// 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-clt.h"
#include "rtrs-log.h"

#define MIN_MAX_RECONN_ATT -1
#define MAX_MAX_RECONN_ATT 9999

static void rtrs_clt_sess_release(struct kobject *kobj)
{
	struct rtrs_clt_sess *sess;

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

	free_sess(sess);
}

static struct kobj_type ktype_sess = {
	.sysfs_ops = &kobj_sysfs_ops,
	.release = rtrs_clt_sess_release
};

static void rtrs_clt_sess_stats_release(struct kobject *kobj)
{
	struct rtrs_clt_stats *stats;

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

	free_percpu(stats->pcpu_stats);

	kfree(stats);
}

static struct kobj_type ktype_stats = {
	.sysfs_ops = &kobj_sysfs_ops,
	.release = rtrs_clt_sess_stats_release,
};

static ssize_t max_reconnect_attempts_show(struct device *dev,
					   struct device_attribute *attr,
					   char *page)
{
	struct rtrs_clt *clt = container_of(dev, struct rtrs_clt, dev);

	return sysfs_emit(page, "%d\n",
			  rtrs_clt_get_max_reconnect_attempts(clt));
}

static ssize_t max_reconnect_attempts_store(struct device *dev,
					    struct device_attribute *attr,
					    const char *buf,
					    size_t count)
{
	int value;
	int ret;
	struct rtrs_clt *clt  = container_of(dev, struct rtrs_clt, dev);

	ret = kstrtoint(buf, 10, &value);
	if (ret) {
		rtrs_err(clt, "%s: failed to convert string '%s' to int\n",
			  attr->attr.name, buf);
		return ret;
	}
	if (value > MAX_MAX_RECONN_ATT ||
		     value < MIN_MAX_RECONN_ATT) {
		rtrs_err(clt,
			  "%s: invalid range (provided: '%s', accepted: min: %d, max: %d)\n",
			  attr->attr.name, buf, MIN_MAX_RECONN_ATT,
			  MAX_MAX_RECONN_ATT);
		return -EINVAL;
	}
	rtrs_clt_set_max_reconnect_attempts(clt, value);

	return count;
}

static DEVICE_ATTR_RW(max_reconnect_attempts);

static ssize_t mpath_policy_show(struct device *dev,
				 struct device_attribute *attr,
				 char *page)
{
	struct rtrs_clt *clt;

	clt = container_of(dev, struct rtrs_clt, dev);

	switch (clt->mp_policy) {
	case MP_POLICY_RR:
		return sysfs_emit(page, "round-robin (RR: %d)\n",
				  clt->mp_policy);
	case MP_POLICY_MIN_INFLIGHT:
		return sysfs_emit(page, "min-inflight (MI: %d)\n",
				  clt->mp_policy);
	case MP_POLICY_MIN_LATENCY:
		return sysfs_emit(page, "min-latency (ML: %d)\n",
				  clt->mp_policy);
	default:
		return sysfs_emit(page, "Unknown (%d)\n", clt->mp_policy);
	}
}

static ssize_t mpath_policy_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf,
				  size_t count)
{
	struct rtrs_clt *clt;
	int value;
	int ret;
	size_t len = 0;

	clt = container_of(dev, struct rtrs_clt, dev);

	ret = kstrtoint(buf, 10, &value);
	if (!ret && (value == MP_POLICY_RR ||
		     value == MP_POLICY_MIN_INFLIGHT ||
		     value == MP_POLICY_MIN_LATENCY)) {
		clt->mp_policy = value;
		return count;
	}

	/* distinguish "mi" and "min-latency" with length */
	len = strnlen(buf, NAME_MAX);
	if (buf[len - 1] == '\n')
		len--;

	if (!strncasecmp(buf, "round-robin", 11) ||
	    (len == 2 && !strncasecmp(buf, "rr", 2)))
		clt->mp_policy = MP_POLICY_RR;
	else if (!strncasecmp(buf, "min-inflight", 12) ||
		 (len == 2 && !strncasecmp(buf, "mi", 2)))
		clt->mp_policy = MP_POLICY_MIN_INFLIGHT;
	else if (!strncasecmp(buf, "min-latency", 11) ||
		 (len == 2 && !strncasecmp(buf, "ml", 2)))
		clt->mp_policy = MP_POLICY_MIN_LATENCY;
	else
		return -EINVAL;

	return count;
}

static DEVICE_ATTR_RW(mpath_policy);

static ssize_t add_path_show(struct device *dev,
			     struct device_attribute *attr, char *page)
{
	return sysfs_emit(
		page,
		"Usage: echo [<source addr>@]<destination addr> > %s\n\n*addr ::= [ ip:<ipv4|ipv6> | gid:<gid> ]\n",
		attr->attr.name);
}

static ssize_t add_path_store(struct device *dev,
			      struct device_attribute *attr,
			      const char *buf, size_t count)
{
	struct sockaddr_storage srcaddr, dstaddr;
	struct rtrs_addr addr = {
		.src = &srcaddr,
		.dst = &dstaddr
	};
	struct rtrs_clt *clt;
	const char *nl;
	size_t len;
	int err;

	clt = container_of(dev, struct rtrs_clt, dev);

	nl = strchr(buf, '\n');
	if (nl)
		len = nl - buf;
	else
		len = count;
	err = rtrs_addr_to_sockaddr(buf, len, clt->port, &addr);
	if (err)
		return -EINVAL;

	err = rtrs_clt_create_path_from_sysfs(clt, &addr);
	if (err)
		return err;

	return count;
}

static DEVICE_ATTR_RW(add_path);

static ssize_t rtrs_clt_state_show(struct kobject *kobj,
				    struct kobj_attribute *attr, char *page)
{
	struct rtrs_clt_sess *sess;

	sess = container_of(kobj, struct rtrs_clt_sess, kobj);
	if (sess->state == RTRS_CLT_CONNECTED)
		return sysfs_emit(page, "connected\n");

	return sysfs_emit(page, "disconnected\n");
}

static struct kobj_attribute rtrs_clt_state_attr =
	__ATTR(state, 0444, rtrs_clt_state_show, NULL);

static ssize_t rtrs_clt_reconnect_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_clt_reconnect_store(struct kobject *kobj,
					 struct kobj_attribute *attr,
					 const char *buf, size_t count)
{
	struct rtrs_clt_sess *sess;
	int ret;

	sess = container_of(kobj, struct rtrs_clt_sess, kobj);
	if (!sysfs_streq(buf, "1")) {
		rtrs_err(sess->clt, "%s: unknown value: '%s'\n",
			  attr->attr.name, buf);
		return -EINVAL;
	}
	ret = rtrs_clt_reconnect_from_sysfs(sess);
	if (ret)
		return ret;

	return count;
}

static struct kobj_attribute rtrs_clt_reconnect_attr =
	__ATTR(reconnect, 0644, rtrs_clt_reconnect_show,
	       rtrs_clt_reconnect_store);

static ssize_t rtrs_clt_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_clt_disconnect_store(struct kobject *kobj,
					  struct kobj_attribute *attr,
					  const char *buf, size_t count)
{
	struct rtrs_clt_sess *sess;
	int ret;

	sess = container_of(kobj, struct rtrs_clt_sess, kobj);
	if (!sysfs_streq(buf, "1")) {
		rtrs_err(sess->clt, "%s: unknown value: '%s'\n",
			  attr->attr.name, buf);
		return -EINVAL;
	}
	ret = rtrs_clt_disconnect_from_sysfs(sess);
	if (ret)
		return ret;

	return count;
}

static struct kobj_attribute rtrs_clt_disconnect_attr =
	__ATTR(disconnect, 0644, rtrs_clt_disconnect_show,
	       rtrs_clt_disconnect_store);

static ssize_t rtrs_clt_remove_path_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_clt_remove_path_store(struct kobject *kobj,
					   struct kobj_attribute *attr,
					   const char *buf, size_t count)
{
	struct rtrs_clt_sess *sess;
	int ret;

	sess = container_of(kobj, struct rtrs_clt_sess, kobj);
	if (!sysfs_streq(buf, "1")) {
		rtrs_err(sess->clt, "%s: unknown value: '%s'\n",
			  attr->attr.name, buf);
		return -EINVAL;
	}
	ret = rtrs_clt_remove_path_from_sysfs(sess, &attr->attr);
	if (ret)
		return ret;

	return count;
}

static struct kobj_attribute rtrs_clt_remove_path_attr =
	__ATTR(remove_path, 0644, rtrs_clt_remove_path_show,
	       rtrs_clt_remove_path_store);

STAT_ATTR(struct rtrs_clt_stats, cpu_migration,
	  rtrs_clt_stats_migration_cnt_to_str,
	  rtrs_clt_reset_cpu_migr_stats);

STAT_ATTR(struct rtrs_clt_stats, reconnects,
	  rtrs_clt_stats_reconnects_to_str,
	  rtrs_clt_reset_reconnects_stat);

STAT_ATTR(struct rtrs_clt_stats, rdma,
	  rtrs_clt_stats_rdma_to_str,
	  rtrs_clt_reset_rdma_stats);

STAT_ATTR(struct rtrs_clt_stats, reset_all,
	  rtrs_clt_reset_all_help,
	  rtrs_clt_reset_all_stats);

static struct attribute *rtrs_clt_stats_attrs[] = {
	&cpu_migration_attr.attr,
	&reconnects_attr.attr,
	&rdma_attr.attr,
	&reset_all_attr.attr,
	NULL
};

static const struct attribute_group rtrs_clt_stats_attr_group = {
	.attrs = rtrs_clt_stats_attrs,
};

static ssize_t rtrs_clt_hca_port_show(struct kobject *kobj,
				       struct kobj_attribute *attr,
				       char *page)
{
	struct rtrs_clt_sess *sess;

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

	return sysfs_emit(page, "%u\n", sess->hca_port);
}

static struct kobj_attribute rtrs_clt_hca_port_attr =
	__ATTR(hca_port, 0444, rtrs_clt_hca_port_show, NULL);

static ssize_t rtrs_clt_hca_name_show(struct kobject *kobj,
				       struct kobj_attribute *attr,
				       char *page)
{
	struct rtrs_clt_sess *sess;

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

	return sysfs_emit(page, "%s\n", sess->hca_name);
}

static struct kobj_attribute rtrs_clt_hca_name_attr =
	__ATTR(hca_name, 0444, rtrs_clt_hca_name_show, NULL);

static ssize_t rtrs_clt_cur_latency_show(struct kobject *kobj,
				    struct kobj_attribute *attr,
				    char *page)
{
	struct rtrs_clt_sess *sess;

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

	return sysfs_emit(page, "%lld ns\n",
			  ktime_to_ns(sess->s.hb_cur_latency));
}

static struct kobj_attribute rtrs_clt_cur_latency_attr =
	__ATTR(cur_latency, 0444, rtrs_clt_cur_latency_show, NULL);

static ssize_t rtrs_clt_src_addr_show(struct kobject *kobj,
				       struct kobj_attribute *attr,
				       char *page)
{
	struct rtrs_clt_sess *sess;
	int len;

	sess = container_of(kobj, struct rtrs_clt_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_clt_src_addr_attr =
	__ATTR(src_addr, 0444, rtrs_clt_src_addr_show, NULL);

static ssize_t rtrs_clt_dst_addr_show(struct kobject *kobj,
				       struct kobj_attribute *attr,
				       char *page)
{
	struct rtrs_clt_sess *sess;
	int len;

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

static struct kobj_attribute rtrs_clt_dst_addr_attr =
	__ATTR(dst_addr, 0444, rtrs_clt_dst_addr_show, NULL);

static struct attribute *rtrs_clt_sess_attrs[] = {
	&rtrs_clt_hca_name_attr.attr,
	&rtrs_clt_hca_port_attr.attr,
	&rtrs_clt_src_addr_attr.attr,
	&rtrs_clt_dst_addr_attr.attr,
	&rtrs_clt_state_attr.attr,
	&rtrs_clt_reconnect_attr.attr,
	&rtrs_clt_disconnect_attr.attr,
	&rtrs_clt_remove_path_attr.attr,
	&rtrs_clt_cur_latency_attr.attr,
	NULL,
};

static const struct attribute_group rtrs_clt_sess_attr_group = {
	.attrs = rtrs_clt_sess_attrs,
};

int rtrs_clt_create_sess_files(struct rtrs_clt_sess *sess)
{
	struct rtrs_clt *clt = sess->clt;
	char str[NAME_MAX];
	int err;
	struct rtrs_addr path = {
		.src = &sess->s.src_addr,
		.dst = &sess->s.dst_addr,
	};

	rtrs_addr_to_str(&path, str, sizeof(str));
	err = kobject_init_and_add(&sess->kobj, &ktype_sess, clt->kobj_paths,
				   "%s", str);
	if (err) {
		pr_err("kobject_init_and_add: %d\n", err);
		kobject_put(&sess->kobj);
		return err;
	}
	err = sysfs_create_group(&sess->kobj, &rtrs_clt_sess_attr_group);
	if (err) {
		pr_err("sysfs_create_group(): %d\n", err);
		goto put_kobj;
	}
	err = kobject_init_and_add(&sess->stats->kobj_stats, &ktype_stats,
				   &sess->kobj, "stats");
	if (err) {
		pr_err("kobject_init_and_add: %d\n", err);
		kobject_put(&sess->stats->kobj_stats);
		goto remove_group;
	}

	err = sysfs_create_group(&sess->stats->kobj_stats,
				 &rtrs_clt_stats_attr_group);
	if (err) {
		pr_err("failed to create stats sysfs group, err: %d\n", err);
		goto put_kobj_stats;
	}

	return 0;

put_kobj_stats:
	kobject_del(&sess->stats->kobj_stats);
	kobject_put(&sess->stats->kobj_stats);
remove_group:
	sysfs_remove_group(&sess->kobj, &rtrs_clt_sess_attr_group);
put_kobj:
	kobject_del(&sess->kobj);
	kobject_put(&sess->kobj);

	return err;
}

void rtrs_clt_destroy_sess_files(struct rtrs_clt_sess *sess,
				  const struct attribute *sysfs_self)
{
	kobject_del(&sess->stats->kobj_stats);
	kobject_put(&sess->stats->kobj_stats);
	if (sysfs_self)
		sysfs_remove_file_self(&sess->kobj, sysfs_self);
	kobject_del(&sess->kobj);
}

static struct attribute *rtrs_clt_attrs[] = {
	&dev_attr_max_reconnect_attempts.attr,
	&dev_attr_mpath_policy.attr,
	&dev_attr_add_path.attr,
	NULL,
};

static const struct attribute_group rtrs_clt_attr_group = {
	.attrs = rtrs_clt_attrs,
};

int rtrs_clt_create_sysfs_root_files(struct rtrs_clt *clt)
{
	return sysfs_create_group(&clt->dev.kobj, &rtrs_clt_attr_group);
}

void rtrs_clt_destroy_sysfs_root(struct rtrs_clt *clt)
{
	sysfs_remove_group(&clt->dev.kobj, &rtrs_clt_attr_group);

	if (clt->kobj_paths) {
		kobject_del(clt->kobj_paths);
		kobject_put(clt->kobj_paths);
	}
}