From 589affa7c90d4f032b554162350625fd5aefb75b Mon Sep 17 00:00:00 2001
From: Donald Buczek <buczek@molgen.mpg.de>
Date: Fri, 1 Jul 2016 17:10:02 +0200
Subject: [PATCH] add lchown() , lmitime()

---
 clusterd | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/clusterd b/clusterd
index 5a0d3a7..5335d89 100755
--- a/clusterd
+++ b/clusterd
@@ -511,6 +511,54 @@ sub udp_rx_amdtardata {
 	system '/sbin/make-automaps';
 }
 
+our ($machine,$SYS_lchown,$SYS_mknod,$lmtime_sub);
+chomp($machine=`uname -m`);
+if ($machine eq 'i686') {
+	$SYS_lchown=198;		# __NR_lchown32  in /usr/include/asm/unistd.h
+	$SYS_mknod=14;			# __NR_mknod
+} elsif ($machine eq 'x86_64') {
+	$SYS_lchown=94;			# __NR_lchown in /usr/include/asm-x86_64/unistd.h
+	$SYS_mknod=133;			# __NR_mknod
+} elsif ($machine eq 'alpha') {
+	$SYS_lchown=208;		# SYS_lchown in /usr/include/syscall.h
+	$SYS_mknod=14;			# SYS_mknod
+} elsif ($machine eq 'amd64') {
+	$SYS_lchown=254;		# SYS_lchown in /usr/include/syscall.h
+	$SYS_mknod=14; 			# SYS_mknod
+} else {
+	warn "unknown machine type $machine: symlink ownership can't be set.\n";
+	warn "unknown machine type $machine: named pipes,character and block devices can't be created\n";
+}
+if ($machine eq 'x86_64') {
+	our $SYS_utimensat=280;			# /usr/include/asm/unistd_64.h
+	our $AT_FDCWD=-100;			# /usr/include/fcntl.h
+	our $UTIME_OMIT=(1<<30)-2;		# /usr/include/bits/stat.h
+	our $AT_SYMLINK_NOFOLLOW=0x100;		# /usr/include/fcntl.h
+
+	$lmtime_sub=sub {
+		my ($path,$mtime)=@_;
+		my $tsa=pack 'qqqq',0,$UTIME_OMIT,$mtime,0;
+		syscall($SYS_utimensat,$AT_FDCWD,$path,$tsa,$AT_SYMLINK_NOFOLLOW)==0 or return warn "$path: failed to lmtime: $!\n";
+	}
+} else {
+	$lmtime_sub=sub {
+		my ($path,$mtime)=@_;
+		warn "$path: don't known how to change symlink mtime on target architecture\n";
+	}
+}
+
+sub lchown {
+	my ($uid,$gid,$path)=@_;
+	$SYS_lchown or return;
+	syscall($SYS_lchown,$path,$uid+0,$gid+0)==0 or return warn "$path: failed to lchown: $!\n";
+}
+
+sub lmtime {
+	my ($mtime,$path)=@_;
+	$lmtime_sub or return;
+	$lmtime_sub->($path,$mtime);
+}
+
 sub udp_rx_filedata {
 
 # set rx_filedata_done as a side effect