[Libguestfs] [PATCH 12/12 (NOT FOR REVIEW)] hivex: Implement adding and deleting child nodes.
Richard W.M. Jones
rjones at redhat.com
Wed Feb 3 18:38:38 UTC 2010
WIP ...
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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>From 520c38b211a35cb77d8bec98aa4d77dfb8042aad Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Wed, 3 Feb 2010 18:10:38 +0000
Subject: [PATCH 12/12] hivex: Implement adding and deleting child nodes.
---
hivex/hivex.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
hivex/hivex.h | 4 ++
hivex/hivex.pod | 18 +++++++
3 files changed, 167 insertions(+), 0 deletions(-)
diff --git a/hivex/hivex.c b/hivex/hivex.c
index af36868..f197cd3 100644
--- a/hivex/hivex.c
+++ b/hivex/hivex.c
@@ -1952,6 +1952,151 @@ hivex_commit (hive_h *h, const char *filename, int flags)
return 0;
}
+#if 0
+hive_node_h
+hivex_node_add_child (hive_h *h, hive_node_h parent, const char *name)
+{
+ if (!h->writable) {
+ errno = EROFS;
+ return 0;
+ }
+
+ if (!IS_VALID_BLOCK (h, parent) || !BLOCK_ID_EQ (h, parent, "nk")) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ if (name == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+
+
+
+
+
+}
+#endif
+
+#if 0
+/* Callback from hivex_node_delete_child which is called to delete a
+ * node AFTER its subnodes have been visited. The subnodes have been
+ * deleted but we still have to delete any lf/lh/li/ri records and the
+ * value list block and values, followed by deleting the node itself.
+ */
+static int
+delete_node (hive_h *h, void *opaque, hive_node_h node, const char *name)
+{
+ hive_node_h *unused;
+ size_t *blocks;
+ if (get_children (h, node, &unused, &blocks) == -1)
+ return -1;
+ free (unused);
+
+ /* We don't care what's in these intermediate blocks, so we can just
+ * delete them unconditionally.
+ */
+ size_t i;
+ for (i = 0; blocks[i] != 0; ++i)
+ mark_block_unused (h, blocks[i]);
+
+ free (blocks);
+
+ /* Delete the values in the node. */
+ if (delete_values (h, node) == -1)
+ return -1;
+
+ /* XXX We should decrement the refcount. Deleting the SK is tricky
+ * because we don't yet know about the sk_prev and sk_next fields.
+
+ mark_block_unused (node->sk);
+ */
+
+ /* XXX Should do this:
+ if (node->classname != -1)
+ mark_block_unused (node->classname);
+ */
+
+ /* Delete the node itself. */
+ mark_block_unused (h, node);
+
+ return 0;
+}
+
+int
+hivex_node_delete_child (hive_h *h, hive_node_h node)
+{
+ if (!h->writable) {
+ errno = EROFS;
+ return -1;
+ }
+
+ if (!IS_VALID_BLOCK (h, node) || !BLOCK_ID_EQ (h, node, "nk")) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ if (node == hivex_root (h)) {
+ if (h->msglvl >= 2)
+ fprintf (stderr, "hivex_node_delete_child: cannot delete root node\n");
+ errno = EINVAL;
+ return -1;
+ }
+
+ hive_node_h parent = hivex_node_parent (h, node);
+ if (parent == 0)
+ return -1;
+
+ /* Delete node and all its children and values recursively. */
+ static const struct hivex_visitor visitor = { .node_end = delete_node };
+ if (hivex_visit_node (h, node, &visitor, sizeof visitor, NULL, 0) == -1)
+ return -1;
+
+ /* Delete the link from parent to child. We need to find the lf/lh
+ * record which contains the offset and remove the offset from that
+ * record, then decrement the element count in that record, and
+ * decrement the overall number of subkeys stored in the parent
+ * node.
+ */
+ hive_node_h *unused;
+ size_t *blocks;
+ if (get_children (h, parent, &unused, &blocks) == -1)
+ return -1;
+
+ size_t i, j;
+ for (i = 0; blocks[i] != 0; ++i) {
+ struct ntreg_hbin_block *block =
+ (struct ntreg_hbin_block *) (h->addr + blocks[i]);
+
+ if (block->id[0] == 'l' && (block->id[1] == 'f' || block->id[1] == 'h')) {
+ struct ntreg_lf_record *lf = (struct ntreg_lf_record *) block;
+
+ size_t nr_subkeys_in_lf = le16toh (lf->nr_keys);
+
+ for (j = 0; j < nr_subkeys_in_lf; ++j)
+ if (le32toh (lf->keys[j].offset) + 0x1000 == node) {
+ for (; j < nr_subkeys_in_lf - 1; ++j)
+ memcpy (&lf->keys[j], &lf->keys[j+1], sizeof (lf->keys[j]));
+ lf->nr_keys = htole16 (nr_subkeys_in_lf - 1);
+ goto found;
+ }
+ }
+ }
+ if (h->msglvl >= 2)
+ fprintf (stderr, "hivex_node_delete_child: could not find parent to child link\n");
+ errno = ENOTSUP;
+ return -1;
+
+ found:;
+ struct ntreg_nk_record *nk = (struct ntreg_nk_record *) (h->addr + node);
+ size_t nr_subkeys_in_nk = le32toh (nk->nr_subkeys);
+ nk->nr_subkeys = htole32 (nr_subkeys_in_nk - 1);
+
+ return 0;
+}
+#endif
+
int
hivex_node_set_values (hive_h *h, hive_node_h node,
size_t nr_values, const hive_set_value *values,
diff --git a/hivex/hivex.h b/hivex/hivex.h
index 6a3cb3a..296a1a5 100644
--- a/hivex/hivex.h
+++ b/hivex/hivex.h
@@ -111,6 +111,10 @@ extern int hivex_visit (hive_h *h, const struct hivex_visitor *visitor, size_t l
extern int hivex_visit_node (hive_h *h, hive_node_h node, const struct hivex_visitor *visitor, size_t len, void *opaque, int flags);
extern int hivex_commit (hive_h *h, const char *filename, int flags);
+#if 0
+extern hive_node_h hivex_node_add_child (hive_h *h, hive_node_h parent, const char *name);
+extern int hivex_node_delete_child (hive_h *h, hive_node_h node);
+#endif
struct hive_set_value {
char *key;
diff --git a/hivex/hivex.pod b/hivex/hivex.pod
index 5df75aa..34ff253 100644
--- a/hivex/hivex.pod
+++ b/hivex/hivex.pod
@@ -379,6 +379,24 @@ operations on the hive after committing, including making more
modifications. If you no longer wish to use the hive, call
C<hivex_close> after this.
+=item hive_node_h hivex_node_add_child (hive_h *h, hive_node_h parent, const char *name);
+
+Add a new child node named C<name> to the existing node C<parent>.
+The new child initially has no subnodes and contains no keys or
+values. The parent must not have an existing child called C<name>, so
+if you want to overwrite an existing child, call
+C<hivex_node_delete_child> first.
+
+Returns the node handle. On error this returns 0 and sets errno.
+
+=item int hivex_node_delete_child (hive_h *h, hive_node_h node);
+
+Delete the node C<node>. All values at the node and all subnodes are
+deleted (recursively). The C<node> handle and the handles of all
+subnodes become invalid. You cannot delete the root node.
+
+Returns 0 on success. On error this returns -1 and sets errno.
+
=item hive_set_value
The typedef C<hive_set_value> is used in conjunction with the
--
1.6.5.2
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