X-Git-Url: https://git.distorted.org.uk/~mdw/checkpath/blobdiff_plain/d8e113174e0b2ceff6426ba27104343c8f41d447..fffc1e8c9a4e3beb27ca439bd873759e0f00e0b8:/checkpath.c

diff --git a/checkpath.c b/checkpath.c
index 85c4b09..e594201 100644
--- a/checkpath.c
+++ b/checkpath.c
@@ -5,7 +5,7 @@
  * (c) 1999 Mark Wooding
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of chkpath.
  *
@@ -13,12 +13,12 @@
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
- * 
+ *
  * chkpath is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with chkpath; if not, write to the Free Software Foundation,
  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
@@ -26,6 +26,8 @@
 
 /*----- Header files ------------------------------------------------------*/
 
+#include "config.h"
+
 #include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
@@ -41,6 +43,7 @@
 
 #include <mLib/alloc.h>
 #include <mLib/dstr.h>
+#include <mLib/macros.h>
 
 #include "checkpath.h"
 
@@ -486,30 +489,95 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
   return (bad);
 }
 
-/* --- @checkpath_setids@ --- *
+/* --- @checkpath_addgid@ --- *
+ *
+ * Arguments:	@struct checkpath *cp@ = pointer to block to fill in
+ *		@gid_t g@ = group id to add
+ *
+ * Returns:	Zero if successful, nonzero if the array is full.
+ *
+ * Use:		Adds the group @g@ to the structure.
+ */
+
+int checkpath_addgid(struct checkpath *cp, gid_t g)
+{
+  int i;
+
+  for (i = 0; i < cp->cp_gids; i++) {
+    if (cp->cp_gid[i] == g)
+      return (0);
+  }
+  if (cp->cp_gids >= N(cp->cp_gid))
+    return (-1);
+  cp->cp_gid[cp->cp_gids++] = g;
+  return (0);
+}
+
+/* --- @checkpath_setuid@ --- *
  *
  * Arguments:	@struct checkpath *cp@ = pointer to block to fill in
  *
  * Returns:	---
  *
- * Use:		Fills in the user ids and things in the structure.
+ * Use:		Fills in the @cp_uid@ slot of the structure with the real uid
+ *		of the current process.
  */
 
-void checkpath_setids(struct checkpath *cp)
+void checkpath_setuid(struct checkpath *cp) { cp->cp_uid = getuid(); }
+
+/* --- @checkpath_setgid@ --- *
+ *
+ * Arguments:	@struct checkpath *cp@ = pointer to block to fill in
+ *
+ * Returns:	Zero if successful, nonzero if the array is full.
+ *
+ * Use:		Adds the real gid of the current process to the @cp_gid@
+ *		array.
+ */
+
+int checkpath_setgid(struct checkpath *cp)
+  { return (checkpath_addgid(cp, getgid())); }
+
+/* --- @checkpath_setgroups@ --- *
+ *
+ * Arguments:	@struct checkpath *cp@ = pointer to block to fill in
+ *
+ * Returns:	Zero if successful, nonzero if the array is full.
+ *
+ * Use:		Adds the current process's supplementary groups to the
+ *		@cp_gid@ table.
+ */
+
+int checkpath_setgroups(struct checkpath *cp)
 {
-  int n, i;
-  gid_t g = getgid();
+  int i, n;
+  gid_t gg[NGROUPS_MAX];
 
-  cp->cp_uid = getuid();
-  n = getgroups(sizeof(cp->cp_gid) / sizeof(cp->cp_gid[0]), cp->cp_gid);
-  
+  n = getgroups(N(gg), gg);
   for (i = 0; i < n; i++) {
-    if (cp->cp_gid[i] == g)
-      goto gid_ok;
+    if (checkpath_addgid(cp, gg[i]))
+      return (-1);
   }
-  cp->cp_gid[n++] = g;
-gid_ok:
-  cp->cp_gids = n;
+  return (0);
+}
+
+/* --- @checkpath_setids@ --- *
+ *
+ * Arguments:	@struct checkpath *cp@ = pointer to block to fill in
+ *
+ * Returns:	---
+ *
+ * Use:		Fills in the user ids and things in the structure.  This is
+ *		equivalent to setting @cp_gids = 0@ and then calling
+ *		@_setuid@, @_setgid@ and @_setgroups@.  It can't fail.
+ */
+
+void checkpath_setids(struct checkpath *cp)
+{
+  cp->cp_gids = 0;
+  checkpath_setuid(cp);
+  checkpath_setgid(cp);
+  checkpath_setgroups(cp);
 }
 
 /*----- That's all, folks -------------------------------------------------*/