From 4749c3ef854e3a5d3dd3cc0ccd2dcb7e05d583bd Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 30 Apr 2015 12:12:00 +0200 Subject: [PATCH] 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 Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller --- Documentation/networking/tc-actions-env-rules.txt | 2 -- include/net/sch_generic.h | 2 -- include/uapi/linux/pkt_cls.h | 3 +++ net/sched/act_api.c | 5 ----- net/sched/act_pedit.c | 5 +---- 5 files changed, 4 insertions(+), 13 deletions(-) diff --git a/Documentation/networking/tc-actions-env-rules.txt b/Documentation/networking/tc-actions-env-rules.txt index 70d6cf608251..95c71716b2e2 100644 --- a/Documentation/networking/tc-actions-env-rules.txt +++ b/Documentation/networking/tc-actions-env-rules.txt @@ -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. diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 6d778efcfdfd..994b5a092f33 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -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; } diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h index bf08e76bf505..6810ca43a80a 100644 --- a/include/uapi/linux/pkt_cls.h +++ b/include/uapi/linux/pkt_cls.h @@ -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) diff --git a/net/sched/act_api.c b/net/sched/act_api.c index 3d43e4979f27..af427a3dbcba 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -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) diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c index 59649d588d79..17e6d6669c7f 100644 --- a/net/sched/act_pedit.c +++ b/net/sched/act_pedit.c @@ -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); -- 2.20.1