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net: ipv4: refactor __ip_route_output_key_hash

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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: David Ahern <dsahern@gmail.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern 2017-05-25 10:42:33 -07:00 committed by David S. Miller
parent 5dafc87f40
commit 3abd1ade67
3 changed files with 38 additions and 26 deletions
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9
include/net/route.h
View File

@ -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,
const struct sk_buff *skb);
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,

2
net/ipv4/icmp.c
View File

@ -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;

53
net/ipv4/route.c
View File

@ -2246,29 +2246,40 @@ add:
* Major route resolver routine.
*/
struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
const struct sk_buff *skb)
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)
{