From 50c504a20a754ca37b5e1f4e660cd687769a7dca Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 10 Dec 2020 14:25:04 -0800 Subject: [PATCH] mptcp: parse and act on incoming FASTCLOSE option parse the MPTCP FASTCLOSE subtype. If provided key matches the local one, schedule the work queue to close (with tcp reset) all subflows. The MPTCP socket moves to closed state immediately. Reviewed-by: Matthieu Baerts Signed-off-by: Florian Westphal Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/options.c | 17 +++++++++++++++++ net/mptcp/protocol.c | 33 +++++++++++++++++++++++++++++++++ net/mptcp/protocol.h | 4 ++++ 3 files changed, 54 insertions(+) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 1ca60d9da3ef..5e7d7755d1a6 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -282,6 +282,16 @@ static void mptcp_parse_option(const struct sk_buff *skb, pr_debug("RM_ADDR: id=%d", mp_opt->rm_id); break; + case MPTCPOPT_MP_FASTCLOSE: + if (opsize != TCPOLEN_MPTCP_FASTCLOSE) + break; + + ptr += 2; + mp_opt->rcvr_key = get_unaligned_be64(ptr); + ptr += 8; + mp_opt->fastclose = 1; + break; + default: break; } @@ -299,6 +309,7 @@ void mptcp_get_options(const struct sk_buff *skb, mp_opt->mp_join = 0; mp_opt->add_addr = 0; mp_opt->ahmac = 0; + mp_opt->fastclose = 0; mp_opt->port = 0; mp_opt->rm_addr = 0; mp_opt->dss = 0; @@ -942,6 +953,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) return; + if (mp_opt.fastclose && + msk->local_key == mp_opt.rcvr_key) { + WRITE_ONCE(msk->rcv_fastclose, true); + mptcp_schedule_work((struct sock *)msk); + } + if (mp_opt.add_addr && add_addr_hmac_valid(msk, &mp_opt)) { struct mptcp_addr_info addr; diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2540d82742ac..cb8b7adf218a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2217,6 +2217,36 @@ static bool mptcp_check_close_timeout(const struct sock *sk) return true; } +static void mptcp_check_fastclose(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow, *tmp; + struct sock *sk = &msk->sk.icsk_inet.sk; + + if (likely(!READ_ONCE(msk->rcv_fastclose))) + return; + + mptcp_token_destroy(msk); + + list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { + struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); + + lock_sock(tcp_sk); + if (tcp_sk->sk_state != TCP_CLOSE) { + tcp_send_active_reset(tcp_sk, GFP_ATOMIC); + tcp_set_state(tcp_sk, TCP_CLOSE); + } + release_sock(tcp_sk); + } + + inet_sk_state_store(sk, TCP_CLOSE); + sk->sk_shutdown = SHUTDOWN_MASK; + smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ + set_bit(MPTCP_DATA_READY, &msk->flags); + set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags); + + mptcp_close_wake_up(sk); +} + static void mptcp_worker(struct work_struct *work) { struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); @@ -2233,6 +2263,9 @@ static void mptcp_worker(struct work_struct *work) mptcp_check_data_fin_ack(sk); __mptcp_flush_join_list(msk); + + mptcp_check_fastclose(msk); + if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) __mptcp_close_subflow(msk); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index a5bc9599ae5c..7cf9d110b85f 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -23,6 +23,7 @@ #define OPTION_MPTCP_ADD_ADDR BIT(6) #define OPTION_MPTCP_ADD_ADDR6 BIT(7) #define OPTION_MPTCP_RM_ADDR BIT(8) +#define OPTION_MPTCP_FASTCLOSE BIT(9) /* MPTCP option subtypes */ #define MPTCPOPT_MP_CAPABLE 0 @@ -58,6 +59,7 @@ #define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 24 #define TCPOLEN_MPTCP_PORT_LEN 4 #define TCPOLEN_MPTCP_RM_ADDR_BASE 4 +#define TCPOLEN_MPTCP_FASTCLOSE 12 /* MPTCP MP_JOIN flags */ #define MPTCPOPT_BACKUP BIT(0) @@ -110,6 +112,7 @@ struct mptcp_options_received { u16 data_len; u16 mp_capable : 1, mp_join : 1, + fastclose : 1, dss : 1, add_addr : 1, rm_addr : 1, @@ -237,6 +240,7 @@ struct mptcp_sock { bool fully_established; bool rcv_data_fin; bool snd_data_fin_enable; + bool rcv_fastclose; bool use_64bit_ack; /* Set when we received a 64-bit DSN */ spinlock_t join_list_lock; struct sock *ack_hint; -- GitLab