// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2023 Bootlin
 *
 */
#include "common.h"
#include "netlink.h"

#include <linux/phy.h>
#include <linux/phy_link_topology.h>
#include <linux/sfp.h>

struct phy_req_info {
	struct ethnl_req_info		base;
	struct phy_device_node		*pdn;
};

#define PHY_REQINFO(__req_base) \
	container_of(__req_base, struct phy_req_info, base)

const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1] = {
	[ETHTOOL_A_PHY_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
};

/* Caller holds rtnl */
static ssize_t
ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
		     struct netlink_ext_ack *extack)
{
	struct phy_req_info *req_info = PHY_REQINFO(req_base);
	struct phy_device_node *pdn = req_info->pdn;
	struct phy_device *phydev = pdn->phy;
	size_t size = 0;

	ASSERT_RTNL();

	/* ETHTOOL_A_PHY_INDEX */
	size += nla_total_size(sizeof(u32));

	/* ETHTOOL_A_DRVNAME */
	if (phydev->drv)
		size += nla_total_size(strlen(phydev->drv->name) + 1);

	/* ETHTOOL_A_NAME */
	size += nla_total_size(strlen(dev_name(&phydev->mdio.dev)) + 1);

	/* ETHTOOL_A_PHY_UPSTREAM_TYPE */
	size += nla_total_size(sizeof(u32));

	if (phy_on_sfp(phydev)) {
		const char *upstream_sfp_name = sfp_get_name(pdn->parent_sfp_bus);

		/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
		if (upstream_sfp_name)
			size += nla_total_size(strlen(upstream_sfp_name) + 1);

		/* ETHTOOL_A_PHY_UPSTREAM_INDEX */
		size += nla_total_size(sizeof(u32));
	}

	/* ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME */
	if (phydev->sfp_bus) {
		const char *sfp_name = sfp_get_name(phydev->sfp_bus);

		if (sfp_name)
			size += nla_total_size(strlen(sfp_name) + 1);
	}

	return size;
}

static int
ethnl_phy_fill_reply(const struct ethnl_req_info *req_base, struct sk_buff *skb)
{
	struct phy_req_info *req_info = PHY_REQINFO(req_base);
	struct phy_device_node *pdn = req_info->pdn;
	struct phy_device *phydev = pdn->phy;
	enum phy_upstream ptype;

	ptype = pdn->upstream_type;

	if (nla_put_u32(skb, ETHTOOL_A_PHY_INDEX, phydev->phyindex) ||
	    nla_put_string(skb, ETHTOOL_A_PHY_NAME, dev_name(&phydev->mdio.dev)) ||
	    nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_TYPE, ptype))
		return -EMSGSIZE;

	if (phydev->drv &&
	    nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, phydev->drv->name))
		return -EMSGSIZE;

	if (ptype == PHY_UPSTREAM_PHY) {
		struct phy_device *upstream = pdn->upstream.phydev;
		const char *sfp_upstream_name;

		/* Parent index */
		if (nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_INDEX, upstream->phyindex))
			return -EMSGSIZE;

		if (pdn->parent_sfp_bus) {
			sfp_upstream_name = sfp_get_name(pdn->parent_sfp_bus);
			if (sfp_upstream_name &&
			    nla_put_string(skb, ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,
					   sfp_upstream_name))
				return -EMSGSIZE;
		}
	}

	if (phydev->sfp_bus) {
		const char *sfp_name = sfp_get_name(phydev->sfp_bus);

		if (sfp_name &&
		    nla_put_string(skb, ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,
				   sfp_name))
			return -EMSGSIZE;
	}

	return 0;
}

static int ethnl_phy_parse_request(struct ethnl_req_info *req_base,
				   struct nlattr **tb,
				   struct netlink_ext_ack *extack)
{
	struct phy_link_topology *topo = req_base->dev->link_topo;
	struct phy_req_info *req_info = PHY_REQINFO(req_base);
	struct phy_device *phydev;

	phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_PHY_HEADER],
				      extack);
	if (!phydev)
		return 0;

	if (IS_ERR(phydev))
		return PTR_ERR(phydev);

	if (!topo)
		return 0;

	req_info->pdn = xa_load(&topo->phys, phydev->phyindex);

	return 0;
}

int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
{
	struct phy_req_info req_info = {};
	struct nlattr **tb = info->attrs;
	struct sk_buff *rskb;
	void *reply_payload;
	int reply_len;
	int ret;

	ret = ethnl_parse_header_dev_get(&req_info.base,
					 tb[ETHTOOL_A_PHY_HEADER],
					 genl_info_net(info), info->extack,
					 true);
	if (ret < 0)
		return ret;

	rtnl_lock();

	ret = ethnl_phy_parse_request(&req_info.base, tb, info->extack);
	if (ret < 0)
		goto err_unlock_rtnl;

	/* No PHY, return early */
	if (!req_info.pdn)
		goto err_unlock_rtnl;

	ret = ethnl_phy_reply_size(&req_info.base, info->extack);
	if (ret < 0)
		goto err_unlock_rtnl;
	reply_len = ret + ethnl_reply_header_size();

	rskb = ethnl_reply_init(reply_len, req_info.base.dev,
				ETHTOOL_MSG_PHY_GET_REPLY,
				ETHTOOL_A_PHY_HEADER,
				info, &reply_payload);
	if (!rskb) {
		ret = -ENOMEM;
		goto err_unlock_rtnl;
	}

	ret = ethnl_phy_fill_reply(&req_info.base, rskb);
	if (ret)
		goto err_free_msg;

	rtnl_unlock();
	ethnl_parse_header_dev_put(&req_info.base);
	genlmsg_end(rskb, reply_payload);

	return genlmsg_reply(rskb, info);

err_free_msg:
	nlmsg_free(rskb);
err_unlock_rtnl:
	rtnl_unlock();
	ethnl_parse_header_dev_put(&req_info.base);
	return ret;
}

struct ethnl_phy_dump_ctx {
	struct phy_req_info	*phy_req_info;
	unsigned long ifindex;
	unsigned long phy_index;
};

int ethnl_phy_start(struct netlink_callback *cb)
{
	const struct genl_info *info = genl_info_dump(cb);
	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
	int ret;

	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));

	ctx->phy_req_info = kzalloc(sizeof(*ctx->phy_req_info), GFP_KERNEL);
	if (!ctx->phy_req_info)
		return -ENOMEM;

	ret = ethnl_parse_header_dev_get(&ctx->phy_req_info->base,
					 info->attrs[ETHTOOL_A_PHY_HEADER],
					 sock_net(cb->skb->sk), cb->extack,
					 false);
	ctx->ifindex = 0;
	ctx->phy_index = 0;

	if (ret)
		kfree(ctx->phy_req_info);

	return ret;
}

int ethnl_phy_done(struct netlink_callback *cb)
{
	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;

	if (ctx->phy_req_info->base.dev)
		ethnl_parse_header_dev_put(&ctx->phy_req_info->base);

	kfree(ctx->phy_req_info);

	return 0;
}

static int ethnl_phy_dump_one_dev(struct sk_buff *skb, struct net_device *dev,
				  struct netlink_callback *cb)
{
	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
	struct phy_req_info *pri = ctx->phy_req_info;
	struct phy_device_node *pdn;
	int ret = 0;
	void *ehdr;

	if (!dev->link_topo)
		return 0;

	xa_for_each_start(&dev->link_topo->phys, ctx->phy_index, pdn, ctx->phy_index) {
		ehdr = ethnl_dump_put(skb, cb, ETHTOOL_MSG_PHY_GET_REPLY);
		if (!ehdr) {
			ret = -EMSGSIZE;
			break;
		}

		ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_PHY_HEADER);
		if (ret < 0) {
			genlmsg_cancel(skb, ehdr);
			break;
		}

		pri->pdn = pdn;
		ret = ethnl_phy_fill_reply(&pri->base, skb);
		if (ret < 0) {
			genlmsg_cancel(skb, ehdr);
			break;
		}

		genlmsg_end(skb, ehdr);
	}

	return ret;
}

int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
	struct net *net = sock_net(skb->sk);
	struct net_device *dev;
	int ret = 0;

	rtnl_lock();

	if (ctx->phy_req_info->base.dev) {
		ret = ethnl_phy_dump_one_dev(skb, ctx->phy_req_info->base.dev, cb);
	} else {
		for_each_netdev_dump(net, dev, ctx->ifindex) {
			ret = ethnl_phy_dump_one_dev(skb, dev, cb);
			if (ret)
				break;

			ctx->phy_index = 0;
		}
	}
	rtnl_unlock();

	return ret;
}