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Diffstat (limited to 'pkg/abi/linux/file.go')
| -rw-r--r-- | pkg/abi/linux/file.go | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/pkg/abi/linux/file.go b/pkg/abi/linux/file.go new file mode 100644 index 000000000..81ff9fe9e --- /dev/null +++ b/pkg/abi/linux/file.go @@ -0,0 +1,267 @@ +// 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.googlesource.com/gvisor/pkg/abi" + "gvisor.googlesource.com/gvisor/pkg/binary" +) + +// Constants for open(2). +const ( + O_ACCMODE = 00000003 + O_RDONLY = 00000000 + O_WRONLY = 00000001 + O_RDWR = 00000002 + O_CREAT = 00000100 + O_EXCL = 00000200 + O_NOCTTY = 00000400 + O_TRUNC = 00001000 + O_APPEND = 00002000 + O_NONBLOCK = 00004000 + O_ASYNC = 00020000 + O_DIRECT = 00040000 + O_LARGEFILE = 00100000 + O_DIRECTORY = 00200000 + O_NOFOLLOW = 00400000 + O_CLOEXEC = 02000000 + O_SYNC = 04010000 + O_PATH = 010000000 +) + +// 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 ( + FileTypeMask = 0170000 + ModeSocket = 0140000 + ModeSymlink = 0120000 + ModeRegular = 0100000 + ModeBlockDevice = 060000 + ModeDirectory = 040000 + ModeCharacterDevice = 020000 + ModeNamedPipe = 010000 + + ModeSetUID = 04000 + ModeSetGID = 02000 + ModeSticky = 01000 + + 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 preadv2/pwritev2. +const ( + RWF_HIPRI = 0x00000001 + RWF_DSYNC = 0x00000002 + RWF_SYNC = 0x00000004 + RWF_VALID = RWF_HIPRI | RWF_DSYNC | RWF_SYNC +) + +// Stat represents struct stat. +type Stat struct { + Dev uint64 + Ino uint64 + Nlink uint64 + Mode uint32 + UID uint32 + GID uint32 + X_pad0 int32 + Rdev uint64 + Size int64 + Blksize int64 + Blocks int64 + ATime Timespec + MTime Timespec + CTime Timespec + X_unused [3]int64 +} + +// SizeOfStat is the size of a Stat struct. +var SizeOfStat = binary.Size(Stat{}) + +// FileMode represents a mode_t. +type FileMode uint + +// 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) +} + +// 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, "|") +} + +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 +) |