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Date: Wed, 24 May 2017 11:19:05 -0700
From: Roopa Prabhu <roopa@...ulusnetworks.com>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org, dsahern@...il.com,
nikolay@...ulusnetworks.com
Subject: [PATCH net-next 2/8] net: ipv4: refactor ip_route_input_noref
From: David Ahern <dsahern@...il.com>
A later patch wants access to the fib result on an input route lookup
with the rcu lock held. Refactor ip_route_input_noref pushing the logic
between rcu_read_lock ... rcu_read_unlock into a new helper that takes
the fib_result as an input arg.
Signed-off-by: David Ahern <dsahern@...il.com>
Signed-off-by: Roopa Prabhu <roopa@...ulusnetworks.com>
---
include/net/route.h | 3 +++
net/ipv4/route.c | 66 ++++++++++++++++++++++++++++++-----------------------
2 files changed, 40 insertions(+), 29 deletions(-)
diff --git a/include/net/route.h b/include/net/route.h
index 5a92347..8d209ad 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -180,6 +180,9 @@ static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4
int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
u8 tos, struct net_device *devin);
+int ip_route_input_rcu(struct sk_buff *skb, __be32 dst, __be32 src,
+ u8 tos, struct net_device *devin,
+ struct fib_result *res);
static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
u8 tos, struct net_device *devin)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index f787208..fe7b765 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1852,9 +1852,9 @@ static int ip_mkroute_input(struct sk_buff *skb,
*/
static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
- u8 tos, struct net_device *dev)
+ u8 tos, struct net_device *dev,
+ struct fib_result *res)
{
- struct fib_result res;
struct in_device *in_dev = __in_dev_get_rcu(dev);
struct ip_tunnel_info *tun_info;
struct flowi4 fl4;
@@ -1884,8 +1884,8 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
goto martian_source;
- res.fi = NULL;
- res.table = NULL;
+ res->fi = NULL;
+ res->table = NULL;
if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
goto brd_input;
@@ -1921,17 +1921,17 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
fl4.daddr = daddr;
fl4.saddr = saddr;
fl4.flowi4_uid = sock_net_uid(net, NULL);
- err = fib_lookup(net, &fl4, &res, 0);
+ err = fib_lookup(net, &fl4, res, 0);
if (err != 0) {
if (!IN_DEV_FORWARD(in_dev))
err = -EHOSTUNREACH;
goto no_route;
}
- if (res.type == RTN_BROADCAST)
+ if (res->type == RTN_BROADCAST)
goto brd_input;
- if (res.type == RTN_LOCAL) {
+ if (res->type == RTN_LOCAL) {
err = fib_validate_source(skb, saddr, daddr, tos,
0, dev, in_dev, &itag);
if (err < 0)
@@ -1943,10 +1943,10 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
err = -EHOSTUNREACH;
goto no_route;
}
- if (res.type != RTN_UNICAST)
+ if (res->type != RTN_UNICAST)
goto martian_destination;
- err = ip_mkroute_input(skb, &res, in_dev, daddr, saddr, tos);
+ err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos);
out: return err;
brd_input:
@@ -1960,14 +1960,14 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
goto martian_source;
}
flags |= RTCF_BROADCAST;
- res.type = RTN_BROADCAST;
+ res->type = RTN_BROADCAST;
RT_CACHE_STAT_INC(in_brd);
local_input:
do_cache = false;
- if (res.fi) {
+ if (res->fi) {
if (!itag) {
- rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
+ rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
if (rt_cache_valid(rth)) {
skb_dst_set_noref(skb, &rth->dst);
err = 0;
@@ -1978,7 +1978,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
}
rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
- flags | RTCF_LOCAL, res.type,
+ flags | RTCF_LOCAL, res->type,
IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
if (!rth)
goto e_nobufs;
@@ -1988,18 +1988,18 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
rth->dst.tclassid = itag;
#endif
rth->rt_is_input = 1;
- if (res.table)
- rth->rt_table_id = res.table->tb_id;
+ if (res->table)
+ rth->rt_table_id = res->table->tb_id;
RT_CACHE_STAT_INC(in_slow_tot);
- if (res.type == RTN_UNREACHABLE) {
+ if (res->type == RTN_UNREACHABLE) {
rth->dst.input= ip_error;
rth->dst.error= -err;
rth->rt_flags &= ~RTCF_LOCAL;
}
if (do_cache) {
- struct fib_nh *nh = &FIB_RES_NH(res);
+ struct fib_nh *nh = &FIB_RES_NH(*res);
rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
@@ -2019,9 +2019,9 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
no_route:
RT_CACHE_STAT_INC(in_no_route);
- res.type = RTN_UNREACHABLE;
- res.fi = NULL;
- res.table = NULL;
+ res->type = RTN_UNREACHABLE;
+ res->fi = NULL;
+ res->table = NULL;
goto local_input;
/*
@@ -2051,11 +2051,22 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
u8 tos, struct net_device *dev)
{
- int res;
+ struct fib_result res;
+ int err;
tos &= IPTOS_RT_MASK;
rcu_read_lock();
+ err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
+ rcu_read_unlock();
+ return err;
+}
+EXPORT_SYMBOL(ip_route_input_noref);
+
+/* called with rcu_read_lock held */
+int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ u8 tos, struct net_device *dev, struct fib_result *res)
+{
/* Multicast recognition logic is moved from route cache to here.
The problem was that too many Ethernet cards have broken/missing
hardware multicast filters :-( As result the host on multicasting
@@ -2070,6 +2081,7 @@ int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
if (ipv4_is_multicast(daddr)) {
struct in_device *in_dev = __in_dev_get_rcu(dev);
int our = 0;
+ int err = -EINVAL;
if (in_dev)
our = ip_check_mc_rcu(in_dev, daddr, saddr,
@@ -2085,7 +2097,6 @@ int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
ip_hdr(skb)->protocol);
}
- res = -EINVAL;
if (our
#ifdef CONFIG_IP_MROUTE
||
@@ -2093,17 +2104,14 @@ int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
IN_DEV_MFORWARD(in_dev))
#endif
) {
- res = ip_route_input_mc(skb, daddr, saddr,
+ err = ip_route_input_mc(skb, daddr, saddr,
tos, dev, our);
}
- rcu_read_unlock();
- return res;
+ return err;
}
- res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
- rcu_read_unlock();
- return res;
+
+ return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
}
-EXPORT_SYMBOL(ip_route_input_noref);
/* called with rcu_read_lock() */
static struct rtable *__mkroute_output(const struct fib_result *res,
--
1.9.1
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