xref: /freebsd/sys/fs/tarfs/tarfs_subr.c (revision 9768746b)
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_RW | CTLFLAG_TUN,
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_RW | CTLFLAG_TUN,
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 	tnp = malloc(sizeof(struct tarfs_node), M_TARFSNODE, M_WAITOK | M_ZERO);
175 	mtx_init(&tnp->lock, "tarfs node lock", NULL, MTX_DEF);
176 	tnp->gen = arc4random();
177 	tnp->tmp = tmp;
178 	if (namelen > 0) {
179 		tnp->name = malloc(namelen + 1, M_TARFSNAME, M_WAITOK);
180 		tnp->namelen = namelen;
181 		memcpy(tnp->name, name, namelen);
182 		tnp->name[namelen] = '\0';
183 	}
184 	tnp->type = type;
185 	tnp->uid = uid;
186 	tnp->gid = gid;
187 	tnp->mode = mode;
188 	tnp->nlink = 1;
189 	vfs_timestamp(&tnp->atime);
190 	tnp->mtime.tv_sec = mtime;
191 	tnp->birthtime = tnp->atime;
192 	tnp->ctime = tnp->mtime;
193 	if (parent != NULL) {
194 		tnp->ino = alloc_unr(tmp->ino_unr);
195 	}
196 	tnp->offset = off;
197 	tnp->size = tnp->physize = sz;
198 	switch (type) {
199 	case VDIR:
200 		MPASS(parent != tnp);
201 		MPASS(parent != NULL || tmp->root == NULL);
202 		TAILQ_INIT(&tnp->dir.dirhead);
203 		tnp->nlink++;
204 		if (parent == NULL) {
205 			tnp->ino = TARFS_ROOTINO;
206 		}
207 		tnp->physize = 0;
208 		break;
209 	case VLNK:
210 		tnp->link.name = malloc(sz + 1, M_TARFSNAME,
211 		    M_WAITOK);
212 		tnp->link.namelen = sz;
213 		memcpy(tnp->link.name, linkname, sz);
214 		tnp->link.name[sz] = '\0';
215 		break;
216 	case VREG:
217 		/* create dummy block map */
218 		tnp->nblk = 1;
219 		tnp->blk = malloc(sizeof(*tnp->blk), M_TARFSBLK, M_WAITOK);
220 		tnp->blk[0].i = 0;
221 		tnp->blk[0].o = 0;
222 		tnp->blk[0].l = tnp->physize;
223 		break;
224 	case VFIFO:
225 		/* Nothing extra to do */
226 		break;
227 	case VBLK:
228 	case VCHR:
229 		tnp->rdev = rdev;
230 		tnp->physize = 0;
231 		break;
232 	default:
233 		panic("%s: type %d not allowed", __func__, type);
234 	}
235 	if (parent != NULL) {
236 		MPASS(parent->type == VDIR);
237 		TARFS_NODE_LOCK(parent);
238 		TAILQ_INSERT_TAIL(&parent->dir.dirhead, tnp, dirents);
239 		parent->size += sizeof(struct tarfs_node);
240 		tnp->parent = parent;
241 		if (type == VDIR) {
242 			parent->nlink++;
243 		}
244 		TARFS_NODE_UNLOCK(parent);
245 	} else {
246 		tnp->parent = tnp;
247 	}
248 	MPASS(tnp->ino != 0);
249 
250 	TARFS_ALLNODES_LOCK(tmp);
251 	TAILQ_INSERT_TAIL(&tmp->allnodes, tnp, entries);
252 	TARFS_ALLNODES_UNLOCK(tmp);
253 
254 	*retnode = tnp;
255 	tmp->nfiles++;
256 	return (0);
257 }
258 
259 #define is09(ch) ((ch) >= '0' && (ch) <= '9')
260 
261 int
262 tarfs_load_blockmap(struct tarfs_node *tnp, size_t realsize)
263 {
264 	struct tarfs_blk *blk = NULL;
265 	char *map = NULL;
266 	size_t nmap = 0, nblk = 0;
267 	char *p, *q;
268 	ssize_t res;
269 	unsigned int i;
270 	long n;
271 
272 	/*
273 	 * Load the entire map into memory.  We don't know how big it is,
274 	 * but as soon as we start reading it we will know how many
275 	 * entries it contains, and then we can count newlines.
276 	 */
277 	do {
278 		nmap++;
279 		if (tnp->size < nmap * TARFS_BLOCKSIZE) {
280 			TARFS_DPF(MAP, "%s: map too large\n", __func__);
281 			goto bad;
282 		}
283 		/* grow the map */
284 		map = realloc(map, nmap * TARFS_BLOCKSIZE + 1, M_TARFSBLK,
285 		    M_ZERO | M_WAITOK);
286 		/* read an additional block */
287 		res = tarfs_io_read_buf(tnp->tmp, false,
288 		    map + (nmap - 1) * TARFS_BLOCKSIZE,
289 		    tnp->offset + (nmap - 1) * TARFS_BLOCKSIZE,
290 		    TARFS_BLOCKSIZE);
291 		if (res < 0)
292 			return (-res);
293 		else if (res < TARFS_BLOCKSIZE)
294 			return (EIO);
295 		map[nmap * TARFS_BLOCKSIZE] = '\0'; /* sentinel */
296 		if (nblk == 0) {
297 			n = strtol(p = map, &q, 10);
298 			if (q == p || *q != '\n' || n < 1)
299 				goto syntax;
300 			nblk = n;
301 		}
302 		for (n = 0, p = map; *p != '\0'; ++p) {
303 			if (*p == '\n') {
304 				++n;
305 			}
306 		}
307 		TARFS_DPF(MAP, "%s: %ld newlines in map\n", __func__, n);
308 	} while (n < nblk * 2 + 1);
309 	TARFS_DPF(MAP, "%s: block map length %zu\n", __func__, nblk);
310 	blk = malloc(sizeof(*blk) * nblk, M_TARFSBLK, M_WAITOK | M_ZERO);
311 	p = strchr(map, '\n') + 1;
312 	for (i = 0; i < nblk; i++) {
313 		if (i == 0)
314 			blk[i].i = nmap * TARFS_BLOCKSIZE;
315 		else
316 			blk[i].i = blk[i - 1].i + blk[i - 1].l;
317 		n = strtol(p, &q, 10);
318 		if (q == p || *q != '\n' || n < 0)
319 			goto syntax;
320 		p = q + 1;
321 		blk[i].o = n;
322 		n = strtol(p, &q, 10);
323 		if (q == p || *q != '\n' || n < 0)
324 			goto syntax;
325 		p = q + 1;
326 		blk[i].l = n;
327 		TARFS_DPF(MAP, "%s: %3d %12zu %12zu %12zu\n", __func__,
328 		    i, blk[i].i, blk[i].o, blk[i].l);
329 		/*
330 		 * Check block alignment if the block is of non-zero
331 		 * length (a zero-length block indicates the end of a
332 		 * trailing hole).  Checking i indirectly checks the
333 		 * previous block's l.  It's ok for the final block to
334 		 * have an uneven length.
335 		 */
336 		if (blk[i].l == 0) {
337 			TARFS_DPF(MAP, "%s: zero-length block\n", __func__);
338 		} else if (blk[i].i % TARFS_BLOCKSIZE != 0 ||
339 		    blk[i].o % TARFS_BLOCKSIZE != 0) {
340 			TARFS_DPF(MAP, "%s: misaligned map entry\n", __func__);
341 			goto bad;
342 		}
343 		/*
344 		 * Check that this block starts after the end of the
345 		 * previous one.
346 		 */
347 		if (i > 0 && blk[i].o < blk[i - 1].o + blk[i - 1].l) {
348 			TARFS_DPF(MAP, "%s: overlapping map entries\n", __func__);
349 			goto bad;
350 		}
351 		/*
352 		 * Check that the block is within the file, both
353 		 * physically and logically.
354 		 */
355 		if (blk[i].i + blk[i].l > tnp->physize ||
356 		    blk[i].o + blk[i].l > realsize) {
357 			TARFS_DPF(MAP, "%s: map overflow\n", __func__);
358 			goto bad;
359 		}
360 	}
361 	free(map, M_TARFSBLK);
362 
363 	/* store in node */
364 	free(tnp->blk, M_TARFSBLK);
365 	tnp->nblk = nblk;
366 	tnp->blk = blk;
367 	tnp->size = realsize;
368 	return (0);
369 syntax:
370 	TARFS_DPF(MAP, "%s: syntax error in block map\n", __func__);
371 bad:
372 	free(map, M_TARFSBLK);
373 	free(blk, M_TARFSBLK);
374 	return (EINVAL);
375 }
376 
377 void
378 tarfs_free_node(struct tarfs_node *tnp)
379 {
380 	struct tarfs_mount *tmp;
381 
382 	MPASS(tnp != NULL);
383 	tmp = tnp->tmp;
384 
385 	switch (tnp->type) {
386 	case VLNK:
387 		if (tnp->link.name)
388 			free(tnp->link.name, M_TARFSNAME);
389 		break;
390 	default:
391 		break;
392 	}
393 	if (tnp->name != NULL)
394 		free(tnp->name, M_TARFSNAME);
395 	if (tnp->blk != NULL)
396 		free(tnp->blk, M_TARFSBLK);
397 	if (tnp->ino >= TARFS_MININO)
398 		free_unr(tmp->ino_unr, tnp->ino);
399 	free(tnp, M_TARFSNODE);
400 	tmp->nfiles--;
401 }
402 
403 int
404 tarfs_read_file(struct tarfs_node *tnp, size_t len, struct uio *uiop)
405 {
406 	struct uio auio;
407 	size_t resid = len;
408 	size_t copylen;
409 	unsigned int i;
410 	int error;
411 
412 	TARFS_DPF(VNODE, "%s(%s, %zu, %zu)\n", __func__,
413 	    tnp->name, uiop->uio_offset, resid);
414 	for (i = 0; i < tnp->nblk && resid > 0; ++i) {
415 		if (uiop->uio_offset > tnp->blk[i].o + tnp->blk[i].l) {
416 			/* skip this block */
417 			continue;
418 		}
419 		while (resid > 0 &&
420 		    uiop->uio_offset < tnp->blk[i].o) {
421 			/* move out some zeroes... */
422 			copylen = tnp->blk[i].o - uiop->uio_offset;
423 			if (copylen > resid)
424 				copylen = resid;
425 			if (copylen > ZERO_REGION_SIZE)
426 				copylen = ZERO_REGION_SIZE;
427 			auio = *uiop;
428 			auio.uio_offset = 0;
429 			auio.uio_resid = copylen;
430 			error = uiomove(__DECONST(void *, zero_region),
431 			    copylen, &auio);
432 			if (error != 0)
433 				return (error);
434 			TARFS_DPF(MAP, "%s(%s) = zero %zu\n", __func__,
435 			    tnp->name, copylen - auio.uio_resid);
436 			uiop->uio_offset += copylen - auio.uio_resid;
437 			uiop->uio_resid -= copylen - auio.uio_resid;
438 			resid -= copylen - auio.uio_resid;
439 		}
440 		while (resid > 0 &&
441 		    uiop->uio_offset < tnp->blk[i].o + tnp->blk[i].l) {
442 			/* now actual data */
443 			copylen = tnp->blk[i].l;
444 			if (copylen > resid)
445 				copylen = resid;
446 			auio = *uiop;
447 			auio.uio_offset = tnp->offset + tnp->blk[i].i +
448 			    uiop->uio_offset - tnp->blk[i].o;
449 			auio.uio_resid = copylen;
450 			error = tarfs_io_read(tnp->tmp, false, &auio);
451 			if (error != 0)
452 				return (error);
453 			TARFS_DPF(MAP, "%s(%s) = data %zu\n", __func__,
454 			    tnp->name, copylen - auio.uio_resid);
455 			uiop->uio_offset += copylen - auio.uio_resid;
456 			uiop->uio_resid -= copylen - auio.uio_resid;
457 			resid -= copylen - auio.uio_resid;
458 		}
459 	}
460 	TARFS_DPF(VNODE, "%s(%s) = %zu\n", __func__,
461 	    tnp->name, len - resid);
462 	return (0);
463 }
464 
465 /*
466  * XXX ugly file flag parser which could easily be a finite state machine
467  * driven by a small precomputed table.
468  *
469  * Note that unlike strtofflags(3), we make no attempt to handle negated
470  * flags, since they shouldn't appear in tar files.
471  */
472 static const struct tarfs_flag {
473 	const char *name;
474 	unsigned int flag;
475 } tarfs_flags[] = {
476 	{ "nodump",	UF_NODUMP },
477 	{ "uchg",	UF_IMMUTABLE },
478 	{ "uappnd",	UF_APPEND },
479 	{ "opaque",	UF_OPAQUE },
480 	{ "uunlnk",	UF_NOUNLINK },
481 	{ "arch",	SF_ARCHIVED },
482 	{ "schg",	SF_IMMUTABLE },
483 	{ "sappnd",	SF_APPEND },
484 	{ "sunlnk",	SF_NOUNLINK },
485 	{ NULL, 0 },
486 };
487 
488 unsigned int
489 tarfs_strtofflags(const char *str, char **end)
490 {
491 	const struct tarfs_flag *tf;
492 	const char *p, *q;
493 	unsigned int ret;
494 
495 	ret = 0;
496 	for (p = q = str; *q != '\0'; p = q + 1) {
497 		for (q = p; *q != '\0' && *q != ','; ++q) {
498 			if (*q < 'a' || *q > 'z') {
499 				goto end;
500 			}
501 			/* nothing */
502 		}
503 		for (tf = tarfs_flags; tf->name != NULL; tf++) {
504 			if (strncmp(tf->name, p, q - p) == 0 &&
505 			    tf->name[q - p] == '\0') {
506 				TARFS_DPF(ALLOC, "%s: %.*s = 0x%06x\n", __func__,
507 				    (int)(q - p), p, tf->flag);
508 				ret |= tf->flag;
509 				break;
510 			}
511 		}
512 		if (tf->name == NULL) {
513 			TARFS_DPF(ALLOC, "%s: %.*s = 0x??????\n",
514 			    __func__, (int)(q - p), p);
515 			goto end;
516 		}
517 	}
518 end:
519 	if (*end != NULL) {
520 		*end = __DECONST(char *, q);
521 	}
522 	return (ret);
523 }
524