xref: /netbsd-src/usr.sbin/puffs/mount_9p/node.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: node.c,v 1.29 2020/06/01 13:30:52 uwe Exp $	*/
2 
3 /*
4  * Copyright (c) 2007  Antti Kantee.  All Rights Reserved.
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  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 #ifndef lint
30 __RCSID("$NetBSD: node.c,v 1.29 2020/06/01 13:30:52 uwe Exp $");
31 #endif /* !lint */
32 
33 #include <assert.h>
34 #include <errno.h>
35 #include <puffs.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 
39 #include "ninepuffs.h"
40 #include "nineproto.h"
41 
42 static void *
43 nodecmp(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
44 {
45 	struct vattr *vap = &pn->pn_va;
46 	struct qid9p *qid = arg;
47 
48 	if (vap->va_fileid == qid->qidpath && vap->va_gen == qid->qidvers)
49 		return pn;
50 
51 	return NULL;
52 }
53 
54 static int
55 do_getattr(struct puffs_usermount *pu, struct puffs_node *pn, struct vattr *vap)
56 {
57 	AUTOVAR(pu);
58 	struct p9pnode *p9n = pn->pn_data;
59 
60 	tag = NEXTTAG(p9p);
61 	p9pbuf_put_1(pb, P9PROTO_T_STAT);
62 	p9pbuf_put_2(pb, tag);
63 	p9pbuf_put_4(pb, p9n->fid_base);
64 	GETRESPONSE(pb);
65 
66 	if (p9pbuf_get_type(pb) != P9PROTO_R_STAT) {
67 		rv = proto_handle_rerror(pu, pb);
68 		goto out;
69 	}
70 	rv = proto_expect_stat(pu, pb, vap);
71 
72  out:
73 	RETURN(rv);
74 }
75 
76 int
77 puffs9p_node_getattr(struct puffs_usermount *pu, void *opc, struct vattr *vap,
78 	const struct puffs_cred *pcr)
79 {
80 	struct puffs_node *pn = opc;
81 	int rv;
82 
83 	rv = do_getattr(pu, pn, &pn->pn_va);
84 	if (rv == 0)
85 		memcpy(vap, &pn->pn_va, sizeof(struct vattr));
86 	return rv;
87 }
88 
89 int
90 puffs9p_node_lookup(struct puffs_usermount *pu, void *opc, struct puffs_newinfo *pni,
91 	const struct puffs_cn *pcn)
92 {
93 	AUTOVAR(pu);
94 	struct vattr va;
95 	struct puffs_node *pn, *pn_dir = opc;
96 	struct p9pnode *p9n_dir = pn_dir->pn_data;
97 	p9pfid_t tfid = NEXTFID(p9p);
98 	struct qid9p newqid;
99 	uint16_t nqid;
100 
101 	tag = NEXTTAG(p9p);
102 	p9pbuf_put_1(pb, P9PROTO_T_WALK);
103 	p9pbuf_put_2(pb, tag);
104 	p9pbuf_put_4(pb, p9n_dir->fid_base);
105 	p9pbuf_put_4(pb, tfid);
106 	p9pbuf_put_2(pb, 1);
107 	p9pbuf_put_str(pb, pcn->pcn_name);
108 	GETRESPONSE(pb);
109 
110 	rv = proto_expect_walk_nqids(pu, pb, &nqid);
111 	if (rv) {
112 		rv = ENOENT;
113 		goto out;
114 	}
115 	if (nqid != 1) {
116 		rv = EPROTO;
117 		goto out;
118 	}
119 	if ((rv = proto_getqid(pb, &newqid)))
120 		goto out;
121 
122 	/* we get the parent vers in walk(?)  compensate */
123 	p9pbuf_recycleout(pb);
124 	tag = NEXTTAG(p9p);
125 	p9pbuf_put_1(pb, P9PROTO_T_STAT);
126 	p9pbuf_put_2(pb, tag);
127 	p9pbuf_put_4(pb, tfid);
128 	GETRESPONSE(pb);
129 	if ((rv = proto_expect_stat(pu, pb, &va)) != 0) {
130 		proto_cc_clunkfid(pu, tfid, 0);
131 		rv = ENOENT;
132 		goto out;
133 	}
134 	if (newqid.qidpath != va.va_fileid) {
135 		proto_cc_clunkfid(pu, tfid, 0);
136 		rv = EPROTO;
137 		goto out;
138 	}
139 	newqid.qidvers = va.va_gen;
140 
141 	pn = puffs_pn_nodewalk(pu, nodecmp, &newqid);
142 	if (pn == NULL)
143 		pn = newp9pnode_qid(pu, &newqid, tfid);
144 	else
145 		proto_cc_clunkfid(pu, tfid, 0);
146 	/* assert pn */
147 	memcpy(&pn->pn_va, &va, sizeof(va));
148 
149 	puffs_newinfo_setcookie(pni, pn);
150 	puffs_newinfo_setvtype(pni, pn->pn_va.va_type);
151 	puffs_newinfo_setsize(pni, pn->pn_va.va_size);
152 	puffs_newinfo_setrdev(pni, pn->pn_va.va_rdev);
153 
154  out:
155 	RETURN(rv);
156 }
157 
158 /*
159  * Problem is that 9P doesn't allow seeking into a directory.  So we
160  * maintain a list of active fids for any given directory.  They
161  * start living at the first read and exist either until the directory
162  * is closed or until they reach the end.
163  */
164 int
165 puffs9p_node_readdir(struct puffs_usermount *pu, void *opc, struct dirent *dent,
166 	off_t *readoff, size_t *reslen, const struct puffs_cred *pcr,
167 	int *eofflag, off_t *cookies, size_t *ncookies)
168 {
169 	AUTOVAR(pu);
170 	struct puffs_node *pn = opc;
171 	struct p9pnode *p9n = pn->pn_data;
172 	struct vattr va;
173 	struct dirfid *dfp;
174 	char *name;
175 	uint32_t count;
176 	uint16_t statsize;
177 
178 	rv = getdfwithoffset(pu, p9n, *readoff, &dfp);
179 	if (rv)
180 		goto out;
181 
182 	tag = NEXTTAG(p9p);
183 	p9pbuf_put_1(pb, P9PROTO_T_READ);
184 	p9pbuf_put_2(pb, tag);
185 	p9pbuf_put_4(pb, dfp->fid);
186 	p9pbuf_put_8(pb, *readoff);
187 	p9pbuf_put_4(pb, *reslen); /* XXX */
188 	GETRESPONSE(pb);
189 
190 	p9pbuf_get_4(pb, &count);
191 
192 	/*
193 	 * if count is 0, assume we at end-of-dir.  dfp is no longer
194 	 * useful, so nuke it
195 	 */
196 	if (count == 0) {
197 		*eofflag = 1;
198 		releasedf(pu, dfp);
199 		goto out;
200 	}
201 
202 	while (count > 0) {
203 		if ((rv = proto_getstat(pu, pb, &va, &name, &statsize))) {
204 			/*
205 			 * If there was an error, it's unlikely we'll be
206 			 * coming back, so just nuke the dfp.  If we do
207 			 * come back for some strange reason, we'll just
208 			 * regen it.
209 			 */
210 			releasedf(pu, dfp);
211 			goto out;
212 		}
213 
214 		puffs_nextdent(&dent, name, va.va_fileid,
215 		    puffs_vtype2dt(va.va_type), reslen);
216 
217 		count -= statsize;
218 		*readoff += statsize;
219 		dfp->seekoff += statsize;
220 		free(name);
221 	}
222 
223 	storedf(p9n, dfp);
224 
225  out:
226 	RETURN(rv);
227 }
228 
229 int
230 puffs9p_node_setattr(struct puffs_usermount *pu, void *opc,
231 	const struct vattr *va, const struct puffs_cred *pcr)
232 {
233 	AUTOVAR(pu);
234 	struct puffs_node *pn = opc;
235 	struct p9pnode *p9n = pn->pn_data;
236 
237 	tag = NEXTTAG(p9p);
238 	p9pbuf_put_1(pb, P9PROTO_T_WSTAT);
239 	p9pbuf_put_2(pb, tag);
240 	p9pbuf_put_4(pb, p9n->fid_base);
241 	proto_make_stat(pu, pb, va, NULL, pn->pn_va.va_type);
242 	GETRESPONSE(pb);
243 
244 	if (p9pbuf_get_type(pb) != P9PROTO_R_WSTAT) {
245 		rv = proto_handle_rerror(pu, pb);
246 	}
247 
248  out:
249 	RETURN(rv);
250 }
251 
252 /*
253  * Ok, time to get clever.  There are two possible cases: we are
254  * opening a file or we are opening a directory.
255  *
256  * If it's a directory, don't bother opening it here, but rather
257  * wait until readdir, since it's probable we need to be able to
258  * open a directory there in any case.
259  *
260  * If it's a regular file, open it here with whatever credentials
261  * we happen to have.   Let the upper layers of the kernel worry
262  * about permission control.
263  */
264 int
265 puffs9p_node_open(struct puffs_usermount *pu, void *opc, int mode,
266 	const struct puffs_cred *pcr)
267 {
268 	struct puffs_cc *pcc = puffs_cc_getcc(pu);
269 	struct puffs9p *p9p = puffs_getspecific(pu);
270 	struct puffs_node *pn = opc;
271 	struct p9pnode *p9n = pn->pn_data;
272 	p9pfid_t nfid;
273 	int error = 0;
274 
275 	puffs_setback(pcc, PUFFS_SETBACK_INACT_N1);
276 	if (pn->pn_va.va_type != VDIR) {
277 		if (mode & FREAD && p9n->fid_read == P9P_INVALFID) {
278 			nfid = NEXTFID(p9p);
279 			error = proto_cc_open(pu, p9n->fid_base, nfid,
280 			    P9PROTO_OMODE_READ);
281 			if (error)
282 				return error;
283 			p9n->fid_read = nfid;
284 		}
285 		if (mode & FWRITE && p9n->fid_write == P9P_INVALFID) {
286 			nfid = NEXTFID(p9p);
287 			error = proto_cc_open(pu, p9n->fid_base, nfid,
288 			    P9PROTO_OMODE_WRITE);
289 			if (error)
290 				return error;
291 			p9n->fid_write = nfid;
292 		}
293 	}
294 
295 	return 0;
296 }
297 
298 int
299 puffs9p_node_inactive(struct puffs_usermount *pu, void *opc)
300 {
301 	struct puffs_node *pn = opc;
302 	struct p9pnode *p9n = pn->pn_data;
303 
304 	if (pn->pn_va.va_type == VDIR) {
305 		nukealldf(pu, p9n);
306 	} else  {
307 		if (p9n->fid_read != P9P_INVALFID) {
308 			proto_cc_clunkfid(pu, p9n->fid_read, 0);
309 			p9n->fid_read = P9P_INVALFID;
310 		}
311 		if (p9n->fid_write != P9P_INVALFID) {
312 			proto_cc_clunkfid(pu, p9n->fid_write, 0);
313 			p9n->fid_write = P9P_INVALFID;
314 		}
315 	}
316 
317 	return 0;
318 }
319 
320 int
321 puffs9p_node_read(struct puffs_usermount *pu, void *opc, uint8_t *buf,
322 	off_t offset, size_t *resid, const struct puffs_cred *pcr,
323 	int ioflag)
324 {
325 	AUTOVAR(pu);
326 	struct puffs_node *pn = opc;
327 	struct p9pnode *p9n = pn->pn_data;
328 	uint32_t count;
329 	size_t nread;
330 
331 	nread = 0;
332 	while (*resid > 0 && (uint64_t)(offset+nread) < pn->pn_va.va_size) {
333 		tag = NEXTTAG(p9p);
334 		p9pbuf_put_1(pb, P9PROTO_T_READ);
335 		p9pbuf_put_2(pb, tag);
336 		p9pbuf_put_4(pb, p9n->fid_read);
337 		p9pbuf_put_8(pb, offset+nread);
338 		p9pbuf_put_4(pb, MIN((uint32_t)*resid,p9p->maxreq-24));
339 		GETRESPONSE(pb);
340 
341 		if (p9pbuf_get_type(pb) != P9PROTO_R_READ) {
342 			rv = proto_handle_rerror(pu, pb);
343 			break;
344 		}
345 
346 		p9pbuf_get_4(pb, &count);
347 		if ((rv = p9pbuf_read_data(pb, buf + nread, count)))
348 			break;
349 
350 		if (count == 0)
351 			break;
352 
353 		*resid -= count;
354 		nread += count;
355 
356 		p9pbuf_recycleout(pb);
357 	}
358 
359  out:
360 	RETURN(rv);
361 }
362 
363 int
364 puffs9p_node_write(struct puffs_usermount *pu, void *opc, uint8_t *buf,
365 	off_t offset, size_t *resid, const struct puffs_cred *cred,
366 	int ioflag)
367 {
368 	AUTOVAR(pu);
369 	struct puffs_node *pn = opc;
370 	struct p9pnode *p9n = pn->pn_data;
371 	uint32_t chunk, count;
372 	size_t nwrite;
373 
374 	if (ioflag & PUFFS_IO_APPEND)
375 		offset = pn->pn_va.va_size;
376 
377 	nwrite = 0;
378 	while (*resid > 0) {
379 		chunk = MIN(*resid, p9p->maxreq-32);
380 
381 		tag = NEXTTAG(p9p);
382 		p9pbuf_put_1(pb, P9PROTO_T_WRITE);
383 		p9pbuf_put_2(pb, tag);
384 		p9pbuf_put_4(pb, p9n->fid_write);
385 		p9pbuf_put_8(pb, offset+nwrite);
386 		p9pbuf_put_4(pb, chunk);
387 		p9pbuf_write_data(pb, buf+nwrite, chunk);
388 		GETRESPONSE(pb);
389 
390 		if (p9pbuf_get_type(pb) != P9PROTO_R_WRITE) {
391 			rv = proto_handle_rerror(pu, pb);
392 			break;
393 		}
394 
395 		p9pbuf_get_4(pb, &count);
396 		*resid -= count;
397 		nwrite += count;
398 
399 		if (count != chunk) {
400 			rv = EPROTO;
401 			break;
402 		}
403 
404 		p9pbuf_recycleout(pb);
405 	}
406 
407  out:
408 	RETURN(rv);
409 }
410 
411 static int
412 nodecreate(struct puffs_usermount *pu, struct puffs_node *pn,
413 	struct puffs_newinfo *pni, const char *name,
414 	const struct vattr *vap, uint32_t dirbit)
415 {
416 	AUTOVAR(pu);
417 	struct puffs_node *pn_new;
418 	struct p9pnode *p9n = pn->pn_data;
419 	p9pfid_t nfid = NEXTFID(p9p);
420 	struct qid9p nqid;
421 	int tries = 0;
422 
423  again:
424 	if (++tries > 5) {
425 		rv = EPROTO;
426 		goto out;
427 	}
428 
429 	rv = proto_cc_dupfid(pu, p9n->fid_base, nfid);
430 	if (rv)
431 		goto out;
432 
433 	tag = NEXTTAG(p9p);
434 	p9pbuf_put_1(pb, P9PROTO_T_CREATE);
435 	p9pbuf_put_2(pb, tag);
436 	p9pbuf_put_4(pb, nfid);
437 	p9pbuf_put_str(pb, name);
438 	p9pbuf_put_4(pb, dirbit | (vap->va_mode & 0777));
439 	p9pbuf_put_1(pb, 0);
440 	if (p9p->protover == P9PROTO_VERSION_U)
441 		p9pbuf_put_str(pb, ""); /* extension[s] */
442 	GETRESPONSE(pb);
443 
444 	rv = proto_expect_qid(pu, pb, P9PROTO_R_CREATE, &nqid);
445 	if (rv)
446 		goto out;
447 
448 	/*
449 	 * Now, little problem here: create returns an *open* fid.
450 	 * So, clunk it and walk the parent directory to get a fid
451 	 * which is not open for I/O yet.
452 	 */
453 	proto_cc_clunkfid(pu, nfid, 0);
454 	nfid = NEXTFID(p9p);
455 
456 	p9pbuf_recycleout(pb);
457 	tag = NEXTTAG(p9p);
458 	p9pbuf_put_1(pb, P9PROTO_T_WALK);
459 	p9pbuf_put_2(pb, tag);
460 	p9pbuf_put_4(pb, p9n->fid_base);
461 	p9pbuf_put_4(pb, nfid);
462 	p9pbuf_put_2(pb, 1);
463 	p9pbuf_put_str(pb, name);
464 	GETRESPONSE(pb);
465 
466 	/*
467 	 * someone removed it already? try again
468 	 * note: this is kind of lose/lose
469 	 */
470 	if (p9pbuf_get_type(pb) != P9PROTO_R_WALK)
471 		goto again;
472 
473 	pn_new = newp9pnode_va(pu, vap, nfid);
474 	qid2vattr(&pn_new->pn_va, &nqid);
475 	puffs_newinfo_setcookie(pni, pn_new);
476 
477  out:
478 	RETURN(rv);
479 }
480 
481 int
482 puffs9p_node_create(struct puffs_usermount *pu, void *opc, struct puffs_newinfo *pni,
483 	const struct puffs_cn *pcn, const struct vattr *va)
484 {
485 
486 	return nodecreate(pu, opc, pni, pcn->pcn_name, va, 0);
487 }
488 
489 int
490 puffs9p_node_mkdir(struct puffs_usermount *pu, void *opc, struct puffs_newinfo *pni,
491 	const struct puffs_cn *pcn, const struct vattr *va)
492 {
493 
494 	return nodecreate(pu, opc, pni, pcn->pcn_name,
495 	    va, P9PROTO_CPERM_DIR);
496 }
497 
498 /*
499  * Need to be a bit clever again: the fid is clunked no matter if
500  * the remove succeeds or not.  Re-getting a fid would be way too
501  * difficult in case the remove failed for a valid reason (directory
502  * not empty etcetc.).  So walk ourselves another fid to prod the
503  * ice with.
504  */
505 static int
506 noderemove(struct puffs_usermount *pu, struct puffs_node *pn)
507 {
508 	AUTOVAR(pu);
509 	struct p9pnode *p9n = pn->pn_data;
510 	p9pfid_t testfid = NEXTFID(p9p);
511 
512 	rv = proto_cc_dupfid(pu, p9n->fid_base, testfid);
513 	if (rv)
514 		goto out;
515 
516 	tag = NEXTTAG(p9p);
517 	p9pbuf_put_1(pb, P9PROTO_T_REMOVE);
518 	p9pbuf_put_2(pb, tag);
519 	p9pbuf_put_4(pb, testfid);
520 
521 	/*
522 	 * XXX: error handling isn't very robust, but doom is impending
523 	 * anyway, so just accept we're going belly up and play dead
524 	 */
525 	GETRESPONSE(pb);
526 
527 	if (p9pbuf_get_type(pb) != P9PROTO_R_REMOVE) {
528 		rv = proto_handle_rerror(pu, pb);
529 	} else {
530 		proto_cc_clunkfid(pu, p9n->fid_base, 0);
531 		p9n->fid_base = P9P_INVALFID;
532 		puffs_pn_remove(pn);
533 	}
534 
535  out:
536 	RETURN(rv);
537 }
538 
539 int
540 puffs9p_node_remove(struct puffs_usermount *pu, void *opc, void *targ,
541 	const struct puffs_cn *pcn)
542 {
543 	struct puffs_cc *pcc = puffs_cc_getcc(pu);
544 	struct puffs_node *pn = targ;
545 	int rv;
546 
547 	if (pn->pn_va.va_type == VDIR)
548 		return EISDIR;
549 
550 	rv = noderemove(pu, pn);
551 	if (rv == 0)
552 		puffs_setback(pcc, PUFFS_SETBACK_NOREF_N2);
553 
554 	return rv;
555 }
556 
557 int
558 puffs9p_node_rmdir(struct puffs_usermount *pu, void *opc, void *targ,
559 	const struct puffs_cn *pcn)
560 {
561 	struct puffs_cc *pcc = puffs_cc_getcc(pu);
562 	struct puffs_node *pn = targ;
563 	int rv;
564 
565 	if (pn->pn_va.va_type != VDIR)
566 		return ENOTDIR;
567 
568 	rv = noderemove(pu, pn);
569 	if (rv == 0)
570 		puffs_setback(pcc, PUFFS_SETBACK_NOREF_N2);
571 
572 	return rv;
573 }
574 
575 int
576 puffs9p_node_rename(struct puffs_usermount *pu,
577 		    void *src_dir, void *src, const struct puffs_cn *pcn_src,
578 		    void *targ_dir, void *targ, const struct puffs_cn *pcn_targ)
579 {
580 	AUTOVAR(pu);
581 	struct puffs_node *pn_src = src;
582 	struct p9pnode *p9n_src = pn_src->pn_data;
583 
584 	/*
585 	 * 9P rename can only change the last pathname component.
586 	 * Return EXDEV for attempts to move a file to a different
587 	 * directory to make mv(1) fall back to copying.
588 	 */
589 	if (src_dir != targ_dir) {
590 		rv = EXDEV;
591 		goto out;
592 	}
593 
594 	/* 9P doesn't allow to overwrite in rename */
595 	if (targ) {
596 		struct puffs_node *pn_targ = targ;
597 
598 		rv = noderemove(pu, pn_targ);
599 		if (rv)
600 			goto out;
601 	}
602 
603 	tag = NEXTTAG(p9p);
604 	p9pbuf_put_1(pb, P9PROTO_T_WSTAT);
605 	p9pbuf_put_2(pb, tag);
606 	p9pbuf_put_4(pb, p9n_src->fid_base);
607 	proto_make_stat(pu, pb, NULL, pcn_targ->pcn_name, pn_src->pn_va.va_type);
608 	GETRESPONSE(pb);
609 
610 	if (p9pbuf_get_type(pb) != P9PROTO_R_WSTAT)
611 		rv = proto_handle_rerror(pu, pb);
612 
613  out:
614 	RETURN(rv);
615 }
616 
617 /*
618  * - "here's one"
619  * - "9P"
620  * ~ "i'm not dead"
621  * - "you're not fooling anyone you know, you'll be stone dead in a minute
622  * - "he says he's not quite dead"
623  * - "isn't there anything you could do?"
624  * - *clunk*!
625  * - "thanks"
626  */
627 int
628 puffs9p_node_reclaim(struct puffs_usermount *pu, void *opc)
629 {
630 	struct puffs_node *pn = opc;
631 	struct p9pnode *p9n = pn->pn_data;
632 
633 	assert(LIST_EMPTY(&p9n->dir_openlist));
634 	assert(p9n->fid_read == P9P_INVALFID && p9n->fid_write == P9P_INVALFID);
635 
636 	proto_cc_clunkfid(pu, p9n->fid_base, 0);
637 	free(p9n);
638 	puffs_pn_put(pn);
639 
640 	return 0;
641 }
642