summaryrefslogtreecommitdiffstats
path: root/net/mptcp/subflow.c
AgeCommit message (Collapse)AuthorFilesLines
2020-06-18mptcp: drop MP_JOIN request sock on syn cookiesPaolo Abeni1-8/+10
Currently any MPTCP socket using syn cookies will fallback to TCP at 3rd ack time. In case of MP_JOIN requests, the RFC mandate closing the child and sockets, but the existing error paths do not handle the syncookie scenario correctly. Address the issue always forcing the child shutdown in case of MP_JOIN fallback. Fixes: ae2dd7164943 ("mptcp: handle tcp fallback when using syn cookies") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-18mptcp: cache msk on MP_JOIN init_reqPaolo Abeni1-22/+17
The msk ownership is transferred to the child socket at 3rd ack time, so that we avoid more lookups later. If the request does not reach the 3rd ack, the MSK reference is dropped at request sock release time. As a side effect, fallback is now tracked by a NULL msk reference instead of zeroed 'mp_join' field. This will simplify the next patch. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-15mptcp: fix memory leak in mptcp_subflow_create_socket()Wei Yongjun1-1/+3
socket malloced by sock_create_kern() should be release before return in the error handling, otherwise it cause memory leak. unreferenced object 0xffff88810910c000 (size 1216): comm "00000003_test_m", pid 12238, jiffies 4295050289 (age 54.237s) hex dump (first 32 bytes): 01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 2f 30 0a 81 88 ff ff ........./0..... backtrace: [<00000000e877f89f>] sock_alloc_inode+0x18/0x1c0 [<0000000093d1dd51>] alloc_inode+0x63/0x1d0 [<000000005673fec6>] new_inode_pseudo+0x14/0xe0 [<00000000b5db6be8>] sock_alloc+0x3c/0x260 [<00000000e7e3cbb2>] __sock_create+0x89/0x620 [<0000000023e48593>] mptcp_subflow_create_socket+0xc0/0x5e0 [<00000000419795e4>] __mptcp_socket_create+0x1ad/0x3f0 [<00000000b2f942e8>] mptcp_stream_connect+0x281/0x4f0 [<00000000c80cd5cc>] __sys_connect_file+0x14d/0x190 [<00000000dc761f11>] __sys_connect+0x128/0x160 [<000000008b14e764>] __x64_sys_connect+0x6f/0xb0 [<000000007b4f93bd>] do_syscall_64+0xa1/0x530 [<00000000d3e770b6>] entry_SYSCALL_64_after_hwframe+0x49/0xb3 Fixes: 2303f994b3e1 ("mptcp: Associate MPTCP context with TCP socket") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-10mptcp: don't leak msk in token containerPaolo Abeni1-0/+1
If a listening MPTCP socket has unaccepted sockets at close time, the related msks are freed via mptcp_sock_destruct(), which in turn does not invoke the proto->destroy() method nor the mptcp_token_destroy() function. Due to the above, the child msk socket is not removed from the token container, leading to later UaF. Address the issue explicitly removing the token even in the above error path. Fixes: 79c0949e9a09 ("mptcp: Add key generation and token tree") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-30mptcp: fix NULL ptr dereference in MP_JOIN error pathPaolo Abeni1-4/+16
When token lookup on MP_JOIN 3rd ack fails, the server socket closes with a reset the incoming child. Such socket has the 'is_mptcp' flag set, but no msk socket associated - due to the failed lookup. While crafting the reset packet mptcp_established_options_mp() will try to dereference the child's master socket, causing a NULL ptr dereference. This change addresses the issue with explicit fallback to TCP in such error path. Fixes: 729cd6436f35 ("mptcp: cope better with MP_JOIN failure") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-5/+10
The MSCC bug fix in 'net' had to be slightly adjusted because the register accesses are done slightly differently in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-22mptcp: use untruncated hash in ADD_ADDR HMACTodd Malsbary1-5/+10
There is some ambiguity in the RFC as to whether the ADD_ADDR HMAC is the rightmost 64 bits of the entire hash or of the leftmost 160 bits of the hash. The intention, as clarified with the author of the RFC, is the entire hash. This change returns the entire hash from mptcp_crypto_hmac_sha (instead of only the first 160 bits), and moves any truncation/selection operation on the hash to the caller. Fixes: 12555a2d97e5 ("mptcp: use rightmost 64 bits in ADD_ADDR HMAC") Reviewed-by: Christoph Paasch <cpaasch@apple.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Todd Malsbary <todd.malsbary@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-16mptcp: Use 32-bit DATA_ACK when possibleChristoph Paasch1-0/+2
RFC8684 allows to send 32-bit DATA_ACKs as long as the peer is not sending 64-bit data-sequence numbers. The 64-bit DSN is only there for extreme scenarios when a very high throughput subflow is combined with a long-RTT subflow such that the high-throughput subflow wraps around the 32-bit sequence number space within an RTT of the high-RTT subflow. It is thus a rare scenario and we should try to use the 32-bit DATA_ACK instead as long as possible. It allows to reduce the TCP-option overhead by 4 bytes, thus makes space for an additional SACK-block. It also makes tcpdumps much easier to read when the DSN and DATA_ACK are both either 32 or 64-bit. Signed-off-by: Christoph Paasch <cpaasch@apple.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-0/+10
Move the bpf verifier trace check into the new switch statement in HEAD. Resolve the overlapping changes in hinic, where bug fixes overlap the addition of VF support. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15mptcp: cope better with MP_JOIN failurePaolo Abeni1-6/+9
Currently, on MP_JOIN failure we reset the child socket, but leave the request socket untouched. tcp_check_req will deal with it according to the 'tcp_abort_on_overflow' sysctl value - by default the req socket will stay alive. The above leads to inconsistent behavior on MP JOIN failure, and bad listener overflow accounting. This patch addresses the issue leveraging the infrastructure just introduced to ask the TCP stack to drop the req on failure. The child socket is not freed anymore by subflow_syn_recv_sock(), instead it's moved to a dead state and will be disposed by the next sock_put done by the TCP stack, so that listener overflow accounting is not affected by MP JOIN failure. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Christoph Paasch <cpaasch@apple.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15mptcp: add new sock flag to deal with join subflowsPaolo Abeni1-0/+3
MP_JOIN subflows must not land into the accept queue. Currently tcp_check_req() calls an mptcp specific helper to detect such scenario. Such helper leverages the subflow context to check for MP_JOIN subflows. We need to deal also with MP JOIN failures, even when the subflow context is not available due allocation failure. A possible solution would be changing the syn_recv_sock() signature to allow returning a more descriptive action/ error code and deal with that in tcp_check_req(). Since the above need is MPTCP specific, this patch instead uses a TCP request socket hole to add a MPTCP specific flag. Such flag is used by the MPTCP syn_recv_sock() to tell tcp_check_req() how to deal with the request socket. This change is a no-op for !MPTCP build, and makes the MPTCP code simpler. It allows also the next patch to deal correctly with MP JOIN failure. v1 -> v2: - be more conservative on drop_req initialization (Mat) RFC -> v1: - move the drop_req bit inside tcp_request_sock (Eric) Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Reviewed-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-07mptcp: set correct vfs info for subflowsPaolo Abeni1-0/+10
When a subflow is created via mptcp_subflow_create_socket(), a new 'struct socket' is allocated, with a new i_ino value. When inspecting TCP sockets via the procfs and or the diag interface, the above ones are not related to the process owning the MPTCP master socket, even if they are a logical part of it ('ss -p' shows an empty process field) Additionally, subflows created by the path manager get the uid/gid from the running workqueue. Subflows are part of the owning MPTCP master socket, let's adjust the vfs info to reflect this. After this patch, 'ss' correctly displays subflows as belonging to the msk socket creator. Fixes: 2303f994b3e1 ("mptcp: Associate MPTCP context with TCP socket") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-31/+55
Conflicts were all overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30mptcp: fix uninitialized value accessPaolo Abeni1-1/+1
tcp_v{4,6}_syn_recv_sock() set 'own_req' only when returning a not NULL 'child', let's check 'own_req' only if child is available to avoid an - unharmful - UBSAN splat. v1 -> v2: - reference the correct hash Fixes: 4c8941de781c ("mptcp: avoid flipping mp_capable field in syn_recv_sock()") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30mptcp: move option parsing into mptcp_incoming_options()Paolo Abeni1-31/+34
The mptcp_options_received structure carries several per packet flags (mp_capable, mp_join, etc.). Such fields must be cleared on each packet, even on dropped ones or packet not carrying any MPTCP options, but the current mptcp code clears them only on TCP option reset. On several races/corner cases we end-up with stray bits in incoming options, leading to WARN_ON splats. e.g.: [ 171.164906] Bad mapping: ssn=32714 map_seq=1 map_data_len=32713 [ 171.165006] WARNING: CPU: 1 PID: 5026 at net/mptcp/subflow.c:533 warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531) [ 171.167632] Modules linked in: ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel geneve ip6_udp_tunnel udp_tunnel macsec macvtap tap ipvlan macvlan 8021q garp mrp xfrm_interface veth netdevsim nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun binfmt_misc intel_rapl_msr intel_rapl_common rfkill kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel joydev virtio_balloon pcspkr i2c_piix4 sunrpc ip_tables xfs libcrc32c crc32c_intel serio_raw virtio_console ata_generic virtio_blk virtio_net net_failover failover ata_piix libata [ 171.199464] CPU: 1 PID: 5026 Comm: repro Not tainted 5.7.0-rc1.mptcp_f227fdf5d388+ #95 [ 171.200886] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014 [ 171.202546] RIP: 0010:warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531) [ 171.206537] Code: c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1d 8b 55 3c 44 89 e6 48 c7 c7 20 51 13 95 e8 37 8b 22 fe <0f> 0b 48 83 c4 08 5b 5d 41 5c c3 89 4c 24 04 e8 db d6 94 fe 8b 4c [ 171.220473] RSP: 0018:ffffc90000150560 EFLAGS: 00010282 [ 171.221639] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 171.223108] RDX: 0000000000000000 RSI: 0000000000000008 RDI: fffff5200002a09e [ 171.224388] RBP: ffff8880aa6e3c00 R08: 0000000000000001 R09: fffffbfff2ec9955 [ 171.225706] R10: ffffffff9764caa7 R11: fffffbfff2ec9954 R12: 0000000000007fca [ 171.227211] R13: ffff8881066f4a7f R14: ffff8880aa6e3c00 R15: 0000000000000020 [ 171.228460] FS: 00007f8623719740(0000) GS:ffff88810be00000(0000) knlGS:0000000000000000 [ 171.230065] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 171.231303] CR2: 00007ffdab190a50 CR3: 00000001038ea006 CR4: 0000000000160ee0 [ 171.232586] Call Trace: [ 171.233109] <IRQ> [ 171.233531] get_mapping_status (linux-mptcp/net/mptcp/subflow.c:691) [ 171.234371] mptcp_subflow_data_available (linux-mptcp/net/mptcp/subflow.c:736 linux-mptcp/net/mptcp/subflow.c:832) [ 171.238181] subflow_state_change (linux-mptcp/net/mptcp/subflow.c:1085 (discriminator 1)) [ 171.239066] tcp_fin (linux-mptcp/net/ipv4/tcp_input.c:4217) [ 171.240123] tcp_data_queue (linux-mptcp/./include/linux/compiler.h:199 linux-mptcp/net/ipv4/tcp_input.c:4822) [ 171.245083] tcp_rcv_established (linux-mptcp/./include/linux/skbuff.h:1785 linux-mptcp/./include/net/tcp.h:1774 linux-mptcp/./include/net/tcp.h:1847 linux-mptcp/net/ipv4/tcp_input.c:5238 linux-mptcp/net/ipv4/tcp_input.c:5730) [ 171.254089] tcp_v4_rcv (linux-mptcp/./include/linux/spinlock.h:393 linux-mptcp/net/ipv4/tcp_ipv4.c:2009) [ 171.258969] ip_protocol_deliver_rcu (linux-mptcp/net/ipv4/ip_input.c:204 (discriminator 1)) [ 171.260214] ip_local_deliver_finish (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/ipv4/ip_input.c:232) [ 171.261389] ip_local_deliver (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:252) [ 171.265884] ip_rcv (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:539) [ 171.273666] process_backlog (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/core/dev.c:6135) [ 171.275328] net_rx_action (linux-mptcp/net/core/dev.c:6572 linux-mptcp/net/core/dev.c:6640) [ 171.280472] __do_softirq (linux-mptcp/./arch/x86/include/asm/jump_label.h:25 linux-mptcp/./include/linux/jump_label.h:200 linux-mptcp/./include/trace/events/irq.h:142 linux-mptcp/kernel/softirq.c:293) [ 171.281379] do_softirq_own_stack (linux-mptcp/arch/x86/entry/entry_64.S:1083) [ 171.282358] </IRQ> We could address the issue clearing explicitly the relevant fields in several places - tcp_parse_option, tcp_fast_parse_options, possibly others. Instead we move the MPTCP option parsing into the already existing mptcp ingress hook, so that we need to clear the fields in a single place. This allows us dropping an MPTCP hook from the TCP code and removing the quite large mptcp_options_received from the tcp_sock struct. On the flip side, the MPTCP sockets will traverse the option space twice (in tcp_parse_option() and in mptcp_incoming_options(). That looks acceptable: we already do that for syn and 3rd ack packets, plain TCP socket will benefit from it, and even MPTCP sockets will experience better code locality, reducing the jumps between TCP and MPTCP code. v1 -> v2: - rebased on current '-net' tree Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30mptcp: consolidate synack processing.Paolo Abeni1-3/+24
Currently the MPTCP code uses 2 hooks to process syn-ack packets, mptcp_rcv_synsent() and the sk_rx_dst_set() callback. We can drop the first, moving the relevant code into the latter, reducing the hooking into the TCP code. This is also needed by the next patch. v1 -> v2: - use local tcp sock ptr instead of casting the sk variable several times - DaveM Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-25mptcp: fix race in msk status updatePaolo Abeni1-1/+1
Currently subflow_finish_connect() changes unconditionally any msk socket status other than TCP_ESTABLISHED. If an unblocking connect() races with close(), we can end-up triggering: IPv4: Attempt to release TCP socket in state 1 00000000e32b8b7e when the msk socket is disposed. Be sure to enter the established status only from SYN_SENT. Fixes: c3c123d16c0e ("net: mptcp: don't hang in mptcp_sendmsg() after TCP fallback") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-25tcp: mptcp: use mptcp receive buffer space to select rcv windowFlorian Westphal1-0/+18
In MPTCP, the receive window is shared across all subflows, because it refers to the mptcp-level sequence space. MPTCP receivers already place incoming packets on the mptcp socket receive queue and will charge it to the mptcp socket rcvbuf until userspace consumes the data. Update __tcp_select_window to use the occupancy of the parent/mptcp socket instead of the subflow socket in case the tcp socket is part of a logical mptcp connection. This commit doesn't change choice of initial window for passive or active connections. While it would be possible to change those as well, this adds complexity (especially when handling MP_JOIN requests). Furthermore, the MPTCP RFC specifically says that a MPTCP sender 'MUST NOT use the RCV.WND field of a TCP segment at the connection level if it does not also carry a DSS option with a Data ACK field.' SYN/SYNACK packets do not carry a DSS option with a Data ACK field. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-20mptcp: drop req socket remote_key* fieldsPaolo Abeni1-10/+10
We don't need them, as we can use the current ingress opt data instead. Setting them in syn_recv_sock() may causes inconsistent mptcp socket status, as per previous commit. Fixes: cc7972ea1932 ("mptcp: parse and emit MP_CAPABLE option according to v1 spec") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-20mptcp: avoid flipping mp_capable field in syn_recv_sock()Paolo Abeni1-16/+30
If multiple CPUs races on the same req_sock in syn_recv_sock(), flipping such field can cause inconsistent child socket status. When racing, the CPU losing the req ownership may still change the mptcp request socket mp_capable flag while the CPU owning the request is cloning the socket, leaving the child socket with 'is_mptcp' set but no 'mp_capable' flag. Such socket will stay with 'conn' field cleared, heading to oops in later mptcp callback. Address the issue tracking the fallback status in a local variable. Fixes: 58b09919626b ("mptcp: create msk early") 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: David S. Miller <davem@davemloft.net>
2020-04-18mptcp: fix 'Attempt to release TCP socket in state' warningsFlorian Westphal1-1/+7
We need to set sk_state to CLOSED, else we will get following: IPv4: Attempt to release TCP socket in state 3 00000000b95f109e IPv4: Attempt to release TCP socket in state 10 00000000b95f109e First one is from inet_sock_destruct(), second one from mptcp_sk_clone failure handling. Setting sk_state to CLOSED isn't enough, we also need to orphan sk so it has DEAD flag set. Otherwise, a very similar warning is printed from inet_sock_destruct(). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-18mptcp: fix splat when incoming connection is never accepted before exit/closeFlorian Westphal1-1/+24
Following snippet (replicated from syzkaller reproducer) generates warning: "IPv4: Attempt to release TCP socket in state 1". int main(void) { struct sockaddr_in sin1 = { .sin_family = 2, .sin_port = 0x4e20, .sin_addr.s_addr = 0x010000e0, }; struct sockaddr_in sin2 = { .sin_family = 2, .sin_addr.s_addr = 0x0100007f, }; struct sockaddr_in sin3 = { .sin_family = 2, .sin_port = 0x4e20, .sin_addr.s_addr = 0x0100007f, }; int r0 = socket(0x2, 0x1, 0x106); int r1 = socket(0x2, 0x1, 0x106); bind(r1, (void *)&sin1, sizeof(sin1)); connect(r1, (void *)&sin2, sizeof(sin2)); listen(r1, 3); return connect(r0, (void *)&sin3, 0x4d); } Reason is that the newly generated mptcp socket is closed via the ulp release of the tcp listener socket when its accept backlog gets purged. To fix this, delay setting the ESTABLISHED state until after userspace calls accept and via mptcp specific destructor. Fixes: 58b09919626bf ("mptcp: create msk early") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/9 Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-02mptcp: subflow: check parent mptcp socket on subflow state changeFlorian Westphal1-2/+1
This is needed at least until proper MPTCP-Level fin/reset signalling gets added: We wake parent when a subflow changes, but we should do this only when all subflows have closed, not just one. Schedule the mptcp worker and tell it to check eof state on all subflows. Only flag mptcp socket as closed and wake userspace processes blocking in poll if all subflows have closed. Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29mptcp: add and use MIB counter infrastructureFlorian Westphal1-6/+27
Exported via same /proc file as the Linux TCP MIB counters, so "netstat -s" or "nstat" will show them automatically. The MPTCP MIB counters are allocated in a distinct pcpu area in order to avoid bloating/wasting TCP pcpu memory. Counters are allocated once the first MPTCP socket is created in a network namespace and free'd on exit. If no sockets have been allocated, all-zero mptcp counters are shown. The MIB counter list is taken from the multipath-tcp.org kernel, but only a few counters have been picked up so far. The counter list can be increased at any time later on. v2 -> v3: - remove 'inline' in foo.c files (David S. Miller) Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29mptcp: allow dumping subflow context to userspaceDavide Caratti1-0/+2
add ulp-specific diagnostic functions, so that subflow information can be dumped to userspace programs like 'ss'. v2 -> v3: - uapi: use bit macros appropriate for userspace Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29mptcp: Add handling of outgoing MP_JOIN requestsPeter Krystad1-2/+148
Subflow creation may be initiated by the path manager when the primary connection is fully established and a remote address has been received via ADD_ADDR. Create an in-kernel sock and use kernel_connect() to initiate connection. Passive sockets can't acquire the mptcp socket lock at subflow creation time, so an additional list protected by a new spinlock is used to track the MPJ subflows. Such list is spliced into conn_list tail every time the msk socket lock is acquired, so that it will not interfere with data flow on the original connection. Data flow and connection failover not addressed by this commit. Co-developed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Florian Westphal <fw@strlen.de> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29mptcp: Add handling of incoming MP_JOIN requestsPeter Krystad1-16/+142
Process the MP_JOIN option in a SYN packet with the same flow as MP_CAPABLE but when the third ACK is received add the subflow to the MPTCP socket subflow list instead of adding it to the TCP socket accept queue. The subflow is added at the end of the subflow list so it will not interfere with the existing subflows operation and no data is expected to be transmitted on it. Co-developed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Florian Westphal <fw@strlen.de> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29mptcp: Add path manager interfacePeter Krystad1-2/+2
Add enough of a path manager interface to allow sending of ADD_ADDR when an incoming MPTCP connection is created. Capable of sending only a single IPv4 ADD_ADDR option. The 'pm_data' element of the connection sock will need to be expanded to handle multiple interfaces and IPv6. Partial processing of the incoming ADD_ADDR is included so the path manager notification of that event happens at the proper time, which involves validating the incoming address information. This is a skeleton interface definition for events generated by MPTCP. Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Co-developed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Florian Westphal <fw@strlen.de> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Co-developed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-23net: mptcp: don't hang in mptcp_sendmsg() after TCP fallbackDavide Caratti1-0/+6
it's still possible for packetdrill to hang in mptcp_sendmsg(), when the MPTCP socket falls back to regular TCP (e.g. after receiving unsupported flags/version during the three-way handshake). Adjust MPTCP socket state earlier, to ensure correct functionality of mptcp_sendmsg() even in case of TCP fallback. Fixes: 767d3ded5fb8 ("net: mptcp: don't hang before sending 'MP capable with data'") Fixes: 1954b86016cf ("mptcp: Check connection state before attempting send") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-19mptcp: rename fourth ack fieldPaolo Abeni1-1/+1
The name is misleading, it actually tracks the 'fully established' status. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-17mptcp: move msk state update to subflow_syn_recv_sock()Paolo Abeni1-0/+2
After commit 58b09919626b ("mptcp: create msk early"), the msk socket is already available at subflow_syn_recv_sock() time. Let's move there the state update, to mirror more closely the first subflow state. The above will also help multiple subflow supports. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-15mptcp: drop unneeded checksPaolo Abeni1-11/+7
After the previous patch subflow->conn is always != NULL and is never changed. We can drop a bunch of now unneeded checks. v1 -> v2: - rebased on top of commit 2398e3991bda ("mptcp: always include dack if possible.") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-15mptcp: create msk earlyPaolo Abeni1-11/+21
This change moves the mptcp socket allocation from mptcp_accept() to subflow_syn_recv_sock(), so that subflow->conn is now always set for the non fallback scenario. It allows cleaning up a bit mptcp_accept() reducing the additional locking and will allow fourther cleanup in the next patch. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26mptcp: avoid work queue scheduling if possibleFlorian Westphal1-2/+2
We can't lock_sock() the mptcp socket from the subflow data_ready callback, it would result in ABBA deadlock with the subflow socket lock. We can however grab the spinlock: if that succeeds and the mptcp socket is not owned at the moment, we can process the new skbs right away without deferring this to the work queue. This avoids the schedule_work and hence the small delay until the work item is processed. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26mptcp: remove mptcp_read_actorFlorian Westphal1-5/+13
Only used to discard stale data from the subflow, so move it where needed. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-26mptcp: add and use mptcp_data_ready helperFlorian Westphal1-10/+4
allows us to schedule the work queue to drain the ssk receive queue in a followup patch. This is needed to avoid sending all-to-pessimistic mptcp-level acknowledgements. At this time, the ack_seq is what was last read by userspace instead of the highest in-sequence number queued for reading. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-30mptcp: Fix undefined mptcp_handle_ipv6_mapped for modular IPV6Geert Uytterhoeven1-3/+3
If CONFIG_MPTCP=y, CONFIG_MPTCP_IPV6=n, and CONFIG_IPV6=m: ERROR: "mptcp_handle_ipv6_mapped" [net/ipv6/ipv6.ko] undefined! This does not happen if CONFIG_MPTCP_IPV6=y, as CONFIG_MPTCP_IPV6 selects CONFIG_IPV6, and thus forces CONFIG_IPV6 builtin. As exporting a symbol for an empty function would be a bit wasteful, fix this by providing a dummy version of mptcp_handle_ipv6_mapped() for the CONFIG_MPTCP_IPV6=n case. Rename mptcp_handle_ipv6_mapped() to mptcpv6_handle_mapped(), to make it clear this is a pure-IPV6 function, just like mptcpv6_init(). Fixes: cec37a6e41aae7bf ("mptcp: Handle MP_CAPABLE options for outgoing connections") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-29mptcp: handle tcp fallback when using syn cookiesFlorian Westphal1-1/+4
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: cec37a6e41aae7bf ("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>
2020-01-29mptcp: Fix build with PROC_FS disabled.David S. Miller1-0/+2
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>
2020-01-25mptcp: Fix code formattingMat Martineau1-2/+2
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>
2020-01-24mptcp: process MP_CAPABLE data optionChristoph Paasch1-5/+35
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>
2020-01-24mptcp: parse and emit MP_CAPABLE option according to v1 specChristoph Paasch1-2/+12
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>
2020-01-24mptcp: add subflow write space signalling and mptcp_pollFlorian Westphal1-0/+3
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>
2020-01-24mptcp: Implement MPTCP receive pathMat Martineau1-3/+380
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>
2020-01-24mptcp: Add key generation and token treePeter Krystad1-7/+62
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>
2020-01-24mptcp: Handle MP_CAPABLE options for outgoing connectionsPeter Krystad1-1/+267
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>
2020-01-24mptcp: Associate MPTCP context with TCP socketPeter Krystad1-0/+119
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>