On Fri, 2016-08-19 at 18:41 +0200, Andrew Yourtchenko wrote:
> This allows "ip -6 route save" to save the expiry for the routes
> that have it, such that it can be correctly restored later by
> "ip -6 route restore".
>
> If a route has RTF_EXPIRES set, generate RTA_EXPIRES value which
> will be used to restore the flag and expiry value by already
> existing code in rtm_to_fib6_config.
>
> The expiry was already being saved as part of RTA_CACHEINFO
> in rtnl_put_cacheinfo(), but adding code to generate RTF_EXPIRES upon save
> looked more appropriate than redundant cherrypicking from
> RTA_CACHEINFO upon restore.
>
> Signed-off-by: Andrew Yourtchenko <ayour...@gmail.com>
> ---
> Changes since v1 [1]:
> * fixed the indentation in a multiline function call
> as per David Miller's review
>
> [1] v1: http://marc.info/?l=linux-netdev&m=147135597422280&w=2
>
> net/ipv6/route.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 4981755..f5b987d 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -3244,6 +3244,14 @@ static int rt6_fill_node(struct net *net,
> if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0)
> goto nla_put_failure;
>
> + /* Can't rely on expires == 0. It is zero if no expires flag,
> + * or if the timing is precisely at expiry. So, recheck the flag.
> + */
> + if (rt->rt6i_flags & RTF_EXPIRES)
> + if (nla_put_u32(skb, RTA_EXPIRES,
> + expires > 0 ? expires / HZ : 0))
> + goto nla_put_failure;
> +
Why sending (kernel -> user) the value in second units, while the other
direction (user -> kernel) expects hz ?
iproute2$ git grep -n RTA_EXPIRES
include/linux/rtnetlink.h:389: RTA_EXPIRES,
ip/iproute.c:930: addattr32(&req.n, sizeof(req),
RTA_EXPIRES, expires*hz);
kernel patch : (32bc201e1974976b7d3fea9a9b17bb7392ca6394)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2809,6 +2810,15 @@ static int rtm_to_fib6_config(struct sk_buff *skb,
struct nlmsghdr *nlh,
if (tb[RTA_ENCAP_TYPE])
cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
+ if (tb[RTA_EXPIRES]) {
+ unsigned long timeout =
addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
+
+ if (addrconf_finite_timeout(timeout)) {
+ cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
+ cfg->fc_flags |= RTF_EXPIRES;
+ }
+ }
+
