Commit Graph

585 Commits

Author SHA1 Message Date
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
Willem de Bruijn
678ca42d68 ip: remove tx_flags from ipcm_cookie and use same logic for v4 and v6
skb_shinfo(skb)->tx_flags is derived from sk->sk_tsflags, possibly
after modification by __sock_cmsg_send, by calling sock_tx_timestamp.

The IPv4 and IPv6 paths do this conversion differently. In IPv4, the
individual protocols that support tx timestamps call this function
and store the result in ipc.tx_flags. In IPv6, sock_tx_timestamp is
called in __ip6_append_data.

There is no need to store both tx_flags and ts_flags in the cookie
as one is derived from the other. Convert when setting up the cork
and remove the redundant field. This is similar to IPv6, only have
the conversion happen only once per datagram, in ip(6)_setup_cork.

Also change __ip6_append_data to match __ip_append_data. Only update
tskey if timestamping is enabled with OPT_ID. The SOCK_.. test is
redundant: only valid protocols can have non-zero cork->tx_flags.

After this change the IPv4 and IPv6 logic is the same.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07 10:58:49 +09:00
Willem de Bruijn
351782067b ipv4: ipcm_cookie initializers
Initialize the cookie in one location to reduce code duplication and
avoid bugs from inconsistent initialization, such as that fixed in
commit 9887cba199 ("ip: limit use of gso_size to udp").

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07 10:58:49 +09:00
Jesus Sanchez-Palencia
bc969a9778 net: ipv4: Hook into time based transmission
Add a transmit_time field to struct inet_cork, then copy the
timestamp from the CMSG cookie at ip_setup_cork() so we can
safely copy it into the skb later during __ip_make_skb().

For the raw fast path, just perform the copy at raw_send_hdrinc().

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-04 22:30:27 +09:00
Linus Torvalds
a11e1d432b Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL
The poll() changes were not well thought out, and completely
unexplained.  They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead.  That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case.  The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
  individually because that would just be unnecessarily messy  - Linus ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28 10:40:47 -07:00
Paolo Abeni
6c206b2009 udp: fix rx queue len reported by diag and proc interface
After commit 6b229cf77d ("udp: add batching to udp_rmem_release()")
the sk_rmem_alloc field does not measure exactly anymore the
receive queue length, because we batch the rmem release. The issue
is really apparent only after commit 0d4a6608f6 ("udp: do rmem bulk
free even if the rx sk queue is empty"): the user space can easily
check for an empty socket with not-0 queue length reported by the 'ss'
tool or the procfs interface.

We need to use a custom UDP helper to report the correct queue length,
taking into account the forward allocation deficit.

Reported-by: trevor.francis@46labs.com
Fixes: 6b229cf77d ("UDP: add batching to udp_rmem_release()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-08 19:55:15 -04:00
Linus Torvalds
1c8c5a9d38 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Add Maglev hashing scheduler to IPVS, from Inju Song.

 2) Lots of new TC subsystem tests from Roman Mashak.

 3) Add TCP zero copy receive and fix delayed acks and autotuning with
    SO_RCVLOWAT, from Eric Dumazet.

 4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard
    Brouer.

 5) Add ttl inherit support to vxlan, from Hangbin Liu.

 6) Properly separate ipv6 routes into their logically independant
    components. fib6_info for the routing table, and fib6_nh for sets of
    nexthops, which thus can be shared. From David Ahern.

 7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP
    messages from XDP programs. From Nikita V. Shirokov.

 8) Lots of long overdue cleanups to the r8169 driver, from Heiner
    Kallweit.

 9) Add BTF ("BPF Type Format"), from Martin KaFai Lau.

10) Add traffic condition monitoring to iwlwifi, from Luca Coelho.

11) Plumb extack down into fib_rules, from Roopa Prabhu.

12) Add Flower classifier offload support to igb, from Vinicius Costa
    Gomes.

13) Add UDP GSO support, from Willem de Bruijn.

14) Add documentation for eBPF helpers, from Quentin Monnet.

15) Add TLS tx offload to mlx5, from Ilya Lesokhin.

16) Allow applications to be given the number of bytes available to read
    on a socket via a control message returned from recvmsg(), from
    Soheil Hassas Yeganeh.

17) Add x86_32 eBPF JIT compiler, from Wang YanQing.

18) Add AF_XDP sockets, with zerocopy support infrastructure as well.
    From Björn Töpel.

19) Remove indirect load support from all of the BPF JITs and handle
    these operations in the verifier by translating them into native BPF
    instead. From Daniel Borkmann.

20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha.

21) Allow XDP programs to do lookups in the main kernel routing tables
    for forwarding. From David Ahern.

22) Allow drivers to store hardware state into an ELF section of kernel
    dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy.

23) Various RACK and loss detection improvements in TCP, from Yuchung
    Cheng.

24) Add TCP SACK compression, from Eric Dumazet.

25) Add User Mode Helper support and basic bpfilter infrastructure, from
    Alexei Starovoitov.

26) Support ports and protocol values in RTM_GETROUTE, from Roopa
    Prabhu.

27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard
    Brouer.

28) Add lots of forwarding selftests, from Petr Machata.

29) Add generic network device failover driver, from Sridhar Samudrala.

* ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits)
  strparser: Add __strp_unpause and use it in ktls.
  rxrpc: Fix terminal retransmission connection ID to include the channel
  net: hns3: Optimize PF CMDQ interrupt switching process
  net: hns3: Fix for VF mailbox receiving unknown message
  net: hns3: Fix for VF mailbox cannot receiving PF response
  bnx2x: use the right constant
  Revert "net: sched: cls: Fix offloading when ingress dev is vxlan"
  net: dsa: b53: Fix for brcm tag issue in Cygnus SoC
  enic: fix UDP rss bits
  netdev-FAQ: clarify DaveM's position for stable backports
  rtnetlink: validate attributes in do_setlink()
  mlxsw: Add extack messages for port_{un, }split failures
  netdevsim: Add extack error message for devlink reload
  devlink: Add extack to reload and port_{un, }split operations
  net: metrics: add proper netlink validation
  ipmr: fix error path when ipmr_new_table fails
  ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds
  net: hns3: remove unused hclgevf_cfg_func_mta_filter
  netfilter: provide udp*_lib_lookup for nf_tproxy
  qed*: Utilize FW 8.37.2.0
  ...
2018-06-06 18:39:49 -07:00
David S. Miller
fd129f8941 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-06-05

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

The main changes are:

1) Add a new BPF hook for sendmsg similar to existing hooks for bind and
   connect: "This allows to override source IP (including the case when it's
   set via cmsg(3)) and destination IP:port for unconnected UDP (slow path).
   TCP and connected UDP (fast path) are not affected. This makes UDP support
   complete, that is, connected UDP is handled by connect hooks, unconnected
   by sendmsg ones.", from Andrey.

2) Rework of the AF_XDP API to allow extending it in future for type writer
   model if necessary. In this mode a memory window is passed to hardware
   and multiple frames might be filled into that window instead of just one
   that is the case in the current fixed frame-size model. With the new
   changes made this can be supported without having to add a new descriptor
   format. Also, core bits for the zero-copy support for AF_XDP have been
   merged as agreed upon, where i40e bits will be routed via Jeff later on.
   Various improvements to documentation and sample programs included as
   well, all from Björn and Magnus.

3) Given BPF's flexibility, a new program type has been added to implement
   infrared decoders. Quote: "The kernel IR decoders support the most
   widely used IR protocols, but there are many protocols which are not
   supported. [...] There is a 'long tail' of unsupported IR protocols,
   for which lircd is need to decode the IR. IR encoding is done in such
   a way that some simple circuit can decode it; therefore, BPF is ideal.
   [...] user-space can define a decoder in BPF, attach it to the rc
   device through the lirc chardev.", from Sean.

4) Several improvements and fixes to BPF core, among others, dumping map
   and prog IDs into fdinfo which is a straight forward way to correlate
   BPF objects used by applications, removing an indirect call and therefore
   retpoline in all map lookup/update/delete calls by invoking the callback
   directly for 64 bit archs, adding a new bpf_skb_cgroup_id() BPF helper
   for tc BPF programs to have an efficient way of looking up cgroup v2 id
   for policy or other use cases. Fixes to make sure we zero tunnel/xfrm
   state that hasn't been filled, to allow context access wrt pt_regs in
   32 bit archs for tracing, and last but not least various test cases
   for fixes that landed in bpf earlier, from Daniel.

5) Get rid of the ndo_xdp_flush API and extend the ndo_xdp_xmit with
   a XDP_XMIT_FLUSH flag instead which allows to avoid one indirect
   call as flushing is now merged directly into ndo_xdp_xmit(), from Jesper.

6) Add a new bpf_get_current_cgroup_id() helper that can be used in
   tracing to retrieve the cgroup id from the current process in order
   to allow for e.g. aggregation of container-level events, from Yonghong.

7) Two follow-up fixes for BTF to reject invalid input values and
   related to that also two test cases for BPF kselftests, from Martin.

8) Various API improvements to the bpf_fib_lookup() helper, that is,
   dropping MPLS bits which are not fully hashed out yet, rejecting
   invalid helper flags, returning error for unsupported address
   families as well as renaming flowlabel to flowinfo, from David.

9) Various fixes and improvements to sockmap BPF kselftests in particular
   in proper error detection and data verification, from Prashant.

10) Two arm32 BPF JIT improvements. One is to fix imm range check with
    regards to whether immediate fits into 24 bits, and a naming cleanup
    to get functions related to rsh handling consistent to those handling
    lsh, from Wang.

11) Two compile warning fixes in BPF, one for BTF and a false positive
    to silent gcc in stack_map_get_build_id_offset(), from Arnd.

12) Add missing seg6.h header into tools include infrastructure in order
    to fix compilation of BPF kselftests, from Mathieu.

13) Several formatting cleanups in the BPF UAPI helper description that
    also fix an error during rst2man compilation, from Quentin.

14) Hide an unused variable in sk_msg_convert_ctx_access() when IPv6 is
    not built into the kernel, from Yue.

15) Remove a useless double assignment in dev_map_enqueue(), from Colin.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-05 12:42:19 -04:00
Arnd Bergmann
6e86000c2c netfilter: provide udp*_lib_lookup for nf_tproxy
It is now possible to enable the libified nf_tproxy modules without
also enabling NETFILTER_XT_TARGET_TPROXY, which throws off the
ifdef logic in the udp core code:

net/ipv6/netfilter/nf_tproxy_ipv6.o: In function `nf_tproxy_get_sock_v6':
nf_tproxy_ipv6.c:(.text+0x1a8): undefined reference to `udp6_lib_lookup'
net/ipv4/netfilter/nf_tproxy_ipv4.o: In function `nf_tproxy_get_sock_v4':
nf_tproxy_ipv4.c:(.text+0x3d0): undefined reference to `udp4_lib_lookup'

We can actually simplify the conditions now to provide the two functions
exactly when they are needed.

Fixes: 45ca4e0cf2 ("netfilter: Libify xt_TPROXY")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-05 10:55:05 -04:00
Linus Torvalds
408afb8d78 Merge branch 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull aio updates from Al Viro:
 "Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly.

  The only thing I'm holding back for a day or so is Adam's aio ioprio -
  his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case),
  but let it sit in -next for decency sake..."

* 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  aio: sanitize the limit checking in io_submit(2)
  aio: fold do_io_submit() into callers
  aio: shift copyin of iocb into io_submit_one()
  aio_read_events_ring(): make a bit more readable
  aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way
  aio: take list removal to (some) callers of aio_complete()
  aio: add missing break for the IOCB_CMD_FDSYNC case
  random: convert to ->poll_mask
  timerfd: convert to ->poll_mask
  eventfd: switch to ->poll_mask
  pipe: convert to ->poll_mask
  crypto: af_alg: convert to ->poll_mask
  net/rxrpc: convert to ->poll_mask
  net/iucv: convert to ->poll_mask
  net/phonet: convert to ->poll_mask
  net/nfc: convert to ->poll_mask
  net/caif: convert to ->poll_mask
  net/bluetooth: convert to ->poll_mask
  net/sctp: convert to ->poll_mask
  net/tipc: convert to ->poll_mask
  ...
2018-06-04 13:57:43 -07:00
Andrey Ignatov
1cedee13d2 bpf: Hooks for sys_sendmsg
In addition to already existing BPF hooks for sys_bind and sys_connect,
the patch provides new hooks for sys_sendmsg.

It leverages existing BPF program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR`
that provides access to socket itlself (properties like family, type,
protocol) and user-passed `struct sockaddr *` so that BPF program can
override destination IP and port for system calls such as sendto(2) or
sendmsg(2) and/or assign source IP to the socket.

The hooks are implemented as two new attach types:
`BPF_CGROUP_UDP4_SENDMSG` and `BPF_CGROUP_UDP6_SENDMSG` for UDPv4 and
UDPv6 correspondingly.

UDPv4 and UDPv6 separate attach types for same reason as sys_bind and
sys_connect hooks, i.e. to prevent reading from / writing to e.g.
user_ip6 fields when user passes sockaddr_in since it'd be out-of-bound.

The difference with already existing hooks is sys_sendmsg are
implemented only for unconnected UDP.

For TCP it doesn't make sense to change user-provided `struct sockaddr *`
at sendto(2)/sendmsg(2) time since socket either was already connected
and has source/destination set or wasn't connected and call to
sendto(2)/sendmsg(2) would lead to ENOTCONN anyway.

Connected UDP is already handled by sys_connect hooks that can override
source/destination at connect time and use fast-path later, i.e. these
hooks don't affect UDP fast-path.

Rewriting source IP is implemented differently than that in sys_connect
hooks. When sys_sendmsg is used with unconnected UDP it doesn't work to
just bind socket to desired local IP address since source IP can be set
on per-packet basis by using ancillary data (cmsg(3)). So no matter if
socket is bound or not, source IP has to be rewritten on every call to
sys_sendmsg.

To do so two new fields are added to UAPI `struct bpf_sock_addr`;
* `msg_src_ip4` to set source IPv4 for UDPv4;
* `msg_src_ip6` to set source IPv6 for UDPv6.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-28 17:41:02 +02:00
Christoph Hellwig
db5051ead6 net: convert datagram_poll users tp ->poll_mask
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26 09:16:44 +02:00
Willem de Bruijn
ff06342cbc udp: exclude gso from xfrm paths
UDP GSO delays final datagram construction to the GSO layer. This
conflicts with protocol transformations.

Fixes: bec1f6f697 ("udp: generate gso with UDP_SEGMENT")
CC: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-23 14:48:44 -04:00
Christoph Hellwig
c350637227 proc: introduce proc_create_net{,_data}
Variants of proc_create{,_data} that directly take a struct seq_operations
and deal with network namespaces in ->open and ->release.  All callers of
proc_create + seq_open_net converted over, and seq_{open,release}_net are
removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16 07:24:30 +02:00
Christoph Hellwig
a3d2599b24 ipv{4,6}/udp{,lite}: simplify proc registration
Remove a couple indirections to make the code look like most other
protocols.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16 07:23:35 +02:00
David S. Miller
b2d6cee117 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The bpf syscall and selftests conflicts were trivial
overlapping changes.

The r8169 change involved moving the added mdelay from 'net' into a
different function.

A TLS close bug fix overlapped with the splitting of the TLS state
into separate TX and RX parts.  I just expanded the tests in the bug
fix from "ctx->conf == X" into "ctx->tx_conf == X && ctx->rx_conf
== X".

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-11 20:53:22 -04:00
Andrey Ignatov
1b97013bfb ipv4: fix memory leaks in udp_sendmsg, ping_v4_sendmsg
Fix more memory leaks in ip_cmsg_send() callers. Part of them were fixed
earlier in 919483096b.

* udp_sendmsg one was there since the beginning when linux sources were
  first added to git;
* ping_v4_sendmsg one was copy/pasted in c319b4d76b.

Whenever return happens in udp_sendmsg() or ping_v4_sendmsg() IP options
have to be freed if they were allocated previously.

Add label so that future callers (if any) can use it instead of kfree()
before return that is easy to forget.

Fixes: c319b4d76b (net: ipv4: add IPPROTO_ICMP socket kind)
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-11 12:00:58 -04:00
Paolo Abeni
69678bcd4d udp: fix SO_BINDTODEVICE
Damir reported a breakage of SO_BINDTODEVICE for UDP sockets.
In absence of VRF devices, after commit fb74c27735 ("net:
ipv4: add second dif to udp socket lookups") the dif mismatch
isn't fatal anymore for UDP socket lookup with non null
sk_bound_dev_if, breaking SO_BINDTODEVICE semantics.

This changeset addresses the issue making the dif match mandatory
again in the above scenario.

Reported-by: Damir Mansurov <dnman@oktetlabs.ru>
Fixes: fb74c27735 ("net: ipv4: add second dif to udp socket lookups")
Fixes: 1801b570dd ("net: ipv6: add second dif to udp socket lookups")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-10 15:42:52 -04:00
Davidlohr Bueso
88ab31081b net/udp: Update udp_encap_needed static key to modern api
No changes in refcount semantics -- key init is false; replace

static_key_enable         with   static_branch_enable
static_key_slow_inc|dec   with   static_branch_inc|dec
static_key_false          with   static_branch_unlikely

Added a '_key' suffix to udp and udpv6 encap_needed, for better
self documentation.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-10 15:13:34 -04:00
Alexander Duyck
dfec0ee22c udp: Record gso_segs when supporting UDP segmentation offload
We need to record the number of segments that will be generated when this
frame is segmented. The expectation is that if gso_size is set then
gso_segs is set as well. Without this some drivers such as ixgbe get
confused if they attempt to offload this as they record 0 segments for the
entire packet instead of the correct value.

Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-08 22:30:05 -04:00
Willem de Bruijn
a8c744a8b4 udp: disable gso with no_check_tx
Syzbot managed to send a udp gso packet without checksum offload into
the gso stack by disabling tx checksum (UDP_NO_CHECK6_TX). This
triggered the skb_warn_bad_offload.

  RIP: 0010:skb_warn_bad_offload+0x2bc/0x600 net/core/dev.c:2658
   skb_gso_segment include/linux/netdevice.h:4038 [inline]
   validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3120
   __dev_queue_xmit+0xbf8/0x34c0 net/core/dev.c:3577
   dev_queue_xmit+0x17/0x20 net/core/dev.c:3618

UDP_NO_CHECK6_TX sets skb->ip_summed to CHECKSUM_NONE just after the
udp gso integrity checks in udp_(v6_)send_skb. Extend those checks to
catch and fail in this case.

After the integrity checks jump directly to the CHECKSUM_PARTIAL case
to avoid reading the no_check_tx flags again (a TOCTTOU race).

Fixes: bec1f6f697 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-01 14:20:14 -04:00
Willem de Bruijn
2e8de85763 udp: add gso segment cmsg
Allow specifying segment size in the send call.

The new control message performs the same function as socket option
UDP_SEGMENT while avoiding the extra system call.

[ Export udp_cmsg_send for ipv6. -DaveM ]

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-26 15:08:51 -04:00
Willem de Bruijn
bec1f6f697 udp: generate gso with UDP_SEGMENT
Support generic segmentation offload for udp datagrams. Callers can
concatenate and send at once the payload of multiple datagrams with
the same destination.

To set segment size, the caller sets socket option UDP_SEGMENT to the
length of each discrete payload. This value must be smaller than or
equal to the relevant MTU.

A follow-up patch adds cmsg UDP_SEGMENT to specify segment size on a
per send call basis.

Total byte length may then exceed MTU. If not an exact multiple of
segment size, the last segment will be shorter.

The implementation adds a gso_size field to the udp socket, ip(v6)
cmsg cookie and inet_cork structure to be able to set the value at
setsockopt or cmsg time and to work with both lockless and corked
paths.

Initial benchmark numbers show UDP GSO about as expensive as TCP GSO.

    tcp tso
     3197 MB/s 54232 msg/s 54232 calls/s
         6,457,754,262      cycles

    tcp gso
     1765 MB/s 29939 msg/s 29939 calls/s
        11,203,021,806      cycles

    tcp without tso/gso *
      739 MB/s 12548 msg/s 12548 calls/s
        11,205,483,630      cycles

    udp
      876 MB/s 14873 msg/s 624666 calls/s
        11,205,777,429      cycles

    udp gso
     2139 MB/s 36282 msg/s 36282 calls/s
        11,204,374,561      cycles

   [*] after reverting commit 0a6b2a1dc2
       ("tcp: switch to GSO being always on")

Measured total system cycles ('-a') for one core while pinning both
the network receive path and benchmark process to that core:

  perf stat -a -C 12 -e cycles \
    ./udpgso_bench_tx -C 12 -4 -D "$DST" -l 4

Note the reduction in calls/s with GSO. Bytes per syscall drops
increases from 1470 to 61818.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-26 15:08:04 -04:00
Willem de Bruijn
1cd7884dfd udp: expose inet cork to udp
UDP segmentation offload needs access to inet_cork in the udp layer.
Pass the struct to ip(6)_make_skb instead of allocating it on the
stack in that function itself.

This patch is a noop otherwise.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-26 15:06:46 -04:00
David S. Miller
d4069fe6fc Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-03-31

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

The main changes are:

1) Add raw BPF tracepoint API in order to have a BPF program type that
   can access kernel internal arguments of the tracepoints in their
   raw form similar to kprobes based BPF programs. This infrastructure
   also adds a new BPF_RAW_TRACEPOINT_OPEN command to BPF syscall which
   returns an anon-inode backed fd for the tracepoint object that allows
   for automatic detach of the BPF program resp. unregistering of the
   tracepoint probe on fd release, from Alexei.

2) Add new BPF cgroup hooks at bind() and connect() entry in order to
   allow BPF programs to reject, inspect or modify user space passed
   struct sockaddr, and as well a hook at post bind time once the port
   has been allocated. They are used in FB's container management engine
   for implementing policy, replacing fragile LD_PRELOAD wrapper
   intercepting bind() and connect() calls that only works in limited
   scenarios like glibc based apps but not for other runtimes in
   containerized applications, from Andrey.

3) BPF_F_INGRESS flag support has been added to sockmap programs for
   their redirect helper call bringing it in line with cls_bpf based
   programs. Support is added for both variants of sockmap programs,
   meaning for tx ULP hooks as well as recv skb hooks, from John.

4) Various improvements on BPF side for the nfp driver, besides others
   this work adds BPF map update and delete helper call support from
   the datapath, JITing of 32 and 64 bit XADD instructions as well as
   offload support of bpf_get_prandom_u32() call. Initial implementation
   of nfp packet cache has been tackled that optimizes memory access
   (see merge commit for further details), from Jakub and Jiong.

5) Removal of struct bpf_verifier_env argument from the print_bpf_insn()
   API has been done in order to prepare to use print_bpf_insn() soon
   out of perf tool directly. This makes the print_bpf_insn() API more
   generic and pushes the env into private data. bpftool is adjusted
   as well with the print_bpf_insn() argument removal, from Jiri.

6) Couple of cleanups and prep work for the upcoming BTF (BPF Type
   Format). The latter will reuse the current BPF verifier log as
   well, thus bpf_verifier_log() is further generalized, from Martin.

7) For bpf_getsockopt() and bpf_setsockopt() helpers, IPv4 IP_TOS read
   and write support has been added in similar fashion to existing
   IPv6 IPV6_TCLASS socket option we already have, from Nikita.

8) Fixes in recent sockmap scatterlist API usage, which did not use
   sg_init_table() for initialization thus triggering a BUG_ON() in
   scatterlist API when CONFIG_DEBUG_SG was enabled. This adds and
   uses a small helper sg_init_marker() to properly handle the affected
   cases, from Prashant.

9) Let the BPF core follow IDR code convention and therefore use the
   idr_preload() and idr_preload_end() helpers, which would also help
   idr_alloc_cyclic() under GFP_ATOMIC to better succeed under memory
   pressure, from Shaohua.

10) Last but not least, a spelling fix in an error message for the
    BPF cookie UID helper under BPF sample code, from Colin.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31 23:33:04 -04:00
Andrey Ignatov
d74bad4e74 bpf: Hooks for sys_connect
== The problem ==

See description of the problem in the initial patch of this patch set.

== The solution ==

The patch provides much more reliable in-kernel solution for the 2nd
part of the problem: making outgoing connecttion from desired IP.

It adds new attach types `BPF_CGROUP_INET4_CONNECT` and
`BPF_CGROUP_INET6_CONNECT` for program type
`BPF_PROG_TYPE_CGROUP_SOCK_ADDR` that can be used to override both
source and destination of a connection at connect(2) time.

Local end of connection can be bound to desired IP using newly
introduced BPF-helper `bpf_bind()`. It allows to bind to only IP though,
and doesn't support binding to port, i.e. leverages
`IP_BIND_ADDRESS_NO_PORT` socket option. There are two reasons for this:
* looking for a free port is expensive and can affect performance
  significantly;
* there is no use-case for port.

As for remote end (`struct sockaddr *` passed by user), both parts of it
can be overridden, remote IP and remote port. It's useful if an
application inside cgroup wants to connect to another application inside
same cgroup or to itself, but knows nothing about IP assigned to the
cgroup.

Support is added for IPv4 and IPv6, for TCP and UDP.

IPv4 and IPv6 have separate attach types for same reason as sys_bind
hooks, i.e. to prevent reading from / writing to e.g. user_ip6 fields
when user passes sockaddr_in since it'd be out-of-bound.

== Implementation notes ==

The patch introduces new field in `struct proto`: `pre_connect` that is
a pointer to a function with same signature as `connect` but is called
before it. The reason is in some cases BPF hooks should be called way
before control is passed to `sk->sk_prot->connect`. Specifically
`inet_dgram_connect` autobinds socket before calling
`sk->sk_prot->connect` and there is no way to call `bpf_bind()` from
hooks from e.g. `ip4_datagram_connect` or `ip6_datagram_connect` since
it'd cause double-bind. On the other hand `proto.pre_connect` provides a
flexible way to add BPF hooks for connect only for necessary `proto` and
call them at desired time before `connect`. Since `bpf_bind()` is
allowed to bind only to IP and autobind in `inet_dgram_connect` binds
only port there is no chance of double-bind.

bpf_bind() sets `force_bind_address_no_port` to bind to only IP despite
of value of `bind_address_no_port` socket field.

bpf_bind() sets `with_lock` to `false` when calling to __inet_bind()
and __inet6_bind() since all call-sites, where bpf_bind() is called,
already hold socket lock.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-31 02:15:54 +02:00
Kirill Tkhai
2f635ceeb2 net: Drop pernet_operations::async
Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27 13:18:09 -04:00
Joe Perches
d6444062f8 net: Use octal not symbolic permissions
Prefer the direct use of octal for permissions.

Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace
and some typing.

Miscellanea:

o Whitespace neatening around these conversions.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-26 12:07:48 -04:00
Kirill Tkhai
fc18999ed2 net: Convert udp_sysctl_ops
These pernet_operations just initialize udp4 defaults.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 13:00:46 -04:00
Tonghao Zhang
1e80295158 udp: Move the udp sysctl to namespace.
This patch moves the udp_rmem_min, udp_wmem_min
to namespace and init the udp_l3mdev_accept explicitly.

The udp_rmem_min/udp_wmem_min affect udp rx/tx queue,
with this patch namespaces can set them differently.

Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-16 12:03:30 -04:00
David S. Miller
f5c0c6f429 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-02-19 18:46:11 -05:00
Alexey Kodanev
15f35d49c9 udplite: fix partial checksum initialization
Since UDP-Lite is always using checksum, the following path is
triggered when calculating pseudo header for it:

  udp4_csum_init() or udp6_csum_init()
    skb_checksum_init_zero_check()
      __skb_checksum_validate_complete()

The problem can appear if skb->len is less than CHECKSUM_BREAK. In
this particular case __skb_checksum_validate_complete() also invokes
__skb_checksum_complete(skb). If UDP-Lite is using partial checksum
that covers only part of a packet, the function will return bad
checksum and the packet will be dropped.

It can be fixed if we skip skb_checksum_init_zero_check() and only
set the required pseudo header checksum for UDP-Lite with partial
checksum before udp4_csum_init()/udp6_csum_init() functions return.

Fixes: ed70fcfcee ("net: Call skb_checksum_init in IPv4")
Fixes: e4f45b7f40 ("net: Call skb_checksum_init in IPv6")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16 15:57:42 -05:00
Kirill Tkhai
f84c6821aa net: Convert pernet_subsys, registered from inet_init()
arp_net_ops just addr/removes /proc entry.

devinet_ops allocates and frees duplicate of init_net tables
and (un)registers sysctl entries.

fib_net_ops allocates and frees pernet tables, creates/destroys
netlink socket and (un)initializes /proc entries. Foreign
pernet_operations do not touch them.

ip_rt_proc_ops only modifies pernet /proc entries.

xfrm_net_ops creates/destroys /proc entries, allocates/frees
pernet statistics, hashes and tables, and (un)initializes
sysctl files. These are not touched by foreigh pernet_operations

xfrm4_net_ops allocates/frees private pernet memory, and
configures sysctls.

sysctl_route_ops creates/destroys sysctls.

rt_genid_ops only initializes fields of just allocated net.

ipv4_inetpeer_ops allocated/frees net private memory.

igmp_net_ops just creates/destroys /proc files and socket,
noone else interested in.

tcp_sk_ops seems to be safe, because tcp_sk_init() does not
depend on any other pernet_operations modifications. Iteration
over hash table in inet_twsk_purge() is made under RCU lock,
and it's safe to iterate the table this way. Removing from
the table happen from inet_twsk_deschedule_put(), but this
function is safe without any extern locks, as it's synchronized
inside itself. There are many examples, it's used in different
context. So, it's safe to leave tcp_sk_exit_batch() unlocked.

tcp_net_metrics_ops is synchronized on tcp_metrics_lock and safe.

udplite4_net_ops only creates/destroys pernet /proc file.

icmp_sk_ops creates percpu sockets, not touched by foreign
pernet_operations.

ipmr_net_ops creates/destroys pernet fib tables, (un)registers
fib rules and /proc files. This seem to be safe to execute
in parallel with foreign pernet_operations.

af_inet_ops just sets up default parameters of newly created net.

ipv4_mib_ops creates and destroys pernet percpu statistics.

raw_net_ops, tcp4_net_ops, udp4_net_ops, ping_v4_net_ops
and ip_proc_ops only create/destroy pernet /proc files.

ip4_frags_ops creates and destroys sysctl file.

So, it's safe to make the pernet_operations async.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13 10:36:08 -05:00
Linus Torvalds
a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Linus Torvalds
b2fe5fa686 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Significantly shrink the core networking routing structures. Result
    of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf

 2) Add netdevsim driver for testing various offloads, from Jakub
    Kicinski.

 3) Support cross-chip FDB operations in DSA, from Vivien Didelot.

 4) Add a 2nd listener hash table for TCP, similar to what was done for
    UDP. From Martin KaFai Lau.

 5) Add eBPF based queue selection to tun, from Jason Wang.

 6) Lockless qdisc support, from John Fastabend.

 7) SCTP stream interleave support, from Xin Long.

 8) Smoother TCP receive autotuning, from Eric Dumazet.

 9) Lots of erspan tunneling enhancements, from William Tu.

10) Add true function call support to BPF, from Alexei Starovoitov.

11) Add explicit support for GRO HW offloading, from Michael Chan.

12) Support extack generation in more netlink subsystems. From Alexander
    Aring, Quentin Monnet, and Jakub Kicinski.

13) Add 1000BaseX, flow control, and EEE support to mvneta driver. From
    Russell King.

14) Add flow table abstraction to netfilter, from Pablo Neira Ayuso.

15) Many improvements and simplifications to the NFP driver bpf JIT,
    from Jakub Kicinski.

16) Support for ipv6 non-equal cost multipath routing, from Ido
    Schimmel.

17) Add resource abstration to devlink, from Arkadi Sharshevsky.

18) Packet scheduler classifier shared filter block support, from Jiri
    Pirko.

19) Avoid locking in act_csum, from Davide Caratti.

20) devinet_ioctl() simplifications from Al viro.

21) More TCP bpf improvements from Lawrence Brakmo.

22) Add support for onlink ipv6 route flag, similar to ipv4, from David
    Ahern.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1925 commits)
  tls: Add support for encryption using async offload accelerator
  ip6mr: fix stale iterator
  net/sched: kconfig: Remove blank help texts
  openvswitch: meter: Use 64-bit arithmetic instead of 32-bit
  tcp_nv: fix potential integer overflow in tcpnv_acked
  r8169: fix RTL8168EP take too long to complete driver initialization.
  qmi_wwan: Add support for Quectel EP06
  rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK
  ipmr: Fix ptrdiff_t print formatting
  ibmvnic: Wait for device response when changing MAC
  qlcnic: fix deadlock bug
  tcp: release sk_frag.page in tcp_disconnect
  ipv4: Get the address of interface correctly.
  net_sched: gen_estimator: fix lockdep splat
  net: macb: Handle HRESP error
  net/mlx5e: IPoIB, Fix copy-paste bug in flow steering refactoring
  ipv6: addrconf: break critical section in addrconf_verify_rtnl()
  ipv6: change route cache aging logic
  i40e/i40evf: Update DESC_NEEDED value to reflect larger value
  bnxt_en: cleanup DIM work on device shutdown
  ...
2018-01-31 14:31:10 -08:00
David Ahern
9515a2e082 net/ipv4: Allow send to local broadcast from a socket bound to a VRF
Message sends to the local broadcast address (255.255.255.255) require
uc_index or sk_bound_dev_if to be set to an egress device. However,
responses or only received if the socket is bound to the device. This
is overly constraining for processes running in an L3 domain. This
patch allows a socket bound to the VRF device to send to the local
broadcast address by using IP_UNICAST_IF to set the egress interface
with packet receipt handled by the VRF binding.

Similar to IP_MULTICAST_IF, relax the constraint on setting
IP_UNICAST_IF if a socket is bound to an L3 master device. In this
case allow uc_index to be set to an enslaved if sk_bound_dev_if is
an L3 master device and is the master device for the ifindex.

In udp and raw sendmsg, allow uc_index to override the oif if
uc_index master device is oif (ie., the oif is an L3 master and the
index is an L3 slave).

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-25 21:51:31 -05:00
Alexey Dobriyan
96890d6252 net: delete /proc THIS_MODULE references
/proc has been ignoring struct file_operations::owner field for 10 years.
Specifically, it started with commit 786d7e1612
("Fix rmmod/read/write races in /proc entries"). Notice the chunk where
inode->i_fop is initialized with proxy struct file_operations for
regular files:

	-               if (de->proc_fops)
	-                       inode->i_fop = de->proc_fops;
	+               if (de->proc_fops) {
	+                       if (S_ISREG(inode->i_mode))
	+                               inode->i_fop = &proc_reg_file_ops;
	+                       else
	+                               inode->i_fop = de->proc_fops;
	+               }

VFS stopped pinning module at this point.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 15:01:33 -05:00
Soheil Hassas Yeganeh
0a38806f31 net: revert "Update RFS target at poll for tcp/udp"
On multi-threaded processes, one common architecture is to have
one (or a small number of) threads polling sockets, and a
considerably larger pool of threads reading form and writing to the
sockets. When we set RPS core on tcp_poll() or udp_poll() we essentially
steer all packets of all the polled FDs to one (or small number of)
cores, creaing a bottleneck and/or RPS misprediction.

Another common architecture is to shard FDs among threads pinned
to cores. In such a setting, setting RPS core in tcp_poll() and
udp_poll() is redundant because the RFS core is correctly
set in recvmsg and sendmsg.

Thus, revert the following commit:
c3f1dbaf6e ("net: Update RFS target at poll for tcp/udp").

Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-05 11:14:57 -05:00
Martin KaFai Lau
f0b1e64c13 udp: Move udp[46]_portaddr_hash() to net/ip[v6].h
This patch moves the udp[46]_portaddr_hash()
to net/ip[v6].h.  The function name is renamed to
ipv[46]_portaddr_hash().

It will be used by a later patch which adds a second listener
hashtable hashed by the address and port.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-03 10:18:28 -05:00
Paolo Abeni
e94a62f507 net/reuseport: drop legacy code
Since commit e32ea7e747 ("soreuseport: fast reuseport UDP socket
selection") and commit c125e80b88 ("soreuseport: fast reuseport
TCP socket selection") the relevant reuseport socket matching the current
packet is selected by the reuseport_select_sock() call. The only
exceptions are invalid BPF filters/filters returning out-of-range
indices.
In the latter case the code implicitly falls back to using the hash
demultiplexing, but instead of selecting the socket inside the
reuseport_select_sock() function, it relies on the hash selection
logic introduced with the early soreuseport implementation.

With this patch, in case of a BPF filter returning a bad socket
index value, we fall back to hash-based selection inside the
reuseport_select_sock() body, so that we can drop some duplicate
code in the ipv4 and ipv6 stack.

This also allows faster lookup in the above scenario and will allow
us to avoid computing the hash value for successful, BPF based
demultiplexing - in a later patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-30 10:56:32 -05:00
Al Viro
ade994f4f6 net: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:20:04 -05:00
Linus Torvalds
5bbcc0f595 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "Highlights:

   1) Maintain the TCP retransmit queue using an rbtree, with 1GB
      windows at 100Gb this really has become necessary. From Eric
      Dumazet.

   2) Multi-program support for cgroup+bpf, from Alexei Starovoitov.

   3) Perform broadcast flooding in hardware in mv88e6xxx, from Andrew
      Lunn.

   4) Add meter action support to openvswitch, from Andy Zhou.

   5) Add a data meta pointer for BPF accessible packets, from Daniel
      Borkmann.

   6) Namespace-ify almost all TCP sysctl knobs, from Eric Dumazet.

   7) Turn on Broadcom Tags in b53 driver, from Florian Fainelli.

   8) More work to move the RTNL mutex down, from Florian Westphal.

   9) Add 'bpftool' utility, to help with bpf program introspection.
      From Jakub Kicinski.

  10) Add new 'cpumap' type for XDP_REDIRECT action, from Jesper
      Dangaard Brouer.

  11) Support 'blocks' of transformations in the packet scheduler which
      can span multiple network devices, from Jiri Pirko.

  12) TC flower offload support in cxgb4, from Kumar Sanghvi.

  13) Priority based stream scheduler for SCTP, from Marcelo Ricardo
      Leitner.

  14) Thunderbolt networking driver, from Amir Levy and Mika Westerberg.

  15) Add RED qdisc offloadability, and use it in mlxsw driver. From
      Nogah Frankel.

  16) eBPF based device controller for cgroup v2, from Roman Gushchin.

  17) Add some fundamental tracepoints for TCP, from Song Liu.

  18) Remove garbage collection from ipv6 route layer, this is a
      significant accomplishment. From Wei Wang.

  19) Add multicast route offload support to mlxsw, from Yotam Gigi"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2177 commits)
  tcp: highest_sack fix
  geneve: fix fill_info when link down
  bpf: fix lockdep splat
  net: cdc_ncm: GetNtbFormat endian fix
  openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start
  netem: remove unnecessary 64 bit modulus
  netem: use 64 bit divide by rate
  tcp: Namespace-ify sysctl_tcp_default_congestion_control
  net: Protect iterations over net::fib_notifier_ops in fib_seq_sum()
  ipv6: set all.accept_dad to 0 by default
  uapi: fix linux/tls.h userspace compilation error
  usbnet: ipheth: prevent TX queue timeouts when device not ready
  vhost_net: conditionally enable tx polling
  uapi: fix linux/rxrpc.h userspace compilation errors
  net: stmmac: fix LPI transitioning for dwmac4
  atm: horizon: Fix irq release error
  net-sysfs: trigger netlink notification on ifalias change via sysfs
  openvswitch: Using kfree_rcu() to simplify the code
  openvswitch: Make local function ovs_nsh_key_attr_size() static
  openvswitch: Fix return value check in ovs_meter_cmd_features()
  ...
2017-11-15 11:56:19 -08:00
Mark Rutland
6aa7de0591 locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25 11:01:08 +02:00
David S. Miller
f8ddadc4db Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
There were quite a few overlapping sets of changes here.

Daniel's bug fix for off-by-ones in the new BPF branch instructions,
along with the added allowances for "data_end > ptr + x" forms
collided with the metadata additions.

Along with those three changes came veritifer test cases, which in
their final form I tried to group together properly.  If I had just
trimmed GIT's conflict tags as-is, this would have split up the
meta tests unnecessarily.

In the socketmap code, a set of preemption disabling changes
overlapped with the rename of bpf_compute_data_end() to
bpf_compute_data_pointers().

Changes were made to the mv88e6060.c driver set addr method
which got removed in net-next.

The hyperv transport socket layer had a locking change in 'net'
which overlapped with a change of socket state macro usage
in 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-22 13:39:14 +01:00
Craig Gallek
1b5f962e71 soreuseport: fix initialization race
Syzkaller stumbled upon a way to trigger
WARNING: CPU: 1 PID: 13881 at net/core/sock_reuseport.c:41
reuseport_alloc+0x306/0x3b0 net/core/sock_reuseport.c:39

There are two initialization paths for the sock_reuseport structure in a
socket: Through the udp/tcp bind paths of SO_REUSEPORT sockets or through
SO_ATTACH_REUSEPORT_[CE]BPF before bind.  The existing implementation
assumedthat the socket lock protected both of these paths when it actually
only protects the SO_ATTACH_REUSEPORT path.  Syzkaller triggered this
double allocation by running these paths concurrently.

This patch moves the check for double allocation into the reuseport_alloc
function which is protected by a global spin lock.

Fixes: e32ea7e747 ("soreuseport: fast reuseport UDP socket selection")
Fixes: c125e80b88 ("soreuseport: fast reuseport TCP socket selection")
Signed-off-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-22 02:03:51 +01:00
Matteo Croce
197df02cb3 udp: make some messages more descriptive
In the UDP code there are two leftover error messages with very few meaning.
Replace them with a more descriptive error message as some users
reported them as "strange network error".

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-21 02:52:35 +01:00
David S. Miller
d93fa2ba64 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-10-09 20:11:09 -07:00
Paolo Abeni
996b44fcef udp: fix bcast packet reception
The commit bc044e8db7 ("udp: perform source validation for
mcast early demux") does not take into account that broadcast packets
lands in the same code path and they need different checks for the
source address - notably, zero source address are valid for bcast
and invalid for mcast.

As a result, 2nd and later broadcast packets with 0 source address
landing to the same socket are dropped. This breaks dhcp servers.

Since we don't have stringent performance requirements for ingress
broadcast traffic, fix it by disabling UDP early demux such traffic.

Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Fixes: bc044e8db7 ("udp: perform source validation for mcast early demux")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-09 10:28:25 -07:00
David S. Miller
53954cf8c5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Just simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-05 18:19:22 -07:00
Paolo Abeni
bc044e8db7 udp: perform source validation for mcast early demux
The UDP early demux can leverate the rx dst cache even for
multicast unconnected sockets.

In such scenario the ipv4 source address is validated only on
the first packet in the given flow. After that, when we fetch
the dst entry  from the socket rx cache, we stop enforcing
the rp_filter and we even start accepting any kind of martian
addresses.

Disabling the dst cache for unconnected multicast socket will
cause large performace regression, nearly reducing by half the
max ingress tput.

Instead we factor out a route helper to completely validate an
skb source address for multicast packets and we call it from
the UDP early demux for mcast packets landing on unconnected
sockets, after successful fetching the related cached dst entry.

This still gives a measurable, but limited performance
regression:

		rp_filter = 0		rp_filter = 1
edmux disabled:	1182 Kpps		1127 Kpps
edmux before:	2238 Kpps		2238 Kpps
edmux after:	2037 Kpps		2019 Kpps

The above figures are on top of current net tree.
Applying the net-next commit 6e617de84e ("net: avoid a full
fib lookup when rp_filter is disabled.") the delta with
rp_filter == 0 will decrease even more.

Fixes: 421b3885bf ("udp: ipv4: Add udp early demux")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01 03:55:47 +01:00
Paolo Abeni
7487449c86 IPv4: early demux can return an error code
Currently no error is emitted, but this infrastructure will
used by the next patch to allow source address validation
for mcast sockets.
Since early demux can do a route lookup and an ipv4 route
lookup can return an error code this is consistent with the
current ipv4 route infrastructure.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01 03:55:47 +01:00
Paolo Abeni
0d4a6608f6 udp: do rmem bulk free even if the rx sk queue is empty
The commit 6b229cf77d ("udp: add batching to udp_rmem_release()")
reduced greatly the cacheline contention between the BH and the US
reader batching the rmem updates in most scenarios.

Such optimization is explicitly avoided if the US reader is faster
then BH processing.

My fault, I initially suggested this kind of behavior due to concerns
of possible regressions with small sk_rcvbuf values. Tests showed
such concerns are misplaced, so this commit relaxes the condition
for rmem bulk updates, obtaining small but measurable performance
gain in the scenario described above.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-20 14:28:52 -07:00
Paolo Abeni
ca2c1418ef udp: drop head states only when all skb references are gone
After commit 0ddf3fb2c4 ("udp: preserve skb->dst if required
for IP options processing") we clear the skb head state as soon
as the skb carrying them is first processed.

Since the same skb can be processed several times when MSG_PEEK
is used, we can end up lacking the required head states, and
eventually oopsing.

Fix this clearing the skb head state only when processing the
last skb reference.

Reported-by: Eric Dumazet <edumazet@google.com>
Fixes: 0ddf3fb2c4 ("udp: preserve skb->dst if required for IP options processing")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-07 20:02:39 -07:00
Linus Torvalds
aae3dbb477 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Support ipv6 checksum offload in sunvnet driver, from Shannon
    Nelson.

 2) Move to RB-tree instead of custom AVL code in inetpeer, from Eric
    Dumazet.

 3) Allow generic XDP to work on virtual devices, from John Fastabend.

 4) Add bpf device maps and XDP_REDIRECT, which can be used to build
    arbitrary switching frameworks using XDP. From John Fastabend.

 5) Remove UFO offloads from the tree, gave us little other than bugs.

 6) Remove the IPSEC flow cache, from Florian Westphal.

 7) Support ipv6 route offload in mlxsw driver.

 8) Support VF representors in bnxt_en, from Sathya Perla.

 9) Add support for forward error correction modes to ethtool, from
    Vidya Sagar Ravipati.

10) Add time filter for packet scheduler action dumping, from Jamal Hadi
    Salim.

11) Extend the zerocopy sendmsg() used by virtio and tap to regular
    sockets via MSG_ZEROCOPY. From Willem de Bruijn.

12) Significantly rework value tracking in the BPF verifier, from Edward
    Cree.

13) Add new jump instructions to eBPF, from Daniel Borkmann.

14) Rework rtnetlink plumbing so that operations can be run without
    taking the RTNL semaphore. From Florian Westphal.

15) Support XDP in tap driver, from Jason Wang.

16) Add 32-bit eBPF JIT for ARM, from Shubham Bansal.

17) Add Huawei hinic ethernet driver.

18) Allow to report MD5 keys in TCP inet_diag dumps, from Ivan
    Delalande.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1780 commits)
  i40e: point wb_desc at the nvm_wb_desc during i40e_read_nvm_aq
  i40e: avoid NVM acquire deadlock during NVM update
  drivers: net: xgene: Remove return statement from void function
  drivers: net: xgene: Configure tx/rx delay for ACPI
  drivers: net: xgene: Read tx/rx delay for ACPI
  rocker: fix kcalloc parameter order
  rds: Fix non-atomic operation on shared flag variable
  net: sched: don't use GFP_KERNEL under spin lock
  vhost_net: correctly check tx avail during rx busy polling
  net: mdio-mux: add mdio_mux parameter to mdio_mux_init()
  rxrpc: Make service connection lookup always check for retry
  net: stmmac: Delete dead code for MDIO registration
  gianfar: Fix Tx flow control deactivation
  cxgb4: Ignore MPS_TX_INT_CAUSE[Bubble] for T6
  cxgb4: Fix pause frame count in t4_get_port_stats
  cxgb4: fix memory leak
  tun: rename generic_xdp to skb_xdp
  tun: reserve extra headroom only when XDP is set
  net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping
  net: dsa: bcm_sf2: Advertise number of egress queues
  ...
2017-09-06 14:45:08 -07:00
Ingo Molnar
edc2988c54 Merge branch 'linus' into locking/core, to fix up conflicts
Conflicts:
	mm/page_alloc.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-04 11:01:18 +02:00
David S. Miller
6026e043d0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01 17:42:05 -07:00
Yossi Kuperman
e8a732d1bc udp: fix secpath leak
After commit dce4551cb2 ("udp: preserve head state for IP_CMSG_PASSSEC")
we preserve the secpath for the whole skb lifecycle, but we also
end up leaking a reference to it.

We must clear the head state on skb reception, if secpath is
present.

Fixes: dce4551cb2 ("udp: preserve head state for IP_CMSG_PASSSEC")
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01 10:29:34 -07:00
Paolo Abeni
64f0f5d18a udp6: set rx_dst_cookie on rx_dst updates
Currently, in the udp6 code, the dst cookie is not initialized/updated
concurrently with the RX dst used by early demux.

As a result, the dst_check() in the early_demux path always fails,
the rx dst cache is always invalidated, and we can't really
leverage significant gain from the demux lookup.

Fix it adding udp6 specific variant of sk_rx_dst_set() and use it
to set the dst cookie when the dst entry is really changed.

The issue is there since the introduction of early demux for ipv6.

Fixes: 5425077d73 ("net: ipv6: Add early demux handler for UDP unicast")
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 20:09:13 -07:00
Ingo Molnar
10c9850cb2 Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-25 11:04:51 +02:00
Willem de Bruijn
ab2fb7e324 udp: remove unreachable ufo branches
Remove two references to ufo in the udp send path that are no longer
reachable now that ufo has been removed.

Commit 85f1bd9a7b ("udp: consistently apply ufo or fragmentation")
is a fix to ufo. It is safe to revert what remains of it.

Also, no skb can enter ip_append_page with skb_is_gso true now that
skb_shinfo(skb)->gso_type is no longer set in ip_append_page/_data.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-22 14:27:18 -07:00
David S. Miller
e2a7c34fb2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-08-21 17:06:42 -07:00
Matthew Dawson
a0917e0bc6 datagram: When peeking datagrams with offset < 0 don't skip empty skbs
Due to commit e6afc8ace6 ("udp: remove
headers from UDP packets before queueing"), when udp packets are being
peeked the requested extra offset is always 0 as there is no need to skip
the udp header.  However, when the offset is 0 and the next skb is
of length 0, it is only returned once.  The behaviour can be seen with
the following python script:

from socket import *;
f=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0);
g=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0);
f.bind(('::', 0));
addr=('::1', f.getsockname()[1]);
g.sendto(b'', addr)
g.sendto(b'b', addr)
print(f.recvfrom(10, MSG_PEEK));
print(f.recvfrom(10, MSG_PEEK));

Where the expected output should be the empty string twice.

Instead, make sk_peek_offset return negative values, and pass those values
to __skb_try_recv_datagram/__skb_try_recv_from_queue.  If the passed offset
to __skb_try_recv_from_queue is negative, the checked skb is never skipped.
__skb_try_recv_from_queue will then ensure the offset is reset back to 0
if a peek is requested without an offset, unless no packets are found.

Also simplify the if condition in __skb_try_recv_from_queue.  If _off is
greater then 0, and off is greater then or equal to skb->len, then
(_off || skb->len) must always be true assuming skb->len >= 0 is always
true.

Also remove a redundant check around a call to sk_peek_offset in af_unix.c,
as it double checked if MSG_PEEK was set in the flags.

V2:
 - Moved the negative fixup into __skb_try_recv_from_queue, and remove now
redundant checks
 - Fix peeking in udp{,v6}_recvmsg to report the right value when the
offset is 0

V3:
 - Marked new branch in __skb_try_recv_from_queue as unlikely.

Signed-off-by: Matthew Dawson <matthew@mjdsystems.ca>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-18 15:12:54 -07:00
Ingo Molnar
040cca3ab2 Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
	include/linux/mm_types.h
	mm/huge_memory.c

I removed the smp_mb__before_spinlock() like the following commit does:

  8b1b436dd1 ("mm, locking: Rework {set,clear,mm}_tlb_flush_pending()")

and fixed up the affected commits.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-11 13:51:59 +02:00
David S. Miller
3b2b69efec Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Mainline had UFO fixes, but UFO is removed in net-next so we
take the HEAD hunks.

Minor context conflict in bcmsysport statistics bug fix.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10 12:11:16 -07:00
Willem de Bruijn
85f1bd9a7b udp: consistently apply ufo or fragmentation
When iteratively building a UDP datagram with MSG_MORE and that
datagram exceeds MTU, consistently choose UFO or fragmentation.

Once skb_is_gso, always apply ufo. Conversely, once a datagram is
split across multiple skbs, do not consider ufo.

Sendpage already maintains the first invariant, only add the second.
IPv6 does not have a sendpage implementation to modify.

A gso skb must have a partial checksum, do not follow sk_no_check_tx
in udp_send_skb.

Found by syzkaller.

Fixes: e89e9cf539 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10 09:52:12 -07:00
Paolo Bonzini
7a34bcb8b2 jump_label: Do not use unserialized static_key_enabled()
Any use of key->enabled (that is static_key_enabled and static_key_count)
outside jump_label_lock should handle its own serialization.  The only
two that are not doing so are the UDP encapsulation static keys.  Change
them to use static_key_enable, which now correctly tests key->enabled under
the jump label lock.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1501601046-35683-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-10 12:28:56 +02:00
David Ahern
60d9b03141 net: ipv4: add second dif to multicast source filter
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07 11:39:22 -07:00
David Ahern
3fa6f616a7 net: ipv4: add second dif to inet socket lookups
Add a second device index, sdif, to inet socket lookups. sdif is the
index for ingress devices enslaved to an l3mdev. It allows the lookups
to consider the enslaved device as well as the L3 domain when searching
for a socket.

TCP moves the data in the cb. Prior to tcp_v4_rcv (e.g., early demux) the
ingress index is obtained from IPCB using inet_sdif and after the cb move
in  tcp_v4_rcv the tcp_v4_sdif helper is used.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07 11:39:21 -07:00
David Ahern
fb74c27735 net: ipv4: add second dif to udp socket lookups
Add a second device index, sdif, to udp socket lookups. sdif is the
index for ingress devices enslaved to an l3mdev. It allows the lookups
to consider the enslaved device as well as the L3 domain when searching
for a socket.

Early demux lookups are handled in the next patch as part of INET_MATCH
changes.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07 11:39:21 -07:00
Paolo Abeni
3bdefdf9d9 udp: no need to preserve skb->dst
__ip_options_echo() does not need anymore skb->dst, so we can
avoid explicitly preserving it for its own sake.

This is almost a revert of commit 0ddf3fb2c4 ("udp: preserve
skb->dst if required for IP options processing") plus some
lifting to fit later changes.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 20:51:12 -07:00
Paolo Abeni
c9f2c1ae12 udp6: fix socket leak on early demux
When an early demuxed packet reaches __udp6_lib_lookup_skb(), the
sk reference is retrieved and used, but the relevant reference
count is leaked and the socket destructor is never called.
Beyond leaking the sk memory, if there are pending UDP packets
in the receive queue, even the related accounted memory is leaked.

In the long run, this will cause persistent forward allocation errors
and no UDP skbs (both ipv4 and ipv6) will be able to reach the
user-space.

Fix this by explicitly accessing the early demux reference before
the lookup, and properly decreasing the socket reference count
after usage.

Also drop the skb_steal_sock() in __udp6_lib_lookup_skb(), and
the now obsoleted comment about "socket cache".

The newly added code is derived from the current ipv4 code for the
similar path.

v1 -> v2:
  fixed the __udp6_lib_rcv() return code for resubmission,
  as suggested by Eric

Reported-by: Sam Edwards <CFSworks@gmail.com>
Reported-by: Marc Haber <mh+netdev@zugschlus.de>
Fixes: 5425077d73 ("net: ipv6: Add early demux handler for UDP unicast")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-29 14:19:03 -07:00
Paolo Abeni
9688f9b020 udp: unbreak build lacking CONFIG_XFRM
We must use pre-processor conditional block or suitable accessors to
manipulate skb->sp elsewhere builds lacking the CONFIG_XFRM will break.

Fixes: dce4551cb2 ("udp: preserve head state for IP_CMSG_PASSSEC")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-26 09:35:29 -07:00
Paolo Abeni
dce4551cb2 udp: preserve head state for IP_CMSG_PASSSEC
Paul Moore reported a SELinux/IP_PASSSEC regression
caused by missing skb->sp at recvmsg() time. We need to
preserve the skb head state to process the IP_CMSG_PASSSEC
cmsg.

With this commit we avoid releasing the skb head state in the
BH even if a secpath is attached to the current skb, and stores
the skb status (with/without head states) in the scratch area,
so that we can access it at skb deallocation time, without
incurring in cache-miss penalties.

This also avoids misusing the skb CB for ipv6 packets,
as introduced by the commit 0ddf3fb2c4 ("udp: preserve
skb->dst if required for IP options processing").

Clean a bit the scratch area helpers implementation, to
reduce the code differences between 32 and 64 bits build.

Reported-by: Paul Moore <paul@paul-moore.com>
Fixes: 0a463c78d2 ("udp: avoid a cache miss on dequeue")
Fixes: 0ddf3fb2c4 ("udp: preserve skb->dst if required for IP options processing")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-25 10:00:58 -07:00
Paolo Abeni
0ddf3fb2c4 udp: preserve skb->dst if required for IP options processing
Eric noticed that in udp_recvmsg() we still need to access
skb->dst while processing the IP options.
Since commit 0a463c78d2 ("udp: avoid a cache miss on dequeue")
skb->dst is no more available at recvmsg() time and bad things
will happen if we enter the relevant code path.

This commit address the issue, avoid clearing skb->dst if
any IP options are present into the relevant skb.
Since the IP CB is contained in the first skb cacheline, we can
test it to decide to leverage the consume_stateless_skb()
optimization, without measurable additional cost in the faster
path.

v1 -> v2: updated commit message tags

Fixes: 0a463c78d2 ("udp: avoid a cache miss on dequeue")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-18 12:00:13 -07:00
Reshetova, Elena
41c6d650f6 net: convert sock.sk_refcnt from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 07:39:08 -07:00
Paolo Abeni
b26bbdae46 udp: move scratch area helpers into the include file
So that they can be later used by the IPv6 code, too.
Also lift the comments a bit.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-27 15:43:56 -04:00
Paolo Abeni
9bd780f5e0 udp: fix poll()
Michael reported an UDP breakage caused by the commit b65ac44674
("udp: try to avoid 2 cache miss on dequeue").
The function __first_packet_length() can update the checksum bits
of the pending skb, making the scratched area out-of-sync, and
setting skb->csum, if the skb was previously in need of checksum
validation.

On later recvmsg() for such skb, checksum validation will be
invoked again - due to the wrong udp_skb_csum_unnecessary()
value - and will fail, causing the valid skb to be dropped.

This change addresses the issue refreshing the scratch area in
__first_packet_length() after the possible checksum update.

Fixes: b65ac44674 ("udp: try to avoid 2 cache miss on dequeue")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-23 11:18:43 -04:00
Paolo Abeni
dd99e425be udp: prefetch rmem_alloc in udp_queue_rcv_skb()
On UDP packets processing, if the BH is the bottle-neck, it
always sees a cache miss while updating rmem_alloc; try to
avoid it prefetching the value as soon as we have the socket
available.

Performances under flood with multiple NIC rx queues used are
unaffected, but when a single NIC rx queue is in use, this
gives ~10% performance improvement.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21 11:38:11 -04:00
Wei Wang
d24406c85d udp: call dst_hold_safe() in udp_sk_rx_set_dst()
In udp_v4/6_early_demux() code, we try to hold dst->__refcnt for
dst with DST_NOCACHE flag. This is because later in udp_sk_rx_dst_set()
function, we will try to cache this dst in sk for connected case.
However, a better way to achieve this is to not try to hold dst in
early_demux(), but in udp_sk_rx_dst_set(), call dst_hold_safe(). This
approach is also more consistant with how tcp is handling it. And it
will make later changes simpler.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17 22:53:59 -04:00
Paolo Abeni
b65ac44674 udp: try to avoid 2 cache miss on dequeue
when udp_recvmsg() is executed, on x86_64 and other archs, most skb
fields are on cold cachelines.
If the skb are linear and the kernel don't need to compute the udp
csum, only a handful of skb fields are required by udp_recvmsg().
Since we already use skb->dev_scratch to cache hot data, and
there are 32 bits unused on 64 bit archs, use such field to cache
as much data as we can, and try to prefetch on dequeue the relevant
fields that are left out.

This can save up to 2 cache miss per packet.

v1 -> v2:
  - changed udp_dev_scratch fields types to u{32,16} variant,
    replaced bitfiled with bool

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-12 10:01:29 -04:00
Paolo Abeni
0a463c78d2 udp: avoid a cache miss on dequeue
Since UDP no more uses sk->destructor, we can clear completely
the skb head state before enqueuing. Amend and use
skb_release_head_state() for that.

All head states share a single cacheline, which is not
normally used/accesses on dequeue. We can avoid entirely accessing
such cacheline implementing and using in the UDP code a specialized
skb free helper which ignores the skb head state.

This saves a cacheline miss at skb deallocation time.

v1 -> v2:
  replaced secpath_reset() with skb_release_head_state()

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-12 10:01:29 -04:00
David S. Miller
c6cd850d65 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-05-18 16:11:32 -04:00
Andrey Vagin
de321ed384 net: fix __skb_try_recv_from_queue to return the old behavior
This function has to return NULL on a error case, because there is a
separate error variable.

The offset has to be changed only if skb is returned

v2: fix udp code to not use an extra variable

Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: David S. Miller <davem@davemloft.net>
Fixes: 65101aeca5 ("net/sock: factor out dequeue/peek with offset cod")
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-18 10:32:58 -04:00
Paolo Abeni
a3f96c47c8 udp: make *udp*_queue_rcv_skb() functions static
Since the udp memory accounting refactor, we don't need any more
to export the *udp*_queue_rcv_skb(). Make them static and fix
a couple of sparse warnings:

net/ipv4/udp.c:1615:5: warning: symbol 'udp_queue_rcv_skb' was not
declared. Should it be static?
net/ipv6/udp.c:572:5: warning: symbol 'udpv6_queue_rcv_skb' was not
declared. Should it be static?

Fixes: 850cbaddb5 ("udp: use it's own memory accounting schema")
Fixes: c915fe13cb ("udplite: fix NULL pointer dereference")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-18 10:23:33 -04:00
Colin Ian King
64f5102dcb udp: make function udp_skb_dtor_locked static
Function udp_skb_dtor_locked does not need to be in global scope
so make it static to fix sparse warning:

net/ipv4/udp.c: warning: symbol 'udp_skb_dtor_locked' was not
declared. Should it be static?

Fixes: 6dfb4367cd ("udp: keep the sk_receive_queue held when splicing")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-18 10:12:40 -04:00
Paolo Abeni
6dfb4367cd udp: keep the sk_receive_queue held when splicing
On packet reception, when we are forced to splice the
sk_receive_queue, we can keep the related lock held, so
that we can avoid re-acquiring it, if fwd memory
scheduling is required.

v1 -> v2:
  the rx_queue_lock_held param in udp_rmem_release() is
  now a bool

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-16 15:41:30 -04:00
Paolo Abeni
2276f58ac5 udp: use a separate rx queue for packet reception
under udp flood the sk_receive_queue spinlock is heavily contended.
This patch try to reduce the contention on such lock adding a
second receive queue to the udp sockets; recvmsg() looks first
in such queue and, only if empty, tries to fetch the data from
sk_receive_queue. The latter is spliced into the newly added
queue every time the receive path has to acquire the
sk_receive_queue lock.

The accounting of forward allocated memory is still protected with
the sk_receive_queue lock, so udp_rmem_release() needs to acquire
both locks when the forward deficit is flushed.

On specific scenarios we can end up acquiring and releasing the
sk_receive_queue lock multiple times; that will be covered by
the next patch

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-16 15:41:29 -04:00
David S. Miller
3efa70d78f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The conflict was an interaction between a bug fix in the
netvsc driver in 'net' and an optimization of the RX path
in 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07 16:29:30 -05:00
Julian Anastasov
0dec879f63 net: use dst_confirm_neigh for UDP, RAW, ICMP, L2TP
When same struct dst_entry can be used for many different
neighbours we can not use it for pending confirmations.

The datagram protocols can use MSG_CONFIRM to confirm the
neighbour. When used with MSG_PROBE we do not reach the
code where neighbour is confirmed, so we have to do the
same slow lookup by using the dst_confirm_neigh() helper.
When MSG_PROBE is not used, ip_append_data/ip6_append_data
will set the skb flag dst_pending_confirm.

Reported-by: YueHaibing <yuehaibing@huawei.com>
Fixes: 5110effee8 ("net: Do delayed neigh confirmation.")
Fixes: f2bb4bedf3 ("ipv4: Cache output routes in fib_info nexthops.")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07 13:07:47 -05:00
Eric Dumazet
69629464e0 udp: properly cope with csum errors
Dmitry reported that UDP sockets being destroyed would trigger the
WARN_ON(atomic_read(&sk->sk_rmem_alloc)); in inet_sock_destruct()

It turns out we do not properly destroy skb(s) that have wrong UDP
checksum.

Thanks again to syzkaller team.

Fixes : 7c13f97ffd ("udp: do fwd memory scheduling on dequeue")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07 11:19:00 -05:00
Robert Shearman
63a6fff353 net: Avoid receiving packets with an l3mdev on unbound UDP sockets
Packets arriving in a VRF currently are delivered to UDP sockets that
aren't bound to any interface. TCP defaults to not delivering packets
arriving in a VRF to unbound sockets. IP route lookup and socket
transmit both assume that unbound means using the default table and
UDP applications that haven't been changed to be aware of VRFs may not
function correctly in this case since they may not be able to handle
overlapping IP address ranges, or be able to send packets back to the
original sender if required.

So add a sysctl, udp_l3mdev_accept, to control this behaviour with it
being analgous to the existing tcp_l3mdev_accept, namely to allow a
process to have a VRF-global listen socket. Have this default to off
as this is the behaviour that users will expect, given that there is
no explicit mechanism to set unmodified VRF-unaware application into a
default VRF.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-30 15:00:58 -05:00
Josef Bacik
fe38d2a1c8 inet: collapse ipv4/v6 rcv_saddr_equal functions into one
We pass these per-protocol equal functions around in various places, but
we can just have one function that checks the sk->sk_family and then do
the right comparison function.  I've also changed the ipv4 version to
not cast to inet_sock since it is unneeded.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18 13:04:28 -05:00
Eric Garver
df560056d9 udp: inuse checks can quit early for reuseport
UDP lib inuse checks will walk the entire hash bucket to check if the
portaddr is in use. In the case of reuseport we can stop searching when
we find a matching reuseport.

On a 16-core VM a test program that spawns 16 threads that each bind to
1024 sockets (one per 10ms) takes 1m45s. With this change it takes 11s.

Also add a cond_resched() when the port is not specified.

Signed-off-by: Eric Garver <e@erig.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-06 20:56:48 -05:00
Linus Torvalds
7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
Eric Dumazet
02ab0d139c udp: udp_rmem_release() should touch sk_rmem_alloc later
In flood situations, keeping sk_rmem_alloc at a high value
prevents producers from touching the socket.

It makes sense to lower sk_rmem_alloc only at the end
of udp_rmem_release() after the thread draining receive
queue in udp_recvmsg() finished the writes to sk_forward_alloc.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-09 22:12:21 -05:00
Eric Dumazet
6b229cf77d udp: add batching to udp_rmem_release()
If udp_recvmsg() constantly releases sk_rmem_alloc
for every read packet, it gives opportunity for
producers to immediately grab spinlocks and desperatly
try adding another packet, causing false sharing.

We can add a simple heuristic to give the signal
by batches of ~25 % of the queue capacity.

This patch considerably increases performance under
flood by about 50 %, since the thread draining the queue
is no longer slowed by false sharing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-09 22:12:21 -05:00
Eric Dumazet
c84d949057 udp: copy skb->truesize in the first cache line
In UDP RX handler, we currently clear skb->dev before skb
is added to receive queue, because device pointer is no longer
available once we exit from RCU section.

Since this first cache line is always hot, lets reuse this space
to store skb->truesize and thus avoid a cache line miss at
udp_recvmsg()/udp_skb_destructor time while receive queue
spinlock is held.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-09 22:12:21 -05:00
Eric Dumazet
4b272750db udp: add busylocks in RX path
Idea of busylocks is to let producers grab an extra spinlock
to relieve pressure on the receive_queue spinlock shared by consumer.

This behavior is requested only once socket receive queue is above
half occupancy.

Under flood, this means that only one producer can be in line
trying to acquire the receive_queue spinlock.

These busylock can be allocated on a per cpu manner, instead of a
per socket one (that would consume a cache line per socket)

This patch considerably improves UDP behavior under stress,
depending on number of NIC RX queues and/or RPS spread.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-09 22:12:21 -05:00
Eric Dumazet
c8c8b12709 udp: under rx pressure, try to condense skbs
Under UDP flood, many softirq producers try to add packets to
UDP receive queue, and one user thread is burning one cpu trying
to dequeue packets as fast as possible.

Two parts of the per packet cost are :
- copying payload from kernel space to user space,
- freeing memory pieces associated with skb.

If socket is under pressure, softirq handler(s) can try to pull in
skb->head the payload of the packet if it fits.

Meaning the softirq handler(s) can free/reuse the page fragment
immediately, instead of letting udp_recvmsg() do this hundreds of usec
later, possibly from another node.

Additional gains :
- We reduce skb->truesize and thus can store more packets per SO_RCVBUF
- We avoid cache line misses at copyout() time and consume_skb() time,
and avoid one put_page() with potential alien freeing on NUMA hosts.

This comes at the cost of a copy, bounded to available tail room, which
is usually small. (We might have to fix GRO_MAX_HEAD which looks bigger
than necessary)

This patch gave me about 5 % increase in throughput in my tests.

skb_condense() helper could probably used in other contexts.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-08 13:25:07 -05:00