1 /* Copyright (c) 2006, 2021, Oracle and/or its affiliates.
2 
3    This program is free software; you can redistribute it and/or modify
4    it under the terms of the GNU General Public License, version 2.0,
5    as published by the Free Software Foundation.
6 
7    This program is also distributed with certain software (including
8    but not limited to OpenSSL) that is licensed under separate terms,
9    as designated in a particular file or component or in included license
10    documentation.  The authors of MySQL hereby grant you an additional
11    permission to link the program and your derivative works with the
12    separately licensed software that they have included with MySQL.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License, version 2.0, for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */
22 
23 #ifndef HOSTNAME_INCLUDED
24 #define HOSTNAME_INCLUDED
25 
26 #include "my_global.h"                          /* uint */
27 #include "hash_filo.h"
28 
29 #ifdef HAVE_NETINET_IN_H
30 #include <netinet/in.h>
31 #endif
32 
33 struct Host_errors
34 {
35 public:
36   Host_errors();
37   ~Host_errors();
38 
39   void reset();
40   void aggregate(const Host_errors *errors);
41 
42   /** Number of connect errors. */
43   ulong m_connect;
44 
45   /** Number of host blocked errors. */
46   ulong m_host_blocked;
47   /** Number of transient errors from getnameinfo(). */
48   ulong m_nameinfo_transient;
49   /** Number of permanent errors from getnameinfo(). */
50   ulong m_nameinfo_permanent;
51   /** Number of errors from is_hostname_valid(). */
52   ulong m_format;
53   /** Number of transient errors from getaddrinfo(). */
54   ulong m_addrinfo_transient;
55   /** Number of permanent errors from getaddrinfo(). */
56   ulong m_addrinfo_permanent;
57   /** Number of errors from Forward-Confirmed reverse DNS checks. */
58   ulong m_FCrDNS;
59   /** Number of errors from host grants. */
60   ulong m_host_acl;
61   /** Number of errors from missing auth plugin. */
62   ulong m_no_auth_plugin;
63   /** Number of errors from auth plugin. */
64   ulong m_auth_plugin;
65   /** Number of errors from authentication plugins. */
66   ulong m_handshake;
67   /** Number of errors from proxy user. */
68   ulong m_proxy_user;
69   /** Number of errors from proxy user acl. */
70   ulong m_proxy_user_acl;
71   /** Number of errors from authentication. */
72   ulong m_authentication;
73   /** Number of errors from ssl. */
74   ulong m_ssl;
75   /** Number of errors from max user connection. */
76   ulong m_max_user_connection;
77   /** Number of errors from max user connection per hour. */
78   ulong m_max_user_connection_per_hour;
79   /** Number of errors from the default database. */
80   ulong m_default_database;
81   /** Number of errors from init_connect. */
82   ulong m_init_connect;
83   /** Number of errors from the server itself. */
84   ulong m_local;
85 
has_errorHost_errors86   bool has_error() const
87   {
88     return ((m_host_blocked != 0)
89       || (m_nameinfo_transient != 0)
90       || (m_nameinfo_permanent != 0)
91       || (m_format != 0)
92       || (m_addrinfo_transient != 0)
93       || (m_addrinfo_permanent != 0)
94       || (m_FCrDNS != 0)
95       || (m_host_acl != 0)
96       || (m_no_auth_plugin != 0)
97       || (m_auth_plugin != 0)
98       || (m_handshake != 0)
99       || (m_proxy_user != 0)
100       || (m_proxy_user_acl != 0)
101       || (m_authentication != 0)
102       || (m_ssl != 0)
103       || (m_max_user_connection != 0)
104       || (m_max_user_connection_per_hour != 0)
105       || (m_default_database != 0)
106       || (m_init_connect != 0)
107       || (m_local != 0));
108   }
109 
sum_connect_errorsHost_errors110   void sum_connect_errors()
111   {
112     /* Current (historical) behavior: */
113     m_connect= m_handshake;
114   }
115 
clear_connect_errorsHost_errors116   void clear_connect_errors()
117   {
118     m_connect= 0;
119   }
120 };
121 
122 /** Size of IP address string in the hash cache. */
123 #define HOST_ENTRY_KEY_SIZE INET6_ADDRSTRLEN
124 
125 /**
126   An entry in the hostname hash table cache.
127 
128   Host name cache does two things:
129     - caches host names to save DNS look ups;
130     - counts errors from IP.
131 
132   Host name can be empty (that means DNS look up failed),
133   but errors still are counted.
134 */
135 class Host_entry : public hash_filo_element
136 {
137 public:
next()138   Host_entry *next()
139   { return (Host_entry*) hash_filo_element::next(); }
140 
141   /**
142     Client IP address. This is the key used with the hash table.
143 
144     The client IP address is always expressed in IPv6, even when the
145     network IPv6 stack is not present.
146 
147     This IP address is never used to connect to a socket.
148   */
149   char ip_key[HOST_ENTRY_KEY_SIZE];
150 
151   /**
152     One of the host names for the IP address. May be a zero length string.
153   */
154   char m_hostname[HOSTNAME_LENGTH + 1];
155   /** Length in bytes of @c m_hostname. */
156   uint m_hostname_length;
157   /** The hostname is validated and used for authorization. */
158   bool m_host_validated;
159   ulonglong m_first_seen;
160   ulonglong m_last_seen;
161   ulonglong m_first_error_seen;
162   ulonglong m_last_error_seen;
163   /** Error statistics. */
164   Host_errors m_errors;
165 
set_error_timestamps(ulonglong now)166   void set_error_timestamps(ulonglong now)
167   {
168     if (m_first_error_seen == 0)
169       m_first_error_seen= now;
170     m_last_error_seen= now;
171   }
172 };
173 
174 #define RC_OK 0
175 #define RC_BLOCKED_HOST 1
176 int ip_to_hostname(struct sockaddr_storage *ip_storage,
177                    const char *ip_string,
178                    char **hostname, uint *connect_errors);
179 
180 void inc_host_errors(const char *ip_string, Host_errors *errors);
181 void reset_host_connect_errors(const char *ip_string);
182 bool hostname_cache_init(uint size);
183 void hostname_cache_free();
184 void hostname_cache_refresh(void);
185 uint hostname_cache_size();
186 void hostname_cache_resize(uint size);
187 void hostname_cache_lock();
188 void hostname_cache_unlock();
189 Host_entry *hostname_cache_first();
190 
191 #endif /* HOSTNAME_INCLUDED */
192