[MPTCP][PATCH v8 mptcp-next 0/4] add MP_CAPABLE 'C' flag

[MPTCP][PATCH v8 mptcp-next 0/4] add MP_CAPABLE 'C' flag

[Geliang Tang]

v8:
 - drop add_cached in v7
 - tag: export/20210525T061510

v7:
 - use add_cached instead of add_list
 - tag: export/20210524T060340

v6:
 - rename mptcp_pm_add_entry to mptcp_pm_anno_entry
 - update mptcp_pm_free_add_list
 - update code in mptcp_pm_nl_add_addr_received
 - tag: export/20210514T055902

v5:
 - add a new patch "mptcp: add add_list in mptcp_pm_data"
 - fix !CONFIG_SYSCTL case
 - tag: export/20210507T174457

v4:
 - rename mptcp_is_allow_join_id0 to mptcp_allow_join_id0
 - rename deny_join_id0 in mptcp_pm_data to remote_deny_join_id0
 - add comments for self test cases
 - apply: export/20210504T064955 +
          "data checksum support" +
          "data checksum support cleanups"

v3:
 - use 'u8 allow_join_initial_addr_port'
 - drop the spinlock in patch 3

v2:
 - rename join_denied to allow_join_id0 in mptcp_out_options
 - rename join_denied to deny_join_id0 in mptcp_options_received
 - add a new function mptcp_pm_deny_join_id0_received
 - move deny_join_id0 flag from mptcp_sock to mptcp_pm_data
 - check deny_join_id0 flag in mptcp_pm_create_subflow_or_signal_addr
instead of in mptcp_syn_options.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/183

Geliang Tang (4):
  mptcp: add sysctl allow_join_initial_addr_port
  mptcp: add allow_join_id0 in mptcp_out_options
  mptcp: add deny_join_id0 in mptcp_options_received
  selftests: mptcp: add deny_join_id0 testcases

 Documentation/networking/mptcp-sysctl.rst     | 13 ++++
 include/net/mptcp.h                           |  3 +-
 net/mptcp/ctrl.c                              | 16 ++++
 net/mptcp/options.c                           | 12 +++
 net/mptcp/pm.c                                |  1 +
 net/mptcp/pm_netlink.c                        |  3 +-
 net/mptcp/protocol.h                          | 11 ++-
 net/mptcp/subflow.c                           |  3 +
 .../testing/selftests/net/mptcp/mptcp_join.sh | 75 ++++++++++++++++++-
 9 files changed, 131 insertions(+), 6 deletions(-)

-- 
2.31.1

[MPTCP][PATCH v8 mptcp-next 1/4] mptcp: add sysctl allow_join_initial_addr_port

[Geliang Tang]

This patch added a new sysctl, named allow_join_initial_addr_port, to
control whether allow peers to send join requests to the IP address and
port number used by the initial subflow.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 Documentation/networking/mptcp-sysctl.rst | 13 +++++++++++++
 net/mptcp/ctrl.c                          | 16 ++++++++++++++++
 net/mptcp/protocol.h                      |  1 +
 3 files changed, 30 insertions(+)

diff --git a/Documentation/networking/mptcp-sysctl.rst b/Documentation/networking/mptcp-sysctl.rst
index ee06fd782465..76d939e688b8 100644
--- a/Documentation/networking/mptcp-sysctl.rst
+++ b/Documentation/networking/mptcp-sysctl.rst
@@ -32,3 +32,16 @@ checksum_enabled - BOOLEAN
 	per-namespace sysctl.
 
 	Default: 0
+
+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
+	sent to the peer at connection time, and whether such join requests are
+	accepted or denied.
+
+	Joins to addresses advertised with ADD_ADDR are not affected by this
+	value.
+
+	This is a per-namespace sysctl.
+
+	Default: 1
diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
index 6c2639bb9c19..7d738bd06f2c 100644
--- a/net/mptcp/ctrl.c
+++ b/net/mptcp/ctrl.c
@@ -24,6 +24,7 @@ struct mptcp_pernet {
 	u8 mptcp_enabled;
 	unsigned int add_addr_timeout;
 	u8 checksum_enabled;
+	u8 allow_join_initial_addr_port;
 };
 
 static struct mptcp_pernet *mptcp_get_pernet(struct net *net)
@@ -46,11 +47,17 @@ int mptcp_is_checksum_enabled(struct net *net)
 	return mptcp_get_pernet(net)->checksum_enabled;
 }
 
+int mptcp_allow_join_id0(struct net *net)
+{
+	return mptcp_get_pernet(net)->allow_join_initial_addr_port;
+}
+
 static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 {
 	pernet->mptcp_enabled = 1;
 	pernet->add_addr_timeout = TCP_RTO_MAX;
 	pernet->checksum_enabled = 0;
+	pernet->allow_join_initial_addr_port = 1;
 }
 
 #ifdef CONFIG_SYSCTL
@@ -80,6 +87,14 @@ static struct ctl_table mptcp_sysctl_table[] = {
 		.extra1       = SYSCTL_ZERO,
 		.extra2       = SYSCTL_ONE
 	},
+	{
+		.procname = "allow_join_initial_addr_port",
+		.maxlen = sizeof(u8),
+		.mode = 0644,
+		.proc_handler = proc_dou8vec_minmax,
+		.extra1       = SYSCTL_ZERO,
+		.extra2       = SYSCTL_ONE
+	},
 	{}
 };
 
@@ -98,6 +113,7 @@ static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
 	table[0].data = &pernet->mptcp_enabled;
 	table[1].data = &pernet->add_addr_timeout;
 	table[2].data = &pernet->checksum_enabled;
+	table[3].data = &pernet->allow_join_initial_addr_port;
 
 	hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);
 	if (!hdr)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 16e50caf200e..c07db980b5da 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -543,6 +543,7 @@ static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *su
 int mptcp_is_enabled(struct net *net);
 unsigned int mptcp_get_add_addr_timeout(struct net *net);
 int mptcp_is_checksum_enabled(struct net *net);
+int mptcp_allow_join_id0(struct net *net);
 void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
 				     struct mptcp_options_received *mp_opt);
 bool mptcp_subflow_data_available(struct sock *sk);
-- 
2.31.1

[MPTCP][PATCH v8 mptcp-next 2/4] mptcp: add allow_join_id0 in mptcp_out_options

[Geliang Tang]

This patch defined a new flag MPTCP_CAP_DENY_JOIN_ID0 for the third bit,
labeled "C" of the MP_CAPABLE option.

Add a new flag allow_join_id0 in struct mptcp_out_options. If this flag is
set, send out the MP_CAPABLE option with the flag MPTCP_CAP_DENY_JOIN_ID0.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 include/net/mptcp.h  | 3 ++-
 net/mptcp/options.c  | 6 ++++++
 net/mptcp/protocol.h | 6 ++++--
 net/mptcp/subflow.c  | 1 +
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index d61bbbf11979..cb580b06152f 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -67,7 +67,8 @@ struct mptcp_out_options {
 	u8 backup;
 	u8 reset_reason:4,
 	   reset_transient:1,
-	   csum_reqd:1;
+	   csum_reqd:1,
+	   allow_join_id0:1;
 	u32 nonce;
 	u64 thmac;
 	u32 token;
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 1aec01686c1a..1e921b5103bf 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -400,6 +400,7 @@ bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
 	if (subflow->request_mptcp) {
 		opts->suboptions = OPTION_MPTCP_MPC_SYN;
 		opts->csum_reqd = mptcp_is_checksum_enabled(sock_net(sk));
+		opts->allow_join_id0 = mptcp_allow_join_id0(sock_net(sk));
 		*size = TCPOLEN_MPTCP_MPC_SYN;
 		return true;
 	} else if (subflow->request_join) {
@@ -488,6 +489,7 @@ static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb,
 		opts->sndr_key = subflow->local_key;
 		opts->rcvr_key = subflow->remote_key;
 		opts->csum_reqd = READ_ONCE(msk->csum_enabled);
+		opts->allow_join_id0 = mptcp_allow_join_id0(sock_net(sk));
 
 		/* Section 3.1.
 		 * The MP_CAPABLE option is carried on the SYN, SYN/ACK, and ACK
@@ -825,6 +827,7 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
 		opts->suboptions = OPTION_MPTCP_MPC_SYNACK;
 		opts->sndr_key = subflow_req->local_key;
 		opts->csum_reqd = subflow_req->csum_reqd;
+		opts->allow_join_id0 = subflow_req->allow_join_id0;
 		*size = TCPOLEN_MPTCP_MPC_SYNACK;
 		pr_debug("subflow_req=%p, local_key=%llu",
 			 subflow_req, subflow_req->local_key);
@@ -1199,6 +1202,9 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
 		if (opts->csum_reqd)
 			flag |= MPTCP_CAP_CHECKSUM_REQD;
 
+		if (!opts->allow_join_id0)
+			flag |= MPTCP_CAP_DENY_JOIN_ID0;
+
 		*ptr++ = mptcp_option(MPTCPOPT_MP_CAPABLE, len,
 				      MPTCP_SUPPORTED_VERSION,
 				      flag);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index c07db980b5da..1201ab04bcdf 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -79,8 +79,9 @@
 #define MPTCP_VERSION_MASK	(0x0F)
 #define MPTCP_CAP_CHECKSUM_REQD	BIT(7)
 #define MPTCP_CAP_EXTENSIBILITY	BIT(6)
+#define MPTCP_CAP_DENY_JOIN_ID0	BIT(5)
 #define MPTCP_CAP_HMAC_SHA256	BIT(0)
-#define MPTCP_CAP_FLAG_MASK	(0x3F)
+#define MPTCP_CAP_FLAG_MASK	(0x1F)
 
 /* MPTCP DSS flags */
 #define MPTCP_DSS_DATA_FIN	BIT(4)
@@ -352,7 +353,8 @@ struct mptcp_subflow_request_sock {
 	u16	mp_capable : 1,
 		mp_join : 1,
 		backup : 1,
-		csum_reqd : 1;
+		csum_reqd : 1,
+		allow_join_id0 : 1;
 	u8	local_id;
 	u8	remote_id;
 	u64	local_key;
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 2f13d795c2fc..0f4dc708e9b2 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -109,6 +109,7 @@ static void subflow_init_req(struct request_sock *req, const struct sock *sk_lis
 	subflow_req->mp_capable = 0;
 	subflow_req->mp_join = 0;
 	subflow_req->csum_reqd = mptcp_is_checksum_enabled(sock_net(sk_listener));
+	subflow_req->allow_join_id0 = mptcp_allow_join_id0(sock_net(sk_listener));
 	subflow_req->msk = NULL;
 	mptcp_token_init_request(req);
 }
-- 
2.31.1

[MPTCP][PATCH v8 mptcp-next 3/4] mptcp: add deny_join_id0 in mptcp_options_received

[Geliang Tang]

This patch added a new flag named deny_join_id0 in struct
mptcp_options_received. Set it when MP_CAPABLE with the flag
MPTCP_CAP_DENYJOIN_ID0 is received.

Also add a new flag remote_deny_join_id0 in struct mptcp_pm_data. When the
flag deny_join_id0 is set, set this remote_deny_join_id0 flag.

In mptcp_pm_create_subflow_or_signal_addr, if the remote_deny_join_id0 flag
is set, and the remote address id is zero, stop this connection.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/options.c    | 6 ++++++
 net/mptcp/pm.c         | 1 +
 net/mptcp/pm_netlink.c | 3 ++-
 net/mptcp/protocol.h   | 4 +++-
 net/mptcp/subflow.c    | 2 ++
 5 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 1e921b5103bf..0d30008f0313 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -83,6 +83,9 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		if (flags & MPTCP_CAP_CHECKSUM_REQD)
 			mp_opt->csum_reqd = 1;
 
+		if (flags & MPTCP_CAP_DENY_JOIN_ID0)
+			mp_opt->deny_join_id0 = 1;
+
 		mp_opt->mp_capable = 1;
 		if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) {
 			mp_opt->sndr_key = get_unaligned_be64(ptr);
@@ -360,6 +363,7 @@ void mptcp_get_options(const struct sock *sk,
 	mp_opt->mp_prio = 0;
 	mp_opt->reset = 0;
 	mp_opt->csum_reqd = READ_ONCE(msk->csum_enabled);
+	mp_opt->deny_join_id0 = 0;
 
 	length = (th->doff * 4) - sizeof(struct tcphdr);
 	ptr = (const unsigned char *)(th + 1);
@@ -1047,6 +1051,8 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 	}
 
 	mptcp_get_options(sk, skb, &mp_opt);
+	if (mp_opt.deny_join_id0)
+		WRITE_ONCE(msk->pm.remote_deny_join_id0, true);
 	if (!check_fully_established(msk, sk, subflow, skb, &mp_opt))
 		return;
 
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 9d00fa6d22e9..639271e09604 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -320,6 +320,7 @@ void mptcp_pm_data_init(struct mptcp_sock *msk)
 	WRITE_ONCE(msk->pm.addr_signal, 0);
 	WRITE_ONCE(msk->pm.accept_addr, false);
 	WRITE_ONCE(msk->pm.accept_subflow, false);
+	WRITE_ONCE(msk->pm.remote_deny_join_id0, false);
 	msk->pm.status = 0;
 
 	spin_lock_init(&msk->pm.lock);
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 09722598994d..e6a3f0a550bf 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -451,7 +451,8 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 
 	/* check if should create a new subflow */
 	if (msk->pm.local_addr_used < local_addr_max &&
-	    msk->pm.subflows < subflows_max) {
+	    msk->pm.subflows < subflows_max &&
+	    !READ_ONCE(msk->pm.remote_deny_join_id0)) {
 		local = select_local_address(pernet, msk);
 		if (local) {
 			struct mptcp_addr_info remote = { 0 };
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 1201ab04bcdf..bdf4a832975d 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -138,7 +138,8 @@ struct mptcp_options_received {
 		mp_prio : 1,
 		echo : 1,
 		csum_reqd : 1,
-		backup : 1;
+		backup : 1,
+		deny_join_id0 : 1;
 	u32	token;
 	u32	nonce;
 	u64	thmac;
@@ -193,6 +194,7 @@ struct mptcp_pm_data {
 	bool		work_pending;
 	bool		accept_addr;
 	bool		accept_subflow;
+	bool		remote_deny_join_id0;
 	u8		add_addr_signaled;
 	u8		add_addr_accepted;
 	u8		local_addr_used;
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 0f4dc708e9b2..629be94f4d75 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -408,6 +408,8 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 
 		if (mp_opt.csum_reqd)
 			WRITE_ONCE(mptcp_sk(parent)->csum_enabled, true);
+		if (mp_opt.deny_join_id0)
+			WRITE_ONCE(mptcp_sk(parent)->pm.remote_deny_join_id0, true);
 		subflow->mp_capable = 1;
 		subflow->can_ack = 1;
 		subflow->remote_key = mp_opt.sndr_key;
-- 
2.31.1

[MPTCP][PATCH v8 mptcp-next 4/4] selftests: mptcp: add deny_join_id0 testcases

[Geliang Tang]

This patch added a new argument '-d' for mptcp_join.sh script, to invoke
the testcases for the MP_CAPABLE 'C' flag.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 .../testing/selftests/net/mptcp/mptcp_join.sh | 75 ++++++++++++++++++-
 1 file changed, 74 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 523c7797f30a..9a191c1a5de8 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -139,6 +139,17 @@ reset_with_checksum()
 	ip netns exec $ns2 sysctl -q net.mptcp.checksum_enabled=$ns2_enable
 }
 
+reset_with_allow_join_id0()
+{
+	local ns1_enable=$1
+	local ns2_enable=$2
+
+	reset
+
+	ip netns exec $ns1 sysctl -q net.mptcp.allow_join_initial_addr_port=$ns1_enable
+	ip netns exec $ns2 sysctl -q net.mptcp.allow_join_initial_addr_port=$ns2_enable
+}
+
 ip -Version > /dev/null 2>&1
 if [ $? -ne 0 ];then
 	echo "SKIP: Could not run test without ip tool"
@@ -1462,6 +1473,63 @@ checksum_tests()
 	chk_csum_nr "checksum test 1 0"
 }
 
+deny_join_id0_tests()
+{
+	# subflow allow join id0 ns1
+	reset_with_allow_join_id0 1 0
+	ip netns exec $ns1 ./pm_nl_ctl limits 1 1
+	ip netns exec $ns2 ./pm_nl_ctl limits 1 1
+	ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+	run_tests $ns1 $ns2 10.0.1.1
+	chk_join_nr "single subflow allow join id0 ns1" 1 1 1
+
+	# subflow allow join id0 ns2
+	reset_with_allow_join_id0 0 1
+	ip netns exec $ns1 ./pm_nl_ctl limits 1 1
+	ip netns exec $ns2 ./pm_nl_ctl limits 1 1
+	ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+	run_tests $ns1 $ns2 10.0.1.1
+	chk_join_nr "single subflow allow join id0 ns2" 0 0 0
+
+	# signal address allow join id0 ns1
+	# ADD_ADDRs are not affected by allow_join_id0 value.
+	reset_with_allow_join_id0 1 0
+	ip netns exec $ns1 ./pm_nl_ctl limits 1 1
+	ip netns exec $ns2 ./pm_nl_ctl limits 1 1
+	ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+	run_tests $ns1 $ns2 10.0.1.1
+	chk_join_nr "signal address allow join id0 ns1" 1 1 1
+	chk_add_nr 1 1
+
+	# signal address allow join id0 ns2
+	# ADD_ADDRs are not affected by allow_join_id0 value.
+	reset_with_allow_join_id0 0 1
+	ip netns exec $ns1 ./pm_nl_ctl limits 1 1
+	ip netns exec $ns2 ./pm_nl_ctl limits 1 1
+	ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+	run_tests $ns1 $ns2 10.0.1.1
+	chk_join_nr "signal address allow join id0 ns2" 1 1 1
+	chk_add_nr 1 1
+
+	# subflow and address allow join id0 ns1
+	reset_with_allow_join_id0 1 0
+	ip netns exec $ns1 ./pm_nl_ctl limits 2 2
+	ip netns exec $ns2 ./pm_nl_ctl limits 2 2
+	ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+	ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+	run_tests $ns1 $ns2 10.0.1.1
+	chk_join_nr "subflow and address allow join id0 1" 2 2 2
+
+	# subflow and address allow join id0 ns2
+	reset_with_allow_join_id0 0 1
+	ip netns exec $ns1 ./pm_nl_ctl limits 2 2
+	ip netns exec $ns2 ./pm_nl_ctl limits 2 2
+	ip netns exec $ns1 ./pm_nl_ctl add 10.0.2.1 flags signal
+	ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
+	run_tests $ns1 $ns2 10.0.1.1
+	chk_join_nr "subflow and address allow join id0 2" 1 1 1
+}
+
 all_tests()
 {
 	subflows_tests
@@ -1476,6 +1544,7 @@ all_tests()
 	add_addr_ports_tests
 	syncookies_tests
 	checksum_tests
+	deny_join_id0_tests
 }
 
 usage()
@@ -1493,6 +1562,7 @@ usage()
 	echo "  -p add_addr_ports_tests"
 	echo "  -k syncookies_tests"
 	echo "  -S checksum_tests"
+	echo "  -d deny_join_id0_tests"
 	echo "  -c capture pcap files"
 	echo "  -C enable data checksum"
 	echo "  -h help"
@@ -1528,7 +1598,7 @@ if [ $do_all_tests -eq 1 ]; then
 	exit $ret
 fi
 
-while getopts 'fsltra64bpkchCS' opt; do
+while getopts 'fsltra64bpkdchCS' opt; do
 	case $opt in
 		f)
 			subflows_tests
@@ -1566,6 +1636,9 @@ while getopts 'fsltra64bpkchCS' opt; do
 		S)
 			checksum_tests
 			;;
+		d)
+			deny_join_id0_tests
+			;;
 		c)
 			;;
 		C)
-- 
2.31.1

Re: [MPTCP][PATCH v8 mptcp-next 3/4] mptcp: add deny_join_id0 in mptcp_options_received

[Paolo Abeni]

Hello,

On Tue, 2021-05-25 at 17:17 +0800, Geliang Tang wrote:
> diff --git a/net/mptcp/options.c b/net/mptcp/options.c
> index 1e921b5103bf..0d30008f0313 100644
> --- a/net/mptcp/options.c
> +++ b/net/mptcp/options.c
> @@ -83,6 +83,9 @@ static void mptcp_parse_option(const struct sk_buff *skb,
>  		if (flags & MPTCP_CAP_CHECKSUM_REQD)
>  			mp_opt->csum_reqd = 1;
>  
> +		if (flags & MPTCP_CAP_DENY_JOIN_ID0)
> +			mp_opt->deny_join_id0 = 1;
> +
>  		mp_opt->mp_capable = 1;
>  		if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) {
>  			mp_opt->sndr_key = get_unaligned_be64(ptr);
> @@ -360,6 +363,7 @@ void mptcp_get_options(const struct sock *sk,
>  	mp_opt->mp_prio = 0;
>  	mp_opt->reset = 0;
>  	mp_opt->csum_reqd = READ_ONCE(msk->csum_enabled);
> +	mp_opt->deny_join_id0 = 0;
>  
>  	length = (th->doff * 4) - sizeof(struct tcphdr);
>  	ptr = (const unsigned char *)(th + 1);
> @@ -1047,6 +1051,8 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
>  	}
>  
>  	mptcp_get_options(sk, skb, &mp_opt);
> +	if (mp_opt.deny_join_id0)
> +		WRITE_ONCE(msk->pm.remote_deny_join_id0, true);

I'm sorry for the long delay. Overall LGTM. The only thing I see worth
mentioning is the above test: is done for each incoming packet, but we
really need to check it for MPC ACK packet, right? if so the test
should be probably moved into the suitable section of
check_fully_established() - e.g. after the 'if (!mp_opt->mp_capable) {'
block.

No need for a resend, a squash-to patch will suffice  - if my above
assumption is correct.

BTW it looks like there are no check for the C bit being unmodified
between MPC syn and MPC ack, and AFAICS the RFC don't mention that
case. I think/guess we can simply fetch the MPC ack value.

Cheers,

Paolo

p.s. this really means acked-by ;)

Re: [MPTCP][PATCH v8 mptcp-next 0/4] add MP_CAPABLE 'C' flag

[Mat Martineau]

On Tue, 25 May 2021, Geliang Tang wrote:

> v8:
> - drop add_cached in v7
> - tag: export/20210525T061510
>

Thanks Geliang. v8 looks fine to me for the export branch. I think Paolo's 
concerns have been addressed, at least as I understand them.

Maybe best to apply to the export branch after the Thursday meeting just 
to be sure.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>


-Mat


> v7:
> - use add_cached instead of add_list
> - tag: export/20210524T060340
>
> v6:
> - rename mptcp_pm_add_entry to mptcp_pm_anno_entry
> - update mptcp_pm_free_add_list
> - update code in mptcp_pm_nl_add_addr_received
> - tag: export/20210514T055902
>
> v5:
> - add a new patch "mptcp: add add_list in mptcp_pm_data"
> - fix !CONFIG_SYSCTL case
> - tag: export/20210507T174457
>
> v4:
> - rename mptcp_is_allow_join_id0 to mptcp_allow_join_id0
> - rename deny_join_id0 in mptcp_pm_data to remote_deny_join_id0
> - add comments for self test cases
> - apply: export/20210504T064955 +
>          "data checksum support" +
>          "data checksum support cleanups"
>
> v3:
> - use 'u8 allow_join_initial_addr_port'
> - drop the spinlock in patch 3
>
> v2:
> - rename join_denied to allow_join_id0 in mptcp_out_options
> - rename join_denied to deny_join_id0 in mptcp_options_received
> - add a new function mptcp_pm_deny_join_id0_received
> - move deny_join_id0 flag from mptcp_sock to mptcp_pm_data
> - check deny_join_id0 flag in mptcp_pm_create_subflow_or_signal_addr
> instead of in mptcp_syn_options.
>
> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/183
>
> Geliang Tang (4):
>  mptcp: add sysctl allow_join_initial_addr_port
>  mptcp: add allow_join_id0 in mptcp_out_options
>  mptcp: add deny_join_id0 in mptcp_options_received
>  selftests: mptcp: add deny_join_id0 testcases
>
> Documentation/networking/mptcp-sysctl.rst     | 13 ++++
> include/net/mptcp.h                           |  3 +-
> net/mptcp/ctrl.c                              | 16 ++++
> net/mptcp/options.c                           | 12 +++
> net/mptcp/pm.c                                |  1 +
> net/mptcp/pm_netlink.c                        |  3 +-
> net/mptcp/protocol.h                          | 11 ++-
> net/mptcp/subflow.c                           |  3 +
> .../testing/selftests/net/mptcp/mptcp_join.sh | 75 ++++++++++++++++++-
> 9 files changed, 131 insertions(+), 6 deletions(-)
>
> -- 
> 2.31.1
>
>
>

--
Mat Martineau
Intel

Re: [MPTCP][PATCH v8 mptcp-next 0/4] add MP_CAPABLE 'C' flag

[Matthieu Baerts]

Hi Geliang, Mat, Paolo,

On 25/05/2021 11:17, Geliang Tang wrote:
> 
> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/183
> 
> Geliang Tang (4):
>   mptcp: add sysctl allow_join_initial_addr_port
>   mptcp: add allow_join_id0 in mptcp_out_options
>   mptcp: add deny_join_id0 in mptcp_options_received
>   selftests: mptcp: add deny_join_id0 testcases

Thank you for the patches and the reviews!

Now applied in our tree with the additional Squash-to patch:

- 02acfcf0689f: mptcp: add sysctl allow_join_initial_addr_port
- cd1b6f6c2d8c: mptcp: add allow_join_id0 in mptcp_out_options
- ef3b48916d09: mptcp: add deny_join_id0 in mptcp_options_received
- 0704c54e490d: selftests: mptcp: add deny_join_id0 testcases
- Results: 1ba3eb627299..ae2f6282fc03

- de073c6ce650: "squashed" in "mptcp: add deny_join_id0 in
mptcp_options_received"
- Results: ae2f6282fc03..4e92195bd477

Builds and tests are now in progress:

https://cirrus-ci.com/github/multipath-tcp/mptcp_net-next/export/20210611T143831
https://github.com/multipath-tcp/mptcp_net-next/actions/workflows/build-validation.yml?query=branch:export/20210611T143831

Cheers,
Matt
-- 
Tessares | Belgium | Hybrid Access Solutions
www.tessares.net