55 Commits
Author SHA1 Message Date
Paolo Abeni 5e939544f9 mptcp: fix uninit-value in mptcp_established_options
syzbot reported the following uninit splat:

  BUG: KMSAN: uninit-value in mptcp_write_data_fin net/mptcp/options.c:542 [inline]
  BUG: KMSAN: uninit-value in mptcp_established_options_dss net/mptcp/options.c:590 [inline]
  BUG: KMSAN: uninit-value in mptcp_established_options+0x112f/0x3530 net/mptcp/options.c:874
   mptcp_write_data_fin net/mptcp/options.c:542 [inline]
   mptcp_established_options_dss net/mptcp/options.c:590 [inline]
   mptcp_established_options+0x112f/0x3530 net/mptcp/options.c:874
   tcp_established_options+0x312/0xcc0 net/ipv4/tcp_output.c:1192
   __tcp_transmit_skb+0x5dc/0x5fe0 net/ipv4/tcp_output.c:1575
   __tcp_send_ack+0x967/0xad0 net/ipv4/tcp_output.c:4499
   tcp_send_ack+0x3d/0x60 net/ipv4/tcp_output.c:4505
   mptcp_subflow_shutdown+0x164/0x690 net/mptcp/protocol.c:3137
   mptcp_check_send_data_fin+0x31b/0x3d0 net/mptcp/protocol.c:3218
   __mptcp_wr_shutdown net/mptcp/protocol.c:3234 [inline]
   __mptcp_close+0x860/0x1360 net/mptcp/protocol.c:3313
   mptcp_close+0x42/0x260 net/mptcp/protocol.c:3367
   inet_release+0x1ee/0x2a0 net/ipv4/af_inet.c:442
   __sock_release net/socket.c:722 [inline]
   sock_close+0xd6/0x2f0 net/socket.c:1514
   __fput+0x60e/0x1010 fs/file_table.c:510
   ____fput+0x25/0x30 fs/file_table.c:538
   task_work_run+0x208/0x2b0 kernel/task_work.c:233
   resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
   __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
   exit_to_user_mode_loop+0x306/0x1b60 kernel/entry/common.c:98
   __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
   syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
   syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
   __do_fast_syscall_32+0x2c7/0x460 arch/x86/entry/syscall_32.c:310
   do_fast_syscall_32+0x37/0x80 arch/x86/entry/syscall_32.c:332
   do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:370
   entry_SYSENTER_compat_after_hwframe+0x84/0x8e

  Local variable opts created at:
   __tcp_transmit_skb+0x4d/0x5fe0 net/ipv4/tcp_output.c:1536
   __tcp_send_ack+0x967/0xad0 net/ipv4/tcp_output.c:4499

The output path currently omits initializing the mptcp extension
`use_map` flag in a few corner cases.

Address the issue always zeroing all the extensions flags before
eventually initializing the individual bits. To that extent, introduce
and use a struct_group to avoid multiple bitwise operations.

Fixes: cfcceb7a39 ("tcp: shrink per-packet memset in __tcp_transmit_skb()")
Cc: stable@vger.kernel.org
Reported-by: syzbot+ff020673c5e3d94d9478@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ff020673c5e3d94d9478
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-10-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:27 -07:00
Matthieu Baerts (NGI0) 6e83166dd8 mptcp: sched: remove mptcp_sched_data
This is a follow-up of commit b68b106b0f ("mptcp: sched: reduce size
for unused data"), now removing the mptcp_sched_data structure.

Now is a good time to do that, because the previously mentioned WIP work
has been updated, no longer depending on this structure.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250413-net-next-mptcp-sched-mib-sft-misc-v2-1-0f83a4350150@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-15 08:21:46 -07:00
Geliang Tang fa3ee9dd80 mptcp: sysctl: add available_path_managers
Similarly to net.mptcp.available_schedulers, this patch adds a new one
net.mptcp.available_path_managers to list the available path managers.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250313-net-next-mptcp-pm-ops-intro-v1-11-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20 10:14:49 +01:00
Geliang Tang 1305b0c22e mptcp: pm: define struct mptcp_pm_ops
In order to allow users to develop their own BPF-based path manager,
this patch defines a struct ops "mptcp_pm_ops" for an MPTCP path
manager, which contains a set of interfaces. Currently only init()
and release() interfaces are included, subsequent patches will add
others step by step.

Add a set of functions to register, unregister, find and validate a
given path manager struct ops.

"list" is used to add this path manager to mptcp_pm_list list when
it is registered. "name" is used to identify this path manager.
mptcp_pm_find() uses "name" to find a path manager on the list.

mptcp_pm_unregister is not used in this set, but will be invoked in
.unreg of struct bpf_struct_ops. mptcp_pm_validate() will be invoked
in .validate of struct bpf_struct_ops. That's why they are exported.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250313-net-next-mptcp-pm-ops-intro-v1-6-f4e4a88efc50@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20 10:14:48 +01:00
Geliang Tang 9771a96a7a mptcp: sched: split get_subflow interface into two
get_retrans() interface of the burst packet scheduler invokes a sleeping
function mptcp_pm_subflow_chk_stale(), which calls __lock_sock_fast().
So get_retrans() interface should be set with BPF_F_SLEEPABLE flag in
BPF. But get_send() interface of this scheduler can't be set with
BPF_F_SLEEPABLE flag since it's invoked in ack_update_msk() under mptcp
data lock.

So this patch has to split get_subflow() interface of packet scheduer into
two interfaces: get_send() and get_retrans(). Then we can set get_retrans()
interface alone with BPF_F_SLEEPABLE flag.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250221-net-next-mptcp-pm-misc-cleanup-3-v1-8-2b70ab1cee79@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-24 18:23:44 -08:00
Matthieu Baerts (NGI0) 6982826fe5 mptcp: fallback to TCP after SYN+MPC drops
Some middleboxes might be nasty with MPTCP, and decide to drop packets
with MPTCP options, instead of just dropping the MPTCP options (or
letting them pass...).

In this case, it sounds better to fallback to "plain" TCP after 2
retransmissions, and try again.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/477
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240909-net-next-mptcp-fallback-x-mpc-v1-2-da7ebb4cd2a3@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-11 15:57:50 -07:00
Gregory Detal 73c900aa36 mptcp: add net.mptcp.available_schedulers
The sysctl lists the available schedulers that can be set using
net.mptcp.scheduler similarly to net.ipv4.tcp_available_congestion_control.

Signed-off-by: Gregory Detal <gregory.detal@gmail.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Tested-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20240514011335.176158-5-martineau@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-13 18:29:23 -07:00
Geliang Tang 740ebe35bd mptcp: add struct mptcp_sched_ops
This patch defines struct mptcp_sched_ops, which has three struct members,
name, owner and list, and four function pointers: init(), release() and
get_subflow().

The scheduler function get_subflow() have a struct mptcp_sched_data
parameter, which contains a reinject flag for retrans or not, a subflows
number and a mptcp_subflow_context array.

Add the scheduler registering, unregistering and finding functions to add,
delete and find a packet scheduler on the global list mptcp_sched_list.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20230821-upstream-net-next-20230818-v1-3-0c860fb256a8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-22 17:31:18 -07:00
Matthieu Baerts 3fff88186f mptcp: remove MPTCP 'ifdef' in TCP SYN cookies
To ease the maintenance, it is often recommended to avoid having #ifdef
preprocessor conditions.

Here the section related to CONFIG_MPTCP was quite short but the next
commit needs to add more code around. It is then cleaner to move
specific MPTCP code to functions located in net/mptcp directory.

Now that mptcp_subflow_request_sock_ops structure can be static, it can
also be marked as "read only after init".

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-12 13:11:24 -08:00
Jiri Olsa f1d41f7720 mptcp, btf: Add struct mptcp_sock definition when CONFIG_MPTCP is disabled
The btf_sock_ids array needs struct mptcp_sock BTF ID for the
bpf_skc_to_mptcp_sock helper.

When CONFIG_MPTCP is disabled, the 'struct mptcp_sock' is not
defined and resolve_btfids will complain with:

  [...]
  BTFIDS  vmlinux
  WARN: resolve_btfids: unresolved symbol mptcp_sock
  [...]

Add an empty definition for struct mptcp_sock when CONFIG_MPTCP
is disabled.

Fixes: 3bc253c2e6 ("bpf: Add bpf_skc_to_mptcp_sock_proto")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220802163324.1873044-1-jolsa@kernel.org
2022-08-08 15:30:45 +02:00
Geliang Tang f7657ff4a7 mptcp: move MPTCPOPT_HMAC_LEN to net/mptcp.h
Move macro MPTCPOPT_HMAC_LEN definition from net/mptcp/protocol.h to
include/net/mptcp.h.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-09 12:19:23 +01:00
Jakub Kicinski 1ef0736c07 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-05-23

We've added 113 non-merge commits during the last 26 day(s) which contain
a total of 121 files changed, 7425 insertions(+), 1586 deletions(-).

The main changes are:

1) Speed up symbol resolution for kprobes multi-link attachments, from Jiri Olsa.

2) Add BPF dynamic pointer infrastructure e.g. to allow for dynamically sized ringbuf
   reservations without extra memory copies, from Joanne Koong.

3) Big batch of libbpf improvements towards libbpf 1.0 release, from Andrii Nakryiko.

4) Add BPF link iterator to traverse links via seq_file ops, from Dmitrii Dolgov.

5) Add source IP address to BPF tunnel key infrastructure, from Kaixi Fan.

6) Refine unprivileged BPF to disable only object-creating commands, from Alan Maguire.

7) Fix JIT blinding of ld_imm64 when they point to subprogs, from Alexei Starovoitov.

8) Add BPF access to mptcp_sock structures and their meta data, from Geliang Tang.

9) Add new BPF helper for access to remote CPU's BPF map elements, from Feng Zhou.

10) Allow attaching 64-bit cookie to BPF link of fentry/fexit/fmod_ret, from Kui-Feng Lee.

11) Follow-ups to typed pointer support in BPF maps, from Kumar Kartikeya Dwivedi.

12) Add busy-poll test cases to the XSK selftest suite, from Magnus Karlsson.

13) Improvements in BPF selftest test_progs subtest output, from Mykola Lysenko.

14) Fill bpf_prog_pack allocator areas with illegal instructions, from Song Liu.

15) Add generic batch operations for BPF map-in-map cases, from Takshak Chahande.

16) Make bpf_jit_enable more user friendly when permanently on 1, from Tiezhu Yang.

17) Fix an array overflow in bpf_trampoline_get_progs(), from Yuntao Wang.

====================

Link: https://lore.kernel.org/r/20220523223805.27931-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-23 16:07:14 -07:00
Geliang Tang 3bc253c2e6 bpf: Add bpf_skc_to_mptcp_sock_proto
This patch implements a new struct bpf_func_proto, named
bpf_skc_to_mptcp_sock_proto. Define a new bpf_id BTF_SOCK_TYPE_MPTCP,
and a new helper bpf_skc_to_mptcp_sock(), which invokes another new
helper bpf_mptcp_sock_from_subflow() in net/mptcp/bpf.c to get struct
mptcp_sock from a given subflow socket.

v2: Emit BTF type, add func_id checks in verifier.c and bpf_trace.c,
remove build check for CONFIG_BPF_JIT
v5: Drop EXPORT_SYMBOL (Martin)

Co-developed-by: Nicolas Rybowski <nicolas.rybowski@tessares.net>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Nicolas Rybowski <nicolas.rybowski@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220519233016.105670-2-mathew.j.martineau@linux.intel.com
2022-05-20 15:29:00 -07:00
Paolo Abeni ea66758c17 tcp: allow MPTCP to update the announced window
The MPTCP RFC requires that the MPTCP-level receive window's
right edge never moves backward. Currently the MPTCP code
enforces such constraint while tracking the right edge, but it
does not reflects it on the wire, as MPTCP lacks a suitable hook
to update accordingly the TCP header.

This change modifies the existing mptcp_write_options() hook,
providing the current packet's TCP header to the MPTCP protocol,
so that the next patch could implement the above mentioned
constraint.

No functional changes intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-05 19:00:15 -07:00
Geliang Tang 1e39e5a32a mptcp: infinite mapping sending
This patch adds the infinite mapping sending logic.

Add a new flag send_infinite_map in struct mptcp_subflow_context. Set
it true when a single contiguous subflow is in use and the
allow_infinite_fallback flag is true in mptcp_pm_mp_fail_received().

In mptcp_sendmsg_frag(), if this flag is true, call the new function
mptcp_update_infinite_map() to set the infinite mapping.

Add a new flag infinite_map in struct mptcp_ext, set it true in
mptcp_update_infinite_map(), and check this flag in a new helper
mptcp_check_infinite_map().

In mptcp_update_infinite_map(), set data_len to 0, and clear the
send_infinite_map flag, then do fallback.

In mptcp_established_options(), use the helper mptcp_check_infinite_map()
to let the infinite mapping DSS can be sent out in the fallback mode.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-23 11:51:05 +01:00
Matthieu Baerts f8e9ce4a6e mptcp: mptcp_parse_option is no longer exported
Options parsing in now done from mptcp_incoming_options().

mptcp_parse_option() has been removed from mptcp.h when CONFIG_MPTCP is
defined but not when it is not.

Fixes: cfde141ea3 ("mptcp: move option parsing into mptcp_incoming_options()")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-16 20:52:04 -08:00
Jakub Kicinski 7df621a3ee Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
include/net/sock.h
  7b50ecfcc6 ("net: Rename ->stream_memory_read to ->sock_is_readable")
  4c1e34c0db ("vsock: Enable y2038 safe timeval for timeout")

drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
  0daa55d033 ("octeontx2-af: cn10k: debugfs for dumping LMTST map table")
  e77bcdd1f6 ("octeontx2-af: Display all enabled PF VF rsrc_alloc entries.")

Adjacent code addition in both cases, keep both.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-28 10:43:58 -07:00
Davide Caratti f7cc8890f3 mptcp: fix corrupt receiver key in MPC + data + checksum
using packetdrill it's possible to observe that the receiver key contains
random values when clients transmit MP_CAPABLE with data and checksum (as
specified in RFC8684 ยง3.1). Fix the layout of mptcp_out_options, to avoid
using the skb extension copy when writing the MP_CAPABLE sub-option.

Fixes: d7b2690837 ("mptcp: shrink mptcp_out_options struct")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/233
Reported-by: Poorva Sonparote <psonparo@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/20211027203855.264600-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-28 08:19:06 -07:00
Florian Westphal 61bc6e82f9 mptcp: add new mptcp_fill_diag helper
Will be re-used from getsockopt path.
Since diag can be a module, we can't export the helper from diag, it
needs to be moved to core.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-18 14:20:00 +01:00
Geliang Tang c25aeb4e09 mptcp: MP_FAIL suboption sending
This patch added the MP_FAIL suboption sending support.

Add a new flag named send_mp_fail in struct mptcp_subflow_context. If
this flag is set, send out MP_FAIL suboption.

Add a new member fail_seq in struct mptcp_out_options to save the data
sequence number to put into the MP_FAIL suboption.

An MP_FAIL option could be included in a RST or on the subflow-level
ACK.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:34 +01:00
Paolo Abeni d7b2690837 mptcp: shrink mptcp_out_options struct
After the previous patch we can alias with a union several
fields in mptcp_out_options. Such struct is stack allocated and
memset() for each plain TCP out packet. Every saved byted counts.

Before:
pahole -EC mptcp_out_options
 # ...
/* size: 136, cachelines: 3, members: 17 */

After:
pahole -EC mptcp_out_options
 # ...
/* size: 56, cachelines: 1, members: 9 */

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:34 +01:00
Jianguo Wu 6787b7e350 mptcp: avoid processing packet if a subflow reset
If check_fully_established() causes a subflow reset, it should not
continue to process the packet in tcp_data_queue().
Add a return value to mptcp_incoming_options(), and return false if a
subflow has been reset, else return true. Then drop the packet in
tcp_data_queue()/tcp_rcv_state_process() if mptcp_incoming_options()
return false.

Fixes: d582484726 ("mptcp: fix fallback for MP_JOIN subflows")
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-09 18:38:53 -07:00
Geliang Tang bab6b88e05 mptcp: add allow_join_id0 in mptcp_out_options
This patch defined a new flag MPTCP_CAP_DENY_JOIN_ID0 for the third bit,
labeled "C" of the MP_CAPABLE option.

Add a new flag allow_join_id0 in struct mptcp_out_options. If this flag is
set, send out the MP_CAPABLE option with the flag MPTCP_CAP_DENY_JOIN_ID0.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-22 14:36:01 -07:00
Geliang Tang 208e8f6692 mptcp: receive checksum for MP_CAPABLE with data
This patch added a new member named csum in struct mptcp_options_received.

When parsing the MP_CAPABLE with data, if the checksum is enabled,
adjust the expected_opsize. If the receiving option length matches the
length with the data checksum, get the checksum value and save it in
mp_opt->csum. And in mptcp_incoming_options, pass it to mpext->csum.

We always parse any csum/nocsum combination and delay the presence check
to later code, to allow reset if missing.

Additionally, in the TX path, use the newly introduce ext field to avoid
MPTCP csum recomputation on TCP retransmission and unneeded csum update
on when setting the data fin_flag.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-18 11:40:11 -07:00
Geliang Tang 06fe1719aa mptcp: add csum_reqd in mptcp_out_options
This patch added a new member csum_reqd in struct mptcp_out_options and
struct mptcp_subflow_request_sock. Initialized it with the helper
function mptcp_is_checksum_enabled().

In mptcp_write_options, if this field is enabled, send out the MP_CAPABLE
suboption with the MPTCP_CAP_CHECKSUM_REQD flag.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-18 11:40:11 -07:00