[PATCH mptcp-net mptcp-next v4 00/15] mptcp: pm: drop TCP TS with ADD_ADDRv6 + port

[PATCH mptcp-net mptcp-next v4 00/15] mptcp: pm: drop TCP TS with ADD_ADDRv6 + port

[Matthieu Baerts (NGI0)]

Currently, it is possible to add a "signal" MPTCP endpoint with a v6
address and a port, or to directly request to send an ADD_ADDR with a v6
address and a port, but such signalling option cannot be sent when TCP
timestamps is used due to a lack of option space. Instead of simply
dropping such ADD_ADDR, the TCP timestamps can be dropped only for this
packet.

- Patch 1: fix for PREEMPT_RT kernels, for -net.

- Patches 2-4: small cleanups to avoid computing ADD/RM_ADDR twice.

- Patches 5-8: the new feature, controlled by a new sysctl knob.

- Patch 9: extra checks in the selftests.

- Patches 10-15: refactoring/cleanups: some of them were part of a
  previous patch: "mptcp: pm: clearer ADD_ADDR related helpers names"
  [1].

Note that the mptcp/add_addr/add_addr6_port_ts_server.pkt packetdrill
test is supposed to fail with this series, until this PR is applied:

  https://github.com/multipath-tcp/packetdrill/pull/198

Link: https://lore.kernel.org/20260415-mptcp-inc-limits-v5-20-e54c3bf80e4e@kernel.org [1]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Changes in v4:
- Patches 2-4: uniform "size" type: signed for all suboptions. (Mat)
- Dropped previous patch 16.
- Link to v3: https://patch.msgid.link/20260520-mptcp-add-addr6-port-ts-v3-0-bffa658a7678@kernel.org

Changes in v3:
- Patch 1: sk_stop_timer() should still be called under rcu.
- Patches 6-7: split + s/has_ts/add_addr_drop_ts/.
- Link to v2: https://patch.msgid.link/20260519-mptcp-add-addr6-port-ts-v2-0-3b36a51e6a86@kernel.org

Changes in v2:
- Patch 1: new.
- Patch 3: reset size in mptcp_pm_add_addr_signal for dropped options.
- Patches 4-5: split from previous patch 3. (Paolo)
- Patch 4: fix typo.
- Patch 5: fix reverse Xmas tree order + change label. (Paolo)
- Patch 6: back to v6 connection.
- Patch 10: fix comment.
- Patch 14: fix typo.
- Link to v1: https://patch.msgid.link/20260518-mptcp-add-addr6-port-ts-v1-0-f1ca26977fcd@kernel.org

---
Matthieu Baerts (NGI0) (15):
      [mptcp-net] mptcp: pm: avoid sleeping while holding rcu_read_lock
      mptcp: options: suboptions sizes can be negative
      mptcp: pm: avoid computing rm_addr size twice
      mptcp: pm: avoid computing add_addr size twice
      mptcp: introduce add_addr_v6_port_drop_ts sysctl knob
      tcp: allow mptcp to drop TS for some packets
      mptcp: pm: drop TCP TS with ADD_ADDRv6 + port
      selftests: mptcp: validate ADD_ADDRv6 + TS + port
      selftests: mptcp: always check sent/dropped ADD_ADDRs
      mptcp: pm: use for_each_subflow helper
      mptcp: pm: rename add_entry structure to add_addr
      mptcp: pm: uniform announced addresses helpers
      mptcp: pm: remove add_ prefix from timer
      mptcp: pm: make mptcp_pm_add_addr_send_ack static
      mptcp: pm: avoid using del_timer directly

 Documentation/networking/mptcp-sysctl.rst       |  13 ++
 include/net/mptcp.h                             |   3 +-
 net/ipv4/tcp_output.c                           |   6 +-
 net/mptcp/ctrl.c                                |  18 ++-
 net/mptcp/options.c                             |  65 +++-----
 net/mptcp/pm.c                                  | 189 ++++++++++++++----------
 net/mptcp/pm_kernel.c                           |  22 +--
 net/mptcp/pm_userspace.c                        |   6 +-
 net/mptcp/protocol.h                            |  46 ++----
 net/mptcp/subflow.c                             |   4 +-
 tools/testing/selftests/net/mptcp/mptcp_join.sh |  83 +++++------
 11 files changed, 240 insertions(+), 215 deletions(-)
---
base-commit: 4d6bda29d05f8789f40c095d5d08396ffd6b470f
change-id: 20260508-mptcp-add-addr6-port-ts-371653e0f843

Best regards,
--  
Matthieu Baerts (NGI0) <matttbe@kernel.org>

[PATCH mptcp-net mptcp-next v4 01/15] mptcp: pm: avoid sleeping while holding rcu_read_lock

[Matthieu Baerts (NGI0)]

sk_stop_timer_sync() calls del_timer_sync(), which spin-waits for the
timer callback to complete on non-RT kernels. But on PREEMPT_RT, it can
sleep. Sleeping inside an RCU read-side critical section might trigger a
lockdep splat.

Instead, keep a reference to the timer, under rcu_read_lock, and call
sk_stop_timer*() without the RCU lock.

While at it, apply the reversed Xmas order when declaring variables.

Fixes: 426358d9be7c ("mptcp: fix a race in mptcp_pm_del_add_timer()")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
For -net.
v3: sk_stop_timer() should still be called under rcu.
---
 net/mptcp/pm.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 35427bee2963..851f6886ad23 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -401,9 +401,9 @@ struct mptcp_pm_add_entry *
 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 		       const struct mptcp_addr_info *addr, bool check_id)
 {
-	struct mptcp_pm_add_entry *entry;
 	struct sock *sk = (struct sock *)msk;
-	bool stop_timer = false;
+	struct mptcp_pm_add_entry *entry;
+	struct timer_list *timer = NULL;
 
 	rcu_read_lock();
 
@@ -411,7 +411,7 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 	entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 	if (entry && (!check_id || entry->addr.id == addr->id)) {
 		entry->retrans_times = ADD_ADDR_RETRANS_MAX;
-		stop_timer = true;
+		timer = &entry->add_timer;
 	}
 	if (!check_id && entry)
 		list_del(&entry->list);
@@ -420,14 +420,14 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 	/* Note: entry might have been removed by another thread.
 	 * We hold rcu_read_lock() to ensure it is not freed under us.
 	 */
-	if (stop_timer) {
-		if (check_id)
-			sk_stop_timer(sk, &entry->add_timer);
-		else
-			sk_stop_timer_sync(sk, &entry->add_timer);
-	}
+	if (timer && check_id)
+		sk_stop_timer(sk, timer);
 
 	rcu_read_unlock();
+
+	if (timer && !check_id)
+		sk_stop_timer_sync(sk, timer);
+
 	return entry;
 }
 

-- 
2.53.0

[PATCH mptcp-next v4 02/15] mptcp: options: suboptions sizes can be negative

[Matthieu Baerts (NGI0)]

Use a signed int for the returned size, because when other options are
dropped, the size can be negative, e.g. to send an echo ADD_ADDR with a
v4 address, and no port.

The behaviour is not changed, because it was working as expected with an
overflow. But it is clearer like this, and it will help later on.

Even if, for the moment, only the ADD_ADDR size can be negative in some
cases, a signed int is now used for all mptcp_established_options_*()
helpers, not to mismatch the type, and as a question of uniformity.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
v4: also switch to a signed int for other helpers. (Mat)
---
 net/mptcp/options.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 2b35bdc113a5..b88e6c314b54 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -447,8 +447,7 @@ static void clear_3rdack_retransmission(struct sock *sk)
 }
 
 static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb,
-					 bool snd_data_fin_enable,
-					 unsigned int *size,
+					 bool snd_data_fin_enable, int *size,
 					 struct mptcp_out_options *opts)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
@@ -560,8 +559,7 @@ static void mptcp_write_data_fin(struct mptcp_subflow_context *subflow,
 }
 
 static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
-					  bool snd_data_fin_enable,
-					  unsigned int *size,
+					  bool snd_data_fin_enable, int *size,
 					  struct mptcp_out_options *opts)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
@@ -654,8 +652,8 @@ static u64 add_addr_generate_hmac(u64 key1, u64 key2,
 	return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]);
 }
 
-static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *skb,
-					       unsigned int *size,
+static bool mptcp_established_options_add_addr(struct sock *sk,
+					       struct sk_buff *skb, int *size,
 					       unsigned int remaining,
 					       struct mptcp_out_options *opts)
 {
@@ -718,8 +716,7 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *
 	return true;
 }
 
-static bool mptcp_established_options_rm_addr(struct sock *sk,
-					      unsigned int *size,
+static bool mptcp_established_options_rm_addr(struct sock *sk, int *size,
 					      unsigned int remaining,
 					      struct mptcp_out_options *opts)
 {
@@ -748,8 +745,7 @@ 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,
+static bool mptcp_established_options_mp_prio(struct sock *sk, int *size,
 					      unsigned int remaining,
 					      struct mptcp_out_options *opts)
 {
@@ -775,7 +771,7 @@ static bool mptcp_established_options_mp_prio(struct sock *sk,
 }
 
 static noinline bool mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb,
-						   unsigned int *size,
+						   int *size,
 						   unsigned int remaining,
 						   struct mptcp_out_options *opts)
 {
@@ -793,8 +789,7 @@ 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,
+static bool mptcp_established_options_fastclose(struct sock *sk, int *size,
 						unsigned int remaining,
 						struct mptcp_out_options *opts)
 {
@@ -816,8 +811,7 @@ static bool mptcp_established_options_fastclose(struct sock *sk,
 	return true;
 }
 
-static bool mptcp_established_options_mp_fail(struct sock *sk,
-					      unsigned int *size,
+static bool mptcp_established_options_mp_fail(struct sock *sk, int *size,
 					      unsigned int remaining,
 					      struct mptcp_out_options *opts)
 {
@@ -845,9 +839,9 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
-	unsigned int opt_size = 0;
 	bool snd_data_fin;
 	bool ret = false;
+	int opt_size = 0;
 
 	opts->suboptions = 0;
 
@@ -875,7 +869,7 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 	if (mptcp_established_options_mp(sk, skb, snd_data_fin, &opt_size, opts))
 		ret = true;
 	else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &opt_size, opts)) {
-		unsigned int mp_fail_size;
+		int mp_fail_size;
 
 		ret = true;
 		if (mptcp_established_options_mp_fail(sk, &mp_fail_size,

-- 
2.53.0

[PATCH mptcp-next v4 03/15] mptcp: pm: avoid computing rm_addr size twice

[Matthieu Baerts (NGI0)]

mptcp_rm_addr_len helper was called twice: in mptcp_pm_rm_addr_signal,
then just after in mptcp_established_options_rm_addr. Both to check the
remaining space.

The second call is not needed: if there is not enough space,
mptcp_pm_rm_addr_signal will return false, and the caller,
mptcp_established_options_rm_addr, will do the same without re-checking
the size again. Instead, mptcp_pm_rm_addr_signal can directly set the
size.

While at it, move mptcp_rm_addr_len to pm.c, as it is now only used
there, once.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
v4: use signed int for the new size parameter. (Mat)
---
 net/mptcp/options.c  | 11 ++---------
 net/mptcp/pm.c       | 11 ++++++++++-
 net/mptcp/protocol.h | 10 +---------
 3 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index b88e6c314b54..3960c6d93177 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -723,19 +723,12 @@ static bool mptcp_established_options_rm_addr(struct sock *sk, int *size,
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 	struct mptcp_rm_list rm_list;
-	int i, len;
+	int i;
 
 	if (!mptcp_pm_should_rm_signal(msk) ||
-	    !(mptcp_pm_rm_addr_signal(msk, remaining, &rm_list)))
+	    !(mptcp_pm_rm_addr_signal(msk, remaining, &rm_list, size)))
 		return false;
 
-	len = mptcp_rm_addr_len(&rm_list);
-	if (len < 0)
-		return false;
-	if (remaining < len)
-		return false;
-
-	*size = len;
 	opts->suboptions |= OPTION_MPTCP_RM_ADDR;
 	opts->rm_list = rm_list;
 
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 851f6886ad23..3d5dc711a866 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -961,8 +961,16 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 	return ret;
 }
 
+static int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
+{
+	if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
+		return -EINVAL;
+
+	return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
+}
+
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
-			     struct mptcp_rm_list *rm_list)
+			     struct mptcp_rm_list *rm_list, int *size)
 {
 	int ret = false, len;
 	u8 rm_addr;
@@ -982,6 +990,7 @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 	if (remaining < len)
 		goto out_unlock;
 
+	*size = len;
 	*rm_list = msk->pm.rm_list_tx;
 	WRITE_ONCE(msk->pm.addr_signal, rm_addr);
 	ret = true;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 2321ad4d845d..e9d97fb471ce 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1224,20 +1224,12 @@ static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
 	return len;
 }
 
-static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
-{
-	if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
-		return -EINVAL;
-
-	return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
-}
-
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 			      unsigned int opt_size, unsigned int remaining,
 			      struct mptcp_addr_info *addr, bool *echo,
 			      bool *drop_other_suboptions);
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
-			     struct mptcp_rm_list *rm_list);
+			     struct mptcp_rm_list *rm_list, int *len);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,

-- 
2.53.0

[PATCH mptcp-next v4 04/15] mptcp: pm: avoid computing add_addr size twice

[Matthieu Baerts (NGI0)]

mptcp_add_addr_len helper was called twice: in mptcp_pm_add_addr_signal,
then just after in mptcp_established_options_add_addr. Both to check
the remaining space.

The second call is not needed: if there is not enough space,
mptcp_pm_add_addr_signal will return false, and the caller,
mptcp_established_options_add_addr, will do the same without re-checking
the size again. Instead, mptcp_pm_add_addr_signal can directly set the
size.

Note that the returned size can be negative when other suboptions are
dropped, e.g. to send an echo ADD_ADDR with a v4 address, and no port.

While at it:

 - move mptcp_add_addr_len to pm.c, as it is now only used from there

 - use 'int' in mptcp_add_addr_len for the size, instead of having a mix

 - use a bool for 'ret' in mptcp_pm_add_addr_signal

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
v2: reset size in mptcp_pm_add_addr_signal if other options are dropped.
---
 net/mptcp/options.c  | 16 +++-------------
 net/mptcp/pm.c       | 26 ++++++++++++++++++++++----
 net/mptcp/protocol.h | 17 +----------------
 3 files changed, 26 insertions(+), 33 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 3960c6d93177..9525b22c3db8 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -660,34 +660,25 @@ static bool mptcp_established_options_add_addr(struct sock *sk,
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 	bool drop_other_suboptions = false;
-	unsigned int opt_size = *size;
 	struct mptcp_addr_info addr;
 	bool echo;
-	int len;
 
 	/* add addr will strip the existing options, be sure to avoid breaking
 	 * MPC/MPJ handshakes
 	 */
 	if (!mptcp_pm_should_add_signal(msk) ||
 	    (opts->suboptions & (OPTION_MPTCP_MPJ_ACK | OPTION_MPTCP_MPC_ACK)) ||
-	    !mptcp_pm_add_addr_signal(msk, skb, opt_size, remaining, &addr,
-		    &echo, &drop_other_suboptions))
+	    !mptcp_pm_add_addr_signal(msk, skb, size, remaining, &addr, &echo,
+				      &drop_other_suboptions))
 		return false;
 
 	/*
 	 * Later on, mptcp_write_options() will enforce mutually exclusion with
 	 * DSS, bail out if such option is set and we can't drop it.
 	 */
-	if (drop_other_suboptions)
-		remaining += opt_size;
-	else if (opts->suboptions & OPTION_MPTCP_DSS)
+	if (!drop_other_suboptions && opts->suboptions & OPTION_MPTCP_DSS)
 		return false;
 
-	len = mptcp_add_addr_len(addr.family, echo, !!addr.port);
-	if (remaining < len)
-		return false;
-
-	*size = len;
 	if (drop_other_suboptions) {
 		pr_debug("drop other suboptions\n");
 		opts->suboptions = 0;
@@ -698,7 +689,6 @@ static bool mptcp_established_options_add_addr(struct sock *sk,
 		 * options
 		 */
 		opts->ahmac = 0;
-		*size -= opt_size;
 	}
 	opts->addr = addr;
 	opts->suboptions |= OPTION_MPTCP_ADD_ADDR;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 3d5dc711a866..ae6eabdc2ac1 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -888,14 +888,30 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
 	}
 }
 
+static int mptcp_add_addr_len(int family, bool echo, bool port)
+{
+	int len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
+
+	if (family == AF_INET6)
+		len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
+	if (!echo)
+		len += MPTCPOPT_THMAC_LEN;
+	/* account for 2 trailing 'nop' options */
+	if (port)
+		len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
+
+	return len;
+}
+
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
-			      unsigned int opt_size, unsigned int remaining,
+			      int *size, int remaining,
 			      struct mptcp_addr_info *addr, bool *echo,
 			      bool *drop_other_suboptions)
 {
 	bool skip_add_addr = false;
-	int ret = false;
+	bool ret = false;
 	u8 add_addr;
+	int len = 0;
 	u8 family;
 	bool port;
 
@@ -910,7 +926,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 	 * if any, will be carried by the 'original' TCP ack
 	 */
 	if (skb && skb_is_tcp_pure_ack(skb)) {
-		remaining += opt_size;
+		len -= *size;
 		*drop_other_suboptions = true;
 	}
 
@@ -927,7 +943,8 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 		family = msk->pm.local.family;
 	}
 
-	if (remaining < mptcp_add_addr_len(family, *echo, port)) {
+	len += mptcp_add_addr_len(family, *echo, port);
+	if (len > remaining) {
 		struct net *net = sock_net((struct sock *)msk);
 
 		if (!*drop_other_suboptions)
@@ -943,6 +960,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 	}
 
 	ret = true;
+	*size = len;
 
 drop_signal_mark:
 	WRITE_ONCE(msk->pm.addr_signal, add_addr);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index e9d97fb471ce..7379a49342e6 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1209,23 +1209,8 @@ static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
 	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
 }
 
-static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
-{
-	u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
-
-	if (family == AF_INET6)
-		len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
-	if (!echo)
-		len += MPTCPOPT_THMAC_LEN;
-	/* account for 2 trailing 'nop' options */
-	if (port)
-		len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
-
-	return len;
-}
-
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
-			      unsigned int opt_size, unsigned int remaining,
+			      int *size, int remaining,
 			      struct mptcp_addr_info *addr, bool *echo,
 			      bool *drop_other_suboptions);
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,

-- 
2.53.0

[PATCH mptcp-next v4 05/15] mptcp: introduce add_addr_v6_port_drop_ts sysctl knob

[Matthieu Baerts (NGI0)]

This sysctl is going to be used in the next commits to drop TCP
timestamps option, to be able to send an ADD_ADDR with a v6 IP address
and a port number. It is enabled by default.

This knob is explicitly disabled in the MPTCP Join selftest, with the
"signal addr list progresses after tx drop" subtest, to continue
verifying the previous behaviour where the ADD_ADDR is not sent due to a
lack of space.

While at it, move syn_retrans_before_tcp_fallback down from struct
mptcp_pernet, to avoid creating another 3 bytes hole.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
v2: split (Paolo) + fix new sysctl name in selftests.
---
 Documentation/networking/mptcp-sysctl.rst       | 13 +++++++++++++
 net/mptcp/ctrl.c                                | 18 +++++++++++++++++-
 net/mptcp/protocol.h                            |  1 +
 tools/testing/selftests/net/mptcp/mptcp_join.sh |  1 +
 4 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/Documentation/networking/mptcp-sysctl.rst b/Documentation/networking/mptcp-sysctl.rst
index 1eb6af26b4a7..b9b5f58e0625 100644
--- a/Documentation/networking/mptcp-sysctl.rst
+++ b/Documentation/networking/mptcp-sysctl.rst
@@ -21,6 +21,19 @@ add_addr_timeout - INTEGER (seconds)
 
 	Default: 120
 
+add_addr_v6_port_drop_ts - BOOLEAN
+	Control whether preparing an ADD_ADDR with an IPv6 address and a port
+	should drop the TCP timestamps option to have enough option space to
+	send the signal.
+
+	If there is not enough option space, and the TCP timestamps option
+	cannot be dropped, the signal cannot be sent. Note that dropping the TCP
+	timestamps option for one packet of the connection could disrupt some
+	middleboxes: even if it should be unlikely, they could drop the packet
+	or block the connection. This is a per-namespace sysctl.
+
+	Default: 1 (enabled)
+
 allow_join_initial_addr_port - BOOLEAN
 	Allow peers to send join requests to the IP address and port number used
 	by the initial subflow if the value is 1. This controls a flag that is
diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
index d96130e49942..c94a192f4118 100644
--- a/net/mptcp/ctrl.c
+++ b/net/mptcp/ctrl.c
@@ -32,12 +32,13 @@ struct mptcp_pernet {
 	unsigned int close_timeout;
 	unsigned int stale_loss_cnt;
 	atomic_t active_disable_times;
-	u8 syn_retrans_before_tcp_fallback;
 	unsigned long active_disable_stamp;
+	u8 syn_retrans_before_tcp_fallback;
 	u8 mptcp_enabled;
 	u8 checksum_enabled;
 	u8 allow_join_initial_addr_port;
 	u8 pm_type;
+	u8 add_addr_v6_port_drop_ts;
 	char scheduler[MPTCP_SCHED_NAME_MAX];
 	char path_manager[MPTCP_PM_NAME_MAX];
 };
@@ -94,6 +95,11 @@ const char *mptcp_get_scheduler(const struct net *net)
 	return mptcp_get_pernet(net)->scheduler;
 }
 
+unsigned int mptcp_add_addr_v6_port_drop_ts(const struct net *net)
+{
+	return mptcp_get_pernet(net)->add_addr_v6_port_drop_ts;
+}
+
 static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 {
 	pernet->mptcp_enabled = 1;
@@ -108,6 +114,7 @@ static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 	pernet->pm_type = MPTCP_PM_TYPE_KERNEL;
 	strscpy(pernet->scheduler, "default", sizeof(pernet->scheduler));
 	strscpy(pernet->path_manager, "kernel", sizeof(pernet->path_manager));
+	pernet->add_addr_v6_port_drop_ts = 1;
 }
 
 #ifdef CONFIG_SYSCTL
@@ -362,6 +369,14 @@ static struct ctl_table mptcp_sysctl_table[] = {
 		.mode = 0444,
 		.proc_handler = proc_available_path_managers,
 	},
+	{
+		.procname = "add_addr_v6_port_drop_ts",
+		.maxlen = sizeof(u8),
+		.mode = 0644,
+		.proc_handler = proc_dou8vec_minmax,
+		.extra1       = SYSCTL_ZERO,
+		.extra2       = SYSCTL_ONE
+	},
 };
 
 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
@@ -389,6 +404,7 @@ static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
 	table[10].data = &pernet->syn_retrans_before_tcp_fallback;
 	table[11].data = &pernet->path_manager;
 	/* table[12] is for available_path_managers which is read-only info */
+	table[13].data = &pernet->add_addr_v6_port_drop_ts;
 
 	hdr = register_net_sysctl_sz(net, MPTCP_SYSCTL_PATH, table,
 				     ARRAY_SIZE(mptcp_sysctl_table));
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 7379a49342e6..1c9376c5e8f0 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -799,6 +799,7 @@ unsigned int mptcp_close_timeout(const struct sock *sk);
 int mptcp_get_pm_type(const struct net *net);
 const char *mptcp_get_path_manager(const struct net *net);
 const char *mptcp_get_scheduler(const struct net *net);
+unsigned int mptcp_add_addr_v6_port_drop_ts(const struct net *net);
 
 void mptcp_active_disable(struct sock *sk);
 bool mptcp_active_should_disable(struct sock *ssk);
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index f008a14006b9..d894efe1fb02 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -3313,6 +3313,7 @@ add_addr_ports_tests()
 	if reset "signal addr list progresses after tx drop"; then
 		pm_nl_set_limits $ns1 0 2
 		pm_nl_set_limits $ns2 1 0
+		ip netns exec $ns1 sysctl -q net.mptcp.add_addr_v6_port_drop_ts=0 2>/dev/null || true
 		ip netns exec $ns1 sysctl -q net.ipv4.tcp_timestamps=1
 		ip netns exec $ns2 sysctl -q net.ipv4.tcp_timestamps=1
 

-- 
2.53.0

[PATCH mptcp-next v4 06/15] tcp: allow mptcp to drop TS for some packets

[Matthieu Baerts (NGI0)]

With TCP-timestamps (padded) taking 12 bytes and ADD_ADDR IPv6 + port
taking 30 bytes, the 40-byte limit for the TCP options is reached. In
this case, it is then not possible to send the address signal.

The idea is to let MPTCP dropping the TCP-timestamps option for some
specific packets, to be able to send some specific pure ACK carrying >28
bytes of MPTCP options, like with this specific ADD_ADDR. A new
parameter is passed from tcp_established_options to the MPTCP side to
indicate if the TCP TS option is used, and if it should be dropped. The
next commit implements the part on MPTCP side, but split into two
patches to help TCP maintainers to identify the modifications on TCP
side. This feature will be controlled by a new add_addr_v6_port_drop_ts
MPTCP sysctl knob.

It is important to keep in mind that dropping the TCP timestamps option
for one packet of the connection could eventually disrupt some
middleboxes: even if it should be unlikely, they could drop the packet
or even block the connection. That's why this new feature will be
controlled by a sysctl knob.

Note that it would be technically possible to squeeze both options into
the header if the ADD_ADDR is first written, and then the TCP timestamps
without the NOPs preceding it. But this means more modifications on TCP
side, plus some middleboxes could still be disrupted by that.

About the implementation, instead of passing a new boolean (drop_ts),
another option would be to pass the whole option structure (opts),
but 'struct tcp_out_options' is currently defined in tcp_output.c, and
would need to be exported. Plus that means the removal of the TCP TS
option would be done on the MPTCP side, and not here on the TCP side.
It feels clearer to remove other TCP options from the TCP side, than
hiding that from the MPTCP side.

Yet an other alternative would be to pass the size already taken by the
other TCP options, and have a way to drop them all when needed. But this
feels better to target only the timestamps option where dropping it
should be safe, even if it is currently the only option that would be
set before MPTCP, when MPTCP is used.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
v3: split from the next commit
---
 include/net/mptcp.h   | 3 ++-
 net/ipv4/tcp_output.c | 6 +++++-
 net/mptcp/options.c   | 3 ++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index aef2dbeb847b..e3adeee04962 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -153,7 +153,7 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
 			  struct mptcp_out_options *opts);
 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 			       unsigned int *size, unsigned int remaining,
-			       struct mptcp_out_options *opts);
+			       bool *drop_ts, struct mptcp_out_options *opts);
 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);
 
 void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
@@ -272,6 +272,7 @@ static inline bool mptcp_established_options(struct sock *sk,
 					     struct sk_buff *skb,
 					     unsigned int *size,
 					     unsigned int remaining,
+					     bool *drop_ts,
 					     struct mptcp_out_options *opts)
 {
 	return false;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index ef0c10cd31c7..53ee4c8f5f8c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1181,12 +1181,16 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
 	 */
 	if (sk_is_mptcp(sk)) {
 		unsigned int remaining = MAX_TCP_OPTION_SPACE - size;
+		bool drop_ts = opts->options & OPTION_TS;
 		unsigned int opt_size = 0;
 
 		if (mptcp_established_options(sk, skb, &opt_size, remaining,
-					      &opts->mptcp)) {
+					      &drop_ts, &opts->mptcp)) {
 			opts->options |= OPTION_MPTCP;
 			size += opt_size;
+
+			if (drop_ts)
+				opts->options &= ~OPTION_TS;
 		}
 	}
 
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 9525b22c3db8..c5635c8781ae 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -818,7 +818,7 @@ static bool mptcp_established_options_mp_fail(struct sock *sk, int *size,
 
 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 			       unsigned int *size, unsigned int remaining,
-			       struct mptcp_out_options *opts)
+			       bool *drop_ts, struct mptcp_out_options *opts)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
@@ -827,6 +827,7 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 	int opt_size = 0;
 
 	opts->suboptions = 0;
+	*drop_ts = false;
 
 	/* Force later mptcp_write_options(), but do not use any actual
 	 * option space.

-- 
2.53.0

[PATCH mptcp-next v4 07/15] mptcp: pm: drop TCP TS with ADD_ADDRv6 + port

[Matthieu Baerts (NGI0)]

With TCP-timestamps (padded) taking 12 bytes and ADD_ADDR IPv6 + port
taking 30 bytes, the 40-byte limit for the TCP options is reached. In
this case, it is then not possible to send the signal.

To be able to send this ADD_ADDR, the TCP timestamps option can now be
dropped. This is done, when needed by setting the *drop_ts parameter
from mptcp_established_options. This feature is controlled by a new
net.mptcp.add_addr_v6_port_drop_ts sysctl knob, enabled by default.

It is important to keep in mind that dropping the TCP timestamps option
for one packet of the connection could eventually disrupt some
middleboxes: even if it should be unlikely, they could drop the packet
or even block the connection. That's why this new feature can be
controlled by a sysctl knob.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/448
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
v2: split + fix reverse Xmas tree order + change label (Paolo)
v3: split the TCP part in the previous patch + s/has_ts/add_addr_drop_ts
---
 net/mptcp/options.c  |  8 ++++++--
 net/mptcp/pm.c       | 12 +++++++++++-
 net/mptcp/protocol.h |  2 +-
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index c5635c8781ae..4673530018bf 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -655,6 +655,7 @@ static u64 add_addr_generate_hmac(u64 key1, u64 key2,
 static bool mptcp_established_options_add_addr(struct sock *sk,
 					       struct sk_buff *skb, int *size,
 					       unsigned int remaining,
+					       bool *drop_ts,
 					       struct mptcp_out_options *opts)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
@@ -669,7 +670,7 @@ static bool mptcp_established_options_add_addr(struct sock *sk,
 	if (!mptcp_pm_should_add_signal(msk) ||
 	    (opts->suboptions & (OPTION_MPTCP_MPJ_ACK | OPTION_MPTCP_MPC_ACK)) ||
 	    !mptcp_pm_add_addr_signal(msk, skb, size, remaining, &addr, &echo,
-				      &drop_other_suboptions))
+				      &drop_other_suboptions, drop_ts))
 		return false;
 
 	/*
@@ -822,6 +823,7 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
+	bool add_addr_drop_ts = *drop_ts;
 	bool snd_data_fin;
 	bool ret = false;
 	int opt_size = 0;
@@ -872,10 +874,12 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 
 	*size += opt_size;
 	remaining -= opt_size;
-	if (mptcp_established_options_add_addr(sk, skb, &opt_size, remaining, opts)) {
+	if (mptcp_established_options_add_addr(sk, skb, &opt_size, remaining,
+					       &add_addr_drop_ts, opts)) {
 		*size += opt_size;
 		remaining -= opt_size;
 		ret = true;
+		*drop_ts = add_addr_drop_ts;
 	} else if (mptcp_established_options_rm_addr(sk, &opt_size, remaining, opts)) {
 		*size += opt_size;
 		remaining -= opt_size;
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index ae6eabdc2ac1..f63c6b117f97 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -906,7 +906,7 @@ static int mptcp_add_addr_len(int family, bool echo, bool port)
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 			      int *size, int remaining,
 			      struct mptcp_addr_info *addr, bool *echo,
-			      bool *drop_other_suboptions)
+			      bool *drop_other_suboptions, bool *drop_ts)
 {
 	bool skip_add_addr = false;
 	bool ret = false;
@@ -950,6 +950,13 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 		if (!*drop_other_suboptions)
 			goto out_unlock;
 
+		if (*drop_ts && mptcp_add_addr_v6_port_drop_ts(net)) {
+			/* OK without TCP Timestamps? */
+			len -= TCPOLEN_TSTAMP_ALIGNED;
+			if (len <= remaining)
+				goto enough_space;
+		}
+
 		if (*echo) {
 			MPTCP_INC_STATS(net, MPTCP_MIB_ECHOADDTXDROP);
 		} else {
@@ -959,6 +966,9 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 		goto drop_signal_mark;
 	}
 
+	*drop_ts = false;
+
+enough_space:
 	ret = true;
 	*size = len;
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 1c9376c5e8f0..bf4607c1fd04 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1213,7 +1213,7 @@ static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 			      int *size, int remaining,
 			      struct mptcp_addr_info *addr, bool *echo,
-			      bool *drop_other_suboptions);
+			      bool *drop_other_suboptions, bool *drop_ts);
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			     struct mptcp_rm_list *rm_list, int *len);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);

-- 
2.53.0

[PATCH mptcp-next v4 08/15] selftests: mptcp: validate ADD_ADDRv6 + TS + port

[Matthieu Baerts (NGI0)]

This validates the feature added by parent commit, where it is now
possible to send an ADD_ADDR with a v6 IP address and a port number,
while the connection is using TCP Timestamps.

This test is simply a copy of the previous one: "signal address with
port", but using IPv6 addresses. This test is only executed if the
add_addr_v6_port_drop_ts sysctl knob is available. If not, it means the
kernel doesn't support this feature.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
v2: switch back to IPv6 for the main connection to use a v6 socket.
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index d894efe1fb02..30dbdcdf5e4a 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -3214,6 +3214,17 @@ add_addr_ports_tests()
 		chk_add_nr 1 1 1
 	fi
 
+	# signal address v6 with port
+	if reset "signal address v6 with port" &&
+	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/add_addr_v6_port_drop_ts'; then
+		pm_nl_set_limits $ns1 0 1
+		pm_nl_set_limits $ns2 1 1
+		pm_nl_add_endpoint $ns1 dead:beef:2::1 flags signal port 10100
+		run_tests $ns1 $ns2 dead:beef:1::1
+		chk_join_nr 1 1 1
+		chk_add_nr 1 1 1
+	fi
+
 	# subflow and signal with port
 	if reset "subflow and signal with port"; then
 		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal port 10100

-- 
2.53.0

[PATCH mptcp-next v4 09/15] selftests: mptcp: always check sent/dropped ADD_ADDRs

[Matthieu Baerts (NGI0)]

Before, they were only checked on demand, but it seems better to check
them each time received ADD_ADDRs are checked.

Errors are only reported when the counter exists, and the value is not
the expected one. This is similar to what is done in chk_join_nr: it
reduces the output, and avoids a lot of 'skip' when validating older
kernels. Also here, some tests need to adapt the default expected
counters, e.g. when ADD_ADDR echo are dropped on the reception side, or
it is not possible to send an ADD_ADDR due to the limited option space.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 71 ++++++++++---------------
 1 file changed, 27 insertions(+), 44 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 30dbdcdf5e4a..550a6b6117a9 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -87,6 +87,10 @@ unset fb_mpc_data
 unset fb_md5_sig
 unset fb_dss
 
+unset add_addr_tx_nr
+unset add_addr_echo_tx_nr
+unset add_addr_drop_tx_nr
+
 # generated using "nfbpf_compile '(ip && (ip[54] & 0xf0) == 0x30) ||
 #				  (ip6 && (ip6[74] & 0xf0) == 0x30)'"
 CBPF_MPTCP_SUBOPTION_ADD_ADDR="14,
@@ -1710,6 +1714,9 @@ chk_add_nr()
 	local ack_nr=$port_nr
 	local mis_syn_nr=0
 	local mis_ack_nr=0
+	local add_tx_nr=${add_addr_tx_nr:-${add_nr}}
+	local echo_tx_nr=${add_addr_echo_tx_nr:-${echo_nr}}
+	local drop_tx_nr=${add_addr_drop_tx_nr:-0}
 	local ns_tx=$ns1
 	local ns_rx=$ns2
 	local tx=""
@@ -1811,50 +1818,25 @@ chk_add_nr()
 			print_ok
 		fi
 	fi
-}
 
-chk_add_tx_nr()
-{
-	local add_tx_nr=$1
-	local echo_tx_nr=$2
-	local count
-
-	print_check "add addr tx"
-	count=$(mptcp_lib_get_counter ${ns1} "MPTcpExtAddAddrTx")
-	if [ -z "$count" ]; then
-		print_skip
+	count=$(mptcp_lib_get_counter ${ns_tx} "MPTcpExtAddAddrTx")
 	# Tolerate more ADD_ADDR then expected (if any), due to retransmissions
-	elif [ "$count" != "$add_tx_nr" ] &&
-	     { [ "$add_tx_nr" -eq 0 ] || [ "$count" -lt "$add_tx_nr" ]; }; then
+	if [ -n "$count" ] && [ "$count" != "$add_tx_nr" ] &&
+	   { [ "$add_tx_nr" -eq 0 ] || [ "$count" -lt "$add_tx_nr" ]; }; then
+		print_check "add addr tx"
 		fail_test "got $count ADD_ADDR[s] TX, expected $add_tx_nr"
-	else
-		print_ok
 	fi
 
-	print_check "add addr echo tx"
-	count=$(mptcp_lib_get_counter ${ns2} "MPTcpExtEchoAddTx")
-	if [ -z "$count" ]; then
-		print_skip
-	elif [ "$count" != "$echo_tx_nr" ]; then
+	count=$(mptcp_lib_get_counter ${ns_rx} "MPTcpExtEchoAddTx")
+	if [ -n "$count" ] && [ "$count" != "$echo_tx_nr" ]; then
+		print_check "add addr echo tx"
 		fail_test "got $count ADD_ADDR echo[s] TX, expected $echo_tx_nr"
-	else
-		print_ok
 	fi
-}
 
-chk_add_drop_tx_nr()
-{
-	local drop_tx_nr=$1
-	local count
-
-	print_check "add addr tx drop"
-	count=$(mptcp_lib_get_counter ${ns1} "MPTcpExtAddAddrTxDrop")
-	if [ -z "$count" ]; then
-		print_skip
-	elif [ "$count" != "$drop_tx_nr" ]; then
+	count=$(mptcp_lib_get_counter ${ns_tx} "MPTcpExtAddAddrTxDrop")
+	if [ -n "$count" ] && [ "$count" != "$drop_tx_nr" ]; then
+		print_check "add addr tx drop"
 		fail_test "got $count ADD_ADDR drop[s] TX, expected $drop_tx_nr"
-	else
-		print_ok
 	fi
 }
 
@@ -2267,7 +2249,6 @@ signal_address_tests()
 		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
 		run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 0 0 0
-		chk_add_tx_nr 1 1
 		chk_add_nr 1 1
 	fi
 
@@ -2545,8 +2526,8 @@ add_addr_timeout_tests()
 		speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 1 1 1
-		chk_add_tx_nr 4 4
-		chk_add_nr 4 0
+		add_addr_echo_tx_nr=4 \
+			chk_add_nr 4 0
 	fi
 
 	# add_addr timeout IPv6
@@ -2557,7 +2538,8 @@ add_addr_timeout_tests()
 		speed=slow \
 			run_tests $ns1 $ns2 dead:beef:1::1
 		chk_join_nr 1 1 1
-		chk_add_nr 4 0
+		add_addr_echo_tx_nr=4 \
+			chk_add_nr 4 0
 	fi
 
 	# signal addresses timeout
@@ -2569,7 +2551,8 @@ add_addr_timeout_tests()
 		speed=10 \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 2 2 2
-		chk_add_nr 8 0
+		add_addr_echo_tx_nr=8 \
+			chk_add_nr 8 0
 	fi
 
 	# signal invalid addresses timeout
@@ -2582,7 +2565,8 @@ add_addr_timeout_tests()
 			run_tests $ns1 $ns2 10.0.1.1
 		join_syn_tx=2 \
 			chk_join_nr 1 1 1
-		chk_add_nr 8 0
+		add_addr_echo_tx_nr=7 \
+			chk_add_nr 8 0
 	fi
 }
 
@@ -3331,9 +3315,8 @@ add_addr_ports_tests()
 		pm_nl_add_endpoint $ns1 dead:beef:2::1 flags signal port 10100
 		pm_nl_add_endpoint $ns1 dead:beef:3::1 flags signal
 		run_tests $ns1 $ns2 dead:beef:1::1
-		chk_add_drop_tx_nr 1
-		chk_add_tx_nr 1 1
-		chk_add_nr 1 1 0
+		add_addr_drop_tx_nr=1 \
+			chk_add_nr 1 1 0
 	fi
 }
 

-- 
2.53.0

[PATCH mptcp-next v4 10/15] mptcp: pm: use for_each_subflow helper

[Matthieu Baerts (NGI0)]

Similar to most places in the MPTCP code. So instead of passing the
subflow list and use list_for_each_entry(subflow, list, node), pass the
msk and use mptcp_for_each_subflow(msk, subflow).

That's clearer and more uniform with the rest.

While at it, add 'pm_' prefix for the exported one to easily identify
the origin. Plus replace 'lookup' by 'has', because a bool is returned.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm.c           |  6 +++---
 net/mptcp/pm_kernel.c    | 12 ++++++------
 net/mptcp/pm_userspace.c |  2 +-
 net/mptcp/protocol.h     |  4 ++--
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index f63c6b117f97..08d06090a0a0 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -115,14 +115,14 @@ static bool mptcp_pm_is_init_remote_addr(struct mptcp_sock *msk,
 	return mptcp_addresses_equal(&mpc_remote, remote, remote->port);
 }
 
-bool mptcp_lookup_subflow_by_saddr(const struct list_head *list,
-				   const struct mptcp_addr_info *saddr)
+bool mptcp_pm_has_subflow_saddr(const struct mptcp_sock *msk,
+				const struct mptcp_addr_info *saddr)
 {
 	struct mptcp_subflow_context *subflow;
 	struct mptcp_addr_info cur;
 	struct sock_common *skc;
 
-	list_for_each_entry(subflow, list, node) {
+	mptcp_for_each_subflow(msk, subflow) {
 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 
 		mptcp_local_address(skc, &cur);
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index ae28c96adb91..8436e66daab6 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -96,13 +96,13 @@ u8 mptcp_pm_get_limit_extra_subflows(const struct mptcp_sock *msk)
 }
 EXPORT_SYMBOL_GPL(mptcp_pm_get_limit_extra_subflows);
 
-static bool lookup_subflow_by_daddr(const struct list_head *list,
-				    const struct mptcp_addr_info *daddr)
+static bool has_subflow_daddr(const struct mptcp_sock *msk,
+			      const struct mptcp_addr_info *daddr)
 {
 	struct mptcp_subflow_context *subflow;
 	struct mptcp_addr_info cur;
 
-	list_for_each_entry(subflow, list, node) {
+	mptcp_for_each_subflow(msk, subflow) {
 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 
 		if (!((1 << inet_sk_state_load(ssk)) &
@@ -673,7 +673,7 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 	mptcp_pm_addr_send_ack(msk);
 	mptcp_mpc_endpoint_setup(msk);
 
-	if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
+	if (has_subflow_daddr(msk, &remote))
 		return;
 
 	/* pick id 0 port, if none is provided the remote address */
@@ -1099,7 +1099,7 @@ static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
 			goto next;
 
 		lock_sock(sk);
-		remove_subflow = mptcp_lookup_subflow_by_saddr(&msk->conn_list, addr);
+		remove_subflow = mptcp_pm_has_subflow_saddr(msk, addr);
 		mptcp_pm_remove_anno_addr(msk, addr, remove_subflow &&
 					  !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));
 
@@ -1237,7 +1237,7 @@ static void mptcp_pm_flush_addrs_and_subflows(struct mptcp_sock *msk,
 
 	entry = list_prepare_entry(entry, rm_list, list);
 	list_for_each_entry_continue(entry, rm_list, list) {
-		if (mptcp_lookup_subflow_by_saddr(&msk->conn_list, &entry->addr))
+		if (mptcp_pm_has_subflow_saddr(msk, &entry->addr))
 			slist.ids[slist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr);
 
 		if (mptcp_remove_anno_list_by_saddr(msk, &entry->addr))
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index d285df7d41d2..74d00b2f2a76 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -283,7 +283,7 @@ void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
 	/* only delete if either announced or matching a subflow */
 	if (mptcp_remove_anno_list_by_saddr(msk, &entry->addr))
 		anno_nr++;
-	else if (!mptcp_lookup_subflow_by_saddr(&msk->conn_list, &entry->addr))
+	else if (!mptcp_pm_has_subflow_saddr(msk, &entry->addr))
 		return;
 
 	alist.ids[alist.nr++] = entry->addr.id;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index bf4607c1fd04..1d9834252515 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1139,8 +1139,8 @@ bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
 struct mptcp_pm_add_entry *
 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 		       const struct mptcp_addr_info *addr, bool check_id);
-bool mptcp_lookup_subflow_by_saddr(const struct list_head *list,
-				   const struct mptcp_addr_info *saddr);
+bool mptcp_pm_has_subflow_saddr(const struct mptcp_sock *msk,
+				const struct mptcp_addr_info *saddr);
 bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
 				     const struct mptcp_addr_info *addr);
 int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,

-- 
2.53.0

[PATCH mptcp-next v4 11/15] mptcp: pm: rename add_entry structure to add_addr

[Matthieu Baerts (NGI0)]

Using only the 'add' prefix is confusing: does it refer to a generic
added entry or address, or specifically to ADD_ADDRs. Using add_addr
removes this confusion.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm.c       | 22 +++++++++++-----------
 net/mptcp/protocol.h |  2 +-
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 08d06090a0a0..3d930298d9d8 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -12,7 +12,7 @@
 
 #define ADD_ADDR_RETRANS_MAX	3
 
-struct mptcp_pm_add_entry {
+struct mptcp_pm_add_addr {
 	struct list_head	list;
 	struct mptcp_addr_info	addr;
 	u8			retrans_times;
@@ -133,11 +133,11 @@ bool mptcp_pm_has_subflow_saddr(const struct mptcp_sock *msk,
 	return false;
 }
 
-static struct mptcp_pm_add_entry *
+static struct mptcp_pm_add_addr *
 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 				const struct mptcp_addr_info *addr)
 {
-	struct mptcp_pm_add_entry *entry;
+	struct mptcp_pm_add_addr *entry;
 
 	lockdep_assert_held(&msk->pm.lock);
 
@@ -152,7 +152,7 @@ mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
 				     const struct mptcp_addr_info *addr)
 {
-	struct mptcp_pm_add_entry *entry;
+	struct mptcp_pm_add_addr *entry;
 	bool ret;
 
 	entry = mptcp_pm_del_add_timer(msk, addr, false);
@@ -164,7 +164,7 @@ bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
 
 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
 {
-	struct mptcp_pm_add_entry *entry;
+	struct mptcp_pm_add_addr *entry;
 	struct mptcp_addr_info saddr;
 	bool ret = false;
 
@@ -340,8 +340,8 @@ static unsigned int mptcp_adjust_add_addr_timeout(struct mptcp_sock *msk)
 
 static void mptcp_pm_add_timer(struct timer_list *timer)
 {
-	struct mptcp_pm_add_entry *entry = timer_container_of(entry, timer,
-							      add_timer);
+	struct mptcp_pm_add_addr *entry = timer_container_of(entry, timer,
+							     add_timer);
 	struct mptcp_sock *msk = entry->sock;
 	struct sock *sk = (struct sock *)msk;
 	unsigned int timeout = 0;
@@ -397,12 +397,12 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
 	sock_put(sk);
 }
 
-struct mptcp_pm_add_entry *
+struct mptcp_pm_add_addr *
 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 		       const struct mptcp_addr_info *addr, bool check_id)
 {
 	struct sock *sk = (struct sock *)msk;
-	struct mptcp_pm_add_entry *entry;
+	struct mptcp_pm_add_addr *entry;
 	struct timer_list *timer = NULL;
 
 	rcu_read_lock();
@@ -434,7 +434,7 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr)
 {
-	struct mptcp_pm_add_entry *add_entry = NULL;
+	struct mptcp_pm_add_addr *add_entry = NULL;
 	struct sock *sk = (struct sock *)msk;
 	unsigned int timeout;
 
@@ -471,7 +471,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 
 static void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
 {
-	struct mptcp_pm_add_entry *entry, *tmp;
+	struct mptcp_pm_add_addr *entry, *tmp;
 	struct sock *sk = (struct sock *)msk;
 	LIST_HEAD(free_list);
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 1d9834252515..52af825c3f8e 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1136,7 +1136,7 @@ int mptcp_pm_mp_prio_send_ack(struct mptcp_sock *msk,
 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr);
 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
-struct mptcp_pm_add_entry *
+struct mptcp_pm_add_addr *
 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 		       const struct mptcp_addr_info *addr, bool check_id);
 bool mptcp_pm_has_subflow_saddr(const struct mptcp_sock *msk,

-- 
2.53.0

[PATCH mptcp-next v4 12/15] mptcp: pm: uniform announced addresses helpers

[Matthieu Baerts (NGI0)]

Similar to the previous commit, only using the 'add' or 'anno' prefixes
is confusing -- generally associated to the action of adding something,
or the Latin name for "year" -- and lack of uniformity.

This has been causing issues in the past, e.g. del_add_timer seemed to
suggest the goal is to delete a previously added timer.

Instead, use the mptcp_pm_announced_ prefix.

While at it, slightly improves some helpers:

- mptcp_lookup_anno_list_by_saddr: no need to specify what is used to do
  the lookup: mptcp_pm_announced_lookup.

- mptcp_pm_sport_in_anno_list: it doesn't just compare the port, but the
  whole address linked to the sublow: mptcp_pm_announced_has_ssk.

- mptcp_pm_alloc_anno_list: it allocates one item of the list, not a
  whole list: mptcp_pm_announced_alloc.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
v2: also update comment mentioning mptcp_pm_announced_del_timer.
---
 net/mptcp/options.c      |  2 +-
 net/mptcp/pm.c           | 35 +++++++++++++++++------------------
 net/mptcp/pm_kernel.c    | 10 +++++-----
 net/mptcp/pm_userspace.c |  4 ++--
 net/mptcp/protocol.h     | 12 ++++++------
 net/mptcp/subflow.c      |  4 ++--
 6 files changed, 33 insertions(+), 34 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 4673530018bf..5d9bfd559310 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -1218,7 +1218,7 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 				MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR);
 			} else {
 				mptcp_pm_add_addr_echoed(msk, &mp_opt.addr);
-				mptcp_pm_del_add_timer(msk, &mp_opt.addr, true);
+				mptcp_pm_announced_del_timer(msk, &mp_opt.addr, true);
 				MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD);
 			}
 
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 3d930298d9d8..0f05222ecda2 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -134,8 +134,8 @@ bool mptcp_pm_has_subflow_saddr(const struct mptcp_sock *msk,
 }
 
 static struct mptcp_pm_add_addr *
-mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
-				const struct mptcp_addr_info *addr)
+mptcp_pm_announced_lookup(const struct mptcp_sock *msk,
+			  const struct mptcp_addr_info *addr)
 {
 	struct mptcp_pm_add_addr *entry;
 
@@ -149,26 +149,26 @@ mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 	return NULL;
 }
 
-bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
-				     const struct mptcp_addr_info *addr)
+bool mptcp_pm_announced_remove(struct mptcp_sock *msk,
+			       const struct mptcp_addr_info *addr)
 {
 	struct mptcp_pm_add_addr *entry;
 	bool ret;
 
-	entry = mptcp_pm_del_add_timer(msk, addr, false);
+	entry = mptcp_pm_announced_del_timer(msk, addr, false);
 	ret = entry;
 	kfree_rcu(entry, rcu);
 
 	return ret;
 }
 
-bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
+bool mptcp_pm_announced_has_ssk(struct mptcp_sock *msk, const struct sock *ssk)
 {
 	struct mptcp_pm_add_addr *entry;
 	struct mptcp_addr_info saddr;
 	bool ret = false;
 
-	mptcp_local_address((struct sock_common *)sk, &saddr);
+	mptcp_local_address((struct sock_common *)ssk, &saddr);
 
 	spin_lock_bh(&msk->pm.lock);
 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
@@ -364,7 +364,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
 
 	spin_lock_bh(&msk->pm.lock);
 
-	/* The cancel path (mptcp_pm_del_add_timer()) can race with this
+	/* The cancel path (mptcp_pm_announced_del_timer()) can race with this
 	 * callback. Once cancel updates retrans_times to MAX, suppress further
 	 * retransmissions here. If this callback acquires pm.lock first, one
 	 * final transmit attempt is still possible.
@@ -398,8 +398,8 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
 }
 
 struct mptcp_pm_add_addr *
-mptcp_pm_del_add_timer(struct mptcp_sock *msk,
-		       const struct mptcp_addr_info *addr, bool check_id)
+mptcp_pm_announced_del_timer(struct mptcp_sock *msk,
+			     const struct mptcp_addr_info *addr, bool check_id)
 {
 	struct sock *sk = (struct sock *)msk;
 	struct mptcp_pm_add_addr *entry;
@@ -408,7 +408,7 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 	rcu_read_lock();
 
 	spin_lock_bh(&msk->pm.lock);
-	entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
+	entry = mptcp_pm_announced_lookup(msk, addr);
 	if (entry && (!check_id || entry->addr.id == addr->id)) {
 		entry->retrans_times = ADD_ADDR_RETRANS_MAX;
 		timer = &entry->add_timer;
@@ -431,7 +431,7 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 	return entry;
 }
 
-bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
+bool mptcp_pm_announced_alloc(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr)
 {
 	struct mptcp_pm_add_addr *add_entry = NULL;
@@ -440,8 +440,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 
 	lockdep_assert_held(&msk->pm.lock);
 
-	add_entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
-
+	add_entry = mptcp_pm_announced_lookup(msk, addr);
 	if (add_entry) {
 		if (WARN_ON_ONCE(mptcp_pm_is_kernel(msk)))
 			return false;
@@ -469,7 +468,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 	return true;
 }
 
-static void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
+static void mptcp_pm_free_announced_list(struct mptcp_sock *msk)
 {
 	struct mptcp_pm_add_addr *entry, *tmp;
 	struct sock *sk = (struct sock *)msk;
@@ -739,7 +738,7 @@ void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 
 	spin_lock_bh(&pm->lock);
 
-	if (mptcp_lookup_anno_list_by_saddr(msk, addr) && READ_ONCE(pm->work_pending))
+	if (mptcp_pm_announced_lookup(msk, addr) && READ_ONCE(pm->work_pending))
 		mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
 
 	spin_unlock_bh(&pm->lock);
@@ -983,7 +982,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 	 * let the PM state machine progress.
 	 */
 	if (skip_add_addr) {
-		mptcp_pm_del_add_timer(msk, addr, true);
+		mptcp_pm_announced_del_timer(msk, addr, true);
 		mptcp_pm_subflow_established(msk);
 	}
 	return ret;
@@ -1171,7 +1170,7 @@ static void mptcp_pm_ops_release(struct mptcp_sock *msk)
 
 void mptcp_pm_destroy(struct mptcp_sock *msk)
 {
-	mptcp_pm_free_anno_list(msk);
+	mptcp_pm_free_announced_list(msk);
 	mptcp_pm_ops_release(msk);
 }
 
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index 8436e66daab6..331f6fa99014 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -374,7 +374,7 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 		/* If the alloc fails, we are on memory pressure, not worth
 		 * continuing, and trying to create subflows.
 		 */
-		if (!mptcp_pm_alloc_anno_list(msk, &local.addr))
+		if (!mptcp_pm_announced_alloc(msk, &local.addr))
 			return;
 
 		__clear_bit(endp_id, msk->pm.id_avail_bitmap);
@@ -1054,7 +1054,7 @@ int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-static void mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
+static void mptcp_pm_remove_announced(struct mptcp_sock *msk,
 				      const struct mptcp_addr_info *addr,
 				      bool force)
 {
@@ -1063,7 +1063,7 @@ static void mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
 
 	list.ids[list.nr++] = mptcp_endp_get_local_id(msk, addr);
 
-	announced = mptcp_remove_anno_list_by_saddr(msk, addr);
+	announced = mptcp_pm_announced_remove(msk, addr);
 	if (announced || force) {
 		spin_lock_bh(&msk->pm.lock);
 		if (announced)
@@ -1100,7 +1100,7 @@ static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
 
 		lock_sock(sk);
 		remove_subflow = mptcp_pm_has_subflow_saddr(msk, addr);
-		mptcp_pm_remove_anno_addr(msk, addr, remove_subflow &&
+		mptcp_pm_remove_announced(msk, addr, remove_subflow &&
 					  !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));
 
 		list.ids[0] = mptcp_endp_get_local_id(msk, addr);
@@ -1240,7 +1240,7 @@ static void mptcp_pm_flush_addrs_and_subflows(struct mptcp_sock *msk,
 		if (mptcp_pm_has_subflow_saddr(msk, &entry->addr))
 			slist.ids[slist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr);
 
-		if (mptcp_remove_anno_list_by_saddr(msk, &entry->addr))
+		if (mptcp_pm_announced_remove(msk, &entry->addr))
 			alist.ids[alist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr);
 
 		if (slist.nr == MPTCP_RM_IDS_MAX ||
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 74d00b2f2a76..ad6ba658e5a5 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -228,7 +228,7 @@ int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
 	lock_sock(sk);
 	spin_lock_bh(&msk->pm.lock);
 
-	if (mptcp_pm_alloc_anno_list(msk, &addr_val.addr)) {
+	if (mptcp_pm_announced_alloc(msk, &addr_val.addr)) {
 		msk->pm.add_addr_signaled++;
 		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
 		mptcp_pm_addr_send_ack(msk);
@@ -281,7 +281,7 @@ void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
 	int anno_nr = 0;
 
 	/* only delete if either announced or matching a subflow */
-	if (mptcp_remove_anno_list_by_saddr(msk, &entry->addr))
+	if (mptcp_pm_announced_remove(msk, &entry->addr))
 		anno_nr++;
 	else if (!mptcp_pm_has_subflow_saddr(msk, &entry->addr))
 		return;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 52af825c3f8e..27a0354a1ebd 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1133,16 +1133,16 @@ int mptcp_pm_mp_prio_send_ack(struct mptcp_sock *msk,
 			      struct mptcp_addr_info *addr,
 			      struct mptcp_addr_info *rem,
 			      u8 bkup);
-bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
+bool mptcp_pm_announced_alloc(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr);
-bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
 struct mptcp_pm_add_addr *
-mptcp_pm_del_add_timer(struct mptcp_sock *msk,
-		       const struct mptcp_addr_info *addr, bool check_id);
+mptcp_pm_announced_del_timer(struct mptcp_sock *msk,
+			     const struct mptcp_addr_info *addr, bool check_id);
+bool mptcp_pm_announced_remove(struct mptcp_sock *msk,
+			       const struct mptcp_addr_info *addr);
+bool mptcp_pm_announced_has_ssk(struct mptcp_sock *msk, const struct sock *ssk);
 bool mptcp_pm_has_subflow_saddr(const struct mptcp_sock *msk,
 				const struct mptcp_addr_info *saddr);
-bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
-				     const struct mptcp_addr_info *addr);
 int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
 			  struct genl_info *info);
 int mptcp_userspace_pm_set_flags(struct mptcp_pm_addr_entry *local,
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index d562e149606f..8e386899ceb9 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -235,7 +235,7 @@ static int subflow_check_req(struct request_sock *req,
 			pr_debug("syn inet_sport=%d %d\n",
 				 ntohs(inet_sk(sk_listener)->inet_sport),
 				 ntohs(inet_sk((struct sock *)subflow_req->msk)->inet_sport));
-			if (!mptcp_pm_sport_in_anno_list(subflow_req->msk, sk_listener)) {
+			if (!mptcp_pm_announced_has_ssk(subflow_req->msk, sk_listener)) {
 				SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTSYNRX);
 				subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT);
 				return -EPERM;
@@ -926,7 +926,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 				pr_debug("ack inet_sport=%d %d\n",
 					 ntohs(inet_sk(sk)->inet_sport),
 					 ntohs(inet_sk((struct sock *)owner)->inet_sport));
-				if (!mptcp_pm_sport_in_anno_list(owner, sk)) {
+				if (!mptcp_pm_announced_has_ssk(owner, sk)) {
 					SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTACKRX);
 					subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT);
 					goto dispose_child;

-- 
2.53.0

[PATCH mptcp-next v4 13/15] mptcp: pm: remove add_ prefix from timer

[Matthieu Baerts (NGI0)]

Similar to the two previous commits, using the 'add' prefix is
confusing, also confirmed by [1].

Now that the structure has been renamed to include 'add_addr' in its
name, easier to know the timer is linked to the ADD_ADDR, no need to
add the confusing prefix, or an unneeded longer one.

While at it, also update the ADD_ADDR timer helper to clearly specify it
is linked to ADD_ADDR, and it is not there to add a new timer.

Link: https://lore.kernel.org/20251117100745.1913963-1-edumazet@google.com [1]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 0f05222ecda2..6c0468f1609b 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -17,7 +17,7 @@ struct mptcp_pm_add_addr {
 	struct mptcp_addr_info	addr;
 	u8			retrans_times;
 	bool			timer_done;
-	struct timer_list	add_timer;
+	struct timer_list	timer;
 	struct mptcp_sock	*sock;
 	struct rcu_head		rcu;
 };
@@ -338,10 +338,10 @@ static unsigned int mptcp_adjust_add_addr_timeout(struct mptcp_sock *msk)
 	return rto;
 }
 
-static void mptcp_pm_add_timer(struct timer_list *timer)
+static void mptcp_pm_add_addr_timer(struct timer_list *timer)
 {
 	struct mptcp_pm_add_addr *entry = timer_container_of(entry, timer,
-							     add_timer);
+							     timer);
 	struct mptcp_sock *msk = entry->sock;
 	struct sock *sk = (struct sock *)msk;
 	unsigned int timeout = 0;
@@ -411,7 +411,7 @@ mptcp_pm_announced_del_timer(struct mptcp_sock *msk,
 	entry = mptcp_pm_announced_lookup(msk, addr);
 	if (entry && (!check_id || entry->addr.id == addr->id)) {
 		entry->retrans_times = ADD_ADDR_RETRANS_MAX;
-		timer = &entry->add_timer;
+		timer = &entry->timer;
 	}
 	if (!check_id && entry)
 		list_del(&entry->list);
@@ -458,12 +458,12 @@ bool mptcp_pm_announced_alloc(struct mptcp_sock *msk,
 	add_entry->sock = msk;
 	add_entry->retrans_times = 0;
 
-	timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
+	timer_setup(&add_entry->timer, mptcp_pm_add_addr_timer, 0);
 reset_timer:
 	add_entry->timer_done = false;
 	timeout = mptcp_adjust_add_addr_timeout(msk);
 	if (timeout)
-		sk_reset_timer(sk, &add_entry->add_timer, jiffies + timeout);
+		sk_reset_timer(sk, &add_entry->timer, jiffies + timeout);
 
 	return true;
 }
@@ -482,7 +482,7 @@ static void mptcp_pm_free_announced_list(struct mptcp_sock *msk)
 
 	list_for_each_entry_safe(entry, tmp, &free_list, list) {
 		if (!entry->timer_done)
-			sk_stop_timer_sync(sk, &entry->add_timer);
+			sk_stop_timer_sync(sk, &entry->timer);
 		kfree_rcu(entry, rcu);
 	}
 }

-- 
2.53.0

[PATCH mptcp-next v4 14/15] mptcp: pm: make mptcp_pm_add_addr_send_ack static

[Matthieu Baerts (NGI0)]

Only used in pm.c.

Note that the signature is added above: it is easier than moving the
code around, because this helper depends on mptcp_pm_schedule_work which
is declared below.

While at it, explicitly mark it as to be called while pm->lock is held.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm.c       | 4 +++-
 net/mptcp/protocol.h | 1 -
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 6c0468f1609b..a781e21d74f3 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -226,6 +226,7 @@ static bool subflow_in_rm_list(const struct mptcp_subflow_context *subflow,
 	return false;
 }
 
+static void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
 static void
 mptcp_pm_addr_send_ack_avoid_list(struct mptcp_sock *msk,
 				  const struct mptcp_rm_list *rm_list)
@@ -744,7 +745,8 @@ void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 	spin_unlock_bh(&pm->lock);
 }
 
-void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk)
+/* To be called while pm->lock is held */
+static void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk)
 {
 	if (!mptcp_pm_should_add_signal(msk))
 		return;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 27a0354a1ebd..71bb522483ef 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1117,7 +1117,6 @@ void mptcp_pm_add_addr_received(const struct sock *ssk,
 				const struct mptcp_addr_info *addr);
 void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr);
-void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
 void mptcp_pm_send_ack(struct mptcp_sock *msk,
 		       struct mptcp_subflow_context *subflow,
 		       bool prio, bool backup);

-- 
2.53.0

[PATCH mptcp-next v4 15/15] mptcp: pm: avoid using del_timer directly

[Matthieu Baerts (NGI0)]

mptcp_pm_announced_del_timer() removes the matched ADD_ADDR entry (if
found) from the ADD_ADDR list only if check_id is false. That's
dangerous, and not clear, because it means the caller should be free the
entry only in some cases, and it easy to miss that.

Instead, make it static, and call it from mptcp_pm_add_addr_echoed,
which is the only other case where mptcp_pm_add_addr_del_timer should be
called with check_id set to true. Bonus with that: a second call to
mptcp_pm_add_addr_lookup_by_addr() can be avoided.

Note that instead of adding the signature above to avoid a compilation
issue because this helper is called before the definition of the
function, the whole helper is moved above where it is first called. Its
content is untouched, except the addition of the 'static' keyboard.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/options.c  |  1 -
 net/mptcp/pm.c       | 75 +++++++++++++++++++++++++++-------------------------
 net/mptcp/protocol.h |  3 ---
 3 files changed, 39 insertions(+), 40 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 5d9bfd559310..b8ef59632638 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -1218,7 +1218,6 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 				MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR);
 			} else {
 				mptcp_pm_add_addr_echoed(msk, &mp_opt.addr);
-				mptcp_pm_announced_del_timer(msk, &mp_opt.addr, true);
 				MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD);
 			}
 
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index a781e21d74f3..452b17b9330c 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -149,6 +149,40 @@ mptcp_pm_announced_lookup(const struct mptcp_sock *msk,
 	return NULL;
 }
 
+static struct mptcp_pm_add_addr *
+mptcp_pm_announced_del_timer(struct mptcp_sock *msk,
+			     const struct mptcp_addr_info *addr, bool check_id)
+{
+	struct sock *sk = (struct sock *)msk;
+	struct mptcp_pm_add_addr *entry;
+	struct timer_list *timer = NULL;
+
+	rcu_read_lock();
+
+	spin_lock_bh(&msk->pm.lock);
+	entry = mptcp_pm_announced_lookup(msk, addr);
+	if (entry && (!check_id || entry->addr.id == addr->id)) {
+		entry->retrans_times = ADD_ADDR_RETRANS_MAX;
+		timer = &entry->timer;
+	}
+	if (!check_id && entry)
+		list_del(&entry->list);
+	spin_unlock_bh(&msk->pm.lock);
+
+	/* Note: entry might have been removed by another thread.
+	 * We hold rcu_read_lock() to ensure it is not freed under us.
+	 */
+	if (timer && check_id)
+		sk_stop_timer(sk, timer);
+
+	rcu_read_unlock();
+
+	if (timer && !check_id)
+		sk_stop_timer_sync(sk, timer);
+
+	return entry;
+}
+
 bool mptcp_pm_announced_remove(struct mptcp_sock *msk,
 			       const struct mptcp_addr_info *addr)
 {
@@ -398,40 +432,6 @@ static void mptcp_pm_add_addr_timer(struct timer_list *timer)
 	sock_put(sk);
 }
 
-struct mptcp_pm_add_addr *
-mptcp_pm_announced_del_timer(struct mptcp_sock *msk,
-			     const struct mptcp_addr_info *addr, bool check_id)
-{
-	struct sock *sk = (struct sock *)msk;
-	struct mptcp_pm_add_addr *entry;
-	struct timer_list *timer = NULL;
-
-	rcu_read_lock();
-
-	spin_lock_bh(&msk->pm.lock);
-	entry = mptcp_pm_announced_lookup(msk, addr);
-	if (entry && (!check_id || entry->addr.id == addr->id)) {
-		entry->retrans_times = ADD_ADDR_RETRANS_MAX;
-		timer = &entry->timer;
-	}
-	if (!check_id && entry)
-		list_del(&entry->list);
-	spin_unlock_bh(&msk->pm.lock);
-
-	/* Note: entry might have been removed by another thread.
-	 * We hold rcu_read_lock() to ensure it is not freed under us.
-	 */
-	if (timer && check_id)
-		sk_stop_timer(sk, timer);
-
-	rcu_read_unlock();
-
-	if (timer && !check_id)
-		sk_stop_timer_sync(sk, timer);
-
-	return entry;
-}
-
 bool mptcp_pm_announced_alloc(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr)
 {
@@ -731,15 +731,18 @@ void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr)
 {
 	struct mptcp_pm_data *pm = &msk->pm;
+	struct mptcp_pm_add_addr *entry;
 
 	pr_debug("msk=%p\n", msk);
 
-	if (!READ_ONCE(pm->work_pending))
+	entry = mptcp_pm_announced_del_timer(msk, addr, true);
+
+	if (!entry || !READ_ONCE(pm->work_pending))
 		return;
 
 	spin_lock_bh(&pm->lock);
 
-	if (mptcp_pm_announced_lookup(msk, addr) && READ_ONCE(pm->work_pending))
+	if (READ_ONCE(pm->work_pending))
 		mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
 
 	spin_unlock_bh(&pm->lock);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 71bb522483ef..b63571400c6a 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1134,9 +1134,6 @@ int mptcp_pm_mp_prio_send_ack(struct mptcp_sock *msk,
 			      u8 bkup);
 bool mptcp_pm_announced_alloc(struct mptcp_sock *msk,
 			      const struct mptcp_addr_info *addr);
-struct mptcp_pm_add_addr *
-mptcp_pm_announced_del_timer(struct mptcp_sock *msk,
-			     const struct mptcp_addr_info *addr, bool check_id);
 bool mptcp_pm_announced_remove(struct mptcp_sock *msk,
 			       const struct mptcp_addr_info *addr);
 bool mptcp_pm_announced_has_ssk(struct mptcp_sock *msk, const struct sock *ssk);

-- 
2.53.0

Re: [PATCH mptcp-net mptcp-next v4 00/15] mptcp: pm: drop TCP TS with ADD_ADDRv6 + port

[MPTCP CI]

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Unstable: 1 failed test(s): packetdrill_add_addr ⚠️ 
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/26616464627

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/50fb9dc2cfe6
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1102593


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Re: [PATCH mptcp-net mptcp-next v4 00/15] mptcp: pm: drop TCP TS with ADD_ADDRv6 + port

[Mat Martineau]

On Fri, 29 May 2026, Matthieu Baerts (NGI0) wrote:

> Currently, it is possible to add a "signal" MPTCP endpoint with a v6
> address and a port, or to directly request to send an ADD_ADDR with a v6
> address and a port, but such signalling option cannot be sent when TCP
> timestamps is used due to a lack of option space. Instead of simply
> dropping such ADD_ADDR, the TCP timestamps can be dropped only for this
> packet.
>
> - Patch 1: fix for PREEMPT_RT kernels, for -net.
>
> - Patches 2-4: small cleanups to avoid computing ADD/RM_ADDR twice.
>
> - Patches 5-8: the new feature, controlled by a new sysctl knob.
>
> - Patch 9: extra checks in the selftests.
>
> - Patches 10-15: refactoring/cleanups: some of them were part of a
>  previous patch: "mptcp: pm: clearer ADD_ADDR related helpers names"
>  [1].
>
> Note that the mptcp/add_addr/add_addr6_port_ts_server.pkt packetdrill
> test is supposed to fail with this series, until this PR is applied:
>
>  https://github.com/multipath-tcp/packetdrill/pull/198
>
> Link: https://lore.kernel.org/20260415-mptcp-inc-limits-v5-20-e54c3bf80e4e@kernel.org [1]
> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> ---
> Changes in v4:
> - Patches 2-4: uniform "size" type: signed for all suboptions. (Mat)
> - Dropped previous patch 16.
> - Link to v3: https://patch.msgid.link/20260520-mptcp-add-addr6-port-ts-v3-0-bffa658a7678@kernel.org

Hi Matthieu -

Thank you for the updates in v4, all of my concerns are addressed and I 
agree that this approach to fitting ADD_ADDR headers w/ IPv6 seems like 
the best tradeoff.

I'll also give a +1 on the packetdrill PR.

For the series:

Reviewed-by: Mat Martineau <martineau@kernel.org>

>
> Changes in v3:
> - Patch 1: sk_stop_timer() should still be called under rcu.
> - Patches 6-7: split + s/has_ts/add_addr_drop_ts/.
> - Link to v2: https://patch.msgid.link/20260519-mptcp-add-addr6-port-ts-v2-0-3b36a51e6a86@kernel.org
>
> Changes in v2:
> - Patch 1: new.
> - Patch 3: reset size in mptcp_pm_add_addr_signal for dropped options.
> - Patches 4-5: split from previous patch 3. (Paolo)
> - Patch 4: fix typo.
> - Patch 5: fix reverse Xmas tree order + change label. (Paolo)
> - Patch 6: back to v6 connection.
> - Patch 10: fix comment.
> - Patch 14: fix typo.
> - Link to v1: https://patch.msgid.link/20260518-mptcp-add-addr6-port-ts-v1-0-f1ca26977fcd@kernel.org
>
> ---
> Matthieu Baerts (NGI0) (15):
>      [mptcp-net] mptcp: pm: avoid sleeping while holding rcu_read_lock
>      mptcp: options: suboptions sizes can be negative
>      mptcp: pm: avoid computing rm_addr size twice
>      mptcp: pm: avoid computing add_addr size twice
>      mptcp: introduce add_addr_v6_port_drop_ts sysctl knob
>      tcp: allow mptcp to drop TS for some packets
>      mptcp: pm: drop TCP TS with ADD_ADDRv6 + port
>      selftests: mptcp: validate ADD_ADDRv6 + TS + port
>      selftests: mptcp: always check sent/dropped ADD_ADDRs
>      mptcp: pm: use for_each_subflow helper
>      mptcp: pm: rename add_entry structure to add_addr
>      mptcp: pm: uniform announced addresses helpers
>      mptcp: pm: remove add_ prefix from timer
>      mptcp: pm: make mptcp_pm_add_addr_send_ack static
>      mptcp: pm: avoid using del_timer directly
>
> Documentation/networking/mptcp-sysctl.rst       |  13 ++
> include/net/mptcp.h                             |   3 +-
> net/ipv4/tcp_output.c                           |   6 +-
> net/mptcp/ctrl.c                                |  18 ++-
> net/mptcp/options.c                             |  65 +++-----
> net/mptcp/pm.c                                  | 189 ++++++++++++++----------
> net/mptcp/pm_kernel.c                           |  22 +--
> net/mptcp/pm_userspace.c                        |   6 +-
> net/mptcp/protocol.h                            |  46 ++----
> net/mptcp/subflow.c                             |   4 +-
> tools/testing/selftests/net/mptcp/mptcp_join.sh |  83 +++++------
> 11 files changed, 240 insertions(+), 215 deletions(-)
> ---
> base-commit: 4d6bda29d05f8789f40c095d5d08396ffd6b470f
> change-id: 20260508-mptcp-add-addr6-port-ts-371653e0f843
>
> Best regards,
> --
> Matthieu Baerts (NGI0) <matttbe@kernel.org>
>
>
>

Re: [PATCH mptcp-net mptcp-next v4 00/15] mptcp: pm: drop TCP TS with ADD_ADDRv6 + port

[Matthieu Baerts]

Hi Mat,

On 30/05/2026 04:12, Mat Martineau wrote:
> On Fri, 29 May 2026, Matthieu Baerts (NGI0) wrote:
> 
>> Currently, it is possible to add a "signal" MPTCP endpoint with a v6
>> address and a port, or to directly request to send an ADD_ADDR with a v6
>> address and a port, but such signalling option cannot be sent when TCP
>> timestamps is used due to a lack of option space. Instead of simply
>> dropping such ADD_ADDR, the TCP timestamps can be dropped only for this
>> packet.
>>
>> - Patch 1: fix for PREEMPT_RT kernels, for -net.
>>
>> - Patches 2-4: small cleanups to avoid computing ADD/RM_ADDR twice.
>>
>> - Patches 5-8: the new feature, controlled by a new sysctl knob.
>>
>> - Patch 9: extra checks in the selftests.
>>
>> - Patches 10-15: refactoring/cleanups: some of them were part of a
>>  previous patch: "mptcp: pm: clearer ADD_ADDR related helpers names"
>>  [1].
>>
>> Note that the mptcp/add_addr/add_addr6_port_ts_server.pkt packetdrill
>> test is supposed to fail with this series, until this PR is applied:
>>
>>  https://github.com/multipath-tcp/packetdrill/pull/198
>>
>> Link: https://lore.kernel.org/20260415-mptcp-inc-limits-v5-20-
>> e54c3bf80e4e@kernel.org [1]
>> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
>> ---
>> Changes in v4:
>> - Patches 2-4: uniform "size" type: signed for all suboptions. (Mat)
>> - Dropped previous patch 16.
>> - Link to v3: https://patch.msgid.link/20260520-mptcp-add-addr6-port-
>> ts-v3-0-bffa658a7678@kernel.org
> 
> Hi Matthieu -
> 
> Thank you for the updates in v4, all of my concerns are addressed and I
> agree that this approach to fitting ADD_ADDR headers w/ IPv6 seems like
> the best tradeoff.
> 
> I'll also give a +1 on the packetdrill PR.

Thank you! Merged!
> For the series:
> 
> Reviewed-by: Mat Martineau <martineau@kernel.org>

Thank you for the review! Now in our tree:

New patches for t/upstream-net and t/upstream:
- c619bf382586: mptcp: pm: avoid sleeping while holding rcu_read_lock
- Results: ba5ea3e35898..b744d5cbf545 (export-net)
- Results: 24c473fa6c91..0a3014718f01 (export)

Tests are now in progress:

- export-net:
https://github.com/multipath-tcp/mptcp_net-next/commit/8f01bd3c80a4051904fdb16bc4a7d2d56e01b102/checks

New patches for t/upstream:
- 140b3313d086: mptcp: options: suboptions sizes can be negative
- ecb59042f997: mptcp: pm: avoid computing rm_addr size twice
- e152c63b3234: mptcp: pm: avoid computing add_addr size twice
- 3e1f23bf6d20: mptcp: introduce add_addr_v6_port_drop_ts sysctl knob
- be190e710733: tcp: allow mptcp to drop TS for some packets
- 2bbbbbf511cf: mptcp: pm: drop TCP TS with ADD_ADDRv6 + port
- 12de239a0b82: selftests: mptcp: validate ADD_ADDRv6 + TS + port
- a701782ba7ce: selftests: mptcp: always check sent/dropped ADD_ADDRs
- f72cd39ee480: mptcp: pm: use for_each_subflow helper
- 29db124b818c: mptcp: pm: rename add_entry structure to add_addr
- 35e6e38f8cad: mptcp: pm: uniform announced addresses helpers
- 5b33e846c45a: mptcp: pm: remove add_ prefix from timer
- 1c5f13b9f12e: mptcp: pm: make mptcp_pm_add_addr_send_ack static
- 54551d64573b: mptcp: pm: avoid using del_timer directly
- Results: 0a3014718f01..75370a1de11f (export)

Tests are now in progress:

- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/228692121494a157d7050d141422c9b49c19ca25/checks

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.