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2021-12-17mptcp: enforce HoL-blocking estimationPaolo Abeni
The MPTCP packet scheduler has sub-optimal behavior with asymmetric subflows: if the faster subflow-level cwin is closed, the packet scheduler can enqueue "too much" data on a slower subflow. When all the data on the faster subflow is acked, if the mptcp-level cwin is closed, and link utilization becomes suboptimal. The solution is implementing blest-like[1] HoL-blocking estimation, transmitting only on the subflow with the shorter estimated time to flush the queued memory. If such subflows cwin is closed, we wait even if other subflows are available. This is quite simpler than the original blest implementation, as we leverage the pacing rate provided by the TCP socket. To get a more accurate estimation for the subflow linger-time, we maintain a per-subflow weighted average of such info. Additionally drop magic numbers usage in favor of newly defined macros and use more meaningful names for status variable. [1] http://dl.ifip.org/db/conf/networking/networking2016/1570234725.pdf Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/137 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>
2021-12-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-14mptcp: fix deadlock in __mptcp_push_pending()Maxim Galaganov
__mptcp_push_pending() may call mptcp_flush_join_list() with subflow socket lock held. If such call hits mptcp_sockopt_sync_all() then subsequently __mptcp_sockopt_sync() could try to lock the subflow socket for itself, causing a deadlock. sysrq: Show Blocked State task:ss-server state:D stack: 0 pid: 938 ppid: 1 flags:0x00000000 Call Trace: <TASK> __schedule+0x2d6/0x10c0 ? __mod_memcg_state+0x4d/0x70 ? csum_partial+0xd/0x20 ? _raw_spin_lock_irqsave+0x26/0x50 schedule+0x4e/0xc0 __lock_sock+0x69/0x90 ? do_wait_intr_irq+0xa0/0xa0 __lock_sock_fast+0x35/0x50 mptcp_sockopt_sync_all+0x38/0xc0 __mptcp_push_pending+0x105/0x200 mptcp_sendmsg+0x466/0x490 sock_sendmsg+0x57/0x60 __sys_sendto+0xf0/0x160 ? do_wait_intr_irq+0xa0/0xa0 ? fpregs_restore_userregs+0x12/0xd0 __x64_sys_sendto+0x20/0x30 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9ba546c2d0 RSP: 002b:00007ffdc3b762d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f9ba56c8060 RCX: 00007f9ba546c2d0 RDX: 000000000000077a RSI: 0000000000e5e180 RDI: 0000000000000234 RBP: 0000000000cc57f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9ba56c8060 R13: 0000000000b6ba60 R14: 0000000000cc7840 R15: 41d8685b1d7901b8 </TASK> Fix the issue by using __mptcp_flush_join_list() instead of plain mptcp_flush_join_list() inside __mptcp_push_pending(), as suggested by Florian. The sockopt sync will be deferred to the workqueue. Fixes: 1b3e7ede1365 ("mptcp: setsockopt: handle SO_KEEPALIVE and SO_PRIORITY") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/244 Suggested-by: Florian Westphal <fw@strlen.de> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Maxim Galaganov <max@internet.ru> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-14mptcp: clear 'kern' flag from fallback socketsFlorian Westphal
The mptcp ULP extension relies on sk->sk_sock_kern being set correctly: It prevents setsockopt(fd, IPPROTO_TCP, TCP_ULP, "mptcp", 6); from working for plain tcp sockets (any userspace-exposed socket). But in case of fallback, accept() can return a plain tcp sk. In such case, sk is still tagged as 'kernel' and setsockopt will work. This will crash the kernel, The subflow extension has a NULL ctx->conn mptcp socket: BUG: KASAN: null-ptr-deref in subflow_data_ready+0x181/0x2b0 Call Trace: tcp_data_ready+0xf8/0x370 [..] Fixes: cf7da0d66cc1 ("mptcp: Create SUBFLOW socket for incoming connections") 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>
2021-12-07mptcp: expose mptcp_check_and_set_pendingMaxim Galaganov
Expose the mptcp_check_and_set_pending() function for use inside MPTCP sockopt code. The next patch will call it when TCP_CORK is cleared or TCP_NODELAY is set on the MPTCP socket in order to push pending data from mptcp_release_cb(). Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Maxim Galaganov <max@internet.ru> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-07mptcp: add SIOCINQ, OUTQ and OUTQNSD ioctlsFlorian Westphal
Allows to query in-sequence data ready for read(), total bytes in write queue and total bytes in write queue that have not yet been sent. v2: remove unneeded READ_ONCE() (Paolo Abeni) v3: check for new data unconditionally in SIOCINQ ioctl (Mat Martineau) 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>
2021-12-07mptcp: add TCP_INQ cmsg supportFlorian Westphal
Support the TCP_INQ setsockopt. This is a boolean that tells recvmsg path to include the remaining in-sequence bytes in the cmsg data. v2: do not use CB(skb)->offset, increment map_seq instead (Paolo Abeni) v3: adjust CB(skb)->map_seq when taking skb from ofo queue (Paolo Abeni) Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/224 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>
2021-11-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
drivers/net/ipa/ipa_main.c 8afc7e471ad3 ("net: ipa: separate disabling setup from modem stop") 76b5fbcd6b47 ("net: ipa: kill ipa_modem_init()") Duplicated include, drop one. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-20mptcp: use delegate action to schedule 3rd ack retransPaolo Abeni
Scheduling a delack in mptcp_established_options_mp() is not a good idea: such function is called by tcp_send_ack() and the pending delayed ack will be cleared shortly after by the tcp_event_ack_sent() call in __tcp_transmit_skb(). Instead use the mptcp delegated action infrastructure to schedule the delayed ack after the current bh processing completes. Additionally moves the schedule_3rdack_retransmission() helper into protocol.c to avoid making it visible in a different compilation unit. Fixes: ec3edaa7ca6ce02f ("mptcp: Add handling of outgoing MP_JOIN requests") 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>
2021-11-16net: cache align tcp_memory_allocated, tcp_sockets_allocatedEric Dumazet
tcp_memory_allocated and tcp_sockets_allocated often share a common cache line, source of false sharing. Also take care of udp_memory_allocated and mptcp_sockets_allocated. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-28tcp: factorize ip_summed settingEric Dumazet
Setting skb->ip_summed to CHECKSUM_PARTIAL can be centralized in tcp_stream_alloc_skb() and __mptcp_do_alloc_tx_skb() instead of being done multiple times. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-28tcp: no longer set skb->reserved_tailroomEric Dumazet
TCP/MPTCP sendmsg() no longer puts payload in skb->head, we can remove not needed code. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-28tcp: cleanup tcp_remove_empty_skb() useEric Dumazet
All tcp_remove_empty_skb() callers now use tcp_write_queue_tail() for the skb argument, we can therefore factorize code. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-27mptcp: drop unused sk in mptcp_push_releaseGeliang Tang
Since mptcp_set_timeout() had removed from mptcp_push_release() in commit 33d41c9cd74c5 ("mptcp: more accurate timeout"), the argument sk in mptcp_push_release() became useless. Let's drop it. Fixes: 33d41c9cd74c5 ("mptcp: more accurate timeout") Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Geliang Tang <geliang.tang@suse.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-27mptcp: allocate fwd memory separately on the rx and tx pathPaolo Abeni
All the mptcp receive path is protected by the msk socket spinlock. As consequences, the tx path has to play a few tricks to allocate the forward memory without acquiring the spinlock multiple times, making the overall TX path quite complex. This patch tries to clean-up a bit the tx path, using completely separated fwd memory allocation, for the rx and the tx path. The forward memory allocated in the rx path is now accounted in msk->rmem_fwd_alloc and is (still) protected by the msk socket spinlock. To cope with the above we provide a few MPTCP-specific variants for the helpers to charge, uncharge, reclaim and free the forward memory in the receive path. msk->sk_forward_alloc now accounts only the forward memory for the tx path, we can use the plain core sock helper to manipulate it and drop quite a bit of complexity. On memory pressure, both rx and tx fwd memories are reclaimed. 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>
2021-10-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
tools/testing/selftests/net/ioam6.sh 7b1700e009cc ("selftests: net: modify IOAM tests for undef bits") bf77b1400a56 ("selftests: net: Test for the IOAM encapsulation with IPv6") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-08mptcp: fix possible stall on recvmsg()Paolo Abeni
recvmsg() can enter an infinite loop if the caller provides the MSG_WAITALL, the data present in the receive queue is not sufficient to fulfill the request, and no more data is received by the peer. When the above happens, mptcp_wait_data() will always return with no wait, as the MPTCP_DATA_READY flag checked by such function is set and never cleared in such code path. Leveraging the above syzbot was able to trigger an RCU stall: rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=0af/1/0x4000000000000000 softirq=10678/10678 fqs=1 (t=10500 jiffies g=13089 q=109) rcu: rcu_preempt kthread starved for 10497 jiffies! g13089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6236 schedule+0xd3/0x270 kernel/sched/core.c:6315 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8510 Comm: syz-executor827 Not tainted 5.15.0-rc2-next-20210920-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:84 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0xc8/0x180 mm/kasan/generic.c:189 Code: 38 00 74 ed 48 8d 50 08 eb 09 48 83 c0 01 48 39 d0 74 7a 80 38 00 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 <48> 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00 RSP: 0018:ffffc9000cd676c8 EFLAGS: 00000283 RAX: ffffed100e9a110e RBX: ffffed100e9a110f RCX: ffffffff88ea062a RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888074d08870 RBP: ffffed100e9a110e R08: 0000000000000001 R09: ffff888074d08877 R10: ffffed100e9a110e R11: 0000000000000000 R12: ffff888074d08000 R13: ffff888074d08000 R14: ffff888074d08088 R15: ffff888074d08000 FS: 0000555556d8e300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 S: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000180 CR3: 0000000068909000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:101 [inline] test_and_clear_bit include/asm-generic/bitops/instrumented-atomic.h:83 [inline] mptcp_release_cb+0x14a/0x210 net/mptcp/protocol.c:3016 release_sock+0xb4/0x1b0 net/core/sock.c:3204 mptcp_wait_data net/mptcp/protocol.c:1770 [inline] mptcp_recvmsg+0xfd1/0x27b0 net/mptcp/protocol.c:2080 inet6_recvmsg+0x11b/0x5e0 net/ipv6/af_inet6.c:659 sock_recvmsg_nosec net/socket.c:944 [inline] ____sys_recvmsg+0x527/0x600 net/socket.c:2626 ___sys_recvmsg+0x127/0x200 net/socket.c:2670 do_recvmmsg+0x24d/0x6d0 net/socket.c:2764 __sys_recvmmsg net/socket.c:2843 [inline] __do_sys_recvmmsg net/socket.c:2866 [inline] __se_sys_recvmmsg net/socket.c:2859 [inline] __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2859 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc200d2dc39 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 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 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc5758e5a8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc200d2dc39 RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000f0b5ff R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000003 R13: 00007ffc5758e5d0 R14: 00007ffc5758e5c0 R15: 0000000000000003 Fix the issue by replacing the MPTCP_DATA_READY bit with direct inspection of the msk receive queue. Reported-and-tested-by: syzbot+3360da629681aa0d22fe@syzkaller.appspotmail.com Fixes: 7a6a6cbc3e59 ("mptcp: recvmsg() can drain data from multiple subflow") 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>
2021-09-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
drivers/net/phy/bcm7xxx.c d88fd1b546ff ("net: phy: bcm7xxx: Fixed indirect MMD operations") f68d08c437f9 ("net: phy: bcm7xxx: Add EPHY entry for 72165") net/sched/sch_api.c b193e15ac69d ("net: prevent user from passing illegal stab size") 69508d43334e ("net_sched: Use struct_size() and flex_array_size() helpers") Both cases trivial - adjacent code additions. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-30net: introduce and use lock_sock_fast_nested()Paolo Abeni
Syzkaller reported a false positive deadlock involving the nl socket lock and the subflow socket lock: MPTCP: kernel_bind error, err=-98 ============================================ WARNING: possible recursive locking detected 5.15.0-rc1-syzkaller #0 Not tainted -------------------------------------------- syz-executor998/6520 is trying to acquire lock: ffff8880795718a0 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738 but task is already holding lock: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-sk_lock-AF_INET); lock(k-sk_lock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor998/6520: #0: ffffffff8d176c50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x3e0/0x580 net/netlink/genetlink.c:790 #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720 stack backtrace: CPU: 1 PID: 6520 Comm: syz-executor998 Not tainted 5.15.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2944 [inline] check_deadlock kernel/locking/lockdep.c:2987 [inline] validate_chain kernel/locking/lockdep.c:3776 [inline] __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 lock_sock_fast+0x36/0x100 net/core/sock.c:3229 mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431 __sock_release net/socket.c:649 [inline] sock_release+0x87/0x1b0 net/socket.c:677 mptcp_pm_nl_create_listen_socket+0x238/0x2c0 net/mptcp/pm_netlink.c:900 mptcp_nl_cmd_add_addr+0x359/0x930 net/mptcp/pm_netlink.c:1170 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_no_sendpage+0x101/0x150 net/core/sock.c:2980 kernel_sendpage.part.0+0x1a0/0x340 net/socket.c:3504 kernel_sendpage net/socket.c:3501 [inline] sock_sendpage+0xe5/0x140 net/socket.c:1003 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xae9/0x1240 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1314 [inline] __se_sys_sendfile64 fs/read_write.c:1300 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1300 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f215cb69969 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 00 00 90 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 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc96bb3868 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f215cbad072 RCX: 00007f215cb69969 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00007ffc96bb3a08 R09: 00007ffc96bb3a08 R10: 0000000100000002 R11: 0000000000000246 R12: 00007ffc96bb387c R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 the problem originates from uncorrect lock annotation in the mptcp code and is only visible since commit 2dcb96bacce3 ("net: core: Correct the sock::sk_lock.owned lockdep annotations"), but is present since the port-based endpoint support initial implementation. This patch addresses the issue introducing a nested variant of lock_sock_fast() and using it in the relevant code path. Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port") Fixes: 2dcb96bacce3 ("net: core: Correct the sock::sk_lock.owned lockdep annotations") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Reported-and-tested-by: syzbot+1dd53f7a89b299d59eaf@syzkaller.appspotmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-25mptcp: re-arm retransmit timer if data is pendingFlorian Westphal
The retransmit head will be NULL in case there is no in-flight data (meaning all data injected into network has been acked). In that case the retransmit timer is stopped. This is only correct if there is no more pending, not-yet-sent data. If there is, the retransmit timer needs to set the PENDING bit again so that mptcp tries to send the remaining (new) data once a subflow can accept more data. Also, mptcp_subflow_get_retrans() has to be called unconditionally. This function checks for subflows that have become unresponsive and marks them as stale, so in the case where the rtx queue is empty, subflows will never be marked stale which prevents available backup subflows from becoming eligible for transmit. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/226 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: David S. Miller <davem@davemloft.net>
2021-09-25mptcp: remove tx_pending_dataFlorian Westphal
The update on recovery is not correct. msk->tx_pending_data += msk->snd_nxt - rtx_head->data_seq; will update tx_pending_data multiple times when a subflow is declared stale while earlier recovery is still in progress. This means that tx_pending_data will still be positive even after all data as has been transmitted. Rather than fix it, remove this field: there are no consumers. The outstanding data byte count can be computed either via "msk->write_seq - rtx_head->data_seq" or "msk->write_seq - msk->snd_una". The latter is more recent/accurate estimate as rtx_head adjustment is deferred until mptcp lock can be acquired. 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: David S. Miller <davem@davemloft.net>
2021-09-25mptcp: use lockdep_assert_held_once() instead of open-coding itPaolo Abeni
We have a few more places where the mptcp code duplicates lockdep_assert_held_once(). Let's use the existing macro and avoid a bunch of compiler's conditional. 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: David S. Miller <davem@davemloft.net>
2021-09-25mptcp: do not shrink snd_nxt when recoveringFlorian Westphal
When recovering after a link failure, snd_nxt should not be set to a lower value. Else, update of snd_nxt is broken because: msk->snd_nxt += ret; (where ret is number of bytes sent) assumes that snd_nxt always moves forward. After reduction, its possible that snd_nxt update gets out of sync: dfrag we just sent might have had a data sequence number even past recovery_snd_nxt. This change factors the common msk state update to a helper and updates snd_nxt based on the current dfrag data sequence number. The conditional is required for the recovery phase where we may re-transmit old dfrags that are before current snd_nxt. After this change, snd_nxt only moves forward and covers all in-sequence data that was transmitted. recovery_snd_nxt is retained to detect when recovery has completed. Fixes: 1e1d9d6f119c5 ("mptcp: handle pending data on closed subflow") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-23mptcp: stop relying on tcp_tx_skb_cachePaolo Abeni
We want to revert the skb TX cache, but MPTCP is currently using it unconditionally. Rework the MPTCP tx code, so that tcp_tx_skb_cache is not needed anymore: do the whole coalescing check, skb allocation skb initialization/update inside mptcp_sendmsg_frag(), quite alike the current TCP code. 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>
2021-09-23mptcp: ensure tx skbs always have the MPTCP extPaolo Abeni
Due to signed/unsigned comparison, the expression: info->size_goal - skb->len > 0 evaluates to true when the size goal is smaller than the skb size. That results in lack of tx cache refill, so that the skb allocated by the core TCP code lacks the required MPTCP skb extensions. Due to the above, syzbot is able to trigger the following WARN_ON(): WARNING: CPU: 1 PID: 810 at net/mptcp/protocol.c:1366 mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366 Modules linked in: CPU: 1 PID: 810 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366 Code: ff 4c 8b 74 24 50 48 8b 5c 24 58 e9 0f fb ff ff e8 13 44 8b f8 4c 89 e7 45 31 ed e8 98 57 2e fe e9 81 f4 ff ff e8 fe 43 8b f8 <0f> 0b 41 bd ea ff ff ff e9 6f f4 ff ff 4c 89 e7 e8 b9 8e d2 f8 e9 RSP: 0018:ffffc9000531f6a0 EFLAGS: 00010216 RAX: 000000000000697f RBX: 0000000000000000 RCX: ffffc90012107000 RDX: 0000000000040000 RSI: ffffffff88eac9e2 RDI: 0000000000000003 RBP: ffff888078b15780 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff88eac017 R11: 0000000000000000 R12: ffff88801de0a280 R13: 0000000000006b58 R14: ffff888066278280 R15: ffff88803c2fe9c0 FS: 00007fd9f866e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faebcb2f718 CR3: 00000000267cb000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mptcp_push_pending+0x1fb/0x6b0 net/mptcp/protocol.c:1547 mptcp_release_cb+0xfe/0x210 net/mptcp/protocol.c:3003 release_sock+0xb4/0x1b0 net/core/sock.c:3206 sk_stream_wait_memory+0x604/0xed0 net/core/stream.c:145 mptcp_sendmsg+0xc39/0x1bc0 net/mptcp/protocol.c:1749 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:643 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_write_iter+0x2a0/0x3e0 net/socket.c:1057 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x40b/0x640 fs/read_write.c:507 vfs_write+0x7cf/0xae0 fs/read_write.c:594 ksys_write+0x1ee/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: ff ff 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 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd9f866e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 00000000000e7b78 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 0000000000a9fb1f R14: 00007fd9f866e300 R15: 0000000000022000 Fix the issue rewriting the relevant expression to avoid sign-related problems - note: size_goal is always >= 0. Additionally, ensure that the skb in the tx cache always carries the relevant extension. Reported-and-tested-by: syzbot+263a248eec3e875baa7b@syzkaller.appspotmail.com Fixes: 1094c6fe7280 ("mptcp: fix possible divide by zero") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-22mptcp: ensure tx skbs always have the MPTCP extPaolo Abeni
Due to signed/unsigned comparison, the expression: info->size_goal - skb->len > 0 evaluates to true when the size goal is smaller than the skb size. That results in lack of tx cache refill, so that the skb allocated by the core TCP code lacks the required MPTCP skb extensions. Due to the above, syzbot is able to trigger the following WARN_ON(): WARNING: CPU: 1 PID: 810 at net/mptcp/protocol.c:1366 mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366 Modules linked in: CPU: 1 PID: 810 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366 Code: ff 4c 8b 74 24 50 48 8b 5c 24 58 e9 0f fb ff ff e8 13 44 8b f8 4c 89 e7 45 31 ed e8 98 57 2e fe e9 81 f4 ff ff e8 fe 43 8b f8 <0f> 0b 41 bd ea ff ff ff e9 6f f4 ff ff 4c 89 e7 e8 b9 8e d2 f8 e9 RSP: 0018:ffffc9000531f6a0 EFLAGS: 00010216 RAX: 000000000000697f RBX: 0000000000000000 RCX: ffffc90012107000 RDX: 0000000000040000 RSI: ffffffff88eac9e2 RDI: 0000000000000003 RBP: ffff888078b15780 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff88eac017 R11: 0000000000000000 R12: ffff88801de0a280 R13: 0000000000006b58 R14: ffff888066278280 R15: ffff88803c2fe9c0 FS: 00007fd9f866e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faebcb2f718 CR3: 00000000267cb000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mptcp_push_pending+0x1fb/0x6b0 net/mptcp/protocol.c:1547 mptcp_release_cb+0xfe/0x210 net/mptcp/protocol.c:3003 release_sock+0xb4/0x1b0 net/core/sock.c:3206 sk_stream_wait_memory+0x604/0xed0 net/core/stream.c:145 mptcp_sendmsg+0xc39/0x1bc0 net/mptcp/protocol.c:1749 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:643 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_write_iter+0x2a0/0x3e0 net/socket.c:1057 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x40b/0x640 fs/read_write.c:507 vfs_write+0x7cf/0xae0 fs/read_write.c:594 ksys_write+0x1ee/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: ff ff 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 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd9f866e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 00000000000e7b78 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 0000000000a9fb1f R14: 00007fd9f866e300 R15: 0000000000022000 Fix the issue rewriting the relevant expression to avoid sign-related problems - note: size_goal is always >= 0. Additionally, ensure that the skb in the tx cache always carries the relevant extension. Reported-and-tested-by: syzbot+263a248eec3e875baa7b@syzkaller.appspotmail.com Fixes: 1094c6fe7280 ("mptcp: fix possible divide by zero") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-03mptcp: Only send extra TCP acks in eligible socket statesMat Martineau
Recent changes exposed a bug where specifically-timed requests to the path manager netlink API could trigger a divide-by-zero in __tcp_select_window(), as syzkaller does: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 0 PID: 9667 Comm: syz-executor.0 Not tainted 5.14.0-rc6+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:__tcp_select_window+0x509/0xa60 net/ipv4/tcp_output.c:3016 Code: 44 89 ff e8 c9 29 e9 fd 45 39 e7 0f 8d 20 ff ff ff e8 db 28 e9 fd 44 89 e3 e9 13 ff ff ff e8 ce 28 e9 fd 44 89 e0 44 89 e3 99 <f7> 7c 24 04 29 d3 e9 fc fe ff ff e8 b7 28 e9 fd 44 89 f1 48 89 ea RSP: 0018:ffff888031ccf020 EFLAGS: 00010216 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000040000 RDX: 0000000000000000 RSI: ffff88811532c080 RDI: 0000000000000002 RBP: 0000000000000000 R08: ffffffff835807c2 R09: 0000000000000000 R10: 0000000000000004 R11: ffffed1020b92441 R12: 0000000000000000 R13: 1ffff11006399e08 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fa4c8344700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f424000 CR3: 000000003e4e2003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: tcp_select_window net/ipv4/tcp_output.c:264 [inline] __tcp_transmit_skb+0xc00/0x37a0 net/ipv4/tcp_output.c:1351 __tcp_send_ack.part.0+0x3ec/0x760 net/ipv4/tcp_output.c:3972 __tcp_send_ack net/ipv4/tcp_output.c:3978 [inline] tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3978 mptcp_pm_nl_addr_send_ack+0x1ab/0x380 net/mptcp/pm_netlink.c:654 mptcp_pm_remove_addr+0x161/0x200 net/mptcp/pm.c:58 mptcp_nl_remove_id_zero_address+0x197/0x460 net/mptcp/pm_netlink.c:1328 mptcp_nl_cmd_del_addr+0x98b/0xd40 net/mptcp/pm_netlink.c:1359 genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792 netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0x14e/0x190 net/socket.c:724 ____sys_sendmsg+0x709/0x870 net/socket.c:2403 ___sys_sendmsg+0xff/0x170 net/socket.c:2457 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae mptcp_pm_nl_addr_send_ack() was attempting to send a TCP ACK on the first subflow in the MPTCP socket's connection list without validating that the subflow was in a suitable connection state. To address this, always validate subflow state when sending extra ACKs on subflows for address advertisement or subflow priority change. Fixes: 84dfe3677a6f ("mptcp: send out dedicated ADD_ADDR packet") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/229 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> Acked-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-01mptcp: fix possible divide by zeroPaolo Abeni
Florian noted that if mptcp_alloc_tx_skb() allocation fails in __mptcp_push_pending(), we can end-up invoking mptcp_push_release()/tcp_push() with a zero mss, causing a divide by 0 error. This change addresses the issue refactoring the skb allocation code checking if skb collapsing will happen for sure and doing the skb allocation only after such check. Skb allocation will now happen only after the call to tcp_send_mss() which correctly initializes mss_now. As side bonuses we now fill the skb tx cache only when needed, and this also clean-up a bit the output path. v1 -> v2: - use lockdep_assert_held_once() - Jakub - fix indentation - Jakub Reported-by: Florian Westphal <fw@strlen.de> Fixes: 724cfd2ee8aa ("mptcp: allocate TX skbs in msk context") 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>
2021-08-27mptcp: make the locking tx schema more readablePaolo Abeni
Florian noted the locking schema used by __mptcp_push_pending() is hard to follow, let's add some more descriptive comments and drop an unneeded and confusing check. Suggested-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>
2021-08-27mptcp: consolidate in_opt sub-options fields in a bitmaskPaolo Abeni
This makes input options processing more consistent with output ones and will simplify the next patch. Also avoid clearing the suboption field after processing it, since it's not needed. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: add mibs for stale subflows processingPaolo Abeni
This allows monitoring exceptional events like active backup scenarios. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: faster active backup recoveryPaolo Abeni
The msk can use backup subflows to transmit in-sequence data only if there are no other active subflow. On active backup scenario, the MPTCP connection can do forward progress only due to MPTCP retransmissions - rtx can pick backup subflows. This patch introduces a new flag flow MPTCP subflows: if the underlying TCP connection made no progresses for long time, and there are other less problematic subflows available, the given subflow become stale. Stale subflows are not considered active: if all non backup subflows become stale, the MPTCP scheduler can pick backup subflows for plain transmissions. Stale subflows can return in active state, as soon as any reply from the peer is observed. Active backup scenarios can now leverage the available b/w with no restrinction. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: handle pending data on closed subflowPaolo Abeni
The PM can close active subflow, e.g. due to ingress RM_ADDR option. Such subflow could carry data still unacked at the MPTCP-level, both in the write and the rtx_queue, which has never reached the other peer. Currently the mptcp-level retransmission will deliver such data, but at a very low rate (at most 1 DSM for each MPTCP rtx interval). We can speed-up the recovery a lot, moving all the unacked in the tcp write_queue, so that it will be pushed again via other subflows, at the speed allowed by them. Also make available the new helper for later patches. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: less aggressive retransmission strategyPaolo Abeni
The current mptcp re-inject strategy is very aggressive, we have mptcp-level retransmissions even on single subflow connection, if the link in-use is lossy. Let's be a little more conservative: we do retransmit only if at least a subflow has write and rtx queue empty. Additionally use the backup subflows only if the active subflows are stale - no progresses in at least an rtx period and ignore stale subflows for rtx timeout update Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14mptcp: more accurate timeoutPaolo Abeni
As reported by Maxim, we have a lot of MPTCP-level retransmissions when multilple links with different latencies are in use. This patch refactor the mptcp-level timeout accounting so that the maximum of all the active subflow timeout is used. To avoid traversing the subflow list multiple times, the update is performed inside the packet scheduler. Additionally clean-up a bit timeout handling. 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>
2021-07-09mptcp: properly account bulk freed memoryPaolo Abeni
After commit 879526030c8b ("mptcp: protect the rx path with the msk socket spinlock") the rmem currently used by a given msk is really sk_rmem_alloc - rmem_released. The safety check in mptcp_data_ready() does not take the above in due account, as a result legit incoming data is kept in subflow receive queue with no reason, delaying or blocking MPTCP-level ack generation. This change addresses the issue introducing a new helper to fetch the rmem memory and using it as needed. Additionally add a MIB counter for the exceptional event described above - the peer is misbehaving. Finally, introduce the required annotation when rmem_released is updated. Fixes: 879526030c8b ("mptcp: protect the rx path with the msk socket spinlock") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/211 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>
2021-06-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Trivial conflict in net/netfilter/nf_tables_api.c. Duplicate fix in tools/testing/selftests/net/devlink_port_split.py - take the net-next version. skmsg, and L4 bpf - keep the bpf code but remove the flags and err params. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-28mptcp: fix 'masking a bool' warningMatthieu Baerts
Dan Carpenter reported an issue introduced in commit fde56eea01f9 ("mptcp: refine mptcp_cleanup_rbuf") where a new boolean (ack_pending) is masked with 0x9. This is not the intention to ignore values by using a boolean. This variable should not have a 'bool' type: we should keep the 'u8' to allow this comparison. Fixes: fde56eea01f9 ("mptcp: refine mptcp_cleanup_rbuf") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-22mptcp: refine mptcp_cleanup_rbufPaolo Abeni
The current cleanup rbuf tries a bit too hard to avoid acquiring the subflow socket lock. We may end-up delaying the needed ack, or skip acking a blocked subflow. Address the above extending the conditions used to trigger the cleanup to reflect more closely what TCP does and invoking tcp_cleanup_rbuf() on all the active subflows. Note that we can't replicate the exact tests implemented in tcp_cleanup_rbuf(), as MPTCP lacks some of the required info - e.g. ping-pong mode. 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>
2021-06-22mptcp: avoid race on msk state changesPaolo Abeni
The msk socket state is currently updated in a few spots without owning the msk socket lock itself. Some of such operations are safe, as they happens before exposing the msk socket to user-space and can't race with other changes. A couple of them, at connect time, can actually race with close() or shutdown(), leaving breaking the socket state machine. This change addresses the issue moving such update under the msk socket lock with the usual: <acquire spinlock> <check sk lock onwers> <ev defer to release_cb> scheme. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/56 Fixes: 8fd738049ac3 ("mptcp: fallback in case of simultaneous connect") Fixes: c3c123d16c0e ("net: mptcp: don't hang in mptcp_sendmsg() after TCP fallback") 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>
2021-06-22mptcp: drop redundant test in move_skbs_to_msk()Paolo Abeni
Currently we check the msk state to avoid enqueuing new skbs at msk shutdown time. Such test is racy - as we can't acquire the msk socket lock - and useless, as the caller already checked the subflow field 'disposable', covering the same scenario in a race free manner - read and updated under the ssk socket lock. 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>
2021-06-22mptcp: don't clear MPTCP_DATA_READY in sk_wait_event()Paolo Abeni
If we don't flush entirely the receive queue, we need set again such bit later. We can simply avoid clearing it. 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>
2021-06-22mptcp: use fast lock for subflows when possiblePaolo Abeni
There are a bunch of callsite where the ssk socket lock is acquired using the full-blown version eligible for the fast variant. Let's move to the latter. 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>
2021-06-22mptcp: drop tx skb cachePaolo Abeni
The mentioned cache was introduced to reduce the number of skb allocation in atomic context, but the required complexity is excessive. This change remove the mentioned cache. 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>
2021-06-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Trivial conflicts in net/can/isotp.c and tools/testing/selftests/net/mptcp/mptcp_connect.sh scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c to include/linux/ptp_clock_kernel.h in -next so re-apply the fix there. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-18mptcp: tune re-injections for csum enabled modePaolo Abeni
If the MPTCP-level checksum is enabled, on re-injections we must spool a complete DSS, or the receive side will not be able to compute the csum and process any data. 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>
2021-06-18mptcp: add csum_reqd in mptcp_options_receivedGeliang Tang
This patch added a new flag csum_reqd in struct mptcp_options_received, if the flag MPTCP_CAP_CHECKSUM_REQD is set in the receiving MP_CAPABLE suboption, set this flag. In mptcp_sk_clone and subflow_finish_connect, if the csum_reqd flag is set, enable the msk->csum_enabled flag. Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-18mptcp: generate the data checksumGeliang Tang
This patch added a new member named csum in struct mptcp_ext, implemented a new function named mptcp_generate_data_checksum(). Generate the data checksum in mptcp_sendmsg_frag, save it in mpext->csum. Note that we must generate the csum for zero window probe, too. Do the csum update incrementally, to avoid multiple csum computation when the data is appended to existing skb. Note that in a later patch we will skip unneeded csum related operation. Changes not included here to keep the delta small. Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-18mptcp: add csum_enabled in mptcp_sockGeliang Tang
This patch added a new member named csum_enabled in struct mptcp_sock, used a dummy mptcp_is_checksum_enabled() helper to initialize it. Also added a new member named mptcpi_csum_enabled in struct mptcp_info to expose the csum_enabled flag. Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-10mptcp: fix soft lookup in subflow_error_report()Paolo Abeni
Maxim reported a soft lookup in subflow_error_report(): watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:0] RIP: 0010:native_queued_spin_lock_slowpath RSP: 0018:ffffa859c0003bc0 EFLAGS: 00000202 RAX: 0000000000000101 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff9195c2772d88 RSI: 0000000000000000 RDI: ffff9195c2772d88 RBP: ffff9195c2772d00 R08: 00000000000067b0 R09: c6e31da9eb1e44f4 R10: ffff9195ef379700 R11: ffff9195edb50710 R12: ffff9195c2772d88 R13: ffff9195f500e3d0 R14: ffff9195ef379700 R15: ffff9195ef379700 FS: 0000000000000000(0000) GS:ffff91961f400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000407000 CR3: 0000000002988000 CR4: 00000000000006f0 Call Trace: <IRQ> _raw_spin_lock_bh subflow_error_report mptcp_subflow_data_available __mptcp_move_skbs_from_subflow mptcp_data_ready tcp_data_queue tcp_rcv_established tcp_v4_do_rcv tcp_v4_rcv ip_protocol_deliver_rcu ip_local_deliver_finish __netif_receive_skb_one_core netif_receive_skb rtl8139_poll 8139too __napi_poll net_rx_action __do_softirq __irq_exit_rcu common_interrupt </IRQ> The calling function - mptcp_subflow_data_available() - can be invoked from different contexts: - plain ssk socket lock - ssk socket lock + mptcp_data_lock - ssk socket lock + mptcp_data_lock + msk socket lock. Since subflow_error_report() tries to acquire the mptcp_data_lock, the latter two call chains will cause soft lookup. This change addresses the issue moving the error reporting call to outer functions, where the held locks list is known and the we can acquire only the needed one. Reported-by: Maxim Galaganov <max@internet.ru> Fixes: 15cc10453398 ("mptcp: deliver ssk errors to msk") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/199 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>
generated by cgit v1.2.3 (git 2.46.0) at 2025-07-28 23:35:50 +0000