add a version field to prevent mayhem if different data gets stored

1 files changed, 7 insertions, 3 deletions

diff --git a/src/lib/libc/stdlib/icdb.c b/src/lib/libc/stdlib/icdb.c
index 077c59a1e4..35747c065f 100644
--- a/src/lib/libc/stdlib/icdb.c
+++ b/src/lib/libc/stdlib/icdb.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: icdb.c,v 1.1 2015/11/18 16:46:49 tedu Exp $ */
+/* $OpenBSD: icdb.c,v 1.2 2015/11/18 17:59:56 tedu Exp $ */
 /*
  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
  *
@@ -77,6 +77,7 @@
  */
 struct icdbinfo {
         uint32_t magic;         /* magic */
+        uint32_t version;       /* user specified version */
         uint32_t nentries;      /* number of entries stored */
         uint32_t entrysize;     /* size of each entry */
         uint32_t indexsize;     /* number of entries in hash index */
@@ -112,7 +113,7 @@ roundup(uint32_t num)
 }
 
 struct icdb *
-icdb_new(uint32_t nentries, uint32_t entrysize,
+icdb_new(uint32_t version, uint32_t nentries, uint32_t entrysize,
     uint32_t nkeys, uint32_t *keysizes, uint32_t *keyoffsets)
 {
         struct icdb *db;
@@ -133,6 +134,7 @@ icdb_new(uint32_t nentries, uint32_t entrysize,
         db->info = info;
         db->fd = -1;
         info->magic = magic;
+        info->version = version;
         if (nentries)
                 if ((db->entries = reallocarray(NULL, nentries, entrysize)))
                         db->allocated = nentries;
@@ -146,7 +148,7 @@ icdb_new(uint32_t nentries, uint32_t entrysize,
 }
 
 struct icdb *
-icdb_open(const char *name, int flags)
+icdb_open(const char *name, int flags, uint32_t version)
 {
         struct icdb *db = NULL;
         struct icdbinfo *info;
@@ -166,6 +168,8 @@ icdb_open(const char *name, int flags)
         info = (struct icdbinfo *)ptr;
         if (info->magic != magic)
                 goto fail;
+        if (info->version != version)
+                goto fail;
 
         if (!(db = calloc(1, sizeof(*db))))
                 goto fail;