Updated setgroups patch

[Nathan Neulinger]

This is based off the 1999-02-13 snapshot. This also has Magnus's
requested changes to better conform to existing coding standards and
patch minimization.

Effect of the patch:
	@ARLA_KNFS@ option in configure.in and xfs/bsd/Makefile.in changed to
		XFS_CFLAGS
	support for transarc style setgroups behavior. This causes the
setgroups system
		call (and therefore the initgroups and setgroups library calls) to
		retain the current pag. This is needed for programs like 'su' and
'ksu' to
		be able to continue to access afs. The necessary code has been added
		to the xfs_syscalls.c file for linux only, but should be easy enough
to
		adapt for other kernels.
	configure option --enable-setgroups added to add support for transarc
style
		setgroups behavior
	added XFS_CFLAGS to DEFS in xfs/linux/Makefile.in

-- Nathan
	

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diff --exclude=configure -ur arla-1999-02-13/configure.in
arla-1999-02-13-patched/configure.in
--- arla-1999-02-13/configure.in	Fri Feb 12 19:56:27 1999
+++ arla-1999-02-13-patched/configure.in	Wed Feb 17 20:31:31 1999
@@ -46,6 +46,12 @@
   AC_MSG_RESULT(none)
 fi
 
+dnl
+dnl Initially no extra options for xfs compile
+dnl
+XFS_CFLAGS=""
+AC_SUBST(XFS_CFLAGS)
+
 dnl 
 dnl See if there is any X11 present
 dnl
@@ -355,11 +361,18 @@
 
 # Do we want knfs ?
 
-ARLA_KNFS=""
 AC_ARG_ENABLE(knfs,
 [  --enable-knfs           make afs nfs-mountable],
-[ARLA_KNFS="-DARLA_KNFS"])
-AC_SUBST(ARLA_KNFS)
+[XFS_CFLAGS="$XFS_CFLAGS -DARLA_KNFS"
+AC_SUBST(XFS_CFLAGS)])
+
+dnl
+dnl If we want transarc style setgroups behavior
+dnl
+AC_ARG_ENABLE(setgroups,
+[  --enable-setgroups           make setgroups system call retain PAG],
+[XFS_CFLAGS="$XFS_CFLAGS -DARLA_SETGROUPS"
+AC_SUBST(XFS_CFLAGS)])
 
 dnl
 dnl If we want to use pthreads
diff --exclude=configure -ur arla-1999-02-13/xfs/bsd/Makefile.in
arla-1999-02-13-patched/xfs/bsd/Makefile.in
--- arla-1999-02-13/xfs/bsd/Makefile.in	Thu Feb  4 15:08:42 1999
+++ arla-1999-02-13-patched/xfs/bsd/Makefile.in	Wed Feb 17 20:41:26 1999
@@ -36,7 +36,7 @@
 		  -I$(srcdir)/../include \
 		  @KRB_INC_FLAGS@
 
-DEFS		= @DEFS@ $(INCDEFS) -DXFS_DEBUG @ARLA_KNFS@
+DEFS		= @DEFS@ $(INCDEFS) -DXFS_DEBUG @XFS_CFLAGS@
 @OSF1_TRUE at CFLAGS= @KERNEL_CFLAGS@
 @OSF1_FALSE at CFLAGS	= @CFLAGS@ @KERNEL_CFLAGS@ -Wno-unused
 
diff --exclude=configure -ur arla-1999-02-13/xfs/linux/Makefile.in
arla-1999-02-13-patched/xfs/linux/Makefile.in
--- arla-1999-02-13/xfs/linux/Makefile.in	Fri Jan  1 23:46:39 1999
+++ arla-1999-02-13-patched/xfs/linux/Makefile.in	Wed Feb 17 20:41:44
1999
@@ -28,7 +28,7 @@
 
 XFS_BIN		= $(MODULE)
 
-DEFS		= @DEFS@ @KERNEL_CFLAGS@ -DDEBUG
+DEFS		= @DEFS@ @KERNEL_CFLAGS@ -DDEBUG @XFS_CFLAGS@
 INC		= -I$(srcdir)/../include \
 		  -I../../include \
 		  -I$(srcdir)/../../include
diff --exclude=configure -ur arla-1999-02-13/xfs/linux/xfs_syscalls.c
arla-1999-02-13-patched/xfs/linux/xfs_syscalls.c
--- arla-1999-02-13/xfs/linux/xfs_syscalls.c	Sun Jan 24 16:53:56 1999
+++ arla-1999-02-13-patched/xfs/linux/xfs_syscalls.c	Wed Feb 17 20:43:49
1999
@@ -106,7 +106,8 @@
 }
 
 static int
-xfs_setpag_call(void)
+xfs_set_pag(int part_one, 
+	  int part_two)
 {
     int i ;
 
@@ -152,8 +153,16 @@
 
     }
 
-    current->groups[0] = pag_part_one ;
-    current->groups[1] = pag_part_two++ ;
+    current->groups[0] = part_one ;
+    current->groups[1] = part_two ;
+
+    return 0;
+}
+
+static int
+xfs_setpag_call(void)
+{
+    xfs_set_pag(pag_part_one, pag_part_two++);
 
     if (pag_part_two > XFS_PAG2_ULIM) {
 	pag_part_one++ ;
@@ -541,21 +550,54 @@
     return error;
 }
 
-typedef int (*sys_call_routine)(int operation,
+typedef int (*afs_sys_call_routine)(int operation,
 				char *a_pathP,
 				int a_opcode,
 				struct ViceIoctl *a_paramsP,
 				int a_followSymlinks);
+static afs_sys_call_routine *old_afs_syscall=NULL;
 
-extern sys_call_routine sys_call_table[];
+#if defined(ARLA_SETGROUPS)
+typedef int (*setgroups_sys_call_routine)(int gidsetsize,
+					gid_t *grouplist);
+setgroups_sys_call_routine old_setgroups_syscall=NULL;
+#endif
 
-static sys_call_routine old_afs_syscall=NULL;
+extern void *sys_call_table[];
+
+#if defined(ARLA_SETGROUPS)
+asmlinkage int
+sys_pag_setgroups (int gidsetsize, 
+		gid_t *grouplist)
+{
+    int res = 0;
+    pag_t oldpag = 0;
+
+    if (xfs_is_pag()) {
+    oldpag = xfs_get_pag();
+    }
+    if (old_setgroups_syscall) {
+    res = old_setgroups_syscall(gidsetsize, grouplist);
+    } else {
+    printk(KERN_EMERG "XFS Panic: Old setgroups syscall is NULL");
+    res = -EINVAL;
+    }
+
+    if ( oldpag )
+    xfs_set_pag((oldpag>>16) & 0x0000FFFF, oldpag & 0x0000FFFF);
+    return res;
+}
+#endif
 
 void
 install_afs_syscall (void)
 {
     old_afs_syscall = sys_call_table[__NR_afs_syscall];
     sys_call_table[__NR_afs_syscall] = &sys_afs;
+#if defined(ARLA_SETGROUPS)
+    old_setgroups_syscall = sys_call_table[__NR_setgroups];
+    sys_call_table[__NR_setgroups] = &sys_pag_setgroups;
+#endif
 }
 
 void
@@ -565,4 +607,13 @@
 	sys_call_table[__NR_afs_syscall] = old_afs_syscall;
 	old_afs_syscall = NULL;
     }
+#if defined(ARLA_SETGROUPS)
+    if (old_setgroups_syscall) {
+    /* check to make sure no-one else overloaded setgroups call */
+    if ( sys_call_table[__NR_setgroups] != &sys_pag_setgroups )
+        printk(KERN_EMERG "XFS Panic: setgroups syscall did not
match.");
+    sys_call_table[__NR_setgroups] = old_setgroups_syscall;
+    old_setgroups_syscall = NULL;
+    }
+#endif
 }
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