file.c
/*
* security/tomoyo/file.c
*
* Implementation of the Domain-Based Mandatory Access Control.
*
* Copyright (C) 2005-2009 NTT DATA CORPORATION
*
* Version: 2.2.0 2009/04/01
*
*/
#include "common.h"
/* Keyword array for single path operations. */
static const char *tomoyo_path_keyword[TOMOYO_MAX_PATH_OPERATION] = {
[TOMOYO_TYPE_READ_WRITE] = "read/write",
[TOMOYO_TYPE_EXECUTE] = "execute",
[TOMOYO_TYPE_READ] = "read",
[TOMOYO_TYPE_WRITE] = "write",
[TOMOYO_TYPE_CREATE] = "create",
[TOMOYO_TYPE_UNLINK] = "unlink",
[TOMOYO_TYPE_MKDIR] = "mkdir",
[TOMOYO_TYPE_RMDIR] = "rmdir",
[TOMOYO_TYPE_MKFIFO] = "mkfifo",
[TOMOYO_TYPE_MKSOCK] = "mksock",
[TOMOYO_TYPE_MKBLOCK] = "mkblock",
[TOMOYO_TYPE_MKCHAR] = "mkchar",
[TOMOYO_TYPE_TRUNCATE] = "truncate",
[TOMOYO_TYPE_SYMLINK] = "symlink",
[TOMOYO_TYPE_REWRITE] = "rewrite",
[TOMOYO_TYPE_IOCTL] = "ioctl",
[TOMOYO_TYPE_CHMOD] = "chmod",
[TOMOYO_TYPE_CHOWN] = "chown",
[TOMOYO_TYPE_CHGRP] = "chgrp",
[TOMOYO_TYPE_CHROOT] = "chroot",
[TOMOYO_TYPE_MOUNT] = "mount",
[TOMOYO_TYPE_UMOUNT] = "unmount",
};
/* Keyword array for double path operations. */
static const char *tomoyo_path2_keyword[TOMOYO_MAX_PATH2_OPERATION] = {
[TOMOYO_TYPE_LINK] = "link",
[TOMOYO_TYPE_RENAME] = "rename",
[TOMOYO_TYPE_PIVOT_ROOT] = "pivot_root",
};
/**
* tomoyo_path2keyword - Get the name of single path operation.
*
* @operation: Type of operation.
*
* Returns the name of single path operation.
*/
const char *tomoyo_path2keyword(const u8 operation)
{
return (operation < TOMOYO_MAX_PATH_OPERATION)
? tomoyo_path_keyword[operation] : NULL;
}
/**
* tomoyo_path22keyword - Get the name of double path operation.
*
* @operation: Type of operation.
*
* Returns the name of double path operation.
*/
const char *tomoyo_path22keyword(const u8 operation)
{
return (operation < TOMOYO_MAX_PATH2_OPERATION)
? tomoyo_path2_keyword[operation] : NULL;
}
/**
* tomoyo_strendswith - Check whether the token ends with the given token.
*
* @name: The token to check.
* @tail: The token to find.
*
* Returns true if @name ends with @tail, false otherwise.
*/
static bool tomoyo_strendswith(const char *name, const char *tail)
{
int len;
if (!name || !tail)
return false;
len = strlen(name) - strlen(tail);
return len >= 0 && !strcmp(name + len, tail);
}
/**
* tomoyo_get_path - Get realpath.
*
* @path: Pointer to "struct path".
*
* Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
*/
static struct tomoyo_path_info *tomoyo_get_path(struct path *path)
{
int error;
struct tomoyo_path_info_with_data *buf = kzalloc(sizeof(*buf),
GFP_KERNEL);
if (!buf)
return NULL;
/* Reserve one byte for appending "/". */
error = tomoyo_realpath_from_path2(path, buf->body,
sizeof(buf->body) - 2);
if (!error) {
buf->head.name = buf->body;
tomoyo_fill_path_info(&buf->head);
return &buf->head;
}
kfree(buf);
return NULL;
}
static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
const char *filename2,
struct tomoyo_domain_info *const domain,
const bool is_delete);
static int tomoyo_update_path_acl(const u8 type, const char *filename,
struct tomoyo_domain_info *const domain,
const bool is_delete);
/*
* tomoyo_globally_readable_list is used for holding list of pathnames which
* are by default allowed to be open()ed for reading by any process.
*
* An entry is added by
*
* # echo 'allow_read /lib/libc-2.5.so' > \
* /sys/kernel/security/tomoyo/exception_policy
*
* and is deleted by
*
* # echo 'delete allow_read /lib/libc-2.5.so' > \
* /sys/kernel/security/tomoyo/exception_policy
*
* and all entries are retrieved by
*
* # grep ^allow_read /sys/kernel/security/tomoyo/exception_policy
*
* In the example above, any process is allowed to
* open("/lib/libc-2.5.so", O_RDONLY).
* One exception is, if the domain which current process belongs to is marked
* as "ignore_global_allow_read", current process can't do so unless explicitly
* given "allow_read /lib/libc-2.5.so" to the domain which current process
* belongs to.
*/
LIST_HEAD(tomoyo_globally_readable_list);
/**
* tomoyo_update_globally_readable_entry - Update "struct tomoyo_globally_readable_file_entry" list.
*
* @filename: Filename unconditionally permitted to open() for reading.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_globally_readable_entry(const char *filename,
const bool is_delete)
{
struct tomoyo_globally_readable_file_entry *entry = NULL;
struct tomoyo_globally_readable_file_entry *ptr;
const struct tomoyo_path_info *saved_filename;
int error = is_delete ? -ENOENT : -ENOMEM;
if (!tomoyo_is_correct_path(filename, 1, 0, -1))
return -EINVAL;
saved_filename = tomoyo_get_name(filename);
if (!saved_filename)
return -ENOMEM;
if (!is_delete)
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
if (ptr->filename != saved_filename)
continue;
ptr->is_deleted = is_delete;
error = 0;
break;
}
if (!is_delete && error && tomoyo_memory_ok(entry)) {
entry->filename = saved_filename;
saved_filename = NULL;
list_add_tail_rcu(&entry->list, &tomoyo_globally_readable_list);
entry = NULL;
error = 0;
}
mutex_unlock(&tomoyo_policy_lock);
tomoyo_put_name(saved_filename);
kfree(entry);
return error;
}
/**
* tomoyo_is_globally_readable_file - Check if the file is unconditionnaly permitted to be open()ed for reading.
*
* @filename: The filename to check.
*
* Returns true if any domain can open @filename for reading, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static bool tomoyo_is_globally_readable_file(const struct tomoyo_path_info *
filename)
{
struct tomoyo_globally_readable_file_entry *ptr;
bool found = false;
list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
if (!ptr->is_deleted &&
tomoyo_path_matches_pattern(filename, ptr->filename)) {
found = true;
break;
}
}
return found;
}
/**
* tomoyo_write_globally_readable_policy - Write "struct tomoyo_globally_readable_file_entry" list.
*
* @data: String to parse.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
int tomoyo_write_globally_readable_policy(char *data, const bool is_delete)
{
return tomoyo_update_globally_readable_entry(data, is_delete);
}
/**
* tomoyo_read_globally_readable_policy - Read "struct tomoyo_globally_readable_file_entry" list.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns true on success, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head)
{
struct list_head *pos;
bool done = true;
list_for_each_cookie(pos, head->read_var2,
&tomoyo_globally_readable_list) {
struct tomoyo_globally_readable_file_entry *ptr;
ptr = list_entry(pos,
struct tomoyo_globally_readable_file_entry,
list);
if (ptr->is_deleted)
continue;
done = tomoyo_io_printf(head, TOMOYO_KEYWORD_ALLOW_READ "%s\n",
ptr->filename->name);
if (!done)
break;
}
return done;
}
/* tomoyo_pattern_list is used for holding list of pathnames which are used for
* converting pathnames to pathname patterns during learning mode.
*
* An entry is added by
*
* # echo 'file_pattern /proc/\$/mounts' > \
* /sys/kernel/security/tomoyo/exception_policy
*
* and is deleted by
*
* # echo 'delete file_pattern /proc/\$/mounts' > \
* /sys/kernel/security/tomoyo/exception_policy
*
* and all entries are retrieved by
*
* # grep ^file_pattern /sys/kernel/security/tomoyo/exception_policy
*
* In the example above, if a process which belongs to a domain which is in
* learning mode requested open("/proc/1/mounts", O_RDONLY),
* "allow_read /proc/\$/mounts" is automatically added to the domain which that
* process belongs to.
*
* It is not a desirable behavior that we have to use /proc/\$/ instead of
* /proc/self/ when current process needs to access only current process's
* information. As of now, LSM version of TOMOYO is using __d_path() for
* calculating pathname. Non LSM version of TOMOYO is using its own function
* which pretends as if /proc/self/ is not a symlink; so that we can forbid
* current process from accessing other process's information.
*/
LIST_HEAD(tomoyo_pattern_list);
/**
* tomoyo_update_file_pattern_entry - Update "struct tomoyo_pattern_entry" list.
*
* @pattern: Pathname pattern.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_file_pattern_entry(const char *pattern,
const bool is_delete)
{
struct tomoyo_pattern_entry *entry = NULL;
struct tomoyo_pattern_entry *ptr;
const struct tomoyo_path_info *saved_pattern;
int error = is_delete ? -ENOENT : -ENOMEM;
saved_pattern = tomoyo_get_name(pattern);
if (!saved_pattern)
return error;
if (!saved_pattern->is_patterned)
goto out;
if (!is_delete)
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
if (saved_pattern != ptr->pattern)
continue;
ptr->is_deleted = is_delete;
error = 0;
break;
}
if (!is_delete && error && tomoyo_memory_ok(entry)) {
entry->pattern = saved_pattern;
saved_pattern = NULL;
list_add_tail_rcu(&entry->list, &tomoyo_pattern_list);
entry = NULL;
error = 0;
}
mutex_unlock(&tomoyo_policy_lock);
out:
kfree(entry);
tomoyo_put_name(saved_pattern);
return error;
}
/**
* tomoyo_get_file_pattern - Get patterned pathname.
*
* @filename: The filename to find patterned pathname.
*
* Returns pointer to pathname pattern if matched, @filename otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static const struct tomoyo_path_info *
tomoyo_get_file_pattern(const struct tomoyo_path_info *filename)
{
struct tomoyo_pattern_entry *ptr;
const struct tomoyo_path_info *pattern = NULL;
list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
if (ptr->is_deleted)
continue;
if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
continue;
pattern = ptr->pattern;
if (tomoyo_strendswith(pattern->name, "/\\*")) {
/* Do nothing. Try to find the better match. */
} else {
/* This would be the better match. Use this. */
break;
}
}
if (pattern)
filename = pattern;
return filename;
}
/**
* tomoyo_write_pattern_policy - Write "struct tomoyo_pattern_entry" list.
*
* @data: String to parse.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
int tomoyo_write_pattern_policy(char *data, const bool is_delete)
{
return tomoyo_update_file_pattern_entry(data, is_delete);
}
/**
* tomoyo_read_file_pattern - Read "struct tomoyo_pattern_entry" list.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns true on success, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head)
{
struct list_head *pos;
bool done = true;
list_for_each_cookie(pos, head->read_var2, &tomoyo_pattern_list) {
struct tomoyo_pattern_entry *ptr;
ptr = list_entry(pos, struct tomoyo_pattern_entry, list);
if (ptr->is_deleted)
continue;
done = tomoyo_io_printf(head, TOMOYO_KEYWORD_FILE_PATTERN
"%s\n", ptr->pattern->name);
if (!done)
break;
}
return done;
}
/*
* tomoyo_no_rewrite_list is used for holding list of pathnames which are by
* default forbidden to modify already written content of a file.
*
* An entry is added by
*
* # echo 'deny_rewrite /var/log/messages' > \
* /sys/kernel/security/tomoyo/exception_policy
*
* and is deleted by
*
* # echo 'delete deny_rewrite /var/log/messages' > \
* /sys/kernel/security/tomoyo/exception_policy
*
* and all entries are retrieved by
*
* # grep ^deny_rewrite /sys/kernel/security/tomoyo/exception_policy
*
* In the example above, if a process requested to rewrite /var/log/messages ,
* the process can't rewrite unless the domain which that process belongs to
* has "allow_rewrite /var/log/messages" entry.
*
* It is not a desirable behavior that we have to add "\040(deleted)" suffix
* when we want to allow rewriting already unlink()ed file. As of now,
* LSM version of TOMOYO is using __d_path() for calculating pathname.
* Non LSM version of TOMOYO is using its own function which doesn't append
* " (deleted)" suffix if the file is already unlink()ed; so that we don't
* need to worry whether the file is already unlink()ed or not.
*/
LIST_HEAD(tomoyo_no_rewrite_list);
/**
* tomoyo_update_no_rewrite_entry - Update "struct tomoyo_no_rewrite_entry" list.
*
* @pattern: Pathname pattern that are not rewritable by default.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_no_rewrite_entry(const char *pattern,
const bool is_delete)
{
struct tomoyo_no_rewrite_entry *entry = NULL;
struct tomoyo_no_rewrite_entry *ptr;
const struct tomoyo_path_info *saved_pattern;
int error = is_delete ? -ENOENT : -ENOMEM;
if (!tomoyo_is_correct_path(pattern, 0, 0, 0))
return -EINVAL;
saved_pattern = tomoyo_get_name(pattern);
if (!saved_pattern)
return error;
if (!is_delete)
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
if (ptr->pattern != saved_pattern)
continue;
ptr->is_deleted = is_delete;
error = 0;
break;
}
if (!is_delete && error && tomoyo_memory_ok(entry)) {
entry->pattern = saved_pattern;
saved_pattern = NULL;
list_add_tail_rcu(&entry->list, &tomoyo_no_rewrite_list);
entry = NULL;
error = 0;
}
mutex_unlock(&tomoyo_policy_lock);
tomoyo_put_name(saved_pattern);
kfree(entry);
return error;
}
/**
* tomoyo_is_no_rewrite_file - Check if the given pathname is not permitted to be rewrited.
*
* @filename: Filename to check.
*
* Returns true if @filename is specified by "deny_rewrite" directive,
* false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static bool tomoyo_is_no_rewrite_file(const struct tomoyo_path_info *filename)
{
struct tomoyo_no_rewrite_entry *ptr;
bool found = false;
list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
if (ptr->is_deleted)
continue;
if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
continue;
found = true;
break;
}
return found;
}
/**
* tomoyo_write_no_rewrite_policy - Write "struct tomoyo_no_rewrite_entry" list.
*
* @data: String to parse.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
int tomoyo_write_no_rewrite_policy(char *data, const bool is_delete)
{
return tomoyo_update_no_rewrite_entry(data, is_delete);
}
/**
* tomoyo_read_no_rewrite_policy - Read "struct tomoyo_no_rewrite_entry" list.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns true on success, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head)
{
struct list_head *pos;
bool done = true;
list_for_each_cookie(pos, head->read_var2, &tomoyo_no_rewrite_list) {
struct tomoyo_no_rewrite_entry *ptr;
ptr = list_entry(pos, struct tomoyo_no_rewrite_entry, list);
if (ptr->is_deleted)
continue;
done = tomoyo_io_printf(head, TOMOYO_KEYWORD_DENY_REWRITE
"%s\n", ptr->pattern->name);
if (!done)
break;
}
return done;
}
/**
* tomoyo_update_file_acl - Update file's read/write/execute ACL.
*
* @filename: Filename.
* @perm: Permission (between 1 to 7).
* @domain: Pointer to "struct tomoyo_domain_info".
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* This is legacy support interface for older policy syntax.
* Current policy syntax uses "allow_read/write" instead of "6",
* "allow_read" instead of "4", "allow_write" instead of "2",
* "allow_execute" instead of "1".
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_file_acl(const char *filename, u8 perm,
struct tomoyo_domain_info * const domain,
const bool is_delete)
{
if (perm > 7 || !perm) {
printk(KERN_DEBUG "%s: Invalid permission '%d %s'\n",
__func__, perm, filename);
return -EINVAL;
}
if (filename[0] != '@' && tomoyo_strendswith(filename, "/"))
/*
* Only 'allow_mkdir' and 'allow_rmdir' are valid for
* directory permissions.
*/
return 0;
if (perm & 4)
tomoyo_update_path_acl(TOMOYO_TYPE_READ, filename, domain,
is_delete);
if (perm & 2)
tomoyo_update_path_acl(TOMOYO_TYPE_WRITE, filename, domain,
is_delete);
if (perm & 1)
tomoyo_update_path_acl(TOMOYO_TYPE_EXECUTE, filename, domain,
is_delete);
return 0;
}
/**
* tomoyo_path_acl2 - Check permission for single path operation.
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @filename: Filename to check.
* @perm: Permission.
* @may_use_pattern: True if patterned ACL is permitted.
*
* Returns 0 on success, -EPERM otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_path_acl2(const struct tomoyo_domain_info *domain,
const struct tomoyo_path_info *filename,
const u32 perm, const bool may_use_pattern)
{
struct tomoyo_acl_info *ptr;
int error = -EPERM;
list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
struct tomoyo_path_acl *acl;
if (ptr->type != TOMOYO_TYPE_PATH_ACL)
continue;
acl = container_of(ptr, struct tomoyo_path_acl, head);
if (perm <= 0xFFFF) {
if (!(acl->perm & perm))
continue;
} else {
if (!(acl->perm_high & (perm >> 16)))
continue;
}
if (may_use_pattern || !acl->filename->is_patterned) {
if (!tomoyo_path_matches_pattern(filename,
acl->filename))
continue;
} else {
continue;
}
error = 0;
break;
}
return error;
}
/**
* tomoyo_check_file_acl - Check permission for opening files.
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @filename: Filename to check.
* @operation: Mode ("read" or "write" or "read/write" or "execute").
*
* Returns 0 on success, -EPERM otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_check_file_acl(const struct tomoyo_domain_info *domain,
const struct tomoyo_path_info *filename,
const u8 operation)
{
u32 perm = 0;
if (!tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE))
return 0;
if (operation == 6)
perm = 1 << TOMOYO_TYPE_READ_WRITE;
else if (operation == 4)
perm = 1 << TOMOYO_TYPE_READ;
else if (operation == 2)
perm = 1 << TOMOYO_TYPE_WRITE;
else if (operation == 1)
perm = 1 << TOMOYO_TYPE_EXECUTE;
else
BUG();
return tomoyo_path_acl2(domain, filename, perm, operation != 1);
}
/**
* tomoyo_check_file_perm2 - Check permission for opening files.
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @filename: Filename to check.
* @perm: Mode ("read" or "write" or "read/write" or "execute").
* @operation: Operation name passed used for verbose mode.
* @mode: Access control mode.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_check_file_perm2(struct tomoyo_domain_info * const domain,
const struct tomoyo_path_info *filename,
const u8 perm, const char *operation,
const u8 mode)
{
const bool is_enforce = (mode == 3);
const char *msg = "<unknown>";
int error = 0;
if (!filename)
return 0;
error = tomoyo_check_file_acl(domain, filename, perm);
if (error && perm == 4 && !domain->ignore_global_allow_read
&& tomoyo_is_globally_readable_file(filename))
error = 0;
if (perm == 6)
msg = tomoyo_path2keyword(TOMOYO_TYPE_READ_WRITE);
else if (perm == 4)
msg = tomoyo_path2keyword(TOMOYO_TYPE_READ);
else if (perm == 2)
msg = tomoyo_path2keyword(TOMOYO_TYPE_WRITE);
else if (perm == 1)
msg = tomoyo_path2keyword(TOMOYO_TYPE_EXECUTE);
else
BUG();
if (!error)
return 0;
if (tomoyo_verbose_mode(domain))
printk(KERN_WARNING "TOMOYO-%s: Access '%s(%s) %s' denied "
"for %s\n", tomoyo_get_msg(is_enforce), msg, operation,
filename->name, tomoyo_get_last_name(domain));
if (is_enforce)
return error;
if (mode == 1 && tomoyo_domain_quota_is_ok(domain)) {
/* Don't use patterns for execute permission. */
const struct tomoyo_path_info *patterned_file = (perm != 1) ?
tomoyo_get_file_pattern(filename) : filename;
tomoyo_update_file_acl(patterned_file->name, perm,
domain, false);
}
return 0;
}
/**
* tomoyo_write_file_policy - Update file related list.
*
* @data: String to parse.
* @domain: Pointer to "struct tomoyo_domain_info".
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
int tomoyo_write_file_policy(char *data, struct tomoyo_domain_info *domain,
const bool is_delete)
{
char *filename = strchr(data, ' ');
char *filename2;
unsigned int perm;
u8 type;
if (!filename)
return -EINVAL;
*filename++ = '\0';
if (sscanf(data, "%u", &perm) == 1)
return tomoyo_update_file_acl(filename, (u8) perm, domain,
is_delete);
if (strncmp(data, "allow_", 6))
goto out;
data += 6;
for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++) {
if (strcmp(data, tomoyo_path_keyword[type]))
continue;
return tomoyo_update_path_acl(type, filename, domain,
is_delete);
}
filename2 = strchr(filename, ' ');
if (!filename2)
goto out;
*filename2++ = '\0';
for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++) {
if (strcmp(data, tomoyo_path2_keyword[type]))
continue;
return tomoyo_update_path2_acl(type, filename, filename2,
domain, is_delete);
}
out:
return -EINVAL;
}
/**
* tomoyo_update_path_acl - Update "struct tomoyo_path_acl" list.
*
* @type: Type of operation.
* @filename: Filename.
* @domain: Pointer to "struct tomoyo_domain_info".
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_path_acl(const u8 type, const char *filename,
struct tomoyo_domain_info *const domain,
const bool is_delete)
{
static const u32 rw_mask =
(1 << TOMOYO_TYPE_READ) | (1 << TOMOYO_TYPE_WRITE);
const struct tomoyo_path_info *saved_filename;
struct tomoyo_acl_info *ptr;
struct tomoyo_path_acl *entry = NULL;
int error = is_delete ? -ENOENT : -ENOMEM;
const u32 perm = 1 << type;
if (!domain)
return -EINVAL;
if (!tomoyo_is_correct_path(filename, 0, 0, 0))
return -EINVAL;
saved_filename = tomoyo_get_name(filename);
if (!saved_filename)
return -ENOMEM;
if (!is_delete)
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
struct tomoyo_path_acl *acl =
container_of(ptr, struct tomoyo_path_acl, head);
if (ptr->type != TOMOYO_TYPE_PATH_ACL)
continue;
if (acl->filename != saved_filename)
continue;
if (is_delete) {
if (perm <= 0xFFFF)
acl->perm &= ~perm;
else
acl->perm_high &= ~(perm >> 16);
if ((acl->perm & rw_mask) != rw_mask)
acl->perm &= ~(1 << TOMOYO_TYPE_READ_WRITE);
else if (!(acl->perm & (1 << TOMOYO_TYPE_READ_WRITE)))
acl->perm &= ~rw_mask;
} else {
if (perm <= 0xFFFF)
acl->perm |= perm;
else
acl->perm_high |= (perm >> 16);
if ((acl->perm & rw_mask) == rw_mask)
acl->perm |= 1 << TOMOYO_TYPE_READ_WRITE;
else if (acl->perm & (1 << TOMOYO_TYPE_READ_WRITE))
acl->perm |= rw_mask;
}
error = 0;
break;
}
if (!is_delete && error && tomoyo_memory_ok(entry)) {
entry->head.type = TOMOYO_TYPE_PATH_ACL;
if (perm <= 0xFFFF)
entry->perm = perm;
else
entry->perm_high = (perm >> 16);
if (perm == (1 << TOMOYO_TYPE_READ_WRITE))
entry->perm |= rw_mask;
entry->filename = saved_filename;
saved_filename = NULL;
list_add_tail_rcu(&entry->head.list, &domain->acl_info_list);
entry = NULL;
error = 0;
}
mutex_unlock(&tomoyo_policy_lock);
kfree(entry);
tomoyo_put_name(saved_filename);
return error;
}
/**
* tomoyo_update_path2_acl - Update "struct tomoyo_path2_acl" list.
*
* @type: Type of operation.
* @filename1: First filename.
* @filename2: Second filename.
* @domain: Pointer to "struct tomoyo_domain_info".
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
const char *filename2,
struct tomoyo_domain_info *const domain,
const bool is_delete)
{
const struct tomoyo_path_info *saved_filename1;
const struct tomoyo_path_info *saved_filename2;
struct tomoyo_acl_info *ptr;
struct tomoyo_path2_acl *entry = NULL;
int error = is_delete ? -ENOENT : -ENOMEM;
const u8 perm = 1 << type;
if (!domain)
return -EINVAL;
if (!tomoyo_is_correct_path(filename1, 0, 0, 0) ||
!tomoyo_is_correct_path(filename2, 0, 0, 0))
return -EINVAL;
saved_filename1 = tomoyo_get_name(filename1);
saved_filename2 = tomoyo_get_name(filename2);
if (!saved_filename1 || !saved_filename2)
goto out;
if (!is_delete)
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
struct tomoyo_path2_acl *acl =
container_of(ptr, struct tomoyo_path2_acl, head);
if (ptr->type != TOMOYO_TYPE_PATH2_ACL)
continue;
if (acl->filename1 != saved_filename1 ||
acl->filename2 != saved_filename2)
continue;
if (is_delete)
acl->perm &= ~perm;
else
acl->perm |= perm;
error = 0;
break;
}
if (!is_delete && error && tomoyo_memory_ok(entry)) {
entry->head.type = TOMOYO_TYPE_PATH2_ACL;
entry->perm = perm;
entry->filename1 = saved_filename1;
saved_filename1 = NULL;
entry->filename2 = saved_filename2;
saved_filename2 = NULL;
list_add_tail_rcu(&entry->head.list, &domain->acl_info_list);
entry = NULL;
error = 0;
}
mutex_unlock(&tomoyo_policy_lock);
out:
tomoyo_put_name(saved_filename1);
tomoyo_put_name(saved_filename2);
kfree(entry);
return error;
}
/**
* tomoyo_path_acl - Check permission for single path operation.
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @type: Type of operation.
* @filename: Filename to check.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_path_acl(struct tomoyo_domain_info *domain, const u8 type,
const struct tomoyo_path_info *filename)
{
if (!tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE))
return 0;
return tomoyo_path_acl2(domain, filename, 1 << type, 1);
}
/**
* tomoyo_path2_acl - Check permission for double path operation.
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @type: Type of operation.
* @filename1: First filename to check.
* @filename2: Second filename to check.
*
* Returns 0 on success, -EPERM otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_path2_acl(const struct tomoyo_domain_info *domain,
const u8 type,
const struct tomoyo_path_info *filename1,
const struct tomoyo_path_info *filename2)
{
struct tomoyo_acl_info *ptr;
const u8 perm = 1 << type;
int error = -EPERM;
if (!tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE))
return 0;
list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
struct tomoyo_path2_acl *acl;
if (ptr->type != TOMOYO_TYPE_PATH2_ACL)
continue;
acl = container_of(ptr, struct tomoyo_path2_acl, head);
if (!(acl->perm & perm))
continue;
if (!tomoyo_path_matches_pattern(filename1, acl->filename1))
continue;
if (!tomoyo_path_matches_pattern(filename2, acl->filename2))
continue;
error = 0;
break;
}
return error;
}
/**
* tomoyo_path_permission2 - Check permission for single path operation.
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @operation: Type of operation.
* @filename: Filename to check.
* @mode: Access control mode.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_path_permission2(struct tomoyo_domain_info *const domain,
u8 operation,
const struct tomoyo_path_info *filename,
const u8 mode)
{
const char *msg;
int error;
const bool is_enforce = (mode == 3);
if (!mode)
return 0;
next:
error = tomoyo_path_acl(domain, operation, filename);
msg = tomoyo_path2keyword(operation);
if (!error)
goto ok;
if (tomoyo_verbose_mode(domain))
printk(KERN_WARNING "TOMOYO-%s: Access '%s %s' denied for %s\n",
tomoyo_get_msg(is_enforce), msg, filename->name,
tomoyo_get_last_name(domain));
if (mode == 1 && tomoyo_domain_quota_is_ok(domain)) {
const char *name = tomoyo_get_file_pattern(filename)->name;
tomoyo_update_path_acl(operation, name, domain, false);
}
if (!is_enforce)
error = 0;
ok:
/*
* Since "allow_truncate" doesn't imply "allow_rewrite" permission,
* we need to check "allow_rewrite" permission if the filename is
* specified by "deny_rewrite" keyword.
*/
if (!error && operation == TOMOYO_TYPE_TRUNCATE &&
tomoyo_is_no_rewrite_file(filename)) {
operation = TOMOYO_TYPE_REWRITE;
goto next;
}
return error;
}
/**
* tomoyo_check_exec_perm - Check permission for "execute".
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @filename: Check permission for "execute".
*
* Returns 0 on success, negativevalue otherwise.
*
* Caller holds tomoyo_read_lock().
*/
int tomoyo_check_exec_perm(struct tomoyo_domain_info *domain,
const struct tomoyo_path_info *filename)
{
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
if (!mode)
return 0;
return tomoyo_check_file_perm2(domain, filename, 1, "do_execve", mode);
}
/**
* tomoyo_check_open_permission - Check permission for "read" and "write".
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @path: Pointer to "struct path".
* @flag: Flags for open().
*
* Returns 0 on success, negative value otherwise.
*/
int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
struct path *path, const int flag)
{
const u8 acc_mode = ACC_MODE(flag);
int error = -ENOMEM;
struct tomoyo_path_info *buf;
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
const bool is_enforce = (mode == 3);
int idx;
if (!mode || !path->mnt)
return 0;
if (acc_mode == 0)
return 0;
if (path->dentry->d_inode && S_ISDIR(path->dentry->d_inode->i_mode))
/*
* I don't check directories here because mkdir() and rmdir()
* don't call me.
*/
return 0;
idx = tomoyo_read_lock();
buf = tomoyo_get_path(path);
if (!buf)
goto out;
error = 0;
/*
* If the filename is specified by "deny_rewrite" keyword,
* we need to check "allow_rewrite" permission when the filename is not
* opened for append mode or the filename is truncated at open time.
*/
if ((acc_mode & MAY_WRITE) &&
((flag & O_TRUNC) || !(flag & O_APPEND)) &&
(tomoyo_is_no_rewrite_file(buf))) {
error = tomoyo_path_permission2(domain, TOMOYO_TYPE_REWRITE,
buf, mode);
}
if (!error)
error = tomoyo_check_file_perm2(domain, buf, acc_mode, "open",
mode);
if (!error && (flag & O_TRUNC))
error = tomoyo_path_permission2(domain, TOMOYO_TYPE_TRUNCATE,
buf, mode);
out:
kfree(buf);
tomoyo_read_unlock(idx);
if (!is_enforce)
error = 0;
return error;
}
/**
* tomoyo_path_perm - Check permission for "create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock", "mkblock", "mkchar", "truncate", "symlink", "ioctl", "chmod", "chown", "chgrp", "chroot", "mount" and "unmount".
*
* @operation: Type of operation.
* @path: Pointer to "struct path".
*
* Returns 0 on success, negative value otherwise.
*/
int tomoyo_path_perm(const u8 operation, struct path *path)
{
int error = -ENOMEM;
struct tomoyo_path_info *buf;
struct tomoyo_domain_info *domain = tomoyo_domain();
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
const bool is_enforce = (mode == 3);
int idx;
if (!mode || !path->mnt)
return 0;
idx = tomoyo_read_lock();
buf = tomoyo_get_path(path);
if (!buf)
goto out;
switch (operation) {
case TOMOYO_TYPE_MKDIR:
case TOMOYO_TYPE_RMDIR:
case TOMOYO_TYPE_CHROOT:
if (!buf->is_dir) {
/*
* tomoyo_get_path() reserves space for appending "/."
*/
strcat((char *) buf->name, "/");
tomoyo_fill_path_info(buf);
}
}
error = tomoyo_path_permission2(domain, operation, buf, mode);
out:
kfree(buf);
tomoyo_read_unlock(idx);
if (!is_enforce)
error = 0;
return error;
}
/**
* tomoyo_check_rewrite_permission - Check permission for "rewrite".
*
* @filp: Pointer to "struct file".
*
* Returns 0 on success, negative value otherwise.
*/
int tomoyo_check_rewrite_permission(struct file *filp)
{
int error = -ENOMEM;
struct tomoyo_domain_info *domain = tomoyo_domain();
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
const bool is_enforce = (mode == 3);
struct tomoyo_path_info *buf;
int idx;
if (!mode || !filp->f_path.mnt)
return 0;
idx = tomoyo_read_lock();
buf = tomoyo_get_path(&filp->f_path);
if (!buf)
goto out;
if (!tomoyo_is_no_rewrite_file(buf)) {
error = 0;
goto out;
}
error = tomoyo_path_permission2(domain, TOMOYO_TYPE_REWRITE, buf, mode);
out:
kfree(buf);
tomoyo_read_unlock(idx);
if (!is_enforce)
error = 0;
return error;
}
/**
* tomoyo_path2_perm - Check permission for "rename", "link" and "pivot_root".
*
* @operation: Type of operation.
* @path1: Pointer to "struct path".
* @path2: Pointer to "struct path".
*
* Returns 0 on success, negative value otherwise.
*/
int tomoyo_path2_perm(const u8 operation, struct path *path1,
struct path *path2)
{
int error = -ENOMEM;
struct tomoyo_path_info *buf1, *buf2;
struct tomoyo_domain_info *domain = tomoyo_domain();
const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
const bool is_enforce = (mode == 3);
const char *msg;
int idx;
if (!mode || !path1->mnt || !path2->mnt)
return 0;
idx = tomoyo_read_lock();
buf1 = tomoyo_get_path(path1);
buf2 = tomoyo_get_path(path2);
if (!buf1 || !buf2)
goto out;
{
struct dentry *dentry = path1->dentry;
if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
/*
* tomoyo_get_path() reserves space for appending "/."
*/
if (!buf1->is_dir) {
strcat((char *) buf1->name, "/");
tomoyo_fill_path_info(buf1);
}
if (!buf2->is_dir) {
strcat((char *) buf2->name, "/");
tomoyo_fill_path_info(buf2);
}
}
}
error = tomoyo_path2_acl(domain, operation, buf1, buf2);
msg = tomoyo_path22keyword(operation);
if (!error)
goto out;
if (tomoyo_verbose_mode(domain))
printk(KERN_WARNING "TOMOYO-%s: Access '%s %s %s' "
"denied for %s\n", tomoyo_get_msg(is_enforce),
msg, buf1->name, buf2->name,
tomoyo_get_last_name(domain));
if (mode == 1 && tomoyo_domain_quota_is_ok(domain)) {
const char *name1 = tomoyo_get_file_pattern(buf1)->name;
const char *name2 = tomoyo_get_file_pattern(buf2)->name;
tomoyo_update_path2_acl(operation, name1, name2, domain,
false);
}
out:
kfree(buf1);
kfree(buf2);
tomoyo_read_unlock(idx);
if (!is_enforce)
error = 0;
return error;
}
