From 129e406e1811538c1afc9c8e97d61bb18eed3363 Mon Sep 17 00:00:00 2001 From: Kui-Feng Lee Date: Thu, 8 Feb 2024 14:06:49 -0800 Subject: [PATCH] net/ipv6: set expires in rt6_add_dflt_router(). Pass the duration of a lifetime (in seconds) to the function rt6_add_dflt_router() so that it can properly set the expiration time. The function ndisc_router_discovery() is the only one that calls rt6_add_dflt_router(), and it will later set the expiration time for the route created by rt6_add_dflt_router(). However, there is a gap of time between calling rt6_add_dflt_router() and setting the expiration time in ndisc_router_discovery(). During this period, there is a possibility that a new route may be removed from the routing table. By setting the correct expiration time in rt6_add_dflt_router(), we can prevent this from happening. The reason for setting RTF_EXPIRES in rt6_add_dflt_router() is to start the Garbage Collection (GC) timer, as it only activates when a route with RTF_EXPIRES is added to a table. Suggested-by: David Ahern Reviewed-by: Hangbin Liu Reviewed-by: David Ahern Signed-off-by: Kui-Feng Lee Signed-off-by: David S. Miller --- include/net/ip6_route.h | 3 ++- net/ipv6/ndisc.c | 3 ++- net/ipv6/route.c | 4 +++- 3 files changed, 7 insertions(+), 3 deletions(-) diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 28b065790261..52a51c69aa9d 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -170,7 +170,8 @@ struct fib6_info *rt6_get_dflt_router(struct net *net, struct fib6_info *rt6_add_dflt_router(struct net *net, const struct in6_addr *gwaddr, struct net_device *dev, unsigned int pref, - u32 defrtr_usr_metric); + u32 defrtr_usr_metric, + int lifetime); void rt6_purge_dflt_routers(struct net *net); diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index a19999b30bc0..a68462668158 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1382,7 +1382,8 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) neigh_release(neigh); rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, - skb->dev, pref, defrtr_usr_metric); + skb->dev, pref, defrtr_usr_metric, + lifetime); if (!rt) { ND_PRINTK(0, err, "RA: %s failed to add default route\n", diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 63b4c6056582..98abba8f15cd 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -4355,7 +4355,8 @@ struct fib6_info *rt6_add_dflt_router(struct net *net, const struct in6_addr *gwaddr, struct net_device *dev, unsigned int pref, - u32 defrtr_usr_metric) + u32 defrtr_usr_metric, + int lifetime) { struct fib6_config cfg = { .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT, @@ -4368,6 +4369,7 @@ struct fib6_info *rt6_add_dflt_router(struct net *net, .fc_nlinfo.portid = 0, .fc_nlinfo.nlh = NULL, .fc_nlinfo.nl_net = net, + .fc_expires = jiffies_to_clock_t(lifetime * HZ), }; cfg.fc_gateway = *gwaddr;