* Increasing XT_EXTENSION_MAXNAMELEN to 32
@ 2012-09-29 15:53 Cong Wang
2012-09-29 16:46 ` Jan Engelhardt
0 siblings, 1 reply; 4+ messages in thread
From: Cong Wang @ 2012-09-29 15:53 UTC (permalink / raw)
To: netfilter-devel; +Cc: Pablo Neira Ayuso, Patrick McHardy
Hi, netfilter experts,
A customer wants to increase XT_EXTENSION_MAXNAMELEN to at least 31 (1
for '\0'), so I just increase it to 32. Do you have any comments or
objections for the following patch?
The vmlinux size increases by 768 bytes with my allyesconfig:
% size vmlinux
text data bss dec hex filename
15158877 3942208 11812864 30913949 1d7b59d vmlinux
% size vmlinux.AFTER
text data bss dec hex filename
15158877 3942976 11812864 30914717 1d7b89d vmlinux.AFTER
I know probably the user-space part needs to update too, here is just
the kernel part patch for you to review. And I only did compile test.
Thanks!
---
diff --git a/include/linux/netfilter/x_tables.h
b/include/linux/netfilter/x_tables.h
index 8d674a7..24b4dd4 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -4,7 +4,7 @@
#include <linux/types.h>
#define XT_FUNCTION_MAXNAMELEN 30
-#define XT_EXTENSION_MAXNAMELEN 29
+#define XT_EXTENSION_MAXNAMELEN 32
#define XT_TABLE_MAXNAMELEN 32
struct xt_entry_match {
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: Increasing XT_EXTENSION_MAXNAMELEN to 32
2012-09-29 15:53 Increasing XT_EXTENSION_MAXNAMELEN to 32 Cong Wang
@ 2012-09-29 16:46 ` Jan Engelhardt
2012-09-29 18:47 ` Pablo Neira Ayuso
0 siblings, 1 reply; 4+ messages in thread
From: Jan Engelhardt @ 2012-09-29 16:46 UTC (permalink / raw)
To: Cong Wang; +Cc: netfilter-devel, Pablo Neira Ayuso, Patrick McHardy
On Saturday 2012-09-29 17:53, Cong Wang wrote:
>Hi, netfilter experts,
>
>A customer wants to increase XT_EXTENSION_MAXNAMELEN to at least 31 (1
>for '\0'), so I just increase it to 32. Do you have any comments or
>objections for the following patch?
This is a no-no. You are breaking the ABI.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Increasing XT_EXTENSION_MAXNAMELEN to 32
2012-09-29 16:46 ` Jan Engelhardt
@ 2012-09-29 18:47 ` Pablo Neira Ayuso
2012-10-02 4:21 ` Cong Wang
0 siblings, 1 reply; 4+ messages in thread
From: Pablo Neira Ayuso @ 2012-09-29 18:47 UTC (permalink / raw)
To: Jan Engelhardt; +Cc: Cong Wang, netfilter-devel, Patrick McHardy
On Sat, Sep 29, 2012 at 06:46:22PM +0200, Jan Engelhardt wrote:
> On Saturday 2012-09-29 17:53, Cong Wang wrote:
>
> >Hi, netfilter experts,
> >
> >A customer wants to increase XT_EXTENSION_MAXNAMELEN to at least 31 (1
> >for '\0'), so I just increase it to 32. Do you have any comments or
> >objections for the following patch?
>
> This is a no-no. You are breaking the ABI.
Agreed. Sorry Cong, you cannot do that.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Increasing XT_EXTENSION_MAXNAMELEN to 32
2012-09-29 18:47 ` Pablo Neira Ayuso
@ 2012-10-02 4:21 ` Cong Wang
0 siblings, 0 replies; 4+ messages in thread
From: Cong Wang @ 2012-10-02 4:21 UTC (permalink / raw)
To: Pablo Neira Ayuso; +Cc: Jan Engelhardt, netfilter-devel, Patrick McHardy
On Sat, 2012-09-29 at 20:47 +0200, Pablo Neira Ayuso wrote:
> On Sat, Sep 29, 2012 at 06:46:22PM +0200, Jan Engelhardt wrote:
> > On Saturday 2012-09-29 17:53, Cong Wang wrote:
> >
> > >Hi, netfilter experts,
> > >
> > >A customer wants to increase XT_EXTENSION_MAXNAMELEN to at least 31 (1
> > >for '\0'), so I just increase it to 32. Do you have any comments or
> > >objections for the following patch?
> >
> > This is a no-no. You are breaking the ABI.
>
> Agreed. Sorry Cong, you cannot do that.
Ok, no problem.
I knew this could break user-space iptables, so there must be some other
applications relying on this ABI too, hmm... I will tell the customer
this is not possible to change.
Thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-10-02 4:21 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2012-09-29 15:53 Increasing XT_EXTENSION_MAXNAMELEN to 32 Cong Wang
2012-09-29 16:46 ` Jan Engelhardt
2012-09-29 18:47 ` Pablo Neira Ayuso
2012-10-02 4:21 ` Cong Wang
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