// 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)
{
*size = embedded_bootconfig_data_end - embedded_bootconfig_data;
return (*size) ? embedded_bootconfig_data : NULL;
}
#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)
{
return memblock_alloc(size, SMP_CACHE_BYTES);
}
static inline void __init xbc_free_mem(void *addr, size_t size, bool early)
{
if (early)
memblock_free(addr, size);
else if (addr)
memblock_free_late(__pa(addr), size);
}
#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)
{
if (!xbc_data)
return -ENODEV;
if (node_size)
*node_size = xbc_node_num;
if (data_size)
*data_size = xbc_data_size;
return 0;
}
static int __init xbc_parse_error(const char *msg, const char *p)
{
xbc_err_msg = msg;
xbc_err_pos = (int)(p - xbc_data);
return -EINVAL;
}
/**
* 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)
{
if (unlikely(!xbc_data))
return NULL;
return xbc_nodes;
}
/**
* 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)
{
return node - &xbc_nodes[0];
}
/**
* 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)
{
return node->parent == XBC_NODE_MAX ? NULL : &xbc_nodes[node->parent];
}
/**
* 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)
{
return node->child ? &xbc_nodes[node->child] : NULL;
}
/**
* 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)
{
return node->next ? &xbc_nodes[node->next] : NULL;
}
/**
* 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)
{
int offset = node->data & ~XBC_VALUE;
if (WARN_ON(offset >= xbc_data_size))
return NULL;
return xbc_data + offset;
}
static bool __init
xbc_node_match_prefix(struct xbc_node *node, const char **prefix)
{
const char *p = xbc_node_get_data(node);
int len = strlen(p);
if (strncmp(*prefix, p, len))
return false;
p = *prefix + len;
if (*p == '.')
p++;
else if (*p != '\0')
return false;
*prefix = p;
return true;
}
/**
* 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)
{
struct xbc_node *node;
if (parent)
node = xbc_node_get_subkey(parent);
else
node = xbc_root_node();
while (node && xbc_node_is_key(node)) {
if (!xbc_node_match_prefix(node, &key))
node = xbc_node_get_next(node);
else if (*key != '\0')
node = xbc_node_get_subkey(node);
else
break;
}
return node;
}
/**
* 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)
{
struct xbc_node *node = xbc_node_find_subkey(parent, key);
if (!node || !xbc_node_is_key(node))
return NULL;
node = xbc_node_get_child(node);
if (node && !xbc_node_is_value(node))
return NULL;
if (vnode)
*vnode = node;
return node ? xbc_node_get_data(node) : "";
}
/**
* 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)
{
uint16_t keys[XBC_DEPTH_MAX];
int depth = 0, ret = 0, total = 0;
if (!node || node == root)
return -EINVAL;
if (xbc_node_is_value(node))
node = xbc_node_get_parent(node);
while (node && node != root) {
keys[depth++] = xbc_node_index(node);
if (depth == XBC_DEPTH_MAX)
return -ERANGE;
node = xbc_node_get_parent(node);
}
if (!node && root)
return -EINVAL;
while (--depth >= 0) {
node = xbc_nodes + keys[depth];
ret = snprintf(buf, size, "%s%s", xbc_node_get_data(node),
depth ? "." : "");
if (ret < 0)
return ret;
if (ret > size) {
size = 0;
} else {
size -= ret;
buf += ret;
}
total += ret;
}
return total;
}
/**
* 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)
{
struct xbc_node *next;
if (unlikely(!xbc_data))
return NULL;
if (!node) { /* First try */
node = root;
if (!node)
node = xbc_nodes;
} else {
/* Leaf node may have a subkey */
next = xbc_node_get_subkey(node);
if (next) {
node = next;
goto found;
}
if (node == root) /* @root was a leaf, no child node. */
return NULL;
while (!node->next) {
node = xbc_node_get_parent(node);
if (node == root)
return NULL;
/* User passed a node which is not uder parent */
if (WARN_ON(!node))
return NULL;
}
node = xbc_node_get_next(node);
}
found:
while (node && !xbc_node_is_leaf(node))
node = xbc_node_get_child(node);
return 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)
{
/* tip must be passed */
if (WARN_ON(!leaf))
return NULL;
*leaf = xbc_node_find_next_leaf(root, *leaf);
if (!*leaf)
return NULL;
if ((*leaf)->child)
return xbc_node_get_data(xbc_node_get_child(*leaf));
else
return ""; /* No value key */
}
/* XBC parse and tree build */
static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag)
{
unsigned long offset = data - xbc_data;
if (WARN_ON(offset >= XBC_DATA_MAX))
return -EINVAL;
node->data = (uint16_t)offset | flag;
node->child = 0;
node->next = 0;
return 0;
}
static struct xbc_node * __init xbc_add_node(char *data, uint32_t flag)
{
struct xbc_node *node;
if (xbc_node_num == XBC_NODE_MAX)
return NULL;
node = &xbc_nodes[xbc_node_num++];
if (xbc_init_node(node, data, flag) < 0)
return NULL;
return node;
}
static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node)
{
while (node->next)
node = xbc_node_get_next(node);
return node;
}
static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node)
{
while (node->child)
node = xbc_node_get_child(node);
return node;
}
static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, bool head)
{
struct xbc_node *sib, *node = xbc_add_node(data, flag);
if (node) {
if (!last_parent) {
/* Ignore @head in this case */
node->parent = XBC_NODE_MAX;
sib = xbc_last_sibling(xbc_nodes);
sib->next = xbc_node_index(node);
} else {
node->parent = xbc_node_index(last_parent);
if (!last_parent->child || head) {
node->next = last_parent->child;
last_parent->child = xbc_node_index(node);
} else {
sib = xbc_node_get_child(last_parent);
sib = xbc_last_sibling(sib);
sib->next = xbc_node_index(node);
}
}
} else
xbc_parse_error("Too many nodes", data);
return node;
}
static inline struct xbc_node * __init xbc_add_sibling(char *data, uint32_t flag)
{
return __xbc_add_sibling(data, flag, false);
}
static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint32_t flag)
{
return __xbc_add_sibling(data, flag, true);
}
static inline __init struct xbc_node *xbc_add_child(char *data, uint32_t flag)
{
struct xbc_node *node = xbc_add_sibling(data, flag);
if (node)
last_parent = node;
return node;
}
static inline __init bool xbc_valid_keyword(char *key)
{
if (key[0] == '\0')
return false;
while (isalnum(*key) || *key == '-' || *key == '_')
key++;
return *key == '\0';
}
static char *skip_comment(char *p)
{
char *ret;
ret = strchr(p, '\n');
if (!ret)
ret = p + strlen(p);
else
ret++;
return ret;
}
static char *skip_spaces_until_newline(char *p)
{
while (isspace(*p) && *p != '\n')
p++;
return p;
}
static int __init __xbc_open_brace(char *p)
{
/* Push the last key as open brace */
open_brace[brace_index++] = xbc_node_index(last_parent);
if (brace_index >= XBC_DEPTH_MAX)
return xbc_parse_error("Exceed max depth of braces", p);
return 0;
}
static int __init __xbc_close_brace(char *p)
{
brace_index--;
if (!last_parent || brace_index < 0 ||
(open_brace[brace_index] != xbc_node_index(last_parent)))
return xbc_parse_error("Unexpected closing brace", p);
if (brace_index == 0)
last_parent = NULL;
else
last_parent = &xbc_nodes[open_brace[brace_index - 1]];
return 0;
}
/*
* 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)
{
char *p, *v = *__v;
int c, quotes = 0;
v = skip_spaces(v);
while (*v == '#') {
v = skip_comment(v);
v = skip_spaces(v);
}
if (*v == '"' || *v == '\'') {
quotes = *v;
v++;
}
p = v - 1;
while ((c = *++p)) {
if (!isprint(c) && !isspace(c))
return xbc_parse_error("Non printable value", p);
if (quotes) {
if (c != quotes)
continue;
quotes = 0;
*p++ = '\0';
p = skip_spaces_until_newline(p);
c = *p;
if (c && !strchr(",;\n#}", c))
return xbc_parse_error("No value delimiter", p);
if (*p)
p++;
break;
}
if (strchr(",;\n#}", c)) {
*p++ = '\0';
v = strim(v);
break;
}
}
if (quotes)
return xbc_parse_error("No closing quotes", p);
if (c == '#') {
p = skip_comment(p);
c = '\n'; /* A comment must be treated as a newline */
}
*__n = p;
*__v = v;
return c;
}
static int __init xbc_parse_array(char **__v)
{
struct xbc_node *node;
char *next;
int c = 0;
if (last_parent->child)
last_parent = xbc_node_get_child(last_parent);
do {
c = __xbc_parse_value(__v, &next);
if (c < 0)
return c;
node = xbc_add_child(*__v, XBC_VALUE);
if (!node)
return -ENOMEM;
*__v = next;
} while (c == ',');
node->child = 0;
return c;
}
static inline __init
struct xbc_node *find_match_node(struct xbc_node *node, char *k)
{
while (node) {
if (!strcmp(xbc_node_get_data(node), k))
break;
node = xbc_node_get_next(node);
}
return node;
}
static int __init __xbc_add_key(char *k)
{
struct xbc_node *node, *child;
if (!xbc_valid_keyword(k))
return xbc_parse_error("Invalid keyword", k);
if (unlikely(xbc_node_num == 0))
goto add_node;
if (!last_parent) /* the first level */
node = find_match_node(xbc_nodes, k);
else {
child = xbc_node_get_child(last_parent);
/* Since the value node is the first child, skip it. */
if (child && xbc_node_is_value(child))
child = xbc_node_get_next(child);
node = find_match_node(child, k);
}
if (node)
last_parent = node;
else {
add_node:
node = xbc_add_child(k, XBC_KEY);
if (!node)
return -ENOMEM;
}
return 0;
}
static int __init __xbc_parse_keys(char *k)
{
char *p;
int ret;
k = strim(k);
while ((p = strchr(k, '.'))) {
*p++ = '\0';
ret = __xbc_add_key(k);
if (ret)
return ret;
k = p;
}
return __xbc_add_key(k);
}
static int __init xbc_parse_kv(char **k, char *v, int op)
{
struct xbc_node *prev_parent = last_parent;
struct xbc_node *child;
char *next;
int c, ret;
ret = __xbc_parse_keys(*k);
if (ret)
return ret;
c = __xbc_parse_value(&v, &next);
if (c < 0)
return c;
child = xbc_node_get_child(last_parent);
if (child && xbc_node_is_value(child)) {
if (op == '=')
return xbc_parse_error("Value is redefined", v);
if (op == ':') {
unsigned short nidx = child->next;
xbc_init_node(child, v, XBC_VALUE);
child->next = nidx; /* keep subkeys */
goto array;
}
/* op must be '+' */
last_parent = xbc_last_child(child);
}
/* The value node should always be the first child */
if (!xbc_add_head_sibling(v, XBC_VALUE))
return -ENOMEM;
array:
if (c == ',') { /* Array */
c = xbc_parse_array(&next);
if (c < 0)
return c;
}
last_parent = prev_parent;
if (c == '}') {
ret = __xbc_close_brace(next - 1);
if (ret < 0)
return ret;
}
*k = next;
return 0;
}
static int __init xbc_parse_key(char **k, char *n)
{
struct xbc_node *prev_parent = last_parent;
int ret;
*k = strim(*k);
if (**k != '\0') {
ret = __xbc_parse_keys(*k);
if (ret)
return ret;
last_parent = prev_parent;
}
*k = n;
return 0;
}
static int __init xbc_open_brace(char **k, char *n)
{
int ret;
ret = __xbc_parse_keys(*k);
if (ret)
return ret;
*k = n;
return __xbc_open_brace(n - 1);
}
static int __init xbc_close_brace(char **k, char *n)
{
int ret;
ret = xbc_parse_key(k, n);
if (ret)
return ret;
/* k is updated in xbc_parse_key() */
return __xbc_close_brace(n - 1);
}
static int __init xbc_verify_tree(void)
{
int i, depth, len, wlen;
struct xbc_node *n, *m;
/* Brace closing */
if (brace_index) {
n = &xbc_nodes[open_brace[brace_index]];
return xbc_parse_error("Brace is not closed",
xbc_node_get_data(n));
}
/* Empty tree */
if (xbc_node_num == 0) {
xbc_parse_error("Empty config", xbc_data);
return -ENOENT;
}
for (i = 0; i < xbc_node_num; i++) {
if (xbc_nodes[i].next > xbc_node_num) {
return xbc_parse_error("No closing brace",
xbc_node_get_data(xbc_nodes + i));
}
}
/* Key tree limitation check */
n = &xbc_nodes[0];
depth = 1;
len = 0;
while (n) {
wlen = strlen(xbc_node_get_data(n)) + 1;
len += wlen;
if (len > XBC_KEYLEN_MAX)
return xbc_parse_error("Too long key length",
xbc_node_get_data(n));
m = xbc_node_get_child(n);
if (m && xbc_node_is_key(m)) {
n = m;
depth++;
if (depth > XBC_DEPTH_MAX)
return xbc_parse_error("Too many key words",
xbc_node_get_data(n));
continue;
}
len -= wlen;
m = xbc_node_get_next(n);
while (!m) {
n = xbc_node_get_parent(n);
if (!n)
break;
len -= strlen(xbc_node_get_data(n)) + 1;
depth--;
m = xbc_node_get_next(n);
}
n = m;
}
return 0;
}
/* Need to setup xbc_data and xbc_nodes before call this. */
static int __init xbc_parse_tree(void)
{
char *p, *q;
int ret = 0, c;
last_parent = NULL;
p = xbc_data;
do {
q = strpbrk(p, "{}=+;:\n#");
if (!q) {
p = skip_spaces(p);
if (*p != '\0')
ret = xbc_parse_error("No delimiter", p);
break;
}
c = *q;
*q++ = '\0';
switch (c) {
case ':':
case '+':
if (*q++ != '=') {
ret = xbc_parse_error(c == '+' ?
"Wrong '+' operator" :
"Wrong ':' operator",
q - 2);
break;
}
fallthrough;
case '=':
ret = xbc_parse_kv(&p, q, c);
break;
case '{':
ret = xbc_open_brace(&p, q);
break;
case '#':
q = skip_comment(q);
fallthrough;
case ';':
case '\n':
ret = xbc_parse_key(&p, q);
break;
case '}':
ret = xbc_close_brace(&p, q);
break;
}
} while (!ret);
return ret;
}
/**
* _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_free_mem(xbc_data, xbc_data_size, early);
xbc_data = NULL;
xbc_data_size = 0;
xbc_node_num = 0;
xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX, early);
xbc_nodes = NULL;
brace_index = 0;
}
/**
* 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)
{
int ret;
if (epos)
*epos = -1;
if (xbc_data) {
if (emsg)
*emsg = "Bootconfig is already initialized";
return -EBUSY;
}
if (size > XBC_DATA_MAX || size == 0) {
if (emsg)
*emsg = size ? "Config data is too big" :
"Config data is empty";
return -ERANGE;
}
xbc_data = xbc_alloc_mem(size + 1);
if (!xbc_data) {
if (emsg)
*emsg = "Failed to allocate bootconfig data";
return -ENOMEM;
}
memcpy(xbc_data, data, size);
xbc_data[size] = '\0';
xbc_data_size = size + 1;
xbc_nodes = xbc_alloc_mem(sizeof(struct xbc_node) * XBC_NODE_MAX);
if (!xbc_nodes) {
if (emsg)
*emsg = "Failed to allocate bootconfig nodes";
_xbc_exit(true);
return -ENOMEM;
}
memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);
ret = xbc_parse_tree();
if (!ret)
ret = xbc_verify_tree();
if (ret < 0) {
if (epos)
*epos = xbc_err_pos;
if (emsg)
*emsg = xbc_err_msg;
_xbc_exit(true);
} else
ret = xbc_node_num;
return ret;
}
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