Commit de68dca1 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

inet: add a redirect generation id in inetpeer 



Now inetpeer is the place where we cache redirect information for ipv4
destinations, we must be able to invalidate informations when a route is
added/removed on host.

As inetpeer is not yet namespace aware, this patch adds a shared
redirect_genid, and a per inetpeer redirect_genid. This might be changed
later if inetpeer becomes ns aware.

Cache information for one inerpeer is valid as long as its
redirect_genid has the same value than global redirect_genid.

Reported-by: default avatarArkadiusz Miśkiewicz <a.miskiewicz@gmail.com>
Tested-by: default avatarArkadiusz Miśkiewicz <a.miskiewicz@gmail.com>
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0884d7aa

include/net/inetpeer.h

+1 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ struct inet_peer { 


	u32			metrics[RTAX_MAX];

	u32			rate_tokens;	/* rate limiting for ICMP */

	int			redirect_genid;

	unsigned long		rate_last;

	unsigned long		pmtu_expires;

	u32			pmtu_orig;

net/ipv4/route.c

+9 −1
Original line number Diff line number Diff line
@@ -131,6 +131,7 @@ static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 
static int ip_rt_min_pmtu __read_mostly		= 512 + 20 + 20;

static int ip_rt_min_advmss __read_mostly	= 256;

static int rt_chain_length_max __read_mostly	= 20;

static int redirect_genid;



/*

 *	Interface to generic destination cache.
@@ -837,6 +838,7 @@ static void rt_cache_invalidate(struct net *net) 


	get_random_bytes(&shuffle, sizeof(shuffle));

	atomic_add(shuffle + 1U, &net->ipv4.rt_genid);

	redirect_genid++;

}



/*
@@ -1391,8 +1393,10 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, 


				peer = rt->peer;

				if (peer) {

					if (peer->redirect_learned.a4 != new_gw) {

					if (peer->redirect_learned.a4 != new_gw ||

					    peer->redirect_genid != redirect_genid) {

						peer->redirect_learned.a4 = new_gw;

						peer->redirect_genid = redirect_genid;

						atomic_inc(&__rt_peer_genid);

					}

					check_peer_redir(&rt->dst, peer);
@@ -1701,6 +1705,8 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 
		if (peer) {

			check_peer_pmtu(dst, peer);



			if (peer->redirect_genid != redirect_genid)

				peer->redirect_learned.a4 = 0;

			if (peer->redirect_learned.a4 &&

			    peer->redirect_learned.a4 != rt->rt_gateway) {

				if (check_peer_redir(dst, peer))
@@ -1857,6 +1863,8 @@ static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4, 
		dst_init_metrics(&rt->dst, peer->metrics, false);



		check_peer_pmtu(&rt->dst, peer);

		if (peer->redirect_genid != redirect_genid)

			peer->redirect_learned.a4 = 0;

		if (peer->redirect_learned.a4 &&

		    peer->redirect_learned.a4 != rt->rt_gateway) {

			rt->rt_gateway = peer->redirect_learned.a4;

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