[ovs-dev] [PATCH v7 09/11] netdev-offload-tc: Create psample netlink socket

[Chris Mi]

Create psample netlink socket as a pre-step towards receiving sampled
packets.

Signed-off-by: Chris Mi <cmi at nvidia.com>
Reviewed-by: Eli Britstein <elibr at nvidia.com>
---
 lib/netdev-offload-tc.c | 43 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/lib/netdev-offload-tc.c b/lib/netdev-offload-tc.c
index a81003a98..daaa1d1a1 100644
--- a/lib/netdev-offload-tc.c
+++ b/lib/netdev-offload-tc.c
@@ -18,6 +18,7 @@
 
 #include <errno.h>
 #include <linux/if_ether.h>
+#include <linux/psample.h>
 
 #include "dpif.h"
 #include "hash.h"
@@ -51,6 +52,7 @@ static bool multi_mask_per_prio = false;
 static bool block_support = false;
 
 static dpif_netlink_sflow_upcall_callback *upcall_cb;
+static int psample_family;
 
 struct netlink_field {
     int offset;
@@ -2254,6 +2256,46 @@ netdev_tc_register_sflow_upcall_cb(dpif_netlink_sflow_upcall_callback *cb)
     upcall_cb = cb;
 }
 
+static struct nl_sock *
+netdev_tc_psample_init(void)
+{
+    unsigned int psample_mcgroup;
+    struct nl_sock *sock;
+    int error;
+
+    if (nl_lookup_genl_family(PSAMPLE_GENL_NAME, &psample_family)) {
+        VLOG_INFO("%s: Generic Netlink family '%s' does not exist. "
+                  "Please make sure the kernel module psample is loaded",
+                  __func__, PSAMPLE_GENL_NAME);
+        return NULL;
+    }
+
+    if (nl_lookup_genl_mcgroup(PSAMPLE_GENL_NAME,
+                               PSAMPLE_NL_MCGRP_SAMPLE_NAME,
+                               &psample_mcgroup)) {
+        VLOG_INFO("%s: Failed to join multicast group '%s' for Generic "
+                  "Netlink family '%s'", __func__,
+                  PSAMPLE_NL_MCGRP_SAMPLE_NAME,
+                  PSAMPLE_GENL_NAME);
+        return NULL;
+    }
+
+    error = nl_sock_create(NETLINK_GENERIC, &sock);
+    if (error) {
+        VLOG_INFO("%s: Failed to create psample socket", __func__);
+        return NULL;
+    }
+
+    error = nl_sock_join_mcgroup(sock, psample_mcgroup);
+    if (error) {
+        VLOG_INFO("%s: Failed to join psample mcgroup", __func__);
+        nl_sock_destroy(sock);
+        return NULL;
+    }
+
+    return sock;
+}
+
 static int
 netdev_tc_init_flow_api(struct netdev *netdev)
 {
@@ -2288,6 +2330,7 @@ netdev_tc_init_flow_api(struct netdev *netdev)
         block_id = get_block_id_from_netdev(netdev);
 
         probe_multi_mask_per_prio(ifindex);
+        netdev_tc_psample_init();
         ovsthread_once_done(&once);
     }
 
-- 
2.26.2