Commit 859844e5 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'net-ipv6-Address-checks-need-to-consider-the-L3-domain' 



David Ahern says:

====================
net/ipv6: Address checks need to consider the L3 domain

IPv6 prohibits a local address from being used as a gateway for a route.
However, it is ok for the gateway to be a local address in a different L3
domain (e.g., VRF). This allows, for example, veth pairs to connect VRFs.

ip6_route_info_create calls ipv6_chk_addr_and_flags for gateway addresses
to determine if the address is a local one, but ipv6_chk_addr_and_flags
does not currently consider L3 domains. As a result routes can not be
added in one VRF with a nexthop that points to a local address in a
second VRF.

Resolve by comparing the l3mdev for the passed in device and requiring an
l3mdev match with the device containing an address. The intent of checking
for an address on the specified device versus any device in the domain is
mantained by a new argument to skip the check between the passed in device
and the device with the address.

Patch 1 moves the gateway validation from ip6_route_info_create into a
helper; the function is long enough and refactoring drops the indent
level.

Patch 2 adds a skip_dev_check argument to ipv6_chk_addr_and_flags to
allow a device to always be passed yet skip the device check when
looking at addresses and fixes up a few ipv6_chk_addr callers that
pass a NULL device.

Patch 3 adds l3mdev checks to ipv6_chk_addr_and_flags.

Patches 4 and 5 do some refactoring to the fib_tests script and then
patch 6 adds nexthop validation tests.

v4
- separated l3mdev check into a separate patch (patch 3 of this set)
  as suggested by Kirill
- consolidated dev and ipv6_chk_addr_and_flags call into 1 if (Kirill)
- added a temp variable for gw type (Kirill)

v3
- set skip_dev_check in ipv6_chk_addr based on dev == NULL (per
  comment from Ido)

v2
- handle 2 variations of route spec with sane error path
- add test cases
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 1ad2ff02 654d3a78

include/net/addrconf.h

+2 −2
Original line number Diff line number Diff line
@@ -69,8 +69,8 @@ int addrconf_set_dstaddr(struct net *net, void __user *arg); 
int ipv6_chk_addr(struct net *net, const struct in6_addr *addr,

		  const struct net_device *dev, int strict);

int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,

			    const struct net_device *dev, int strict,

			    u32 banned_flags);

			    const struct net_device *dev, bool skip_dev_check,

			    int strict, u32 banned_flags);



#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)

int ipv6_chk_home_addr(struct net *net, const struct in6_addr *addr);

net/ipv6/addrconf.c

+23 −3
Original line number Diff line number Diff line
@@ -1851,22 +1851,42 @@ static int ipv6_count_addresses(const struct inet6_dev *idev) 
int ipv6_chk_addr(struct net *net, const struct in6_addr *addr,

		  const struct net_device *dev, int strict)

{

	return ipv6_chk_addr_and_flags(net, addr, dev, strict, IFA_F_TENTATIVE);

	return ipv6_chk_addr_and_flags(net, addr, dev, !dev,

				       strict, IFA_F_TENTATIVE);

}

EXPORT_SYMBOL(ipv6_chk_addr);



/* device argument is used to find the L3 domain of interest. If

 * skip_dev_check is set, then the ifp device is not checked against

 * the passed in dev argument. So the 2 cases for addresses checks are:

 *   1. does the address exist in the L3 domain that dev is part of

 *      (skip_dev_check = true), or

 *

 *   2. does the address exist on the specific device

 *      (skip_dev_check = false)

 */

int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,

			    const struct net_device *dev, int strict,

			    u32 banned_flags)

			    const struct net_device *dev, bool skip_dev_check,

			    int strict, u32 banned_flags)

{

	unsigned int hash = inet6_addr_hash(net, addr);

	const struct net_device *l3mdev;

	struct inet6_ifaddr *ifp;

	u32 ifp_flags;



	rcu_read_lock();



	l3mdev = l3mdev_master_dev_rcu(dev);

	if (skip_dev_check)

		dev = NULL;



	hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {

		if (!net_eq(dev_net(ifp->idev->dev), net))

			continue;



		if (l3mdev_master_dev_rcu(ifp->idev->dev) != l3mdev)

			continue;



		/* Decouple optimistic from tentative for evaluation here.

		 * Ban optimistic addresses explicitly, when required.

		 */

net/ipv6/anycast.c

+6 −3
Original line number Diff line number Diff line
@@ -66,7 +66,11 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr) 
		return -EPERM;

	if (ipv6_addr_is_multicast(addr))

		return -EINVAL;

	if (ipv6_chk_addr(net, addr, NULL, 0))



	if (ifindex)

		dev = __dev_get_by_index(net, ifindex);



	if (ipv6_chk_addr_and_flags(net, addr, dev, true, 0, IFA_F_TENTATIVE))

		return -EINVAL;



	pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
@@ -90,8 +94,7 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr) 
			dev = __dev_get_by_flags(net, IFF_UP,

						 IFF_UP | IFF_LOOPBACK);

		}

	} else

		dev = __dev_get_by_index(net, ifindex);

	}



	if (!dev) {

		err = -ENODEV;

net/ipv6/datagram.c

+3 −2
Original line number Diff line number Diff line
@@ -801,8 +801,9 @@ int ip6_datagram_send_ctl(struct net *net, struct sock *sk, 
			if (addr_type != IPV6_ADDR_ANY) {

				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;

				if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&

				    !ipv6_chk_addr(net, &src_info->ipi6_addr,

						   strict ? dev : NULL, 0) &&

				    !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,

							     dev, !strict, 0,

							     IFA_F_TENTATIVE) &&

				    !ipv6_chk_acast_addr_src(net, dev,

							     &src_info->ipi6_addr))

					err = -EINVAL;

net/ipv6/ip6_tunnel.c

+8 −4
Original line number Diff line number Diff line
@@ -758,9 +758,11 @@ int ip6_tnl_rcv_ctl(struct ip6_tnl *t, 
			ldev = dev_get_by_index_rcu(net, p->link);



		if ((ipv6_addr_is_multicast(laddr) ||

		     likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&

		     likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,

						    0, IFA_F_TENTATIVE))) &&

		    ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||

		     likely(!ipv6_chk_addr(net, raddr, NULL, 0))))

		     likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,

						     0, IFA_F_TENTATIVE))))

			ret = 1;

	}

	return ret;
@@ -990,12 +992,14 @@ int ip6_tnl_xmit_ctl(struct ip6_tnl *t, 
		if (p->link)

			ldev = dev_get_by_index_rcu(net, p->link);



		if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))

		if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,

						      0, IFA_F_TENTATIVE)))

			pr_warn("%s xmit: Local address not yet configured!\n",

				p->name);

		else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&

			 !ipv6_addr_is_multicast(raddr) &&

			 unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))

			 unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,

							  true, 0, IFA_F_TENTATIVE)))

			pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",

				p->name);

		else

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