1 files changed, 67 insertions, 6 deletions

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index e0d21c0607e5..b63574d6b812 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -282,6 +282,15 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		pr_debug("RM_ADDR: id=%d", mp_opt->rm_id);
 		break;
 
+	case MPTCPOPT_MP_PRIO:
+		if (opsize != TCPOLEN_MPTCP_PRIO)
+			break;
+
+		mp_opt->mp_prio = 1;
+		mp_opt->backup = *ptr++ & MPTCP_PRIO_BKUP;
+		pr_debug("MP_PRIO: prio=%d", mp_opt->backup);
+		break;
+
 	case MPTCPOPT_MP_FASTCLOSE:
 		if (opsize != TCPOLEN_MPTCP_FASTCLOSE)
 			break;
@@ -313,6 +322,7 @@ void mptcp_get_options(const struct sk_buff *skb,
 	mp_opt->port = 0;
 	mp_opt->rm_addr = 0;
 	mp_opt->dss = 0;
+	mp_opt->mp_prio = 0;
 
 	length = (th->doff * 4) - sizeof(struct tcphdr);
 	ptr = (const unsigned char *)(th + 1);
@@ -498,8 +508,8 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
+	u64 snd_data_fin_enable, ack_seq;
 	unsigned int dss_size = 0;
-	u64 snd_data_fin_enable;
 	struct mptcp_ext *mpext;
 	unsigned int ack_size;
 	bool ret = false;
@@ -531,13 +541,14 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
 		return ret;
 	}
 
+	ack_seq = READ_ONCE(msk->ack_seq);
 	if (READ_ONCE(msk->use_64bit_ack)) {
 		ack_size = TCPOLEN_MPTCP_DSS_ACK64;
-		opts->ext_copy.data_ack = READ_ONCE(msk->ack_seq);
+		opts->ext_copy.data_ack = ack_seq;
 		opts->ext_copy.ack64 = 1;
 	} else {
 		ack_size = TCPOLEN_MPTCP_DSS_ACK32;
-		opts->ext_copy.data_ack32 = (uint32_t)READ_ONCE(msk->ack_seq);
+		opts->ext_copy.data_ack32 = (uint32_t)ack_seq;
 		opts->ext_copy.ack64 = 0;
 	}
 	opts->ext_copy.use_ack = 1;
@@ -679,6 +690,29 @@ static bool mptcp_established_options_rm_addr(struct sock *sk,
 	return true;
 }
 
+static bool mptcp_established_options_mp_prio(struct sock *sk,
+					      unsigned int *size,
+					      unsigned int remaining,
+					      struct mptcp_out_options *opts)
+{
+	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+
+	if (!subflow->send_mp_prio)
+		return false;
+
+	/* account for the trailing 'nop' option */
+	if (remaining < TCPOLEN_MPTCP_PRIO_ALIGN)
+		return false;
+
+	*size = TCPOLEN_MPTCP_PRIO_ALIGN;
+	opts->suboptions |= OPTION_MPTCP_PRIO;
+	opts->backup = subflow->request_bkup;
+
+	pr_debug("prio=%d", opts->backup);
+
+	return true;
+}
+
 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 			       unsigned int *size, unsigned int remaining,
 			       struct mptcp_out_options *opts)
@@ -721,6 +755,12 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 		ret = true;
 	}
 
+	if (mptcp_established_options_mp_prio(sk, &opt_size, remaining, opts)) {
+		*size += opt_size;
+		remaining -= opt_size;
+		ret = true;
+	}
+
 	return ret;
 }
 
@@ -828,7 +868,7 @@ fully_established:
 		clear_3rdack_retransmission(ssk);
 		mptcp_pm_subflow_established(msk, subflow);
 	} else {
-		mptcp_pm_fully_established(msk);
+		mptcp_pm_fully_established(msk, ssk, GFP_ATOMIC);
 	}
 	return true;
 
@@ -879,8 +919,7 @@ static void ack_update_msk(struct mptcp_sock *msk,
 		msk->wnd_end = new_wnd_end;
 
 	/* this assumes mptcp_incoming_options() is invoked after tcp_ack() */
-	if (after64(msk->wnd_end, READ_ONCE(msk->snd_nxt)) &&
-	    sk_stream_memory_free(ssk))
+	if (after64(msk->wnd_end, READ_ONCE(msk->snd_nxt)))
 		__mptcp_check_push(sk, ssk);
 
 	if (after64(new_snd_una, old_snd_una)) {
@@ -986,6 +1025,10 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 			mptcp_pm_del_add_timer(msk, &addr);
 			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD);
 		}
+
+		if (mp_opt.port)
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_PORTADD);
+
 		mp_opt.add_addr = 0;
 	}
 
@@ -994,6 +1037,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 		mp_opt.rm_addr = 0;
 	}
 
+	if (mp_opt.mp_prio) {
+		mptcp_pm_mp_prio_received(sk, mp_opt.backup);
+		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIORX);
+		mp_opt.mp_prio = 0;
+	}
+
 	if (!mp_opt.dss)
 		return;
 
@@ -1168,6 +1217,18 @@ mp_capable_done:
 				      0, opts->rm_id);
 	}
 
+	if (OPTION_MPTCP_PRIO & opts->suboptions) {
+		const struct sock *ssk = (const struct sock *)tp;
+		struct mptcp_subflow_context *subflow;
+
+		subflow = mptcp_subflow_ctx(ssk);
+		subflow->send_mp_prio = 0;
+
+		*ptr++ = mptcp_option(MPTCPOPT_MP_PRIO,
+				      TCPOLEN_MPTCP_PRIO,
+				      opts->backup, TCPOPT_NOP);
+	}
+
 	if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) {
 		*ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
 				      TCPOLEN_MPTCP_MPJ_SYN,