xref: /freebsd/contrib/lib9p/pack.c (revision d7d962ead0b6e5e8a39202d0590022082bf5bfb6)
1 /*
2  * Copyright 2016 Jakub Klama <jceel@FreeBSD.org>
3  * All rights reserved
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted providing that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24  * POSSIBILITY OF SUCH DAMAGE.
25  *
26  */
27 
28 /*
29  * Based on libixp code: ©2007-2010 Kris Maglione <maglione.k at Gmail>
30  */
31 
32 #include <stdlib.h>
33 #include <string.h>
34 #include <assert.h>
35 #include <sys/types.h>
36 #include <sys/param.h>
37 #ifdef __APPLE__
38 # include "apple_endian.h"
39 #else
40 # include <sys/endian.h>
41 #endif
42 #include <sys/uio.h>
43 #include "lib9p.h"
44 #include "lib9p_impl.h"
45 #include "log.h"
46 
47 #define N(ary)          (sizeof(ary) / sizeof(*ary))
48 #define STRING_SIZE(s)  (L9P_WORD + (s != NULL ? (uint16_t)strlen(s) : 0))
49 #define QID_SIZE        (L9P_BYTE + L9P_DWORD + L9P_QWORD)
50 
51 static ssize_t l9p_iov_io(struct l9p_message *, void *, size_t);
52 static inline ssize_t l9p_pu8(struct l9p_message *, uint8_t *);
53 static inline ssize_t l9p_pu16(struct l9p_message *, uint16_t *);
54 static inline ssize_t l9p_pu32(struct l9p_message *, uint32_t *);
55 static inline ssize_t l9p_pu64(struct l9p_message *, uint64_t *);
56 static ssize_t l9p_pustring(struct l9p_message *, char **s);
57 static ssize_t l9p_pustrings(struct l9p_message *, uint16_t *, char **, size_t);
58 static ssize_t l9p_puqid(struct l9p_message *, struct l9p_qid *);
59 static ssize_t l9p_puqids(struct l9p_message *, uint16_t *, struct l9p_qid *q);
60 
61 /*
62  * Transfer data from incoming request, or to outgoing response,
63  * using msg to track position and direction within request/response.
64  *
65  * Returns the number of bytes actually transferred (which is always
66  * just len itself, converted to signed), or -1 if we ran out of space.
67  *
68  * Note that if we return -1, subsequent l9p_iov_io() calls with
69  * the same (and not-reset) msg and len > 0 will also return -1.
70  * This means most users can just check the *last* call for failure.
71  */
72 static ssize_t
73 l9p_iov_io(struct l9p_message *msg, void *buffer, size_t len)
74 {
75 	size_t done = 0;
76 	size_t left = len;
77 
78 	assert(msg != NULL);
79 
80 	if (len == 0)
81 		return (0);
82 
83 	if (msg->lm_cursor_iov >= msg->lm_niov)
84 		return (-1);
85 
86 	assert(buffer != NULL);
87 
88 	while (left > 0) {
89 		size_t idx = msg->lm_cursor_iov;
90 		size_t space = msg->lm_iov[idx].iov_len - msg->lm_cursor_offset;
91 		size_t towrite = MIN(space, left);
92 
93 		if (msg->lm_mode == L9P_PACK) {
94 			memcpy((char *)msg->lm_iov[idx].iov_base +
95 			    msg->lm_cursor_offset, (char *)buffer + done,
96 			    towrite);
97 		}
98 
99 		if (msg->lm_mode == L9P_UNPACK) {
100 			memcpy((char *)buffer + done,
101 			    (char *)msg->lm_iov[idx].iov_base +
102 			    msg->lm_cursor_offset, towrite);
103 		}
104 
105 		msg->lm_cursor_offset += towrite;
106 
107 		done += towrite;
108 		left -= towrite;
109 
110 		if (space - towrite == 0) {
111 			/* Advance to next iov */
112 			msg->lm_cursor_iov++;
113 			msg->lm_cursor_offset = 0;
114 
115 			if (msg->lm_cursor_iov >= msg->lm_niov && left > 0)
116 				return (-1);
117 		}
118 	}
119 
120 	msg->lm_size += done;
121 	return ((ssize_t)done);
122 }
123 
124 /*
125  * Pack or unpack a byte (8 bits).
126  *
127  * Returns 1 (success, 1 byte) or -1 (error).
128  */
129 static inline ssize_t
130 l9p_pu8(struct l9p_message *msg, uint8_t *val)
131 {
132 
133 	return (l9p_iov_io(msg, val, sizeof (uint8_t)));
134 }
135 
136 /*
137  * Pack or unpack 16-bit value.
138  *
139  * Returns 2 or -1.
140  */
141 static inline ssize_t
142 l9p_pu16(struct l9p_message *msg, uint16_t *val)
143 {
144 #if _BYTE_ORDER != _LITTLE_ENDIAN
145 	/*
146 	 * The ifdefs are annoying, but there is no need
147 	 * for all of this foolery on little-endian hosts,
148 	 * and I don't expect the compiler to optimize it
149 	 * all away.
150 	 */
151 	uint16_t copy;
152 	ssize_t ret;
153 
154 	if (msg->lm_mode == L9P_PACK) {
155 		copy = htole16(*val);
156 		return (l9p_iov_io(msg, &copy, sizeof (uint16_t)));
157 	}
158 	ret = l9p_iov_io(msg, val, sizeof (uint16_t));
159 	*val = le16toh(*val);
160 	return (ret);
161 #else
162 	return (l9p_iov_io(msg, val, sizeof (uint16_t)));
163 #endif
164 }
165 
166 /*
167  * Pack or unpack 32-bit value.
168  *
169  * Returns 4 or -1.
170  */
171 static inline ssize_t
172 l9p_pu32(struct l9p_message *msg, uint32_t *val)
173 {
174 #if _BYTE_ORDER != _LITTLE_ENDIAN
175 	uint32_t copy;
176 	ssize_t ret;
177 
178 	if (msg->lm_mode == L9P_PACK) {
179 		copy = htole32(*val);
180 		return (l9p_iov_io(msg, &copy, sizeof (uint32_t)));
181 	}
182 	ret = l9p_iov_io(msg, val, sizeof (uint32_t));
183 	*val = le32toh(*val);
184 	return (ret);
185 #else
186 	return (l9p_iov_io(msg, val, sizeof (uint32_t)));
187 #endif
188 }
189 
190 /*
191  * Pack or unpack 64-bit value.
192  *
193  * Returns 8 or -1.
194  */
195 static inline ssize_t
196 l9p_pu64(struct l9p_message *msg, uint64_t *val)
197 {
198 #if _BYTE_ORDER != _LITTLE_ENDIAN
199 	uint64_t copy;
200 	ssize_t ret;
201 
202 	if (msg->lm_mode == L9P_PACK) {
203 		copy = htole64(*val);
204 		return (l9p_iov_io(msg, &copy, sizeof (uint64_t)));
205 	}
206 	ret = l9p_iov_io(msg, val, sizeof (uint32_t));
207 	*val = le64toh(*val);
208 	return (ret);
209 #else
210 	return (l9p_iov_io(msg, val, sizeof (uint64_t)));
211 #endif
212 }
213 
214 /*
215  * Pack or unpack a string, encoded as 2-byte length followed by
216  * string bytes.  The returned length is 2 greater than the
217  * length of the string itself.
218  *
219  * When unpacking, this allocates a new string (NUL-terminated).
220  *
221  * Return -1 on error (not space, or failed to allocate string,
222  * or illegal string).
223  *
224  * Note that pustring (and hence pustrings) can return an error
225  * even when l9p_iov_io succeeds.
226  */
227 static ssize_t
228 l9p_pustring(struct l9p_message *msg, char **s)
229 {
230 	uint16_t len;
231 
232 	if (msg->lm_mode == L9P_PACK)
233 		len = *s != NULL ? (uint16_t)strlen(*s) : 0;
234 
235 	if (l9p_pu16(msg, &len) < 0)
236 		return (-1);
237 
238 	if (msg->lm_mode == L9P_UNPACK) {
239 		*s = l9p_calloc(1, len + 1);
240 		if (*s == NULL)
241 			return (-1);
242 	}
243 
244 	if (l9p_iov_io(msg, *s, len) < 0)
245 		return (-1);
246 
247 	if (msg->lm_mode == L9P_UNPACK) {
248 		/*
249 		 * An embedded NUL byte in a string is illegal.
250 		 * We don't necessarily have to check (we'll just
251 		 * treat it as a shorter string), but checking
252 		 * seems like a good idea.
253 		 */
254 		if (memchr(*s, '\0', len) != NULL)
255 			return (-1);
256 	}
257 
258 	return ((ssize_t)len + 2);
259 }
260 
261 /*
262  * Pack or unpack a number (*num) of strings (but at most max of
263  * them).
264  *
265  * Returns the number of bytes transferred, including the packed
266  * number of strings.  If packing and the packed number of strings
267  * was reduced, the original *num value is unchanged; only the
268  * wire-format number is reduced.  If unpacking and the input
269  * number of strings exceeds the max, the incoming *num is reduced
270  * to lim, if needed.  (NOTE ASYMMETRY HERE!)
271  *
272  * Returns -1 on error.
273  */
274 static ssize_t
275 l9p_pustrings(struct l9p_message *msg, uint16_t *num, char **strings,
276     size_t max)
277 {
278 	size_t i, lim;
279 	ssize_t r, ret;
280 	uint16_t adjusted;
281 
282 	if (msg->lm_mode == L9P_PACK) {
283 		lim = *num;
284 		if (lim > max)
285 			lim = max;
286 		adjusted = (uint16_t)lim;
287 		r = l9p_pu16(msg, &adjusted);
288 	} else {
289 		r = l9p_pu16(msg, num);
290 		lim = *num;
291 		if (lim > max)
292 			*num = (uint16_t)(lim = max);
293 	}
294 	if (r < 0)
295 		return (-1);
296 
297 	for (i = 0; i < lim; i++) {
298 		ret = l9p_pustring(msg, &strings[i]);
299 		if (ret < 1)
300 			return (-1);
301 
302 		r += ret;
303 	}
304 
305 	return (r);
306 }
307 
308 /*
309  * Pack or unpack a qid.
310  *
311  * Returns 13 (success) or -1 (error).
312  */
313 static ssize_t
314 l9p_puqid(struct l9p_message *msg, struct l9p_qid *qid)
315 {
316 	ssize_t r;
317 	uint8_t type;
318 
319 	if (msg->lm_mode == L9P_PACK) {
320 		type = qid->type;
321 		r = l9p_pu8(msg, &type);
322 	} else {
323 		r = l9p_pu8(msg, &type);
324 		qid->type = type;
325 	}
326 	if (r > 0)
327 		r = l9p_pu32(msg, &qid->version);
328 	if (r > 0)
329 		r = l9p_pu64(msg, &qid->path);
330 
331 	return (r > 0 ? QID_SIZE : r);
332 }
333 
334 /*
335  * Pack or unpack *num qids.
336  *
337  * Returns 2 + 13 * *num (after possibly setting *num), or -1 on error.
338  */
339 static ssize_t
340 l9p_puqids(struct l9p_message *msg, uint16_t *num, struct l9p_qid *qids)
341 {
342 	size_t i, lim;
343 	ssize_t ret, r;
344 
345 	r = l9p_pu16(msg, num);
346 	if (r > 0) {
347 		for (i = 0, lim = *num; i < lim; i++) {
348 			ret = l9p_puqid(msg, &qids[i]);
349 			if (ret < 0)
350 				return (-1);
351 			r += ret;
352 		}
353 	}
354 	return (r);
355 }
356 
357 /*
358  * Pack or unpack a l9p_stat.
359  *
360  * These have variable size, and the size further depends on
361  * the protocol version.
362  *
363  * Returns the number of bytes packed/unpacked, or -1 on error.
364  */
365 ssize_t
366 l9p_pustat(struct l9p_message *msg, struct l9p_stat *stat,
367     enum l9p_version version)
368 {
369 	ssize_t r = 0;
370 	uint16_t size;
371 
372 	/* The on-wire size field excludes the size of the size field. */
373 	if (msg->lm_mode == L9P_PACK)
374 		size = l9p_sizeof_stat(stat, version) - 2;
375 
376 	r += l9p_pu16(msg, &size);
377 	r += l9p_pu16(msg, &stat->type);
378 	r += l9p_pu32(msg, &stat->dev);
379 	r += l9p_puqid(msg, &stat->qid);
380 	r += l9p_pu32(msg, &stat->mode);
381 	r += l9p_pu32(msg, &stat->atime);
382 	r += l9p_pu32(msg, &stat->mtime);
383 	r += l9p_pu64(msg, &stat->length);
384 	r += l9p_pustring(msg, &stat->name);
385 	r += l9p_pustring(msg, &stat->uid);
386 	r += l9p_pustring(msg, &stat->gid);
387 	r += l9p_pustring(msg, &stat->muid);
388 
389 	if (version >= L9P_2000U) {
390 		r += l9p_pustring(msg, &stat->extension);
391 		r += l9p_pu32(msg, &stat->n_uid);
392 		r += l9p_pu32(msg, &stat->n_gid);
393 		r += l9p_pu32(msg, &stat->n_muid);
394 	}
395 
396 	if (r < size + 2)
397 		return (-1);
398 
399 	return (r);
400 }
401 
402 /*
403  * Pack or unpack a variable-length dirent.
404  *
405  * If unpacking, the name field is malloc()ed and the caller must
406  * free it.
407  *
408  * Returns the wire-format length, or -1 if we ran out of room.
409  */
410 ssize_t
411 l9p_pudirent(struct l9p_message *msg, struct l9p_dirent *de)
412 {
413 	ssize_t r, s;
414 
415 	r = l9p_puqid(msg, &de->qid);
416 	r += l9p_pu64(msg, &de->offset);
417 	r += l9p_pu8(msg, &de->type);
418 	s = l9p_pustring(msg, &de->name);
419 	if (r < QID_SIZE + 8 + 1 || s < 0)
420 		return (-1);
421 	return (r + s);
422 }
423 
424 /*
425  * Pack or unpack a request or response (fcall).
426  *
427  * Returns 0 on success, -1 on error.  (It's up to the caller
428  * to call l9p_freefcall on our failure.)
429  */
430 int
431 l9p_pufcall(struct l9p_message *msg, union l9p_fcall *fcall,
432     enum l9p_version version)
433 {
434 	uint32_t length = 0;
435 	ssize_t r;
436 
437 	/*
438 	 * Get overall length, type, and tag, which should appear
439 	 * in all messages.  If not even that works, abort immediately.
440 	 */
441 	l9p_pu32(msg, &length);
442 	l9p_pu8(msg, &fcall->hdr.type);
443 	r = l9p_pu16(msg, &fcall->hdr.tag);
444 	if (r < 0)
445 		return (-1);
446 
447 	/*
448 	 * Decode remainder of message.	 When unpacking, this may
449 	 * allocate memory, even if we fail during the decode.
450 	 * Note that the initial fcall is zeroed out, though, so
451 	 * we can just freefcall() to release whatever might have
452 	 * gotten allocated, if the unpack fails due to a short
453 	 * packet.
454 	 */
455 	switch (fcall->hdr.type) {
456 	case L9P_TVERSION:
457 	case L9P_RVERSION:
458 		l9p_pu32(msg, &fcall->version.msize);
459 		r = l9p_pustring(msg, &fcall->version.version);
460 		break;
461 
462 	case L9P_TAUTH:
463 		l9p_pu32(msg, &fcall->tauth.afid);
464 		r = l9p_pustring(msg, &fcall->tauth.uname);
465 		if (r < 0)
466 			break;
467 		r = l9p_pustring(msg, &fcall->tauth.aname);
468 		if (r < 0)
469 			break;
470 		if (version >= L9P_2000U)
471 			r = l9p_pu32(msg, &fcall->tauth.n_uname);
472 		break;
473 
474 	case L9P_RAUTH:
475 		r = l9p_puqid(msg, &fcall->rauth.aqid);
476 		break;
477 
478 	case L9P_TATTACH:
479 		l9p_pu32(msg, &fcall->hdr.fid);
480 		l9p_pu32(msg, &fcall->tattach.afid);
481 		r = l9p_pustring(msg, &fcall->tattach.uname);
482 		if (r < 0)
483 			break;
484 		r = l9p_pustring(msg, &fcall->tattach.aname);
485 		if (r < 0)
486 			break;
487 		if (version >= L9P_2000U)
488 			r = l9p_pu32(msg, &fcall->tattach.n_uname);
489 		break;
490 
491 	case L9P_RATTACH:
492 		r = l9p_puqid(msg, &fcall->rattach.qid);
493 		break;
494 
495 	case L9P_RERROR:
496 		r = l9p_pustring(msg, &fcall->error.ename);
497 		if (r < 0)
498 			break;
499 		if (version >= L9P_2000U)
500 			r = l9p_pu32(msg, &fcall->error.errnum);
501 		break;
502 
503 	case L9P_RLERROR:
504 		r = l9p_pu32(msg, &fcall->error.errnum);
505 		break;
506 
507 	case L9P_TFLUSH:
508 		r = l9p_pu16(msg, &fcall->tflush.oldtag);
509 		break;
510 
511 	case L9P_RFLUSH:
512 		break;
513 
514 	case L9P_TWALK:
515 		l9p_pu32(msg, &fcall->hdr.fid);
516 		l9p_pu32(msg, &fcall->twalk.newfid);
517 		r = l9p_pustrings(msg, &fcall->twalk.nwname,
518 		    fcall->twalk.wname, N(fcall->twalk.wname));
519 		break;
520 
521 	case L9P_RWALK:
522 		r = l9p_puqids(msg, &fcall->rwalk.nwqid, fcall->rwalk.wqid);
523 		break;
524 
525 	case L9P_TOPEN:
526 		l9p_pu32(msg, &fcall->hdr.fid);
527 		r = l9p_pu8(msg, &fcall->topen.mode);
528 		break;
529 
530 	case L9P_ROPEN:
531 		l9p_puqid(msg, &fcall->ropen.qid);
532 		r = l9p_pu32(msg, &fcall->ropen.iounit);
533 		break;
534 
535 	case L9P_TCREATE:
536 		l9p_pu32(msg, &fcall->hdr.fid);
537 		r = l9p_pustring(msg, &fcall->tcreate.name);
538 		if (r < 0)
539 			break;
540 		l9p_pu32(msg, &fcall->tcreate.perm);
541 		r = l9p_pu8(msg, &fcall->tcreate.mode);
542 		if (version >= L9P_2000U)
543 			r = l9p_pustring(msg, &fcall->tcreate.extension);
544 		break;
545 
546 	case L9P_RCREATE:
547 		l9p_puqid(msg, &fcall->rcreate.qid);
548 		r = l9p_pu32(msg, &fcall->rcreate.iounit);
549 		break;
550 
551 	case L9P_TREAD:
552 	case L9P_TREADDIR:
553 		l9p_pu32(msg, &fcall->hdr.fid);
554 		l9p_pu64(msg, &fcall->io.offset);
555 		r = l9p_pu32(msg, &fcall->io.count);
556 		break;
557 
558 	case L9P_RREAD:
559 	case L9P_RREADDIR:
560 		r = l9p_pu32(msg, &fcall->io.count);
561 		break;
562 
563 	case L9P_TWRITE:
564 		l9p_pu32(msg, &fcall->hdr.fid);
565 		l9p_pu64(msg, &fcall->io.offset);
566 		r = l9p_pu32(msg, &fcall->io.count);
567 		break;
568 
569 	case L9P_RWRITE:
570 		r = l9p_pu32(msg, &fcall->io.count);
571 		break;
572 
573 	case L9P_TCLUNK:
574 	case L9P_TSTAT:
575 	case L9P_TREMOVE:
576 	case L9P_TSTATFS:
577 		r = l9p_pu32(msg, &fcall->hdr.fid);
578 		break;
579 
580 	case L9P_RCLUNK:
581 	case L9P_RREMOVE:
582 		break;
583 
584 	case L9P_RSTAT:
585 	{
586 		uint16_t size = l9p_sizeof_stat(&fcall->rstat.stat,
587 		    version);
588 		l9p_pu16(msg, &size);
589 		r = l9p_pustat(msg, &fcall->rstat.stat, version);
590 	}
591 		break;
592 
593 	case L9P_TWSTAT:
594 	{
595 		uint16_t size;
596 		l9p_pu32(msg, &fcall->hdr.fid);
597 		l9p_pu16(msg, &size);
598 		r = l9p_pustat(msg, &fcall->twstat.stat, version);
599 	}
600 		break;
601 
602 	case L9P_RWSTAT:
603 		break;
604 
605 	case L9P_RSTATFS:
606 		l9p_pu32(msg, &fcall->rstatfs.statfs.type);
607 		l9p_pu32(msg, &fcall->rstatfs.statfs.bsize);
608 		l9p_pu64(msg, &fcall->rstatfs.statfs.blocks);
609 		l9p_pu64(msg, &fcall->rstatfs.statfs.bfree);
610 		l9p_pu64(msg, &fcall->rstatfs.statfs.bavail);
611 		l9p_pu64(msg, &fcall->rstatfs.statfs.files);
612 		l9p_pu64(msg, &fcall->rstatfs.statfs.ffree);
613 		l9p_pu64(msg, &fcall->rstatfs.statfs.fsid);
614 		r = l9p_pu32(msg, &fcall->rstatfs.statfs.namelen);
615 		break;
616 
617 	case L9P_TLOPEN:
618 		l9p_pu32(msg, &fcall->hdr.fid);
619 		r = l9p_pu32(msg, &fcall->tlopen.flags);
620 		break;
621 
622 	case L9P_RLOPEN:
623 		l9p_puqid(msg, &fcall->rlopen.qid);
624 		r = l9p_pu32(msg, &fcall->rlopen.iounit);
625 		break;
626 
627 	case L9P_TLCREATE:
628 		l9p_pu32(msg, &fcall->hdr.fid);
629 		r = l9p_pustring(msg, &fcall->tlcreate.name);
630 		if (r < 0)
631 			break;
632 		l9p_pu32(msg, &fcall->tlcreate.flags);
633 		l9p_pu32(msg, &fcall->tlcreate.mode);
634 		r = l9p_pu32(msg, &fcall->tlcreate.gid);
635 		break;
636 
637 	case L9P_RLCREATE:
638 		l9p_puqid(msg, &fcall->rlcreate.qid);
639 		r = l9p_pu32(msg, &fcall->rlcreate.iounit);
640 		break;
641 
642 	case L9P_TSYMLINK:
643 		l9p_pu32(msg, &fcall->hdr.fid);
644 		r = l9p_pustring(msg, &fcall->tsymlink.name);
645 		if (r < 0)
646 			break;
647 		r = l9p_pustring(msg, &fcall->tsymlink.symtgt);
648 		if (r < 0)
649 			break;
650 		r = l9p_pu32(msg, &fcall->tlcreate.gid);
651 		break;
652 
653 	case L9P_RSYMLINK:
654 		r = l9p_puqid(msg, &fcall->rsymlink.qid);
655 		break;
656 
657 	case L9P_TMKNOD:
658 		l9p_pu32(msg, &fcall->hdr.fid);
659 		r = l9p_pustring(msg, &fcall->tmknod.name);
660 		if (r < 0)
661 			break;
662 		l9p_pu32(msg, &fcall->tmknod.mode);
663 		l9p_pu32(msg, &fcall->tmknod.major);
664 		l9p_pu32(msg, &fcall->tmknod.minor);
665 		r = l9p_pu32(msg, &fcall->tmknod.gid);
666 		break;
667 
668 	case L9P_RMKNOD:
669 		r = l9p_puqid(msg, &fcall->rmknod.qid);
670 		break;
671 
672 	case L9P_TRENAME:
673 		l9p_pu32(msg, &fcall->hdr.fid);
674 		l9p_pu32(msg, &fcall->trename.dfid);
675 		r = l9p_pustring(msg, &fcall->trename.name);
676 		break;
677 
678 	case L9P_RRENAME:
679 		break;
680 
681 	case L9P_TREADLINK:
682 		r = l9p_pu32(msg, &fcall->hdr.fid);
683 		break;
684 
685 	case L9P_RREADLINK:
686 		r = l9p_pustring(msg, &fcall->rreadlink.target);
687 		break;
688 
689 	case L9P_TGETATTR:
690 		l9p_pu32(msg, &fcall->hdr.fid);
691 		r = l9p_pu64(msg, &fcall->tgetattr.request_mask);
692 		break;
693 
694 	case L9P_RGETATTR:
695 		l9p_pu64(msg, &fcall->rgetattr.valid);
696 		l9p_puqid(msg, &fcall->rgetattr.qid);
697 		l9p_pu32(msg, &fcall->rgetattr.mode);
698 		l9p_pu32(msg, &fcall->rgetattr.uid);
699 		l9p_pu32(msg, &fcall->rgetattr.gid);
700 		l9p_pu64(msg, &fcall->rgetattr.nlink);
701 		l9p_pu64(msg, &fcall->rgetattr.rdev);
702 		l9p_pu64(msg, &fcall->rgetattr.size);
703 		l9p_pu64(msg, &fcall->rgetattr.blksize);
704 		l9p_pu64(msg, &fcall->rgetattr.blocks);
705 		l9p_pu64(msg, &fcall->rgetattr.atime_sec);
706 		l9p_pu64(msg, &fcall->rgetattr.atime_nsec);
707 		l9p_pu64(msg, &fcall->rgetattr.mtime_sec);
708 		l9p_pu64(msg, &fcall->rgetattr.mtime_nsec);
709 		l9p_pu64(msg, &fcall->rgetattr.ctime_sec);
710 		l9p_pu64(msg, &fcall->rgetattr.ctime_nsec);
711 		l9p_pu64(msg, &fcall->rgetattr.btime_sec);
712 		l9p_pu64(msg, &fcall->rgetattr.btime_nsec);
713 		l9p_pu64(msg, &fcall->rgetattr.gen);
714 		r = l9p_pu64(msg, &fcall->rgetattr.data_version);
715 		break;
716 
717 	case L9P_TSETATTR:
718 		l9p_pu32(msg, &fcall->hdr.fid);
719 		l9p_pu32(msg, &fcall->tsetattr.valid);
720 		l9p_pu32(msg, &fcall->tsetattr.mode);
721 		l9p_pu32(msg, &fcall->tsetattr.uid);
722 		l9p_pu32(msg, &fcall->tsetattr.gid);
723 		l9p_pu64(msg, &fcall->tsetattr.size);
724 		l9p_pu64(msg, &fcall->tsetattr.atime_sec);
725 		l9p_pu64(msg, &fcall->tsetattr.atime_nsec);
726 		l9p_pu64(msg, &fcall->tsetattr.mtime_sec);
727 		r = l9p_pu64(msg, &fcall->tsetattr.mtime_nsec);
728 		break;
729 
730 	case L9P_RSETATTR:
731 		break;
732 
733 	case L9P_TXATTRWALK:
734 		l9p_pu32(msg, &fcall->hdr.fid);
735 		l9p_pu32(msg, &fcall->txattrwalk.newfid);
736 		r = l9p_pustring(msg, &fcall->txattrwalk.name);
737 		break;
738 
739 	case L9P_RXATTRWALK:
740 		r = l9p_pu64(msg, &fcall->rxattrwalk.size);
741 		break;
742 
743 	case L9P_TXATTRCREATE:
744 		l9p_pu32(msg, &fcall->hdr.fid);
745 		r = l9p_pustring(msg, &fcall->txattrcreate.name);
746 		if (r < 0)
747 			break;
748 		l9p_pu64(msg, &fcall->txattrcreate.attr_size);
749 		r = l9p_pu32(msg, &fcall->txattrcreate.flags);
750 		break;
751 
752 	case L9P_RXATTRCREATE:
753 		break;
754 
755 	case L9P_TFSYNC:
756 		r = l9p_pu32(msg, &fcall->hdr.fid);
757 		break;
758 
759 	case L9P_RFSYNC:
760 		break;
761 
762 	case L9P_TLOCK:
763 		l9p_pu32(msg, &fcall->hdr.fid);
764 		l9p_pu8(msg, &fcall->tlock.type);
765 		l9p_pu32(msg, &fcall->tlock.flags);
766 		l9p_pu64(msg, &fcall->tlock.start);
767 		l9p_pu64(msg, &fcall->tlock.length);
768 		l9p_pu32(msg, &fcall->tlock.proc_id);
769 		r = l9p_pustring(msg, &fcall->tlock.client_id);
770 		break;
771 
772 	case L9P_RLOCK:
773 		r = l9p_pu8(msg, &fcall->rlock.status);
774 		break;
775 
776 	case L9P_TGETLOCK:
777 		l9p_pu32(msg, &fcall->hdr.fid);
778 		/* FALLTHROUGH */
779 
780 	case L9P_RGETLOCK:
781 		l9p_pu8(msg, &fcall->getlock.type);
782 		l9p_pu64(msg, &fcall->getlock.start);
783 		l9p_pu64(msg, &fcall->getlock.length);
784 		l9p_pu32(msg, &fcall->getlock.proc_id);
785 		r = l9p_pustring(msg, &fcall->getlock.client_id);
786 		break;
787 
788 	case L9P_TLINK:
789 		l9p_pu32(msg, &fcall->tlink.dfid);
790 		l9p_pu32(msg, &fcall->hdr.fid);
791 		r = l9p_pustring(msg, &fcall->tlink.name);
792 		break;
793 
794 	case L9P_RLINK:
795 		break;
796 
797 	case L9P_TMKDIR:
798 		l9p_pu32(msg, &fcall->hdr.fid);
799 		r = l9p_pustring(msg, &fcall->tmkdir.name);
800 		if (r < 0)
801 			break;
802 		l9p_pu32(msg, &fcall->tmkdir.mode);
803 		r = l9p_pu32(msg, &fcall->tmkdir.gid);
804 		break;
805 
806 	case L9P_RMKDIR:
807 		r = l9p_puqid(msg, &fcall->rmkdir.qid);
808 		break;
809 
810 	case L9P_TRENAMEAT:
811 		l9p_pu32(msg, &fcall->hdr.fid);
812 		r = l9p_pustring(msg, &fcall->trenameat.oldname);
813 		if (r < 0)
814 			break;
815 		l9p_pu32(msg, &fcall->trenameat.newdirfid);
816 		r = l9p_pustring(msg, &fcall->trenameat.newname);
817 		break;
818 
819 	case L9P_RRENAMEAT:
820 		break;
821 
822 	case L9P_TUNLINKAT:
823 		l9p_pu32(msg, &fcall->hdr.fid);
824 		r = l9p_pustring(msg, &fcall->tunlinkat.name);
825 		if (r < 0)
826 			break;
827 		r = l9p_pu32(msg, &fcall->tunlinkat.flags);
828 		break;
829 
830 	case L9P_RUNLINKAT:
831 		break;
832 
833 	default:
834 		L9P_LOG(L9P_ERROR, "%s(): missing case for type %d",
835 		    __func__, fcall->hdr.type);
836 		break;
837 	}
838 
839 	/* Check for over- or under-run, or pustring error. */
840 	if (r < 0)
841 		return (-1);
842 
843 	if (msg->lm_mode == L9P_PACK) {
844 		/* Rewind to the beginning and install size at front. */
845 		uint32_t len = (uint32_t)msg->lm_size;
846 		msg->lm_cursor_offset = 0;
847 		msg->lm_cursor_iov = 0;
848 
849 		/*
850 		 * Subtract 4 bytes from current size, becase we're
851 		 * overwriting size (rewinding message to the beginning)
852 		 * and writing again, which will increase it 4 more.
853 		 */
854 		msg->lm_size -= sizeof(uint32_t);
855 
856 		if (fcall->hdr.type == L9P_RREAD ||
857 		    fcall->hdr.type == L9P_RREADDIR)
858 			len += fcall->io.count;
859 
860 		l9p_pu32(msg, &len);
861 	}
862 
863 	return (0);
864 }
865 
866 /*
867  * Free any strings or other data malloc'ed in the process of
868  * packing or unpacking an fcall.
869  */
870 void
871 l9p_freefcall(union l9p_fcall *fcall)
872 {
873 	uint16_t i;
874 
875 	switch (fcall->hdr.type) {
876 
877 	case L9P_TVERSION:
878 	case L9P_RVERSION:
879 		free(fcall->version.version);
880 		return;
881 
882 	case L9P_TATTACH:
883 		free(fcall->tattach.aname);
884 		free(fcall->tattach.uname);
885 		return;
886 
887 	case L9P_TWALK:
888 		for (i = 0; i < fcall->twalk.nwname; i++)
889 			free(fcall->twalk.wname[i]);
890 		return;
891 
892 	case L9P_TCREATE:
893 	case L9P_TOPEN:
894 		free(fcall->tcreate.name);
895 		free(fcall->tcreate.extension);
896 		return;
897 
898 	case L9P_RSTAT:
899 		l9p_freestat(&fcall->rstat.stat);
900 		return;
901 
902 	case L9P_TWSTAT:
903 		l9p_freestat(&fcall->twstat.stat);
904 		return;
905 
906 	case L9P_TLCREATE:
907 		free(fcall->tlcreate.name);
908 		return;
909 
910 	case L9P_TSYMLINK:
911 		free(fcall->tsymlink.name);
912 		free(fcall->tsymlink.symtgt);
913 		return;
914 
915 	case L9P_TMKNOD:
916 		free(fcall->tmknod.name);
917 		return;
918 
919 	case L9P_TRENAME:
920 		free(fcall->trename.name);
921 		return;
922 
923 	case L9P_RREADLINK:
924 		free(fcall->rreadlink.target);
925 		return;
926 
927 	case L9P_TXATTRWALK:
928 		free(fcall->txattrwalk.name);
929 		return;
930 
931 	case L9P_TXATTRCREATE:
932 		free(fcall->txattrcreate.name);
933 		return;
934 
935 	case L9P_TLOCK:
936 		free(fcall->tlock.client_id);
937 		return;
938 
939 	case L9P_TGETLOCK:
940 	case L9P_RGETLOCK:
941 		free(fcall->getlock.client_id);
942 		return;
943 
944 	case L9P_TLINK:
945 		free(fcall->tlink.name);
946 		return;
947 
948 	case L9P_TMKDIR:
949 		free(fcall->tmkdir.name);
950 		return;
951 
952 	case L9P_TRENAMEAT:
953 		free(fcall->trenameat.oldname);
954 		free(fcall->trenameat.newname);
955 		return;
956 
957 	case L9P_TUNLINKAT:
958 		free(fcall->tunlinkat.name);
959 		return;
960 	}
961 }
962 
963 void
964 l9p_freestat(struct l9p_stat *stat)
965 {
966 	free(stat->name);
967 	free(stat->extension);
968 	free(stat->uid);
969 	free(stat->gid);
970 	free(stat->muid);
971 }
972 
973 uint16_t
974 l9p_sizeof_stat(struct l9p_stat *stat, enum l9p_version version)
975 {
976 	uint16_t size = L9P_WORD /* size */
977 	    + L9P_WORD /* type */
978 	    + L9P_DWORD /* dev */
979 	    + QID_SIZE /* qid */
980 	    + 3 * L9P_DWORD /* mode, atime, mtime */
981 	    + L9P_QWORD /* length */
982 	    + STRING_SIZE(stat->name)
983 	    + STRING_SIZE(stat->uid)
984 	    + STRING_SIZE(stat->gid)
985 	    + STRING_SIZE(stat->muid);
986 
987 	if (version >= L9P_2000U) {
988 		size += STRING_SIZE(stat->extension)
989 		    + 3 * L9P_DWORD;
990 	}
991 
992 	return (size);
993 }
994