/*
 * cmd_gpt.c -- GPT (GUID Partition Table) handling command
 *
 * Copyright (C) 2015
 * Lukasz Majewski <l.majewski@majess.pl>
 *
 * Copyright (C) 2012 Samsung Electronics
 * author: Lukasz Majewski <l.majewski@samsung.com>
 * author: Piotr Wilczek <p.wilczek@samsung.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <malloc.h>
#include <command.h>
#include <part_efi.h>
#include <exports.h>
#include <linux/ctype.h>
#include <div64.h>
#include <memalign.h>

/**
 * extract_env(): Expand env name from string format '&{env_name}'
 *                and return pointer to the env (if the env is set)
 *
 * @param str - pointer to string
 * @param env - pointer to pointer to extracted env
 *
 * @return - zero on successful expand and env is set
 */
static int extract_env(const char *str, char **env)
{
        int ret = -1;
        char *e, *s;
#ifdef CONFIG_RANDOM_UUID
        char uuid_str[UUID_STR_LEN + 1];
#endif

        if (!str || strlen(str) < 4)
                return -1;

        if (!((strncmp(str, "${", 2) == 0) && (str[strlen(str) - 1] == '}')))
                return -1;

        s = strdup(str);
        if (s == NULL)
                return -1;

        memset(s + strlen(s) - 1, '\0', 1);
        memmove(s, s + 2, strlen(s) - 1);

        e = getenv(s);
        if (e == NULL) {
#ifdef CONFIG_RANDOM_UUID
                debug("%s unset. ", str);
                gen_rand_uuid_str(uuid_str, UUID_STR_FORMAT_GUID);
                setenv(s, uuid_str);

                e = getenv(s);
                if (e) {
                        debug("Set to random.\n");
                        ret = 0;
                } else {
                        debug("Can't get random UUID.\n");
                }
#else
                debug("%s unset.\n", str);
#endif
        } else {
                debug("%s get from environment.\n", str);
                ret = 0;
        }

        *env = e;
        free(s);

        return ret;
}

/**
 * extract_val(): Extract value from a key=value pair list (comma separated).
 *                Only value for the given key is returend.
 *                Function allocates memory for the value, remember to free!
 *
 * @param str - pointer to string with key=values pairs
 * @param key - pointer to the key to search for
 *
 * @return - pointer to allocated string with the value
 */
static char *extract_val(const char *str, const char *key)
{
        char *v, *k;
        char *s, *strcopy;
        char *new = NULL;

        strcopy = strdup(str);
        if (strcopy == NULL)
                return NULL;

        s = strcopy;
        while (s) {
                v = strsep(&s, ",");
                if (!v)
                        break;
                k = strsep(&v, "=");
                if (!k)
                        break;
                if  (strcmp(k, key) == 0) {
                        new = strdup(v);
                        break;
                }
        }

        free(strcopy);

        return new;
}

/**
 * found_key(): Found key without value in parameter list (comma separated).
 *
 * @param str - pointer to string with key
 * @param key - pointer to the key to search for
 *
 * @return - true on found key
 */
static bool found_key(const char *str, const char *key)
{
        char *k;
        char *s, *strcopy;
        bool result = false;

        strcopy = strdup(str);
        if (!strcopy)
                return NULL;

        s = strcopy;
        while (s) {
                k = strsep(&s, ",");
                if (!k)
                        break;
                if  (strcmp(k, key) == 0) {
                        result = true;
                        break;
                }
        }

        free(strcopy);

        return result;
}

/**
 * set_gpt_info(): Fill partition information from string
 *              function allocates memory, remember to free!
 *
 * @param dev_desc - pointer block device descriptor
 * @param str_part - pointer to string with partition information
 * @param str_disk_guid - pointer to pointer to allocated string with disk guid
 * @param partitions - pointer to pointer to allocated partitions array
 * @param parts_count - number of partitions
 *
 * @return - zero on success, otherwise error
 *
 */
static int set_gpt_info(struct blk_desc *dev_desc,
                        const char *str_part,
                        char **str_disk_guid,
                        disk_partition_t **partitions,
                        u8 *parts_count)
{
        char *tok, *str, *s;
        int i;
        char *val, *p;
        int p_count;
        disk_partition_t *parts;
        int errno = 0;
        uint64_t size_ll, start_ll;
        lbaint_t offset = 0;

        debug("%s:  lba num: 0x%x %d\n", __func__,
              (unsigned int)dev_desc->lba, (unsigned int)dev_desc->lba);

        if (str_part == NULL)
                return -1;

        str = strdup(str_part);

        /* extract disk guid */
        s = str;
        val = extract_val(str, "uuid_disk");
        if (!val) {
#ifdef CONFIG_RANDOM_UUID
                *str_disk_guid = malloc(UUID_STR_LEN + 1);
                gen_rand_uuid_str(*str_disk_guid, UUID_STR_FORMAT_STD);
#else
                free(str);
                return -2;
#endif
        } else {
                val = strsep(&val, ";");
                if (extract_env(val, &p))
                        p = val;
                *str_disk_guid = strdup(p);
                free(val);
                /* Move s to first partition */
                strsep(&s, ";");
        }
        if (strlen(s) == 0)
                return -3;

        i = strlen(s) - 1;
        if (s[i] == ';')
                s[i] = '\0';

        /* calculate expected number of partitions */
        p_count = 1;
        p = s;
        while (*p) {
                if (*p++ == ';')
                        p_count++;
        }

        /* allocate memory for partitions */
        parts = calloc(sizeof(disk_partition_t), p_count);

        /* retrieve partitions data from string */
        for (i = 0; i < p_count; i++) {
                tok = strsep(&s, ";");

                if (tok == NULL)
                        break;

                /* uuid */
                val = extract_val(tok, "uuid");
                if (!val) {
                        /* 'uuid' is optional if random uuid's are enabled */
#ifdef CONFIG_RANDOM_UUID
                        gen_rand_uuid_str(parts[i].uuid, UUID_STR_FORMAT_STD);
#else
                        errno = -4;
                        goto err;
#endif
                } else {
                        if (extract_env(val, &p))
                                p = val;
                        if (strlen(p) >= sizeof(parts[i].uuid)) {
                                printf("Wrong uuid format for partition %d\n", i);
                                errno = -4;
                                goto err;
                        }
                        strcpy((char *)parts[i].uuid, p);
                        free(val);
                }
#ifdef CONFIG_PARTITION_TYPE_GUID
                /* guid */
                val = extract_val(tok, "type");
                if (val) {
                        /* 'type' is optional */
                        if (extract_env(val, &p))
                                p = val;
                        if (strlen(p) >= sizeof(parts[i].type_guid)) {
                                printf("Wrong type guid format for partition %d\n",
                                       i);
                                errno = -4;
                                goto err;
                        }
                        strcpy((char *)parts[i].type_guid, p);
                        free(val);
                }
#endif
                /* name */
                val = extract_val(tok, "name");
                if (!val) { /* name is mandatory */
                        errno = -4;
                        goto err;
                }
                if (extract_env(val, &p))
                        p = val;
                if (strlen(p) >= sizeof(parts[i].name)) {
                        errno = -4;
                        goto err;
                }
                strcpy((char *)parts[i].name, p);
                free(val);

                /* size */
                val = extract_val(tok, "size");
                if (!val) { /* 'size' is mandatory */
                        errno = -4;
                        goto err;
                }
                if (extract_env(val, &p))
                        p = val;
                if ((strcmp(p, "-") == 0)) {
                        /* Let part efi module to auto extend the size */
                        parts[i].size = 0;
                } else {
                        size_ll = ustrtoull(p, &p, 0);
                        parts[i].size = lldiv(size_ll, dev_desc->blksz);
                }

                free(val);

                /* start address */
                val = extract_val(tok, "start");
                if (val) { /* start address is optional */
                        if (extract_env(val, &p))
                                p = val;
                        start_ll = ustrtoull(p, &p, 0);
                        parts[i].start = lldiv(start_ll, dev_desc->blksz);
                        free(val);
                }

                offset += parts[i].size + parts[i].start;

                /* bootable */
                if (found_key(tok, "bootable"))
                        parts[i].bootable = 1;
        }

        *parts_count = p_count;
        *partitions = parts;
        free(str);

        return 0;
err:
        free(str);
        free(*str_disk_guid);
        free(parts);

        return errno;
}

static int gpt_default(struct blk_desc *blk_dev_desc, const char *str_part)
{
        int ret;
        char *str_disk_guid;
        u8 part_count = 0;
        disk_partition_t *partitions = NULL;

        /* fill partitions */
        ret = set_gpt_info(blk_dev_desc, str_part,
                        &str_disk_guid, &partitions, &part_count);
        if (ret) {
                if (ret == -1)
                        printf("No partition list provided\n");
                if (ret == -2)
                        printf("Missing disk guid\n");
                if ((ret == -3) || (ret == -4))
                        printf("Partition list incomplete\n");
                return -1;
        }

        /* save partitions layout to disk */
        ret = gpt_restore(blk_dev_desc, str_disk_guid, partitions, part_count);
        free(str_disk_guid);
        free(partitions);

        return ret;
}

static int gpt_verify(struct blk_desc *blk_dev_desc, const char *str_part)
{
        ALLOC_CACHE_ALIGN_BUFFER_PAD(gpt_header, gpt_head, 1,
                                     blk_dev_desc->blksz);
        disk_partition_t *partitions = NULL;
        gpt_entry *gpt_pte = NULL;
        char *str_disk_guid;
        u8 part_count = 0;
        int ret = 0;

        /* fill partitions */
        ret = set_gpt_info(blk_dev_desc, str_part,
                        &str_disk_guid, &partitions, &part_count);
        if (ret) {
                if (ret == -1) {
                        printf("No partition list provided - only basic check\n");
                        ret = gpt_verify_headers(blk_dev_desc, gpt_head,
                                                 &gpt_pte);
                        goto out;
                }
                if (ret == -2)
                        printf("Missing disk guid\n");
                if ((ret == -3) || (ret == -4))
                        printf("Partition list incomplete\n");
                return -1;
        }

        /* Check partition layout with provided pattern */
        ret = gpt_verify_partitions(blk_dev_desc, partitions, part_count,
                                    gpt_head, &gpt_pte);
        free(str_disk_guid);
        free(partitions);
 out:
        free(gpt_pte);
        return ret;
}

/**
 * do_gpt(): Perform GPT operations
 *
 * @param cmdtp - command name
 * @param flag
 * @param argc
 * @param argv
 *
 * @return zero on success; otherwise error
 */
static int do_gpt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
        int ret = CMD_RET_SUCCESS;
        int dev = 0;
        char *ep;
        struct blk_desc *blk_dev_desc = NULL;

        if (argc < 4 || argc > 5)
                return CMD_RET_USAGE;

        dev = (int)simple_strtoul(argv[3], &ep, 10);
        if (!ep || ep[0] != '\0') {
                printf("'%s' is not a number\n", argv[3]);
                return CMD_RET_USAGE;
        }
        blk_dev_desc = blk_get_dev(argv[2], dev);
        if (!blk_dev_desc) {
                printf("%s: %s dev %d NOT available\n",
                       __func__, argv[2], dev);
                return CMD_RET_FAILURE;
        }

        if ((strcmp(argv[1], "write") == 0) && (argc == 5)) {
                printf("Writing GPT: ");
                ret = gpt_default(blk_dev_desc, argv[4]);
        } else if ((strcmp(argv[1], "verify") == 0)) {
                ret = gpt_verify(blk_dev_desc, argv[4]);
                printf("Verify GPT: ");
        } else {
                return CMD_RET_USAGE;
        }

        if (ret) {
                printf("error!\n");
                return CMD_RET_FAILURE;
        }

        printf("success!\n");
        return CMD_RET_SUCCESS;
}

U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt,
        "GUID Partition Table",
        "<command> <interface> <dev> <partitions_list>\n"
        " - GUID partition table restoration and validity check\n"
        " Restore or verify GPT information on a device connected\n"
        " to interface\n"
        " Example usage:\n"
        " gpt write mmc 0 $partitions\n"
        " gpt verify mmc 0 $partitions\n"
);