NDBM: check for bogus name given to create call

[exim.git] / src / src / dbstuff.h

diff --git a/src/src/dbstuff.h b/src/src/dbstuff.h
index a5905231e448324ef3dae7289a706f78d866882c..296a8e18c663d129246765dd1692230da8181a99 100644 (file)
--- a/src/src/dbstuff.h
+++ b/src/src/dbstuff.h
@@ -434,8 +434,19 @@ interface */
 /* Access functions */
 
 /* EXIM_DBOPEN - returns a EXIM_DB *, NULL if failed */
-# define EXIM_DBOPEN__(name, dirname, flags, mode, dbpp) \
-       *(dbpp) = dbm_open(CS name, flags, mode)
+/* Check that the name given is not present. This catches
+a directory name; otherwise we would create the name.pag and
+name.dir files in the directory's parent. */
+
+# define EXIM_DBOPEN__(name, dirname, flags, mode, dbpp)               \
+       {                                                               \
+       struct stat st;                                                 \
+       *(dbpp) =    !(flags & O_CREAT)                                 \
+                || lstat(CCS (name), &st) != 0 && errno == ENOENT      \
+         ? dbm_open(CS (name), (flags), (mode))                                \
+        : (errno = (st.st_mode & S_IFMT) == S_IFDIR ? EISDIR : EEXIST, \
+          NULL);                                                       \
+       }
 
 /* EXIM_DBGET - returns TRUE if successful, FALSE otherwise */
 # define EXIM_DBGET(db, key, data)      \