+static int ebt_verify_pointers(struct ebt_replace *repl,
+ struct ebt_table_info *newinfo)
+{
+ unsigned int limit = repl->entries_size;
+ unsigned int valid_hooks = repl->valid_hooks;
+ unsigned int offset = 0;
+ int i;
+
+ for (i = 0; i < NF_BR_NUMHOOKS; i++)
+ newinfo->hook_entry[i] = NULL;
+
+ newinfo->entries_size = repl->entries_size;
+ newinfo->nentries = repl->nentries;
+
+ while (offset < limit) {
+ size_t left = limit - offset;
+ struct ebt_entry *e = (void *)newinfo->entries + offset;
+
+ if (left < sizeof(unsigned int))
+ break;
+
+ for (i = 0; i < NF_BR_NUMHOOKS; i++) {
+ if ((valid_hooks & (1 << i)) == 0)
+ continue;
+ if ((char __user *)repl->hook_entry[i] ==
+ repl->entries + offset)
+ break;
+ }
+
+ if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
+ if (e->bitmask != 0) {
+ /* we make userspace set this right,
+ so there is no misunderstanding */
+ BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
+ "in distinguisher\n");
+ return -EINVAL;
+ }
+ if (i != NF_BR_NUMHOOKS)
+ newinfo->hook_entry[i] = (struct ebt_entries *)e;
+ if (left < sizeof(struct ebt_entries))
+ break;
+ offset += sizeof(struct ebt_entries);
+ } else {
+ if (left < sizeof(struct ebt_entry))
+ break;
+ if (left < e->next_offset)
+ break;
+ offset += e->next_offset;
+ }
+ }
+ if (offset != limit) {
+ BUGPRINT("entries_size too small\n");
+ return -EINVAL;
+ }
+
+ /* check if all valid hooks have a chain */
+ for (i = 0; i < NF_BR_NUMHOOKS; i++) {
+ if (!newinfo->hook_entry[i] &&
+ (valid_hooks & (1 << i))) {
+ BUGPRINT("Valid hook without chain\n");
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+