forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
384 lines
10 KiB
384 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* Filesystem parameter parser. |
|
* |
|
* Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. |
|
* Written by David Howells ([email protected]) |
|
*/ |
|
|
|
#include <linux/export.h> |
|
#include <linux/fs_context.h> |
|
#include <linux/fs_parser.h> |
|
#include <linux/slab.h> |
|
#include <linux/security.h> |
|
#include <linux/namei.h> |
|
#include "internal.h" |
|
|
|
static const struct constant_table bool_names[] = { |
|
{ "0", false }, |
|
{ "1", true }, |
|
{ "false", false }, |
|
{ "no", false }, |
|
{ "true", true }, |
|
{ "yes", true }, |
|
{ }, |
|
}; |
|
|
|
static const struct constant_table * |
|
__lookup_constant(const struct constant_table *tbl, const char *name) |
|
{ |
|
for ( ; tbl->name; tbl++) |
|
if (strcmp(name, tbl->name) == 0) |
|
return tbl; |
|
return NULL; |
|
} |
|
|
|
/** |
|
* lookup_constant - Look up a constant by name in an ordered table |
|
* @tbl: The table of constants to search. |
|
* @name: The name to look up. |
|
* @not_found: The value to return if the name is not found. |
|
*/ |
|
int lookup_constant(const struct constant_table *tbl, const char *name, int not_found) |
|
{ |
|
const struct constant_table *p = __lookup_constant(tbl, name); |
|
|
|
return p ? p->value : not_found; |
|
} |
|
EXPORT_SYMBOL(lookup_constant); |
|
|
|
static inline bool is_flag(const struct fs_parameter_spec *p) |
|
{ |
|
return p->type == NULL; |
|
} |
|
|
|
static const struct fs_parameter_spec *fs_lookup_key( |
|
const struct fs_parameter_spec *desc, |
|
struct fs_parameter *param, bool *negated) |
|
{ |
|
const struct fs_parameter_spec *p, *other = NULL; |
|
const char *name = param->key; |
|
bool want_flag = param->type == fs_value_is_flag; |
|
|
|
*negated = false; |
|
for (p = desc; p->name; p++) { |
|
if (strcmp(p->name, name) != 0) |
|
continue; |
|
if (likely(is_flag(p) == want_flag)) |
|
return p; |
|
other = p; |
|
} |
|
if (want_flag) { |
|
if (name[0] == 'n' && name[1] == 'o' && name[2]) { |
|
for (p = desc; p->name; p++) { |
|
if (strcmp(p->name, name + 2) != 0) |
|
continue; |
|
if (!(p->flags & fs_param_neg_with_no)) |
|
continue; |
|
*negated = true; |
|
return p; |
|
} |
|
} |
|
} |
|
return other; |
|
} |
|
|
|
/* |
|
* fs_parse - Parse a filesystem configuration parameter |
|
* @fc: The filesystem context to log errors through. |
|
* @desc: The parameter description to use. |
|
* @param: The parameter. |
|
* @result: Where to place the result of the parse |
|
* |
|
* Parse a filesystem configuration parameter and attempt a conversion for a |
|
* simple parameter for which this is requested. If successful, the determined |
|
* parameter ID is placed into @result->key, the desired type is indicated in |
|
* @result->t and any converted value is placed into an appropriate member of |
|
* the union in @result. |
|
* |
|
* The function returns the parameter number if the parameter was matched, |
|
* -ENOPARAM if it wasn't matched and @desc->ignore_unknown indicated that |
|
* unknown parameters are okay and -EINVAL if there was a conversion issue or |
|
* the parameter wasn't recognised and unknowns aren't okay. |
|
*/ |
|
int __fs_parse(struct p_log *log, |
|
const struct fs_parameter_spec *desc, |
|
struct fs_parameter *param, |
|
struct fs_parse_result *result) |
|
{ |
|
const struct fs_parameter_spec *p; |
|
|
|
result->uint_64 = 0; |
|
|
|
p = fs_lookup_key(desc, param, &result->negated); |
|
if (!p) |
|
return -ENOPARAM; |
|
|
|
if (p->flags & fs_param_deprecated) |
|
warn_plog(log, "Deprecated parameter '%s'", param->key); |
|
|
|
/* Try to turn the type we were given into the type desired by the |
|
* parameter and give an error if we can't. |
|
*/ |
|
if (is_flag(p)) { |
|
if (param->type != fs_value_is_flag) |
|
return inval_plog(log, "Unexpected value for '%s'", |
|
param->key); |
|
result->boolean = !result->negated; |
|
} else { |
|
int ret = p->type(log, p, param, result); |
|
if (ret) |
|
return ret; |
|
} |
|
return p->opt; |
|
} |
|
EXPORT_SYMBOL(__fs_parse); |
|
|
|
/** |
|
* fs_lookup_param - Look up a path referred to by a parameter |
|
* @fc: The filesystem context to log errors through. |
|
* @param: The parameter. |
|
* @want_bdev: T if want a blockdev |
|
* @_path: The result of the lookup |
|
*/ |
|
int fs_lookup_param(struct fs_context *fc, |
|
struct fs_parameter *param, |
|
bool want_bdev, |
|
struct path *_path) |
|
{ |
|
struct filename *f; |
|
unsigned int flags = 0; |
|
bool put_f; |
|
int ret; |
|
|
|
switch (param->type) { |
|
case fs_value_is_string: |
|
f = getname_kernel(param->string); |
|
if (IS_ERR(f)) |
|
return PTR_ERR(f); |
|
put_f = true; |
|
break; |
|
case fs_value_is_filename: |
|
f = param->name; |
|
put_f = false; |
|
break; |
|
default: |
|
return invalf(fc, "%s: not usable as path", param->key); |
|
} |
|
|
|
ret = filename_lookup(param->dirfd, f, flags, _path, NULL); |
|
if (ret < 0) { |
|
errorf(fc, "%s: Lookup failure for '%s'", param->key, f->name); |
|
goto out; |
|
} |
|
|
|
if (want_bdev && |
|
!S_ISBLK(d_backing_inode(_path->dentry)->i_mode)) { |
|
path_put(_path); |
|
_path->dentry = NULL; |
|
_path->mnt = NULL; |
|
errorf(fc, "%s: Non-blockdev passed as '%s'", |
|
param->key, f->name); |
|
ret = -ENOTBLK; |
|
} |
|
|
|
out: |
|
if (put_f) |
|
putname(f); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL(fs_lookup_param); |
|
|
|
static int fs_param_bad_value(struct p_log *log, struct fs_parameter *param) |
|
{ |
|
return inval_plog(log, "Bad value for '%s'", param->key); |
|
} |
|
|
|
int fs_param_is_bool(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
int b; |
|
if (param->type != fs_value_is_string) |
|
return fs_param_bad_value(log, param); |
|
b = lookup_constant(bool_names, param->string, -1); |
|
if (b == -1) |
|
return fs_param_bad_value(log, param); |
|
result->boolean = b; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_bool); |
|
|
|
int fs_param_is_u32(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
int base = (unsigned long)p->data; |
|
if (param->type != fs_value_is_string || |
|
kstrtouint(param->string, base, &result->uint_32) < 0) |
|
return fs_param_bad_value(log, param); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_u32); |
|
|
|
int fs_param_is_s32(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
if (param->type != fs_value_is_string || |
|
kstrtoint(param->string, 0, &result->int_32) < 0) |
|
return fs_param_bad_value(log, param); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_s32); |
|
|
|
int fs_param_is_u64(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
if (param->type != fs_value_is_string || |
|
kstrtoull(param->string, 0, &result->uint_64) < 0) |
|
return fs_param_bad_value(log, param); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_u64); |
|
|
|
int fs_param_is_enum(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
const struct constant_table *c; |
|
if (param->type != fs_value_is_string) |
|
return fs_param_bad_value(log, param); |
|
c = __lookup_constant(p->data, param->string); |
|
if (!c) |
|
return fs_param_bad_value(log, param); |
|
result->uint_32 = c->value; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_enum); |
|
|
|
int fs_param_is_string(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
if (param->type != fs_value_is_string || !*param->string) |
|
return fs_param_bad_value(log, param); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_string); |
|
|
|
int fs_param_is_blob(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
if (param->type != fs_value_is_blob) |
|
return fs_param_bad_value(log, param); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_blob); |
|
|
|
int fs_param_is_fd(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
switch (param->type) { |
|
case fs_value_is_string: |
|
if (kstrtouint(param->string, 0, &result->uint_32) < 0) |
|
break; |
|
if (result->uint_32 <= INT_MAX) |
|
return 0; |
|
break; |
|
case fs_value_is_file: |
|
result->uint_32 = param->dirfd; |
|
if (result->uint_32 <= INT_MAX) |
|
return 0; |
|
break; |
|
default: |
|
break; |
|
} |
|
return fs_param_bad_value(log, param); |
|
} |
|
EXPORT_SYMBOL(fs_param_is_fd); |
|
|
|
int fs_param_is_blockdev(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_blockdev); |
|
|
|
int fs_param_is_path(struct p_log *log, const struct fs_parameter_spec *p, |
|
struct fs_parameter *param, struct fs_parse_result *result) |
|
{ |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(fs_param_is_path); |
|
|
|
#ifdef CONFIG_VALIDATE_FS_PARSER |
|
/** |
|
* validate_constant_table - Validate a constant table |
|
* @tbl: The constant table to validate. |
|
* @tbl_size: The size of the table. |
|
* @low: The lowest permissible value. |
|
* @high: The highest permissible value. |
|
* @special: One special permissible value outside of the range. |
|
*/ |
|
bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, |
|
int low, int high, int special) |
|
{ |
|
size_t i; |
|
bool good = true; |
|
|
|
if (tbl_size == 0) { |
|
pr_warn("VALIDATE C-TBL: Empty\n"); |
|
return true; |
|
} |
|
|
|
for (i = 0; i < tbl_size; i++) { |
|
if (!tbl[i].name) { |
|
pr_err("VALIDATE C-TBL[%zu]: Null\n", i); |
|
good = false; |
|
} else if (i > 0 && tbl[i - 1].name) { |
|
int c = strcmp(tbl[i-1].name, tbl[i].name); |
|
|
|
if (c == 0) { |
|
pr_err("VALIDATE C-TBL[%zu]: Duplicate %s\n", |
|
i, tbl[i].name); |
|
good = false; |
|
} |
|
if (c > 0) { |
|
pr_err("VALIDATE C-TBL[%zu]: Missorted %s>=%s\n", |
|
i, tbl[i-1].name, tbl[i].name); |
|
good = false; |
|
} |
|
} |
|
|
|
if (tbl[i].value != special && |
|
(tbl[i].value < low || tbl[i].value > high)) { |
|
pr_err("VALIDATE C-TBL[%zu]: %s->%d const out of range (%d-%d)\n", |
|
i, tbl[i].name, tbl[i].value, low, high); |
|
good = false; |
|
} |
|
} |
|
|
|
return good; |
|
} |
|
|
|
/** |
|
* fs_validate_description - Validate a parameter description |
|
* @name: The parameter name to search for. |
|
* @desc: The parameter description to validate. |
|
*/ |
|
bool fs_validate_description(const char *name, |
|
const struct fs_parameter_spec *desc) |
|
{ |
|
const struct fs_parameter_spec *param, *p2; |
|
bool good = true; |
|
|
|
for (param = desc; param->name; param++) { |
|
/* Check for duplicate parameter names */ |
|
for (p2 = desc; p2 < param; p2++) { |
|
if (strcmp(param->name, p2->name) == 0) { |
|
if (is_flag(param) != is_flag(p2)) |
|
continue; |
|
pr_err("VALIDATE %s: PARAM[%s]: Duplicate\n", |
|
name, param->name); |
|
good = false; |
|
} |
|
} |
|
} |
|
return good; |
|
} |
|
#endif /* CONFIG_VALIDATE_FS_PARSER */
|
|
|