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

[Larysa Zaremba <larysa.zaremba@intel.com>]

On Fri, Jul 21, 2023 at 09:44:17AM -0700, Stanislav Fomichev wrote:
> 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 need to send v4 with some minor changes anyway, so will add in v4.

> 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
> > > >
> > >