From: David Ahern <dsah...@gmail.com>
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
that takes the fib_result as an input arg.
To keep the name length under control remove the leading underscores
from the name. _rcu is added to the name of the new helper indicating
it is called with the rcu read lock held.
Signed-off-by: David Ahern <dsah...@gmail.com>
Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com>
---
include/net/route.h | 7 ++++++-
net/ipv4/icmp.c | 2 +-
net/ipv4/route.c | 57 +++++++++++++++++++++++++++++++----------------------
3 files changed, 40 insertions(+), 26 deletions(-)
diff --git a/include/net/route.h b/include/net/route.h
index 2cc0e14..5a92347 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -115,11 +115,16 @@ struct rt_cache_stat {
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,
+ const struct sk_buff *skb,
+ struct fib_result *res);
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,
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 43318b5..5610971 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -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;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 655d9ee..f787208 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2246,29 +2246,22 @@ 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,
- const struct sk_buff *skb)
+struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4
*fl4,
+ const struct sk_buff *skb,
+ struct fib_result *res)
{
struct net_device *dev_out = NULL;
+ int orig_oif = fl4->flowi4_oif;
__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;
+ struct rtable *rth;
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();
if (fl4->saddr) {
rth = ERR_PTR(-EINVAL);
if (ipv4_is_multicast(fl4->saddr) ||
@@ -2354,15 +2347,15 @@ 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))) {
@@ -2387,17 +2380,17 @@ 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;
}
@@ -2410,20 +2403,36 @@ struct rtable *__ip_route_output_key_hash(struct net
*net, struct flowi4 *fl4,
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:
+ return rth;
+}
+
+struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
+ const struct sk_buff *skb)
+{
+ struct fib_result res;
+ struct rtable *rth;
+
+ res.tclassid = 0;
+ res.fi = NULL;
+ res.table = NULL;
+
+ rcu_read_lock();
+ rth = ip_route_output_key_hash_rcu(net, fl4, &res, mp_hash);
rcu_read_unlock();
+
return rth;
}
-EXPORT_SYMBOL_GPL(__ip_route_output_key_hash);
+EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32
cookie)
{
--
1.9.1
