c006c49afef15284c98d7da909b5654c8217952b
1 /*
2 * SysDB - src/include/frontend/proto.h
3 * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #ifndef SDB_FRONTEND_PROTO_H
29 #define SDB_FRONTEND_PROTO_H 1
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
35 /*
36 * The SysDB frontend protocol is based on messages being passed between the
37 * client and the server. Each message includes a header containing the
38 * message type which is usually a status or command code, the length of the
39 * message not including the header, and the message body. The content of the
40 * message body depends on the message type. Both, the message type and length
41 * are stored in an unsigned 32bit integer in network byte-order.
42 *
43 * 1 3 4 6
44 * 0 6 2 8 4
45 * +-------------------------------+-------------------------------+
46 * | message type | message length |
47 * +-------------------------------+-------------------------------+
48 * | message body ...
49 *
50 */
52 /* status codes returned to a client */
53 typedef enum {
54 /*
55 * CONNECTION_OK:
56 * Indicates that a command was successful. The message body will usually
57 * be empty but may contain a string providing unformatted information
58 * providing more details.
59 *
60 * 0 32 64
61 * +---------------+---------------+
62 * | message type | length |
63 * +---------------+---------------+
64 * | optional status message ... |
65 */
66 CONNECTION_OK = 0,
68 /*
69 * CONNECTION_DATA:
70 * Indicates that a data query was successful. The message body will
71 * contain the type of the data and the result encoded as a JSON string.
72 * The type is the same as the command code of the respective command (see
73 * below) and is stored as an unsigned 32bit integer in network
74 * byte-order. The result may be empty (but the type is still included).
75 *
76 * 0 32 64
77 * +---------------+---------------+
78 * | message type | length |
79 * +---------------+---------------+
80 * | result type | result ... |
81 * +---------------+ |
82 * | ... |
83 */
84 CONNECTION_DATA,
86 /*
87 * CONNECTION_ERROR:
88 * Indicates that a command has failed. The message body will contain a
89 * string describing the error.
90 *
91 * 0 32 64
92 * +---------------+---------------+
93 * | message type | length |
94 * +---------------+---------------+
95 * | error message ... |
96 */
97 CONNECTION_ERROR,
99 /*
100 * CONNECTION_LOG:
101 * Indicates an asynchronous log message. The message body will contain
102 * the message string providing informational or warning logs. Log
103 * messages may be sent to the client any time.
104 *
105 * 0 32 64
106 * +---------------+---------------+
107 * | message type | length |
108 * +---------------+---------------+
109 * | log message ... |
110 */
111 CONNECTION_LOG,
112 } sdb_conn_status_t;
114 /* accepted commands / state of the connection */
115 typedef enum {
116 /*
117 * CONNECTION_IDLE:
118 * This is an internal state used for idle connections.
119 */
120 CONNECTION_IDLE = 0,
122 /*
123 * CONNECTION_PING:
124 * Check if the current connection is still alive. The server will reply
125 * with CONNECTION_OK if it was able to handle the command.
126 */
127 CONNECTION_PING,
129 /*
130 * CONNECTION_STARTUP:
131 * Setup of a client connection. The message body shall include the
132 * username of the user contacting the server. The server may then send
133 * further requests to the client for authentication (not implemented
134 * yet). Once the setup and authentication was successful, the server
135 * replies with CONNECTION_OK. Further information may be requested from
136 * the server using special messages specific to the authentication
137 * method. The server does not send any asynchronous messages before
138 * startup is complete.
139 */
140 CONNECTION_STARTUP,
142 /*
143 * Querying the server. On success, the server replies with
144 * CONNECTION_DATA.
145 *
146 * The command codes listed here are used, both, for sending a query to
147 * the server and to indicate the response type from a query in a DATA
148 * message.
149 */
151 /*
152 * CONNECTION_QUERY:
153 * Execute a query in the server. The message body shall include a single
154 * query command as a text string. Multiple commands are ignored by the
155 * server entirely.
156 */
157 CONNECTION_QUERY,
159 /*
160 * CONNECTION_FETCH:
161 * Execute the 'FETCH' command in the server. The message body shall
162 * include the hostname of the host to be retrieved.
163 */
164 CONNECTION_FETCH,
166 /*
167 * CONNECTION_LIST:
168 * Execute the 'LIST' command in the server.
169 */
170 CONNECTION_LIST,
172 /*
173 * CONNECTION_LOOKUP:
174 * Execute the 'LOOKUP' command in the server. The message body shall
175 * include the conditional expression of the 'MATCHING' clause.
176 */
177 CONNECTION_LOOKUP,
179 /*
180 * CONNECTION_TIMESERIES:
181 * Execute the 'TIMESERIES' command in the server. This command is not yet
182 * supported on the wire. Use CONNECTION_QUERY instead.
183 */
184 CONNECTION_TIMESERIES,
186 /*
187 * Command subcomponents.
188 */
190 /*
191 * CONNECTION_EXPR:
192 * A parsed expression. Only used internally.
193 */
194 CONNECTION_EXPR,
195 } sdb_conn_state_t;
197 #ifdef __cplusplus
198 } /* extern "C" */
199 #endif
201 #endif /* ! SDB_FRONTEND_PROTO_H */
203 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */