1 /*
2  * Copyright 2007-2012 Niels Provos and Nick Mathewson
3  * Copyright 2000-2007 Niels Provos <provos@citi.umich.edu>
4  * Copyright 2003 Michael A. Davis <mike@datanerds.net>
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  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <winsock2.h>
30 #include <windows.h>
31 #include <sys/types.h>
32 #include <sys/queue.h>
33 #include <limits.h>
34 #include <signal.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <errno.h>
39 
40 #include "event2/util.h"
41 #include "event2/event-config.h"
42 #include "util-internal.h"
43 #include "log-internal.h"
44 #include "event2/event.h"
45 #include "event-internal.h"
46 #include "evmap-internal.h"
47 #include "event2/thread.h"
48 #include "evthread-internal.h"
49 
50 #define XFREE(ptr) do { if (ptr) mm_free(ptr); } while (0)
51 
52 extern struct event_list timequeue;
53 extern struct event_list addqueue;
54 
55 struct win_fd_set {
56 	u_int fd_count;
57 	SOCKET fd_array[1];
58 };
59 
60 /* MSDN says this is required to handle SIGFPE */
61 volatile double SIGFPE_REQ = 0.0f;
62 
63 struct idx_info {
64 	int read_pos_plus1;
65 	int write_pos_plus1;
66 };
67 
68 struct win32op {
69 	unsigned num_fds_in_fd_sets;
70 	int resize_out_sets;
71 	struct win_fd_set *readset_in;
72 	struct win_fd_set *writeset_in;
73 	struct win_fd_set *readset_out;
74 	struct win_fd_set *writeset_out;
75 	struct win_fd_set *exset_out;
76 	unsigned signals_are_broken : 1;
77 };
78 
79 static void *win32_init(struct event_base *);
80 static int win32_add(struct event_base *, evutil_socket_t, short old, short events, void *_idx);
81 static int win32_del(struct event_base *, evutil_socket_t, short old, short events, void *_idx);
82 static int win32_dispatch(struct event_base *base, struct timeval *);
83 static void win32_dealloc(struct event_base *);
84 
85 struct eventop win32ops = {
86 	"win32",
87 	win32_init,
88 	win32_add,
89 	win32_del,
90 	win32_dispatch,
91 	win32_dealloc,
92 	0, /* doesn't need reinit */
93 	0, /* No features supported. */
94 	sizeof(struct idx_info),
95 };
96 
97 #define FD_SET_ALLOC_SIZE(n) ((sizeof(struct win_fd_set) + ((n)-1)*sizeof(SOCKET)))
98 
99 static int
grow_fd_sets(struct win32op * op,unsigned new_num_fds)100 grow_fd_sets(struct win32op *op, unsigned new_num_fds)
101 {
102 	size_t size;
103 
104 	EVUTIL_ASSERT(new_num_fds >= op->readset_in->fd_count &&
105 	       new_num_fds >= op->writeset_in->fd_count);
106 	EVUTIL_ASSERT(new_num_fds >= 1);
107 
108 	size = FD_SET_ALLOC_SIZE(new_num_fds);
109 	if (!(op->readset_in = mm_realloc(op->readset_in, size)))
110 		return (-1);
111 	if (!(op->writeset_in = mm_realloc(op->writeset_in, size)))
112 		return (-1);
113 	op->resize_out_sets = 1;
114 	op->num_fds_in_fd_sets = new_num_fds;
115 	return (0);
116 }
117 
118 static int
do_fd_set(struct win32op * op,struct idx_info * ent,evutil_socket_t s,int read)119 do_fd_set(struct win32op *op, struct idx_info *ent, evutil_socket_t s, int read)
120 {
121 	struct win_fd_set *set = read ? op->readset_in : op->writeset_in;
122 	if (read) {
123 		if (ent->read_pos_plus1 > 0)
124 			return (0);
125 	} else {
126 		if (ent->write_pos_plus1 > 0)
127 			return (0);
128 	}
129 	if (set->fd_count == op->num_fds_in_fd_sets) {
130 		if (grow_fd_sets(op, op->num_fds_in_fd_sets*2))
131 			return (-1);
132 		/* set pointer will have changed and needs reiniting! */
133 		set = read ? op->readset_in : op->writeset_in;
134 	}
135 	set->fd_array[set->fd_count] = s;
136 	if (read)
137 		ent->read_pos_plus1 = set->fd_count+1;
138 	else
139 		ent->write_pos_plus1 = set->fd_count+1;
140 	return (set->fd_count++);
141 }
142 
143 static int
do_fd_clear(struct event_base * base,struct win32op * op,struct idx_info * ent,int read)144 do_fd_clear(struct event_base *base,
145 			struct win32op *op, struct idx_info *ent, int read)
146 {
147 	int i;
148 	struct win_fd_set *set = read ? op->readset_in : op->writeset_in;
149 	if (read) {
150 		i = ent->read_pos_plus1 - 1;
151 		ent->read_pos_plus1 = 0;
152 	} else {
153 		i = ent->write_pos_plus1 - 1;
154 		ent->write_pos_plus1 = 0;
155 	}
156 	if (i < 0)
157 		return (0);
158 	if (--set->fd_count != (unsigned)i) {
159 		struct idx_info *ent2;
160 		SOCKET s2;
161 		s2 = set->fd_array[i] = set->fd_array[set->fd_count];
162 
163 		ent2 = evmap_io_get_fdinfo(&base->io, s2);
164 
165 		if (!ent2) /* This indicates a bug. */
166 			return (0);
167 		if (read)
168 			ent2->read_pos_plus1 = i+1;
169 		else
170 			ent2->write_pos_plus1 = i+1;
171 	}
172 	return (0);
173 }
174 
175 #define NEVENT 32
176 void *
win32_init(struct event_base * _base)177 win32_init(struct event_base *_base)
178 {
179 	struct win32op *winop;
180 	size_t size;
181 	if (!(winop = mm_calloc(1, sizeof(struct win32op))))
182 		return NULL;
183 	winop->num_fds_in_fd_sets = NEVENT;
184 	size = FD_SET_ALLOC_SIZE(NEVENT);
185 	if (!(winop->readset_in = mm_malloc(size)))
186 		goto err;
187 	if (!(winop->writeset_in = mm_malloc(size)))
188 		goto err;
189 	if (!(winop->readset_out = mm_malloc(size)))
190 		goto err;
191 	if (!(winop->writeset_out = mm_malloc(size)))
192 		goto err;
193 	if (!(winop->exset_out = mm_malloc(size)))
194 		goto err;
195 	winop->readset_in->fd_count = winop->writeset_in->fd_count = 0;
196 	winop->readset_out->fd_count = winop->writeset_out->fd_count
197 		= winop->exset_out->fd_count = 0;
198 
199 	if (evsig_init(_base) < 0)
200 		winop->signals_are_broken = 1;
201 
202 	return (winop);
203  err:
204 	XFREE(winop->readset_in);
205 	XFREE(winop->writeset_in);
206 	XFREE(winop->readset_out);
207 	XFREE(winop->writeset_out);
208 	XFREE(winop->exset_out);
209 	XFREE(winop);
210 	return (NULL);
211 }
212 
213 int
win32_add(struct event_base * base,evutil_socket_t fd,short old,short events,void * _idx)214 win32_add(struct event_base *base, evutil_socket_t fd,
215 			 short old, short events, void *_idx)
216 {
217 	struct win32op *win32op = base->evbase;
218 	struct idx_info *idx = _idx;
219 
220 	if ((events & EV_SIGNAL) && win32op->signals_are_broken)
221 		return (-1);
222 
223 	if (!(events & (EV_READ|EV_WRITE)))
224 		return (0);
225 
226 	event_debug(("%s: adding event for %d", __func__, (int)fd));
227 	if (events & EV_READ) {
228 		if (do_fd_set(win32op, idx, fd, 1)<0)
229 			return (-1);
230 	}
231 	if (events & EV_WRITE) {
232 		if (do_fd_set(win32op, idx, fd, 0)<0)
233 			return (-1);
234 	}
235 	return (0);
236 }
237 
238 int
win32_del(struct event_base * base,evutil_socket_t fd,short old,short events,void * _idx)239 win32_del(struct event_base *base, evutil_socket_t fd, short old, short events,
240 		  void *_idx)
241 {
242 	struct win32op *win32op = base->evbase;
243 	struct idx_info *idx = _idx;
244 
245 	event_debug(("%s: Removing event for "EV_SOCK_FMT,
246 		__func__, EV_SOCK_ARG(fd)));
247 	if (events & EV_READ)
248 		do_fd_clear(base, win32op, idx, 1);
249 	if (events & EV_WRITE)
250 		do_fd_clear(base, win32op, idx, 0);
251 
252 	return 0;
253 }
254 
255 static void
fd_set_copy(struct win_fd_set * out,const struct win_fd_set * in)256 fd_set_copy(struct win_fd_set *out, const struct win_fd_set *in)
257 {
258 	out->fd_count = in->fd_count;
259 	memcpy(out->fd_array, in->fd_array, in->fd_count * (sizeof(SOCKET)));
260 }
261 
262 /*
263   static void dump_fd_set(struct win_fd_set *s)
264   {
265   unsigned int i;
266   printf("[ ");
267   for(i=0;i<s->fd_count;++i)
268   printf("%d ",(int)s->fd_array[i]);
269   printf("]\n");
270   }
271 */
272 
273 int
win32_dispatch(struct event_base * base,struct timeval * tv)274 win32_dispatch(struct event_base *base, struct timeval *tv)
275 {
276 	struct win32op *win32op = base->evbase;
277 	int res = 0;
278 	unsigned j, i;
279 	int fd_count;
280 	SOCKET s;
281 
282 	if (win32op->resize_out_sets) {
283 		size_t size = FD_SET_ALLOC_SIZE(win32op->num_fds_in_fd_sets);
284 		if (!(win32op->readset_out = mm_realloc(win32op->readset_out, size)))
285 			return (-1);
286 		if (!(win32op->exset_out = mm_realloc(win32op->exset_out, size)))
287 			return (-1);
288 		if (!(win32op->writeset_out = mm_realloc(win32op->writeset_out, size)))
289 			return (-1);
290 		win32op->resize_out_sets = 0;
291 	}
292 
293 	fd_set_copy(win32op->readset_out, win32op->readset_in);
294 	fd_set_copy(win32op->exset_out, win32op->writeset_in);
295 	fd_set_copy(win32op->writeset_out, win32op->writeset_in);
296 
297 	fd_count =
298 	    (win32op->readset_out->fd_count > win32op->writeset_out->fd_count) ?
299 	    win32op->readset_out->fd_count : win32op->writeset_out->fd_count;
300 
301 	if (!fd_count) {
302 		long msec = tv ? evutil_tv_to_msec(tv) : LONG_MAX;
303 		/* Sleep's DWORD argument is unsigned long */
304 		if (msec < 0)
305 			msec = LONG_MAX;
306 		/* Windows doesn't like you to call select() with no sockets */
307 		Sleep(msec);
308 		return (0);
309 	}
310 
311 	EVBASE_RELEASE_LOCK(base, th_base_lock);
312 
313 	res = select(fd_count,
314 		     (struct fd_set*)win32op->readset_out,
315 		     (struct fd_set*)win32op->writeset_out,
316 		     (struct fd_set*)win32op->exset_out, tv);
317 
318 	EVBASE_ACQUIRE_LOCK(base, th_base_lock);
319 
320 	event_debug(("%s: select returned %d", __func__, res));
321 
322 	if (res <= 0) {
323 		return res;
324 	}
325 
326 	if (win32op->readset_out->fd_count) {
327 		i = rand() % win32op->readset_out->fd_count;
328 		for (j=0; j<win32op->readset_out->fd_count; ++j) {
329 			if (++i >= win32op->readset_out->fd_count)
330 				i = 0;
331 			s = win32op->readset_out->fd_array[i];
332 			evmap_io_active(base, s, EV_READ);
333 		}
334 	}
335 	if (win32op->exset_out->fd_count) {
336 		i = rand() % win32op->exset_out->fd_count;
337 		for (j=0; j<win32op->exset_out->fd_count; ++j) {
338 			if (++i >= win32op->exset_out->fd_count)
339 				i = 0;
340 			s = win32op->exset_out->fd_array[i];
341 			evmap_io_active(base, s, EV_WRITE);
342 		}
343 	}
344 	if (win32op->writeset_out->fd_count) {
345 		SOCKET s;
346 		i = rand() % win32op->writeset_out->fd_count;
347 		for (j=0; j<win32op->writeset_out->fd_count; ++j) {
348 			if (++i >= win32op->writeset_out->fd_count)
349 				i = 0;
350 			s = win32op->writeset_out->fd_array[i];
351 			evmap_io_active(base, s, EV_WRITE);
352 		}
353 	}
354 	return (0);
355 }
356 
357 void
win32_dealloc(struct event_base * _base)358 win32_dealloc(struct event_base *_base)
359 {
360 	struct win32op *win32op = _base->evbase;
361 
362 	evsig_dealloc(_base);
363 	if (win32op->readset_in)
364 		mm_free(win32op->readset_in);
365 	if (win32op->writeset_in)
366 		mm_free(win32op->writeset_in);
367 	if (win32op->readset_out)
368 		mm_free(win32op->readset_out);
369 	if (win32op->writeset_out)
370 		mm_free(win32op->writeset_out);
371 	if (win32op->exset_out)
372 		mm_free(win32op->exset_out);
373 	/* XXXXX free the tree. */
374 
375 	memset(win32op, 0, sizeof(*win32op));
376 	mm_free(win32op);
377 }
378