Rewrite integrity calculation and checks

[wimlib] / src / resource.c

diff --git a/src/resource.c b/src/resource.c
index 51bde70822c7ab33e5341ef33fdb63cd0e64fa83..c29ed4fb76d54985100304c592cec514d3d18452 100644 (file)
--- a/src/resource.c
+++ b/src/resource.c
@@ -810,6 +810,8 @@ int read_metadata_resource(WIMStruct *w, struct image_metadata *imd)
                goto out_free_security_data;
        }
 
+       DEBUG("Reading root dentry");
+
        /* Allocate memory for the root dentry and read it into memory */
        dentry = MALLOC(sizeof(struct dentry));
        if (!dentry) {
@@ -824,8 +826,16 @@ int read_metadata_resource(WIMStruct *w, struct image_metadata *imd)
        /* This is the root dentry, so set its parent to itself. */
        dentry->parent = dentry;
 
-       if (ret != 0)
-               goto out_free_dentry_tree;
+       if (ret == 0 && dentry->length == 0) {
+               ERROR("Metadata resource cannot begin with end-of-directory entry!");
+               ret = WIMLIB_ERR_INVALID_DENTRY;
+       }
+
+       if (ret != 0) {
+               FREE(dentry);
+               goto out_free_security_data;
+       }
+
        inode_add_dentry(dentry, dentry->d_inode);
 
        /* Now read the entire directory entry tree into memory. */
@@ -887,16 +897,12 @@ int write_metadata_resource(WIMStruct *w)
        u64 metadata_original_size;
        const struct wim_security_data *sd;
 
-       DEBUG("Writing metadata resource for image %d", w->current_image);
+       DEBUG("Writing metadata resource for image %d (offset = %"PRIu64")",
+             w->current_image, ftello(w->out_fp));
 
        root = wim_root_dentry(w);
        sd = wim_security_data(w);
 
-       /* We do not allow the security data pointer to be NULL, although it may
-        * point to an empty security data with no entries. */
-       wimlib_assert(root != NULL);
-       wimlib_assert(sd != NULL);
-
        /* Offset of first child of the root dentry.  It's equal to:
         * - The total length of the security data, rounded to the next 8-byte
         *   boundary,
@@ -904,7 +910,7 @@ int write_metadata_resource(WIMStruct *w)
         * - plus 8 bytes for an end-of-directory entry following the root
         *   dentry (shouldn't really be needed, but just in case...)
         */
-       subdir_offset = ((sd->total_length + 7) & ~7) +
+       subdir_offset = (((u64)sd->total_length + 7) & ~7) +
                        dentry_correct_total_length(root) + 8;
 
        /* Calculate the subdirectory offsets for the entire dentry tree. */
@@ -935,8 +941,6 @@ int write_metadata_resource(WIMStruct *w)
         * it. */
        lte = wim_metadata_lookup_table_entry(w);
 
-       wimlib_assert(lte != NULL);
-
        /* Write the metadata resource to the output WIM using the proper
         * compression type.  The lookup table entry for the metadata resource
         * is updated. */
@@ -960,12 +964,10 @@ int write_metadata_resource(WIMStruct *w)
         * */
        lookup_table_unlink(w->lookup_table, lte);
        lookup_table_insert(w->lookup_table, lte);
-
-       wimlib_assert(lte->out_refcnt == 0);
        lte->out_refcnt = 1;
 
-       /* Make sure that the resource entry is written marked with the metadata
-        * flag. */
+       /* Make sure that the lookup table entry for this metadata resource is
+        * marked with the metadata flag. */
        lte->output_resource_entry.flags |= WIM_RESHDR_FLAG_METADATA;
 out:
        /* All the data has been written to the new WIM; no need for the buffer