obj/dbm.c: Copy the elements between the struct DBT and

datum. Otherwise on an Alpha where the size fields are different sizes,
casting loses with random stack garbage.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@8786 dc483132-0cff-0310-8789-dd5450dbe970

diff --git a/src/util/db2/ChangeLog b/src/util/db2/ChangeLog
index 9d240ec940a349ce51f6063ce9fdcec896325bd7..17ef23d8c42082179dfd95d4d053c9fc5338761c 100644 (file)
--- a/src/util/db2/ChangeLog
+++ b/src/util/db2/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jul 23 16:08:43 1996  Ezra Peisach  <epeisach@kangaroo.mit.edu>
+
+       * hash/dbm.c: Copy elements from the datum to an internal
+       DBT. Handles case of differences in size of size fields.
+
 Fri Jun 21 00:07:57 1996  Marc Horowitz  <marc@mit.edu>
 
        * hash/dbm.c (delete, store): dbm_rdonly() doesn't exist on some

diff --git a/src/util/db2/hash/dbm.c b/src/util/db2/hash/dbm.c
index a5a31f45bc6fb3a2d2256f481367ba8c2e829b56..c4ba92beb40dbfa5611a418e56ce4a136d259be2 100644 (file)
--- a/src/util/db2/hash/dbm.c
+++ b/src/util/db2/hash/dbm.c
@@ -49,6 +49,14 @@ static char sccsid[] = "@(#)dbm.c    8.6 (Berkeley) 11/7/95";
 #include "db-ndbm.h"
 #include "hash.h"
 
+/* If the two size fields of datum and DBMT are not equal, then
+ * casting between structures will result in stack garbage being
+ * transfered. Has been observed for DEC Alpha OSF, but will handle
+ *  the general case.
+ */
+
+#define NEED_COPY
+
 /*
  *
  * This package provides dbm and ndbm compatible interfaces to DB.
@@ -189,7 +197,17 @@ dbm_fetch(db, key)
        datum retval;
        int status;
 
+#ifdef NEED_COPY
+       DBT k, r;
+
+       k.data = key.dptr;
+       k.size = key.dsize;
+       status = (db->get)(db, &k, &r, 0);
+       retval.dptr = r.data;
+       retval.dsize = r.size;
+#else
        status = (db->get)(db, (DBT *)&key, (DBT *)&retval, 0);
+#endif
        if (status) {
                retval.dptr = NULL;
                retval.dsize = 0;
@@ -209,7 +227,15 @@ dbm_firstkey(db)
        int status;
        datum retdata, retkey;
 
+#ifdef NEED_COPY
+       DBT k, r;
+
+       status = (db->seq)(db, &k, &r, R_FIRST);
+       retkey.dptr = k.data;
+       retkey.dsize = k.size;
+#else
        status = (db->seq)(db, (DBT *)&retkey, (DBT *)&retdata, R_FIRST);
+#endif
        if (status)
                retkey.dptr = NULL;
        return (retkey);
@@ -227,7 +253,15 @@ dbm_nextkey(db)
        int status;
        datum retdata, retkey;
 
+#ifdef NEED_COPY
+       DBT k, r;
+
+       status = (db->seq)(db, &k, &r, R_NEXT);
+       retkey.dptr = k.data;
+       retkey.dsize = k.size;
+#else
        status = (db->seq)(db, (DBT *)&retkey, (DBT *)&retdata, R_NEXT);
+#endif
        if (status)
                retkey.dptr = NULL;
        return (retkey);
@@ -245,7 +279,15 @@ dbm_delete(db, key)
 {
        int status;
 
+#ifdef NEED_COPY
+       DBT k;
+
+       k.data = key.dptr;
+       k.size = key.dsize;
+       status = (db->del)(db, &k, 0);
+#else
        status = (db->del)(db, (DBT *)&key, 0);
+#endif
        if (status)
                return (-1);
        else
@@ -264,8 +306,19 @@ dbm_store(db, key, content, flags)
        datum key, content;
        int flags;
 {
+#ifdef NEED_COPY
+       DBT k, c;
+
+       k.data = key.dptr;
+       k.size = key.dsize;
+       c.data = content.dptr;
+       c.size = content.dsize;
+       return ((db->put)(db, &k, &c,
+           (flags == DBM_INSERT) ? R_NOOVERWRITE : 0));
+#else
        return ((db->put)(db, (DBT *)&key, (DBT *)&content,
            (flags == DBM_INSERT) ? R_NOOVERWRITE : 0));
+#endif
 }
 
 int