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

From: Varun Chandramohan <[email-masked]>
Date: Fri, 21 Sep 2007 10:00:35 +0530

Krishna Kumar2 wrote:
> Varun Chandramohan <[email-masked]> 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