syscallcompat

Documentation

Overview

Package syscallcompat wraps Linux-specific syscalls.

Index

• Constants
• func Dup3(oldfd int, newfd int, flags int) (err error)
• func EnospcPrealloc(fd int, off int64, len int64) (err error)
• func Faccessat(dirfd int, path string, mode uint32) error
• func Fallocate(fd int, mode uint32, off int64, len int64) (err error)
• func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)
• func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
• func Fstatat(dirfd int, path string, stat *unix.Stat_t, flags int) (err error)
• func Getdents(fd int) ([]fuse.DirEntry, error)
• func IsENOSPC(err error) bool
• func Linkat(olddirfd int, oldpath string, newdirfd int, newpath string, flags int) (err error)
• func Mkdirat(dirfd int, path string, mode uint32) (err error)
• func Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
• func OpenNofollow(baseDir string, relPath string, flags int, mode uint32) (fd int, err error)
• func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
• func Readlinkat(dirfd int, path string) (string, error)
• func Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error)
• func Symlinkat(oldpath string, newdirfd int, newpath string) (err error)
• func Unix2syscall(u unix.Stat_t) syscall.Stat_t
• func Unlinkat(dirfd int, path string, flags int) (err error)

Constants

const O_DIRECT = syscall.O_DIRECT

O_DIRECT means oncached I/O on Linux. No direct equivalent on MacOS and defined to zero there.

const PATH_MAX = 4096

PATH_MAX is the maximum allowed path length on Linux. It is not defined on Darwin, so we use the Linux value.

Functions

func Dup3

func Dup3(oldfd int, newfd int, flags int) (err error)

Dup3 wraps the Dup3 syscall. We want to use Dup3 rather than Dup2 because Dup2 is not implemented on arm64.

func EnospcPrealloc

func EnospcPrealloc(fd int, off int64, len int64) (err error)

EnospcPrealloc preallocates ciphertext space without changing the file size. This guarantees that we don't run out of space while writing a ciphertext block (that would corrupt the block).

func Faccessat

func Faccessat(dirfd int, path string, mode uint32) error

Faccessat exists both in Linux and in MacOS 10.10+, but the Linux version DOES NOT support any flags. Emulate AT_SYMLINK_NOFOLLOW like glibc does.

func Fallocate

func Fallocate(fd int, mode uint32, off int64, len int64) (err error)

Fallocate wraps the Fallocate syscall.

func Fchmodat

func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)

Fchmodat syscall.

func Fchownat

func Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)

Fchownat syscall.

func Fstatat

func Fstatat(dirfd int, path string, stat *unix.Stat_t, flags int) (err error)

Fstatat syscall.

func Getdents

func Getdents(fd int) ([]fuse.DirEntry, error)

Getdents syscall.

func IsENOSPC

func IsENOSPC(err error) bool

IsENOSPC tries to find out if "err" is a (potentially wrapped) ENOSPC error.

func Linkat

func Linkat(olddirfd int, oldpath string, newdirfd int, newpath string, flags int) (err error)

Linkat exists both in Linux and in MacOS 10.10+.

func Mkdirat

func Mkdirat(dirfd int, path string, mode uint32) (err error)

Mkdirat syscall.

func Mknodat

func Mknodat(dirfd int, path string, mode uint32, dev int) (err error)

Mknodat wraps the Mknodat syscall.

func OpenNofollow

func OpenNofollow(baseDir string, relPath string, flags int, mode uint32) (fd int, err error)

OpenNofollow opens the file/dir at "relPath" in a way that is secure against symlink attacks. Symlinks that are part of "relPath" are never followed. This function is implemented by walking the directory tree, starting at "baseDir", using the Openat syscall with the O_NOFOLLOW flag. Symlinks that are part of the "baseDir" path are followed.

func Openat

func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)

Openat wraps the Openat syscall.

func Readlinkat

func Readlinkat(dirfd int, path string) (string, error)

Readlinkat exists both in Linux and in MacOS 10.10+. We may add an emulated version for users on older MacOS versions if there is demand. Buffer allocation is handled internally, unlike the bare unix.Readlinkat.

func Renameat

func Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error)

Renameat wraps the Renameat syscall.

func Symlinkat

func Symlinkat(oldpath string, newdirfd int, newpath string) (err error)

Symlinkat syscall.

func Unix2syscall

func Unix2syscall(u unix.Stat_t) syscall.Stat_t

Unix2syscall converts a unix.Stat_t struct to a syscall.Stat_t struct. A direct cast does not work because the padding is named differently in unix.Stat_t for some reason ("X__unused" in syscall, "_" in unix).

func Unlinkat

func Unlinkat(dirfd int, path string, flags int) (err error)

Unlinkat syscall.