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Commit 4749c3ef authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

net: sched: remove TC_MUNGED bits 



Not used.

pedit sets TC_MUNGED when packet content was altered, but all the core
does is unset MUNGED again and then set OK2MUNGE.

And the latter isn't tested anywhere. So lets remove both
TC_MUNGED and TC_OK2MUNGE.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7eee8cd4

Documentation/networking/tc-actions-env-rules.txt

+0 −2
Original line number Diff line number Diff line
@@ -14,8 +14,6 @@ resets them for you, so invoke skb_act_clone() rather than skb_clone(). 


2) If you munge any packet thou shalt call pskb_expand_head in the case

someone else is referencing the skb. After that you "own" the skb.

You must also tell us if it is ok to munge the packet (TC_OK2MUNGE),

this way any action downstream can stomp on the packet.



3) Dropping packets you don't own is a no-no. You simply return

TC_ACT_SHOT to the caller and they will drop it.

include/net/sch_generic.h

+0 −2
Original line number Diff line number Diff line
@@ -755,8 +755,6 @@ static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask, 


	if (n) {

		n->tc_verd = SET_TC_VERD(n->tc_verd, 0);

		n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);

		n->tc_verd = CLR_TC_MUNGED(n->tc_verd);

	}

	return n;

}

include/uapi/linux/pkt_cls.h

+3 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ bits 9,10,11: redirect counter - redirect TTL. Loop avoidance 
 *

 * */



#ifndef __KERNEL__

/* backwards compat for userspace only */

#define TC_MUNGED          _TC_MAKEMASK1(0)

#define SET_TC_MUNGED(v)   ( TC_MUNGED | (v & ~TC_MUNGED))

#define CLR_TC_MUNGED(v)   ( v & ~TC_MUNGED)
@@ -42,6 +44,7 @@ bits 9,10,11: redirect counter - redirect TTL. Loop avoidance 
#define TC_OK2MUNGE        _TC_MAKEMASK1(1)

#define SET_TC_OK2MUNGE(v)   ( TC_OK2MUNGE | (v & ~TC_OK2MUNGE))

#define CLR_TC_OK2MUNGE(v)   ( v & ~TC_OK2MUNGE)

#endif



#define S_TC_VERD          _TC_MAKE32(2)

#define M_TC_VERD          _TC_MAKEMASK(4,S_TC_VERD)

net/sched/act_api.c

+0 −5
Original line number Diff line number Diff line
@@ -392,11 +392,6 @@ int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions, 
	list_for_each_entry(a, actions, list) {

repeat:

		ret = a->ops->act(skb, a, res);

		if (TC_MUNGED & skb->tc_verd) {

			/* copied already, allow trampling */

			skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);

			skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);

		}

		if (ret == TC_ACT_REPEAT)

			goto repeat;	/* we need a ttl - JHS */

		if (ret != TC_ACT_PIPE)

net/sched/act_pedit.c

+1 −4
Original line number Diff line number Diff line
@@ -108,7 +108,7 @@ static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, 
		     struct tcf_result *res)

{

	struct tcf_pedit *p = a->priv;

	int i, munged = 0;

	int i;

	unsigned int off;



	if (skb_unclone(skb, GFP_ATOMIC))
@@ -156,11 +156,8 @@ static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, 
			*ptr = ((*ptr & tkey->mask) ^ tkey->val);

			if (ptr == &_data)

				skb_store_bits(skb, off + offset, ptr, 4);

			munged++;

		}



		if (munged)

			skb->tc_verd = SET_TC_MUNGED(skb->tc_verd);

		goto done;

	} else

		WARN(1, "pedit BUG: index %d\n", p->tcf_index);