[PATCH mptcp-next v4 0/8] The infinite mapping support

[PATCH mptcp-next v4 0/8] The infinite mapping support

[Geliang Tang]

v4:
 - update patch 1 and patch 2

v3:
 - drop MPTCP_INFINITE_DONE flag
 - drop MAPPING_INFINITE
 - add mptcp_is_data_contiguous helper
 - add the fallback check
 - The u32 target testcase has not been completed yet.

v2:
 - add MPTCP_INFINITE_DONE flag
 - add MAPPING_INFINITE mapping status
 - add start_seq in the msk

v1:
 - add noncontiguous flag
 - add the mibs check
 - tag: export/20210904T080009

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/216

Geliang Tang (8):
  mptcp: track and update contiguous data status
  mptcp: add last_fully_acked_dss_start_seq in the msk
  mptcp: infinite mapping sending
  mptcp: add the fallback check
  mptcp: infinite mapping receiving
  mptcp: add mib for infinite map sending
  selftests: mptcp: add infinite map mibs check
  DO-NOT-MERGE: mptcp: mp_fail test

 include/net/mptcp.h                           |  3 +-
 net/mptcp/mib.c                               |  1 +
 net/mptcp/mib.h                               |  1 +
 net/mptcp/options.c                           |  6 +-
 net/mptcp/pm.c                                |  6 ++
 net/mptcp/protocol.c                          | 47 +++++++++++++++-
 net/mptcp/protocol.h                          | 19 +++++++
 net/mptcp/subflow.c                           | 55 +++++++++---------
 .../testing/selftests/net/mptcp/mptcp_join.sh | 56 +++++++++++++++++++
 9 files changed, 163 insertions(+), 31 deletions(-)

-- 
2.31.1

[PATCH mptcp-next v4 1/8] mptcp: track and update contiguous data status

[Geliang Tang]

This patch added a new member last_retrans_seq in the msk to track the
last retransmitting sequence number.

Add a new helper named mptcp_is_data_contiguous() to check whether the
data is contiguous on a subflow.

When a bad checksum is detected and a single contiguous subflow is in
use, don't send RST + MP_FAIL, send data_ack + MP_FAIL instead.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/protocol.c | 15 +++++++++++++--
 net/mptcp/protocol.h |  6 ++++++
 net/mptcp/subflow.c  | 12 ++++++------
 3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index ff574d62073f..b766b36e6c93 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1102,8 +1102,13 @@ static void __mptcp_clean_una(struct sock *sk)
 		msk->recovery = false;
 
 out:
-	if (cleaned && tcp_under_memory_pressure(sk))
-		__mptcp_mem_reclaim_partial(sk);
+	if (cleaned) {
+		if (mptcp_is_data_contiguous(msk))
+			msk->last_retrans_seq = msk->snd_una - 1;
+
+		if (tcp_under_memory_pressure(sk))
+			__mptcp_mem_reclaim_partial(sk);
+	}
 
 	if (snd_una == READ_ONCE(msk->snd_nxt) &&
 	    snd_una == READ_ONCE(msk->write_seq)) {
@@ -2419,6 +2424,7 @@ static void __mptcp_retrans(struct sock *sk)
 	struct mptcp_data_frag *dfrag;
 	size_t copied = 0;
 	struct sock *ssk;
+	u64 retrans_seq;
 	int ret;
 
 	mptcp_clean_una_wakeup(sk);
@@ -2464,6 +2470,9 @@ static void __mptcp_retrans(struct sock *sk)
 		dfrag->already_sent = max(dfrag->already_sent, info.sent);
 		tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
 			 info.size_goal);
+		retrans_seq = dfrag->data_seq + info.sent;
+		if (after64(retrans_seq, msk->last_retrans_seq))
+			msk->last_retrans_seq = retrans_seq;
 	}
 
 	release_sock(ssk);
@@ -2889,6 +2898,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
 	msk->snd_una = msk->write_seq;
 	msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
 	msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
+	msk->last_retrans_seq = subflow_req->idsn - 1;
 
 	if (mp_opt->suboptions & OPTIONS_MPTCP_MPC) {
 		msk->can_ack = true;
@@ -3145,6 +3155,7 @@ void mptcp_finish_connect(struct sock *ssk)
 	WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
 	WRITE_ONCE(msk->can_ack, 1);
 	WRITE_ONCE(msk->snd_una, msk->write_seq);
+	WRITE_ONCE(msk->last_retrans_seq, subflow->idsn - 1);
 
 	mptcp_pm_new_connection(msk, ssk, 0);
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index d516fb6578cc..eb3473d128d4 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -227,6 +227,7 @@ struct mptcp_sock {
 	u64		ack_seq;
 	u64		rcv_wnd_sent;
 	u64		rcv_data_fin_seq;
+	u64		last_retrans_seq;
 	int		wmem_reserved;
 	struct sock	*last_snd;
 	int		snd_burst;
@@ -625,6 +626,11 @@ static inline bool mptcp_has_another_subflow(struct sock *ssk)
 	return false;
 }
 
+static inline bool mptcp_is_data_contiguous(struct mptcp_sock *msk)
+{
+	return before64(msk->last_retrans_seq, msk->snd_una);
+}
+
 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 1de7ce883c37..b07803ed3053 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1166,15 +1166,15 @@ 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)) {
+		if (mptcp_has_another_subflow(ssk) || !mptcp_is_data_contiguous(msk)) {
+			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);
 		}
-		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;
 	}
-- 
2.31.1

[PATCH mptcp-next v4 2/8] mptcp: add last_fully_acked_dss_start_seq in the msk

[Geliang Tang]

This patch added a new member named last_fully_acked_dss_start_seq to the
msk to keep track of the beginning of the last fully-acked data segment.
This would be updated in __mptcp_clean_una.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/protocol.c | 3 +++
 net/mptcp/protocol.h | 1 +
 2 files changed, 4 insertions(+)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b766b36e6c93..b056672541df 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1071,6 +1071,7 @@ static void __mptcp_clean_una(struct sock *sk)
 			WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
 		}
 
+		msk->last_fully_acked_dss_start_seq = dfrag->data_seq;
 		dfrag_clear(sk, dfrag);
 		cleaned = true;
 	}
@@ -2899,6 +2900,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
 	msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
 	msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
 	msk->last_retrans_seq = subflow_req->idsn - 1;
+	msk->last_fully_acked_dss_start_seq = subflow_req->idsn - 1;
 
 	if (mp_opt->suboptions & OPTIONS_MPTCP_MPC) {
 		msk->can_ack = true;
@@ -3156,6 +3158,7 @@ void mptcp_finish_connect(struct sock *ssk)
 	WRITE_ONCE(msk->can_ack, 1);
 	WRITE_ONCE(msk->snd_una, msk->write_seq);
 	WRITE_ONCE(msk->last_retrans_seq, subflow->idsn - 1);
+	WRITE_ONCE(msk->last_fully_acked_dss_start_seq, subflow->idsn - 1);
 
 	mptcp_pm_new_connection(msk, ssk, 0);
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index eb3473d128d4..2f8a8589668c 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -224,6 +224,7 @@ struct mptcp_sock {
 	u64		remote_key;
 	u64		write_seq;
 	u64		snd_nxt;
+	u64		last_fully_acked_dss_start_seq;
 	u64		ack_seq;
 	u64		rcv_wnd_sent;
 	u64		rcv_data_fin_seq;
-- 
2.31.1

[PATCH mptcp-next v4 3/8] mptcp: infinite mapping sending

[Geliang Tang]

This patch added the infinite mapping sending logic.

Added a new flag send_infinite_map in struct mptcp_subflow_context. Set
it true when a single contiguous subflow is in use in
mptcp_pm_mp_fail_received.

In mptcp_sendmsg_frag, if this flag is true, call the new function
mptcp_update_infinite_map to set the infinite mapping.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 include/net/mptcp.h  |  3 ++-
 net/mptcp/options.c  |  6 ++++--
 net/mptcp/pm.c       |  6 ++++++
 net/mptcp/protocol.c | 19 +++++++++++++++++++
 net/mptcp/protocol.h | 12 ++++++++++++
 5 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index f83fa48408b3..29e930540ea2 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -35,7 +35,8 @@ struct mptcp_ext {
 			frozen:1,
 			reset_transient:1;
 	u8		reset_reason:4,
-			csum_reqd:1;
+			csum_reqd:1,
+			infinite_map:1;
 };
 
 #define MPTCP_RM_IDS_MAX	8
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 422f4acfb3e6..9c175c298ff6 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -816,8 +816,10 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 
 	opts->suboptions = 0;
 
-	if (unlikely(__mptcp_check_fallback(msk)))
-		return false;
+	if (unlikely(__mptcp_check_fallback(msk))) {
+		if (!mptcp_check_infinite_map(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)) {
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 6ab386ff3294..4fad1fe8ba10 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -251,7 +251,13 @@ 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);
+	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
+
 	pr_debug("fail_seq=%llu", fail_seq);
+
+	if (!mptcp_has_another_subflow(sk) && mptcp_is_data_contiguous(msk))
+		subflow->send_infinite_map = 1;
 }
 
 /* path manager helpers */
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b056672541df..ffef7e1f061b 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1279,6 +1279,23 @@ 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 void mptcp_update_infinite_map(struct mptcp_sock *msk, struct sock *ssk,
+				      struct mptcp_ext *mpext)
+{
+	if (!mpext)
+		return;
+
+	mpext->infinite_map = 1;
+	mpext->data_seq = READ_ONCE(msk->last_fully_acked_dss_start_seq);
+	mpext->subflow_seq = 0;
+	mpext->data_len = 0;
+	mpext->csum = 0;
+
+	mptcp_subflow_ctx(ssk)->send_infinite_map = 0;
+	pr_fallback(msk);
+	__mptcp_do_fallback(msk);
+}
+
 static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 			      struct mptcp_data_frag *dfrag,
 			      struct mptcp_sendmsg_info *info)
@@ -1411,6 +1428,8 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 out:
 	if (READ_ONCE(msk->csum_enabled))
 		mptcp_update_data_checksum(skb, copy);
+	if (mptcp_subflow_ctx(ssk)->send_infinite_map)
+		mptcp_update_infinite_map(msk, ssk, mpext);
 	mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
 	return copy;
 }
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 2f8a8589668c..cb26183aec9b 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,
+		send_infinite_map : 1,
 		rx_eof : 1,
 		can_ack : 1,        /* only after processing the remote a key */
 		disposable : 1,	    /* ctx can be free at ulp release time */
@@ -874,6 +875,17 @@ static inline void mptcp_do_fallback(struct sock *sk)
 
 #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
 
+static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
+{
+	struct mptcp_ext *mpext;
+
+	mpext = skb ? mptcp_get_ext(skb) : NULL;
+	if (mpext && mpext->infinite_map)
+		return true;
+
+	return false;
+}
+
 static inline bool subflow_simultaneous_connect(struct sock *sk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
-- 
2.31.1

[PATCH mptcp-next v4 4/8] mptcp: add the fallback check

[Geliang Tang]

This patch added the fallback check in subflow_check_data_avail. Only do
the fallback when the msk isn't fallen back yet.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/subflow.c | 46 +++++++++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index b07803ed3053..89173f70707e 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1164,35 +1164,37 @@ static bool subflow_check_data_avail(struct sock *ssk)
 	return false;
 
 fallback:
-	/* RFC 8684 section 3.7. */
-	if (subflow->send_mp_fail) {
-		if (mptcp_has_another_subflow(ssk) || !mptcp_is_data_contiguous(msk)) {
+	if (!__mptcp_check_fallback(msk)) {
+		/* RFC 8684 section 3.7. */
+		if (subflow->send_mp_fail) {
+			if (mptcp_has_another_subflow(ssk) || !mptcp_is_data_contiguous(msk)) {
+				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);
+			}
+			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
+			 */
 			ssk->sk_err = EBADMSG;
 			tcp_set_state(ssk, TCP_CLOSE);
 			subflow->reset_transient = 0;
-			subflow->reset_reason = MPTCP_RST_EMIDDLEBOX;
+			subflow->reset_reason = MPTCP_RST_EMPTCP;
 			tcp_send_active_reset(ssk, GFP_ATOMIC);
-			while ((skb = skb_peek(&ssk->sk_receive_queue)))
-				sk_eat_skb(ssk, skb);
+			WRITE_ONCE(subflow->data_avail, 0);
+			return false;
 		}
-		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
-		 */
-		ssk->sk_err = EBADMSG;
-		tcp_set_state(ssk, TCP_CLOSE);
-		subflow->reset_transient = 0;
-		subflow->reset_reason = MPTCP_RST_EMPTCP;
-		tcp_send_active_reset(ssk, GFP_ATOMIC);
-		WRITE_ONCE(subflow->data_avail, 0);
-		return false;
+		__mptcp_do_fallback(msk);
 	}
-
-	__mptcp_do_fallback(msk);
 	skb = skb_peek(&ssk->sk_receive_queue);
 	subflow->map_valid = 1;
 	subflow->map_seq = READ_ONCE(msk->ack_seq);
-- 
2.31.1

[PATCH mptcp-next v4 5/8] mptcp: infinite mapping receiving

[Geliang Tang]

This patch added the infinite mapping receiving logic. When the infinite
mapping is received, set the map_data_len of the subflow to 0.

In subflow_check_data_avail, only reset the subflow when the map_data_len
of the subflow is non-zero.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/subflow.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 89173f70707e..fd44996a7b9a 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -968,6 +968,7 @@ static enum mapping_status get_mapping_status(struct sock *ssk,
 	data_len = mpext->data_len;
 	if (data_len == 0) {
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX);
+		subflow->map_data_len = 0;
 		return MAPPING_INVALID;
 	}
 
@@ -1180,7 +1181,7 @@ static bool subflow_check_data_avail(struct sock *ssk)
 			return true;
 		}
 
-		if (subflow->mp_join || subflow->fully_established) {
+		if ((subflow->mp_join || subflow->fully_established) && subflow->map_data_len) {
 			/* fatal protocol error, close the socket.
 			 * subflow_error_report() will introduce the appropriate barriers
 			 */
-- 
2.31.1

[PATCH mptcp-next v4 6/8] mptcp: add mib for infinite map sending

[Geliang Tang]

This patch added a new mib named MPTCP_MIB_INFINITEMAPTX, increase it
when a infinite mapping has been sent out.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/mib.c      | 1 +
 net/mptcp/mib.h      | 1 +
 net/mptcp/protocol.c | 1 +
 3 files changed, 3 insertions(+)

diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index b21ff9be04c6..ab55afdcae22 100644
--- a/net/mptcp/mib.c
+++ b/net/mptcp/mib.c
@@ -24,6 +24,7 @@ static const struct snmp_mib mptcp_snmp_list[] = {
 	SNMP_MIB_ITEM("MPJoinAckRx", MPTCP_MIB_JOINACKRX),
 	SNMP_MIB_ITEM("MPJoinAckHMacFailure", MPTCP_MIB_JOINACKMAC),
 	SNMP_MIB_ITEM("DSSNotMatching", MPTCP_MIB_DSSNOMATCH),
+	SNMP_MIB_ITEM("InfiniteMapTx", MPTCP_MIB_INFINITEMAPTX),
 	SNMP_MIB_ITEM("InfiniteMapRx", MPTCP_MIB_INFINITEMAPRX),
 	SNMP_MIB_ITEM("DSSNoMatchTCP", MPTCP_MIB_DSSTCPMISMATCH),
 	SNMP_MIB_ITEM("DataCsumErr", MPTCP_MIB_DATACSUMERR),
diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index ecd3d8b117e0..7901f1338d15 100644
--- a/net/mptcp/mib.h
+++ b/net/mptcp/mib.h
@@ -17,6 +17,7 @@ enum linux_mptcp_mib_field {
 	MPTCP_MIB_JOINACKRX,		/* Received an ACK + MP_JOIN */
 	MPTCP_MIB_JOINACKMAC,		/* HMAC was wrong on ACK + MP_JOIN */
 	MPTCP_MIB_DSSNOMATCH,		/* Received a new mapping that did not match the previous one */
+	MPTCP_MIB_INFINITEMAPTX,	/* Sent an infinite mapping */
 	MPTCP_MIB_INFINITEMAPRX,	/* Received an infinite mapping */
 	MPTCP_MIB_DSSTCPMISMATCH,	/* DSS-mapping did not map with TCP's sequence numbers */
 	MPTCP_MIB_DATACSUMERR,		/* The data checksum fail */
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index ffef7e1f061b..d035119b41cb 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1291,6 +1291,7 @@ static void mptcp_update_infinite_map(struct mptcp_sock *msk, struct sock *ssk,
 	mpext->data_len = 0;
 	mpext->csum = 0;
 
+	MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX);
 	mptcp_subflow_ctx(ssk)->send_infinite_map = 0;
 	pr_fallback(msk);
 	__mptcp_do_fallback(msk);
-- 
2.31.1

[PATCH mptcp-next v4 7/8] selftests: mptcp: add infinite map mibs check

[Geliang Tang]

This patch added a function chk_infi_nr to check the mibs for the
infinite mapping.

Signed-off-by: Geliang Tang <geliangtang@gmail.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 255793c5ac4f..fe0c8f3164a7 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -615,6 +615,43 @@ chk_fail_nr()
 	fi
 }
 
+chk_infi_nr()
+{
+	local mp_infi_nr_tx=$1
+	local mp_infi_nr_rx=$2
+	local count
+	local dump_stats
+
+	printf "%-39s %s" " " "itx"
+	count=`ip netns exec $ns1 nstat -as | grep InfiniteMapTx | awk '{print $2}'`
+	[ -z "$count" ] && count=0
+	if [ "$count" != "$mp_infi_nr_tx" ]; then
+		echo "[fail] got $count infinite map[s] TX expected $mp_infi_nr_tx"
+		ret=1
+		dump_stats=1
+	else
+		echo -n "[ ok ]"
+	fi
+
+	echo -n " - irx   "
+	count=`ip netns exec $ns2 nstat -as | grep InfiniteMapRx | awk '{print $2}'`
+	[ -z "$count" ] && count=0
+	if [ "$count" != "$mp_infi_nr_rx" ]; then
+		echo "[fail] got $count infinite map[s] RX expected $mp_infi_nr_rx"
+		ret=1
+		dump_stats=1
+	else
+		echo "[ ok ]"
+	fi
+
+	if [ "${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"
@@ -665,6 +702,7 @@ chk_join_nr()
 	if [ $checksum -eq 1 ]; then
 		chk_csum_nr
 		chk_fail_nr 0 0
+		chk_infi_nr 0 0
 	fi
 }
 
-- 
2.31.1

[PATCH mptcp-next v4 8/8] DO-NOT-MERGE: mptcp: mp_fail test

[Geliang Tang]

./mptcp_join.sh -Cf

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 d035119b41cb..5be8023f27ca 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1297,6 +1297,8 @@ static void mptcp_update_infinite_map(struct mptcp_sock *msk, struct sock *ssk,
 	__mptcp_do_fallback(msk);
 }
 
+static int j;
+
 static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 			      struct mptcp_data_frag *dfrag,
 			      struct mptcp_sendmsg_info *info)
@@ -1431,6 +1433,13 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 		mptcp_update_data_checksum(skb, copy);
 	if (mptcp_subflow_ctx(ssk)->send_infinite_map)
 		mptcp_update_infinite_map(msk, ssk, mpext);
+
+	pr_debug("%s j=%d", __func__, j++);
+	if (j == 20)
+		skb->data_len = 1;
+	if (j > 40)
+		j = 0;
+
 	mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
 	return copy;
 }
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index fe0c8f3164a7..38663f6373b8 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -977,6 +977,24 @@ 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
+
+	exit
+
+	# 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
+
 	reset
 	run_tests $ns1 $ns2 10.0.1.1
 	chk_join_nr "no JOIN" "0" "0" "0"
-- 
2.31.1

Re: [PATCH mptcp-next v4 1/8] mptcp: track and update contiguous data status

[Mat Martineau]

On Sat, 18 Sep 2021, Geliang Tang wrote:

> This patch added a new member last_retrans_seq in the msk to track the
> last retransmitting sequence number.
>
> Add a new helper named mptcp_is_data_contiguous() to check whether the
> data is contiguous on a subflow.
>
> When a bad checksum is detected and a single contiguous subflow is in
> use, don't send RST + MP_FAIL, send data_ack + MP_FAIL instead.
>
> Signed-off-by: Geliang Tang <geliangtang@gmail.com>
> ---
> net/mptcp/protocol.c | 15 +++++++++++++--
> net/mptcp/protocol.h |  6 ++++++
> net/mptcp/subflow.c  | 12 ++++++------
> 3 files changed, 25 insertions(+), 8 deletions(-)
>
> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> index ff574d62073f..b766b36e6c93 100644
> --- a/net/mptcp/protocol.c
> +++ b/net/mptcp/protocol.c
> @@ -1102,8 +1102,13 @@ static void __mptcp_clean_una(struct sock *sk)
> 		msk->recovery = false;
>
> out:
> -	if (cleaned && tcp_under_memory_pressure(sk))
> -		__mptcp_mem_reclaim_partial(sk);
> +	if (cleaned) {
> +		if (mptcp_is_data_contiguous(msk))
> +			msk->last_retrans_seq = msk->snd_una - 1;
> +
> +		if (tcp_under_memory_pressure(sk))
> +			__mptcp_mem_reclaim_partial(sk);
> +	}
>
> 	if (snd_una == READ_ONCE(msk->snd_nxt) &&
> 	    snd_una == READ_ONCE(msk->write_seq)) {
> @@ -2419,6 +2424,7 @@ static void __mptcp_retrans(struct sock *sk)
> 	struct mptcp_data_frag *dfrag;
> 	size_t copied = 0;
> 	struct sock *ssk;
> +	u64 retrans_seq;
> 	int ret;
>
> 	mptcp_clean_una_wakeup(sk);
> @@ -2464,6 +2470,9 @@ static void __mptcp_retrans(struct sock *sk)
> 		dfrag->already_sent = max(dfrag->already_sent, info.sent);
> 		tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
> 			 info.size_goal);
> +		retrans_seq = dfrag->data_seq + info.sent;
> +		if (after64(retrans_seq, msk->last_retrans_seq))
> +			msk->last_retrans_seq = retrans_seq;
> 	}
>
> 	release_sock(ssk);
> @@ -2889,6 +2898,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
> 	msk->snd_una = msk->write_seq;
> 	msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd;
> 	msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
> +	msk->last_retrans_seq = subflow_req->idsn - 1;
>
> 	if (mp_opt->suboptions & OPTIONS_MPTCP_MPC) {
> 		msk->can_ack = true;
> @@ -3145,6 +3155,7 @@ void mptcp_finish_connect(struct sock *ssk)
> 	WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
> 	WRITE_ONCE(msk->can_ack, 1);
> 	WRITE_ONCE(msk->snd_una, msk->write_seq);
> +	WRITE_ONCE(msk->last_retrans_seq, subflow->idsn - 1);
>
> 	mptcp_pm_new_connection(msk, ssk, 0);
>
> diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
> index d516fb6578cc..eb3473d128d4 100644
> --- a/net/mptcp/protocol.h
> +++ b/net/mptcp/protocol.h
> @@ -227,6 +227,7 @@ struct mptcp_sock {
> 	u64		ack_seq;
> 	u64		rcv_wnd_sent;
> 	u64		rcv_data_fin_seq;
> +	u64		last_retrans_seq;
> 	int		wmem_reserved;
> 	struct sock	*last_snd;
> 	int		snd_burst;
> @@ -625,6 +626,11 @@ static inline bool mptcp_has_another_subflow(struct sock *ssk)
> 	return false;
> }
>
> +static inline bool mptcp_is_data_contiguous(struct mptcp_sock *msk)
> +{
> +	return before64(msk->last_retrans_seq, msk->snd_una);
> +}

As I mentioned in 
https://lore.kernel.org/mptcp/69c4ec57-94ed-4631-317a-617f994bc77@linux.intel.com/ 
I don't think this is enough to be sure the subflow stream is fully 
contiguous (the one remaining subflow has flushed out all MPTCP-level 
retransmissions).

MPTCP can do multiple retransmissions of the same MPTCP-level data, so it 
seems necessary to track the last sequence number using the 32-bit TCP 
sequence number on the subflow. For example, storing a copy of 
tcp_sk(ssk)->snd_nxt after the tcp_push() call in __mptcp_retrans(). Then 
in mptcp_data_ready() we can compare that retransmitted snd_nxt copy with 
tcp_sk(ssk)->snd_una, very similar to the code added to 
__mptcp_clean_una() above.

Anyone have a simpler idea?

- Mat


> +
> 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 1de7ce883c37..b07803ed3053 100644
> --- a/net/mptcp/subflow.c
> +++ b/net/mptcp/subflow.c
> @@ -1166,15 +1166,15 @@ 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)) {
> +		if (mptcp_has_another_subflow(ssk) || !mptcp_is_data_contiguous(msk)) {
> +			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);
> 		}
> -		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;
> 	}
> -- 
> 2.31.1
>
>
>

--
Mat Martineau
Intel

Re: [PATCH mptcp-next v4 3/8] mptcp: infinite mapping sending

[Mat Martineau]

On Sat, 18 Sep 2021, Geliang Tang wrote:

> This patch added the infinite mapping sending logic.
>
> Added a new flag send_infinite_map in struct mptcp_subflow_context. Set
> it true when a single contiguous subflow is in use in
> mptcp_pm_mp_fail_received.
>
> In mptcp_sendmsg_frag, if this flag is true, call the new function
> mptcp_update_infinite_map to set the infinite mapping.
>
> Signed-off-by: Geliang Tang <geliangtang@gmail.com>
> ---
> include/net/mptcp.h  |  3 ++-
> net/mptcp/options.c  |  6 ++++--
> net/mptcp/pm.c       |  6 ++++++
> net/mptcp/protocol.c | 19 +++++++++++++++++++
> net/mptcp/protocol.h | 12 ++++++++++++
> 5 files changed, 43 insertions(+), 3 deletions(-)
>
> diff --git a/include/net/mptcp.h b/include/net/mptcp.h
> index f83fa48408b3..29e930540ea2 100644
> --- a/include/net/mptcp.h
> +++ b/include/net/mptcp.h
> @@ -35,7 +35,8 @@ struct mptcp_ext {
> 			frozen:1,
> 			reset_transient:1;
> 	u8		reset_reason:4,
> -			csum_reqd:1;
> +			csum_reqd:1,
> +			infinite_map:1;
> };
>
> #define MPTCP_RM_IDS_MAX	8
> diff --git a/net/mptcp/options.c b/net/mptcp/options.c
> index 422f4acfb3e6..9c175c298ff6 100644
> --- a/net/mptcp/options.c
> +++ b/net/mptcp/options.c
> @@ -816,8 +816,10 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
>
> 	opts->suboptions = 0;
>
> -	if (unlikely(__mptcp_check_fallback(msk)))
> -		return false;
> +	if (unlikely(__mptcp_check_fallback(msk))) {
> +		if (!mptcp_check_infinite_map(skb))
> +			return false;
> +	}

This could be

if (unlikely(__mptcp_check_fallback(msk) && !mptcp_check_infinite_map(skb)))
...

(line-wrapped as needed)

rather than nesting the if's.


Mat


>
> 	if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) {
> 		if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {
> diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
> index 6ab386ff3294..4fad1fe8ba10 100644
> --- a/net/mptcp/pm.c
> +++ b/net/mptcp/pm.c
> @@ -251,7 +251,13 @@ 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);
> +	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
> +
> 	pr_debug("fail_seq=%llu", fail_seq);
> +
> +	if (!mptcp_has_another_subflow(sk) && mptcp_is_data_contiguous(msk))
> +		subflow->send_infinite_map = 1;
> }
>
> /* path manager helpers */
> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> index b056672541df..ffef7e1f061b 100644
> --- a/net/mptcp/protocol.c
> +++ b/net/mptcp/protocol.c
> @@ -1279,6 +1279,23 @@ 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 void mptcp_update_infinite_map(struct mptcp_sock *msk, struct sock *ssk,
> +				      struct mptcp_ext *mpext)
> +{
> +	if (!mpext)
> +		return;
> +
> +	mpext->infinite_map = 1;
> +	mpext->data_seq = READ_ONCE(msk->last_fully_acked_dss_start_seq);
> +	mpext->subflow_seq = 0;
> +	mpext->data_len = 0;
> +	mpext->csum = 0;
> +
> +	mptcp_subflow_ctx(ssk)->send_infinite_map = 0;
> +	pr_fallback(msk);
> +	__mptcp_do_fallback(msk);
> +}
> +
> static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
> 			      struct mptcp_data_frag *dfrag,
> 			      struct mptcp_sendmsg_info *info)
> @@ -1411,6 +1428,8 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
> out:
> 	if (READ_ONCE(msk->csum_enabled))
> 		mptcp_update_data_checksum(skb, copy);
> +	if (mptcp_subflow_ctx(ssk)->send_infinite_map)
> +		mptcp_update_infinite_map(msk, ssk, mpext);
> 	mptcp_subflow_ctx(ssk)->rel_write_seq += copy;
> 	return copy;
> }
> diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
> index 2f8a8589668c..cb26183aec9b 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,
> +		send_infinite_map : 1,
> 		rx_eof : 1,
> 		can_ack : 1,        /* only after processing the remote a key */
> 		disposable : 1,	    /* ctx can be free at ulp release time */
> @@ -874,6 +875,17 @@ static inline void mptcp_do_fallback(struct sock *sk)
>
> #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a)
>
> +static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
> +{
> +	struct mptcp_ext *mpext;
> +
> +	mpext = skb ? mptcp_get_ext(skb) : NULL;
> +	if (mpext && mpext->infinite_map)
> +		return true;
> +
> +	return false;
> +}
> +
> static inline bool subflow_simultaneous_connect(struct sock *sk)
> {
> 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
> -- 
> 2.31.1
>
>
>

--
Mat Martineau
Intel