Commit c7ac7452 authored by Gang Yan's avatar Gang Yan Committed by Jakub Kicinski
Browse files

selftests: mptcp: add helpers to get subflow_info 



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: default avatarGeliang Tang <geliang@kernel.org>
Signed-off-by: default avatarGeliang Tang <geliang@kernel.org>
Signed-off-by: default avatarGang Yan <yangang@kylinos.cn>
Reviewed-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250502-net-next-mptcp-sft-inc-cover-v1-6-68eec95898fb@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent caa6811c

tools/testing/selftests/net/mptcp/mptcp_diag.c

+157 −2
Original line number Diff line number Diff line
@@ -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;

}