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1 /*
2  * Copyright © 2008 Kristian Høgsberg
3  * Copyright © 2013 Jason Ekstrand
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining
6  * a copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sublicense, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the
14  * next paragraph) shall be included in all copies or substantial
15  * portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20  * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
21  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
22  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
24  * SOFTWARE.
25  */
26 
27 #define _GNU_SOURCE
28 
29 #include <math.h>
30 #include <stdlib.h>
31 #include <stdint.h>
32 #include <string.h>
33 #include <stdio.h>
34 #include <errno.h>
35 #include <sys/uio.h>
36 #include <fcntl.h>
37 #include <unistd.h>
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <time.h>
41 #include <ffi.h>
42 
43 #include "wayland-util.h"
44 #include "wayland-private.h"
45 #include "wayland-os.h"
46 
47 static inline uint32_t
div_roundup(uint32_t n,size_t a)48 div_roundup(uint32_t n, size_t a)
49 {
50 	/* The cast to uint64_t is necessary to prevent overflow when rounding
51 	 * values close to UINT32_MAX. After the division it is again safe to
52 	 * cast back to uint32_t.
53 	 */
54 	return (uint32_t) (((uint64_t) n + (a - 1)) / a);
55 }
56 
57 struct wl_buffer {
58 	char data[4096];
59 	uint32_t head, tail;
60 };
61 
62 #define MASK(i) ((i) & 4095)
63 
64 #define MAX_FDS_OUT	28
65 #define CLEN		(CMSG_LEN(MAX_FDS_OUT * sizeof(int32_t)))
66 
67 struct wl_connection {
68 	struct wl_buffer in, out;
69 	struct wl_buffer fds_in, fds_out;
70 	int fd;
71 	int want_flush;
72 };
73 
74 static int
wl_buffer_put(struct wl_buffer * b,const void * data,size_t count)75 wl_buffer_put(struct wl_buffer *b, const void *data, size_t count)
76 {
77 	uint32_t head, size;
78 
79 	if (count > sizeof(b->data)) {
80 		wl_log("Data too big for buffer (%d > %d).\n",
81 		       count, sizeof(b->data));
82 		errno = E2BIG;
83 		return -1;
84 	}
85 
86 	head = MASK(b->head);
87 	if (head + count <= sizeof b->data) {
88 		memcpy(b->data + head, data, count);
89 	} else {
90 		size = sizeof b->data - head;
91 		memcpy(b->data + head, data, size);
92 		memcpy(b->data, (const char *) data + size, count - size);
93 	}
94 
95 	b->head += count;
96 
97 	return 0;
98 }
99 
100 static void
wl_buffer_put_iov(struct wl_buffer * b,struct iovec * iov,int * count)101 wl_buffer_put_iov(struct wl_buffer *b, struct iovec *iov, int *count)
102 {
103 	uint32_t head, tail;
104 
105 	head = MASK(b->head);
106 	tail = MASK(b->tail);
107 	if (head < tail) {
108 		iov[0].iov_base = b->data + head;
109 		iov[0].iov_len = tail - head;
110 		*count = 1;
111 	} else if (tail == 0) {
112 		iov[0].iov_base = b->data + head;
113 		iov[0].iov_len = sizeof b->data - head;
114 		*count = 1;
115 	} else {
116 		iov[0].iov_base = b->data + head;
117 		iov[0].iov_len = sizeof b->data - head;
118 		iov[1].iov_base = b->data;
119 		iov[1].iov_len = tail;
120 		*count = 2;
121 	}
122 }
123 
124 static void
wl_buffer_get_iov(struct wl_buffer * b,struct iovec * iov,int * count)125 wl_buffer_get_iov(struct wl_buffer *b, struct iovec *iov, int *count)
126 {
127 	uint32_t head, tail;
128 
129 	head = MASK(b->head);
130 	tail = MASK(b->tail);
131 	if (tail < head) {
132 		iov[0].iov_base = b->data + tail;
133 		iov[0].iov_len = head - tail;
134 		*count = 1;
135 	} else if (head == 0) {
136 		iov[0].iov_base = b->data + tail;
137 		iov[0].iov_len = sizeof b->data - tail;
138 		*count = 1;
139 	} else {
140 		iov[0].iov_base = b->data + tail;
141 		iov[0].iov_len = sizeof b->data - tail;
142 		iov[1].iov_base = b->data;
143 		iov[1].iov_len = head;
144 		*count = 2;
145 	}
146 }
147 
148 static void
wl_buffer_copy(struct wl_buffer * b,void * data,size_t count)149 wl_buffer_copy(struct wl_buffer *b, void *data, size_t count)
150 {
151 	uint32_t tail, size;
152 
153 	tail = MASK(b->tail);
154 	if (tail + count <= sizeof b->data) {
155 		memcpy(data, b->data + tail, count);
156 	} else {
157 		size = sizeof b->data - tail;
158 		memcpy(data, b->data + tail, size);
159 		memcpy((char *) data + size, b->data, count - size);
160 	}
161 }
162 
163 static uint32_t
wl_buffer_size(struct wl_buffer * b)164 wl_buffer_size(struct wl_buffer *b)
165 {
166 	return b->head - b->tail;
167 }
168 
169 struct wl_connection *
wl_connection_create(int fd)170 wl_connection_create(int fd)
171 {
172 	struct wl_connection *connection;
173 
174 	connection = zalloc(sizeof *connection);
175 	if (connection == NULL)
176 		return NULL;
177 
178 	connection->fd = fd;
179 
180 	return connection;
181 }
182 
183 static void
close_fds(struct wl_buffer * buffer,int max)184 close_fds(struct wl_buffer *buffer, int max)
185 {
186 	int32_t fds[sizeof(buffer->data) / sizeof(int32_t)], i, count;
187 	size_t size;
188 
189 	size = wl_buffer_size(buffer);
190 	if (size == 0)
191 		return;
192 
193 	wl_buffer_copy(buffer, fds, size);
194 	count = size / sizeof fds[0];
195 	if (max > 0 && max < count)
196 		count = max;
197 	size = count * sizeof fds[0];
198 	for (i = 0; i < count; i++)
199 		close(fds[i]);
200 	buffer->tail += size;
201 }
202 
203 void
wl_connection_close_fds_in(struct wl_connection * connection,int max)204 wl_connection_close_fds_in(struct wl_connection *connection, int max)
205 {
206 	close_fds(&connection->fds_in, max);
207 }
208 
209 int
wl_connection_destroy(struct wl_connection * connection)210 wl_connection_destroy(struct wl_connection *connection)
211 {
212 	int fd = connection->fd;
213 
214 	close_fds(&connection->fds_out, -1);
215 	close_fds(&connection->fds_in, -1);
216 	free(connection);
217 
218 	return fd;
219 }
220 
221 void
wl_connection_copy(struct wl_connection * connection,void * data,size_t size)222 wl_connection_copy(struct wl_connection *connection, void *data, size_t size)
223 {
224 	wl_buffer_copy(&connection->in, data, size);
225 }
226 
227 void
wl_connection_consume(struct wl_connection * connection,size_t size)228 wl_connection_consume(struct wl_connection *connection, size_t size)
229 {
230 	connection->in.tail += size;
231 }
232 
233 static void
build_cmsg(struct wl_buffer * buffer,char * data,int * clen)234 build_cmsg(struct wl_buffer *buffer, char *data, int *clen)
235 {
236 	struct cmsghdr *cmsg;
237 	size_t size;
238 
239 	size = wl_buffer_size(buffer);
240 	if (size > MAX_FDS_OUT * sizeof(int32_t))
241 		size = MAX_FDS_OUT * sizeof(int32_t);
242 
243 	if (size > 0) {
244 		cmsg = (struct cmsghdr *) data;
245 		cmsg->cmsg_level = SOL_SOCKET;
246 		cmsg->cmsg_type = SCM_RIGHTS;
247 		cmsg->cmsg_len = CMSG_LEN(size);
248 		wl_buffer_copy(buffer, CMSG_DATA(cmsg), size);
249 		*clen = cmsg->cmsg_len;
250 	} else {
251 		*clen = 0;
252 	}
253 }
254 
255 static int
decode_cmsg(struct wl_buffer * buffer,struct msghdr * msg)256 decode_cmsg(struct wl_buffer *buffer, struct msghdr *msg)
257 {
258 	struct cmsghdr *cmsg;
259 	size_t size, max, i;
260 	int overflow = 0;
261 
262 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL;
263 	     cmsg = CMSG_NXTHDR(msg, cmsg)) {
264 		if (cmsg->cmsg_level != SOL_SOCKET ||
265 		    cmsg->cmsg_type != SCM_RIGHTS)
266 			continue;
267 
268 		size = cmsg->cmsg_len - CMSG_LEN(0);
269 		max = sizeof(buffer->data) - wl_buffer_size(buffer);
270 		if (size > max || overflow) {
271 			overflow = 1;
272 			size /= sizeof(int32_t);
273 			for (i = 0; i < size; i++)
274 				close(((int*)CMSG_DATA(cmsg))[i]);
275 		} else if (wl_buffer_put(buffer, CMSG_DATA(cmsg), size) < 0) {
276 				return -1;
277 		}
278 	}
279 
280 	if (overflow) {
281 		errno = EOVERFLOW;
282 		return -1;
283 	}
284 
285 	return 0;
286 }
287 
288 int
wl_connection_flush(struct wl_connection * connection)289 wl_connection_flush(struct wl_connection *connection)
290 {
291 	struct iovec iov[2];
292 	struct msghdr msg;
293 	char cmsg[CLEN];
294 	int len = 0, count, clen;
295 	uint32_t tail;
296 
297 	if (!connection->want_flush)
298 		return 0;
299 
300 	tail = connection->out.tail;
301 	while (connection->out.head - connection->out.tail > 0) {
302 		wl_buffer_get_iov(&connection->out, iov, &count);
303 
304 		build_cmsg(&connection->fds_out, cmsg, &clen);
305 
306 		msg.msg_name = NULL;
307 		msg.msg_namelen = 0;
308 		msg.msg_iov = iov;
309 		msg.msg_iovlen = count;
310 		msg.msg_control = (clen > 0) ? cmsg : NULL;
311 		msg.msg_controllen = clen;
312 		msg.msg_flags = 0;
313 
314 		do {
315 			len = sendmsg(connection->fd, &msg,
316 				      MSG_NOSIGNAL | MSG_DONTWAIT);
317 		} while (len == -1 && errno == EINTR);
318 
319 		if (len == -1)
320 			return -1;
321 
322 		close_fds(&connection->fds_out, MAX_FDS_OUT);
323 
324 		connection->out.tail += len;
325 	}
326 
327 	connection->want_flush = 0;
328 
329 	return connection->out.head - tail;
330 }
331 
332 uint32_t
wl_connection_pending_input(struct wl_connection * connection)333 wl_connection_pending_input(struct wl_connection *connection)
334 {
335 	return wl_buffer_size(&connection->in);
336 }
337 
338 int
wl_connection_read(struct wl_connection * connection)339 wl_connection_read(struct wl_connection *connection)
340 {
341 	struct iovec iov[2];
342 	struct msghdr msg;
343 	char cmsg[CLEN];
344 	int len, count, ret;
345 
346 	if (wl_buffer_size(&connection->in) >= sizeof(connection->in.data)) {
347 		errno = EOVERFLOW;
348 		return -1;
349 	}
350 
351 	wl_buffer_put_iov(&connection->in, iov, &count);
352 
353 	msg.msg_name = NULL;
354 	msg.msg_namelen = 0;
355 	msg.msg_iov = iov;
356 	msg.msg_iovlen = count;
357 	msg.msg_control = cmsg;
358 	msg.msg_controllen = sizeof cmsg;
359 	msg.msg_flags = 0;
360 
361 	do {
362 		len = wl_os_recvmsg_cloexec(connection->fd, &msg, MSG_DONTWAIT);
363 	} while (len < 0 && errno == EINTR);
364 
365 	if (len <= 0)
366 		return len;
367 
368 	ret = decode_cmsg(&connection->fds_in, &msg);
369 	if (ret)
370 		return -1;
371 
372 	connection->in.head += len;
373 
374 	return wl_connection_pending_input(connection);
375 }
376 
377 int
wl_connection_write(struct wl_connection * connection,const void * data,size_t count)378 wl_connection_write(struct wl_connection *connection,
379 		    const void *data, size_t count)
380 {
381 	if (connection->out.head - connection->out.tail +
382 	    count > ARRAY_LENGTH(connection->out.data)) {
383 		connection->want_flush = 1;
384 		if (wl_connection_flush(connection) < 0)
385 			return -1;
386 	}
387 
388 	if (wl_buffer_put(&connection->out, data, count) < 0)
389 		return -1;
390 
391 	connection->want_flush = 1;
392 
393 	return 0;
394 }
395 
396 int
wl_connection_queue(struct wl_connection * connection,const void * data,size_t count)397 wl_connection_queue(struct wl_connection *connection,
398 		    const void *data, size_t count)
399 {
400 	if (connection->out.head - connection->out.tail +
401 	    count > ARRAY_LENGTH(connection->out.data)) {
402 		connection->want_flush = 1;
403 		if (wl_connection_flush(connection) < 0)
404 			return -1;
405 	}
406 
407 	return wl_buffer_put(&connection->out, data, count);
408 }
409 
410 int
wl_message_count_arrays(const struct wl_message * message)411 wl_message_count_arrays(const struct wl_message *message)
412 {
413 	int i, arrays;
414 
415 	for (i = 0, arrays = 0; message->signature[i]; i++) {
416 		if (message->signature[i] == 'a')
417 			arrays++;
418 	}
419 
420 	return arrays;
421 }
422 
423 int
wl_connection_get_fd(struct wl_connection * connection)424 wl_connection_get_fd(struct wl_connection *connection)
425 {
426 	return connection->fd;
427 }
428 
429 static int
wl_connection_put_fd(struct wl_connection * connection,int32_t fd)430 wl_connection_put_fd(struct wl_connection *connection, int32_t fd)
431 {
432 	if (wl_buffer_size(&connection->fds_out) == MAX_FDS_OUT * sizeof fd) {
433 		connection->want_flush = 1;
434 		if (wl_connection_flush(connection) < 0)
435 			return -1;
436 	}
437 
438 	return wl_buffer_put(&connection->fds_out, &fd, sizeof fd);
439 }
440 
441 const char *
get_next_argument(const char * signature,struct argument_details * details)442 get_next_argument(const char *signature, struct argument_details *details)
443 {
444 	details->nullable = 0;
445 	for(; *signature; ++signature) {
446 		switch(*signature) {
447 		case 'i':
448 		case 'u':
449 		case 'f':
450 		case 's':
451 		case 'o':
452 		case 'n':
453 		case 'a':
454 		case 'h':
455 			details->type = *signature;
456 			return signature + 1;
457 		case '?':
458 			details->nullable = 1;
459 		}
460 	}
461 	details->type = '\0';
462 	return signature;
463 }
464 
465 int
arg_count_for_signature(const char * signature)466 arg_count_for_signature(const char *signature)
467 {
468 	int count = 0;
469 	for(; *signature; ++signature) {
470 		switch(*signature) {
471 		case 'i':
472 		case 'u':
473 		case 'f':
474 		case 's':
475 		case 'o':
476 		case 'n':
477 		case 'a':
478 		case 'h':
479 			++count;
480 		}
481 	}
482 	return count;
483 }
484 
485 int
wl_message_get_since(const struct wl_message * message)486 wl_message_get_since(const struct wl_message *message)
487 {
488 	int since;
489 
490 	since = atoi(message->signature);
491 
492 	if (since == 0)
493 		since = 1;
494 
495 	return since;
496 }
497 
498 void
wl_argument_from_va_list(const char * signature,union wl_argument * args,int count,va_list ap)499 wl_argument_from_va_list(const char *signature, union wl_argument *args,
500 			 int count, va_list ap)
501 {
502 	int i;
503 	const char *sig_iter;
504 	struct argument_details arg;
505 
506 	sig_iter = signature;
507 	for (i = 0; i < count; i++) {
508 		sig_iter = get_next_argument(sig_iter, &arg);
509 
510 		switch(arg.type) {
511 		case 'i':
512 			args[i].i = va_arg(ap, int32_t);
513 			break;
514 		case 'u':
515 			args[i].u = va_arg(ap, uint32_t);
516 			break;
517 		case 'f':
518 			args[i].f = va_arg(ap, wl_fixed_t);
519 			break;
520 		case 's':
521 			args[i].s = va_arg(ap, const char *);
522 			break;
523 		case 'o':
524 			args[i].o = va_arg(ap, struct wl_object *);
525 			break;
526 		case 'n':
527 			args[i].o = va_arg(ap, struct wl_object *);
528 			break;
529 		case 'a':
530 			args[i].a = va_arg(ap, struct wl_array *);
531 			break;
532 		case 'h':
533 			args[i].h = va_arg(ap, int32_t);
534 			break;
535 		case '\0':
536 			return;
537 		}
538 	}
539 }
540 
541 static void
wl_closure_clear_fds(struct wl_closure * closure)542 wl_closure_clear_fds(struct wl_closure *closure)
543 {
544 	const char *signature = closure->message->signature;
545 	struct argument_details arg;
546 	int i;
547 
548 	for (i = 0; i < closure->count; i++) {
549 		signature = get_next_argument(signature, &arg);
550 		if (arg.type == 'h')
551 			closure->args[i].h = -1;
552 	}
553 }
554 
555 static struct wl_closure *
wl_closure_init(const struct wl_message * message,uint32_t size,int * num_arrays,union wl_argument * args)556 wl_closure_init(const struct wl_message *message, uint32_t size,
557                 int *num_arrays, union wl_argument *args)
558 {
559 	struct wl_closure *closure;
560 	int count;
561 
562 	count = arg_count_for_signature(message->signature);
563 	if (count > WL_CLOSURE_MAX_ARGS) {
564 		wl_log("too many args (%d)\n", count);
565 		errno = EINVAL;
566 		return NULL;
567 	}
568 
569 	if (size) {
570 		*num_arrays = wl_message_count_arrays(message);
571 		closure = malloc(sizeof *closure + size +
572 				 *num_arrays * sizeof(struct wl_array));
573 	} else {
574 		closure = malloc(sizeof *closure);
575 	}
576 
577 	if (!closure) {
578 		errno = ENOMEM;
579 		return NULL;
580 	}
581 
582 	if (args)
583 		memcpy(closure->args, args, count * sizeof *args);
584 
585 	closure->message = message;
586 	closure->count = count;
587 
588 	/* Set these all to -1 so we can close any that have been
589 	 * set to a real value during wl_closure_destroy().
590 	 * We may have copied a bunch of fds into the closure with
591 	 * memcpy previously, but those are undup()d client fds
592 	 * that we would have replaced anyway.
593 	 */
594 	wl_closure_clear_fds(closure);
595 
596 	return closure;
597 }
598 
599 struct wl_closure *
wl_closure_marshal(struct wl_object * sender,uint32_t opcode,union wl_argument * args,const struct wl_message * message)600 wl_closure_marshal(struct wl_object *sender, uint32_t opcode,
601 		   union wl_argument *args,
602 		   const struct wl_message *message)
603 {
604 	struct wl_closure *closure;
605 	struct wl_object *object;
606 	int i, count, fd, dup_fd;
607 	const char *signature;
608 	struct argument_details arg;
609 
610 	closure = wl_closure_init(message, 0, NULL, args);
611 	if (closure == NULL)
612 		return NULL;
613 
614 	count = closure->count;
615 
616 	signature = message->signature;
617 	for (i = 0; i < count; i++) {
618 		signature = get_next_argument(signature, &arg);
619 
620 		switch (arg.type) {
621 		case 'f':
622 		case 'u':
623 		case 'i':
624 			break;
625 		case 's':
626 			if (!arg.nullable && args[i].s == NULL)
627 				goto err_null;
628 			break;
629 		case 'o':
630 			if (!arg.nullable && args[i].o == NULL)
631 				goto err_null;
632 			break;
633 		case 'n':
634 			object = args[i].o;
635 			if (!arg.nullable && object == NULL)
636 				goto err_null;
637 
638 			closure->args[i].n = object ? object->id : 0;
639 			break;
640 		case 'a':
641 			if (!arg.nullable && args[i].a == NULL)
642 				goto err_null;
643 			break;
644 		case 'h':
645 			fd = args[i].h;
646 			dup_fd = wl_os_dupfd_cloexec(fd, 0);
647 			if (dup_fd < 0) {
648 				wl_closure_destroy(closure);
649 				wl_log("error marshalling arguments for %s: dup failed: %s\n",
650 				       message->name, strerror(errno));
651 				return NULL;
652 			}
653 			closure->args[i].h = dup_fd;
654 			break;
655 		default:
656 			wl_abort("unhandled format code: '%c'\n", arg.type);
657 			break;
658 		}
659 	}
660 
661 	closure->sender_id = sender->id;
662 	closure->opcode = opcode;
663 
664 	return closure;
665 
666 err_null:
667 	wl_closure_destroy(closure);
668 	wl_log("error marshalling arguments for %s (signature %s): "
669 	       "null value passed for arg %i\n", message->name,
670 	       message->signature, i);
671 	errno = EINVAL;
672 	return NULL;
673 }
674 
675 struct wl_closure *
wl_closure_vmarshal(struct wl_object * sender,uint32_t opcode,va_list ap,const struct wl_message * message)676 wl_closure_vmarshal(struct wl_object *sender, uint32_t opcode, va_list ap,
677 		    const struct wl_message *message)
678 {
679 	union wl_argument args[WL_CLOSURE_MAX_ARGS];
680 
681 	wl_argument_from_va_list(message->signature, args,
682 				 WL_CLOSURE_MAX_ARGS, ap);
683 
684 	return wl_closure_marshal(sender, opcode, args, message);
685 }
686 
687 struct wl_closure *
wl_connection_demarshal(struct wl_connection * connection,uint32_t size,struct wl_map * objects,const struct wl_message * message)688 wl_connection_demarshal(struct wl_connection *connection,
689 			uint32_t size,
690 			struct wl_map *objects,
691 			const struct wl_message *message)
692 {
693 	uint32_t *p, *next, *end, length, length_in_u32, id;
694 	int fd;
695 	char *s;
696 	int i, count, num_arrays;
697 	const char *signature;
698 	struct argument_details arg;
699 	struct wl_closure *closure;
700 	struct wl_array *array_extra;
701 
702 	/* Space for sender_id and opcode */
703 	if (size < 2 * sizeof *p) {
704 		wl_log("message too short, invalid header\n");
705 		wl_connection_consume(connection, size);
706 		errno = EINVAL;
707 		return NULL;
708 	}
709 
710 	closure = wl_closure_init(message, size, &num_arrays, NULL);
711 	if (closure == NULL) {
712 		wl_connection_consume(connection, size);
713 		return NULL;
714 	}
715 
716 	count = closure->count;
717 
718 	array_extra = closure->extra;
719 	p = (uint32_t *)(closure->extra + num_arrays);
720 	end = p + size / sizeof *p;
721 
722 	wl_connection_copy(connection, p, size);
723 	closure->sender_id = *p++;
724 	closure->opcode = *p++ & 0x0000ffff;
725 
726 	signature = message->signature;
727 	for (i = 0; i < count; i++) {
728 		signature = get_next_argument(signature, &arg);
729 
730 		if (arg.type != 'h' && p + 1 > end) {
731 			wl_log("message too short, "
732 			       "object (%d), message %s(%s)\n",
733 			       closure->sender_id, message->name,
734 			       message->signature);
735 			errno = EINVAL;
736 			goto err;
737 		}
738 
739 		switch (arg.type) {
740 		case 'u':
741 			closure->args[i].u = *p++;
742 			break;
743 		case 'i':
744 			closure->args[i].i = *p++;
745 			break;
746 		case 'f':
747 			closure->args[i].f = *p++;
748 			break;
749 		case 's':
750 			length = *p++;
751 
752 			if (length == 0) {
753 				closure->args[i].s = NULL;
754 				break;
755 			}
756 
757 			length_in_u32 = div_roundup(length, sizeof *p);
758 			if ((uint32_t) (end - p) < length_in_u32) {
759 				wl_log("message too short, "
760 				       "object (%d), message %s(%s)\n",
761 				       closure->sender_id, message->name,
762 				       message->signature);
763 				errno = EINVAL;
764 				goto err;
765 			}
766 			next = p + length_in_u32;
767 
768 			s = (char *) p;
769 
770 			if (length > 0 && s[length - 1] != '\0') {
771 				wl_log("string not nul-terminated, "
772 				       "message %s(%s)\n",
773 				       message->name, message->signature);
774 				errno = EINVAL;
775 				goto err;
776 			}
777 
778 			closure->args[i].s = s;
779 			p = next;
780 			break;
781 		case 'o':
782 			id = *p++;
783 			closure->args[i].n = id;
784 
785 			if (id == 0 && !arg.nullable) {
786 				wl_log("NULL object received on non-nullable "
787 				       "type, message %s(%s)\n", message->name,
788 				       message->signature);
789 				errno = EINVAL;
790 				goto err;
791 			}
792 			break;
793 		case 'n':
794 			id = *p++;
795 			closure->args[i].n = id;
796 
797 			if (id == 0 && !arg.nullable) {
798 				wl_log("NULL new ID received on non-nullable "
799 				       "type, message %s(%s)\n", message->name,
800 				       message->signature);
801 				errno = EINVAL;
802 				goto err;
803 			}
804 
805 			if (wl_map_reserve_new(objects, id) < 0) {
806 				wl_log("not a valid new object id (%u), "
807 				       "message %s(%s)\n",
808 				       id, message->name, message->signature);
809 				errno = EINVAL;
810 				goto err;
811 			}
812 
813 			break;
814 		case 'a':
815 			length = *p++;
816 
817 			length_in_u32 = div_roundup(length, sizeof *p);
818 			if ((uint32_t) (end - p) < length_in_u32) {
819 				wl_log("message too short, "
820 				       "object (%d), message %s(%s)\n",
821 				       closure->sender_id, message->name,
822 				       message->signature);
823 				errno = EINVAL;
824 				goto err;
825 			}
826 			next = p + length_in_u32;
827 
828 			array_extra->size = length;
829 			array_extra->alloc = 0;
830 			array_extra->data = p;
831 
832 			closure->args[i].a = array_extra++;
833 			p = next;
834 			break;
835 		case 'h':
836 			if (connection->fds_in.tail == connection->fds_in.head) {
837 				wl_log("file descriptor expected, "
838 				       "object (%d), message %s(%s)\n",
839 				       closure->sender_id, message->name,
840 				       message->signature);
841 				errno = EINVAL;
842 				goto err;
843 			}
844 
845 			wl_buffer_copy(&connection->fds_in, &fd, sizeof fd);
846 			connection->fds_in.tail += sizeof fd;
847 			closure->args[i].h = fd;
848 			break;
849 		default:
850 			wl_abort("unknown type\n");
851 			break;
852 		}
853 	}
854 
855 	wl_connection_consume(connection, size);
856 
857 	return closure;
858 
859  err:
860 	wl_closure_destroy(closure);
861 	wl_connection_consume(connection, size);
862 
863 	return NULL;
864 }
865 
866 bool
wl_object_is_zombie(struct wl_map * map,uint32_t id)867 wl_object_is_zombie(struct wl_map *map, uint32_t id)
868 {
869 	uint32_t flags;
870 
871 	/* Zombie objects only exist on the client side. */
872 	if (map->side == WL_MAP_SERVER_SIDE)
873 		return false;
874 
875 	/* Zombie objects can only have been created by the client. */
876 	if (id >= WL_SERVER_ID_START)
877 		return false;
878 
879 	flags = wl_map_lookup_flags(map, id);
880 	return !!(flags & WL_MAP_ENTRY_ZOMBIE);
881 }
882 
883 int
wl_closure_lookup_objects(struct wl_closure * closure,struct wl_map * objects)884 wl_closure_lookup_objects(struct wl_closure *closure, struct wl_map *objects)
885 {
886 	struct wl_object *object;
887 	const struct wl_message *message;
888 	const char *signature;
889 	struct argument_details arg;
890 	int i, count;
891 	uint32_t id;
892 
893 	message = closure->message;
894 	signature = message->signature;
895 	count = arg_count_for_signature(signature);
896 	for (i = 0; i < count; i++) {
897 		signature = get_next_argument(signature, &arg);
898 		switch (arg.type) {
899 		case 'o':
900 			id = closure->args[i].n;
901 			closure->args[i].o = NULL;
902 
903 			object = wl_map_lookup(objects, id);
904 			if (wl_object_is_zombie(objects, id)) {
905 				/* references object we've already
906 				 * destroyed client side */
907 				object = NULL;
908 			} else if (object == NULL && id != 0) {
909 				wl_log("unknown object (%u), message %s(%s)\n",
910 				       id, message->name, message->signature);
911 				errno = EINVAL;
912 				return -1;
913 			}
914 
915 			if (object != NULL && message->types[i] != NULL &&
916 			    !wl_interface_equal((object)->interface,
917 						message->types[i])) {
918 				wl_log("invalid object (%u), type (%s), "
919 				       "message %s(%s)\n",
920 				       id, (object)->interface->name,
921 				       message->name, message->signature);
922 				errno = EINVAL;
923 				return -1;
924 			}
925 			closure->args[i].o = object;
926 		}
927 	}
928 
929 	return 0;
930 }
931 
932 static void
convert_arguments_to_ffi(const char * signature,uint32_t flags,union wl_argument * args,int count,ffi_type ** ffi_types,void ** ffi_args)933 convert_arguments_to_ffi(const char *signature, uint32_t flags,
934 			 union wl_argument *args,
935 			 int count, ffi_type **ffi_types, void** ffi_args)
936 {
937 	int i;
938 	const char *sig_iter;
939 	struct argument_details arg;
940 
941 	sig_iter = signature;
942 	for (i = 0; i < count; i++) {
943 		sig_iter = get_next_argument(sig_iter, &arg);
944 
945 		switch(arg.type) {
946 		case 'i':
947 			ffi_types[i] = &ffi_type_sint32;
948 			ffi_args[i] = &args[i].i;
949 			break;
950 		case 'u':
951 			ffi_types[i] = &ffi_type_uint32;
952 			ffi_args[i] = &args[i].u;
953 			break;
954 		case 'f':
955 			ffi_types[i] = &ffi_type_sint32;
956 			ffi_args[i] = &args[i].f;
957 			break;
958 		case 's':
959 			ffi_types[i] = &ffi_type_pointer;
960 			ffi_args[i] = &args[i].s;
961 			break;
962 		case 'o':
963 			ffi_types[i] = &ffi_type_pointer;
964 			ffi_args[i] = &args[i].o;
965 			break;
966 		case 'n':
967 			if (flags & WL_CLOSURE_INVOKE_CLIENT) {
968 				ffi_types[i] = &ffi_type_pointer;
969 				ffi_args[i] = &args[i].o;
970 			} else {
971 				ffi_types[i] = &ffi_type_uint32;
972 				ffi_args[i] = &args[i].n;
973 			}
974 			break;
975 		case 'a':
976 			ffi_types[i] = &ffi_type_pointer;
977 			ffi_args[i] = &args[i].a;
978 			break;
979 		case 'h':
980 			ffi_types[i] = &ffi_type_sint32;
981 			ffi_args[i] = &args[i].h;
982 			break;
983 		default:
984 			wl_abort("unknown type\n");
985 			break;
986 		}
987 	}
988 }
989 
990 void
wl_closure_invoke(struct wl_closure * closure,uint32_t flags,struct wl_object * target,uint32_t opcode,void * data)991 wl_closure_invoke(struct wl_closure *closure, uint32_t flags,
992 		  struct wl_object *target, uint32_t opcode, void *data)
993 {
994 	int count;
995 	ffi_cif cif;
996 	ffi_type *ffi_types[WL_CLOSURE_MAX_ARGS + 2];
997 	void * ffi_args[WL_CLOSURE_MAX_ARGS + 2];
998 	void (* const *implementation)(void);
999 
1000 	count = arg_count_for_signature(closure->message->signature);
1001 
1002 	ffi_types[0] = &ffi_type_pointer;
1003 	ffi_args[0] = &data;
1004 	ffi_types[1] = &ffi_type_pointer;
1005 	ffi_args[1] = &target;
1006 
1007 	convert_arguments_to_ffi(closure->message->signature, flags, closure->args,
1008 				 count, ffi_types + 2, ffi_args + 2);
1009 
1010 	ffi_prep_cif(&cif, FFI_DEFAULT_ABI,
1011 		     count + 2, &ffi_type_void, ffi_types);
1012 
1013 	implementation = target->implementation;
1014 	if (!implementation[opcode]) {
1015 		wl_abort("listener function for opcode %u of %s is NULL\n",
1016 			 opcode, target->interface->name);
1017 	}
1018 	ffi_call(&cif, implementation[opcode], NULL, ffi_args);
1019 
1020 	wl_closure_clear_fds(closure);
1021 }
1022 
1023 void
wl_closure_dispatch(struct wl_closure * closure,wl_dispatcher_func_t dispatcher,struct wl_object * target,uint32_t opcode)1024 wl_closure_dispatch(struct wl_closure *closure, wl_dispatcher_func_t dispatcher,
1025 		    struct wl_object *target, uint32_t opcode)
1026 {
1027 	dispatcher(target->implementation, target, opcode, closure->message,
1028 		   closure->args);
1029 
1030 	wl_closure_clear_fds(closure);
1031 }
1032 
1033 static int
copy_fds_to_connection(struct wl_closure * closure,struct wl_connection * connection)1034 copy_fds_to_connection(struct wl_closure *closure,
1035 		       struct wl_connection *connection)
1036 {
1037 	const struct wl_message *message = closure->message;
1038 	uint32_t i, count;
1039 	struct argument_details arg;
1040 	const char *signature = message->signature;
1041 	int fd;
1042 
1043 	count = arg_count_for_signature(signature);
1044 	for (i = 0; i < count; i++) {
1045 		signature = get_next_argument(signature, &arg);
1046 		if (arg.type != 'h')
1047 			continue;
1048 
1049 		fd = closure->args[i].h;
1050 		if (wl_connection_put_fd(connection, fd)) {
1051 			wl_log("request could not be marshaled: "
1052 			       "can't send file descriptor");
1053 			return -1;
1054 		}
1055 		closure->args[i].h = -1;
1056 	}
1057 
1058 	return 0;
1059 }
1060 
1061 
1062 static uint32_t
buffer_size_for_closure(struct wl_closure * closure)1063 buffer_size_for_closure(struct wl_closure *closure)
1064 {
1065 	const struct wl_message *message = closure->message;
1066 	int i, count;
1067 	struct argument_details arg;
1068 	const char *signature;
1069 	uint32_t size, buffer_size = 0;
1070 
1071 	signature = message->signature;
1072 	count = arg_count_for_signature(signature);
1073 	for (i = 0; i < count; i++) {
1074 		signature = get_next_argument(signature, &arg);
1075 
1076 		switch (arg.type) {
1077 		case 'h':
1078 			break;
1079 		case 'u':
1080 		case 'i':
1081 		case 'f':
1082 		case 'o':
1083 		case 'n':
1084 			buffer_size++;
1085 			break;
1086 		case 's':
1087 			if (closure->args[i].s == NULL) {
1088 				buffer_size++;
1089 				break;
1090 			}
1091 
1092 			size = strlen(closure->args[i].s) + 1;
1093 			buffer_size += 1 + div_roundup(size, sizeof(uint32_t));
1094 			break;
1095 		case 'a':
1096 			if (closure->args[i].a == NULL) {
1097 				buffer_size++;
1098 				break;
1099 			}
1100 
1101 			size = closure->args[i].a->size;
1102 			buffer_size += (1 + div_roundup(size, sizeof(uint32_t)));
1103 			break;
1104 		default:
1105 			break;
1106 		}
1107 	}
1108 
1109 	return buffer_size + 2;
1110 }
1111 
1112 static int
serialize_closure(struct wl_closure * closure,uint32_t * buffer,size_t buffer_count)1113 serialize_closure(struct wl_closure *closure, uint32_t *buffer,
1114 		  size_t buffer_count)
1115 {
1116 	const struct wl_message *message = closure->message;
1117 	unsigned int i, count, size;
1118 	uint32_t *p, *end;
1119 	struct argument_details arg;
1120 	const char *signature;
1121 
1122 	if (buffer_count < 2)
1123 		goto overflow;
1124 
1125 	p = buffer + 2;
1126 	end = buffer + buffer_count;
1127 
1128 	signature = message->signature;
1129 	count = arg_count_for_signature(signature);
1130 	for (i = 0; i < count; i++) {
1131 		signature = get_next_argument(signature, &arg);
1132 
1133 		if (arg.type == 'h')
1134 			continue;
1135 
1136 		if (p + 1 > end)
1137 			goto overflow;
1138 
1139 		switch (arg.type) {
1140 		case 'u':
1141 			*p++ = closure->args[i].u;
1142 			break;
1143 		case 'i':
1144 			*p++ = closure->args[i].i;
1145 			break;
1146 		case 'f':
1147 			*p++ = closure->args[i].f;
1148 			break;
1149 		case 'o':
1150 			*p++ = closure->args[i].o ? closure->args[i].o->id : 0;
1151 			break;
1152 		case 'n':
1153 			*p++ = closure->args[i].n;
1154 			break;
1155 		case 's':
1156 			if (closure->args[i].s == NULL) {
1157 				*p++ = 0;
1158 				break;
1159 			}
1160 
1161 			size = strlen(closure->args[i].s) + 1;
1162 			*p++ = size;
1163 
1164 			if (p + div_roundup(size, sizeof *p) > end)
1165 				goto overflow;
1166 
1167 			memcpy(p, closure->args[i].s, size);
1168 			p += div_roundup(size, sizeof *p);
1169 			break;
1170 		case 'a':
1171 			if (closure->args[i].a == NULL) {
1172 				*p++ = 0;
1173 				break;
1174 			}
1175 
1176 			size = closure->args[i].a->size;
1177 			*p++ = size;
1178 
1179 			if (p + div_roundup(size, sizeof *p) > end)
1180 				goto overflow;
1181 
1182 			memcpy(p, closure->args[i].a->data, size);
1183 			p += div_roundup(size, sizeof *p);
1184 			break;
1185 		default:
1186 			break;
1187 		}
1188 	}
1189 
1190 	size = (p - buffer) * sizeof *p;
1191 
1192 	buffer[0] = closure->sender_id;
1193 	buffer[1] = size << 16 | (closure->opcode & 0x0000ffff);
1194 
1195 	return size;
1196 
1197 overflow:
1198 	errno = ERANGE;
1199 	return -1;
1200 }
1201 
1202 int
wl_closure_send(struct wl_closure * closure,struct wl_connection * connection)1203 wl_closure_send(struct wl_closure *closure, struct wl_connection *connection)
1204 {
1205 	int size;
1206 	uint32_t buffer_size;
1207 	uint32_t *buffer;
1208 	int result;
1209 
1210 	if (copy_fds_to_connection(closure, connection))
1211 		return -1;
1212 
1213 	buffer_size = buffer_size_for_closure(closure);
1214 	buffer = zalloc(buffer_size * sizeof buffer[0]);
1215 	if (buffer == NULL)
1216 		return -1;
1217 
1218 	size = serialize_closure(closure, buffer, buffer_size);
1219 	if (size < 0) {
1220 		free(buffer);
1221 		return -1;
1222 	}
1223 
1224 	result = wl_connection_write(connection, buffer, size);
1225 	free(buffer);
1226 
1227 	return result;
1228 }
1229 
1230 int
wl_closure_queue(struct wl_closure * closure,struct wl_connection * connection)1231 wl_closure_queue(struct wl_closure *closure, struct wl_connection *connection)
1232 {
1233 	int size;
1234 	uint32_t buffer_size;
1235 	uint32_t *buffer;
1236 	int result;
1237 
1238 	if (copy_fds_to_connection(closure, connection))
1239 		return -1;
1240 
1241 	buffer_size = buffer_size_for_closure(closure);
1242 	buffer = malloc(buffer_size * sizeof buffer[0]);
1243 	if (buffer == NULL)
1244 		return -1;
1245 
1246 	size = serialize_closure(closure, buffer, buffer_size);
1247 	if (size < 0) {
1248 		free(buffer);
1249 		return -1;
1250 	}
1251 
1252 	result = wl_connection_queue(connection, buffer, size);
1253 	free(buffer);
1254 
1255 	return result;
1256 }
1257 
1258 void
wl_closure_print(struct wl_closure * closure,struct wl_object * target,int send)1259 wl_closure_print(struct wl_closure *closure, struct wl_object *target, int send)
1260 {
1261 	int i;
1262 	struct argument_details arg;
1263 	const char *signature = closure->message->signature;
1264 	struct timespec tp;
1265 	unsigned int time;
1266 
1267 	clock_gettime(CLOCK_REALTIME, &tp);
1268 	time = (tp.tv_sec * 1000000L) + (tp.tv_nsec / 1000);
1269 
1270 	fprintf(stderr, "[%10.3f] %s%s@%u.%s(",
1271 		time / 1000.0,
1272 		send ? " -> " : "",
1273 		target->interface->name, target->id,
1274 		closure->message->name);
1275 
1276 	for (i = 0; i < closure->count; i++) {
1277 		signature = get_next_argument(signature, &arg);
1278 		if (i > 0)
1279 			fprintf(stderr, ", ");
1280 
1281 		switch (arg.type) {
1282 		case 'u':
1283 			fprintf(stderr, "%u", closure->args[i].u);
1284 			break;
1285 		case 'i':
1286 			fprintf(stderr, "%d", closure->args[i].i);
1287 			break;
1288 		case 'f':
1289 			fprintf(stderr, "%f",
1290 				wl_fixed_to_double(closure->args[i].f));
1291 			break;
1292 		case 's':
1293 			if (closure->args[i].s)
1294 				fprintf(stderr, "\"%s\"", closure->args[i].s);
1295 			else
1296 				fprintf(stderr, "nil");
1297 			break;
1298 		case 'o':
1299 			if (closure->args[i].o)
1300 				fprintf(stderr, "%s@%u",
1301 					closure->args[i].o->interface->name,
1302 					closure->args[i].o->id);
1303 			else
1304 				fprintf(stderr, "nil");
1305 			break;
1306 		case 'n':
1307 			fprintf(stderr, "new id %s@",
1308 				(closure->message->types[i]) ?
1309 				 closure->message->types[i]->name :
1310 				  "[unknown]");
1311 			if (closure->args[i].n != 0)
1312 				fprintf(stderr, "%u", closure->args[i].n);
1313 			else
1314 				fprintf(stderr, "nil");
1315 			break;
1316 		case 'a':
1317 			fprintf(stderr, "array");
1318 			break;
1319 		case 'h':
1320 			fprintf(stderr, "fd %d", closure->args[i].h);
1321 			break;
1322 		}
1323 	}
1324 
1325 	fprintf(stderr, ")\n");
1326 }
1327 
1328 static int
wl_closure_close_fds(struct wl_closure * closure)1329 wl_closure_close_fds(struct wl_closure *closure)
1330 {
1331 	int i;
1332 	struct argument_details arg;
1333 	const char *signature = closure->message->signature;
1334 
1335 	for (i = 0; i < closure->count; i++) {
1336 		signature = get_next_argument(signature, &arg);
1337 		if (arg.type == 'h' && closure->args[i].h != -1)
1338 			close(closure->args[i].h);
1339 	}
1340 
1341 	return 0;
1342 }
1343 
1344 void
wl_closure_destroy(struct wl_closure * closure)1345 wl_closure_destroy(struct wl_closure *closure)
1346 {
1347 	/* wl_closure_destroy has free() semantics */
1348 	if (!closure)
1349 		return;
1350 
1351 	wl_closure_close_fds(closure);
1352 	free(closure);
1353 }
1354