/*
 * (C) Copyright 2000-2008
 * 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>

#ifdef MTD_OLD
# include <linux/mtd/mtd.h>
#else
# define  __user	/* nothing */
# include <mtd/mtd-user.h>
#endif

#include "fw_env.h"

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

typedef struct envdev_s {
	char devname[16];		/* Device name */
	ulong devoff;			/* Device offset */
	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 DEVOFFSET(i)  envdevices[(i)].devoff
#define ENVSIZE(i)    envdevices[(i)].env_size
#define DEVESIZE(i)   envdevices[(i)].erase_size

#define CFG_ENV_SIZE ENVSIZE(curdev)

#define ENV_SIZE      getenvsize()

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

static env_t environment;

static int HaveRedundEnv = 0;

static unsigned char active_flag = 1;
static unsigned char obsolete_flag = 0;


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

static char default_environment[] = {
#if defined(CONFIG_BOOTARGS)
	"bootargs=" CONFIG_BOOTARGS "\0"
#endif
#if defined(CONFIG_BOOTCOMMAND)
	"bootcmd=" CONFIG_BOOTCOMMAND "\0"
#endif
#if defined(CONFIG_RAMBOOTCOMMAND)
	"ramboot=" CONFIG_RAMBOOTCOMMAND "\0"
#endif
#if defined(CONFIG_NFSBOOTCOMMAND)
	"nfsboot=" CONFIG_NFSBOOTCOMMAND "\0"
#endif
#if defined(CONFIG_BOOTDELAY) && (CONFIG_BOOTDELAY >= 0)
	"bootdelay=" MK_STR (CONFIG_BOOTDELAY) "\0"
#endif
#if defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0)
	"baudrate=" MK_STR (CONFIG_BAUDRATE) "\0"
#endif
#ifdef	CONFIG_LOADS_ECHO
	"loads_echo=" MK_STR (CONFIG_LOADS_ECHO) "\0"
#endif
#ifdef	CONFIG_ETHADDR
	"ethaddr=" MK_STR (CONFIG_ETHADDR) "\0"
#endif
#ifdef	CONFIG_ETH1ADDR
	"eth1addr=" MK_STR (CONFIG_ETH1ADDR) "\0"
#endif
#ifdef	CONFIG_ETH2ADDR
	"eth2addr=" MK_STR (CONFIG_ETH2ADDR) "\0"
#endif
#ifdef	CONFIG_ETH3ADDR
	"eth3addr=" MK_STR (CONFIG_ETH3ADDR) "\0"
#endif
#ifdef	CONFIG_ETHPRIME
	"ethprime=" CONFIG_ETHPRIME "\0"
#endif
#ifdef	CONFIG_IPADDR
	"ipaddr=" MK_STR (CONFIG_IPADDR) "\0"
#endif
#ifdef	CONFIG_SERVERIP
	"serverip=" MK_STR (CONFIG_SERVERIP) "\0"
#endif
#ifdef	CFG_AUTOLOAD
	"autoload=" CFG_AUTOLOAD "\0"
#endif
#ifdef	CONFIG_ROOTPATH
	"rootpath=" MK_STR (CONFIG_ROOTPATH) "\0"
#endif
#ifdef	CONFIG_GATEWAYIP
	"gatewayip=" MK_STR (CONFIG_GATEWAYIP) "\0"
#endif
#ifdef	CONFIG_NETMASK
	"netmask=" MK_STR (CONFIG_NETMASK) "\0"
#endif
#ifdef	CONFIG_HOSTNAME
	"hostname=" MK_STR (CONFIG_HOSTNAME) "\0"
#endif
#ifdef	CONFIG_BOOTFILE
	"bootfile=" MK_STR (CONFIG_BOOTFILE) "\0"
#endif
#ifdef	CONFIG_LOADADDR
	"loadaddr=" MK_STR (CONFIG_LOADADDR) "\0"
#endif
#ifdef	CONFIG_PREBOOT
	"preboot=" CONFIG_PREBOOT "\0"
#endif
#ifdef	CONFIG_CLOCKS_IN_MHZ
	"clocks_in_mhz=" "1" "\0"
#endif
#if defined(CONFIG_PCI_BOOTDELAY) && (CONFIG_PCI_BOOTDELAY > 0)
	"pcidelay=" MK_STR (CONFIG_PCI_BOOTDELAY) "\0"
#endif
#ifdef  CONFIG_EXTRA_ENV_SETTINGS
	CONFIG_EXTRA_ENV_SETTINGS
#endif
	"\0"			/* Termimate env_t data with 2 NULs */
};

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

#if defined(CONFIG_FILE)
static int get_config (char *);
#endif
static inline ulong getenvsize (void)
{
	ulong rc = CFG_ENV_SIZE - sizeof (long);

	if (HaveRedundEnv)
		rc -= sizeof (char);
	return rc;
}

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

	if (env_init ())
		return (NULL);

	for (env = environment.data; *env; env = nxt + 1) {
		char *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
 */
int fw_printenv (int argc, char *argv[])
{
	char *env, *nxt;
	int i, n_flag;
	int rc = 0;

	if (env_init ())
		return (-1);

	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 (-1);
				}
			}

			printf ("%s\n", env);
		}
		return (0);
	}

	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 (-1);
		}
	} else {
		n_flag = 0;
	}

	for (i = 1; i < argc; ++i) {	/* print single env variables   */
		char *name = argv[i];
		char *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 (-1);
				}
			}
			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);
			rc = -1;
		}
	}

	return (rc);
}

/*
 * 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;
	char *env, *nxt;
	char *oldval = NULL;
	char *name;

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

	if (env_init ())
		return (errno);

	name = argv[1];

	/*
	 * search if variable with this name already exists
	 */
	for (nxt = 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) {
		char *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, (uint8_t*) 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 = NULL;

	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);
	if (HaveRedundEnv) {
		len += sizeof (environment.flags);
	}

	if (mode == O_RDWR) {
		if (HaveRedundEnv) {
			/* 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;
		}
		printf ("Unlocking flash...\n");
		erase.length = DEVESIZE (otherdev);
		erase.start = DEVOFFSET (otherdev);
		ioctl (fdr, MEMUNLOCK, &erase);

		if (HaveRedundEnv) {
			erase.length = DEVESIZE (curdev);
			erase.start = DEVOFFSET (curdev);
			ioctl (fd, MEMUNLOCK, &erase);
			environment.flags = active_flag;
		}

		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, DEVOFFSET (otherdev) + CFG_ENV_SIZE, SEEK_SET)
				== -1) {
				fprintf (stderr, "seek error on %s: %s\n",
					DEVNAME (otherdev),
					strerror (errno));
				return (-1);
			}
			if ((rc = read (fdr, data, resid)) != resid) {
				fprintf (stderr,
					"read error on %s: %s\n",
					DEVNAME (otherdev),
					strerror (errno));
				return (-1);
			}
		}

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

		erase.length = DEVESIZE (otherdev);
		erase.start = DEVOFFSET (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 (lseek (fdr, DEVOFFSET (otherdev), SEEK_SET) == -1) {
			fprintf (stderr,
				"seek error on %s: %s\n",
				DEVNAME (otherdev), strerror (errno));
			return (-1);
		}
		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);
		}
		if (HaveRedundEnv) {
			/* change flag on current active env partition */
			if (lseek (fd, DEVOFFSET (curdev) + 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);
			}
		}
		printf ("Done\n");
		printf ("Locking ...\n");
		erase.length = DEVESIZE (otherdev);
		erase.start = DEVOFFSET (otherdev);
		ioctl (fdr, MEMLOCK, &erase);
		if (HaveRedundEnv) {
			erase.length = DEVESIZE (curdev);
			erase.start = DEVOFFSET (curdev);
			ioctl (fd, MEMLOCK, &erase);
			if (close (fdr)) {
				fprintf (stderr,
					"I/O error on %s: %s\n",
					DEVNAME (otherdev),
					strerror (errno));
				return (-1);
			}
		}
		printf ("Done\n");
	} else {

		if (lseek (fd, DEVOFFSET (curdev), SEEK_SET) == -1) {
			fprintf (stderr,
				"seek error on %s: %s\n",
				DEVNAME (curdev), strerror (errno));
			return (-1);
		}
		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 char *envmatch (char * s1, char * 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;
	char *addr1;

	int crc2, crc2_ok;
	char flag1, flag2, *addr2;

	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, (uint8_t *) environment.data, ENV_SIZE))
			   == environment.crc);
	if (!HaveRedundEnv) {
		if (!crc1_ok) {
			fprintf (stderr,
				"Warning: Bad CRC, using default environment\n");
			memcpy(environment.data, default_environment, sizeof default_environment);
		}
	} 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, (uint8_t *) 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");
			memcpy(environment.data, default_environment, sizeof default_environment);
			curdev = 0;
			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);
		}
	}
	return (0);
}


static int parse_config ()
{
	struct stat st;

#if defined(CONFIG_FILE)
	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
	if (get_config (CONFIG_FILE)) {
		fprintf (stderr,
			"Cannot parse config file: %s\n", strerror (errno));
		return 1;
	}
#else
	strcpy (DEVNAME (0), DEVICE1_NAME);
	DEVOFFSET (0) = DEVICE1_OFFSET;
	ENVSIZE (0) = ENV1_SIZE;
	DEVESIZE (0) = DEVICE1_ESIZE;
#ifdef HAVE_REDUND
	strcpy (DEVNAME (1), DEVICE2_NAME);
	DEVOFFSET (1) = DEVICE2_OFFSET;
	ENVSIZE (1) = ENV2_SIZE;
	DEVESIZE (1) = DEVICE2_ESIZE;
	HaveRedundEnv = 1;
#endif
#endif
	if (stat (DEVNAME (0), &st)) {
		fprintf (stderr,
			"Cannot access MTD device %s: %s\n",
			DEVNAME (0), strerror (errno));
		return 1;
	}

	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
		fprintf (stderr,
			"Cannot access MTD device %s: %s\n",
			DEVNAME (1), strerror (errno));
		return 1;
	}
	return 0;
}

#if defined(CONFIG_FILE)
static int get_config (char *fname)
{
	FILE *fp;
	int i = 0;
	int rc;
	char dump[128];

	if ((fp = fopen (fname, "r")) == NULL) {
		return 1;
	}

	while ((i < 2) && ((rc = fscanf (fp, "%s %lx %lx %lx",
				  DEVNAME (i),
				  &DEVOFFSET (i),
				  &ENVSIZE (i),
				  &DEVESIZE (i)  )) != EOF)) {

		/* Skip incomplete conversions and comment strings */
		if ((rc < 3) || (*DEVNAME (i) == '#')) {
			fgets (dump, sizeof (dump), fp);	/* Consume till end */
			continue;
		}

		i++;
	}
	fclose (fp);

	HaveRedundEnv = i - 1;
	if (!i) {			/* No valid entries found */
		errno = EINVAL;
		return 1;
	} else
		return 0;
}
#endif