[PATCH 3/3 Rev4] Initialize and fill IPv6 route age

[PATCH 3/3 Rev4] Initialize and fill IPv6 route age

[Varun Chandramohan]

The age field of the ipv6 route structures are initilized with the current timeval at the time of route
creation. When the route dump is called the route age value stored in the structure is subtracted from the
present timeval and the difference is passed on as the route age.

Signed-off-by: Varun Chandramohan <varunc@linux.vnet.ibm.com>
---
 include/net/ip6_fib.h |    1 +
 net/ipv6/addrconf.c   |    5 +++++
 net/ipv6/route.c      |   14 ++++++++++++++
 3 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index c48ea87..e30a1cf 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -98,6 +98,7 @@ struct rt6_info
 	
 	u32				rt6i_flags;
 	u32				rt6i_metric;
+	time_t				rt6i_age;
 	atomic_t			rt6i_ref;
 	struct fib6_table		*rt6i_table;
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 91ef3be..e77c6ad 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4182,6 +4182,7 @@ EXPORT_SYMBOL(unregister_inet6addr_notif
 
 int __init addrconf_init(void)
 {
+	struct timeval tv;
 	int err = 0;
 
 	/* The addrconf netdev notifier requires that loopback_dev
@@ -4209,10 +4210,14 @@ int __init addrconf_init(void)
 	if (err)
 		return err;
 
+	do_gettimeofday(&tv);
 	ip6_null_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+	ip6_null_entry.rt6i_age = tv.tv_sec;
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 	ip6_prohibit_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+	ip6_prohibit_entry.rt6i_age = tv.tv_sec;
 	ip6_blk_hole_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+	ip6_blk_hole_entry.rt6i_age = tv.tv_sec;
 #endif
 
 	register_netdevice_notifier(&ipv6_dev_notf);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 55ea80f..e9a9d00 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -600,7 +600,14 @@ static int __ip6_ins_rt(struct rt6_info
 {
 	int err;
 	struct fib6_table *table;
+	struct timeval tv;
 
+	do_gettimeofday(&tv);
+	/* Update the timeval for new routes
+	 * We add it here to make it common irrespective
+	 * of how the new route is added.
+	 */
+	rt->rt6i_age = tv.tv_sec;
 	table = rt->rt6i_table;
 	write_lock_bh(&table->tb6_lock);
 	err = fib6_add(&table->tb6_root, rt, info);
@@ -2112,6 +2119,7 @@ static inline size_t rt6_nlmsg_size(void
 	       + nla_total_size(4) /* RTA_IIF */
 	       + nla_total_size(4) /* RTA_OIF */
 	       + nla_total_size(4) /* RTA_PRIORITY */
+	       + nla_total_size(4) /*RTA_AGE*/
 	       + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
 	       + nla_total_size(sizeof(struct rta_cacheinfo));
 }
@@ -2123,6 +2131,7 @@ static int rt6_fill_node(struct sk_buff
 {
 	struct rtmsg *rtm;
 	struct nlmsghdr *nlh;
+	struct timeval tv;
 	long expires;
 	u32 table;
 
@@ -2186,6 +2195,11 @@ static int rt6_fill_node(struct sk_buff
 		if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0)
 			NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
 	}
+	
+	do_gettimeofday(&tv);
+	if (rt->rt6i_age) {
+		NLA_PUT_U32(skb, RTA_AGE, (tv.tv_sec - rt->rt6i_age));
+	}
 
 	if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
 		goto nla_put_failure;
-- 
1.4.3.4

Re: [PATCH 3/3 Rev4] Initialize and fill IPv6 route age

[Krishna Kumar2]

Varun Chandramohan <varunc@linux.vnet.ibm.com> wrote on 09/20/2007 08:59:03
PM:

> @@ -2123,6 +2131,7 @@ static int rt6_fill_node(struct sk_buff
>  {
>     struct rtmsg *rtm;
>     struct nlmsghdr *nlh;
> +   struct timeval tv;
>     long expires;
>     u32 table;
>
> @@ -2186,6 +2195,11 @@ static int rt6_fill_node(struct sk_buff
>        if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0)
>           NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
>     }
> +
> +   do_gettimeofday(&tv);
> +   if (rt->rt6i_age) {
> +      NLA_PUT_U32(skb, RTA_AGE, (tv.tv_sec - rt->rt6i_age));
> +   }

Will rt6i_age ever be zero with this new patch? If it can be zero,
the code should really be keeping the "tv" declaration and
do_gettimeofday() inside the "if (rt->rt6i_age)" check.

And from your Patch2/3:

int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
-                          u32 tb_id, u8 type, u8 scope, __be32 dst, int
dst_len, u8 tos,
+                          u32 tb_id, u8 type, u8 scope, __be32 dst, int
dst_len, u8 tos, time_t age,
                           struct fib_info *fi, unsigned int flags)
 {
             struct nlmsghdr *nlh;
             struct rtmsg *rtm;
+            struct timeval tv;

             nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags);
             if (nlh == NULL)
@@ -985,6 +987,11 @@ int fib_dump_info(struct sk_buff *skb, u
                                     NLA_PUT_U32(skb, RTA_FLOW,
fi->fib_nh[0].nh_tclassid);
 #endif
             }
+
+            do_gettimeofday(&tv);
+            if (age) {
+                        NLA_PUT_U32(skb, RTA_AGE, (tv.tv_sec - age));
+            }

Don't you want to return time the first time (and get zero)? Otherwise
RTA_AGE is not returned to user. Something like:

            do_gettimeofday(&tv);
            NLA_PUT_U32(skb, RTA_AGE, (tv.tv_sec - age));

Once again, can age ever be zero?

- KK

Re: [PATCH 3/3 Rev4] Initialize and fill IPv6 route age

[Varun Chandramohan]

Krishna Kumar2 wrote:
> Varun Chandramohan <varunc@linux.vnet.ibm.com> wrote on 09/20/2007 08:59:03
> PM:
>
>   
>> @@ -2123,6 +2131,7 @@ static int rt6_fill_node(struct sk_buff
>>  {
>>     struct rtmsg *rtm;
>>     struct nlmsghdr *nlh;
>> +   struct timeval tv;
>>     long expires;
>>     u32 table;
>>
>> @@ -2186,6 +2195,11 @@ static int rt6_fill_node(struct sk_buff
>>        if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0)
>>           NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
>>     }
>> +
>> +   do_gettimeofday(&tv);
>> +   if (rt->rt6i_age) {
>> +      NLA_PUT_U32(skb, RTA_AGE, (tv.tv_sec - rt->rt6i_age));
>> +   }
>>     
>
> Will rt6i_age ever be zero with this new patch? If it can be zero,
> the code should really be keeping the "tv" declaration and
> do_gettimeofday() inside the "if (rt->rt6i_age)" check.
>
>   
No, it will be zero only if some new code added doesnt initialize the
route age. I will update this change in my next patch release.
> And from your Patch2/3:
>
> int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
> -                          u32 tb_id, u8 type, u8 scope, __be32 dst, int
> dst_len, u8 tos,
> +                          u32 tb_id, u8 type, u8 scope, __be32 dst, int
> dst_len, u8 tos, time_t age,
>                            struct fib_info *fi, unsigned int flags)
>  {
>              struct nlmsghdr *nlh;
>              struct rtmsg *rtm;
> +            struct timeval tv;
>
>              nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags);
>              if (nlh == NULL)
> @@ -985,6 +987,11 @@ int fib_dump_info(struct sk_buff *skb, u
>                                      NLA_PUT_U32(skb, RTA_FLOW,
> fi->fib_nh[0].nh_tclassid);
>  #endif
>              }
> +
> +            do_gettimeofday(&tv);
> +            if (age) {
> +                        NLA_PUT_U32(skb, RTA_AGE, (tv.tv_sec - age));
> +            }
>
> Don't you want to return time the first time (and get zero)? Otherwise
> RTA_AGE is not returned to user. Something like:
>
>   
The first time it will be zero.
>             do_gettimeofday(&tv);
>             NLA_PUT_U32(skb, RTA_AGE, (tv.tv_sec - age));
>
> Once again, can age ever be zero?
>
>   
same as above.
> - KK
>
>