net: sched: introduce support for multiple filter chain pointers registration

So far, there was possible only to register a single filter chain
pointer to block->chain[0]. However, when the blocks will get shareable,
we need to allow multiple filter chain pointers registration.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index bd9125b..17d8cfd 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -275,8 +275,7 @@ typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
 
 struct tcf_chain {
        struct tcf_proto __rcu *filter_chain;
-       tcf_chain_head_change_t *chain_head_change;
-       void *chain_head_change_priv;
+       struct list_head filter_chain_list;
        struct list_head list;
        struct tcf_block *block;
        u32 index; /* chain index */

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 6708b69..e6b16b3 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -179,6 +179,12 @@ static void tcf_proto_destroy(struct tcf_proto *tp)
        kfree_rcu(tp, rcu);
 }
 
+struct tcf_filter_chain_list_item {
+       struct list_head list;
+       tcf_chain_head_change_t *chain_head_change;
+       void *chain_head_change_priv;
+};
+
 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
                                          u32 chain_index)
 {
@@ -187,6 +193,7 @@ static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
        chain = kzalloc(sizeof(*chain), GFP_KERNEL);
        if (!chain)
                return NULL;
+       INIT_LIST_HEAD(&chain->filter_chain_list);
        list_add_tail(&chain->list, &block->chain_list);
        chain->block = block;
        chain->index = chain_index;
@@ -194,12 +201,19 @@ static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
        return chain;
 }
 
+static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
+                                      struct tcf_proto *tp_head)
+{
+       if (item->chain_head_change)
+               item->chain_head_change(tp_head, item->chain_head_change_priv);
+}
 static void tcf_chain_head_change(struct tcf_chain *chain,
                                  struct tcf_proto *tp_head)
 {
-       if (chain->chain_head_change)
-               chain->chain_head_change(tp_head,
-                                        chain->chain_head_change_priv);
+       struct tcf_filter_chain_list_item *item;
+
+       list_for_each_entry(item, &chain->filter_chain_list, list)
+               tcf_chain_head_change_item(item, tp_head);
 }
 
 static void tcf_chain_flush(struct tcf_chain *chain)
@@ -280,6 +294,50 @@ static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
        tcf_block_offload_cmd(block, q, ei, TC_BLOCK_UNBIND);
 }
 
+static int
+tcf_chain_head_change_cb_add(struct tcf_chain *chain,
+                            struct tcf_block_ext_info *ei,
+                            struct netlink_ext_ack *extack)
+{
+       struct tcf_filter_chain_list_item *item;
+
+       item = kmalloc(sizeof(*item), GFP_KERNEL);
+       if (!item) {
+               NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
+               return -ENOMEM;
+       }
+       item->chain_head_change = ei->chain_head_change;
+       item->chain_head_change_priv = ei->chain_head_change_priv;
+       if (chain->filter_chain)
+               tcf_chain_head_change_item(item, chain->filter_chain);
+       list_add(&item->list, &chain->filter_chain_list);
+       return 0;
+}
+
+static void
+tcf_chain_head_change_cb_del(struct tcf_chain *chain,
+                            struct tcf_block_ext_info *ei)
+{
+       struct tcf_filter_chain_list_item *item;
+
+       list_for_each_entry(item, &chain->filter_chain_list, list) {
+               if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
+                   (item->chain_head_change == ei->chain_head_change &&
+                    item->chain_head_change_priv == ei->chain_head_change_priv)) {
+                       tcf_chain_head_change_item(item, NULL);
+                       list_del(&item->list);
+                       kfree(item);
+                       return;
+               }
+       }
+       WARN_ON(1);
+}
+
+static struct tcf_chain *tcf_block_chain_zero(struct tcf_block *block)
+{
+       return list_first_entry(&block->chain_list, struct tcf_chain, list);
+}
+
 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                      struct tcf_block_ext_info *ei,
                      struct netlink_ext_ack *extack)
@@ -302,9 +360,10 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
                err = -ENOMEM;
                goto err_chain_create;
        }
-       WARN_ON(!ei->chain_head_change);
-       chain->chain_head_change = ei->chain_head_change;
-       chain->chain_head_change_priv = ei->chain_head_change_priv;
+       err = tcf_chain_head_change_cb_add(tcf_block_chain_zero(block),
+                                          ei, extack);
+       if (err)
+               goto err_chain_head_change_cb_add;
        block->net = qdisc_net(q);
        block->q = q;
        tcf_block_offload_bind(block, q, ei);
@@ -313,6 +372,8 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
 
 err_chain_create:
        kfree(block);
+err_chain_head_change_cb_add:
+       kfree(chain);
        return err;
 }
 EXPORT_SYMBOL(tcf_block_get_ext);
@@ -351,6 +412,7 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
         */
        if (!block)
                return;
+       tcf_chain_head_change_cb_del(tcf_block_chain_zero(block), ei);
        list_for_each_entry(chain, &block->chain_list, list)
                tcf_chain_hold(chain);
 
@@ -364,8 +426,7 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
                tcf_chain_put(chain);
 
        /* Finally, put chain 0 and allow block to be freed. */
-       chain = list_first_entry(&block->chain_list, struct tcf_chain, list);
-       tcf_chain_put(chain);
+       tcf_chain_put(tcf_block_chain_zero(block));
 }
 EXPORT_SYMBOL(tcf_block_put_ext);