Function acl_get

sql/sql_acl.cc:3833–3922

*/

privilege_t acl_get(const char *host, const char *ip,
                    const char *user, const char *db, my_bool db_is_pattern)
{
  privilege_t host_access(ALL_KNOWN_ACL), db_access(NO_ACL);
  uint i;
  const char *tmp_db;
  acl_entry *entry;
  DBUG_ENTER("acl_get");

  // Key length, without the trailing '\0' byte
  constexpr size_t key_data_size= IP_ADDR_STRLEN + 1/*'\0'*/ +
                                  USERNAME_LENGTH + 1/*'\0'*/ +
                                  NAME_LEN/*database*/;
  /*
    Let's reserve extra MY_CS_MBMAXLEN bytes in the buffer.
    This is to catch cases when a too long database name gets truncated:
      key.length() will return a length in the range:
      [key_data_size + 1, key_data_size + MY_CS_MBMAXLEN].
  */
  CharBuffer<key_data_size + MY_CS_MBMAXLEN> key;
  key.append(Lex_cstring_strlen(safe_str(ip))).append_char('\0')
     .append(Lex_cstring_strlen(user)).append_char('\0');
  tmp_db= key.end();
  key.append_opt_casedn(files_charset_info, Lex_cstring_strlen(db),
                        lower_case_table_names);
  db= tmp_db;

  if (key.length() > key_data_size) // db name was truncated
    DBUG_RETURN(NO_ACL);        // no privileges for an invalid db name

  mysql_mutex_lock(&acl_cache->lock);
  if (!db_is_pattern &&
      (entry= acl_cache->search((uchar*) key.ptr(), key.length())))
  {
    db_access=entry->access;
    mysql_mutex_unlock(&acl_cache->lock);
    DBUG_PRINT("exit", ("access: 0x%llx",  (longlong) db_access));
    DBUG_RETURN(db_access);
  }

  /*
    Check if there are some access rights for database and user
  */
  if (ACL_DB *acl_db= acl_db_find(db,user, host, ip, db_is_pattern))
  {
    db_access= acl_db->access;
    if (acl_db->host.hostname)
      goto exit; // Fully specified. Take it
    /* the host table is not used for roles */
    if ((!host || !host[0]) && !acl_db->host.hostname &&
        find_acl_role(Lex_cstring_strlen(user), false))
      goto exit;
  }

  if (!db_access)
    goto exit;					// Can't be better

  /*