Commit c129412f authored by wenxu's avatar wenxu Committed by Jakub Kicinski
Browse files

net/sched: sch_frag: add generic packet fragment support. 



Currently kernel tc subsystem can do conntrack in cat_ct. But when several
fragment packets go through the act_ct, function tcf_ct_handle_fragments
will defrag the packets to a big one. But the last action will redirect
mirred to a device which maybe lead the reassembly big packet over the mtu
of target device.

This patch add support for a xmit hook to mirred, that gets executed before
xmiting the packet. Then, when act_ct gets loaded, it configs that hook.
The frag xmit hook maybe reused by other modules.

Signed-off-by: default avatarwenxu <wenxu@ucloud.cn>
Acked-by: default avatarCong Wang <cong.wang@bytedance.com>
Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent fa6d6399

include/net/act_api.h

+6 −0
Original line number Diff line number Diff line
@@ -239,6 +239,12 @@ int tcf_action_check_ctrlact(int action, struct tcf_proto *tp, 
			     struct netlink_ext_ack *newchain);

struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,

					 struct tcf_chain *newchain);



#ifdef CONFIG_INET

DECLARE_STATIC_KEY_FALSE(tcf_frag_xmit_count);

#endif



int tcf_dev_queue_xmit(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb));

#endif /* CONFIG_NET_CLS_ACT */



static inline void tcf_action_stats_update(struct tc_action *a, u64 bytes,

include/net/sch_generic.h

+2 −0
Original line number Diff line number Diff line
@@ -1281,4 +1281,6 @@ void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc, 
void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,

				struct tcf_block *block);



int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb));



#endif

net/sched/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 


obj-y	:= sch_generic.o sch_mq.o



obj-$(CONFIG_INET)		+= sch_frag.o

obj-$(CONFIG_NET_SCHED)		+= sch_api.o sch_blackhole.o

obj-$(CONFIG_NET_CLS)		+= cls_api.o

obj-$(CONFIG_NET_CLS_ACT)	+= act_api.o

net/sched/act_api.c

+16 −0
Original line number Diff line number Diff line
@@ -22,6 +22,22 @@ 
#include <net/act_api.h>

#include <net/netlink.h>



#ifdef CONFIG_INET

DEFINE_STATIC_KEY_FALSE(tcf_frag_xmit_count);

EXPORT_SYMBOL_GPL(tcf_frag_xmit_count);

#endif



int tcf_dev_queue_xmit(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb))

{

#ifdef CONFIG_INET

	if (static_branch_unlikely(&tcf_frag_xmit_count))

		return sch_frag_xmit_hook(skb, xmit);

#endif



	return xmit(skb);

}

EXPORT_SYMBOL_GPL(tcf_dev_queue_xmit);



static void tcf_action_goto_chain_exec(const struct tc_action *a,

				       struct tcf_result *res)

{

net/sched/act_ct.c

+3 −0
Original line number Diff line number Diff line
@@ -1541,6 +1541,8 @@ static int __init ct_init_module(void) 
	if (err)

		goto err_register;



	static_branch_inc(&tcf_frag_xmit_count);



	return 0;



err_register:
@@ -1552,6 +1554,7 @@ err_tbl_init: 


static void __exit ct_cleanup_module(void)

{

	static_branch_dec(&tcf_frag_xmit_count);

	tcf_unregister_action(&act_ct_ops, &ct_net_ops);

	tcf_ct_flow_tables_uninit();

	destroy_workqueue(act_ct_wq);

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