// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2013 The Chromium OS Authors.
 */

#include <common.h>
#include <command.h>
#include <dm.h>
#include <env.h>
#include <malloc.h>
#include <asm/unaligned.h>
#include <linux/string.h>
#include <tpm-common.h>
#include "tpm-user-utils.h"

static struct udevice *tpm_dev;

/**
 * Print a byte string in hexdecimal format, 16-bytes per line.
 *
 * @param data          byte string to be printed
 * @param count         number of bytes to be printed
 */
void print_byte_string(u8 *data, size_t count)
{
        int i, print_newline = 0;

        for (i = 0; i < count; i++) {
                printf(" %02x", data[i]);
                print_newline = (i % 16 == 15);
                if (print_newline)
                        putc('\n');
        }
        /* Avoid duplicated newline at the end */
        if (!print_newline)
                putc('\n');
}

/**
 * Convert a text string of hexdecimal values into a byte string.
 *
 * @param bytes         text string of hexdecimal values with no space
 *                      between them
 * @param data          output buffer for byte string.  The caller has to make
 *                      sure it is large enough for storing the output.  If
 *                      NULL is passed, a large enough buffer will be allocated,
 *                      and the caller must free it.
 * @param count_ptr     output variable for the length of byte string
 * @return pointer to output buffer
 */
void *parse_byte_string(char *bytes, u8 *data, size_t *count_ptr)
{
        char byte[3];
        size_t count, length;
        int i;

        if (!bytes)
                return NULL;
        length = strlen(bytes);
        count = length / 2;

        if (!data)
                data = malloc(count);
        if (!data)
                return NULL;

        byte[2] = '\0';
        for (i = 0; i < length; i += 2) {
                byte[0] = bytes[i];
                byte[1] = bytes[i + 1];
                data[i / 2] = (u8)hextoul(byte, NULL);
        }

        if (count_ptr)
                *count_ptr = count;

        return data;
}

/**
 * report_return_code() - Report any error and return failure or success
 *
 * @param return_code   TPM command return code
 * @return value of enum command_ret_t
 */
int report_return_code(int return_code)
{
        if (return_code) {
                printf("Error: %d\n", return_code);
                return CMD_RET_FAILURE;
        } else {
                return CMD_RET_SUCCESS;
        }
}

/**
 * Return number of values defined by a type string.
 *
 * @param type_str      type string
 * @return number of values of type string
 */
int type_string_get_num_values(const char *type_str)
{
        return strlen(type_str);
}

/**
 * Return total size of values defined by a type string.
 *
 * @param type_str      type string
 * @return total size of values of type string, or 0 if type string
 *  contains illegal type character.
 */
size_t type_string_get_space_size(const char *type_str)
{
        size_t size;

        for (size = 0; *type_str; type_str++) {
                switch (*type_str) {
                case 'b':
                        size += 1;
                        break;
                case 'w':
                        size += 2;
                        break;
                case 'd':
                        size += 4;
                        break;
                default:
                        return 0;
                }
        }

        return size;
}

/**
 * Allocate a buffer large enough to hold values defined by a type
 * string.  The caller has to free the buffer.
 *
 * @param type_str      type string
 * @param count         pointer for storing size of buffer
 * @return pointer to buffer or NULL on error
 */
void *type_string_alloc(const char *type_str, u32 *count)
{
        void *data;
        size_t size;

        size = type_string_get_space_size(type_str);
        if (!size)
                return NULL;
        data = malloc(size);
        if (data)
                *count = size;

        return data;
}

/**
 * Pack values defined by a type string into a buffer.  The buffer must have
 * large enough space.
 *
 * @param type_str      type string
 * @param values        text strings of values to be packed
 * @param data          output buffer of values
 * @return 0 on success, non-0 on error
 */
int type_string_pack(const char *type_str, char * const values[],
                     u8 *data)
{
        size_t offset;
        u32 value;

        for (offset = 0; *type_str; type_str++, values++) {
                value = simple_strtoul(values[0], NULL, 0);
                switch (*type_str) {
                case 'b':
                        data[offset] = value;
                        offset += 1;
                        break;
                case 'w':
                        put_unaligned_be16(value, data + offset);
                        offset += 2;
                        break;
                case 'd':
                        put_unaligned_be32(value, data + offset);
                        offset += 4;
                        break;
                default:
                        return -1;
                }
        }

        return 0;
}

/**
 * Read values defined by a type string from a buffer, and write these values
 * to environment variables.
 *
 * @param type_str      type string
 * @param data          input buffer of values
 * @param vars          names of environment variables
 * @return 0 on success, non-0 on error
 */
int type_string_write_vars(const char *type_str, u8 *data,
                           char * const vars[])
{
        size_t offset;
        u32 value;

        for (offset = 0; *type_str; type_str++, vars++) {
                switch (*type_str) {
                case 'b':
                        value = data[offset];
                        offset += 1;
                        break;
                case 'w':
                        value = get_unaligned_be16(data + offset);
                        offset += 2;
                        break;
                case 'd':
                        value = get_unaligned_be32(data + offset);
                        offset += 4;
                        break;
                default:
                        return -1;
                }
                if (env_set_ulong(*vars, value))
                        return -1;
        }

        return 0;
}

static int tpm_show_device(void)
{
        struct udevice *dev;
        char buf[80];
        int n = 0, rc;

        for_each_tpm_device(dev) {
                rc = tpm_get_desc(dev, buf, sizeof(buf));
                if (rc < 0)
                        printf("device %d: can't get info\n", n);
                else
                        printf("device %d: %s\n", n, buf);

                n++;
        };

        return 0;
}

static int tpm_set_device(unsigned long num)
{
        struct udevice *dev;
        unsigned long n = 0;
        int rc = CMD_RET_FAILURE;

        for_each_tpm_device(dev) {
                if (n == num) {
                        rc = 0;
                        break;
                }

                n++;
        }

        if (!rc)
                tpm_dev = dev;

        return rc;
}

int get_tpm(struct udevice **devp)
{
        int rc;

        /*
         * To keep a backward compatibility with previous code,
         * if a tpm device is not explicitly set, we set the first one.
         */
        if (!tpm_dev) {
                rc = tpm_set_device(0);
                if (rc) {
                        printf("Couldn't set TPM 0 (rc = %d)\n", rc);
                        return CMD_RET_FAILURE;
                }
        }

        if (devp)
                *devp = tpm_dev;

        return 0;
}

int do_tpm_device(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
        unsigned long num;
        int rc;

        if (argc == 2) {
                num = dectoul(argv[1], NULL);

                rc = tpm_set_device(num);
                if (rc)
                        printf("Couldn't set TPM %lu (rc = %d)\n", num, rc);
        } else {
                rc = tpm_show_device();
        }

        return rc;
}

int do_tpm_info(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
        struct udevice *dev;
        char buf[80];
        int rc;

        rc = get_tpm(&dev);
        if (rc)
                return rc;
        rc = tpm_get_desc(dev, buf, sizeof(buf));
        if (rc < 0) {
                printf("Couldn't get TPM info (%d)\n", rc);
                return CMD_RET_FAILURE;
        }
        printf("%s\n", buf);

        return 0;
}

int do_tpm_init(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
        struct udevice *dev;
        int rc;

        if (argc != 1)
                return CMD_RET_USAGE;
        rc = get_tpm(&dev);
        if (rc)
                return rc;

        return report_return_code(tpm_init(dev));
}

int do_tpm(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
        struct cmd_tbl *tpm_commands, *cmd;
        struct tpm_chip_priv *priv;
        struct udevice *dev;
        unsigned int size;
        int ret;

        if (argc < 2)
                return CMD_RET_USAGE;

        ret = get_tpm(&dev);
        if (ret)
                return ret;

        priv = dev_get_uclass_priv(dev);

        /* Below getters return NULL if the desired stack is not built */
        switch (priv->version) {
        case TPM_V1:
                tpm_commands = get_tpm1_commands(&size);
                break;
        case TPM_V2:
                tpm_commands = get_tpm2_commands(&size);
                break;
        default:
                tpm_commands = NULL;
        }

        if (!tpm_commands)
                return CMD_RET_USAGE;

        cmd = find_cmd_tbl(argv[1], tpm_commands, size);
        if (!cmd)
                return CMD_RET_USAGE;

        return cmd->cmd(cmdtp, flag, argc - 1, argv + 1);
}