[PATCH 5.11 212/254] net: Consolidate common blackhole dst ops

From: Greg Kroah-Hartman
Date: Mon Mar 29 2021 - 05:01:58 EST


From: Daniel Borkmann <daniel@xxxxxxxxxxxxx>

[ Upstream commit c4c877b2732466b4c63217baad05c96f775912c7 ]

Move generic blackhole dst ops to the core and use them from both
ipv4_dst_blackhole_ops and ip6_dst_blackhole_ops where possible. No
functional change otherwise. We need these also in other locations
and having to define them over and over again is not great.

Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/net/dst.h | 11 +++++++++++
net/core/dst.c | 38 ++++++++++++++++++++++++++++++++++++++
net/ipv4/route.c | 45 ++++++++-------------------------------------
net/ipv6/route.c | 36 +++++++++---------------------------
4 files changed, 66 insertions(+), 64 deletions(-)

diff --git a/include/net/dst.h b/include/net/dst.h
index 10f0a8399867..8d7cf51766c4 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -533,4 +533,15 @@ static inline void skb_dst_update_pmtu_no_confirm(struct sk_buff *skb, u32 mtu)
dst->ops->update_pmtu(dst, NULL, skb, mtu, false);
}

+struct dst_entry *dst_blackhole_check(struct dst_entry *dst, u32 cookie);
+void dst_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
+ struct sk_buff *skb, u32 mtu, bool confirm_neigh);
+void dst_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
+ struct sk_buff *skb);
+u32 *dst_blackhole_cow_metrics(struct dst_entry *dst, unsigned long old);
+struct neighbour *dst_blackhole_neigh_lookup(const struct dst_entry *dst,
+ struct sk_buff *skb,
+ const void *daddr);
+unsigned int dst_blackhole_mtu(const struct dst_entry *dst);
+
#endif /* _NET_DST_H */
diff --git a/net/core/dst.c b/net/core/dst.c
index 0c01bd8d9d81..5f6315601776 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -237,6 +237,44 @@ void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old)
}
EXPORT_SYMBOL(__dst_destroy_metrics_generic);

+struct dst_entry *dst_blackhole_check(struct dst_entry *dst, u32 cookie)
+{
+ return NULL;
+}
+
+u32 *dst_blackhole_cow_metrics(struct dst_entry *dst, unsigned long old)
+{
+ return NULL;
+}
+
+struct neighbour *dst_blackhole_neigh_lookup(const struct dst_entry *dst,
+ struct sk_buff *skb,
+ const void *daddr)
+{
+ return NULL;
+}
+
+void dst_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
+ struct sk_buff *skb, u32 mtu,
+ bool confirm_neigh)
+{
+}
+EXPORT_SYMBOL_GPL(dst_blackhole_update_pmtu);
+
+void dst_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
+ struct sk_buff *skb)
+{
+}
+EXPORT_SYMBOL_GPL(dst_blackhole_redirect);
+
+unsigned int dst_blackhole_mtu(const struct dst_entry *dst)
+{
+ unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+ return mtu ? : dst->dev->mtu;
+}
+EXPORT_SYMBOL_GPL(dst_blackhole_mtu);
+
static struct dst_ops md_dst_ops = {
.family = AF_UNSPEC,
};
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index e26652ff7059..983b4db1868f 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2682,44 +2682,15 @@ out:
return rth;
}

-static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
-{
- return NULL;
-}
-
-static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
-{
- unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
-
- return mtu ? : dst->dev->mtu;
-}
-
-static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
- struct sk_buff *skb, u32 mtu,
- bool confirm_neigh)
-{
-}
-
-static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
- struct sk_buff *skb)
-{
-}
-
-static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
- unsigned long old)
-{
- return NULL;
-}
-
static struct dst_ops ipv4_dst_blackhole_ops = {
- .family = AF_INET,
- .check = ipv4_blackhole_dst_check,
- .mtu = ipv4_blackhole_mtu,
- .default_advmss = ipv4_default_advmss,
- .update_pmtu = ipv4_rt_blackhole_update_pmtu,
- .redirect = ipv4_rt_blackhole_redirect,
- .cow_metrics = ipv4_rt_blackhole_cow_metrics,
- .neigh_lookup = ipv4_neigh_lookup,
+ .family = AF_INET,
+ .default_advmss = ipv4_default_advmss,
+ .neigh_lookup = ipv4_neigh_lookup,
+ .check = dst_blackhole_check,
+ .cow_metrics = dst_blackhole_cow_metrics,
+ .update_pmtu = dst_blackhole_update_pmtu,
+ .redirect = dst_blackhole_redirect,
+ .mtu = dst_blackhole_mtu,
};

struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 188e114b29b4..0bbfaa55e3c8 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -258,34 +258,16 @@ static struct dst_ops ip6_dst_ops_template = {
.confirm_neigh = ip6_confirm_neigh,
};

-static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
-{
- unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
-
- return mtu ? : dst->dev->mtu;
-}
-
-static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
- struct sk_buff *skb, u32 mtu,
- bool confirm_neigh)
-{
-}
-
-static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
- struct sk_buff *skb)
-{
-}
-
static struct dst_ops ip6_dst_blackhole_ops = {
- .family = AF_INET6,
- .destroy = ip6_dst_destroy,
- .check = ip6_dst_check,
- .mtu = ip6_blackhole_mtu,
- .default_advmss = ip6_default_advmss,
- .update_pmtu = ip6_rt_blackhole_update_pmtu,
- .redirect = ip6_rt_blackhole_redirect,
- .cow_metrics = dst_cow_metrics_generic,
- .neigh_lookup = ip6_dst_neigh_lookup,
+ .family = AF_INET6,
+ .default_advmss = ip6_default_advmss,
+ .neigh_lookup = ip6_dst_neigh_lookup,
+ .check = ip6_dst_check,
+ .destroy = ip6_dst_destroy,
+ .cow_metrics = dst_cow_metrics_generic,
+ .update_pmtu = dst_blackhole_update_pmtu,
+ .redirect = dst_blackhole_redirect,
+ .mtu = dst_blackhole_mtu,
};

static const u32 ip6_template_metrics[RTAX_MAX] = {
--
2.30.1