[PATCH net-next 5/7] mptcp: send out MP_FAIL when data checksum fails
From: Mat Martineau <hidden>
Date: 2021-08-24 23:26:40
Also in:
mptcp
Subsystem:
networking [general], networking [mptcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthieu Baerts, Mat Martineau, Linus Torvalds
From: Geliang Tang <redacted> When a bad checksum is detected, set the send_mp_fail flag to send out the MP_FAIL option. Add a new function mptcp_has_another_subflow() to check whether there's only a single subflow. When multiple subflows are in use, close the affected subflow with a RST that includes an MP_FAIL option and discard the data with the bad checksum. Set the sk_state of the subsocket to TCP_CLOSE, then the flag MPTCP_WORK_CLOSE_SUBFLOW will be set in subflow_sched_work_if_closed, and the subflow will be closed. When a single subfow is in use, temporarily handled by sending MP_FAIL with a RST too. Signed-off-by: Geliang Tang <redacted> Signed-off-by: Mat Martineau <redacted> --- net/mptcp/protocol.h | 13 +++++++++++++ net/mptcp/subflow.c | 15 +++++++++++++++ 2 files changed, 28 insertions(+)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 9ee5676e70c6..57a50b1194a9 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h@@ -614,6 +614,19 @@ static inline void mptcp_subflow_tcp_fallback(struct sock *sk, inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops; } +static inline bool mptcp_has_another_subflow(struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk), *tmp; + struct mptcp_sock *msk = mptcp_sk(subflow->conn); + + mptcp_for_each_subflow(msk, tmp) { + if (tmp != subflow) + return true; + } + + return false; +} + void __init mptcp_proto_init(void); #if IS_ENABLED(CONFIG_MPTCP_IPV6) int __init mptcp_proto_v6_init(void);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 8c43aa14897a..dba8ad700fb8 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c@@ -910,6 +910,7 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff * csum = csum_partial(&header, sizeof(header), subflow->map_data_csum); if (unlikely(csum_fold(csum))) { MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR); + subflow->send_mp_fail = 1; return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY; }
@@ -1157,6 +1158,20 @@ static bool subflow_check_data_avail(struct sock *ssk) fallback: /* RFC 8684 section 3.7. */ + if (subflow->send_mp_fail) { + if (mptcp_has_another_subflow(ssk)) { + while ((skb = skb_peek(&ssk->sk_receive_queue))) + sk_eat_skb(ssk, skb); + } + 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); + WRITE_ONCE(subflow->data_avail, 0); + return true; + } + if (subflow->mp_join || subflow->fully_established) { /* fatal protocol error, close the socket. * subflow_error_report() will introduce the appropriate barriers
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2.33.0