[PATCH bpf-next v2] selftests/bpf: Properly enable hwtstamp in xdp_hw_metadata

[PATCH bpf-next v2] selftests/bpf: Properly enable hwtstamp in xdp_hw_metadata

[Stanislav Fomichev]

The existing timestamping_enable() is a no-op because it applies
to the socket-related path that we are not verifying here
anymore. (but still leaving the code around hoping we can
have xdp->skb path verified here as well)

  poll: 1 (0)
  xsk_ring_cons__peek: 1
  0xf64788: rx_desc[0]->addr=100000000008000 addr=8100 comp_addr=8000
  rx_hash: 3697961069
  rx_timestamp:  1674657672142214773 (sec:1674657672.1422)
  XDP RX-time:   1674657709561774876 (sec:1674657709.5618) delta sec:37.4196
  AF_XDP time:   1674657709561871034 (sec:1674657709.5619) delta
sec:0.0001 (96.158 usec)
  0xf64788: complete idx=8 addr=8000

Also, maybe something to archive here, see [0] for Jesper's note
about NIC vs host clock delta.

0: https://lore.kernel.org/bpf/f3a116dc-1b14-3432-ad20-a36179ef0608@redhat.com/

v2:
- Restore original value (Martin)

Fixes: 297a3f124155 ("selftests/bpf: Simple program to dump XDP RX metadata")
Reported-by: Jesper Dangaard Brouer <jbrouer@redhat.com>
Tested-by: Jesper Dangaard Brouer <jbrouer@redhat.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
 tools/testing/selftests/bpf/xdp_hw_metadata.c | 45 ++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
index 0008f0f239e8..3823b1c499cc 100644
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -24,6 +24,7 @@
 #include <linux/net_tstamp.h>
 #include <linux/udp.h>
 #include <linux/sockios.h>
+#include <linux/net_tstamp.h>
 #include <sys/mman.h>
 #include <net/if.h>
 #include <poll.h>
@@ -278,13 +279,53 @@ static int rxq_num(const char *ifname)
 
 	ret = ioctl(fd, SIOCETHTOOL, &ifr);
 	if (ret < 0)
-		error(-1, errno, "socket");
+		error(-1, errno, "ioctl(SIOCETHTOOL)");
 
 	close(fd);
 
 	return ch.rx_count + ch.combined_count;
 }
 
+static void hwtstamp_ioctl(int op, const char *ifname, struct hwtstamp_config *cfg)
+{
+	struct ifreq ifr = {
+		.ifr_data = (void *)cfg,
+	};
+	strcpy(ifr.ifr_name, ifname);
+	int fd, ret;
+
+	fd = socket(AF_UNIX, SOCK_DGRAM, 0);
+	if (fd < 0)
+		error(-1, errno, "socket");
+
+	ret = ioctl(fd, op, &ifr);
+	if (ret < 0)
+		error(-1, errno, "ioctl(%d)", op);
+
+	close(fd);
+}
+
+static struct hwtstamp_config saved_hwtstamp_cfg;
+static const char *saved_hwtstamp_ifname;
+
+static void hwtstamp_restore(void)
+{
+	hwtstamp_ioctl(SIOCSHWTSTAMP, saved_hwtstamp_ifname, &saved_hwtstamp_cfg);
+}
+
+static void hwtstamp_enable(const char *ifname)
+{
+	struct hwtstamp_config cfg = {
+		.rx_filter = HWTSTAMP_FILTER_ALL,
+	};
+
+	hwtstamp_ioctl(SIOCGHWTSTAMP, ifname, &saved_hwtstamp_cfg);
+	saved_hwtstamp_ifname = strdup(ifname);
+	atexit(hwtstamp_restore);
+
+	hwtstamp_ioctl(SIOCSHWTSTAMP, ifname, &cfg);
+}
+
 static void cleanup(void)
 {
 	LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
@@ -341,6 +382,8 @@ int main(int argc, char *argv[])
 
 	printf("rxq: %d\n", rxq);
 
+	hwtstamp_enable(ifname);
+
 	rx_xsk = malloc(sizeof(struct xsk) * rxq);
 	if (!rx_xsk)
 		error(-1, ENOMEM, "malloc");
-- 
2.39.1.456.gfc5497dd1b-goog

Re: [PATCH bpf-next v2] selftests/bpf: Properly enable hwtstamp in xdp_hw_metadata

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Martin KaFai Lau <martin.lau@kernel.org>:

On Thu, 26 Jan 2023 14:50:30 -0800 you wrote:
> The existing timestamping_enable() is a no-op because it applies
> to the socket-related path that we are not verifying here
> anymore. (but still leaving the code around hoping we can
> have xdp->skb path verified here as well)
> 
>   poll: 1 (0)
>   xsk_ring_cons__peek: 1
>   0xf64788: rx_desc[0]->addr=100000000008000 addr=8100 comp_addr=8000
>   rx_hash: 3697961069
>   rx_timestamp:  1674657672142214773 (sec:1674657672.1422)
>   XDP RX-time:   1674657709561774876 (sec:1674657709.5618) delta sec:37.4196
>   AF_XDP time:   1674657709561871034 (sec:1674657709.5619) delta
> sec:0.0001 (96.158 usec)
>   0xf64788: complete idx=8 addr=8000
> 
> [...]

Here is the summary with links:
  - [bpf-next,v2] selftests/bpf: Properly enable hwtstamp in xdp_hw_metadata
    https://git.kernel.org/bpf/bpf-next/c/a5f3a3f7c172

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH bpf-next v2] selftests/bpf: Properly enable hwtstamp in xdp_hw_metadata

[Jesper Dangaard Brouer]

On 26/01/2023 23.50, Stanislav Fomichev wrote:
> The existing timestamping_enable() is a no-op because it applies
> to the socket-related path that we are not verifying here
> anymore. (but still leaving the code around hoping we can
> have xdp->skb path verified here as well)
> 
>    poll: 1 (0)
>    xsk_ring_cons__peek: 1
>    0xf64788: rx_desc[0]->addr=100000000008000 addr=8100 comp_addr=8000
>    rx_hash: 3697961069
>    rx_timestamp:  1674657672142214773 (sec:1674657672.1422)
>    XDP RX-time:   1674657709561774876 (sec:1674657709.5618) delta sec:37.4196
>    AF_XDP time:   1674657709561871034 (sec:1674657709.5619) delta
> sec:0.0001 (96.158 usec)
>    0xf64788: complete idx=8 addr=8000
> 

Again for the record, this output is from my devel version of
xdp_hw_metadata and not what is currently upstream.

Small nit below, which is too late as this is already applied.

> Also, maybe something to archive here, see [0] for Jesper's note
> about NIC vs host clock delta.
> 
> 0: https://lore.kernel.org/bpf/f3a116dc-1b14-3432-ad20-a36179ef0608@redhat.com/
> 
> v2:
> - Restore original value (Martin)
> 
> Fixes: 297a3f124155 ("selftests/bpf: Simple program to dump XDP RX metadata")
> Reported-by: Jesper Dangaard Brouer <jbrouer@redhat.com>
> Tested-by: Jesper Dangaard Brouer <jbrouer@redhat.com>
> Signed-off-by: Stanislav Fomichev <sdf@google.com>
> ---
>   tools/testing/selftests/bpf/xdp_hw_metadata.c | 45 ++++++++++++++++++-
>   1 file changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> index 0008f0f239e8..3823b1c499cc 100644
> --- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
> +++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> @@ -24,6 +24,7 @@
>   #include <linux/net_tstamp.h>
>   #include <linux/udp.h>
>   #include <linux/sockios.h>
> +#include <linux/net_tstamp.h>
>   #include <sys/mman.h>
>   #include <net/if.h>
>   #include <poll.h>
> @@ -278,13 +279,53 @@ static int rxq_num(const char *ifname)
>   
>   	ret = ioctl(fd, SIOCETHTOOL, &ifr);
>   	if (ret < 0)
> -		error(-1, errno, "socket");
> +		error(-1, errno, "ioctl(SIOCETHTOOL)");
>   
>   	close(fd);
>   
>   	return ch.rx_count + ch.combined_count;
>   }
>   
> +static void hwtstamp_ioctl(int op, const char *ifname, struct hwtstamp_config *cfg)
> +{
> +	struct ifreq ifr = {
> +		.ifr_data = (void *)cfg,
> +	};
> +	strcpy(ifr.ifr_name, ifname);

I would use strncpy like:

  strncpy(ifr.ifr_name, ifname, IFNAMSIZ - 1);

> +	int fd, ret;
> +
> +	fd = socket(AF_UNIX, SOCK_DGRAM, 0);
> +	if (fd < 0)
> +		error(-1, errno, "socket");
> +
> +	ret = ioctl(fd, op, &ifr);
> +	if (ret < 0)
> +		error(-1, errno, "ioctl(%d)", op);
> +
> +	close(fd);
> +}
> +
> +static struct hwtstamp_config saved_hwtstamp_cfg;
> +static const char *saved_hwtstamp_ifname;
> +
> +static void hwtstamp_restore(void)
> +{
> +	hwtstamp_ioctl(SIOCSHWTSTAMP, saved_hwtstamp_ifname, &saved_hwtstamp_cfg);
> +}
> +
> +static void hwtstamp_enable(const char *ifname)
> +{
> +	struct hwtstamp_config cfg = {
> +		.rx_filter = HWTSTAMP_FILTER_ALL,
> +	};
> +
> +	hwtstamp_ioctl(SIOCGHWTSTAMP, ifname, &saved_hwtstamp_cfg);
> +	saved_hwtstamp_ifname = strdup(ifname);
> +	atexit(hwtstamp_restore);
> +
> +	hwtstamp_ioctl(SIOCSHWTSTAMP, ifname, &cfg);
> +}
> +
>   static void cleanup(void)
>   {
>   	LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
> @@ -341,6 +382,8 @@ int main(int argc, char *argv[])
>   
>   	printf("rxq: %d\n", rxq);
>   
> +	hwtstamp_enable(ifname);
> +
>   	rx_xsk = malloc(sizeof(struct xsk) * rxq);
>   	if (!rx_xsk)
>   		error(-1, ENOMEM, "malloc");

Re: [PATCH bpf-next v2] selftests/bpf: Properly enable hwtstamp in xdp_hw_metadata

[Stanislav Fomichev]

On Fri, Jan 27, 2023 at 5:36 AM Jesper Dangaard Brouer
<jbrouer@redhat.com> wrote:
>
>
>
> On 26/01/2023 23.50, Stanislav Fomichev wrote:
> > The existing timestamping_enable() is a no-op because it applies
> > to the socket-related path that we are not verifying here
> > anymore. (but still leaving the code around hoping we can
> > have xdp->skb path verified here as well)
> >
> >    poll: 1 (0)
> >    xsk_ring_cons__peek: 1
> >    0xf64788: rx_desc[0]->addr=100000000008000 addr=8100 comp_addr=8000
> >    rx_hash: 3697961069
> >    rx_timestamp:  1674657672142214773 (sec:1674657672.1422)
> >    XDP RX-time:   1674657709561774876 (sec:1674657709.5618) delta sec:37.4196
> >    AF_XDP time:   1674657709561871034 (sec:1674657709.5619) delta
> > sec:0.0001 (96.158 usec)
> >    0xf64788: complete idx=8 addr=8000
> >
>
> Again for the record, this output is from my devel version of
> xdp_hw_metadata and not what is currently upstream.

Yeah, that's fine, I just wanted to record it somewhere :-)

> Small nit below, which is too late as this is already applied.
>
> > Also, maybe something to archive here, see [0] for Jesper's note
> > about NIC vs host clock delta.
> >
> > 0: https://lore.kernel.org/bpf/f3a116dc-1b14-3432-ad20-a36179ef0608@redhat.com/
> >
> > v2:
> > - Restore original value (Martin)
> >
> > Fixes: 297a3f124155 ("selftests/bpf: Simple program to dump XDP RX metadata")
> > Reported-by: Jesper Dangaard Brouer <jbrouer@redhat.com>
> > Tested-by: Jesper Dangaard Brouer <jbrouer@redhat.com>
> > Signed-off-by: Stanislav Fomichev <sdf@google.com>
> > ---
> >   tools/testing/selftests/bpf/xdp_hw_metadata.c | 45 ++++++++++++++++++-
> >   1 file changed, 44 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> > index 0008f0f239e8..3823b1c499cc 100644
> > --- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
> > +++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> > @@ -24,6 +24,7 @@
> >   #include <linux/net_tstamp.h>
> >   #include <linux/udp.h>
> >   #include <linux/sockios.h>
> > +#include <linux/net_tstamp.h>
> >   #include <sys/mman.h>
> >   #include <net/if.h>
> >   #include <poll.h>
> > @@ -278,13 +279,53 @@ static int rxq_num(const char *ifname)
> >
> >       ret = ioctl(fd, SIOCETHTOOL, &ifr);
> >       if (ret < 0)
> > -             error(-1, errno, "socket");
> > +             error(-1, errno, "ioctl(SIOCETHTOOL)");
> >
> >       close(fd);
> >
> >       return ch.rx_count + ch.combined_count;
> >   }
> >
> > +static void hwtstamp_ioctl(int op, const char *ifname, struct hwtstamp_config *cfg)
> > +{
> > +     struct ifreq ifr = {
> > +             .ifr_data = (void *)cfg,
> > +     };
> > +     strcpy(ifr.ifr_name, ifname);
>
> I would use strncpy like:
>
>   strncpy(ifr.ifr_name, ifname, IFNAMSIZ - 1);

Good point, maybe we can fold this into some of the next patches to
this file. Since this is for internal dev consumption, doesn't look
like a huge deal to me to deserve a separate patch.

> > +     int fd, ret;
> > +
> > +     fd = socket(AF_UNIX, SOCK_DGRAM, 0);
> > +     if (fd < 0)
> > +             error(-1, errno, "socket");
> > +
> > +     ret = ioctl(fd, op, &ifr);
> > +     if (ret < 0)
> > +             error(-1, errno, "ioctl(%d)", op);
> > +
> > +     close(fd);
> > +}
> > +
> > +static struct hwtstamp_config saved_hwtstamp_cfg;
> > +static const char *saved_hwtstamp_ifname;
> > +
> > +static void hwtstamp_restore(void)
> > +{
> > +     hwtstamp_ioctl(SIOCSHWTSTAMP, saved_hwtstamp_ifname, &saved_hwtstamp_cfg);
> > +}
> > +
> > +static void hwtstamp_enable(const char *ifname)
> > +{
> > +     struct hwtstamp_config cfg = {
> > +             .rx_filter = HWTSTAMP_FILTER_ALL,
> > +     };
> > +
> > +     hwtstamp_ioctl(SIOCGHWTSTAMP, ifname, &saved_hwtstamp_cfg);
> > +     saved_hwtstamp_ifname = strdup(ifname);
> > +     atexit(hwtstamp_restore);
> > +
> > +     hwtstamp_ioctl(SIOCSHWTSTAMP, ifname, &cfg);
> > +}
> > +
> >   static void cleanup(void)
> >   {
> >       LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
> > @@ -341,6 +382,8 @@ int main(int argc, char *argv[])
> >
> >       printf("rxq: %d\n", rxq);
> >
> > +     hwtstamp_enable(ifname);
> > +
> >       rx_xsk = malloc(sizeof(struct xsk) * rxq);
> >       if (!rx_xsk)
> >               error(-1, ENOMEM, "malloc");
>