提交 · 8bce6d7d0d1ede22af334ee241841e9278365278 · openanolis / cloud-kernel

02 10月, 2014 29 次提交

udp: Generalize skb_udp_segment · 8bce6d7d

由 Tom Herbert 提交于 9月 29, 2014

skb_udp_segment is the function called from udp4_ufo_fragment to
segment a UDP tunnel packet. This function currently assumes
segmentation is transparent Ethernet bridging (i.e. VXLAN
encapsulation). This patch generalizes the function to
operate on either Ethertype or IP protocol.

The inner_protocol field must be set to the protocol of the inner
header. This can now be either an Ethertype or an IP protocol
(in a union). A new flag in the skbuff indicates which type is
effective. skb_set_inner_protocol and skb_set_inner_ipproto
helper functions were added to set the inner_protocol. These
functions are called from the point where the tunnel encapsulation
is occuring.

When skb_udp_tunnel_segment is called, the function to segment the
inner packet is selected based on the inner IP or Ethertype. In the
case of an IP protocol encapsulation, the function is derived from
inet[6]_offloads. In the case of Ethertype, skb->protocol is
set to the inner_protocol and skb_mac_gso_segment is called. (GRE
currently does this, but it might be possible to lookup the protocol
in offload_base and call the appropriate segmenation function
directly).
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

8bce6d7d

Merge branch 'bpf-next' · f44d61cd

由 David S. Miller 提交于 10月 01, 2014

Alexei Starovoitov says:

====================
bpf: add search pruning optimization and tests

patch #1 commit log explains why eBPF verifier has to examine some
instructions multiple times and describes the search pruning optimization
that improves verification speed for branchy programs and allows more
complex programs to be verified successfully.
This patch completes the core verifier logic.

patch #2 adds more verifier tests related to branches and search pruning

I'm still working on Andy's 'bitmask for stack slots' suggestion. It will be
done on top of this patch.

The current verifier algorithm is brute force depth first search with
state pruning. If anyone can come up with another algorithm that demonstrates
better results, we'll replace the algorithm without affecting user space.

Note verifier doesn't guarantee that all possible valid programs are accepted.
Overly complex programs may still be rejected.
Verifier improvements/optimizations will guarantee that if a program
was passing verification in the past, it will still be passing.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

f44d61cd

bpf: add tests to verifier testsuite · fd10c2ef

由 Alexei Starovoitov 提交于 9月 29, 2014

add 4 extra tests to cover jump verification better
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fd10c2ef

bpf: add search pruning optimization to verifier · f1bca824

由 Alexei Starovoitov 提交于 9月 29, 2014

consider C program represented in eBPF:
int filter(int arg)
{
    int a, b, c, *ptr;

    if (arg == 1)
        ptr = &a;
    else if (arg == 2)
        ptr = &b;
    else
        ptr = &c;

    *ptr = 0;
    return 0;
}
eBPF verifier has to follow all possible paths through the program
to recognize that '*ptr = 0' instruction would be safe to execute
in all situations.
It's doing it by picking a path towards the end and observes changes
to registers and stack at every insn until it reaches bpf_exit.
Then it comes back to one of the previous branches and goes towards
the end again with potentially different values in registers.
When program has a lot of branches, the number of possible combinations
of branches is huge, so verifer has a hard limit of walking no more
than 32k instructions. This limit can be reached and complex (but valid)
programs could be rejected. Therefore it's important to recognize equivalent
verifier states to prune this depth first search.

Basic idea can be illustrated by the program (where .. are some eBPF insns):
    1: ..
    2: if (rX == rY) goto 4
    3: ..
    4: ..
    5: ..
    6: bpf_exit
In the first pass towards bpf_exit the verifier will walk insns: 1, 2, 3, 4, 5, 6
Since insn#2 is a branch the verifier will remember its state in verifier stack
to come back to it later.
Since insn#4 is marked as 'branch target', the verifier will remember its state
in explored_states[4] linked list.
Once it reaches insn#6 successfully it will pop the state recorded at insn#2 and
will continue.
Without search pruning optimization verifier would have to walk 4, 5, 6 again,
effectively simulating execution of insns 1, 2, 4, 5, 6
With search pruning it will check whether state at #4 after jumping from #2
is equivalent to one recorded in explored_states[4] during first pass.
If there is an equivalent state, verifier can prune the search at #4 and declare
this path to be safe as well.
In other words two states at #4 are equivalent if execution of 1, 2, 3, 4 insns
and 1, 2, 4 insns produces equivalent registers and stack.
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

f1bca824

net: fec: implement rx_copybreak to improve rx performance · 1b7bde6d

由 Nimrod Andy 提交于 9月 30, 2014

- Copy short frames and keep the buffers mapped, re-allocate skb instead of
  memory copy for long frames.
- Add support for setting/getting rx_copybreak using generic ethtool tunable

Changes V3:
* As Eric Dumazet's suggestion that removing the copybreak module parameter
  and only keep the ethtool API support for rx_copybreak.

Changes V2:
* Implements rx_copybreak
* Rx_copybreak provides module parameter to change this value
* Add tunable_ops support for rx_copybreak
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NFrank Li <Frank.Li@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1b7bde6d

net: avoid one atomic operation in skb_clone() · ce1a4ea3

由 Eric Dumazet 提交于 10月 01, 2014

Fast clone cloning can actually avoid an atomic_inc(), if we
guarantee prior clone_ref value is 1.

This requires a change kfree_skbmem(), to perform the
atomic_dec_and_test() on clone_ref before setting fclone to
SKB_FCLONE_UNAVAILABLE.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ce1a4ea3

net/dccp/ccid.c: add __init to ccid_activate · e500f488

由 Fabian Frederick 提交于 10月 01, 2014

ccid_activate is only called by __init ccid_initialize_builtins in same module.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

e500f488

net/dccp/proto.c: add __init to dccp_mib_init · 0c5b8a46

由 Fabian Frederick 提交于 10月 01, 2014

dccp_mib_init is only called by __init dccp_init in same module.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

0c5b8a46

r8169: add support for Byte Queue Limits · 1e918876

由 Florian Westphal 提交于 10月 01, 2014

tested on RTL8168d/8111d model using 'super_netperf 40' with TCP/UDP_STREAM.

Output of
while true; do
    for n in inflight limit; do
          echo -n $n\ ; cat $n;
    done;
    sleep 1;
done

during netperf run, 100mbit peer:

inflight 0
limit 3028
inflight 6056
limit 4542

[ trimmed output for brevity, no limit/inflight changes during
  test steady-state ]

limit 4542
inflight 3028
limit 6122
inflight 0
limit 6122
[ changed cable to 1gbit peer, restart netperf ]
inflight 37850
limit 36336
inflight 33308
limit 31794
inflight 33308
limit 31794
inflight 27252
limit 25738
[ again, no changes during test ]
inflight 27252
limit 25738
inflight 0
limit 28766
[ change cable to 100mbit peer, restart netperf ]
limit 28766
inflight 27370
limit 28766
inflight 4542
limit 5990
inflight 6056
limit 4542
[ .. ]
inflight 6056
limit 4542
inflight 0

[end of test]

Cc: Francois Romieu <romieu@fr.zoreil.com>
Cc: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NEric Dumazet <edumazet@google.com>
Acked-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1e918876

net: cleanup and document skb fclone layout · d0bf4a9e

由 Eric Dumazet 提交于 9月 29, 2014

Lets use a proper structure to clearly document and implement
skb fast clones.

Then, we might experiment more easily alternative layouts.

This patch adds a new skb_fclone_busy() helper, used by tcp and xfrm,
to stop leaking of implementation details.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

d0bf4a9e

tcp: abort orphan sockets stalling on zero window probes · b248230c

由 Yuchung Cheng 提交于 9月 29, 2014

Currently we have two different policies for orphan sockets
that repeatedly stall on zero window ACKs. If a socket gets
a zero window ACK when it is transmitting data, the RTO is
used to probe the window. The socket is aborted after roughly
tcp_orphan_retries() retries (as in tcp_write_timeout()).

But if the socket was idle when it received the zero window ACK,
and later wants to send more data, we use the probe timer to
probe the window. If the receiver always returns zero window ACKs,
icsk_probes keeps getting reset in tcp_ack() and the orphan socket
can stall forever until the system reaches the orphan limit (as
commented in tcp_probe_timer()). This opens up a simple attack
to create lots of hanging orphan sockets to burn the memory
and the CPU, as demonstrated in the recent netdev post "TCP
connection will hang in FIN_WAIT1 after closing if zero window is
advertised." http://www.spinics.net/lists/netdev/msg296539.html

This patch follows the design in RTO-based probe: we abort an orphan
socket stalling on zero window when the probe timer reaches both
the maximum backoff and the maximum RTO. For example, an 100ms RTT
connection will timeout after roughly 153 seconds (0.3 + 0.6 +
.... + 76.8) if the receiver keeps the window shut. If the orphan
socket passes this check, but the system already has too many orphans
(as in tcp_out_of_resources()), we still abort it but we'll also
send an RST packet as the connection may still be active.

In addition, we change TCP_USER_TIMEOUT to cover (life or dead)
sockets stalled on zero-window probes. This changes the semantics
of TCP_USER_TIMEOUT slightly because it previously only applies
when the socket has pending transmission.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Reported-by: NAndrey Dmitrov <andrey.dmitrov@oktetlabs.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

b248230c

cipso: add __init to cipso_v4_cache_init · cb57659a

由 Fabian Frederick 提交于 10月 01, 2014

cipso_v4_cache_init is only called by __init cipso_v4_init
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

cb57659a

inet: frags: add __init to ip4_frags_ctl_register · 57a02c39

由 Fabian Frederick 提交于 10月 01, 2014

ip4_frags_ctl_register is only called by __init ipfrag_init
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

57a02c39

tcp: add __init to tcp_init_mem · 47d7a88c

由 Fabian Frederick 提交于 10月 01, 2014

tcp_init_mem is only called by __init tcp_init.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

47d7a88c

r8169:call "rtl8168_driver_start" "rtl8168_driver_stop" only when hardware dash function is enabled · ee7a1beb