Re: [PATCH bpf-next v3 20/21] selftests/bpf: Check VLAN tag and proto in xdp_metadata

From: Stanislav Fomichev <sdf@google.com>
To: "Zaremba, Larysa" <larysa.zaremba@intel.com>
Cc: "bpf@vger.kernel.org" <bpf@vger.kernel.org>,
	"ast@kernel.org" <ast@kernel.org>,
	 "daniel@iogearbox.net" <daniel@iogearbox.net>,
	"andrii@kernel.org" <andrii@kernel.org>,
	 "martin.lau@linux.dev" <martin.lau@linux.dev>,
	"song@kernel.org" <song@kernel.org>, "yhs@fb.com" <yhs@fb.com>,
	 "john.fastabend@gmail.com" <john.fastabend@gmail.com>,
	"kpsingh@kernel.org" <kpsingh@kernel.org>,
	 "haoluo@google.com" <haoluo@google.com>,
	"jolsa@kernel.org" <jolsa@kernel.org>,
	David Ahern <dsahern@gmail.com>,
	 Jakub Kicinski <kuba@kernel.org>,
	Willem de Bruijn <willemb@google.com>,
	 "Brouer, Jesper" <brouer@redhat.com>,
	"Burakov, Anatoly" <anatoly.burakov@intel.com>,
	 "Lobakin, Aleksander" <aleksander.lobakin@intel.com>,
	Magnus Karlsson <magnus.karlsson@gmail.com>,
	 "Tahhan, Maryam" <mtahhan@redhat.com>,
	 "xdp-hints@xdp-project.net" <xdp-hints@xdp-project.net>,
	 "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH bpf-next v3 20/21] selftests/bpf: Check VLAN tag and proto in xdp_metadata
Date: Fri, 21 Jul 2023 09:44:17 -0700	[thread overview]
Message-ID: <CAKH8qBtqCnewzcn_rfgNYPYD3oWSaDbf0ws6bDKL3H6gK7x6cg@mail.gmail.com> (raw)
In-Reply-To: <ZLo29C1kpx99+u6G@lincoln>

On Fri, Jul 21, 2023 at 12:47 AM Zaremba, Larysa
<larysa.zaremba@intel.com> wrote:
>
> On Thu, Jul 20, 2023 at 03:14:15PM -0700, Stanislav Fomichev wrote:
> > On 07/19, Larysa Zaremba wrote:
> > > Verify, whether VLAN tag and proto are set correctly.
> > >
> > > To simulate "stripped" VLAN tag on veth, send test packet from VLAN
> > > interface.
> > >
> > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> >
> > Acked-by: Stanislav Fomichev <sdf@google.com>
> >
> > > ---
> > >  .../selftests/bpf/prog_tests/xdp_metadata.c   | 22 +++++++++++++++++--
> > >  .../selftests/bpf/progs/xdp_metadata.c        |  4 ++++
> > >  2 files changed, 24 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > > index 1877e5c6d6c7..6665cf0c59cc 100644
> > > --- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > > +++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
> > > @@ -38,7 +38,15 @@
> > >  #define TX_MAC "00:00:00:00:00:01"
> > >  #define RX_MAC "00:00:00:00:00:02"
> > >
> > > +#define VLAN_ID 59
> > > +#define VLAN_ID_STR "59"
> >
> > I was looking whether we have some str(x) macro in the selftests,
> > but doesn't look like we have any...
> >
>
> I could add one, if you could hint me at the file, where it would need to go.
> Or just add it locally for now?

Up to you. I feel like it's fine as is.

I was expecting to find something like the following in
tools/testing/selftests/bpf/testing_helpers.h:

#define __TO_STR(x) #x
#define TO_STR(x) __TO_STR(x)

We have similar patterns in:
tools/testing/selftests/bpf/sdt.h (_SDT_ARG_CONSTRAINT_STRING)
tools/testing/selftests/kvm/x86_64/smm_test.c (XSTR)
tools/tracing/rtla/src/utils.c (STR)

But nothing "generic" it seems...

> > > +#define VLAN_PROTO "802.1Q"
> > > +#define VLAN_PID htons(ETH_P_8021Q)
> > > +#define TX_NAME_VLAN TX_NAME "." VLAN_ID_STR
> > > +#define RX_NAME_VLAN RX_NAME "." VLAN_ID_STR
> > > +
> > >  #define XDP_RSS_TYPE_L4 BIT(3)
> > > +#define VLAN_VID_MASK 0xfff
> > >
> > >  struct xsk {
> > >     void *umem_area;
> > > @@ -215,6 +223,12 @@ static int verify_xsk_metadata(struct xsk *xsk)
> > >     if (!ASSERT_NEQ(meta->rx_hash_type & XDP_RSS_TYPE_L4, 0, "rx_hash_type"))
> > >             return -1;
> > >
> > > +   if (!ASSERT_EQ(meta->rx_vlan_tci & VLAN_VID_MASK, VLAN_ID, "rx_vlan_tci"))
> > > +           return -1;
> > > +
> > > +   if (!ASSERT_EQ(meta->rx_vlan_proto, VLAN_PID, "rx_vlan_proto"))
> > > +           return -1;
> > > +
> > >     xsk_ring_cons__release(&xsk->rx, 1);
> > >     refill_rx(xsk, comp_addr);
> > >
> > > @@ -248,10 +262,14 @@ void test_xdp_metadata(void)
> > >
> > >     SYS(out, "ip link set dev " TX_NAME " address " TX_MAC);
> > >     SYS(out, "ip link set dev " TX_NAME " up");
> > > -   SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME);
> > > +
> > > +   SYS(out, "ip link add link " TX_NAME " " TX_NAME_VLAN
> > > +            " type vlan proto " VLAN_PROTO " id " VLAN_ID_STR);
> > > +   SYS(out, "ip link set dev " TX_NAME_VLAN " up");
> > > +   SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME_VLAN);
> > >
> > >     /* Avoid ARP calls */
> > > -   SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME);
> > > +   SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME_VLAN);
> > >     close_netns(tok);
> > >
> > >     tok = open_netns(RX_NETNS_NAME);
> > > diff --git a/tools/testing/selftests/bpf/progs/xdp_metadata.c b/tools/testing/selftests/bpf/progs/xdp_metadata.c
> > > index d151d406a123..d3111649170e 100644
> > > --- a/tools/testing/selftests/bpf/progs/xdp_metadata.c
> > > +++ b/tools/testing/selftests/bpf/progs/xdp_metadata.c
> > > @@ -23,6 +23,9 @@ extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
> > >                                      __u64 *timestamp) __ksym;
> > >  extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
> > >                                 enum xdp_rss_hash_type *rss_type) __ksym;
> > > +extern int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
> > > +                                   __u16 *vlan_tci,
> > > +                                   __be16 *vlan_proto) __ksym;
> > >
> > >  SEC("xdp")
> > >  int rx(struct xdp_md *ctx)
> > > @@ -57,6 +60,7 @@ int rx(struct xdp_md *ctx)
> > >             meta->rx_timestamp = 1;
> > >
> > >     bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash, &meta->rx_hash_type);
> > > +   bpf_xdp_metadata_rx_vlan_tag(ctx, &meta->rx_vlan_tci, &meta->rx_vlan_proto);
> > >
> > >     return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
> > >  }
> > > --
> > > 2.41.0
> > >
> >