From f284c0c7732189fa77567dc061c5f4205c4fa05b Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Thu, 6 Jan 2022 16:20:15 -0800 Subject: mptcp: implement fastclose xmit path Allow the MPTCP xmit path to add MP_FASTCLOSE suboption on RST egress packets. Additionally reorder related options writing to reduce the number of conditionals required in the fast path. Co-developed-by: Geliang Tang Signed-off-by: Geliang Tang Co-developed-by: Matthieu Baerts Signed-off-by: Matthieu Baerts Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/options.c | 57 +++++++++++++++++++++++++++++++++++++++++----------- net/mptcp/protocol.h | 1 + 2 files changed, 46 insertions(+), 12 deletions(-) (limited to 'net') diff --git a/net/mptcp/options.c b/net/mptcp/options.c index fe98e4f475ba..46d35a235f35 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -768,6 +768,28 @@ static noinline bool mptcp_established_options_rst(struct sock *sk, struct sk_bu return true; } +static bool mptcp_established_options_fastclose(struct sock *sk, + unsigned int *size, + unsigned int remaining, + struct mptcp_out_options *opts) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); + struct mptcp_sock *msk = mptcp_sk(subflow->conn); + + if (likely(!subflow->send_fastclose)) + return false; + + if (remaining < TCPOLEN_MPTCP_FASTCLOSE) + return false; + + *size = TCPOLEN_MPTCP_FASTCLOSE; + opts->suboptions |= OPTION_MPTCP_FASTCLOSE; + opts->rcvr_key = msk->remote_key; + + pr_debug("FASTCLOSE key=%llu", opts->rcvr_key); + return true; +} + static bool mptcp_established_options_mp_fail(struct sock *sk, unsigned int *size, unsigned int remaining, @@ -806,10 +828,12 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, return false; if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) { - if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) { + if (mptcp_established_options_fastclose(sk, &opt_size, remaining, opts) || + mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) { *size += opt_size; remaining -= opt_size; } + /* 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; @@ -1251,17 +1275,8 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, ptr += 2; } - /* RST is mutually exclusive with everything else */ - if (unlikely(OPTION_MPTCP_RST & opts->suboptions)) { - *ptr++ = mptcp_option(MPTCPOPT_RST, - TCPOLEN_MPTCP_RST, - opts->reset_transient, - opts->reset_reason); - return; - } - - /* DSS, MPC, MPJ and ADD_ADDR are mutually exclusive, see - * mptcp_established_options*() + /* DSS, MPC, MPJ, ADD_ADDR, FASTCLOSE and RST are mutually exclusive, + * see mptcp_established_options*() */ if (likely(OPTION_MPTCP_DSS & opts->suboptions)) { struct mptcp_ext *mpext = &opts->ext_copy; @@ -1447,6 +1462,24 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, ptr += 1; } } + } else if (unlikely(OPTION_MPTCP_FASTCLOSE & opts->suboptions)) { + /* FASTCLOSE is mutually exclusive with others except RST */ + *ptr++ = mptcp_option(MPTCPOPT_MP_FASTCLOSE, + TCPOLEN_MPTCP_FASTCLOSE, + 0, 0); + put_unaligned_be64(opts->rcvr_key, ptr); + ptr += 2; + + if (OPTION_MPTCP_RST & opts->suboptions) + goto mp_rst; + return; + } else if (unlikely(OPTION_MPTCP_RST & opts->suboptions)) { +mp_rst: + *ptr++ = mptcp_option(MPTCPOPT_RST, + TCPOLEN_MPTCP_RST, + opts->reset_transient, + opts->reset_reason); + return; } if (OPTION_MPTCP_PRIO & opts->suboptions) { diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 0486c9f5b38b..f177936ff67d 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -423,6 +423,7 @@ struct mptcp_subflow_context { backup : 1, send_mp_prio : 1, send_mp_fail : 1, + send_fastclose : 1, rx_eof : 1, can_ack : 1, /* only after processing the remote a key */ disposable : 1, /* ctx can be free at ulp release time */ -- cgit v1.2.3-58-ga151