[MPTCP][PATCH v5 mptcp-next 0/5] MP_FAIL support

[MPTCP][PATCH v5 mptcp-next 0/5] MP_FAIL support

[Geliang Tang]

From: Geliang Tang <geliangtang@xiaomi.com>

v5:
 - patch 1, change "ret = true;" to "return true;"
 - patch 3, in the single-subflow case, send MP_FAIL and receive the
   echo, then temporarily handled by reset.

v4:
 - just deal with the multiple subflows case, put the single subflow
   case into the new 'infinite mapping' part.

v3:
 - respond with MP_FAIL
 - add single subflow check
 - add infinite mapping sending and receiving
 - export/20210626T054902

v2:
 - MP_FAIL logic:
   * Peer B send a DSS to peer A, and the data has been modify by the
  middleboxes, then peer A detects the bad checksum.
   * In the multiple subflows case, peer A sends MP_FAIL+RST back to peer B,
  and peer A discards the data following the bad data sequence number. Peer
  B receives this MP_FAIL+RST, and close this subflow.
   * In the single subflow case, using the simple implementation, peer A
  sends MP_FAIL back to peer B, and peer A fallback to a regular TCP. Peer
  B receives this MP_FAIL, and fallback to a regular TCP.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/52

Geliang Tang (5):
  mptcp: MP_FAIL suboption sending
  mptcp: MP_FAIL suboption receiving
  mptcp: send out MP_FAIL when data checksum fails
  mptcp: add the mibs for MP_FAIL
  selftests: mptcp: add MP_FAIL mibs check

 include/net/mptcp.h                           |  5 +-
 net/mptcp/mib.c                               |  2 +
 net/mptcp/mib.h                               |  2 +
 net/mptcp/options.c                           | 78 ++++++++++++++++++-
 net/mptcp/pm.c                                | 20 +++++
 net/mptcp/protocol.h                          | 20 +++++
 net/mptcp/subflow.c                           | 18 +++++
 .../testing/selftests/net/mptcp/mptcp_join.sh | 38 +++++++++
 8 files changed, 178 insertions(+), 5 deletions(-)

-- 
2.31.1

[MPTCP][PATCH v5 mptcp-next 1/5] mptcp: MP_FAIL suboption sending

[Geliang Tang]

From: Geliang Tang <geliangtang@xiaomi.com>

This patch added the MP_FAIL suboption sending support.

Add a new flag named send_mp_fail in struct mptcp_subflow_context. If
this flag is set, send out MP_FAIL suboption.

Add a new member fail_seq in struct mptcp_out_options to save the data
sequence number to put into the MP_FAIL suboption.

An MP_FAIL option could be included in a RST or on the subflow-level
ACK.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
---
 include/net/mptcp.h  |  5 +++-
 net/mptcp/options.c  | 61 +++++++++++++++++++++++++++++++++++++++++---
 net/mptcp/protocol.h |  3 +++
 3 files changed, 64 insertions(+), 5 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index d0b9e4a7121f..6c8c8592153d 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -60,7 +60,10 @@ struct mptcp_out_options {
 	u16 suboptions;
 	u64 sndr_key;
 	u64 rcvr_key;
-	u64 ahmac;
+	union {
+		u64 ahmac;
+		u64 fail_seq;
+	};
 	struct mptcp_addr_info local;
 	struct mptcp_addr_info remote;
 	struct mptcp_rm_list rm_list;
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 6803de5d4209..a7365379096d 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -754,7 +754,7 @@ static bool mptcp_established_options_mp_prio(struct sock *sk,
 	return true;
 }
 
-static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb,
+static noinline bool mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb,
 						   unsigned int *size,
 						   unsigned int remaining,
 						   struct mptcp_out_options *opts)
@@ -762,12 +762,36 @@ static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_bu
 	const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 
 	if (remaining < TCPOLEN_MPTCP_RST)
-		return;
+		return false;
 
 	*size = TCPOLEN_MPTCP_RST;
 	opts->suboptions |= OPTION_MPTCP_RST;
 	opts->reset_transient = subflow->reset_transient;
 	opts->reset_reason = subflow->reset_reason;
+
+	return true;
+}
+
+static bool mptcp_established_options_mp_fail(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_fail)
+		return false;
+
+	if (remaining < TCPOLEN_MPTCP_FAIL)
+		return false;
+
+	*size = TCPOLEN_MPTCP_FAIL;
+	opts->suboptions |= OPTION_MPTCP_FAIL;
+	opts->fail_seq = subflow->map_seq;
+
+	pr_debug("MP_FAIL fail_seq=%llu", opts->fail_seq);
+
+	return true;
 }
 
 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
@@ -786,15 +810,30 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 		return false;
 
 	if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) {
-		mptcp_established_options_rst(sk, skb, size, remaining, opts);
+		if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {
+			*size += opt_size;
+			remaining -= opt_size;
+		}
+		if (mptcp_established_options_rst(sk, skb, &opt_size, remaining, opts)) {
+			*size += opt_size;
+			remaining -= opt_size;
+		}
 		return true;
 	}
 
 	snd_data_fin = mptcp_data_fin_enabled(msk);
 	if (mptcp_established_options_mp(sk, skb, snd_data_fin, &opt_size, remaining, opts))
 		ret = true;
-	else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &opt_size, remaining, opts))
+	else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &opt_size, remaining, opts)) {
 		ret = true;
+		if (opts->ext_copy.use_ack) {
+			if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {
+				*size += opt_size;
+				remaining -= opt_size;
+				return true;
+			}
+		}
+	}
 
 	/* we reserved enough space for the above options, and exceeding the
 	 * TCP option space would be fatal
@@ -1343,6 +1382,20 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
 				      opts->backup, TCPOPT_NOP);
 	}
 
+	if (OPTION_MPTCP_FAIL & opts->suboptions) {
+		const struct sock *ssk = (const struct sock *)tp;
+		struct mptcp_subflow_context *subflow;
+
+		subflow = mptcp_subflow_ctx(ssk);
+		subflow->send_mp_fail = 0;
+
+		*ptr++ = mptcp_option(MPTCPOPT_MP_FAIL,
+				      TCPOLEN_MPTCP_FAIL,
+				      0, 0);
+		put_unaligned_be64(opts->fail_seq, ptr);
+		ptr += 2;
+	}
+
 	if (OPTION_MPTCP_MPJ_SYN & opts->suboptions) {
 		*ptr++ = mptcp_option(MPTCPOPT_MP_JOIN,
 				      TCPOLEN_MPTCP_MPJ_SYN,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 34ad1c4bc29f..ea4ab9b9d6db 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -26,6 +26,7 @@
 #define OPTION_MPTCP_FASTCLOSE	BIT(8)
 #define OPTION_MPTCP_PRIO	BIT(9)
 #define OPTION_MPTCP_RST	BIT(10)
+#define OPTION_MPTCP_FAIL	BIT(11)
 
 /* MPTCP option subtypes */
 #define MPTCPOPT_MP_CAPABLE	0
@@ -67,6 +68,7 @@
 #define TCPOLEN_MPTCP_PRIO_ALIGN	4
 #define TCPOLEN_MPTCP_FASTCLOSE		12
 #define TCPOLEN_MPTCP_RST		4
+#define TCPOLEN_MPTCP_FAIL		12
 
 #define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM	(TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
 
@@ -428,6 +430,7 @@ struct mptcp_subflow_context {
 		mpc_map : 1,
 		backup : 1,
 		send_mp_prio : 1,
+		send_mp_fail : 1,
 		rx_eof : 1,
 		can_ack : 1,        /* only after processing the remote a key */
 		disposable : 1,	    /* ctx can be free at ulp release time */
-- 
2.31.1

[MPTCP][PATCH v5 mptcp-next 2/5] mptcp: MP_FAIL suboption receiving

[Geliang Tang]

From: Geliang Tang <geliangtang@xiaomi.com>

This patch added handling for receiving MP_FAIL suboption.

Add a new members mp_fail and fail_seq in struct mptcp_options_received.
When MP_FAIL suboption is received, set mp_fail to 1 and save the sequence
number to fail_seq.

Then invoke mptcp_pm_mp_fail_received to deal with the MP_FAIL suboption.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
---
 net/mptcp/options.c  | 16 ++++++++++++++++
 net/mptcp/pm.c       |  5 +++++
 net/mptcp/protocol.h |  3 +++
 3 files changed, 24 insertions(+)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index a7365379096d..62085834782d 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -336,6 +336,16 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		mp_opt->reset_reason = *ptr;
 		break;
 
+	case MPTCPOPT_MP_FAIL:
+		if (opsize != TCPOLEN_MPTCP_FAIL)
+			break;
+
+		ptr += 2;
+		mp_opt->mp_fail = 1;
+		mp_opt->fail_seq = get_unaligned_be64(ptr);
+		pr_debug("MP_FAIL: data_seq=%llu", mp_opt->fail_seq);
+		break;
+
 	default:
 		break;
 	}
@@ -364,6 +374,7 @@ void mptcp_get_options(const struct sock *sk,
 	mp_opt->reset = 0;
 	mp_opt->csum_reqd = READ_ONCE(msk->csum_enabled);
 	mp_opt->deny_join_id0 = 0;
+	mp_opt->mp_fail = 0;
 
 	length = (th->doff * 4) - sizeof(struct tcphdr);
 	ptr = (const unsigned char *)(th + 1);
@@ -1138,6 +1149,11 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 		mp_opt.mp_prio = 0;
 	}
 
+	if (mp_opt.mp_fail) {
+		mptcp_pm_mp_fail_received(sk, mp_opt.fail_seq);
+		mp_opt.mp_fail = 0;
+	}
+
 	if (mp_opt.reset) {
 		subflow->reset_seen = 1;
 		subflow->reset_reason = mp_opt.reset_reason;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 692614c1f552..f37a014b4875 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -249,6 +249,11 @@ void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup)
 	mptcp_event(MPTCP_EVENT_SUB_PRIORITY, mptcp_sk(subflow->conn), sk, GFP_ATOMIC);
 }
 
+void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
+{
+	pr_debug("fail_seq=%llu", fail_seq);
+}
+
 /* path manager helpers */
 
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index ea4ab9b9d6db..19533e5778a6 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -139,6 +139,7 @@ struct mptcp_options_received {
 		add_addr : 1,
 		rm_addr : 1,
 		mp_prio : 1,
+		mp_fail : 1,
 		echo : 1,
 		csum_reqd : 1,
 		backup : 1,
@@ -160,6 +161,7 @@ struct mptcp_options_received {
 	u64	ahmac;
 	u8	reset_reason:4;
 	u8	reset_transient:1;
+	u64	fail_seq;
 };
 
 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
@@ -726,6 +728,7 @@ void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 				 struct mptcp_addr_info *addr,
 				 u8 bkup);
+void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
 struct mptcp_pm_add_entry *
-- 
2.31.1

[MPTCP][PATCH v5 mptcp-next 3/5] mptcp: send out MP_FAIL when data checksum fails

[Geliang Tang]

From: Geliang Tang <geliangtang@xiaomi.com>

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, send back an MP_FAIL option on the
subflow-level ACK. And the receiver of this MP_FAIL respond with an
MP_FAIL in the reverse direction.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
---
 net/mptcp/pm.c       | 14 ++++++++++++++
 net/mptcp/protocol.h | 14 ++++++++++++++
 net/mptcp/subflow.c  | 17 +++++++++++++++++
 3 files changed, 45 insertions(+)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index f37a014b4875..4a5cf1261ee0 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -251,7 +251,21 @@ void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup)
 
 void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
 {
+	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+
 	pr_debug("fail_seq=%llu", fail_seq);
+
+	if (!mptcp_has_another_subflow(sk)) {
+		if (!subflow->mp_fail_expect_echo) {
+			subflow->send_mp_fail = 1;
+		} else {
+			subflow->mp_fail_expect_echo = 0;
+			/* TODO the single-subflow case is temporarily
+			 * handled by reset.
+			 */
+			mptcp_subflow_reset(sk);
+		}
+	}
 }
 
 /* path manager helpers */
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 19533e5778a6..1622d6434785 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -433,6 +433,7 @@ struct mptcp_subflow_context {
 		backup : 1,
 		send_mp_prio : 1,
 		send_mp_fail : 1,
+		mp_fail_expect_echo : 1,
 		rx_eof : 1,
 		can_ack : 1,        /* only after processing the remote a key */
 		disposable : 1,	    /* ctx can be free at ulp release time */
@@ -614,6 +615,19 @@ 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 1151926d335b..a69839520472 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 +1158,22 @@ 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)) {
+			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 {
+			subflow->mp_fail_expect_echo = 1;
+		}
+		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
-- 
2.31.1

[MPTCP][PATCH v5 mptcp-next 4/5] mptcp: add the mibs for MP_FAIL

[Geliang Tang]

From: Geliang Tang <geliangtang@xiaomi.com>

This patch added the mibs for MP_FAIL: MPTCP_MIB_MPFAILTX and
MPTCP_MIB_MPFAILRX.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
---
 net/mptcp/mib.c     | 2 ++
 net/mptcp/mib.h     | 2 ++
 net/mptcp/options.c | 1 +
 net/mptcp/pm.c      | 1 +
 net/mptcp/subflow.c | 1 +
 5 files changed, 7 insertions(+)

diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index 3a7c4e7b2d79..b21ff9be04c6 100644
--- a/net/mptcp/mib.c
+++ b/net/mptcp/mib.c
@@ -44,6 +44,8 @@ static const struct snmp_mib mptcp_snmp_list[] = {
 	SNMP_MIB_ITEM("RmSubflow", MPTCP_MIB_RMSUBFLOW),
 	SNMP_MIB_ITEM("MPPrioTx", MPTCP_MIB_MPPRIOTX),
 	SNMP_MIB_ITEM("MPPrioRx", MPTCP_MIB_MPPRIORX),
+	SNMP_MIB_ITEM("MPFailTx", MPTCP_MIB_MPFAILTX),
+	SNMP_MIB_ITEM("MPFailRx", MPTCP_MIB_MPFAILRX),
 	SNMP_MIB_ITEM("RcvPruned", MPTCP_MIB_RCVPRUNED),
 	SNMP_MIB_ITEM("SubflowStale", MPTCP_MIB_SUBFLOWSTALE),
 	SNMP_MIB_ITEM("SubflowRecover", MPTCP_MIB_SUBFLOWRECOVER),
diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index 8ec16c991aac..ecd3d8b117e0 100644
--- a/net/mptcp/mib.h
+++ b/net/mptcp/mib.h
@@ -37,6 +37,8 @@ enum linux_mptcp_mib_field {
 	MPTCP_MIB_RMSUBFLOW,		/* Remove a subflow */
 	MPTCP_MIB_MPPRIOTX,		/* Transmit a MP_PRIO */
 	MPTCP_MIB_MPPRIORX,		/* Received a MP_PRIO */
+	MPTCP_MIB_MPFAILTX,		/* Transmit a MP_FAIL */
+	MPTCP_MIB_MPFAILRX,		/* Received a MP_FAIL */
 	MPTCP_MIB_RCVPRUNED,		/* Incoming packet dropped due to memory limit */
 	MPTCP_MIB_SUBFLOWSTALE,		/* Subflows entered 'stale' status */
 	MPTCP_MIB_SUBFLOWRECOVER,	/* Subflows returned to active status after being stale */
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 62085834782d..c915cc144d75 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -1151,6 +1151,7 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 
 	if (mp_opt.mp_fail) {
 		mptcp_pm_mp_fail_received(sk, mp_opt.fail_seq);
+		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILRX);
 		mp_opt.mp_fail = 0;
 	}
 
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 4a5cf1261ee0..3509345774a5 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -258,6 +258,7 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
 	if (!mptcp_has_another_subflow(sk)) {
 		if (!subflow->mp_fail_expect_echo) {
 			subflow->send_mp_fail = 1;
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX);
 		} else {
 			subflow->mp_fail_expect_echo = 0;
 			/* TODO the single-subflow case is temporarily
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index a69839520472..c25b1d961206 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -911,6 +911,7 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *
 	if (unlikely(csum_fold(csum))) {
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR);
 		subflow->send_mp_fail = 1;
+		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPFAILTX);
 		return subflow->mp_join ? MAPPING_INVALID : MAPPING_DUMMY;
 	}
 
-- 
2.31.1

[MPTCP][PATCH v5 mptcp-next 5/5] selftests: mptcp: add MP_FAIL mibs check

[Geliang Tang]

From: Geliang Tang <geliangtang@xiaomi.com>

This patch added a function chk_fail_nr to check the mibs for MP_FAIL.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
---
 .../testing/selftests/net/mptcp/mptcp_join.sh | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 937e861e9490..551fcce7c2f2 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -566,6 +566,43 @@ chk_csum_nr()
 	fi
 }
 
+chk_fail_nr()
+{
+	local mp_fail_nr_tx=$1
+	local mp_fail_nr_rx=$2
+	local count
+	local dump_stats
+
+	printf "%-39s %s" " " "ftx"
+	count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPFailTx | awk '{print $2}'`
+	[ -z "$count" ] && count=0
+	if [ "$count" != "$mp_fail_nr_tx" ]; then
+		echo "[fail] got $count MP_FAIL[s] TX expected $mp_fail_nr_tx"
+		ret=1
+		dump_stats=1
+	else
+		echo -n "[ ok ]"
+	fi
+
+	echo -n " - frx   "
+	count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPFailRx | awk '{print $2}'`
+	[ -z "$count" ] && count=0
+	if [ "$count" != "$mp_fail_nr_rx" ]; then
+		echo "[fail] got $count MP_FAIL[s] RX expected $mp_fail_nr_rx"
+		ret=1
+		dump_stats=1
+	else
+		echo "[ ok ]"
+	fi
+
+	if [ "${dump_stats}" = 1 ]; then
+		echo Server ns stats
+		ip netns exec $ns1 nstat -as | grep MPTcp
+		echo Client ns stats
+		ip netns exec $ns2 nstat -as | grep MPTcp
+	fi
+}
+
 chk_join_nr()
 {
 	local msg="$1"
@@ -615,6 +652,7 @@ chk_join_nr()
 	fi
 	if [ $checksum -eq 1 ]; then
 		chk_csum_nr
+		chk_fail_nr 0 0
 	fi
 }
 
-- 
2.31.1

Re: [MPTCP][PATCH v5 mptcp-next 1/5] mptcp: MP_FAIL suboption sending

[Paolo Abeni]

On Mon, 2021-07-26 at 14:45 +0800, Geliang Tang wrote:
> From: Geliang Tang <geliangtang@xiaomi.com>
> 
> This patch added the MP_FAIL suboption sending support.
> 
> Add a new flag named send_mp_fail in struct mptcp_subflow_context. If
> this flag is set, send out MP_FAIL suboption.
> 
> Add a new member fail_seq in struct mptcp_out_options to save the data
> sequence number to put into the MP_FAIL suboption.
> 
> An MP_FAIL option could be included in a RST or on the subflow-level
> ACK.
> 
> Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
> ---
>  include/net/mptcp.h  |  5 +++-
>  net/mptcp/options.c  | 61 +++++++++++++++++++++++++++++++++++++++++---
>  net/mptcp/protocol.h |  3 +++
>  3 files changed, 64 insertions(+), 5 deletions(-)
> 
> diff --git a/include/net/mptcp.h b/include/net/mptcp.h
> index d0b9e4a7121f..6c8c8592153d 100644
> --- a/include/net/mptcp.h
> +++ b/include/net/mptcp.h
> @@ -60,7 +60,10 @@ struct mptcp_out_options {
>  	u16 suboptions;
>  	u64 sndr_key;
>  	u64 rcvr_key;
> -	u64 ahmac;
> +	union {
> +		u64 ahmac;
> +		u64 fail_seq;
> +	};
>  	struct mptcp_addr_info local;
>  	struct mptcp_addr_info remote;
>  	struct mptcp_rm_list rm_list;

This will conflict with: "mptcp: shrink mptcp_out_options struct". If
this series is merged before the "mptcp: shrink mptcp_out_options
struct" series, I think we can just add the new field here without any
union and do the aliasing the the shirnk' patch.

Otherwise ("mptcp: shrink mptcp_out_options struct" merged first), I
think:

		struct mptcp_ext ext_copy;

should be replace with:
		struct {
			struct mptcp_ext ext_copy;
			u64 ahmac;
		};

mptcp_out_options should not change size that way.

Cheers

Paolo

Re: [MPTCP][PATCH v5 mptcp-next 0/5] MP_FAIL support

[Mat Martineau]

On Mon, 26 Jul 2021, Geliang Tang wrote:

> From: Geliang Tang <geliangtang@xiaomi.com>
>
> v5:
> - patch 1, change "ret = true;" to "return true;"
> - patch 3, in the single-subflow case, send MP_FAIL and receive the
>   echo, then temporarily handled by reset.
>

Hi Geliang -

Thanks for the v5 changes. The changes are looking good in terms of manual 
code review. Since the selftest changes in patch 5 only confirm that 
MP_FAIL was not sent, I'm going to do some testing tomorrow to force 
checksum failures in single and multiple subflow cases so I can check some 
packet traces. It would be good to have some packetdrill checksum test 
cases to cover that, but we don't yet.


- Mat


> v4:
> - just deal with the multiple subflows case, put the single subflow
>   case into the new 'infinite mapping' part.
>
> v3:
> - respond with MP_FAIL
> - add single subflow check
> - add infinite mapping sending and receiving
> - export/20210626T054902
>
> v2:
> - MP_FAIL logic:
>   * Peer B send a DSS to peer A, and the data has been modify by the
>  middleboxes, then peer A detects the bad checksum.
>   * In the multiple subflows case, peer A sends MP_FAIL+RST back to peer B,
>  and peer A discards the data following the bad data sequence number. Peer
>  B receives this MP_FAIL+RST, and close this subflow.
>   * In the single subflow case, using the simple implementation, peer A
>  sends MP_FAIL back to peer B, and peer A fallback to a regular TCP. Peer
>  B receives this MP_FAIL, and fallback to a regular TCP.
>
> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/52
>
> Geliang Tang (5):
>  mptcp: MP_FAIL suboption sending
>  mptcp: MP_FAIL suboption receiving
>  mptcp: send out MP_FAIL when data checksum fails
>  mptcp: add the mibs for MP_FAIL
>  selftests: mptcp: add MP_FAIL mibs check
>
> include/net/mptcp.h                           |  5 +-
> net/mptcp/mib.c                               |  2 +
> net/mptcp/mib.h                               |  2 +
> net/mptcp/options.c                           | 78 ++++++++++++++++++-
> net/mptcp/pm.c                                | 20 +++++
> net/mptcp/protocol.h                          | 20 +++++
> net/mptcp/subflow.c                           | 18 +++++
> .../testing/selftests/net/mptcp/mptcp_join.sh | 38 +++++++++
> 8 files changed, 178 insertions(+), 5 deletions(-)
>
> -- 
> 2.31.1
>
>
>

--
Mat Martineau
Intel

Re: [MPTCP][PATCH v5 mptcp-next 1/5] mptcp: MP_FAIL suboption sending

[Geliang Tang]

Hi Paolo,

Paolo Abeni <pabeni@redhat.com> 于2021年7月26日周一 下午7:10写道：
>
> On Mon, 2021-07-26 at 14:45 +0800, Geliang Tang wrote:
> > From: Geliang Tang <geliangtang@xiaomi.com>
> >
> > This patch added the MP_FAIL suboption sending support.
> >
> > Add a new flag named send_mp_fail in struct mptcp_subflow_context. If
> > this flag is set, send out MP_FAIL suboption.
> >
> > Add a new member fail_seq in struct mptcp_out_options to save the data
> > sequence number to put into the MP_FAIL suboption.
> >
> > An MP_FAIL option could be included in a RST or on the subflow-level
> > ACK.
> >
> > Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
> > ---
> >  include/net/mptcp.h  |  5 +++-
> >  net/mptcp/options.c  | 61 +++++++++++++++++++++++++++++++++++++++++---
> >  net/mptcp/protocol.h |  3 +++
> >  3 files changed, 64 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/net/mptcp.h b/include/net/mptcp.h
> > index d0b9e4a7121f..6c8c8592153d 100644
> > --- a/include/net/mptcp.h
> > +++ b/include/net/mptcp.h
> > @@ -60,7 +60,10 @@ struct mptcp_out_options {
> >       u16 suboptions;
> >       u64 sndr_key;
> >       u64 rcvr_key;
> > -     u64 ahmac;
> > +     union {
> > +             u64 ahmac;
> > +             u64 fail_seq;
> > +     };
> >       struct mptcp_addr_info local;
> >       struct mptcp_addr_info remote;
> >       struct mptcp_rm_list rm_list;
>
> This will conflict with: "mptcp: shrink mptcp_out_options struct". If
> this series is merged before the "mptcp: shrink mptcp_out_options
> struct" series, I think we can just add the new field here without any
> union and do the aliasing the the shirnk' patch.
>
> Otherwise ("mptcp: shrink mptcp_out_options struct" merged first), I
> think:
>
>                 struct mptcp_ext ext_copy;
>
> should be replace with:
>                 struct {
>                         struct mptcp_ext ext_copy;
>                         u64 ahmac;
>                 };

Do you mean that:

                struct mptcp_ext ext_copy;
should be replaced with:
                 struct {
                         struct mptcp_ext ext_copy;
                         u64 fail_seq;
                 };
?

Then the whole union is like this:

       union {
               struct {
                       u64 sndr_key;
                       u64 rcvr_key;
               };
               struct {
                       struct mptcp_addr_info addr;
                       u64 ahmac;
               };
               struct {
                       struct mptcp_ext ext_copy;
                       u64 fail_seq;
               };
               struct {
                       u32 nonce;
                       u32 token;
                       u64 thmac;
                       u8 hmac[20];
               };
       };

Do I understand correctly?

Thanks,
-Geliang






>
> mptcp_out_options should not change size that way.
>
> Cheers
>
> Paolo
>

Re: [MPTCP][PATCH v5 mptcp-next 0/5] MP_FAIL support

[Geliang Tang]

[-- Attachment #1: Type: text/plain, Size: 2837 bytes --]

Hi Mat,

Mat Martineau <mathew.j.martineau@linux.intel.com> 于2021年7月28日周三 上午8:27写道：
>
> On Mon, 26 Jul 2021, Geliang Tang wrote:
>
> > From: Geliang Tang <geliangtang@xiaomi.com>
> >
> > v5:
> > - patch 1, change "ret = true;" to "return true;"
> > - patch 3, in the single-subflow case, send MP_FAIL and receive the
> >   echo, then temporarily handled by reset.
> >
>
> Hi Geliang -
>
> Thanks for the v5 changes. The changes are looking good in terms of manual
> code review. Since the selftest changes in patch 5 only confirm that
> MP_FAIL was not sent, I'm going to do some testing tomorrow to force
> checksum failures in single and multiple subflow cases so I can check some
> packet traces. It would be good to have some packetdrill checksum test
> cases to cover that, but we don't yet.

I use a similar test for MP_FAIL to force checksum failures. I have put
it in the attachment.

Thanks,
-Geliang

>
>
> - Mat
>
>
> > v4:
> > - just deal with the multiple subflows case, put the single subflow
> >   case into the new 'infinite mapping' part.
> >
> > v3:
> > - respond with MP_FAIL
> > - add single subflow check
> > - add infinite mapping sending and receiving
> > - export/20210626T054902
> >
> > v2:
> > - MP_FAIL logic:
> >   * Peer B send a DSS to peer A, and the data has been modify by the
> >  middleboxes, then peer A detects the bad checksum.
> >   * In the multiple subflows case, peer A sends MP_FAIL+RST back to peer B,
> >  and peer A discards the data following the bad data sequence number. Peer
> >  B receives this MP_FAIL+RST, and close this subflow.
> >   * In the single subflow case, using the simple implementation, peer A
> >  sends MP_FAIL back to peer B, and peer A fallback to a regular TCP. Peer
> >  B receives this MP_FAIL, and fallback to a regular TCP.
> >
> > Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/52
> >
> > Geliang Tang (5):
> >  mptcp: MP_FAIL suboption sending
> >  mptcp: MP_FAIL suboption receiving
> >  mptcp: send out MP_FAIL when data checksum fails
> >  mptcp: add the mibs for MP_FAIL
> >  selftests: mptcp: add MP_FAIL mibs check
> >
> > include/net/mptcp.h                           |  5 +-
> > net/mptcp/mib.c                               |  2 +
> > net/mptcp/mib.h                               |  2 +
> > net/mptcp/options.c                           | 78 ++++++++++++++++++-
> > net/mptcp/pm.c                                | 20 +++++
> > net/mptcp/protocol.h                          | 20 +++++
> > net/mptcp/subflow.c                           | 18 +++++
> > .../testing/selftests/net/mptcp/mptcp_join.sh | 38 +++++++++
> > 8 files changed, 178 insertions(+), 5 deletions(-)
> >
> > --
> > 2.31.1
> >
> >
> >
>
> --
> Mat Martineau
> Intel

[-- Attachment #2: 0001-mptcp-mp_fail-test.patch --]
[-- Type: text/x-patch, Size: 2192 bytes --]

From 0bd5d26b8cdeb296de3fdf93bd4f08781e02a853 Mon Sep 17 00:00:00 2001
From: Geliang Tang <geliangtang@gmail.com>
Date: Wed, 14 Jul 2021 15:25:28 +0800
Subject: [PATCH] mptcp: mp_fail test

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/protocol.c                           |  9 +++++++++
 .../testing/selftests/net/mptcp/mptcp_join.sh  | 18 ++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 8eb2626503d7..59e04f9c6906 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1275,6 +1275,8 @@ static void mptcp_update_data_checksum(struct sk_buff *skb, int added)
 	mpext->csum = csum_fold(csum_block_add(csum, skb_checksum(skb, offset, added, 0), offset));
 }
 
+static int i;
+
 static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 			      struct mptcp_data_frag *dfrag,
 			      struct mptcp_sendmsg_info *info)
@@ -1376,6 +1378,13 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 out:
 	if (READ_ONCE(msk->csum_enabled))
 		mptcp_update_data_checksum(tail, ret);
+
+	pr_debug("%s i=%d", __func__, i++);
+	if (i == 20)
+		tail->data_len = 1;
+	if (i > 40)
+		i = 0;
+
 	mptcp_subflow_ctx(ssk)->rel_write_seq += ret;
 	return ret;
 }
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 551fcce7c2f2..8495ca54d563 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -927,6 +927,24 @@ chk_link_usage()
 
 subflows_tests()
 {
+	# 1 subflow
+	reset
+	ip netns exec $ns1 ./pm_nl_ctl limits 0 2
+	ip netns exec $ns2 ./pm_nl_ctl limits 0 2
+	run_tests $ns1 $ns2 10.0.1.1 0 0 0 slow
+	chk_join_nr "1 subflow" 0 0 0
+
+	# multiple subflows
+	reset
+	ip netns exec $ns1 ./pm_nl_ctl limits 0 2
+	ip netns exec $ns2 ./pm_nl_ctl limits 0 2
+	ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+	ip netns exec $ns2 ./pm_nl_ctl add 10.0.2.2 flags subflow
+	run_tests $ns1 $ns2 10.0.1.1 0 0 0 slow
+	chk_join_nr "multiple subflows" 2 2 2
+
+	exit
+
 	reset
 	run_tests $ns1 $ns2 10.0.1.1
 	chk_join_nr "no JOIN" "0" "0" "0"
-- 
2.31.1