net: sched: add termination action to allow goto chain

Introduce new type of termination action called "goto_chain". This allows
user to specify a chain to be processed. This action type is
then processed as a return value in tcf_classify loop in similar
way as "reclassify" is, only it does not reset to the first filter
in chain but rather reset to the first filter of the desired chain.

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

diff --git a/include/net/act_api.h b/include/net/act_api.h
index b22c6f3d6710bf6092e08fbe8f24ed6d71e50f53..26ffd8333f50fc6406e42c3536646a34df428f56 100644 (file)
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -42,6 +42,7 @@ struct tc_action {
        struct gnet_stats_basic_cpu __percpu *cpu_bstats;
        struct gnet_stats_queue __percpu *cpu_qstats;
        struct tc_cookie        *act_cookie;
+       struct tcf_chain        *goto_chain;
 };
 #define tcf_head       common.tcfa_head
 #define tcf_index      common.tcfa_index

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 569b5654c30c34b2a8032ccc7efa02ca3736fcf3..368850194c94bd751750c40194efd262f10015c0 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -193,8 +193,13 @@ struct Qdisc_ops {
 
 
 struct tcf_result {
-       unsigned long   class;
-       u32             classid;
+       union {
+               struct {
+                       unsigned long   class;
+                       u32             classid;
+               };
+               const struct tcf_proto *goto_tp;
+       };
 };
 
 struct tcf_proto_ops {

diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index d613be3b3239e476d728ffa323347ef42e97eaec..1b9aa9e6b4fd0289436fd6a4288f8d5f9d2121c4 100644 (file)
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h
@@ -51,6 +51,7 @@ enum {
        (((combined) & (~TC_ACT_EXT_VAL_MASK)) == opcode)
 
 #define TC_ACT_JUMP __TC_ACT_EXT(1)
+#define TC_ACT_GOTO_CHAIN __TC_ACT_EXT(2)
 
 /* Action type identifiers*/
 enum {

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index e389eb45b484fbdbf08fe61e9279f68b53c52607..0ecf2a858767a768f00ce08f30fb57f0a6dc50c2 100644 (file)
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -28,6 +28,31 @@
 #include <net/act_api.h>
 #include <net/netlink.h>
 
+static int tcf_action_goto_chain_init(struct tc_action *a, struct tcf_proto *tp)
+{
+       u32 chain_index = a->tcfa_action & TC_ACT_EXT_VAL_MASK;
+
+       if (!tp)
+               return -EINVAL;
+       a->goto_chain = tcf_chain_get(tp->chain->block, chain_index);
+       if (!a->goto_chain)
+               return -ENOMEM;
+       return 0;
+}
+
+static void tcf_action_goto_chain_fini(struct tc_action *a)
+{
+       tcf_chain_put(a->goto_chain);
+}
+
+static void tcf_action_goto_chain_exec(const struct tc_action *a,
+                                      struct tcf_result *res)
+{
+       const struct tcf_chain *chain = a->goto_chain;
+
+       res->goto_tp = rcu_dereference_bh(chain->filter_chain);
+}
+
 static void free_tcf(struct rcu_head *head)
 {
        struct tc_action *p = container_of(head, struct tc_action, tcfa_rcu);
@@ -39,6 +64,8 @@ static void free_tcf(struct rcu_head *head)
                kfree(p->act_cookie->data);
                kfree(p->act_cookie);
        }
+       if (p->goto_chain)
+               tcf_action_goto_chain_fini(p);
 
        kfree(p);
 }
@@ -465,6 +492,8 @@ repeat:
                                else /* faulty graph, stop pipeline */
                                        return TC_ACT_OK;
                        }
+               } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
+                       tcf_action_goto_chain_exec(a, res);
                }
 
                if (ret != TC_ACT_PIPE)
@@ -657,6 +686,17 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
        if (err != ACT_P_CREATED)
                module_put(a_o->owner);
 
+       if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN)) {
+               err = tcf_action_goto_chain_init(a, tp);
+               if (err) {
+                       LIST_HEAD(actions);
+
+                       list_add_tail(&a->list, &actions);
+                       tcf_action_destroy(&actions, bind);
+                       return ERR_PTR(err);
+               }
+       }
+
        return a;
 
 err_mod:

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 9e0c4bb82528ba34c1a7324f9ecaa2202f7f08fe..4020b8d932a1a6dfac9a856dc8d5b53adb0645d6 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -307,8 +307,12 @@ reclassify:
 
                err = tp->classify(skb, tp, res);
 #ifdef CONFIG_NET_CLS_ACT
-               if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode))
+               if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
                        goto reset;
+               } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
+                       old_tp = res->goto_tp;
+                       goto reset;
+               }
 #endif
                if (err >= 0)
                        return err;