Commit Graph

77 Commits

Author SHA1 Message Date
Geert Uytterhoeven
389b8fb3c4 mptcp: MPTCP_HMAC_TEST should depend on MPTCP
As the MPTCP HMAC test is integrated into the MPTCP code, it can be
built only when MPTCP is enabled.  Hence when MPTCP is disabled, asking
the user if the test code should be enabled is futile.

Wrap the whole block of MPTCP-specific config options inside a check for
MPTCP.  While at it, drop the "default n" for MPTCP_HMAC_TEST, as that
is the default anyway.

Fixes: 65492c5a6a ("mptcp: move from sha1 (v0) to sha256 (v1)")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-30 09:55:37 +01:00
Geert Uytterhoeven
8e1974a2a0 mptcp: Fix incorrect IPV6 dependency check
If CONFIG_MPTCP=y, CONFIG_MPTCP_IPV6=n, and CONFIG_IPV6=m:

    net/mptcp/protocol.o: In function `__mptcp_tcp_fallback':
    protocol.c:(.text+0x786): undefined reference to `inet6_stream_ops'

Fix this by checking for CONFIG_MPTCP_IPV6 instead of CONFIG_IPV6, like
is done in all other places in the mptcp code.

Fixes: 8ab183deb2 ("mptcp: cope with later TCP fallback")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-30 09:55:37 +01:00
Florian Westphal
ae2dd71649 mptcp: handle tcp fallback when using syn cookies
We can't deal with syncookie mode yet, the syncookie rx path will create
tcp reqsk, i.e. we get OOB access because we treat tcp reqsk as mptcp reqsk one:

TCP: SYN flooding on port 20002. Sending cookies.
BUG: KASAN: slab-out-of-bounds in subflow_syn_recv_sock+0x451/0x4d0 net/mptcp/subflow.c:191
Read of size 1 at addr ffff8881167bc148 by task syz-executor099/2120
 subflow_syn_recv_sock+0x451/0x4d0 net/mptcp/subflow.c:191
 tcp_get_cookie_sock+0xcf/0x520 net/ipv4/syncookies.c:209
 cookie_v6_check+0x15a5/0x1e90 net/ipv6/syncookies.c:252
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1123 [inline]
 [..]

Bug can be reproduced via "sysctl net.ipv4.tcp_syncookies=2".

Note that MPTCP should work with syncookies (4th ack would carry needed
state), but it appears better to sort that out in -next so do tcp
fallback for now.

I removed the MPTCP ifdef for tcp_rsk "is_mptcp" member because
if (IS_ENABLED()) is easier to read than "#ifdef IS_ENABLED()/#endif" pair.

Cc: Eric Dumazet <edumazet@google.com>
Fixes: cec37a6e41 ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-29 17:45:20 +01:00
Florian Westphal
b2c5b614ca mptcp: avoid a lockdep splat when mcast group was joined
syzbot triggered following lockdep splat:

ffffffff82d2cd40 (rtnl_mutex){+.+.}, at: ip_mc_drop_socket+0x52/0x180
but task is already holding lock:
ffff8881187a2310 (sk_lock-AF_INET){+.+.}, at: mptcp_close+0x18/0x30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:
-> #1 (sk_lock-AF_INET){+.+.}:
       lock_acquire+0xee/0x230
       lock_sock_nested+0x89/0xc0
       do_ip_setsockopt.isra.0+0x335/0x22f0
       ip_setsockopt+0x35/0x60
       tcp_setsockopt+0x5d/0x90
       __sys_setsockopt+0xf3/0x190
       __x64_sys_setsockopt+0x61/0x70
       do_syscall_64+0x72/0x300
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (rtnl_mutex){+.+.}:
       check_prevs_add+0x2b7/0x1210
       __lock_acquire+0x10b6/0x1400
       lock_acquire+0xee/0x230
       __mutex_lock+0x120/0xc70
       ip_mc_drop_socket+0x52/0x180
       inet_release+0x36/0xe0
       __sock_release+0xfd/0x130
       __mptcp_close+0xa8/0x1f0
       inet_release+0x7f/0xe0
       __sock_release+0x69/0x130
       sock_close+0x18/0x20
       __fput+0x179/0x400
       task_work_run+0xd5/0x110
       do_exit+0x685/0x1510
       do_group_exit+0x7e/0x170
       __x64_sys_exit_group+0x28/0x30
       do_syscall_64+0x72/0x300
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

The trigger is:
  socket(AF_INET, SOCK_STREAM, 0x106 /* IPPROTO_MPTCP */) = 4
  setsockopt(4, SOL_IP, MCAST_JOIN_GROUP, {gr_interface=7, gr_group={sa_family=AF_INET, sin_port=htons(20003), sin_addr=inet_addr("224.0.0.2")}}, 136) = 0
  exit(0)

Which results in a call to rtnl_lock while we are holding
the parent mptcp socket lock via
mptcp_close -> lock_sock(msk) -> inet_release -> ip_mc_drop_socket -> rtnl_lock().

>From lockdep point of view we thus have both
'rtnl_lock; lock_sock' and 'lock_sock; rtnl_lock'.

Fix this by stealing the msk conn_list and doing the subflow close
without holding the msk lock.

Fixes: cec37a6e41 ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-29 17:45:20 +01:00
Florian Westphal
50e741bb3b mptcp: fix panic on user pointer access
Its not possible to call the kernel_(s|g)etsockopt functions here,
the address points to user memory:

General protection fault in user access. Non-canonical address?
WARNING: CPU: 1 PID: 5352 at arch/x86/mm/extable.c:77 ex_handler_uaccess+0xba/0xe0 arch/x86/mm/extable.c:77
Kernel panic - not syncing: panic_on_warn set ...
[..]
Call Trace:
 fixup_exception+0x9d/0xcd arch/x86/mm/extable.c:178
 general_protection+0x2d/0x40 arch/x86/entry/entry_64.S:1202
 do_ip_getsockopt+0x1f6/0x1860 net/ipv4/ip_sockglue.c:1323
 ip_getsockopt+0x87/0x1c0 net/ipv4/ip_sockglue.c:1561
 tcp_getsockopt net/ipv4/tcp.c:3691 [inline]
 tcp_getsockopt+0x8c/0xd0 net/ipv4/tcp.c:3685
 kernel_getsockopt+0x121/0x1f0 net/socket.c:3736
 mptcp_getsockopt+0x69/0x90 net/mptcp/protocol.c:830
 __sys_getsockopt+0x13a/0x220 net/socket.c:2175

We can call tcp_get/setsockopt functions instead.  Doing so fixes
crashing, but still leaves rtnl related lockdep splat:

     WARNING: possible circular locking dependency detected
     5.5.0-rc6 #2 Not tainted
     ------------------------------------------------------
     syz-executor.0/16334 is trying to acquire lock:
     ffffffff84f7a080 (rtnl_mutex){+.+.}, at: do_ip_setsockopt.isra.0+0x277/0x3820 net/ipv4/ip_sockglue.c:644
     but task is already holding lock:
     ffff888116503b90 (sk_lock-AF_INET){+.+.}, at: lock_sock include/net/sock.h:1516 [inline]
     ffff888116503b90 (sk_lock-AF_INET){+.+.}, at: mptcp_setsockopt+0x28/0x90 net/mptcp/protocol.c:1284

     which lock already depends on the new lock.
     the existing dependency chain (in reverse order) is:

     -> #1 (sk_lock-AF_INET){+.+.}:
            lock_sock_nested+0xca/0x120 net/core/sock.c:2944
            lock_sock include/net/sock.h:1516 [inline]
            do_ip_setsockopt.isra.0+0x281/0x3820 net/ipv4/ip_sockglue.c:645
            ip_setsockopt+0x44/0xf0 net/ipv4/ip_sockglue.c:1248
            udp_setsockopt+0x5d/0xa0 net/ipv4/udp.c:2639
            __sys_setsockopt+0x152/0x240 net/socket.c:2130
            __do_sys_setsockopt net/socket.c:2146 [inline]
            __se_sys_setsockopt net/socket.c:2143 [inline]
            __x64_sys_setsockopt+0xba/0x150 net/socket.c:2143
            do_syscall_64+0xbd/0x5b0 arch/x86/entry/common.c:294
            entry_SYSCALL_64_after_hwframe+0x49/0xbe

     -> #0 (rtnl_mutex){+.+.}:
            check_prev_add kernel/locking/lockdep.c:2475 [inline]
            check_prevs_add kernel/locking/lockdep.c:2580 [inline]
            validate_chain kernel/locking/lockdep.c:2970 [inline]
            __lock_acquire+0x1fb2/0x4680 kernel/locking/lockdep.c:3954
            lock_acquire+0x127/0x330 kernel/locking/lockdep.c:4484
            __mutex_lock_common kernel/locking/mutex.c:956 [inline]
            __mutex_lock+0x158/0x1340 kernel/locking/mutex.c:1103
            do_ip_setsockopt.isra.0+0x277/0x3820 net/ipv4/ip_sockglue.c:644
            ip_setsockopt+0x44/0xf0 net/ipv4/ip_sockglue.c:1248
            tcp_setsockopt net/ipv4/tcp.c:3159 [inline]
            tcp_setsockopt+0x8c/0xd0 net/ipv4/tcp.c:3153
            kernel_setsockopt+0x121/0x1f0 net/socket.c:3767
            mptcp_setsockopt+0x69/0x90 net/mptcp/protocol.c:1288
            __sys_setsockopt+0x152/0x240 net/socket.c:2130
            __do_sys_setsockopt net/socket.c:2146 [inline]
            __se_sys_setsockopt net/socket.c:2143 [inline]
            __x64_sys_setsockopt+0xba/0x150 net/socket.c:2143
            do_syscall_64+0xbd/0x5b0 arch/x86/entry/common.c:294
            entry_SYSCALL_64_after_hwframe+0x49/0xbe

     other info that might help us debug this:

      Possible unsafe locking scenario:

            CPU0                    CPU1
            ----                    ----
       lock(sk_lock-AF_INET);
                                    lock(rtnl_mutex);
                                    lock(sk_lock-AF_INET);
       lock(rtnl_mutex);

The lockdep complaint is because we hold mptcp socket lock when calling
the sk_prot get/setsockopt handler, and those might need to acquire the
rtnl mutex.  Normally, order is:

rtnl_lock(sk) -> lock_sock

Whereas for mptcp the order is

lock_sock(mptcp_sk) rtnl_lock -> lock_sock(subflow_sk)

We can avoid this by releasing the mptcp socket lock early, but, as Paolo
points out, we need to get/put the subflow socket refcount before doing so
to avoid race with concurrent close().

Fixes: 717e79c867 ("mptcp: Add setsockopt()/getsockopt() socket operations")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-29 17:45:19 +01:00
Florian Westphal
c9fd9c5f4b mptcp: defer freeing of cached ext until last moment
access to msk->cached_ext is only legal if the msk is locked or all
concurrent accesses are impossible.

Furthermore, once we start to tear down, we must make sure nothing else
can step in and allocate a new cached ext.

So place this code in the destroy callback where it belongs.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-29 17:45:19 +01:00
David S. Miller
f6f7d8cf55 mptcp: Fix build with PROC_FS disabled.
net/mptcp/subflow.c: In function ‘mptcp_subflow_create_socket’:
net/mptcp/subflow.c:624:25: error: ‘struct netns_core’ has no member named ‘sock_inuse’

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-29 10:39:23 +01:00
Mat Martineau
edc7e4898d mptcp: Fix code formatting
checkpatch.pl had a few complaints in the last set of MPTCP patches:

ERROR: code indent should use tabs where possible
+^I         subflow, sk->sk_family, icsk->icsk_af_ops, target, mapped);$

CHECK: Comparison to NULL could be written "!new_ctx"
+	if (new_ctx == NULL) {

ERROR: "foo * bar" should be "foo *bar"
+static const struct proto_ops * tcp_proto_ops(struct sock *sk)

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-25 08:14:39 +01:00
Florian Westphal
e42f1ac626 mptcp: do not inherit inet proto ops
We need to initialise the struct ourselves, else we expose tcp-specific
callbacks such as tcp_splice_read which will then trigger splat because
the socket is an mptcp one:

BUG: KASAN: slab-out-of-bounds in tcp_mstamp_refresh+0x80/0xa0 net/ipv4/tcp_output.c:57
Write of size 8 at addr ffff888116aa21d0 by task syz-executor.0/5478

CPU: 1 PID: 5478 Comm: syz-executor.0 Not tainted 5.5.0-rc6 #3
Call Trace:
 tcp_mstamp_refresh+0x80/0xa0 net/ipv4/tcp_output.c:57
 tcp_rcv_space_adjust+0x72/0x7f0 net/ipv4/tcp_input.c:612
 tcp_read_sock+0x622/0x990 net/ipv4/tcp.c:1674
 tcp_splice_read+0x20b/0xb40 net/ipv4/tcp.c:791
 do_splice+0x1259/0x1560 fs/splice.c:1205

To prevent build error with ipv6, add the recv/sendmsg function
declaration to ipv6.h.  The functions are already accessible "thanks"
to retpoline related work, but they are currently only made visible
by socket.c specific INDIRECT_CALLABLE macros.

Reported-by: Christoph Paasch <cpaasch@apple.com>
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>
2020-01-25 08:14:39 +01:00
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
Paolo Abeni
57040755a3 mptcp: allow collapsing consecutive sendpages on the same substream
If the current sendmsg() lands on the same subflow we used last, we
can try to collapse the data.

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
Paolo Abeni
7a6a6cbc3e mptcp: recvmsg() can drain data from multiple subflows
With the previous patch in place, the msk can detect which subflow
has the current map with a simple walk, let's update the main
loop to always select the 'current' subflow. The exit conditions now
closely mirror tcp_recvmsg() to get expected timeout and signal
behavior.

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: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
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
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
717e79c867 mptcp: Add setsockopt()/getsockopt() socket operations
set/getsockopt behaviour with multiple subflows is undefined.
Therefore, for now, we return -EOPNOTSUPP unless we're in fallback mode.

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
214984901a mptcp: Add shutdown() socket operation
Call shutdown on all subflows in use on the given socket, or on the
fallback socket.

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
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
cf7da0d66c mptcp: Create SUBFLOW socket for incoming connections
Add subflow_request_sock type that extends tcp_request_sock
and add an is_mptcp flag to tcp_request_sock distinguish them.

Override the listen() and accept() methods of the MPTCP
socket proto_ops so they may act on the subflow socket.

Override the conn_request() and syn_recv_sock() handlers
in the inet_connection_sock to handle incoming MPTCP
SYNs and the ACK to the response SYN.

Add handling in tcp_output.c to add MP_CAPABLE to an outgoing
SYN-ACK response for a subflow_request_sock.

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: 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: 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