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* mptcp: add dummy icsk_sync_mss()Paolo Abeni2020-02-271-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot noted that the master MPTCP socket lacks the icsk_sync_mss callback, and was able to trigger a null pointer dereference: BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 8e171067 P4D 8e171067 PUD 93fa2067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 8984 Comm: syz-executor066 Not tainted 5.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffffc900020b7b80 EFLAGS: 00010246 RAX: 1ffff110124ba600 RBX: 0000000000000000 RCX: ffff88809fefa600 RDX: ffff8880994cdb18 RSI: 0000000000000000 RDI: ffff8880925d3140 RBP: ffffc900020b7bd8 R08: ffffffff870225be R09: fffffbfff140652a R10: fffffbfff140652a R11: 0000000000000000 R12: ffff8880925d35d0 R13: ffff8880925d3140 R14: dffffc0000000000 R15: 1ffff110124ba6ba FS: 0000000001a0b880(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000000a6d6f000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cipso_v4_sock_setattr+0x34b/0x470 net/ipv4/cipso_ipv4.c:1888 netlbl_sock_setattr+0x2a7/0x310 net/netlabel/netlabel_kapi.c:989 smack_netlabel security/smack/smack_lsm.c:2425 [inline] smack_inode_setsecurity+0x3da/0x4a0 security/smack/smack_lsm.c:2716 security_inode_setsecurity+0xb2/0x140 security/security.c:1364 __vfs_setxattr_noperm+0x16f/0x3e0 fs/xattr.c:197 vfs_setxattr fs/xattr.c:224 [inline] setxattr+0x335/0x430 fs/xattr.c:451 __do_sys_fsetxattr fs/xattr.c:506 [inline] __se_sys_fsetxattr+0x130/0x1b0 fs/xattr.c:495 __x64_sys_fsetxattr+0xbf/0xd0 fs/xattr.c:495 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x440199 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffcadc19e48 EFLAGS: 00000246 ORIG_RAX: 00000000000000be RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440199 RDX: 0000000020000200 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000003 R09: 00000000004002c8 R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000401a20 R13: 0000000000401ab0 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: CR2: 0000000000000000 Address the issue adding a dummy icsk_sync_mss callback. To properly sync the subflows mss and options list we need some additional infrastructure, which will land to net-next. Reported-by: syzbot+f4dfece964792d80b139@syzkaller.appspotmail.com Fixes: 2303f994b3e1 ("mptcp: Associate MPTCP context with TCP socket") 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>
* mptcp: Protect subflow socket options before connection completesMat Martineau2020-02-171-29/+19
| | | | | | | | | | | | | | Userspace should not be able to directly manipulate subflow socket options before a connection is established since it is not yet known if it will be an MPTCP subflow or a TCP fallback subflow. TCP fallback subflows can be more directly controlled by userspace because they are regular TCP connections, while MPTCP subflow sockets need to be configured for the specific needs of MPTCP. Use the same logic as sendmsg/recvmsg to ensure that socket option calls are only passed through to known TCP fallback subflows. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* mptcp: make the symbol 'mptcp_sk_clone_lock' staticChen Wandun2020-02-101-1/+1
| | | | | | | | | Fix the following sparse warning: net/mptcp/protocol.c:646:13: warning: symbol 'mptcp_sk_clone_lock' was not declared. Should it be static? Fixes: b0519de8b3f1 ("mptcp: fix use-after-free for ipv6") Signed-off-by: Chen Wandun <chenwandun@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* mptcp: fix use-after-free for ipv6Florian Westphal2020-02-061-3/+33
| | | | | | | | | | | | | | | | | | | | | | | Turns out that when we accept a new subflow, the newly created inet_sk(tcp_sk)->pinet6 points at the ipv6_pinfo structure of the listener socket. This wasn't caught by the selftest because it closes the accepted fd before the listening one. adding a close(listenfd) after accept returns is enough: BUG: KASAN: use-after-free in inet6_getname+0x6ba/0x790 Read of size 1 at addr ffff88810e310866 by task mptcp_connect/2518 Call Trace: inet6_getname+0x6ba/0x790 __sys_getpeername+0x10b/0x250 __x64_sys_getpeername+0x6f/0xb0 also alter test program to exercise this. Reported-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* mptcp: fix use-after-free on tcp fallbackFlorian Westphal2020-02-051-70/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an mptcp socket connects to a tcp peer or when a middlebox interferes with tcp options, mptcp needs to fall back to plain tcp. Problem is that mptcp is trying to be too clever in this case: It attempts to close the mptcp meta sk and transparently replace it with the (only) subflow tcp sk. Unfortunately, this is racy -- the socket is already exposed to userspace. Any parallel calls to send/recv/setsockopt etc. can cause use-after-free: BUG: KASAN: use-after-free in atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:693 [inline] CPU: 1 PID: 2083 Comm: syz-executor.1 Not tainted 5.5.0 #2 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:693 [inline] queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] do_raw_spin_lock include/linux/spinlock.h:181 [inline] __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline] _raw_spin_lock_bh+0x71/0xd0 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:343 [inline] __lock_sock+0x105/0x190 net/core/sock.c:2414 lock_sock_nested+0x10f/0x140 net/core/sock.c:2938 lock_sock include/net/sock.h:1516 [inline] mptcp_setsockopt+0x2f/0x1f0 net/mptcp/protocol.c:800 __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+0xb7/0x3d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 While the use-after-free can be resolved, there is another problem: sock->ops and sock->sk assignments are not atomic, i.e. we may get calls into mptcp functions with sock->sk already pointing at the subflow socket, or calls into tcp functions with a mptcp meta sk. Remove the fallback code and call the relevant functions for the (only) subflow in case the mptcp socket is connected to tcp peer. Reported-by: Christoph Paasch <cpaasch@apple.com> Diagnosed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Tested-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* mptcp: Fix incorrect IPV6 dependency checkGeert Uytterhoeven2020-01-301-1/+1
| | | | | | | | | | | | | | | 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: 8ab183deb26a3b79 ("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>
* mptcp: avoid a lockdep splat when mcast group was joinedFlorian Westphal2020-01-291-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: cec37a6e41aae7bf ("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>
* mptcp: fix panic on user pointer accessFlorian Westphal2020-01-291-18/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 717e79c867ca5 ("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>
* mptcp: defer freeing of cached ext until last momentFlorian Westphal2020-01-291-2/+4
| | | | | | | | | | | | | 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>
* mptcp: Fix code formattingMat Martineau2020-01-251-1/+1
| | | | | | | | | | | | | | | | 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>
* mptcp: do not inherit inet proto opsFlorian Westphal2020-01-251-19/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mptcp: cope with later TCP fallbackPaolo Abeni2020-01-241-17/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mptcp: process MP_CAPABLE data optionChristoph Paasch2020-01-241-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mptcp: new sysctl to control the activation per NSMatthieu Baerts2020-01-241-4/+12
| | | | | | | | | | | | | | | | | | 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>
* mptcp: allow collapsing consecutive sendpages on the same substreamPaolo Abeni2020-01-241-15/+60
| | | | | | | | | 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>
* mptcp: recvmsg() can drain data from multiple subflowsPaolo Abeni2020-01-241-10/+168
| | | | | | | | | | | | | | | | | | | | | | 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>
* mptcp: add subflow write space signalling and mptcp_pollFlorian Westphal2020-01-241-0/+53
| | | | | | | | | | | | | | | | | | 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>
* mptcp: Implement MPTCP receive pathMat Martineau2020-01-241-0/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mptcp: Write MPTCP DSS headers to outgoing data packetsMat Martineau2020-01-241-2/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mptcp: Add setsockopt()/getsockopt() socket operationsPeter Krystad2020-01-241-0/+58
| | | | | | | | | | | 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>
* mptcp: Add shutdown() socket operationPeter Krystad2020-01-241-0/+66
| | | | | | | | | | | 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>
* mptcp: Add key generation and token treePeter Krystad2020-01-241-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* mptcp: Create SUBFLOW socket for incoming connectionsPeter Krystad2020-01-241-5/+231
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mptcp: Handle MP_CAPABLE options for outgoing connectionsPeter Krystad2020-01-241-22/+141
| | | | | | | | | | | | | | | | | 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>
* mptcp: Associate MPTCP context with TCP socketPeter Krystad2020-01-241-6/+126
| | | | | | | | | | | | | | | | | | | 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>
* mptcp: Add MPTCP socket stubsMat Martineau2020-01-241-0/+142
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>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 13:53:16 +0100