/*
 * state.c - state handling tool
 *
 * Copyright (c) 2014 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * 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.
 */
#include <libudev.h>
#include <common.h>
#include <dirent.h>
#include <getopt.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <dt.h>

#include <asm/byteorder.h>
#include <linux/types.h>
#include <mtd/mtd-abi.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>

static int verbose;

enum state_variable_type {
	STATE_TYPE_INVALID = 0,
	STATE_TYPE_ENUM,
	STATE_TYPE_U32,
	STATE_TYPE_MAC,
};

struct state_backend;

struct state {
	struct list_head variables;
	const char *name;
	struct list_head list;
	struct state_backend *backend;
	uint32_t magic;
	int dirty;
};

struct state_backend {
	int (*load)(struct state_backend *backend, struct state *state);
	int (*save)(struct state_backend *backend, struct state *state);
	const char *name;
	char *path;
};

/* list of all registered state instances */
static LIST_HEAD(state_list);

/* instance of a single variable */
struct state_variable {
	enum state_variable_type type;
	struct list_head list;
	char *name;
	void *raw;
	int raw_size;
	int index;
};

/* A variable type (uint32, enum32) */
struct variable_type {
	enum state_variable_type type;
	const char *type_name;
	struct list_head list;
	int (*export)(struct state_variable *, struct device_node *);
	int (*init)(struct state_variable *, struct device_node *);
	struct state_variable *(*create)(struct state *state,
			const char *name, struct device_node *);
	char *(*get)(struct state_variable *);
	int (*set)(struct state_variable *, const char *val);
	void (*info)(struct state_variable *);
};

/*
 *  uint32
 */
struct state_uint32 {
	struct state_variable var;
	struct param_d *param;
	uint32_t value;
	uint32_t value_default;
};

static int state_var_compare(struct list_head *a, struct list_head *b)
{
	struct state_variable *va = list_entry(a, struct state_variable, list);
	struct state_variable *vb = list_entry(b, struct state_variable, list);

	if (va->index == vb->index)
		return 0;

	return va->index < vb->index ? -1 : 1;
}

static int state_add_variable(struct state *state, struct state_variable *var)
{
	list_add_sort(&var->list, &state->variables, state_var_compare);

	return 0;
}

static inline struct state_uint32 *to_state_uint32(struct state_variable *s)
{
	return container_of(s, struct state_uint32, var);
}

static int state_uint32_export(struct state_variable *var,
		struct device_node *node)
{
	struct state_uint32 *su32 = to_state_uint32(var);
	int ret;

	ret = of_property_write_u32(node, "default", su32->value_default);
	if (ret)
		return ret;

	return of_property_write_u32(node, "value", su32->value);
}

static int state_uint32_init(struct state_variable *sv,
		struct device_node *node)
{
	int len;
	const __be32 *value, *value_default;
	struct state_uint32 *su32 = to_state_uint32(sv);

	value_default = of_get_property(node, "default", &len);
	if (value_default && len != sizeof(uint32_t))
		return -EINVAL;

	value = of_get_property(node, "value", &len);
	if (value && len != sizeof(uint32_t))
		return -EINVAL;

	if (value_default)
		su32->value_default = be32_to_cpu(*value_default);
	if (value)
		su32->value = be32_to_cpu(*value);
	else
		su32->value = su32->value_default;

	return 0;
}

static struct state_variable *state_uint32_create(struct state *state,
		const char *name, struct device_node *node)
{
	struct state_uint32 *su32;

	su32 = xzalloc(sizeof(*su32));

	pr_debug("%s: %s\n", __func__, name);

	su32->var.raw_size = sizeof(uint32_t);
	su32->var.raw = &su32->value;

	return &su32->var;
}

static int state_uint32_set(struct state_variable *var, const char *val)
{
	struct state_uint32 *su32 = to_state_uint32(var);

	su32->value = strtoul(val, NULL, 0);

	return 0;
}

static char *state_uint32_get(struct state_variable *var)
{
	struct state_uint32 *su32 = to_state_uint32(var);
	char *str;
	int ret;

	ret = asprintf(&str, "%d", su32->value);
	if (ret < 0)
		return ERR_PTR(-ENOMEM);

	return str;
}

/*
 *  enum32
 */
struct state_enum32 {
	struct state_variable var;
	struct param_d *param;
	uint32_t value;
	uint32_t value_default;
	const char **names;
	int num_names;
};

static inline struct state_enum32 *to_state_enum32(struct state_variable *s)
{
	return container_of(s, struct state_enum32, var);
}

static int state_enum32_export(struct state_variable *var,
		struct device_node *node)
{
	struct state_enum32 *enum32 = to_state_enum32(var);
	int ret, i, len;
	char *prop, *str;

	ret = of_property_write_u32(node, "default", enum32->value_default);
	if (ret)
		return ret;

	ret = of_property_write_u32(node, "value", enum32->value);
	if (ret)
		return ret;

	len = 0;

	for (i = 0; i < enum32->num_names; i++)
		len += strlen(enum32->names[i]) + 1;

	prop = xzalloc(len);
	str = prop;

	for (i = 0; i < enum32->num_names; i++)
		str += sprintf(str, "%s", enum32->names[i]) + 1;

	ret = of_set_property(node, "names", prop, len, 1);

	free(prop);

	return ret;
}

static int state_enum32_init(struct state_variable *sv, struct device_node *node)
{
	struct state_enum32 *enum32 = to_state_enum32(sv);
	int len;
	const __be32 *value, *value_default;

	value = of_get_property(node, "value", &len);
	if (value && len != sizeof(uint32_t))
		return -EINVAL;

	value_default = of_get_property(node, "default", &len);
	if (value_default && len != sizeof(uint32_t))
		return -EINVAL;

	if (value_default)
		enum32->value_default = be32_to_cpu(*value_default);
	if (value)
		enum32->value = be32_to_cpu(*value);
	else
		enum32->value = enum32->value_default;

	return 0;
}

static struct state_variable *state_enum32_create(struct state *state,
		const char *name, struct device_node *node)
{
	struct state_enum32 *enum32;
	int ret, i, num_names;

	enum32 = xzalloc(sizeof(*enum32));

	num_names = of_property_count_strings(node, "names");

	enum32->names = xzalloc(sizeof(char *) * num_names);
	enum32->num_names = num_names;
	enum32->var.raw_size = sizeof(uint32_t);
	enum32->var.raw = &enum32->value;

	for (i = 0; i < num_names; i++) {
		const char *name;

		ret = of_property_read_string_index(node, "names", i, &name);
		if (ret)
			goto out;
		enum32->names[i] = strdup(name);
	}

	pr_debug("%s: %s\n", __func__, name);

	return &enum32->var;
out:
	free(enum32->names);
	free(enum32);
	return ERR_PTR(ret);
}

static int state_enum32_set(struct state_variable *sv, const char *val)
{
	struct state_enum32 *enum32 = to_state_enum32(sv);
	int i;

	for (i = 0; i < enum32->num_names; i++) {
		if (!strcmp(enum32->names[i], val)) {
			enum32->value = i;
			return 0;
		}
	}

	return -EINVAL;
}

static char *state_enum32_get(struct state_variable *var)
{
	struct state_enum32 *enum32 = to_state_enum32(var);
	char *str;
	int ret;

	ret = asprintf(&str, "%s", enum32->names[enum32->value]);
	if (ret < 0)
		return ERR_PTR(-ENOMEM);

	return str;
}

static void state_enum32_info(struct state_variable *var)
{
	struct state_enum32 *enum32 = to_state_enum32(var);
	int i;

	printf(", values=[");

	for (i = 0; i < enum32->num_names; i++)
		printf("%s%s", enum32->names[i],
				i == enum32->num_names - 1 ? "" : ",");
	printf("]");
}

/*
 *  MAC address
 */
struct state_mac {
	struct state_variable var;
	struct param_d *param;
	uint8_t value[6];
	uint8_t value_default[6];
};

static inline struct state_mac *to_state_mac(struct state_variable *s)
{
	return container_of(s, struct state_mac, var);
}

static int state_mac_export(struct state_variable *var,
		struct device_node *node)
{
	struct state_mac *mac = to_state_mac(var);
	int ret;

	ret = of_property_write_u8_array(node, "default", mac->value_default, 6);
	if (ret)
		return ret;

	return of_property_write_u8_array(node, "value", mac->value, 6);
}

static int state_mac_init(struct state_variable *sv, struct device_node *node)
{
	struct state_mac *mac = to_state_mac(sv);
	uint8_t value[6] = {};
	uint8_t value_default[6] = {};

	of_property_read_u8_array(node, "default", value_default, 6);
	memcpy(mac->value_default, value_default, 6);

	if (!of_property_read_u8_array(node, "value", value, 6))
		memcpy(mac->value, value, 6);
	else
		memcpy(mac->value, value_default, 6);

	return 0;
}

static struct state_variable *state_mac_create(struct state *state,
		const char *name, struct device_node *node)
{
	struct state_mac *mac;
	int ret;

	mac = xzalloc(sizeof(*mac));

	mac->var.raw_size = 6;
	mac->var.raw = mac->value;

	pr_debug("%s: %s\n", __func__, name);

	return &mac->var;
out:
	free(mac);
	return ERR_PTR(ret);
}

int string_to_ethaddr(const char *str, uint8_t enetaddr[6])
{
	int reg;
	char *e;

	if (!str || strlen(str) != 17) {
		memset(enetaddr, 0, 6);
		return -EINVAL;
	}

	if (str[2] != ':' || str[5] != ':' || str[8] != ':' ||
			str[11] != ':' || str[14] != ':')
		return -EINVAL;

	for (reg = 0; reg < 6; ++reg) {
		enetaddr[reg] = strtoul(str, &e, 16);
		str = e + 1;
	}

	return 0;
}

static int state_mac_set(struct state_variable *var, const char *val)
{
	struct state_mac *mac = to_state_mac(var);
	char mac_save[6];
	int ret;

	ret = string_to_ethaddr(val, mac_save);
	if (ret)
		return ret;

	memcpy(mac->value, mac_save, 6);

	return 0;
}

static char *state_mac_get(struct state_variable *var)
{
	struct state_mac *mac = to_state_mac(var);
	char *str;
	int ret;

	ret = asprintf(&str, "%02x:%02x:%02x:%02x:%02x:%02x",
			mac->value[0], mac->value[1], mac->value[2],
			mac->value[3], mac->value[4], mac->value[5]);
	if (ret < 0)
		return ERR_PTR(-ENOMEM);

	return str;
}

static struct variable_type types[] =  {
	{
		.type = STATE_TYPE_U32,
		.type_name = "uint32",
		.export = state_uint32_export,
		.init = state_uint32_init,
		.create = state_uint32_create,
		.set = state_uint32_set,
		.get = state_uint32_get,
	}, {
		.type = STATE_TYPE_ENUM,
		.type_name = "enum32",
		.export = state_enum32_export,
		.init = state_enum32_init,
		.create = state_enum32_create,
		.set = state_enum32_set,
		.get = state_enum32_get,
		.info = state_enum32_info,
	}, {
		.type = STATE_TYPE_MAC,
		.type_name = "mac",
		.export = state_mac_export,
		.init = state_mac_init,
		.create = state_mac_create,
		.set = state_mac_set,
		.get = state_mac_get,
	},
};

static struct variable_type *state_find_type(enum state_variable_type type)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(types); i++) {
		if (type == types[i].type) {
			return &types[i];
		}
	}

	return NULL;
}

static struct variable_type *state_find_type_by_name(const char *name)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(types); i++) {
		if (!strcmp(name, types[i].type_name)) {
			return &types[i];
		}
	}

	return NULL;
}

/*
 * Generic state functions
 */

static struct state *state_new(const char *name)
{
	struct state *state;
	int ret;

	state = xzalloc(sizeof(*state));
	state->name = name;
	INIT_LIST_HEAD(&state->variables);

	list_add_tail(&state->list, &state_list);

	return state;
}

static void state_release(struct state *state)
{
	free(state);
}

static struct device_node *state_to_node(struct state *state)
{
	struct device_node *root, *node;
	struct state_variable *sv;
	int ret;

	root = of_new_node(NULL, NULL);

	list_for_each_entry(sv, &state->variables, list) {
		struct variable_type *vtype;
		char *name;

		asprintf(&name, "%s@%d", sv->name, sv->index);
		node = of_new_node(root, name);
		free(name);

		vtype = state_find_type(sv->type);
		if (!vtype) {
			ret = -ENOENT;
			goto out;
		}

		of_set_property(node, "type", vtype->type_name,
				strlen(vtype->type_name) + 1, 1);

		ret = vtype->export(sv, node);
		if (ret)
			goto out;
	}

	of_property_write_u32(root, "magic", state->magic);

	return root;
out:
	of_delete_node(root);
	return ERR_PTR(ret);
}

static struct state_variable *state_find_var(struct state *state, const char *name)
{
	struct state_variable *sv;

	list_for_each_entry(sv, &state->variables, list) {
		if (!strcmp(sv->name, name))
			return sv;
	}

	return NULL;
}

static char *state_get_var(struct state *state, const char *var)
{
	struct state_variable *sv;
	struct variable_type *vtype;

	sv = state_find_var(state, var);
	if (!sv)
		return NULL;

	vtype = state_find_type(sv->type);

	return vtype->get(sv);
}

static int state_set_var(struct state *state, const char *var, const char *val)
{
	struct state_variable *sv;
	struct variable_type *vtype;
	int ret;

	sv = state_find_var(state, var);
	if (!sv)
		return -ENOENT;

	vtype = state_find_type(sv->type);

	if (!vtype->set)
		return -EPERM;

	ret = vtype->set(sv, val);
	if (ret)
		return ret;

	state->dirty = 1;

	return 0;
}

static int state_variable_from_node(struct state *state, struct device_node *node,
		bool create)
{
	struct variable_type *vtype;
	struct state_variable *sv;
	char *name, *indexs;
	int index = 0;
	const char *type_name = NULL;

	of_property_read_string(node, "type", &type_name);
	if (!type_name)
		return -EINVAL;

	vtype = state_find_type_by_name(type_name);
	if (!vtype)
		return -ENOENT;

	name = strdup(node->name);
	indexs = strchr(name, '@');
	if (indexs) {
		*indexs++ = 0;
		index = strtoul(indexs, NULL, 10);
	}

	if (create) {
		sv = vtype->create(state, name, node);
		if (IS_ERR(sv)) {
			int ret = PTR_ERR(sv);
			pr_err("failed to create %s: %s\n", name, strerror(-ret));
			return ret;
		}
		sv->name = name;
		sv->type = vtype->type;
		sv->index = index;
		state_add_variable(state, sv);
	} else {
		sv = state_find_var(state, name);
		if (IS_ERR(sv)) {
			int ret = PTR_ERR(sv);
			pr_err("no such variable: %s: %s\n", name, strerror(-ret));
			return ret;
		}
	}

	vtype->init(sv, node);

	return 0;
}

int state_from_node(struct state *state, struct device_node *node, bool create)
{
	struct device_node *child;
	int ret;
	uint32_t magic;

	of_property_read_u32(node, "magic", &magic);

	if (create) {
		state->magic = magic;
	} else {
		if (state->magic && state->magic != magic) {
			pr_err("invalid magic 0x%08x, should be 0x%08x\n",
					magic, state->magic);
			return -EINVAL;
		}
	}

	for_each_child_of_node(node, child) {
		ret = state_variable_from_node(state, child, create);
		if (ret)
			return ret;
	}

	return 0;
}

/*
 * state_new_from_node - create a new state instance from a device_node
 *
 * @name	The name of the new state instance
 * @node	The device_node describing the new state instance
 */
struct state *state_new_from_node(const char *name, struct device_node *node)
{
	struct state *state;
	int ret;

	state = state_new(name);
	if (!state)
		return ERR_PTR(-EINVAL);

	ret = state_from_node(state, node, 1);
	if (ret) {
		state_release(state);
		return ERR_PTR(ret);
	}

	return state;
}

/*
 * state_by_name - find a state instance by name
 *
 * @name	The name of the state instance
 */
struct state *state_by_name(const char *name)
{
	struct state *s;

	list_for_each_entry(s, &state_list, list) {
		if (!strcmp(name, s->name))
			return s;
	}

	return NULL;
}

/*
 * state_load - load a state from the backing store
 *
 * @state	The state instance to load
 */
int state_load(struct state *state)
{
	int ret;

	if (!state->backend)
		return -ENOSYS;

	ret = state->backend->load(state->backend, state);
	if (ret)
		return ret;

	state->dirty = 0;

	return 0;
}

/*
 * state_save - save a state to the backing store
 *
 * @state	The state instance to save
 */
int state_save(struct state *state)
{
	int ret;

	if (!state->backend)
		return -ENOSYS;

	ret = state->backend->save(state->backend, state);
	if (ret)
		return ret;

	state->dirty = 0;

	return 0;
}

void state_info(void)
{
	struct state *s;

	printf("registered state instances:\n");

	list_for_each_entry(s, &state_list, list) {
		printf("%-20s ", s->name);
		if (s->backend)
			printf("(backend: %s, path: %s)\n", s->backend->name, s->backend->path);
		else
			printf("(no backend)\n");
	}
}

static int get_meminfo(const char *path, struct mtd_info_user *meminfo)
{
	int fd, ret;

	fd = open(path, O_RDWR);
	if (fd < 0)
		return -errno;

	ret = ioctl(fd, MEMGETINFO, meminfo);

	close(fd);

	if (ret)
		return -errno;

	return 0;
}

/*
 * Raw backend implementation
 */
struct state_backend_raw {
	struct state_backend backend;
	struct state *state;
	unsigned long size_data; /* The raw data size (without magic and crc) */
	unsigned long size_full;
	unsigned long step; /* The step in bytes between two copies */
	off_t offset; /* offset in the storage file */
	size_t size; /* size of the storage area */
	int need_erase;
	int num_copy_read; /* The first successfully read copy */
};

struct backend_raw_header {
	uint32_t magic;
	uint16_t reserved;
	uint16_t data_len;
	uint32_t data_crc;
	uint32_t header_crc;
};

static int backend_raw_load_one(struct state_backend_raw *backend_raw,
		int fd, off_t offset)
{
	struct state *state = backend_raw->state;
	uint32_t crc;
	void *off;
	struct state_variable *sv;
	struct backend_raw_header header = {};
	int ret, len;
	void *buf;

	ret = lseek(fd, offset, SEEK_SET);
	if (ret < 0)
		return ret;

	ret = read(fd, &header, sizeof(header));
	if (ret < 0)
		return ret;
	if (ret < sizeof(header))
		return -EINVAL;

	crc = crc32(0, &header, sizeof(header) - sizeof(uint32_t));
	if (crc != header.header_crc) {
		pr_err("invalid header crc, calculated 0x%08x, found 0x%08x\n",
				crc, header.header_crc);
		return -EINVAL;
	}

	if (state->magic && state->magic != header.magic) {
		pr_err("invalid magic 0x%08x, should be 0x%08x\n",
				header.magic, state->magic);
		return -EINVAL;
	}

	buf = xzalloc(header.data_len);

	ret = read(fd, buf, header.data_len);
	if (ret < 0)
		return ret;
	if (ret < header.data_len)
		return -EINVAL;

	crc = crc32(0, buf, header.data_len);
	if (crc != header.data_crc) {
		pr_err("invalid crc, calculated 0x%08x, found 0x%08x\n",
				crc, header.data_crc);
		return -EINVAL;
	}

	off = buf;
	len = header.data_len;

	list_for_each_entry(sv, &state->variables, list) {
		if (len < sv->raw_size) {
			break;
		}
		memcpy(sv->raw, off, sv->raw_size);
		off += sv->raw_size;
		len -= sv->raw_size;
	}

	free(buf);

	return 0;
}

static int state_backend_raw_load(struct state_backend *backend, struct state *state)
{
	struct state_backend_raw *backend_raw = container_of(backend,
			struct state_backend_raw, backend);
	int ret = 0, fd, i;

	fd = open(backend->path, O_RDONLY);
	if (fd < 0)
		return fd;

	for (i = 0; i < 2; i++) {
		off_t offset = backend_raw->offset + i * backend_raw->step;

		ret = backend_raw_load_one(backend_raw, fd, offset);
		if (!ret) {
			backend_raw->num_copy_read = i;
			pr_debug("copy %d successfully loaded\n", i);
			break;
		}
	}

	close(fd);

	return ret;
}

static int backend_raw_write_one(struct state_backend_raw *backend_raw,
		int fd, int num, void *buf, size_t size)
{
	int ret;
	off_t offset = backend_raw->offset + num * backend_raw->step;

	pr_debug("%s: 0x%08lx 0x%08x\n", __func__, offset, size);

	if (backend_raw->need_erase) {
		struct erase_info_user erase = {
			.start = offset,
			.length = backend_raw->step,
		};

		ret = ioctl(fd, MEMERASE, &erase);
		if (ret < 0)
			return -errno;
	}

	ret = lseek(fd, offset, SEEK_SET);
	if (ret < 0)
		return -errno;

	ret = write(fd, buf, size);
	if (ret < 0)
		return -errno;

	return 0;
}

static int state_backend_raw_save(struct state_backend *backend, struct state *state)
{
	struct state_backend_raw *backend_raw = container_of(backend,
			struct state_backend_raw, backend);
	int ret = 0, size, fd;
	void *buf, *freep, *off, *data, *tmp;
	struct backend_raw_header *header;
	struct state_variable *sv;

	size = backend_raw->size_data + sizeof(struct backend_raw_header);

	freep = off = buf = xzalloc(size);

	header = buf;
	data = buf + sizeof(*header);

	tmp = data;
	list_for_each_entry(sv, &state->variables, list) {
		memcpy(tmp, sv->raw, sv->raw_size);
		tmp += sv->raw_size;
	}

	header->magic = state->magic;
	header->data_len = backend_raw->size_data;
	header->data_crc = crc32(0, data, backend_raw->size_data);
	header->header_crc = crc32(0, header, sizeof(*header) - sizeof(uint32_t));

	fd = open(backend->path, O_WRONLY);
	if (fd < 0)
		return fd;

	ret = backend_raw_write_one(backend_raw, fd, !backend_raw->num_copy_read, buf, size);
	if (ret)
		goto out;

	ret = backend_raw_write_one(backend_raw, fd, backend_raw->num_copy_read, buf, size);
	if (ret)
		goto out;

	pr_debug("wrote state to %s\n", backend->path);
out:
	close(fd);
	free(buf);

	return ret;
}

/*
 * state_backend_raw_file - create a raw file backend store for a state instance
 *
 * @state	The state instance to work on
 * @path	The path where the state will be stored to
 * @offset	The offset in the storage file
 * @size	The maximum size to use in the storage file
 *
 * This backend stores raw binary data from a state instance. The binary data is
 * protected with a magic value which has to match and a crc32 that must be valid.
 * Up to four copies are stored if there is sufficient space available.
 * @path can be a path to a device or a regular file. When it's a device @size may
 * be 0. The four copies are spread to different eraseblocks if approriate for this
 * device.
 */
int state_backend_raw_file(struct state *state, const char *path, off_t offset,
		size_t size)
{
	struct state_backend_raw *backend_raw;
	struct state_backend *backend;
	struct state_variable *sv;
	int ret;
	struct stat s;
	struct mtd_info_user meminfo;

	if (state->backend)
		return -EBUSY;

	ret = stat(path, &s);
	if (!ret && !S_ISCHR(s.st_mode) && !S_ISBLK(s.st_mode)) {
		if (size == 0)
			size = s.st_size;
		else if (offset + size > s.st_size)
			return -EINVAL;
	}

	backend_raw = xzalloc(sizeof(*backend_raw));
	backend = &backend_raw->backend;

	backend->load = state_backend_raw_load;
	backend->save = state_backend_raw_save;
	backend->path = strdup(path);
	backend->name = "raw";

	list_for_each_entry(sv, &state->variables, list)
		backend_raw->size_data += sv->raw_size;

	backend_raw->state = state;
	backend_raw->offset = offset;
	backend_raw->size_full = backend_raw->size_data + sizeof(struct backend_raw_header);

	state->backend = backend;

	ret = get_meminfo(backend->path, &meminfo);
	if (!ret) {
		if (!size)
			size = meminfo.size;
		if (!(meminfo.flags & MTD_NO_ERASE))
			backend_raw->need_erase = 1;
		backend_raw->step = ALIGN(backend_raw->size_full, meminfo.erasesize);
		if (verbose)
			fprintf(stderr, "%s is a mtd of size %d, adjust stepsize to %ld\n",
					path, meminfo.size, backend_raw->step);
	} else {
		backend_raw->step = backend_raw->size_full;
	}

	backend_raw->size = size;

	if (backend_raw->size / backend_raw->step < 2) {
		pr_err("not enough space for two copies, have %d, need %d\n",
				backend_raw->size, backend_raw->step * 2);
		ret = -ENOSPC;
		goto err;
	}

	return 0;
err:
	free(backend_raw);
	return ret;
}

static struct state *state_get(const char *name)
{
	struct device_node *root, *node, *partition_node;
	char *path;
	struct state *state;
	int ret;
	const char *backend_type = NULL;
	struct state_variable *v;
	char *devpath;
	off_t offset;
	size_t size;

	root = of_read_proc_devicetree();
	if (IS_ERR(root)) {
		fprintf(stderr, "Unable to read devicetree from /proc/device-tree: %s\n",
				strerror(-PTR_ERR(root)));
		return ERR_CAST(root);
	}

	of_set_root_node(root);

	node = of_find_node_by_path_or_alias(root, name);
	if (!node) {
		fprintf(stderr, "no such node: %s\n", name);
		return ERR_PTR(-ENOENT);
	}

	if (verbose > 1) {
		printf("found state node %s:\n", node->full_name);
		of_print_nodes(node, 0);
	}

	state = state_new_from_node("state", node);
	if (IS_ERR(state)) {
		fprintf(stderr, "unable to initlialize state: %s\n",
				strerror(PTR_ERR(state)));
		return ERR_CAST(state);
	}

	partition_node = of_parse_phandle(node, "backend", 0);
	if (!partition_node) {
		fprintf(stderr, "cannot find backend node in %s\n", node->full_name);
		exit (1);
	}

	ret = of_get_devicepath(partition_node, &devpath, &offset, &size);
	if (ret) {
		fprintf(stderr, "Cannot find backend path in %s\n", node->full_name);
		return ERR_PTR(ret);
	}

	of_property_read_string(node, "backend-type", &backend_type);
	if (!strcmp(backend_type, "raw"))
		ret = state_backend_raw_file(state, devpath, offset, size);
	else
                fprintf(stderr, "invalid backend type: %s\n", backend_type);

	if (ret) {
		fprintf(stderr, "Cannot initialize backend: %s\n", strerror(-ret));
		return ERR_PTR(ret);
	}

	return state;
}

enum opt {
	OPT_DUMP_SHELL = 1,
};

static struct option long_options[] = {
	{"get",		required_argument,	0,	'g' },
	{"set",		required_argument,	0,	's' },
	{"name",	required_argument,	0,	'n' },
	{"dump",	no_argument,		0,	'd' },
	{"dump-shell",	no_argument,		0,	OPT_DUMP_SHELL },
	{"init",	no_argument,		0,	'i' },
	{"verbose",	no_argument,		0,	'v' },
	{"help",	no_argument,		0,	'h' },
};

static void usage(char *name)
{
	printf(
"Usage: %s [OPTIONS]\n"
"\n"
"-g, --get <variable>                      get the value of a variable\n"
"-s, --set <variable>=<value>              set the value of a variable\n"
"-n, --name <name>                         specify the state to use (default=\"state\")\n"
"-d, --dump                                dump the state\n"
"--dump-shell                              dump the state suitable for shell sourcing\n"
"--init                                    initialize the state (do not load from storage)\n"
"-v, --verbose                             increase verbosity\n"
"--help                                    this help\n",
	name);
}

#define state_for_each_var(state, var) \
	list_for_each_entry(var, &(state)->variables, list)

struct state_set_get {
	char *arg;
	int get;
	struct list_head list;
};

int main(int argc, char *argv[])
{
	struct state *state;
	struct state_variable *v;
	int ret, c, option_index;
	int do_dump = 0, do_dump_shell = 0, do_initialize = 0;
	struct state_set_get *sg;
	struct list_head sg_list;
	char *statename = "state";

	INIT_LIST_HEAD(&sg_list);

	while (1) {
		c = getopt_long(argc, argv, "hg:s:divn:", long_options, &option_index);
		if (c < 0)
			break;
		switch (c) {
		case 'h':
			usage(argv[0]);
			exit(0);
		case 'g':
			sg = xzalloc(sizeof(*sg));
			sg->get = 1;
			sg->arg = optarg;
			list_add_tail(&sg->list, &sg_list);
			break;
		case 's':
			sg = xzalloc(sizeof(*sg));
			sg->get = 0;
			sg->arg = optarg;
			list_add_tail(&sg->list, &sg_list);
			break;
		case 'd':
			do_dump = 1;
			break;
		case 'i':
			do_initialize = 1;
			break;
		case OPT_DUMP_SHELL:
			do_dump_shell = 1;
			break;
		case 'v':
			verbose++;
			break;
		case 'n':
			statename = optarg;
		}
	}

	state = state_get(statename);
	if (IS_ERR(state))
		exit(1);

	ret = state_load(state);
	if (!do_initialize && ret) {
		fprintf(stderr, "Cannot load state: %s\n", strerror(-ret));
		exit(1);
	}

	if (do_dump) {
		state_for_each_var(state, v) {
			struct variable_type *vtype;
			vtype = state_find_type(v->type);
			printf("%s=%s", v->name, vtype->get(v));
			if (verbose) {
				printf(", type=%s", vtype->type_name);
				if (vtype->info)
					vtype->info(v);
			}
			printf("\n");
		}
	}

	if (do_dump_shell) {
		state_for_each_var(state, v) {
			struct variable_type *vtype;
			vtype = state_find_type(v->type);
			printf("STATE_%s=\"%s\"\n", v->name, vtype->get(v));
		}
	}

	list_for_each_entry(sg, &sg_list, list) {
		if (sg->get) {
			char *val = state_get_var(state, sg->arg);
			if (!val) {
				fprintf(stderr, "no such variable: %s\n", sg->arg);
				exit (1);
			}

			printf("%s\n", val);
		} else {
			char *var, *val;

			var = sg->arg;
			val = index(sg->arg, '=');
			if (!val) {
				fprintf(stderr, "usage: -s var=val\n");
				exit (1);
			}
			*val++ = '\0';
			ret = state_set_var(state, var, val);
			if (ret) {
				fprintf(stderr, "Failed to set variable %s to %s: %s\n",
						var, val, strerror(-ret));
				exit(1);
			}
		}
	}

	if (do_initialize || state->dirty) {
		ret = state_save(state);
		if (ret) {
			fprintf(stderr, "Failed to save state: %s\n", strerror(-ret));
			exit(1);
		}
	}

	return 0;
}