          const char *path,
    //          const char *name,
    //          const void *value,
    //          size_t size,
    //          int flags
    //      );
    //
    //  darwin:
    //      int setxattr(
    //          const char *path,
    //          const char *name,
    //          void *value,
    //          size_t size,
    //          u_int32_t position,
    //          int options
    //      );
    //
    // position specifies the offset within the extended attribute. In the
    // current implementation, only the resource fork extended attribute makes
    // use of this argument. For all others, position is reserved. We simply
    // default to setting it to zero.
    return setxattr(path, attr, xattrPointer(data), len(data), 0, flags)
}

func Lsetxattr(link string, attr string, data []byte, flags int) (err error) {
    return setxattr(link, attr, xattrPointer(data), len(data), 0, flags|XATTR_NOFOLLOW)
}

//sys   fsetxattr(fd int, attr string, data *byte, size int, position uint32, options int) (err error)

func Fsetxattr(fd int, attr string, data []byte, flags int) (err error) {
    return fsetxattr(fd, attr, xattrPointer(data), len(data), 0, 0)
}

//sys   removexattr(path string, attr string, options int) (err error)

func Removexattr(path string, attr string) (err error) {
    // We wrap around and explicitly zero out the options provided to the OS X
    // implementation of removexattr, we do so for interoperability with the
    // linux variant.
    return removexattr(path, attr, 0)
}

func Lremovexattr(link string, attr string) (err error) {
    return removexattr(link, attr, XATTR_NOFOLLOW)
}

//sys   fremovexattr(fd int, attr string, options int) (err error)

func Fremovexattr(fd int, attr string) (err error) {
    return fremovexattr(fd, attr, 0)
}

//sys   listxattr(path string, dest *byte, size int, options int) (sz int, err error)

func Listxattr(path string, dest []byte) (sz int, err error) {
    return listxattr(path, xattrPointer(dest), len(dest), 0)
}

func Llistxattr(link string, dest []byte) (sz int, err error) {
    return listxattr(link, xattrPointer(dest), len(dest), XATTR_NOFOLLOW)
}

//sys   flistxattr(fd int, dest *byte, size int, options int) (sz int, err error)

func Flistxattr(fd int, dest []byte) (sz int, err error) {
    return flistxattr(fd, xattrPointer(dest), len(dest), 0)
}

func setattrlistTimes(path string, times []Timespec, flags int) error {
    _p0, err := BytePtrFromString(path)
    if err != nil {
        return err
    }

    var attrList attrList
    attrList.bitmapCount = ATTR_BIT_MAP_COUNT
    attrList.CommonAttr = ATTR_CMN_MODTIME | ATTR_CMN_ACCTIME

    // order is mtime, atime: the opposite of Chtimes
    attributes := [2]Timespec{times[1], times[0]}
    options := 0
    if flags&AT_SYMLINK_NOFOLLOW != 0 {
        options |= FSOPT_NOFOLLOW
    }
    return setattrlist(
        _p0,
        unsafe.Pointer(&attrList),
        unsafe.Pointer(&attributes),
        unsafe.Sizeof(attributes),
        options)
}

//sys setattrlist(path *byte, list unsafe.Pointer, buf unsafe.Pointer, size uintptr, options int) (err error)

func utimensat(dirfd int, path string, times *[2]Timespec, flags int) error {
    // Darwin doesn't support SYS_UTIMENSAT
    return ENOSYS
}

/*
 * Wrapped
 */

//sys   kill(pid int, signum int, posix int) (err error)

func Kill(pid int, signum syscall.Signal) (err error) { return kill(pid, int(signum), 1) }

//sys   ioctl(fd int, req uint, arg uintptr) (err error)

// ioctl itself should not be exposed directly, but additional get/set
// functions for specific types are permissible.

// IoctlSetInt performs an ioctl operation which sets an integer value
// on fd, using the specified request number.
func IoctlSetInt(fd int, req uint, value int) error {
    return ioctl(fd, req, uintptr(value))
}

func ioctlSetWinsize(fd int, req uint, value *Winsize) error {
    return ioctl(fd, req, uintptr(unsafe.Pointer(value)))
}

func ioctlSetTermios(fd int, req uint, value *Termios) error {
    return ioctl(fd, req, uintptr(unsafe.Pointer(value)))
}

// IoctlGetInt performs an ioctl operation which gets an integer value
// from fd, using the specified request number.
func IoctlGetInt(fd int, req uint) (int, error) {
    var value int
    err := ioctl(fd, req, uintptr(unsafe.Pointer(&value)))
    return value, err
}

func IoctlGetWinsize(fd int, req uint) (*Winsize, error) {
    var value Winsize
    err := ioctl(fd, req, uintptr(unsafe.Pointer(&value)))
    return &value, err
}

func IoctlGetTermios(fd int, req uint) (*Termios, error) {
    var value Termios
    err := ioctl(fd, req, uintptr(unsafe.Pointer(&value)))
    return &value, err
}

func Uname(uname *Utsname) error {
    mib := []_C_int{CTL_KERN, KERN_OSTYPE}
    n := unsafe.Sizeof(uname.Sysname)
    if err := sysctl(mib, &uname.Sysname[0], &n, nil, 0); err != nil {
        return err
    }

    mib = []_C_int{CTL_KERN, KERN_HOSTNAME}
    n = unsafe.Sizeof(uname.Nodename)
    if err := sysctl(mib, &uname.Nodename[0], &n, nil, 0); err != nil {
        return err
    }

    mib = []_C_int{CTL_KERN, KERN_OSRELEASE}
    n = unsafe.Sizeof(uname.Release)
    if err := sysctl(mib, &uname.Release[0], &n, nil, 0); err != nil {
        return err
    }

    mib = []_C_int{CTL_KERN, KERN_VERSION}
    n = unsafe.Sizeof(uname.Version)
    if err := sysctl(mib, &uname.Version[0], &n, nil, 0); err != nil {
        return err
    }

    // The version might have newlines or tabs in it, convert them to
    // spaces.
    for i, b := range uname.Version {
        if b == '\n' || b == '\t' {
            if i == len(uname.Version)-1 {
                uname.Version[i] = 0
            } else {
                uname.Version[i] = ' '
            }
        }
    }

    mib = []_C_int{CTL_HW, HW_MACHINE}
    n = unsafe.Sizeof(uname.Machine)
    if err := sysctl(mib, &uname.Machine[0], &n, nil, 0); err != nil {
        return err
    }

    return nil
}

func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
    if raceenabled {
        raceReleaseMerge(unsafe.Pointer(&ioSync))
    }
    var length = int64(count)
    err = sendfile(infd, outfd, *offset, &length, nil, 0)
    written = int(length)
    return
}

//sys   sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error)

/*
 * Exposed directly
 */
//sys   Access(path string, mode uint32) (err error)
//sys   Adjtime(delta *Timeval, olddelta *Timeval) (err error)
//sys   Chdir(path string) (err error)
//sys   Chflags(path string, flags int) (err error)
//sys   Chmod(path string, mode uint32) (err error)
//sys   Chown(path string, uid int, gid int) (err error)
//sys   Chroot(path string) (err error)
//sys   ClockGettime(clockid int32, time *Timespec) (err error)
//sys   Close(fd int) (err error)
//sys   Dup(fd int) (nfd int, err error)
//sys   Dup2(from int, to int) (err error)
//sys   Exchangedata(path1 string, path2 string, options int) (err error)
//sys   Exit(code int)
//sys   Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
//sys   Fchdir(fd int) (err error)
//sys   Fchflags(fd int, flags int) (err error)
//sys   Fchmod(fd int, mode uint32) (err error)
//sys   Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)
//sys   Fchown(fd int, uid int, gid int) (err error)
//sys   Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
//sys   Flock(fd int, how int) (err error)
//sys   Fpathconf(fd int, name int) (val int, err error)
//sys   Fsync(fd int) (err error)
//sys   Ftruncate(fd int, length int64) (err error)
//sys   Getdtablesize() (size int)
//sysnb Getegid() (egid int)
//sysnb Geteuid() (uid int)
//sysnb Getgid() (gid int)
//sysnb Getpgid(pid int) (pgid int, err error)
//sysnb Getpgrp() (pgrp int)
//sysnb Getpid() (pid int)
//sysnb Getppid() (ppid int)
//sys   Getpriority(which int, who int) (prio int, err error)
//sysnb Getrlimit(which int, lim *Rlimit) (err error)
//sysnb Getrusage(who int, rusage *Rusage) (err error)
//sysnb Getsid(pid int) (sid int, err error)
//sysnb Getuid() (uid int)
//sysnb Issetugid() (tainted bool)
//sys   Kqueue() (fd int, err error)
//sys   Lchown(path string, uid int, gid int) (err error)
//sys   Link(path string, link string) (err error)
//sys   Linkat(pathfd int, path string, linkfd int, link string, flags int) (err error)
//sys   Listen(s int, backlog int) (err error)
//sys   Mkdir(path string, mode uint32) (err error)
//sys   Mkdirat(dirfd int, path string, mode uint32) (err error)
//sys   Mkfifo(path string, mode uint32) (err error)
//sys   Mknod(path string, mode uint32, dev int) (err error)
//sys   Open(path string, mode int, perm uint32) (fd int, err error)
//sys   Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error)
//sys   Pathconf(path string, name int) (val 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   read(fd int, p []byte) (n int, err error)
//sys   Readlink(path string, buf []byte) (n int, err error)
//sys   Readlinkat(dirfd int, path string, buf []byte) (n int, err error)
//sys   Rename(from string, to string) (err error)
//sys   Renameat(fromfd int, from string, tofd int, to string) (err error)
//sys   Revoke(path string) (err error)
//sys   Rmdir(path string) (err error)
//sys   Seek(fd int, offset int64, whence int) (newoffset int64, err error) = SYS_LSEEK
//sys   Select(n int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (err error)
//sys   Setegid(egid int) (err error)
//sysnb Seteuid(euid int) (err error)
//sysnb Setgid(gid int) (err error)
//sys   Setlogin(name string) (err error)
//sysnb Setpgid(pid int, pgid int) (err error)
//sys   Setpriority(which int, who int, prio int) (err error)
//sys   Setprivexec(flag int) (err error)
//sysnb Setregid(rgid int, egid int) (err error)
//sysnb Setreuid(ruid int, euid int) (err error)
//sysnb Setrlimit(which int, lim *Rlimit) (err error)
//sysnb Setsid() (pid int, err error)
//sysnb Settimeofday(tp *Timeval) (err error)
//sysnb Setuid(uid int) (err error)
//sys   Symlink(path string, link string) (err error)
//sys   Symlinkat(oldpath string, newdirfd int, newpath string) (err error)
//sys   Sync() (err error)
//sys   Truncate(path string, length int64) (err error)
//sys   Umask(newmask int) (oldmask int)
//sys   Undelete(path string) (err error)
//sys   Unlink(path string) (err error)
//sys   Unlinkat(dirfd int, path string, flags int) (err error)
//sys   Unmount(path string, flags int) (err error)
//sys   write(fd int, p []byte) (n int, err error)
//sys   mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
//sys   munmap(addr uintptr, length uintptr) (err error)
//sys   readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
//sys   writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE

/*
 * Unimplemented
 */
// Profil
// Sigaction
// Sigprocmask
// Getlogin
// Sigpending
// Sigaltstack
// Ioctl
// Reboot
// Execve
// Vfork
// Sbrk
// Sstk
// Ovadvise
// Mincore
// Setitimer
// Swapon
// Select
// Sigsuspend
// Readv
// Writev
// Nfssvc
// Getfh
// Quotactl
// Mount
// Csops
// Waitid
// Add_profil
// Kdebug_trace
// Sigreturn
// Atsocket
// Kqueue_from_portset_np
// Kqueue_portset
// Getattrlist
// Setattrlist
// Getdirentriesattr
// Searchfs
// Delete
// Copyfile
// Watchevent
// Waitevent
// Modwatch
// Fsctl
// Initgroups
// Posix_spawn
// Nfsclnt
// Fhopen
// Minherit
// Semsys
// Msgsys
// Shmsys
// Semctl
// Semget
// Semop
// Msgctl
// Msgget
// Msgsnd
// Msgrcv
// Shmat
// Shmctl
// Shmdt
// Shmget
// Shm_open
// Shm_unlink
// Sem_open
// Sem_close
// Sem_unlink
// Sem_wait
// Sem_trywait
// Sem_post
// Sem_getvalue
// Sem_init
// Sem_destroy
// Open_extended
// Umask_extended
// Stat_extended
// Lstat_extended
// Fstat_extended
// Chmod_extended
// Fchmod_extended
// Access_extended
// Settid
// Gettid
// Setsgroups
// Getsgroups
// Setwgroups
// Getwgroups
// Mkfifo_extended
// Mkdir_extended
// Identitysvc
// Shared_region_check_np
// Shared_region_map_np
// __pthread_mutex_destroy
// __pthread_mutex_init
// __pthread_mutex_lock
// __pthread_mutex_trylock
// __pthread_mutex_unlock
// __pthread_cond_init
// __pthread_cond_destroy
// __pthread_cond_broadcast
// __pthread_cond_signal
// Setsid_with_pid
// __pthread_cond_timedwait
// Aio_fsync
// Aio_return
// Aio_suspend
// Aio_cancel
// Aio_error
// Aio_read
// Aio_write
// Lio_listio
// __pthread_cond_wait
// Iopolicysys
// __pthread_kill
// __pthread_sigmask
// __sigwait
// __disable_threadsignal
// __pthread_markcancel
// __pthread_canceled
// __semwait_signal
// Proc_info
// sendfile
// Stat64_extended
// Lstat64_extended
// Fstat64_extended
// __pthread_chdir
// __pthread_fchdir
// Audit
// Auditon
// Getauid
// Setauid
// Getaudit
// Setaudit
// Getaudit_addr
// Setaudit_addr
// Auditctl
// Bsdthread_create
// Bsdthread_terminate
// Stack_snapshot
// Bsdthread_register
// Workq_open
// Workq_ops
// __mac_execve
// __mac_syscall
// __mac_get_file
// __mac_set_file
// __mac_get_link
// __mac_set_link
// __mac_get_proc
// __mac_set_proc
// __mac_get_fd
// __mac_set_fd
// __mac_get_pid
// __mac_get_lcid
// __mac_get_lctx
// __mac_set_lctx
// Setlcid
// Read_nocancel
// Write_nocancel
// Open_nocancel
// Close_nocancel
// Wait4_nocancel
// Recvmsg_nocancel
// Sendmsg_nocancel
// Recvfrom_nocancel
// Accept_nocancel
// Fcntl_nocancel
// Select_nocancel
// Fsync_nocancel
// Connect_nocancel
// Sigsuspend_nocancel
// Readv_nocancel
// Writev_nocancel
// Sendto_nocancel
// Pread_nocancel
// Pwrite_nocancel
// Waitid_nocancel
// Poll_nocancel
// Msgsnd_nocancel
// Msgrcv_nocancel
// Sem_wait_nocancel
// Aio_suspend_nocancel
// __sigwait_nocancel
// __semwait_signal_nocancel
// __mac_mount
// __mac_get_mount
// __mac_getfsstat