selftests: mptcp: support MPTCP_PM_CMD_REMOVE

This change updates the "pm_nl_ctl" testing sample with a "rem"
(remove) option to support the newly added netlink interface command
MPTCP_PM_CMD_REMOVE to issue a REMOVE_ADDR signal over the
chosen MPTCP connection.

E.g. ./pm_nl_ctl rem token 823274047 id 23
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

@@ -28,6 +28,7 @@ static void syntax(char *argv[])
 	fprintf(stderr, "%s add|get|set|del|flush|dump|accept [<args>]\n", argv[0]);
 	fprintf(stderr, "\tadd [flags signal|subflow|backup|fullmesh] [id <nr>] [dev <name>] <ip>\n");
 	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, "\tdel <id> [<ip>]\n");
 	fprintf(stderr, "\tget <id>\n");
 	fprintf(stderr, "\tset [<ip>] [id <nr>] flags [no]backup|[no]fullmesh [port <nr>]\n");
@@ -172,6 +173,55 @@ static int resolve_mptcp_pm_netlink(int fd)
 	return genl_parse_getfamily((void *)data);
 }
 
+int remove_addr(int fd, int pm_family, int argc, char *argv[])
+{
+	char data[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
+		  NLMSG_ALIGN(sizeof(struct genlmsghdr)) +
+		  1024];
+	struct nlmsghdr *nh;
+	struct rtattr *rta;
+	u_int32_t token;
+	u_int8_t id;
+	int off = 0;
+	int arg;
+
+	memset(data, 0, sizeof(data));
+	nh = (void *)data;
+	off = init_genl_req(data, pm_family, MPTCP_PM_CMD_REMOVE,
+			    MPTCP_PM_VER);
+
+	if (argc < 6)
+		syntax(argv);
+
+	for (arg = 2; arg < argc; arg++) {
+		if (!strcmp(argv[arg], "id")) {
+			if (++arg >= argc)
+				error(1, 0, " missing id value");
+
+			id = atoi(argv[arg]);
+			rta = (void *)(data + off);
+			rta->rta_type = MPTCP_PM_ATTR_LOC_ID;
+			rta->rta_len = RTA_LENGTH(1);
+			memcpy(RTA_DATA(rta), &id, 1);
+			off += NLMSG_ALIGN(rta->rta_len);
+		} else if (!strcmp(argv[arg], "token")) {
+			if (++arg >= argc)
+				error(1, 0, " missing token value");
+
+			token = atoi(argv[arg]);
+			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);
+		} else
+			error(1, 0, "unknown keyword %s", argv[arg]);
+	}
+
+	do_nl_req(fd, nh, off, 0);
+	return 0;
+}
+
 int announce_addr(int fd, int pm_family, int argc, char *argv[])
 {
 	char data[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
@@ -917,6 +967,8 @@ int main(int argc, char *argv[])
 		return add_addr(fd, pm_family, argc, argv);
 	else if (!strcmp(argv[1], "ann"))
 		return announce_addr(fd, pm_family, argc, argv);
+	else if (!strcmp(argv[1], "rem"))
+		return remove_addr(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"))