linux/lib/bootconfig.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Extra Boot Config
 * Masami Hiramatsu <[email protected]>
 */

/*
 * NOTE: This is only for tools/bootconfig, because tools/bootconfig will
 * run the parser sanity test.
 * This does NOT mean lib/bootconfig.c is available in the user space.
 * However, if you change this file, please make sure the tools/bootconfig
 * has no issue on building and running.
 */
#include <linux/bootconfig.h>

#ifdef __KERNEL__
#include <linux/bug.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/string.h>

#ifdef CONFIG_BOOT_CONFIG_EMBED
/* embedded_bootconfig_data is defined in bootconfig-data.S */
extern __visible const char embedded_bootconfig_data[];
extern __visible const char embedded_bootconfig_data_end[];

const char * __init xbc_get_embedded_bootconfig(size_t *size)
{ … }
#endif
#endif

/*
 * Extra Boot Config (XBC) is given as tree-structured ascii text of
 * key-value pairs on memory.
 * xbc_parse() parses the text to build a simple tree. Each tree node is
 * simply a key word or a value. A key node may have a next key node or/and
 * a child node (both key and value). A value node may have a next value
 * node (for array).
 */

static struct xbc_node *xbc_nodes __initdata;
static int xbc_node_num __initdata;
static char *xbc_data __initdata;
static size_t xbc_data_size __initdata;
static struct xbc_node *last_parent __initdata;
static const char *xbc_err_msg __initdata;
static int xbc_err_pos __initdata;
static int open_brace[XBC_DEPTH_MAX] __initdata;
static int brace_index __initdata;

#ifdef __KERNEL__
static inline void * __init xbc_alloc_mem(size_t size)
{ … }

static inline void __init xbc_free_mem(void *addr, size_t size, bool early)
{ … }

#else /* !__KERNEL__ */

static inline void *xbc_alloc_mem(size_t size)
{
	return malloc(size);
}

static inline void xbc_free_mem(void *addr, size_t size, bool early)
{
	free(addr);
}
#endif
/**
 * xbc_get_info() - Get the information of loaded boot config
 * @node_size: A pointer to store the number of nodes.
 * @data_size: A pointer to store the size of bootconfig data.
 *
 * Get the number of used nodes in @node_size if it is not NULL,
 * and the size of bootconfig data in @data_size if it is not NULL.
 * Return 0 if the boot config is initialized, or return -ENODEV.
 */
int __init xbc_get_info(int *node_size, size_t *data_size)
{ … }

static int __init xbc_parse_error(const char *msg, const char *p)
{ … }

/**
 * xbc_root_node() - Get the root node of extended boot config
 *
 * Return the address of root node of extended boot config. If the
 * extended boot config is not initiized, return NULL.
 */
struct xbc_node * __init xbc_root_node(void)
{ … }

/**
 * xbc_node_index() - Get the index of XBC node
 * @node: A target node of getting index.
 *
 * Return the index number of @node in XBC node list.
 */
int __init xbc_node_index(struct xbc_node *node)
{ … }

/**
 * xbc_node_get_parent() - Get the parent XBC node
 * @node: An XBC node.
 *
 * Return the parent node of @node. If the node is top node of the tree,
 * return NULL.
 */
struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node)
{ … }

/**
 * xbc_node_get_child() - Get the child XBC node
 * @node: An XBC node.
 *
 * Return the first child node of @node. If the node has no child, return
 * NULL.
 */
struct xbc_node * __init xbc_node_get_child(struct xbc_node *node)
{ … }

/**
 * xbc_node_get_next() - Get the next sibling XBC node
 * @node: An XBC node.
 *
 * Return the NEXT sibling node of @node. If the node has no next sibling,
 * return NULL. Note that even if this returns NULL, it doesn't mean @node
 * has no siblings. (You also has to check whether the parent's child node
 * is @node or not.)
 */
struct xbc_node * __init xbc_node_get_next(struct xbc_node *node)
{ … }

/**
 * xbc_node_get_data() - Get the data of XBC node
 * @node: An XBC node.
 *
 * Return the data (which is always a null terminated string) of @node.
 * If the node has invalid data, warn and return NULL.
 */
const char * __init xbc_node_get_data(struct xbc_node *node)
{ … }

static bool __init
xbc_node_match_prefix(struct xbc_node *node, const char **prefix)
{ … }

/**
 * xbc_node_find_subkey() - Find a subkey node which matches given key
 * @parent: An XBC node.
 * @key: A key string.
 *
 * Search a key node under @parent which matches @key. The @key can contain
 * several words jointed with '.'. If @parent is NULL, this searches the
 * node from whole tree. Return NULL if no node is matched.
 */
struct xbc_node * __init
xbc_node_find_subkey(struct xbc_node *parent, const char *key)
{ … }

/**
 * xbc_node_find_value() - Find a value node which matches given key
 * @parent: An XBC node.
 * @key: A key string.
 * @vnode: A container pointer of found XBC node.
 *
 * Search a value node under @parent whose (parent) key node matches @key,
 * store it in *@vnode, and returns the value string.
 * The @key can contain several words jointed with '.'. If @parent is NULL,
 * this searches the node from whole tree. Return the value string if a
 * matched key found, return NULL if no node is matched.
 * Note that this returns 0-length string and stores NULL in *@vnode if the
 * key has no value. And also it will return the value of the first entry if
 * the value is an array.
 */
const char * __init
xbc_node_find_value(struct xbc_node *parent, const char *key,
		    struct xbc_node **vnode)
{ … }

/**
 * xbc_node_compose_key_after() - Compose partial key string of the XBC node
 * @root: Root XBC node
 * @node: Target XBC node.
 * @buf: A buffer to store the key.
 * @size: The size of the @buf.
 *
 * Compose the partial key of the @node into @buf, which is starting right
 * after @root (@root is not included.) If @root is NULL, this returns full
 * key words of @node.
 * Returns the total length of the key stored in @buf. Returns -EINVAL
 * if @node is NULL or @root is not the ancestor of @node or @root is @node,
 * or returns -ERANGE if the key depth is deeper than max depth.
 * This is expected to be used with xbc_find_node() to list up all (child)
 * keys under given key.
 */
int __init xbc_node_compose_key_after(struct xbc_node *root,
				      struct xbc_node *node,
				      char *buf, size_t size)
{ … }

/**
 * xbc_node_find_next_leaf() - Find the next leaf node under given node
 * @root: An XBC root node
 * @node: An XBC node which starts from.
 *
 * Search the next leaf node (which means the terminal key node) of @node
 * under @root node (including @root node itself).
 * Return the next node or NULL if next leaf node is not found.
 */
struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root,
						 struct xbc_node *node)
{ … }

/**
 * xbc_node_find_next_key_value() - Find the next key-value pair nodes
 * @root: An XBC root node
 * @leaf: A container pointer of XBC node which starts from.
 *
 * Search the next leaf node (which means the terminal key node) of *@leaf
 * under @root node. Returns the value and update *@leaf if next leaf node
 * is found, or NULL if no next leaf node is found.
 * Note that this returns 0-length string if the key has no value, or
 * the value of the first entry if the value is an array.
 */
const char * __init xbc_node_find_next_key_value(struct xbc_node *root,
						 struct xbc_node **leaf)
{ … }

/* XBC parse and tree build */

static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag)
{ … }

static struct xbc_node * __init xbc_add_node(char *data, uint32_t flag)
{ … }

static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node)
{ … }

static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node)
{ … }

static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, bool head)
{ … }

static inline struct xbc_node * __init xbc_add_sibling(char *data, uint32_t flag)
{ … }

static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint32_t flag)
{ … }

static inline __init struct xbc_node *xbc_add_child(char *data, uint32_t flag)
{ … }

static inline __init bool xbc_valid_keyword(char *key)
{ … }

static char *skip_comment(char *p)
{ … }

static char *skip_spaces_until_newline(char *p)
{ … }

static int __init __xbc_open_brace(char *p)
{ … }

static int __init __xbc_close_brace(char *p)
{ … }

/*
 * Return delimiter or error, no node added. As same as lib/cmdline.c,
 * you can use " around spaces, but can't escape " for value.
 */
static int __init __xbc_parse_value(char **__v, char **__n)
{ … }

static int __init xbc_parse_array(char **__v)
{ … }

static inline __init
struct xbc_node *find_match_node(struct xbc_node *node, char *k)
{ … }

static int __init __xbc_add_key(char *k)
{ … }

static int __init __xbc_parse_keys(char *k)
{ … }

static int __init xbc_parse_kv(char **k, char *v, int op)
{ … }

static int __init xbc_parse_key(char **k, char *n)
{ … }

static int __init xbc_open_brace(char **k, char *n)
{ … }

static int __init xbc_close_brace(char **k, char *n)
{ … }

static int __init xbc_verify_tree(void)
{ … }

/* Need to setup xbc_data and xbc_nodes before call this. */
static int __init xbc_parse_tree(void)
{ … }

/**
 * _xbc_exit() - Clean up all parsed bootconfig
 * @early: Set true if this is called before budy system is initialized.
 *
 * This clears all data structures of parsed bootconfig on memory.
 * If you need to reuse xbc_init() with new boot config, you can
 * use this.
 */
void __init _xbc_exit(bool early)
{ … }

/**
 * xbc_init() - Parse given XBC file and build XBC internal tree
 * @data: The boot config text original data
 * @size: The size of @data
 * @emsg: A pointer of const char * to store the error message
 * @epos: A pointer of int to store the error position
 *
 * This parses the boot config text in @data. @size must be smaller
 * than XBC_DATA_MAX.
 * Return the number of stored nodes (>0) if succeeded, or -errno
 * if there is any error.
 * In error cases, @emsg will be updated with an error message and
 * @epos will be updated with the error position which is the byte offset
 * of @buf. If the error is not a parser error, @epos will be -1.
 */
int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)
{ … }