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2024-04-13mptcp: don't account accept() of non-MPC client as fallback to TCPDavide Caratti
commit 7a1b3490f47e88ec4cbde65f1a77a0f4bc972282 upstream. Current MPTCP servers increment MPTcpExtMPCapableFallbackACK when they accept non-MPC connections. As reported by Christoph, this is "surprising" because the counter might become greater than MPTcpExtMPCapableSYNRX. MPTcpExtMPCapableFallbackACK counter's name suggests it should only be incremented when a connection was seen using MPTCP options, then a fallback to TCP has been done. Let's do that by incrementing it when the subflow context of an inbound MPC connection attempt is dropped. Also, update mptcp_connect.sh kselftest, to ensure that the above MIB does not increment in case a pure TCP client connects to a MPTCP server. Fixes: fc518953bc9c ("mptcp: add and use MIB counter infrastructure") Cc: stable@vger.kernel.org Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/449 Signed-off-by: Davide Caratti <dcaratti@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://lore.kernel.org/r/20240329-upstream-net-20240329-fallback-mib-v1-1-324a8981da48@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22mptcp: avoid setting TCP_CLOSE state twiceMatthieu Baerts
commit 3ba14528684f528566fb7d956bfbfb958b591d86 upstream. tcp_set_state() is called from tcp_done() already. There is then no need to first set the state to TCP_CLOSE, then call tcp_done(). Fixes: d582484726c4 ("mptcp: fix fallback for MP_JOIN subflows") Cc: stable@vger.kernel.org Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/362 Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14mptcp: use proper req destructor for IPv6Mat Martineau
From: Matthieu Baerts <matthieu.baerts@tessares.net> commit d3295fee3c756ece33ac0d935e172e68c0a4161b upstream. Before, only the destructor from TCP request sock in IPv4 was called even if the subflow was IPv6. It is important to use the right destructor to avoid memory leaks with some advanced IPv6 features, e.g. when the request socks contain specific IPv6 options. Fixes: 79c0949e9a09 ("mptcp: Add key generation and token tree") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Cc: stable@vger.kernel.org # 5.10 Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14mptcp: dedicated request sock for subflow in v6Mat Martineau
From: Matthieu Baerts <matthieu.baerts@tessares.net> commit 34b21d1ddc8ace77a8fa35c1b1e06377209e0dae upstream. tcp_request_sock_ops structure is specific to IPv4. It should then not be used with MPTCP subflows on top of IPv6. For example, it contains the 'family' field, initialised to AF_INET. This 'family' field is used by TCP FastOpen code to generate the cookie but also by TCP Metrics, SELinux and SYN Cookies. Using the wrong family will not lead to crashes but displaying/using/checking wrong things. Note that 'send_reset' callback from request_sock_ops structure is used in some error paths. It is then also important to use the correct one for IPv4 or IPv6. The slab name can also be different in IPv4 and IPv6, it will be used when printing some log messages. The slab pointer will anyway be the same because the object size is the same for both v4 and v6. A BUILD_BUG_ON() has also been added to make sure this size is the same. Fixes: cec37a6e41aa ("mptcp: Handle MP_CAPABLE options for outgoing connections") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Cc: stable@vger.kernel.org # 5.10 Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14mptcp: remove MPTCP 'ifdef' in TCP SYN cookiesMat Martineau
From: Matthieu Baerts <matthieu.baerts@tessares.net> commit 3fff88186f047627bb128d65155f42517f8e448f upstream. To ease the maintenance, it is often recommended to avoid having #ifdef preprocessor conditions. Here the section related to CONFIG_MPTCP was quite short but the next commit needs to add more code around. It is then cleaner to move specific MPTCP code to functions located in net/mptcp directory. Now that mptcp_subflow_request_sock_ops structure can be static, it can also be marked as "read only after init". Suggested-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Cc: stable@vger.kernel.org # 5.10 Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14mptcp: mark ops structures as ro_after_initMat Martineau
From: Florian Westphal <fw@strlen.de> commit 51fa7f8ebf0e25c7a9039fa3988a623d5f3855aa upstream. These structures are initialised from the init hooks, so we can't make them 'const'. But no writes occur afterwards, so we can use ro_after_init. Also, remove bogus EXPORT_SYMBOL, the only access comes from ip stack, not from kernel modules. Cc: stable@vger.kernel.org # 5.10 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06mptcp: don't return sockets in foreign netnsFlorian Westphal
[ Upstream commit ea1300b9df7c8e8b65695a08b8f6aaf4b25fec9c ] mptcp_token_get_sock() may return a mptcp socket that is in a different net namespace than the socket that received the token value. The mptcp syncookie code path had an explicit check for this, this moves the test into mptcp_token_get_sock() function. Eventually token.c should be converted to pernet storage, but such change is not suitable for net tree. Fixes: 2c5ebd001d4f0 ("mptcp: refactor token container") 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14mptcp: generate subflow hmac after mptcp_finish_join()Jianguo Wu
[ Upstream commit 0a4d8e96e4fd687af92b961d5cdcea0fdbde05fe ] For outgoing subflow join, when recv SYNACK, in subflow_finish_connect(), the mptcp_finish_join() may return false in some cases, and send a RESET to remote, and no local hmac is required. So generate subflow hmac after mptcp_finish_join(). Fixes: ec3edaa7ca6c ("mptcp: Add handling of outgoing MP_JOIN requests") Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23mptcp: do not warn on bad input from the networkPaolo Abeni
[ Upstream commit 61e710227e97172355d5f150d5c78c64175d9fb2 ] warn_bad_map() produces a kernel WARN on bad input coming from the network. Use pr_debug() to avoid spamming the system log. Additionally, when the right bound check fails, warn_bad_map() reports the wrong ssn value, let's fix it. Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/107 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10mptcp: always parse mptcp options for MPC reqskPaolo Abeni
[ Upstream commit 06f9a435b3aa12f4de6da91f11fdce8ce7b46205 ] In subflow_syn_recv_sock() we currently skip options parsing for OoO packet, given that such packets may not carry the relevant MPC option. If the peer generates an MPC+data TSO packet and some of the early segments are lost or get reorder, we server will ignore the peer key, causing transient, unexpected fallback to TCP. The solution is always parsing the incoming MPTCP options, and do the fallback only for in-order packets. This actually cleans the existing code a bit. Fixes: d22f4988ffec ("mptcp: process MP_CAPABLE data option") Reported-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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03mptcp: avoid error message on infinite mappingPaolo Abeni
commit 3ed0a585bfadb6bd7080f11184adbc9edcce7dbc upstream. Another left-over. Avoid flooding dmesg with useless text, we already have a MIB for that event. Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path") 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19mptcp: fix splat when closing unaccepted socketPaolo Abeni
[ Upstream commit 578c18eff1627d6a911f08f4cf351eca41fdcc7d ] If userspace exits before calling accept() on a listener that had at least one new connection ready, we get: Attempt to release TCP socket in state 8 This happens because the mptcp socket gets cloned when the TCP connection is ready, but the socket is never exposed to userspace. The client additionally sends a DATA_FIN, which brings connection into CLOSE_WAIT state. This in turn prevents the orphan+state reset fixup in mptcp_sock_destruct() from doing its job. Fixes: 3721b9b64676b ("mptcp: Track received DATA_FIN sequence number and add related helpers") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/185 Tested-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> Link: https://lore.kernel.org/r/20210507001638.225468-1-mathew.j.martineau@linux.intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30ipv6: weaken the v4mapped source checkJakub Kicinski
[ Upstream commit dcc32f4f183ab8479041b23a1525d48233df1d43 ] This reverts commit 6af1799aaf3f1bc8defedddfa00df3192445bbf3. Commit 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped source address") introduced an input check against v4mapped addresses. Use of such addresses on the wire is indeed questionable and not allowed on public Internet. As the commit pointed out https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02 lists potential issues. Unfortunately there are applications which use v4mapped addresses, and breaking them is a clear regression. For example v4mapped addresses (or any semi-valid addresses, really) may be used for uni-direction event streams or packet export. Since the issue which sparked the addition of the check was with TCP and request_socks in particular push the check down to TCPv6 and DCCP. This restores the ability to receive UDPv6 packets with v4mapped address as the source. Keep using the IPSTATS_MIB_INHDRERRORS statistic to minimize the user-visible changes. Fixes: 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped source address") Reported-by: Sunyi Shao <sunyishao@fb.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-07mptcp: do not wakeup listener for MPJ subflowsPaolo Abeni
commit 52557dbc7538ecceb27ef2206719a47a8039a335 upstream. MPJ subflows are not exposed as fds to user spaces. As such, incoming MPJ subflows are removed from the accept queue by tcp_check_req()/tcp_get_cookie_sock(). Later tcp_child_process() invokes subflow_data_ready() on the parent socket regardless of the subflow kind, leading to poll wakeups even if the later accept will block. Address the issue by double-checking the queue state before waking the user-space. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/164 Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-27mptcp: fix NULL ptr dereference on bad MPJPaolo Abeni
If an msk listener receives an MPJ carrying an invalid token, it will zero the request socket msk entry. That should later cause fallback and subflow reset - as per RFC - at subflow_syn_recv_sock() time due to failing hmac validation. Since commit 4cf8b7e48a09 ("subflow: introduce and use mptcp_can_accept_new_subflow()"), we unconditionally dereference - in mptcp_can_accept_new_subflow - the subflow request msk before performing hmac validation. In the above scenario we hit a NULL ptr dereference. Address the issue doing the hmac validation earlier. Fixes: 4cf8b7e48a09 ("subflow: introduce and use mptcp_can_accept_new_subflow()") Tested-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Link: https://lore.kernel.org/r/03b2cfa3ac80d8fc18272edc6442a9ddf0b1e34e.1606400227.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Minor conflicts in net/mptcp/protocol.h and tools/testing/selftests/net/Makefile. In both cases code was added on both sides in the same place so just keep both. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10mptcp: subflows garbage collectionPaolo Abeni
The msk can close MP_JOIN subflows if the initial handshake fails. Currently such subflows are kept alive in the conn_list until the msk itself is closed. Beyond the wasted memory, we could end-up sending the DATA_FIN and the DATA_FIN ack on such socket, even after a reset. Fixes: 43b54c6ee382 ("mptcp: Use full MPTCP-level disconnect state machine") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10mptcp: fix fallback for MP_JOIN subflowsPaolo Abeni
Additional/MP_JOIN subflows that do not pass some initial handshake tests currently causes fallback to TCP. That is an RFC violation: we should instead reset the subflow and leave the the msk untouched. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/91 Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-09net: mptcp: make DACK4/DACK8 usage consistent among all subflowsDavide Caratti
using packetdrill it's possible to observe the same MPTCP DSN being acked by different subflows with DACK4 and DACK8. This is in contrast with what specified in RFC8684 ยง3.3.2: if an MPTCP endpoint transmits a 64-bit wide DSN, it MUST be acknowledged with a 64-bit wide DACK. Fix 'use_64bit_ack' variable to make it a property of MPTCP sockets, not TCP subflows. Fixes: a0c1d0eafd1e ("mptcp: Use 32-bit DATA_ACK when possible") Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Small conflict around locking in rxrpc_process_event() - channel_lock moved to bundle in next, while state lock needs _bh() from net. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-06mptcp: more DATA FIN fixesPaolo Abeni
Currently data fin on data packet are not handled properly: the 'rcv_data_fin_seq' field is interpreted as the last sequence number carrying a valid data, but for data fin packet with valid maps we currently store map_seq + map_len, that is, the next value. The 'write_seq' fields carries instead the value subseguent to the last valid byte, so in mptcp_write_data_fin() we never detect correctly the last DSS map. Fixes: 7279da6145bb ("mptcp: Use MPTCP-level flag for sending DATA_FIN") Fixes: 1a49b2c2a501 ("mptcp: Handle incoming 32-bit DATA_FIN values") 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>
2020-10-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Rejecting non-native endian BTF overlapped with the addition of support for it. The rest were more simple overlapping changes, except the renesas ravb binding update, which had to follow a file move as well as a YAML conversion. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-29mptcp: Handle incoming 32-bit DATA_FIN valuesMat Martineau
The peer may send a DATA_FIN mapping with either a 32-bit or 64-bit sequence number. When a 32-bit sequence number is received for the DATA_FIN, it must be expanded to 64 bits before comparing it to the last acked sequence number. This expansion was missing. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/93 Fixes: 3721b9b64676 ("mptcp: Track received DATA_FIN sequence number and add related helpers") Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24mptcp: add mptcp_destroy_common helperGeliang Tang
This patch added a new helper named mptcp_destroy_common containing the shared code between mptcp_destroy() and mptcp_sock_destruct(). Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24mptcp: remove addr and subflow in PM netlinkGeliang Tang
This patch implements the remove announced addr and subflow logic in PM netlink. When the PM netlink removes an address, we traverse all the existing msk sockets to find the relevant sockets. We add a new list named anno_list in mptcp_pm_data, to record all the announced addrs. In the traversing, we check if it has been recorded. If it has been, we trigger the RM_ADDR signal. We also check if this address is in conn_list. If it is, we remove the subflow which using this local address. Since we call mptcp_pm_free_anno_list in mptcp_destroy, we need to move __mptcp_init_sock before the mptcp_is_enabled check in mptcp_init_sock. Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net> Suggested-by: Paolo Abeni <pabeni@redhat.com> Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-23mptcp: Wake up MPTCP worker when DATA_FIN found on a TCP FIN packetMat Martineau
When receiving a DATA_FIN MPTCP option on a TCP FIN packet, the DATA_FIN information would be stored but the MPTCP worker did not get scheduled. In turn, the MPTCP socket state would remain in TCP_ESTABLISHED and no blocked operations would be awakened. TCP FIN packets are seen by the MPTCP socket when moving skbs out of the subflow receive queues, so schedule the MPTCP worker when a skb with DATA_FIN but no data payload is moved from a subflow queue. Other cases (DATA_FIN on a bare TCP ACK or on a packet with data payload) are already handled. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/84 Fixes: 43b54c6ee382 ("mptcp: Use full MPTCP-level disconnect state machine") Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Two minor conflicts: 1) net/ipv4/route.c, adding a new local variable while moving another local variable and removing it's initial assignment. 2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes. One pretty prints the port mode differently, whilst another changes the driver to try and obtain the port mode from the port node rather than the switch node. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-17mptcp: fix integer overflow in mptcp_subflow_discard_data()Paolo Abeni
Christoph reported an infinite loop in the subflow receive path under stress condition. If there are multiple subflows, each of them using a large send buffer, the delta between the sequence number used by MPTCP-level retransmission can and the current msk->ack_seq can be greater than MAX_INT. In the above scenario, when calling mptcp_subflow_discard_data(), such delta will be truncated to int, and could result in a negative number: no bytes will be dropped, and subflow_check_data_avail() will try again to process the same packet, looping forever. This change addresses the issue by expanding the 'limit' size to 64 bits, so that overflows are not possible anymore. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/87 Fixes: 6719331c2f73 ("mptcp: trigger msk processing even for OoO data") Reported-and-tested-by: Christoph Paasch <cpaasch@apple.com> 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>
2020-09-14mptcp: call tcp_cleanup_rbuf on subflowsPaolo Abeni
That is needed to let the subflows announce promptly when new space is available in the receive buffer. tcp_cleanup_rbuf() is currently a static function, drop the scope modifier and add a declaration in the TCP header. 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>
2020-09-14mptcp: allow creating non-backup subflowsPaolo Abeni
Currently the 'backup' attribute of local endpoint is ignored. Let's use it for the MP_JOIN handshake 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>
2020-09-14mptcp: move address attribute into mptcp_addr_infoPaolo Abeni
So that can be accessed easily from the subflow creation helper. No functional change intended. 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>
2020-09-14mptcp: add OoO related mibsPaolo Abeni
Add a bunch of MPTCP mibs related to MPTCP OoO data processing. 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>
2020-09-14mptcp: cleanup mptcp_subflow_discard_data()Paolo Abeni
There is no need to use the tcp_read_sock(), we can simply drop the skb. Additionally try to look at the next buffer for in order data. This both simplifies the code and avoid unneeded indirect calls. 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>
2020-09-14mptcp: move ooo skbs into msk out of order queue.Paolo Abeni
Add an RB-tree to cope with OoO (at MPTCP level) data. __mptcp_move_skb() insert into the RB tree "future" data, eventually coalescing skb as allowed by the MPTCP DSN. To simplify sequence accounting, move the DSN inside the cb. After successfully enqueuing in sequence data, check if we can use any data from the RB tree. Additionally move the data_fin check after spooling data from the OoO tree, otherwise we could miss shutdown events. The RB tree code is copied as verbatim as possible from tcp_data_queue_ofo(), with a few simplifications due to the fact that MPTCP doesn't need to cope with sacks. All bugs here are added by me. 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>
2020-09-14mptcp: trigger msk processing even for OoO dataPaolo Abeni
This is a prerequisite to allow receiving data from multiple subflows without re-injection. Instead of dropping the OoO - "future" data in subflow_check_data_avail(), call into __mptcp_move_skbs() and let the msk drop that. To avoid code duplication factor out the mptcp_subflow_discard_data() helper. Note that __mptcp_move_skbs() can now find multiple subflows with data avail (comprising to-be-discarded data), so must update the byte counter incrementally. v1 -> v2: - fix checkpatch issues (unsigned -> unsigned int) 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>
2020-09-14mptcp: set data_ready status bit in subflow_check_data_avail()Paolo Abeni
This simplify mptcp_subflow_data_available() and will made follow-up patches simpler. Additionally remove the unneeded checks on subflow copied_seq: we always whole skbs out of subflows. 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>
2020-09-14mptcp: rethink 'is writable' conditionalPaolo Abeni
Currently, when checking for the 'msk is writable' condition, we look at the individual subflows write space. That works well while we send data via a single subflow, but will not as soon as we will enable concurrent xmit on multiple subflows. With this change msk becomes writable when the following conditions hold: - the socket has some free write space - there is at least a subflow with write free space Additionally we need to set the NOSPACE bit on all subflows before blocking. 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>
2020-09-10mptcp: fix subflow's remote_id issuesGeliang Tang
This patch set the init remote_id to zero, otherwise it will be a random number. Then it added the missing subflow's remote_id setting code both in __mptcp_subflow_connect and in subflow_ulp_clone. Fixes: 01cacb00b35cb ("mptcp: add netlink-based PM") Fixes: ec3edaa7ca6ce ("mptcp: Add handling of outgoing MP_JOIN requests") Fixes: f296234c98a8f ("mptcp: Add handling of incoming MP_JOIN requests") Signed-off-by: Geliang Tang <geliangtang@gmail.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-07mptcp: fix warn at shutdown time for unaccepted msk socketsPaolo Abeni
With commit b93df08ccda3 ("mptcp: explicitly track the fully established status"), the status of unaccepted mptcp closed in mptcp_sock_destruct() changes from TCP_SYN_RECV to TCP_ESTABLISHED. As a result mptcp_sock_destruct() does not perform the proper cleanup and inet_sock_destruct() will later emit a warn. Address the issue updating the condition tested in mptcp_sock_destruct(). Also update the related comment. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/66 Reported-and-tested-by: Christoph Paasch <cpaasch@apple.com> Fixes: b93df08ccda3 ("mptcp: explicitly track the fully established status") 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>
2020-08-05mptcp: be careful on subflow creationPaolo Abeni
Nicolas reported the following oops: [ 1521.392541] BUG: kernel NULL pointer dereference, address: 00000000000000c0 [ 1521.394189] #PF: supervisor read access in kernel mode [ 1521.395376] #PF: error_code(0x0000) - not-present page [ 1521.396607] PGD 0 P4D 0 [ 1521.397156] Oops: 0000 [#1] SMP PTI [ 1521.398020] CPU: 0 PID: 22986 Comm: kworker/0:2 Not tainted 5.8.0-rc4+ #109 [ 1521.399618] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 1521.401728] Workqueue: events mptcp_worker [ 1521.402651] RIP: 0010:mptcp_subflow_create_socket+0xf1/0x1c0 [ 1521.403954] Code: 24 08 89 44 24 04 48 8b 7a 18 e8 2a 48 d4 ff 8b 44 24 04 85 c0 75 7a 48 8b 8b 78 02 00 00 48 8b 54 24 08 48 8d bb 80 00 00 00 <48> 8b 89 c0 00 00 00 48 89 8a c0 00 00 00 48 8b 8b 78 02 00 00 8b [ 1521.408201] RSP: 0000:ffffabc4002d3c60 EFLAGS: 00010246 [ 1521.409433] RAX: 0000000000000000 RBX: ffffa0b9ad8c9a00 RCX: 0000000000000000 [ 1521.411096] RDX: ffffa0b9ae78a300 RSI: 00000000fffffe01 RDI: ffffa0b9ad8c9a80 [ 1521.412734] RBP: ffffa0b9adff2e80 R08: ffffa0b9af02d640 R09: ffffa0b9ad923a00 [ 1521.414333] R10: ffffabc4007139f8 R11: fefefefefefefeff R12: ffffabc4002d3cb0 [ 1521.415918] R13: ffffa0b9ad91fa58 R14: ffffa0b9ad8c9f9c R15: 0000000000000000 [ 1521.417592] FS: 0000000000000000(0000) GS:ffffa0b9af000000(0000) knlGS:0000000000000000 [ 1521.419490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1521.420839] CR2: 00000000000000c0 CR3: 000000002951e006 CR4: 0000000000160ef0 [ 1521.422511] Call Trace: [ 1521.423103] __mptcp_subflow_connect+0x94/0x1f0 [ 1521.425376] mptcp_pm_create_subflow_or_signal_addr+0x200/0x2a0 [ 1521.426736] mptcp_worker+0x31b/0x390 [ 1521.431324] process_one_work+0x1fc/0x3f0 [ 1521.432268] worker_thread+0x2d/0x3b0 [ 1521.434197] kthread+0x117/0x130 [ 1521.435783] ret_from_fork+0x22/0x30 on some unconventional configuration. The MPTCP protocol is trying to create a subflow for an unaccepted server socket. That is allowed by the RFC, even if subflow creation will likely fail. Unaccepted sockets have still a NULL sk_socket field, avoid the issue by failing earlier. Reported-and-tested-by: Nicolas Rybowski <nicolas.rybowski@tessares.net> Fixes: 7d14b0d2b9b3 ("mptcp: set correct vfs info for subflows") 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>
2020-07-31mptcp: enable JOIN requests even if cookies are in useFlorian Westphal
JOIN requests do not work in syncookie mode -- for HMAC validation, the peers nonce and the mptcp token (to obtain the desired connection socket the join is for) are required, but this information is only present in the initial syn. So either we need to drop all JOIN requests once a listening socket enters syncookie mode, or we need to store enough state to reconstruct the request socket later. This adds a state table (1024 entries) to store the data present in the MP_JOIN syn request and the random nonce used for the cookie syn/ack. When a MP_JOIN ACK passed cookie validation, the table is consulted to rebuild the request socket from it. An alternate approach would be to "cancel" syn-cookie mode and force MP_JOIN to always use a syn queue entry. However, doing so brings the backlog over the configured queue limit. v2: use req->syncookie, not (removed) want_cookie arg Suggested-by: Paolo Abeni <pabeni@redhat.com> 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>
2020-07-31mptcp: subflow: add mptcp_subflow_init_cookie_req helperFlorian Westphal
Will be used to initialize the mptcp request socket when a MP_CAPABLE request was handled in syncookie mode, i.e. when a TCP ACK containing a MP_CAPABLE option is a valid syncookie value. Normally (non-cookie case), MPTCP will generate a unique 32 bit connection ID and stores it in the MPTCP token storage to be able to retrieve the mptcp socket for subflow joining. In syncookie case, we do not want to store any state, so just generate the unique ID and use it in the reply. This means there is a small window where another connection could generate the same token. When Cookie ACK comes back, we check that the token has not been registered in the mean time. If it was, the connection needs to fall back to TCP. Changes in v2: - use req->syncookie instead of passing 'want_cookie' arg to ->init_req() (Eric Dumazet) 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>
2020-07-31mptcp: rename and export mptcp_subflow_request_sock_opsFlorian Westphal
syncookie code path needs to create an mptcp request sock. Prepare for this and add mptcp prefix plus needed export of ops struct. 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>
2020-07-31mptcp: subflow: split subflow_init_reqFlorian Westphal
When syncookie support is added, we will need to add a variant of subflow_init_req() helper. It will do almost same thing except that it will not compute/add a token to the mptcp token tree. To avoid excess copy&paste, this commit splits away part of the code into a new helper, __subflow_init_req, that can then be re-used from the 'no insert' function added in a followup change. 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>
2020-07-31mptcp: token: move retry to callerFlorian Westphal
Once syncookie support is added, no state will be stored anymore when the syn/ack is generated in syncookie mode. When the ACK comes back, the generated key will be taken from the TCP ACK, the token is re-generated and inserted into the token tree. This means we can't retry with a new key when the token is already taken in the syncookie case. Therefore, move the retry logic to the caller to prepare for syncookie support in mptcp. 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>
2020-07-28mptcp: Only use subflow EOF signaling on fallback connectionsMat Martineau
The MPTCP state machine handles disconnections on non-fallback connections, but the mptcp_sock still needs to get notified when fallback subflows disconnect. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-28mptcp: Use full MPTCP-level disconnect state machineMat Martineau
RFC 8684 appendix D describes the connection state machine for MPTCP. This patch implements the DATA_FIN / DATA_ACK exchanges and MPTCP-level socket state changes described in that appendix, rather than simply sending DATA_FIN along with TCP FIN when disconnecting subflows. DATA_FIN is now sent and acknowledged before shutting down the subflows. Received DATA_FIN information (if not part of a data packet) is written to the MPTCP socket when the incoming DSS option is parsed by the subflow, and the MPTCP worker is scheduled to process the flag. DATA_FIN received as part of a full DSS mapping will be handled when the mapping is processed. The DATA_FIN is acknowledged by the worker if the reader is caught up. If there is still data to be moved to the MPTCP-level queue, ack_seq will be incremented to account for the DATA_FIN when it reaches the end of the stream and a DATA_ACK will be sent to the peer. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23subflow: introduce and use mptcp_can_accept_new_subflow()Paolo Abeni
So that we can easily perform some basic PM-related adimission checks before creating the child socket. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Tested-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23subflow: use rsk_ops->send_reset()Paolo Abeni
tcp_send_active_reset() is more prone to transient errors (memory allocation or xmit queue full): in stress conditions the kernel may drop the egress packet, and the client will be stuck. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Tested-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23subflow: explicitly check for plain tcp rskPaolo Abeni
When syncookie are in use, the TCP stack may feed into subflow_syn_recv_sock() plain TCP request sockets. We can't access mptcp_subflow_request_sock-specific fields on such sockets. Explicitly check the rsk ops to do safe accesses. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Tested-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>