Better setgid by Christopher

git-svn-id: https://svn.fhem.de/fhem/trunk@1204 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/CHANGED

@@ -3,8 +3,8 @@
   - feature: the usb command tries to flash unflashed CULs on linux
   - feature: FHEMWEB: jsonp support, .holiday and .cfg added to Edit Files
   - feature: SVG: filled area support, some ls/lw fixes
-  - feature: WOL (wake on lan) module added
-
+  - feature: WOL (wake on lan) module added (by Matthias)
+  - feature: additional groups from /etc/groups are applied (Christopher)
 
 - 2011-12-31 (5.2)
   - bugfix:  applying smallscreen attributes to firefox/opera

fhem/fhem.pl

@@ -253,17 +253,29 @@ if(int(@ARGV) != 1 && int(@ARGV) != 2) {
 # If started as root, and there is a fhem user in the /etc/passwd, su to it
 if($^O !~ m/Win/ && $< == 0) {
 
-  my @gr = getgrnam("dialout");
-  if(@gr) {
-    use POSIX qw(setgid);
-    setgid($gr[2]);
-  }
-
   my @pw = getpwnam("fhem");
   if(@pw) {
-    use POSIX qw(setuid);
+    use POSIX qw(setuid setgid);
+
+    # set primary group
+    setgid($pw[3]);
+
+    # read all secondary groups into an array:
+    my @groups;
+    while ( my ($name, $pw, $gid, $members) = getgrent() ) {
+      push(@groups, $gid) if ( grep($_ eq $pw[0],split(/\s+/,$members)) );
+    }
+
+    # set the secondary groups via $)
+    if (@groups) {
+      $) = "$pw[3] ".join(" ",@groups);
+    } else {
+      $) = "$pw[3] $pw[3]";
+    }
+
     setuid($pw[2]);
   }
+
 }
 
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