1 files changed, 248 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/net_timestamping.c b/tools/testing/selftests/bpf/progs/net_timestamping.c
new file mode 100644
index 000000000000..b4c2f0f2be11
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/net_timestamping.c
@@ -0,0 +1,248 @@
+#include "vmlinux.h"
+#include "bpf_tracing_net.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include "bpf_misc.h"
+#include "bpf_kfuncs.h"
+#include <errno.h>
+
+__u32 monitored_pid = 0;
+
+int nr_active;
+int nr_snd;
+int nr_passive;
+int nr_sched;
+int nr_txsw;
+int nr_ack;
+
+struct sk_stg {
+	__u64 sendmsg_ns;	/* record ts when sendmsg is called */
+};
+
+struct sk_tskey {
+	u64 cookie;
+	u32 tskey;
+};
+
+struct delay_info {
+	u64 sendmsg_ns;		/* record ts when sendmsg is called */
+	u32 sched_delay;	/* SCHED_CB - sendmsg_ns */
+	u32 snd_sw_delay;	/* SND_SW_CB - SCHED_CB */
+	u32 ack_delay;		/* ACK_CB - SND_SW_CB */
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_SK_STORAGE);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+	__type(key, int);
+	__type(value, struct sk_stg);
+} sk_stg_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct sk_tskey);
+	__type(value, struct delay_info);
+	__uint(max_entries, 1024);
+} time_map SEC(".maps");
+
+static u64 delay_tolerance_nsec = 10000000000; /* 10 second as an example */
+
+extern int bpf_sock_ops_enable_tx_tstamp(struct bpf_sock_ops_kern *skops, u64 flags) __ksym;
+
+static int bpf_test_sockopt(void *ctx, const struct sock *sk, int expected)
+{
+	int tmp, new = SK_BPF_CB_TX_TIMESTAMPING;
+	int opt = SK_BPF_CB_FLAGS;
+	int level = SOL_SOCKET;
+
+	if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)) != expected)
+		return 1;
+
+	if (bpf_getsockopt(ctx, level, opt, &tmp, sizeof(tmp)) != expected ||
+	    (!expected && tmp != new))
+		return 1;
+
+	return 0;
+}
+
+static bool bpf_test_access_sockopt(void *ctx, const struct sock *sk)
+{
+	if (bpf_test_sockopt(ctx, sk, -EOPNOTSUPP))
+		return true;
+	return false;
+}
+
+static bool bpf_test_access_load_hdr_opt(struct bpf_sock_ops *skops)
+{
+	u8 opt[3] = {0};
+	int load_flags = 0;
+	int ret;
+
+	ret = bpf_load_hdr_opt(skops, opt, sizeof(opt), load_flags);
+	if (ret != -EOPNOTSUPP)
+		return true;
+
+	return false;
+}
+
+static bool bpf_test_access_cb_flags_set(struct bpf_sock_ops *skops)
+{
+	int ret;
+
+	ret = bpf_sock_ops_cb_flags_set(skops, 0);
+	if (ret != -EOPNOTSUPP)
+		return true;
+
+	return false;
+}
+
+/* In the timestamping callbacks, we're not allowed to call the following
+ * BPF CALLs for the safety concern. Return false if expected.
+ */
+static bool bpf_test_access_bpf_calls(struct bpf_sock_ops *skops,
+				      const struct sock *sk)
+{
+	if (bpf_test_access_sockopt(skops, sk))
+		return true;
+
+	if (bpf_test_access_load_hdr_opt(skops))
+		return true;
+
+	if (bpf_test_access_cb_flags_set(skops))
+		return true;
+
+	return false;
+}
+
+static bool bpf_test_delay(struct bpf_sock_ops *skops, const struct sock *sk)
+{
+	struct bpf_sock_ops_kern *skops_kern;
+	u64 timestamp = bpf_ktime_get_ns();
+	struct skb_shared_info *shinfo;
+	struct delay_info dinfo = {0};
+	struct sk_tskey key = {0};
+	struct delay_info *val;
+	struct sk_buff *skb;
+	struct sk_stg *stg;
+	u64 prior_ts, delay;
+
+	if (bpf_test_access_bpf_calls(skops, sk))
+		return false;
+
+	skops_kern = bpf_cast_to_kern_ctx(skops);
+	skb = skops_kern->skb;
+	shinfo = bpf_core_cast(skb->head + skb->end, struct skb_shared_info);
+
+	key.cookie = bpf_get_socket_cookie(skops);
+	if (!key.cookie)
+		return false;
+
+	if (skops->op == BPF_SOCK_OPS_TSTAMP_SENDMSG_CB) {
+		stg = bpf_sk_storage_get(&sk_stg_map, (void *)sk, 0, 0);
+		if (!stg)
+			return false;
+		dinfo.sendmsg_ns = stg->sendmsg_ns;
+		bpf_sock_ops_enable_tx_tstamp(skops_kern, 0);
+		key.tskey = shinfo->tskey;
+		if (!key.tskey)
+			return false;
+		bpf_map_update_elem(&time_map, &key, &dinfo, BPF_ANY);
+		return true;
+	}
+
+	key.tskey = shinfo->tskey;
+	if (!key.tskey)
+		return false;
+
+	val = bpf_map_lookup_elem(&time_map, &key);
+	if (!val)
+		return false;
+
+	switch (skops->op) {
+	case BPF_SOCK_OPS_TSTAMP_SCHED_CB:
+		val->sched_delay = timestamp - val->sendmsg_ns;
+		delay = val->sched_delay;
+		break;
+	case BPF_SOCK_OPS_TSTAMP_SND_SW_CB:
+		prior_ts = val->sched_delay + val->sendmsg_ns;
+		val->snd_sw_delay = timestamp - prior_ts;
+		delay = val->snd_sw_delay;
+		break;
+	case BPF_SOCK_OPS_TSTAMP_ACK_CB:
+		prior_ts = val->snd_sw_delay + val->sched_delay + val->sendmsg_ns;
+		val->ack_delay = timestamp - prior_ts;
+		delay = val->ack_delay;
+		break;
+	}
+
+	if (delay >= delay_tolerance_nsec)
+		return false;
+
+	/* Since it's the last one, remove from the map after latency check */
+	if (skops->op == BPF_SOCK_OPS_TSTAMP_ACK_CB)
+		bpf_map_delete_elem(&time_map, &key);
+
+	return true;
+}
+
+SEC("fentry/tcp_sendmsg_locked")
+int BPF_PROG(trace_tcp_sendmsg_locked, struct sock *sk, struct msghdr *msg,
+	     size_t size)
+{
+	__u32 pid = bpf_get_current_pid_tgid() >> 32;
+	u64 timestamp = bpf_ktime_get_ns();
+	u32 flag = sk->sk_bpf_cb_flags;
+	struct sk_stg *stg;
+
+	if (pid != monitored_pid || !flag)
+		return 0;
+
+	stg = bpf_sk_storage_get(&sk_stg_map, sk, 0,
+				 BPF_SK_STORAGE_GET_F_CREATE);
+	if (!stg)
+		return 0;
+
+	stg->sendmsg_ns = timestamp;
+	nr_snd += 1;
+	return 0;
+}
+
+SEC("sockops")
+int skops_sockopt(struct bpf_sock_ops *skops)
+{
+	struct bpf_sock *bpf_sk = skops->sk;
+	const struct sock *sk;
+
+	if (!bpf_sk)
+		return 1;
+
+	sk = (struct sock *)bpf_skc_to_tcp_sock(bpf_sk);
+	if (!sk)
+		return 1;
+
+	switch (skops->op) {
+	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+		nr_active += !bpf_test_sockopt(skops, sk, 0);
+		break;
+	case BPF_SOCK_OPS_TSTAMP_SENDMSG_CB:
+		if (bpf_test_delay(skops, sk))
+			nr_snd += 1;
+		break;
+	case BPF_SOCK_OPS_TSTAMP_SCHED_CB:
+		if (bpf_test_delay(skops, sk))
+			nr_sched += 1;
+		break;
+	case BPF_SOCK_OPS_TSTAMP_SND_SW_CB:
+		if (bpf_test_delay(skops, sk))
+			nr_txsw += 1;
+		break;
+	case BPF_SOCK_OPS_TSTAMP_ACK_CB:
+		if (bpf_test_delay(skops, sk))
+			nr_ack += 1;
+		break;
+	}
+
+	return 1;
+}
+
+char _license[] SEC("license") = "GPL";