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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: Florian Westphal <fw@strlen.de>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Florian Westphal 2015-04-30 12:12:00 +02:00 committed by David S. Miller
parent 7eee8cd4d8
commit 4749c3ef85
5 changed files with 4 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/networking/tc-actions-env-rules.txt
View File

@ -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.

2
include/net/sch_generic.h
View File

@ -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;
}

3
include/uapi/linux/pkt_cls.h
View File

@ -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)

5
net/sched/act_api.c
View File

@ -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)

5
net/sched/act_pedit.c
View File

@ -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);