RDMA/rtrs: server: sysfs interface functions

// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * RDMA Transport Layer

 *

 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.

 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.

 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.

 */

#undef pr_fmt

#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt

#include "rtrs-pri.h"

#include "rtrs-srv.h"

#include "rtrs-log.h"

static void rtrs_srv_release(struct kobject *kobj)

{

	struct rtrs_srv_sess *sess;

	sess = container_of(kobj, struct rtrs_srv_sess, kobj);

	kfree(sess);

}

static struct kobj_type ktype = {

	.sysfs_ops	= &kobj_sysfs_ops,

	.release	= rtrs_srv_release,

};

static ssize_t rtrs_srv_disconnect_show(struct kobject *kobj,

					 struct kobj_attribute *attr,

					 char *page)

{

	return scnprintf(page, PAGE_SIZE, "Usage: echo 1 > %s\n",

			 attr->attr.name);

}

static ssize_t rtrs_srv_disconnect_store(struct kobject *kobj,

					  struct kobj_attribute *attr,

					  const char *buf, size_t count)

{

	struct rtrs_srv_sess *sess;

	struct rtrs_sess *s;

	char str[MAXHOSTNAMELEN];

	sess = container_of(kobj, struct rtrs_srv_sess, kobj);

	s = &sess->s;

	if (!sysfs_streq(buf, "1")) {

		rtrs_err(s, "%s: invalid value: '%s'\n",

			  attr->attr.name, buf);

		return -EINVAL;

	}

	sockaddr_to_str((struct sockaddr *)&sess->s.dst_addr, str, sizeof(str));

	rtrs_info(s, "disconnect for path %s requested\n", str);

	close_sess(sess);

	return count;

}

static struct kobj_attribute rtrs_srv_disconnect_attr =

	__ATTR(disconnect, 0644,

	       rtrs_srv_disconnect_show, rtrs_srv_disconnect_store);

static ssize_t rtrs_srv_hca_port_show(struct kobject *kobj,

				       struct kobj_attribute *attr,

				       char *page)

{

	struct rtrs_srv_sess *sess;

	struct rtrs_con *usr_con;

	sess = container_of(kobj, typeof(*sess), kobj);

	usr_con = sess->s.con[0];

	return scnprintf(page, PAGE_SIZE, "%u\n",

			 usr_con->cm_id->port_num);

}

static struct kobj_attribute rtrs_srv_hca_port_attr =

	__ATTR(hca_port, 0444, rtrs_srv_hca_port_show, NULL);

static ssize_t rtrs_srv_hca_name_show(struct kobject *kobj,

				       struct kobj_attribute *attr,

				       char *page)

{

	struct rtrs_srv_sess *sess;

	sess = container_of(kobj, struct rtrs_srv_sess, kobj);

	return scnprintf(page, PAGE_SIZE, "%s\n",

			 sess->s.dev->ib_dev->name);

}

static struct kobj_attribute rtrs_srv_hca_name_attr =

	__ATTR(hca_name, 0444, rtrs_srv_hca_name_show, NULL);

static ssize_t rtrs_srv_src_addr_show(struct kobject *kobj,

				       struct kobj_attribute *attr,

				       char *page)

{

	struct rtrs_srv_sess *sess;

	int cnt;

	sess = container_of(kobj, struct rtrs_srv_sess, kobj);

	cnt = sockaddr_to_str((struct sockaddr *)&sess->s.dst_addr,

			      page, PAGE_SIZE);

	return cnt + scnprintf(page + cnt, PAGE_SIZE - cnt, "\n");

}

static struct kobj_attribute rtrs_srv_src_addr_attr =

	__ATTR(src_addr, 0444, rtrs_srv_src_addr_show, NULL);

static ssize_t rtrs_srv_dst_addr_show(struct kobject *kobj,

				       struct kobj_attribute *attr,

				       char *page)

{

	struct rtrs_srv_sess *sess;

	int cnt;

	sess = container_of(kobj, struct rtrs_srv_sess, kobj);

	cnt = sockaddr_to_str((struct sockaddr *)&sess->s.src_addr,

			      page, PAGE_SIZE);

	return cnt + scnprintf(page + cnt, PAGE_SIZE - cnt, "\n");

}

static struct kobj_attribute rtrs_srv_dst_addr_attr =

	__ATTR(dst_addr, 0444, rtrs_srv_dst_addr_show, NULL);

static struct attribute *rtrs_srv_sess_attrs[] = {

	&rtrs_srv_hca_name_attr.attr,

	&rtrs_srv_hca_port_attr.attr,

	&rtrs_srv_src_addr_attr.attr,

	&rtrs_srv_dst_addr_attr.attr,

	&rtrs_srv_disconnect_attr.attr,

	NULL,

};

static struct attribute_group rtrs_srv_sess_attr_group = {

	.attrs = rtrs_srv_sess_attrs,

};

STAT_ATTR(struct rtrs_srv_stats, rdma,

	  rtrs_srv_stats_rdma_to_str,

	  rtrs_srv_reset_rdma_stats);

static struct attribute *rtrs_srv_stats_attrs[] = {

	&rdma_attr.attr,

	NULL,

};

static struct attribute_group rtrs_srv_stats_attr_group = {

	.attrs = rtrs_srv_stats_attrs,

};

static void rtrs_srv_dev_release(struct device *dev)

{

	struct rtrs_srv *srv = container_of(dev, struct rtrs_srv, dev);

	kfree(srv);

}

static int rtrs_srv_create_once_sysfs_root_folders(struct rtrs_srv_sess *sess)

{

	struct rtrs_srv *srv = sess->srv;

	int err = 0;

	mutex_lock(&srv->paths_mutex);

	if (srv->dev_ref++) {

		/*

		 * Device needs to be registered only on the first session

		 */

		goto unlock;

	}

	srv->dev.class = rtrs_dev_class;

	srv->dev.release = rtrs_srv_dev_release;

	err = dev_set_name(&srv->dev, "%s", sess->s.sessname);

	if (err)

		goto unlock;

	/*

	 * Suppress user space notification until

	 * sysfs files are created

	 */

	dev_set_uevent_suppress(&srv->dev, true);

	err = device_register(&srv->dev);

	if (err) {

		pr_err("device_register(): %d\n", err);

		goto put;

	}

	srv->kobj_paths = kobject_create_and_add("paths", &srv->dev.kobj);

	if (!srv->kobj_paths) {

		pr_err("kobject_create_and_add(): %d\n", err);

		device_unregister(&srv->dev);

		goto unlock;

	}

	dev_set_uevent_suppress(&srv->dev, false);

	kobject_uevent(&srv->dev.kobj, KOBJ_ADD);

	goto unlock;

put:

	put_device(&srv->dev);

unlock:

	mutex_unlock(&srv->paths_mutex);

	return err;

}

static void

rtrs_srv_destroy_once_sysfs_root_folders(struct rtrs_srv_sess *sess)

{

	struct rtrs_srv *srv = sess->srv;

	mutex_lock(&srv->paths_mutex);

	if (!--srv->dev_ref) {

		kobject_del(srv->kobj_paths);

		kobject_put(srv->kobj_paths);

		mutex_unlock(&srv->paths_mutex);

		device_unregister(&srv->dev);

	} else {

		mutex_unlock(&srv->paths_mutex);

	}

}

static void rtrs_srv_sess_stats_release(struct kobject *kobj)

{

	struct rtrs_srv_stats *stats;

	stats = container_of(kobj, struct rtrs_srv_stats, kobj_stats);

	kfree(stats);

}

static struct kobj_type ktype_stats = {

	.sysfs_ops = &kobj_sysfs_ops,

	.release = rtrs_srv_sess_stats_release,

};

static int rtrs_srv_create_stats_files(struct rtrs_srv_sess *sess)

{

	int err;

	struct rtrs_sess *s = &sess->s;

	err = kobject_init_and_add(&sess->stats->kobj_stats, &ktype_stats,

				   &sess->kobj, "stats");

	if (err) {

		rtrs_err(s, "kobject_init_and_add(): %d\n", err);

		return err;

	}

	err = sysfs_create_group(&sess->stats->kobj_stats,

				 &rtrs_srv_stats_attr_group);

	if (err) {

		rtrs_err(s, "sysfs_create_group(): %d\n", err);

		goto err;

	}

	return 0;

err:

	kobject_del(&sess->stats->kobj_stats);

	kobject_put(&sess->stats->kobj_stats);

	return err;

}

int rtrs_srv_create_sess_files(struct rtrs_srv_sess *sess)

{

	struct rtrs_srv *srv = sess->srv;

	struct rtrs_sess *s = &sess->s;

	char str[NAME_MAX];

	int err, cnt;

	cnt = sockaddr_to_str((struct sockaddr *)&sess->s.dst_addr,

			      str, sizeof(str));

	cnt += scnprintf(str + cnt, sizeof(str) - cnt, "@");

	sockaddr_to_str((struct sockaddr *)&sess->s.src_addr,

			str + cnt, sizeof(str) - cnt);

	err = rtrs_srv_create_once_sysfs_root_folders(sess);

	if (err)

		return err;

	err = kobject_init_and_add(&sess->kobj, &ktype, srv->kobj_paths,

				   "%s", str);

	if (err) {

		rtrs_err(s, "kobject_init_and_add(): %d\n", err);

		goto destroy_root;

	}

	err = sysfs_create_group(&sess->kobj, &rtrs_srv_sess_attr_group);

	if (err) {

		rtrs_err(s, "sysfs_create_group(): %d\n", err);

		goto put_kobj;

	}

	err = rtrs_srv_create_stats_files(sess);

	if (err)

		goto remove_group;

	return 0;

remove_group:

	sysfs_remove_group(&sess->kobj, &rtrs_srv_sess_attr_group);

put_kobj:

	kobject_del(&sess->kobj);

	kobject_put(&sess->kobj);

destroy_root:

	rtrs_srv_destroy_once_sysfs_root_folders(sess);

	return err;

}

void rtrs_srv_destroy_sess_files(struct rtrs_srv_sess *sess)

{

	if (sess->kobj.state_in_sysfs) {

		kobject_del(&sess->stats->kobj_stats);

		kobject_put(&sess->stats->kobj_stats);

		kobject_del(&sess->kobj);

		kobject_put(&sess->kobj);

		rtrs_srv_destroy_once_sysfs_root_folders(sess);

	}

}