[ovs-dev] [PATCH v18 3/8] dpif-offload-provider: Introduce dpif-offload-provider layer

[Chris Mi]

Some offload actions require functionality that is not netdev
based, but dpif. For example, sFlow action requires to create
a psample netlink socket to receive the sampled packets from
TC or kernel driver.

Create dpif-offload-provider layer to support such actions.

Signed-off-by: Chris Mi <cmi at nvidia.com>
Reviewed-by: Eli Britstein <elibr at nvidia.com>
---
 lib/automake.mk             |  2 ++
 lib/dpif-offload-provider.h | 52 +++++++++++++++++++++++++++++++++++++
 lib/dpif-offload.c          | 43 ++++++++++++++++++++++++++++++
 lib/dpif-provider.h         |  4 ++-
 4 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 lib/dpif-offload-provider.h
 create mode 100644 lib/dpif-offload.c

diff --git a/lib/automake.mk b/lib/automake.mk
index 46f869a33..9259f57de 100644
--- a/lib/automake.mk
+++ b/lib/automake.mk
@@ -127,6 +127,8 @@ lib_libopenvswitch_la_SOURCES = \
 	lib/dpif-netdev-private.h \
 	lib/dpif-netdev-perf.c \
 	lib/dpif-netdev-perf.h \
+	lib/dpif-offload.c \
+	lib/dpif-offload-provider.h \
 	lib/dpif-provider.h \
 	lib/dpif.c \
 	lib/dpif.h \
diff --git a/lib/dpif-offload-provider.h b/lib/dpif-offload-provider.h
new file mode 100644
index 000000000..3b94740df
--- /dev/null
+++ b/lib/dpif-offload-provider.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef DPIF_OFFLOAD_PROVIDER_H
+#define DPIF_OFFLOAD_PROVIDER_H
+
+struct dpif;
+struct dpif_offload_sflow;
+
+/* Datapath interface offload structure, to be defined by each implementation
+ * of a datapath interface.
+ */
+struct dpif_offload_class {
+    /* Type of dpif offload in this class, e.g. "system", "netdev", etc.
+     *
+     * One of the providers should supply a "system" type, since this is
+     * the type assumed if no type is specified when opening a dpif. */
+    const char *type;
+
+    /* Called when the dpif offload provider is registered. */
+    int (*init)(void);
+
+    /* Free all dpif offload resources. */
+    void (*destroy)(void);
+
+    /* Arranges for the poll loop for an upcall handler to wake up when psample
+     * has a message queued to be received. */
+    void (*sflow_recv_wait)(void);
+
+    /* Polls for an upcall from psample for an upcall handler.
+     * Return 0 for success. */
+    int (*sflow_recv)(struct dpif_offload_sflow *sflow);
+};
+
+void dpif_offload_sflow_recv_wait(const struct dpif *dpif);
+int dpif_offload_sflow_recv(const struct dpif *dpif,
+                            struct dpif_offload_sflow *sflow);
+
+#endif /* DPIF_OFFLOAD_PROVIDER_H */
diff --git a/lib/dpif-offload.c b/lib/dpif-offload.c
new file mode 100644
index 000000000..f2bf3e634
--- /dev/null
+++ b/lib/dpif-offload.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+#include <errno.h>
+
+#include "dpif-provider.h"
+
+void
+dpif_offload_sflow_recv_wait(const struct dpif *dpif)
+{
+    const struct dpif_offload_class *offload_class = dpif->offload_class;
+
+    if (offload_class && offload_class->sflow_recv_wait) {
+        offload_class->sflow_recv_wait();
+    }
+}
+
+int
+dpif_offload_sflow_recv(const struct dpif *dpif,
+                        struct dpif_offload_sflow *sflow)
+{
+    const struct dpif_offload_class *offload_class = dpif->offload_class;
+
+    if (offload_class && offload_class->sflow_recv) {
+        return offload_class->sflow_recv(sflow);
+    }
+
+    return EOPNOTSUPP;
+}
diff --git a/lib/dpif-provider.h b/lib/dpif-provider.h
index 27e3a7658..37b3d3618 100644
--- a/lib/dpif-provider.h
+++ b/lib/dpif-provider.h
@@ -22,8 +22,9 @@
  * exposed over OpenFlow as a single switch.  Datapaths and the collections of
  * ports that they contain may be fixed or dynamic. */
 
-#include "openflow/openflow.h"
 #include "dpif.h"
+#include "dpif-offload-provider.h"
+#include "openflow/openflow.h"
 #include "util.h"
 
 #ifdef  __cplusplus
@@ -35,6 +36,7 @@ extern "C" {
  * This structure should be treated as opaque by dpif implementations. */
 struct dpif {
     const struct dpif_class *dpif_class;
+    const struct dpif_offload_class *offload_class;
     char *base_name;
     char *full_name;
     uint8_t netflow_engine_type;
-- 
2.30.2