From 0c1f78a49af721490a5ad70b73e8b4d382465dae Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 27 Jun 2022 18:02:35 -0700 Subject: mptcp: fix error mibs accounting The current accounting for MP_FAIL and FASTCLOSE is not very accurate: both can be increased even when the related option is not really sent. Move the accounting into the correct place. Fixes: eb7f33654dc1 ("mptcp: add the mibs for MP_FAIL") Fixes: 1e75629cb964 ("mptcp: add the mibs for MP_FASTCLOSE") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/options.c | 5 +++-- net/mptcp/pm.c | 1 - net/mptcp/subflow.c | 4 +--- 3 files changed, 4 insertions(+), 6 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index be3b918a6d15..2a6351d55a7d 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -765,6 +765,7 @@ static noinline bool mptcp_established_options_rst(struct sock *sk, struct sk_bu opts->suboptions |= OPTION_MPTCP_RST; opts->reset_transient = subflow->reset_transient; opts->reset_reason = subflow->reset_reason; + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPRSTTX); return true; } @@ -788,6 +789,7 @@ static bool mptcp_established_options_fastclose(struct sock *sk, opts->rcvr_key = msk->remote_key; pr_debug("FASTCLOSE key=%llu", opts->rcvr_key); + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFASTCLOSETX); return true; } @@ -809,6 +811,7 @@ static bool mptcp_established_options_mp_fail(struct sock *sk, opts->fail_seq = subflow->map_seq; pr_debug("MP_FAIL fail_seq=%llu", opts->fail_seq); + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX); return true; } @@ -833,13 +836,11 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) { *size += opt_size; remaining -= opt_size; - MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFASTCLOSETX); } /* MP_RST can be used with MP_FASTCLOSE and MP_FAIL if there is room */ if (mptcp_established_options_rst(sk, skb, &opt_size, remaining, opts)) { *size += opt_size; remaining -= opt_size; - MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPRSTTX); } return true; } diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 59a85220edc9..91a62b598de4 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -310,7 +310,6 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq) pr_debug("send MP_FAIL response and infinite map"); subflow->send_mp_fail = 1; - MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX); subflow->send_infinite_map = 1; } else if (!sock_flag(sk, SOCK_DEAD)) { pr_debug("MP_FAIL response received"); diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 8841e8cd9ad8..50ad19adc003 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -958,10 +958,8 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff * subflow->map_data_csum); if (unlikely(csum)) { MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR); - if (subflow->mp_join || subflow->valid_csum_seen) { + if (subflow->mp_join || subflow->valid_csum_seen) subflow->send_mp_fail = 1; - MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPFAILTX); - } return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY; } -- cgit v1.2.3-71-gd317 From 31bf11de146c3f8892093ff39f8f9b3069d6a852 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 27 Jun 2022 18:02:36 -0700 Subject: mptcp: introduce MAPPING_BAD_CSUM This allow moving a couple of conditional out of the fast path, making the code more easy to follow and will simplify the next patch. Fixes: ae66fb2ba6c3 ("mptcp: Do TCP fallback on early DSS checksum failure") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/subflow.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 50ad19adc003..42a7c18a1c24 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -843,7 +843,8 @@ enum mapping_status { MAPPING_INVALID, MAPPING_EMPTY, MAPPING_DATA_FIN, - MAPPING_DUMMY + MAPPING_DUMMY, + MAPPING_BAD_CSUM }; static void dbg_bad_map(struct mptcp_subflow_context *subflow, u32 ssn) @@ -958,9 +959,7 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff * subflow->map_data_csum); if (unlikely(csum)) { MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR); - if (subflow->mp_join || subflow->valid_csum_seen) - subflow->send_mp_fail = 1; - return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY; + return MAPPING_BAD_CSUM; } subflow->valid_csum_seen = 1; @@ -1182,10 +1181,8 @@ static bool subflow_check_data_avail(struct sock *ssk) status = get_mapping_status(ssk, msk); trace_subflow_check_data_avail(status, skb_peek(&ssk->sk_receive_queue)); - if (unlikely(status == MAPPING_INVALID)) - goto fallback; - - if (unlikely(status == MAPPING_DUMMY)) + if (unlikely(status == MAPPING_INVALID || status == MAPPING_DUMMY || + status == MAPPING_BAD_CSUM)) goto fallback; if (status != MAPPING_OK) @@ -1227,7 +1224,10 @@ no_data: fallback: if (!__mptcp_check_fallback(msk)) { /* RFC 8684 section 3.7. */ - if (subflow->send_mp_fail) { + if (status == MAPPING_BAD_CSUM && + (subflow->mp_join || subflow->valid_csum_seen)) { + subflow->send_mp_fail = 1; + if (!READ_ONCE(msk->allow_infinite_fallback)) { ssk->sk_err = EBADMSG; tcp_set_state(ssk, TCP_CLOSE); -- cgit v1.2.3-71-gd317 From 76a13b315709b5b65a7b65caf9ede9a8a38d8930 Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Mon, 27 Jun 2022 18:02:37 -0700 Subject: mptcp: invoke MP_FAIL response when needed mptcp_mp_fail_no_response shouldn't be invoked on each worker run, it should be invoked only when MP_FAIL response timeout occurs. This patch refactors the MP_FAIL response logic. It leverages the fact that only the MPC/first subflow can gracefully fail to avoid unneeded subflows traversal: the failing subflow can be only msk->first. A new 'fail_tout' field is added to the subflow context to record the MP_FAIL response timeout and use such field to reliably share the timeout timer between the MP_FAIL event and the MPTCP socket close timeout. Finally, a new ack is generated to send out MP_FAIL notification as soon as we hit the relevant condition, instead of waiting a possibly unbound time for the next data packet. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/281 Fixes: d9fb797046c5 ("mptcp: Do not traverse the subflow connection list without lock") Co-developed-by: Paolo Abeni Signed-off-by: Paolo Abeni Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/pm.c | 9 +++--- net/mptcp/protocol.c | 77 ++++++++++++++++++++++++++++++++-------------------- net/mptcp/protocol.h | 3 +- net/mptcp/subflow.c | 38 ++++++++++++++++++++------ 4 files changed, 82 insertions(+), 45 deletions(-) diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 91a62b598de4..45e2a48397b9 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -299,22 +299,21 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_sock *msk = mptcp_sk(subflow->conn); - struct sock *s = (struct sock *)msk; pr_debug("fail_seq=%llu", fail_seq); if (!READ_ONCE(msk->allow_infinite_fallback)) return; - if (!READ_ONCE(subflow->mp_fail_response_expect)) { + if (!subflow->fail_tout) { pr_debug("send MP_FAIL response and infinite map"); subflow->send_mp_fail = 1; subflow->send_infinite_map = 1; - } else if (!sock_flag(sk, SOCK_DEAD)) { + tcp_send_ack(sk); + } else { pr_debug("MP_FAIL response received"); - - sk_stop_timer(s, &s->sk_timer); + WRITE_ONCE(subflow->fail_tout, 0); } } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 17e13396024a..e6fcb61443dd 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -500,7 +500,7 @@ static void mptcp_set_timeout(struct sock *sk) __mptcp_set_timeout(sk, tout); } -static bool tcp_can_send_ack(const struct sock *ssk) +static inline bool tcp_can_send_ack(const struct sock *ssk) { return !((1 << inet_sk_state_load(ssk)) & (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN)); @@ -2175,21 +2175,6 @@ static void mptcp_retransmit_timer(struct timer_list *t) sock_put(sk); } -static struct mptcp_subflow_context * -mp_fail_response_expect_subflow(struct mptcp_sock *msk) -{ - struct mptcp_subflow_context *subflow, *ret = NULL; - - mptcp_for_each_subflow(msk, subflow) { - if (READ_ONCE(subflow->mp_fail_response_expect)) { - ret = subflow; - break; - } - } - - return ret; -} - static void mptcp_timeout_timer(struct timer_list *t) { struct sock *sk = from_timer(sk, t, sk_timer); @@ -2518,27 +2503,50 @@ reset_timer: mptcp_reset_timer(sk); } +/* schedule the timeout timer for the relevant event: either close timeout + * or mp_fail timeout. The close timeout takes precedence on the mp_fail one + */ +void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout) +{ + struct sock *sk = (struct sock *)msk; + unsigned long timeout, close_timeout; + + if (!fail_tout && !sock_flag(sk, SOCK_DEAD)) + return; + + close_timeout = inet_csk(sk)->icsk_mtup.probe_timestamp - tcp_jiffies32 + jiffies + TCP_TIMEWAIT_LEN; + + /* the close timeout takes precedence on the fail one, and here at least one of + * them is active + */ + timeout = sock_flag(sk, SOCK_DEAD) ? close_timeout : fail_tout; + + sk_reset_timer(sk, &sk->sk_timer, timeout); +} + static void mptcp_mp_fail_no_response(struct mptcp_sock *msk) { - struct mptcp_subflow_context *subflow; - struct sock *ssk; + struct sock *ssk = msk->first; bool slow; - subflow = mp_fail_response_expect_subflow(msk); - if (subflow) { - pr_debug("MP_FAIL doesn't respond, reset the subflow"); + if (!ssk) + return; - ssk = mptcp_subflow_tcp_sock(subflow); - slow = lock_sock_fast(ssk); - mptcp_subflow_reset(ssk); - unlock_sock_fast(ssk, slow); - } + pr_debug("MP_FAIL doesn't respond, reset the subflow"); + + slow = lock_sock_fast(ssk); + mptcp_subflow_reset(ssk); + WRITE_ONCE(mptcp_subflow_ctx(ssk)->fail_tout, 0); + unlock_sock_fast(ssk, slow); + + mptcp_reset_timeout(msk, 0); } static void mptcp_worker(struct work_struct *work) { struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); struct sock *sk = &msk->sk.icsk_inet.sk; + unsigned long fail_tout; int state; lock_sock(sk); @@ -2575,7 +2583,9 @@ static void mptcp_worker(struct work_struct *work) if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags)) __mptcp_retrans(sk); - mptcp_mp_fail_no_response(msk); + fail_tout = msk->first ? READ_ONCE(mptcp_subflow_ctx(msk->first)->fail_tout) : 0; + if (fail_tout && time_after(jiffies, fail_tout)) + mptcp_mp_fail_no_response(msk); unlock: release_sock(sk); @@ -2822,6 +2832,7 @@ static void __mptcp_destroy_sock(struct sock *sk) static void mptcp_close(struct sock *sk, long timeout) { struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk = mptcp_sk(sk); bool do_cancel_work = false; lock_sock(sk); @@ -2840,10 +2851,16 @@ static void mptcp_close(struct sock *sk, long timeout) cleanup: /* orphan all the subflows */ inet_csk(sk)->icsk_mtup.probe_timestamp = tcp_jiffies32; - mptcp_for_each_subflow(mptcp_sk(sk), subflow) { + mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); bool slow = lock_sock_fast_nested(ssk); + /* since the close timeout takes precedence on the fail one, + * cancel the latter + */ + if (ssk == msk->first) + subflow->fail_tout = 0; + sock_orphan(ssk); unlock_sock_fast(ssk, slow); } @@ -2852,13 +2869,13 @@ cleanup: sock_hold(sk); pr_debug("msk=%p state=%d", sk, sk->sk_state); if (mptcp_sk(sk)->token) - mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL); + mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL); if (sk->sk_state == TCP_CLOSE) { __mptcp_destroy_sock(sk); do_cancel_work = true; } else { - sk_reset_timer(sk, &sk->sk_timer, jiffies + TCP_TIMEWAIT_LEN); + mptcp_reset_timeout(msk, 0); } release_sock(sk); if (do_cancel_work) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 200f89f6d62f..1d2d71711872 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -468,7 +468,6 @@ struct mptcp_subflow_context { local_id_valid : 1, /* local_id is correctly initialized */ valid_csum_seen : 1; /* at least one csum validated */ enum mptcp_data_avail data_avail; - bool mp_fail_response_expect; u32 remote_nonce; u64 thmac; u32 local_nonce; @@ -482,6 +481,7 @@ struct mptcp_subflow_context { u8 stale_count; long delegated_status; + unsigned long fail_tout; ); @@ -662,6 +662,7 @@ void mptcp_get_options(const struct sk_buff *skb, void mptcp_finish_connect(struct sock *sk); void __mptcp_set_connected(struct sock *sk); +void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout); static inline bool mptcp_is_fully_established(struct sock *sk) { return inet_sk_state_load(sk) == TCP_ESTABLISHED && diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 42a7c18a1c24..8dfea6a8a82f 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -971,7 +971,6 @@ static enum mapping_status get_mapping_status(struct sock *ssk, { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); bool csum_reqd = READ_ONCE(msk->csum_enabled); - struct sock *sk = (struct sock *)msk; struct mptcp_ext *mpext; struct sk_buff *skb; u16 data_len; @@ -1013,9 +1012,6 @@ static enum mapping_status get_mapping_status(struct sock *ssk, pr_debug("infinite mapping received"); MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX); subflow->map_data_len = 0; - if (!sock_flag(ssk, SOCK_DEAD)) - sk_stop_timer(sk, &sk->sk_timer); - return MAPPING_INVALID; } @@ -1162,6 +1158,33 @@ static bool subflow_can_fallback(struct mptcp_subflow_context *subflow) return !subflow->fully_established; } +static void mptcp_subflow_fail(struct mptcp_sock *msk, struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + unsigned long fail_tout; + + /* greceful failure can happen only on the MPC subflow */ + if (WARN_ON_ONCE(ssk != READ_ONCE(msk->first))) + return; + + /* since the close timeout take precedence on the fail one, + * no need to start the latter when the first is already set + */ + if (sock_flag((struct sock *)msk, SOCK_DEAD)) + return; + + /* we don't need extreme accuracy here, use a zero fail_tout as special + * value meaning no fail timeout at all; + */ + fail_tout = jiffies + TCP_RTO_MAX; + if (!fail_tout) + fail_tout = 1; + WRITE_ONCE(subflow->fail_tout, fail_tout); + tcp_send_ack(ssk); + + mptcp_reset_timeout(msk, subflow->fail_tout); +} + static bool subflow_check_data_avail(struct sock *ssk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); @@ -1236,11 +1259,8 @@ fallback: tcp_send_active_reset(ssk, GFP_ATOMIC); while ((skb = skb_peek(&ssk->sk_receive_queue))) sk_eat_skb(ssk, skb); - } else if (!sock_flag(ssk, SOCK_DEAD)) { - WRITE_ONCE(subflow->mp_fail_response_expect, true); - sk_reset_timer((struct sock *)msk, - &((struct sock *)msk)->sk_timer, - jiffies + TCP_RTO_MAX); + } else { + mptcp_subflow_fail(msk, ssk); } WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA); return true; -- cgit v1.2.3-71-gd317 From d51991e2e31477853e5b9c1005ac617707077286 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 27 Jun 2022 18:02:38 -0700 Subject: mptcp: fix shutdown vs fallback race If the MPTCP socket shutdown happens before a fallback to TCP, and all the pending data have been already spooled, we never close the TCP connection. Address the issue explicitly checking for critical condition at fallback time. Fixes: 1e39e5a32ad7 ("mptcp: infinite mapping sending") Fixes: 0348c690ed37 ("mptcp: add the fallback check") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/options.c | 2 +- net/mptcp/protocol.c | 2 +- net/mptcp/protocol.h | 19 ++++++++++++++++--- net/mptcp/subflow.c | 2 +- 4 files changed, 19 insertions(+), 6 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 2a6351d55a7d..aead331866a0 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -967,7 +967,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, goto reset; subflow->mp_capable = 0; pr_fallback(msk); - __mptcp_do_fallback(msk); + mptcp_do_fallback(ssk); return false; } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e6fcb61443dd..e63bc2bb7fff 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1245,7 +1245,7 @@ static void mptcp_update_infinite_map(struct mptcp_sock *msk, MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX); mptcp_subflow_ctx(ssk)->send_infinite_map = 0; pr_fallback(msk); - __mptcp_do_fallback(msk); + mptcp_do_fallback(ssk); } static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 1d2d71711872..9860179bfd5e 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -927,12 +927,25 @@ static inline void __mptcp_do_fallback(struct mptcp_sock *msk) set_bit(MPTCP_FALLBACK_DONE, &msk->flags); } -static inline void mptcp_do_fallback(struct sock *sk) +static inline void mptcp_do_fallback(struct sock *ssk) { - struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); - struct mptcp_sock *msk = mptcp_sk(subflow->conn); + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct sock *sk = subflow->conn; + struct mptcp_sock *msk; + msk = mptcp_sk(sk); __mptcp_do_fallback(msk); + if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) { + gfp_t saved_allocation = ssk->sk_allocation; + + /* we are in a atomic (BH) scope, override ssk default for data + * fin allocation + */ + ssk->sk_allocation = GFP_ATOMIC; + ssk->sk_shutdown |= SEND_SHUTDOWN; + tcp_shutdown(ssk, SEND_SHUTDOWN); + ssk->sk_allocation = saved_allocation; + } } #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 8dfea6a8a82f..b34b96fb742f 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1279,7 +1279,7 @@ fallback: return false; } - __mptcp_do_fallback(msk); + mptcp_do_fallback(ssk); } skb = skb_peek(&ssk->sk_receive_queue); -- cgit v1.2.3-71-gd317 From f745a3ebdfb9041d3a55e66eb345895cd8ecc90c Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 27 Jun 2022 18:02:39 -0700 Subject: mptcp: consistent map handling on failure When the MPTCP receive path reach a non fatal fall-back condition, e.g. when the MPC sockets must fall-back to TCP, the existing code is a little self-inconsistent: it reports that new data is available - return true - but sets the MPC flag to the opposite value. As the consequence read operations in some exceptional scenario may block unexpectedly. Address the issue setting the correct MPC read status. Additionally avoid some code duplication in the fatal fall-back scenario. Fixes: 9c81be0dbc89 ("mptcp: add MP_FAIL response support") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/subflow.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index b34b96fb742f..03862103665d 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1252,17 +1252,12 @@ fallback: subflow->send_mp_fail = 1; if (!READ_ONCE(msk->allow_infinite_fallback)) { - ssk->sk_err = EBADMSG; - tcp_set_state(ssk, TCP_CLOSE); subflow->reset_transient = 0; subflow->reset_reason = MPTCP_RST_EMIDDLEBOX; - tcp_send_active_reset(ssk, GFP_ATOMIC); - while ((skb = skb_peek(&ssk->sk_receive_queue))) - sk_eat_skb(ssk, skb); - } else { - mptcp_subflow_fail(msk, ssk); + goto reset; } - WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA); + mptcp_subflow_fail(msk, ssk); + WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_DATA_AVAIL); return true; } @@ -1270,10 +1265,14 @@ fallback: /* fatal protocol error, close the socket. * subflow_error_report() will introduce the appropriate barriers */ - ssk->sk_err = EBADMSG; - tcp_set_state(ssk, TCP_CLOSE); subflow->reset_transient = 0; subflow->reset_reason = MPTCP_RST_EMPTCP; + +reset: + ssk->sk_err = EBADMSG; + tcp_set_state(ssk, TCP_CLOSE); + while ((skb = skb_peek(&ssk->sk_receive_queue))) + sk_eat_skb(ssk, skb); tcp_send_active_reset(ssk, GFP_ATOMIC); WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA); return false; -- cgit v1.2.3-71-gd317 From 6aeed9045071f2252ff4e98fc13d1e304f33e5b0 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 27 Jun 2022 18:02:40 -0700 Subject: mptcp: fix race on unaccepted mptcp sockets When the listener socket owning the relevant request is closed, it frees the unaccepted subflows and that causes later deletion of the paired MPTCP sockets. The mptcp socket's worker can run in the time interval between such delete operations. When that happens, any access to msk->first will cause an UaF access, as the subflow cleanup did not cleared such field in the mptcp socket. Address the issue explicitly traversing the listener socket accept queue at close time and performing the needed cleanup on the pending msk. Note that the locking is a bit tricky, as we need to acquire the msk socket lock, while still owning the subflow socket one. Fixes: 86e39e04482b ("mptcp: keep track of local endpoint still available for each msk") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/protocol.c | 5 +++++ net/mptcp/protocol.h | 2 ++ net/mptcp/subflow.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 59 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e63bc2bb7fff..e475212f2618 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2331,6 +2331,11 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, kfree_rcu(subflow, rcu); } else { /* otherwise tcp will dispose of the ssk and subflow ctx */ + if (ssk->sk_state == TCP_LISTEN) { + tcp_set_state(ssk, TCP_CLOSE); + mptcp_subflow_queue_clean(ssk); + inet_csk_listen_stop(ssk); + } __tcp_close(ssk, 0); /* close acquired an extra ref */ diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 9860179bfd5e..c14d70c036d0 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -306,6 +306,7 @@ struct mptcp_sock { u32 setsockopt_seq; char ca_name[TCP_CA_NAME_MAX]; + struct mptcp_sock *dl_next; }; #define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock) @@ -608,6 +609,7 @@ void mptcp_close_ssk(struct sock *sk, struct sock *ssk, struct mptcp_subflow_context *subflow); void mptcp_subflow_send_ack(struct sock *ssk); void mptcp_subflow_reset(struct sock *ssk); +void mptcp_subflow_queue_clean(struct sock *ssk); void mptcp_sock_graft(struct sock *sk, struct socket *parent); struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk); diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 03862103665d..63e8892ec807 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1723,6 +1723,58 @@ static void subflow_state_change(struct sock *sk) } } +void mptcp_subflow_queue_clean(struct sock *listener_ssk) +{ + struct request_sock_queue *queue = &inet_csk(listener_ssk)->icsk_accept_queue; + struct mptcp_sock *msk, *next, *head = NULL; + struct request_sock *req; + + /* build a list of all unaccepted mptcp sockets */ + spin_lock_bh(&queue->rskq_lock); + for (req = queue->rskq_accept_head; req; req = req->dl_next) { + struct mptcp_subflow_context *subflow; + struct sock *ssk = req->sk; + struct mptcp_sock *msk; + + if (!sk_is_mptcp(ssk)) + continue; + + subflow = mptcp_subflow_ctx(ssk); + if (!subflow || !subflow->conn) + continue; + + /* skip if already in list */ + msk = mptcp_sk(subflow->conn); + if (msk->dl_next || msk == head) + continue; + + msk->dl_next = head; + head = msk; + } + spin_unlock_bh(&queue->rskq_lock); + if (!head) + return; + + /* can't acquire the msk socket lock under the subflow one, + * or will cause ABBA deadlock + */ + release_sock(listener_ssk); + + for (msk = head; msk; msk = next) { + struct sock *sk = (struct sock *)msk; + bool slow; + + slow = lock_sock_fast_nested(sk); + next = msk->dl_next; + msk->first = NULL; + msk->dl_next = NULL; + unlock_sock_fast(sk, slow); + } + + /* we are still under the listener msk socket lock */ + lock_sock_nested(listener_ssk, SINGLE_DEPTH_NESTING); +} + static int subflow_ulp_init(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); -- cgit v1.2.3-71-gd317 From 42fb6cddec3b306c9f6ef136b6438e0de1836431 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 27 Jun 2022 18:02:41 -0700 Subject: selftests: mptcp: more stable diag tests The mentioned test-case still use an hard-coded-len sleep to wait for a relative large number of connection to be established. On very slow VM and with debug build such timeout could be exceeded, causing failures in our CI. Address the issue polling for the expected condition several times, up to an unreasonable high amount of time. On reasonably fast system the self-tests will be faster then before, on very slow one we will still catch the correct condition. Fixes: df62f2ec3df6 ("selftests/mptcp: add diag interface tests") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- tools/testing/selftests/net/mptcp/diag.sh | 48 +++++++++++++++++++++++++------ 1 file changed, 40 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh index 9dd43d7d957b..515859a5168b 100755 --- a/tools/testing/selftests/net/mptcp/diag.sh +++ b/tools/testing/selftests/net/mptcp/diag.sh @@ -61,6 +61,39 @@ chk_msk_nr() __chk_nr "grep -c token:" $* } +wait_msk_nr() +{ + local condition="grep -c token:" + local expected=$1 + local timeout=20 + local msg nr + local max=0 + local i=0 + + shift 1 + msg=$* + + while [ $i -lt $timeout ]; do + nr=$(ss -inmHMN $ns | $condition) + [ $nr == $expected ] && break; + [ $nr -gt $max ] && max=$nr + i=$((i + 1)) + sleep 1 + done + + printf "%-50s" "$msg" + if [ $i -ge $timeout ]; then + echo "[ fail ] timeout while expecting $expected max $max last $nr" + ret=$test_cnt + elif [ $nr != $expected ]; then + echo "[ fail ] expected $expected found $nr" + ret=$test_cnt + else + echo "[ ok ]" + fi + test_cnt=$((test_cnt+1)) +} + chk_msk_fallback_nr() { __chk_nr "grep -c fallback" $* @@ -146,7 +179,7 @@ ip -n $ns link set dev lo up echo "a" | \ timeout ${timeout_test} \ ip netns exec $ns \ - ./mptcp_connect -p 10000 -l -t ${timeout_poll} \ + ./mptcp_connect -p 10000 -l -t ${timeout_poll} -w 20 \ 0.0.0.0 >/dev/null & wait_local_port_listen $ns 10000 chk_msk_nr 0 "no msk on netns creation" @@ -155,7 +188,7 @@ chk_msk_listen 10000 echo "b" | \ timeout ${timeout_test} \ ip netns exec $ns \ - ./mptcp_connect -p 10000 -r 0 -t ${timeout_poll} \ + ./mptcp_connect -p 10000 -r 0 -t ${timeout_poll} -w 20 \ 127.0.0.1 >/dev/null & wait_connected $ns 10000 chk_msk_nr 2 "after MPC handshake " @@ -167,13 +200,13 @@ flush_pids echo "a" | \ timeout ${timeout_test} \ ip netns exec $ns \ - ./mptcp_connect -p 10001 -l -s TCP -t ${timeout_poll} \ + ./mptcp_connect -p 10001 -l -s TCP -t ${timeout_poll} -w 20 \ 0.0.0.0 >/dev/null & wait_local_port_listen $ns 10001 echo "b" | \ timeout ${timeout_test} \ ip netns exec $ns \ - ./mptcp_connect -p 10001 -r 0 -t ${timeout_poll} \ + ./mptcp_connect -p 10001 -r 0 -t ${timeout_poll} -w 20 \ 127.0.0.1 >/dev/null & wait_connected $ns 10001 chk_msk_fallback_nr 1 "check fallback" @@ -184,7 +217,7 @@ for I in `seq 1 $NR_CLIENTS`; do echo "a" | \ timeout ${timeout_test} \ ip netns exec $ns \ - ./mptcp_connect -p $((I+10001)) -l -w 10 \ + ./mptcp_connect -p $((I+10001)) -l -w 20 \ -t ${timeout_poll} 0.0.0.0 >/dev/null & done wait_local_port_listen $ns $((NR_CLIENTS + 10001)) @@ -193,12 +226,11 @@ for I in `seq 1 $NR_CLIENTS`; do echo "b" | \ timeout ${timeout_test} \ ip netns exec $ns \ - ./mptcp_connect -p $((I+10001)) -w 10 \ + ./mptcp_connect -p $((I+10001)) -w 20 \ -t ${timeout_poll} 127.0.0.1 >/dev/null & done -sleep 1.5 -chk_msk_nr $((NR_CLIENTS*2)) "many msk socket present" +wait_msk_nr $((NR_CLIENTS*2)) "many msk socket present" flush_pids exit $ret -- cgit v1.2.3-71-gd317 From 06e445f740c1a0fe5d16b3dff8a4ef18e124e54e Mon Sep 17 00:00:00 2001 From: Ossama Othman Date: Mon, 27 Jun 2022 18:02:42 -0700 Subject: mptcp: fix conflict with Including before the C library header causes symbol redefinition errors at compile-time due to duplicate declarations and definitions in the header included by . Explicitly include before in when __KERNEL__ is not defined so that the C library compatibility logic in is enabled when including in user space code. Fixes: c11c5906bc0a ("mptcp: add MPTCP_SUBFLOW_ADDRS getsockopt support") Signed-off-by: Ossama Othman Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- include/uapi/linux/mptcp.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h index 921963589904..dfe19bf13f4c 100644 --- a/include/uapi/linux/mptcp.h +++ b/include/uapi/linux/mptcp.h @@ -2,16 +2,17 @@ #ifndef _UAPI_MPTCP_H #define _UAPI_MPTCP_H +#ifndef __KERNEL__ +#include /* for sockaddr_in and sockaddr_in6 */ +#include /* for struct sockaddr */ +#endif + #include #include #include /* for sockaddr_in */ #include /* for sockaddr_in6 */ #include /* for sockaddr_storage and sa_family */ -#ifndef __KERNEL__ -#include /* for struct sockaddr */ -#endif - #define MPTCP_SUBFLOW_FLAG_MCAP_REM _BITUL(0) #define MPTCP_SUBFLOW_FLAG_MCAP_LOC _BITUL(1) #define MPTCP_SUBFLOW_FLAG_JOIN_REM _BITUL(2) -- cgit v1.2.3-71-gd317 From fd37c2ecb21f7aee04ccca5f561469f07d00063c Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Mon, 27 Jun 2022 18:02:43 -0700 Subject: selftests: mptcp: Initialize variables to quiet gcc 12 warnings In a few MPTCP selftest tools, gcc 12 complains that the 'sock' variable might be used uninitialized. This is a false positive because the only code path that could lead to uninitialized access is where getaddrinfo() fails, but the local xgetaddrinfo() wrapper exits if such a failure occurs. Initialize the 'sock' variable anyway to allow the tools to build with gcc 12. Fixes: 048d19d444be ("mptcp: add basic kselftest for mptcp") Acked-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- tools/testing/selftests/net/mptcp/mptcp_connect.c | 2 +- tools/testing/selftests/net/mptcp/mptcp_inq.c | 2 +- tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c index 8628aa61b763..e2ea6c126c99 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_connect.c +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c @@ -265,7 +265,7 @@ static void sock_test_tcpulp(int sock, int proto, unsigned int line) static int sock_listen_mptcp(const char * const listenaddr, const char * const port) { - int sock; + int sock = -1; struct addrinfo hints = { .ai_protocol = IPPROTO_TCP, .ai_socktype = SOCK_STREAM, diff --git a/tools/testing/selftests/net/mptcp/mptcp_inq.c b/tools/testing/selftests/net/mptcp/mptcp_inq.c index 29f75e2a1116..8672d898f8cd 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_inq.c +++ b/tools/testing/selftests/net/mptcp/mptcp_inq.c @@ -88,7 +88,7 @@ static void xgetaddrinfo(const char *node, const char *service, static int sock_listen_mptcp(const char * const listenaddr, const char * const port) { - int sock; + int sock = -1; struct addrinfo hints = { .ai_protocol = IPPROTO_TCP, .ai_socktype = SOCK_STREAM, diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c index ac9a4d9c1764..ae61f39556ca 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c +++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c @@ -136,7 +136,7 @@ static void xgetaddrinfo(const char *node, const char *service, static int sock_listen_mptcp(const char * const listenaddr, const char * const port) { - int sock; + int sock = -1; struct addrinfo hints = { .ai_protocol = IPPROTO_TCP, .ai_socktype = SOCK_STREAM, -- cgit v1.2.3-71-gd317