/*

   * (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>

   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  
  #include <common.h>
  #include <command.h>
  #include <environment.h>

  #include <linux/stddef.h>

  #include <search.h>
  #include <errno.h>

  #include <malloc.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,

  };

  /*
   * 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;
  }

  /*
   * Look up the variable from the default environment
   */

  char *env_get_default(const char *name)

  {
  	char *ret_val;
  	unsigned long really_valid = gd->env_valid;
  	unsigned long real_gd_flags = gd->flags;
  
  	/* Pretend that the image is bad. */
  	gd->flags &= ~GD_FLG_ENV_READY;

  	gd->env_valid = ENV_INVALID;

  	ret_val = env_get(name);

  	gd->env_valid = really_valid;
  	gd->flags = real_gd_flags;
  	return ret_val;
  }

  void set_default_env(const char *s)

  {

  	int flags = 0;

  	if (sizeof(default_environment) > ENV_SIZE) {

  		puts("*** Error - default environment is too large
  
  ");

  		return;
  	}

  	if (s) {
  		if (*s == '!') {
  			printf("*** Warning - %s, "
  				"using default environment
  
  ",

  				s + 1);

  		} else {

  			flags = H_INTERACTIVE;

  			puts(s);
  		}
  	} else {

  		debug("Using default environment
  ");

  	}

  	if (himport_r(&env_htab, (char *)default_environment,

  			sizeof(default_environment), '\0', flags, 0,

  			0, NULL) == 0)

  		pr_err("Environment import failed: errno = %d
  ", errno);

  	gd->flags |= GD_FLG_ENV_READY;

  	gd->flags |= GD_FLG_ENV_DEFAULT;

  }

  
  /* [re]set individual variables to their value in the default environment */
  int set_default_vars(int nvars, char * const vars[])
  {
  	/*
  	 * Special use-case: import from default environment
  	 * (and use \0 as a separator)
  	 */
  	return himport_r(&env_htab, (const char *)default_environment,

  				sizeof(default_environment), '\0',

  				H_NOCLEAR | H_INTERACTIVE, 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)

  {

  	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) {
  			set_default_env("!bad CRC");

  			return -EIO;

  		}
  	}

  	if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,

  			0, NULL)) {

  		gd->flags |= GD_FLG_ENV_READY;

  		return 0;

  	}

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

  
  	set_default_env("!import failed");

  	return -EIO;

  }

  #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
  static unsigned char env_flags;

  int env_import_redund(const char *buf1, int buf1_read_fail,
  		      const char *buf2, int buf2_read_fail)

  {
  	int crc1_ok, crc2_ok;
  	env_t *ep, *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
  ");
  	} else if (buf1_read_fail || buf2_read_fail) {
  		puts("*** Warning - some problems detected ");
  		puts("reading environment; recovered successfully
  ");
  	}
  
  	if (buf1_read_fail && buf2_read_fail) {
  		set_default_env("!bad env area");
  		return -EIO;
  	} else if (!buf1_read_fail && buf2_read_fail) {
  		gd->env_valid = ENV_VALID;
  		return env_import((char *)tmp_env1, 1);
  	} else if (buf1_read_fail && !buf2_read_fail) {
  		gd->env_valid = ENV_REDUND;
  		return env_import((char *)tmp_env2, 1);
  	}

  	crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
  			tmp_env1->crc;
  	crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
  			tmp_env2->crc;
  
  	if (!crc1_ok && !crc2_ok) {
  		set_default_env("!bad CRC");

  		return -EIO;

  	} 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;

  	}

  	if (gd->env_valid == ENV_VALID)

  		ep = tmp_env1;
  	else
  		ep = tmp_env2;
  
  	env_flags = ep->flags;
  	return env_import((char *)ep, 0);
  }
  #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
  ", 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_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 */

  		set_default_env(NULL);

  #else

  		bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);

  		set_default_env("!bad CRC");

  #endif

  	} else {

  		env_load();

  	}

  }

  #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD)

  int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf)
  {

  	ENTRY *match;
  	int found, idx;

  	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)

  			break;

  		cmdv[found++] = buf;

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

  	}

  	qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
  
  	if (idx)
  		cmdv[found++] = "...";

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