/* Intel Ethernet Switch Host Interface Driver
 * Copyright(c) 2013 - 2014 Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 * The full GNU General Public License is included in this distribution in
 * the file called "COPYING".
 *
 * Contact Information:
 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 */

#include "fm10k_tlv.h"

/**
 *  fm10k_tlv_msg_init - Initialize message block for TLV data storage
 *  @msg: Pointer to message block
 *  @msg_id: Message ID indicating message type
 *
 *  This function return success if provided with a valid message pointer
 **/
s32 fm10k_tlv_msg_init(u32 *msg, u16 msg_id)
{
	/* verify pointer is not NULL */
	if (!msg)
		return FM10K_ERR_PARAM;

	*msg = (FM10K_TLV_FLAGS_MSG << FM10K_TLV_FLAGS_SHIFT) | msg_id;

	return 0;
}

/**
 *  fm10k_tlv_attr_put_null_string - Place null terminated string on message
 *  @msg: Pointer to message block
 *  @attr_id: Attribute ID
 *  @string: Pointer to string to be stored in attribute
 *
 *  This function will reorder a string to be CPU endian and store it in
 *  the attribute buffer.  It will return success if provided with a valid
 *  pointers.
 **/
s32 fm10k_tlv_attr_put_null_string(u32 *msg, u16 attr_id,
				   const unsigned char *string)
{
	u32 attr_data = 0, len = 0;
	u32 *attr;

	/* verify pointers are not NULL */
	if (!string || !msg)
		return FM10K_ERR_PARAM;

	attr = &msg[FM10K_TLV_DWORD_LEN(*msg)];

	/* copy string into local variable and then write to msg */
	do {
		/* write data to message */
		if (len && !(len % 4)) {
			attr[len / 4] = attr_data;
			attr_data = 0;
		}

		/* record character to offset location */
		attr_data |= (u32)(*string) << (8 * (len % 4));
		len++;

		/* test for NULL and then increment */
	} while (*(string++));

	/* write last piece of data to message */
	attr[(len + 3) / 4] = attr_data;

	/* record attribute header, update message length */
	len <<= FM10K_TLV_LEN_SHIFT;
	attr[0] = len | attr_id;

	/* add header length to length */
	len += FM10K_TLV_HDR_LEN << FM10K_TLV_LEN_SHIFT;
	*msg += FM10K_TLV_LEN_ALIGN(len);

	return 0;
}

/**
 *  fm10k_tlv_attr_get_null_string - Get null terminated string from attribute
 *  @attr: Pointer to attribute
 *  @string: Pointer to location of destination string
 *
 *  This function pulls the string back out of the attribute and will place
 *  it in the array pointed by by string.  It will return success if provided
 *  with a valid pointers.
 **/
s32 fm10k_tlv_attr_get_null_string(u32 *attr, unsigned char *string)
{
	u32 len;

	/* verify pointers are not NULL */
	if (!string || !attr)
		return FM10K_ERR_PARAM;

	len = *attr >> FM10K_TLV_LEN_SHIFT;
	attr++;

	while (len--)
		string[len] = (u8)(attr[len / 4] >> (8 * (len % 4)));

	return 0;
}

/**
 *  fm10k_tlv_attr_put_mac_vlan - Store MAC/VLAN attribute in message
 *  @msg: Pointer to message block
 *  @attr_id: Attribute ID
 *  @mac_addr: MAC address to be stored
 *
 *  This function will reorder a MAC address to be CPU endian and store it
 *  in the attribute buffer.  It will return success if provided with a
 *  valid pointers.
 **/
s32 fm10k_tlv_attr_put_mac_vlan(u32 *msg, u16 attr_id,
				const u8 *mac_addr, u16 vlan)
{
	u32 len = ETH_ALEN << FM10K_TLV_LEN_SHIFT;
	u32 *attr;

	/* verify pointers are not NULL */
	if (!msg || !mac_addr)
		return FM10K_ERR_PARAM;

	attr = &msg[FM10K_TLV_DWORD_LEN(*msg)];

	/* record attribute header, update message length */
	attr[0] = len | attr_id;

	/* copy value into local variable and then write to msg */
	attr[1] = le32_to_cpu(*(const __le32 *)&mac_addr[0]);
	attr[2] = le16_to_cpu(*(const __le16 *)&mac_addr[4]);
	attr[2] |= (u32)vlan << 16;

	/* add header length to length */
	len += FM10K_TLV_HDR_LEN << FM10K_TLV_LEN_SHIFT;
	*msg += FM10K_TLV_LEN_ALIGN(len);

	return 0;
}

/**
 *  fm10k_tlv_attr_get_mac_vlan - Get MAC/VLAN stored in attribute
 *  @attr: Pointer to attribute
 *  @attr_id: Attribute ID
 *  @mac_addr: location of buffer to store MAC address
 *
 *  This function pulls the MAC address back out of the attribute and will
 *  place it in the array pointed by by mac_addr.  It will return success
 *  if provided with a valid pointers.
 **/
s32 fm10k_tlv_attr_get_mac_vlan(u32 *attr, u8 *mac_addr, u16 *vlan)
{
	/* verify pointers are not NULL */
	if (!mac_addr || !attr)
		return FM10K_ERR_PARAM;

	*(__le32 *)&mac_addr[0] = cpu_to_le32(attr[1]);
	*(__le16 *)&mac_addr[4] = cpu_to_le16((u16)(attr[2]));
	*vlan = (u16)(attr[2] >> 16);

	return 0;
}

/**
 *  fm10k_tlv_attr_put_bool - Add header indicating value "true"
 *  @msg: Pointer to message block
 *  @attr_id: Attribute ID
 *
 *  This function will simply add an attribute header, the fact
 *  that the header is here means the attribute value is true, else
 *  it is false.  The function will return success if provided with a
 *  valid pointers.
 **/
s32 fm10k_tlv_attr_put_bool(u32 *msg, u16 attr_id)
{
	/* verify pointers are not NULL */
	if (!msg)
		return FM10K_ERR_PARAM;

	/* record attribute header */
	msg[FM10K_TLV_DWORD_LEN(*msg)] = attr_id;

	/* add header length to length */
	*msg += FM10K_TLV_HDR_LEN << FM10K_TLV_LEN_SHIFT;

	return 0;
}

/**
 *  fm10k_tlv_attr_put_value - Store integer value attribute in message
 *  @msg: Pointer to message block
 *  @attr_id: Attribute ID
 *  @value: Value to be written
 *  @len: Size of value
 *
 *  This function will place an integer value of up to 8 bytes in size
 *  in a message attribute.  The function will return success provided
 *  that msg is a valid pointer, and len is 1, 2, 4, or 8.
 **/
s32 fm10k_tlv_attr_put_value(u32 *msg, u16 attr_id, s64 value, u32 len)
{
	u32 *attr;

	/* verify non-null msg and len is 1, 2, 4, or 8 */
	if (!msg || !len || len > 8 || (len & (len - 1)))
		return FM10K_ERR_PARAM;

	attr = &msg[FM10K_TLV_DWORD_LEN(*msg)];

	if (len < 4) {
		attr[1] = (u32)value & ((0x1ul << (8 * len)) - 1);
	} else {
		attr[1] = (u32)value;
		if (len > 4)
			attr[2] = (u32)(value >> 32);
	}

	/* record attribute header, update message length */
	len <<= FM10K_TLV_LEN_SHIFT;
	attr[0] = len | attr_id;

	/* add header length to length */
	len += FM10K_TLV_HDR_LEN << FM10K_TLV_LEN_SHIFT;
	*msg += FM10K_TLV_LEN_ALIGN(len);

	return 0;
}

/**
 *  fm10k_tlv_attr_get_value - Get integer value stored in attribute
 *  @attr: Pointer to attribute
 *  @value: Pointer to destination buffer
 *  @len: Size of value
 *
 *  This function will place an integer value of up to 8 bytes in size
 *  in the offset pointed to by value.  The function will return success
 *  provided that pointers are valid and the len value matches the
 *  attribute length.
 **/
s32 fm10k_tlv_attr_get_value(u32 *attr, void *value, u32 len)
{
	/* verify pointers are not NULL */
	if (!attr || !value)
		return FM10K_ERR_PARAM;

	if ((*attr >> FM10K_TLV_LEN_SHIFT) != len)
		return FM10K_ERR_PARAM;

	if (len == 8)
		*(u64 *)value = ((u64)attr[2] << 32) | attr[1];
	else if (len == 4)
		*(u32 *)value = attr[1];
	else if (len == 2)
		*(u16 *)value = (u16)attr[1];
	else
		*(u8 *)value = (u8)attr[1];

	return 0;
}

/**
 *  fm10k_tlv_attr_put_le_struct - Store little endian structure in message
 *  @msg: Pointer to message block
 *  @attr_id: Attribute ID
 *  @le_struct: Pointer to structure to be written
 *  @len: Size of le_struct
 *
 *  This function will place a little endian structure value in a message
 *  attribute.  The function will return success provided that all pointers
 *  are valid and length is a non-zero multiple of 4.
 **/
s32 fm10k_tlv_attr_put_le_struct(u32 *msg, u16 attr_id,
				 const void *le_struct, u32 len)
{
	const __le32 *le32_ptr = (const __le32 *)le_struct;
	u32 *attr;
	u32 i;

	/* verify non-null msg and len is in 32 bit words */
	if (!msg || !len || (len % 4))
		return FM10K_ERR_PARAM;

	attr = &msg[FM10K_TLV_DWORD_LEN(*msg)];

	/* copy le32 structure into host byte order at 32b boundaries */
	for (i = 0; i < (len / 4); i++)
		attr[i + 1] = le32_to_cpu(le32_ptr[i]);

	/* record attribute header, update message length */
	len <<= FM10K_TLV_LEN_SHIFT;
	attr[0] = len | attr_id;

	/* add header length to length */
	len += FM10K_TLV_HDR_LEN << FM10K_TLV_LEN_SHIFT;
	*msg += FM10K_TLV_LEN_ALIGN(len);

	return 0;
}

/**
 *  fm10k_tlv_attr_get_le_struct - Get little endian struct form attribute
 *  @attr: Pointer to attribute
 *  @le_struct: Pointer to structure to be written
 *  @len: Size of structure
 *
 *  This function will place a little endian structure in the buffer
 *  pointed to by le_struct.  The function will return success
 *  provided that pointers are valid and the len value matches the
 *  attribute length.
 **/
s32 fm10k_tlv_attr_get_le_struct(u32 *attr, void *le_struct, u32 len)
{
	__le32 *le32_ptr = (__le32 *)le_struct;
	u32 i;

	/* verify pointers are not NULL */
	if (!le_struct || !attr)
		return FM10K_ERR_PARAM;

	if ((*attr >> FM10K_TLV_LEN_SHIFT) != len)
		return FM10K_ERR_PARAM;

	attr++;

	for (i = 0; len; i++, len -= 4)
		le32_ptr[i] = cpu_to_le32(attr[i]);

	return 0;
}

/**
 *  fm10k_tlv_attr_nest_start - Start a set of nested attributes
 *  @msg: Pointer to message block
 *  @attr_id: Attribute ID
 *
 *  This function will mark off a new nested region for encapsulating
 *  a given set of attributes.  The idea is if you wish to place a secondary
 *  structure within the message this mechanism allows for that.  The
 *  function will return NULL on failure, and a pointer to the start
 *  of the nested attributes on success.
 **/
u32 *fm10k_tlv_attr_nest_start(u32 *msg, u16 attr_id)
{
	u32 *attr;

	/* verify pointer is not NULL */
	if (!msg)
		return NULL;

	attr = &msg[FM10K_TLV_DWORD_LEN(*msg)];

	attr[0] = attr_id;

	/* return pointer to nest header */
	return attr;
}

/**
 *  fm10k_tlv_attr_nest_start - Start a set of nested attributes
 *  @msg: Pointer to message block
 *
 *  This function closes off an existing set of nested attributes.  The
 *  message pointer should be pointing to the parent of the nest.  So in
 *  the case of a nest within the nest this would be the outer nest pointer.
 *  This function will return success provided all pointers are valid.
 **/
s32 fm10k_tlv_attr_nest_stop(u32 *msg)
{
	u32 *attr;
	u32 len;

	/* verify pointer is not NULL */
	if (!msg)
		return FM10K_ERR_PARAM;

	/* locate the nested header and retrieve its length */
	attr = &msg[FM10K_TLV_DWORD_LEN(*msg)];
	len = (attr[0] >> FM10K_TLV_LEN_SHIFT) << FM10K_TLV_LEN_SHIFT;

	/* only include nest if data was added to it */
	if (len) {
		len += FM10K_TLV_HDR_LEN << FM10K_TLV_LEN_SHIFT;
		*msg += len;
	}

	return 0;
}

/**
 *  fm10k_tlv_attr_validate - Validate attribute metadata
 *  @attr: Pointer to attribute
 *  @tlv_attr: Type and length info for attribute
 *
 *  This function does some basic validation of the input TLV.  It
 *  verifies the length, and in the case of null terminated strings
 *  it verifies that the last byte is null.  The function will
 *  return FM10K_ERR_PARAM if any attribute is malformed, otherwise
 *  it returns 0.
 **/
static s32 fm10k_tlv_attr_validate(u32 *attr,
				   const struct fm10k_tlv_attr *tlv_attr)
{
	u32 attr_id = *attr & FM10K_TLV_ID_MASK;
	u16 len = *attr >> FM10K_TLV_LEN_SHIFT;

	/* verify this is an attribute and not a message */
	if (*attr & (FM10K_TLV_FLAGS_MSG << FM10K_TLV_FLAGS_SHIFT))
		return FM10K_ERR_PARAM;

	/* search through the list of attributes to find a matching ID */
	while (tlv_attr->id < attr_id)
		tlv_attr++;

	/* if didn't find a match then we should exit */
	if (tlv_attr->id != attr_id)
		return FM10K_NOT_IMPLEMENTED;

	/* move to start of attribute data */
	attr++;

	switch (tlv_attr->type) {
	case FM10K_TLV_NULL_STRING:
		if (!len ||
		    (attr[(len - 1) / 4] & (0xFF << (8 * ((len - 1) % 4)))))
			return FM10K_ERR_PARAM;
		if (len > tlv_attr->len)
			return FM10K_ERR_PARAM;
		break;
	case FM10K_TLV_MAC_ADDR:
		if (len != ETH_ALEN)
			return FM10K_ERR_PARAM;
		break;
	case FM10K_TLV_BOOL:
		if (len)
			return FM10K_ERR_PARAM;
		break;
	case FM10K_TLV_UNSIGNED:
	case FM10K_TLV_SIGNED:
		if (len != tlv_attr->len)
			return FM10K_ERR_PARAM;
		break;
	case FM10K_TLV_LE_STRUCT:
		/* struct must be 4 byte aligned */
		if ((len % 4) || len != tlv_attr->len)
			return FM10K_ERR_PARAM;
		break;
	case FM10K_TLV_NESTED:
		/* nested attributes must be 4 byte aligned */
		if (len % 4)
			return FM10K_ERR_PARAM;
		break;
	default:
		/* attribute id is mapped to bad value */
		return FM10K_ERR_PARAM;
	}

	return 0;
}

/**
 *  fm10k_tlv_attr_parse - Parses stream of attribute data
 *  @attr: Pointer to attribute list
 *  @results: Pointer array to store pointers to attributes
 *  @tlv_attr: Type and length info for attributes
 *
 *  This function validates a stream of attributes and parses them
 *  up into an array of pointers stored in results.  The function will
 *  return FM10K_ERR_PARAM on any input or message error,
 *  FM10K_NOT_IMPLEMENTED for any attribute that is outside of the array
 *  and 0 on success.
 **/
s32 fm10k_tlv_attr_parse(u32 *attr, u32 **results,
			 const struct fm10k_tlv_attr *tlv_attr)
{
	u32 i, attr_id, offset = 0;
	s32 err = 0;
	u16 len;

	/* verify pointers are not NULL */
	if (!attr || !results)
		return FM10K_ERR_PARAM;

	/* initialize results to NULL */
	for (i = 0; i < FM10K_TLV_RESULTS_MAX; i++)
		results[i] = NULL;

	/* pull length from the message header */
	len = *attr >> FM10K_TLV_LEN_SHIFT;

	/* no attributes to parse if there is no length */
	if (!len)
		return 0;

	/* no attributes to parse, just raw data, message becomes attribute */
	if (!tlv_attr) {
		results[0] = attr;
		return 0;
	}

	/* move to start of attribute data */
	attr++;

	/* run through list parsing all attributes */
	while (offset < len) {
		attr_id = *attr & FM10K_TLV_ID_MASK;

		if (attr_id < FM10K_TLV_RESULTS_MAX)
			err = fm10k_tlv_attr_validate(attr, tlv_attr);
		else
			err = FM10K_NOT_IMPLEMENTED;

		if (err < 0)
			return err;
		if (!err)
			results[attr_id] = attr;

		/* update offset */
		offset += FM10K_TLV_DWORD_LEN(*attr) * 4;

		/* move to next attribute */
		attr = &attr[FM10K_TLV_DWORD_LEN(*attr)];
	}

	/* we should find ourselves at the end of the list */
	if (offset != len)
		return FM10K_ERR_PARAM;

	return 0;
}