mptcp: drop duplicate header inclusions

The headers net/tcp.h, net/genetlink.h and uapi/linux/mptcp.h are included
in protocol.h already, no need to include them again directly. This patch
removes these duplicate header inclusions.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-1-c436ba5e569b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: fix possible deadlock in subflow diag

Syzbot and Eric reported a lockdep splat in the subflow diag:

WARNING: possible circular locking dependency detected
6.8.0-rc4-syzkaller-00212-g40b9385dd8e6 #0 Not tainted

syz-executor.2/24141 is trying to acquire lock:
ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at:
tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at:
tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137

but task is already holding lock:
ffffc9000135e488 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock
include/linux/spinlock.h:351 [inline]
ffffc9000135e488 (&h->lhash2[i].lock){+.+.}-{2:2}, at:
inet_diag_dump_icsk+0x39f/0x1f80 net/ipv4/inet_diag.c:1038

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&h->lhash2[i].lock){+.+.}-{2:2}:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
__inet_hash+0x335/0xbe0 net/ipv4/inet_hashtables.c:743
inet_csk_listen_start+0x23a/0x320 net/ipv4/inet_connection_sock.c:1261
__inet_listen_sk+0x2a2/0x770 net/ipv4/af_inet.c:217
inet_listen+0xa3/0x110 net/ipv4/af_inet.c:239
rds_tcp_listen_init+0x3fd/0x5a0 net/rds/tcp_listen.c:316
rds_tcp_init_net+0x141/0x320 net/rds/tcp.c:577
ops_init+0x352/0x610 net/core/net_namespace.c:136
__register_pernet_operations net/core/net_namespace.c:1214 [inline]
register_pernet_operations+0x2cb/0x660 net/core/net_namespace.c:1283
register_pernet_device+0x33/0x80 net/core/net_namespace.c:1370
rds_tcp_init+0x62/0xd0 net/rds/tcp.c:735
do_one_initcall+0x238/0x830 init/main.c:1236
do_initcall_level+0x157/0x210 init/main.c:1298
do_initcalls+0x3f/0x80 init/main.c:1314
kernel_init_freeable+0x42f/0x5d0 init/main.c:1551
kernel_init+0x1d/0x2a0 init/main.c:1441
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242

-> #0 (k-sk_lock-AF_INET6){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
lock_sock_fast include/net/sock.h:1723 [inline]
subflow_get_info+0x166/0xd20 net/mptcp/diag.c:28
tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137
inet_sk_diag_fill+0x10ed/0x1e00 net/ipv4/inet_diag.c:345
inet_diag_dump_icsk+0x55b/0x1f80 net/ipv4/inet_diag.c:1061
__inet_diag_dump+0x211/0x3a0 net/ipv4/inet_diag.c:1263
inet_diag_dump_compat+0x1c1/0x2d0 net/ipv4/inet_diag.c:1371
netlink_dump+0x59b/0xc80 net/netlink/af_netlink.c:2264
__netlink_dump_start+0x5df/0x790 net/netlink/af_netlink.c:2370
netlink_dump_start include/linux/netlink.h:338 [inline]
inet_diag_rcv_msg_compat+0x209/0x4c0 net/ipv4/inet_diag.c:1405
sock_diag_rcv_msg+0xe7/0x410
netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:745
____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
___sys_sendmsg net/socket.c:2638 [inline]
__sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77

As noted by Eric we can break the lock dependency chain avoid
dumping any extended info for the mptcp subflow listener:
nothing actually useful is presented there.

Fixes: b8adb69a7d29 ("mptcp: fix lockless access in subflow ULP diag")
Cc: stable@vger.kernel.org
Reported-by: Eric Dumazet <edumazet@google.com>
Closes: https://lore.kernel.org/netdev/CANn89iJ=Oecw6OZDwmSYc9HJKQ_G32uN11L+oUcMu+TOD5Xiaw@mail.gmail.com/
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240223-upstream-net-20240223-misc-fixes-v1-9-162e87e48497@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: fix data races on local_id

The local address id is accessed lockless by the NL PM, add
all the required ONCE annotation. There is a caveat: the local
id can be initialized late in the subflow life-cycle, and its
validity is controlled by the local_id_valid flag.

Remove such flag and encode the validity in the local_id field
itself with negative value before initialization. That allows
accessing the field consistently with a single read operation.

Fixes: 0ee4261a3681 ("mptcp: implement mptcp_pm_remove_subflow")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: fix lockless access in subflow ULP diag

Since the introduction of the subflow ULP diag interface, the
dump callback accessed all the subflow data with lockless.

We need either to annotate all the read and write operation accordingly,
or acquire the subflow socket lock. Let's do latter, even if slower, to
avoid a diffstat havoc.

Fixes: 5147dfb50832 ("mptcp: allow dumping subflow context to userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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>