update chain jumps when removing a chain

diff --git a/ebtables.c b/ebtables.c
index d09f422..b1027f5 100644 (file)
--- a/ebtables.c
+++ b/ebtables.c
@@ -201,8 +201,10 @@ static void initialize_entry(struct ebt_u_entry *e)
        strcpy(e->logical_out, "");
        e->m_list = NULL;
        e->w_list = NULL;
-       // the init function of the standard target should have put the verdict
-       // on CONTINUE
+       /*
+        * the init function of the standard target should have put the verdict
+        * on CONTINUE
+        */
        e->t = (struct ebt_entry_target *)find_target(EBT_STANDARD_TARGET);
        if (!e->t)
                print_bug("Couldn't load standard target");
@@ -1473,14 +1475,20 @@ static void check_for_references(int chain_nr)
                e = entries->entries;
                j = 0;
                while (e) {
+                       int chain_jmp;
+
                        j++;
                        if (strcmp(e->t->u.name, EBT_STANDARD_TARGET)) {
                                e = e->next;
                                continue;
                        }
-                       if (((struct ebt_standard_target *)e->t)->verdict == chain_nr)
+                       chain_jmp = ((struct ebt_standard_target *)e->t)->verdict;
+                       if (chain_jmp == chain_nr)
                                print_error("Can't delete the chain, it's referenced "
                                   "in chain %s, rule %d", entries->name, j);
+                       /* adjust the chain jumps when necessary */
+                       if (chain_jmp > chain_nr)
+                               ((struct ebt_standard_target *)e->t)->verdict--;
                        e = e->next;
                }
        }
@@ -1698,7 +1706,9 @@ int main(int argc, char *argv[])
                                if (replace.selected_hook < NF_BR_NUMHOOKS)
                                        print_error("You can't remove a standard chain");
                                /*
-                                * if the chain is referenced, don't delete it
+                                * if the chain is referenced, don't delete it,
+                                * also decrement jumps to a chain behind the
+                                * one we're deleting
                                 */
                                check_for_references(replace.selected_hook - NF_BR_NUMHOOKS);
                                flush_chains();