[PATCH mptcp-net v3 0/2] mptcp: support MP_PRIO signals with userspace PMs

[PATCH mptcp-net v3 0/2] mptcp: support MP_PRIO signals with userspace PMs

[Kishen Maloor]

This patch series updates MPTCP_PM_CMD_SET_FLAGS to allow userspace PMs
to issue MP_PRIO signals over a selected (by local and remote address+port)
subflow in a MPTCP connection. It also adds self tests for this
change.

This patch series has been rebased to the series (in review) titled
"Locking fixes for subflow flag changes".

v2:
-userspace_pm.sh: added a sleep after issuing the MP_PRIO signal.

v3:
-use local and remote address+port (instead of address ID) alongwith the
connection token to select a subflow.

Kishen Maloor (2):
  mptcp: netlink: issue MP_PRIO signals from userspace PMs
  selftests: mptcp: userspace PM support for MP_PRIO signals

 net/mptcp/pm_netlink.c                        | 30 ++++++--
 net/mptcp/pm_userspace.c                      | 30 ++++++++
 net/mptcp/protocol.h                          |  8 +-
 tools/testing/selftests/net/mptcp/pm_nl_ctl.c | 73 ++++++++++++++++++-
 .../selftests/net/mptcp/userspace_pm.sh       | 32 ++++++++
 5 files changed, 165 insertions(+), 8 deletions(-)

--
2.31.1

[PATCH mptcp-net v3 1/2] mptcp: netlink: issue MP_PRIO signals from userspace PMs

[Kishen Maloor]

This change updates MPTCP_PM_CMD_SET_FLAGS to allow userspace PMs
to issue MP_PRIO signals over a specific subflow selected by
the connection token, local and remote address+port.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/286
Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment")
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
---
v3:
-use local and remote address+port (instead of address ID) alongwith the
connection token to select a subflow.
---
 net/mptcp/pm_netlink.c   | 30 +++++++++++++++++++++++++-----
 net/mptcp/pm_userspace.c | 30 ++++++++++++++++++++++++++++++
 net/mptcp/protocol.h     |  8 +++++++-
 3 files changed, 62 insertions(+), 6 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 05c6a95e9c28..602892f2f921 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -717,9 +717,10 @@ void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
 	}
 }
 
-static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
-					struct mptcp_addr_info *addr,
-					u8 bkup)
+int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
+				 struct mptcp_addr_info *addr,
+				 struct mptcp_addr_info *rem,
+				 u8 bkup)
 {
 	struct mptcp_subflow_context *subflow;
 
@@ -728,7 +729,7 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 	mptcp_for_each_subflow(msk, subflow) {
 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 		struct sock *sk = (struct sock *)msk;
-		struct mptcp_addr_info local;
+		struct mptcp_addr_info local, remote;
 		bool slow;
 
 		local_address((struct sock_common *)ssk, &local);
@@ -736,6 +737,12 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 			continue;
 
 		slow = lock_sock_fast(ssk);
+		if (rem && rem->family != AF_UNSPEC) {
+			remote_address((struct sock_common *)ssk, &remote);
+			if (!mptcp_addresses_equal(&remote, rem, rem->port))
+				continue;
+		}
+
 		if (subflow->backup != bkup)
 			msk->last_snd = NULL;
 		subflow->backup = bkup;
@@ -1839,7 +1846,7 @@ static int mptcp_nl_set_flags(struct net *net,
 
 		lock_sock(sk);
 		if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
-			ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
+			ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
 		if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
 			mptcp_pm_nl_fullmesh(msk, addr);
 		release_sock(sk);
@@ -1855,6 +1862,9 @@ static int mptcp_nl_set_flags(struct net *net,
 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
 {
 	struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, }, *entry;
+	struct mptcp_pm_addr_entry remote = { .addr = { .family = AF_UNSPEC }, };
+	struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
+	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
 	u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
@@ -1867,6 +1877,12 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
 	if (ret < 0)
 		return ret;
 
+	if (attr_rem) {
+		ret = mptcp_pm_parse_entry(attr_rem, info, false, &remote);
+		if (ret < 0)
+			return ret;
+	}
+
 	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
 		bkup = 1;
 	if (addr.addr.family == AF_UNSPEC) {
@@ -1875,6 +1891,10 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
 			return -EOPNOTSUPP;
 	}
 
+	if (token)
+		return mptcp_userspace_pm_set_flags(sock_net(skb->sk),
+						    token, &addr, &remote, bkup);
+
 	spin_lock_bh(&pernet->lock);
 	entry = __lookup_addr(pernet, &addr.addr, lookup_by_id);
 	if (!entry) {
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 26212bebc5ed..51e2f066d54f 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -420,3 +420,33 @@ int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
 	sock_put((struct sock *)msk);
 	return err;
 }
+
+int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
+				 struct mptcp_pm_addr_entry *loc,
+				 struct mptcp_pm_addr_entry *rem, u8 bkup)
+{
+	struct mptcp_sock *msk;
+	int ret = -EINVAL;
+	u32 token_val;
+
+	token_val = nla_get_u32(token);
+
+	msk = mptcp_token_get_sock(net, token_val);
+	if (!msk)
+		return ret;
+
+	if (!mptcp_pm_is_userspace(msk))
+		goto set_flags_err;
+
+	if (loc->addr.family == AF_UNSPEC ||
+	    rem->addr.family == AF_UNSPEC)
+		goto set_flags_err;
+
+	lock_sock((struct sock *)msk);
+	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
+	release_sock((struct sock *)msk);
+
+set_flags_err:
+	sock_put((struct sock *)msk);
+	return ret;
+}
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 033c995772dc..480c5320b86e 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -772,6 +772,10 @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
 			       const struct mptcp_rm_list *rm_list);
 void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
 void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
+int mptcp_pm_nl_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,
 			      const struct mptcp_pm_addr_entry *entry);
 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
@@ -788,7 +792,9 @@ int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
 						   unsigned int id,
 						   u8 *flags, int *ifindex);
-
+int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
+				 struct mptcp_pm_addr_entry *loc,
+				 struct mptcp_pm_addr_entry *rem, u8 bkup);
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 			   const struct mptcp_addr_info *addr,
 			   bool echo);
-- 
2.31.1

[PATCH mptcp-net v3 2/2] selftests: mptcp: userspace PM support for MP_PRIO signals

[Kishen Maloor]

This change updates the testing sample (pm_nl_ctl) to exercise
the updated MPTCP_PM_CMD_SET_FLAGS command for userspace PMs to
issue MP_PRIO signals over the selected subflow.

E.g. ./pm_nl_ctl set 10.0.1.2 port 47234 flags backup token 823274047 rip 10.0.1.1 rport 50003

userspace_pm.sh has a new selftest that invokes this command.

Fixes: 259a834fadda ("selftests: mptcp: functional tests for the userspace PM type")
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
---
v2:
-added a sleep after issuing the MP_PRIO signal in userspace_pm.sh.

v3:
-updated test to pass local and remote address+port to aid in selecting a
subflow.
---
 tools/testing/selftests/net/mptcp/pm_nl_ctl.c | 73 ++++++++++++++++++-
 .../selftests/net/mptcp/userspace_pm.sh       | 32 ++++++++
 2 files changed, 103 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
index 6a2f4b981e1d..cb79f0719e3b 100644
--- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
+++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
@@ -39,7 +39,7 @@ static void syntax(char *argv[])
 	fprintf(stderr, "\tdsf lip <local-ip> lport <local-port> rip <remote-ip> rport <remote-port> token <token>\n");
 	fprintf(stderr, "\tdel <id> [<ip>]\n");
 	fprintf(stderr, "\tget <id>\n");
-	fprintf(stderr, "\tset [<ip>] [id <nr>] flags [no]backup|[no]fullmesh [port <nr>]\n");
+	fprintf(stderr, "\tset [<ip>] [id <nr>] flags [no]backup|[no]fullmesh [port <nr>] [token <token>] [rip <ip>] [rport <port>]\n");
 	fprintf(stderr, "\tflush\n");
 	fprintf(stderr, "\tdump\n");
 	fprintf(stderr, "\tlimits [<rcv addr max> <subflow max>]\n");
@@ -1279,7 +1279,10 @@ int set_flags(int fd, int pm_family, int argc, char *argv[])
 	struct rtattr *rta, *nest;
 	struct nlmsghdr *nh;
 	u_int32_t flags = 0;
+	u_int32_t token = 0;
+	u_int16_t rport = 0;
 	u_int16_t family;
+	void *rip = NULL;
 	int nest_start;
 	int use_id = 0;
 	u_int8_t id;
@@ -1339,7 +1342,13 @@ int set_flags(int fd, int pm_family, int argc, char *argv[])
 		error(1, 0, " missing flags keyword");
 
 	for (; arg < argc; arg++) {
-		if (!strcmp(argv[arg], "flags")) {
+		if (!strcmp(argv[arg], "token")) {
+			if (++arg >= argc)
+				error(1, 0, " missing token value");
+
+			/* token */
+			token = atoi(argv[arg]);
+		} else if (!strcmp(argv[arg], "flags")) {
 			char *tok, *str;
 
 			/* flags */
@@ -1378,12 +1387,72 @@ int set_flags(int fd, int pm_family, int argc, char *argv[])
 			rta->rta_len = RTA_LENGTH(2);
 			memcpy(RTA_DATA(rta), &port, 2);
 			off += NLMSG_ALIGN(rta->rta_len);
+		} else if (!strcmp(argv[arg], "rport")) {
+			if (++arg >= argc)
+				error(1, 0, " missing remote port");
+
+			rport = atoi(argv[arg]);
+		} else if (!strcmp(argv[arg], "rip")) {
+			if (++arg >= argc)
+				error(1, 0, " missing remote ip");
+
+			rip = argv[arg];
 		} else {
 			error(1, 0, "unknown keyword %s", argv[arg]);
 		}
 	}
 	nest->rta_len = off - nest_start;
 
+	/* token */
+	if (token) {
+		rta = (void *)(data + off);
+		rta->rta_type = MPTCP_PM_ATTR_TOKEN;
+		rta->rta_len = RTA_LENGTH(4);
+		memcpy(RTA_DATA(rta), &token, 4);
+		off += NLMSG_ALIGN(rta->rta_len);
+	}
+
+	/* remote addr/port */
+	if (rip) {
+		nest_start = off;
+		nest = (void *)(data + off);
+		nest->rta_type = NLA_F_NESTED | MPTCP_PM_ATTR_ADDR_REMOTE;
+		nest->rta_len = RTA_LENGTH(0);
+		off += NLMSG_ALIGN(nest->rta_len);
+
+		/* addr data */
+		rta = (void *)(data + off);
+		if (inet_pton(AF_INET, rip, RTA_DATA(rta))) {
+			family = AF_INET;
+			rta->rta_type = MPTCP_PM_ADDR_ATTR_ADDR4;
+			rta->rta_len = RTA_LENGTH(4);
+		} else if (inet_pton(AF_INET6, rip, RTA_DATA(rta))) {
+			family = AF_INET6;
+			rta->rta_type = MPTCP_PM_ADDR_ATTR_ADDR6;
+			rta->rta_len = RTA_LENGTH(16);
+		} else {
+			error(1, errno, "can't parse ip %s", (char *)rip);
+		}
+		off += NLMSG_ALIGN(rta->rta_len);
+
+		/* family */
+		rta = (void *)(data + off);
+		rta->rta_type = MPTCP_PM_ADDR_ATTR_FAMILY;
+		rta->rta_len = RTA_LENGTH(2);
+		memcpy(RTA_DATA(rta), &family, 2);
+		off += NLMSG_ALIGN(rta->rta_len);
+
+		if (rport) {
+			rta = (void *)(data + off);
+			rta->rta_type = MPTCP_PM_ADDR_ATTR_PORT;
+			rta->rta_len = RTA_LENGTH(2);
+			memcpy(RTA_DATA(rta), &rport, 2);
+			off += NLMSG_ALIGN(rta->rta_len);
+		}
+
+		nest->rta_len = off - nest_start;
+	}
+
 	do_nl_req(fd, nh, off, 0);
 	return 0;
 }
diff --git a/tools/testing/selftests/net/mptcp/userspace_pm.sh b/tools/testing/selftests/net/mptcp/userspace_pm.sh
index 78d0bb640b11..abe3d4ebe554 100755
--- a/tools/testing/selftests/net/mptcp/userspace_pm.sh
+++ b/tools/testing/selftests/net/mptcp/userspace_pm.sh
@@ -770,10 +770,42 @@ test_subflows()
 	rm -f "$evts"
 }
 
+test_prio()
+{
+	local count
+
+	# Send MP_PRIO signal from client to server machine
+	ip netns exec "$ns2" ./pm_nl_ctl set 10.0.1.2 port "$client4_port" flags backup token "$client4_token" rip 10.0.1.1 rport "$server4_port"
+	sleep 0.5
+
+	# Check TX
+	stdbuf -o0 -e0 printf "MP_PRIO TX                                                 \t"
+	count=$(ip netns exec "$ns2" nstat -as | grep MPTcpExtMPPrioTx | awk '{print $2}')
+	[ -z "$count" ] && count=0
+	if [ $count != 1 ]; then
+		stdbuf -o0 -e0 printf "[FAIL]\n"
+		exit 1
+	else
+		stdbuf -o0 -e0 printf "[OK]\n"
+	fi
+
+	# Check RX
+	stdbuf -o0 -e0 printf "MP_PRIO RX                                                 \t"
+	count=$(ip netns exec "$ns1" nstat -as | grep MPTcpExtMPPrioRx | awk '{print $2}')
+	[ -z "$count" ] && count=0
+	if [ $count != 1 ]; then
+		stdbuf -o0 -e0 printf "[FAIL]\n"
+		exit 1
+	else
+		stdbuf -o0 -e0 printf "[OK]\n"
+	fi
+}
+
 make_connection
 make_connection "v6"
 test_announce
 test_remove
 test_subflows
+test_prio
 
 exit 0
-- 
2.31.1

Re: [PATCH mptcp-net v3 1/2] mptcp: netlink: issue MP_PRIO signals from userspace PMs

[Mat Martineau]

On Tue, 28 Jun 2022, Kishen Maloor wrote:

> This change updates MPTCP_PM_CMD_SET_FLAGS to allow userspace PMs
> to issue MP_PRIO signals over a specific subflow selected by
> the connection token, local and remote address+port.
>
> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/286
> Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment")
> Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
> ---
> v3:
> -use local and remote address+port (instead of address ID) alongwith the
> connection token to select a subflow.
> ---
> net/mptcp/pm_netlink.c   | 30 +++++++++++++++++++++++++-----
> net/mptcp/pm_userspace.c | 30 ++++++++++++++++++++++++++++++
> net/mptcp/protocol.h     |  8 +++++++-
> 3 files changed, 62 insertions(+), 6 deletions(-)
>
> diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
> index 05c6a95e9c28..602892f2f921 100644
> --- a/net/mptcp/pm_netlink.c
> +++ b/net/mptcp/pm_netlink.c
> @@ -717,9 +717,10 @@ void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
> 	}
> }
>
> -static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
> -					struct mptcp_addr_info *addr,
> -					u8 bkup)
> +int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
> +				 struct mptcp_addr_info *addr,
> +				 struct mptcp_addr_info *rem,
> +				 u8 bkup)
> {
> 	struct mptcp_subflow_context *subflow;
>
> @@ -728,7 +729,7 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
> 	mptcp_for_each_subflow(msk, subflow) {
> 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
> 		struct sock *sk = (struct sock *)msk;
> -		struct mptcp_addr_info local;
> +		struct mptcp_addr_info local, remote;
> 		bool slow;
>
> 		local_address((struct sock_common *)ssk, &local);
> @@ -736,6 +737,12 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
> 			continue;
>
> 		slow = lock_sock_fast(ssk);
> +		if (rem && rem->family != AF_UNSPEC) {
> +			remote_address((struct sock_common *)ssk, &remote);
> +			if (!mptcp_addresses_equal(&remote, rem, rem->port))
> +				continue;
> +		}

Hi Kishen -

Thanks for the v3!

The CI build failed because the ssk lock is not released before this 
'continue' statement. The sparse error message was pretty vague, though.

remote_address() is only checking sock_common fields that don't change, I 
don't think the ssk lock is required (it's used this way elsewhere in the 
code). So this new hunk of code should be before the lock_sock_fast() 
call.


- Mat



> +
> 		if (subflow->backup != bkup)
> 			msk->last_snd = NULL;
> 		subflow->backup = bkup;
> @@ -1839,7 +1846,7 @@ static int mptcp_nl_set_flags(struct net *net,
>
> 		lock_sock(sk);
> 		if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
> -			ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
> +			ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
> 		if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
> 			mptcp_pm_nl_fullmesh(msk, addr);
> 		release_sock(sk);
> @@ -1855,6 +1862,9 @@ static int mptcp_nl_set_flags(struct net *net,
> static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
> {
> 	struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, }, *entry;
> +	struct mptcp_pm_addr_entry remote = { .addr = { .family = AF_UNSPEC }, };
> +	struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
> +	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
> 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
> 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
> 	u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
> @@ -1867,6 +1877,12 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
> 	if (ret < 0)
> 		return ret;
>
> +	if (attr_rem) {
> +		ret = mptcp_pm_parse_entry(attr_rem, info, false, &remote);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> 	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
> 		bkup = 1;
> 	if (addr.addr.family == AF_UNSPEC) {
> @@ -1875,6 +1891,10 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
> 			return -EOPNOTSUPP;
> 	}
>
> +	if (token)
> +		return mptcp_userspace_pm_set_flags(sock_net(skb->sk),
> +						    token, &addr, &remote, bkup);
> +
> 	spin_lock_bh(&pernet->lock);
> 	entry = __lookup_addr(pernet, &addr.addr, lookup_by_id);
> 	if (!entry) {
> diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
> index 26212bebc5ed..51e2f066d54f 100644
> --- a/net/mptcp/pm_userspace.c
> +++ b/net/mptcp/pm_userspace.c
> @@ -420,3 +420,33 @@ int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
> 	sock_put((struct sock *)msk);
> 	return err;
> }
> +
> +int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
> +				 struct mptcp_pm_addr_entry *loc,
> +				 struct mptcp_pm_addr_entry *rem, u8 bkup)
> +{
> +	struct mptcp_sock *msk;
> +	int ret = -EINVAL;
> +	u32 token_val;
> +
> +	token_val = nla_get_u32(token);
> +
> +	msk = mptcp_token_get_sock(net, token_val);
> +	if (!msk)
> +		return ret;
> +
> +	if (!mptcp_pm_is_userspace(msk))
> +		goto set_flags_err;
> +
> +	if (loc->addr.family == AF_UNSPEC ||
> +	    rem->addr.family == AF_UNSPEC)
> +		goto set_flags_err;
> +
> +	lock_sock((struct sock *)msk);
> +	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
> +	release_sock((struct sock *)msk);
> +
> +set_flags_err:
> +	sock_put((struct sock *)msk);
> +	return ret;
> +}
> diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
> index 033c995772dc..480c5320b86e 100644
> --- a/net/mptcp/protocol.h
> +++ b/net/mptcp/protocol.h
> @@ -772,6 +772,10 @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
> 			       const struct mptcp_rm_list *rm_list);
> void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
> void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
> +int mptcp_pm_nl_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,
> 			      const struct mptcp_pm_addr_entry *entry);
> void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
> @@ -788,7 +792,9 @@ int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
> int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
> 						   unsigned int id,
> 						   u8 *flags, int *ifindex);
> -
> +int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
> +				 struct mptcp_pm_addr_entry *loc,
> +				 struct mptcp_pm_addr_entry *rem, u8 bkup);
> int mptcp_pm_announce_addr(struct mptcp_sock *msk,
> 			   const struct mptcp_addr_info *addr,
> 			   bool echo);
> -- 
> 2.31.1
>
>
>

--
Mat Martineau
Intel

Re: [PATCH mptcp-net v3 1/2] mptcp: netlink: issue MP_PRIO signals from userspace PMs

[Kishen Maloor]

On 6/28/22 3:57 PM, Mat Martineau wrote:
> On Tue, 28 Jun 2022, Kishen Maloor wrote:
> 
>> This change updates MPTCP_PM_CMD_SET_FLAGS to allow userspace PMs
>> to issue MP_PRIO signals over a specific subflow selected by
>> the connection token, local and remote address+port.
>>
>> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/286
>> Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment")
>> Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
>> ---
>> v3:
>> -use local and remote address+port (instead of address ID) alongwith the
>> connection token to select a subflow.
>> ---
>> net/mptcp/pm_netlink.c   | 30 +++++++++++++++++++++++++-----
>> net/mptcp/pm_userspace.c | 30 ++++++++++++++++++++++++++++++
>> net/mptcp/protocol.h     |  8 +++++++-
>> 3 files changed, 62 insertions(+), 6 deletions(-)
>>
>> diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
>> index 05c6a95e9c28..602892f2f921 100644
>> --- a/net/mptcp/pm_netlink.c
>> +++ b/net/mptcp/pm_netlink.c
>> @@ -717,9 +717,10 @@ void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
>>     }
>> }
>>
>> -static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
>> -                    struct mptcp_addr_info *addr,
>> -                    u8 bkup)
>> +int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
>> +                 struct mptcp_addr_info *addr,
>> +                 struct mptcp_addr_info *rem,
>> +                 u8 bkup)
>> {
>>     struct mptcp_subflow_context *subflow;
>>
>> @@ -728,7 +729,7 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
>>     mptcp_for_each_subflow(msk, subflow) {
>>         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
>>         struct sock *sk = (struct sock *)msk;
>> -        struct mptcp_addr_info local;
>> +        struct mptcp_addr_info local, remote;
>>         bool slow;
>>
>>         local_address((struct sock_common *)ssk, &local);
>> @@ -736,6 +737,12 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
>>             continue;
>>
>>         slow = lock_sock_fast(ssk);
>> +        if (rem && rem->family != AF_UNSPEC) {
>> +            remote_address((struct sock_common *)ssk, &remote);
>> +            if (!mptcp_addresses_equal(&remote, rem, rem->port))
>> +                continue;
>> +        }
> 
> Hi Kishen -
> 
> Thanks for the v3!
> 
> The CI build failed because the ssk lock is not released before this 'continue' statement. The sparse error message was pretty vague, though.
> 
> remote_address() is only checking sock_common fields that don't change, I don't think the ssk lock is required (it's used this way elsewhere in the code). So this new hunk of code should be before the lock_sock_fast() call.

Thanks, Mat. I just happened to miss this while resolving conflicts here during my rebase to your series.
I shall post a v4 shortly.

> 
> 
> - Mat
> 
> 
> 
>> +
>>         if (subflow->backup != bkup)
>>             msk->last_snd = NULL;
>>         subflow->backup = bkup;
>> @@ -1839,7 +1846,7 @@ static int mptcp_nl_set_flags(struct net *net,
>>
>>         lock_sock(sk);
>>         if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
>> -            ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
>> +            ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
>>         if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
>>             mptcp_pm_nl_fullmesh(msk, addr);
>>         release_sock(sk);
>> @@ -1855,6 +1862,9 @@ static int mptcp_nl_set_flags(struct net *net,
>> static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
>> {
>>     struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, }, *entry;
>> +    struct mptcp_pm_addr_entry remote = { .addr = { .family = AF_UNSPEC }, };
>> +    struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
>> +    struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
>>     struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
>>     struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
>>     u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
>> @@ -1867,6 +1877,12 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
>>     if (ret < 0)
>>         return ret;
>>
>> +    if (attr_rem) {
>> +        ret = mptcp_pm_parse_entry(attr_rem, info, false, &remote);
>> +        if (ret < 0)
>> +            return ret;
>> +    }
>> +
>>     if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
>>         bkup = 1;
>>     if (addr.addr.family == AF_UNSPEC) {
>> @@ -1875,6 +1891,10 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
>>             return -EOPNOTSUPP;
>>     }
>>
>> +    if (token)
>> +        return mptcp_userspace_pm_set_flags(sock_net(skb->sk),
>> +                            token, &addr, &remote, bkup);
>> +
>>     spin_lock_bh(&pernet->lock);
>>     entry = __lookup_addr(pernet, &addr.addr, lookup_by_id);
>>     if (!entry) {
>> diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
>> index 26212bebc5ed..51e2f066d54f 100644
>> --- a/net/mptcp/pm_userspace.c
>> +++ b/net/mptcp/pm_userspace.c
>> @@ -420,3 +420,33 @@ int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
>>     sock_put((struct sock *)msk);
>>     return err;
>> }
>> +
>> +int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
>> +                 struct mptcp_pm_addr_entry *loc,
>> +                 struct mptcp_pm_addr_entry *rem, u8 bkup)
>> +{
>> +    struct mptcp_sock *msk;
>> +    int ret = -EINVAL;
>> +    u32 token_val;
>> +
>> +    token_val = nla_get_u32(token);
>> +
>> +    msk = mptcp_token_get_sock(net, token_val);
>> +    if (!msk)
>> +        return ret;
>> +
>> +    if (!mptcp_pm_is_userspace(msk))
>> +        goto set_flags_err;
>> +
>> +    if (loc->addr.family == AF_UNSPEC ||
>> +        rem->addr.family == AF_UNSPEC)
>> +        goto set_flags_err;
>> +
>> +    lock_sock((struct sock *)msk);
>> +    ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
>> +    release_sock((struct sock *)msk);
>> +
>> +set_flags_err:
>> +    sock_put((struct sock *)msk);
>> +    return ret;
>> +}
>> diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
>> index 033c995772dc..480c5320b86e 100644
>> --- a/net/mptcp/protocol.h
>> +++ b/net/mptcp/protocol.h
>> @@ -772,6 +772,10 @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
>>                    const struct mptcp_rm_list *rm_list);
>> void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
>> void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
>> +int mptcp_pm_nl_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,
>>                   const struct mptcp_pm_addr_entry *entry);
>> void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
>> @@ -788,7 +792,9 @@ int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
>> int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
>>                            unsigned int id,
>>                            u8 *flags, int *ifindex);
>> -
>> +int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
>> +                 struct mptcp_pm_addr_entry *loc,
>> +                 struct mptcp_pm_addr_entry *rem, u8 bkup);
>> int mptcp_pm_announce_addr(struct mptcp_sock *msk,
>>                const struct mptcp_addr_info *addr,
>>                bool echo);
>> -- 
>> 2.31.1
>>
>>
>>
> 
> -- 
> Mat Martineau
> Intel