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net: ipv4: refactor ip_route_input_noref

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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@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 10:42:34 -07:00
committed by David S. Miller
parent 3abd1ade67
commit 5510cdf7be
2 changed files with 40 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
include/net/route.h
View File

@@ -178,6 +178,9 @@ 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, int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
u8 tos, struct net_device *devin); 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, static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
u8 tos, struct net_device *devin) u8 tos, struct net_device *devin)

66
net/ipv4/route.c
View File

@@ -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, 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 in_device *in_dev = __in_dev_get_rcu(dev);
struct ip_tunnel_info *tun_info; struct ip_tunnel_info *tun_info;
struct flowi4 fl4; 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)) if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
goto martian_source; goto martian_source;
res.fi = NULL; res->fi = NULL;
res.table = NULL; res->table = NULL;
if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
goto brd_input; 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.daddr = daddr;
fl4.saddr = saddr; fl4.saddr = saddr;
fl4.flowi4_uid = sock_net_uid(net, NULL); 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 (err != 0) {
if (!IN_DEV_FORWARD(in_dev)) if (!IN_DEV_FORWARD(in_dev))
err = -EHOSTUNREACH; err = -EHOSTUNREACH;
goto no_route; goto no_route;
} }
if (res.type == RTN_BROADCAST) if (res->type == RTN_BROADCAST)
goto brd_input; goto brd_input;
if (res.type == RTN_LOCAL) { if (res->type == RTN_LOCAL) {
err = fib_validate_source(skb, saddr, daddr, tos, err = fib_validate_source(skb, saddr, daddr, tos,
0, dev, in_dev, &itag); 0, dev, in_dev, &itag);
if (err < 0) if (err < 0)
@@ -1943,10 +1943,10 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
err = -EHOSTUNREACH; err = -EHOSTUNREACH;
goto no_route; goto no_route;
} }
if (res.type != RTN_UNICAST) if (res->type != RTN_UNICAST)
goto martian_destination; 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; out: return err;
brd_input: brd_input:
@@ -1960,14 +1960,14 @@ brd_input:
goto martian_source; goto martian_source;
} }
flags |= RTCF_BROADCAST; flags |= RTCF_BROADCAST;
res.type = RTN_BROADCAST; res->type = RTN_BROADCAST;
RT_CACHE_STAT_INC(in_brd); RT_CACHE_STAT_INC(in_brd);
local_input: local_input:
do_cache = false; do_cache = false;
if (res.fi) { if (res->fi) {
if (!itag) { 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)) { if (rt_cache_valid(rth)) {
skb_dst_set_noref(skb, &rth->dst); skb_dst_set_noref(skb, &rth->dst);
err = 0; err = 0;
@@ -1978,7 +1978,7 @@ local_input:
} }
rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 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); IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
if (!rth) if (!rth)
goto e_nobufs; goto e_nobufs;
@@ -1988,18 +1988,18 @@ local_input:
rth->dst.tclassid = itag; rth->dst.tclassid = itag;
#endif #endif
rth->rt_is_input = 1; rth->rt_is_input = 1;
if (res.table) if (res->table)
rth->rt_table_id = res.table->tb_id; rth->rt_table_id = res->table->tb_id;
RT_CACHE_STAT_INC(in_slow_tot); RT_CACHE_STAT_INC(in_slow_tot);
if (res.type == RTN_UNREACHABLE) { if (res->type == RTN_UNREACHABLE) {
rth->dst.input= ip_error; rth->dst.input= ip_error;
rth->dst.error= -err; rth->dst.error= -err;
rth->rt_flags &= ~RTCF_LOCAL; rth->rt_flags &= ~RTCF_LOCAL;
} }
if (do_cache) { 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); rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
if (lwtunnel_input_redirect(rth->dst.lwtstate)) { if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
@@ -2019,9 +2019,9 @@ local_input:
no_route: no_route:
RT_CACHE_STAT_INC(in_no_route); RT_CACHE_STAT_INC(in_no_route);
res.type = RTN_UNREACHABLE; res->type = RTN_UNREACHABLE;
res.fi = NULL; res->fi = NULL;
res.table = NULL; res->table = NULL;
goto local_input; goto local_input;
/* /*
@@ -2051,11 +2051,22 @@ martian_source:
int ip_route_input_noref(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) u8 tos, struct net_device *dev)
{ {
int res; struct fib_result res;
int err;
tos &= IPTOS_RT_MASK; tos &= IPTOS_RT_MASK;
rcu_read_lock(); 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. /* Multicast recognition logic is moved from route cache to here.
The problem was that too many Ethernet cards have broken/missing The problem was that too many Ethernet cards have broken/missing
hardware multicast filters :-( As result the host on multicasting 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)) { if (ipv4_is_multicast(daddr)) {
struct in_device *in_dev = __in_dev_get_rcu(dev); struct in_device *in_dev = __in_dev_get_rcu(dev);
int our = 0; int our = 0;
int err = -EINVAL;
if (in_dev) if (in_dev)
our = ip_check_mc_rcu(in_dev, daddr, saddr, 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); ip_hdr(skb)->protocol);
} }
res = -EINVAL;
if (our if (our
#ifdef CONFIG_IP_MROUTE #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)) IN_DEV_MFORWARD(in_dev))
#endif #endif
) { ) {
res = ip_route_input_mc(skb, daddr, saddr, err = ip_route_input_mc(skb, daddr, saddr,
tos, dev, our); tos, dev, our);
} }
rcu_read_unlock(); return err;
return res;
} }
res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
rcu_read_unlock(); return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
return res;
} }
EXPORT_SYMBOL(ip_route_input_noref);
/* called with rcu_read_lock() */ /* called with rcu_read_lock() */
static struct rtable *__mkroute_output(const struct fib_result *res, static struct rtable *__mkroute_output(const struct fib_result *res,