Without TFO, any subsequent connect() call after a successful one returns
-1 EISCONN. The last API update ensured that __inet_stream_connect() can
return -1 EINPROGRESS in response to sendmsg() when TFO is in use to
indicate that the connection is now in progress. Unfortunately since this
function is used both for connect() and sendmsg(), it has the undesired
side effect of making connect() now return -1 EINPROGRESS as well after
a successful call, while at the same time poll() returns POLLOUT. This
can confuse some applications which happen to call connect() and to
check for -1 EISCONN to ensure the connection is usable, and for which
EINPROGRESS indicates a need to poll, causing a loop.

This problem was encountered in haproxy where a call to connect() is
precisely used in certain cases to confirm a connection's readiness.
While arguably haproxy's behaviour should be improved here, it seems
important to aim at a more robust behaviour when the goal of the new
API is to make it easier to implement TFO in existing applications.

This patch simply ensures that we preserve the same semantics as in
the non-TFO case on the connect() syscall when using TFO, while still
returning -1 EINPROGRESS on sendmsg(). For this we simply tell
__inet_stream_connect() whether we're doing a regular connect() or in
fact connecting for a sendmsg() call.

Cc: Wei Wang <weiwan@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Wei Wang says:

====================
net/tcp-fastopen: Add new userspace API support

The patch series is to add support for new userspace API for TCP fastopen
sockets.
In the current code, user has to call sendto()/sendmsg() with special flag
MSG_FASTOPEN for TCP fastopen sockets. This API is quite different from the
normal TCP socket API and can be cumbersome for applications to make use
fastopen sockets.
So this new patch introduces a new way of using TCP fastopen sockets which
is similar to normal TCP sockets with a new sockopt TCP_FASTOPEN_CONNECT.
More details about it is described in the third patch.
(First 2 patches are preparations for the third patch.)
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a new socket option, TCP_FASTOPEN_CONNECT, as an
alternative way to perform Fast Open on the active side (client). Prior
to this patch, a client needs to replace the connect() call with
sendto(MSG_FASTOPEN). This can be cumbersome for applications who want
to use Fast Open: these socket operations are often done in lower layer
libraries used by many other applications. Changing these libraries
and/or the socket call sequences are not trivial. A more convenient
approach is to perform Fast Open by simply enabling a socket option when
the socket is created w/o changing other socket calls sequence:
  s = socket()
    create a new socket
  setsockopt(s, IPPROTO_TCP, TCP_FASTOPEN_CONNECT …);
    newly introduced sockopt
    If set, new functionality described below will be used.
    Return ENOTSUPP if TFO is not supported or not enabled in the
    kernel.

  connect()
    With cookie present, return 0 immediately.
    With no cookie, initiate 3WHS with TFO cookie-request option and
    return -1 with errno = EINPROGRESS.

  write()/sendmsg()
    With cookie present, send out SYN with data and return the number of
    bytes buffered.
    With no cookie, and 3WHS not yet completed, return -1 with errno =
    EINPROGRESS.
    No MSG_FASTOPEN flag is needed.

  read()
    Return -1 with errno = EWOULDBLOCK/EAGAIN if connect() is called but
    write() is not called yet.
    Return -1 with errno = EWOULDBLOCK/EAGAIN if connection is
    established but no msg is received yet.
    Return number of bytes read if socket is established and there is
    msg received.

The new API simplifies life for applications that always perform a write()
immediately after a successful connect(). Such applications can now take
advantage of Fast Open by merely making one new setsockopt() call at the time
of creating the socket. Nothing else about the application's socket call
sequence needs to change.
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove __sk_dst_reset() in the failure handling because __sk_dst_reset()
will eventually get called when sk is released. No need to handle it in
the protocol specific connect call.
This is also to make the code path consistent with ipv4.
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Refactor the cookie check logic in tcp_send_syn_data() into a function.
This function will be called else where in later changes.
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace rumtime with runtime.
Signed-off-by: NHayes Wang <hayeswang@realtek.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace spaces with tabs. Fix indentation to be multiples of tabs, not
a mixture or tabs and spaces.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
BPF tracepoints

This set adds tracepoints to BPF for better introspection and
debugging. The first two patches are prerequisite for the actual
third patch that adds the tracepoints. I think the first two are
small and straight forward enough that they could ideally go via
net-next, but I'm also open to other suggestions on how to route
them in case that's not applicable (it would reduce potential
merge conflicts on BPF side, though). For details, please see
individual patches.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work adds a number of tracepoints to paths that are either
considered slow-path or exception-like states, where monitoring or
inspecting them would be desirable.

For bpf(2) syscall, tracepoints have been placed for main commands
when they succeed. In XDP case, tracepoint is for exceptions, that
is, f.e. on abnormal BPF program exit such as unknown or XDP_ABORTED
return code, or when error occurs during XDP_TX action and the packet
could not be forwarded.

Both have been split into separate event headers, and can be further
extended. Worst case, if they unexpectedly should get into our way in
future, they can also removed [1]. Of course, these tracepoints (like
any other) can be analyzed by eBPF itself, etc. Example output:

  # ./perf record -a -e bpf:* sleep 10
  # ./perf script
  sock_example  6197 [005]   283.980322:      bpf:bpf_map_create: map type=ARRAY ufd=4 key=4 val=8 max=256 flags=0
  sock_example  6197 [005]   283.980721:       bpf:bpf_prog_load: prog=a5ea8fa30ea6849c type=SOCKET_FILTER ufd=5
  sock_example  6197 [005]   283.988423:   bpf:bpf_prog_get_type: prog=a5ea8fa30ea6849c type=SOCKET_FILTER
  sock_example  6197 [005]   283.988443: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[06 00 00 00] val=[00 00 00 00 00 00 00 00]
  [...]
  sock_example  6197 [005]   288.990868: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[01 00 00 00] val=[14 00 00 00 00 00 00 00]
       swapper     0 [005]   289.338243:    bpf:bpf_prog_put_rcu: prog=a5ea8fa30ea6849c type=SOCKET_FILTER

  [1] https://lwn.net/Articles/705270/Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for the __print_hex_str() macro that was added for
tracing, so that user space tools such as perf can understand
it as well.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For upcoming tracepoint support for BPF, we want to dump the program's
tag. Format should be similar to __print_hex(), but without spacing.
Add a __print_hex_str() variant for exactly that purpose that reuses
trace_print_hex_seq().
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_add_backlog() can use skb_condense() helper to get better
gains and less SKB_TRUESIZE() magic. This only happens when socket
backlog has to be used.

Some attacks involve specially crafted out of order tiny TCP packets,
clogging the ofo queue of (many) sockets.
Then later, expensive collapse happens, trying to copy all these skbs
into single ones.
This unfortunately does not work if each skb has no neighbor in TCP
sequence order.

By using skb_condense() if the skb could not be coalesced to a prior
one, we defeat these kind of threats, potentially saving 4K per skb
(or more, since this is one page fragment).

A typical NAPI driver allocates gro packets with GRO_MAX_HEAD bytes
in skb->head, meaning the copy done by skb_condense() is limited to
about 200 bytes.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5-updates-2017-24-01

The first seven patches from Or Gerlitz in this series further enhances
the mlx5 SRIOV switchdev mode to support offloading IPv6 tunnels using the
TC tunnel key set (encap) and unset (decap) actions.

Or Gerlitz says:
========================
As part of doing this change, few cleanups are done in the IPv4 code,
later we move to use the full tunnel key info provided to the driver as
the key for our internal hashing which is used to identify cases where
the same tunnel is used for encapsulating multiple flows. As done in the
IPv4 case, the control path for offloading IPv6 tunnels uses route/neigh
lookups and construction of the IPv6 tunnel headers on the encap path and
matching on the outer hears in the decap path.

The last patch of the series enlarges the HW FDB size for the switchdev mode,
so it has now room to contain offloaded flows as many as min(max number
of HW flow counters supported, max HW table size supported).
========================

Next to Or's series you can find several patches handling several topics.

From Mohamad, add support for SRIOV VF min rate guarantee by using the
TSAR BW share weights mechanism.

From Or, Two patches to enable Eth VFs to query their min-inline value for
user-space.
for that we move a mlx5 low level min inline helper function from mlx5
ethernet driver into the core driver and then use it in mlx5_ib to expose
the inline mode to rdma applications through libmlx5.

From Kamal Heib, Reduce memory consumption on kdump kernel.

From Shaker Daibes, code reuse in CQE compression control logic
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We shuffled some code around and added some new case statements here and
now "res" isn't initialized on all paths.

Fixes: 01fd12bb ("tipc: make replicast a user selectable option")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce optional 128-bit action cookie.
Like all other cookie schemes in the networking world (eg in protocols
like http or existing kernel fib protocol field, etc) the idea is to save
user state that when retrieved serves as a correlator. The kernel
_should not_ intepret it.  The user can store whatever they wish in the
128 bits.

Sample exercise(showing variable length use of cookie)

.. create an accept action with cookie a1b2c3d4
sudo $TC actions add action ok index 1 cookie a1b2c3d4

.. dump all gact actions..
sudo $TC -s actions ls action gact

    action order 0: gact action pass
     random type none pass val 0
     index 1 ref 1 bind 0 installed 5 sec used 5 sec
    Action statistics:
    Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
    backlog 0b 0p requeues 0
    cookie a1b2c3d4

.. bind the accept action to a filter..
sudo $TC filter add dev lo parent ffff: protocol ip prio 1 \
u32 match ip dst 127.0.0.1/32 flowid 1:1 action gact index 1

... send some traffic..
$ ping 127.0.0.1 -c 3
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.020 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.027 ms
64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.038 ms
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Stephen Hemminger says:

====================
netvsc driver enhancements for net-next

Lots of little things in here. Support for minor more ethtool control,
negotiation of offload parameters with host (based on FreeBSD) and
several cleanups.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To improve performance, netvsc can call network stack directly and
avoid the local backlog queue. This is safe since incoming packets are
handled in softirq context already because the receive function
callback is called from a tasklet.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use kernel for_each_clear_bit macro to simplify finding next
available send section.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Report packets and bytes transferred through a vmbus channel via ethtool.
This supersedes need for per-cpu statistics.

Example:
$ ethtool -S eth0
NIC statistics:
...
     tx_queue_0_packets: 3523179
     tx_queue_0_bytes: 505370920
     rx_queue_0_packets: 41430490
     rx_queue_0_bytes: 62714661254
     tx_queue_1_packets: 0
     tx_queue_1_bytes: 0
     rx_queue_1_packets: 0
     rx_queue_1_bytes: 0
...
Reviewed-by: NLong Li <longli@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NSimon Xiao <sixiao@microsoft.com>
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most drivers do not increment transmit statistics until after the
transmit is completed. This will also be necessary for BQL support.

Slight additional complexity because the netvsc driver aggregates
multiple packets into one transmit.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since now keep track of per-queue outstanding sends, we can avoid
one atomic update by removing no longer needed per-device atomic.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All caller's already have pointer to netvsc_device so pass it.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All the caller's/callee's know that the format of the device_add
parameter is a netvsc_device_info struct.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do manual optimizations of receive path:
  - remove checks for impossible conditions (but keep checks
    for bad data from host)
  - pass argument down, rather than having callee recompute what
    is already known
  - remove indirection about receive buffer datalength
  - remove dependence on VLAN_TAG_PRESENCE
  - use _hot/_cold and likely/unlikely
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Put all the per-channel state together in one data struct.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes set but never used warnings
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The netvsc select queue function was missing many of the flow caching
features that exist in default tx queue selection. Add the same
logic to remember queue based on socket and implement two level
mapping (like RSS).
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow setting receive indirection table. Also uses the system standard
for initialization.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows for number of channels to be managed in a manner similar
to existing hardware drivers. It also removes the restriction of
maximum 8 channels and allows as many as the host will allow.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For some cases it is useful to be able to change RSS key value.
For example, replacing RSS key with a symmetric hash.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Report current components used in RSS hash.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Report actual number of receive queues to ethtool.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Redo how Hyper-V network driver negotiates offload features. Query the
host to determine offload settings, and use the result.

Also:
  * disable IPv4 header checksum offload (not used by Linux)
  * enable TSO only if host supports
  * enable UDP checksum offload if supported
  * don't advertise support for checksumming of non-IP protocols
  * adjust GSO maximum segment size
  * enable HIGHDMA
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ring buffer mapping now handles the wraparound case
inside get_next_pkt_raw. Therefore it is not necessary to have an
additional special receive staging buffer.

See commit 1562edaed8c164ca5199 ("Drivers: hv: ring_buffer: count on
wrap around mappings")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Andrew Lunn says:

====================
External MDIO support for mv88e6xxx

The mv88e6390 family of switches has two MDIO busses, one internal to
the switch and a second one for external usage. Older generations of switches
have a single MDIO bus, which is used both internally and externally.

Refactor the existing MDIO driver code to allow for multiple MDIO
busses, and implement the second MDIO bus on mv88e6390.

This is a rewrite of a patch previously submitted as part of "Batch
3". It has been broken up into 5 smaller patches. A compatible string
is now used in the device tree to indicate the external MDIO bus.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With all the infrastructure in place, implement access to the external
MDIO bus on the 6390 family.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mv88e6390 has multiple MDIO busses. Generalize the parsing of the
device tree to support multiple mdio nodes. The external mdio bus has
a compatible strings to indicate it is external.

Keep a linked list of busses, placing the external mdio bus at the
tail of the list. When within the driver an mdio bus is needed,
e.g. for EEE or SERDES, use the head of the list which should be the
internal bus.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Have the MDIO bus driver code allocate a private structure and make
the chip a member of it. This will allow us to add further members in
the future.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for supporting multiple MDIO busses, pass the mii_bus
structure to all PHY operations. It will in future then be clear on
which MDIO bus the operation should be performed.

For reads/write from phylib, the mii_bus is readily available. However
some internal code also access the PHY, e.g. for EEE and SERDES. Make
this code use the one and only currently available MDIO bus.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mv88e6165 family has the internal PHYs mapped directly onto the
SMI register space as the switch. So the registers can be read
directly. Put a wrapper around this, in preparation for changing the
signature in order to support the external MDIO bus of the 6390.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>