xref: /freebsd/sys/fs/tarfs/tarfs_subr.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a) 
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2013 Juniper Networks, Inc.
5  * Copyright (c) 2022-2023 Klara, Inc.
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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include "opt_tarfs.h"
30 
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <sys/systm.h>
34 #include <sys/buf.h>
35 #include <sys/fcntl.h>
36 #include <sys/libkern.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/mount.h>
40 #include <sys/namei.h>
41 #include <sys/proc.h>
42 #include <sys/queue.h>
43 #include <sys/sysctl.h>
44 #include <sys/vnode.h>
45 
46 #include <vm/vm_param.h>
47 
48 #include <fs/tarfs/tarfs.h>
49 #include <fs/tarfs/tarfs_dbg.h>
50 
51 MALLOC_DEFINE(M_TARFSNAME, "tarfs name", "tarfs file names");
52 MALLOC_DEFINE(M_TARFSBLK, "tarfs blk", "tarfs block maps");
53 
54 SYSCTL_NODE(_vfs, OID_AUTO, tarfs, CTLFLAG_RW, 0, "Tar filesystem");
55 
56 unsigned int tarfs_ioshift = TARFS_IOSHIFT_DEFAULT;
57 
58 static int
59 tarfs_sysctl_handle_ioshift(SYSCTL_HANDLER_ARGS)
60 {
61 	unsigned int tmp;
62 	int error;
63 
64 	tmp = *(unsigned int *)arg1;
65 	if ((error = SYSCTL_OUT(req, &tmp, sizeof(tmp))) != 0)
66 		return (error);
67 	if (req->newptr != NULL) {
68 		if ((error = SYSCTL_IN(req, &tmp, sizeof(tmp))) != 0)
69 			return (error);
70 		if (tmp == 0)
71 			tmp = TARFS_IOSHIFT_DEFAULT;
72 		if (tmp < TARFS_IOSHIFT_MIN)
73 			tmp = TARFS_IOSHIFT_MIN;
74 		if (tmp > TARFS_IOSHIFT_MAX)
75 			tmp = TARFS_IOSHIFT_MAX;
76 		*(unsigned int *)arg1 = tmp;
77 	}
78 	return (0);
79 }
80 
81 SYSCTL_PROC(_vfs_tarfs, OID_AUTO, ioshift,
82     CTLTYPE_UINT | CTLFLAG_MPSAFE | CTLFLAG_RWTUN,
83     &tarfs_ioshift, 0, tarfs_sysctl_handle_ioshift, "IU",
84     "Tar filesystem preferred I/O size (log 2)");
85 
86 #ifdef TARFS_DEBUG
87 int tarfs_debug;
88 SYSCTL_INT(_vfs_tarfs, OID_AUTO, debug, CTLFLAG_RWTUN,
89     &tarfs_debug, 0, "Tar filesystem debug mask");
90 #endif	/* TARFS_DEBUG */
91 
92 struct tarfs_node *
93 tarfs_lookup_node(struct tarfs_node *tnp, struct tarfs_node *f,
94     struct componentname *cnp)
95 {
96 	boolean_t found;
97 	struct tarfs_node *entry;
98 
99 	TARFS_DPF(LOOKUP, "%s: name: %.*s\n", __func__, (int)cnp->cn_namelen,
100 	    cnp->cn_nameptr);
101 
102 	found = false;
103 	TAILQ_FOREACH(entry, &tnp->dir.dirhead, dirents) {
104 		if (f != NULL && entry != f)
105 			continue;
106 
107 		if (entry->namelen == cnp->cn_namelen &&
108 		    bcmp(entry->name, cnp->cn_nameptr,
109 		    entry->namelen) == 0) {
110 			found = 1;
111 			break;
112 		}
113 	}
114 
115 	if (found) {
116 		if (entry->type == VREG && entry->other != NULL) {
117 			TARFS_DPF_IFF(LOOKUP, "%s: following hard link %p\n",
118 			    __func__, entry);
119 			entry = entry->other;
120 		}
121 		TARFS_DPF(LOOKUP, "%s: found tarfs_node %p\n", __func__,
122 		    entry);
123 		return (entry);
124 	}
125 
126 	TARFS_DPF(LOOKUP, "%s: no match found\n", __func__);
127 	return (NULL);
128 }
129 
130 struct tarfs_node *
131 tarfs_lookup_dir(struct tarfs_node *tnp, off_t cookie)
132 {
133 	struct tarfs_node *current;
134 
135 	TARFS_DPF(LOOKUP, "%s: tarfs_node %p, cookie %jd\n", __func__, tnp,
136 	    cookie);
137 	TARFS_DPF(LOOKUP, "%s: name: %s\n", __func__,
138 	    (tnp->name == NULL) ? "<<root>>" : tnp->name);
139 
140 	if (cookie == tnp->dir.lastcookie &&
141 	    tnp->dir.lastnode != NULL) {
142 		TARFS_DPF(LOOKUP, "%s: Using cached entry: tarfs_node %p, "
143 		    "cookie %jd\n", __func__, tnp->dir.lastnode,
144 		    tnp->dir.lastcookie);
145 		return (tnp->dir.lastnode);
146 	}
147 
148 	TAILQ_FOREACH(current, &tnp->dir.dirhead, dirents) {
149 		TARFS_DPF(LOOKUP, "%s: tarfs_node %p, current %p, ino %lu\n",
150 		    __func__, tnp, current, current->ino);
151 		TARFS_DPF_IFF(LOOKUP, current->name != NULL,
152 		    "%s: name: %s\n", __func__, current->name);
153 		if (current->ino == cookie) {
154 			TARFS_DPF(LOOKUP, "%s: Found entry: tarfs_node %p, "
155 			    "cookie %lu\n", __func__, current,
156 			    current->ino);
157 			break;
158 		}
159 	}
160 
161 	return (current);
162 }
163 
164 int
165 tarfs_alloc_node(struct tarfs_mount *tmp, const char *name, size_t namelen,
166     enum vtype type, off_t off, size_t sz, time_t mtime, uid_t uid, gid_t gid,
167     mode_t mode, unsigned int flags, const char *linkname, dev_t rdev,
168     struct tarfs_node *parent, struct tarfs_node **retnode)
169 {
170 	struct tarfs_node *tnp;
171 
172 	TARFS_DPF(ALLOC, "%s(%.*s)\n", __func__, (int)namelen, name);
173 
174 	if (parent != NULL && parent->type != VDIR)
175 		return (ENOTDIR);
176 	tnp = malloc(sizeof(struct tarfs_node), M_TARFSNODE, M_WAITOK | M_ZERO);
177 	mtx_init(&tnp->lock, "tarfs node lock", NULL, MTX_DEF);
178 	tnp->gen = arc4random();
179 	tnp->tmp = tmp;
180 	if (namelen > 0) {
181 		tnp->name = malloc(namelen + 1, M_TARFSNAME, M_WAITOK);
182 		tnp->namelen = namelen;
183 		memcpy(tnp->name, name, namelen);
184 		tnp->name[namelen] = '\0';
185 	}
186 	tnp->type = type;
187 	tnp->uid = uid;
188 	tnp->gid = gid;
189 	tnp->mode = mode;
190 	tnp->nlink = 1;
191 	vfs_timestamp(&tnp->atime);
192 	tnp->mtime.tv_sec = mtime;
193 	tnp->birthtime = tnp->atime;
194 	tnp->ctime = tnp->mtime;
195 	if (parent != NULL) {
196 		tnp->ino = alloc_unr(tmp->ino_unr);
197 	}
198 	tnp->offset = off;
199 	tnp->size = tnp->physize = sz;
200 	switch (type) {
201 	case VDIR:
202 		MPASS(parent != tnp);
203 		MPASS(parent != NULL || tmp->root == NULL);
204 		TAILQ_INIT(&tnp->dir.dirhead);
205 		tnp->nlink++;
206 		if (parent == NULL) {
207 			tnp->ino = TARFS_ROOTINO;
208 		}
209 		tnp->physize = 0;
210 		break;
211 	case VLNK:
212 		tnp->link.name = malloc(sz + 1, M_TARFSNAME,
213 		    M_WAITOK);
214 		tnp->link.namelen = sz;
215 		memcpy(tnp->link.name, linkname, sz);
216 		tnp->link.name[sz] = '\0';
217 		break;
218 	case VREG:
219 		/* create dummy block map */
220 		tnp->nblk = 1;
221 		tnp->blk = malloc(sizeof(*tnp->blk), M_TARFSBLK, M_WAITOK);
222 		tnp->blk[0].i = 0;
223 		tnp->blk[0].o = 0;
224 		tnp->blk[0].l = tnp->physize;
225 		break;
226 	case VFIFO:
227 		/* Nothing extra to do */
228 		break;
229 	case VBLK:
230 	case VCHR:
231 		tnp->rdev = rdev;
232 		tnp->physize = 0;
233 		break;
234 	default:
235 		panic("%s: type %d not allowed", __func__, type);
236 	}
237 	if (parent != NULL) {
238 		TARFS_NODE_LOCK(parent);
239 		TAILQ_INSERT_TAIL(&parent->dir.dirhead, tnp, dirents);
240 		parent->size += sizeof(struct tarfs_node);
241 		tnp->parent = parent;
242 		if (type == VDIR) {
243 			parent->nlink++;
244 		}
245 		TARFS_NODE_UNLOCK(parent);
246 	} else {
247 		tnp->parent = tnp;
248 	}
249 	MPASS(tnp->ino != 0);
250 
251 	TARFS_ALLNODES_LOCK(tmp);
252 	TAILQ_INSERT_TAIL(&tmp->allnodes, tnp, entries);
253 	TARFS_ALLNODES_UNLOCK(tmp);
254 
255 	*retnode = tnp;
256 	tmp->nfiles++;
257 	return (0);
258 }
259 
260 #define is09(ch) ((ch) >= '0' && (ch) <= '9')
261 
262 int
263 tarfs_load_blockmap(struct tarfs_node *tnp, size_t realsize)
264 {
265 	struct tarfs_blk *blk = NULL;
266 	char *map = NULL;
267 	size_t nmap = 0, nblk = 0;
268 	char *p, *q;
269 	ssize_t res;
270 	unsigned int i;
271 	long n;
272 
273 	/*
274 	 * Load the entire map into memory.  We don't know how big it is,
275 	 * but as soon as we start reading it we will know how many
276 	 * entries it contains, and then we can count newlines.
277 	 */
278 	do {
279 		nmap++;
280 		if (tnp->size < nmap * TARFS_BLOCKSIZE) {
281 			TARFS_DPF(MAP, "%s: map too large\n", __func__);
282 			goto bad;
283 		}
284 		/* grow the map */
285 		map = realloc(map, nmap * TARFS_BLOCKSIZE + 1, M_TARFSBLK,
286 		    M_ZERO | M_WAITOK);
287 		/* read an additional block */
288 		res = tarfs_io_read_buf(tnp->tmp, false,
289 		    map + (nmap - 1) * TARFS_BLOCKSIZE,
290 		    tnp->offset + (nmap - 1) * TARFS_BLOCKSIZE,
291 		    TARFS_BLOCKSIZE);
292 		if (res < 0)
293 			return (-res);
294 		else if (res < TARFS_BLOCKSIZE)
295 			return (EIO);
296 		map[nmap * TARFS_BLOCKSIZE] = '\0'; /* sentinel */
297 		if (nblk == 0) {
298 			n = strtol(p = map, &q, 10);
299 			if (q == p || *q != '\n' || n < 1)
300 				goto syntax;
301 			nblk = n;
302 		}
303 		for (n = 0, p = map; *p != '\0'; ++p) {
304 			if (*p == '\n') {
305 				++n;
306 			}
307 		}
308 		TARFS_DPF(MAP, "%s: %ld newlines in map\n", __func__, n);
309 	} while (n < nblk * 2 + 1);
310 	TARFS_DPF(MAP, "%s: block map length %zu\n", __func__, nblk);
311 	blk = malloc(sizeof(*blk) * nblk, M_TARFSBLK, M_WAITOK | M_ZERO);
312 	p = strchr(map, '\n') + 1;
313 	for (i = 0; i < nblk; i++) {
314 		if (i == 0)
315 			blk[i].i = nmap * TARFS_BLOCKSIZE;
316 		else
317 			blk[i].i = blk[i - 1].i + blk[i - 1].l;
318 		n = strtol(p, &q, 10);
319 		if (q == p || *q != '\n' || n < 0)
320 			goto syntax;
321 		p = q + 1;
322 		blk[i].o = n;
323 		n = strtol(p, &q, 10);
324 		if (q == p || *q != '\n' || n < 0)
325 			goto syntax;
326 		p = q + 1;
327 		blk[i].l = n;
328 		TARFS_DPF(MAP, "%s: %3d %12zu %12zu %12zu\n", __func__,
329 		    i, blk[i].i, blk[i].o, blk[i].l);
330 		/*
331 		 * Check block alignment if the block is of non-zero
332 		 * length (a zero-length block indicates the end of a
333 		 * trailing hole).  Checking i indirectly checks the
334 		 * previous block's l.  It's ok for the final block to
335 		 * have an uneven length.
336 		 */
337 		if (blk[i].l == 0) {
338 			TARFS_DPF(MAP, "%s: zero-length block\n", __func__);
339 		} else if (blk[i].i % TARFS_BLOCKSIZE != 0 ||
340 		    blk[i].o % TARFS_BLOCKSIZE != 0) {
341 			TARFS_DPF(MAP, "%s: misaligned map entry\n", __func__);
342 			goto bad;
343 		}
344 		/*
345 		 * Check that this block starts after the end of the
346 		 * previous one.
347 		 */
348 		if (i > 0 && blk[i].o < blk[i - 1].o + blk[i - 1].l) {
349 			TARFS_DPF(MAP, "%s: overlapping map entries\n", __func__);
350 			goto bad;
351 		}
352 		/*
353 		 * Check that the block is within the file, both
354 		 * physically and logically.
355 		 */
356 		if (blk[i].i + blk[i].l > tnp->physize ||
357 		    blk[i].o + blk[i].l > realsize) {
358 			TARFS_DPF(MAP, "%s: map overflow\n", __func__);
359 			goto bad;
360 		}
361 	}
362 	free(map, M_TARFSBLK);
363 
364 	/* store in node */
365 	free(tnp->blk, M_TARFSBLK);
366 	tnp->nblk = nblk;
367 	tnp->blk = blk;
368 	tnp->size = realsize;
369 	return (0);
370 syntax:
371 	TARFS_DPF(MAP, "%s: syntax error in block map\n", __func__);
372 bad:
373 	free(map, M_TARFSBLK);
374 	free(blk, M_TARFSBLK);
375 	return (EINVAL);
376 }
377 
378 void
379 tarfs_free_node(struct tarfs_node *tnp)
380 {
381 	struct tarfs_mount *tmp;
382 
383 	MPASS(tnp != NULL);
384 	tmp = tnp->tmp;
385 
386 	switch (tnp->type) {
387 	case VREG:
388 		if (tnp->nlink-- > 1)
389 			return;
390 		if (tnp->other != NULL)
391 			tarfs_free_node(tnp->other);
392 		break;
393 	case VDIR:
394 		if (tnp->nlink-- > 2)
395 			return;
396 		if (tnp->parent != NULL && tnp->parent != tnp)
397 			tarfs_free_node(tnp->parent);
398 		break;
399 	case VLNK:
400 		if (tnp->link.name)
401 			free(tnp->link.name, M_TARFSNAME);
402 		break;
403 	default:
404 		break;
405 	}
406 	if (tnp->name != NULL)
407 		free(tnp->name, M_TARFSNAME);
408 	if (tnp->blk != NULL)
409 		free(tnp->blk, M_TARFSBLK);
410 	if (tnp->ino >= TARFS_MININO)
411 		free_unr(tmp->ino_unr, tnp->ino);
412 	TAILQ_REMOVE(&tmp->allnodes, tnp, entries);
413 	free(tnp, M_TARFSNODE);
414 	tmp->nfiles--;
415 }
416 
417 int
418 tarfs_read_file(struct tarfs_node *tnp, size_t len, struct uio *uiop)
419 {
420 	struct uio auio;
421 	size_t resid = len;
422 	size_t copylen;
423 	unsigned int i;
424 	int error;
425 
426 	TARFS_DPF(VNODE, "%s(%s, %zu, %zu)\n", __func__,
427 	    tnp->name, uiop->uio_offset, resid);
428 	for (i = 0; i < tnp->nblk && resid > 0; ++i) {
429 		if (uiop->uio_offset > tnp->blk[i].o + tnp->blk[i].l) {
430 			/* skip this block */
431 			continue;
432 		}
433 		while (resid > 0 &&
434 		    uiop->uio_offset < tnp->blk[i].o) {
435 			/* move out some zeroes... */
436 			copylen = tnp->blk[i].o - uiop->uio_offset;
437 			if (copylen > resid)
438 				copylen = resid;
439 			if (copylen > ZERO_REGION_SIZE)
440 				copylen = ZERO_REGION_SIZE;
441 			auio = *uiop;
442 			auio.uio_offset = 0;
443 			auio.uio_resid = copylen;
444 			error = uiomove(__DECONST(void *, zero_region),
445 			    copylen, &auio);
446 			if (error != 0)
447 				return (error);
448 			TARFS_DPF(MAP, "%s(%s) = zero %zu\n", __func__,
449 			    tnp->name, copylen - auio.uio_resid);
450 			uiop->uio_offset += copylen - auio.uio_resid;
451 			uiop->uio_resid -= copylen - auio.uio_resid;
452 			resid -= copylen - auio.uio_resid;
453 		}
454 		while (resid > 0 &&
455 		    uiop->uio_offset < tnp->blk[i].o + tnp->blk[i].l) {
456 			/* now actual data */
457 			copylen = tnp->blk[i].l;
458 			if (copylen > resid)
459 				copylen = resid;
460 			auio = *uiop;
461 			auio.uio_offset = tnp->offset + tnp->blk[i].i +
462 			    uiop->uio_offset - tnp->blk[i].o;
463 			auio.uio_resid = copylen;
464 			error = tarfs_io_read(tnp->tmp, false, &auio);
465 			if (error != 0)
466 				return (error);
467 			TARFS_DPF(MAP, "%s(%s) = data %zu\n", __func__,
468 			    tnp->name, copylen - auio.uio_resid);
469 			uiop->uio_offset += copylen - auio.uio_resid;
470 			uiop->uio_resid -= copylen - auio.uio_resid;
471 			resid -= copylen - auio.uio_resid;
472 		}
473 	}
474 	TARFS_DPF(VNODE, "%s(%s) = %zu\n", __func__,
475 	    tnp->name, len - resid);
476 	return (0);
477 }
478 
479 /*
480  * XXX ugly file flag parser which could easily be a finite state machine
481  * driven by a small precomputed table.
482  *
483  * Note that unlike strtofflags(3), we make no attempt to handle negated
484  * flags, since they shouldn't appear in tar files.
485  */
486 static const struct tarfs_flag {
487 	const char *name;
488 	unsigned int flag;
489 } tarfs_flags[] = {
490 	{ "nodump",	UF_NODUMP },
491 	{ "uchg",	UF_IMMUTABLE },
492 	{ "uappnd",	UF_APPEND },
493 	{ "opaque",	UF_OPAQUE },
494 	{ "uunlnk",	UF_NOUNLINK },
495 	{ "arch",	SF_ARCHIVED },
496 	{ "schg",	SF_IMMUTABLE },
497 	{ "sappnd",	SF_APPEND },
498 	{ "sunlnk",	SF_NOUNLINK },
499 	{ NULL, 0 },
500 };
501 
502 unsigned int
503 tarfs_strtofflags(const char *str, char **end)
504 {
505 	const struct tarfs_flag *tf;
506 	const char *p, *q;
507 	unsigned int ret;
508 
509 	ret = 0;
510 	for (p = q = str; *q != '\0'; p = q + 1) {
511 		for (q = p; *q != '\0' && *q != ','; ++q) {
512 			if (*q < 'a' || *q > 'z') {
513 				goto end;
514 			}
515 			/* nothing */
516 		}
517 		for (tf = tarfs_flags; tf->name != NULL; tf++) {
518 			if (strncmp(tf->name, p, q - p) == 0 &&
519 			    tf->name[q - p] == '\0') {
520 				TARFS_DPF(ALLOC, "%s: %.*s = 0x%06x\n", __func__,
521 				    (int)(q - p), p, tf->flag);
522 				ret |= tf->flag;
523 				break;
524 			}
525 		}
526 		if (tf->name == NULL) {
527 			TARFS_DPF(ALLOC, "%s: %.*s = 0x??????\n",
528 			    __func__, (int)(q - p), p);
529 			goto end;
530 		}
531 	}
532 end:
533 	if (*end != NULL) {
534 		*end = __DECONST(char *, q);
535 	}
536 	return (ret);
537 }
538