1 /*
2  * Copyright (c) 2009-2012 Red Hat, Inc.
3  *
4  * All rights reserved.
5  *
6  * Authors: Christine Caulfield (ccaulfie@redhat.com)
7  *          Fabio M. Di Nitto   (fdinitto@redhat.com)
8  *
9  * This software licensed under BSD license, the text of which follows:
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions are met:
13  *
14  * - Redistributions of source code must retain the above copyright notice,
15  *   this list of conditions and the following disclaimer.
16  * - Redistributions in binary form must reproduce the above copyright notice,
17  *   this list of conditions and the following disclaimer in the documentation
18  *   and/or other materials provided with the distribution.
19  * - Neither the name of the MontaVista Software, Inc. nor the names of its
20  *   contributors may be used to endorse or promote products derived from this
21  *   software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTIBUTORS "AS IS"
24  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
27  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
33  * THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #ifndef COROSYNC_VOTEQUORUM_H_DEFINED
37 #define COROSYNC_VOTEQUORUM_H_DEFINED
38 
39 #include <corosync/corotypes.h>
40 
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44 
45 /**
46  * @brief votequorum_handle_t
47  */
48 typedef uint64_t votequorum_handle_t;
49 
50 #define VOTEQUORUM_INFO_TWONODE                  1
51 #define VOTEQUORUM_INFO_QUORATE                  2
52 #define VOTEQUORUM_INFO_WAIT_FOR_ALL             4
53 #define VOTEQUORUM_INFO_LAST_MAN_STANDING        8
54 #define VOTEQUORUM_INFO_AUTO_TIE_BREAKER         16
55 #define VOTEQUORUM_INFO_ALLOW_DOWNSCALE          32
56 #define VOTEQUORUM_INFO_QDEVICE_REGISTERED       64
57 #define VOTEQUORUM_INFO_QDEVICE_ALIVE            128
58 #define VOTEQUORUM_INFO_QDEVICE_CAST_VOTE        256
59 #define VOTEQUORUM_INFO_QDEVICE_MASTER_WINS      512
60 
61 #define VOTEQUORUM_QDEVICE_NODEID                0
62 #define VOTEQUORUM_QDEVICE_MAX_NAME_LEN          255
63 #define VOTEQUORUM_QDEVICE_DEFAULT_TIMEOUT       10000
64 #define VOTEQUORUM_QDEVICE_DEFAULT_SYNC_TIMEOUT  30000
65 
66 #define VOTEQUORUM_NODESTATE_MEMBER              1
67 #define VOTEQUORUM_NODESTATE_DEAD                2
68 #define VOTEQUORUM_NODESTATE_LEAVING             3
69 
70 /** @} */
71 
72 /**
73  * @brief The votequorum_info struct
74  */
75 struct votequorum_info {
76 	unsigned int node_id;
77 	unsigned int node_state;
78 	unsigned int node_votes;
79 	unsigned int node_expected_votes;
80 	unsigned int highest_expected;
81 	unsigned int total_votes;
82 	unsigned int quorum;
83 	unsigned int flags;
84 	unsigned int qdevice_votes;
85 	char qdevice_name[VOTEQUORUM_QDEVICE_MAX_NAME_LEN];
86 };
87 
88 /**
89  * @brief The votequorum_node_t struct
90  */
91 typedef struct {
92 	uint32_t nodeid;
93 	uint32_t state;
94 } votequorum_node_t;
95 
96 /**
97  * @brief The votequorum_ring_id_t struct
98  */
99 typedef struct {
100 	uint32_t nodeid;
101 	uint64_t seq;
102 } votequorum_ring_id_t;
103 
104 /**
105  * @brief The votequorum_quorum_notification_fn_t callback
106  */
107 typedef void (*votequorum_quorum_notification_fn_t) (
108 	votequorum_handle_t handle,
109 	uint64_t context,
110 	uint32_t quorate,
111 	uint32_t node_list_entries,
112 	votequorum_node_t node_list[]);
113 
114 typedef void (*votequorum_nodelist_notification_fn_t) (
115 	votequorum_handle_t handle,
116 	uint64_t context,
117 	votequorum_ring_id_t ring_id,
118 	uint32_t node_list_entries,
119 	uint32_t node_list[]);
120 
121 /**
122  * @brief The votequorum_expectedvotes_notification_fn_t callback
123  */
124 typedef void (*votequorum_expectedvotes_notification_fn_t) (
125 	votequorum_handle_t handle,
126 	uint64_t context,
127 	uint32_t expected_votes);
128 
129 /**
130  * @brief The votequorum_callbacks_t struct
131  */
132 typedef struct {
133 	votequorum_quorum_notification_fn_t votequorum_quorum_notify_fn;
134 	votequorum_expectedvotes_notification_fn_t votequorum_expectedvotes_notify_fn;
135 	votequorum_nodelist_notification_fn_t votequorum_nodelist_notify_fn;
136 } votequorum_callbacks_t;
137 
138 /**
139  * @brief Create a new quorum connection
140  * @param handle
141  * @param callbacks
142  * @return
143  */
144 cs_error_t votequorum_initialize (
145 	votequorum_handle_t *handle,
146 	votequorum_callbacks_t *callbacks);
147 
148 /**
149  * @brief Close the quorum handle
150  * @param handle
151  * @return
152  */
153 cs_error_t votequorum_finalize (
154 	votequorum_handle_t handle);
155 
156 /**
157  * @brief Dispatch messages and configuration changes
158  * @param handle
159  * @param dispatch_types
160  * @return
161  */
162 cs_error_t votequorum_dispatch (
163 	votequorum_handle_t handle,
164 	cs_dispatch_flags_t dispatch_types);
165 
166 /**
167  * @brief Get a file descriptor on which to poll.
168  *
169  * @note votequorum_handle_t is NOT a file descriptor and may not be used directly.
170  *
171  * @param handle
172  * @param fd
173  * @return
174  */
175 cs_error_t votequorum_fd_get (
176 	votequorum_handle_t handle,
177 	int *fd);
178 
179 /**
180  * @brief Get quorum information.
181  * @param handle
182  * @param nodeid
183  * @param info
184  * @return
185  */
186 cs_error_t votequorum_getinfo (
187 	votequorum_handle_t handle,
188 	unsigned int nodeid,
189 	struct votequorum_info *info);
190 
191 /**
192  * @brief set expected_votes
193  * @param handle
194  * @param expected_votes
195  * @return
196  */
197 cs_error_t votequorum_setexpected (
198 	votequorum_handle_t handle,
199 	unsigned int expected_votes);
200 
201 /**
202  * @brief set votes for a node
203  * @param handle
204  * @param nodeid
205  * @param votes
206  * @return
207  */
208 cs_error_t votequorum_setvotes (
209 	votequorum_handle_t handle,
210 	unsigned int nodeid,
211 	unsigned int votes);
212 
213 /**
214  * @brief Track node and quorum changes
215  * @param handle
216  * @param context
217  * @param flags
218  * @return
219  */
220 cs_error_t votequorum_trackstart (
221 	votequorum_handle_t handle,
222 	uint64_t context,
223         unsigned int flags);
224 
225 /**
226  * @brief votequorum_trackstop
227  * @param handle
228  * @return
229  */
230 cs_error_t votequorum_trackstop (
231 	votequorum_handle_t handle);
232 
233 /**
234  * @brief Save and retrieve private data/context
235  * @param handle
236  * @param context
237  * @return
238  */
239 cs_error_t votequorum_context_get (
240 	votequorum_handle_t handle,
241 	void **context);
242 
243 /**
244  * @brief votequorum_context_set
245  * @param handle
246  * @param context
247  * @return
248  */
249 cs_error_t votequorum_context_set (
250 	votequorum_handle_t handle,
251 	void *context);
252 
253 /**
254  * @brief Register a quorum device
255  *
256  * it will be DEAD until polled
257  *
258  * @param handle
259  * @param name
260  * @return
261  */
262 cs_error_t votequorum_qdevice_register (
263 	votequorum_handle_t handle,
264 	const char *name);
265 
266 /**
267  * @brief Unregister a quorum device
268  * @param handle
269  * @param name
270  * @return
271  */
272 cs_error_t votequorum_qdevice_unregister (
273 	votequorum_handle_t handle,
274 	const char *name);
275 
276 /**
277  * @brief Update registered name of a quorum device
278  * @param handle
279  * @param oldname
280  * @param newname
281  * @return
282  */
283 cs_error_t votequorum_qdevice_update (
284 	votequorum_handle_t handle,
285 	const char *oldname,
286 	const char *newname);
287 
288 /**
289  * @brief Poll a quorum device
290  * @param handle
291  * @param name
292  * @param cast_vote
293  * @param ring_id
294  * @return
295  */
296 cs_error_t votequorum_qdevice_poll (
297 	votequorum_handle_t handle,
298 	const char *name,
299 	unsigned int cast_vote,
300 	votequorum_ring_id_t ring_id);
301 
302 /**
303  * @brief Allow qdevice to tell votequorum if master_wins can be enabled or not
304  * @param handle
305  * @param name
306  * @param allow
307  * @return
308  */
309 cs_error_t votequorum_qdevice_master_wins (
310 	votequorum_handle_t handle,
311 	const char *name,
312 	unsigned int allow);
313 
314 #ifdef __cplusplus
315 }
316 #endif
317 #endif /* COROSYNC_VOTEQUORUM_H_DEFINED */
318