Commit 381f4dca authored by Sabrina Dubroca's avatar Sabrina Dubroca Committed by David S. Miller
Browse files

ipv6: clean up anycast when an interface is destroyed 



If we try to rmmod the driver for an interface while sockets with
setsockopt(JOIN_ANYCAST) are alive, some refcounts aren't cleaned up
and we get stuck on:

  unregister_netdevice: waiting for ens3 to become free. Usage count = 1

If we LEAVE_ANYCAST/close everything before rmmod'ing, there is no
problem.

We need to perform a cleanup similar to the one for multicast in
addrconf_ifdown(how == 1).

Signed-off-by: default avatarSabrina Dubroca <sd@queasysnail.net>
Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent dcbc0054

include/net/addrconf.h

+1 −0
Original line number Diff line number Diff line
@@ -204,6 +204,7 @@ void ipv6_sock_ac_close(struct sock *sk); 


int ipv6_dev_ac_inc(struct net_device *dev, const struct in6_addr *addr);

int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr);

void ipv6_ac_destroy_dev(struct inet6_dev *idev);

bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,

			 const struct in6_addr *addr);

bool ipv6_chk_acast_addr_src(struct net *net, struct net_device *dev,

net/ipv6/addrconf.c

+5 −3
Original line number Diff line number Diff line
@@ -3094,11 +3094,13 @@ static int addrconf_ifdown(struct net_device *dev, int how) 


	write_unlock_bh(&idev->lock);



	/* Step 5: Discard multicast list */

	if (how)

	/* Step 5: Discard anycast and multicast list */

	if (how) {

		ipv6_ac_destroy_dev(idev);

		ipv6_mc_destroy_dev(idev);

	else

	} else {

		ipv6_mc_down(idev);

	}



	idev->tstamp = jiffies;

net/ipv6/anycast.c

+21 −0
Original line number Diff line number Diff line
@@ -351,6 +351,27 @@ static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr) 
	return __ipv6_dev_ac_dec(idev, addr);

}



void ipv6_ac_destroy_dev(struct inet6_dev *idev)

{

	struct ifacaddr6 *aca;



	write_lock_bh(&idev->lock);

	while ((aca = idev->ac_list) != NULL) {

		idev->ac_list = aca->aca_next;

		write_unlock_bh(&idev->lock);



		addrconf_leave_solict(idev, &aca->aca_addr);



		dst_hold(&aca->aca_rt->dst);

		ip6_del_rt(aca->aca_rt);



		aca_put(aca);



		write_lock_bh(&idev->lock);

	}

	write_unlock_bh(&idev->lock);

}



/*

 *	check if the interface has this anycast address

 *	called with rcu_read_lock()

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