[PATCH net-next 0/7] selftests: mptcp: increase code coverage

[PATCH net-next 0/7] selftests: mptcp: increase code coverage

[Matthieu Baerts (NGI0)]

Here are various patches slightly improving MPTCP code coverage:

- Patch 1: avoid a harmless 'grep: write error' warning.

- Patch 2: use getaddrinfo() with IPPROTO_MPTCP in more places.

- Patch 3-6: prepare and add support to get info for a specific subflow
  when giving the 5-tuple.

- Patch 7: validate the previous patch and cover "subflow_get_info_size"
  in the kernel code (mptcp_diag.c).

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Gang Yan (5):
      selftests: mptcp: add struct params in mptcp_diag
      selftests: mptcp: refactor send_query parameters for code clarity
      selftests: mptcp: refactor NLMSG handling with 'proto'
      selftests: mptcp: add helpers to get subflow_info
      selftests: mptcp: add chk_sublfow in diag.sh

Geliang Tang (1):
      selftests: mptcp: sockopt: use IPPROTO_MPTCP for getaddrinfo

Matthieu Baerts (NGI0) (1):
      selftests: mptcp: info: hide 'grep: write error' warnings

 tools/testing/selftests/net/mptcp/diag.sh         |  32 +++
 tools/testing/selftests/net/mptcp/mptcp_diag.c    | 228 +++++++++++++++++++---
 tools/testing/selftests/net/mptcp/mptcp_inq.c     |  16 +-
 tools/testing/selftests/net/mptcp/mptcp_lib.sh    |   7 +-
 tools/testing/selftests/net/mptcp/mptcp_sockopt.c |  16 +-
 5 files changed, 257 insertions(+), 42 deletions(-)
---
base-commit: 630cb33ccfcd04563598d0f0edd96c94ddf3352d
change-id: 20250502-net-next-mptcp-sft-inc-cover-f5eda7035432

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

[PATCH net-next 1/7] selftests: mptcp: info: hide 'grep: write error' warnings

[Matthieu Baerts (NGI0)]

mptcp_lib_get_info_value() will only print the first entry that match
the filter because of the ';q' at the end. As a consequence, the 'sed'
command could finish before the previous 'grep' one and print a 'write
error' warning because it is trying to write data to the closed pipe.

Such warnings are not interesting, they can be hidden by muting stderr
here for grep.

While at it, clearly indicate that mptcp_lib_get_info_value() will only
print the first matched entry to avoid confusions later on.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_lib.sh | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index 051e289d79676c5feb9f46da67a08116548f4b47..99c87cd6e25563e220263c813223206ef6f4b311 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -331,12 +331,15 @@ mptcp_lib_result_print_all_tap() {
 
 # get the value of keyword $1 in the line marked by keyword $2
 mptcp_lib_get_info_value() {
-	grep "${2}" | sed -n 's/.*\('"${1}"':\)\([0-9a-f:.]*\).*$/\2/p;q'
+	grep "${2}" 2>/dev/null |
+		sed -n 's/.*\('"${1}"':\)\([0-9a-f:.]*\).*$/\2/p;q'
+		# the ';q' at the end limits to the first matched entry.
 }
 
 # $1: info name ; $2: evts_ns ; [$3: event type; [$4: addr]]
 mptcp_lib_evts_get_info() {
-	grep "${4:-}" "${2}" | mptcp_lib_get_info_value "${1}" "^type:${3:-1},"
+	grep "${4:-}" "${2}" 2>/dev/null |
+		mptcp_lib_get_info_value "${1}" "^type:${3:-1},"
 }
 
 # $1: PID

-- 
2.48.1

[PATCH net-next 2/7] selftests: mptcp: sockopt: use IPPROTO_MPTCP for getaddrinfo

[Matthieu Baerts (NGI0)]

From: Geliang Tang <tanggeliang@kylinos.cn>

getaddrinfo MPTCP is recently supported in glibc and IPPROTO_MPTCP for
getaddrinfo is used in mptcp_connect.c. But in mptcp_sockopt.c and
mptcp_inq.c, IPPROTO_TCP are still used for getaddrinfo, So this patch
updates them.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_inq.c     | 16 ++++++++++++----
 tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 16 ++++++++++++----
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_inq.c b/tools/testing/selftests/net/mptcp/mptcp_inq.c
index 218aac46732125c005212d0d561ae3bce8f91a74..3cf1e2a612cef911028f46569563d16dd5d32129 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_inq.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_inq.c
@@ -72,13 +72,21 @@ static const char *getxinfo_strerr(int err)
 }
 
 static void xgetaddrinfo(const char *node, const char *service,
-			 const struct addrinfo *hints,
+			 struct addrinfo *hints,
 			 struct addrinfo **res)
 {
+again:
 	int err = getaddrinfo(node, service, hints, res);
 
 	if (err) {
-		const char *errstr = getxinfo_strerr(err);
+		const char *errstr;
+
+		if (err == EAI_SOCKTYPE) {
+			hints->ai_protocol = IPPROTO_TCP;
+			goto again;
+		}
+
+		errstr = getxinfo_strerr(err);
 
 		fprintf(stderr, "Fatal: getaddrinfo(%s:%s): %s\n",
 			node ? node : "", service ? service : "", errstr);
@@ -91,7 +99,7 @@ static int sock_listen_mptcp(const char * const listenaddr,
 {
 	int sock = -1;
 	struct addrinfo hints = {
-		.ai_protocol = IPPROTO_TCP,
+		.ai_protocol = IPPROTO_MPTCP,
 		.ai_socktype = SOCK_STREAM,
 		.ai_flags = AI_PASSIVE | AI_NUMERICHOST
 	};
@@ -136,7 +144,7 @@ static int sock_connect_mptcp(const char * const remoteaddr,
 			      const char * const port, int proto)
 {
 	struct addrinfo hints = {
-		.ai_protocol = IPPROTO_TCP,
+		.ai_protocol = IPPROTO_MPTCP,
 		.ai_socktype = SOCK_STREAM,
 	};
 	struct addrinfo *a, *addr;
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
index 926b0be87c9905e763cfb5ba6df974d3518f0b49..9934a68df23708ecb413c4ab26523989e3b9f158 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
@@ -159,13 +159,21 @@ static const char *getxinfo_strerr(int err)
 }
 
 static void xgetaddrinfo(const char *node, const char *service,
-			 const struct addrinfo *hints,
+			 struct addrinfo *hints,
 			 struct addrinfo **res)
 {
+again:
 	int err = getaddrinfo(node, service, hints, res);
 
 	if (err) {
-		const char *errstr = getxinfo_strerr(err);
+		const char *errstr;
+
+		if (err == EAI_SOCKTYPE) {
+			hints->ai_protocol = IPPROTO_TCP;
+			goto again;
+		}
+
+		errstr = getxinfo_strerr(err);
 
 		fprintf(stderr, "Fatal: getaddrinfo(%s:%s): %s\n",
 			node ? node : "", service ? service : "", errstr);
@@ -178,7 +186,7 @@ static int sock_listen_mptcp(const char * const listenaddr,
 {
 	int sock = -1;
 	struct addrinfo hints = {
-		.ai_protocol = IPPROTO_TCP,
+		.ai_protocol = IPPROTO_MPTCP,
 		.ai_socktype = SOCK_STREAM,
 		.ai_flags = AI_PASSIVE | AI_NUMERICHOST
 	};
@@ -223,7 +231,7 @@ static int sock_connect_mptcp(const char * const remoteaddr,
 			      const char * const port, int proto)
 {
 	struct addrinfo hints = {
-		.ai_protocol = IPPROTO_TCP,
+		.ai_protocol = IPPROTO_MPTCP,
 		.ai_socktype = SOCK_STREAM,
 	};
 	struct addrinfo *a, *addr;

-- 
2.48.1

[PATCH net-next 3/7] selftests: mptcp: add struct params in mptcp_diag

[Matthieu Baerts (NGI0)]

From: Gang Yan <yangang@kylinos.cn>

This patch adds a struct named 'params' to save 'target_token' and other
future parameters. This structure facilitates future function expansions.

Co-developed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_diag.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c
index 37d5015ad08c44485f1964593ecb1a7b25d95934..ea7cb1128044ab7f9bad50cb29856c2e290f385f 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_diag.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_diag.c
@@ -19,6 +19,10 @@
 #define IPPROTO_MPTCP 262
 #endif
 
+struct params {
+	__u32 target_token;
+};
+
 struct mptcp_info {
 	__u8	mptcpi_subflows;
 	__u8	mptcpi_add_addr_signal;
@@ -237,7 +241,7 @@ static void get_mptcpinfo(__u32 token)
 	close(fd);
 }
 
-static void parse_opts(int argc, char **argv, __u32 *target_token)
+static void parse_opts(int argc, char **argv, struct params *p)
 {
 	int c;
 
@@ -250,7 +254,7 @@ static void parse_opts(int argc, char **argv, __u32 *target_token)
 			die_usage(0);
 			break;
 		case 't':
-			sscanf(optarg, "%x", target_token);
+			sscanf(optarg, "%x", &p->target_token);
 			break;
 		default:
 			die_usage(1);
@@ -261,10 +265,12 @@ static void parse_opts(int argc, char **argv, __u32 *target_token)
 
 int main(int argc, char *argv[])
 {
-	__u32 target_token;
+	struct params p = { 0 };
 
-	parse_opts(argc, argv, &target_token);
-	get_mptcpinfo(target_token);
+	parse_opts(argc, argv, &p);
+
+	if (p.target_token)
+		get_mptcpinfo(p.target_token);
 
 	return 0;
 }

-- 
2.48.1

[PATCH net-next 4/7] selftests: mptcp: refactor send_query parameters for code clarity

[Matthieu Baerts (NGI0)]

From: Gang Yan <yangang@kylinos.cn>

This patch use 'inet_diag_req_v2' instead of 'token' as parameters of
send_query, and construct the req in 'get_mptcpinfo'.

This modification enhances the clarity of the code, and prepare for the
dump_subflow_info.

Co-developed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_diag.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c
index ea7cb1128044ab7f9bad50cb29856c2e290f385f..76135aba71ad24c25c7babb6875e8a6dd7636b21 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_diag.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_diag.c
@@ -62,7 +62,7 @@ static void die_usage(int r)
 	exit(r);
 }
 
-static void send_query(int fd, __u32 token)
+static void send_query(int fd, struct inet_diag_req_v2 *r)
 {
 	struct sockaddr_nl nladdr = {
 		.nl_family = AF_NETLINK
@@ -76,19 +76,13 @@ static void send_query(int fd, __u32 token)
 			.nlmsg_type = SOCK_DIAG_BY_FAMILY,
 			.nlmsg_flags = NLM_F_REQUEST
 		},
-		.r = {
-			.sdiag_family = AF_INET,
-			/* Real proto is set via INET_DIAG_REQ_PROTOCOL */
-			.sdiag_protocol = IPPROTO_TCP,
-			.id.idiag_cookie[0] = token,
-		}
+		.r = *r
 	};
 	struct rtattr rta_proto;
 	struct iovec iov[6];
 	int iovlen = 1;
 	__u32 proto;
 
-	req.r.idiag_ext |= (1 << (INET_DIAG_INFO - 1));
 	proto = IPPROTO_MPTCP;
 	rta_proto.rta_type = INET_DIAG_REQ_PROTOCOL;
 	rta_proto.rta_len = RTA_LENGTH(sizeof(proto));
@@ -229,13 +223,20 @@ static void recv_nlmsg(int fd)
 
 static void get_mptcpinfo(__u32 token)
 {
+	struct inet_diag_req_v2 r = {
+		.sdiag_family           = AF_INET,
+		/* Real proto is set via INET_DIAG_REQ_PROTOCOL */
+		.sdiag_protocol         = IPPROTO_TCP,
+		.idiag_ext              = 1 << (INET_DIAG_INFO - 1),
+		.id.idiag_cookie[0]     = token,
+	};
 	int fd;
 
 	fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG);
 	if (fd < 0)
 		die_perror("Netlink socket");
 
-	send_query(fd, token);
+	send_query(fd, &r);
 	recv_nlmsg(fd);
 
 	close(fd);

-- 
2.48.1

[PATCH net-next 5/7] selftests: mptcp: refactor NLMSG handling with 'proto'

[Matthieu Baerts (NGI0)]

From: Gang Yan <yangang@kylinos.cn>

This patch introduces the '__u32 proto' variable to the 'send_query' and
'recv_nlmsg' functions for further extending function.

In the 'send_query' function, the inclusion of this variable makes the
structure clearer and more readable.

In the 'recv_nlmsg' function, the '__u32 proto' variable ensures that
the 'diag_info' field remains unmodified when processing IPPROTO_TCP data,
thereby preventing unintended transformation into 'mptcp_info' format.

While at it, increment iovlen directly when an item is added to simplify
this portion of the code and improve its readaility.

Co-developed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_diag.c | 38 ++++++++++++++------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c
index 76135aba71ad24c25c7babb6875e8a6dd7636b21..cc0326548e4ec44060da83f1f77e498bcedc82a9 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_diag.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_diag.c
@@ -62,7 +62,7 @@ static void die_usage(int r)
 	exit(r);
 }
 
-static void send_query(int fd, struct inet_diag_req_v2 *r)
+static void send_query(int fd, struct inet_diag_req_v2 *r, __u32 proto)
 {
 	struct sockaddr_nl nladdr = {
 		.nl_family = AF_NETLINK
@@ -80,21 +80,22 @@ static void send_query(int fd, struct inet_diag_req_v2 *r)
 	};
 	struct rtattr rta_proto;
 	struct iovec iov[6];
-	int iovlen = 1;
-	__u32 proto;
+	int iovlen = 0;
 
-	proto = IPPROTO_MPTCP;
-	rta_proto.rta_type = INET_DIAG_REQ_PROTOCOL;
-	rta_proto.rta_len = RTA_LENGTH(sizeof(proto));
-
-	iov[0] = (struct iovec) {
+	iov[iovlen++] = (struct iovec) {
 		.iov_base = &req,
 		.iov_len = sizeof(req)
 	};
-	iov[iovlen] = (struct iovec){ &rta_proto, sizeof(rta_proto)};
-	iov[iovlen + 1] = (struct iovec){ &proto, sizeof(proto)};
-	req.nlh.nlmsg_len += RTA_LENGTH(sizeof(proto));
-	iovlen += 2;
+
+	if (proto == IPPROTO_MPTCP) {
+		rta_proto.rta_type = INET_DIAG_REQ_PROTOCOL;
+		rta_proto.rta_len = RTA_LENGTH(sizeof(proto));
+
+		iov[iovlen++] = (struct iovec){ &rta_proto, sizeof(rta_proto)};
+		iov[iovlen++] = (struct iovec){ &proto, sizeof(proto)};
+		req.nlh.nlmsg_len += RTA_LENGTH(sizeof(proto));
+	}
+
 	struct msghdr msg = {
 		.msg_name = &nladdr,
 		.msg_namelen = sizeof(nladdr),
@@ -158,7 +159,7 @@ static void print_info_msg(struct mptcp_info *info)
 	printf("bytes_acked:      %llu\n", info->mptcpi_bytes_acked);
 }
 
-static void parse_nlmsg(struct nlmsghdr *nlh)
+static void parse_nlmsg(struct nlmsghdr *nlh, __u32 proto)
 {
 	struct inet_diag_msg *r = NLMSG_DATA(nlh);
 	struct rtattr *tb[INET_DIAG_MAX + 1];
@@ -167,7 +168,7 @@ static void parse_nlmsg(struct nlmsghdr *nlh)
 			   nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*r)),
 			   NLA_F_NESTED);
 
-	if (tb[INET_DIAG_INFO]) {
+	if (proto == IPPROTO_MPTCP && tb[INET_DIAG_INFO]) {
 		int len = RTA_PAYLOAD(tb[INET_DIAG_INFO]);
 		struct mptcp_info *info;
 
@@ -183,7 +184,7 @@ static void parse_nlmsg(struct nlmsghdr *nlh)
 	}
 }
 
-static void recv_nlmsg(int fd)
+static void recv_nlmsg(int fd, __u32 proto)
 {
 	char rcv_buff[8192];
 	struct nlmsghdr *nlh = (struct nlmsghdr *)rcv_buff;
@@ -216,7 +217,7 @@ static void recv_nlmsg(int fd)
 			       -(err->error), strerror(-(err->error)));
 			break;
 		}
-		parse_nlmsg(nlh);
+		parse_nlmsg(nlh, proto);
 		nlh = NLMSG_NEXT(nlh, len);
 	}
 }
@@ -230,14 +231,15 @@ static void get_mptcpinfo(__u32 token)
 		.idiag_ext              = 1 << (INET_DIAG_INFO - 1),
 		.id.idiag_cookie[0]     = token,
 	};
+	__u32 proto = IPPROTO_MPTCP;
 	int fd;
 
 	fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG);
 	if (fd < 0)
 		die_perror("Netlink socket");
 
-	send_query(fd, &r);
-	recv_nlmsg(fd);
+	send_query(fd, &r, proto);
+	recv_nlmsg(fd, proto);
 
 	close(fd);
 }

-- 
2.48.1

[PATCH net-next 6/7] selftests: mptcp: add helpers to get subflow_info

[Matthieu Baerts (NGI0)]

From: Gang Yan <yangang@kylinos.cn>

This patch adds 'get_subflow_info' in 'mptcp_diag', which can check whether
a TCP connection is an MPTCP subflow based on the "INET_ULP_INFO_MPTCP"
with tcp_diag method.

The helper 'print_subflow_info' in 'mptcp_diag' can print the subflow_filed
of an MPTCP subflow for further checking the 'subflow_info' through
inet_diag method.

The example of the whole output should be:

  $ ./mptcp_diag -s "127.0.0.1:10000 127.0.0.1:38984"
  127.0.0.1:10000 -> 127.0.0.1:38984
  It's a mptcp subflow, the subflow info:
   flags:Mec token:0000(id:0)/4278e77e(id:0) seq:9288466187236176036 \
   sfseq:1 ssnoff:2317083055 maplen:215

Co-developed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_diag.c | 159 ++++++++++++++++++++++++-
 1 file changed, 157 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c
index cc0326548e4ec44060da83f1f77e498bcedc82a9..e084796e804d28e93d04c30cca937fe21be43388 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_diag.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_diag.c
@@ -8,6 +8,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <linux/tcp.h>
+#include <arpa/inet.h>
 
 #include <unistd.h>
 #include <stdlib.h>
@@ -19,8 +20,13 @@
 #define IPPROTO_MPTCP 262
 #endif
 
+#define parse_rtattr_nested(tb, max, rta) \
+	(parse_rtattr_flags((tb), (max), RTA_DATA(rta), RTA_PAYLOAD(rta), \
+			    NLA_F_NESTED))
+
 struct params {
 	__u32 target_token;
+	char subflow_addrs[1024];
 };
 
 struct mptcp_info {
@@ -50,6 +56,37 @@ struct mptcp_info {
 	__u32	mptcpi_last_ack_recv;
 };
 
+enum {
+	MPTCP_SUBFLOW_ATTR_UNSPEC,
+	MPTCP_SUBFLOW_ATTR_TOKEN_REM,
+	MPTCP_SUBFLOW_ATTR_TOKEN_LOC,
+	MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ,
+	MPTCP_SUBFLOW_ATTR_MAP_SEQ,
+	MPTCP_SUBFLOW_ATTR_MAP_SFSEQ,
+	MPTCP_SUBFLOW_ATTR_SSN_OFFSET,
+	MPTCP_SUBFLOW_ATTR_MAP_DATALEN,
+	MPTCP_SUBFLOW_ATTR_FLAGS,
+	MPTCP_SUBFLOW_ATTR_ID_REM,
+	MPTCP_SUBFLOW_ATTR_ID_LOC,
+	MPTCP_SUBFLOW_ATTR_PAD,
+
+	__MPTCP_SUBFLOW_ATTR_MAX
+};
+
+#define MPTCP_SUBFLOW_ATTR_MAX (__MPTCP_SUBFLOW_ATTR_MAX - 1)
+
+#define MPTCP_SUBFLOW_FLAG_MCAP_REM		_BITUL(0)
+#define MPTCP_SUBFLOW_FLAG_MCAP_LOC		_BITUL(1)
+#define MPTCP_SUBFLOW_FLAG_JOIN_REM		_BITUL(2)
+#define MPTCP_SUBFLOW_FLAG_JOIN_LOC		_BITUL(3)
+#define MPTCP_SUBFLOW_FLAG_BKUP_REM		_BITUL(4)
+#define MPTCP_SUBFLOW_FLAG_BKUP_LOC		_BITUL(5)
+#define MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED	_BITUL(6)
+#define MPTCP_SUBFLOW_FLAG_CONNECTED		_BITUL(7)
+#define MPTCP_SUBFLOW_FLAG_MAPVALID		_BITUL(8)
+
+#define rta_getattr(type, value)		(*(type *)RTA_DATA(value))
+
 static void die_perror(const char *msg)
 {
 	perror(msg);
@@ -58,7 +95,9 @@ static void die_perror(const char *msg)
 
 static void die_usage(int r)
 {
-	fprintf(stderr, "Usage: mptcp_diag -t\n");
+	fprintf(stderr, "Usage:\n"
+			"mptcp_diag -t <token>\n"
+			"mptcp_diag -s \"<saddr>:<sport> <daddr>:<dport>\"\n");
 	exit(r);
 }
 
@@ -159,6 +198,66 @@ static void print_info_msg(struct mptcp_info *info)
 	printf("bytes_acked:      %llu\n", info->mptcpi_bytes_acked);
 }
 
+/*
+ * 'print_subflow_info' is from 'mptcp_subflow_info'
+ * which is a function in 'misc/ss.c' of iproute2.
+ */
+static void print_subflow_info(struct rtattr *tb[])
+{
+	u_int32_t flags = 0;
+
+	printf("It's a mptcp subflow, the subflow info:\n");
+	if (tb[MPTCP_SUBFLOW_ATTR_FLAGS]) {
+		char caps[32 + 1] = { 0 }, *cap = &caps[0];
+
+		flags = rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_FLAGS]);
+
+		if (flags & MPTCP_SUBFLOW_FLAG_MCAP_REM)
+			*cap++ = 'M';
+		if (flags & MPTCP_SUBFLOW_FLAG_MCAP_LOC)
+			*cap++ = 'm';
+		if (flags & MPTCP_SUBFLOW_FLAG_JOIN_REM)
+			*cap++ = 'J';
+		if (flags & MPTCP_SUBFLOW_FLAG_JOIN_LOC)
+			*cap++ = 'j';
+		if (flags & MPTCP_SUBFLOW_FLAG_BKUP_REM)
+			*cap++ = 'B';
+		if (flags & MPTCP_SUBFLOW_FLAG_BKUP_LOC)
+			*cap++ = 'b';
+		if (flags & MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED)
+			*cap++ = 'e';
+		if (flags & MPTCP_SUBFLOW_FLAG_CONNECTED)
+			*cap++ = 'c';
+		if (flags & MPTCP_SUBFLOW_FLAG_MAPVALID)
+			*cap++ = 'v';
+
+		if (flags)
+			printf(" flags:%s", caps);
+	}
+	if (tb[MPTCP_SUBFLOW_ATTR_TOKEN_REM] &&
+	    tb[MPTCP_SUBFLOW_ATTR_TOKEN_LOC] &&
+	    tb[MPTCP_SUBFLOW_ATTR_ID_REM] &&
+	    tb[MPTCP_SUBFLOW_ATTR_ID_LOC])
+		printf(" token:%04x(id:%u)/%04x(id:%u)",
+		       rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_TOKEN_REM]),
+		       rta_getattr(__u8, tb[MPTCP_SUBFLOW_ATTR_ID_REM]),
+		       rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_TOKEN_LOC]),
+		       rta_getattr(__u8, tb[MPTCP_SUBFLOW_ATTR_ID_LOC]));
+	if (tb[MPTCP_SUBFLOW_ATTR_MAP_SEQ])
+		printf(" seq:%llu",
+		       rta_getattr(__u64, tb[MPTCP_SUBFLOW_ATTR_MAP_SEQ]));
+	if (tb[MPTCP_SUBFLOW_ATTR_MAP_SFSEQ])
+		printf(" sfseq:%u",
+		       rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_MAP_SFSEQ]));
+	if (tb[MPTCP_SUBFLOW_ATTR_SSN_OFFSET])
+		printf(" ssnoff:%u",
+		       rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_SSN_OFFSET]));
+	if (tb[MPTCP_SUBFLOW_ATTR_MAP_DATALEN])
+		printf(" maplen:%u",
+		       rta_getattr(__u32, tb[MPTCP_SUBFLOW_ATTR_MAP_DATALEN]));
+	printf("\n");
+}
+
 static void parse_nlmsg(struct nlmsghdr *nlh, __u32 proto)
 {
 	struct inet_diag_msg *r = NLMSG_DATA(nlh);
@@ -182,6 +281,22 @@ static void parse_nlmsg(struct nlmsghdr *nlh, __u32 proto)
 		}
 		print_info_msg(info);
 	}
+	if (proto == IPPROTO_TCP && tb[INET_DIAG_ULP_INFO]) {
+		struct rtattr *ulpinfo[INET_ULP_INFO_MAX + 1] = { 0 };
+
+		parse_rtattr_nested(ulpinfo, INET_ULP_INFO_MAX,
+				    tb[INET_DIAG_ULP_INFO]);
+
+		if (ulpinfo[INET_ULP_INFO_MPTCP]) {
+			struct rtattr *sfinfo[MPTCP_SUBFLOW_ATTR_MAX + 1] = { 0 };
+
+			parse_rtattr_nested(sfinfo, MPTCP_SUBFLOW_ATTR_MAX,
+					    ulpinfo[INET_ULP_INFO_MPTCP]);
+			print_subflow_info(sfinfo);
+		} else {
+			printf("It's a normal TCP!\n");
+		}
+	}
 }
 
 static void recv_nlmsg(int fd, __u32 proto)
@@ -244,6 +359,39 @@ static void get_mptcpinfo(__u32 token)
 	close(fd);
 }
 
+static void get_subflow_info(char *subflow_addrs)
+{
+	struct inet_diag_req_v2 r = {
+		.sdiag_family           = AF_INET,
+		.sdiag_protocol         = IPPROTO_TCP,
+		.idiag_ext              = 1 << (INET_DIAG_INFO - 1),
+		.id.idiag_cookie[0]     = INET_DIAG_NOCOOKIE,
+		.id.idiag_cookie[1]     = INET_DIAG_NOCOOKIE,
+	};
+	char saddr[64], daddr[64];
+	int sport, dport;
+	int ret;
+	int fd;
+
+	ret = sscanf(subflow_addrs, "%[^:]:%d %[^:]:%d", saddr, &sport, daddr, &dport);
+	if (ret != 4)
+		die_perror("IP PORT Pairs has style problems!");
+
+	printf("%s:%d -> %s:%d\n", saddr, sport, daddr, dport);
+
+	fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG);
+	if (fd < 0)
+		die_perror("Netlink socket");
+
+	r.id.idiag_sport = htons(sport);
+	r.id.idiag_dport = htons(dport);
+
+	inet_pton(AF_INET, saddr, &r.id.idiag_src);
+	inet_pton(AF_INET, daddr, &r.id.idiag_dst);
+	send_query(fd, &r, IPPROTO_TCP);
+	recv_nlmsg(fd, IPPROTO_TCP);
+}
+
 static void parse_opts(int argc, char **argv, struct params *p)
 {
 	int c;
@@ -251,7 +399,7 @@ static void parse_opts(int argc, char **argv, struct params *p)
 	if (argc < 2)
 		die_usage(1);
 
-	while ((c = getopt(argc, argv, "ht:")) != -1) {
+	while ((c = getopt(argc, argv, "ht:s:")) != -1) {
 		switch (c) {
 		case 'h':
 			die_usage(0);
@@ -259,6 +407,10 @@ static void parse_opts(int argc, char **argv, struct params *p)
 		case 't':
 			sscanf(optarg, "%x", &p->target_token);
 			break;
+		case 's':
+			strncpy(p->subflow_addrs, optarg,
+				sizeof(p->subflow_addrs) - 1);
+			break;
 		default:
 			die_usage(1);
 			break;
@@ -275,6 +427,9 @@ int main(int argc, char *argv[])
 	if (p.target_token)
 		get_mptcpinfo(p.target_token);
 
+	if (p.subflow_addrs[0] != '\0')
+		get_subflow_info(p.subflow_addrs);
+
 	return 0;
 }
 

-- 
2.48.1

[PATCH net-next 7/7] selftests: mptcp: add chk_sublfow in diag.sh

[Matthieu Baerts (NGI0)]

From: Gang Yan <yangang@kylinos.cn>

This patch aims to add chk_dump_subflow in diag.sh. The subflow's
info can be obtained through "ss -tin", then use the 'mptcp_diag'
to verify the token in subflow_info.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/524
Co-developed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/diag.sh | 32 +++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
index e7a75341f0f32304ff4e58c9b2500d405124dc74..7a3cb4c09e450f0ae570015c4724ec268c6dc19f 100755
--- a/tools/testing/selftests/net/mptcp/diag.sh
+++ b/tools/testing/selftests/net/mptcp/diag.sh
@@ -225,6 +225,37 @@ chk_dump_one()
 	fi
 }
 
+chk_dump_subflow()
+{
+	local inet_diag_token
+	local subflow_line
+	local ss_output
+	local ss_token
+	local msg
+
+	ss_output=$(ss -tniN $ns)
+
+	subflow_line=$(echo "$ss_output" | \
+		       grep -m1 -Eo '[0-9.]+:[0-9].+ +[0-9.]+:[0-9.]+')
+
+	ss_token=$(echo "$ss_output" | grep -m1 -Eo 'token:[^ ]+')
+
+	inet_diag_token=$(ip netns exec $ns ./mptcp_diag -s "$subflow_line" | \
+			  grep -Eo 'token:[^ ]+')
+
+	msg="....chk dump_subflow"
+
+	mptcp_lib_print_title "$msg"
+	if [ -n "$ss_token" ] && [ "$ss_token" = "$inet_diag_token" ]; then
+		mptcp_lib_pr_ok
+		mptcp_lib_result_pass "${msg}"
+	else
+		mptcp_lib_pr_fail "expected $ss_token found $inet_diag_token"
+		mptcp_lib_result_fail "${msg}"
+		ret=${KSFT_FAIL}
+	fi
+}
+
 msk_info_get_value()
 {
 	local port="${1}"
@@ -316,6 +347,7 @@ chk_msk_fallback_nr 0 "....chk no fallback"
 chk_msk_inuse 2
 chk_msk_cestab 2
 chk_dump_one
+chk_dump_subflow
 flush_pids
 
 chk_msk_inuse 0 "2->0"

-- 
2.48.1

Re: [PATCH net-next 0/7] selftests: mptcp: increase code coverage

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 02 May 2025 14:29:20 +0200 you wrote:
> Here are various patches slightly improving MPTCP code coverage:
> 
> - Patch 1: avoid a harmless 'grep: write error' warning.
> 
> - Patch 2: use getaddrinfo() with IPPROTO_MPTCP in more places.
> 
> - Patch 3-6: prepare and add support to get info for a specific subflow
>   when giving the 5-tuple.
> 
> [...]

Here is the summary with links:
  - [net-next,1/7] selftests: mptcp: info: hide 'grep: write error' warnings
    https://git.kernel.org/netdev/net-next/c/6d0eb15c6501
  - [net-next,2/7] selftests: mptcp: sockopt: use IPPROTO_MPTCP for getaddrinfo
    https://git.kernel.org/netdev/net-next/c/dd367e81b79a
  - [net-next,3/7] selftests: mptcp: add struct params in mptcp_diag
    https://git.kernel.org/netdev/net-next/c/cd732d5110a2
  - [net-next,4/7] selftests: mptcp: refactor send_query parameters for code clarity
    https://git.kernel.org/netdev/net-next/c/3fea468dca4f
  - [net-next,5/7] selftests: mptcp: refactor NLMSG handling with 'proto'
    https://git.kernel.org/netdev/net-next/c/caa6811ccaed
  - [net-next,6/7] selftests: mptcp: add helpers to get subflow_info
    https://git.kernel.org/netdev/net-next/c/c7ac7452df70
  - [net-next,7/7] selftests: mptcp: add chk_sublfow in diag.sh
    https://git.kernel.org/netdev/net-next/c/110f8f77fd8d

You are awesome, thank you!
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