Commit 129e406e authored by Kui-Feng Lee's avatar Kui-Feng Lee Committed by David S. Miller
Browse files

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: default avatarDavid Ahern <dsahern@kernel.org>
Reviewed-by: default avatarHangbin Liu <liuhangbin@gmail.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarKui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9c52994e

include/net/ip6_route.h

+2 −1
Original line number Diff line number Diff line
@@ -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);

net/ipv6/ndisc.c

+2 −1
Original line number Diff line number Diff line
@@ -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",

net/ipv6/route.c

+3 −1
Original line number Diff line number Diff line
@@ -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;