1 /*
2    Unix SMB/CIFS implementation.
3    main select loop and event handling
4    wrapper for http://git.lysator.liu.se/liboop/
5 
6    Copyright (C) Stefan Metzmacher 2005
7 
8      ** NOTE! The following LGPL license applies to the tevent
9      ** library. This does NOT imply that all of Samba is released
10      ** under the LGPL
11 
12    This library is free software; you can redistribute it and/or
13    modify it under the terms of the GNU Lesser General Public
14    License as published by the Free Software Foundation; either
15    version 3 of the License, or (at your option) any later version.
16 
17    This library is distributed in the hope that it will be useful,
18    but WITHOUT ANY WARRANTY; without even the implied warranty of
19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20    Lesser General Public License for more details.
21 
22    You should have received a copy of the GNU Lesser General Public
23    License along with this library; if not, see <http://www.gnu.org/licenses/>.
24 */
25 
26 #include "events.h"
27 #include "events_internal.h"
28 
29 #include <oop.h>
30 
31 /*
32  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
33 
34  NOTE: this code compiles fine, but is completely *UNTESTED*
35        and is only committed as an example
36 
37  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
38 */
39 
40 static int oop_event_context_destructor(struct tevent_context *ev)
41 {
42 	oop_source_sys *oop_sys = ev->additional_data;
43 
44 	oop_sys_delete(oop_sys);
45 
46 	return 0;
47 }
48 
49 /*
50   create a oop_event_context structure.
51 */
52 static int oop_event_context_init(struct tevent_context *ev, void *private_data)
53 {
54 	oop_source_sys *oop_sys = private_data;
55 
56 	if (!oop_sys) {
57 		oop_sys = oop_sys_new();
58 		if (!oop_sys) {
59 			return -1;
60 		}
61 
62 		talloc_set_destructor(ev, oop_event_context_destructor);
63 	}
64 
65 	ev->additional_data = oop_sys;
66 
67 	return 0;
68 }
69 
70 static void *oop_event_fd_handler(oop_source *oop, int fd, oop_event oop_type, void *ptr)
71 {
72 	struct tevent_fd *fde = ptr;
73 
74 	if (fd != fde->fd) return OOP_ERROR;
75 
76 	switch(oop_type) {
77 		case OOP_READ:
78 			fde->handler(fde->event_ctx, fde, EVENT_FD_READ, fde->private_data);
79 			return OOP_CONTINUE;
80 		case OOP_WRITE:
81 			fde->handler(fde->event_ctx, fde, EVENT_FD_WRITE, fde->private_data);
82 			return OOP_CONTINUE;
83 		case OOP_EXCEPTION:
84 			return OOP_ERROR;
85 		case OOP_NUM_EVENTS:
86 			return OOP_ERROR;
87 	}
88 
89 	return OOP_ERROR;
90 }
91 
92 /*
93   destroy an fd_event
94 */
95 static int oop_event_fd_destructor(struct tevent_fd *fde)
96 {
97 	struct tevent_context *ev = fde->event_ctx;
98 	oop_source_sys *oop_sys = ev->additional_data;
99 	oop_source *oop = oop_sys_source(oop_sys);
100 
101 	if (fde->flags & EVENT_FD_READ)
102 		oop->cancel_fd(oop, fde->fd, OOP_READ);
103 	if (fde->flags & EVENT_FD_WRITE)
104 		oop->cancel_fd(oop, fde->fd, OOP_WRITE);
105 
106 	if (fde->flags & EVENT_FD_AUTOCLOSE) {
107 		close(fde->fd);
108 		fde->fd = -1;
109 	}
110 
111 	return 0;
112 }
113 
114 /*
115   add a fd based event
116   return NULL on failure (memory allocation error)
117 */
118 static struct tevent_fd *oop_event_add_fd(struct tevent_context *ev, TALLOC_CTX *mem_ctx,
119 					 int fd, uint16_t flags,
120 					 event_fd_handler_t handler,
121 					 void *private_data)
122 {
123 	struct tevent_fd *fde;
124 	oop_source_sys *oop_sys = ev->additional_data;
125 	oop_source *oop = oop_sys_source(oop_sys);
126 
127 	fde = talloc(mem_ctx?mem_ctx:ev, struct tevent_fd);
128 	if (!fde) return NULL;
129 
130 	fde->event_ctx		= ev;
131 	fde->fd			= fd;
132 	fde->flags		= flags;
133 	fde->handler		= handler;
134 	fde->private_data	= private_data;
135 	fde->additional_flags	= 0;
136 	fde->additional_data	= NULL;
137 
138 	if (fde->flags & EVENT_FD_READ)
139 		oop->on_fd(oop, fde->fd, OOP_READ, oop_event_fd_handler, fde);
140 	if (fde->flags & EVENT_FD_WRITE)
141 		oop->on_fd(oop, fde->fd, OOP_WRITE, oop_event_fd_handler, fde);
142 
143 	talloc_set_destructor(fde, oop_event_fd_destructor);
144 
145 	return fde;
146 }
147 
148 /*
149   return the fd event flags
150 */
151 static uint16_t oop_event_get_fd_flags(struct tevent_fd *fde)
152 {
153 	return fde->flags;
154 }
155 
156 /*
157   set the fd event flags
158 */
159 static void oop_event_set_fd_flags(struct tevent_fd *fde, uint16_t flags)
160 {
161 	oop_source_sys *oop_sys;
162 	oop_source *oop;
163 
164 	oop_sys = fde->event_ctx->additional_data;
165 	oop = oop_sys_source(oop_sys);
166 
167 	if ((fde->flags & EVENT_FD_READ)&&(!(flags & EVENT_FD_READ)))
168 		oop->cancel_fd(oop, fde->fd, OOP_READ);
169 
170 	if ((!(fde->flags & EVENT_FD_READ))&&(flags & EVENT_FD_READ))
171 		oop->on_fd(oop, fde->fd, OOP_READ, oop_event_fd_handler, fde);
172 
173 	if ((fde->flags & EVENT_FD_WRITE)&&(!(flags & EVENT_FD_WRITE)))
174 		oop->cancel_fd(oop, fde->fd, OOP_WRITE);
175 
176 	if ((!(fde->flags & EVENT_FD_WRITE))&&(flags & EVENT_FD_WRITE))
177 		oop->on_fd(oop, fde->fd, OOP_WRITE, oop_event_fd_handler, fde);
178 
179 	fde->flags = flags;
180 }
181 
182 static int oop_event_timed_destructor(struct tevent_timer *te);
183 
184 static int oop_event_timed_deny_destructor(struct tevent_timer *te)
185 {
186 	return -1;
187 }
188 
189 static void *oop_event_timed_handler(oop_source *oop, struct timeval t, void *ptr)
190 {
191 	struct tevent_timer *te = ptr;
192 
193 	/* deny the handler to free the event */
194 	talloc_set_destructor(te, oop_event_timed_deny_destructor);
195 	te->handler(te->event_ctx, te, t, te->private_data);
196 
197 	talloc_set_destructor(te, oop_event_timed_destructor);
198 	talloc_free(te);
199 
200 	return OOP_CONTINUE;
201 }
202 
203 /*
204   destroy a timed event
205 */
206 static int oop_event_timed_destructor(struct tevent_timer *te)
207 {
208 	struct tevent_context *ev = te->event_ctx;
209 	oop_source_sys *oop_sys = ev->additional_data;
210 	oop_source *oop = oop_sys_source(oop_sys);
211 
212 	oop->cancel_time(oop, te->next_event, oop_event_timed_handler, te);
213 
214 	return 0;
215 }
216 
217 /*
218   add a timed event
219   return NULL on failure (memory allocation error)
220 */
221 static struct tevent_timer *oop_event_add_timed(struct tevent_context *ev, TALLOC_CTX *mem_ctx,
222 					       struct timeval next_event,
223 					       event_timed_handler_t handler,
224 					       void *private_data)
225 {
226 	oop_source_sys *oop_sys = ev->additional_data;
227 	oop_source *oop = oop_sys_source(oop_sys);
228 	struct tevent_timer *te;
229 
230 	te = talloc(mem_ctx?mem_ctx:ev, struct tevent_timer);
231 	if (te == NULL) return NULL;
232 
233 	te->event_ctx		= ev;
234 	te->next_event		= next_event;
235 	te->handler		= handler;
236 	te->private_data	= private_data;
237 	te->additional_data	= NULL;
238 
239 	oop->on_time(oop, te->next_event, oop_event_timed_handler, te);
240 
241 	talloc_set_destructor(te, oop_event_timed_destructor);
242 
243 	return te;
244 }
245 
246 /*
247   do a single event loop using the events defined in ev
248 */
249 static int oop_event_loop_once(struct tevent_context *ev)
250 {
251 	void *oop_ret;
252 	oop_source_sys *oop_sys = ev->additional_data;
253 
254 	oop_ret = oop_sys_run_once(oop_sys);
255 	if (oop_ret == OOP_CONTINUE) {
256 		return 0;
257 	}
258 
259 	return -1;
260 }
261 
262 /*
263   return on failure or (with 0) if all fd events are removed
264 */
265 static int oop_event_loop_wait(struct tevent_context *ev)
266 {
267 	void *oop_ret;
268 	oop_source_sys *oop_sys = ev->additional_data;
269 
270 	oop_ret = oop_sys_run(oop_sys);
271 	if (oop_ret == OOP_CONTINUE) {
272 		return 0;
273 	}
274 
275 	return -1;
276 }
277 
278 static const struct event_ops event_oop_ops = {
279 	.context_init	= oop_event_context_init,
280 	.add_fd		= oop_event_add_fd,
281 	.get_fd_flags	= oop_event_get_fd_flags,
282 	.set_fd_flags	= oop_event_set_fd_flags,
283 	.add_timer	= oop_event_add_timed,
284 	.add_signal	= common_event_add_signal,
285 	.loop_once	= oop_event_loop_once,
286 	.loop_wait	= oop_event_loop_wait,
287 };
288 
289 const struct event_ops *event_liboop_get_ops(void)
290 {
291 	return &event_oop_ops;
292 }
293