/*
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <linux/mtd/mtd.h>
#include "fw_env.h"

typedef	unsigned char	uchar;

#define	CMD_GETENV	"fw_printenv"
#define	CMD_SETENV	"fw_setenv"

typedef struct envdev_s {
	uchar devname[16]; /* Device name */
	ulong env_size;    /* environment size */
	ulong erase_size;  /* device erase size */
} envdev_t;

static envdev_t envdevices[2];
static int curdev;

#define DEVNAME(i)    envdevices[(i)].devname
#define ENVSIZE(i)    envdevices[(i)].env_size
#define DEVESIZE(i)   envdevices[(i)].erase_size

#define CFG_ENV_SIZE ENVSIZE(curdev)

#ifdef HAVE_REDUND
#define ENV_SIZE (CFG_ENV_SIZE - sizeof(long) - 1)
#else
#define ENV_SIZE (CFG_ENV_SIZE - sizeof(long))
#endif

typedef struct environment_s {
	ulong	crc;		/* CRC32 over data bytes	*/
	uchar   flags;      /* active or obsolete */
	uchar *data;
} env_t;

static env_t environment;
static int valid = 0;

#ifdef HAVE_REDUND
static uchar active_flag = 1;
static uchar obsolete_flag = 0;
#endif

#define XMK_STR(x)	#x
#define MK_STR(x)	XMK_STR(x)

static uchar default_environment[] = {
#ifdef	CONFIG_BOOTARGS
	"bootargs="	CONFIG_BOOTARGS			"\0"
#endif
#ifdef	CONFIG_BOOTCOMMAND
	"bootcmd="	CONFIG_BOOTCOMMAND		"\0"
#endif
#if (CONFIG_BOOTDELAY >= 0)
	"bootdelay="	MK_STR(CONFIG_BOOTDELAY)	"\0"
#endif
#if (CONFIG_BAUDRATE >= 0)
	"baudrate="	MK_STR(CONFIG_BAUDRATE)		"\0"
#endif
#ifdef	CONFIG_ETHADDR
	"ethaddr="	MK_STR(CONFIG_ETHADDR)		"\0"
#endif
#ifdef	CONFIG_IPADDR
	"ipaddr="	MK_STR(CONFIG_IPADDR)		"\0"
#endif
#ifdef	CONFIG_SERVERIP
	"serverip="	MK_STR(CONFIG_SERVERIP)		"\0"
#endif
	"\0"
};

static int  flash_io (int mode);
static uchar *envmatch(uchar *s1, uchar *s2);
static int env_init(void);
static int parse_config(void);


/*
 * Search the environment for a variable.
 * Return the value, if found, or NULL, if not found.
 */
unsigned char *fw_getenv (unsigned char *name)
{
	uchar *env, *nxt;

	if (env_init())
		return (NULL);

	for (env=environment.data; *env; env=nxt+1) {
		uchar *val;

		for (nxt=env; *nxt; ++nxt) {
			if (nxt >= &environment.data[ENV_SIZE]) {
				fprintf (stderr, "## Error: "
					"environment not terminated\n");
				return (NULL);
			}
		}
		val=envmatch(name, env);
		if (!val)
			continue;
		return (val);
	}
	return (NULL);
}

/*
 * Print the current definition of one, or more, or all
 * environment variables
 */
void fw_printenv(int argc, char *argv[])
{
	uchar *env, *nxt;
	int i, n_flag;

	if (env_init())
		return;

	if (argc == 1) {		/* Print all env variables	*/
		for (env=environment.data; *env; env=nxt+1) {
			for (nxt=env; *nxt; ++nxt) {
				if (nxt >= &environment.data[ENV_SIZE]) {
					fprintf (stderr, "## Error: "
						"environment not terminated\n");
					return;
				}
			}

			printf("%s\n", env);
		}
		return;
	}

	if (strcmp(argv[1], "-n") == 0) {
		n_flag = 1;
		++argv;
		--argc;
		if (argc != 2) {
			fprintf (stderr, "## Error: "
				"`-n' option requires exactly one argument\n");
			return;
		}
	} else {
		n_flag = 0;
	}

	for (i=1; i<argc; ++i) {	/* print single env variables	*/
		uchar *name = argv[i];
		uchar *val = NULL;

		for (env=environment.data; *env; env=nxt+1) {

			for (nxt=env; *nxt; ++nxt) {
				if (nxt >= &environment.data[ENV_SIZE]) {
					fprintf (stderr, "## Error: "
						"environment not terminated\n");
					return;
				}
			}
			val=envmatch(name, env);
			if (val) {
				if (!n_flag) {
					fputs (name, stdout);
					putc  ('=',  stdout);
				}
				puts  (val);
				break;
			}
		}
		if (!val)
			fprintf (stderr, "## Error: \"%s\" not defined\n",
			 name);
	}
}

/*
 * Deletes or sets environment variables. Returns errno style error codes:
 * 0	  - OK
 * EINVAL - need at least 1 argument
 * EROFS  - certain variables ("ethaddr", "serial#") cannot be
 *	    modified or deleted
 *
 */
int fw_setenv (int argc, char *argv[])
{
	int  i, len;
	uchar *env, *nxt;
	uchar *oldval = NULL;
	uchar *name;

	if (argc < 2) {
		return (EINVAL);
	}

	if (env_init())
		return (errno);

	name = argv[1];

	/*
	 * search if variable with this name already exists
	 */
	for (env=environment.data; *env; env=nxt+1) {
		for (nxt=env; *nxt; ++nxt) {
			if (nxt >= &environment.data[ENV_SIZE]) {
				fprintf (stderr, "## Error: "
					"environment not terminated\n");
				return (EINVAL);
			}
		}
		if ((oldval=envmatch(name, env)) != NULL)
			break;
	}

	/*
	 * Delete any existing definition
	 */
	if (oldval) {
		/*
		 * Ethernet Address and serial# can be set only once
		 */
		if ((strcmp (name, "ethaddr") == 0) ||
		    (strcmp (name, "serial#") == 0) ) {
			fprintf (stderr, "Can't overwrite \"%s\"\n", name);
			return (EROFS);
		}

		if (*++nxt == '\0') {
			*env = '\0';
		} else {
			for (;;) {
				*env = *nxt++;
				if ((*env == '\0') && (*nxt == '\0'))
					break;
				++env;
			}
		}
		*++env = '\0';
	}

	/* Delete only ? */
	if (argc < 3)
		goto WRITE_FLASH;

	/*
	 * Append new definition at the end
	 */
	for (env=environment.data; *env || *(env+1); ++env)
		;
	if (env > environment.data)
		++env;
	/*
	 * Overflow when:
	 * "name" + "=" + "val" +"\0\0"  > CFG_ENV_SIZE - (env-environment)
	 */
	len = strlen(name) + 2;
	/* add '=' for first arg, ' ' for all others */
	for (i=2; i<argc; ++i) {
		len += strlen(argv[i]) + 1;
	}
	if (len > (&environment.data[ENV_SIZE]-env)) {
		fprintf (stderr,
			"Error: environment overflow, \"%s\" deleted\n",
			name);
		return (-1);
	}
	while ((*env = *name++) != '\0')
		env++;
	for (i=2; i<argc; ++i) {
		uchar *val = argv[i];

		*env = (i==2) ? '=' : ' ';
		while ((*++env = *val++) != '\0')
			;
	}

	/* end is marked with double '\0' */
	*++env = '\0';

WRITE_FLASH:

	/* Update CRC */
	environment.crc = crc32(0, environment.data, ENV_SIZE);

	/* write environment back to flash */
	if (flash_io (O_RDWR)) {
		fprintf (stderr,
			"Error: can't write fw_env to flash\n");
		return (-1);
	}

	return (0);
}

static int flash_io (int mode)
{
	int fd, fdr, rc, otherdev, len, resid;
	erase_info_t erase;
	char *data;

	if ((fd = open(DEVNAME(curdev), mode)) < 0) {
		fprintf (stderr, 
				 "Can't open %s: %s\n", 
				 DEVNAME(curdev), strerror(errno));
		return (-1);
	}

	len = sizeof(environment.crc) + sizeof(environment.flags);

	if (mode == O_RDWR) {
#ifdef HAVE_REDUND
		/* switch to next partition for writing */
		otherdev = !curdev;
		if ((fdr = open(DEVNAME(otherdev), mode)) < 0) {
			fprintf (stderr, 
					 "Can't open %s: %s\n", 
					 DEVNAME(otherdev), strerror(errno));
			return (-1);
		}
#else
		otherdev = curdev;
		fdr = fd;
		len = sizeof(environment.crc);
#endif
		printf("Unlocking flash...\n");
		erase.length = DEVESIZE(otherdev);
		erase.start = 0;
		ioctl (fdr, MEMUNLOCK, &erase);

#ifdef HAVE_REDUND
		erase.length = DEVESIZE(curdev);
		erase.start = 0;
		ioctl (fd, MEMUNLOCK, &erase);
		environment.flags = active_flag;
#endif
		printf("Done\n");
		resid = DEVESIZE(otherdev) - CFG_ENV_SIZE;
		if (resid) {
			if ((data = malloc(resid)) == NULL) {
				fprintf(stderr, 
				  "Cannot malloc %d bytes: %s\n",
				  resid, strerror(errno));
				return (-1);
			}
			if (lseek (fdr, CFG_ENV_SIZE, SEEK_SET) == -1) {
				fprintf (stderr,
				  "seek error on %s: %s\n", 
				   DEVNAME(curdev), strerror(errno));
				return (-1);
			}
			if ((rc = read (fdr, data, resid)) != resid) {
				fprintf (stderr,
				  "read error on %s: %s\n", 
				  DEVNAME(curdev), strerror(errno));
				return (-1);
			}
			if (lseek (fdr, 0, SEEK_SET) == -1) {
				fprintf (stderr,
				  "seek error on %s: %s\n", 
				  DEVNAME(curdev), strerror(errno));
				return (-1);
			}
		}

		printf("Erasing old environment...\n");

		erase.length = DEVESIZE(otherdev);
		if (ioctl (fdr, MEMERASE, &erase) != 0) {
			fprintf (stderr, "MTD erase error on %s: %s\n",
			  DEVNAME(otherdev), strerror(errno));
			return (-1);
		}

		printf("Done\n");

		printf("Writing environment to %s...\n",DEVNAME(otherdev));
		if (write(fdr, &environment, len) != len) {
			fprintf (stderr,
			  "CRC write error on %s: %s\n", 
			  DEVNAME(otherdev), strerror(errno));
			return (-1);
		}
		if (write(fdr, environment.data, ENV_SIZE) != ENV_SIZE) {
			fprintf (stderr,
			  "Write error on %s: %s\n", 
			  DEVNAME(otherdev), strerror(errno));
			return (-1);
		}
		if (resid) {
			if (write (fdr, data, resid) != resid) {
				fprintf (stderr,
				 "write error on %s: %s\n", 
				  DEVNAME(curdev), strerror(errno));
				return (-1);
			}
			free(data);
		}
#ifdef HAVE_REDUND
		/* change flag on current active env partition */
		if (lseek (fd, sizeof(ulong), SEEK_SET) == -1) {
			fprintf (stderr,
			  "seek error on %s: %s\n", 
			  DEVNAME(curdev), strerror(errno));
			return (-1);
		}
		if (write (fd, &obsolete_flag, sizeof(obsolete_flag)) != 
			sizeof(obsolete_flag)) {
			fprintf (stderr,
			 "Write error on %s: %s\n", 
			 DEVNAME(curdev), strerror(errno));
			return (-1);
		}
#endif
		printf("Done\n");
		printf("Locking ...\n");
		erase.length = DEVESIZE(otherdev);
		erase.start = 0;
		ioctl (fdr, MEMLOCK, &erase);
#ifdef HAVE_REDUND
		erase.length = DEVESIZE(curdev);
		erase.start = 0;
		ioctl (fd, MEMLOCK, &erase);
		if (close(fdr)) {
			fprintf (stderr,
			 "I/O error on %s: %s\n", 
			 DEVNAME(otherdev), strerror(errno));
			return (-1);
		}
#endif
		printf("Done\n");
	} else {
#ifndef HAVE_REDUND
		len = sizeof(environment.crc);
#endif
		if (read (fd, &environment, len) != len) {
			fprintf (stderr,
			 "CRC read error on %s: %s\n", 
			 DEVNAME(curdev), strerror(errno));
			return (-1);
		}
		if ((rc = read (fd, environment.data, ENV_SIZE)) != ENV_SIZE) {
			fprintf (stderr,
			 "Read error on %s: %s\n", 
			  DEVNAME(curdev), strerror(errno));
			return (-1);
		}
	}

	if (close(fd)) {
		fprintf (stderr,
		  "I/O error on %s: %s\n", 
		  DEVNAME(curdev), strerror(errno));
		return (-1);
	}

	/* everything ok */
	return (0);
}

/*
 * s1 is either a simple 'name', or a 'name=value' pair.
 * s2 is a 'name=value' pair.
 * If the names match, return the value of s2, else NULL.
 */

static uchar *
envmatch (uchar *s1, uchar *s2)
{

	while (*s1 == *s2++)
		if (*s1++ == '=')
			return(s2);
	if (*s1 == '\0' && *(s2-1) == '=')
		return(s2);
	return(NULL);
}

/*
 * Prevent confusion if running from erased flash memory
 */
static int env_init(void)
{
	int crc1, crc1_ok;
	uchar *addr1;
#ifdef HAVE_REDUND
	int crc2, crc2_ok;
	uchar flag1, flag2, *addr2;
#endif

	
	if (!valid) {

		if (parse_config()) /* should fill envdevices */
			return 1;

		if ((addr1 = calloc (1, ENV_SIZE)) == NULL) {
			fprintf (stderr, 
			 "Not enough memory for environment (%ld bytes)\n",
			 ENV_SIZE);
			return (errno);
		}

		/* read environment from FLASH to local buffer */
		environment.data = addr1;
		curdev = 0;
		if (flash_io (O_RDONLY)) {
			return (errno);
		}

		crc1_ok = ((crc1 = crc32(0, environment.data, ENV_SIZE)) 
			 == environment.crc);
#ifndef HAVE_REDUND
		if (!crc1_ok) {
			fprintf (stderr, 
			 "Warning: Bad CRC, using default environment\n");
			environment.data = default_environment;
			free(addr1);
		}
#else
		flag1 = environment.flags;
		
		curdev = 1;
		if ((addr2 = calloc (1, ENV_SIZE)) == NULL) {
			fprintf (stderr, 
			 "Not enough memory for environment (%ld bytes)\n",
			 ENV_SIZE);
			return (errno);
		}		
		environment.data = addr2;

		if (flash_io (O_RDONLY)) {
			return (errno);
		}

		crc2_ok = ((crc2 = crc32(0, environment.data, ENV_SIZE)) 
				   == environment.crc);
		flag2 = environment.flags;
		
		if (crc1_ok && ! crc2_ok) {
			environment.data  = addr1;
			environment.flags = flag1;
			environment.crc = crc1;
			curdev = 0;
			free(addr2);
		}
		else if (! crc1_ok && crc2_ok) {
			environment.data  = addr2;
			environment.flags = flag2;
			environment.crc = crc2;
			curdev = 1;
			free(addr1);
		}
		else if (! crc1_ok && ! crc2_ok) {
			fprintf (stderr, 
			 "Warning: Bad CRC, using default environment\n");
			environment.data = default_environment;
			curdev = 0;
			free(addr2);
			free(addr1);
		}
		else if (flag1 == active_flag && flag2 == obsolete_flag) {
			environment.data  = addr1;
			environment.flags = flag1;
			environment.crc = crc1;
			curdev = 0;
			free(addr2);
		}
		else if (flag1 == obsolete_flag && flag2 == active_flag) {
			environment.data  = addr2;
			environment.flags = flag2;
			environment.crc = crc2;
			curdev = 1;
			free(addr1);
		}
		else if (flag1 == flag2) {
			environment.data  = addr1;
			environment.flags = flag1;
			environment.crc = crc1;
			curdev = 0;
			free(addr2);
		}
		else if (flag1 == 0xFF)	{
			environment.data  = addr1;
			environment.flags = flag1;
			environment.crc = crc1;
			curdev = 0;
			free(addr2);
		}
		else if (flag2 == 0xFF) {
			environment.data  = addr2;
			environment.flags = flag2;
			environment.crc = crc2;
			curdev = 1;
			free(addr1);
		}
#endif		
		valid = 1;
	}
	return (0);
}


static int parse_config()
{
	struct stat st;

	if (stat (DEVICE1_NAME, &st)) {
		fprintf (stderr, 
		 "Cannot access MTD device %s: %s\n", 
		 DEVICE1_NAME, strerror(errno));
		return 1;
	}

	strcpy(DEVNAME(0), DEVICE1_NAME);
	ENVSIZE(0) = ENV1_SIZE;
	DEVESIZE(0) = DEVICE1_ESIZE;
#ifdef HAVE_REDUND
	if (stat (DEVICE2_NAME, &st)) {
		fprintf (stderr, 
		 "Cannot access MTD device %s: %s\n", 
		 DEVICE2_NAME, strerror(errno));
		return 1;
	}
	strcpy(DEVNAME(1), DEVICE2_NAME);
	ENVSIZE(1) = ENV2_SIZE;
	DEVESIZE(1) = DEVICE2_ESIZE;
#endif
	return 0;
}