1 files changed, 384 insertions, 0 deletions
diff --git a/pkg/abi/linux/file.go b/pkg/abi/linux/file.go
new file mode 100644
index 000000000..e11ca2d62
--- /dev/null
+++ b/pkg/abi/linux/file.go
@@ -0,0 +1,384 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package linux
+
+import (
+	"fmt"
+	"strings"
+
+	"gvisor.dev/gvisor/pkg/abi"
+	"gvisor.dev/gvisor/pkg/binary"
+)
+
+// Constants for open(2).
+const (
+	O_ACCMODE  = 000000003
+	O_RDONLY   = 000000000
+	O_WRONLY   = 000000001
+	O_RDWR     = 000000002
+	O_CREAT    = 000000100
+	O_EXCL     = 000000200
+	O_NOCTTY   = 000000400
+	O_TRUNC    = 000001000
+	O_APPEND   = 000002000
+	O_NONBLOCK = 000004000
+	O_DSYNC    = 000010000
+	O_ASYNC    = 000020000
+	O_NOATIME  = 001000000
+	O_CLOEXEC  = 002000000
+	O_SYNC     = 004000000 // __O_SYNC in Linux
+	O_PATH     = 010000000
+	O_TMPFILE  = 020000000 // __O_TMPFILE in Linux
+)
+
+// Constants for fstatat(2).
+const (
+	AT_SYMLINK_NOFOLLOW = 0x100
+)
+
+// Constants for mount(2).
+const (
+	MS_RDONLY      = 0x1
+	MS_NOSUID      = 0x2
+	MS_NODEV       = 0x4
+	MS_NOEXEC      = 0x8
+	MS_SYNCHRONOUS = 0x10
+	MS_REMOUNT     = 0x20
+	MS_MANDLOCK    = 0x40
+	MS_DIRSYNC     = 0x80
+	MS_NOATIME     = 0x400
+	MS_NODIRATIME  = 0x800
+	MS_BIND        = 0x1000
+	MS_MOVE        = 0x2000
+	MS_REC         = 0x4000
+
+	MS_POSIXACL    = 0x10000
+	MS_UNBINDABLE  = 0x20000
+	MS_PRIVATE     = 0x40000
+	MS_SLAVE       = 0x80000
+	MS_SHARED      = 0x100000
+	MS_RELATIME    = 0x200000
+	MS_KERNMOUNT   = 0x400000
+	MS_I_VERSION   = 0x800000
+	MS_STRICTATIME = 0x1000000
+
+	MS_MGC_VAL = 0xC0ED0000
+	MS_MGC_MSK = 0xffff0000
+)
+
+// Constants for umount2(2).
+const (
+	MNT_FORCE       = 0x1
+	MNT_DETACH      = 0x2
+	MNT_EXPIRE      = 0x4
+	UMOUNT_NOFOLLOW = 0x8
+)
+
+// Constants for unlinkat(2).
+const (
+	AT_REMOVEDIR = 0x200
+)
+
+// Constants for linkat(2) and fchownat(2).
+const (
+	AT_SYMLINK_FOLLOW = 0x400
+	AT_EMPTY_PATH     = 0x1000
+)
+
+// Constants for all file-related ...at(2) syscalls.
+const (
+	AT_FDCWD = -100
+)
+
+// Special values for the ns field in utimensat(2).
+const (
+	UTIME_NOW  = ((1 << 30) - 1)
+	UTIME_OMIT = ((1 << 30) - 2)
+)
+
+// MaxSymlinkTraversals is the maximum number of links that will be followed by
+// the kernel to resolve a symlink.
+const MaxSymlinkTraversals = 40
+
+// Constants for flock(2).
+const (
+	LOCK_SH = 1 // shared lock
+	LOCK_EX = 2 // exclusive lock
+	LOCK_NB = 4 // or'd with one of the above to prevent blocking
+	LOCK_UN = 8 // remove lock
+)
+
+// Values for mode_t.
+const (
+	S_IFMT   = 0170000
+	S_IFSOCK = 0140000
+	S_IFLNK  = 0120000
+	S_IFREG  = 0100000
+	S_IFBLK  = 060000
+	S_IFDIR  = 040000
+	S_IFCHR  = 020000
+	S_IFIFO  = 010000
+
+	FileTypeMask        = S_IFMT
+	ModeSocket          = S_IFSOCK
+	ModeSymlink         = S_IFLNK
+	ModeRegular         = S_IFREG
+	ModeBlockDevice     = S_IFBLK
+	ModeDirectory       = S_IFDIR
+	ModeCharacterDevice = S_IFCHR
+	ModeNamedPipe       = S_IFIFO
+
+	S_ISUID = 04000
+	S_ISGID = 02000
+	S_ISVTX = 01000
+
+	ModeSetUID = S_ISUID
+	ModeSetGID = S_ISGID
+	ModeSticky = S_ISVTX
+
+	ModeUserAll     = 0700
+	ModeUserRead    = 0400
+	ModeUserWrite   = 0200
+	ModeUserExec    = 0100
+	ModeGroupAll    = 0070
+	ModeGroupRead   = 0040
+	ModeGroupWrite  = 0020
+	ModeGroupExec   = 0010
+	ModeOtherAll    = 0007
+	ModeOtherRead   = 0004
+	ModeOtherWrite  = 0002
+	ModeOtherExec   = 0001
+	PermissionsMask = 0777
+)
+
+// Values for linux_dirent64.d_type.
+const (
+	DT_UNKNOWN = 0
+	DT_FIFO    = 1
+	DT_CHR     = 2
+	DT_DIR     = 4
+	DT_BLK     = 6
+	DT_REG     = 8
+	DT_LNK     = 10
+	DT_SOCK    = 12
+	DT_WHT     = 14
+)
+
+// DirentType are the friendly strings for linux_dirent64.d_type.
+var DirentType = abi.ValueSet{
+	DT_UNKNOWN: "DT_UNKNOWN",
+	DT_FIFO:    "DT_FIFO",
+	DT_CHR:     "DT_CHR",
+	DT_DIR:     "DT_DIR",
+	DT_BLK:     "DT_BLK",
+	DT_REG:     "DT_REG",
+	DT_LNK:     "DT_LNK",
+	DT_SOCK:    "DT_SOCK",
+	DT_WHT:     "DT_WHT",
+}
+
+// Values for preadv2/pwritev2.
+const (
+	// NOTE(b/120162627): gVisor does not implement the RWF_HIPRI feature, but
+	// the flag is accepted as a valid flag argument for preadv2/pwritev2 and
+	// silently ignored.
+	RWF_HIPRI = 0x00000001
+	RWF_DSYNC = 0x00000002
+	RWF_SYNC  = 0x00000004
+	RWF_VALID = RWF_HIPRI | RWF_DSYNC | RWF_SYNC
+)
+
+// SizeOfStat is the size of a Stat struct.
+var SizeOfStat = binary.Size(Stat{})
+
+// Flags for statx.
+const (
+	AT_STATX_SYNC_TYPE    = 0x6000
+	AT_STATX_SYNC_AS_STAT = 0x0000
+	AT_STATX_FORCE_SYNC   = 0x2000
+	AT_STATX_DONT_SYNC    = 0x4000
+)
+
+// Mask values for statx.
+const (
+	STATX_TYPE        = 0x00000001
+	STATX_MODE        = 0x00000002
+	STATX_NLINK       = 0x00000004
+	STATX_UID         = 0x00000008
+	STATX_GID         = 0x00000010
+	STATX_ATIME       = 0x00000020
+	STATX_MTIME       = 0x00000040
+	STATX_CTIME       = 0x00000080
+	STATX_INO         = 0x00000100
+	STATX_SIZE        = 0x00000200
+	STATX_BLOCKS      = 0x00000400
+	STATX_BASIC_STATS = 0x000007ff
+	STATX_BTIME       = 0x00000800
+	STATX_ALL         = 0x00000fff
+	STATX__RESERVED   = 0x80000000
+)
+
+// Bitmasks for Statx.Attributes and Statx.AttributesMask, from
+// include/uapi/linux/stat.h.
+const (
+	STATX_ATTR_COMPRESSED = 0x00000004
+	STATX_ATTR_IMMUTABLE  = 0x00000010
+	STATX_ATTR_APPEND     = 0x00000020
+	STATX_ATTR_NODUMP     = 0x00000040
+	STATX_ATTR_ENCRYPTED  = 0x00000800
+	STATX_ATTR_AUTOMOUNT  = 0x00001000
+)
+
+// Statx represents struct statx.
+//
+// +marshal
+type Statx struct {
+	Mask           uint32
+	Blksize        uint32
+	Attributes     uint64
+	Nlink          uint32
+	UID            uint32
+	GID            uint32
+	Mode           uint16
+	_              uint16
+	Ino            uint64
+	Size           uint64
+	Blocks         uint64
+	AttributesMask uint64
+	Atime          StatxTimestamp
+	Btime          StatxTimestamp
+	Ctime          StatxTimestamp
+	Mtime          StatxTimestamp
+	RdevMajor      uint32
+	RdevMinor      uint32
+	DevMajor       uint32
+	DevMinor       uint32
+}
+
+// SizeOfStatx is the size of a Statx struct.
+var SizeOfStatx = binary.Size(Statx{})
+
+// FileMode represents a mode_t.
+type FileMode uint16
+
+// Permissions returns just the permission bits.
+func (m FileMode) Permissions() FileMode {
+	return m & PermissionsMask
+}
+
+// FileType returns just the file type bits.
+func (m FileMode) FileType() FileMode {
+	return m & FileTypeMask
+}
+
+// ExtraBits returns everything but the file type and permission bits.
+func (m FileMode) ExtraBits() FileMode {
+	return m &^ (PermissionsMask | FileTypeMask)
+}
+
+// IsDir returns true if file type represents a directory.
+func (m FileMode) IsDir() bool {
+	return m.FileType() == S_IFDIR
+}
+
+// String returns a string representation of m.
+func (m FileMode) String() string {
+	var s []string
+	if ft := m.FileType(); ft != 0 {
+		s = append(s, fileType.Parse(uint64(ft)))
+	}
+	if eb := m.ExtraBits(); eb != 0 {
+		s = append(s, modeExtraBits.Parse(uint64(eb)))
+	}
+	s = append(s, fmt.Sprintf("0o%o", m.Permissions()))
+	return strings.Join(s, "|")
+}
+
+// DirentType maps file types to dirent types appropriate for (struct
+// dirent)::d_type.
+func (m FileMode) DirentType() uint8 {
+	switch m.FileType() {
+	case ModeSocket:
+		return DT_SOCK
+	case ModeSymlink:
+		return DT_LNK
+	case ModeRegular:
+		return DT_REG
+	case ModeBlockDevice:
+		return DT_BLK
+	case ModeDirectory:
+		return DT_DIR
+	case ModeCharacterDevice:
+		return DT_CHR
+	case ModeNamedPipe:
+		return DT_FIFO
+	default:
+		return DT_UNKNOWN
+	}
+}
+
+var modeExtraBits = abi.FlagSet{
+	{
+		Flag: ModeSetUID,
+		Name: "S_ISUID",
+	},
+	{
+		Flag: ModeSetGID,
+		Name: "S_ISGID",
+	},
+	{
+		Flag: ModeSticky,
+		Name: "S_ISVTX",
+	},
+}
+
+var fileType = abi.ValueSet{
+	ModeSocket:          "S_IFSOCK",
+	ModeSymlink:         "S_IFLINK",
+	ModeRegular:         "S_IFREG",
+	ModeBlockDevice:     "S_IFBLK",
+	ModeDirectory:       "S_IFDIR",
+	ModeCharacterDevice: "S_IFCHR",
+	ModeNamedPipe:       "S_IFIFO",
+}
+
+// Constants for memfd_create(2). Source: include/uapi/linux/memfd.h
+const (
+	MFD_CLOEXEC       = 0x0001
+	MFD_ALLOW_SEALING = 0x0002
+)
+
+// Constants related to file seals. Source: include/uapi/{asm-generic,linux}/fcntl.h
+const (
+	F_LINUX_SPECIFIC_BASE = 1024
+	F_ADD_SEALS           = F_LINUX_SPECIFIC_BASE + 9
+	F_GET_SEALS           = F_LINUX_SPECIFIC_BASE + 10
+
+	F_SEAL_SEAL   = 0x0001 // Prevent further seals from being set.
+	F_SEAL_SHRINK = 0x0002 // Prevent file from shrinking.
+	F_SEAL_GROW   = 0x0004 // Prevent file from growing.
+	F_SEAL_WRITE  = 0x0008 // Prevent writes.
+)
+
+// Constants related to fallocate(2). Source: include/uapi/linux/falloc.h
+const (
+	FALLOC_FL_KEEP_SIZE      = 0x01
+	FALLOC_FL_PUNCH_HOLE     = 0x02
+	FALLOC_FL_NO_HIDE_STALE  = 0x04
+	FALLOC_FL_COLLAPSE_RANGE = 0x08
+	FALLOC_FL_ZERO_RANGE     = 0x10
+	FALLOC_FL_INSERT_RANGE   = 0x20
+	FALLOC_FL_UNSHARE_RANGE  = 0x40
+)