Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/samples/bpf/tcp_dumpstats_kern.c b/samples/bpf/tcp_dumpstats_kern.c
new file mode 100644
index 0000000..8557913
--- /dev/null
+++ b/samples/bpf/tcp_dumpstats_kern.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Refer to samples/bpf/tcp_bpf.readme for the instructions on
+ * how to run this sample program.
+ */
+#include <linux/bpf.h>
+
+#include "bpf_helpers.h"
+#include "bpf_endian.h"
+
+#define INTERVAL 1000000000ULL
+
+int _version SEC("version") = 1;
+char _license[] SEC("license") = "GPL";
+
+struct {
+ __u32 type;
+ __u32 map_flags;
+ int *key;
+ __u64 *value;
+} bpf_next_dump SEC(".maps") = {
+ .type = BPF_MAP_TYPE_SK_STORAGE,
+ .map_flags = BPF_F_NO_PREALLOC,
+};
+
+SEC("sockops")
+int _sockops(struct bpf_sock_ops *ctx)
+{
+ struct bpf_tcp_sock *tcp_sk;
+ struct bpf_sock *sk;
+ __u64 *next_dump;
+ __u64 now;
+
+ switch (ctx->op) {
+ case BPF_SOCK_OPS_TCP_CONNECT_CB:
+ bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
+ return 1;
+ case BPF_SOCK_OPS_RTT_CB:
+ break;
+ default:
+ return 1;
+ }
+
+ sk = ctx->sk;
+ if (!sk)
+ return 1;
+
+ next_dump = bpf_sk_storage_get(&bpf_next_dump, sk, 0,
+ BPF_SK_STORAGE_GET_F_CREATE);
+ if (!next_dump)
+ return 1;
+
+ now = bpf_ktime_get_ns();
+ if (now < *next_dump)
+ return 1;
+
+ tcp_sk = bpf_tcp_sock(sk);
+ if (!tcp_sk)
+ return 1;
+
+ *next_dump = now + INTERVAL;
+
+ bpf_printk("dsack_dups=%u delivered=%u\n",
+ tcp_sk->dsack_dups, tcp_sk->delivered);
+ bpf_printk("delivered_ce=%u icsk_retransmits=%u\n",
+ tcp_sk->delivered_ce, tcp_sk->icsk_retransmits);
+
+ return 1;
+}