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authorFlorian Westphal <fw@strlen.de>2011-12-16 18:35:15 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2011-12-23 14:50:19 +0100
commit0354b48f633ae435acbc01b470a1ce8cfeff3e9f (patch)
tree48a2b84c4298194cd51a55b89b7c9cb2714c0840
parent3f1e6d3fd37bd4f25e5b19f1c7ca21850426c33f (diff)
downloadlinux-linaro-0354b48f633ae435acbc01b470a1ce8cfeff3e9f.tar.gz
netfilter: xt_connbytes: handle negation correctly
"! --connbytes 23:42" should match if the packet/byte count is not in range. As there is no explict "invert match" toggle in the match structure, userspace swaps the from and to arguments (i.e., as if "--connbytes 42:23" were given). However, "what <= 23 && what >= 42" will always be false. Change things so we use "||" in case "from" is larger than "to". This change may look like it breaks backwards compatibility when "to" is 0. However, older iptables binaries will refuse "connbytes 42:0", and current releases treat it to mean "! --connbytes 0:42", so we should be fine. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r--net/netfilter/xt_connbytes.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/net/netfilter/xt_connbytes.c b/net/netfilter/xt_connbytes.c
index 5b138506690..9ddf1c3bfb3 100644
--- a/net/netfilter/xt_connbytes.c
+++ b/net/netfilter/xt_connbytes.c
@@ -87,10 +87,10 @@ connbytes_mt(const struct sk_buff *skb, struct xt_action_param *par)
break;
}
- if (sinfo->count.to)
+ if (sinfo->count.to >= sinfo->count.from)
return what <= sinfo->count.to && what >= sinfo->count.from;
- else
- return what >= sinfo->count.from;
+ else /* inverted */
+ return what < sinfo->count.to || what > sinfo->count.from;
}
static int connbytes_mt_check(const struct xt_mtchk_param *par)