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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-12-23 13:16:21 +0100
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-12-23 13:55:38 +0100
commitf92e31c94f953a68309dab7df75f5f9cc67caa7a (patch)
treee3c25f232b44a99d40db49521d1974ddbb67df2c /lib/common/hardlink.c
parent9db873364de85e6b5f972dbd2bada80591ef8af4 (diff)
Add simple sqfs_tree_node_t hardlink detection to libcommon
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/common/hardlink.c')
-rw-r--r--lib/common/hardlink.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/lib/common/hardlink.c b/lib/common/hardlink.c
new file mode 100644
index 0000000..c1fca8a
--- /dev/null
+++ b/lib/common/hardlink.c
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * hardlink.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "common.h"
+
+#include <stdlib.h>
+#include <assert.h>
+#include <stdio.h>
+
+static size_t count_nodes(const sqfs_tree_node_t *n)
+{
+ size_t count = n->children == NULL ? 1 : 0;
+
+ for (n = n->children; n != NULL; n = n->next)
+ count += count_nodes(n);
+
+ return count;
+}
+
+static size_t map_nodes(const sqfs_tree_node_t **list,
+ const sqfs_tree_node_t *n,
+ size_t idx)
+{
+ if (n->children == NULL)
+ list[idx++] = n;
+
+ for (n = n->children; n != NULL; n = n->next)
+ idx = map_nodes(list, n, idx);
+
+ return idx;
+}
+
+int sqfs_tree_find_hard_links(const sqfs_tree_node_t *root,
+ sqfs_hard_link_t **out)
+{
+ sqfs_hard_link_t *hardlinks = NULL, *lnk = NULL;
+ const sqfs_tree_node_t **list = NULL;
+ size_t i, j, count;
+ const char *name;
+ bool is_dup;
+
+ count = count_nodes(root);
+ list = malloc(sizeof(list[0]) * count);
+ if (list == NULL)
+ goto fail;
+
+ map_nodes(list, root, 0);
+
+ for (i = 0; i < count; ++i) {
+ name = (const char *)list[i]->name;
+ if (!is_filename_sane(name, false))
+ continue;
+
+ is_dup = false;
+
+ for (j = 0; j < i; ++j) {
+ if (list[j]->inode->base.inode_number ==
+ list[i]->inode->base.inode_number) {
+ name = (const char *)list[j]->name;
+ if (!is_filename_sane(name, false))
+ continue;
+
+ is_dup = true;
+ break;
+ }
+ }
+
+ if (is_dup) {
+ lnk = calloc(1, sizeof(*lnk));
+ if (lnk == NULL)
+ goto fail;
+
+ lnk->inode_number = list[j]->inode->base.inode_number;
+ lnk->target = sqfs_tree_node_get_path(list[j]);
+ if (lnk->target == NULL)
+ goto fail;
+
+ if (canonicalize_name(lnk->target) == 0) {
+ lnk->next = hardlinks;
+ hardlinks = lnk;
+ } else {
+ free(lnk->target);
+ free(lnk);
+ }
+ }
+ }
+
+ *out = hardlinks;
+ return 0;
+fail:
+ perror("detecting hard links in file system tree");
+ free(lnk);
+ while (hardlinks != NULL) {
+ lnk = hardlinks;
+ hardlinks = hardlinks->next;
+ free(lnk->target);
+ free(lnk);
+ }
+ free(list);
+ return -1;
+}