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Commit 9fbb704c authored by David Ahern's avatar David Ahern Committed by David S. Miller
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net/ipv6: Refactor gateway validation on route add 



Move gateway validation code from ip6_route_info_create into
ip6_validate_gw. Code move plus adjustments to handle the potential
reset of dev and idev and to make checkpatch happy.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Reviewed-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1ad2ff02

net/ipv6/route.c

+66 −54
Original line number Diff line number Diff line
@@ -2550,7 +2550,7 @@ static struct rt6_info *ip6_nh_lookup_table(struct net *net, 


static int ip6_route_check_nh_onlink(struct net *net,

				     struct fib6_config *cfg,

				     struct net_device *dev,

				     const struct net_device *dev,

				     struct netlink_ext_ack *extack)

{

	u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;
@@ -2626,6 +2626,68 @@ static int ip6_route_check_nh(struct net *net, 
	return err;

}



static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,

			   struct net_device **_dev, struct inet6_dev **idev,

			   struct netlink_ext_ack *extack)

{

	const struct in6_addr *gw_addr = &cfg->fc_gateway;

	int gwa_type = ipv6_addr_type(gw_addr);

	const struct net_device *dev = *_dev;

	int err = -EINVAL;



	/* if gw_addr is local we will fail to detect this in case

	 * address is still TENTATIVE (DAD in progress). rt6_lookup()

	 * will return already-added prefix route via interface that

	 * prefix route was assigned to, which might be non-loopback.

	 */

	if (ipv6_chk_addr_and_flags(net, gw_addr,

				    gwa_type & IPV6_ADDR_LINKLOCAL ?

				    dev : NULL, 0, 0)) {

		NL_SET_ERR_MSG(extack, "Invalid gateway address");

		goto out;

	}



	if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {

		/* IPv6 strictly inhibits using not link-local

		 * addresses as nexthop address.

		 * Otherwise, router will not able to send redirects.

		 * It is very good, but in some (rare!) circumstances

		 * (SIT, PtP, NBMA NOARP links) it is handy to allow

		 * some exceptions. --ANK

		 * We allow IPv4-mapped nexthops to support RFC4798-type

		 * addressing

		 */

		if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {

			NL_SET_ERR_MSG(extack, "Invalid gateway address");

			goto out;

		}



		if (cfg->fc_flags & RTNH_F_ONLINK)

			err = ip6_route_check_nh_onlink(net, cfg, dev, extack);

		else

			err = ip6_route_check_nh(net, cfg, _dev, idev);



		if (err)

			goto out;

	}



	/* reload in case device was changed */

	dev = *_dev;



	err = -EINVAL;

	if (!dev) {

		NL_SET_ERR_MSG(extack, "Egress device not specified");

		goto out;

	} else if (dev->flags & IFF_LOOPBACK) {

		NL_SET_ERR_MSG(extack,

			       "Egress device can not be loopback device for this route");

		goto out;

	}

	err = 0;

out:

	return err;

}



static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,

					      struct netlink_ext_ack *extack)

{
@@ -2808,61 +2870,11 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg, 
	}



	if (cfg->fc_flags & RTF_GATEWAY) {

		const struct in6_addr *gw_addr;

		int gwa_type;



		gw_addr = &cfg->fc_gateway;

		gwa_type = ipv6_addr_type(gw_addr);



		/* if gw_addr is local we will fail to detect this in case

		 * address is still TENTATIVE (DAD in progress). rt6_lookup()

		 * will return already-added prefix route via interface that

		 * prefix route was assigned to, which might be non-loopback.

		 */

		err = -EINVAL;

		if (ipv6_chk_addr_and_flags(net, gw_addr,

					    gwa_type & IPV6_ADDR_LINKLOCAL ?

					    dev : NULL, 0, 0)) {

			NL_SET_ERR_MSG(extack, "Invalid gateway address");

			goto out;

		}

		rt->rt6i_gateway = *gw_addr;



		if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {

			/* IPv6 strictly inhibits using not link-local

			   addresses as nexthop address.

			   Otherwise, router will not able to send redirects.

			   It is very good, but in some (rare!) circumstances

			   (SIT, PtP, NBMA NOARP links) it is handy to allow

			   some exceptions. --ANK

			   We allow IPv4-mapped nexthops to support RFC4798-type

			   addressing

			 */

			if (!(gwa_type & (IPV6_ADDR_UNICAST |

					  IPV6_ADDR_MAPPED))) {

				NL_SET_ERR_MSG(extack,

					       "Invalid gateway address");

				goto out;

			}



			if (cfg->fc_flags & RTNH_F_ONLINK) {

				err = ip6_route_check_nh_onlink(net, cfg, dev,

								extack);

			} else {

				err = ip6_route_check_nh(net, cfg, &dev, &idev);

			}

		err = ip6_validate_gw(net, cfg, &dev, &idev, extack);

		if (err)

			goto out;

		}

		err = -EINVAL;

		if (!dev) {

			NL_SET_ERR_MSG(extack, "Egress device not specified");

			goto out;

		} else if (dev->flags & IFF_LOOPBACK) {

			NL_SET_ERR_MSG(extack,

				       "Egress device can not be loopback device for this route");

			goto out;

		}



		rt->rt6i_gateway = cfg->fc_gateway;

	}



	err = -ENODEV;