selftests: mptcp: support MPTCP_PM_CMD_SUBFLOW_DESTROY

This change updates the "pm_nl_ctl" testing sample with a "dsf"
(destroy subflow) option to support the newly added netlink interface
command MPTCP_PM_CMD_SUBFLOW_DESTROY over the chosen MPTCP connection.

E.g. ./pm_nl_ctl dsf lip 10.0.2.1 lport 44567 rip 10.0.2.2 rport 56789
token 823274047

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -30,6 +30,7 @@ static void syntax(char *argv[])
 	fprintf(stderr, "\tann <local-ip> id <local-id> token <token> [port <local-port>] [dev <name>]\n");
 	fprintf(stderr, "\trem id <local-id> token <token>\n");
 	fprintf(stderr, "\tcsf lip <local-ip> lid <local-id> rip <remote-ip> rport <remote-port> token <token>\n");
+	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");
@@ -174,6 +175,118 @@ static int resolve_mptcp_pm_netlink(int fd)
 	return genl_parse_getfamily((void *)data);
 }
 
+int dsf(int fd, int pm_family, int argc, char *argv[])
+{
+	char data[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
+		  NLMSG_ALIGN(sizeof(struct genlmsghdr)) +
+		  1024];
+	struct rtattr *rta, *addr;
+	u_int16_t family, port;
+	struct nlmsghdr *nh;
+	u_int32_t token;
+	int addr_start;
+	int off = 0;
+	int arg;
+
+	const char *params[5];
+
+	memset(params, 0, 5 * sizeof(const char *));
+
+	memset(data, 0, sizeof(data));
+	nh = (void *)data;
+	off = init_genl_req(data, pm_family, MPTCP_PM_CMD_SUBFLOW_DESTROY,
+			    MPTCP_PM_VER);
+
+	if (argc < 12)
+		syntax(argv);
+
+	/* Params recorded in this order:
+	 * <local-ip>, <local-port>, <remote-ip>, <remote-port>, <token>
+	 */
+	for (arg = 2; arg < argc; arg++) {
+		if (!strcmp(argv[arg], "lip")) {
+			if (++arg >= argc)
+				error(1, 0, " missing local IP");
+
+			params[0] = argv[arg];
+		} else if (!strcmp(argv[arg], "lport")) {
+			if (++arg >= argc)
+				error(1, 0, " missing local port");
+
+			params[1] = argv[arg];
+		} else if (!strcmp(argv[arg], "rip")) {
+			if (++arg >= argc)
+				error(1, 0, " missing remote IP");
+
+			params[2] = argv[arg];
+		} else if (!strcmp(argv[arg], "rport")) {
+			if (++arg >= argc)
+				error(1, 0, " missing remote port");
+
+			params[3] = argv[arg];
+		} else if (!strcmp(argv[arg], "token")) {
+			if (++arg >= argc)
+				error(1, 0, " missing token");
+
+			params[4] = argv[arg];
+		} else
+			error(1, 0, "unknown keyword %s", argv[arg]);
+	}
+
+	for (arg = 0; arg < 4; arg = arg + 2) {
+		/*  addr header */
+		addr_start = off;
+		addr = (void *)(data + off);
+		addr->rta_type = NLA_F_NESTED |
+			((arg == 0) ? MPTCP_PM_ATTR_ADDR : MPTCP_PM_ATTR_ADDR_REMOTE);
+		addr->rta_len = RTA_LENGTH(0);
+		off += NLMSG_ALIGN(addr->rta_len);
+
+		/*  addr data */
+		rta = (void *)(data + off);
+		if (inet_pton(AF_INET, params[arg], 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, params[arg], 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", params[arg]);
+		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);
+
+		/*  port */
+		port = atoi(params[arg + 1]);
+		rta = (void *)(data + off);
+		rta->rta_type = MPTCP_PM_ADDR_ATTR_PORT;
+		rta->rta_len = RTA_LENGTH(2);
+		memcpy(RTA_DATA(rta), &port, 2);
+		off += NLMSG_ALIGN(rta->rta_len);
+
+		addr->rta_len = off - addr_start;
+	}
+
+	/* token */
+	token = atoi(params[4]);
+	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);
+
+	do_nl_req(fd, nh, off, 0);
+
+	return 0;
+}
+
 int csf(int fd, int pm_family, int argc, char *argv[])
 {
 	char data[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
@@ -1098,6 +1211,8 @@ int main(int argc, char *argv[])
 		return remove_addr(fd, pm_family, argc, argv);
 	else if (!strcmp(argv[1], "csf"))
 		return csf(fd, pm_family, argc, argv);
+	else if (!strcmp(argv[1], "dsf"))
+		return dsf(fd, pm_family, argc, argv);
 	else if (!strcmp(argv[1], "del"))
 		return del_addr(fd, pm_family, argc, argv);
 	else if (!strcmp(argv[1], "flush"))