1 /*
2  * Copyright (c) 2014 Philippe De Muyter <phdm@macqel.be>
3  * Copyright (c) 2014 William Manley <will@williammanley.net>
4  * Copyright (c) 2011 Peter Zotov <whitequark@whitequark.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include "defs.h"
31 
32 #include <stdint.h>
33 #include <sys/ioctl.h>
34 #include <linux/types.h>
35 #include <linux/videodev2.h>
36 /* some historical constants */
37 #ifndef V4L2_CID_HCENTER
38 #define V4L2_CID_HCENTER (V4L2_CID_BASE+22)
39 #endif
40 #ifndef V4L2_CID_VCENTER
41 #define V4L2_CID_VCENTER (V4L2_CID_BASE+23)
42 #endif
43 #ifndef V4L2_CID_BAND_STOP_FILTER
44 #define V4L2_CID_BAND_STOP_FILTER (V4L2_CID_BASE+33)
45 #endif
46 
47 #include "xlat/v4l2_device_capabilities_flags.h"
48 #include "xlat/v4l2_buf_types.h"
49 #include "xlat/v4l2_buf_flags.h"
50 #include "xlat/v4l2_framesize_types.h"
51 #include "xlat/v4l2_frameinterval_types.h"
52 #include "xlat/v4l2_fields.h"
53 #include "xlat/v4l2_colorspaces.h"
54 #include "xlat/v4l2_format_description_flags.h"
55 #include "xlat/v4l2_memories.h"
56 #include "xlat/v4l2_control_ids.h"
57 #include "xlat/v4l2_control_types.h"
58 #include "xlat/v4l2_control_flags.h"
59 #include "xlat/v4l2_control_classes.h"
60 #include "xlat/v4l2_streaming_capabilities.h"
61 #include "xlat/v4l2_capture_modes.h"
62 #include "xlat/v4l2_input_types.h"
63 
64 #define FMT_FRACT "%u/%u"
65 #define ARGS_FRACT(x) ((x).numerator), ((x).denominator)
66 
67 #define FMT_RECT "{left=%i, top=%i, width=%i, height=%i}"
68 #define ARGS_RECT(x) (x).left, (x).top, (x).width, (x).height
69 
print_pixelformat(uint32_t fourcc)70 static void print_pixelformat(uint32_t fourcc)
71 {
72 	union {
73 		uint32_t pixelformat;
74 		unsigned char cc[sizeof(uint32_t)];
75 	} u = {
76 		.pixelformat =
77 #if WORDS_BIGENDIAN
78 			htole32(fourcc)
79 #else
80 			fourcc
81 #endif
82 	};
83 	unsigned int i;
84 
85 	tprints("v4l2_fourcc(");
86 	for (i = 0; i < sizeof(u.cc); ++i) {
87 		unsigned int c = u.cc[i];
88 
89 		if (i)
90 			tprints(", ");
91 		if (c == ' ' ||
92 		    (c >= '0' && c <= '9') ||
93 		    (c >= 'A' && c <= 'Z') ||
94 		    (c >= 'a' && c <= 'z')) {
95 			char sym[] = {
96 				'\'',
97 				u.cc[i],
98 				'\''
99 			};
100 			tprints(sym);
101 		} else {
102 			char hex[] = {
103 				'\'',
104 				'\\',
105 				'x',
106 				"0123456789abcdef"[c >> 4],
107 				"0123456789abcdef"[c & 0xf],
108 				'\'',
109 				'\0'
110 			};
111 			tprints(hex);
112 		}
113 	}
114 	tprints(")");
115 }
116 
print_v4l2_format_fmt(const struct v4l2_format * f)117 static void print_v4l2_format_fmt(const struct v4l2_format *f)
118 {
119 	tprints("fmt.");
120 	switch (f->type) {
121 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
122 	case V4L2_BUF_TYPE_VIDEO_OUTPUT: {
123 		const struct v4l2_pix_format *pix = &f->fmt.pix;
124 
125 		tprintf("pix={width=%u, height=%u, pixelformat=",
126 			pix->width, pix->height);
127 		print_pixelformat(pix->pixelformat);
128 		tprints(", field=");
129 		printxval(v4l2_fields, pix->field, "V4L2_FIELD_???");
130 		tprintf(", bytesperline=%u, sizeimage=%u, colorspace=",
131 			pix->bytesperline, pix->sizeimage);
132 		printxval(v4l2_colorspaces, pix->colorspace,
133 			  "V4L2_COLORSPACE_???");
134 		tprints("}");
135 		break;
136 	}
137 #if HAVE_DECL_V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE
138 	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
139 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: {
140 		const struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
141 		unsigned int i, max;
142 
143 		tprintf("pix_mp={width=%u, height=%u, pixelformat=",
144 			pix_mp->width, pix_mp->height);
145 		print_pixelformat(pix_mp->pixelformat);
146 		tprints(", field=");
147 		printxval(v4l2_fields, pix_mp->field, "V4L2_FIELD_???");
148 		tprints(", colorspace=");
149 		printxval(v4l2_colorspaces, pix_mp->colorspace,
150 			  "V4L2_COLORSPACE_???");
151 		tprints("plane_fmt=[");
152 		max = pix_mp->num_planes;
153 		if (max > VIDEO_MAX_PLANES)
154 			max = VIDEO_MAX_PLANES;
155 		for (i = 0; i < max; i++) {
156 			if (i > 0)
157 				tprints(", ");
158 			tprintf("{sizeimage=%u, bytesperline=%u}",
159 				pix_mp->plane_fmt[i].sizeimage,
160 				pix_mp->plane_fmt[i].bytesperline);
161 		}
162 		tprintf("], num_planes=%u}", (unsigned) pix_mp->num_planes);
163 		break;
164 	}
165 #endif
166 
167 	/* TODO: Complete this switch statement */
168 	case V4L2_BUF_TYPE_VIDEO_OVERLAY:
169 #if HAVE_DECL_V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY
170 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
171 #endif
172 		tprints("win={???}");
173 		break;
174 
175 	case V4L2_BUF_TYPE_VBI_CAPTURE:
176 	case V4L2_BUF_TYPE_VBI_OUTPUT:
177 		tprints("vbi={???}");
178 		break;
179 
180 	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
181 	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
182 		tprints("sliced={???}");
183 		break;
184 
185 	default:
186 		tprints("???");
187 		break;
188 	}
189 }
190 
191 int
v4l2_ioctl(struct tcb * tcp,const unsigned int code,long arg)192 v4l2_ioctl(struct tcb *tcp, const unsigned int code, long arg)
193 {
194 	if (!verbose(tcp))
195 		return 0;
196 
197 	switch (code) {
198 	case VIDIOC_QUERYCAP: /* decode on exit */ {
199 		struct v4l2_capability caps;
200 
201 		if (entering(tcp) || syserror(tcp) || umove(tcp, arg, &caps) < 0)
202 			return 0;
203 		tprints(", {driver=");
204 		print_quoted_string((const char *) caps.driver,
205 				    sizeof(caps.driver), QUOTE_0_TERMINATED);
206 		tprints(", card=");
207 		print_quoted_string((const char *) caps.card,
208 				    sizeof(caps.card), QUOTE_0_TERMINATED);
209 		tprints(", bus_info=");
210 		print_quoted_string((const char *) caps.bus_info,
211 				    sizeof(caps.bus_info), QUOTE_0_TERMINATED);
212 		tprintf(", version=%u.%u.%u, capabilities=",
213 			(caps.version >> 16) & 0xFF,
214 			(caps.version >> 8) & 0xFF,
215 			caps.version & 0xFF);
216 		printflags(v4l2_device_capabilities_flags, caps.capabilities,
217 			   "V4L2_CAP_???");
218 #ifdef V4L2_CAP_DEVICE_CAPS
219 		tprints(", device_caps=");
220 		printflags(v4l2_device_capabilities_flags, caps.device_caps,
221 			   "V4L2_CAP_???");
222 #endif
223 		tprints("}");
224 		return 1;
225 	}
226 
227 #ifdef VIDIOC_ENUM_FRAMESIZES
228 	case VIDIOC_ENUM_FRAMESIZES: /* decode on exit */ {
229 		struct v4l2_frmsizeenum s;
230 
231 		if (entering(tcp) || umove(tcp, arg, &s) < 0)
232 			return 0;
233 		tprintf(", {index=%u, pixel_format=", s.index);
234 		print_pixelformat(s.pixel_format);
235 
236 		if (!syserror(tcp)) {
237 			tprints(", type=");
238 			printxval(v4l2_framesize_types, s.type, "V4L2_FRMSIZE_TYPE_???");
239 			switch (s.type) {
240 			case V4L2_FRMSIZE_TYPE_DISCRETE:
241 				tprintf(", discrete={width=%u, height=%u}",
242 					s.discrete.width, s.discrete.height);
243 				break;
244 			case V4L2_FRMSIZE_TYPE_STEPWISE:
245 				tprintf(", stepwise={min_width=%u, max_width=%u, "
246 					"step_width=%u, min_height=%u, max_height=%u, "
247 					"step_height=%u}",
248 					s.stepwise.min_width, s.stepwise.max_width,
249 					s.stepwise.step_width, s.stepwise.min_height,
250 					s.stepwise.max_height, s.stepwise.step_height);
251 				break;
252 			}
253 		}
254 		tprints("}");
255 		return 1;
256 	}
257 #endif /* VIDIOC_ENUM_FRAMESIZES */
258 
259 	case VIDIOC_G_FMT:
260 	case VIDIOC_S_FMT:
261 	case VIDIOC_TRY_FMT: {
262 		struct v4l2_format f;
263 
264 		if (umove(tcp, arg, &f) < 0)
265 			return 0;
266 		if (entering(tcp)) {
267 			tprints(", {type=");
268 			printxval(v4l2_buf_types, f.type, "V4L2_BUF_TYPE_???");
269 		}
270 		if ((entering(tcp) && code != VIDIOC_G_FMT)
271 		    || (exiting(tcp) && !syserror(tcp))) {
272 			tprints(exiting(tcp) && code != VIDIOC_G_FMT ? " => " : ", ");
273 			print_v4l2_format_fmt(&f);
274 		}
275 		if (exiting(tcp))
276 			tprints("}");
277 		return 1;
278 	}
279 
280 	case VIDIOC_ENUM_FMT: {
281 		struct v4l2_fmtdesc f;
282 
283 		if (entering(tcp) || umove(tcp, arg, &f) < 0)
284 			return 0;
285 
286 		tprintf(", {index=%u", f.index);
287 		if (!syserror(tcp)) {
288 			tprints(", type=");
289 			printxval(v4l2_buf_types, f.type, "V4L2_BUF_TYPE_???");
290 			tprints(", flags=");
291 			printflags(v4l2_format_description_flags, f.flags,
292 				   "V4L2_FMT_FLAG_???");
293 			tprints(", description=");
294 			print_quoted_string((const char *) f.description,
295 					    sizeof(f.description),
296 					    QUOTE_0_TERMINATED);
297 			tprints(", pixelformat=");
298 			print_pixelformat(f.pixelformat);
299 		}
300 		tprints("}");
301 		return 1;
302 	}
303 
304 	case VIDIOC_G_PARM:
305 	case VIDIOC_S_PARM: {
306 		struct v4l2_streamparm s;
307 
308 		if (entering(tcp) && code == VIDIOC_G_PARM)
309 			return 1;
310 		if (exiting(tcp) && syserror(tcp))
311 			return code == VIDIOC_S_PARM;
312 		if (umove(tcp, arg, &s) < 0)
313 			return 0;
314 		if (entering(tcp)) {
315 			tprints(", {type=");
316 			printxval(v4l2_buf_types, s.type, "V4L2_BUF_TYPE_???");
317 		}
318 
319 		tprints(exiting(tcp) && code == VIDIOC_S_PARM ? " => {" : ", {");
320 		if (s.type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
321 			struct v4l2_captureparm *cap = &s.parm.capture;
322 
323 			tprints("capability=");
324 			printflags(v4l2_streaming_capabilities,
325 				   cap->capability, "V4L2_CAP_???");
326 
327 			tprints(", capturemode=");
328 			printflags(v4l2_capture_modes,
329 				   cap->capturemode, "V4L2_MODE_???");
330 
331 			tprintf(", timeperframe=" FMT_FRACT,
332 				ARGS_FRACT(cap->timeperframe));
333 
334 			tprintf(", extendedmode=%u, readbuffers=%u",
335 				cap->extendedmode,
336 				cap->readbuffers);
337 		} else
338 			tprints("...");
339 		tprints("}");
340 		if (exiting(tcp))
341 			tprints("}");
342 		return 1;
343 	}
344 
345 	case VIDIOC_QUERYCTRL: {
346 		struct v4l2_queryctrl c;
347 
348 		if (umove(tcp, arg, &c) < 0)
349 			return 0;
350 		/* 'id' field must be printed :
351 		* on enter
352 		* on exit if !syserror(tcp) && V4L2_CTRL_FLAG_NEXT_CTRL was set
353 		*/
354 		if (entering(tcp)
355 		    || (exiting(tcp) && tcp->auxstr && !syserror(tcp))) {
356 			tprints(exiting(tcp) ? " => " : ", {id=");
357 #ifdef V4L2_CTRL_FLAG_NEXT_CTRL
358 			tcp->auxstr = (c.id & V4L2_CTRL_FLAG_NEXT_CTRL) ? "" : NULL;
359 			if (tcp->auxstr) {
360 				tprints("V4L2_CTRL_FLAG_NEXT_CTRL|");
361 				c.id &= ~V4L2_CTRL_FLAG_NEXT_CTRL;
362 			}
363 #endif
364 			printxval(v4l2_control_ids, c.id, "V4L2_CID_???");
365 		}
366 		if (exiting(tcp)) {
367 			if (!syserror(tcp)) {
368 				tprints(", type=");
369 				printxval(v4l2_control_types, c.type,
370 					  "V4L2_CTRL_TYPE_???");
371 				tprints(", name=");
372 				print_quoted_string((const char *) c.name,
373 						    sizeof(c.name),
374 						    QUOTE_0_TERMINATED);
375 				tprintf(", minimum=%i, maximum=%i, step=%i, "
376 					"default_value=%i, flags=",
377 					c.minimum, c.maximum,
378 					c.step, c.default_value);
379 				printflags(v4l2_control_flags, c.flags,
380 					   "V4L2_CTRL_FLAG_???");
381 			}
382 			tprints("}");
383 		}
384 		return 1;
385 	}
386 
387 	case VIDIOC_G_CTRL:
388 	case VIDIOC_S_CTRL: {
389 		struct v4l2_control c;
390 
391 		if (entering(tcp) || umove(tcp, arg, &c) < 0)
392 			return 0;
393 		tprints(", {id=");
394 		printxval(v4l2_control_ids, c.id, "V4L2_CID_???");
395 		if (!syserror(tcp) || code != VIDIOC_G_CTRL)
396 			tprintf(", value=%i", c.value);
397 		tprints("}");
398 		return 1;
399 	}
400 
401 #ifdef VIDIOC_S_EXT_CTRLS
402 	case VIDIOC_S_EXT_CTRLS:
403 	case VIDIOC_TRY_EXT_CTRLS:
404 	case VIDIOC_G_EXT_CTRLS: {
405 		struct v4l2_ext_controls c;
406 		unsigned int n;
407 		bool must_print_values;
408 
409 		if (entering(tcp) && code == VIDIOC_G_EXT_CTRLS)
410 			return 0;
411 		if (exiting(tcp) && syserror(tcp) && code != VIDIOC_G_EXT_CTRLS)
412 			return 0;
413 		must_print_values = ((entering(tcp) && code != VIDIOC_G_EXT_CTRLS)
414 				     || (exiting(tcp) && !syserror(tcp)));
415 		if (umove(tcp, arg, &c) < 0)
416 			return 0;
417 		tprints(code != VIDIOC_G_EXT_CTRLS && exiting(tcp) ? " => " : ", ");
418 		tprints("{ctrl_class=");
419 		printxval(v4l2_control_classes, c.ctrl_class,
420 			  "V4L2_CTRL_CLASS_???");
421 		tprintf(", count=%u", c.count);
422 		if (exiting(tcp) && syserror(tcp))
423 			tprintf(", error_idx=%u", c.error_idx);
424 		tprints(", controls=[");
425 		for (n = 0; n < c.count; ++n) {
426 			struct v4l2_ext_control ctrl;
427 
428 			if (n > 0)
429 				tprints(", ");
430 			if (umove(tcp, (long) (c.controls + n), &ctrl) < 0)
431 				break;
432 			if (abbrev(tcp) && n == 2) {
433 				tprints("...");
434 				break;
435 			}
436 			tprints("{id=");
437 			printxval(v4l2_control_ids, ctrl.id, "V4L2_CID_???");
438 # if HAVE_DECL_V4L2_CTRL_TYPE_STRING
439 			tprintf(", size=%u", ctrl.size);
440 			if (ctrl.size > 0) {
441 				if (must_print_values) {
442 					tprints(", string=");
443 					printstr(tcp, (long) ctrl.string, ctrl.size);
444 				}
445 			} else
446 # endif
447 			{
448 				if (must_print_values) {
449 					tprintf(", value=%i, value64=%lld", ctrl.value,
450 						(long long) ctrl.value64);
451 				}
452 			}
453 			tprints("}");
454 		}
455 		tprints("]}");
456 		return 1;
457 	}
458 #endif /* VIDIOC_S_EXT_CTRLS */
459 
460 	case VIDIOC_ENUMSTD: {
461 		struct v4l2_standard s;
462 
463 		if (umove(tcp, arg, &s) < 0)
464 			return 0;
465 		if (entering(tcp))
466 			tprintf(", {index=%i", s.index);
467 		else {
468 			if (!syserror(tcp)) {
469 				tprints(", name=");
470 				print_quoted_string((const char *) s.name,
471 						    sizeof(s.name),
472 						    QUOTE_0_TERMINATED);
473 				tprintf(", frameperiod=" FMT_FRACT, ARGS_FRACT(s.frameperiod));
474 				tprintf(", framelines=%i", s.framelines);
475 			}
476 			tprints("}");
477 		}
478 		return 1;
479 	}
480 
481 	case VIDIOC_G_STD:
482 	case VIDIOC_S_STD: {
483 		v4l2_std_id s;
484 
485 		if (code == VIDIOC_G_STD && exiting(tcp) && syserror(tcp))
486 			return 0;
487 		if (umove(tcp, arg, &s) < 0)
488 			return 0;
489 		if ((code == VIDIOC_S_STD) == entering(tcp))
490 			tprintf(", std=%#llx", (unsigned long long) s);
491 		return 1;
492 	}
493 
494 	case VIDIOC_ENUMINPUT: {
495 		struct v4l2_input i;
496 
497 		if (entering(tcp) || umove(tcp, arg, &i) < 0)
498 			return 0;
499 		tprintf(", {index=%i", i.index);
500 		if (!syserror(tcp)) {
501 			tprints(", name=");
502 			print_quoted_string((const char *) i.name,
503 					    sizeof(i.name), QUOTE_0_TERMINATED);
504 			tprints(", type=");
505 			printxval(v4l2_input_types, i.type,
506 				  "V4L2_INPUT_TYPE_???");
507 		}
508 		tprints("}");
509 		return 1;
510 	}
511 
512 	case VIDIOC_G_INPUT:
513 	case VIDIOC_S_INPUT: {
514 		int index;
515 
516 		if (entering(tcp) || syserror(tcp) || umove(tcp, arg, &index) < 0)
517 			return 0;
518 
519 		tprintf(", index=%i", index);
520 		return 1;
521 	}
522 
523 #ifdef VIDIOC_ENUM_FRAMEINTERVALS
524 	case VIDIOC_ENUM_FRAMEINTERVALS: {
525 		struct v4l2_frmivalenum f;
526 
527 		if (entering(tcp) || umove(tcp, arg, &f) < 0)
528 			return 0;
529 		tprintf(", {index=%i, pixel_format=", f.index);
530 		print_pixelformat(f.pixel_format);
531 		tprintf(", width=%u, height=%u", f.width, f.height);
532 		if (!syserror(tcp)) {
533 			tprints(", type=");
534 			printxval(v4l2_frameinterval_types, f.type,
535 				  "V4L2_FRMIVAL_TYPE_???");
536 			switch (f.type) {
537 			case V4L2_FRMIVAL_TYPE_DISCRETE:
538 				tprintf(", discrete=" FMT_FRACT,
539 					ARGS_FRACT(f.discrete));
540 				break;
541 			case V4L2_FRMIVAL_TYPE_STEPWISE:
542 			case V4L2_FRMSIZE_TYPE_CONTINUOUS:
543 				tprintf(", stepwise={min=" FMT_FRACT ", max="
544 					FMT_FRACT ", step=" FMT_FRACT "}",
545 					ARGS_FRACT(f.stepwise.min),
546 					ARGS_FRACT(f.stepwise.max),
547 					ARGS_FRACT(f.stepwise.step));
548 				break;
549 			}
550 		}
551 		tprints("}");
552 		return 1;
553 	}
554 #endif /* VIDIOC_ENUM_FRAMEINTERVALS */
555 
556 	case VIDIOC_CROPCAP: {
557 		struct v4l2_cropcap c;
558 
559 		if (entering(tcp) || umove(tcp, arg, &c) < 0)
560 			return 0;
561 		tprints(", {type=");
562 		printxval(v4l2_buf_types, c.type, "V4L2_BUF_TYPE_???");
563 		if (!syserror(tcp))
564 			tprintf(", bounds=" FMT_RECT ", defrect=" FMT_RECT ", "
565 				"pixelaspect=" FMT_FRACT, ARGS_RECT(c.bounds),
566 				ARGS_RECT(c.defrect), ARGS_FRACT(c.pixelaspect));
567 		tprints("}");
568 		return 1;
569 	}
570 
571 	case VIDIOC_S_CROP: {
572 		struct v4l2_crop c;
573 
574 		if (exiting(tcp) || umove(tcp, arg, &c) < 0)
575 			return 0;
576 		tprints(", {type=");
577 		printxval(v4l2_buf_types, c.type, "V4L2_BUF_TYPE_???");
578 		tprintf(", c=" FMT_RECT "}", ARGS_RECT(c.c));
579 		return 1;
580 	}
581 
582 	case VIDIOC_G_FBUF:
583 	case VIDIOC_S_FBUF: {
584 		struct v4l2_framebuffer b;
585 
586 		if (syserror(tcp) && code == VIDIOC_G_FBUF)
587 			return 0;
588 		if (entering(tcp) || umove(tcp, arg, &b) < 0)
589 			return 0;
590 		tprintf(", {capability=%x, flags=%x, base=%p}",
591 			b.capability, b.flags, b.base);
592 		return 1;
593 	}
594 
595 #ifdef VIDIOC_CREATE_BUFS
596 	case VIDIOC_CREATE_BUFS: {
597 		struct v4l2_create_buffers b;
598 
599 		if (exiting(tcp) && syserror(tcp))
600 			return 1;
601 		if (umove(tcp, arg, &b) < 0)
602 			return 0;
603 		if (entering(tcp)) {
604 			tprintf(", {count=%u, memory=", b.count);
605 			printxval(v4l2_memories, b.memory, "V4L2_MEMORY_???");
606 			tprints(", format={type=");
607 			printxval(v4l2_buf_types, b.format.type, "V4L2_BUF_TYPE_???");
608 			tprints(", ");
609 			print_v4l2_format_fmt(&b.format);
610 			tprints("}}");
611 			return 1;
612 		} else {
613 			static const char fmt[] = "{index=%u, count=%u}";
614 			static char outstr[sizeof(fmt) + sizeof(int) * 6];
615 
616 			sprintf(outstr, fmt, b.index, b.count);
617 			tcp->auxstr = outstr;
618 			return 1 + RVAL_STR;
619 		}
620 	}
621 #endif /* VIDIOC_CREATE_BUFS */
622 
623 	case VIDIOC_REQBUFS: {
624 		struct v4l2_requestbuffers reqbufs;
625 
626 		if (umove(tcp, arg, &reqbufs) < 0)
627 			return 0;
628 		if (entering(tcp)) {
629 			tprintf(", {count=%u, type=", reqbufs.count);
630 			printxval(v4l2_buf_types, reqbufs.type, "V4L2_BUF_TYPE_???");
631 			tprints(", memory=");
632 			printxval(v4l2_memories, reqbufs.memory, "V4L2_MEMORY_???");
633 			tprints("}");
634 			return 1;
635 		} else if (syserror(tcp))
636 			return 1;
637 		else {
638 			static char outstr[sizeof("{count=}") + sizeof(int) * 3];
639 
640 			sprintf(outstr, "{count=%u}", reqbufs.count);
641 			tcp->auxstr = outstr;
642 			return 1 + RVAL_STR;
643 		}
644 	}
645 
646 	case VIDIOC_QUERYBUF:
647 	case VIDIOC_QBUF:
648 	case VIDIOC_DQBUF: {
649 		struct v4l2_buffer b;
650 
651 		if (umove(tcp, arg, &b) < 0)
652 			return 0;
653 		if (entering(tcp)) {
654 			tprints(", {type=");
655 			printxval(v4l2_buf_types, b.type, "V4L2_BUF_TYPE_???");
656 			if (code != VIDIOC_DQBUF)
657 				tprintf(", index=%u", b.index);
658 		} else {
659 			if (!syserror(tcp)) {
660 				if (code == VIDIOC_DQBUF)
661 					tprintf(", index=%u", b.index);
662 				tprints(", memory=");
663 				printxval(v4l2_memories, b.memory, "V4L2_MEMORY_???");
664 
665 				if (b.memory == V4L2_MEMORY_MMAP) {
666 					tprintf(", m.offset=%#x", b.m.offset);
667 				} else if (b.memory == V4L2_MEMORY_USERPTR) {
668 					tprintf(", m.userptr=%#lx", b.m.userptr);
669 				}
670 
671 				tprintf(", length=%u, bytesused=%u, flags=",
672 					b.length, b.bytesused);
673 				printflags(v4l2_buf_flags, b.flags, "V4L2_BUF_FLAG_???");
674 				if (code == VIDIOC_DQBUF)
675 					tprintf(", timestamp = {%ju.%06ju}",
676 						(uintmax_t)b.timestamp.tv_sec,
677 						(uintmax_t)b.timestamp.tv_usec);
678 				tprints(", ...");
679 			}
680 			tprints("}");
681 		}
682 		return 1;
683 	}
684 
685 	case VIDIOC_STREAMON:
686 	case VIDIOC_STREAMOFF: {
687 		int type;
688 
689 		if (umove(tcp, arg, &type) < 0)
690 			return 0;
691 		if (entering(tcp)) {
692 			tprints(", ");
693 			printxval(v4l2_buf_types, type, "V4L2_BUF_TYPE_???");
694 		}
695 		return 1;
696 	}
697 
698 	default: /* decode on exit */
699 		return 0;
700 	}
701 }
702