common/autoboot.c - platform/external/u-boot - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2000
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  */

 #include <common.h>
 #include <autoboot.h>
 #include <bootretry.h>
 #include <cli.h>
 #include <command.h>
 #include <console.h>
 #include <env.h>
 #include <fdtdec.h>
 #include <hash.h>
 #include <memalign.h>
 #include <menu.h>
 #include <post.h>
 #include <time.h>
 #include <u-boot/sha256.h>
 #include <bootcount.h>

 DECLARE_GLOBAL_DATA_PTR;

 #define MAX_DELAY_STOP_STR 32

 #ifndef DEBUG_BOOTKEYS
 #define DEBUG_BOOTKEYS 0
 #endif
 #define debug_bootkeys(fmt, args...)		\
 	debug_cond(DEBUG_BOOTKEYS, fmt, ##args)

 /* Stored value of bootdelay, used by autoboot_command() */
 static int stored_bootdelay;
 static int menukey;

 #ifdef CONFIG_AUTOBOOT_ENCRYPTION
 #define AUTOBOOT_STOP_STR_SHA256 CONFIG_AUTOBOOT_STOP_STR_SHA256
 #else
 #define AUTOBOOT_STOP_STR_SHA256 ""
 #endif

 #ifdef CONFIG_USE_AUTOBOOT_MENUKEY
 #define AUTOBOOT_MENUKEY CONFIG_USE_AUTOBOOT_MENUKEY
 #else
 #define AUTOBOOT_MENUKEY 0
 #endif

 /*
  * Use a "constant-length" time compare function for this
  * hash compare:
  *
  * https://crackstation.net/hashing-security.htm
  */
 static int slow_equals(u8 *a, u8 *b, int len)
 {
 	int diff = 0;
 	int i;

 	for (i = 0; i < len; i++)
 		diff |= a[i] ^ b[i];

 	return diff == 0;
 }

 /**
  * passwd_abort_sha256() - check for a hashed key sequence to abort booting
  *
  * This checks for the user entering a SHA256 hash within a given time.
  *
  * @etime: Timeout value ticks (stop when get_ticks() reachs this)
  * @return 0 if autoboot should continue, 1 if it should stop
  */
 static int passwd_abort_sha256(uint64_t etime)
 {
 	const char *sha_env_str = env_get("bootstopkeysha256");
 	u8 sha_env[SHA256_SUM_LEN];
 	u8 *sha;
 	char *presskey;
 	const char *algo_name = "sha256";
 	u_int presskey_len = 0;
 	int abort = 0;
 	int size = sizeof(sha);
 	int ret;

 	if (sha_env_str == NULL)
 		sha_env_str = AUTOBOOT_STOP_STR_SHA256;

 	/*
 	 * Generate the binary value from the environment hash value
 	 * so that we can compare this value with the computed hash
 	 * from the user input
 	 */
 	ret = hash_parse_string(algo_name, sha_env_str, sha_env);
 	if (ret) {
 		printf("Hash %s not supported!\n", algo_name);
 		return 0;
 	}

 	presskey = malloc_cache_aligned(MAX_DELAY_STOP_STR);
 	sha = malloc_cache_aligned(SHA256_SUM_LEN);
 	size = SHA256_SUM_LEN;
 	/*
 	 * We don't know how long the stop-string is, so we need to
 	 * generate the sha256 hash upon each input character and
 	 * compare the value with the one saved in the environment
 	 */
 	do {
 		if (tstc()) {
 			/* Check for input string overflow */
 			if (presskey_len >= MAX_DELAY_STOP_STR) {
 				free(presskey);
 				free(sha);
 				return 0;
 			}

 			presskey[presskey_len++] = getc();

 			/* Calculate sha256 upon each new char */
 			hash_block(algo_name, (const void *)presskey,
 				   presskey_len, sha, &size);

 			/* And check if sha matches saved value in env */
 			if (slow_equals(sha, sha_env, SHA256_SUM_LEN))
 				abort = 1;
 		}
 	} while (!abort && get_ticks() <= etime);

 	free(presskey);
 	free(sha);
 	return abort;
 }

 /**
  * passwd_abort_key() - check for a key sequence to aborted booting
  *
  * This checks for the user entering a string within a given time.
  *
  * @etime: Timeout value ticks (stop when get_ticks() reachs this)
  * @return 0 if autoboot should continue, 1 if it should stop
  */
 static int passwd_abort_key(uint64_t etime)
 {
 	int abort = 0;
 	struct {
 		char *str;
 		u_int len;
 		int retry;
 	}
 	delaykey[] = {
 		{ .str = env_get("bootdelaykey"),  .retry = 1 },
 		{ .str = env_get("bootstopkey"),   .retry = 0 },
 	};

 	char presskey[MAX_DELAY_STOP_STR];
 	u_int presskey_len = 0;
 	u_int presskey_max = 0;
 	u_int i;

 #  ifdef CONFIG_AUTOBOOT_DELAY_STR
 	if (delaykey[0].str == NULL)
 		delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
 #  endif
 #  ifdef CONFIG_AUTOBOOT_STOP_STR
 	if (delaykey[1].str == NULL)
 		delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;
 #  endif

 	for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
 		delaykey[i].len = delaykey[i].str == NULL ?
 				    0 : strlen(delaykey[i].str);
 		delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
 				    MAX_DELAY_STOP_STR : delaykey[i].len;

 		presskey_max = presskey_max > delaykey[i].len ?
 				    presskey_max : delaykey[i].len;

 		debug_bootkeys("%s key:<%s>\n",
 			       delaykey[i].retry ? "delay" : "stop",
 			       delaykey[i].str ? delaykey[i].str : "NULL");
 	}

 	/* In order to keep up with incoming data, check timeout only
 	 * when catch up.
 	 */
 	do {
 		if (tstc()) {
 			if (presskey_len < presskey_max) {
 				presskey[presskey_len++] = getc();
 			} else {
 				for (i = 0; i < presskey_max - 1; i++)
 					presskey[i] = presskey[i + 1];

 				presskey[i] = getc();
 			}
 		}

 		for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
 			if (delaykey[i].len > 0 &&
 			    presskey_len >= delaykey[i].len &&
 				memcmp(presskey + presskey_len -
 					delaykey[i].len, delaykey[i].str,
 					delaykey[i].len) == 0) {
 					debug_bootkeys("got %skey\n",
 						delaykey[i].retry ? "delay" :
 						"stop");

 				/* don't retry auto boot */
 				if (!delaykey[i].retry)
 					bootretry_dont_retry();
 				abort = 1;
 			}
 		}
 	} while (!abort && get_ticks() <= etime);

 	return abort;
 }

 /***************************************************************************
  * Watch for 'delay' seconds for autoboot stop or autoboot delay string.
  * returns: 0 -  no key string, allow autoboot 1 - got key string, abort
  */
 static int abortboot_key_sequence(int bootdelay)
 {
 	int abort;
 	uint64_t etime = endtick(bootdelay);

 #  ifdef CONFIG_AUTOBOOT_PROMPT
 	/*
 	 * CONFIG_AUTOBOOT_PROMPT includes the %d for all boards.
 	 * To print the bootdelay value upon bootup.
 	 */
 	printf(CONFIG_AUTOBOOT_PROMPT, bootdelay);
 #  endif

 	if (IS_ENABLED(CONFIG_AUTOBOOT_ENCRYPTION))
 		abort = passwd_abort_sha256(etime);
 	else
 		abort = passwd_abort_key(etime);
 	if (!abort)
 		debug_bootkeys("key timeout\n");

 	return abort;
 }

 static int abortboot_single_key(int bootdelay)
 {
 	int abort = 0;
 	unsigned long ts;

 	printf("Hit any key to stop autoboot: %2d ", bootdelay);

 	/*
 	 * Check if key already pressed
 	 */
 	if (tstc()) {	/* we got a key press	*/
 		(void) getc();  /* consume input	*/
 		puts("\b\b\b 0");
 		abort = 1;	/* don't auto boot	*/
 	}

 	while ((bootdelay > 0) && (!abort)) {
 		--bootdelay;
 		/* delay 1000 ms */
 		ts = get_timer(0);
 		do {
 			if (tstc()) {	/* we got a key press	*/
 				int key;

 				abort  = 1;	/* don't auto boot	*/
 				bootdelay = 0;	/* no more delay	*/
 				key = getc(); /* consume input	*/
 				if (IS_ENABLED(CONFIG_USE_AUTOBOOT_MENUKEY))
 					menukey = key;
 				break;
 			}
 			udelay(10000);
 		} while (!abort && get_timer(ts) < 1000);

 		printf("\b\b\b%2d ", bootdelay);
 	}

 	putc('\n');

 	return abort;
 }

 static int abortboot(int bootdelay)
 {
 	int abort = 0;

 	if (bootdelay >= 0) {
 		if (IS_ENABLED(CONFIG_AUTOBOOT_KEYED))
 			abort = abortboot_key_sequence(bootdelay);
 		else
 			abort = abortboot_single_key(bootdelay);
 	}

 	if (IS_ENABLED(CONFIG_SILENT_CONSOLE) && abort)
 		gd->flags &= ~GD_FLG_SILENT;

 	return abort;
 }

 static void process_fdt_options(const void *blob)
 {
 #ifdef CONFIG_SYS_TEXT_BASE
 	ulong addr;

 	/* Add an env variable to point to a kernel payload, if available */
 	addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
 	if (addr)
 		env_set_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));

 	/* Add an env variable to point to a root disk, if available */
 	addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
 	if (addr)
 		env_set_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 #endif /* CONFIG_SYS_TEXT_BASE */
 }

 const char *bootdelay_process(void)
 {
 	char *s;
 	int bootdelay;

 	bootcount_inc();

 	s = env_get("bootdelay");
 	bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;

 	if (IS_ENABLED(CONFIG_OF_CONTROL))
 		bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
 						  bootdelay);

 	debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);

 	if (IS_ENABLED(CONFIG_AUTOBOOT_MENU_SHOW))
 		bootdelay = menu_show(bootdelay);
 	bootretry_init_cmd_timeout();

 #ifdef CONFIG_POST
 	if (gd->flags & GD_FLG_POSTFAIL) {
 		s = env_get("failbootcmd");
 	} else
 #endif /* CONFIG_POST */
 	if (bootcount_error())
 		s = env_get("altbootcmd");
 	else
 		s = env_get("bootcmd");

 	if (IS_ENABLED(CONFIG_OF_CONTROL))
 		process_fdt_options(gd->fdt_blob);
 	stored_bootdelay = bootdelay;

 	return s;
 }

 void autoboot_command(const char *s)
 {
 	debug("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");

 	if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
 		bool lock;
 		int prev;

 		lock = IS_ENABLED(CONFIG_AUTOBOOT_KEYED) &&
 			!IS_ENABLED(CONFIG_AUTOBOOT_KEYED_CTRLC);
 		if (lock)
 			prev = disable_ctrlc(1); /* disable Ctrl-C checking */

 		run_command_list(s, -1, 0);

 		if (lock)
 			disable_ctrlc(prev);	/* restore Ctrl-C checking */
 	}

 	if (IS_ENABLED(CONFIG_USE_AUTOBOOT_MENUKEY) &&
 	    menukey == AUTOBOOT_MENUKEY) {
 		s = env_get("menucmd");
 		if (s)
 			run_command_list(s, -1, 0);
 	}
 }
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* (C) Copyright 2000
	* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
	*/

	#include <common.h>
	#include <autoboot.h>
	#include <bootretry.h>
	#include <cli.h>
	#include <command.h>
	#include <console.h>
	#include <env.h>
	#include <fdtdec.h>
	#include <hash.h>
	#include <memalign.h>
	#include <menu.h>
	#include <post.h>
	#include <time.h>
	#include <u-boot/sha256.h>
	#include <bootcount.h>

	DECLARE_GLOBAL_DATA_PTR;

	#define MAX_DELAY_STOP_STR 32

	#ifndef DEBUG_BOOTKEYS
	#define DEBUG_BOOTKEYS 0
	#endif
	#define debug_bootkeys(fmt, args...) \
	debug_cond(DEBUG_BOOTKEYS, fmt, ##args)

	/* Stored value of bootdelay, used by autoboot_command() */
	static int stored_bootdelay;
	static int menukey;

	#ifdef CONFIG_AUTOBOOT_ENCRYPTION
	#define AUTOBOOT_STOP_STR_SHA256 CONFIG_AUTOBOOT_STOP_STR_SHA256
	#else
	#define AUTOBOOT_STOP_STR_SHA256 ""
	#endif

	#ifdef CONFIG_USE_AUTOBOOT_MENUKEY
	#define AUTOBOOT_MENUKEY CONFIG_USE_AUTOBOOT_MENUKEY
	#else
	#define AUTOBOOT_MENUKEY 0
	#endif

	/*
	* Use a "constant-length" time compare function for this
	* hash compare:
	*
	* https://crackstation.net/hashing-security.htm
	*/
	static int slow_equals(u8 a, u8 b, int len)
	{
	int diff = 0;
	int i;

	for (i = 0; i < len; i++)
	diff \|= a[i] ^ b[i];

	return diff == 0;
	}

	/**
	* passwd_abort_sha256() - check for a hashed key sequence to abort booting
	*
	* This checks for the user entering a SHA256 hash within a given time.
	*
	* @etime: Timeout value ticks (stop when get_ticks() reachs this)
	* @return 0 if autoboot should continue, 1 if it should stop
	*/
	static int passwd_abort_sha256(uint64_t etime)
	{
	const char *sha_env_str = env_get("bootstopkeysha256");
	u8 sha_env[SHA256_SUM_LEN];
	u8 *sha;
	char *presskey;
	const char *algo_name = "sha256";
	u_int presskey_len = 0;
	int abort = 0;
	int size = sizeof(sha);
	int ret;

	if (sha_env_str == NULL)
	sha_env_str = AUTOBOOT_STOP_STR_SHA256;

	/*
	* Generate the binary value from the environment hash value
	* so that we can compare this value with the computed hash
	* from the user input
	*/
	ret = hash_parse_string(algo_name, sha_env_str, sha_env);
	if (ret) {
	printf("Hash %s not supported!\n", algo_name);
	return 0;
	}

	presskey = malloc_cache_aligned(MAX_DELAY_STOP_STR);
	sha = malloc_cache_aligned(SHA256_SUM_LEN);
	size = SHA256_SUM_LEN;
	/*
	* We don't know how long the stop-string is, so we need to
	* generate the sha256 hash upon each input character and
	* compare the value with the one saved in the environment
	*/
	do {
	if (tstc()) {
	/* Check for input string overflow */
	if (presskey_len >= MAX_DELAY_STOP_STR) {
	free(presskey);
	free(sha);
	return 0;
	}

	presskey[presskey_len++] = getc();

	/* Calculate sha256 upon each new char */
	hash_block(algo_name, (const void *)presskey,
	presskey_len, sha, &size);

	/* And check if sha matches saved value in env */
	if (slow_equals(sha, sha_env, SHA256_SUM_LEN))
	abort = 1;
	}
	} while (!abort && get_ticks() <= etime);

	free(presskey);
	free(sha);
	return abort;
	}

	/**
	* passwd_abort_key() - check for a key sequence to aborted booting
	*
	* This checks for the user entering a string within a given time.
	*
	* @etime: Timeout value ticks (stop when get_ticks() reachs this)
	* @return 0 if autoboot should continue, 1 if it should stop
	*/
	static int passwd_abort_key(uint64_t etime)
	{
	int abort = 0;
	struct {
	char *str;
	u_int len;
	int retry;
	}
	delaykey[] = {
	{ .str = env_get("bootdelaykey"), .retry = 1 },
	{ .str = env_get("bootstopkey"), .retry = 0 },
	};

	char presskey[MAX_DELAY_STOP_STR];
	u_int presskey_len = 0;
	u_int presskey_max = 0;
	u_int i;

	# ifdef CONFIG_AUTOBOOT_DELAY_STR
	if (delaykey[0].str == NULL)
	delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
	# endif
	# ifdef CONFIG_AUTOBOOT_STOP_STR
	if (delaykey[1].str == NULL)
	delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;
	# endif

	for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
	delaykey[i].len = delaykey[i].str == NULL ?
	0 : strlen(delaykey[i].str);
	delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
	MAX_DELAY_STOP_STR : delaykey[i].len;

	presskey_max = presskey_max > delaykey[i].len ?
	presskey_max : delaykey[i].len;

	debug_bootkeys("%s key:<%s>\n",
	delaykey[i].retry ? "delay" : "stop",
	delaykey[i].str ? delaykey[i].str : "NULL");
	}

	/* In order to keep up with incoming data, check timeout only
	* when catch up.
	*/
	do {
	if (tstc()) {
	if (presskey_len < presskey_max) {
	presskey[presskey_len++] = getc();
	} else {
	for (i = 0; i < presskey_max - 1; i++)
	presskey[i] = presskey[i + 1];

	presskey[i] = getc();
	}
	}

	for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
	if (delaykey[i].len > 0 &&
	presskey_len >= delaykey[i].len &&
	memcmp(presskey + presskey_len -
	delaykey[i].len, delaykey[i].str,
	delaykey[i].len) == 0) {
	debug_bootkeys("got %skey\n",
	delaykey[i].retry ? "delay" :
	"stop");

	/* don't retry auto boot */
	if (!delaykey[i].retry)
	bootretry_dont_retry();
	abort = 1;
	}
	}
	} while (!abort && get_ticks() <= etime);

	return abort;
	}

	/***************************************************************************
	* Watch for 'delay' seconds for autoboot stop or autoboot delay string.
	* returns: 0 - no key string, allow autoboot 1 - got key string, abort
	*/
	static int abortboot_key_sequence(int bootdelay)
	{
	int abort;
	uint64_t etime = endtick(bootdelay);

	# ifdef CONFIG_AUTOBOOT_PROMPT
	/*
	* CONFIG_AUTOBOOT_PROMPT includes the %d for all boards.
	* To print the bootdelay value upon bootup.
	*/
	printf(CONFIG_AUTOBOOT_PROMPT, bootdelay);
	# endif

	if (IS_ENABLED(CONFIG_AUTOBOOT_ENCRYPTION))
	abort = passwd_abort_sha256(etime);
	else
	abort = passwd_abort_key(etime);
	if (!abort)
	debug_bootkeys("key timeout\n");

	return abort;
	}

	static int abortboot_single_key(int bootdelay)
	{
	int abort = 0;
	unsigned long ts;

	printf("Hit any key to stop autoboot: %2d ", bootdelay);

	/*
	* Check if key already pressed
	*/
	if (tstc()) { /* we got a key press */
	(void) getc(); /* consume input */
	puts("\b\b\b 0");
	abort = 1; /* don't auto boot */
	}

	while ((bootdelay > 0) && (!abort)) {
	--bootdelay;
	/* delay 1000 ms */
	ts = get_timer(0);
	do {
	if (tstc()) { /* we got a key press */
	int key;

	abort = 1; /* don't auto boot */
	bootdelay = 0; /* no more delay */
	key = getc(); /* consume input */
	if (IS_ENABLED(CONFIG_USE_AUTOBOOT_MENUKEY))
	menukey = key;
	break;
	}
	udelay(10000);
	} while (!abort && get_timer(ts) < 1000);

	printf("\b\b\b%2d ", bootdelay);
	}

	putc('\n');

	return abort;
	}

	static int abortboot(int bootdelay)
	{
	int abort = 0;

	if (bootdelay >= 0) {
	if (IS_ENABLED(CONFIG_AUTOBOOT_KEYED))
	abort = abortboot_key_sequence(bootdelay);
	else
	abort = abortboot_single_key(bootdelay);
	}

	if (IS_ENABLED(CONFIG_SILENT_CONSOLE) && abort)
	gd->flags &= ~GD_FLG_SILENT;

	return abort;
	}

	static void process_fdt_options(const void *blob)
	{
	#ifdef CONFIG_SYS_TEXT_BASE
	ulong addr;

	/* Add an env variable to point to a kernel payload, if available */
	addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
	if (addr)
	env_set_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));

	/* Add an env variable to point to a root disk, if available */
	addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
	if (addr)
	env_set_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
	#endif /* CONFIG_SYS_TEXT_BASE */
	}

	const char *bootdelay_process(void)
	{
	char *s;
	int bootdelay;

	bootcount_inc();

	s = env_get("bootdelay");
	bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;

	if (IS_ENABLED(CONFIG_OF_CONTROL))
	bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
	bootdelay);

	debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);

	if (IS_ENABLED(CONFIG_AUTOBOOT_MENU_SHOW))
	bootdelay = menu_show(bootdelay);
	bootretry_init_cmd_timeout();

	#ifdef CONFIG_POST
	if (gd->flags & GD_FLG_POSTFAIL) {
	s = env_get("failbootcmd");
	} else
	#endif /* CONFIG_POST */
	if (bootcount_error())
	s = env_get("altbootcmd");
	else
	s = env_get("bootcmd");

	if (IS_ENABLED(CONFIG_OF_CONTROL))
	process_fdt_options(gd->fdt_blob);
	stored_bootdelay = bootdelay;

	return s;
	}

	void autoboot_command(const char *s)
	{
	debug("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");

	if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
	bool lock;
	int prev;

	lock = IS_ENABLED(CONFIG_AUTOBOOT_KEYED) &&
	!IS_ENABLED(CONFIG_AUTOBOOT_KEYED_CTRLC);
	if (lock)
	prev = disable_ctrlc(1); /* disable Ctrl-C checking */

	run_command_list(s, -1, 0);

	if (lock)
	disable_ctrlc(prev); /* restore Ctrl-C checking */
	}

	if (IS_ENABLED(CONFIG_USE_AUTOBOOT_MENUKEY) &&
	menukey == AUTOBOOT_MENUKEY) {
	s = env_get("menucmd");
	if (s)
	run_command_list(s, -1, 0);
	}
	}