forge/linux-pinenote
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

ipv4: Add FLOWI_FLAG_KNOWN_NH

Browse source 
Add flag to request that output route should be
returned with known rt_gateway, in case we want to use
it as nexthop for neighbour resolving.

	The returned route can be cached as follows:

- in NH exception: because the cached routes are not shared
	with other destinations
- in FIB NH: when using gateway because all destinations for
	NH share same gateway

	As last option, to return rt_gateway!=0 we have to
set DST_NOCACHE.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Julian Anastasov 2012-10-08 11:41:19 +00:00 • committed by David S. Miller
commit c92b96553a
2 changed files with 18 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

1
include/net/flow.h
View file

@ -21,6 +21,7 @@ struct flowi_common {
__u8 flowic_flags;
#define FLOWI_FLAG_ANYSRC 0x01
#define FLOWI_FLAG_CAN_SLEEP 0x02
#define FLOWI_FLAG_KNOWN_NH 0x04
__u32 flowic_secid;
};

21
net/ipv4/route.c
View file

@ -1762,6 +1762,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
struct in_device *in_dev;
u16 type = res->type;
struct rtable *rth;
bool do_cache;
in_dev = __in_dev_get_rcu(dev_out);
if (!in_dev)
@ -1798,24 +1799,36 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
}
fnhe = NULL;
do_cache = fi != NULL;
if (fi) {
struct rtable __rcu **prth;
struct fib_nh *nh = &FIB_RES_NH(*res);
fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr);
fnhe = find_exception(nh, fl4->daddr);
if (fnhe)
prth = &fnhe->fnhe_rth;
else
prth = __this_cpu_ptr(FIB_RES_NH(*res).nh_pcpu_rth_output);
else {
if (unlikely(fl4->flowi4_flags &
FLOWI_FLAG_KNOWN_NH &&
!(nh->nh_gw &&
nh->nh_scope == RT_SCOPE_LINK))) {
do_cache = false;
goto add;
}
prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
}
rth = rcu_dereference(*prth);
if (rt_cache_valid(rth)) {
dst_hold(&rth->dst);
return rth;
}
}
add:
rth = rt_dst_alloc(dev_out,
IN_DEV_CONF_GET(in_dev, NOPOLICY),
IN_DEV_CONF_GET(in_dev, NOXFRM),
fi);
do_cache);
if (!rth)
return ERR_PTR(-ENOBUFS);