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  1. 08 Mar, 2016 7 commits
    • Daniel Borkmann's avatar
      bpf, vxlan, geneve, gre: fix usage of dst_cache on xmit · db3c6139
      Daniel Borkmann authored 
      The assumptions from commit 0c1d70af ("net: use dst_cache for vxlan
device"), 468dfffc ("geneve: add dst caching support") and 3c1cb4d2
("net/ipv4: add dst cache support for gre lwtunnels") on dst_cache usage
when ip_tunnel_info is used is unfortunately not always valid as assumed.

While it seems correct for ip_tunnel_info front-ends such as OVS, eBPF
however can fill in ip_tunnel_info for consumers like vxlan, geneve or gre
with different remote dsts, tos, etc, therefore they cannot be assumed as
packet independent.

Right now vxlan, geneve, gre would cache the dst for eBPF and every packet
would reuse the same entry that was first created on the initial route
lookup. eBPF doesn't store/cache the ip_tunnel_info, so each skb may have
a different one.

Fix it by adding a flag that checks the ip_tunnel_info. Also the !tos test
in vxlan needs to be handeled differently in this context as it is currently
inferred from ip_tunnel_info as well if present. ip_tunnel_dst_cache_usable()
helper is added for the three tunnel cases, which checks if we can use dst
cache.

Fixes: 0c1d70af ("net: use dst_cache for vxlan device")
Fixes: 468dfffc ("geneve: add dst caching support")
Fixes: 3c1cb4d2 ("net/ipv4: add dst cache support for gre lwtunnels")
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      db3c6139
    • Daniel Borkmann's avatar
      bpf: support for access to tunnel options · 14ca0751
      Daniel Borkmann authored 
      After eBPF being able to programmatically access/manage tunnel key meta
data via commit d3aa45ce ("bpf: add helpers to access tunnel metadata")
and more recently also for IPv6 through c6c33454 ("bpf: support ipv6
for bpf_skb_{set,get}_tunnel_key"), this work adds two complementary
helpers to generically access their auxiliary tunnel options.

Geneve and vxlan support this facility. For geneve, TLVs can be pushed,
and for the vxlan case its GBP extension. I.e. setting tunnel key for geneve
case only makes sense, if we can also read/write TLVs into it. In the GBP
case, it provides the flexibility to easily map the group policy ID in
combination with other helpers or maps.

I chose to model this as two separate helpers, bpf_skb_{set,get}_tunnel_opt(),
for a couple of reasons. bpf_skb_{set,get}_tunnel_key() is already rather
complex by itself, and there may be cases for tunnel key backends where
tunnel options are not always needed. If we would have integrated this
into bpf_skb_{set,get}_tunnel_key() nevertheless, we are very limited with
remaining helper arguments, so keeping compatibility on structs in case of
passing in a flat buffer gets more cumbersome. Separating both also allows
for more flexibility and future extensibility, f.e. options could be fed
directly from a map, etc.

Moreover, change geneve's xmit path to test only for info->options_len
instead of TUNNEL_GENEVE_OPT flag. This makes it more consistent with vxlan's
xmit path and allows for avoiding to specify a protocol flag in the API on
xmit, so it can be protocol agnostic. Having info->options_len is enough
information that is needed. Tested with vxlan and geneve.
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      14ca0751
    • Daniel Borkmann's avatar
      bpf: allow to propagate df in bpf_skb_set_tunnel_key · 22080870
      Daniel Borkmann authored 
      Added by 9a628224 ("ip_tunnel: Add dont fragment flag."), allow to
feed df flag into tunneling facilities (currently supported on TX by
vxlan, geneve and gre) as a hint from eBPF's bpf_skb_set_tunnel_key()
helper.
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      22080870
    • Daniel Borkmann's avatar
      bpf: make helper function protos static · 577c50aa
      Daniel Borkmann authored 
      They are only used here, so there's no reason they should not be static.
Only the vlan push/pop protos are used in the test_bpf suite.
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      577c50aa
    • Daniel Borkmann's avatar
      bpf: add flags to bpf_skb_store_bytes for clearing hash · 8afd54c8
      Daniel Borkmann authored 
      When overwriting parts of the packet with bpf_skb_store_bytes() that
were fed previously into skb->hash calculation, we should clear the
current hash with skb_clear_hash(), so that a next skb_get_hash() call
can determine the correct hash related to this skb.
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8afd54c8
    • Daniel Borkmann's avatar
      bpf: allow bpf_csum_diff to feed bpf_l3_csum_replace as well · 8050c0f0
      Daniel Borkmann authored 
      Commit 7d672345 ("bpf: add generic bpf_csum_diff helper") added a
generic checksum diff helper that can feed bpf_l4_csum_replace() with
a target __wsum diff that is to be applied to the L4 checksum. This
facility is very flexible, can be cascaded, allows for adding, removing,
or diffing data, or for calculating the pseudo header checksum from
scratch, but it can also be reused for working with the IPv4 header
checksum.

Thus, analogous to bpf_l4_csum_replace(), add a case for header field
value of 0 to change the checksum at a given offset through a new helper
csum_replace_by_diff(). Also, in addition to that, this provides an
easy to use interface for feeding precalculated diffs f.e. coming from
a map. It nicely complements bpf_l3_csum_replace() that currently allows
only for csum updates of 2 and 4 byte diffs.
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8050c0f0
    • David S. Miller's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 810813c4
      David S. Miller authored 
      Several cases of overlapping changes, as well as one instance
(vxlan) of a bug fix in 'net' overlapping with code movement
in 'net-next'.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      810813c4
  3. 07 Mar, 2016 33 commits
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