s3:registry: do not use regdb functions during db upgrade

It is importante to not use the database backend implementation
in the upgrade. Otherwise this would only work as long as this
is the newset version. In future versions of the registry, this
(then) intermediate upgrade step would change in behaviour and not
work as expected any more.

Signed-off-by: Michael Adam <obnox@samba.org>

1 files changed, 141 insertions, 55 deletions

diff --git a/source3/registry/reg_backend_db.c b/source3/registry/reg_backend_db.c
index b306b2cf39..06251e01f9 100644
--- a/source3/registry/reg_backend_db.c
+++ b/source3/registry/reg_backend_db.c
@@ -26,6 +26,7 @@
 #include "registry.h"
 #include "reg_db.h"
 #include "reg_util_internal.h"
+#include "reg_parse_internal.h"
 #include "reg_backend_db.h"
 #include "reg_objects.h"
 #include "nt_printing.h"
@@ -516,22 +517,104 @@ done:
 	return werr;
 }
 
+static bool tdb_data_read_uint32(TDB_DATA *buf, uint32_t *result)
+{
+	const size_t len = sizeof(uint32_t);
+	if (buf->dsize >= len) {
+		*result = IVAL(buf->dptr, 0);
+		buf->dptr += len;
+		buf->dsize -= len;
+		return true;
+	}
+	return false;
+}
+
+static bool tdb_data_read_cstr(TDB_DATA *buf, char **result)
+{
+	const size_t len = strnlen((char*)buf->dptr, buf->dsize) + 1;
+	if (buf->dsize >= len) {
+		*result = (char*)buf->dptr;
+		buf->dptr += len;
+		buf->dsize -= len;
+		return true;
+	}
+	return false;
+}
+
+static bool tdb_data_is_empty(TDB_DATA d) {
+	return (d.dptr == NULL) || (d.dsize == 0);
+}
+
+static bool tdb_data_is_cstr(TDB_DATA d) {
+	if (tdb_data_is_empty(d) || (d.dptr[d.dsize-1] != '\0')) {
+		return false;
+	}
+	return rawmemchr(d.dptr, '\0') == &d.dptr[d.dsize-1];
+}
+
+static bool upgrade_v2_to_v3_check_subkeylist(struct db_context *db,
+					      const char *key,
+					      const char *subkey)
+{
+	static uint32_t zero = 0;
+	static TDB_DATA empty_subkey_list = {
+		.dptr = (unsigned char*)&zero,
+		.dsize = sizeof(uint32_t),
+	};
+	bool success = false;
+	char *path = talloc_asprintf(talloc_tos(), "%s\\%s", key, subkey);
+	strupper_m(path);
+
+	if (!dbwrap_exists(db, string_term_tdb_data(path))) {
+		NTSTATUS status;
+
+		DEBUG(10, ("regdb_upgrade_v2_to_v3: writing subkey list [%s]\n",
+			   path));
+
+		status = dbwrap_store_bystring(db, path, empty_subkey_list,
+					       TDB_INSERT);
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(0, ("regdb_upgrade_v2_to_v3: writing subkey list "
+				  "[%s] failed\n", path));
+			goto done;
+		}
+	}
+	success = true;
+done:
+	talloc_free(path);
+	return success;
+}
+
+static bool upgrade_v2_to_v3_check_parent(struct db_context *db,
+					  const char *key)
+{
+	const char *sep = strrchr_m(key, '\\');
+	if (sep != NULL) {
+		char *pkey = talloc_strndup(talloc_tos(), key, sep-key);
+		if (!dbwrap_exists(db, string_term_tdb_data(pkey))) {
+			DEBUG(0, ("regdb_upgrade_v2_to_v3: missing subkey list "
+				  "[%s]\nrun \"net registry check\"\n", pkey));
+		}
+		talloc_free(pkey);
+	}
+	return true;
+}
+
+
+#define IS_EQUAL(d,s) (((d).dsize == strlen(s)+1) &&	\
+		       (strcmp((char*)(d).dptr, (s)) == 0))
+#define STARTS_WITH(d,s) (((d).dsize > strlen(s)) &&			\
+			  (strncmp((char*)(d).dptr, (s), strlen(s)) == 0))
+#define SSTR(d) (int)(d).dsize , (char*)(d).dptr
+
+
 static int regdb_upgrade_v2_to_v3_fn(struct db_record *rec, void *private_data)
 {
-	const char *keyname;
-	fstring subkeyname;
-	NTSTATUS status;
-	WERROR werr;
-	uint8_t *buf;
-	uint32_t buflen, len;
-	uint32_t num_items;
-	uint32_t i;
-	TDB_DATA key;
-	TDB_DATA value;
 	struct db_context *db = (struct db_context *)private_data;
+	TDB_DATA key = dbwrap_record_get_key(rec);
+	TDB_DATA val = dbwrap_record_get_value(rec);
 
-	key = dbwrap_record_get_key(rec);
-	if (key.dptr == NULL || key.dsize == 0) {
+	if (tdb_data_is_empty(key)) {
 		return 0;
 	}
 
@@ -541,70 +624,73 @@ static int regdb_upgrade_v2_to_v3_fn(struct db_record *rec, void *private_data)
 		return 1;
 	}
 
-	keyname = (const char *)key.dptr;
-
-	if (strncmp(keyname, REGDB_VERSION_KEYNAME,
-		    strlen(REGDB_VERSION_KEYNAME)) == 0)
+	if (IS_EQUAL(key, REGDB_VERSION_KEYNAME) ||
+	    STARTS_WITH(key, REG_VALUE_PREFIX) ||
+	    STARTS_WITH(key, REG_SECDESC_PREFIX))
 	{
+		DEBUG(10, ("regdb_upgrade_v2_to_v3: skipping [%.*s]\n",
+			   SSTR(key)));
 		return 0;
 	}
 
-	if (strncmp(keyname, REG_SORTED_SUBKEYS_PREFIX,
-		    strlen(REG_SORTED_SUBKEYS_PREFIX)) == 0)
-	{
+	if (STARTS_WITH(key, REG_SORTED_SUBKEYS_PREFIX)) {
+		NTSTATUS status;
 		/* Delete the deprecated sorted subkeys cache. */
 
-		DEBUG(10, ("regdb_upgrade_v2_to_v3: deleting [%s]\n", keyname));
+		DEBUG(10, ("regdb_upgrade_v2_to_v3: deleting [%.*s]\n",
+			   SSTR(key)));
 
 		status = dbwrap_record_delete(rec);
 		if (!NT_STATUS_IS_OK(status)) {
-			DEBUG(0, ("regdb_upgrade_v2_to_v3: tdb_delete for [%s] "
-				  "failed!\n", keyname));
+			DEBUG(0, ("regdb_upgrade_v2_to_v3: deleting [%.*s] "
+				  "failed!\n", SSTR(key)));
 			return 1;
 		}
 
 		return 0;
 	}
 
-	if (strncmp(keyname, REG_VALUE_PREFIX, strlen(REG_VALUE_PREFIX)) == 0) {
-		DEBUG(10, ("regdb_upgrade_v2_to_v3: skipping [%s]\n", keyname));
-		return 0;
-	}
-
-	if (strncmp(keyname, REG_SECDESC_PREFIX,
-		    strlen(REG_SECDESC_PREFIX)) == 0)
+	if ( tdb_data_is_cstr(key) &&
+	     hive_info((char*)key.dptr) != NULL )
 	{
-		DEBUG(10, ("regdb_upgrade_v2_to_v3: skipping [%s]\n", keyname));
-		return 0;
-	}
+		/*
+		 * Found a regular subkey list record.
+		 * Walk the list and create the list record for those
+		 * subkeys that don't already have one.
+		 */
+		TDB_DATA pos = val;
+		char *subkey, *path = (char*)key.dptr;
+		uint32_t num_items, found_items = 0;
 
-	/*
-	 * Found a regular subkey list record.
-	 * Walk the list and create the list record for those
-	 * subkeys that don't already have one.
-	 */
-	DEBUG(10, ("regdb_upgrade_v2_to_v3: scanning subkey list of [%s]\n",
-		   keyname));
 
-	value = dbwrap_record_get_value(rec);
-	buf = value.dptr;
-	buflen = value.dsize;
+		DEBUG(10, ("regdb_upgrade_v2_to_v3: scanning subkeylist of "
+			   "[%s]\n", path));
 
-	len = tdb_unpack(buf, buflen, "d", &num_items);
-	if (len == (uint32_t)-1) {
-		/* invalid or empty - skip */
-		return 0;
-	}
+		if (!tdb_data_read_uint32(&pos, &num_items)) {
+			/* invalid or empty - skip */
+			return 0;
+		}
 
-	for (i=0; i<num_items; i++) {
-		len += tdb_unpack(buf+len, buflen-len, "f", subkeyname);
-		DEBUG(10, ("regdb_upgrade_v2_to_v3: "
-			   "writing subkey list for [%s\\%s]\n",
-			   keyname, subkeyname));
-		werr = regdb_store_subkey_list(db, keyname, subkeyname);
-		if (!W_ERROR_IS_OK(werr)) {
-			return 1;
+		while (tdb_data_read_cstr(&pos, &subkey)) {
+			found_items++;
+
+			if (!upgrade_v2_to_v3_check_subkeylist(db, path, subkey))
+			{
+				return 1;
+			}
+
+			if (!upgrade_v2_to_v3_check_parent(db, path)) {
+				return 1;
+			}
 		}
+		if (found_items != num_items) {
+			DEBUG(0, ("regdb_upgrade_v2_to_v3: inconsistent subkey "
+				  "list [%s]\nrun \"net registry check\"\n",
+				  path));
+		}
+	} else {
+		DEBUG(10, ("regdb_upgrade_v2_to_v3: skipping invalid [%.*s]\n"
+			   "run \"net registry check\"\n", SSTR(key)));
 	}
 
 	return 0;