env/common.c - platform/external/u-boot - Gitiles

 /*
  * (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\n\n");
 		return;
 	}

 	if (s) {
 		if (*s == '!') {
 			printf("*** Warning - %s, "
 				"using default environment\n\n",
 				s + 1);
 		} else {
 			flags = H_INTERACTIVE;
 			puts(s);
 		}
 	} else {
 		puts("Using default environment\n\n");
 	}

 	if (himport_r(&env_htab, (char *)default_environment,
 			sizeof(default_environment), '\0', flags, 0,
 			0, NULL) == 0)
 		pr_err("Environment import failed: errno = %d\n", 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);
 }

 #ifdef CONFIG_ENV_AES
 #include <uboot_aes.h>
 /**
  * env_aes_cbc_get_key() - Get AES-128-CBC key for the environment
  *
  * This function shall return 16-byte array containing AES-128 key used
  * to encrypt and decrypt the environment. This function must be overridden
  * by the implementer as otherwise the environment encryption will not
  * work.
  */
 __weak uint8_t *env_aes_cbc_get_key(void)
 {
 	return NULL;
 }

 static int env_aes_cbc_crypt(env_t *env, const int enc)
 {
 	unsigned char *data = env->data;
 	uint8_t *key;
 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
 	uint32_t aes_blocks;

 	key = env_aes_cbc_get_key();
 	if (!key)
 		return -EINVAL;

 	/* First we expand the key. */
 	aes_expand_key(key, key_exp);

 	/* Calculate the number of AES blocks to encrypt. */
 	aes_blocks = ENV_SIZE / AES_KEY_LENGTH;

 	if (enc)
 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
 	else
 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);

 	return 0;
 }
 #else
 static inline int env_aes_cbc_crypt(env_t *env, const int enc)
 {
 	return 0;
 }
 #endif

 /*
  * 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;
 	int ret;

 	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 0;
 		}
 	}

 	/* Decrypt the env if desired. */
 	ret = env_aes_cbc_crypt(ep, 0);
 	if (ret) {
 		pr_err("Failed to decrypt env!\n");
 		set_default_env("!import failed");
 		return ret;
 	}

 	if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
 			0, NULL)) {
 		gd->flags |= GD_FLG_ENV_READY;
 		return 1;
 	}

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

 	set_default_env("!import failed");

 	return 0;
 }

 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 static unsigned char env_flags;

 int env_import_redund(const char *buf1, const char *buf2)
 {
 	int crc1_ok, crc2_ok;
 	env_t *ep, *tmp_env1, *tmp_env2;

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

 	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 0;
 	} 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;
 	int ret;

 	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;
 	}

 	/* Encrypt the env if desired. */
 	ret = env_aes_cbc_crypt(env_out, 1);
 	if (ret)
 		return ret;

 	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
	/*
	* (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\n\n");
	return;
	}

	if (s) {
	if (*s == '!') {
	printf("*** Warning - %s, "
	"using default environment\n\n",
	s + 1);
	} else {
	flags = H_INTERACTIVE;
	puts(s);
	}
	} else {
	puts("Using default environment\n\n");
	}

	if (himport_r(&env_htab, (char *)default_environment,
	sizeof(default_environment), '\0', flags, 0,
	0, NULL) == 0)
	pr_err("Environment import failed: errno = %d\n", 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);
	}

	#ifdef CONFIG_ENV_AES
	#include <uboot_aes.h>
	/**
	* env_aes_cbc_get_key() - Get AES-128-CBC key for the environment
	*
	* This function shall return 16-byte array containing AES-128 key used
	* to encrypt and decrypt the environment. This function must be overridden
	* by the implementer as otherwise the environment encryption will not
	* work.
	*/
	__weak uint8_t *env_aes_cbc_get_key(void)
	{
	return NULL;
	}

	static int env_aes_cbc_crypt(env_t *env, const int enc)
	{
	unsigned char *data = env->data;
	uint8_t *key;
	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
	uint32_t aes_blocks;

	key = env_aes_cbc_get_key();
	if (!key)
	return -EINVAL;

	/* First we expand the key. */
	aes_expand_key(key, key_exp);

	/* Calculate the number of AES blocks to encrypt. */
	aes_blocks = ENV_SIZE / AES_KEY_LENGTH;

	if (enc)
	aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
	else
	aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);

	return 0;
	}
	#else
	static inline int env_aes_cbc_crypt(env_t *env, const int enc)
	{
	return 0;
	}
	#endif

	/*
	* 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;
	int ret;

	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 0;
	}
	}

	/* Decrypt the env if desired. */
	ret = env_aes_cbc_crypt(ep, 0);
	if (ret) {
	pr_err("Failed to decrypt env!\n");
	set_default_env("!import failed");
	return ret;
	}

	if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
	0, NULL)) {
	gd->flags \|= GD_FLG_ENV_READY;
	return 1;
	}

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

	set_default_env("!import failed");

	return 0;
	}

	#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
	static unsigned char env_flags;

	int env_import_redund(const char buf1, const char buf2)
	{
	int crc1_ok, crc2_ok;
	env_t ep, tmp_env1, *tmp_env2;

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

	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 0;
	} 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;
	int ret;

	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;
	}

	/* Encrypt the env if desired. */
	ret = env_aes_cbc_crypt(env_out, 1);
	if (ret)
	return ret;

	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