/*
 * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <string.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/dhcp.h>
#include <ipxe/dhcpopts.h>
#include <ipxe/settings.h>
#include <ipxe/device.h>
#include <ipxe/netdevice.h>
#include <ipxe/init.h>

/** @file
 *
 * Network device configuration settings
 *
 */

/** Network device predefined settings */
const struct setting mac_setting __setting ( SETTING_NETDEV, mac ) = {
	.name = "mac",
	.description = "MAC address",
	.type = &setting_type_hex,
};
const struct setting hwaddr_setting __setting ( SETTING_NETDEV, hwaddr ) = {
	.name = "hwaddr",
	.description = "Hardware address",
	.type = &setting_type_hex,
};
const struct setting bustype_setting __setting ( SETTING_NETDEV, bustype ) = {
	.name = "bustype",
	.description = "Bus type",
	.type = &setting_type_string,
};
const struct setting busloc_setting __setting ( SETTING_NETDEV, busloc ) = {
	.name = "busloc",
	.description = "Bus location",
	.type = &setting_type_uint32,
};
const struct setting busid_setting __setting ( SETTING_NETDEV, busid ) = {
	.name = "busid",
	.description = "Bus ID",
	.type = &setting_type_hex,
};
const struct setting chip_setting __setting ( SETTING_NETDEV, chip ) = {
	.name = "chip",
	.description = "Chip",
	.type = &setting_type_string,
};
const struct setting ifname_setting __setting ( SETTING_NETDEV, ifname ) = {
	.name = "ifname",
	.description = "Interface name",
	.type = &setting_type_string,
};
const struct setting mtu_setting __setting ( SETTING_NETDEV, mtu ) = {
	.name = "mtu",
	.description = "MTU",
	.type = &setting_type_int16,
	.tag = DHCP_MTU,
};

/**
 * Store link-layer address setting
 *
 * @v netdev		Network device
 * @v data		Setting data, or NULL to clear setting
 * @v len		Length of setting data
 * @ret rc		Return status code
 */
static int netdev_store_mac ( struct net_device *netdev,
			      const void *data, size_t len ) {
	struct ll_protocol *ll_protocol = netdev->ll_protocol;

	/* Record new MAC address */
	if ( data ) {
		if ( len != netdev->ll_protocol->ll_addr_len )
			return -EINVAL;
		memcpy ( netdev->ll_addr, data, len );
	} else {
		/* Reset MAC address if clearing setting */
		ll_protocol->init_addr ( netdev->hw_addr, netdev->ll_addr );
	}

	return 0;
}

/**
 * Fetch link-layer address setting
 *
 * @v netdev		Network device
 * @v data		Buffer to fill with setting data
 * @v len		Length of buffer
 * @ret len		Length of setting data, or negative error
 */
static int netdev_fetch_mac ( struct net_device *netdev, void *data,
			      size_t len ) {
	size_t max_len = netdev->ll_protocol->ll_addr_len;

	if ( len > max_len )
		len = max_len;
	memcpy ( data, netdev->ll_addr, len );
	return max_len;
}

/**
 * Fetch hardware address setting
 *
 * @v netdev		Network device
 * @v data		Buffer to fill with setting data
 * @v len		Length of buffer
 * @ret len		Length of setting data, or negative error
 */
static int netdev_fetch_hwaddr ( struct net_device *netdev, void *data,
				 size_t len ) {
	size_t max_len = netdev->ll_protocol->hw_addr_len;

	if ( len > max_len )
		len = max_len;
	memcpy ( data, netdev->hw_addr, len );
	return max_len;
}

/**
 * Fetch bus type setting
 *
 * @v netdev		Network device
 * @v data		Buffer to fill with setting data
 * @v len		Length of buffer
 * @ret len		Length of setting data, or negative error
 */
static int netdev_fetch_bustype ( struct net_device *netdev, void *data,
				  size_t len ) {
	static const char *bustypes[] = {
		[BUS_TYPE_PCI] = "PCI",
		[BUS_TYPE_ISAPNP] = "ISAPNP",
		[BUS_TYPE_EISA] = "EISA",
		[BUS_TYPE_MCA] = "MCA",
		[BUS_TYPE_ISA] = "ISA",
		[BUS_TYPE_TAP] = "TAP",
		[BUS_TYPE_EFI] = "EFI",
		[BUS_TYPE_XEN] = "XEN",
		[BUS_TYPE_HV] = "HV",
		[BUS_TYPE_USB] = "USB",
	};
	struct device_description *desc = &netdev->dev->desc;
	const char *bustype;

	assert ( desc->bus_type < ( sizeof ( bustypes ) /
				    sizeof ( bustypes[0] ) ) );
	bustype = bustypes[desc->bus_type];
	if ( ! bustype )
		return -ENOENT;
	strncpy ( data, bustype, len );
	return strlen ( bustype );
}

/**
 * Fetch bus location setting
 *
 * @v netdev		Network device
 * @v data		Buffer to fill with setting data
 * @v len		Length of buffer
 * @ret len		Length of setting data, or negative error
 */
static int netdev_fetch_busloc ( struct net_device *netdev, void *data,
				 size_t len ) {
	struct device_description *desc = &netdev->dev->desc;
	uint32_t busloc;

	busloc = cpu_to_be32 ( desc->location );
	if ( len > sizeof ( busloc ) )
		len = sizeof ( busloc );
	memcpy ( data, &busloc, len );
	return sizeof ( busloc );
}

/**
 * Fetch bus ID setting
 *
 * @v netdev		Network device
 * @v data		Buffer to fill with setting data
 * @v len		Length of buffer
 * @ret len		Length of setting data, or negative error
 */
static int netdev_fetch_busid ( struct net_device *netdev, void *data,
				size_t len ) {
	struct device_description *desc = &netdev->dev->desc;
	struct dhcp_netdev_desc dhcp_desc;

	dhcp_desc.type = desc->bus_type;
	dhcp_desc.vendor = htons ( desc->vendor );
	dhcp_desc.device = htons ( desc->device );
	if ( len > sizeof ( dhcp_desc ) )
		len = sizeof ( dhcp_desc );
	memcpy ( data, &dhcp_desc, len );
	return sizeof ( dhcp_desc );
}

/**
 * Fetch chip setting
 *
 * @v netdev		Network device
 * @v data		Buffer to fill with setting data
 * @v len		Length of buffer
 * @ret len		Length of setting data, or negative error
 */
static int netdev_fetch_chip ( struct net_device *netdev, void *data,
			       size_t len ) {
	const char *chip = netdev->dev->driver_name;

	strncpy ( data, chip, len );
	return strlen ( chip );
}

/**
 * Fetch ifname setting
 *
 * @v netdev		Network device
 * @v data		Buffer to fill with setting data
 * @v len		Length of buffer
 * @ret len		Length of setting data, or negative error
 */
static int netdev_fetch_ifname ( struct net_device *netdev, void *data,
				 size_t len ) {
	const char *ifname = netdev->name;

	strncpy ( data, ifname, len );
	return strlen ( ifname );
}

/** A network device setting operation */
struct netdev_setting_operation {
	/** Setting */
	const struct setting *setting;
	/** Store setting (or NULL if not supported)
	 *
	 * @v netdev		Network device
	 * @v data		Setting data, or NULL to clear setting
	 * @v len		Length of setting data
	 * @ret rc		Return status code
	 */
	int ( * store ) ( struct net_device *netdev, const void *data,
			  size_t len );
	/** Fetch setting
	 *
	 * @v netdev		Network device
	 * @v data		Buffer to fill with setting data
	 * @v len		Length of buffer
	 * @ret len		Length of setting data, or negative error
	 */
	int ( * fetch ) ( struct net_device *netdev, void *data, size_t len );
};

/** Network device settings */
static struct netdev_setting_operation netdev_setting_operations[] = {
	{ &mac_setting, netdev_store_mac, netdev_fetch_mac },
	{ &hwaddr_setting, NULL, netdev_fetch_hwaddr },
	{ &bustype_setting, NULL, netdev_fetch_bustype },
	{ &busloc_setting, NULL, netdev_fetch_busloc },
	{ &busid_setting, NULL, netdev_fetch_busid },
	{ &chip_setting, NULL, netdev_fetch_chip },
	{ &ifname_setting, NULL, netdev_fetch_ifname },
};

/**
 * Store value of network device setting
 *
 * @v settings		Settings block
 * @v setting		Setting to store
 * @v data		Setting data, or NULL to clear setting
 * @v len		Length of setting data
 * @ret rc		Return status code
 */
static int netdev_store ( struct settings *settings,
			  const struct setting *setting,
			  const void *data, size_t len ) {
	struct net_device *netdev = container_of ( settings, struct net_device,
						   settings.settings );
	struct netdev_setting_operation *op;
	unsigned int i;

	/* Handle network device-specific settings */
	for ( i = 0 ; i < ( sizeof ( netdev_setting_operations ) /
			    sizeof ( netdev_setting_operations[0] ) ) ; i++ ) {
		op = &netdev_setting_operations[i];
		if ( setting_cmp ( setting, op->setting ) == 0 ) {
			if ( op->store ) {
				return op->store ( netdev, data, len );
			} else {
				return -ENOTSUP;
			}
		}
	}

	return generic_settings_store ( settings, setting, data, len );
}

/**
 * Fetch value of network device setting
 *
 * @v settings		Settings block
 * @v setting		Setting to fetch
 * @v data		Buffer to fill with setting data
 * @v len		Length of buffer
 * @ret len		Length of setting data, or negative error
 */
static int netdev_fetch ( struct settings *settings, struct setting *setting,
			  void *data, size_t len ) {
	struct net_device *netdev = container_of ( settings, struct net_device,
						   settings.settings );
	struct netdev_setting_operation *op;
	unsigned int i;

	/* Handle network device-specific settings */
	for ( i = 0 ; i < ( sizeof ( netdev_setting_operations ) /
			    sizeof ( netdev_setting_operations[0] ) ) ; i++ ) {
		op = &netdev_setting_operations[i];
		if ( setting_cmp ( setting, op->setting ) == 0 )
			return op->fetch ( netdev, data, len );
	}

	return generic_settings_fetch ( settings, setting, data, len );
}

/**
 * Clear network device settings
 *
 * @v settings		Settings block
 */
static void netdev_clear ( struct settings *settings ) {
	generic_settings_clear ( settings );
}

/** Network device configuration settings operations */
struct settings_operations netdev_settings_operations = {
	.store = netdev_store,
	.fetch = netdev_fetch,
	.clear = netdev_clear,
};

/**
 * Redirect "netX" settings block
 *
 * @v settings		Settings block
 * @ret settings	Underlying settings block
 */
static struct settings * netdev_redirect ( struct settings *settings ) {
	struct net_device *netdev;

	/* Redirect to "netX" network device */
	netdev = find_netdev ( settings->name );
	if ( netdev ) {
		return netdev_settings ( netdev );
	} else {
		return settings;
	}
}

/** "netX" settings operations */
static struct settings_operations netdev_redirect_settings_operations = {
	.redirect = netdev_redirect,
};

/** "netX" settings */
static struct settings netdev_redirect_settings = {
	.refcnt = NULL,
	.siblings = LIST_HEAD_INIT ( netdev_redirect_settings.siblings ),
	.children = LIST_HEAD_INIT ( netdev_redirect_settings.children ),
	.op = &netdev_redirect_settings_operations,
};

/** Initialise "netX" settings */
static void netdev_redirect_settings_init ( void ) {
	int rc;

	if ( ( rc = register_settings ( &netdev_redirect_settings, NULL,
					"netX" ) ) != 0 ) {
		DBG ( "Could not register netX settings: %s\n",
		      strerror ( rc ) );
		return;
	}
}

/** "netX" settings initialiser */
struct init_fn netdev_redirect_settings_init_fn __init_fn ( INIT_LATE ) = {
	.initialise = netdev_redirect_settings_init,
};

/**
 * Apply network device settings
 *
 * @ret rc		Return status code
 */
static int apply_netdev_settings ( void ) {
	struct net_device *netdev;
	struct settings *settings;
	struct ll_protocol *ll_protocol;
	size_t max_mtu;
	size_t old_mtu;
	size_t mtu;
	int rc;

	/* Process settings for each network device */
	for_each_netdev ( netdev ) {

		/* Get network device settings */
		settings = netdev_settings ( netdev );

		/* Get MTU */
		mtu = fetch_uintz_setting ( settings, &mtu_setting );

		/* Do nothing unless MTU is specified */
		if ( ! mtu )
			continue;

		/* Limit MTU to maximum supported by hardware */
		ll_protocol = netdev->ll_protocol;
		max_mtu = ( netdev->max_pkt_len - ll_protocol->ll_header_len );
		if ( mtu > max_mtu ) {
			DBGC ( netdev, "NETDEV %s cannot support MTU %zd (max "
			       "%zd)\n", netdev->name, mtu, max_mtu );
			mtu = max_mtu;
		}

		/* Update maximum packet length */
		old_mtu = netdev->mtu;
		netdev->mtu = mtu;
		if ( mtu != old_mtu ) {
			DBGC ( netdev, "NETDEV %s MTU is %zd\n",
			       netdev->name, mtu );
		}

		/* Reset network device if MTU has increased */
		if ( netdev_is_open ( netdev ) && ( mtu > old_mtu ) ) {
			if ( ( rc = netdev_reset ( netdev ) ) != 0 ) {
				DBGC ( netdev, "NETDEV %s could not reset: "
				       "%s\n", netdev->name, strerror ( rc ) );
				return rc;
			}
		}
	}

	return 0;
}

/** Network device settings applicator */
struct settings_applicator netdev_applicator __settings_applicator = {
	.apply = apply_netdev_settings,
};