diff options
Diffstat (limited to '')
| -rw-r--r-- | src/syscall/syscall_linux.go | 1292 |
1 files changed, 1292 insertions, 0 deletions
diff --git a/src/syscall/syscall_linux.go b/src/syscall/syscall_linux.go new file mode 100644 index 0000000..b6e8420 --- /dev/null +++ b/src/syscall/syscall_linux.go @@ -0,0 +1,1292 @@ +// Copyright 2009 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. + +// Linux 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 syscall + +import ( + "internal/itoa" + "runtime" + "unsafe" +) + +// N.B. RawSyscall6 is provided via linkname by runtime/internal/syscall. +// +// Errno is uintptr and thus compatible with the runtime/internal/syscall +// definition. + +func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) + +// Pull in entersyscall/exitsyscall for Syscall/Syscall6. +// +// Note that this can't be a push linkname because the runtime already has a +// nameless linkname to export to assembly here and in x/sys. Additionally, +// entersyscall fetches the caller PC and SP and thus can't have a wrapper +// inbetween. + +//go:linkname runtime_entersyscall runtime.entersyscall +func runtime_entersyscall() + +//go:linkname runtime_exitsyscall runtime.exitsyscall +func runtime_exitsyscall() + +// N.B. For the Syscall functions below: +// +// //go:uintptrkeepalive because the uintptr argument may be converted pointers +// that need to be kept alive in the caller (this is implied for RawSyscall6 +// since it has no body). +// +// //go:nosplit because stack copying does not account for uintptrkeepalive, so +// the stack must not grow. Stack copying cannot blindly assume that all +// uintptr arguments are pointers, because some values may look like pointers, +// but not really be pointers, and adjusting their value would break the call. +// +// //go:norace, on RawSyscall, to avoid race instrumentation if RawSyscall is +// called after fork, or from a signal handler. +// +// //go:linkname to ensure ABI wrappers are generated for external callers +// (notably x/sys/unix assembly). + +//go:uintptrkeepalive +//go:nosplit +//go:norace +//go:linkname RawSyscall +func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) { + return RawSyscall6(trap, a1, a2, a3, 0, 0, 0) +} + +//go:uintptrkeepalive +//go:nosplit +//go:linkname Syscall +func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) { + runtime_entersyscall() + // N.B. Calling RawSyscall here is unsafe with atomic coverage + // instrumentation and race mode. + // + // Coverage instrumentation will add a sync/atomic call to RawSyscall. + // Race mode will add race instrumentation to sync/atomic. Race + // instrumentation requires a P, which we no longer have. + // + // RawSyscall6 is fine because it is implemented in assembly and thus + // has no coverage instrumentation. + // + // This is typically not a problem in the runtime because cmd/go avoids + // adding coverage instrumentation to the runtime in race mode. + r1, r2, err = RawSyscall6(trap, a1, a2, a3, 0, 0, 0) + runtime_exitsyscall() + return +} + +//go:uintptrkeepalive +//go:nosplit +//go:linkname Syscall6 +func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) { + runtime_entersyscall() + r1, r2, err = RawSyscall6(trap, a1, a2, a3, a4, a5, a6) + runtime_exitsyscall() + return +} + +func rawSyscallNoError(trap, a1, a2, a3 uintptr) (r1, r2 uintptr) +func rawVforkSyscall(trap, a1, a2, a3 uintptr) (r1 uintptr, err Errno) + +/* + * Wrapped + */ + +func Access(path string, mode uint32) (err error) { + return Faccessat(_AT_FDCWD, path, mode, 0) +} + +func Chmod(path string, mode uint32) (err error) { + return Fchmodat(_AT_FDCWD, path, mode, 0) +} + +func Chown(path string, uid int, gid int) (err error) { + return Fchownat(_AT_FDCWD, path, uid, gid, 0) +} + +func Creat(path string, mode uint32) (fd int, err error) { + return Open(path, O_CREAT|O_WRONLY|O_TRUNC, mode) +} + +func EpollCreate(size int) (fd int, err error) { + if size <= 0 { + return -1, EINVAL + } + return EpollCreate1(0) +} + +func isGroupMember(gid int) bool { + groups, err := Getgroups() + if err != nil { + return false + } + + for _, g := range groups { + if g == gid { + return true + } + } + return false +} + +func isCapDacOverrideSet() bool { + const _CAP_DAC_OVERRIDE = 1 + var c caps + c.hdr.version = _LINUX_CAPABILITY_VERSION_3 + + _, _, err := RawSyscall(SYS_CAPGET, uintptr(unsafe.Pointer(&c.hdr)), uintptr(unsafe.Pointer(&c.data[0])), 0) + + return err == 0 && c.data[0].effective&capToMask(_CAP_DAC_OVERRIDE) != 0 +} + +//sys faccessat(dirfd int, path string, mode uint32) (err error) +//sys faccessat2(dirfd int, path string, mode uint32, flags int) (err error) = _SYS_faccessat2 + +func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) { + if flags == 0 { + return faccessat(dirfd, path, mode) + } + + // Attempt to use the newer faccessat2, which supports flags directly, + // falling back if it doesn't exist. + // + // Don't attempt on Android, which does not allow faccessat2 through + // its seccomp policy [1] on any version of Android as of 2022-12-20. + // + // [1] https://cs.android.com/android/platform/superproject/+/master:bionic/libc/SECCOMP_BLOCKLIST_APP.TXT;l=4;drc=dbb8670dfdcc677f7e3b9262e93800fa14c4e417 + if runtime.GOOS != "android" { + if err := faccessat2(dirfd, path, mode, flags); err != ENOSYS && err != EPERM { + return err + } + } + + // The Linux kernel faccessat system call does not take any flags. + // The glibc faccessat implements the flags itself; see + // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/faccessat.c;hb=HEAD + // Because people naturally expect syscall.Faccessat to act + // like C faccessat, we do the same. + + if flags & ^(_AT_SYMLINK_NOFOLLOW|_AT_EACCESS) != 0 { + return EINVAL + } + + var st Stat_t + if err := fstatat(dirfd, path, &st, flags&_AT_SYMLINK_NOFOLLOW); err != nil { + return err + } + + mode &= 7 + if mode == 0 { + return nil + } + + // Fallback to checking permission bits. + var uid int + if flags&_AT_EACCESS != 0 { + uid = Geteuid() + if uid != 0 && isCapDacOverrideSet() { + // If CAP_DAC_OVERRIDE is set, file access check is + // done by the kernel in the same way as for root + // (see generic_permission() in the Linux sources). + uid = 0 + } + } else { + uid = Getuid() + } + + if uid == 0 { + if mode&1 == 0 { + // Root can read and write any file. + return nil + } + if st.Mode&0111 != 0 { + // Root can execute any file that anybody can execute. + return nil + } + return EACCES + } + + var fmode uint32 + if uint32(uid) == st.Uid { + fmode = (st.Mode >> 6) & 7 + } else { + var gid int + if flags&_AT_EACCESS != 0 { + gid = Getegid() + } else { + gid = Getgid() + } + + if uint32(gid) == st.Gid || isGroupMember(int(st.Gid)) { + fmode = (st.Mode >> 3) & 7 + } else { + fmode = st.Mode & 7 + } + } + + if fmode&mode == mode { + return nil + } + + return EACCES +} + +//sys fchmodat(dirfd int, path string, mode uint32) (err error) +//sys fchmodat2(dirfd int, path string, mode uint32, flags int) (err error) = _SYS_fchmodat2 + +func Fchmodat(dirfd int, path string, mode uint32, flags int) error { + // Linux fchmodat doesn't support the flags parameter, but fchmodat2 does. + // Try fchmodat2 if flags are specified. + if flags != 0 { + err := fchmodat2(dirfd, path, mode, flags) + if err == ENOSYS { + // fchmodat2 isn't available. If the flags are known to be valid, + // return EOPNOTSUPP to indicate that fchmodat doesn't support them. + if flags&^(_AT_SYMLINK_NOFOLLOW|_AT_EMPTY_PATH) != 0 { + return EINVAL + } else if flags&(_AT_SYMLINK_NOFOLLOW|_AT_EMPTY_PATH) != 0 { + return EOPNOTSUPP + } + } + return err + } + return fchmodat(dirfd, path, mode) +} + +//sys linkat(olddirfd int, oldpath string, newdirfd int, newpath string, flags int) (err error) + +func Link(oldpath string, newpath string) (err error) { + return linkat(_AT_FDCWD, oldpath, _AT_FDCWD, newpath, 0) +} + +func Mkdir(path string, mode uint32) (err error) { + return Mkdirat(_AT_FDCWD, path, mode) +} + +func Mknod(path string, mode uint32, dev int) (err error) { + return Mknodat(_AT_FDCWD, path, mode, dev) +} + +func Open(path string, mode int, perm uint32) (fd int, err error) { + return openat(_AT_FDCWD, path, mode|O_LARGEFILE, perm) +} + +//sys openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) + +func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) { + return openat(dirfd, path, flags|O_LARGEFILE, mode) +} + +func Pipe(p []int) error { + return Pipe2(p, 0) +} + +//sysnb pipe2(p *[2]_C_int, flags int) (err error) + +func Pipe2(p []int, flags int) error { + if len(p) != 2 { + return EINVAL + } + var pp [2]_C_int + err := pipe2(&pp, flags) + if err == nil { + p[0] = int(pp[0]) + p[1] = int(pp[1]) + } + return err +} + +//sys readlinkat(dirfd int, path string, buf []byte) (n int, err error) + +func Readlink(path string, buf []byte) (n int, err error) { + return readlinkat(_AT_FDCWD, path, buf) +} + +func Rename(oldpath string, newpath string) (err error) { + return Renameat(_AT_FDCWD, oldpath, _AT_FDCWD, newpath) +} + +func Rmdir(path string) error { + return unlinkat(_AT_FDCWD, path, _AT_REMOVEDIR) +} + +//sys symlinkat(oldpath string, newdirfd int, newpath string) (err error) + +func Symlink(oldpath string, newpath string) (err error) { + return symlinkat(oldpath, _AT_FDCWD, newpath) +} + +func Unlink(path string) error { + return unlinkat(_AT_FDCWD, path, 0) +} + +//sys unlinkat(dirfd int, path string, flags int) (err error) + +func Unlinkat(dirfd int, path string) error { + return unlinkat(dirfd, path, 0) +} + +func Utimes(path string, tv []Timeval) (err error) { + if len(tv) != 2 { + return EINVAL + } + return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0]))) +} + +//sys utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error) + +func UtimesNano(path string, ts []Timespec) (err error) { + if len(ts) != 2 { + return EINVAL + } + return utimensat(_AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0) +} + +func Futimesat(dirfd int, path string, tv []Timeval) (err error) { + if len(tv) != 2 { + return EINVAL + } + return futimesat(dirfd, path, (*[2]Timeval)(unsafe.Pointer(&tv[0]))) +} + +func Futimes(fd int, tv []Timeval) (err error) { + // Believe it or not, this is the best we can do on Linux + // (and is what glibc does). + return Utimes("/proc/self/fd/"+itoa.Itoa(fd), tv) +} + +const ImplementsGetwd = true + +//sys Getcwd(buf []byte) (n int, err error) + +func Getwd() (wd string, err error) { + var buf [PathMax]byte + n, err := Getcwd(buf[0:]) + if err != nil { + return "", err + } + // Getcwd returns the number of bytes written to buf, including the NUL. + if n < 1 || n > len(buf) || buf[n-1] != 0 { + return "", EINVAL + } + // In some cases, Linux can return a path that starts with the + // "(unreachable)" prefix, which can potentially be a valid relative + // path. To work around that, return ENOENT if path is not absolute. + if buf[0] != '/' { + return "", ENOENT + } + + return string(buf[0 : n-1]), nil +} + +func Getgroups() (gids []int, err error) { + n, err := getgroups(0, nil) + if err != nil { + return nil, err + } + if n == 0 { + return nil, nil + } + + // Sanity check group count. Max is 1<<16 on Linux. + if n < 0 || n > 1<<20 { + return nil, EINVAL + } + + a := make([]_Gid_t, n) + n, err = getgroups(n, &a[0]) + if err != nil { + return nil, err + } + gids = make([]int, n) + for i, v := range a[0:n] { + gids[i] = int(v) + } + return +} + +var cgo_libc_setgroups unsafe.Pointer // non-nil if cgo linked. + +func Setgroups(gids []int) (err error) { + n := uintptr(len(gids)) + if n == 0 { + if cgo_libc_setgroups == nil { + if _, _, e1 := AllThreadsSyscall(_SYS_setgroups, 0, 0, 0); e1 != 0 { + err = errnoErr(e1) + } + return + } + if ret := cgocaller(cgo_libc_setgroups, 0, 0); ret != 0 { + err = errnoErr(Errno(ret)) + } + return + } + + a := make([]_Gid_t, len(gids)) + for i, v := range gids { + a[i] = _Gid_t(v) + } + if cgo_libc_setgroups == nil { + if _, _, e1 := AllThreadsSyscall(_SYS_setgroups, n, uintptr(unsafe.Pointer(&a[0])), 0); e1 != 0 { + err = errnoErr(e1) + } + return + } + if ret := cgocaller(cgo_libc_setgroups, n, uintptr(unsafe.Pointer(&a[0]))); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +type WaitStatus uint32 + +// Wait status is 7 bits at bottom, either 0 (exited), +// 0x7F (stopped), or a signal number that caused an exit. +// The 0x80 bit is whether there was a core dump. +// An extra number (exit code, signal causing a stop) +// is in the high bits. At least that's the idea. +// There are various irregularities. For example, the +// "continued" status is 0xFFFF, distinguishing itself +// from stopped via the core dump bit. + +const ( + mask = 0x7F + core = 0x80 + exited = 0x00 + stopped = 0x7F + shift = 8 +) + +func (w WaitStatus) Exited() bool { return w&mask == exited } + +func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != exited } + +func (w WaitStatus) Stopped() bool { return w&0xFF == stopped } + +func (w WaitStatus) Continued() bool { return w == 0xFFFF } + +func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 } + +func (w WaitStatus) ExitStatus() int { + if !w.Exited() { + return -1 + } + return int(w>>shift) & 0xFF +} + +func (w WaitStatus) Signal() Signal { + if !w.Signaled() { + return -1 + } + return Signal(w & mask) +} + +func (w WaitStatus) StopSignal() Signal { + if !w.Stopped() { + return -1 + } + return Signal(w>>shift) & 0xFF +} + +func (w WaitStatus) TrapCause() int { + if w.StopSignal() != SIGTRAP { + return -1 + } + return int(w>>shift) >> 8 +} + +//sys wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error) + +func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) { + var status _C_int + wpid, err = wait4(pid, &status, options, rusage) + if wstatus != nil { + *wstatus = WaitStatus(status) + } + return +} + +func Mkfifo(path string, mode uint32) (err error) { + return Mknod(path, mode|S_IFIFO, 0) +} + +func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) { + if sa.Port < 0 || sa.Port > 0xFFFF { + return nil, 0, EINVAL + } + sa.raw.Family = AF_INET + p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port)) + p[0] = byte(sa.Port >> 8) + p[1] = byte(sa.Port) + sa.raw.Addr = sa.Addr + return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil +} + +func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) { + if sa.Port < 0 || sa.Port > 0xFFFF { + return nil, 0, EINVAL + } + sa.raw.Family = AF_INET6 + p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port)) + p[0] = byte(sa.Port >> 8) + p[1] = byte(sa.Port) + sa.raw.Scope_id = sa.ZoneId + sa.raw.Addr = sa.Addr + return unsafe.Pointer(&sa.raw), SizeofSockaddrInet6, nil +} + +func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) { + name := sa.Name + n := len(name) + if n > len(sa.raw.Path) { + return nil, 0, EINVAL + } + if n == len(sa.raw.Path) && name[0] != '@' { + return nil, 0, EINVAL + } + sa.raw.Family = AF_UNIX + for i := 0; i < n; i++ { + sa.raw.Path[i] = int8(name[i]) + } + // length is family (uint16), name, NUL. + sl := _Socklen(2) + if n > 0 { + sl += _Socklen(n) + 1 + } + if sa.raw.Path[0] == '@' || (sa.raw.Path[0] == 0 && sl > 3) { + // Check sl > 3 so we don't change unnamed socket behavior. + sa.raw.Path[0] = 0 + // Don't count trailing NUL for abstract address. + sl-- + } + + return unsafe.Pointer(&sa.raw), sl, nil +} + +type SockaddrLinklayer struct { + Protocol uint16 + Ifindex int + Hatype uint16 + Pkttype uint8 + Halen uint8 + Addr [8]byte + raw RawSockaddrLinklayer +} + +func (sa *SockaddrLinklayer) sockaddr() (unsafe.Pointer, _Socklen, error) { + if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff { + return nil, 0, EINVAL + } + sa.raw.Family = AF_PACKET + sa.raw.Protocol = sa.Protocol + sa.raw.Ifindex = int32(sa.Ifindex) + sa.raw.Hatype = sa.Hatype + sa.raw.Pkttype = sa.Pkttype + sa.raw.Halen = sa.Halen + sa.raw.Addr = sa.Addr + return unsafe.Pointer(&sa.raw), SizeofSockaddrLinklayer, nil +} + +type SockaddrNetlink struct { + Family uint16 + Pad uint16 + Pid uint32 + Groups uint32 + raw RawSockaddrNetlink +} + +func (sa *SockaddrNetlink) sockaddr() (unsafe.Pointer, _Socklen, error) { + sa.raw.Family = AF_NETLINK + sa.raw.Pad = sa.Pad + sa.raw.Pid = sa.Pid + sa.raw.Groups = sa.Groups + return unsafe.Pointer(&sa.raw), SizeofSockaddrNetlink, nil +} + +func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) { + switch rsa.Addr.Family { + case AF_NETLINK: + pp := (*RawSockaddrNetlink)(unsafe.Pointer(rsa)) + sa := new(SockaddrNetlink) + sa.Family = pp.Family + sa.Pad = pp.Pad + sa.Pid = pp.Pid + sa.Groups = pp.Groups + return sa, nil + + case AF_PACKET: + pp := (*RawSockaddrLinklayer)(unsafe.Pointer(rsa)) + sa := new(SockaddrLinklayer) + sa.Protocol = pp.Protocol + sa.Ifindex = int(pp.Ifindex) + sa.Hatype = pp.Hatype + sa.Pkttype = pp.Pkttype + sa.Halen = pp.Halen + sa.Addr = pp.Addr + return sa, nil + + case AF_UNIX: + pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa)) + sa := new(SockaddrUnix) + if pp.Path[0] == 0 { + // "Abstract" Unix domain socket. + // Rewrite leading NUL as @ for textual display. + // (This is the standard convention.) + // Not friendly to overwrite in place, + // but the callers below don't care. + pp.Path[0] = '@' + } + + // Assume path ends at NUL. + // This is not technically the Linux semantics for + // abstract Unix domain sockets--they are supposed + // to be uninterpreted fixed-size binary blobs--but + // everyone uses this convention. + n := 0 + for n < len(pp.Path) && pp.Path[n] != 0 { + n++ + } + sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n)) + return sa, nil + + case AF_INET: + pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa)) + sa := new(SockaddrInet4) + p := (*[2]byte)(unsafe.Pointer(&pp.Port)) + sa.Port = int(p[0])<<8 + int(p[1]) + sa.Addr = pp.Addr + return sa, nil + + case AF_INET6: + pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa)) + sa := new(SockaddrInet6) + p := (*[2]byte)(unsafe.Pointer(&pp.Port)) + sa.Port = int(p[0])<<8 + int(p[1]) + sa.ZoneId = pp.Scope_id + sa.Addr = pp.Addr + return sa, nil + } + return nil, EAFNOSUPPORT +} + +func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) { + var rsa RawSockaddrAny + var len _Socklen = SizeofSockaddrAny + nfd, err = accept4(fd, &rsa, &len, flags) + if err != nil { + return + } + if len > SizeofSockaddrAny { + panic("RawSockaddrAny too small") + } + sa, err = anyToSockaddr(&rsa) + if err != nil { + Close(nfd) + nfd = 0 + } + return +} + +func Getsockname(fd int) (sa Sockaddr, err error) { + var rsa RawSockaddrAny + var len _Socklen = SizeofSockaddrAny + if err = getsockname(fd, &rsa, &len); err != nil { + return + } + return anyToSockaddr(&rsa) +} + +func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) { + vallen := _Socklen(4) + err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen) + return value, err +} + +func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) { + var value IPMreq + vallen := _Socklen(SizeofIPMreq) + err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen) + return &value, err +} + +func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) { + var value IPMreqn + vallen := _Socklen(SizeofIPMreqn) + err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen) + return &value, err +} + +func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) { + var value IPv6Mreq + vallen := _Socklen(SizeofIPv6Mreq) + err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen) + return &value, err +} + +func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) { + var value IPv6MTUInfo + vallen := _Socklen(SizeofIPv6MTUInfo) + err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen) + return &value, err +} + +func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) { + var value ICMPv6Filter + vallen := _Socklen(SizeofICMPv6Filter) + err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen) + return &value, err +} + +func GetsockoptUcred(fd, level, opt int) (*Ucred, error) { + var value Ucred + vallen := _Socklen(SizeofUcred) + err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen) + return &value, err +} + +func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) { + return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq)) +} + +func recvmsgRaw(fd int, p, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) { + var msg Msghdr + msg.Name = (*byte)(unsafe.Pointer(rsa)) + msg.Namelen = uint32(SizeofSockaddrAny) + var iov Iovec + if len(p) > 0 { + iov.Base = &p[0] + iov.SetLen(len(p)) + } + var dummy byte + if len(oob) > 0 { + if len(p) == 0 { + var sockType int + sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE) + if err != nil { + return + } + // receive at least one normal byte + if sockType != SOCK_DGRAM { + iov.Base = &dummy + iov.SetLen(1) + } + } + msg.Control = &oob[0] + msg.SetControllen(len(oob)) + } + msg.Iov = &iov + msg.Iovlen = 1 + if n, err = recvmsg(fd, &msg, flags); err != nil { + return + } + oobn = int(msg.Controllen) + recvflags = int(msg.Flags) + return +} + +func sendmsgN(fd int, p, oob []byte, ptr unsafe.Pointer, salen _Socklen, flags int) (n int, err error) { + var msg Msghdr + msg.Name = (*byte)(ptr) + msg.Namelen = uint32(salen) + var iov Iovec + if len(p) > 0 { + iov.Base = &p[0] + iov.SetLen(len(p)) + } + var dummy byte + if len(oob) > 0 { + if len(p) == 0 { + var sockType int + sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE) + if err != nil { + return 0, err + } + // send at least one normal byte + if sockType != SOCK_DGRAM { + iov.Base = &dummy + iov.SetLen(1) + } + } + msg.Control = &oob[0] + msg.SetControllen(len(oob)) + } + msg.Iov = &iov + msg.Iovlen = 1 + if n, err = sendmsg(fd, &msg, flags); err != nil { + return 0, err + } + if len(oob) > 0 && len(p) == 0 { + n = 0 + } + return n, nil +} + +// BindToDevice binds the socket associated with fd to device. +func BindToDevice(fd int, device string) (err error) { + return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device) +} + +//sys ptrace(request int, pid int, addr uintptr, data uintptr) (err error) +//sys ptracePtr(request int, pid int, addr uintptr, data unsafe.Pointer) (err error) = SYS_PTRACE + +func ptracePeek(req int, pid int, addr uintptr, out []byte) (count int, err error) { + // The peek requests are machine-size oriented, so we wrap it + // to retrieve arbitrary-length data. + + // The ptrace syscall differs from glibc's ptrace. + // Peeks returns the word in *data, not as the return value. + + var buf [sizeofPtr]byte + + // Leading edge. PEEKTEXT/PEEKDATA don't require aligned + // access (PEEKUSER warns that it might), but if we don't + // align our reads, we might straddle an unmapped page + // boundary and not get the bytes leading up to the page + // boundary. + n := 0 + if addr%sizeofPtr != 0 { + err = ptracePtr(req, pid, addr-addr%sizeofPtr, unsafe.Pointer(&buf[0])) + if err != nil { + return 0, err + } + n += copy(out, buf[addr%sizeofPtr:]) + out = out[n:] + } + + // Remainder. + for len(out) > 0 { + // We use an internal buffer to guarantee alignment. + // It's not documented if this is necessary, but we're paranoid. + err = ptracePtr(req, pid, addr+uintptr(n), unsafe.Pointer(&buf[0])) + if err != nil { + return n, err + } + copied := copy(out, buf[0:]) + n += copied + out = out[copied:] + } + + return n, nil +} + +func PtracePeekText(pid int, addr uintptr, out []byte) (count int, err error) { + return ptracePeek(PTRACE_PEEKTEXT, pid, addr, out) +} + +func PtracePeekData(pid int, addr uintptr, out []byte) (count int, err error) { + return ptracePeek(PTRACE_PEEKDATA, pid, addr, out) +} + +func ptracePoke(pokeReq int, peekReq int, pid int, addr uintptr, data []byte) (count int, err error) { + // As for ptracePeek, we need to align our accesses to deal + // with the possibility of straddling an invalid page. + + // Leading edge. + n := 0 + if addr%sizeofPtr != 0 { + var buf [sizeofPtr]byte + err = ptracePtr(peekReq, pid, addr-addr%sizeofPtr, unsafe.Pointer(&buf[0])) + if err != nil { + return 0, err + } + n += copy(buf[addr%sizeofPtr:], data) + word := *((*uintptr)(unsafe.Pointer(&buf[0]))) + err = ptrace(pokeReq, pid, addr-addr%sizeofPtr, word) + if err != nil { + return 0, err + } + data = data[n:] + } + + // Interior. + for len(data) > sizeofPtr { + word := *((*uintptr)(unsafe.Pointer(&data[0]))) + err = ptrace(pokeReq, pid, addr+uintptr(n), word) + if err != nil { + return n, err + } + n += sizeofPtr + data = data[sizeofPtr:] + } + + // Trailing edge. + if len(data) > 0 { + var buf [sizeofPtr]byte + err = ptracePtr(peekReq, pid, addr+uintptr(n), unsafe.Pointer(&buf[0])) + if err != nil { + return n, err + } + copy(buf[0:], data) + word := *((*uintptr)(unsafe.Pointer(&buf[0]))) + err = ptrace(pokeReq, pid, addr+uintptr(n), word) + if err != nil { + return n, err + } + n += len(data) + } + + return n, nil +} + +func PtracePokeText(pid int, addr uintptr, data []byte) (count int, err error) { + return ptracePoke(PTRACE_POKETEXT, PTRACE_PEEKTEXT, pid, addr, data) +} + +func PtracePokeData(pid int, addr uintptr, data []byte) (count int, err error) { + return ptracePoke(PTRACE_POKEDATA, PTRACE_PEEKDATA, pid, addr, data) +} + +const ( + _NT_PRSTATUS = 1 +) + +func PtraceGetRegs(pid int, regsout *PtraceRegs) (err error) { + var iov Iovec + iov.Base = (*byte)(unsafe.Pointer(regsout)) + iov.SetLen(int(unsafe.Sizeof(*regsout))) + return ptracePtr(PTRACE_GETREGSET, pid, uintptr(_NT_PRSTATUS), unsafe.Pointer(&iov)) +} + +func PtraceSetRegs(pid int, regs *PtraceRegs) (err error) { + var iov Iovec + iov.Base = (*byte)(unsafe.Pointer(regs)) + iov.SetLen(int(unsafe.Sizeof(*regs))) + return ptracePtr(PTRACE_SETREGSET, pid, uintptr(_NT_PRSTATUS), unsafe.Pointer(&iov)) +} + +func PtraceSetOptions(pid int, options int) (err error) { + return ptrace(PTRACE_SETOPTIONS, pid, 0, uintptr(options)) +} + +func PtraceGetEventMsg(pid int) (msg uint, err error) { + var data _C_long + err = ptracePtr(PTRACE_GETEVENTMSG, pid, 0, unsafe.Pointer(&data)) + msg = uint(data) + return +} + +func PtraceCont(pid int, signal int) (err error) { + return ptrace(PTRACE_CONT, pid, 0, uintptr(signal)) +} + +func PtraceSyscall(pid int, signal int) (err error) { + return ptrace(PTRACE_SYSCALL, pid, 0, uintptr(signal)) +} + +func PtraceSingleStep(pid int) (err error) { return ptrace(PTRACE_SINGLESTEP, pid, 0, 0) } + +func PtraceAttach(pid int) (err error) { return ptrace(PTRACE_ATTACH, pid, 0, 0) } + +func PtraceDetach(pid int) (err error) { return ptrace(PTRACE_DETACH, pid, 0, 0) } + +//sys reboot(magic1 uint, magic2 uint, cmd int, arg string) (err error) + +func Reboot(cmd int) (err error) { + return reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, "") +} + +func ReadDirent(fd int, buf []byte) (n int, err error) { + return Getdents(fd, buf) +} + +func direntIno(buf []byte) (uint64, bool) { + return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino)) +} + +func direntReclen(buf []byte) (uint64, bool) { + return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen)) +} + +func direntNamlen(buf []byte) (uint64, bool) { + reclen, ok := direntReclen(buf) + if !ok { + return 0, false + } + return reclen - uint64(unsafe.Offsetof(Dirent{}.Name)), true +} + +//sys mount(source string, target string, fstype string, flags uintptr, data *byte) (err error) + +func Mount(source string, target string, fstype string, flags uintptr, data string) (err error) { + // Certain file systems get rather angry and EINVAL if you give + // them an empty string of data, rather than NULL. + if data == "" { + return mount(source, target, fstype, flags, nil) + } + datap, err := BytePtrFromString(data) + if err != nil { + return err + } + return mount(source, target, fstype, flags, datap) +} + +// Sendto +// Recvfrom +// Socketpair + +/* + * Direct access + */ +//sys Acct(path string) (err error) +//sys Adjtimex(buf *Timex) (state int, err error) +//sys Chdir(path string) (err error) +//sys Chroot(path string) (err error) +//sys Close(fd int) (err error) +//sys Dup(oldfd int) (fd int, err error) +//sys Dup3(oldfd int, newfd int, flags int) (err error) +//sysnb EpollCreate1(flag int) (fd int, err error) +//sysnb EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) +//sys Fallocate(fd int, mode uint32, off int64, len int64) (err error) +//sys Fchdir(fd int) (err error) +//sys Fchmod(fd int, mode uint32) (err error) +//sys Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) +//sys fcntl(fd int, cmd int, arg int) (val int, err error) +//sys Fdatasync(fd int) (err error) +//sys Flock(fd int, how int) (err error) +//sys Fsync(fd int) (err error) +//sys Getdents(fd int, buf []byte) (n int, err error) = SYS_GETDENTS64 +//sysnb Getpgid(pid int) (pgid int, err error) + +func Getpgrp() (pid int) { + pid, _ = Getpgid(0) + return +} + +//sysnb Getpid() (pid int) +//sysnb Getppid() (ppid int) +//sys Getpriority(which int, who int) (prio int, err error) +//sysnb Getrusage(who int, rusage *Rusage) (err error) +//sysnb Gettid() (tid int) +//sys Getxattr(path string, attr string, dest []byte) (sz int, err error) +//sys InotifyAddWatch(fd int, pathname string, mask uint32) (watchdesc int, err error) +//sysnb InotifyInit1(flags int) (fd int, err error) +//sysnb InotifyRmWatch(fd int, watchdesc uint32) (success int, err error) +//sysnb Kill(pid int, sig Signal) (err error) +//sys Klogctl(typ int, buf []byte) (n int, err error) = SYS_SYSLOG +//sys Listxattr(path string, dest []byte) (sz int, err error) +//sys Mkdirat(dirfd int, path string, mode uint32) (err error) +//sys Mknodat(dirfd int, path string, mode uint32, dev int) (err error) +//sys Nanosleep(time *Timespec, leftover *Timespec) (err error) +//sys PivotRoot(newroot string, putold string) (err error) = SYS_PIVOT_ROOT +//sysnb prlimit1(pid int, resource int, newlimit *Rlimit, old *Rlimit) (err error) = SYS_PRLIMIT64 +//sys read(fd int, p []byte) (n int, err error) +//sys Removexattr(path string, attr string) (err error) +//sys Setdomainname(p []byte) (err error) +//sys Sethostname(p []byte) (err error) +//sysnb Setpgid(pid int, pgid int) (err error) +//sysnb Setsid() (pid int, err error) +//sysnb Settimeofday(tv *Timeval) (err error) + +// Provided by runtime.syscall_runtime_doAllThreadsSyscall which stops the +// world and invokes the syscall on each OS thread. Once this function returns, +// all threads are in sync. +// +//go:uintptrescapes +func runtime_doAllThreadsSyscall(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) + +// AllThreadsSyscall performs a syscall on each OS thread of the Go +// runtime. It first invokes the syscall on one thread. Should that +// invocation fail, it returns immediately with the error status. +// Otherwise, it invokes the syscall on all of the remaining threads +// in parallel. It will terminate the program if it observes any +// invoked syscall's return value differs from that of the first +// invocation. +// +// AllThreadsSyscall is intended for emulating simultaneous +// process-wide state changes that require consistently modifying +// per-thread state of the Go runtime. +// +// AllThreadsSyscall is unaware of any threads that are launched +// explicitly by cgo linked code, so the function always returns +// ENOTSUP in binaries that use cgo. +// +//go:uintptrescapes +func AllThreadsSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) { + if cgo_libc_setegid != nil { + return minus1, minus1, ENOTSUP + } + r1, r2, errno := runtime_doAllThreadsSyscall(trap, a1, a2, a3, 0, 0, 0) + return r1, r2, Errno(errno) +} + +// AllThreadsSyscall6 is like AllThreadsSyscall, but extended to six +// arguments. +// +//go:uintptrescapes +func AllThreadsSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) { + if cgo_libc_setegid != nil { + return minus1, minus1, ENOTSUP + } + r1, r2, errno := runtime_doAllThreadsSyscall(trap, a1, a2, a3, a4, a5, a6) + return r1, r2, Errno(errno) +} + +// linked by runtime.cgocall.go +// +//go:uintptrescapes +func cgocaller(unsafe.Pointer, ...uintptr) uintptr + +var cgo_libc_setegid unsafe.Pointer // non-nil if cgo linked. + +const minus1 = ^uintptr(0) + +func Setegid(egid int) (err error) { + if cgo_libc_setegid == nil { + if _, _, e1 := AllThreadsSyscall(SYS_SETRESGID, minus1, uintptr(egid), minus1); e1 != 0 { + err = errnoErr(e1) + } + } else if ret := cgocaller(cgo_libc_setegid, uintptr(egid)); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +var cgo_libc_seteuid unsafe.Pointer // non-nil if cgo linked. + +func Seteuid(euid int) (err error) { + if cgo_libc_seteuid == nil { + if _, _, e1 := AllThreadsSyscall(SYS_SETRESUID, minus1, uintptr(euid), minus1); e1 != 0 { + err = errnoErr(e1) + } + } else if ret := cgocaller(cgo_libc_seteuid, uintptr(euid)); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +var cgo_libc_setgid unsafe.Pointer // non-nil if cgo linked. + +func Setgid(gid int) (err error) { + if cgo_libc_setgid == nil { + if _, _, e1 := AllThreadsSyscall(sys_SETGID, uintptr(gid), 0, 0); e1 != 0 { + err = errnoErr(e1) + } + } else if ret := cgocaller(cgo_libc_setgid, uintptr(gid)); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +var cgo_libc_setregid unsafe.Pointer // non-nil if cgo linked. + +func Setregid(rgid, egid int) (err error) { + if cgo_libc_setregid == nil { + if _, _, e1 := AllThreadsSyscall(sys_SETREGID, uintptr(rgid), uintptr(egid), 0); e1 != 0 { + err = errnoErr(e1) + } + } else if ret := cgocaller(cgo_libc_setregid, uintptr(rgid), uintptr(egid)); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +var cgo_libc_setresgid unsafe.Pointer // non-nil if cgo linked. + +func Setresgid(rgid, egid, sgid int) (err error) { + if cgo_libc_setresgid == nil { + if _, _, e1 := AllThreadsSyscall(sys_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid)); e1 != 0 { + err = errnoErr(e1) + } + } else if ret := cgocaller(cgo_libc_setresgid, uintptr(rgid), uintptr(egid), uintptr(sgid)); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +var cgo_libc_setresuid unsafe.Pointer // non-nil if cgo linked. + +func Setresuid(ruid, euid, suid int) (err error) { + if cgo_libc_setresuid == nil { + if _, _, e1 := AllThreadsSyscall(sys_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid)); e1 != 0 { + err = errnoErr(e1) + } + } else if ret := cgocaller(cgo_libc_setresuid, uintptr(ruid), uintptr(euid), uintptr(suid)); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +var cgo_libc_setreuid unsafe.Pointer // non-nil if cgo linked. + +func Setreuid(ruid, euid int) (err error) { + if cgo_libc_setreuid == nil { + if _, _, e1 := AllThreadsSyscall(sys_SETREUID, uintptr(ruid), uintptr(euid), 0); e1 != 0 { + err = errnoErr(e1) + } + } else if ret := cgocaller(cgo_libc_setreuid, uintptr(ruid), uintptr(euid)); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +var cgo_libc_setuid unsafe.Pointer // non-nil if cgo linked. + +func Setuid(uid int) (err error) { + if cgo_libc_setuid == nil { + if _, _, e1 := AllThreadsSyscall(sys_SETUID, uintptr(uid), 0, 0); e1 != 0 { + err = errnoErr(e1) + } + } else if ret := cgocaller(cgo_libc_setuid, uintptr(uid)); ret != 0 { + err = errnoErr(Errno(ret)) + } + return +} + +//sys Setpriority(which int, who int, prio int) (err error) +//sys Setxattr(path string, attr string, data []byte, flags int) (err error) +//sys Sync() +//sysnb Sysinfo(info *Sysinfo_t) (err error) +//sys Tee(rfd int, wfd int, len int, flags int) (n int64, err error) +//sysnb Tgkill(tgid int, tid int, sig Signal) (err error) +//sysnb Times(tms *Tms) (ticks uintptr, err error) +//sysnb Umask(mask int) (oldmask int) +//sysnb Uname(buf *Utsname) (err error) +//sys Unmount(target string, flags int) (err error) = SYS_UMOUNT2 +//sys Unshare(flags int) (err error) +//sys write(fd int, p []byte) (n int, err error) +//sys exitThread(code int) (err error) = SYS_EXIT +//sys readlen(fd int, p *byte, np int) (n int, err error) = SYS_READ + +// mmap varies by architecture; see syscall_linux_*.go. +//sys munmap(addr uintptr, length uintptr) (err error) + +var mapper = &mmapper{ + active: make(map[*byte][]byte), + mmap: mmap, + munmap: munmap, +} + +func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) { + return mapper.Mmap(fd, offset, length, prot, flags) +} + +func Munmap(b []byte) (err error) { + return mapper.Munmap(b) +} + +//sys Madvise(b []byte, advice int) (err error) +//sys Mprotect(b []byte, prot int) (err error) +//sys Mlock(b []byte) (err error) +//sys Munlock(b []byte) (err error) +//sys Mlockall(flags int) (err error) +//sys Munlockall() (err error) + +// prlimit changes a resource limit. We use a single definition so that +// we can tell StartProcess to not restore the original NOFILE limit. +// This is unexported but can be called from x/sys/unix. +func prlimit(pid int, resource int, newlimit *Rlimit, old *Rlimit) (err error) { + err = prlimit1(pid, resource, newlimit, old) + if err == nil && newlimit != nil && resource == RLIMIT_NOFILE { + origRlimitNofile.Store(nil) + } + return err +} |