// 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 "unsafe" const OS = "linux" /* * Wrapped */ //sys open(path string, mode int, perm int) (fd int, errno int) func Open(path string, mode int, perm int) (fd int, errno int) { return open(path, mode|O_LARGEFILE, perm) } //sys openat(dirfd int, path string, flags int, mode int) (fd int, errno int) func Openat(dirfd int, path string, flags int, mode int) (fd int, errno int) { return openat(dirfd, path, flags|O_LARGEFILE, mode) } //sys pipe(p *[2]_C_int) (errno int) func Pipe(p []int) (errno int) { if len(p) != 2 { return EINVAL } var pp [2]_C_int errno = pipe(&pp) p[0] = int(pp[0]) p[1] = int(pp[1]) return } //sys utimes(path string, times *[2]Timeval) (errno int) func Utimes(path string, tv []Timeval) (errno int) { if len(tv) != 2 { return EINVAL } return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0]))) } //sys futimesat(dirfd int, path *byte, times *[2]Timeval) (errno int) func Futimesat(dirfd int, path string, tv []Timeval) (errno int) { if len(tv) != 2 { return EINVAL } return futimesat(dirfd, StringBytePtr(path), (*[2]Timeval)(unsafe.Pointer(&tv[0]))) } func Futimes(fd int, tv []Timeval) (errno int) { // Believe it or not, this is the best we can do on Linux // (and is what glibc does). return Utimes("/proc/self/fd/"+str(fd), tv) } const ImplementsGetwd = true //sys Getcwd(buf []byte) (n int, errno int) func Getwd() (wd string, errno int) { var buf [PathMax]byte n, err := Getcwd(buf[0:]) if err != 0 { 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 } return string(buf[0 : n-1]), 0 } func Getgroups() (gids []int, errno int) { n, err := getgroups(0, nil) if err != 0 { return nil, errno } if n == 0 { return nil, 0 } // 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 != 0 { return nil, errno } gids = make([]int, n) for i, v := range a[0:n] { gids[i] = int(v) } return } func Setgroups(gids []int) (errno int) { if len(gids) == 0 { return setgroups(0, nil) } a := make([]_Gid_t, len(gids)) for i, v := range gids { a[i] = _Gid_t(v) } return setgroups(len(a), &a[0]) } 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() int { if !w.Signaled() { return -1 } return int(w & mask) } func (w WaitStatus) StopSignal() int { if !w.Stopped() { return -1 } return int(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, errno int) func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, errno int) { var status _C_int wpid, errno = wait4(pid, &status, options, rusage) if wstatus != nil { *wstatus = WaitStatus(status) } return } func Sleep(nsec int64) (errno int) { tv := NsecToTimeval(nsec) _, err := Select(0, nil, nil, nil, &tv) return err } // For testing: clients can set this flag to force // creation of IPv6 sockets to return EAFNOSUPPORT. var SocketDisableIPv6 bool type Sockaddr interface { sockaddr() (ptr uintptr, len _Socklen, errno int) // lowercase; only we can define Sockaddrs } type SockaddrInet4 struct { Port int Addr [4]byte raw RawSockaddrInet4 } func (sa *SockaddrInet4) sockaddr() (uintptr, _Socklen, int) { if sa.Port < 0 || sa.Port > 0xFFFF { return 0, 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) for i := 0; i < len(sa.Addr); i++ { sa.raw.Addr[i] = sa.Addr[i] } return uintptr(unsafe.Pointer(&sa.raw)), SizeofSockaddrInet4, 0 } type SockaddrInet6 struct { Port int Addr [16]byte raw RawSockaddrInet6 } func (sa *SockaddrInet6) sockaddr() (uintptr, _Socklen, int) { if sa.Port < 0 || sa.Port > 0xFFFF { return 0, 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) for i := 0; i < len(sa.Addr); i++ { sa.raw.Addr[i] = sa.Addr[i] } return uintptr(unsafe.Pointer(&sa.raw)), SizeofSockaddrInet6, 0 } type SockaddrUnix struct { Name string raw RawSockaddrUnix } func (sa *SockaddrUnix) sockaddr() (uintptr, _Socklen, int) { name := sa.Name n := len(name) if n >= len(sa.raw.Path) || n == 0 { return 0, 0, EINVAL } sa.raw.Family = AF_UNIX for i := 0; i < n; i++ { sa.raw.Path[i] = int8(name[i]) } if sa.raw.Path[0] == '@' { sa.raw.Path[0] = 0 } // length is family, name, NUL. return uintptr(unsafe.Pointer(&sa.raw)), 1 + _Socklen(n) + 1, 0 } func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, int) { switch rsa.Addr.Family { 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++ } bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0])) sa.Name = string(bytes[0:n]) return sa, 0 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]) for i := 0; i < len(sa.Addr); i++ { sa.Addr[i] = pp.Addr[i] } return sa, 0 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]) for i := 0; i < len(sa.Addr); i++ { sa.Addr[i] = pp.Addr[i] } return sa, 0 } return nil, EAFNOSUPPORT } func Accept(fd int) (nfd int, sa Sockaddr, errno int) { var rsa RawSockaddrAny var len _Socklen = SizeofSockaddrAny nfd, errno = accept(fd, &rsa, &len) if errno != 0 { return } sa, errno = anyToSockaddr(&rsa) if errno != 0 { Close(nfd) nfd = 0 } return } func Getsockname(fd int) (sa Sockaddr, errno int) { var rsa RawSockaddrAny var len _Socklen = SizeofSockaddrAny if errno = getsockname(fd, &rsa, &len); errno != 0 { return } return anyToSockaddr(&rsa) } func Getpeername(fd int) (sa Sockaddr, errno int) { var rsa RawSockaddrAny var len _Socklen = SizeofSockaddrAny if errno = getpeername(fd, &rsa, &len); errno != 0 { return } return anyToSockaddr(&rsa) } func Bind(fd int, sa Sockaddr) (errno int) { ptr, n, err := sa.sockaddr() if err != 0 { return err } return bind(fd, ptr, n) } func Connect(fd int, sa Sockaddr) (errno int) { ptr, n, err := sa.sockaddr() if err != 0 { return err } return connect(fd, ptr, n) } func Socket(domain, typ, proto int) (fd, errno int) { if domain == AF_INET6 && SocketDisableIPv6 { return -1, EAFNOSUPPORT } fd, errno = socket(domain, typ, proto) return } func Socketpair(domain, typ, proto int) (fd [2]int, errno int) { fd, errno = socketpair(domain, typ, proto) return } func SetsockoptInt(fd, level, opt int, value int) (errno int) { var n = int32(value) return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 4) } func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (errno int) { return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(tv)), unsafe.Sizeof(*tv)) } func SetsockoptLinger(fd, level, opt int, l *Linger) (errno int) { return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(l)), unsafe.Sizeof(*l)) } func SetsockoptString(fd, level, opt int, s string) (errno int) { return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), len(s)) } func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, errno int) { var rsa RawSockaddrAny var len _Socklen = SizeofSockaddrAny if n, errno = recvfrom(fd, p, flags, &rsa, &len); errno != 0 { return } from, errno = anyToSockaddr(&rsa) return } func Sendto(fd int, p []byte, flags int, to Sockaddr) (errno int) { ptr, n, err := to.sockaddr() if err != 0 { return err } return sendto(fd, p, flags, ptr, n) } // BindToDevice binds the socket associated with fd to device. func BindToDevice(fd int, device string) (errno int) { return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device) } //sys ptrace(request int, pid int, addr uintptr, data uintptr) (errno int) func ptracePeek(req int, pid int, addr uintptr, out []byte) (count int, errno int) { // 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 { errno = ptrace(req, pid, addr-addr%sizeofPtr, uintptr(unsafe.Pointer(&buf[0]))) if errno != 0 { return 0, errno } n += copy(out, buf[addr%sizeofPtr:]) out = out[n:] } // Remainder. for len(out) > 0 { // We use an internal buffer to gaurantee alignment. // It's not documented if this is necessary, but we're paranoid. errno = ptrace(req, pid, addr+uintptr(n), uintptr(unsafe.Pointer(&buf[0]))) if errno != 0 { return n, errno } copied := copy(out, buf[0:]) n += copied out = out[copied:] } return n, 0 } func PtracePeekText(pid int, addr uintptr, out []byte) (count int, errno int) { return ptracePeek(PTRACE_PEEKTEXT, pid, addr, out) } func PtracePeekData(pid int, addr uintptr, out []byte) (count int, errno int) { return ptracePeek(PTRACE_PEEKDATA, pid, addr, out) } func ptracePoke(pokeReq int, peekReq int, pid int, addr uintptr, data []byte) (count int, errno int) { // 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 errno = ptrace(peekReq, pid, addr-addr%sizeofPtr, uintptr(unsafe.Pointer(&buf[0]))) if errno != 0 { return 0, errno } n += copy(buf[addr%sizeofPtr:], data) word := *((*uintptr)(unsafe.Pointer(&buf[0]))) errno = ptrace(pokeReq, pid, addr-addr%sizeofPtr, word) if errno != 0 { return 0, errno } data = data[n:] } // Interior. for len(data) > sizeofPtr { word := *((*uintptr)(unsafe.Pointer(&data[0]))) errno = ptrace(pokeReq, pid, addr+uintptr(n), word) if errno != 0 { return n, errno } n += sizeofPtr data = data[sizeofPtr:] } // Trailing edge. if len(data) > 0 { var buf [sizeofPtr]byte errno = ptrace(peekReq, pid, addr+uintptr(n), uintptr(unsafe.Pointer(&buf[0]))) if errno != 0 { return n, errno } copy(buf[0:], data) word := *((*uintptr)(unsafe.Pointer(&buf[0]))) errno = ptrace(pokeReq, pid, addr+uintptr(n), word) if errno != 0 { return n, errno } n += len(data) } return n, 0 } func PtracePokeText(pid int, addr uintptr, data []byte) (count int, errno int) { return ptracePoke(PTRACE_POKETEXT, PTRACE_PEEKTEXT, pid, addr, data) } func PtracePokeData(pid int, addr uintptr, data []byte) (count int, errno int) { return ptracePoke(PTRACE_POKEDATA, PTRACE_PEEKDATA, pid, addr, data) } func PtraceGetRegs(pid int, regsout *PtraceRegs) (errno int) { return ptrace(PTRACE_GETREGS, pid, 0, uintptr(unsafe.Pointer(regsout))) } func PtraceSetRegs(pid int, regs *PtraceRegs) (errno int) { return ptrace(PTRACE_SETREGS, pid, 0, uintptr(unsafe.Pointer(regs))) } func PtraceSetOptions(pid int, options int) (errno int) { return ptrace(PTRACE_SETOPTIONS, pid, 0, uintptr(options)) } func PtraceGetEventMsg(pid int) (msg uint, errno int) { var data _C_long errno = ptrace(PTRACE_GETEVENTMSG, pid, 0, uintptr(unsafe.Pointer(&data))) msg = uint(data) return } func PtraceCont(pid int, signal int) (errno int) { return ptrace(PTRACE_CONT, pid, 0, uintptr(signal)) } func PtraceSingleStep(pid int) (errno int) { return ptrace(PTRACE_SINGLESTEP, pid, 0, 0) } func PtraceAttach(pid int) (errno int) { return ptrace(PTRACE_ATTACH, pid, 0, 0) } func PtraceDetach(pid int) (errno int) { return ptrace(PTRACE_DETACH, pid, 0, 0) } // Sendto // Recvfrom // Sendmsg // Recvmsg // Socketpair // Getsockopt /* * Direct access */ //sys Access(path string, mode int) (errno int) //sys Acct(path string) (errno int) //sys Adjtimex(buf *Timex) (state int, errno int) //sys Chdir(path string) (errno int) //sys Chmod(path string, mode int) (errno int) //sys Chroot(path string) (errno int) //sys Close(fd int) (errno int) //sys Creat(path string, mode int) (fd int, errno int) //sys Dup(oldfd int) (fd int, errno int) //sys Dup2(oldfd int, newfd int) (fd int, errno int) //sys EpollCreate(size int) (fd int, errno int) //sys EpollCtl(epfd int, op int, fd int, event *EpollEvent) (errno int) //sys EpollWait(epfd int, events []EpollEvent, msec int) (n int, errno int) //sys Exit(code int) = SYS_EXIT_GROUP //sys Faccessat(dirfd int, path string, mode int, flags int) (errno int) //sys Fallocate(fd int, mode int, off int64, len int64) (errno int) //sys Fchdir(fd int) (errno int) //sys Fchmod(fd int, mode int) (errno int) //sys Fchmodat(dirfd int, path string, mode int, flags int) (errno int) //sys Fchownat(dirfd int, path string, uid int, gid int, flags int) (errno int) //sys fcntl(fd int, cmd int, arg int) (val int, errno int) //sys Fdatasync(fd int) (errno int) //sys Fsync(fd int) (errno int) //sys Ftruncate(fd int, length int64) (errno int) //sys Getdents(fd int, buf []byte) (n int, errno int) = SYS_GETDENTS64 //sys Getpgid(pid int) (pgid int, errno int) //sys Getpgrp() (pid int) //sys Getpid() (pid int) //sys Getppid() (ppid int) //sys Getrlimit(resource int, rlim *Rlimit) (errno int) //sys Getrusage(who int, rusage *Rusage) (errno int) //sys Gettid() (tid int) //sys Gettimeofday(tv *Timeval) (errno int) //sys Kill(pid int, sig int) (errno int) //sys Klogctl(typ int, buf []byte) (n int, errno int) = SYS_SYSLOG //sys Link(oldpath string, newpath string) (errno int) //sys Mkdir(path string, mode int) (errno int) //sys Mkdirat(dirfd int, path string, mode int) (errno int) //sys Mknod(path string, mode int, dev int) (errno int) //sys Mknodat(dirfd int, path string, mode int, dev int) (errno int) //sys Nanosleep(time *Timespec, leftover *Timespec) (errno int) //sys Pause() (errno int) //sys PivotRoot(newroot string, putold string) (errno int) = SYS_PIVOT_ROOT //sys Pread(fd int, p []byte, offset int64) (n int, errno int) = SYS_PREAD64 //sys Pwrite(fd int, p []byte, offset int64) (n int, errno int) = SYS_PWRITE64 //sys Read(fd int, p []byte) (n int, errno int) //sys Readlink(path string, buf []byte) (n int, errno int) //sys Rename(oldpath string, newpath string) (errno int) //sys Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (errno int) //sys Rmdir(path string) (errno int) //sys Setdomainname(p []byte) (errno int) //sys Sethostname(p []byte) (errno int) //sys Setpgid(pid int, pgid int) (errno int) //sys Setrlimit(resource int, rlim *Rlimit) (errno int) //sys Setsid() (pid int, errno int) //sys Settimeofday(tv *Timeval) (errno int) //sys Setuid(uid int) (errno int) //sys Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, errno int) //sys Symlink(oldpath string, newpath string) (errno int) //sys Sync() //sys Sysinfo(info *Sysinfo_t) (errno int) //sys Tee(rfd int, wfd int, len int, flags int) (n int64, errno int) //sys Tgkill(tgid int, tid int, sig int) (errno int) //sys Time(t *Time_t) (tt Time_t, errno int) //sys Times(tms *Tms) (ticks uintptr, errno int) //sys Truncate(path string, length int64) (errno int) //sys Umask(mask int) (oldmask int) //sys Uname(buf *Utsname) (errno int) //sys Unlink(path string) (errno int) //sys Unlinkat(dirfd int, path string) (errno int) //sys Unshare(flags int) (errno int) //sys Ustat(dev int, ubuf *Ustat_t) (errno int) //sys Utime(path string, buf *Utimbuf) (errno int) //sys Write(fd int, p []byte) (n int, errno int) //sys exitThread(code int) (errno int) = SYS_EXIT //sys read(fd int, p *byte, np int) (n int, errno int) //sys write(fd int, p *byte, np int) (n int, errno int) /* * Unimplemented */ // AddKey // AfsSyscall // Alarm // ArchPrctl // Brk // Capget // Capset // ClockGetres // ClockGettime // ClockNanosleep // ClockSettime // Clone // CreateModule // DeleteModule // EpollCtlOld // EpollPwait // EpollWaitOld // Eventfd // Execve // Fadvise64 // Fgetxattr // Flistxattr // Flock // Fork // Fremovexattr // Fsetxattr // Futex // GetKernelSyms // GetMempolicy // GetRobustList // GetThreadArea // Getitimer // Getpmsg // Getpriority // Getxattr // InotifyAddWatch // InotifyInit // InotifyRmWatch // IoCancel // IoDestroy // IoGetevents // IoSetup // IoSubmit // Ioctl // IoprioGet // IoprioSet // KexecLoad // Keyctl // Lgetxattr // Listxattr // Llistxattr // LookupDcookie // Lremovexattr // Lsetxattr // Madvise // Mbind // MigratePages // Mincore // Mlock // Mmap // ModifyLdt // Mount // MovePages // Mprotect // MqGetsetattr // MqNotify // MqOpen // MqTimedreceive // MqTimedsend // MqUnlink // Mremap // Msgctl // Msgget // Msgrcv // Msgsnd // Msync // Munlock // Munlockall // Munmap // Newfstatat // Nfsservctl // Personality // Poll // Ppoll // Prctl // Pselect6 // Ptrace // Putpmsg // QueryModule // Quotactl // Readahead // Readv // Reboot // RemapFilePages // Removexattr // RequestKey // RestartSyscall // RtSigaction // RtSigpending // RtSigprocmask // RtSigqueueinfo // RtSigreturn // RtSigsuspend // RtSigtimedwait // SchedGetPriorityMax // SchedGetPriorityMin // SchedGetaffinity // SchedGetparam // SchedGetscheduler // SchedRrGetInterval // SchedSetaffinity // SchedSetparam // SchedYield // Security // Semctl // Semget // Semop // Semtimedop // Sendfile // SetMempolicy // SetRobustList // SetThreadArea // SetTidAddress // Setpriority // Setxattr // Shmat // Shmctl // Shmdt // Shmget // Sigaltstack // Signalfd // Swapoff // Swapon // Sysfs // TimerCreate // TimerDelete // TimerGetoverrun // TimerGettime // TimerSettime // Timerfd // Tkill (obsolete) // Tuxcall // Umount2 // Uselib // Utimensat // Vfork // Vhangup // Vmsplice // Vserver // Waitid // Writev // _Sysctl