// 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 *buf)
{
        return sysfs_emit(buf, "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);
        /* first remove sysfs itself to avoid deadlock */
        sysfs_remove_file_self(&sess->kobj, &attr->attr);
        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 sysfs_emit(page, "%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 sysfs_emit(page, "%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 len;

        sess = container_of(kobj, struct rtrs_srv_sess, kobj);
        len = sockaddr_to_str((struct sockaddr *)&sess->s.src_addr, page,
                              PAGE_SIZE);
        len += sysfs_emit_at(page, len, "\n");
        return len;
}

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 const 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 const struct attribute_group rtrs_srv_stats_attr_group = {
        .attrs = rtrs_srv_stats_attrs,
};

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;
        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_add(&srv->dev);
        if (err) {
                pr_err("device_add(): %d\n", err);
                put_device(&srv->dev);
                goto unlock;
        }
        srv->kobj_paths = kobject_create_and_add("paths", &srv->dev.kobj);
        if (!srv->kobj_paths) {
                err = -ENOMEM;
                pr_err("kobject_create_and_add(): %d\n", err);
                device_del(&srv->dev);
                put_device(&srv->dev);
                goto unlock;
        }
        dev_set_uevent_suppress(&srv->dev, false);
        kobject_uevent(&srv->dev.kobj, KOBJ_ADD);
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_del(&srv->dev);
                put_device(&srv->dev);
        } else {
                put_device(&srv->dev);
                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);
                kobject_put(&sess->stats->kobj_stats);
                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;
        struct rtrs_addr path = {
                .src = &sess->s.dst_addr,
                .dst = &sess->s.src_addr,
        };

        rtrs_addr_to_str(&path, str, sizeof(str));
        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);
destroy_root:
        kobject_put(&sess->kobj);
        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);
                sysfs_remove_group(&sess->kobj, &rtrs_srv_sess_attr_group);
                kobject_put(&sess->kobj);

                rtrs_srv_destroy_once_sysfs_root_folders(sess);
        }
}