-
-static char *find_collision(struct metadump_struct *md, char *name,
- u32 name_len)
-{
- struct name *val;
- struct rb_node *entry;
- struct name tmp;
- unsigned long checksum;
- int found = 0;
- int i;
-
- tmp.val = name;
- tmp.len = name_len;
- entry = tree_search(&md->name_tree, &tmp.n, name_cmp, 0);
- if (entry) {
- val = rb_entry(entry, struct name, n);
- free(name);
- return val->sub;
- }
-
- val = malloc(sizeof(struct name));
- if (!val) {
- error("cannot sanitize name, not enough memory");
- free(name);
- return NULL;
- }
-
- memset(val, 0, sizeof(*val));
-
- val->val = name;
- val->len = name_len;
- val->sub = malloc(name_len);
- if (!val->sub) {
- error("cannot sanitize name, not enough memory");
- free(val);
- free(name);
- return NULL;
- }
-
- checksum = crc32c(~1, val->val, name_len);
- memset(val->sub, ' ', name_len);
- i = 0;
- while (1) {
- if (crc32c(~1, val->sub, name_len) == checksum &&
- memcmp(val->sub, val->val, val->len)) {
- found = 1;
- break;
- }
-
- if (val->sub[i] == 127) {
- do {
- i++;
- if (i >= name_len)
- break;
- } while (val->sub[i] == 127);
-
- if (i >= name_len)
- break;
- val->sub[i]++;
- if (val->sub[i] == '/')
- val->sub[i]++;
- memset(val->sub, ' ', i);
- i = 0;
- continue;
- } else {
- val->sub[i]++;
- if (val->sub[i] == '/')
- val->sub[i]++;
- }
- }
-
- if (!found) {
- warning(
-"cannot find a hash collision for '%.*s', generating garbage, it won't match indexes",
- val->len, val->val);
- for (i = 0; i < name_len; i++) {
- char c = rand_range(94) + 33;
-
- if (c == '/')
- c++;
- val->sub[i] = c;
- }
- }
-
- tree_insert(&md->name_tree, &val->n, name_cmp);
- return val->sub;
-}
-
-static void sanitize_dir_item(struct metadump_struct *md, struct extent_buffer *eb,
- int slot)
-{
- struct btrfs_dir_item *dir_item;
- char *buf;
- char *garbage;
- unsigned long name_ptr;
- u32 total_len;
- u32 cur = 0;
- u32 this_len;
- u32 name_len;
- int free_garbage = (md->sanitize_names == 1);
-
- dir_item = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
- total_len = btrfs_item_size_nr(eb, slot);
- while (cur < total_len) {
- this_len = sizeof(*dir_item) +
- btrfs_dir_name_len(eb, dir_item) +
- btrfs_dir_data_len(eb, dir_item);
- name_ptr = (unsigned long)(dir_item + 1);
- name_len = btrfs_dir_name_len(eb, dir_item);
-
- if (md->sanitize_names > 1) {
- buf = malloc(name_len);
- if (!buf) {
- error("cannot sanitize name, not enough memory");
- return;
- }
- read_extent_buffer(eb, buf, name_ptr, name_len);
- garbage = find_collision(md, buf, name_len);
- } else {
- garbage = generate_garbage(name_len);
- }
- if (!garbage) {
- error("cannot sanitize name, not enough memory");
- return;
- }
- write_extent_buffer(eb, garbage, name_ptr, name_len);
- cur += this_len;
- dir_item = (struct btrfs_dir_item *)((char *)dir_item +
- this_len);
- if (free_garbage)
- free(garbage);
- }
-}
-
-static void sanitize_inode_ref(struct metadump_struct *md,
- struct extent_buffer *eb, int slot, int ext)
-{
- struct btrfs_inode_extref *extref;
- struct btrfs_inode_ref *ref;
- char *garbage, *buf;
- unsigned long ptr;
- unsigned long name_ptr;
- u32 item_size;
- u32 cur_offset = 0;
- int len;
- int free_garbage = (md->sanitize_names == 1);
-
- item_size = btrfs_item_size_nr(eb, slot);
- ptr = btrfs_item_ptr_offset(eb, slot);
- while (cur_offset < item_size) {
- if (ext) {
- extref = (struct btrfs_inode_extref *)(ptr +
- cur_offset);
- name_ptr = (unsigned long)(&extref->name);
- len = btrfs_inode_extref_name_len(eb, extref);
- cur_offset += sizeof(*extref);
- } else {
- ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
- len = btrfs_inode_ref_name_len(eb, ref);
- name_ptr = (unsigned long)(ref + 1);
- cur_offset += sizeof(*ref);
- }
- cur_offset += len;
-
- if (md->sanitize_names > 1) {
- buf = malloc(len);
- if (!buf) {
- error("cannot sanitize name, not enough memory");
- return;
- }
- read_extent_buffer(eb, buf, name_ptr, len);
- garbage = find_collision(md, buf, len);
- } else {
- garbage = generate_garbage(len);
- }
-
- if (!garbage) {
- error("cannot sanitize name, not enough memory");
- return;
- }
- write_extent_buffer(eb, garbage, name_ptr, len);
- if (free_garbage)
- free(garbage);
- }
-}
-
-static void sanitize_xattr(struct metadump_struct *md,
- struct extent_buffer *eb, int slot)
-{
- struct btrfs_dir_item *dir_item;
- unsigned long data_ptr;
- u32 data_len;
-
- dir_item = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
- data_len = btrfs_dir_data_len(eb, dir_item);
-
- data_ptr = (unsigned long)((char *)(dir_item + 1) +
- btrfs_dir_name_len(eb, dir_item));
- memset_extent_buffer(eb, 0, data_ptr, data_len);
-}
-
-static void sanitize_name(struct metadump_struct *md, u8 *dst,
- struct extent_buffer *src, struct btrfs_key *key,
- int slot)
-{
- struct extent_buffer *eb;
-
- eb = alloc_dummy_eb(src->start, src->len);
- if (!eb) {
- error("cannot sanitize name, not enough memory");
- return;
- }
-
- memcpy(eb->data, src->data, src->len);
-
- switch (key->type) {
- case BTRFS_DIR_ITEM_KEY:
- case BTRFS_DIR_INDEX_KEY:
- sanitize_dir_item(md, eb, slot);
- break;
- case BTRFS_INODE_REF_KEY:
- sanitize_inode_ref(md, eb, slot, 0);
- break;
- case BTRFS_INODE_EXTREF_KEY:
- sanitize_inode_ref(md, eb, slot, 1);
- break;
- case BTRFS_XATTR_ITEM_KEY:
- sanitize_xattr(md, eb, slot);
- break;
- default:
- break;
- }
-
- memcpy(dst, eb->data, eb->len);
- free(eb);
-}
-