linux-stable.git/include/linux/skbuff.h, branch v4.8.2

bpf: fix checksum fixups on bpf_skb_store_bytes

2016-08-08T20:11:43+00:00

bpf_skb_store_bytes() invocations above L2 header need BPF_F_RECOMPUTE_CSUM
flag for updates, so that CHECKSUM_COMPLETE will be fixed up along the way.
Where we ran into an issue with bpf_skb_store_bytes() is when we did a
single-byte update on the IPv6 hoplimit despite using BPF_F_RECOMPUTE_CSUM
flag; simple ping via ICMPv6 triggered a hw csum failure as a result. The
underlying issue has been tracked down to a buffer alignment issue.

Meaning, that csum_partial() computations via skb_postpull_rcsum() and
skb_postpush_rcsum() pair invoked had a wrong result since they operated on
an odd address for the hoplimit, while other computations were done on an
even address. This mix doesn't work as-is with skb_postpull_rcsum(),
skb_postpush_rcsum() pair as it always expects at least half-word alignment
of input buffers, which is normally the case. Thus, instead of these helpers
using csum_sub() and (implicitly) csum_add(), we need to use csum_block_sub(),
csum_block_add(), respectively. For unaligned offsets, they rotate the sum
to align it to a half-word boundary again, otherwise they work the same as
csum_sub() and csum_add().

Adding __skb_postpull_rcsum(), __skb_postpush_rcsum() variants that take the
offset as an input and adapting bpf_skb_store_bytes() to them fixes the hw
csum failures again. The skb_postpull_rcsum(), skb_postpush_rcsum() helpers
use a 0 constant for offset so that the compiler optimizes the offset & 1
test away and generates the same code as with csum_sub()/_add().

Fixes: 608cd71a9c7c ("tc: bpf: generalize pedit action")
Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-07-06T17:35:22+00:00

Conflicts:
	drivers/net/ethernet/mellanox/mlx5/core/en.h
	drivers/net/ethernet/mellanox/mlx5/core/en_main.c
	drivers/net/usb/r8152.c

All three conflicts were overlapping changes.

Signed-off-by: David S. Miller

net: simplify and make pkt_type_ok() available for other users

2016-07-04T22:11:13+00:00

Suggested-by: Daniel Borkmann 
Signed-off-by: Jamal Hadi Salim 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net_sched: fix mirrored packets checksum

2016-07-01T20:19:34+00:00

Similar to commit 9b368814b336 ("net: fix bridge multicast packet checksum validation")
we need to fixup the checksum for CHECKSUM_COMPLETE when
pushing skb on RX path. Otherwise we get similar splats.

Cc: Jamal Hadi Salim 
Cc: Tom Herbert 
Signed-off-by: Cong Wang 
Acked-by: Jamal Hadi Salim 
Signed-off-by: David S. Miller

packet: Use symmetric hash for PACKET_FANOUT_HASH.

2016-07-01T20:07:50+00:00

People who use PACKET_FANOUT_HASH want a symmetric hash, meaning that
they want packets going in both directions on a flow to hash to the
same bucket.

The core kernel SKB hash became non-symmetric when the ipv6 flow label
and other entities were incorporated into the standard flow hash order
to increase entropy.

But there are no users of PACKET_FANOUT_HASH who want an assymetric
hash, they all want a symmetric one.

Therefore, use the flow dissector to compute a flat symmetric hash
over only the protocol, addresses and ports.  This hash does not get
installed into and override the normal skb hash, so this change has
no effect whatsoever on the rest of the stack.

Reported-by: Eric Leblond 
Tested-by: Eric Leblond 
Signed-off-by: David S. Miller

sctp: Add GSO support

2016-06-03T23:37:21+00:00

SCTP has this pecualiarity that its packets cannot be just segmented to
(P)MTU. Its chunks must be contained in IP segments, padding respected.
So we can't just generate a big skb, set gso_size to the fragmentation
point and deliver it to IP layer.

This patch takes a different approach. SCTP will now build a skb as it
would be if it was received using GRO. That is, there will be a cover
skb with protocol headers and children ones containing the actual
segments, already segmented to a way that respects SCTP RFCs.

With that, we can tell skb_segment() to just split based on frag_list,
trusting its sizes are already in accordance.

This way SCTP can benefit from GSO and instead of passing several
packets through the stack, it can pass a single large packet.

v2:
- Added support for receiving GSO frames, as requested by Dave Miller.
- Clear skb->cb if packet is GSO (otherwise it's not used by SCTP)
- Added heuristics similar to what we have in TCP for not generating
  single GSO packets that fills cwnd.
v3:
- consider sctphdr size in skb_gso_transport_seglen()
- rebased due to 5c7cdf339af5 ("gso: Remove arbitrary checks for
  unsupported GSO")

Signed-off-by: Marcelo Ricardo Leitner 
Tested-by: Xin Long 
Signed-off-by: David S. Miller

skbuff: introduce skb_gso_validate_mtu

2016-06-03T23:37:21+00:00

skb_gso_network_seglen is not enough for checking fragment sizes if
skb is using GSO_BY_FRAGS as we have to check frag per frag.

This patch introduces skb_gso_validate_mtu, based on the former, which
will wrap the use case inside it as all calls to skb_gso_network_seglen
were to validate if it fits on a given TMU, and improve the check.

Signed-off-by: Marcelo Ricardo Leitner 
Tested-by: Xin Long 
Signed-off-by: David S. Miller

sk_buff: allow segmenting based on frag sizes

2016-06-03T23:37:21+00:00

This patch allows segmenting a skb based on its frags sizes instead of
based on a fixed value.

Signed-off-by: Marcelo Ricardo Leitner 
Tested-by: Xin Long 
Signed-off-by: David S. Miller

net: suppress warnings on dev_alloc_skb

2016-05-20T23:58:32+00:00

Noticed an allocation failure in a network driver the other day on a 32 bit
system:

DMA-API: debugging out of memory - disabling
bnx2fc: adapter_lookup: hba NULL
lldpad: page allocation failure. order:0, mode:0x4120
Pid: 4556, comm: lldpad Not tainted 2.6.32-639.el6.i686.debug #1
Call Trace:
 [] ? printk+0x19/0x23
 [] ? __alloc_pages_nodemask+0x664/0x830
 [] ? free_object+0x82/0xa0
 [] ? ixgbe_alloc_rx_buffers+0x10b/0x1d0 [ixgbe]
 [] ? ixgbe_configure_rx_ring+0x29f/0x420 [ixgbe]
 [] ? ixgbe_configure_tx_ring+0x15c/0x220 [ixgbe]
 [] ? ixgbe_configure+0x589/0xc00 [ixgbe]
 [] ? ixgbe_open+0xa7/0x5c0 [ixgbe]
 [] ? ixgbe_init_interrupt_scheme+0x5b6/0x970 [ixgbe]
 [] ? ixgbe_setup_tc+0x1a4/0x260 [ixgbe]
 [] ? ixgbe_dcbnl_set_state+0x7f/0x90 [ixgbe]
 [] ? dcb_doit+0x10ed/0x16d0
...

Thought that perhaps the big splat in the logs wasn't really necessecary, as
all call sites for dev_alloc_skb:

a) check the return code for the function

and

b) either print their own error message or have a recovery path that makes the
warning moot.

Fix it by modifying dev_alloc_pages to pass __GFP_NOWARN as a gfp flag to
suppress the warning

applies to the net tree

Signed-off-by: Neil Horman 
CC: "David S. Miller" 
CC: Eric Dumazet 
CC: Alexander Duyck 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: define gso types for IPx over IPv4 and IPv6

2016-05-20T22:03:15+00:00

This patch defines two new GSO definitions SKB_GSO_IPXIP4 and
SKB_GSO_IPXIP6 along with corresponding NETIF_F_GSO_IPXIP4 and
NETIF_F_GSO_IPXIP6. These are used to described IP in IP
tunnel and what the outer protocol is. The inner protocol
can be deduced from other GSO types (e.g. SKB_GSO_TCPV4 and
SKB_GSO_TCPV6). The GSO types of SKB_GSO_IPIP and SKB_GSO_SIT
are removed (these are both instances of SKB_GSO_IPXIP4).
SKB_GSO_IPXIP6 will be used when support for GSO with IP
encapsulation over IPv6 is added.

Signed-off-by: Tom Herbert 
Acked-by: Jeff Kirsher 
Signed-off-by: David S. Miller