Commit Graph

241 Commits

Author SHA1 Message Date
Florian Westphal dc87efdb1a mptcp: add mptcp reset option support
The MPTCP reset option allows to carry a mptcp-specific error code that
provides more information on the nature of a connection reset.

Reset option data received gets stored in the subflow context so it can
be sent to userspace via the 'subflow closed' netlink event.

When a subflow is closed, the desired error code that should be sent to
the peer is also placed in the subflow context structure.

If a reset is sent before subflow establishment could complete, e.g. on
HMAC failure during an MP_JOIN operation, the mptcp skb extension is
used to store the reset information.

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>
2021-04-02 14:21:50 -07:00
Geliang Tang b46a023810 mptcp: rename mptcp_pm_nl_add_addr_send_ack
Since mptcp_pm_nl_add_addr_send_ack is now used for both ADD_ADDR and
RM_ADDR cases, rename it to mptcp_pm_nl_addr_send_ack.

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>
2021-03-26 15:05:15 -07:00
Geliang Tang 8dd5efb1f9 mptcp: send ack for rm_addr
This patch changes the sending ACK conditions for the ADD_ADDR, send an
ACK packet for RM_ADDR too.

In mptcp_pm_remove_addr, invoke mptcp_pm_nl_add_addr_send_ack to send
the ACK packet.

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>
2021-03-26 15:05:15 -07:00
Geliang Tang 557963c383 mptcp: move to next addr when subflow creation fail
When an invalid address was announced, the subflow couldn't be created
for this address. Therefore mptcp_pm_nl_subflow_established couldn't be
invoked. Then the next addresses in the local address list didn't have a
chance to be announced.

This patch invokes the new function mptcp_pm_add_addr_echoed when the
address is echoed. In it, use mptcp_lookup_anno_list_by_saddr to check
whether this address is in the anno_list. If it is, PM schedules the
status MPTCP_PM_SUBFLOW_ESTABLISHED to invoke
mptcp_pm_create_subflow_or_signal_addr to deal with the next address in
the local address list.

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>
2021-03-26 15:05:15 -07:00
Geliang Tang d88c476f4a mptcp: export lookup_anno_list_by_saddr
This patch exported the static function lookup_anno_list_by_saddr, and
renamed it to mptcp_lookup_anno_list_by_saddr.

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>
2021-03-26 15:05:15 -07:00
Geliang Tang 62535200be mptcp: drop unused subflow in mptcp_pm_subflow_established
This patch drops the unused parameter subflow in
mptcp_pm_subflow_established().

Fixes: 926bdeab55 ("mptcp: Implement path manager interface commands")
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>
2021-03-26 15:05:15 -07:00
Geliang Tang f7efc7771e mptcp: drop argument port from mptcp_pm_announce_addr
Drop the redundant argument 'port' from mptcp_pm_announce_addr, use the
port field of another argument 'addr' instead.

Fixes: 0f5c9e3f07 ("mptcp: add port parameter for mptcp_pm_announce_addr")
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>
2021-03-26 15:05:15 -07:00
Paolo Abeni 2d6f5a2b57 mptcp: clean-up the rtx path
After the previous patch we can easily avoid invoking
the workqueue to perform the retransmission, if the
msk socket lock is held at rtx timer expiration.

This also simplifies the relevant code.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2021-03-26 15:05:15 -07:00
Geliang Tang ddd14bb85d mptcp: remove multi subflows in PM
This patch dealt with removing multi subflows in PM:

In mptcp_pm_remove_subflow, changed the input parameter local_id as an
list of removing address ids, and passed the list to
mptcp_pm_nl_rm_subflow_received.

In mptcp_pm_nl_rm_subflow_received, iterated each address id from the
received ids list. Then shut down and closed each address id's subsocket.

In mptcp_nl_remove_subflow_and_signal_addr, put the single address id into
an ids list, and passed it to mptcp_pm_remove_subflow.

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>
2021-03-12 17:47:45 -08:00
Geliang Tang d0b698ca9a mptcp: remove multi addresses in PM
This patch dropped the member rm_id of struct mptcp_pm_data. Use
rm_list_rx in mptcp_pm_nl_rm_addr_received instead of using rm_id.

In mptcp_pm_nl_rm_addr_received, iterated each address id from
pm.rm_list_rx, then shut down and closed each address id's subsocket.

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>
2021-03-12 17:47:45 -08:00
Geliang Tang b5c55f334c mptcp: add rm_list_rx in mptcp_pm_data
This patch added a new member rm_list_rx for struct mptcp_pm_data as an
list of the removing address ids on the incoming direction. Initialized
its nr field to zero in mptcp_pm_data_init.

In mptcp_pm_rm_addr_received, set it as the input rm_list.

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>
2021-03-12 17:47:45 -08:00
Geliang Tang 5c4a824dcb mptcp: add rm_list in mptcp_options_received
This patch changed the member rm_id in struct mptcp_options_received as a
list of the removing address ids, and renamed it to rm_list.

In mptcp_parse_option, parsed the RM_ADDR suboption and filled them into
the rm_list in struct mptcp_options_received.

In mptcp_incoming_options, passed this rm_list to the function
mptcp_pm_rm_addr_received.

It also changed the parameter type of mptcp_pm_rm_addr_received.

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>
2021-03-12 17:47:45 -08:00
Geliang Tang cbde278718 mptcp: add rm_list_tx in mptcp_pm_data
This patch added a new member rm_list_tx for struct mptcp_pm_data as the
removing address list on the outgoing direction. Initialize its nr field
to zero in mptcp_pm_data_init.

In mptcp_pm_remove_anno_addr, put the single address id into an removing
list, and passed it to mptcp_pm_remove_addr.

In mptcp_pm_remove_addr, save the input rm_list to rm_list_tx in struct
mptcp_pm_data.

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>
2021-03-12 17:47:45 -08:00
Geliang Tang 6445e17af7 mptcp: add rm_list in mptcp_out_options
This patch defined a new struct mptcp_rm_list, the ids field was an
array of the removing address ids, the nr field was the valid number of
removing address ids in the array. The array size was definced as a new
macro MPTCP_RM_IDS_MAX. Changed the member rm_id of struct
mptcp_out_options to rm_list.

In mptcp_established_options_rm_addr, invoked mptcp_pm_rm_addr_signal to
get the rm_list. According the number of addresses in it, calculated
the padded RM_ADDR suboption length. And saved the ids array in struct
mptcp_out_options's rm_list member.

In mptcp_write_options, iterated each address id from struct
mptcp_out_options's rm_list member, set the invalid ones as TCPOPT_NOP,
then filled them into the RM_ADDR suboption.

Changed TCPOLEN_MPTCP_RM_ADDR_BASE from 4 to 3.

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>
2021-03-12 17:47:45 -08:00
Davide Caratti 27ab92d999 mptcp: fix length of ADD_ADDR with port sub-option
in current Linux, MPTCP peers advertising endpoints with port numbers use
a sub-option length that wrongly accounts for the trailing TCP NOP. Also,
receivers will only process incoming ADD_ADDR with port having such wrong
sub-option length. Fix this, making ADD_ADDR compliant to RFC8684 §3.4.1.

this can be verified running tcpdump on the kselftests artifacts:

 unpatched kernel:
 [root@bottarga mptcp]# tcpdump -tnnr unpatched.pcap | grep add-addr
 reading from file unpatched.pcap, link-type LINUX_SLL (Linux cooked v1), snapshot length 65535
 IP 10.0.1.1.10000 > 10.0.1.2.53078: Flags [.], ack 101, win 509, options [nop,nop,TS val 214459678 ecr 521312851,mptcp add-addr v1 id 1 a00:201:2774:2d88:7436:85c3:17fd:101], length 0
 IP 10.0.1.2.53078 > 10.0.1.1.10000: Flags [.], ack 101, win 502, options [nop,nop,TS val 521312852 ecr 214459678,mptcp add-addr[bad opt]]

 patched kernel:
 [root@bottarga mptcp]# tcpdump -tnnr patched.pcap | grep add-addr
 reading from file patched.pcap, link-type LINUX_SLL (Linux cooked v1), snapshot length 65535
 IP 10.0.1.1.10000 > 10.0.1.2.38178: Flags [.], ack 101, win 509, options [nop,nop,TS val 3728873902 ecr 2732713192,mptcp add-addr v1 id 1 10.0.2.1:10100 hmac 0xbccdfcbe59292a1f,nop,nop], length 0
 IP 10.0.1.2.38178 > 10.0.1.1.10000: Flags [.], ack 101, win 502, options [nop,nop,TS val 2732713195 ecr 3728873902,mptcp add-addr v1-echo id 1 10.0.2.1:10100,nop,nop], length 0

Fixes: 22fb85ffae ("mptcp: add port support for ADD_ADDR suboption writing")
CC: stable@vger.kernel.org # 5.11+
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-and-tested-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-08 15:02:03 -08:00
David S. Miller d489ded1a3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-16 17:51:13 -08:00
Geliang Tang 0caf3ada24 mptcp: add local addr info in mptcp_info
Add mptcpi_local_addr_used and mptcpi_local_addr_max in struct mptcp_info.

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>
2021-02-15 15:09:14 -08:00
Florian Westphal b911c97c7d mptcp: add netlink event support
Allow userspace (mptcpd) to subscribe to mptcp genl multicast events.
This implementation reuses the same event API as the mptcp kernel fork
to ease integration of existing tools, e.g. mptcpd.

Supported events include:
1. start and close of an mptcp connection
2. start and close of subflows (joins)
3. announce and withdrawals of addresses
4. subflow priority (backup/non-backup) change.

Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2021-02-12 16:31:46 -08:00
Florian Westphal 6c714f1b54 mptcp: pass subflow socket to a few helpers
Pass the first/initial subflow to the existing functions so they can
pass this on to the notification handler that is added later in the
series.

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>
2021-02-12 16:31:45 -08:00
Florian Westphal a141e02e39 mptcp: split __mptcp_close_ssk helper
Prepare for subflow close events:

When mptcp connection is torn down its enough to send the mptcp socket
close notification rather than a subflow close event for all of the
subflows followed by the mptcp close event.

This splits the helper: mptcp_close_ssk() will emit the close
notification, __mptcp_close_ssk will not.

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>
2021-02-12 16:31:45 -08:00
Florian Westphal e980143068 mptcp: move pm netlink work into pm_netlink
Allows to make some functions static and avoids acquire of the pm
spinlock in protocol.c.

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>
2021-02-12 16:31:45 -08:00
Paolo Abeni e3859603ba mptcp: better msk receive window updates
Move mptcp_cleanup_rbuf() related checks inside the mentioned
helper and extend them to mirror TCP checks more closely.

Additionally drop the 'rmem_pending' hack, since commit 879526030c
("mptcp: protect the rx path with the msk socket spinlock") we
can use instead 'rmem_released'.

Fixes: ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling")
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>
2021-02-11 18:30:54 -08:00
Paolo Abeni 64b9cea7a0 mptcp: fix spurious retransmissions
Syzkaller was able to trigger the following splat again:

WARNING: CPU: 1 PID: 12512 at net/mptcp/protocol.c:761 mptcp_reset_timer+0x12a/0x160 net/mptcp/protocol.c:761
Modules linked in:
CPU: 1 PID: 12512 Comm: kworker/1:6 Not tainted 5.10.0-rc6 #52
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_reset_timer+0x12a/0x160 net/mptcp/protocol.c:761
Code: e8 4b 0c ad ff e8 56 21 88 fe 48 b8 00 00 00 00 00 fc ff df 48 c7 04 03 00 00 00 00 48 83 c4 40 5b 5d 41 5c c3 e8 36 21 88 fe <0f> 0b 41 bc c8 00 00 00 eb 98 e8 e7 b1 af fe e9 30 ff ff ff 48 c7
RSP: 0018:ffffc900018c7c68 EFLAGS: 00010293
RAX: ffff888108cb1c80 RBX: 1ffff92000318f8d RCX: ffffffff82ad0307
RDX: 0000000000000000 RSI: ffffffff82ad036a RDI: 0000000000000007
RBP: ffff888113e2d000 R08: ffff888108cb1c80 R09: ffffed10227c5ab7
R10: ffff888113e2d5b7 R11: ffffed10227c5ab6 R12: 0000000000000000
R13: ffff88801f100000 R14: ffff888113e2d5b0 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88811b500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd76a874ef8 CR3: 000000001689c005 CR4: 0000000000170ee0
Call Trace:
 mptcp_worker+0xaa4/0x1560 net/mptcp/protocol.c:2334
 process_one_work+0x8d3/0x1200 kernel/workqueue.c:2272
 worker_thread+0x9c/0x1090 kernel/workqueue.c:2418
 kthread+0x303/0x410 kernel/kthread.c:292
 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:296

The mptcp_worker tries to update the MPTCP retransmission timer
even if such timer is not currently scheduled.

The mptcp_rtx_head() return value is bogus: we can have enqueued
data not yet transmitted. The above may additionally cause spurious,
unneeded MPTCP-level retransmissions.

Fix the issue adding an explicit clearing of the rtx queue before
trying to retransmit and checking for unacked data.
Additionally drop an unneeded timer stop call and the unused
mptcp_rtx_tail() helper.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
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>
2021-02-11 18:30:54 -08:00
Paolo Abeni 15cc104533 mptcp: deliver ssk errors to msk
Currently all errors received on msk subflows are ignored.
We need to catch at least the errors on connect() and
on fallback sockets.

Use a custom sk_error_report callback at subflow level,
and do the real action under the msk socket lock - via
the usual sock_owned_by_user()/release_callback() schema.

Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
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>
2021-02-11 18:30:54 -08:00
Florian Westphal 3abc05d9ef mptcp: pm: add lockdep assertions
Add a few assertions to make sure functions are called with the needed
locks held.
Two functions gain might_sleep annotations because they contain
conditional calls to functions that sleep.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-06 14:35:47 -08:00
Geliang Tang 5bc56388c7 mptcp: add port number check for MP_JOIN
This patch adds two new helpers, subflow_use_different_sport and
subflow_use_different_dport, to check whether the subflow's source or
destination port number is different from the msk's port number. When
receiving the MP_JOIN's SYN/SYNACK/ACK, we do these port number checks
and print out the different port numbers.

And furthermore, when receiving the MP_JOIN's SYN/ACK, we also use a new
helper mptcp_pm_sport_in_anno_list to check whether this port number is
announced. If it isn't, we need to abort this connection.

This patch also populates the local address's port field in
local_address.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-02 18:37:19 -08:00
Geliang Tang 1729cf186d mptcp: create the listening socket for new port
This patch creates a listening socket when an address with a port-number
is added by PM netlink. Then binds the new port to the socket, and
listens for new connections.

When the address is removed or the addresses are flushed by PM netlink,
release the listening socket.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-02 18:37:19 -08:00
Geliang Tang a914e58668 mptcp: drop *_max fields in mptcp_pm_data
This patch drops the per-msk values add_addr_signal_max,
add_addr_accept_max, local_addr_max and subflows_max fields in struct
mptcp_pm_data, uses the pernet *_max values instead. And adds four new
helpers to get the pernet *_max values separately.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-02 18:37:18 -08:00
Davide Caratti ec99a470c7 mptcp: fix length of MP_PRIO suboption
With version 0 of the protocol it was legal to encode the 'Subflow Id' in
the MP_PRIO suboption, to specify which subflow would change its 'Backup'
flag. This has been removed from v1 specification: thus, according to RFC
8684 §3.3.8, the resulting 'Length' for MP_PRIO changed from 4 to 3 byte.

Current Linux generates / parses MP_PRIO according to the old spec, using
'Length' equal to 4, and hardcoding 1 as 'Subflow Id'; RFC compliance can
improve if we change 'Length' in other to become 3, leaving a 'Nop' after
the MP_PRIO suboption. In this way the kernel will emit and accept *only*
MP_PRIO suboptions that are compliant to version 1 of the MPTCP protocol.

 unpatched 5.11-rc kernel:
 [root@bottarga ~]# tcpdump -tnnr unpatched.pcap | grep prio
 reading from file unpatched.pcap, link-type LINUX_SLL (Linux cooked v1)
 dropped privs to tcpdump
 IP 10.0.3.2.48433 > 10.0.1.1.10006: Flags [.], ack 1, win 502, options [nop,nop,TS val 4032325513 ecr 1876514270,mptcp prio non-backup id 1,mptcp dss ack 14084896651682217737], length 0

 patched 5.11-rc kernel:
 [root@bottarga ~]# tcpdump -tnnr patched.pcap | grep prio
 reading from file patched.pcap, link-type LINUX_SLL (Linux cooked v1)
 dropped privs to tcpdump
 IP 10.0.3.2.49735 > 10.0.1.1.10006: Flags [.], ack 1, win 502, options [nop,nop,TS val 1276737699 ecr 2686399734,mptcp prio non-backup,nop,mptcp dss ack 18433038869082491686], length 0

Changes since v2:
 - when accounting for option space, don't increment 'TCPOLEN_MPTCP_PRIO'
   and use 'TCPOLEN_MPTCP_PRIO_ALIGN' instead, thanks to Matthieu Baerts.
Changes since v1:
 - refactor patch to avoid using 'TCPOLEN_MPTCP_PRIO' with its old value,
   thanks to Geliang Tang.

Fixes: 067065422f ("mptcp: add the outgoing MP_PRIO support")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Matteo Croce <mcroce@linux.microsoft.com>
Link: https://lore.kernel.org/r/846cdd41e6ad6ec88ef23fee1552ab39c2f5a3d1.1612184361.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-02 17:34:02 -08:00
Paolo Abeni b19bc2945b mptcp: implement delegated actions
On MPTCP-level ack reception, the packet scheduler
may select a subflow other then the current one.

Prior to this commit we rely on the workqueue to trigger
action on such subflow.

This changeset introduces an infrastructure that allows
any MPTCP subflow to schedule actions (MPTCP xmit) on
others subflows without resorting to (multiple) process
reschedule.

A dummy NAPI instance is used instead. When MPTCP needs to
trigger action an a different subflow, it enqueues the target
subflow on the NAPI backlog and schedule such instance as needed.

The dummy NAPI poll method walks the sockets backlog and tries
to acquire the (BH) socket lock on each of them. If the socket
is owned by the user space, the action will be completed by
the sock release cb, otherwise push is started.

This change leverages the delegated action infrastructure
to avoid invoking the MPTCP worker to spool the pending data,
when the packet scheduler picks a subflow other then the one
currently processing the incoming MPTCP-level ack.

Additionally we further refine the subflow selection
invoking the packet scheduler for each chunk of data
even inside __mptcp_subflow_push_pending().

v1 -> v2:
 - fix possible UaF at shutdown time, resetting sock ops
   after removing the ulp context

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-22 19:21:02 -08:00
Paolo Abeni 5cf92bbadc mptcp: re-enable sndbuf autotune
After commit 6e628cd3a8 ("mptcp: use mptcp release_cb for
delayed tasks"), MPTCP never sets the flag bit SOCK_NOSPACE
on its subflow. As a side effect, autotune never takes place,
as it happens inside tcp_new_space(), which in turn is called
only when the mentioned bit is set.

Let's sendmsg() set the subflows NOSPACE bit when looking for
more memory and use the subflow write_space callback to propagate
the snd buf update and wake-up the user-space.

Additionally, this allows dropping a bunch of duplicate code and
makes the SNDBUF_LIMITED chrono relevant again for MPTCP subflows.

Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-22 19:21:02 -08:00
Paolo Abeni 866f26f2a9 mptcp: always graft subflow socket to parent
Currently, incoming subflows link to the parent socket,
while outgoing ones link to a per subflow socket. The latter
is not really needed, except at the initial connect() time and
for the first subflow.

Always graft the outgoing subflow to the parent socket and
free the unneeded ones early.

This allows some code cleanup, reduces the amount of memory
used and will simplify the next patch

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-22 19:21:02 -08:00
Geliang Tang 40453a5c61 mptcp: add the incoming MP_PRIO support
This patch added the incoming MP_PRIO logic:

Added a flag named mp_prio in struct mptcp_options_received, to mark the
MP_PRIO is received, and save the priority value to struct
mptcp_options_received's backup member. Then invoke
mptcp_pm_mp_prio_received with the receiving subsocket and the backup
value.

In mptcp_pm_mp_prio_received, get the subflow context according the input
subsocket, and change the subflow's backup as the incoming priority value.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-09 18:18:43 -08:00
Geliang Tang 067065422f mptcp: add the outgoing MP_PRIO support
This patch added the outgoing MP_PRIO logic:

In mptcp_pm_nl_mp_prio_send_ack, find the related subflow and subsocket
according to the input parameter addr. Save the input priority value to
suflow's backup, then set subflow's send_mp_prio flag to true, and save
the input priority value to suflow's request_bkup. Finally, send out a
pure ACK on the related subsocket.

In mptcp_established_options_mp_prio, check whether the subflow's
send_mp_prio is set. If it is, this is the packet for sending MP_PRIO.
So save subflow->request_bkup value to mptcp_out_options's backup, and
change the option type to OPTION_MPTCP_PRIO.

In mptcp_write_options, clear the send_mp_prio flag and send out the
MP_PRIO suboption with mptcp_out_options's backup value.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-09 18:18:43 -08:00
Paolo Abeni 219d04992b mptcp: push pending frames when subflow has free space
When multiple subflows are active, we can receive a
window update on subflow with no write space available.
MPTCP will try to push frames on such subflow and will
fail. Pending frames will be pushed only after receiving
a window update on a subflow with some wspace available.

Overall the above could lead to suboptimal aggregate
bandwidth usage.

Instead, we should try to push pending frames as soon as
the subflow reaches both conditions mentioned above.

We can finally enable self-tests with asymmetric links,
as the above makes them finally pass.

Fixes: 6f8a612a33 ("mptcp: keep track of advertised windows right edge")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-17 10:24:47 -08:00
Florian Westphal 50c504a20a mptcp: parse and act on incoming FASTCLOSE option
parse the MPTCP FASTCLOSE subtype.

If provided key matches the local one, schedule the work queue to close
(with tcp reset) all subflows.

The MPTCP socket moves to closed state immediately.

Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-14 17:30:06 -08:00
Geliang Tang ba34c3de71 mptcp: use MPTCPOPT_HMAC_LEN macro
Use the macro MPTCPOPT_HMAC_LEN instead of a constant in struct
mptcp_options_received.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-14 17:30:06 -08:00
Paolo Abeni 5b950ff433 mptcp: link MPC subflow into msk only after accept
Christoph reported the following splat:

WARNING: CPU: 0 PID: 4615 at net/ipv4/inet_connection_sock.c:1031 inet_csk_listen_stop+0x8e8/0xad0 net/ipv4/inet_connection_sock.c:1031
Modules linked in:
CPU: 0 PID: 4615 Comm: syz-executor.4 Not tainted 5.9.0 #37
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:inet_csk_listen_stop+0x8e8/0xad0 net/ipv4/inet_connection_sock.c:1031
Code: 03 00 00 00 e8 79 b2 3d ff e9 ad f9 ff ff e8 1f 76 ba fe be 02 00 00 00 4c 89 f7 e8 62 b2 3d ff e9 14 f9 ff ff e8 08 76 ba fe <0f> 0b e9 97 f8 ff ff e8 fc 75 ba fe be 03 00 00 00 4c 89 f7 e8 3f
RSP: 0018:ffffc900037f7948 EFLAGS: 00010293
RAX: ffff88810a349c80 RBX: ffff888114ee1b00 RCX: ffffffff827b14cd
RDX: 0000000000000000 RSI: ffffffff827b1c38 RDI: 0000000000000005
RBP: ffff88810a2a8000 R08: ffff88810a349c80 R09: fffff520006fef1f
R10: 0000000000000003 R11: fffff520006fef1e R12: ffff888114ee2d00
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff888114ee1d68
FS:  00007f2ac1945700(0000) GS:ffff88811b400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd44798bc0 CR3: 0000000109810002 CR4: 0000000000170ef0
Call Trace:
 __tcp_close+0xd86/0x1110 net/ipv4/tcp.c:2433
 __mptcp_close_ssk+0x256/0x430 net/mptcp/protocol.c:1761
 __mptcp_destroy_sock+0x49b/0x770 net/mptcp/protocol.c:2127
 mptcp_close+0x62d/0x910 net/mptcp/protocol.c:2184
 inet_release+0xe9/0x1f0 net/ipv4/af_inet.c:434
 __sock_release+0xd2/0x280 net/socket.c:596
 sock_close+0x15/0x20 net/socket.c:1277
 __fput+0x276/0x960 fs/file_table.c:281
 task_work_run+0x109/0x1d0 kernel/task_work.c:151
 get_signal+0xe8f/0x1d40 kernel/signal.c:2561
 arch_do_signal+0x88/0x1b60 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0x9b/0xf0 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x22/0x150 kernel/entry/common.c:266
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f2ac1254469
Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ff 49 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007f2ac1944dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffbf RBX: 000000000069bf00 RCX: 00007f2ac1254469
RDX: 0000000000000000 RSI: 0000000000008982 RDI: 0000000000000003
RBP: 000000000069bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000069bf0c
R13: 00007ffeb53f178f R14: 00000000004668b0 R15: 0000000000000003

After commit 0397c6d85f ("mptcp: keep unaccepted MPC subflow into
join list"), the msk's workqueue and/or PM can touch the MPC
subflow - and acquire its socket lock - even if it's still unaccepted.

If the above event races with the relevant listener socket close, we
can end-up with the above splat.

This change addresses the issue delaying the MPC socket insertion
in conn_list at accept time - that is, partially reverting the
blamed commit.

We must additionally ensure that mptcp_pm_fully_established()
happens after accept() time, or the PM will not be able to
handle properly such event - conn_list could be empty otherwise.

In the receive path, we check the subflow list node to ensure
it is out of the listener queue. Be sure client subflows do
not match transiently such condition moving them into the join
list earlier at creation time.

Since we now have multiple mptcp_pm_fully_established() call sites
from different code-paths, said helper can now race with itself.
Use an additional PM status bit to avoid multiple notifications.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/103
Fixes: 0397c6d85f ("mptcp: keep unaccepted MPC subflow into join list"),
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-09 19:31:58 -08:00
Geliang Tang 13ad9f01a2 mptcp: rename add_addr_signal and mptcp_add_addr_status
Since the RM_ADDR signal had been reused with add_addr_signal, it's not
suitable to call it add_addr_signal or mptcp_add_addr_status. So this
patch renamed add_addr_signal to addr_signal, and renamed
mptcp_add_addr_status to mptcp_addr_signal_status.

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>
2020-12-09 19:02:16 -08:00
Geliang Tang 42842a425a mptcp: drop rm_addr_signal flag
This patch reused add_addr_signal for the RM_ADDR announcing signal, by
defining a new ADD_ADDR status named MPTCP_RM_ADDR_SIGNAL. Then the flag
rm_addr_signal in PM could be dropped.

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>
2020-12-09 19:02:15 -08:00
Geliang Tang 0f5c9e3f07 mptcp: add port parameter for mptcp_pm_announce_addr
This patch added a new parameter 'port' for mptcp_pm_announce_addr. If
this parameter is true, we set the MPTCP_ADD_ADDR_PORT bit of the
add_addr_signal. That means the announced address is added with a port
number.

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>
2020-12-09 19:02:15 -08:00
Geliang Tang 4a2777a834 mptcp: add the outgoing ADD_ADDR port support
This patch added a new add_addr_signal type named MPTCP_ADD_ADDR_PORT,
to identify it is an address with port to be added.

It also added a new parameter 'port' for both mptcp_add_addr_len and
mptcp_pm_add_addr_signal.

In mptcp_established_options_add_addr, we check whether the announced
address is added with port. If it is, we put this port number to
mptcp_out_options's port field.

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>
2020-12-09 19:02:15 -08:00
Geliang Tang 2ec72faec8 mptcp: use adding up size to get ADD_ADDR length
This patch uses adding up size to get the ADD_ADDR suboption length rather
than returning the ADD_ADDR size constants.

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>
2020-12-09 19:02:15 -08:00
Geliang Tang 22fb85ffae mptcp: add port support for ADD_ADDR suboption writing
In rfc8684, the length of ADD_ADDR suboption with IPv4 address and port
is 18 octets, but mptcp_write_options is 32-bit aligned, so we need to
pad it to 20 octets. All the other port related option lengths need to
be added up 2 octets similarly.

This patch added a new field 'port' in mptcp_out_options. When this
field is set with a port number, we need to add up 4 octets for the
ADD_ADDR suboption, and put the port number into the suboption.

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>
2020-12-09 19:02:15 -08:00
Paolo Abeni 6e628cd3a8 mptcp: use mptcp release_cb for delayed tasks
We have some tasks triggered by the subflow receive path
which require to access the msk socket status, specifically:
mptcp_clean_una() and mptcp_push_pending()

We have almost everything in place to defer to the msk
release_cb such tasks when the msk sock is owned.

Since the worker is no more used to clean the acked data,
for fallback sockets we need to explicitly flush them.

As an added bonus we can move the wake-up code in __mptcp_clean_una(),
simplify a lot mptcp_poll() and move the timer update under
the data lock.

The worker is now used only to process and send DATA_FIN
packets and do the mptcp-level retransmissions.

Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-30 17:55:23 -08:00
Paolo Abeni 7439d687b7 mptcp: avoid a few atomic ops in the rx path
Extending the data_lock scope in mptcp_incoming_option
we can use that to protect both snd_una and wnd_end.
In the typical case, we will have a single atomic op instead of 2

Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-30 17:55:23 -08:00
Paolo Abeni 724cfd2ee8 mptcp: allocate TX skbs in msk context
Move the TX skbs allocation in mptcp_sendmsg() scope,
and tentatively pre-allocate a skbs number proportional
to the sendmsg() length.

Use the ssk tx skb cache to prevent the subflow allocation.

This allows removing the msk skb extension cache and will
make possible the later patches.

Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-30 17:55:23 -08:00
Paolo Abeni 879526030c mptcp: protect the rx path with the msk socket spinlock
Such spinlock is currently used only to protect the 'owned'
flag inside the socket lock itself. With this patch, we extend
its scope to protect the whole msk receive path and
sk_forward_memory.

Given the above, we can always move data into the msk receive
queue (and OoO queue) from the subflow.

We leverage the previous commit, so that we need to acquire the
spinlock in the tx path only when moving fwd memory.

recvmsg() must now explicitly acquire the socket spinlock
when moving skbs out of sk_receive_queue. To reduce the number of
lock operations required we use a second rx queue and splice the
first into the latter in mptcp_lock_sock(). Additionally rmem
allocated memory is bulk-freed via release_cb()

Acked-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-30 17:55:23 -08:00
Paolo Abeni e93da92896 mptcp: implement wmem reservation
This leverages the previous commit to reserve the wmem
required for the sendmsg() operation when the msk socket
lock is first acquired.
Some heuristics are used to get a reasonable [over] estimation of
the whole memory required. If we can't forward alloc such amount
fallback to a reasonable small chunk, otherwise enter the wait
for memory path.

When sendmsg() needs more memory it looks at wmem_reserved
first and if that is exhausted, move more space from
sk_forward_alloc.

The reserved memory is not persistent and is released at the
next socket unlock via the release_cb().

Overall this will simplify the next patch.

Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-30 17:55:23 -08:00
Paolo Abeni ad80b0fc6e mptcp: open code mptcp variant for lock_sock
This allows invoking an additional callback under the
socket spin lock.

Will be used by the next patches to avoid additional
spin lock contention.

Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-30 17:55:23 -08:00
Paolo Abeni ea4ca586b1 mptcp: refine MPTCP-level ack scheduling
Send timely MPTCP-level ack is somewhat difficult when
the insertion into the msk receive level is performed
by the worker.

It needs TCP-level dup-ack to notify the MPTCP-level
ack_seq increase, as both the TCP-level ack seq and the
rcv window are unchanged.

We can actually avoid processing incoming data with the
worker, and let the subflow or recevmsg() send ack as needed.

When recvmsg() moves the skbs inside the msk receive queue,
the msk space is still unchanged, so tcp_cleanup_rbuf() could
end-up skipping TCP-level ack generation. Anyway, when
__mptcp_move_skbs() is invoked, a known amount of bytes is
going to be consumed soon: we update rcv wnd computation taking
them in account.

Additionally we need to explicitly trigger tcp_cleanup_rbuf()
when recvmsg() consumes a significant amount of the receive buffer.

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>
2020-11-20 15:33:25 -08:00
Florian Westphal fa3fe2b150 mptcp: track window announced to peer
OoO handling attempts to detect when packet is out-of-window by testing
current ack sequence and remaining space vs. sequence number.

This doesn't work reliably. Store the highest allowed sequence number
that we've announced and use it to detect oow packets.

Do this when mptcp options get written to the packet (wire format).
For this to work we need to move the write_options call until after
stack selected a new tcp window.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-20 15:33:25 -08:00
Geliang Tang 84dfe3677a mptcp: send out dedicated ADD_ADDR packet
When ADD_ADDR suboption includes an IPv6 address, the size is 28 octets.
It will not fit when other MPTCP suboptions are included in this packet,
e.g. DSS. So here we send out an ADD_ADDR dedicated packet to carry only
ADD_ADDR suboption, no other MPTCP suboptions.

In mptcp_pm_announce_addr, we check whether this is an IPv6 ADD_ADDR.
If it is, we set the flag MPTCP_ADD_ADDR_IPV6 to true. Then we call
mptcp_pm_nl_add_addr_send_ack to sent out a new pure ACK packet.

In mptcp_established_options_add_addr, we check whether this is a pure
ACK packet for ADD_ADDR. If it is, we drop all other MPTCP suboptions
in this packet, only put ADD_ADDR suboption in it.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
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: Jakub Kicinski <kuba@kernel.org>
2020-11-20 15:33:25 -08:00
Geliang Tang d91d322a72 mptcp: change add_addr_signal type
This patch changed the 'add_addr_signal' type from bool to char, so that
we could encode the addr type there.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
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: Jakub Kicinski <kuba@kernel.org>
2020-11-20 15:33:25 -08:00
Paolo Abeni 0397c6d85f mptcp: keep unaccepted MPC subflow into join list
This will simplify all operation dealing with subflows
before accept time (e.g. data fin processing, add_addr).

The join list is already flushed by mptcp_stream_accept()
before returning the newly created msk to the user space.

This also fixes an potential bug present into the old code:
conn_list was manipulated without helding the msk lock
in mptcp_stream_accept().

Tested-by: Geliang Tang <geliangtang@gmail.com>
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>
2020-11-20 15:33:25 -08:00
Paolo Abeni b2771d2419 mptcp: drop WORKER_RUNNING status bit
Only mptcp_close() can actually cancel the workqueue,
no need to add and use this flag.

Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2020-11-20 15:33:24 -08:00
Florian Westphal 6f8a612a33 mptcp: keep track of advertised windows right edge
Before sending 'x' new bytes also check that the new snd_una would
be within the permitted receive window.

For every ACK that also contains a DSS ack, check whether its tcp-level
receive window would advance the current mptcp window right edge and
update it if so.

Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16 10:46:07 -08:00
Florian Westphal 8edf08649e mptcp: rework poll+nospace handling
MPTCP maintains a status bit, MPTCP_SEND_SPACE, that is set when at
least one subflow and the mptcp socket itself are writeable.

mptcp_poll returns EPOLLOUT if the bit is set.

mptcp_sendmsg makes sure MPTCP_SEND_SPACE gets cleared when last write
has used up all subflows or the mptcp socket wmem.

This reworks nospace handling as follows:

MPTCP_SEND_SPACE is replaced with MPTCP_NOSPACE, i.e. inverted meaning.
This bit is set when the mptcp socket is not writeable.
The mptcp-level ack path schedule will then schedule the mptcp worker
to allow it to free already-acked data (and reduce wmem usage).

This will then wake userspace processes that wait for a POLLOUT event.

sendmsg will set MPTCP_NOSPACE only when it has to wait for more
wmem (blocking I/O case).

poll path will set MPTCP_NOSPACE in case the mptcp socket is
not writeable.

Normal tcp-level notification (SOCK_NOSPACE) is only enabled
in case the subflow socket has no available wmem.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16 10:46:07 -08:00
Paolo Abeni e16163b6e2 mptcp: refactor shutdown and close
We must not close the subflows before all the MPTCP level
data, comprising the DATA_FIN has been acked at the MPTCP
level, otherwise we could be unable to retransmit as needed.

__mptcp_wr_shutdown() shutdown is responsible to check for the
correct status and close all subflows. Is called by the output
path after spooling any data and at shutdown/close time.

In a similar way, __mptcp_destroy_sock() is responsible to clean-up
the MPTCP level status, and is called when the msk transition
to TCP_CLOSE.

The protocol level close() does not force anymore the TCP_CLOSE
status, but orphan the msk socket and all the subflows.
Orphaned msk sockets are forciby closed after a timeout or
when all MPTCP-level data is acked.

There is a caveat about keeping the orphaned subflows around:
the TCP stack can asynchronusly call tcp_cleanup_ulp() on them via
tcp_close(). To prevent accessing freed memory on later MPTCP
level operations, the msk acquires a reference to each subflow
socket and prevent subflow_ulp_release() from releasing the
subflow context before __mptcp_destroy_sock().

The additional subflow references are released by __mptcp_done()
and the async ULP release is detected checking ULP ops. If such
field has been already cleared by the ULP release path, the
dangling context is freed directly by __mptcp_done().

Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16 10:46:07 -08:00
Paolo Abeni eaa2ffabfc mptcp: introduce MPTCP snd_nxt
Track the next MPTCP sequence number used on xmit,
currently always equal to write_next.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16 10:46:07 -08:00
Paolo Abeni f0e6a4cf11 mptcp: add accounting for pending data
Preparation patch to track the data pending in the msk
write queue. No functional change introduced here

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16 10:46:06 -08:00
Paolo Abeni ba8f48f7a4 mptcp: introduce mptcp_schedule_work
remove some of code duplications an allow preventing
rescheduling on close.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16 10:46:06 -08:00
Geliang Tang 93f323b9cc mptcp: add a new sysctl add_addr_timeout
This patch added a new sysctl, named add_addr_timeout, to control the
timeout value (in seconds) of the ADD_ADDR retransmission.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-04 17:45:53 -08:00
Jakub Kicinski 2295cddf99 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor conflicts in net/mptcp/protocol.h and
tools/testing/selftests/net/Makefile.

In both cases code was added on both sides in the same place
so just keep both.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15 12:43:21 -07:00
Paolo Abeni 0e4f35d788 mptcp: subflows garbage collection
The msk can close MP_JOIN subflows if the initial handshake
fails. Currently such subflows are kept alive in the
conn_list until the msk itself is closed.

Beyond the wasted memory, we could end-up sending the
DATA_FIN and the DATA_FIN ack on such socket, even after a
reset.

Fixes: 43b54c6ee3 ("mptcp: Use full MPTCP-level disconnect state machine")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10 11:04:53 -07:00
Paolo Abeni d582484726 mptcp: fix fallback for MP_JOIN subflows
Additional/MP_JOIN subflows that do not pass some initial handshake
tests currently causes fallback to TCP. That is an RFC violation:
we should instead reset the subflow and leave the the msk untouched.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/91
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10 11:04:53 -07:00
Davide Caratti 37198e93ce net: mptcp: make DACK4/DACK8 usage consistent among all subflows
using packetdrill it's possible to observe the same MPTCP DSN being acked
by different subflows with DACK4 and DACK8. This is in contrast with what
specified in RFC8684 §3.3.2: if an MPTCP endpoint transmits a 64-bit wide
DSN, it MUST be acknowledged with a 64-bit wide DACK. Fix 'use_64bit_ack'
variable to make it a property of MPTCP sockets, not TCP subflows.

Fixes: a0c1d0eafd ("mptcp: Use 32-bit DATA_ACK when possible")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-09 08:25:48 -07:00
David S. Miller 8b0308fe31 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Rejecting non-native endian BTF overlapped with the addition
of support for it.

The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-05 18:40:01 -07:00
Matthieu Baerts 456afe01b1 mptcp: ADD_ADDRs with echo bit are smaller
The MPTCP ADD_ADDR suboption with echo-flag=1 has no HMAC, the size is
smaller than the one initially sent without echo-flag=1. We then need to
use the correct size everywhere when we need this echo bit.

Before this patch, the wrong size was reserved but the correct amount of
bytes were written (and read): the remaining bytes contained garbage.

Fixes: 6a6c05a8b0 ("mptcp: send out ADD_ADDR with echo flag")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/95
Reported-and-tested-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03 17:36:37 -07:00
Mat Martineau 1a49b2c2a5 mptcp: Handle incoming 32-bit DATA_FIN values
The peer may send a DATA_FIN mapping with either a 32-bit or 64-bit
sequence number. When a 32-bit sequence number is received for the
DATA_FIN, it must be expanded to 64 bits before comparing it to the
last acked sequence number. This expansion was missing.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/93
Fixes: 3721b9b646 ("mptcp: Track received DATA_FIN sequence number and add related helpers")
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-29 18:15:46 -07:00
Geliang Tang 00cfd77b90 mptcp: retransmit ADD_ADDR when timeout
This patch implemented the retransmition of ADD_ADDR when no ADD_ADDR echo
is received. It added a timer with the announced address. When timeout
occurs, ADD_ADDR will be retransmitted.

Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:34 -07:00
Geliang Tang 5c8c164095 mptcp: add mptcp_destroy_common helper
This patch added a new helper named mptcp_destroy_common containing the
shared code between mptcp_destroy() and mptcp_sock_destruct().

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:34 -07:00
Geliang Tang 0ee4261a36 mptcp: implement mptcp_pm_remove_subflow
This patch implemented the local subflow removing function,
mptcp_pm_remove_subflow, it simply called mptcp_pm_nl_rm_subflow_received
under the PM spin lock.

We use mptcp_pm_remove_subflow to remove a local subflow, so change it's
argument from remote_id to local_id.

We check subflow->local_id in mptcp_pm_nl_rm_subflow_received to remove
a subflow.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:34 -07:00
Geliang Tang b6c0838086 mptcp: remove addr and subflow in PM netlink
This patch implements the remove announced addr and subflow logic in PM
netlink.

When the PM netlink removes an address, we traverse all the existing msk
sockets to find the relevant sockets.

We add a new list named anno_list in mptcp_pm_data, to record all the
announced addrs. In the traversing, we check if it has been recorded.
If it has been, we trigger the RM_ADDR signal.

We also check if this address is in conn_list. If it is, we remove the
subflow which using this local address.

Since we call mptcp_pm_free_anno_list in mptcp_destroy, we need to move
__mptcp_init_sock before the mptcp_is_enabled check in mptcp_init_sock.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:33 -07:00
Geliang Tang 6a6c05a8b0 mptcp: send out ADD_ADDR with echo flag
When the ADD_ADDR suboption has been received, we need to send out the same
ADD_ADDR suboption with echo-flag=1, and no HMAC.

Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:33 -07:00
Geliang Tang d0876b2284 mptcp: add the incoming RM_ADDR support
This patch added the RM_ADDR option parsing logic:

We parsed the incoming options to find if the rm_addr option is received,
and called mptcp_pm_rm_addr_received to schedule PM work to a new status,
named MPTCP_PM_RM_ADDR_RECEIVED.

PM work got this status, and called mptcp_pm_nl_rm_addr_received to handle
it.

In mptcp_pm_nl_rm_addr_received, we closed the subflow matching the rm_id,
and updated PM counter.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:33 -07:00
Geliang Tang 5cb104ae55 mptcp: add the outgoing RM_ADDR support
This patch added a new signal named rm_addr_signal in PM. On outgoing path,
we called mptcp_pm_should_rm_signal to check if rm_addr_signal has been
set. If it has been, we sent out the RM_ADDR option.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:33 -07:00
Geliang Tang f643b8032e mptcp: rename addr_signal and the related functions
This patch renamed addr_signal and the related functions with the explicit
word "add".

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:58:33 -07:00
Paolo Abeni d5f49190de mptcp: allow picking different xmit subflows
Update the scheduler to less trivial heuristic: cache
the last used subflow, and try to send on it a reasonably
long burst of data.

When the burst or the subflow send space is exhausted, pick
the subflow with the lower ratio between write space and
send buffer - that is, the subflow with the greater relative
amount of free space.

v1 -> v2:
 - fix 32 bit build breakage due to 64bits div
 - fix checkpath issues (uint64_t -> u64)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14 13:28:02 -07:00
Paolo Abeni ef0da3b8a2 mptcp: move address attribute into mptcp_addr_info
So that can be accessed easily from the subflow creation
helper. No functional change intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14 13:28:02 -07:00
Paolo Abeni 04e4cd4f7c mptcp: cleanup mptcp_subflow_discard_data()
There is no need to use the tcp_read_sock(), we can
simply drop the skb. Additionally try to look at the
next buffer for in order data.

This both simplifies the code and avoid unneeded indirect
calls.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14 13:28:02 -07:00
Paolo Abeni ab174ad8ef mptcp: move ooo skbs into msk out of order queue.
Add an RB-tree to cope with OoO (at MPTCP level) data.
__mptcp_move_skb() insert into the RB tree "future"
data, eventually coalescing skb as allowed by the
MPTCP DSN.

To simplify sequence accounting, move the DSN inside
the cb.

After successfully enqueuing in sequence data, check
if we can use any data from the RB tree.

Additionally move the data_fin check after spooling
data from the OoO tree, otherwise we could miss shutdown
events.

The RB tree code is copied as verbatim as possible
from tcp_data_queue_ofo(), with a few simplifications
due to the fact that MPTCP doesn't need to cope with
sacks. All bugs here are added by me.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14 13:28:02 -07:00
Paolo Abeni 6719331c2f mptcp: trigger msk processing even for OoO data
This is a prerequisite to allow receiving data from multiple
subflows without re-injection.

Instead of dropping the OoO - "future" data in
subflow_check_data_avail(), call into __mptcp_move_skbs()
and let the msk drop that.

To avoid code duplication factor out the mptcp_subflow_discard_data()
helper.

Note that __mptcp_move_skbs() can now find multiple subflows
with data avail (comprising to-be-discarded data), so must
update the byte counter incrementally.

v1 -> v2:
 - fix checkpatch issues (unsigned -> unsigned int)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14 13:28:02 -07:00
Florian Westphal 9466a1cceb mptcp: enable JOIN requests even if cookies are in use
JOIN requests do not work in syncookie mode -- for HMAC validation, the
peers nonce and the mptcp token (to obtain the desired connection socket
the join is for) are required, but this information is only present in the
initial syn.

So either we need to drop all JOIN requests once a listening socket enters
syncookie mode, or we need to store enough state to reconstruct the request
socket later.

This adds a state table (1024 entries) to store the data present in the
MP_JOIN syn request and the random nonce used for the cookie syn/ack.

When a MP_JOIN ACK passed cookie validation, the table is consulted
to rebuild the request socket from it.

An alternate approach would be to "cancel" syn-cookie mode and force
MP_JOIN to always use a syn queue entry.

However, doing so brings the backlog over the configured queue limit.

v2: use req->syncookie, not (removed) want_cookie arg

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-31 16:55:32 -07:00
Florian Westphal c83a47e50d mptcp: subflow: add mptcp_subflow_init_cookie_req helper
Will be used to initialize the mptcp request socket when a MP_CAPABLE
request was handled in syncookie mode, i.e. when a TCP ACK containing a
MP_CAPABLE option is a valid syncookie value.

Normally (non-cookie case), MPTCP will generate a unique 32 bit connection
ID and stores it in the MPTCP token storage to be able to retrieve the
mptcp socket for subflow joining.

In syncookie case, we do not want to store any state, so just generate the
unique ID and use it in the reply.

This means there is a small window where another connection could generate
the same token.

When Cookie ACK comes back, we check that the token has not been registered
in the mean time.  If it was, the connection needs to fall back to TCP.

Changes in v2:
 - use req->syncookie instead of passing 'want_cookie' arg to ->init_req()
   (Eric Dumazet)

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-31 16:55:32 -07:00
Mat Martineau 3721b9b646 mptcp: Track received DATA_FIN sequence number and add related helpers
Incoming DATA_FIN headers need to propagate the presence of the DATA_FIN
bit and the associated sequence number to the MPTCP layer, even when
arriving on a bare ACK that does not get added to the receive queue. Add
structure members to store the DATA_FIN information and helpers to set
and check those values.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-28 17:02:42 -07:00
Mat Martineau 7279da6145 mptcp: Use MPTCP-level flag for sending DATA_FIN
Since DATA_FIN information is the same for every subflow, store it only
in the mptcp_sock.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-28 17:02:41 -07:00
Paolo Abeni b93df08ccd mptcp: explicitly track the fully established status
Currently accepted msk sockets become established only after
accept() returns the new sk to user-space.

As MP_JOIN request are refused as per RFC spec on non fully
established socket, the above causes mp_join self-tests
instabilities.

This change lets the msk entering the established status
as soon as it receives the 3rd ack and propagates the first
subflow fully established status on the msk socket.

Finally we can change the subflow acceptance condition to
take in account both the sock state and the msk fully
established flag.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23 11:47:24 -07:00
Florian Westphal c1d069e3bf mptcp: move helper to where its used
Only used in token.c.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-21 16:22:18 -07:00
Paolo Abeni 96d890daad mptcp: add msk interations helper
mptcp_token_iter_next() allow traversing all the MPTCP
sockets inside the token container belonging to the given
network namespace with a quite standard iterator semantic.

That will be used by the next patch, but keep the API generic,
as we plan to use this later for PM's sake.

Additionally export mptcp_token_get_sock(), as it also
will be used by the diag module.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-09 12:38:41 -07:00
Florian Westphal b416268b7a mptcp: use mptcp worker for path management
We can re-use the existing work queue to handle path management
instead of a dedicated work queue.  Just move pm_worker to protocol.c,
call it from the mptcp worker and get rid of the msk lock (already held).

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-07 13:02:13 -07:00
Florian Westphal a6b118febb mptcp: add receive buffer auto-tuning
When mptcp is used, userspace doesn't read from the tcp (subflow)
socket but from the parent (mptcp) socket receive queue.

skbs are moved from the subflow socket to the mptcp rx queue either from
'data_ready' callback (if mptcp socket can be locked), a work queue, or
the socket receive function.

This means tcp_rcv_space_adjust() is never called and thus no receive
buffer size auto-tuning is done.

An earlier (not merged) patch added tcp_rcv_space_adjust() calls to the
function that moves skbs from subflow to mptcp socket.
While this enabled autotuning, it also meant tuning was done even if
userspace was reading the mptcp socket very slowly.

This adds mptcp_rcv_space_adjust() and calls it after userspace has
read data from the mptcp socket rx queue.

Its very similar to tcp_rcv_space_adjust, with two differences:

1. The rtt estimate is the largest one observed on a subflow
2. The rcvbuf size and window clamp of all subflows is adjusted
   to the mptcp-level rcvbuf.

Otherwise, we get spurious drops at tcp (subflow) socket level if
the skbs are not moved to the mptcp socket fast enough.

Before:
time mptcp_connect.sh -t -f $((4*1024*1024)) -d 300 -l 0.01% -r 0 -e "" -m mmap
[..]
ns4 MPTCP -> ns3 (10.0.3.2:10108      ) MPTCP   (duration 40823ms) [ OK ]
ns4 MPTCP -> ns3 (10.0.3.2:10109      ) TCP     (duration 23119ms) [ OK ]
ns4 TCP   -> ns3 (10.0.3.2:10110      ) MPTCP   (duration  5421ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10111) MPTCP   (duration 41446ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10112) TCP     (duration 23427ms) [ OK ]
ns4 TCP   -> ns3 (dead:beef:3::2:10113) MPTCP   (duration  5426ms) [ OK ]
Time: 1396 seconds

After:
ns4 MPTCP -> ns3 (10.0.3.2:10108      ) MPTCP   (duration  5417ms) [ OK ]
ns4 MPTCP -> ns3 (10.0.3.2:10109      ) TCP     (duration  5427ms) [ OK ]
ns4 TCP   -> ns3 (10.0.3.2:10110      ) MPTCP   (duration  5422ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10111) MPTCP   (duration  5415ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10112) TCP     (duration  5422ms) [ OK ]
ns4 TCP   -> ns3 (dead:beef:3::2:10113) MPTCP   (duration  5423ms) [ OK ]
Time: 296 seconds

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-01 17:47:55 -07:00
Davide Caratti 8fd738049a mptcp: fallback in case of simultaneous connect
when a MPTCP client tries to connect to itself, tcp_finish_connect() is
never reached. Because of this, depending on the socket current state,
multiple faulty behaviours can be observed:

1) a WARN_ON() in subflow_data_ready() is hit
 WARNING: CPU: 2 PID: 882 at net/mptcp/subflow.c:911 subflow_data_ready+0x18b/0x230
 [...]
 CPU: 2 PID: 882 Comm: gh35 Not tainted 5.7.0+ #187
 [...]
 RIP: 0010:subflow_data_ready+0x18b/0x230
 [...]
 Call Trace:
  tcp_data_queue+0xd2f/0x4250
  tcp_rcv_state_process+0xb1c/0x49d3
  tcp_v4_do_rcv+0x2bc/0x790
  __release_sock+0x153/0x2d0
  release_sock+0x4f/0x170
  mptcp_shutdown+0x167/0x4e0
  __sys_shutdown+0xe6/0x180
  __x64_sys_shutdown+0x50/0x70
  do_syscall_64+0x9a/0x370
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

2) client is stuck forever in mptcp_sendmsg() because the socket is not
   TCP_ESTABLISHED

 crash> bt 4847
 PID: 4847   TASK: ffff88814b2fb100  CPU: 1   COMMAND: "gh35"
  #0 [ffff8881376ff680] __schedule at ffffffff97248da4
  #1 [ffff8881376ff778] schedule at ffffffff9724a34f
  #2 [ffff8881376ff7a0] schedule_timeout at ffffffff97252ba0
  #3 [ffff8881376ff8a8] wait_woken at ffffffff958ab4ba
  #4 [ffff8881376ff940] sk_stream_wait_connect at ffffffff96c2d859
  #5 [ffff8881376ffa28] mptcp_sendmsg at ffffffff97207fca
  #6 [ffff8881376ffbc0] sock_sendmsg at ffffffff96be1b5b
  #7 [ffff8881376ffbe8] sock_write_iter at ffffffff96be1daa
  #8 [ffff8881376ffce8] new_sync_write at ffffffff95e5cb52
  #9 [ffff8881376ffe50] vfs_write at ffffffff95e6547f
 #10 [ffff8881376ffe90] ksys_write at ffffffff95e65d26
 #11 [ffff8881376fff28] do_syscall_64 at ffffffff956088ba
 #12 [ffff8881376fff50] entry_SYSCALL_64_after_hwframe at ffffffff9740008c
     RIP: 00007f126f6956ed  RSP: 00007ffc2a320278  RFLAGS: 00000217
     RAX: ffffffffffffffda  RBX: 0000000020000044  RCX: 00007f126f6956ed
     RDX: 0000000000000004  RSI: 00000000004007b8  RDI: 0000000000000003
     RBP: 00007ffc2a3202a0   R8: 0000000000400720   R9: 0000000000400720
     R10: 0000000000400720  R11: 0000000000000217  R12: 00000000004004b0
     R13: 00007ffc2a320380  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

3) tcpdump captures show that DSS is exchanged even when MP_CAPABLE handshake
   didn't complete.

 $ tcpdump -tnnr bad.pcap
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [S], seq 3208913911, win 65483, options [mss 65495,sackOK,TS val 3291706876 ecr 3291694721,nop,wscale 7,mptcp capable v1], length 0
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [S.], seq 3208913911, ack 3208913912, win 65483, options [mss 65495,sackOK,TS val 3291706876 ecr 3291706876,nop,wscale 7,mptcp capable v1], length 0
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [.], ack 1, win 512, options [nop,nop,TS val 3291706876 ecr 3291706876], length 0
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [F.], seq 1, ack 1, win 512, options [nop,nop,TS val 3291707876 ecr 3291706876,mptcp dss fin seq 0 subseq 0 len 1,nop,nop], length 0
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [.], ack 2, win 512, options [nop,nop,TS val 3291707876 ecr 3291707876], length 0

force a fallback to TCP in these cases, and adjust the main socket
state to avoid hanging in mptcp_sendmsg().

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/35
Reported-by: Christoph Paasch <cpaasch@apple.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:29:38 -07:00
Davide Caratti e1ff9e82e2 net: mptcp: improve fallback to TCP
Keep using MPTCP sockets and a use "dummy mapping" in case of fallback
to regular TCP. When fallback is triggered, skip addition of the MPTCP
option on send.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/11
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/22
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:29:38 -07:00
Paolo Abeni 2c5ebd001d mptcp: refactor token container
Replace the radix tree with a hash table allocated
at boot time. The radix tree has some shortcoming:
a single lock is contented by all the mptcp operation,
the lookup currently use such lock, and traversing
all the items would require a lock, too.

With hash table instead we trade a little memory to
address all the above - a per bucket lock is used.

To hash the MPTCP sockets, we re-use the msk' sk_node
entry: the MPTCP sockets are never hashed by the stack.
Replace the existing hash proto callbacks with a dummy
implementation, annotating the above constraint.

Additionally refactor the token creation to code to:

- limit the number of consecutive attempts to a fixed
maximum. Hitting a hash bucket with a long chain is
considered a failed attempt

- accept() no longer can fail to token management.

- if token creation fails at connect() time, we do
fallback to TCP (before the connection was closed)

v1 -> v2:
 - fix "no newline at end of file" - Jakub

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-26 16:21:39 -07:00
Paolo Abeni d39dceca38 mptcp: add __init annotation on setup functions
Add the missing annotation in some setup-only
functions.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-26 16:21:39 -07:00
David S. Miller 7bed145516 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor overlapping changes in xfrm_device.c, between the double
ESP trailing bug fix setting the XFRM_INIT flag and the changes
in net-next preparing for bonding encryption support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-25 19:29:51 -07:00
Eric Dumazet 9b9e2f250e tcp: move ipv4_specific to tcp include file
Declare ipv4_specific once, in tcp.h were it belongs.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-23 20:10:15 -07:00
Eric Dumazet b03d2142be tcp: move ipv6_specific declaration to remove a warning
ipv6_specific should be declared in tcp include files,
not mptcp.

This removes the following warning :
  CHECK   net/ipv6/tcp_ipv6.c
net/ipv6/tcp_ipv6.c:78:42: warning: symbol 'ipv6_specific' was not declared. Should it be static?

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-23 20:10:15 -07:00
Paolo Abeni 8fd4de1275 mptcp: cache msk on MP_JOIN init_req
The msk ownership is transferred to the child socket at
3rd ack time, so that we avoid more lookups later. If the
request does not reach the 3rd ack, the MSK reference is
dropped at request sock release time.

As a side effect, fallback is now tracked by a NULL msk
reference instead of zeroed 'mp_join' field. This will
simplify the next patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-18 20:25:51 -07:00
Geliang Tang a386bc5b21 mptcp: use list_first_entry_or_null
Use list_first_entry_or_null to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-15 13:04:53 -07:00
Geliang Tang c06c1f87b6 mptcp: drop MPTCP_PM_MAX_ADDR
We have defined MPTCP_PM_ADDR_MAX in pm_netlink.c, so drop this duplicate macro.

Fixes: 1b1c7a0ef7 ("mptcp: Add path manager interface")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-15 13:01:17 -07:00
David S. Miller 13209a8f73 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24 13:47:27 -07:00
Todd Malsbary bd6972226f mptcp: use untruncated hash in ADD_ADDR HMAC
There is some ambiguity in the RFC as to whether the ADD_ADDR HMAC is
the rightmost 64 bits of the entire hash or of the leftmost 160 bits
of the hash.  The intention, as clarified with the author of the RFC,
is the entire hash.

This change returns the entire hash from
mptcp_crypto_hmac_sha (instead of only the first 160 bits), and moves
any truncation/selection operation on the hash to the caller.

Fixes: 12555a2d97 ("mptcp: use rightmost 64 bits in ADD_ADDR HMAC")
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Todd Malsbary <todd.malsbary@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-22 14:21:24 -07:00
Christoph Paasch a0c1d0eafd mptcp: Use 32-bit DATA_ACK when possible
RFC8684 allows to send 32-bit DATA_ACKs as long as the peer is not
sending 64-bit data-sequence numbers. The 64-bit DSN is only there for
extreme scenarios when a very high throughput subflow is combined with a
long-RTT subflow such that the high-throughput subflow wraps around the
32-bit sequence number space within an RTT of the high-RTT subflow.

It is thus a rare scenario and we should try to use the 32-bit DATA_ACK
instead as long as possible. It allows to reduce the TCP-option overhead
by 4 bytes, thus makes space for an additional SACK-block. It also makes
tcpdumps much easier to read when the DSN and DATA_ACK are both either
32 or 64-bit.

Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-16 13:51:10 -07:00
Paolo Abeni cfde141ea3 mptcp: move option parsing into mptcp_incoming_options()
The mptcp_options_received structure carries several per
packet flags (mp_capable, mp_join, etc.). Such fields must
be cleared on each packet, even on dropped ones or packet
not carrying any MPTCP options, but the current mptcp
code clears them only on TCP option reset.

On several races/corner cases we end-up with stray bits in
incoming options, leading to WARN_ON splats. e.g.:

[  171.164906] Bad mapping: ssn=32714 map_seq=1 map_data_len=32713
[  171.165006] WARNING: CPU: 1 PID: 5026 at net/mptcp/subflow.c:533 warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531)
[  171.167632] Modules linked in: ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel geneve ip6_udp_tunnel udp_tunnel macsec macvtap tap ipvlan macvlan 8021q garp mrp xfrm_interface veth netdevsim nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun binfmt_misc intel_rapl_msr intel_rapl_common rfkill kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel joydev virtio_balloon pcspkr i2c_piix4 sunrpc ip_tables xfs libcrc32c crc32c_intel serio_raw virtio_console ata_generic virtio_blk virtio_net net_failover failover ata_piix libata
[  171.199464] CPU: 1 PID: 5026 Comm: repro Not tainted 5.7.0-rc1.mptcp_f227fdf5d388+ #95
[  171.200886] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
[  171.202546] RIP: 0010:warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531)
[  171.206537] Code: c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1d 8b 55 3c 44 89 e6 48 c7 c7 20 51 13 95 e8 37 8b 22 fe <0f> 0b 48 83 c4 08 5b 5d 41 5c c3 89 4c 24 04 e8 db d6 94 fe 8b 4c
[  171.220473] RSP: 0018:ffffc90000150560 EFLAGS: 00010282
[  171.221639] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  171.223108] RDX: 0000000000000000 RSI: 0000000000000008 RDI: fffff5200002a09e
[  171.224388] RBP: ffff8880aa6e3c00 R08: 0000000000000001 R09: fffffbfff2ec9955
[  171.225706] R10: ffffffff9764caa7 R11: fffffbfff2ec9954 R12: 0000000000007fca
[  171.227211] R13: ffff8881066f4a7f R14: ffff8880aa6e3c00 R15: 0000000000000020
[  171.228460] FS:  00007f8623719740(0000) GS:ffff88810be00000(0000) knlGS:0000000000000000
[  171.230065] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  171.231303] CR2: 00007ffdab190a50 CR3: 00000001038ea006 CR4: 0000000000160ee0
[  171.232586] Call Trace:
[  171.233109]  <IRQ>
[  171.233531] get_mapping_status (linux-mptcp/net/mptcp/subflow.c:691)
[  171.234371] mptcp_subflow_data_available (linux-mptcp/net/mptcp/subflow.c:736 linux-mptcp/net/mptcp/subflow.c:832)
[  171.238181] subflow_state_change (linux-mptcp/net/mptcp/subflow.c:1085 (discriminator 1))
[  171.239066] tcp_fin (linux-mptcp/net/ipv4/tcp_input.c:4217)
[  171.240123] tcp_data_queue (linux-mptcp/./include/linux/compiler.h:199 linux-mptcp/net/ipv4/tcp_input.c:4822)
[  171.245083] tcp_rcv_established (linux-mptcp/./include/linux/skbuff.h:1785 linux-mptcp/./include/net/tcp.h:1774 linux-mptcp/./include/net/tcp.h:1847 linux-mptcp/net/ipv4/tcp_input.c:5238 linux-mptcp/net/ipv4/tcp_input.c:5730)
[  171.254089] tcp_v4_rcv (linux-mptcp/./include/linux/spinlock.h:393 linux-mptcp/net/ipv4/tcp_ipv4.c:2009)
[  171.258969] ip_protocol_deliver_rcu (linux-mptcp/net/ipv4/ip_input.c:204 (discriminator 1))
[  171.260214] ip_local_deliver_finish (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/ipv4/ip_input.c:232)
[  171.261389] ip_local_deliver (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:252)
[  171.265884] ip_rcv (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:539)
[  171.273666] process_backlog (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/core/dev.c:6135)
[  171.275328] net_rx_action (linux-mptcp/net/core/dev.c:6572 linux-mptcp/net/core/dev.c:6640)
[  171.280472] __do_softirq (linux-mptcp/./arch/x86/include/asm/jump_label.h:25 linux-mptcp/./include/linux/jump_label.h:200 linux-mptcp/./include/trace/events/irq.h:142 linux-mptcp/kernel/softirq.c:293)
[  171.281379] do_softirq_own_stack (linux-mptcp/arch/x86/entry/entry_64.S:1083)
[  171.282358]  </IRQ>

We could address the issue clearing explicitly the relevant fields
in several places - tcp_parse_option, tcp_fast_parse_options,
possibly others.

Instead we move the MPTCP option parsing into the already existing
mptcp ingress hook, so that we need to clear the fields in a single
place.

This allows us dropping an MPTCP hook from the TCP code and
removing the quite large mptcp_options_received from the tcp_sock
struct. On the flip side, the MPTCP sockets will traverse the
option space twice (in tcp_parse_option() and in
mptcp_incoming_options(). That looks acceptable: we already
do that for syn and 3rd ack packets, plain TCP socket will
benefit from it, and even MPTCP sockets will experience better
code locality, reducing the jumps between TCP and MPTCP code.

v1 -> v2:
 - rebased on current '-net' tree

Fixes: 648ef4b886 ("mptcp: Implement MPTCP receive path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:23:22 -07:00
Paolo Abeni fca5c82c08 mptcp: drop req socket remote_key* fields
We don't need them, as we can use the current ingress opt
data instead. Setting them in syn_recv_sock() may causes
inconsistent mptcp socket status, as per previous commit.

Fixes: cc7972ea19 ("mptcp: parse and emit MP_CAPABLE option according to v1 spec")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-20 12:59:33 -07:00
Florian Westphal 59832e2465 mptcp: subflow: check parent mptcp socket on subflow state change
This is needed at least until proper MPTCP-Level fin/reset
signalling gets added:

We wake parent when a subflow changes, but we should do this only
when all subflows have closed, not just one.

Schedule the mptcp worker and tell it to check eof state on all
subflows.

Only flag mptcp socket as closed and wake userspace processes blocking
in poll if all subflows have closed.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-02 06:59:21 -07:00
Paolo Abeni 01cacb00b3 mptcp: add netlink-based PM
Expose a new netlink family to userspace to control the PM, setting:

 - list of local addresses to be signalled.
 - list of local addresses used to created subflows.
 - maximum number of add_addr option to react

When the msk is fully established, the PM netlink attempts to
announce the 'signal' list via the ADD_ADDR option. Since we
currently lack the ADD_ADDR echo (and related event) only the
first addr is sent.

After exhausting the 'announce' list, the PM tries to create
subflow for each addr in 'local' list, waiting for each
connection to be completed before attempting the next one.

Idea is to add an additional PM hook for ADD_ADDR echo, to allow
the PM netlink announcing multiple addresses, in sequence.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2020-03-29 22:14:49 -07:00
Davide Caratti 5147dfb508 mptcp: allow dumping subflow context to userspace
add ulp-specific diagnostic functions, so that subflow information can be
dumped to userspace programs like 'ss'.

v2 -> v3:
- uapi: use bit macros appropriate for userspace

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Paolo Abeni 3b1d6210a9 mptcp: implement and use MPTCP-level retransmission
On timeout event, schedule a work queue to do the retransmission.
Retransmission code closely resembles the sendmsg() implementation and
re-uses mptcp_sendmsg_frag, providing a dummy msghdr - for flags'
sake - and peeking the relevant dfrag from the rtx head.

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>
2020-03-29 22:14:48 -07:00
Florian Westphal 7948f6cc99 mptcp: allow partial cleaning of rtx head dfrag
After adding wmem accounting for the mptcp socket we could get
into a situation where the mptcp socket can't transmit more data,
and mptcp_clean_una doesn't reduce wmem even if snd_una has advanced
because it currently will only remove entire dfrags.

Allow advancing the dfrag head sequence and reduce wmem,
even though this isn't correct (as we can't release the page).

Because we will soon block on mptcp sk in case wmem is too large,
call sk_stream_write_space() in case we reduced the backlog so
userspace task blocked in sendmsg or poll will be woken up.

This isn't an issue if the send buffer is large, but it is when
SO_SNDBUF is used to reduce it to a lower value.

Note we can still get a deadlock for low SO_SNDBUF values in
case both sides of the connection write to the socket: both could
be blocked due to wmem being too small -- and current mptcp stack
will only increment mptcp ack_seq on recv.

This doesn't happen with the selftest as it uses poll() and
will always call recv if there is data to read.

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>
2020-03-29 22:14:48 -07:00
Paolo Abeni b51f9b80c0 mptcp: introduce MPTCP retransmission timer
The timer will be used to schedule retransmission. It's
frequency is based on the current subflow RTO estimation and
is reset on every una_seq update

The timer is clearer for good by __mptcp_clear_xmit()

Also clean MPTCP rtx queue before each transmission.

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>
2020-03-29 22:14:48 -07:00
Paolo Abeni 18b683bff8 mptcp: queue data for mptcp level retransmission
Keep the send page fragment on an MPTCP level retransmission queue.
The queue entries are allocated inside the page frag allocator,
acquiring an additional reference to the page for each list entry.

Also switch to a custom page frag refill function, to ensure that
the current page fragment can always host an MPTCP rtx queue entry.

The MPTCP rtx queue is flushed at disconnect() and close() time

Note that now we need to call __mptcp_init_sock() regardless of mptcp
enable status, as the destructor will try to walk the rtx_queue.

v2 -> v3:
 - remove 'inline' in foo.c files (David S. Miller)

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>
2020-03-29 22:14:48 -07:00
Paolo Abeni cc9d256698 mptcp: update per unacked sequence on pkt reception
So that we keep per unacked sequence number consistent; since
we update per msk data, use an atomic64 cmpxchg() to protect
against concurrent updates from multiple subflows.

Initialize the snd_una at connect()/accept() time.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
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>
2020-03-29 22:14:48 -07:00
Peter Krystad 926bdeab55 mptcp: Implement path manager interface commands
Fill in more path manager functionality by adding a worker function and
modifying the related stub functions to schedule the worker.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Peter Krystad ec3edaa7ca mptcp: Add handling of outgoing MP_JOIN requests
Subflow creation may be initiated by the path manager when
the primary connection is fully established and a remote
address has been received via ADD_ADDR.

Create an in-kernel sock and use kernel_connect() to
initiate connection.

Passive sockets can't acquire the mptcp socket lock at
subflow creation time, so an additional list protected by
a new spinlock is used to track the MPJ subflows.

Such list is spliced into conn_list tail every time the msk
socket lock is acquired, so that it will not interfere
with data flow on the original connection.

Data flow and connection failover not addressed by this commit.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Peter Krystad f296234c98 mptcp: Add handling of incoming MP_JOIN requests
Process the MP_JOIN option in a SYN packet with the same flow
as MP_CAPABLE but when the third ACK is received add the
subflow to the MPTCP socket subflow list instead of adding it to
the TCP socket accept queue.

The subflow is added at the end of the subflow list so it will not
interfere with the existing subflows operation and no data is
expected to be transmitted on it.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Peter Krystad 1b1c7a0ef7 mptcp: Add path manager interface
Add enough of a path manager interface to allow sending of ADD_ADDR
when an incoming MPTCP connection is created. Capable of sending only
a single IPv4 ADD_ADDR option. The 'pm_data' element of the connection
sock will need to be expanded to handle multiple interfaces and IPv6.
Partial processing of the incoming ADD_ADDR is included so the path
manager notification of that event happens at the proper time, which
involves validating the incoming address information.

This is a skeleton interface definition for events generated by
MPTCP.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Peter Krystad 3df523ab58 mptcp: Add ADD_ADDR handling
Add handling for sending and receiving the ADD_ADDR, ADD_ADDR6,
and RM_ADDR suboptions.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Paolo Abeni 0be534f5c0 mptcp: rename fourth ack field
The name is misleading, it actually tracks the 'fully established'
status.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-19 20:19:34 -07:00
Paolo Abeni 58b0991962 mptcp: create msk early
This change moves the mptcp socket allocation from mptcp_accept() to
subflow_syn_recv_sock(), so that subflow->conn is now always set
for the non fallback scenario.

It allows cleaning up a bit mptcp_accept() reducing the additional
locking and will allow fourther cleanup in the next patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-15 00:19:03 -07:00
Mat Martineau 76c42a29c0 mptcp: Use per-subflow storage for DATA_FIN sequence number
Instead of reading the MPTCP-level sequence number when sending DATA_FIN,
store the data in the subflow so it can be safely accessed when the
subflow TCP headers are written to the packet without the MPTCP-level
lock held. This also allows the MPTCP-level socket to close individual
subflows without closing the MPTCP connection.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-03 17:01:43 -08:00
Florian Westphal 2e52213c79 mptcp: avoid work queue scheduling if possible
We can't lock_sock() the mptcp socket from the subflow data_ready callback,
it would result in ABBA deadlock with the subflow socket lock.

We can however grab the spinlock: if that succeeds and the mptcp socket
is not owned at the moment, we can process the new skbs right away
without deferring this to the work queue.

This avoids the schedule_work and hence the small delay until the
work item is processed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26 20:46:26 -08:00
Florian Westphal bfae9dae44 mptcp: remove mptcp_read_actor
Only used to discard stale data from the subflow, so move
it where needed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26 20:46:26 -08:00
Paolo Abeni 8099201715 mptcp: add work queue skeleton
Will be extended with functionality in followup patches.
Initial user is moving skbs from subflows receive queue to
the mptcp-level receive queue.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26 20:46:26 -08:00
Florian Westphal 101f6f851e mptcp: add and use mptcp_data_ready helper
allows us to schedule the work queue to drain the ssk receive queue in
a followup patch.

This is needed to avoid sending all-to-pessimistic mptcp-level
acknowledgements.  At this time, the ack_seq is what was last read by
userspace instead of the highest in-sequence number queued for reading.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26 20:46:26 -08:00
Florian Westphal d99bfed58d mptcp: fix bogus socket flag values
Dan Carpenter reports static checker warnings due to bogus BIT() usage:

net/mptcp/subflow.c:571 subflow_write_space() warn: test_bit() takes a bit number
net/mptcp/subflow.c:694 subflow_state_change() warn: test_bit() takes a bit number
net/mptcp/protocol.c:261 ssk_check_wmem() warn: test_bit() takes a bit number
[..]

This is harmless (we use bits 1 & 2 instead of 0 and 1), but would
break eventually when adding BIT(5) (or 6, depends on size of 'long').

Just use 0 and 1, the values are only passed to test/set/clear_bit
functions.

Fixes: 648ef4b886 ("mptcp: Implement MPTCP receive path")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-18 12:05:53 -08:00
Paolo Abeni 8ab183deb2 mptcp: cope with later TCP fallback
With MPTCP v1, passive connections can fallback to TCP after the
subflow becomes established:

syn + MP_CAPABLE ->
               <- syn, ack + MP_CAPABLE

ack, seq = 3    ->
        // OoO packet is accepted because in-sequence
        // passive socket is created, is in ESTABLISHED
	// status and tentatively as MP_CAPABLE

ack, seq = 2     ->
        // no MP_CAPABLE opt, subflow should fallback to TCP

We can't use the 'subflow' socket fallback, as we don't have
it available for passive connection.

Instead, when the fallback is detected, replace the mptcp
socket with the underlying TCP subflow. Beyond covering
the above scenario, it makes a TCP fallback socket as efficient
as plain TCP ones.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:08 +01:00
Christoph Paasch d22f4988ff mptcp: process MP_CAPABLE data option
This patch implements the handling of MP_CAPABLE + data option, as per
RFC 6824 bis / RFC 8684: MPTCP v1.

On the server side we can receive the remote key after that the connection
is established. We need to explicitly track the 'missing remote key'
status and avoid emitting a mptcp ack until we get such info.

When a late/retransmitted/OoO pkt carrying MP_CAPABLE[+data] option
is received, we have to propagate the mptcp seq number info to
the msk socket. To avoid ABBA locking issue, explicitly check for
that in recvmsg(), where we own msk and subflow sock locks.

The above also means that an established mp_capable subflow - still
waiting for the remote key - can be 'downgraded' to plain TCP.

Such change could potentially block a reader waiting for new data
forever - as they hook to msk, while later wake-up after the downgrade
will be on subflow only.

The above issue is not handled here, we likely have to get rid of
msk->fallback to handle that cleanly.

Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:08 +01:00
Christoph Paasch cc7972ea19 mptcp: parse and emit MP_CAPABLE option according to v1 spec
This implements MP_CAPABLE options parsing and writing according
to RFC 6824 bis / RFC 8684: MPTCP v1.

Local key is sent on syn/ack, and both keys are sent on 3rd ack.
MP_CAPABLE messages len are updated accordingly. We need the skbuff to
correctly emit the above, so we push the skbuff struct as an argument
all the way from tcp code to the relevant mptcp callbacks.

When processing incoming MP_CAPABLE + data, build a full blown DSS-like
map info, to simplify later processing.  On child socket creation, we
need to record the remote key, if available.

Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:08 +01:00
Paolo Abeni 65492c5a6a mptcp: move from sha1 (v0) to sha256 (v1)
For simplicity's sake use directly sha256 primitives (and pull them
as a required build dep).
Add optional, boot-time self-tests for the hmac function.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:08 +01:00
Matthieu Baerts 784325e9f0 mptcp: new sysctl to control the activation per NS
New MPTCP sockets will return -ENOPROTOOPT if MPTCP support is disabled
for the current net namespace.

We are providing here a way to control access to the feature for those
that need to turn it on or off.

The value of this new sysctl can be different per namespace. We can then
restrict the usage of MPTCP to the selected NS. In case of serious
issues with MPTCP, administrators can now easily turn MPTCP off.

Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:08 +01:00
Florian Westphal 1891c4a076 mptcp: add subflow write space signalling and mptcp_poll
Add new SEND_SPACE flag to indicate that a subflow has enough space to
accept more data for transmission.

It gets cleared at the end of mptcp_sendmsg() in case ssk has run
below the free watermark.

It is (re-set) from the wspace callback.

This allows us to use msk->flags to determine the poll mask.

Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:08 +01:00
Mat Martineau 648ef4b886 mptcp: Implement MPTCP receive path
Parses incoming DSS options and populates outgoing MPTCP ACK
fields. MPTCP fields are parsed from the TCP option header and placed in
an skb extension, allowing the upper MPTCP layer to access MPTCP
options after the skb has gone through the TCP stack.

The subflow implements its own data_ready() ops, which ensures that the
pending data is in sequence - according to MPTCP seq number - dropping
out-of-seq skbs. The DATA_READY bit flag is set if this is the case.
This allows the MPTCP socket layer to determine if more data is
available without having to consult the individual subflows.

It additionally validates the current mapping and propagates EoF events
to the connection socket.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:07 +01:00
Mat Martineau 6d0060f600 mptcp: Write MPTCP DSS headers to outgoing data packets
Per-packet metadata required to write the MPTCP DSS option is written to
the skb_ext area. One write to the socket may contain more than one
packet of data, which is copied to page fragments and mapped in to MPTCP
DSS segments with size determined by the available page fragments and
the maximum mapping length allowed by the MPTCP specification. If
do_tcp_sendpages() splits a DSS segment in to multiple skbs, that's ok -
the later skbs can either have duplicated DSS mapping information or
none at all, and the receiver can handle that.

The current implementation uses the subflow frag cache and tcp
sendpages to avoid excessive code duplication. More work is required to
ensure that it works correctly under memory pressure and to support
MPTCP-level retransmissions.

The MPTCP DSS checksum is not yet implemented.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:07 +01:00
Peter Krystad 79c0949e9a mptcp: Add key generation and token tree
Generate the local keys, IDSN, and token when creating a new socket.
Introduce the token tree to track all tokens in use using a radix tree
with the MPTCP token itself as the index.

Override the rebuild_header callback in inet_connection_sock_af_ops for
creating the local key on a new outgoing connection.

Override the init_req callback of tcp_request_sock_ops for creating the
local key on a new incoming connection.

Will be used to obtain the MPTCP parent socket to handle incoming joins.

Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:07 +01:00
Peter Krystad cec37a6e41 mptcp: Handle MP_CAPABLE options for outgoing connections
Add hooks to tcp_output.c to add MP_CAPABLE to an outgoing SYN request,
to capture the MP_CAPABLE in the received SYN-ACK, to add MP_CAPABLE to
the final ACK of the three-way handshake.

Use the .sk_rx_dst_set() handler in the subflow proto to capture when the
responding SYN-ACK is received and notify the MPTCP connection layer.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:07 +01:00
Peter Krystad 2303f994b3 mptcp: Associate MPTCP context with TCP socket
Use ULP to associate a subflow_context structure with each TCP subflow
socket. Creating these sockets requires new bind and connect functions
to make sure ULP is set up immediately when the subflow sockets are
created.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:07 +01:00
Peter Krystad eda7acddf8 mptcp: Handle MPTCP TCP options
Add hooks to parse and format the MP_CAPABLE option.

This option is handled according to MPTCP version 0 (RFC6824).
MPTCP version 1 MP_CAPABLE (RFC6824bis/RFC8684) will be added later in
coordination with related code changes.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:07 +01:00
Mat Martineau f870fa0b57 mptcp: Add MPTCP socket stubs
Implements the infrastructure for MPTCP sockets.

MPTCP sockets open one in-kernel TCP socket per subflow. These subflow
sockets are only managed by the MPTCP socket that owns them and are not
visible from userspace. This commit allows a userspace program to open
an MPTCP socket with:

  sock = socket(AF_INET, SOCK_STREAM, IPPROTO_MPTCP);

The resulting socket is simply a wrapper around a single regular TCP
socket, without any of the MPTCP protocol implemented over the wire.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 13:44:07 +01:00