[PATCH v2 net-next 07/13] ipv6: Move gateway checks to a fib6_nh setting

David Ahern
2019-03-27T18:38:22Z

The gateway setting is not per fib6_info entry but per-fib6_nh. Add a new
fib_nh_has_gw flag to fib6_nh and convert references to RTF_GATEWAY to
the new flag. For IPv6 address the flag is cheaper than checking that
nh_gw is non-0 like IPv4 does.

While this increases fib6_nh by 8-bytes, the effective allocation size of
a fib6_info is unchanged. The 8 bytes is recovered later with the
fib_nh_common change.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
.../net/ethernet/mellanox/mlxsw/spectrum_router.c | 4 ++--
include/net/ip6_fib.h | 1 +
include/net/ip6_route.h | 4 ++--
net/core/filter.c | 2 +-
net/ipv6/addrconf.c | 25 +++++++++++----------
net/ipv6/ip6_fib.c | 9 +++++---
net/ipv6/route.c | 26 +++++++++++++---------
7 files changed, 41 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 52fed8c7bf1e..663d819a2a32 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -4913,7 +4913,7 @@ static void mlxsw_sp_rt6_destroy(struct mlxsw_sp_rt6 *mlxsw_sp_rt6)
static bool mlxsw_sp_fib6_rt_can_mp(const struct fib6_info *rt)
{
/* RTF_CACHE routes are ignored */
- return (rt->fib6_flags & (RTF_GATEWAY | RTF_ADDRCONF)) == RTF_GATEWAY;
+ return !(rt->fib6_flags & RTF_ADDRCONF) && rt->fib6_nh.fib_nh_has_gw;
}

static struct fib6_info *
@@ -5053,7 +5053,7 @@ static void mlxsw_sp_nexthop6_fini(struct mlxsw_sp *mlxsw_sp,
static bool mlxsw_sp_rt6_is_gateway(const struct mlxsw_sp *mlxsw_sp,
const struct fib6_info *rt)
{
- return rt->fib6_flags & RTF_GATEWAY ||
+ return rt->fib6_nh.fib_nh_has_gw ||
mlxsw_sp_nexthop6_ipip_type(mlxsw_sp, rt, NULL);
}

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 2d2a468b3d6d..3b04b318cf13 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -126,6 +126,7 @@ struct rt6_exception {

struct fib6_nh {
struct in6_addr nh_gw;
+ bool fib_nh_has_gw;
struct net_device *nh_dev;
struct lwtunnel_state *nh_lwtstate;

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 7ab119936e69..95cd8a2f6284 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -68,8 +68,8 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr)

static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
{
- return (f6i->fib6_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
- RTF_GATEWAY;
+ return !(f6i->fib6_flags & (RTF_ADDRCONF|RTF_DYNAMIC)) &&
+ f6i->fib6_nh.fib_nh_has_gw;
}

void ip6_route_input(struct sk_buff *skb);
diff --git a/net/core/filter.c b/net/core/filter.c
index 647c63a7b25b..248207171475 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4677,7 +4677,7 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
if (f6i->fib6_nh.nh_lwtstate)
return BPF_FIB_LKUP_RET_UNSUPP_LWT;

- if (f6i->fib6_flags & RTF_GATEWAY)
+ if (f6i->fib6_nh.fib_nh_has_gw)
*dst = f6i->fib6_nh.nh_gw;

dev = f6i->fib6_nh.nh_dev;
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 4ae17a966ae3..c5ac08fc6cc9 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -173,7 +173,8 @@ static int addrconf_ifdown(struct net_device *dev, int how);
static struct fib6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
int plen,
const struct net_device *dev,
- u32 flags, u32 noflags);
+ u32 flags, u32 noflags,
+ bool no_gw);

static void addrconf_dad_start(struct inet6_ifaddr *ifp);
static void addrconf_dad_work(struct work_struct *w);
@@ -1230,10 +1231,8 @@ cleanup_prefix_route(struct inet6_ifaddr *ifp, unsigned long expires, bool del_r
{
struct fib6_info *f6i;

- f6i = addrconf_get_prefix_route(&ifp->addr,
- ifp->prefix_len,
- ifp->idev->dev,
- 0, RTF_GATEWAY | RTF_DEFAULT);
+ f6i = addrconf_get_prefix_route(&ifp->addr, ifp->prefix_len,
+ ifp->idev->dev, 0, RTF_DEFAULT, true);
if (f6i) {
if (del_rt)
ip6_del_rt(dev_net(ifp->idev->dev), f6i);
@@ -2402,7 +2401,8 @@ addrconf_prefix_route(struct in6_addr *pfx, int plen, u32 metric,
static struct fib6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
int plen,
const struct net_device *dev,
- u32 flags, u32 noflags)
+ u32 flags, u32 noflags,
+ bool no_gw)
{
struct fib6_node *fn;
struct fib6_info *rt = NULL;
@@ -2421,6 +2421,8 @@ static struct fib6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
for_each_fib6_node_rt_rcu(fn) {
if (rt->fib6_nh.nh_dev->ifindex != dev->ifindex)
continue;
+ if (no_gw && rt->fib6_nh.fib_nh_has_gw)
+ continue;
if ((rt->fib6_flags & flags) != flags)
continue;
if ((rt->fib6_flags & noflags) != 0)
@@ -2717,7 +2719,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
pinfo->prefix_len,
dev,
RTF_ADDRCONF | RTF_PREFIX_RT,
- RTF_GATEWAY | RTF_DEFAULT);
+ RTF_DEFAULT, true);

if (rt) {
/* Autoconf prefix route */
@@ -4588,10 +4590,8 @@ static int modify_prefix_route(struct inet6_ifaddr *ifp,
struct fib6_info *f6i;
u32 prio;

- f6i = addrconf_get_prefix_route(&ifp->addr,
- ifp->prefix_len,
- ifp->idev->dev,
- 0, RTF_GATEWAY | RTF_DEFAULT);
+ f6i = addrconf_get_prefix_route(&ifp->addr, ifp->prefix_len,
+ ifp->idev->dev, 0, RTF_DEFAULT, true);
if (!f6i)
return -ENOENT;

@@ -5972,7 +5972,8 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
struct fib6_info *rt;

rt = addrconf_get_prefix_route(&ifp->peer_addr, 128,
- ifp->idev->dev, 0, 0);
+ ifp->idev->dev, 0, 0,
+ false);
if (rt)
ip6_del_rt(net, rt);
}
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index db886085369b..91ce84ecdb57 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -2294,6 +2294,7 @@ static int ipv6_route_seq_show(struct seq_file *seq, void *v)
{
struct fib6_info *rt = v;
struct ipv6_route_iter *iter = seq->private;
+ unsigned int flags = rt->fib6_flags;
const struct net_device *dev;

seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen);
@@ -2303,15 +2304,17 @@ static int ipv6_route_seq_show(struct seq_file *seq, void *v)
#else
seq_puts(seq, "00000000000000000000000000000000 00 ");
#endif
- if (rt->fib6_flags & RTF_GATEWAY)
+ if (rt->fib6_nh.fib_nh_has_gw) {
+ flags |= RTF_GATEWAY;
seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw);
- else
+ } else {
seq_puts(seq, "00000000000000000000000000000000");
+ }

dev = rt->fib6_nh.nh_dev;
seq_printf(seq, " %08x %08x %08x %08x %8s\n",
rt->fib6_metric, atomic_read(&rt->fib6_ref), 0,
- rt->fib6_flags, dev ? dev->name : "");
+ flags, dev ? dev->name : "");
iter->w.leaf = NULL;
return 0;
}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index bd910a266aa7..0e96f7994d9e 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -533,7 +533,7 @@ static void rt6_probe(struct fib6_info *rt)
* Router Reachability Probe MUST be rate-limited
* to no more than one per minute.
*/
- if (!rt || !(rt->fib6_flags & RTF_GATEWAY))
+ if (!rt || !rt->fib6_nh.fib_nh_has_gw)
return;

nh_gw = &rt->fib6_nh.nh_gw;
@@ -595,7 +595,7 @@ static inline enum rt6_nud_state rt6_check_neigh(struct fib6_info *rt)
struct neighbour *neigh;

if (rt->fib6_flags & RTF_NONEXTHOP ||
- !(rt->fib6_flags & RTF_GATEWAY))
+ !rt->fib6_nh.fib_nh_has_gw)
return RT6_NUD_SUCCEED;

rcu_read_lock_bh();
@@ -784,7 +784,7 @@ static struct fib6_info *rt6_select(struct net *net, struct fib6_node *fn,

static bool rt6_is_gw_or_nonexthop(const struct fib6_info *rt)
{
- return (rt->fib6_flags & (RTF_NONEXTHOP | RTF_GATEWAY));
+ return (rt->fib6_flags & RTF_NONEXTHOP) || rt->fib6_nh.fib_nh_has_gw;
}

#ifdef CONFIG_IPV6_ROUTE_INFO
@@ -989,8 +989,11 @@ static void ip6_rt_copy_init(struct rt6_info *rt, struct fib6_info *ort)

rt->rt6i_dst = ort->fib6_dst;
rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
- rt->rt6i_gateway = ort->fib6_nh.nh_gw;
rt->rt6i_flags = ort->fib6_flags;
+ if (ort->fib6_nh.fib_nh_has_gw) {
+ rt->rt6i_gateway = ort->fib6_nh.nh_gw;
+ rt->rt6i_flags |= RTF_GATEWAY;
+ }
rt6_set_from(rt, ort);
#ifdef CONFIG_IPV6_SUBTREES
rt->rt6i_src = ort->fib6_src;
@@ -1870,7 +1873,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
rcu_read_unlock();
return rt;
} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
- !(f6i->fib6_flags & RTF_GATEWAY))) {
+ !f6i->fib6_nh.fib_nh_has_gw)) {
/* Create a RTF_CACHE clone which will not be
* owned by the fib6 tree. It is for the special case where
* the daddr in the skb during the neighbor look-up is different
@@ -2440,7 +2443,7 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
continue;
if (rt->fib6_flags & RTF_REJECT)
break;
- if (!(rt->fib6_flags & RTF_GATEWAY))
+ if (!rt->fib6_nh.fib_nh_has_gw)
continue;
if (fl6->flowi6_oif != rt->fib6_nh.nh_dev->ifindex)
continue;
@@ -2977,6 +2980,7 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
goto out;

fib6_nh->nh_gw = cfg->fc_gateway;
+ fib6_nh->fib_nh_has_gw = 1;
}

err = -ENODEV;
@@ -3138,7 +3142,7 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
} else
rt->fib6_prefsrc.plen = 0;

- rt->fib6_flags = cfg->fc_flags;
+ rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;

return rt;
out:
@@ -3474,7 +3478,8 @@ static struct fib6_info *rt6_get_route_info(struct net *net,
for_each_fib6_node_rt_rcu(fn) {
if (rt->fib6_nh.nh_dev->ifindex != ifindex)
continue;
- if ((rt->fib6_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
+ if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
+ !rt->fib6_nh.fib_nh_has_gw)
continue;
if (!ipv6_addr_equal(&rt->fib6_nh.nh_gw, gwaddr))
continue;
@@ -3795,7 +3800,7 @@ void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
fib6_clean_all(net, fib6_remove_prefsrc, &adni);
}

-#define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY)
+#define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT)

/* Remove routers and update dst entries when gateway turn into host. */
static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
@@ -3803,6 +3808,7 @@ static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
struct in6_addr *gateway = (struct in6_addr *)arg;

if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
+ rt->fib6_nh.fib_nh_has_gw &&
ipv6_addr_equal(gateway, &rt->fib6_nh.nh_gw)) {
return -1;
}
@@ -4591,7 +4597,7 @@ static int rt6_nexthop_info(struct sk_buff *skb, struct fib6_info *rt,
rcu_read_unlock();
}

- if (rt->fib6_flags & RTF_GATEWAY) {
+ if (rt->fib6_nh.fib_nh_has_gw) {
if (nla_put_in6_addr(skb, RTA_GATEWAY, &rt->fib6_nh.nh_gw) < 0)
goto nla_put_failure;
}
--
2.11.0