[TOMOYO #15 4/8] File operation restriction part.

Kentaro Takeda
2009-02-05T09:08:24Z

This file controls file related operations of TOMOYO Linux.

tomoyo/tomoyo.c calls the following six functions in this file.
Each function handles the following access types.

* tomoyo_check_file_perm
sysctl()'s "read" and "write".

* tomoyo_check_exec_perm
"execute".

* tomoyo_check_open_permission
open(2) for "read" and "write".

* tomoyo_check_1path_perm
"create", "unlink", "mkdir", "rmdir", "mkfifo",
"mksock", "mkblock", "mkchar", "truncate" and "symlink".

* tomoyo_check_2path_perm
"rename" and "unlink".

* tomoyo_check_rewrite_permission
"rewrite".
("rewrite" are operations which may lose already recorded data of a file,
i.e. open(!O_APPEND) || open(O_TRUNC) || truncate() || ftruncate())

The functions which actually checks ACLs are the following three functions.
Each function handles the following access types.
ACL directive is expressed by "allow_<access type>".

* tomoyo_check_file_acl
Open() operation and execve() operation.
("read", "write", "read/write" and "execute")

* tomoyo_check_single_write_acl
Directory modification operations with 1 pathname.
("create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock",
"mkblock", "mkchar", "truncate", "symlink" and "rewrite")

* tomoyo_check_double_write_acl
Directory modification operations with 2 pathname.
("link" and "rename")

Also, this file contains handlers of some utility directives
for file related operations.

* "allow_read": specifies globally (for all domains) readable files.
* "path_group": specifies pathname macro.
* "deny_rewrite": restricts rewrite operation.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
---
security/tomoyo/file.c | 1241 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 1241 insertions(+)

--- /dev/null
+++ security-testing-2.6.git/security/tomoyo/file.c
@@ -0,0 +1,1241 @@
+/*
+ * security/tomoyo/file.c
+ *
+ * Implementation of the Domain-Based Mandatory Access Control.
+ *
+ * Copyright (C) 2005-2009 NTT DATA CORPORATION
+ *
+ * Version: 2.2.0-pre 2009/02/01
+ *
+ */
+
+#include "common.h"
+#include "tomoyo.h"
+#include "realpath.h"
+#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
+
+/* Structure for "allow_read" keyword. */
+struct tomoyo_globally_readable_file_entry {
+ struct list_head list;
+ const struct tomoyo_path_info *filename;
+ bool is_deleted;
+};
+
+/* Structure for "file_pattern" keyword. */
+struct tomoyo_pattern_entry {
+ struct list_head list;
+ const struct tomoyo_path_info *pattern;
+ bool is_deleted;
+};
+
+/* Structure for "deny_rewrite" keyword. */
+struct tomoyo_no_rewrite_entry {
+ struct list_head list;
+ const struct tomoyo_path_info *pattern;
+ bool is_deleted;
+};
+
+/* Keyword array for single path operations. */
+static const char *tomoyo_sp_keyword[TOMOYO_MAX_SINGLE_PATH_OPERATION] = {
+ [TOMOYO_TYPE_READ_WRITE_ACL] = "read/write",
+ [TOMOYO_TYPE_EXECUTE_ACL] = "execute",
+ [TOMOYO_TYPE_READ_ACL] = "read",
+ [TOMOYO_TYPE_WRITE_ACL] = "write",
+ [TOMOYO_TYPE_CREATE_ACL] = "create",
+ [TOMOYO_TYPE_UNLINK_ACL] = "unlink",
+ [TOMOYO_TYPE_MKDIR_ACL] = "mkdir",
+ [TOMOYO_TYPE_RMDIR_ACL] = "rmdir",
+ [TOMOYO_TYPE_MKFIFO_ACL] = "mkfifo",
+ [TOMOYO_TYPE_MKSOCK_ACL] = "mksock",
+ [TOMOYO_TYPE_MKBLOCK_ACL] = "mkblock",
+ [TOMOYO_TYPE_MKCHAR_ACL] = "mkchar",
+ [TOMOYO_TYPE_TRUNCATE_ACL] = "truncate",
+ [TOMOYO_TYPE_SYMLINK_ACL] = "symlink",
+ [TOMOYO_TYPE_REWRITE_ACL] = "rewrite",
+};
+
+/* Keyword array for double path operations. */
+static const char *tomoyo_dp_keyword[TOMOYO_MAX_DOUBLE_PATH_OPERATION] = {
+ [TOMOYO_TYPE_LINK_ACL] = "link",
+ [TOMOYO_TYPE_RENAME_ACL] = "rename",
+};
+
+/**
+ * tomoyo_sp2keyword - Get the name of single path operation.
+ *
+ * @operation: Type of operation.
+ *
+ * Returns the name of single path operation.
+ */
+const char *tomoyo_sp2keyword(const u8 operation)
+{
+ return (operation < TOMOYO_MAX_SINGLE_PATH_OPERATION)
+ ? tomoyo_sp_keyword[operation] : NULL;
+}
+
+/**
+ * tomoyo_dp2keyword - Get the name of double path operation.
+ *
+ * @operation: Type of operation.
+ *
+ * Returns the name of double path operation.
+ */
+const char *tomoyo_dp2keyword(const u8 operation)
+{
+ return (operation < TOMOYO_MAX_DOUBLE_PATH_OPERATION)
+ ? tomoyo_dp_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 = tomoyo_alloc(sizeof(*buf));
+
+ 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;
+ }
+ tomoyo_free(buf);
+ return NULL;
+}
+
+/* Lock for domain->acl_info_list. */
+DECLARE_RWSEM(tomoyo_domain_acl_info_list_lock);
+
+static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
+ const char *filename2,
+ struct tomoyo_domain_info *
+ const domain, const bool is_delete);
+static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
+ struct tomoyo_domain_info *
+ const domain, const bool is_delete);
+
+/* The list for "struct tomoyo_globally_readable_file_entry". */
+static LIST_HEAD(tomoyo_globally_readable_list);
+static DECLARE_RWSEM(tomoyo_globally_readable_list_lock);
+
+/**
+ * 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.
+ */
+static int tomoyo_update_globally_readable_entry(const char *filename,
+ const bool is_delete)
+{
+ struct tomoyo_globally_readable_file_entry *new_entry;
+ struct tomoyo_globally_readable_file_entry *ptr;
+ const struct tomoyo_path_info *saved_filename;
+ int error = -ENOMEM;
+
+ if (!tomoyo_is_correct_path(filename, 1, 0, -1, __func__))
+ return -EINVAL;
+ saved_filename = tomoyo_save_name(filename);
+ if (!saved_filename)
+ return -ENOMEM;
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_globally_readable_list_lock);
+ list_for_each_entry(ptr, &tomoyo_globally_readable_list, list) {
+ if (ptr->filename != saved_filename)
+ continue;
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+ new_entry = tomoyo_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->filename = saved_filename;
+ list_add_tail(&new_entry->list, &tomoyo_globally_readable_list);
+ error = 0;
+ out:
+ up_write(&tomoyo_globally_readable_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ 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.
+ */
+static bool tomoyo_is_globally_readable_file(const struct tomoyo_path_info *
+ filename)
+{
+ struct tomoyo_globally_readable_file_entry *ptr;
+ bool found = false;
+ down_read(&tomoyo_globally_readable_list_lock);
+ list_for_each_entry(ptr, &tomoyo_globally_readable_list, list) {
+ if (!ptr->is_deleted &&
+ tomoyo_path_matches_pattern(filename, ptr->filename)) {
+ found = true;
+ break;
+ }
+ }
+ up_read(&tomoyo_globally_readable_list_lock);
+ 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.
+ */
+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.
+ */
+bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head)
+{
+ struct list_head *pos;
+ bool done = true;
+
+ down_read(&tomoyo_globally_readable_list_lock);
+ 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;
+ if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_ALLOW_READ "%s\n",
+ ptr->filename->name)) {
+ done = false;
+ break;
+ }
+ }
+ up_read(&tomoyo_globally_readable_list_lock);
+ return done;
+}
+
+/* The list for "struct tomoyo_pattern_entry". */
+static LIST_HEAD(tomoyo_pattern_list);
+static DECLARE_RWSEM(tomoyo_pattern_list_lock);
+
+/**
+ * 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.
+ */
+static int tomoyo_update_file_pattern_entry(const char *pattern,
+ const bool is_delete)
+{
+ struct tomoyo_pattern_entry *new_entry;
+ struct tomoyo_pattern_entry *ptr;
+ const struct tomoyo_path_info *saved_pattern;
+ int error = -ENOMEM;
+
+ if (!tomoyo_is_correct_path(pattern, 0, 1, 0, __func__))
+ return -EINVAL;
+ saved_pattern = tomoyo_save_name(pattern);
+ if (!saved_pattern)
+ return -ENOMEM;
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_pattern_list_lock);
+ list_for_each_entry(ptr, &tomoyo_pattern_list, list) {
+ if (saved_pattern != ptr->pattern)
+ continue;
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+ new_entry = tomoyo_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->pattern = saved_pattern;
+ list_add_tail(&new_entry->list, &tomoyo_pattern_list);
+ error = 0;
+ out:
+ up_write(&tomoyo_pattern_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ 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.
+ */
+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;
+
+ down_read(&tomoyo_pattern_list_lock);
+ list_for_each_entry(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;
+ }
+ }
+ up_read(&tomoyo_pattern_list_lock);
+ 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.
+ */
+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.
+ */
+bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head)
+{
+ struct list_head *pos;
+ bool done = true;
+
+ down_read(&tomoyo_pattern_list_lock);
+ 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;
+ if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_FILE_PATTERN "%s\n",
+ ptr->pattern->name)) {
+ done = false;
+ break;
+ }
+ }
+ up_read(&tomoyo_pattern_list_lock);
+ return done;
+}
+
+/* The list for "struct tomoyo_no_rewrite_entry". */
+static LIST_HEAD(tomoyo_no_rewrite_list);
+static DECLARE_RWSEM(tomoyo_no_rewrite_list_lock);
+
+/**
+ * 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.
+ */
+static int tomoyo_update_no_rewrite_entry(const char *pattern,
+ const bool is_delete)
+{
+ struct tomoyo_no_rewrite_entry *new_entry, *ptr;
+ const struct tomoyo_path_info *saved_pattern;
+ int error = -ENOMEM;
+
+ if (!tomoyo_is_correct_path(pattern, 0, 0, 0, __func__))
+ return -EINVAL;
+ saved_pattern = tomoyo_save_name(pattern);
+ if (!saved_pattern)
+ return -ENOMEM;
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_no_rewrite_list_lock);
+ list_for_each_entry(ptr, &tomoyo_no_rewrite_list, list) {
+ if (ptr->pattern != saved_pattern)
+ continue;
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+ new_entry = tomoyo_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->pattern = saved_pattern;
+ list_add_tail(&new_entry->list, &tomoyo_no_rewrite_list);
+ error = 0;
+ out:
+ up_write(&tomoyo_no_rewrite_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ 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.
+ */
+static bool tomoyo_is_no_rewrite_file(const struct tomoyo_path_info *filename)
+{
+ struct tomoyo_no_rewrite_entry *ptr;
+ bool found = false;
+
+ down_read(&tomoyo_no_rewrite_list_lock);
+ list_for_each_entry(ptr, &tomoyo_no_rewrite_list, list) {
+ if (ptr->is_deleted)
+ continue;
+ if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
+ continue;
+ found = true;
+ break;
+ }
+ up_read(&tomoyo_no_rewrite_list_lock);
+ 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.
+ */
+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.
+ */
+bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head)
+{
+ struct list_head *pos;
+ bool done = true;
+
+ down_read(&tomoyo_no_rewrite_list_lock);
+ 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;
+ if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_DENY_REWRITE "%s\n",
+ ptr->pattern->name)) {
+ done = false;
+ break;
+ }
+ }
+ up_read(&tomoyo_no_rewrite_list_lock);
+ 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".
+ */
+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_single_path_acl(TOMOYO_TYPE_READ_ACL, filename,
+ domain, is_delete);
+ if (perm & 2)
+ tomoyo_update_single_path_acl(TOMOYO_TYPE_WRITE_ACL, filename,
+ domain, is_delete);
+ if (perm & 1)
+ tomoyo_update_single_path_acl(TOMOYO_TYPE_EXECUTE_ACL,
+ filename, domain, is_delete);
+ return 0;
+}
+
+/**
+ * tomoyo_check_single_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.
+ */
+static int tomoyo_check_single_path_acl2(const struct tomoyo_domain_info *
+ domain,
+ const struct tomoyo_path_info *
+ filename,
+ const u16 perm,
+ const bool may_use_pattern)
+{
+ struct tomoyo_acl_info *ptr;
+ int error = -EPERM;
+
+ down_read(&tomoyo_domain_acl_info_list_lock);
+ list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ struct tomoyo_single_path_acl_record *acl;
+ if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct tomoyo_single_path_acl_record,
+ head);
+ if (!(acl->perm & perm))
+ continue;
+ if (may_use_pattern || !acl->filename->is_patterned) {
+ if (!tomoyo_path_matches_pattern(filename,
+ acl->filename))
+ continue;
+ } else {
+ continue;
+ }
+ error = 0;
+ break;
+ }
+ up_read(&tomoyo_domain_acl_info_list_lock);
+ 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.
+ */
+static int tomoyo_check_file_acl(const struct tomoyo_domain_info *domain,
+ const struct tomoyo_path_info *filename,
+ const u8 operation)
+{
+ u16 perm = 0;
+
+ if (!tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE))
+ return 0;
+ if (operation == 6)
+ perm = 1 << TOMOYO_TYPE_READ_WRITE_ACL;
+ else if (operation == 4)
+ perm = 1 << TOMOYO_TYPE_READ_ACL;
+ else if (operation == 2)
+ perm = 1 << TOMOYO_TYPE_WRITE_ACL;
+ else if (operation == 1)
+ perm = 1 << TOMOYO_TYPE_EXECUTE_ACL;
+ else
+ BUG();
+ return tomoyo_check_single_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.
+ */
+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->flags & TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ) == 0
+ && tomoyo_is_globally_readable_file(filename))
+ error = 0;
+ if (perm == 6)
+ msg = tomoyo_sp2keyword(TOMOYO_TYPE_READ_WRITE_ACL);
+ else if (perm == 4)
+ msg = tomoyo_sp2keyword(TOMOYO_TYPE_READ_ACL);
+ else if (perm == 2)
+ msg = tomoyo_sp2keyword(TOMOYO_TYPE_WRITE_ACL);
+ else if (perm == 1)
+ msg = tomoyo_sp2keyword(TOMOYO_TYPE_EXECUTE_ACL);
+ 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.
+ */
+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_SINGLE_PATH_OPERATION; type++) {
+ if (strcmp(data, tomoyo_sp_keyword[type]))
+ continue;
+ return tomoyo_update_single_path_acl(type, filename,
+ domain, is_delete);
+ }
+ filename2 = strchr(filename, ' ');
+ if (!filename2)
+ goto out;
+ *filename2++ = '\0';
+ for (type = 0; type < TOMOYO_MAX_DOUBLE_PATH_OPERATION; type++) {
+ if (strcmp(data, tomoyo_dp_keyword[type]))
+ continue;
+ return tomoyo_update_double_path_acl(type, filename, filename2,
+ domain, is_delete);
+ }
+ out:
+ return -EINVAL;
+}
+
+/**
+ * tomoyo_update_single_path_acl - Update "struct tomoyo_single_path_acl_record" 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.
+ */
+static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
+ struct tomoyo_domain_info *
+ const domain, const bool is_delete)
+{
+ static const u16 rw_mask =
+ (1 << TOMOYO_TYPE_READ_ACL) | (1 << TOMOYO_TYPE_WRITE_ACL);
+ const struct tomoyo_path_info *saved_filename;
+ struct tomoyo_acl_info *ptr;
+ struct tomoyo_single_path_acl_record *acl;
+ int error = -ENOMEM;
+ const u16 perm = 1 << type;
+
+ if (!domain)
+ return -EINVAL;
+ if (!tomoyo_is_correct_path(filename, 0, 0, 0, __func__))
+ return -EINVAL;
+ saved_filename = tomoyo_save_name(filename);
+ if (!saved_filename)
+ return -ENOMEM;
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_domain_acl_info_list_lock);
+ if (is_delete)
+ goto delete;
+ list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ if (tomoyo_acl_type1(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct tomoyo_single_path_acl_record,
+ head);
+ if (acl->filename != saved_filename)
+ continue;
+ /* Special case. Clear all bits if marked as deleted. */
+ if (ptr->type & TOMOYO_ACL_DELETED)
+ acl->perm = 0;
+ acl->perm |= perm;
+ if ((acl->perm & rw_mask) == rw_mask)
+ acl->perm |= 1 << TOMOYO_TYPE_READ_WRITE_ACL;
+ else if (acl->perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL))
+ acl->perm |= rw_mask;
+ ptr->type &= ~TOMOYO_ACL_DELETED;
+ error = 0;
+ goto out;
+ }
+ /* Not found. Append it to the tail. */
+ acl = tomoyo_alloc_acl_element(TOMOYO_TYPE_SINGLE_PATH_ACL);
+ if (!acl)
+ goto out;
+ acl->perm = perm;
+ if (perm == (1 << TOMOYO_TYPE_READ_WRITE_ACL))
+ acl->perm |= rw_mask;
+ acl->filename = saved_filename;
+ list_add_tail(&acl->head.list, &domain->acl_info_list);
+ error = 0;
+ goto out;
+ delete:
+ error = -ENOENT;
+ list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_SINGLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct tomoyo_single_path_acl_record,
+ head);
+ if (acl->filename != saved_filename)
+ continue;
+ acl->perm &= ~perm;
+ if ((acl->perm & rw_mask) != rw_mask)
+ acl->perm &= ~(1 << TOMOYO_TYPE_READ_WRITE_ACL);
+ else if (!(acl->perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
+ acl->perm &= ~rw_mask;
+ if (!acl->perm)
+ ptr->type |= TOMOYO_ACL_DELETED;
+ error = 0;
+ break;
+ }
+ out:
+ up_write(&tomoyo_domain_acl_info_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ return error;
+}
+
+/**
+ * tomoyo_update_double_path_acl - Update "struct tomoyo_double_path_acl_record" 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.
+ */
+static int tomoyo_update_double_path_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_double_path_acl_record *acl;
+ int error = -ENOMEM;
+ const u8 perm = 1 << type;
+
+ if (!domain)
+ return -EINVAL;
+ if (!tomoyo_is_correct_path(filename1, 0, 0, 0, __func__) ||
+ !tomoyo_is_correct_path(filename2, 0, 0, 0, __func__))
+ return -EINVAL;
+ saved_filename1 = tomoyo_save_name(filename1);
+ saved_filename2 = tomoyo_save_name(filename2);
+ if (!saved_filename1 || !saved_filename2)
+ return -ENOMEM;
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_domain_acl_info_list_lock);
+ if (is_delete)
+ goto delete;
+ list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ if (tomoyo_acl_type1(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct tomoyo_double_path_acl_record,
+ head);
+ if (acl->filename1 != saved_filename1 ||
+ acl->filename2 != saved_filename2)
+ continue;
+ /* Special case. Clear all bits if marked as deleted. */
+ if (ptr->type & TOMOYO_ACL_DELETED)
+ acl->perm = 0;
+ acl->perm |= perm;
+ ptr->type &= ~TOMOYO_ACL_DELETED;
+ error = 0;
+ goto out;
+ }
+ /* Not found. Append it to the tail. */
+ acl = tomoyo_alloc_acl_element(TOMOYO_TYPE_DOUBLE_PATH_ACL);
+ if (!acl)
+ goto out;
+ acl->perm = perm;
+ acl->filename1 = saved_filename1;
+ acl->filename2 = saved_filename2;
+ list_add_tail(&acl->head.list, &domain->acl_info_list);
+ error = 0;
+ goto out;
+ delete:
+ error = -ENOENT;
+ list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct tomoyo_double_path_acl_record,
+ head);
+ if (acl->filename1 != saved_filename1 ||
+ acl->filename2 != saved_filename2)
+ continue;
+ acl->perm &= ~perm;
+ if (!acl->perm)
+ ptr->type |= TOMOYO_ACL_DELETED;
+ error = 0;
+ break;
+ }
+ out:
+ up_write(&tomoyo_domain_acl_info_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ return error;
+}
+
+/**
+ * tomoyo_check_single_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.
+ */
+static int tomoyo_check_single_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_check_single_path_acl2(domain, filename, 1 << type, 1);
+}
+
+/**
+ * tomoyo_check_double_path_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.
+ */
+static int tomoyo_check_double_path_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;
+ down_read(&tomoyo_domain_acl_info_list_lock);
+ list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ struct tomoyo_double_path_acl_record *acl;
+ if (tomoyo_acl_type2(ptr) != TOMOYO_TYPE_DOUBLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct tomoyo_double_path_acl_record,
+ 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;
+ }
+ up_read(&tomoyo_domain_acl_info_list_lock);
+ return error;
+}
+
+/**
+ * tomoyo_check_single_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.
+ */
+static int tomoyo_check_single_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_check_single_path_acl(domain, operation, filename);
+ msg = tomoyo_sp2keyword(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_single_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_ACL &&
+ tomoyo_is_no_rewrite_file(filename)) {
+ operation = TOMOYO_TYPE_REWRITE_ACL;
+ goto next;
+ }
+ return error;
+}
+
+/**
+ * tomoyo_check_file_perm - Check permission for sysctl()'s "read" and "write".
+ *
+ * @domain: Pointer to "struct tomoyo_domain_info".
+ * @filename: Filename to check.
+ * @perm: Mode ("read" or "write" or "read/write").
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_check_file_perm(struct tomoyo_domain_info *domain,
+ const char *filename, const u8 perm)
+{
+ struct tomoyo_path_info name;
+ const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
+
+ if (!mode)
+ return 0;
+ name.name = filename;
+ tomoyo_fill_path_info(&name);
+ return tomoyo_check_file_perm2(domain, &name, perm, "sysctl", mode);
+}
+
+/**
+ * tomoyo_check_exec_perm - Check permission for "execute".
+ *
+ * @domain: Pointer to "struct tomoyo_domain_info".
+ * @filename: Check permission for "execute".
+ * @tmp: Buffer for temporary use.
+ *
+ * Returns 0 on success, negativevalue otherwise.
+ */
+int tomoyo_check_exec_perm(struct tomoyo_domain_info *domain,
+ const struct tomoyo_path_info *filename,
+ struct tomoyo_page_buffer *tmp)
+{
+ 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);
+
+ 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;
+ 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_check_single_path_permission2(domain,
+ TOMOYO_TYPE_REWRITE_ACL,
+ buf, mode);
+ }
+ if (!error)
+ error = tomoyo_check_file_perm2(domain, buf, acc_mode, "open",
+ mode);
+ if (!error && (flag & O_TRUNC))
+ error = tomoyo_check_single_path_permission2(domain,
+ TOMOYO_TYPE_TRUNCATE_ACL,
+ buf, mode);
+ out:
+ tomoyo_free(buf);
+ if (!is_enforce)
+ error = 0;
+ return error;
+}
+
+/**
+ * tomoyo_check_1path_perm - Check permission for "create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock", "mkblock", "mkchar", "truncate" and "symlink".
+ *
+ * @domain: Pointer to "struct tomoyo_domain_info".
+ * @operation: Type of operation.
+ * @path: Pointer to "struct path".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_check_1path_perm(struct tomoyo_domain_info *domain,
+ const u8 operation, struct path *path)
+{
+ 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);
+
+ if (!mode || !path->mnt)
+ return 0;
+ buf = tomoyo_get_path(path);
+ if (!buf)
+ goto out;
+ switch (operation) {
+ case TOMOYO_TYPE_MKDIR_ACL:
+ case TOMOYO_TYPE_RMDIR_ACL:
+ if (!buf->is_dir) {
+ /*
+ * tomoyo_get_path() reserves space for appending "/."
+ */
+ strcat((char *) buf->name, "/");
+ tomoyo_fill_path_info(buf);
+ }
+ }
+ error = tomoyo_check_single_path_permission2(domain, operation, buf,
+ mode);
+ out:
+ tomoyo_free(buf);
+ if (!is_enforce)
+ error = 0;
+ return error;
+}
+
+/**
+ * tomoyo_check_rewrite_permission - Check permission for "rewrite".
+ *
+ * @domain: Pointer to "struct tomoyo_domain_info".
+ * @filp: Pointer to "struct file".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_check_rewrite_permission(struct tomoyo_domain_info *domain,
+ struct file *filp)
+{
+ int error = -ENOMEM;
+ const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
+ const bool is_enforce = (mode == 3);
+ struct tomoyo_path_info *buf;
+
+ if (!mode || !filp->f_path.mnt)
+ return 0;
+ buf = tomoyo_get_path(&filp->f_path);
+ if (!buf)
+ goto out;
+ if (!tomoyo_is_no_rewrite_file(buf)) {
+ error = 0;
+ goto out;
+ }
+ error = tomoyo_check_single_path_permission2(domain,
+ TOMOYO_TYPE_REWRITE_ACL,
+ buf, mode);
+ out:
+ tomoyo_free(buf);
+ if (!is_enforce)
+ error = 0;
+ return error;
+}
+
+/**
+ * tomoyo_check_2path_perm - Check permission for "rename" and "link".
+ *
+ * @domain: Pointer to "struct tomoyo_domain_info".
+ * @operation: Type of operation.
+ * @path1: Pointer to "struct path".
+ * @path2: Pointer to "struct path".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_check_2path_perm(struct tomoyo_domain_info * const domain,
+ const u8 operation, struct path *path1,
+ struct path *path2)
+{
+ int error = -ENOMEM;
+ struct tomoyo_path_info *buf1, *buf2;
+ const u8 mode = tomoyo_check_flags(domain, TOMOYO_MAC_FOR_FILE);
+ const bool is_enforce = (mode == 3);
+ const char *msg;
+
+ if (!mode || !path1->mnt || !path2->mnt)
+ return 0;
+ 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_check_double_path_acl(domain, operation, buf1, buf2);
+ msg = tomoyo_dp2keyword(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_double_path_acl(operation, name1, name2, domain,
+ false);
+ }
+ out:
+ tomoyo_free(buf1);
+ tomoyo_free(buf2);
+ if (!is_enforce)
+ error = 0;
+ return error;
+}

--