diff mbox

PATCH: ipv6: avoid wraparound for expired lifetimes

Message ID 20090625073943.GO21357@jayr.de
State Rejected, archived
Delegated to: David Miller
Headers show

Commit Message

Jens Rosenboom June 25, 2009, 7:39 a.m. UTC 
If the valid or preferred lifetime for an address expires, the kernel
shows huge values for these due to a counter wrap, the following patch
should fix this, at least it did in the test I ran.

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Comments

Ilpo Järvinen June 25, 2009, 8:40 a.m. UTC | #1 
On Thu, 25 Jun 2009, Jens Rosenboom wrote:

> If the valid or preferred lifetime for an address expires, the kernel
> shows huge values for these due to a counter wrap,

I suspect we have plenty of potentially counter-wrapped printouts all 
around the kernel. So you're fixing just a tip of the iceberg.

> the following patch
> should fix this, at least it did in the test I ran.

You must be kidding...

> --- linux-2.6.30.orig/net/ipv6/addrconf.c	2009-06-10 05:05:27.000000000 +0200
> +++ linux-2.6.30/net/ipv6/addrconf.c	2009-06-25 09:33:38.000000000 +0200
> @@ -3361,9 +3361,17 @@
>  		valid = ifa->valid_lft;
>  		if (preferred != INFINITY_LIFE_TIME) {
>  			long tval = (jiffies - ifa->tstamp)/HZ;
> -			preferred -= tval;
> -			if (valid != INFINITY_LIFE_TIME)
> -				valid -= tval;
> +			if (preferred > tval) {
> +				preferred -= tval;
> +			} else {
> +				preferred = 0;
> +			}
> +			if (valid != INFINITY_LIFE_TIME) {
> +				if (valid > tval) {
> +					valid -= tval;
> +				} else {
> +					valid = 0;
> +				}
>  		}

...because of the brace that is missing here, I get:

ijjarvin@pointhope:~/linux/mainline$ make net/ipv6/addrconf.o
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  SYMLINK include/asm -> include/asm-x86
  CALL    scripts/checksyscalls.sh
  CC      net/ipv6/addrconf.o
net/ipv6/addrconf.c: In function inet6_fill_ifaddr:
net/ipv6/addrconf.c:3393: error: invalid storage class for function 
inet6_fill_ifmcaddr
net/ipv6/addrconf.c:3391: warning: ISO C90 forbids mixed declarations and 
code
net/ipv6/addrconf.c:3418: error: invalid storage class for function 
inet6_fill_ifacaddr
net/ipv6/addrconf.c:3450: error: invalid storage class for function 
inet6_dump_addr
net/ipv6/addrconf.c:3531: error: invalid storage class for function 
inet6_dump_ifaddr
net/ipv6/addrconf.c:3538: error: invalid storage class for function 
inet6_dump_ifmcaddr
net/ipv6/addrconf.c:3546: error: invalid storage class for function 
inet6_dump_ifacaddr
net/ipv6/addrconf.c:3554: error: invalid storage class for function 
inet6_rtm_getaddr
net/ipv6/addrconf.c:3604: error: invalid storage class for function 
inet6_ifa_notify
net/ipv6/addrconf.c:3629: error: invalid storage class for function 
ipv6_store_devconf
net/ipv6/addrconf.c:3674: error: invalid storage class for function 
inet6_if_nlmsg_size
net/ipv6/addrconf.c:3691: error: invalid storage class for function 
__snmp6_fill_stats
net/ipv6/addrconf.c:3706: error: invalid storage class for function 
snmp6_fill_stats
net/ipv6/addrconf.c:3719: error: invalid storage class for function 
inet6_fill_ifinfo
net/ipv6/addrconf.c:3787: error: invalid storage class for function 
inet6_dump_ifinfo
net/ipv6/addrconf.c:3840: error: invalid storage class for function 
inet6_prefix_nlmsg_size
net/ipv6/addrconf.c:3849: error: invalid storage class for function 
inet6_fill_prefix
net/ipv6/addrconf.c:3887: error: invalid storage class for function 
inet6_prefix_notify
net/ipv6/addrconf.c:3911: error: invalid storage class for function 
__ipv6_ifa_notify
net/ipv6/addrconf.c:3939: error: invalid storage class for function 
ipv6_ifa_notify
net/ipv6/addrconf.c:3951: error: invalid storage class for function 
addrconf_sysctl_forward
net/ipv6/addrconf.c:3967: error: invalid storage class for function 
addrconf_sysctl_forward_strategy
net/ipv6/addrconf.c:3999: error: invalid storage class for function 
dev_disable_change
net/ipv6/addrconf.c:4010: error: invalid storage class for function 
addrconf_disable_change
net/ipv6/addrconf.c:4030: error: invalid storage class for function 
addrconf_disable_ipv6
net/ipv6/addrconf.c:4055: error: invalid storage class for function 
addrconf_sysctl_disable
net/ipv6/addrconf.c:4081: error: initializer element is not constant
net/ipv6/addrconf.c:4081: error: (near initialization for 
addrconf_sysctl.addrconf_vars[0].proc_handler)
net/ipv6/addrconf.c:4082: error: initializer element is not constant
net/ipv6/addrconf.c:4082: error: (near initialization for 
addrconf_sysctl.addrconf_vars[0].strategy)
net/ipv6/addrconf.c:4304: error: initializer element is not constant
net/ipv6/addrconf.c:4304: error: (near initialization for 
addrconf_sysctl.addrconf_vars[26].proc_handler)
net/ipv6/addrconf.c:4323: error: invalid storage class for function 
__addrconf_sysctl_register
net/ipv6/addrconf.c:4377: error: invalid storage class for function 
__addrconf_sysctl_unregister
net/ipv6/addrconf.c:4391: error: invalid storage class for function 
addrconf_sysctl_register
net/ipv6/addrconf.c:4401: error: invalid storage class for function 
addrconf_sysctl_unregister
net/ipv6/addrconf.c:4410: error: invalid storage class for function 
addrconf_init_net
net/ipv6/addrconf.c:4461: error: invalid storage class for function 
addrconf_exit_net
net/ipv6/addrconf.c:4473: error: initializer element is not constant
net/ipv6/addrconf.c:4473: error: (near initialization for 
addrconf_ops.init)
net/ipv6/addrconf.c:4474: error: initializer element is not constant
net/ipv6/addrconf.c:4474: error: (near initialization for 
addrconf_ops.exit)
net/ipv6/addrconf.c:4486: error: non-static declaration of 
register_inet6addr_notifier follows static declaration
net/ipv6/addrconf.c:4482: error: previous definition of 
register_inet6addr_notifier was here
net/ipv6/addrconf.c:4493: error: non-static declaration of 
unregister_inet6addr_notifier follows static declaration
net/ipv6/addrconf.c:4489: error: previous definition of 
unregister_inet6addr_notifier was here
net/ipv6/addrconf.c:4601: error: expected declaration or statement at end 
of input
make[1]: *** [net/ipv6/addrconf.o] Error 1
make: *** [net/ipv6/addrconf.o] Error 2
ijjarvin@pointhope:~/linux/mainline$
David Miller June 25, 2009, 8:42 a.m. UTC | #2 
From: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>
Date: Thu, 25 Jun 2009 11:40:19 +0300 (EEST)

> On Thu, 25 Jun 2009, Jens Rosenboom wrote:
> 
>> the following patch
>> should fix this, at least it did in the test I ran.
> 
> You must be kidding...

Jens, don't even bother posting patches that fail to
build.

And if you can't get your patches straight, and the
problem is that you're sending something other than
what you actually tested, that's _MUCH_ worse.
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diff mbox

Patch

--- linux-2.6.30.orig/net/ipv6/addrconf.c	2009-06-10 05:05:27.000000000 +0200
+++ linux-2.6.30/net/ipv6/addrconf.c	2009-06-25 09:33:38.000000000 +0200
@@ -3361,9 +3361,17 @@ 
 		valid = ifa->valid_lft;
 		if (preferred != INFINITY_LIFE_TIME) {
 			long tval = (jiffies - ifa->tstamp)/HZ;
-			preferred -= tval;
-			if (valid != INFINITY_LIFE_TIME)
-				valid -= tval;
+			if (preferred > tval) {
+				preferred -= tval;
+			} else {
+				preferred = 0;
+			}
+			if (valid != INFINITY_LIFE_TIME) {
+				if (valid > tval) {
+					valid -= tval;
+				} else {
+					valid = 0;
+				}
 		}
 	} else {
 		preferred = INFINITY_LIFE_TIME;