Commit Graph

9191 Commits

Author SHA1 Message Date
Haishuang Yan cd1aa9c2c6 ip_vti: fix a null pointer deferrence when create vti fallback tunnel
After set fb_tunnels_only_for_init_net to 1, the itn->fb_tunnel_dev will
be NULL and will cause following crash:

[ 2742.849298] BUG: unable to handle kernel NULL pointer dereference at 0000000000000941
[ 2742.851380] PGD 800000042c21a067 P4D 800000042c21a067 PUD 42aaed067 PMD 0
[ 2742.852818] Oops: 0002 [#1] SMP PTI
[ 2742.853570] CPU: 7 PID: 2484 Comm: unshare Kdump: loaded Not tainted 4.18.0-rc8+ #2
[ 2742.855163] Hardware name: Fedora Project OpenStack Nova, BIOS seabios-1.7.5-11.el7 04/01/2014
[ 2742.856970] RIP: 0010:vti_init_net+0x3a/0x50 [ip_vti]
[ 2742.858034] Code: 90 83 c0 48 c7 c2 20 a1 83 c0 48 89 fb e8 6e 3b f6 ff 85 c0 75 22 8b 0d f4 19 00 00 48 8b 93 00 14 00 00 48 8b 14 ca 48 8b 12 <c6> 82 41 09 00 00 04 c6 82 38 09 00 00 45 5b c3 66 0f 1f 44 00 00
[ 2742.861940] RSP: 0018:ffff9be28207fde0 EFLAGS: 00010246
[ 2742.863044] RAX: 0000000000000000 RBX: ffff8a71ebed4980 RCX: 0000000000000013
[ 2742.864540] RDX: 0000000000000000 RSI: 0000000000000013 RDI: ffff8a71ebed4980
[ 2742.866020] RBP: ffff8a71ea717000 R08: ffffffffc083903c R09: ffff8a71ea717000
[ 2742.867505] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a71ebed4980
[ 2742.868987] R13: 0000000000000013 R14: ffff8a71ea5b49c0 R15: 0000000000000000
[ 2742.870473] FS:  00007f02266c9740(0000) GS:ffff8a71ffdc0000(0000) knlGS:0000000000000000
[ 2742.872143] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2742.873340] CR2: 0000000000000941 CR3: 000000042bc20006 CR4: 00000000001606e0
[ 2742.874821] Call Trace:
[ 2742.875358]  ops_init+0x38/0xf0
[ 2742.876078]  setup_net+0xd9/0x1f0
[ 2742.876789]  copy_net_ns+0xb7/0x130
[ 2742.877538]  create_new_namespaces+0x11a/0x1d0
[ 2742.878525]  unshare_nsproxy_namespaces+0x55/0xa0
[ 2742.879526]  ksys_unshare+0x1a7/0x330
[ 2742.880313]  __x64_sys_unshare+0xe/0x20
[ 2742.881131]  do_syscall_64+0x5b/0x180
[ 2742.881933]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reproduce:
echo 1 > /proc/sys/net/core/fb_tunnels_only_for_init_net
modprobe ip_vti
unshare -n

Fixes: 79134e6ce2 ("net: do not create fallback tunnels for non-default namespaces")
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-19 11:26:39 -07:00
Daniel Borkmann 90545cdc3f tcp, ulp: fix leftover icsk_ulp_ops preventing sock from reattach
I found that in BPF sockmap programs once we either delete a socket
from the map or we updated a map slot and the old socket was purged
from the map that these socket can never get reattached into a map
even though their related psock has been dropped entirely at that
point.

Reason is that tcp_cleanup_ulp() leaves the old icsk->icsk_ulp_ops
intact, so that on the next tcp_set_ulp_id() the kernel returns an
-EEXIST thinking there is still some active ULP attached.

BPF sockmap is the only one that has this issue as the other user,
kTLS, only calls tcp_cleanup_ulp() from tcp_v4_destroy_sock() whereas
sockmap semantics allow dropping the socket from the map with all
related psock state being cleaned up.

Fixes: 1aa12bdf1b ("bpf: sockmap, add sock close() hook to remove socks")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-16 14:58:08 -07:00
Daniel Borkmann 037b0b86ec tcp, ulp: add alias for all ulp modules
Lets not turn the TCP ULP lookup into an arbitrary module loader as
we only intend to load ULP modules through this mechanism, not other
unrelated kernel modules:

  [root@bar]# cat foo.c
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <linux/tcp.h>
  #include <linux/in.h>

  int main(void)
  {
      int sock = socket(PF_INET, SOCK_STREAM, 0);
      setsockopt(sock, IPPROTO_TCP, TCP_ULP, "sctp", sizeof("sctp"));
      return 0;
  }

  [root@bar]# gcc foo.c -O2 -Wall
  [root@bar]# lsmod | grep sctp
  [root@bar]# ./a.out
  [root@bar]# lsmod | grep sctp
  sctp                 1077248  4
  libcrc32c              16384  3 nf_conntrack,nf_nat,sctp
  [root@bar]#

Fix it by adding module alias to TCP ULP modules, so probing module
via request_module() will be limited to tcp-ulp-[name]. The existing
modules like kTLS will load fine given tcp-ulp-tls alias, but others
will fail to load:

  [root@bar]# lsmod | grep sctp
  [root@bar]# ./a.out
  [root@bar]# lsmod | grep sctp
  [root@bar]#

Sockmap is not affected from this since it's either built-in or not.

Fixes: 734942cc4e ("tcp: ULP infrastructure")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-16 14:58:07 -07:00
David S. Miller c1617fb4c5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-08-13

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add driver XDP support for veth. This can be used in conjunction with
   redirect of another XDP program e.g. sitting on NIC so the xdp_frame
   can be forwarded to the peer veth directly without modification,
   from Toshiaki.

2) Add a new BPF map type REUSEPORT_SOCKARRAY and prog type SK_REUSEPORT
   in order to provide more control and visibility on where a SO_REUSEPORT
   sk should be located, and the latter enables to directly select a sk
   from the bpf map. This also enables map-in-map for application migration
   use cases, from Martin.

3) Add a new BPF helper bpf_skb_ancestor_cgroup_id() that returns the id
   of cgroup v2 that is the ancestor of the cgroup associated with the
   skb at the ancestor_level, from Andrey.

4) Implement BPF fs map pretty-print support based on BTF data for regular
   hash table and LRU map, from Yonghong.

5) Decouple the ability to attach BTF for a map from the key and value
   pretty-printer in BPF fs, and enable further support of BTF for maps for
   percpu and LPM trie, from Daniel.

6) Implement a better BPF sample of using XDP's CPU redirect feature for
   load balancing SKB processing to remote CPU. The sample implements the
   same XDP load balancing as Suricata does which is symmetric hash based
   on IP and L4 protocol, from Jesper.

7) Revert adding NULL pointer check with WARN_ON_ONCE() in __xdp_return()'s
   critical path as it is ensured that the allocator is present, from Björn.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-13 10:07:23 -07:00
Peter Oskolkov a4fd284a1f ip: process in-order fragments efficiently
This patch changes the runtime behavior of IP defrag queue:
incoming in-order fragments are added to the end of the current
list/"run" of in-order fragments at the tail.

On some workloads, UDP stream performance is substantially improved:

RX: ./udp_stream -F 10 -T 2 -l 60
TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60

with this patchset applied on a 10Gbps receiver:

  throughput=9524.18
  throughput_units=Mbit/s

upstream (net-next):

  throughput=4608.93
  throughput_units=Mbit/s

Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 17:54:18 -07:00
Peter Oskolkov 353c9cb360 ip: add helpers to process in-order fragments faster.
This patch introduces several helper functions/macros that will be
used in the follow-up patch. No runtime changes yet.

The new logic (fully implemented in the second patch) is as follows:

* Nodes in the rb-tree will now contain not single fragments, but lists
  of consecutive fragments ("runs").

* At each point in time, the current "active" run at the tail is
  maintained/tracked. Fragments that arrive in-order, adjacent
  to the previous tail fragment, are added to this tail run without
  triggering the re-balancing of the rb-tree.

* If a fragment arrives out of order with the offset _before_ the tail run,
  it is inserted into the rb-tree as a single fragment.

* If a fragment arrives after the current tail fragment (with a gap),
  it starts a new "tail" run, as is inserted into the rb-tree
  at the end as the head of the new run.

skb->cb is used to store additional information
needed here (suggested by Eric Dumazet).

Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 17:54:18 -07:00
Yuchung Cheng fd2123a3d7 tcp: avoid resetting ACK timer upon receiving packet with ECN CWR flag
Previously commit 9aee400061 ("tcp: ack immediately when a cwr
packet arrives") calls tcp_enter_quickack_mode to force sending
two immediate ACKs upon receiving a packet w/ CWR flag. The side
effect is it'll also reset the delayed ACK timer and interactive
session tracking. This patch removes that side effect by using the
new ACK_NOW flag to force an immmediate ACK.

Packetdrill to demonstrate:

    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 setsockopt(3, SOL_TCP, TCP_CONGESTION, "dctcp", 5) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

   +0 < [ect0] SEW 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
   +0 > SE. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
  +.1 < [ect0] . 1:1(0) ack 1 win 257
   +0 accept(3, ..., ...) = 4

   +0 < [ect0] . 1:1001(1000) ack 1 win 257
   +0 > [ect01] . 1:1(0) ack 1001

   +0 write(4, ..., 1) = 1
   +0 > [ect01] P. 1:2(1) ack 1001

   +0 < [ect0] . 1001:2001(1000) ack 2 win 257
   +0 write(4, ..., 1) = 1
   +0 > [ect01] P. 2:3(1) ack 2001

   +0 < [ect0] . 2001:3001(1000) ack 3 win 257
   +0 < [ect0] . 3001:4001(1000) ack 3 win 257
   // Ack delayed ...

   +.01 < [ce] P. 4001:4501(500) ack 3 win 257
   +0 > [ect01] . 3:3(0) ack 4001
   +0 > [ect01] E. 3:3(0) ack 4501

+.001 read(4, ..., 4500) = 4500
   +0 write(4, ..., 1) = 1
   +0 > [ect01] PE. 3:4(1) ack 4501 win 100

 +.01 < [ect0] W. 4501:5501(1000) ack 4 win 257
   // No delayed ACK on CWR flag
   +0 > [ect01] . 4:4(0) ack 5501

 +.31 < [ect0] . 5501:6501(1000) ack 4 win 257
   +0 > [ect01] . 4:4(0) ack 6501

Fixes: 9aee400061 ("tcp: ack immediately when a cwr packet arrives")
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 11:31:35 -07:00
Yuchung Cheng 15bdd5686c tcp: always ACK immediately on hole repairs
RFC 5681 sec 4.2:
  To provide feedback to senders recovering from losses, the receiver
  SHOULD send an immediate ACK when it receives a data segment that
  fills in all or part of a gap in the sequence space.

When a gap is partially filled, __tcp_ack_snd_check already checks
the out-of-order queue and correctly send an immediate ACK. However
when a gap is fully filled, the previous implementation only resets
pingpong mode which does not guarantee an immediate ACK because the
quick ACK counter may be zero. This patch addresses this issue by
marking the one-time immediate ACK flag instead.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 11:31:35 -07:00
Yuchung Cheng d2ccd7bc8a tcp: avoid resetting ACK timer in DCTCP
The recent fix of acking immediately in DCTCP on CE status change
has an undesirable side-effect: it also resets TCP ack timer and
disables pingpong mode (interactive session). But the CE status
change has nothing to do with them. This patch addresses that by
using the new one-time immediate ACK flag instead of calling
tcp_enter_quickack_mode().

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 11:31:35 -07:00
Yuchung Cheng 466466dc6c tcp: mandate a one-time immediate ACK
Add a new flag to indicate a one-time immediate ACK. This flag is
occasionaly set under specific TCP protocol states in addition to
the more common quickack mechanism for interactive application.

In several cases in the TCP code we want to force an immediate ACK
but do not want to call tcp_enter_quickack_mode() because we do
not want to forget the icsk_ack.pingpong or icsk_ack.ato state.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 11:31:35 -07:00
Martin KaFai Lau 8217ca653e bpf: Enable BPF_PROG_TYPE_SK_REUSEPORT bpf prog in reuseport selection
This patch allows a BPF_PROG_TYPE_SK_REUSEPORT bpf prog to select a
SO_REUSEPORT sk from a BPF_MAP_TYPE_REUSEPORT_ARRAY introduced in
the earlier patch.  "bpf_run_sk_reuseport()" will return -ECONNREFUSED
when the BPF_PROG_TYPE_SK_REUSEPORT prog returns SK_DROP.
The callers, in inet[6]_hashtable.c and ipv[46]/udp.c, are modified to
handle this case and return NULL immediately instead of continuing the
sk search from its hashtable.

It re-uses the existing SO_ATTACH_REUSEPORT_EBPF setsockopt to attach
BPF_PROG_TYPE_SK_REUSEPORT.  The "sk_reuseport_attach_bpf()" will check
if the attaching bpf prog is in the new SK_REUSEPORT or the existing
SOCKET_FILTER type and then check different things accordingly.

One level of "__reuseport_attach_prog()" call is removed.  The
"sk_unhashed() && ..." and "sk->sk_reuseport_cb" tests are pushed
back to "reuseport_attach_prog()" in sock_reuseport.c.  sock_reuseport.c
seems to have more knowledge on those test requirements than filter.c.
In "reuseport_attach_prog()", after new_prog is attached to reuse->prog,
the old_prog (if any) is also directly freed instead of returning the
old_prog to the caller and asking the caller to free.

The sysctl_optmem_max check is moved back to the
"sk_reuseport_attach_filter()" and "sk_reuseport_attach_bpf()".
As of other bpf prog types, the new BPF_PROG_TYPE_SK_REUSEPORT is only
bounded by the usual "bpf_prog_charge_memlock()" during load time
instead of bounded by both bpf_prog_charge_memlock and sysctl_optmem_max.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-11 01:58:46 +02:00
Martin KaFai Lau 2dbb9b9e6d bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORT
This patch adds a BPF_PROG_TYPE_SK_REUSEPORT which can select
a SO_REUSEPORT sk from a BPF_MAP_TYPE_REUSEPORT_ARRAY.  Like other
non SK_FILTER/CGROUP_SKB program, it requires CAP_SYS_ADMIN.

BPF_PROG_TYPE_SK_REUSEPORT introduces "struct sk_reuseport_kern"
to store the bpf context instead of using the skb->cb[48].

At the SO_REUSEPORT sk lookup time, it is in the middle of transiting
from a lower layer (ipv4/ipv6) to a upper layer (udp/tcp).  At this
point,  it is not always clear where the bpf context can be appended
in the skb->cb[48] to avoid saving-and-restoring cb[].  Even putting
aside the difference between ipv4-vs-ipv6 and udp-vs-tcp.  It is not
clear if the lower layer is only ipv4 and ipv6 in the future and
will it not touch the cb[] again before transiting to the upper
layer.

For example, in udp_gro_receive(), it uses the 48 byte NAPI_GRO_CB
instead of IP[6]CB and it may still modify the cb[] after calling
the udp[46]_lib_lookup_skb().  Because of the above reason, if
sk->cb is used for the bpf ctx, saving-and-restoring is needed
and likely the whole 48 bytes cb[] has to be saved and restored.

Instead of saving, setting and restoring the cb[], this patch opts
to create a new "struct sk_reuseport_kern" and setting the needed
values in there.

The new BPF_PROG_TYPE_SK_REUSEPORT and "struct sk_reuseport_(kern|md)"
will serve all ipv4/ipv6 + udp/tcp combinations.  There is no protocol
specific usage at this point and it is also inline with the current
sock_reuseport.c implementation (i.e. no protocol specific requirement).

In "struct sk_reuseport_md", this patch exposes data/data_end/len
with semantic similar to other existing usages.  Together
with "bpf_skb_load_bytes()" and "bpf_skb_load_bytes_relative()",
the bpf prog can peek anywhere in the skb.  The "bind_inany" tells
the bpf prog that the reuseport group is bind-ed to a local
INANY address which cannot be learned from skb.

The new "bind_inany" is added to "struct sock_reuseport" which will be
used when running the new "BPF_PROG_TYPE_SK_REUSEPORT" bpf prog in order
to avoid repeating the "bind INANY" test on
"sk_v6_rcv_saddr/sk->sk_rcv_saddr" every time a bpf prog is run.  It can
only be properly initialized when a "sk->sk_reuseport" enabled sk is
adding to a hashtable (i.e. during "reuseport_alloc()" and
"reuseport_add_sock()").

The new "sk_select_reuseport()" is the main helper that the
bpf prog will use to select a SO_REUSEPORT sk.  It is the only function
that can use the new BPF_MAP_TYPE_REUSEPORT_ARRAY.  As mentioned in
the earlier patch, the validity of a selected sk is checked in
run time in "sk_select_reuseport()".  Doing the check in
verification time is difficult and inflexible (consider the map-in-map
use case).  The runtime check is to compare the selected sk's reuseport_id
with the reuseport_id that we want.  This helper will return -EXXX if the
selected sk cannot serve the incoming request (e.g. reuseport_id
not match).  The bpf prog can decide if it wants to do SK_DROP as its
discretion.

When the bpf prog returns SK_PASS, the kernel will check if a
valid sk has been selected (i.e. "reuse_kern->selected_sk != NULL").
If it does , it will use the selected sk.  If not, the kernel
will select one from "reuse->socks[]" (as before this patch).

The SK_DROP and SK_PASS handling logic will be in the next patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-11 01:58:46 +02:00
Dan Carpenter 70837ffe30 ipv4: frags: precedence bug in ip_expire()
We accidentally removed the parentheses here, but they are required
because '!' has higher precedence than '&'.

Fixes: fa0f527358 ("ip: use rb trees for IP frag queue.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-06 13:15:12 -07:00
Peter Oskolkov fa0f527358 ip: use rb trees for IP frag queue.
Similar to TCP OOO RX queue, it makes sense to use rb trees to store
IP fragments, so that OOO fragments are inserted faster.

Tested:

- a follow-up patch contains a rather comprehensive ip defrag
  self-test (functional)
- ran neper `udp_stream -c -H <host> -F 100 -l 300 -T 20`:
    netstat --statistics
    Ip:
        282078937 total packets received
        0 forwarded
        0 incoming packets discarded
        946760 incoming packets delivered
        18743456 requests sent out
        101 fragments dropped after timeout
        282077129 reassemblies required
        944952 packets reassembled ok
        262734239 packet reassembles failed
   (The numbers/stats above are somewhat better re:
    reassemblies vs a kernel without this patchset. More
    comprehensive performance testing TBD).

Reported-by: Jann Horn <jannh@google.com>
Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-05 17:16:46 -07:00
Peter Oskolkov 7969e5c40d ip: discard IPv4 datagrams with overlapping segments.
This behavior is required in IPv6, and there is little need
to tolerate overlapping fragments in IPv4. This change
simplifies the code and eliminates potential DDoS attack vectors.

Tested: ran ip_defrag selftest (not yet available uptream).

Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-05 17:16:46 -07:00
YueHaibing a01512b14d tcp: remove unneeded variable 'err'
variable 'err' is unmodified after initalization,
so simply cleans up it and returns 0.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03 16:52:07 -07:00
David S. Miller 89b1698c93 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
The BTF conflicts were simple overlapping changes.

The virtio_net conflict was an overlap of a fix of statistics counter,
happening alongisde a move over to a bonafide statistics structure
rather than counting value on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02 10:55:32 -07:00
YueHaibing 1296ee8ffc ip_gre: remove redundant variables t_hlen
After commit ffc2b6ee41 ("ip_gre: fix IFLA_MTU ignored on NEWLINK")
variable t_hlen is assigned values that are never read,
hence they are redundant and can be removed.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:58:15 -07:00
Wei Yongjun 13dde04f5c tcp: remove set but not used variable 'skb_size'
Fixes gcc '-Wunused-but-set-variable' warning:

net/ipv4/tcp_output.c: In function 'tcp_collapse_retrans':
net/ipv4/tcp_output.c:2700:6: warning:
 variable 'skb_size' set but not used [-Wunused-but-set-variable]
  int skb_size, next_skb_size;
      ^

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:57:09 -07:00
Wei Wang 7ec65372ca tcp: add stat of data packet reordering events
Introduce a new TCP stats to record the number of reordering events seen
and expose it in both tcp_info (TCP_INFO) and opt_stats
(SOF_TIMESTAMPING_OPT_STATS).
Application can use this stats to track the frequency of the reordering
events in addition to the existing reordering stats which tracks the
magnitude of the latest reordering event.

Note: this new stats tracks reordering events triggered by ACKs, which
could often be fewer than the actual number of packets being delivered
out-of-order.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:56:10 -07:00
Wei Wang 7e10b6554f tcp: add dsack blocks received stats
Introduce a new TCP stat to record the number of DSACK blocks received
(RFC4989 tcpEStatsStackDSACKDups) and expose it in both tcp_info
(TCP_INFO) and opt_stats (SOF_TIMESTAMPING_OPT_STATS).

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:56:10 -07:00
Wei Wang fb31c9b9f6 tcp: add data bytes retransmitted stats
Introduce a new TCP stat to record the number of bytes retransmitted
(RFC4898 tcpEStatsPerfOctetsRetrans) and expose it in both tcp_info
(TCP_INFO) and opt_stats (SOF_TIMESTAMPING_OPT_STATS).

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:56:10 -07:00
Wei Wang ba113c3aa7 tcp: add data bytes sent stats
Introduce a new TCP stat to record the number of bytes sent
(RFC4898 tcpEStatsPerfHCDataOctetsOut) and expose it in both tcp_info
(TCP_INFO) and opt_stats (SOF_TIMESTAMPING_OPT_STATS).

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:56:10 -07:00
Wei Wang 984988aa72 tcp: add a helper to calculate size of opt_stats
This is to refactor the calculation of the size of opt_stats to a helper
function to make the code cleaner and easier for later changes.

Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:56:10 -07:00
Petr Machata d18c5d1995 net: ipv4: Notify about changes to ip_forward_update_priority
Drivers may make offloading decision based on whether
ip_forward_update_priority is enabled or not. Therefore distribute
netevent notifications to give them a chance to react to a change.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:52:30 -07:00
Petr Machata 432e05d328 net: ipv4: Control SKB reprioritization after forwarding
After IPv4 packets are forwarded, the priority of the corresponding SKB
is updated according to the TOS field of IPv4 header. This overrides any
prioritization done earlier by e.g. an skbedit action or ingress-qos-map
defined at a vlan device.

Such overriding may not always be desirable. Even if the packet ends up
being routed, which implies this is an L3 network node, an administrator
may wish to preserve whatever prioritization was done earlier on in the
pipeline.

Therefore introduce a sysctl that controls this behavior. Keep the
default value at 1 to maintain backward-compatible behavior.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:52:30 -07:00
Vincent Bernat 83ba464515 net: add helpers checking if socket can be bound to nonlocal address
The construction "net->ipv4.sysctl_ip_nonlocal_bind || inet->freebind
|| inet->transparent" is present three times and its IPv6 counterpart
is also present three times. We introduce two small helpers to
characterize these tests uniformly.

Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:50:04 -07:00
Eric Dumazet 4672694bd4 ipv4: frags: handle possible skb truesize change
ip_frag_queue() might call pskb_pull() on one skb that
is already in the fragment queue.

We need to take care of possible truesize change, or we
might have an imbalance of the netns frags memory usage.

IPv6 is immune to this bug, because RFC5722, Section 4,
amended by Errata ID 3089 states :

  When reassembling an IPv6 datagram, if
  one or more its constituent fragments is determined to be an
  overlapping fragment, the entire datagram (and any constituent
  fragments) MUST be silently discarded.

Fixes: 158f323b98 ("net: adjust skb->truesize in pskb_expand_head()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-31 14:41:29 -07:00
Eric Dumazet 56e2c94f05 inet: frag: enforce memory limits earlier
We currently check current frags memory usage only when
a new frag queue is created. This allows attackers to first
consume the memory budget (default : 4 MB) creating thousands
of frag queues, then sending tiny skbs to exceed high_thresh
limit by 2 to 3 order of magnitude.

Note that before commit 648700f76b ("inet: frags: use rhashtables
for reassembly units"), work queue could be starved under DOS,
getting no cpu cycles.
After commit 648700f76b, only the per frag queue timer can eventually
remove an incomplete frag queue and its skbs.

Fixes: b13d3cbfb8 ("inet: frag: move eviction of queues to work queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Peter Oskolkov <posk@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-31 14:41:29 -07:00
Christoph Hellwig dd979b4df8 net: simplify sock_poll_wait
The wait_address argument is always directly derived from the filp
argument, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-30 09:10:25 -07:00
Xin Long 5cbf777cfd route: add support for directed broadcast forwarding
This patch implements the feature described in rfc1812#section-5.3.5.2
and rfc2644. It allows the router to forward directed broadcast when
sysctl bc_forwarding is enabled.

Note that this feature could be done by iptables -j TEE, but it would
cause some problems:
  - target TEE's gateway param has to be set with a specific address,
    and it's not flexible especially when the route wants forward all
    directed broadcasts.
  - this duplicates the directed broadcasts so this may cause side
    effects to applications.

Besides, to keep consistent with other os router like BSD, it's also
necessary to implement it in the route rx path.

Note that route cache needs to be flushed when bc_forwarding is
changed.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-29 12:37:06 -07:00
Neal Cardwell 383d470936 tcp_bbr: fix bw probing to raise in-flight data for very small BDPs
For some very small BDPs (with just a few packets) there was a
quantization effect where the target number of packets in flight
during the super-unity-gain (1.25x) phase of gain cycling was
implicitly truncated to a number of packets no larger than the normal
unity-gain (1.0x) phase of gain cycling. This meant that in multi-flow
scenarios some flows could get stuck with a lower bandwidth, because
they did not push enough packets inflight to discover that there was
more bandwidth available. This was really only an issue in multi-flow
LAN scenarios, where RTTs and BDPs are low enough for this to be an
issue.

This fix ensures that gain cycling can raise inflight for small BDPs
by ensuring that in PROBE_BW mode target inflight values with a
super-unity gain are always greater than inflight values with a gain
<= 1. Importantly, this applies whether the inflight value is
calculated for use as a cwnd value, or as a target inflight value for
the end of the super-unity phase in bbr_is_next_cycle_phase() (both
need to be bigger to ensure we can probe with more packets in flight
reliably).

This is a candidate fix for stable releases.

Fixes: 0f8782ea14 ("tcp_bbr: add BBR congestion control")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Priyaranjan Jha <priyarjha@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-28 22:46:07 -07:00
Lorenzo Bianconi 9fc12023d6 ipv4: remove BUG_ON() from fib_compute_spec_dst
Remove BUG_ON() from fib_compute_spec_dst routine and check
in_dev pointer during flowi4 data structure initialization.
fib_compute_spec_dst routine can be run concurrently with device removal
where ip_ptr net_device pointer is set to NULL. This can happen
if userspace enables pkt info on UDP rx socket and the device
is removed while traffic is flowing

Fixes: 35ebf65e85 ("ipv4: Create and use fib_compute_spec_dst() helper")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-28 19:06:12 -07:00
David S. Miller 7a49d3d4ea Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2018-07-27

1) Extend the output_mark to also support the input direction
   and masking the mark values before applying to the skb.

2) Add a new lookup key for the upcomming xfrm interfaces.

3) Extend the xfrm lookups to match xfrm interface IDs.

4) Add virtual xfrm interfaces. The purpose of these interfaces
   is to overcome the design limitations that the existing
   VTI devices have.

  The main limitations that we see with the current VTI are the
  following:

  VTI interfaces are L3 tunnels with configurable endpoints.
  For xfrm, the tunnel endpoint are already determined by the SA.
  So the VTI tunnel endpoints must be either the same as on the
  SA or wildcards. In case VTI tunnel endpoints are same as on
  the SA, we get a one to one correlation between the SA and
  the tunnel. So each SA needs its own tunnel interface.

  On the other hand, we can have only one VTI tunnel with
  wildcard src/dst tunnel endpoints in the system because the
  lookup is based on the tunnel endpoints. The existing tunnel
  lookup won't work with multiple tunnels with wildcard
  tunnel endpoints. Some usecases require more than on
  VTI tunnel of this type, for example if somebody has multiple
  namespaces and every namespace requires such a VTI.

  VTI needs separate interfaces for IPv4 and IPv6 tunnels.
  So when routing to a VTI, we have to know to which address
  family this traffic class is going to be encapsulated.
  This is a lmitation because it makes routing more complex
  and it is not always possible to know what happens behind the
  VTI, e.g. when the VTI is move to some namespace.

  VTI works just with tunnel mode SAs. We need generic interfaces
  that ensures transfomation, regardless of the xfrm mode and
  the encapsulated address family.

  VTI is configured with a combination GRE keys and xfrm marks.
  With this we have to deal with some extra cases in the generic
  tunnel lookup because the GRE keys on the VTI are actually
  not GRE keys, the GRE keys were just reused for something else.
  All extensions to the VTI interfaces would require to add
  even more complexity to the generic tunnel lookup.

  So to overcome this, we developed xfrm interfaces with the
  following design goal:

  It should be possible to tunnel IPv4 and IPv6 through the same
  interface.

  No limitation on xfrm mode (tunnel, transport and beet).

  Should be a generic virtual interface that ensures IPsec
  transformation, no need to know what happens behind the
  interface.

  Interfaces should be configured with a new key that must match a
  new policy/SA lookup key.

  The lookup logic should stay in the xfrm codebase, no need to
  change or extend generic routing and tunnel lookups.

  Should be possible to use IPsec hardware offloads of the underlying
  interface.

5) Remove xfrm pcpu policy cache. This was added after the flowcache
   removal, but it turned out to make things even worse.
   From Florian Westphal.

6) Allow to update the set mark on SA updates.
   From Nathan Harold.

7) Convert some timestamps to time64_t.
   From Arnd Bergmann.

8) Don't check the offload_handle in xfrm code,
   it is an opaque data cookie for the driver.
   From Shannon Nelson.

9) Remove xfrmi interface ID from flowi. After this pach
   no generic code is touched anymore to do xfrm interface
   lookups. From Benedict Wong.

10) Allow to update the xfrm interface ID on SA updates.
    From Nathan Harold.

11) Don't pass zero to ERR_PTR() in xfrm_resolve_and_create_bundle.
    From YueHaibing.

12) Return more detailed errors on xfrm interface creation.
    From Benedict Wong.

13) Use PTR_ERR_OR_ZERO instead of IS_ERR + PTR_ERR.
    From the kbuild test robot.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27 09:33:37 -07:00
Wei Yongjun b87bac1012 net: igmp: make function __ip_mc_inc_group() static
Fixes the following sparse warnings:

net/ipv4/igmp.c:1391:6: warning:
 symbol '__ip_mc_inc_group' was not declared. Should it be static?

Fixes: 6e2059b53f ("ipv4/igmp: init group mode as INCLUDE when join source group")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-25 16:36:57 -07:00
Wei Yongjun 55477206f1 tcp: make function tcp_retransmit_stamp() static
Fixes the following sparse warnings:

net/ipv4/tcp_timer.c:25:5: warning:
 symbol 'tcp_retransmit_stamp' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-25 16:35:45 -07:00
Lawrence Brakmo 9aee400061 tcp: ack immediately when a cwr packet arrives
We observed high 99 and 99.9% latencies when doing RPCs with DCTCP. The
problem is triggered when the last packet of a request arrives CE
marked. The reply will carry the ECE mark causing TCP to shrink its cwnd
to 1 (because there are no packets in flight). When the 1st packet of
the next request arrives, the ACK was sometimes delayed even though it
is CWR marked, adding up to 40ms to the RPC latency.

This patch insures that CWR marked data packets arriving will be acked
immediately.

Packetdrill script to reproduce the problem:

0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
0.000 setsockopt(3, SOL_TCP, TCP_CONGESTION, "dctcp", 5) = 0
0.000 bind(3, ..., ...) = 0
0.000 listen(3, 1) = 0

0.100 < [ect0] SEW 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
0.100 > SE. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
0.110 < [ect0] . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4

0.200 < [ect0] . 1:1001(1000) ack 1 win 257
0.200 > [ect01] . 1:1(0) ack 1001

0.200 write(4, ..., 1) = 1
0.200 > [ect01] P. 1:2(1) ack 1001

0.200 < [ect0] . 1001:2001(1000) ack 2 win 257
0.200 write(4, ..., 1) = 1
0.200 > [ect01] P. 2:3(1) ack 2001

0.200 < [ect0] . 2001:3001(1000) ack 3 win 257
0.200 < [ect0] . 3001:4001(1000) ack 3 win 257
0.200 > [ect01] . 3:3(0) ack 4001

0.210 < [ce] P. 4001:4501(500) ack 3 win 257

+0.001 read(4, ..., 4500) = 4500
+0 write(4, ..., 1) = 1
+0 > [ect01] PE. 3:4(1) ack 4501

+0.010 < [ect0] W. 4501:5501(1000) ack 4 win 257
// Previously the ACK sequence below would be 4501, causing a long RTO
+0.040~+0.045 > [ect01] . 4:4(0) ack 5501   // delayed ack

+0.311 < [ect0] . 5501:6501(1000) ack 4 win 257  // More data
+0 > [ect01] . 4:4(0) ack 6501     // now acks everything

+0.500 < F. 9501:9501(0) ack 4 win 257

Modified based on comments by Neal Cardwell <ncardwell@google.com>

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-25 16:20:35 -07:00
David S. Miller 19725496da Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-24 19:21:58 -07:00
Willem de Bruijn 2efd4fca70 ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull
Syzbot reported a read beyond the end of the skb head when returning
IPV6_ORIGDSTADDR:

  BUG: KMSAN: kernel-infoleak in put_cmsg+0x5ef/0x860 net/core/scm.c:242
  CPU: 0 PID: 4501 Comm: syz-executor128 Not tainted 4.17.0+ #9
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
  Google 01/01/2011
  Call Trace:
    __dump_stack lib/dump_stack.c:77 [inline]
    dump_stack+0x185/0x1d0 lib/dump_stack.c:113
    kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1125
    kmsan_internal_check_memory+0x138/0x1f0 mm/kmsan/kmsan.c:1219
    kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1261
    copy_to_user include/linux/uaccess.h:184 [inline]
    put_cmsg+0x5ef/0x860 net/core/scm.c:242
    ip6_datagram_recv_specific_ctl+0x1cf3/0x1eb0 net/ipv6/datagram.c:719
    ip6_datagram_recv_ctl+0x41c/0x450 net/ipv6/datagram.c:733
    rawv6_recvmsg+0x10fb/0x1460 net/ipv6/raw.c:521
    [..]

This logic and its ipv4 counterpart read the destination port from
the packet at skb_transport_offset(skb) + 4.

With MSG_MORE and a local SOCK_RAW sender, syzbot was able to cook a
packet that stores headers exactly up to skb_transport_offset(skb) in
the head and the remainder in a frag.

Call pskb_may_pull before accessing the pointer to ensure that it lies
in skb head.

Link: http://lkml.kernel.org/r/CAF=yD-LEJwZj5a1-bAAj2Oy_hKmGygV6rsJ_WOrAYnv-fnayiQ@mail.gmail.com
Reported-by: syzbot+9adb4b567003cac781f0@syzkaller.appspotmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-24 16:35:58 -07:00
Stephen Hemminger e446a2760f net: remove blank lines at end of file
Several files have extra line at end of file.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-24 14:10:43 -07:00
Stephen Hemminger a17922def7 bpfilter: remove trailing newline
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-24 14:10:42 -07:00
Eric Dumazet 58152ecbbc tcp: add tcp_ooo_try_coalesce() helper
In case skb in out_or_order_queue is the result of
multiple skbs coalescing, we would like to get a proper gso_segs
counter tracking, so that future tcp_drop() can report an accurate
number.

I chose to not implement this tracking for skbs in receive queue,
since they are not dropped, unless socket is disconnected.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23 12:01:36 -07:00
Eric Dumazet 8541b21e78 tcp: call tcp_drop() from tcp_data_queue_ofo()
In order to be able to give better diagnostics and detect
malicious traffic, we need to have better sk->sk_drops tracking.

Fixes: 9f5afeae51 ("tcp: use an RB tree for ooo receive queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23 12:01:36 -07:00
Eric Dumazet 3d4bf93ac1 tcp: detect malicious patterns in tcp_collapse_ofo_queue()
In case an attacker feeds tiny packets completely out of order,
tcp_collapse_ofo_queue() might scan the whole rb-tree, performing
expensive copies, but not changing socket memory usage at all.

1) Do not attempt to collapse tiny skbs.
2) Add logic to exit early when too many tiny skbs are detected.

We prefer not doing aggressive collapsing (which copies packets)
for pathological flows, and revert to tcp_prune_ofo_queue() which
will be less expensive.

In the future, we might add the possibility of terminating flows
that are proven to be malicious.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23 12:01:36 -07:00
Eric Dumazet f4a3313d8e tcp: avoid collapses in tcp_prune_queue() if possible
Right after a TCP flow is created, receiving tiny out of order
packets allways hit the condition :

if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
	tcp_clamp_window(sk);

tcp_clamp_window() increases sk_rcvbuf to match sk_rmem_alloc
(guarded by tcp_rmem[2])

Calling tcp_collapse_ofo_queue() in this case is not useful,
and offers a O(N^2) surface attack to malicious peers.

Better not attempt anything before full queue capacity is reached,
forcing attacker to spend lots of resource and allow us to more
easily detect the abuse.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23 12:01:36 -07:00
Eric Dumazet 72cd43ba64 tcp: free batches of packets in tcp_prune_ofo_queue()
Juha-Matti Tilli reported that malicious peers could inject tiny
packets in out_of_order_queue, forcing very expensive calls
to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for
every incoming packet. out_of_order_queue rb-tree can contain
thousands of nodes, iterating over all of them is not nice.

Before linux-4.9, we would have pruned all packets in ofo_queue
in one go, every XXXX packets. XXXX depends on sk_rcvbuf and skbs
truesize, but is about 7000 packets with tcp_rmem[2] default of 6 MB.

Since we plan to increase tcp_rmem[2] in the future to cope with
modern BDP, can not revert to the old behavior, without great pain.

Strategy taken in this patch is to purge ~12.5 % of the queue capacity.

Fixes: 36a6503fed ("tcp: refine tcp_prune_ofo_queue() to not drop all packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23 12:01:36 -07:00
Paolo Abeni 3dd1c9a127 ip: hash fragments consistently
The skb hash for locally generated ip[v6] fragments belonging
to the same datagram can vary in several circumstances:
* for connected UDP[v6] sockets, the first fragment get its hash
  via set_owner_w()/skb_set_hash_from_sk()
* for unconnected IPv6 UDPv6 sockets, the first fragment can get
  its hash via ip6_make_flowlabel()/skb_get_hash_flowi6(), if
  auto_flowlabel is enabled

For the following frags the hash is usually computed via
skb_get_hash().
The above can cause OoO for unconnected IPv6 UDPv6 socket: in that
scenario the egress tx queue can be selected on a per packet basis
via the skb hash.
It may also fool flow-oriented schedulers to place fragments belonging
to the same datagram in different flows.

Fix the issue by copying the skb hash from the head frag into
the others at fragmentation time.

Before this commit:
perf probe -a "dev_queue_xmit skb skb->hash skb->l4_hash:b1@0/8 skb->sw_hash:b1@1/8"
netperf -H $IPV4 -t UDP_STREAM -l 5 -- -m 2000 -n &
perf record -e probe:dev_queue_xmit -e probe:skb_set_owner_w -a sleep 0.1
perf script
probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=3713014309 l4_hash=1 sw_hash=0
probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=0 l4_hash=0 sw_hash=0

After this commit:
probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=2171763177 l4_hash=1 sw_hash=0
probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=2171763177 l4_hash=1 sw_hash=0

Fixes: b73c3d0e4f ("net: Save TX flow hash in sock and set in skbuf on xmit")
Fixes: 67800f9b1f ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23 11:39:30 -07:00
Hangbin Liu 08d3ffcc0c multicast: do not restore deleted record source filter mode to new one
There are two scenarios that we will restore deleted records. The first is
when device down and up(or unmap/remap). In this scenario the new filter
mode is same with previous one. Because we get it from in_dev->mc_list and
we do not touch it during device down and up.

The other scenario is when a new socket join a group which was just delete
and not finish sending status reports. In this scenario, we should use the
current filter mode instead of restore old one. Here are 4 cases in total.

old_socket        new_socket       before_fix       after_fix
  IN(A)             IN(A)           ALLOW(A)         ALLOW(A)
  IN(A)             EX( )           TO_IN( )         TO_EX( )
  EX( )             IN(A)           TO_EX( )         ALLOW(A)
  EX( )             EX( )           TO_EX( )         TO_EX( )

Fixes: 24803f38a5 (igmp: do not remove igmp souce list info when set link down)
Fixes: 1666d49e1d (mld: do not remove mld souce list info when set link down)
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-21 22:58:17 -07:00
Hangbin Liu 0ae0d60a37 multicast: remove useless parameter for group add
Remove the mode parameter for igmp/igmp6_group_added as we can get it
from first parameter.

Fixes: 6e2059b53f (ipv4/igmp: init group mode as INCLUDE when join source group)
Fixes: c7ea20c9da (ipv6/mcast: init as INCLUDE when join SSM INCLUDE group)
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-21 22:46:39 -07:00
Jon Maxwell b701a99e43 tcp: Add tcp_clamp_rto_to_user_timeout() helper to improve accuracy
Create the tcp_clamp_rto_to_user_timeout() helper routine. To calculate
the correct rto, so that the TCP_USER_TIMEOUT socket option is more
accurate. Taking suggestions and feedback into account from
Eric Dumazet, Neal Cardwell and David Laight. Due to the 1st commit we
can avoid the msecs_to_jiffies() and jiffies_to_msecs() dance.

Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-21 10:28:55 -07:00