Re: Fwd: [PATCH] nf_nat_core: eliminate find_appropriate_src call if range is set IP_NAT_RANGE_PROTO_RANDOM bit on

["Changli Gao" <xiaosuo@gmail.com>]

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The attachment is the patch.

On Mon, Jul 7, 2008 at 7:24 PM, Patrick McHardy <kaber@trash.net> wrote:
> Changli Gao wrote:
>>
>> On Mon, Jun 30, 2008 at 8:54 PM, Patrick McHardy <kaber@trash.net> wrote:
>>>
>>> Changli Gao wrote:
>>>>
>>>> ---------- Forwarded message ----------
>>>> From: Changli Gao <xiaosuo@gmail.com>
>>>> Date: 2008/6/30
>>>> Subject: [PATCH] nf_nat_core: eliminate find_appropriate_src call if
>>>> range is set IP_NAT_RANGE_PROTO_RANDOM bit on
>>>> To: netfilter-devel@lists.netfilter.org
>>>> Cc: Changli Gao <xiaosuo@gmail.com>
>>>>
>>>>
>>>> Eliminate find_appropriate_src call if range is set
>>>> IP_NAT_RANGE_PROTO_RANDOM bit on.
>>>
>>> Please explain why the call isn't necessary.
>>>
>> In fact, my patch doesn't change the logic of the code, it just
>> eliminates the uesless call find_appropriate_src. Because the tuple
>> returned by find_appropriate is only useful when the
>> IP_NAT_RANGE_PROTO_RANDOM isn't set on.  instead of testing the bit
>> IP_NAT_RANGE_PROTO_RANDOM after calling find_appropriate_src, I do
>> that before it to eliminate the cost of calling find_appropriate_src.
>
> OK, but it does not apply cleanly because of whitespace mangling.
> Please resend as attachment.
>



-- 
Regards，
Changli Gao(xiaosuo@gmail.com)

[-- Attachment #2: nf_nat_core_opt.diff --]
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--- linux/net/ipv4/netfilter/nf_nat_core.c	2008-06-30 11:12:26.000000000 +0800
+++ linux-new/net/ipv4/netfilter/nf_nat_core.c	2008-06-30 12:22:23.000000000 +0800
@@ -240,12 +240,12 @@
 	   This is only required for source (ie. NAT/masq) mappings.
 	   So far, we don't do local source mappings, so multiple
 	   manips not an issue.  */
-	if (maniptype == IP_NAT_MANIP_SRC) {
+	if (maniptype == IP_NAT_MANIP_SRC &&
+	    !(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) {
 		if (find_appropriate_src(orig_tuple, tuple, range)) {
 			pr_debug("get_unique_tuple: Found current src map\n");
-			if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM))
-				if (!nf_nat_used_tuple(tuple, ct))
-					return;
+			if (!nf_nat_used_tuple(tuple, ct))
+				return;
 		}
 	}