[PATCH net-next V2 3/5] net_sched: flower: Avoid dissection of unmasked keys
From: Hadar Hen Zion <hidden>
Date: 2016-08-17 10:37:59
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
The current flower implementation checks the mask range and set all the
keys included in that range as "used_keys", even if a specific key in
the range has a zero mask.
This behavior can cause a false positive return value of
dissector_uses_key function and unnecessary dissection in
__skb_flow_dissect.
This patch checks explicitly the mask of each key and "used_keys" will
be set accordingly.
Fixes: 77b9900ef53a ('tc: introduce Flower classifier')
Signed-off-by: Hadar Hen Zion <redacted>
Signed-off-by: Jiri Pirko <redacted>
---
net/sched/cls_flower.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 5060801..0080fc0 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c@@ -404,12 +404,10 @@ static int fl_init_hashtable(struct cls_fl_head *head, #define FL_KEY_MEMBER_OFFSET(member) offsetof(struct fl_flow_key, member) #define FL_KEY_MEMBER_SIZE(member) (sizeof(((struct fl_flow_key *) 0)->member)) -#define FL_KEY_MEMBER_END_OFFSET(member) \ - (FL_KEY_MEMBER_OFFSET(member) + FL_KEY_MEMBER_SIZE(member)) -#define FL_KEY_IN_RANGE(mask, member) \ - (FL_KEY_MEMBER_OFFSET(member) <= (mask)->range.end && \ - FL_KEY_MEMBER_END_OFFSET(member) >= (mask)->range.start) +#define FL_KEY_IS_MASKED(mask, member) \ + memchr_inv(((char *)mask) + FL_KEY_MEMBER_OFFSET(member), \ + 0, FL_KEY_MEMBER_SIZE(member)) \ #define FL_KEY_SET(keys, cnt, id, member) \ do { \
@@ -418,9 +416,9 @@ static int fl_init_hashtable(struct cls_fl_head *head, cnt++; \ } while(0); -#define FL_KEY_SET_IF_IN_RANGE(mask, keys, cnt, id, member) \ +#define FL_KEY_SET_IF_MASKED(mask, keys, cnt, id, member) \ do { \ - if (FL_KEY_IN_RANGE(mask, member)) \ + if (FL_KEY_IS_MASKED(mask, member)) \ FL_KEY_SET(keys, cnt, id, member); \ } while(0);
@@ -432,14 +430,14 @@ static void fl_init_dissector(struct cls_fl_head *head, FL_KEY_SET(keys, cnt, FLOW_DISSECTOR_KEY_CONTROL, control); FL_KEY_SET(keys, cnt, FLOW_DISSECTOR_KEY_BASIC, basic); - FL_KEY_SET_IF_IN_RANGE(mask, keys, cnt, - FLOW_DISSECTOR_KEY_ETH_ADDRS, eth); - FL_KEY_SET_IF_IN_RANGE(mask, keys, cnt, - FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4); - FL_KEY_SET_IF_IN_RANGE(mask, keys, cnt, - FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6); - FL_KEY_SET_IF_IN_RANGE(mask, keys, cnt, - FLOW_DISSECTOR_KEY_PORTS, tp); + FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt, + FLOW_DISSECTOR_KEY_ETH_ADDRS, eth); + FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt, + FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4); + FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt, + FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6); + FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt, + FLOW_DISSECTOR_KEY_PORTS, tp); skb_flow_dissector_init(&head->dissector, keys, cnt); }
--
1.8.3.1