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Commit 3abd1ade authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net: ipv4: refactor __ip_route_output_key_hash 



A later patch wants access to the fib result on an output route lookup
with the rcu lock held. Refactor __ip_route_output_key_hash, pushing
the logic between rcu_read_lock ... rcu_read_unlock into a new helper
with the fib_result as an input arg.

To keep the name length under control remove the leading underscores
from the name and add _rcu to the name of the new helper indicating it
is called with the rcu read lock held.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5dafc87f

include/net/route.h

+6 −3
Original line number Diff line number Diff line
@@ -113,13 +113,16 @@ struct in_device; 
int ip_rt_init(void);

void rt_cache_flush(struct net *net);

void rt_flush_dev(struct net_device *dev);

struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *flp,

struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp,

					const struct sk_buff *skb);

struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp,

					    struct fib_result *res,

					    const struct sk_buff *skb);



static inline struct rtable *__ip_route_output_key(struct net *net,

						   struct flowi4 *flp)

{

	return __ip_route_output_key_hash(net, flp, NULL);

	return ip_route_output_key_hash(net, flp, NULL);

}



struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,

net/ipv4/icmp.c

+1 −1
Original line number Diff line number Diff line
@@ -489,7 +489,7 @@ static struct rtable *icmp_route_lookup(struct net *net, 
	fl4->flowi4_oif = l3mdev_master_ifindex(skb_dst(skb_in)->dev);



	security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4));

	rt = __ip_route_output_key_hash(net, fl4, skb_in);

	rt = ip_route_output_key_hash(net, fl4, skb_in);

	if (IS_ERR(rt))

		return rt;

net/ipv4/route.c

+31 −22
Original line number Diff line number Diff line
@@ -2246,29 +2246,40 @@ static struct rtable *__mkroute_output(const struct fib_result *res, 
 * Major route resolver routine.

 */



struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,

struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,

					const struct sk_buff *skb)

{

	struct net_device *dev_out = NULL;

	__u8 tos = RT_FL_TOS(fl4);

	unsigned int flags = 0;

	struct fib_result res;

	struct rtable *rth;

	int orig_oif;

	int err = -ENETUNREACH;



	res.tclassid	= 0;

	res.fi		= NULL;

	res.table	= NULL;



	orig_oif = fl4->flowi4_oif;



	fl4->flowi4_iif = LOOPBACK_IFINDEX;

	fl4->flowi4_tos = tos & IPTOS_RT_MASK;

	fl4->flowi4_scope = ((tos & RTO_ONLINK) ?

			 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);



	rcu_read_lock();

	rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);

	rcu_read_unlock();



	return rth;

}

EXPORT_SYMBOL_GPL(ip_route_output_key_hash);



struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,

					    struct fib_result *res,

					    const struct sk_buff *skb)

{

	struct net_device *dev_out = NULL;

	int orig_oif = fl4->flowi4_oif;

	unsigned int flags = 0;

	struct rtable *rth;

	int err = -ENETUNREACH;



	if (fl4->saddr) {

		rth = ERR_PTR(-EINVAL);

		if (ipv4_is_multicast(fl4->saddr) ||
@@ -2354,15 +2365,15 @@ struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 
			fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);

		dev_out = net->loopback_dev;

		fl4->flowi4_oif = LOOPBACK_IFINDEX;

		res.type = RTN_LOCAL;

		res->type = RTN_LOCAL;

		flags |= RTCF_LOCAL;

		goto make_route;

	}



	err = fib_lookup(net, fl4, &res, 0);

	err = fib_lookup(net, fl4, res, 0);

	if (err) {

		res.fi = NULL;

		res.table = NULL;

		res->fi = NULL;

		res->table = NULL;

		if (fl4->flowi4_oif &&

		    (ipv4_is_multicast(fl4->daddr) ||

		    !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
@@ -2387,43 +2398,41 @@ struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 
			if (fl4->saddr == 0)

				fl4->saddr = inet_select_addr(dev_out, 0,

							      RT_SCOPE_LINK);

			res.type = RTN_UNICAST;

			res->type = RTN_UNICAST;

			goto make_route;

		}

		rth = ERR_PTR(err);

		goto out;

	}



	if (res.type == RTN_LOCAL) {

	if (res->type == RTN_LOCAL) {

		if (!fl4->saddr) {

			if (res.fi->fib_prefsrc)

				fl4->saddr = res.fi->fib_prefsrc;

			if (res->fi->fib_prefsrc)

				fl4->saddr = res->fi->fib_prefsrc;

			else

				fl4->saddr = fl4->daddr;

		}



		/* L3 master device is the loopback for that domain */

		dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(res)) ? :

		dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :

			net->loopback_dev;

		fl4->flowi4_oif = dev_out->ifindex;

		flags |= RTCF_LOCAL;

		goto make_route;

	}



	fib_select_path(net, &res, fl4, skb);

	fib_select_path(net, res, fl4, skb);



	dev_out = FIB_RES_DEV(res);

	dev_out = FIB_RES_DEV(*res);

	fl4->flowi4_oif = dev_out->ifindex;





make_route:

	rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);

	rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);



out:

	rcu_read_unlock();

	return rth;

}

EXPORT_SYMBOL_GPL(__ip_route_output_key_hash);



static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)

{