// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2000-2010
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Andreas Heppel <aheppel@sysgo.de>
 */

#include <common.h>
#include <bootstage.h>
#include <command.h>
#include <env.h>
#include <env_internal.h>
#include <log.h>
#include <sort.h>
#include <asm/global_data.h>
#include <linux/stddef.h>
#include <search.h>
#include <errno.h>
#include <malloc.h>
#include <u-boot/crc.h>
#include <dm/ofnode.h>
#include <net.h>
#include <watchdog.h>

DECLARE_GLOBAL_DATA_PTR;

/************************************************************************
 * Default settings to be used when no valid environment is found
 */
#include <env_default.h>

struct hsearch_data env_htab = {
        .change_ok = env_flags_validate,
};

/*
 * This env_set() function is defined in cmd/nvedit.c, since it calls
 * _do_env_set(), whis is a static function in that file.
 *
 * int env_set(const char *varname, const char *varvalue);
 */

/**
 * Set an environment variable to an integer value
 *
 * @param varname       Environment variable to set
 * @param value         Value to set it to
 * Return: 0 if ok, 1 on error
 */
int env_set_ulong(const char *varname, ulong value)
{
        /* TODO: this should be unsigned */
        char *str = simple_itoa(value);

        return env_set(varname, str);
}

/**
 * Set an environment variable to an value in hex
 *
 * @param varname       Environment variable to set
 * @param value         Value to set it to
 * Return: 0 if ok, 1 on error
 */
int env_set_hex(const char *varname, ulong value)
{
        char str[17];

        sprintf(str, "%lx", value);
        return env_set(varname, str);
}

ulong env_get_hex(const char *varname, ulong default_val)
{
        const char *s;
        ulong value;
        char *endp;

        s = env_get(varname);
        if (s)
                value = hextoul(s, &endp);
        if (!s || endp == s)
                return default_val;

        return value;
}

int eth_env_get_enetaddr(const char *name, uint8_t *enetaddr)
{
        string_to_enetaddr(env_get(name), enetaddr);
        return is_valid_ethaddr(enetaddr);
}

int eth_env_set_enetaddr(const char *name, const uint8_t *enetaddr)
{
        char buf[ARP_HLEN_ASCII + 1];

        if (eth_env_get_enetaddr(name, (uint8_t *)buf))
                return -EEXIST;

        sprintf(buf, "%pM", enetaddr);

        return env_set(name, buf);
}

/*
 * Look up variable from environment,
 * return address of storage for that variable,
 * or NULL if not found
 */
char *env_get(const char *name)
{
        if (gd->flags & GD_FLG_ENV_READY) { /* after import into hashtable */
                struct env_entry e, *ep;

                WATCHDOG_RESET();

                e.key   = name;
                e.data  = NULL;
                hsearch_r(e, ENV_FIND, &ep, &env_htab, 0);

                return ep ? ep->data : NULL;
        }

        /* restricted capabilities before import */
        if (env_get_f(name, (char *)(gd->env_buf), sizeof(gd->env_buf)) >= 0)
                return (char *)(gd->env_buf);

        return NULL;
}

/*
 * Like env_get, but prints an error if envvar isn't defined in the
 * environment.  It always returns what env_get does, so it can be used in
 * place of env_get without changing error handling otherwise.
 */
char *from_env(const char *envvar)
{
        char *ret;

        ret = env_get(envvar);

        if (!ret)
                printf("missing environment variable: %s\n", envvar);

        return ret;
}

static int env_get_from_linear(const char *env, const char *name, char *buf,
                               unsigned len)
{
        const char *p, *end;
        size_t name_len;

        if (name == NULL || *name == '\0')
                return -1;

        name_len = strlen(name);

        for (p = env; *p != '\0'; p = end + 1) {
                const char *value;
                unsigned res;

                for (end = p; *end != '\0'; ++end)
                        if (end - env >= CONFIG_ENV_SIZE)
                                return -1;

                if (strncmp(name, p, name_len) || p[name_len] != '=')
                        continue;
                value = &p[name_len + 1];

                res = end - value;
                memcpy(buf, value, min(len, res + 1));

                if (len <= res) {
                        buf[len - 1] = '\0';
                        printf("env_buf [%u bytes] too small for value of \"%s\"\n",
                               len, name);
                }

                return res;
        }

        return -1;
}

/*
 * Look up variable from environment for restricted C runtime env.
 */
int env_get_f(const char *name, char *buf, unsigned len)
{
        const char *env;

        if (gd->env_valid == ENV_INVALID)
                env = default_environment;
        else
                env = (const char *)gd->env_addr;

        return env_get_from_linear(env, name, buf, len);
}

/**
 * Decode the integer value of an environment variable and return it.
 *
 * @param name          Name of environment variable
 * @param base          Number base to use (normally 10, or 16 for hex)
 * @param default_val   Default value to return if the variable is not
 *                      found
 * Return: the decoded value, or default_val if not found
 */
ulong env_get_ulong(const char *name, int base, ulong default_val)
{
        /*
         * We can use env_get() here, even before relocation, since the
         * environment variable value is an integer and thus short.
         */
        const char *str = env_get(name);

        return str ? simple_strtoul(str, NULL, base) : default_val;
}

/*
 * Read an environment variable as a boolean
 * Return -1 if variable does not exist (default to true)
 */
int env_get_yesno(const char *var)
{
        char *s = env_get(var);

        if (s == NULL)
                return -1;
        return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
                1 : 0;
}

bool env_get_autostart(void)
{
        return env_get_yesno("autostart") == 1;
}

/*
 * Look up the variable from the default environment
 */
char *env_get_default(const char *name)
{
        if (env_get_from_linear(default_environment, name,
                                (char *)(gd->env_buf),
                                sizeof(gd->env_buf)) >= 0)
                return (char *)(gd->env_buf);

        return NULL;
}

void env_set_default(const char *s, int flags)
{
        if (s) {
                if ((flags & H_INTERACTIVE) == 0) {
                        printf("*** Warning - %s, "
                                "using default environment\n\n", s);
                } else {
                        puts(s);
                }
        } else {
                debug("Using default environment\n");
        }

        flags |= H_DEFAULT;
        if (himport_r(&env_htab, default_environment,
                        sizeof(default_environment), '\0', flags, 0,
                        0, NULL) == 0) {
                pr_err("## Error: Environment import failed: errno = %d\n",
                       errno);
                return;
        }

        gd->flags |= GD_FLG_ENV_READY;
        gd->flags |= GD_FLG_ENV_DEFAULT;
}


/* [re]set individual variables to their value in the default environment */
int env_set_default_vars(int nvars, char * const vars[], int flags)
{
        /*
         * Special use-case: import from default environment
         * (and use \0 as a separator)
         */
        flags |= H_NOCLEAR | H_DEFAULT;
        return himport_r(&env_htab, default_environment,
                                sizeof(default_environment), '\0',
                                flags, 0, nvars, vars);
}

/*
 * Check if CRC is valid and (if yes) import the environment.
 * Note that "buf" may or may not be aligned.
 */
int env_import(const char *buf, int check, int flags)
{
        env_t *ep = (env_t *)buf;

        if (check) {
                uint32_t crc;

                memcpy(&crc, &ep->crc, sizeof(crc));

                if (crc32(0, ep->data, ENV_SIZE) != crc) {
                        env_set_default("bad CRC", 0);
                        return -ENOMSG; /* needed for env_load() */
                }
        }

        if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', flags, 0,
                        0, NULL)) {
                gd->flags |= GD_FLG_ENV_READY;
                return 0;
        }

        pr_err("Cannot import environment: errno = %d\n", errno);

        env_set_default("import failed", 0);

        return -EIO;
}

#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
static unsigned char env_flags;

int env_check_redund(const char *buf1, int buf1_read_fail,
                     const char *buf2, int buf2_read_fail)
{
        int crc1_ok = 0, crc2_ok = 0;
        env_t *tmp_env1, *tmp_env2;

        tmp_env1 = (env_t *)buf1;
        tmp_env2 = (env_t *)buf2;

        if (buf1_read_fail && buf2_read_fail) {
                puts("*** Error - No Valid Environment Area found\n");
                return -EIO;
        } else if (buf1_read_fail || buf2_read_fail) {
                puts("*** Warning - some problems detected ");
                puts("reading environment; recovered successfully\n");
        }

        if (!buf1_read_fail)
                crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
                                tmp_env1->crc;
        if (!buf2_read_fail)
                crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
                                tmp_env2->crc;

        if (!crc1_ok && !crc2_ok) {
                return -ENOMSG; /* needed for env_load() */
        } else if (crc1_ok && !crc2_ok) {
                gd->env_valid = ENV_VALID;
        } else if (!crc1_ok && crc2_ok) {
                gd->env_valid = ENV_REDUND;
        } else {
                /* both ok - check serial */
                if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
                        gd->env_valid = ENV_REDUND;
                else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
                        gd->env_valid = ENV_VALID;
                else if (tmp_env1->flags > tmp_env2->flags)
                        gd->env_valid = ENV_VALID;
                else if (tmp_env2->flags > tmp_env1->flags)
                        gd->env_valid = ENV_REDUND;
                else /* flags are equal - almost impossible */
                        gd->env_valid = ENV_VALID;
        }

        return 0;
}

int env_import_redund(const char *buf1, int buf1_read_fail,
                      const char *buf2, int buf2_read_fail,
                      int flags)
{
        env_t *ep;
        int ret;

        ret = env_check_redund(buf1, buf1_read_fail, buf2, buf2_read_fail);

        if (ret == -EIO) {
                env_set_default("bad env area", 0);
                return -EIO;
        } else if (ret == -ENOMSG) {
                env_set_default("bad CRC", 0);
                return -ENOMSG;
        }

        if (gd->env_valid == ENV_VALID)
                ep = (env_t *)buf1;
        else
                ep = (env_t *)buf2;

        env_flags = ep->flags;

        return env_import((char *)ep, 0, flags);
}
#endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */

/* Export the environment and generate CRC for it. */
int env_export(env_t *env_out)
{
        char *res;
        ssize_t len;

        res = (char *)env_out->data;
        len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
        if (len < 0) {
                pr_err("Cannot export environment: errno = %d\n", errno);
                return 1;
        }

        env_out->crc = crc32(0, env_out->data, ENV_SIZE);

#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
        env_out->flags = ++env_flags; /* increase the serial */
#endif

        return 0;
}

void env_relocate(void)
{
#if defined(CONFIG_NEEDS_MANUAL_RELOC)
        env_reloc();
        env_fix_drivers();
        env_htab.change_ok += gd->reloc_off;
#endif
        if (gd->env_valid == ENV_INVALID) {
#if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
                /* Environment not changable */
                env_set_default(NULL, 0);
#else
                bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
                env_set_default("bad CRC", 0);
#endif
        } else {
                env_load();
        }
}

#ifdef CONFIG_AUTO_COMPLETE
int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf,
                 bool dollar_comp)
{
        struct env_entry *match;
        int found, idx;

        if (dollar_comp) {
                /*
                 * When doing $ completion, the first character should
                 * obviously be a '$'.
                 */
                if (var[0] != '$')
                        return 0;

                var++;

                /*
                 * The second one, if present, should be a '{', as some
                 * configuration of the u-boot shell expand ${var} but not
                 * $var.
                 */
                if (var[0] == '{')
                        var++;
                else if (var[0] != '\0')
                        return 0;
        }

        idx = 0;
        found = 0;
        cmdv[0] = NULL;


        while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
                int vallen = strlen(match->key) + 1;

                if (found >= maxv - 2 ||
                    bufsz < vallen + (dollar_comp ? 3 : 0))
                        break;

                cmdv[found++] = buf;

                /* Add the '${' prefix to each var when doing $ completion. */
                if (dollar_comp) {
                        strcpy(buf, "${");
                        buf += 2;
                        bufsz -= 3;
                }

                memcpy(buf, match->key, vallen);
                buf += vallen;
                bufsz -= vallen;

                if (dollar_comp) {
                        /*
                         * This one is a bit odd: vallen already contains the
                         * '\0' character but we need to add the '}' suffix,
                         * hence the buf - 1 here. strcpy() will add the '\0'
                         * character just after '}'. buf is then incremented
                         * to account for the extra '}' we just added.
                         */
                        strcpy(buf - 1, "}");
                        buf++;
                }
        }

        qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);

        if (idx)
                cmdv[found++] = dollar_comp ? "${...}" : "...";

        cmdv[found] = NULL;
        return found;
}
#endif

#ifdef CONFIG_ENV_IMPORT_FDT
void env_import_fdt(void)
{
        const char *path;
        struct ofprop prop;
        ofnode node;
        int res;

        path = env_get("env_fdt_path");
        if (!path || !path[0])
                return;

        node = ofnode_path(path);
        if (!ofnode_valid(node)) {
                printf("Warning: device tree node '%s' not found\n", path);
                return;
        }

        for (res = ofnode_get_first_property(node, &prop);
             !res;
             res = ofnode_get_next_property(&prop)) {
                const char *name, *val;

                val = ofnode_get_property_by_prop(&prop, &name, NULL);
                env_set(name, val);
        }
}
#endif