[TOMOYO #9 (2.6.27-rc7-mm1) 5/6] File operation restriction part.

Kentaro Takeda
2008-09-24T09:07:01Z

This file controls file related operations.

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 | 1134 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 1134 insertions(+)

--- /dev/null
+++ linux-2.6.27-rc7-mm1/security/tomoyo/file.c
@@ -0,0 +1,1134 @@
+/*
+ * security/tomoyo/file.c
+ *
+ * Implementation of the Domain-Based Mandatory Access Control.
+ *
+ * Copyright (C) 2005-2008 NTT DATA CORPORATION
+ *
+ * Version: 2.2.0-pre 2008/09/24
+ *
+ */
+
+#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 globally_readable_file_entry {
+ struct list1_head list;
+ const struct path_info *filename;
+ bool is_deleted;
+};
+
+/* Structure for "file_pattern" keyword. */
+struct pattern_entry {
+ struct list1_head list;
+ const struct path_info *pattern;
+ bool is_deleted;
+};
+
+/* Structure for "deny_rewrite" keyword. */
+struct no_rewrite_entry {
+ struct list1_head list;
+ const struct path_info *pattern;
+ bool is_deleted;
+};
+
+/* Keyword array for single path operations. */
+static const char *sp_keyword[MAX_SINGLE_PATH_OPERATION] = {
+ [TMY_TYPE_READ_WRITE_ACL] = "read/write",
+ [TMY_TYPE_EXECUTE_ACL] = "execute",
+ [TMY_TYPE_READ_ACL] = "read",
+ [TMY_TYPE_WRITE_ACL] = "write",
+ [TMY_TYPE_CREATE_ACL] = "create",
+ [TMY_TYPE_UNLINK_ACL] = "unlink",
+ [TMY_TYPE_MKDIR_ACL] = "mkdir",
+ [TMY_TYPE_RMDIR_ACL] = "rmdir",
+ [TMY_TYPE_MKFIFO_ACL] = "mkfifo",
+ [TMY_TYPE_MKSOCK_ACL] = "mksock",
+ [TMY_TYPE_MKBLOCK_ACL] = "mkblock",
+ [TMY_TYPE_MKCHAR_ACL] = "mkchar",
+ [TMY_TYPE_TRUNCATE_ACL] = "truncate",
+ [TMY_TYPE_SYMLINK_ACL] = "symlink",
+ [TMY_TYPE_REWRITE_ACL] = "rewrite",
+};
+
+/* Keyword array for double path operations. */
+static const char *dp_keyword[MAX_DOUBLE_PATH_OPERATION] = {
+ [TMY_TYPE_LINK_ACL] = "link",
+ [TMY_TYPE_RENAME_ACL] = "rename",
+};
+
+/**
+ * tmy_sp2keyword - Get the name of single path operation.
+ *
+ * @operation: Type of operation.
+ *
+ * Returns the name of single path operation.
+ */
+const char *tmy_sp2keyword(const u8 operation)
+{
+ return (operation < MAX_SINGLE_PATH_OPERATION)
+ ? sp_keyword[operation] : NULL;
+}
+
+/**
+ * tmy_dp2keyword - Get the name of double path operation.
+ *
+ * @operation: Type of operation.
+ *
+ * Returns the name of double path operation.
+ */
+const char *tmy_dp2keyword(const u8 operation)
+{
+ return (operation < MAX_DOUBLE_PATH_OPERATION)
+ ? dp_keyword[operation] : NULL;
+}
+
+/**
+ * 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 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);
+}
+
+/**
+ * tmy_get_path - Get realpath.
+ *
+ * @dentry: Pointer to "struct dentry".
+ * @mnt: Pointer to "struct vfsmount".
+ *
+ * Returns pointer to "struct path_info" on success, NULL otherwise.
+ */
+static struct path_info *tmy_get_path(struct dentry *dentry,
+ struct vfsmount *mnt)
+{
+ int error;
+ struct path_info_with_data *buf = tmy_alloc(sizeof(*buf));
+ if (!buf)
+ return NULL;
+ /* Preserve one byte for appending "/". */
+ error = tmy_realpath_from_dentry2(dentry, mnt, buf->body,
+ sizeof(buf->body) - 2);
+ if (!error) {
+ buf->head.name = buf->body;
+ tmy_fill_path_info(&buf->head);
+ return &buf->head;
+ }
+ tmy_free(buf);
+ return NULL;
+}
+
+static int update_double_path_acl(const u8 type, const char *filename1,
+ const char *filename2,
+ struct domain_info * const domain,
+ const bool is_delete);
+static int update_single_path_acl(const u8 type, const char *filename,
+ struct domain_info * const domain,
+ const bool is_delete);
+
+/* The list for "struct globally_readable_file_entry". */
+static LIST1_HEAD(globally_readable_list);
+
+/**
+ * update_globally_readable_entry - Update "struct 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 update_globally_readable_entry(const char *filename,
+ const bool is_delete)
+{
+ struct globally_readable_file_entry *new_entry;
+ struct globally_readable_file_entry *ptr;
+ static DEFINE_MUTEX(lock);
+ const struct path_info *saved_filename;
+ int error = -ENOMEM;
+ if (!tmy_is_correct_path(filename, 1, 0, -1, __func__))
+ return -EINVAL;
+ saved_filename = tmy_save_name(filename);
+ if (!saved_filename)
+ return -ENOMEM;
+ mutex_lock(&lock);
+ list1_for_each_entry(ptr, &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 = tmy_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->filename = saved_filename;
+ list1_add_tail_mb(&new_entry->list, &globally_readable_list);
+ error = 0;
+out:
+ mutex_unlock(&lock);
+ tmy_update_counter(TMY_UPDATES_COUNTER_EXCEPTION_POLICY);
+ return error;
+}
+
+/**
+ * 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 is_globally_readable_file(const struct path_info *filename)
+{
+ struct globally_readable_file_entry *ptr;
+ list1_for_each_entry(ptr, &globally_readable_list, list) {
+ if (!ptr->is_deleted &&
+ tmy_path_matches_pattern(filename, ptr->filename))
+ return true;
+ }
+ return false;
+}
+
+/**
+ * tmy_write_globally_readable_policy - Write "struct 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 tmy_write_globally_readable_policy(char *data, const bool is_delete)
+{
+ return update_globally_readable_entry(data, is_delete);
+}
+
+/**
+ * tmy_read_globally_readable_policy - Read "struct globally_readable_file_entry" list.
+ *
+ * @head: Pointer to "struct tmy_io_buffer".
+ *
+ * Returns true on success, false otherwise.
+ */
+bool tmy_read_globally_readable_policy(struct tmy_io_buffer *head)
+{
+ struct list1_head *pos;
+ list1_for_each_cookie(pos, head->read_var2, &globally_readable_list) {
+ struct globally_readable_file_entry *ptr;
+ ptr = list1_entry(pos, struct globally_readable_file_entry,
+ list);
+ if (ptr->is_deleted)
+ continue;
+ if (!tmy_io_printf(head, KEYWORD_ALLOW_READ "%s\n",
+ ptr->filename->name))
+ goto out;
+ }
+ return true;
+out:
+ return false;
+}
+
+/* The list for "struct pattern_entry". */
+static LIST1_HEAD(pattern_list);
+
+/**
+ * update_file_pattern_entry - Update "struct pattern_entry" list.
+ *
+ * @pattern: Pathname pattern.
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int update_file_pattern_entry(const char *pattern, const bool is_delete)
+{
+ struct pattern_entry *new_entry;
+ struct pattern_entry *ptr;
+ static DEFINE_MUTEX(lock);
+ const struct path_info *saved_pattern;
+ int error = -ENOMEM;
+ if (!tmy_is_correct_path(pattern, 0, 1, 0, __func__))
+ return -EINVAL;
+ saved_pattern = tmy_save_name(pattern);
+ if (!saved_pattern)
+ return -ENOMEM;
+ mutex_lock(&lock);
+ list1_for_each_entry(ptr, &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 = tmy_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->pattern = saved_pattern;
+ list1_add_tail_mb(&new_entry->list, &pattern_list);
+ error = 0;
+out:
+ mutex_unlock(&lock);
+ tmy_update_counter(TMY_UPDATES_COUNTER_EXCEPTION_POLICY);
+ return error;
+}
+
+/**
+ * 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 path_info *
+get_file_pattern(const struct path_info *filename)
+{
+ struct pattern_entry *ptr;
+ const struct path_info *pattern = NULL;
+ list1_for_each_entry(ptr, &pattern_list, list) {
+ if (ptr->is_deleted)
+ continue;
+ if (!tmy_path_matches_pattern(filename, ptr->pattern))
+ continue;
+ pattern = ptr->pattern;
+ if (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;
+}
+
+/**
+ * tmy_write_pattern_policy - Write "struct pattern_entry" list.
+ *
+ * @data: String to parse.
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tmy_write_pattern_policy(char *data, const bool is_delete)
+{
+ return update_file_pattern_entry(data, is_delete);
+}
+
+/**
+ * tmy_read_file_pattern - Read "struct pattern_entry" list.
+ *
+ * @head: Pointer to "struct tmy_io_buffer".
+ *
+ * Returns true on success, false otherwise.
+ */
+bool tmy_read_file_pattern(struct tmy_io_buffer *head)
+{
+ struct list1_head *pos;
+ list1_for_each_cookie(pos, head->read_var2, &pattern_list) {
+ struct pattern_entry *ptr;
+ ptr = list1_entry(pos, struct pattern_entry, list);
+ if (ptr->is_deleted)
+ continue;
+ if (!tmy_io_printf(head, KEYWORD_FILE_PATTERN "%s\n",
+ ptr->pattern->name))
+ goto out;
+ }
+ return true;
+out:
+ return false;
+}
+
+/* The list for "struct no_rewrite_entry". */
+static LIST1_HEAD(no_rewrite_list);
+
+/**
+ * update_no_rewrite_entry - Update "struct 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 update_no_rewrite_entry(const char *pattern, const bool is_delete)
+{
+ struct no_rewrite_entry *new_entry, *ptr;
+ static DEFINE_MUTEX(lock);
+ const struct path_info *saved_pattern;
+ int error = -ENOMEM;
+ if (!tmy_is_correct_path(pattern, 0, 0, 0, __func__))
+ return -EINVAL;
+ saved_pattern = tmy_save_name(pattern);
+ if (!saved_pattern)
+ return -ENOMEM;
+ mutex_lock(&lock);
+ list1_for_each_entry(ptr, &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 = tmy_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->pattern = saved_pattern;
+ list1_add_tail_mb(&new_entry->list, &no_rewrite_list);
+ error = 0;
+out:
+ mutex_unlock(&lock);
+ tmy_update_counter(TMY_UPDATES_COUNTER_EXCEPTION_POLICY);
+ return error;
+}
+
+/**
+ * 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 is_no_rewrite_file(const struct path_info *filename)
+{
+ struct no_rewrite_entry *ptr;
+ list1_for_each_entry(ptr, &no_rewrite_list, list) {
+ if (ptr->is_deleted)
+ continue;
+ if (!tmy_path_matches_pattern(filename, ptr->pattern))
+ continue;
+ return true;
+ }
+ return false;
+}
+
+/**
+ * tmy_write_no_rewrite_policy - Write "struct 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 tmy_write_no_rewrite_policy(char *data, const bool is_delete)
+{
+ return update_no_rewrite_entry(data, is_delete);
+}
+
+/**
+ * tmy_read_no_rewrite_policy - Read "struct no_rewrite_entry" list.
+ *
+ * @head: Pointer to "struct tmy_io_buffer".
+ *
+ * Returns true on success, false otherwise.
+ */
+bool tmy_read_no_rewrite_policy(struct tmy_io_buffer *head)
+{
+ struct list1_head *pos;
+ list1_for_each_cookie(pos, head->read_var2, &no_rewrite_list) {
+ struct no_rewrite_entry *ptr;
+ ptr = list1_entry(pos, struct no_rewrite_entry, list);
+ if (ptr->is_deleted)
+ continue;
+ if (!tmy_io_printf(head, KEYWORD_DENY_REWRITE "%s\n",
+ ptr->pattern->name))
+ goto out;
+ }
+ return true;
+out:
+ return false;
+}
+
+/**
+ * update_file_acl - Update file's read/write/execute ACL.
+ *
+ * @filename: Filename.
+ * @perm: Permission (between 1 to 7).
+ * @domain: Pointer to "struct 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 update_file_acl(const char *filename, u8 perm,
+ struct 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] != '@' && strendswith(filename, "/"))
+ /*
+ * Only 'allow_mkdir' and 'allow_rmdir' are valid for
+ * directory permissions.
+ */
+ return 0;
+ if (perm & 4)
+ update_single_path_acl(TMY_TYPE_READ_ACL, filename, domain,
+ is_delete);
+ if (perm & 2)
+ update_single_path_acl(TMY_TYPE_WRITE_ACL, filename, domain,
+ is_delete);
+ if (perm & 1)
+ update_single_path_acl(TMY_TYPE_EXECUTE_ACL, filename, domain,
+ is_delete);
+ return 0;
+}
+
+/**
+ * check_single_path_acl2 - Check permission for single path operation.
+ *
+ * @filename: Filename to check.
+ * @perm: Permission.
+ * @may_use_pattern: True if patterned ACL is permitted.
+ *
+ * Returns 0 on success, -EPERM otherwise.
+ */
+static int check_single_path_acl2(const struct path_info *filename,
+ const u16 perm, const bool may_use_pattern)
+{
+ const struct domain_info *domain = tmy_domain(current);
+ struct acl_info *ptr;
+ list1_for_each_entry(ptr, &domain->acl_info_list, list) {
+ struct single_path_acl_record *acl;
+ if (tmy_acl_type2(ptr) != TYPE_SINGLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct single_path_acl_record, head);
+ if (!(acl->perm & perm))
+ continue;
+ if (may_use_pattern || !acl->filename->is_patterned) {
+ if (!tmy_path_matches_pattern(filename,
+ acl->filename))
+ continue;
+ } else {
+ continue;
+ }
+ return 0;
+ }
+ return -EPERM;
+}
+
+/**
+ * check_file_acl - Check permission for opening files.
+ *
+ * @filename: Filename to check.
+ * @operation: Mode ("read" or "write" or "read/write" or "execute").
+ *
+ * Returns 0 on success, -EPERM otherwise.
+ */
+static int check_file_acl(const struct path_info *filename, const u8 operation)
+{
+ u16 perm = 0;
+ if (!tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE))
+ return 0;
+ if (operation == 6)
+ perm = 1 << TMY_TYPE_READ_WRITE_ACL;
+ else if (operation == 4)
+ perm = 1 << TMY_TYPE_READ_ACL;
+ else if (operation == 2)
+ perm = 1 << TMY_TYPE_WRITE_ACL;
+ else if (operation == 1)
+ perm = 1 << TMY_TYPE_EXECUTE_ACL;
+ else
+ BUG();
+ return check_single_path_acl2(filename, perm, operation != 1);
+}
+
+/**
+ * check_file_perm2 - Check permission for opening files.
+ *
+ * @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 check_file_perm2(const struct path_info *filename, const u8 perm,
+ const char *operation, const u8 mode)
+{
+ struct domain_info * const domain = tmy_domain(current);
+ const bool is_enforce = (mode == 3);
+ const char *msg = "<unknown>";
+ int error = 0;
+ if (!filename)
+ return 0;
+ error = check_file_acl(filename, perm);
+ if (error && perm == 4 &&
+ (domain->flags & DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ) == 0 &&
+ is_globally_readable_file(filename))
+ error = 0;
+ if (perm == 6)
+ msg = tmy_sp2keyword(TMY_TYPE_READ_WRITE_ACL);
+ else if (perm == 4)
+ msg = tmy_sp2keyword(TMY_TYPE_READ_ACL);
+ else if (perm == 2)
+ msg = tmy_sp2keyword(TMY_TYPE_WRITE_ACL);
+ else if (perm == 1)
+ msg = tmy_sp2keyword(TMY_TYPE_EXECUTE_ACL);
+ else
+ BUG();
+ if (!error)
+ return 0;
+ if (tmy_verbose_mode())
+ printk(KERN_WARNING "TOMOYO-%s: Access '%s(%s) %s' denied "
+ "for %s\n", tmy_get_msg(is_enforce), msg, operation,
+ filename->name, tmy_get_last_name(domain));
+ if (is_enforce)
+ return error;
+ if (mode == 1 && tmy_check_domain_quota(domain)) {
+ /* Don't use patterns for execute permission. */
+ const struct path_info *patterned_file = (perm != 1) ?
+ get_file_pattern(filename) : filename;
+ update_file_acl(patterned_file->name, perm,
+ domain, false);
+ }
+ return 0;
+}
+
+/**
+ * tmy_write_file_policy - Update file related list.
+ *
+ * @data: String to parse.
+ * @domain: Pointer to "struct domain_info".
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tmy_write_file_policy(char *data, struct 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 update_file_acl(filename, (u8) perm, domain, is_delete);
+ if (strncmp(data, "allow_", 6))
+ goto out;
+ data += 6;
+ for (type = 0; type < MAX_SINGLE_PATH_OPERATION; type++) {
+ if (strcmp(data, sp_keyword[type]))
+ continue;
+ return update_single_path_acl(type, filename,
+ domain, is_delete);
+ }
+ filename2 = strchr(filename, ' ');
+ if (!filename2)
+ goto out;
+ *filename2++ = '\0';
+ for (type = 0; type < MAX_DOUBLE_PATH_OPERATION; type++) {
+ if (strcmp(data, dp_keyword[type]))
+ continue;
+ return update_double_path_acl(type, filename, filename2, domain,
+ is_delete);
+ }
+out:
+ return -EINVAL;
+}
+
+/**
+ * update_single_path_acl - Update "struct single_path_acl_record" list.
+ *
+ * @type: Type of operation.
+ * @filename: Filename.
+ * @domain: Pointer to "struct domain_info".
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int update_single_path_acl(const u8 type, const char *filename,
+ struct domain_info * const domain,
+ const bool is_delete)
+{
+ static const u16 rw_mask =
+ (1 << TMY_TYPE_READ_ACL) | (1 << TMY_TYPE_WRITE_ACL);
+ const struct path_info *saved_filename;
+ struct acl_info *ptr;
+ struct single_path_acl_record *acl;
+ int error = -ENOMEM;
+ const u16 perm = 1 << type;
+ if (!domain)
+ return -EINVAL;
+ if (!tmy_is_correct_path(filename, 0, 0, 0, __func__))
+ return -EINVAL;
+ saved_filename = tmy_save_name(filename);
+ if (!saved_filename)
+ return -ENOMEM;
+ mutex_lock(&domain_acl_lock);
+ if (is_delete)
+ goto delete;
+ list1_for_each_entry(ptr, &domain->acl_info_list, list) {
+ if (tmy_acl_type1(ptr) != TYPE_SINGLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct single_path_acl_record, head);
+ if (acl->filename != saved_filename)
+ continue;
+ /* Special case. Clear all bits if marked as deleted. */
+ if (ptr->type & ACL_DELETED)
+ acl->perm = 0;
+ acl->perm |= perm;
+ if ((acl->perm & rw_mask) == rw_mask)
+ acl->perm |= 1 << TMY_TYPE_READ_WRITE_ACL;
+ else if (acl->perm & (1 << TMY_TYPE_READ_WRITE_ACL))
+ acl->perm |= rw_mask;
+ error = tmy_add_domain_acl(NULL, ptr);
+ goto out;
+ }
+ /* Not found. Append it to the tail. */
+ acl = tmy_alloc_acl_element(TYPE_SINGLE_PATH_ACL);
+ if (!acl)
+ goto out;
+ acl->perm = perm;
+ acl->filename = saved_filename;
+ error = tmy_add_domain_acl(domain, &acl->head);
+ goto out;
+delete:
+ error = -ENOENT;
+ list1_for_each_entry(ptr, &domain->acl_info_list, list) {
+ if (tmy_acl_type2(ptr) != TYPE_SINGLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct single_path_acl_record, head);
+ if (acl->filename != saved_filename)
+ continue;
+ acl->perm &= ~perm;
+ if ((acl->perm & rw_mask) != rw_mask)
+ acl->perm &= ~(1 << TMY_TYPE_READ_WRITE_ACL);
+ else if (!(acl->perm & (1 << TMY_TYPE_READ_WRITE_ACL)))
+ acl->perm &= ~rw_mask;
+ error = tmy_del_domain_acl(acl->perm ? NULL : ptr);
+ break;
+ }
+out:
+ mutex_unlock(&domain_acl_lock);
+ return error;
+}
+
+/**
+ * update_double_path_acl - Update "struct double_path_acl_record" list.
+ *
+ * @type: Type of operation.
+ * @filename1: First filename.
+ * @filename2: Second filename.
+ * @domain: Pointer to "struct domain_info".
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int update_double_path_acl(const u8 type, const char *filename1,
+ const char *filename2,
+ struct domain_info * const domain,
+ const bool is_delete)
+{
+ const struct path_info *saved_filename1;
+ const struct path_info *saved_filename2;
+ struct acl_info *ptr;
+ struct double_path_acl_record *acl;
+ int error = -ENOMEM;
+ const u8 perm = 1 << type;
+ if (!domain)
+ return -EINVAL;
+ if (!tmy_is_correct_path(filename1, 0, 0, 0, __func__) ||
+ !tmy_is_correct_path(filename2, 0, 0, 0, __func__))
+ return -EINVAL;
+ saved_filename1 = tmy_save_name(filename1);
+ saved_filename2 = tmy_save_name(filename2);
+ if (!saved_filename1 || !saved_filename2)
+ return -ENOMEM;
+ mutex_lock(&domain_acl_lock);
+ if (is_delete)
+ goto delete;
+ list1_for_each_entry(ptr, &domain->acl_info_list, list) {
+ if (tmy_acl_type1(ptr) != TYPE_DOUBLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct 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 & ACL_DELETED)
+ acl->perm = 0;
+ acl->perm |= perm;
+ error = tmy_add_domain_acl(NULL, ptr);
+ goto out;
+ }
+ /* Not found. Append it to the tail. */
+ acl = tmy_alloc_acl_element(TYPE_DOUBLE_PATH_ACL);
+ if (!acl)
+ goto out;
+ acl->perm = perm;
+ acl->filename1 = saved_filename1;
+ acl->filename2 = saved_filename2;
+ error = tmy_add_domain_acl(domain, &acl->head);
+ goto out;
+delete:
+ error = -ENOENT;
+ list1_for_each_entry(ptr, &domain->acl_info_list, list) {
+ if (tmy_acl_type2(ptr) != TYPE_DOUBLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct double_path_acl_record, head);
+ if (acl->filename1 != saved_filename1 ||
+ acl->filename2 != saved_filename2)
+ continue;
+ acl->perm &= ~perm;
+ error = tmy_del_domain_acl(acl->perm ? NULL : ptr);
+ break;
+ }
+out:
+ mutex_unlock(&domain_acl_lock);
+ return error;
+}
+
+/**
+ * check_single_path_acl - Check permission for single path operation.
+ *
+ * @type: Type of operation.
+ * @filename: Filename to check.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int check_single_path_acl(const u8 type,
+ const struct path_info *filename)
+{
+ if (!tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE))
+ return 0;
+ return check_single_path_acl2(filename, 1 << type, 1);
+}
+
+/**
+ * check_double_path_acl - Check permission for double path operation.
+ *
+ * @type: Type of operation.
+ * @filename1: First filename to check.
+ * @filename2: Second filename to check.
+ *
+ * Returns 0 on success, -EPERM otherwise.
+ */
+static int check_double_path_acl(const u8 type,
+ const struct path_info *filename1,
+ const struct path_info *filename2)
+{
+ const struct domain_info *domain = tmy_domain(current);
+ struct acl_info *ptr;
+ const u8 perm = 1 << type;
+ if (!tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE))
+ return 0;
+ list1_for_each_entry(ptr, &domain->acl_info_list, list) {
+ struct double_path_acl_record *acl;
+ if (tmy_acl_type2(ptr) != TYPE_DOUBLE_PATH_ACL)
+ continue;
+ acl = container_of(ptr, struct double_path_acl_record, head);
+ if (!(acl->perm & perm))
+ continue;
+ if (!tmy_path_matches_pattern(filename1,
+ acl->filename1))
+ continue;
+ if (!tmy_path_matches_pattern(filename2,
+ acl->filename2))
+ continue;
+ return 0;
+ }
+ return -EPERM;
+}
+
+/**
+ * check_single_path_permission2 - Check permission for single path operation.
+ *
+ * @operation: Type of operation.
+ * @filename: Filename to check.
+ * @mode: Access control mode.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int check_single_path_permission2(u8 operation,
+ const struct path_info *filename,
+ const u8 mode)
+{
+ const char *msg;
+ int error;
+ struct domain_info * const domain = tmy_domain(current);
+ const bool is_enforce = (mode == 3);
+ if (!mode)
+ return 0;
+next:
+ error = check_single_path_acl(operation, filename);
+ msg = tmy_sp2keyword(operation);
+ if (!error)
+ goto ok;
+ if (tmy_verbose_mode())
+ printk(KERN_WARNING "TOMOYO-%s: Access '%s %s' denied for %s\n",
+ tmy_get_msg(is_enforce), msg, filename->name,
+ tmy_get_last_name(domain));
+ if (mode == 1 && tmy_check_domain_quota(domain))
+ update_single_path_acl(operation,
+ get_file_pattern(filename)->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 == TMY_TYPE_TRUNCATE_ACL &&
+ is_no_rewrite_file(filename)) {
+ operation = TMY_TYPE_REWRITE_ACL;
+ goto next;
+ }
+ return error;
+}
+
+/**
+ * tmy_check_file_perm - Check permission for sysctl()'s "read" and "write".
+ *
+ * @filename: Filename to check.
+ * @perm: Mode ("read" or "write" or "read/write").
+ * @operation: Always "sysctl".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tmy_check_file_perm(const char *filename, const u8 perm,
+ const char *operation)
+{
+ struct path_info name;
+ const u8 mode = tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE);
+ if (!mode)
+ return 0;
+ name.name = filename;
+ tmy_fill_path_info(&name);
+ return check_file_perm2(&name, perm, operation, mode);
+}
+
+/**
+ * tmy_check_exec_perm - Check permission for "execute".
+ *
+ * @filename: Check permission for "execute".
+ * @tmp: Buffer for temporal use.
+ *
+ * Returns 0 on success, negativevalue otherwise.
+ */
+int tmy_check_exec_perm(const struct path_info *filename,
+ struct tmy_page_buffer *tmp)
+{
+ const u8 mode = tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE);
+ if (!mode)
+ return 0;
+ return check_file_perm2(filename, 1, "do_execve", mode);
+}
+
+/**
+ * tmy_check_open_permission - Check permission for "read" and "write".
+ *
+ * @dentry: Pointer to "struct dentry".
+ * @mnt: Pointer to "struct vfsmount".
+ * @flag: Flags for open().
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tmy_check_open_permission(struct dentry *dentry, struct vfsmount *mnt,
+ const int flag)
+{
+ const u8 acc_mode = ACC_MODE(flag);
+ int error = -ENOMEM;
+ struct path_info *buf;
+ const u8 mode = tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE);
+ const bool is_enforce = (mode == 3);
+ if (!mode || !mnt)
+ return 0;
+ if (acc_mode == 0)
+ return 0;
+ if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode))
+ /*
+ * I don't check directories here because mkdir() and rmdir()
+ * don't call me.
+ */
+ return 0;
+ buf = tmy_get_path(dentry, mnt);
+ 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)) &&
+ (is_no_rewrite_file(buf))) {
+ error = check_single_path_permission2(TMY_TYPE_REWRITE_ACL,
+ buf, mode);
+ }
+ if (!error)
+ error = check_file_perm2(buf, acc_mode, "open", mode);
+ if (!error && (flag & O_TRUNC))
+ error = check_single_path_permission2(TMY_TYPE_TRUNCATE_ACL,
+ buf, mode);
+out:
+ tmy_free(buf);
+ if (!is_enforce)
+ error = 0;
+ return error;
+}
+
+/**
+ * tmy_check_1path_perm - Check permission for "create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock", "mkblock", "mkchar", "truncate" and "symlink".
+ *
+ * @operation: Type of operation.
+ * @dentry: Pointer to "struct dentry".
+ * @mnt: Pointer to "struct vfsmount".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tmy_check_1path_perm(const u8 operation, struct dentry *dentry,
+ struct vfsmount *mnt)
+{
+ int error = -ENOMEM;
+ struct path_info *buf;
+ const u8 mode = tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE);
+ const bool is_enforce = (mode == 3);
+ if (!mode || !mnt)
+ return 0;
+ buf = tmy_get_path(dentry, mnt);
+ if (!buf)
+ goto out;
+ switch (operation) {
+ case TMY_TYPE_MKDIR_ACL:
+ case TMY_TYPE_RMDIR_ACL:
+ if (!buf->is_dir) {
+ /* tmy_get_path() preserves space for appending "/." */
+ strcat((char *) buf->name, "/");
+ tmy_fill_path_info(buf);
+ }
+ }
+ error = check_single_path_permission2(operation, buf, mode);
+out:
+ tmy_free(buf);
+ if (!is_enforce)
+ error = 0;
+ return error;
+}
+
+/**
+ * tmy_check_rewrite_permission - Check permission for "rewrite".
+ *
+ * @filp: Pointer to "struct file".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tmy_check_rewrite_permission(struct file *filp)
+{
+ int error = -ENOMEM;
+ const u8 mode = tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE);
+ const bool is_enforce = (mode == 3);
+ struct path_info *buf;
+ if (!mode || !filp->f_vfsmnt)
+ return 0;
+ buf = tmy_get_path(filp->f_dentry, filp->f_vfsmnt);
+ if (!buf)
+ goto out;
+ if (!is_no_rewrite_file(buf)) {
+ error = 0;
+ goto out;
+ }
+ error = check_single_path_permission2(TMY_TYPE_REWRITE_ACL, buf, mode);
+out:
+ tmy_free(buf);
+ if (!is_enforce)
+ error = 0;
+ return error;
+}
+
+/**
+ * tmy_check_2path_perm - Check permission for "rename" and "link".
+ *
+ * @operation: Type of operation.
+ * @dentry1: Pointer to "struct dentry".
+ * @mnt1: Pointer to "struct vfsmount".
+ * @dentry2: Pointer to "struct dentry".
+ * @mnt2: Pointer to "struct vfsmount".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tmy_check_2path_perm(const u8 operation,
+ struct dentry *dentry1,
+ struct vfsmount *mnt1,
+ struct dentry *dentry2,
+ struct vfsmount *mnt2)
+{
+ int error = -ENOMEM;
+ struct path_info *buf1, *buf2;
+ struct domain_info * const domain = tmy_domain(current);
+ const u8 mode = tmy_check_flags(TMY_TOMOYO_MAC_FOR_FILE);
+ const bool is_enforce = (mode == 3);
+ const char *msg;
+ if (!mode || !mnt1 || !mnt2)
+ return 0;
+ buf1 = tmy_get_path(dentry1, mnt1);
+ buf2 = tmy_get_path(dentry2, mnt2);
+ if (!buf1 || !buf2)
+ goto out;
+ if (operation == TMY_TYPE_RENAME_ACL) {
+ /* TYPE_LINK_ACL can't reach here for directory. */
+ if (dentry1->d_inode && S_ISDIR(dentry1->d_inode->i_mode)) {
+ /* tmy_get_path() preserves space for appending "/." */
+ if (!buf1->is_dir) {
+ strcat((char *) buf1->name, "/");
+ tmy_fill_path_info(buf1);
+ }
+ if (!buf2->is_dir) {
+ strcat((char *) buf2->name, "/");
+ tmy_fill_path_info(buf2);
+ }
+ }
+ }
+ error = check_double_path_acl(operation, buf1, buf2);
+ msg = tmy_dp2keyword(operation);
+ if (!error)
+ goto out;
+ if (tmy_verbose_mode())
+ printk(KERN_WARNING "TOMOYO-%s: Access '%s %s %s' "
+ "denied for %s\n", tmy_get_msg(is_enforce),
+ msg, buf1->name, buf2->name, tmy_get_last_name(domain));
+ if (mode == 1 && tmy_check_domain_quota(domain))
+ update_double_path_acl(operation,
+ get_file_pattern(buf1)->name,
+ get_file_pattern(buf2)->name,
+ domain, false);
+out:
+ tmy_free(buf1);
+ tmy_free(buf2);
+ if (!is_enforce)
+ error = 0;
+ return error;
+}

--