[PATCH bpf-next v2 1/2] bpf: Add bpf_ktime_get_real_ns

[PATCH bpf-next v2 1/2] bpf: Add bpf_ktime_get_real_ns

[bimmy.pujari]

From: Bimmy Pujari <bimmy.pujari@intel.com>

The existing bpf helper functions to get timestamp return the time
elapsed since system boot. This timestamp is not particularly useful
where epoch timestamp is required or more than one server is involved
and time sync is required. Instead, you want to use CLOCK_REALTIME,
which provides epoch timestamp.
Hence add bfp_ktime_get_real_ns() based around CLOCK_REALTIME.

Signed-off-by: Ashkan Nikravesh <ashkan.nikravesh@intel.com>
Signed-off-by: Bimmy Pujari <bimmy.pujari@intel.com>
---
 drivers/media/rc/bpf-lirc.c    |  2 ++
 include/linux/bpf.h            |  1 +
 include/uapi/linux/bpf.h       |  8 ++++++++
 kernel/bpf/core.c              |  1 +
 kernel/bpf/helpers.c           | 13 +++++++++++++
 kernel/trace/bpf_trace.c       |  2 ++
 tools/include/uapi/linux/bpf.h |  8 ++++++++
 7 files changed, 35 insertions(+)

diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c
index 5bb144435c16..1cae0cfdcbaf 100644
--- a/drivers/media/rc/bpf-lirc.c
+++ b/drivers/media/rc/bpf-lirc.c
@@ -103,6 +103,8 @@ lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_map_peek_elem_proto;
 	case BPF_FUNC_ktime_get_ns:
 		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_real_ns:
+		return &bpf_ktime_get_real_ns_proto;
 	case BPF_FUNC_ktime_get_boot_ns:
 		return &bpf_ktime_get_boot_ns_proto;
 	case BPF_FUNC_tail_call:
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index fc5c901c7542..3179fcc4ef53 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1756,6 +1756,7 @@ extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
 extern const struct bpf_func_proto bpf_get_numa_node_id_proto;
 extern const struct bpf_func_proto bpf_tail_call_proto;
 extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
+extern const struct bpf_func_proto bpf_ktime_get_real_ns_proto;
 extern const struct bpf_func_proto bpf_ktime_get_boot_ns_proto;
 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index a22812561064..198e69a6508d 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3586,6 +3586,13 @@ union bpf_attr {
  * 		the data in *dst*. This is a wrapper of **copy_from_user**\ ().
  * 	Return
  * 		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_ktime_get_real_ns(void)
+ *	Description
+ *		Return the real time in nanoseconds.
+ *		See: **clock_gettime**\ (**CLOCK_REALTIME**)
+ *	Return
+ *		Current *ktime*.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3737,6 +3744,7 @@ union bpf_attr {
 	FN(inode_storage_delete),	\
 	FN(d_path),			\
 	FN(copy_from_user),		\
+	FN(ktime_get_real_ns),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index c4811b139caa..af38af5ffc8b 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2207,6 +2207,7 @@ const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
+const struct bpf_func_proto bpf_ktime_get_real_ns_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
 
 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 5cc7425ee476..776ff58f969d 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -155,6 +155,17 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto = {
 	.ret_type	= RET_INTEGER,
 };
 
+BPF_CALL_0(bpf_ktime_get_real_ns)
+{
+	/* NMI safe access to clock realtime */
+	return ktime_get_real_fast_ns();
+}
+
+const struct bpf_func_proto bpf_ktime_get_real_ns_proto = {
+	.func		= bpf_ktime_get_real_ns,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+};
 BPF_CALL_0(bpf_ktime_get_boot_ns)
 {
 	/* NMI safe access to clock boottime */
@@ -655,6 +666,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 		return &bpf_tail_call_proto;
 	case BPF_FUNC_ktime_get_ns:
 		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_real_ns:
+		return &bpf_ktime_get_real_ns_proto;
 	case BPF_FUNC_ktime_get_boot_ns:
 		return &bpf_ktime_get_boot_ns_proto;
 	case BPF_FUNC_ringbuf_output:
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 36508f46a8db..18b644fff0be 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1165,6 +1165,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_map_peek_elem_proto;
 	case BPF_FUNC_ktime_get_ns:
 		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_real_ns:
+		return &bpf_ktime_get_real_ns_proto;
 	case BPF_FUNC_ktime_get_boot_ns:
 		return &bpf_ktime_get_boot_ns_proto;
 	case BPF_FUNC_tail_call:
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index a22812561064..198e69a6508d 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3586,6 +3586,13 @@ union bpf_attr {
  * 		the data in *dst*. This is a wrapper of **copy_from_user**\ ().
  * 	Return
  * 		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_ktime_get_real_ns(void)
+ *	Description
+ *		Return the real time in nanoseconds.
+ *		See: **clock_gettime**\ (**CLOCK_REALTIME**)
+ *	Return
+ *		Current *ktime*.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3737,6 +3744,7 @@ union bpf_attr {
 	FN(inode_storage_delete),	\
 	FN(d_path),			\
 	FN(copy_from_user),		\
+	FN(ktime_get_real_ns),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
-- 
2.17.1

[PATCH bpf-next v2 2/2] selftests/bpf: Verifying real time helper function

[bimmy.pujari]

From: Bimmy Pujari <bimmy.pujari@intel.com>

Test xdping measures RTT from xdp using monotonic time helper.
Extending xdping test to use real time helper function in order
to verify this helper function.

Signed-off-by: Bimmy Pujari <bimmy.pujari@intel.com>
Signed-off-by: Ashkan Nikravesh <ashkan.nikravesh@intel.com>
---
 .../testing/selftests/bpf/progs/xdping_kern.c | 183 +----------------
 .../testing/selftests/bpf/progs/xdping_kern.h | 193 ++++++++++++++++++
 .../bpf/progs/xdping_realtime_kern.c          |   4 +
 tools/testing/selftests/bpf/test_xdping.sh    |  44 +++-
 4 files changed, 235 insertions(+), 189 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/xdping_kern.h
 create mode 100644 tools/testing/selftests/bpf/progs/xdping_realtime_kern.c

diff --git a/tools/testing/selftests/bpf/progs/xdping_kern.c b/tools/testing/selftests/bpf/progs/xdping_kern.c
index 6b9ca40bd1f4..0a152f6835fe 100644
--- a/tools/testing/selftests/bpf/progs/xdping_kern.c
+++ b/tools/testing/selftests/bpf/progs/xdping_kern.c
@@ -1,184 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-/* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. */
+#undef REALTIME
 
-#define KBUILD_MODNAME "foo"
-#include <stddef.h>
-#include <string.h>
-#include <linux/bpf.h>
-#include <linux/icmp.h>
-#include <linux/in.h>
-#include <linux/if_ether.h>
-#include <linux/if_packet.h>
-#include <linux/if_vlan.h>
-#include <linux/ip.h>
+#include "xdping_kern.h"
 
-#include <bpf/bpf_helpers.h>
-#include <bpf/bpf_endian.h>
-
-#include "xdping.h"
-
-struct {
-	__uint(type, BPF_MAP_TYPE_HASH);
-	__uint(max_entries, 256);
-	__type(key, __u32);
-	__type(value, struct pinginfo);
-} ping_map SEC(".maps");
-
-static __always_inline void swap_src_dst_mac(void *data)
-{
-	unsigned short *p = data;
-	unsigned short dst[3];
-
-	dst[0] = p[0];
-	dst[1] = p[1];
-	dst[2] = p[2];
-	p[0] = p[3];
-	p[1] = p[4];
-	p[2] = p[5];
-	p[3] = dst[0];
-	p[4] = dst[1];
-	p[5] = dst[2];
-}
-
-static __always_inline __u16 csum_fold_helper(__wsum sum)
-{
-	sum = (sum & 0xffff) + (sum >> 16);
-	return ~((sum & 0xffff) + (sum >> 16));
-}
-
-static __always_inline __u16 ipv4_csum(void *data_start, int data_size)
-{
-	__wsum sum;
-
-	sum = bpf_csum_diff(0, 0, data_start, data_size, 0);
-	return csum_fold_helper(sum);
-}
-
-#define ICMP_ECHO_LEN		64
-
-static __always_inline int icmp_check(struct xdp_md *ctx, int type)
-{
-	void *data_end = (void *)(long)ctx->data_end;
-	void *data = (void *)(long)ctx->data;
-	struct ethhdr *eth = data;
-	struct icmphdr *icmph;
-	struct iphdr *iph;
-
-	if (data + sizeof(*eth) + sizeof(*iph) + ICMP_ECHO_LEN > data_end)
-		return XDP_PASS;
-
-	if (eth->h_proto != bpf_htons(ETH_P_IP))
-		return XDP_PASS;
-
-	iph = data + sizeof(*eth);
-
-	if (iph->protocol != IPPROTO_ICMP)
-		return XDP_PASS;
-
-	if (bpf_ntohs(iph->tot_len) - sizeof(*iph) != ICMP_ECHO_LEN)
-		return XDP_PASS;
-
-	icmph = data + sizeof(*eth) + sizeof(*iph);
-
-	if (icmph->type != type)
-		return XDP_PASS;
-
-	return XDP_TX;
-}
-
-SEC("xdpclient")
-int xdping_client(struct xdp_md *ctx)
-{
-	void *data_end = (void *)(long)ctx->data_end;
-	void *data = (void *)(long)ctx->data;
-	struct pinginfo *pinginfo = NULL;
-	struct ethhdr *eth = data;
-	struct icmphdr *icmph;
-	struct iphdr *iph;
-	__u64 recvtime;
-	__be32 raddr;
-	__be16 seq;
-	int ret;
-	__u8 i;
-
-	ret = icmp_check(ctx, ICMP_ECHOREPLY);
-
-	if (ret != XDP_TX)
-		return ret;
-
-	iph = data + sizeof(*eth);
-	icmph = data + sizeof(*eth) + sizeof(*iph);
-	raddr = iph->saddr;
-
-	/* Record time reply received. */
-	recvtime = bpf_ktime_get_ns();
-	pinginfo = bpf_map_lookup_elem(&ping_map, &raddr);
-	if (!pinginfo || pinginfo->seq != icmph->un.echo.sequence)
-		return XDP_PASS;
-
-	if (pinginfo->start) {
-#pragma clang loop unroll(full)
-		for (i = 0; i < XDPING_MAX_COUNT; i++) {
-			if (pinginfo->times[i] == 0)
-				break;
-		}
-		/* verifier is fussy here... */
-		if (i < XDPING_MAX_COUNT) {
-			pinginfo->times[i] = recvtime -
-					     pinginfo->start;
-			pinginfo->start = 0;
-			i++;
-		}
-		/* No more space for values? */
-		if (i == pinginfo->count || i == XDPING_MAX_COUNT)
-			return XDP_PASS;
-	}
-
-	/* Now convert reply back into echo request. */
-	swap_src_dst_mac(data);
-	iph->saddr = iph->daddr;
-	iph->daddr = raddr;
-	icmph->type = ICMP_ECHO;
-	seq = bpf_htons(bpf_ntohs(icmph->un.echo.sequence) + 1);
-	icmph->un.echo.sequence = seq;
-	icmph->checksum = 0;
-	icmph->checksum = ipv4_csum(icmph, ICMP_ECHO_LEN);
-
-	pinginfo->seq = seq;
-	pinginfo->start = bpf_ktime_get_ns();
-
-	return XDP_TX;
-}
-
-SEC("xdpserver")
-int xdping_server(struct xdp_md *ctx)
-{
-	void *data_end = (void *)(long)ctx->data_end;
-	void *data = (void *)(long)ctx->data;
-	struct ethhdr *eth = data;
-	struct icmphdr *icmph;
-	struct iphdr *iph;
-	__be32 raddr;
-	int ret;
-
-	ret = icmp_check(ctx, ICMP_ECHO);
-
-	if (ret != XDP_TX)
-		return ret;
-
-	iph = data + sizeof(*eth);
-	icmph = data + sizeof(*eth) + sizeof(*iph);
-	raddr = iph->saddr;
-
-	/* Now convert request into echo reply. */
-	swap_src_dst_mac(data);
-	iph->saddr = iph->daddr;
-	iph->daddr = raddr;
-	icmph->type = ICMP_ECHOREPLY;
-	icmph->checksum = 0;
-	icmph->checksum = ipv4_csum(icmph, ICMP_ECHO_LEN);
-
-	return XDP_TX;
-}
-
-char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/xdping_kern.h b/tools/testing/selftests/bpf/progs/xdping_kern.h
new file mode 100644
index 000000000000..ca4b62214808
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/xdping_kern.h
@@ -0,0 +1,193 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. */
+
+#define KBUILD_MODNAME "foo"
+#include <stddef.h>
+#include <string.h>
+#include <linux/bpf.h>
+#include <linux/icmp.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#include "xdping.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 256);
+	__type(key, __u32);
+	__type(value, struct pinginfo);
+} ping_map SEC(".maps");
+
+static __always_inline void swap_src_dst_mac(void *data)
+{
+	unsigned short *p = data;
+	unsigned short dst[3];
+
+	dst[0] = p[0];
+	dst[1] = p[1];
+	dst[2] = p[2];
+	p[0] = p[3];
+	p[1] = p[4];
+	p[2] = p[5];
+	p[3] = dst[0];
+	p[4] = dst[1];
+	p[5] = dst[2];
+}
+
+static __always_inline __u16 csum_fold_helper(__wsum sum)
+{
+	sum = (sum & 0xffff) + (sum >> 16);
+	return ~((sum & 0xffff) + (sum >> 16));
+}
+
+static __always_inline __u16 ipv4_csum(void *data_start, int data_size)
+{
+	__wsum sum;
+
+	sum = bpf_csum_diff(0, 0, data_start, data_size, 0);
+	return csum_fold_helper(sum);
+}
+
+#define ICMP_ECHO_LEN		64
+
+static __always_inline int icmp_check(struct xdp_md *ctx, int type)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	struct icmphdr *icmph;
+	struct iphdr *iph;
+
+	if (data + sizeof(*eth) + sizeof(*iph) + ICMP_ECHO_LEN > data_end)
+		return XDP_PASS;
+
+	if (eth->h_proto != bpf_htons(ETH_P_IP))
+		return XDP_PASS;
+
+	iph = data + sizeof(*eth);
+
+	if (iph->protocol != IPPROTO_ICMP)
+		return XDP_PASS;
+
+	if (bpf_ntohs(iph->tot_len) - sizeof(*iph) != ICMP_ECHO_LEN)
+		return XDP_PASS;
+
+	icmph = data + sizeof(*eth) + sizeof(*iph);
+
+	if (icmph->type != type)
+		return XDP_PASS;
+
+	return XDP_TX;
+}
+
+SEC("xdpclient")
+int xdping_client(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct pinginfo *pinginfo = NULL;
+	struct ethhdr *eth = data;
+	struct icmphdr *icmph;
+	struct iphdr *iph;
+	__u64 recvtime;
+	__be32 raddr;
+	__be16 seq;
+	int ret;
+	__u8 i;
+
+	ret = icmp_check(ctx, ICMP_ECHOREPLY);
+
+	if (ret != XDP_TX)
+		return ret;
+
+	iph = data + sizeof(*eth);
+	icmph = data + sizeof(*eth) + sizeof(*iph);
+	raddr = iph->saddr;
+
+	/* Record time reply received. */
+#ifdef REALTIME
+	recvtime = bpf_ktime_get_real_ns();
+#else
+	recvtime = bpf_ktime_get_ns();
+#endif
+	pinginfo = bpf_map_lookup_elem(&ping_map, &raddr);
+	if (!pinginfo || pinginfo->seq != icmph->un.echo.sequence)
+		return XDP_PASS;
+
+	if (pinginfo->start) {
+#pragma clang loop unroll(full)
+		for (i = 0; i < XDPING_MAX_COUNT; i++) {
+			if ((pinginfo->times[i] == 0) ||
+					(pinginfo->start >= recvtime))
+				break;
+		}
+		/* verifier is fussy here... */
+		if (i < XDPING_MAX_COUNT) {
+			pinginfo->times[i] = recvtime -
+					     pinginfo->start;
+			pinginfo->start = 0;
+			i++;
+		}
+		/* No more space for values? */
+		if (i == pinginfo->count || i == XDPING_MAX_COUNT)
+			return XDP_PASS;
+	}
+
+	/* Now convert reply back into echo request. */
+	swap_src_dst_mac(data);
+	iph->saddr = iph->daddr;
+	iph->daddr = raddr;
+	icmph->type = ICMP_ECHO;
+	seq = bpf_htons(bpf_ntohs(icmph->un.echo.sequence) + 1);
+	icmph->un.echo.sequence = seq;
+	icmph->checksum = 0;
+	icmph->checksum = ipv4_csum(icmph, ICMP_ECHO_LEN);
+
+	pinginfo->seq = seq;
+#ifdef REALTIME
+	pinginfo->start = bpf_ktime_get_real_ns();
+#else
+	pinginfo->start = bpf_ktime_get_ns();
+#endif
+
+	return XDP_TX;
+}
+
+SEC("xdpserver")
+int xdping_server(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	struct icmphdr *icmph;
+	struct iphdr *iph;
+	__be32 raddr;
+	int ret;
+
+	ret = icmp_check(ctx, ICMP_ECHO);
+
+	if (ret != XDP_TX)
+		return ret;
+
+	iph = data + sizeof(*eth);
+	icmph = data + sizeof(*eth) + sizeof(*iph);
+	raddr = iph->saddr;
+
+	/* Now convert request into echo reply. */
+	swap_src_dst_mac(data);
+	iph->saddr = iph->daddr;
+	iph->daddr = raddr;
+	icmph->type = ICMP_ECHOREPLY;
+	icmph->checksum = 0;
+	icmph->checksum = ipv4_csum(icmph, ICMP_ECHO_LEN);
+
+	return XDP_TX;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/xdping_realtime_kern.c b/tools/testing/selftests/bpf/progs/xdping_realtime_kern.c
new file mode 100644
index 000000000000..85f9d9bfc5b7
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/xdping_realtime_kern.c
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+#define REALTIME
+
+#include "xdping_kern.h"
diff --git a/tools/testing/selftests/bpf/test_xdping.sh b/tools/testing/selftests/bpf/test_xdping.sh
index c2f0ddb45531..3e357755b279 100755
--- a/tools/testing/selftests/bpf/test_xdping.sh
+++ b/tools/testing/selftests/bpf/test_xdping.sh
@@ -42,11 +42,13 @@ setup()
 	ip addr add ${LOCAL_IP}/24 dev veth1
 	ip netns exec $TARGET_NS ip link set veth0 up
 	ip link set veth1 up
+	ln -s xdping xdping_realtime
 }
 
 cleanup()
 {
 	set +e
+	rm xdping_realtime
 	ip netns delete $TARGET_NS 2>/dev/null
 	ip link del veth1 2>/dev/null
 	if [[ $server_pid -ne 0 ]]; then
@@ -54,7 +56,7 @@ cleanup()
 	fi
 }
 
-test()
+test1()
 {
 	client_args="$1"
 	server_args="$2"
@@ -77,6 +79,28 @@ test()
 	echo "Test client args '$client_args'; server args '$server_args': PASS"
 }
 
+test2()
+{
+	client_args="$1"
+        server_args="$2"
+
+        echo "Test client args '$client_args'; server args '$server_args'"
+
+        server_pid=0
+        if [[ -n "$server_args" ]]; then
+                ip netns exec $TARGET_NS ./xdping_realtime $server_args &
+                server_pid=$!
+                sleep 10
+        fi
+        ./xdping_realtime $client_args $TARGET_IP
+
+        if [[ $server_pid -ne 0 ]]; then
+                kill -TERM $server_pid
+                server_pid=0
+        fi
+
+        echo "Test client args '$client_args'; server args '$server_args': PASS"
+}
 set -e
 
 server_pid=0
@@ -85,14 +109,18 @@ trap cleanup EXIT
 
 setup
 
-for server_args in "" "-I veth0 -s -S" ; do
-	# client in skb mode
-	client_args="-I veth1 -S"
-	test "$client_args" "$server_args"
+for tests in test1 test2; do
+	echo "Running ${tests}:"
+	for server_args in "" "-I veth0 -s -S" ; do
+		# client in skb mode
+		client_args="-I veth1 -S"
+		${tests} "$client_args" "$server_args"
+
+		# client with count of 10 RTT measurements.
+		client_args="-I veth1 -S -c 10"
+		${tests} "$client_args" "$server_args"
+	done
 
-	# client with count of 10 RTT measurements.
-	client_args="-I veth1 -S -c 10"
-	test "$client_args" "$server_args"
 done
 
 echo "OK. All tests passed"
-- 
2.17.1

Re: [PATCH bpf-next v2 1/2] bpf: Add bpf_ktime_get_real_ns

[Maciej Żenczykowski]

On Wed, Sep 23, 2020 at 5:03 PM <bimmy.pujari@intel.com> wrote:
>
> From: Bimmy Pujari <bimmy.pujari@intel.com>
>
> The existing bpf helper functions to get timestamp return the time
> elapsed since system boot. This timestamp is not particularly useful
> where epoch timestamp is required or more than one server is involved
> and time sync is required. Instead, you want to use CLOCK_REALTIME,
> which provides epoch timestamp.
> Hence add bfp_ktime_get_real_ns() based around CLOCK_REALTIME.
>
> Signed-off-by: Ashkan Nikravesh <ashkan.nikravesh@intel.com>
> Signed-off-by: Bimmy Pujari <bimmy.pujari@intel.com>
> ---
>  drivers/media/rc/bpf-lirc.c    |  2 ++
>  include/linux/bpf.h            |  1 +
>  include/uapi/linux/bpf.h       |  8 ++++++++
>  kernel/bpf/core.c              |  1 +
>  kernel/bpf/helpers.c           | 13 +++++++++++++
>  kernel/trace/bpf_trace.c       |  2 ++
>  tools/include/uapi/linux/bpf.h |  8 ++++++++
>  7 files changed, 35 insertions(+)
>
> diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c
> index 5bb144435c16..1cae0cfdcbaf 100644
> --- a/drivers/media/rc/bpf-lirc.c
> +++ b/drivers/media/rc/bpf-lirc.c
> @@ -103,6 +103,8 @@ lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>                 return &bpf_map_peek_elem_proto;
>         case BPF_FUNC_ktime_get_ns:
>                 return &bpf_ktime_get_ns_proto;
> +       case BPF_FUNC_ktime_get_real_ns:
> +               return &bpf_ktime_get_real_ns_proto;
>         case BPF_FUNC_ktime_get_boot_ns:
>                 return &bpf_ktime_get_boot_ns_proto;
>         case BPF_FUNC_tail_call:
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index fc5c901c7542..3179fcc4ef53 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1756,6 +1756,7 @@ extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
>  extern const struct bpf_func_proto bpf_get_numa_node_id_proto;
>  extern const struct bpf_func_proto bpf_tail_call_proto;
>  extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
> +extern const struct bpf_func_proto bpf_ktime_get_real_ns_proto;
>  extern const struct bpf_func_proto bpf_ktime_get_boot_ns_proto;
>  extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
>  extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index a22812561064..198e69a6508d 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -3586,6 +3586,13 @@ union bpf_attr {
>   *             the data in *dst*. This is a wrapper of **copy_from_user**\ ().
>   *     Return
>   *             0 on success, or a negative error in case of failure.
> + *
> + * u64 bpf_ktime_get_real_ns(void)
> + *     Description
> + *             Return the real time in nanoseconds.
> + *             See: **clock_gettime**\ (**CLOCK_REALTIME**)
> + *     Return
> + *             Current *ktime*.
>   */
>  #define __BPF_FUNC_MAPPER(FN)          \
>         FN(unspec),                     \
> @@ -3737,6 +3744,7 @@ union bpf_attr {
>         FN(inode_storage_delete),       \
>         FN(d_path),                     \
>         FN(copy_from_user),             \
> +       FN(ktime_get_real_ns),          \
>         /* */
>
>  /* integer value in 'imm' field of BPF_CALL instruction selects which helper
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index c4811b139caa..af38af5ffc8b 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -2207,6 +2207,7 @@ const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
>  const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
>  const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
>  const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
> +const struct bpf_func_proto bpf_ktime_get_real_ns_proto __weak;
>  const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
>
>  const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index 5cc7425ee476..776ff58f969d 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -155,6 +155,17 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto = {
>         .ret_type       = RET_INTEGER,
>  };
>
> +BPF_CALL_0(bpf_ktime_get_real_ns)
> +{
> +       /* NMI safe access to clock realtime */
> +       return ktime_get_real_fast_ns();
> +}
> +
> +const struct bpf_func_proto bpf_ktime_get_real_ns_proto = {
> +       .func           = bpf_ktime_get_real_ns,
> +       .gpl_only       = true,

imho should be false, this is normally accessible to userspace code
via syscall, no reason why it should be gpl only for bpf

> +       .ret_type       = RET_INTEGER,
> +};
>  BPF_CALL_0(bpf_ktime_get_boot_ns)
>  {
>         /* NMI safe access to clock boottime */
> @@ -655,6 +666,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
>                 return &bpf_tail_call_proto;
>         case BPF_FUNC_ktime_get_ns:
>                 return &bpf_ktime_get_ns_proto;
> +       case BPF_FUNC_ktime_get_real_ns:
> +               return &bpf_ktime_get_real_ns_proto;
>         case BPF_FUNC_ktime_get_boot_ns:
>                 return &bpf_ktime_get_boot_ns_proto;
>         case BPF_FUNC_ringbuf_output:
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 36508f46a8db..18b644fff0be 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1165,6 +1165,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>                 return &bpf_map_peek_elem_proto;
>         case BPF_FUNC_ktime_get_ns:
>                 return &bpf_ktime_get_ns_proto;
> +       case BPF_FUNC_ktime_get_real_ns:
> +               return &bpf_ktime_get_real_ns_proto;
>         case BPF_FUNC_ktime_get_boot_ns:
>                 return &bpf_ktime_get_boot_ns_proto;

should probably be here to stay alpha sorted more or less (also
applies to other places)

>         case BPF_FUNC_tail_call:
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index a22812561064..198e69a6508d 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -3586,6 +3586,13 @@ union bpf_attr {
>   *             the data in *dst*. This is a wrapper of **copy_from_user**\ ().
>   *     Return
>   *             0 on success, or a negative error in case of failure.
> + *
> + * u64 bpf_ktime_get_real_ns(void)
> + *     Description
> + *             Return the real time in nanoseconds.
> + *             See: **clock_gettime**\ (**CLOCK_REALTIME**)
> + *     Return
> + *             Current *ktime*.
>   */
>  #define __BPF_FUNC_MAPPER(FN)          \
>         FN(unspec),                     \
> @@ -3737,6 +3744,7 @@ union bpf_attr {
>         FN(inode_storage_delete),       \
>         FN(d_path),                     \
>         FN(copy_from_user),             \
> +       FN(ktime_get_real_ns),          \
>         /* */
>
>  /* integer value in 'imm' field of BPF_CALL instruction selects which helper
> --
> 2.17.1
>
Maciej Żenczykowski, Kernel Networking Developer @ Google

Re: [PATCH bpf-next v2 1/2] bpf: Add bpf_ktime_get_real_ns

[David Ahern]

On 9/23/20 7:19 PM, Maciej Żenczykowski wrote:
>> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
>> index 5cc7425ee476..776ff58f969d 100644
>> --- a/kernel/bpf/helpers.c
>> +++ b/kernel/bpf/helpers.c
>> @@ -155,6 +155,17 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto = {
>>         .ret_type       = RET_INTEGER,
>>  };
>>
>> +BPF_CALL_0(bpf_ktime_get_real_ns)
>> +{
>> +       /* NMI safe access to clock realtime */
>> +       return ktime_get_real_fast_ns();
>> +}
>> +
>> +const struct bpf_func_proto bpf_ktime_get_real_ns_proto = {
>> +       .func           = bpf_ktime_get_real_ns,
>> +       .gpl_only       = true,
> 
> imho should be false, this is normally accessible to userspace code
> via syscall, no reason why it should be gpl only for bpf
> 

agreed, no reason for the bpf hook to be gpl_only.

Glad to see the v2 of this patch; I wondered what happened to this helper.

RE: [PATCH bpf-next v2 1/2] bpf: Add bpf_ktime_get_real_ns

[Pujari, Bimmy]

-----Original Message-----
From: David Ahern <dsahern@gmail.com> 
Sent: Wednesday, September 23, 2020 7:19 PM
To: Maciej Żenczykowski <maze@google.com>; Pujari, Bimmy <bimmy.pujari@intel.com>
Cc: bpf <bpf@vger.kernel.org>; Linux NetDev <netdev@vger.kernel.org>; mchehab@kernel.org; Alexei Starovoitov <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; Martin Lau <kafai@fb.com>; Nikravesh, Ashkan <ashkan.nikravesh@intel.com>
Subject: Re: [PATCH bpf-next v2 1/2] bpf: Add bpf_ktime_get_real_ns

On 9/23/20 7:19 PM, Maciej Żenczykowski wrote:
>> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 
>> 5cc7425ee476..776ff58f969d 100644
>> --- a/kernel/bpf/helpers.c
>> +++ b/kernel/bpf/helpers.c
>> @@ -155,6 +155,17 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto = {
>>         .ret_type       = RET_INTEGER,
>>  };
>>
>> +BPF_CALL_0(bpf_ktime_get_real_ns)
>> +{
>> +       /* NMI safe access to clock realtime */
>> +       return ktime_get_real_fast_ns(); }
>> +
>> +const struct bpf_func_proto bpf_ktime_get_real_ns_proto = {
>> +       .func           = bpf_ktime_get_real_ns,
>> +       .gpl_only       = true,
> 
> imho should be false, this is normally accessible to userspace code 
> via syscall, no reason why it should be gpl only for bpf
> 

agreed, no reason for the bpf hook to be gpl_only.

Glad to see the v2 of this patch; I wondered what happened to this helper.
BP: Thanks Maciej & Ahern for taking time to look at it. I will update the changes suggested shortly.