ip_rt_bug: 10.0.0.52 -> 255.255.255.255, ?

DISCUSSION Justin P. Mattock 2 participants 5 messages Aug 15, 2011

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Networking Network drivers IPv4/IPv6

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David Miller

maintainer

2011-08-15 05:45 UTC #1 lore raw

First, please contact [email protected] for networking issues.

Second, this is fixed already:

commit d547f727df86059104af2234804fdd538e112015

Author: Julian Anastasov <[email protected]>
Date:   Sun Aug 7 22:20:20 2011 -0700

ipv4: fix the reusing of routing cache entries

compare_keys and ip_route_input_common rely on
rt_oif for distinguishing of input and output routes with same keys values. But sometimes the input route has also same hash chain (keyed by iif != 0) with the output routes (keyed by orig_oif=0). Problem visible if running with small number of rhash_entries.

Fix them to use rt_route_iif instead. By this way
input route can not be returned to users that request output route.

The patch fixes the ip_rt_bug errors that were
reported in ip_local_out context, mostly for 255.255.255.255 destinations.

Signed-off-by Julian Anastasov <[email protected]>

Signed-off-by David S. Miller <[email protected]>

net/ipv4/route.c +2 -1

index e3dec1c..cb7efe0 100644
@@ -731,6 +731,7 @@ static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
 		((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
 		(rt1->rt_mark ^ rt2->rt_mark) |
 		(rt1->rt_key_tos ^ rt2->rt_key_tos) |
+		(rt1->rt_route_iif ^ rt2->rt_route_iif) |
 		(rt1->rt_oif ^ rt2->rt_oif) |
 		(rt1->rt_iif ^ rt2->rt_iif)) == 0;
 }

@@ -2321,8 +2322,8 @@ int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
 		     ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
 		     (rth->rt_iif ^ iif) |
-		     rth->rt_oif |
 		     (rth->rt_key_tos ^ tos)) == 0 &&
+		    rt_is_input_route(rth) &&
 		    rth->rt_mark == skb->mark &&
 		    net_eq(dev_net(rth->dst.dev), net) &&
 		    !rt_is_expired(rth)) {

Justin P. Mattock

author

2011-08-15 05:55 UTC #2 lore raw

Oh.. guess I will wait for those to be put into the Mainline then. Thanks for the info!

Quoted 54 lines

First, please contact [email protected] for networking issues.
Second, this is fixed already:
commit d547f727df86059104af2234804fdd538e112015
Author: Julian Anastasov<[email protected]>
Date:   Sun Aug 7 22:20:20 2011 -0700
ipv4: fix the reusing of routing cache entries
compare_keys and ip_route_input_common rely on
rt_oif for distinguishing of input and output routes with same keys values. But sometimes the input route has also same hash chain (keyed by iif != 0) with the output routes (keyed by orig_oif=0). Problem visible if running with small number of rhash_entries.
Fix them to use rt_route_iif instead. By this way
input route can not be returned to users that request output route.
The patch fixes the ip_rt_bug errors that were
reported in ip_local_out context, mostly for 255.255.255.255 destinations.
Signed-off-by Julian Anastasov<[email protected]>
Signed-off-by David S. Miller<[email protected]>
net/ipv4/route.c +2 -1
index e3dec1c..cb7efe0 100644
@@ -731,6 +731,7 @@ static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
  		((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
  		(rt1->rt_mark ^ rt2->rt_mark) |
  		(rt1->rt_key_tos ^ rt2->rt_key_tos) |
+		(rt1->rt_route_iif ^ rt2->rt_route_iif) |
  		(rt1->rt_oif ^ rt2->rt_oif) |
  		(rt1->rt_iif ^ rt2->rt_iif)) == 0;
  }
@@ -2321,8 +2322,8 @@ int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
  		if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
  		     ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
  		     (rth->rt_iif ^ iif) |
-		     rth->rt_oif |
  		     (rth->rt_key_tos ^ tos)) == 0&&
+		    rt_is_input_route(rth)&&
  		rth->rt_mark == skb->mark&&
  		net_eq(dev_net(rth->dst.dev), net)&&
  		!rt_is_expired(rth)) {

David Miller

maintainer

2011-08-15 05:56 UTC #3 lore raw

From: "Justin P. Mattock" <[email protected]>
Date: Sun, 14 Aug 2011 22:55:02 -0700

Quoted 2 lines

Oh.. guess I will wait for those to be put into the Mainline then. Thanks for the info!

It is in mainline.

Justin P. Mattock

author

2011-08-15 06:09 UTC #4 lore raw

Quoted 8 lines · David Miller

From: "Justin P. Mattock"<[email protected]>
Date: Sun, 14 Aug 2011 22:55:02 -0700
Quoted 2 lines
Oh.. guess I will wait for those to be put into the Mainline then. Thanks for the info!
It is in mainline.

alright.. I see it now. I pulled on thurs/fri but never went any further with the build after that. will clean and build when I get a chance and run it.

Thanks again!

Justin P. Mattock