unix: add various missing syscalls available on Linux

Various syscalls offered by x/sys/unix on Linux are not available on
Solaris and should be, such as Mkfifo, Getwd(), Futimes() and others.
In particular, all of the *at() variants of existing functions were
added where appropriate.

Getgroups() was fixed to use the correct value for its sanity check on
the maximum number of groups.

Utimesnano() was updated to use the native Solaris utimensat function
for setting nanosecond-precision time.

Utimes() was updated to have the same error semantics and checking as
other platforms.

Getgroups(), anysocktoaddr(), and Recvmsg() were fixed to check the
return value before assuming syscall failure instead of relying solely
on errno being set.

mksyscall_solaris.pl needed some updates to better match the output of
the one found in syscall.

mkerrors.sh needed some updates to work out of the box on Solaris,
matching those recently done to the one in syscall.

The signatures (names) of some function parameters were changed to be
consistent with other platforms for the sake of documentation.

Fixes #8609

Change-Id: I9e4e2fee6d3ecfad9f4d845a5702ffde5166e804
Reviewed-on: https://go-review.googlesource.com/14643
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>

unix/syscall_solaris.go

@@ -139,6 +139,8 @@ func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
 	return unsafe.Pointer(&sa.raw), sl, nil
 }
 
+//sys	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) = libsocket.getsockname
+
 func Getsockname(fd int) (sa Sockaddr, err error) {
 	var rsa RawSockaddrAny
 	var len _Socklen = SizeofSockaddrAny
@@ -148,12 +150,23 @@ func Getsockname(fd int) (sa Sockaddr, err error) {
 	return anyToSockaddr(&rsa)
 }
 
-// The const provides a compile-time constant so clients
-// can adjust to whether there is a working Getwd and avoid
-// even linking this function into the binary.  See ../os/getwd.go.
-const ImplementsGetwd = false
+const ImplementsGetwd = true
 
-func Getwd() (string, error) { return "", ENOTSUP }
+//sys	Getcwd(buf []byte) (n int, err error)
+
+func Getwd() (wd string, err error) {
+	var buf [PathMax]byte
+	// Getcwd will return an error if it failed for any reason.
+	_, err = Getcwd(buf[0:])
+	if err != nil {
+		return "", err
+	}
+	n := clen(buf[:])
+	if n < 1 {
+		return "", EINVAL
+	}
+	return string(buf[:n]), nil
+}
 
 /*
  * Wrapped
@@ -164,21 +177,20 @@ func Getwd() (string, error) { return "", ENOTSUP }
 
 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 16 on BSD.
-	if n < 0 || n > 1000 {
+	// Check for error and sanity check group count.  Newer versions of
+	// Solaris allow up to 1024 (NGROUPS_MAX).
+	if n < 0 || n > 1024 {
+		if err != nil {
+			return nil, err
+		}
 		return nil, EINVAL
+	} else if n == 0 {
+		return nil, nil
 	}
 
 	a := make([]_Gid_t, n)
 	n, err = getgroups(n, &a[0])
-	if err != nil {
+	if n == -1 {
 		return nil, err
 	}
 	gids = make([]int, n)
@@ -277,19 +289,38 @@ func Gethostname() (name string, err error) {
 	return name, err
 }
 
+//sys	utimes(path string, times *[2]Timeval) (err error)
+
+func Utimes(path string, tv []Timeval) (err error) {
+	if tv == nil {
+		return utimes(path, nil)
+	}
+	if len(tv) != 2 {
+		return EINVAL
+	}
+	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+}
+
+//sys	utimensat(fd int, path string, times *[2]Timespec, flag int) (err error)
+
 func UtimesNano(path string, ts []Timespec) error {
 	if ts == nil {
-		return Utimes(path, nil)
+		return utimensat(AT_FDCWD, path, nil, 0)
 	}
 	if len(ts) != 2 {
 		return EINVAL
 	}
-	var tv [2]Timeval
-	for i := 0; i < 2; i++ {
-		tv[i].Sec = ts[i].Sec
-		tv[i].Usec = ts[i].Nsec / 1000
+	return utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
+}
+
+func UtimesNanoAt(dirfd int, path string, ts []Timespec, flags int) error {
+	if ts == nil {
+		return utimensat(dirfd, path, nil, flags)
 	}
-	return Utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+	if len(ts) != 2 {
+		return EINVAL
+	}
+	return utimensat(dirfd, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), flags)
 }
 
 //sys	fcntl(fd int, cmd int, arg int) (val int, err error)
@@ -303,6 +334,35 @@ func FcntlFlock(fd uintptr, cmd int, lk *Flock_t) error {
 	return nil
 }
 
+//sys	futimesat(fildes int, path *byte, times *[2]Timeval) (err error)
+
+func Futimesat(dirfd int, path string, tv []Timeval) error {
+	pathp, err := BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+	if tv == nil {
+		return futimesat(dirfd, pathp, nil)
+	}
+	if len(tv) != 2 {
+		return EINVAL
+	}
+	return futimesat(dirfd, pathp, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+}
+
+// Solaris doesn't have an futimes function because it allows NULL to be
+// specified as the path for futimesat.  However, Go doesn't like
+// NULL-style string interfaces, so this simple wrapper is provided.
+func Futimes(fd int, tv []Timeval) error {
+	if tv == nil {
+		return futimesat(fd, nil, nil)
+	}
+	if len(tv) != 2 {
+		return EINVAL
+	}
+	return futimesat(fd, nil, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+}
+
 func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
 	switch rsa.Addr.Family {
 	case AF_UNIX:
@@ -351,7 +411,7 @@ func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 	var rsa RawSockaddrAny
 	var len _Socklen = SizeofSockaddrAny
 	nfd, err = accept(fd, &rsa, &len)
-	if err != nil {
+	if nfd == -1 {
 		return
 	}
 	sa, err = anyToSockaddr(&rsa)
@@ -362,6 +422,8 @@ func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 	return
 }
 
+//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error) = libsocket.recvmsg
+
 func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
 	var msg Msghdr
 	var rsa RawSockaddrAny
@@ -383,7 +445,7 @@ func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from
 	}
 	msg.Iov = &iov
 	msg.Iovlen = 1
-	if n, err = recvmsg(fd, &msg, flags); err != nil {
+	if n, err = recvmsg(fd, &msg, flags); n == -1 {
 		return
 	}
 	oobn = int(msg.Accrightslen)
@@ -438,6 +500,21 @@ func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error)
 	return n, nil
 }
 
+//sys	acct(path *byte) (err error)
+
+func Acct(path string) (err error) {
+	if len(path) == 0 {
+		// Assume caller wants to disable accounting.
+		return acct(nil)
+	}
+
+	pathp, err := BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+	return acct(pathp)
+}
+
 /*
  * Exposed directly
  */
@@ -448,21 +525,29 @@ func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error)
 //sys	Chown(path string, uid int, gid int) (err error)
 //sys	Chroot(path string) (err error)
 //sys	Close(fd int) (err error)
+//sys	Creat(path string, mode uint32) (fd int, err error)
 //sys	Dup(fd int) (nfd int, err error)
+//sys	Dup2(oldfd int, newfd int) (err error)
 //sys	Exit(code int)
 //sys	Fchdir(fd int) (err error)
 //sys	Fchmod(fd int, mode uint32) (err error)
+//sys	Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)
 //sys	Fchown(fd int, uid int, gid int) (err error)
+//sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
+//sys	Fdatasync(fd int) (err error)
 //sys	Fpathconf(fd int, name int) (val int, err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error)
 //sys	Getdents(fd int, buf []byte, basep *uintptr) (n int, err error)
 //sysnb	Getgid() (gid int)
 //sysnb	Getpid() (pid int)
+//sysnb	Getpgid(pid int) (pgid int, err error)
+//sysnb	Getpgrp() (pgid int, err error)
 //sys	Geteuid() (euid int)
 //sys	Getegid() (egid int)
 //sys	Getppid() (ppid int)
 //sys	Getpriority(which int, who int) (n int, err error)
 //sysnb	Getrlimit(which int, lim *Rlimit) (err error)
+//sysnb	Getrusage(who int, rusage *Rusage) (err error)
 //sysnb	Gettimeofday(tv *Timeval) (err error)
 //sysnb	Getuid() (uid int)
 //sys	Kill(pid int, signum syscall.Signal) (err error)
@@ -472,20 +557,33 @@ func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error)
 //sys	Lstat(path string, stat *Stat_t) (err error)
 //sys	Madvise(b []byte, advice int) (err error)
 //sys	Mkdir(path string, mode uint32) (err error)
+//sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
+//sys	Mkfifo(path string, mode uint32) (err error)
+//sys	Mkfifoat(dirfd int, path string, mode uint32) (err error)
 //sys	Mknod(path string, mode uint32, dev int) (err error)
+//sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
+//sys	Mlock(b []byte) (err error)
+//sys	Mlockall(flags int) (err error)
+//sys	Mprotect(b []byte, prot int) (err error)
+//sys	Munlock(b []byte) (err error)
+//sys	Munlockall() (err error)
 //sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
 //sys	Open(path string, mode int, perm uint32) (fd int, err error)
+//sys	Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
 //sys	Pathconf(path string, name int) (val int, err error)
+//sys	Pause() (err error)
 //sys	Pread(fd int, p []byte, offset int64) (n int, err error)
 //sys	Pwrite(fd int, p []byte, offset int64) (n int, err error)
 //sys	read(fd int, p []byte) (n int, err error)
 //sys	Readlink(path string, buf []byte) (n int, err error)
 //sys	Rename(from string, to string) (err error)
+//sys	Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error)
 //sys	Rmdir(path string) (err error)
 //sys	Seek(fd int, offset int64, whence int) (newoffset int64, err error) = lseek
 //sysnb	Setegid(egid int) (err error)
 //sysnb	Seteuid(euid int) (err error)
 //sysnb	Setgid(gid int) (err error)
+//sys	Sethostname(p []byte) (err error)
 //sysnb	Setpgid(pid int, pgid int) (err error)
 //sys	Setpriority(which int, who int, prio int) (err error)
 //sysnb	Setregid(rgid int, egid int) (err error)
@@ -497,12 +595,17 @@ func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error)
 //sys	Stat(path string, stat *Stat_t) (err error)
 //sys	Symlink(path string, link string) (err error)
 //sys	Sync() (err error)
+//sysnb	Times(tms *Tms) (ticks uintptr, err error)
 //sys	Truncate(path string, length int64) (err error)
 //sys	Fsync(fd int) (err error)
 //sys	Ftruncate(fd int, length int64) (err error)
-//sys	Umask(newmask int) (oldmask int)
+//sys	Umask(mask int) (oldmask int)
+//sysnb	Uname(buf *Utsname) (err error)
+//sys	Unmount(target string, flags int) (err error) = libc.umount
 //sys	Unlink(path string) (err error)
-//sys	Utimes(path string, times *[2]Timeval) (err error)
+//sys	Unlinkat(dirfd int, path string) (err error)
+//sys	Ustat(dev int, ubuf *Ustat_t) (err error)
+//sys	Utime(path string, buf *Utimbuf) (err error)
 //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) = libsocket.bind
 //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error) = libsocket.connect
 //sys	mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
@@ -513,10 +616,8 @@ func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error)
 //sys	write(fd int, p []byte) (n int, err error)
 //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error) = libsocket.getsockopt
 //sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) = libsocket.getpeername
-//sys	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error) = libsocket.getsockname
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error) = libsocket.setsockopt
 //sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error) = libsocket.recvfrom
-//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error) = libsocket.recvmsg
 
 func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
 	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procread)), 3, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf), 0, 0, 0)