Add support for a new action: emit_sample.
This action accepts a u32 group id and a variable-length cookie and uses
the psample multicast group to make the packet available for
observability.
The maximum length of the user-defined cookie is set to 16, same as
tc_cookie, to discourage using cookies that will not be offloadable.
Signed-off-by: Adrian Moreno
---
Documentation/netlink/specs/ovs_flow.yaml | 17 +
include/uapi/linux/openvswitch.h | 27 ++
net/openvswitch/Kconfig | 1 +
net/openvswitch/actions.c | 45 +++
net/openvswitch/flow_netlink.c| 33 -
5 files changed, 122 insertions(+), 1 deletion(-)
diff --git a/Documentation/netlink/specs/ovs_flow.yaml
b/Documentation/netlink/specs/ovs_flow.yaml
index 4fdfc6b5cae9..a7ab5593a24f 100644
--- a/Documentation/netlink/specs/ovs_flow.yaml
+++ b/Documentation/netlink/specs/ovs_flow.yaml
@@ -727,6 +727,12 @@ attribute-sets:
name: dec-ttl
type: nest
nested-attributes: dec-ttl-attrs
+ -
+name: emit-sample
+type: nest
+nested-attributes: emit-sample-attrs
+doc: |
+ Sends a packet sample to psample for external observation.
-
name: tunnel-key-attrs
enum-name: ovs-tunnel-key-attr
@@ -938,6 +944,17 @@ attribute-sets:
-
name: gbp
type: u32
+ -
+name: emit-sample-attrs
+enum-name: ovs-emit-sample-attr
+name-prefix: ovs-emit-sample-attr-
+attributes:
+ -
+name: group
+type: u32
+ -
+name: cookie
+type: binary
operations:
name-prefix: ovs-flow-cmd-
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index efc82c318fa2..b91b4c3cc230 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -914,6 +914,30 @@ struct check_pkt_len_arg {
};
#endif
+#define OVS_EMIT_SAMPLE_COOKIE_MAX_SIZE 16
+/**
+ * enum ovs_emit_sample_attr - Attributes for %OVS_ACTION_ATTR_EMIT_SAMPLE
+ * action.
+ *
+ * @OVS_EMIT_SAMPLE_ATTR_GROUP: 32-bit number to identify the source of the
+ * sample.
+ * @OVS_EMIT_SAMPLE_ATTR_COOKIE: A variable-length binary cookie that contains
+ * user-defined metadata. The maximum length is OVS_EMIT_SAMPLE_COOKIE_MAX_SIZE
+ * bytes.
+ *
+ * Sends the packet to the psample multicast group with the specified group and
+ * cookie. It is possible to combine this action with the
+ * %OVS_ACTION_ATTR_TRUNC action to limit the size of the packet being emitted.
+ */
+enum ovs_emit_sample_attr {
+ OVS_EMIT_SAMPLE_ATTR_UNPSEC,
+ OVS_EMIT_SAMPLE_ATTR_GROUP, /* u32 number. */
+ OVS_EMIT_SAMPLE_ATTR_COOKIE,/* Optional, user specified cookie. */
+ __OVS_EMIT_SAMPLE_ATTR_MAX
+};
+
+#define OVS_EMIT_SAMPLE_ATTR_MAX (__OVS_EMIT_SAMPLE_ATTR_MAX - 1)
+
/**
* enum ovs_action_attr - Action types.
*
@@ -966,6 +990,8 @@ struct check_pkt_len_arg {
* of l3 tunnel flag in the tun_flags field of OVS_ACTION_ATTR_ADD_MPLS
* argument.
* @OVS_ACTION_ATTR_DROP: Explicit drop action.
+ * @OVS_ACTION_ATTR_EMIT_SAMPLE: Send a sample of the packet to external
+ * observers via psample.
*
* Only a single header can be set with a single %OVS_ACTION_ATTR_SET. Not all
* fields within a header are modifiable, e.g. the IPv4 protocol and fragment
@@ -1004,6 +1030,7 @@ enum ovs_action_attr {
OVS_ACTION_ATTR_ADD_MPLS, /* struct ovs_action_add_mpls. */
OVS_ACTION_ATTR_DEC_TTL, /* Nested OVS_DEC_TTL_ATTR_*. */
OVS_ACTION_ATTR_DROP, /* u32 error code. */
+ OVS_ACTION_ATTR_EMIT_SAMPLE, /* Nested OVS_EMIT_SAMPLE_ATTR_*. */
__OVS_ACTION_ATTR_MAX,/* Nothing past this will be accepted
* from userspace. */
diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig
index 29a7081858cd..2535f3f9f462 100644
--- a/net/openvswitch/Kconfig
+++ b/net/openvswitch/Kconfig
@@ -10,6 +10,7 @@ config OPENVSWITCH
(NF_CONNTRACK && ((!NF_DEFRAG_IPV6 || NF_DEFRAG_IPV6) && \
(!NF_NAT || NF_NAT) && \
(!NETFILTER_CONNCOUNT ||
NETFILTER_CONNCOUNT)))
+ depends on PSAMPLE || !PSAMPLE
select LIBCRC32C
select MPLS
select NET_MPLS_GSO
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 964225580824..1f555cbba312 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -24,6 +24,11 @@
#include
#include
#include
+
+#if IS_ENABLED(CONFIG_PSAMPLE)
+#include
+#endif
+
#include
#include "datapath.h"
@@ -1299,6 +1304,37 @@ static int execute_dec_ttl(struct sk_buff *skb, struct
sw_flow_key *key)
return 0;
}
+static void execute_emit_sample(struct datapath *dp, struct sk_buff *skb,
+ const struct sw_flow_key *key,
+
