In order to send sampled packets to userspace, NIC driver calls
psample api directly. But it creates a hard dependency on module
psample. Introduce psample_ops to remove the hard dependency.
It is initialized when psample module is loaded and set to NULL
when the module is unloaded.
Reported-by: kernel test robot <l...@intel.com>
Signed-off-by: Chris Mi <c...@nvidia.com>
Reviewed-by: Jiri Pirko <j...@nvidia.com>
---
v1->v2:
- fix sparse errors
v2->v3:
- remove inline
v3->v4:
- add inline back
v4->v5:
- address Jakub's comments
include/net/psample.h | 26 ++++++++++++++++++++++++++
net/psample/psample.c | 14 +++++++++++++-
net/sched/Makefile | 2 +-
net/sched/psample_stub.c | 5 +++++
4 files changed, 45 insertions(+), 2 deletions(-)
create mode 100644 net/sched/psample_stub.c
diff --git a/include/net/psample.h b/include/net/psample.h
index 68ae16bb0a4a..d0f1cfc56f6f 100644
--- a/include/net/psample.h
+++ b/include/net/psample.h
@@ -14,6 +14,15 @@ struct psample_group {
struct rcu_head rcu;
};
+struct psample_ops {
+ void (*sample_packet)(struct psample_group *group, struct sk_buff *skb,
+ u32 trunc_size, int in_ifindex, int out_ifindex,
+ u32 sample_rate);
+
+};
+
+extern const struct psample_ops __rcu *psample_ops __read_mostly;
+
struct psample_group *psample_group_get(struct net *net, u32 group_num);
void psample_group_take(struct psample_group *group);
void psample_group_put(struct psample_group *group);
@@ -35,4 +44,21 @@ static inline void psample_sample_packet(struct
psample_group *group,
#endif
+static inline void
+psample_nic_sample_packet(struct psample_group *group,
+ struct sk_buff *skb, u32 trunc_size,
+ int in_ifindex, int out_ifindex,
+ u32 sample_rate)
+{
+ const struct psample_ops *ops;
+
+ rcu_read_lock();
+ ops = rcu_dereference(psample_ops);
+ if (ops)
+ ops->sample_packet(group, skb, trunc_size,
+ in_ifindex, out_ifindex,
+ sample_rate);
+ rcu_read_unlock();
+}
+
#endif /* __NET_PSAMPLE_H */
diff --git a/net/psample/psample.c b/net/psample/psample.c
index 33e238c965bd..983ca5b698fe 100644
--- a/net/psample/psample.c
+++ b/net/psample/psample.c
@@ -8,6 +8,7 @@
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/module.h>
+#include <linux/rcupdate.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/netlink.h>
@@ -35,6 +36,10 @@ static const struct genl_multicast_group psample_nl_mcgrps[]
= {
static struct genl_family psample_nl_family __ro_after_init;
+static const struct psample_ops psample_sample_ops = {
+ .sample_packet = psample_sample_packet,
+};
+
static int psample_group_nl_fill(struct sk_buff *msg,
struct psample_group *group,
enum psample_command cmd, u32 portid, u32 seq,
@@ -456,11 +461,18 @@ EXPORT_SYMBOL_GPL(psample_sample_packet);
static int __init psample_module_init(void)
{
- return genl_register_family(&psample_nl_family);
+ int ret;
+
+ ret = genl_register_family(&psample_nl_family);
+ if (!ret)
+ RCU_INIT_POINTER(psample_ops, &psample_sample_ops);
+ return ret;
}
static void __exit psample_module_exit(void)
{
+ rcu_assign_pointer(psample_ops, NULL);
+ synchronize_rcu();
genl_unregister_family(&psample_nl_family);
}
diff --git a/net/sched/Makefile b/net/sched/Makefile
index dd14ef413fda..0d92bb98bb26 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -3,7 +3,7 @@
# Makefile for the Linux Traffic Control Unit.
#
-obj-y := sch_generic.o sch_mq.o
+obj-y := sch_generic.o sch_mq.o psample_stub.o
obj-$(CONFIG_INET) += sch_frag.o
obj-$(CONFIG_NET_SCHED) += sch_api.o sch_blackhole.o
diff --git a/net/sched/psample_stub.c b/net/sched/psample_stub.c
new file mode 100644
index 000000000000..0541b8c5100d
--- /dev/null
+++ b/net/sched/psample_stub.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2021 Mellanox Technologies. */
+
+const struct psample_ops __rcu *psample_ops __read_mostly;
+EXPORT_SYMBOL_GPL(psample_ops);
--
2.26.2
