xref: /netbsd-src/lib/libperfuse/perfuse.c (revision 88fcb00c0357f2d7c1774f86a352637bfda96184)
1 /*  $NetBSD: perfuse.c,v 1.16 2011/06/28 16:19:16 manu Exp $ */
2 
3 /*-
4  *  Copyright (c) 2010-2011 Emmanuel Dreyfus. 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
16  *  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17  *  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18  *  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
19  *  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  *  POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <stdio.h>
29 #include <unistd.h>
30 #include <stdlib.h>
31 #include <fcntl.h>
32 #include <string.h>
33 #include <errno.h>
34 #include <puffs.h>
35 #include <sys/types.h>
36 #include <sys/socket.h>
37 #include <sys/extattr.h>
38 #include <sys/un.h>
39 #include <machine/vmparam.h>
40 
41 #define LIBPERFUSE
42 #include "perfuse.h"
43 #include "perfuse_if.h"
44 #include "perfuse_priv.h"
45 
46 int perfuse_diagflags = 0; /* global used only in DPRINTF/DERR/DWARN */
47 extern char **environ;
48 
49 static struct perfuse_state *init_state(void);
50 static int get_fd(const char *);
51 
52 
53 static struct perfuse_state *
54 init_state(void)
55 {
56 	struct perfuse_state *ps;
57 	char opts[1024];
58 
59 	if ((ps = malloc(sizeof(*ps))) == NULL)
60 		DERR(EX_OSERR, "malloc failed");
61 
62 	(void)memset(ps, 0, sizeof(*ps));
63 	ps->ps_max_write = UINT_MAX;
64 	ps->ps_max_readahead = UINT_MAX;
65 
66 	/*
67 	 * Most of the time, access() is broken because the filesystem
68 	 * performs the check with root privileges. glusterfs will do that
69 	 * if the Linux-specific setfsuid() is missing, for instance.
70 	 */
71 	ps->ps_flags |= PS_NO_ACCESS;
72 
73 	/*
74 	 * This is a temporary way to toggle access and creat usage.
75 	 * It would be nice if that could be provided as mount options,
76 	 * but that will not be obvious to do.
77  	 */
78 	if (getenv_r("PERFUSE_OPTIONS", opts, sizeof(opts)) != -1) {
79 		char *optname;
80 		char *last;
81 
82 		 for ((optname = strtok_r(opts, ",", &last));
83 		      optname != NULL;
84 		      (optname = strtok_r(NULL, ",", &last))) {
85 			if (strcmp(optname, "enable_access") == 0)
86 				ps->ps_flags &= ~PS_NO_ACCESS;
87 
88 			if (strcmp(optname, "disable_access") == 0)
89 				ps->ps_flags |= PS_NO_ACCESS;
90 
91 			if (strcmp(optname, "enable_creat") == 0)
92 				ps->ps_flags &= ~PS_NO_CREAT;
93 
94 			if (strcmp(optname, "disable_creat") == 0)
95 				ps->ps_flags |= PS_NO_CREAT;
96 		}
97 	}
98 
99 
100 	return ps;
101 }
102 
103 
104 static int
105 get_fd(data)
106 	const char *data;
107 {
108 	char *string;
109 	const char fdopt[] = "fd=";
110 	char *lastp;
111 	char *opt;
112 	int fd = -1;
113 
114 	if ((string = strdup(data)) == NULL)
115 		return -1;
116 
117 	for (opt = strtok_r(string, ",", &lastp);
118 	     opt != NULL;
119 	     opt = strtok_r(NULL, ",", &lastp)) {
120 		if (strncmp(opt, fdopt, strlen(fdopt)) == 0) {
121 			fd =  atoi(opt + strlen(fdopt));
122 			break;
123 		}
124 	}
125 
126 	/*
127 	 * No file descriptor found
128 	 */
129 	if (fd == -1)
130 		errno = EINVAL;
131 
132 	free(string);
133 	return fd;
134 
135 }
136 
137 int
138 perfuse_open(path, flags, mode)
139 	const char *path;
140 	int flags;
141 	mode_t mode;
142 {
143 	int sv[2];
144 	struct sockaddr_un sun;
145 	struct sockaddr *sa;
146 	char progname[] = _PATH_PERFUSED;
147 	char minus_i[] = "-i";
148 	char fdstr[16];
149 	char *const argv[] = { progname, minus_i, fdstr, NULL};
150 	uint32_t opt;
151 	uint32_t optlen;
152 	int sock_type = SOCK_SEQPACKET;
153 
154 	if (strcmp(path, _PATH_FUSE) != 0)
155 		return open(path, flags, mode);
156 
157 	/*
158 	 * Try SOCK_SEQPACKET then SOCK_DGRAM if unavailable
159 	 */
160 	if ((sv[0] = socket(PF_LOCAL, SOCK_SEQPACKET, 0)) == -1) {
161 		sock_type = SOCK_DGRAM;
162                 DWARNX("SEQPACKET local sockets unavailable, using less "
163 		       "reliable DGRAM sockets. Expect file operation hangs.");
164 
165 		if ((sv[0] = socket(PF_LOCAL, SOCK_DGRAM, 0)) == -1) {
166 #ifdef PERFUSE_DEBUG
167 			DWARN("%s:%d socket failed: %s", __func__, __LINE__);
168 #endif
169 			return -1;
170 		}
171 	}
172 
173 	/*
174 	 * Set a buffer lentgh large enough so that any FUSE packet
175 	 * will fit.
176 	 */
177 	opt = FUSE_BUFSIZE;
178 	optlen = sizeof(opt);
179 	if (setsockopt(sv[0], SOL_SOCKET, SO_SNDBUF, &opt, optlen) != 0)
180 		DWARN("%s: setsockopt SO_SNDBUF to %d failed", __func__, opt);
181 
182 	opt = FUSE_BUFSIZE;
183 	optlen = sizeof(opt);
184 	if (setsockopt(sv[0], SOL_SOCKET, SO_RCVBUF, &opt, optlen) != 0)
185 		DWARN("%s: setsockopt SO_RCVBUF to %d failed", __func__, opt);
186 
187 	sa = (struct sockaddr *)(void *)&sun;
188 	sun.sun_len = sizeof(sun);
189 	sun.sun_family = AF_LOCAL;
190 	(void)strcpy(sun.sun_path, path);
191 
192 	if (connect(sv[0], sa, (socklen_t)sun.sun_len) == 0)
193 		return sv[0];
194 
195 	/*
196 	 * Attempt to run perfused on our own
197 	 * if it does not run yet; In that case
198 	 * we will talk using a socketpair
199 	 * instead of /dev/fuse.
200 	 */
201 	if (socketpair(PF_LOCAL, sock_type, 0, sv) != 0) {
202 		DWARN("%s:%d: socketpair failed", __func__, __LINE__);
203 		return -1;
204 	}
205 
206 	/*
207 	 * Set a buffer lentgh large enough so that any FUSE packet
208 	 * will fit.
209 	 */
210 	opt = 4 * FUSE_BUFSIZE;
211 	optlen = sizeof(opt);
212 	if (setsockopt(sv[0], SOL_SOCKET, SO_SNDBUF, &opt, optlen) != 0)
213 		DWARN("%s: setsockopt SO_SNDBUF to %d failed", __func__, opt);
214 
215 	opt = 4 * FUSE_BUFSIZE;
216 	optlen = sizeof(opt);
217 	if (setsockopt(sv[0], SOL_SOCKET, SO_RCVBUF, &opt, optlen) != 0)
218 		DWARN("%s: setsockopt SO_RCVBUF to %d failed", __func__, opt);
219 
220 	opt = 4 * FUSE_BUFSIZE;
221 	optlen = sizeof(opt);
222 	if (setsockopt(sv[1], SOL_SOCKET, SO_SNDBUF, &opt, optlen) != 0)
223 		DWARN("%s: setsockopt SO_SNDBUF to %d failed", __func__, opt);
224 
225 	opt = 4 * FUSE_BUFSIZE;
226 	optlen = sizeof(opt);
227 	if (setsockopt(sv[1], SOL_SOCKET, SO_RCVBUF, &opt, optlen) != 0)
228 		DWARN("%s: setsockopt SO_RCVBUF to %d failed", __func__, opt);
229 
230 	/*
231 	 * Request peer credentials. This musr be done before first
232 	 * frame is sent.
233 	 */
234 	opt = 1;
235 	optlen = sizeof(opt);
236 	if (setsockopt(sv[1], 0, LOCAL_CREDS, &opt, optlen) != 0)
237 		DWARN("%s: setsockopt LOCAL_CREDS failed", __func__);
238 
239 	(void)sprintf(fdstr, "%d", sv[1]);
240 
241 	switch(fork()) {
242 	case -1:
243 #ifdef PERFUSE_DEBUG
244 		DWARN("%s:%d: fork failed", __func__, __LINE__);
245 #endif
246 		return -1;
247 		/* NOTREACHED */
248 		break;
249 	case 0:
250 		(void)execve(argv[0], argv, environ);
251 #ifdef PERFUSE_DEBUG
252 		DWARN("%s:%d: execve failed", __func__, __LINE__);
253 #endif
254 		return -1;
255 		/* NOTREACHED */
256 		break;
257 	default:
258 		break;
259 	}
260 
261 	return sv[0];
262 }
263 
264 int
265 perfuse_mount(source, target, filesystemtype, mountflags, data)
266 	const char *source;
267 	const char *target;
268 	const char *filesystemtype;
269 	long mountflags;
270 	const void *data;
271 {
272 	int s;
273 	size_t len;
274 	struct perfuse_mount_out *pmo;
275 	struct sockaddr_storage ss;
276 	struct sockaddr_un *sun;
277 	struct sockaddr *sa;
278 	socklen_t sa_len;
279 	size_t sock_len;
280 	char *frame;
281 	char *cp;
282 
283 #ifdef PERFUSE_DEBUG
284 	if (perfuse_diagflags & PDF_MISC)
285 		DPRINTF("%s(\"%s\", \"%s\", \"%s\", 0x%lx, \"%s\")\n",
286 			__func__, source, target, filesystemtype,
287 			mountflags, (const char *)data);
288 #endif
289 
290 	if ((s = get_fd(data)) == -1)
291 		return -1;
292 
293 	/*
294 	 * If we are connected to /dev/fuse, we need a second
295 	 * socket to get replies from perfused.
296 	 * XXX This socket is not removed at exit time yet
297 	 */
298 	sock_len = 0;
299 	sa = (struct sockaddr *)(void *)&ss;
300 	sun = (struct sockaddr_un *)(void *)&ss;
301 	sa_len = sizeof(ss);
302 	if ((getpeername(s, sa, &sa_len) == 0) &&
303 	    (sa->sa_family = AF_LOCAL) &&
304 	    (strcmp(sun->sun_path, _PATH_FUSE) == 0)) {
305 
306 		sun->sun_len = sizeof(*sun);
307 		sun->sun_family = AF_LOCAL;
308 		(void)sprintf(sun->sun_path, "%s/%s-%d",
309 			      _PATH_TMP, getprogname(), getpid());
310 
311 		if (bind(s, sa, (socklen_t)sa->sa_len) != 0)
312 			DERR(EX_OSERR, "%s:%d bind to \"%s\" failed",
313 			     __func__, __LINE__, sun->sun_path);
314 
315 		sock_len = strlen(sun->sun_path) + 1;
316 	}
317 
318 	len = sizeof(*pmo);
319 	len += source ? (uint32_t)strlen(source) + 1 : 0;
320 	len += target ? (uint32_t)strlen(target) + 1 : 0;
321 	len += filesystemtype ? (uint32_t)strlen(filesystemtype) + 1 : 0;
322 	len += data ? (uint32_t)strlen(data) + 1 : 0;
323 	len += sock_len;
324 
325 	if ((frame = malloc(len)) == NULL) {
326 #ifdef PERFUSE_DEBUG
327 		if (perfuse_diagflags & PDF_MISC)
328 			DWARN("%s:%d malloc failed", __func__, __LINE__);
329 #endif
330 		return -1;
331 	}
332 
333 	pmo = (struct perfuse_mount_out *)(void *)frame;
334 	pmo->pmo_len = (uint32_t)len;
335 	pmo->pmo_error = 0;
336 	pmo->pmo_unique = (uint64_t)-1;
337 	(void)strcpy(pmo->pmo_magic, PERFUSE_MOUNT_MAGIC);
338 
339 	pmo->pmo_source_len = source ? (uint32_t)strlen(source) + 1 : 0;
340 	pmo->pmo_target_len = target ? (uint32_t)strlen(target) + 1: 0;
341 	pmo->pmo_filesystemtype_len =
342 	    filesystemtype ? (uint32_t)strlen(filesystemtype) + 1 : 0;
343 	pmo->pmo_mountflags = (uint32_t)mountflags;
344 	pmo->pmo_data_len = data ? (uint32_t)strlen(data) + 1 : 0;
345 	pmo->pmo_sock_len = (uint32_t)sock_len;
346 
347 	cp = (char *)(void *)(pmo + 1);
348 
349 	if (source) {
350 		(void)strcpy(cp, source);
351 		cp += pmo->pmo_source_len;
352 	}
353 
354 	if (target) {
355 		(void)strcpy(cp, target);
356 		cp += pmo->pmo_target_len;
357 	}
358 
359 	if (filesystemtype) {
360 		(void)strcpy(cp, filesystemtype);
361 		cp += pmo->pmo_filesystemtype_len;
362 	}
363 
364 	if (data) {
365 		(void)strcpy(cp, data);
366 		cp += pmo->pmo_data_len;
367 	}
368 
369 	if (sock_len != 0) {
370 		(void)strcpy(cp, sun->sun_path);
371 		cp += pmo->pmo_sock_len;
372 	}
373 
374 	if (send(s, frame, len, MSG_NOSIGNAL) != (ssize_t)len) {
375 #ifdef PERFUSE_DEBUG
376 		DWARN("%s:%d sendto failed", __func__, __LINE__);
377 #endif
378 		return -1;
379 	}
380 
381 	return 0;
382 }
383 
384 
385 uint64_t
386 perfuse_next_unique(pu)
387 	struct puffs_usermount *pu;
388 {
389 	struct perfuse_state *ps;
390 
391 	ps = puffs_getspecific(pu);
392 
393 	return ps->ps_unique++;
394 }
395 
396 struct puffs_usermount *
397 perfuse_init(pc, pmi)
398 	struct perfuse_callbacks *pc;
399 	struct perfuse_mount_info *pmi;
400 {
401 	struct perfuse_state *ps;
402 	struct puffs_usermount *pu;
403 	struct puffs_ops *pops;
404 	const char *source = _PATH_PUFFS;
405 	char *fstype;
406 	unsigned int puffs_flags;
407 	struct puffs_node *pn_root;
408 	struct puffs_pathobj *po_root;
409 
410 	ps = init_state();
411 	ps->ps_owner_uid = pmi->pmi_uid;
412 
413 	if (pmi->pmi_source) {
414 		if ((ps->ps_source = strdup(pmi->pmi_source)) == NULL)
415 			DERR(EX_OSERR, "strdup failed");
416 
417 		source = ps->ps_source;
418 	}
419 
420 	if (pmi->pmi_filesystemtype) {
421 		size_t len;
422 
423 		ps->ps_filesystemtype = strdup(pmi->pmi_filesystemtype);
424 		if (ps->ps_filesystemtype == NULL)
425 			DERR(EX_OSERR, "strdup failed");
426 
427 		len = sizeof("perfuse|") + strlen(ps->ps_filesystemtype) + 1;
428 		if ((fstype = malloc(len)) == NULL)
429 			DERR(EX_OSERR, "malloc failed");
430 
431 		(void)sprintf(fstype, "perfuse|%s", ps->ps_filesystemtype);
432 	} else {
433 		if ((fstype = strdup("perfuse")) == NULL)
434 			DERR(EX_OSERR, "strdup failed");
435 	}
436 
437 	if ((ps->ps_target = strdup(pmi->pmi_target)) == NULL)
438 		DERR(EX_OSERR, "strdup failed");
439 
440 	ps->ps_mountflags = pmi->pmi_mountflags;
441 
442 	/*
443 	 * Some options are forbidden for non root users
444 	 */
445 	if (ps->ps_owner_uid != 0)
446 	    ps->ps_mountflags |= MNT_NOSUID|MNT_NODEV;
447 
448 	PUFFSOP_INIT(pops);
449 	PUFFSOP_SET(pops, perfuse, fs, unmount);
450 	PUFFSOP_SET(pops, perfuse, fs, statvfs);
451 	PUFFSOP_SET(pops, perfuse, fs, sync);
452 	PUFFSOP_SET(pops, perfuse, node, lookup);
453 	PUFFSOP_SET(pops, perfuse, node, create);
454 	PUFFSOP_SET(pops, perfuse, node, mknod);
455 	PUFFSOP_SET(pops, perfuse, node, open);
456 	PUFFSOP_SET(pops, perfuse, node, close);
457 	PUFFSOP_SET(pops, perfuse, node, access);
458 	PUFFSOP_SET(pops, perfuse, node, getattr);
459 	PUFFSOP_SET(pops, perfuse, node, setattr);
460 	PUFFSOP_SET(pops, perfuse, node, poll);
461 #if 0
462 	PUFFSOP_SET(pops, perfuse, node, mmap);
463 #endif
464 	PUFFSOP_SET(pops, perfuse, node, fsync);
465 	PUFFSOP_SET(pops, perfuse, node, seek);
466 	PUFFSOP_SET(pops, perfuse, node, remove);
467 	PUFFSOP_SET(pops, perfuse, node, link);
468 	PUFFSOP_SET(pops, perfuse, node, rename);
469 	PUFFSOP_SET(pops, perfuse, node, mkdir);
470 	PUFFSOP_SET(pops, perfuse, node, rmdir);
471 	PUFFSOP_SET(pops, perfuse, node, symlink);
472 	PUFFSOP_SET(pops, perfuse, node, readdir);
473 	PUFFSOP_SET(pops, perfuse, node, readlink);
474 	PUFFSOP_SET(pops, perfuse, node, reclaim);
475 	PUFFSOP_SET(pops, perfuse, node, inactive);
476 	PUFFSOP_SET(pops, perfuse, node, print);
477 	PUFFSOP_SET(pops, perfuse, node, advlock);
478 	PUFFSOP_SET(pops, perfuse, node, read);
479 	PUFFSOP_SET(pops, perfuse, node, write);
480 #ifdef PUFFS_EXTNAMELEN
481 	PUFFSOP_SET(pops, perfuse, node, getextattr);
482 	PUFFSOP_SET(pops, perfuse, node, setextattr);
483 	PUFFSOP_SET(pops, perfuse, node, listextattr);
484 	PUFFSOP_SET(pops, perfuse, node, deleteextattr);
485 #endif /* PUFFS_EXTNAMELEN */
486 
487 	puffs_flags = PUFFS_KFLAG_WTCACHE;
488 
489 	if (perfuse_diagflags & PDF_PUFFS)
490 		puffs_flags |= PUFFS_FLAG_OPDUMP;
491 
492 	if ((pu = puffs_init(pops, source, fstype, ps, puffs_flags)) == NULL)
493 		DERR(EX_OSERR, "puffs_init failed");
494 
495 	ps->ps_pu = pu;
496 
497 	/*
498 	 * Setup filesystem root
499 	 */
500 	pn_root = perfuse_new_pn(pu, "", NULL);
501 	PERFUSE_NODE_DATA(pn_root)->pnd_ino = FUSE_ROOT_ID;
502 	PERFUSE_NODE_DATA(pn_root)->pnd_parent = pn_root;
503 	puffs_setroot(pu, pn_root);
504 	ps->ps_fsid = pn_root->pn_va.va_fsid;
505 
506 	po_root = puffs_getrootpathobj(pu);
507 	if ((po_root->po_path = strdup("/")) == NULL)
508 		DERRX(EX_OSERR, "perfuse_mount_start() failed");
509 
510 	po_root->po_len = 1;
511 	puffs_path_buildhash(pu, po_root);
512 
513 	puffs_vattr_null(&pn_root->pn_va);
514 	pn_root->pn_va.va_type = VDIR;
515 	pn_root->pn_va.va_mode = 0755;
516 
517 	ps->ps_root = pn_root;
518 
519 	/*
520 	 *  Callbacks
521 	 */
522 	ps->ps_new_msg = pc->pc_new_msg;
523 	ps->ps_xchg_msg = pc->pc_xchg_msg;
524 	ps->ps_destroy_msg = pc->pc_destroy_msg;
525 	ps->ps_get_inhdr = pc->pc_get_inhdr;
526 	ps->ps_get_inpayload = pc->pc_get_inpayload;
527 	ps->ps_get_outhdr = pc->pc_get_outhdr;
528 	ps->ps_get_outpayload = pc->pc_get_outpayload;
529 	ps->ps_umount = pc->pc_umount;
530 
531 	return pu;
532 }
533 
534 void
535 perfuse_setspecific(pu, priv)
536 	struct puffs_usermount *pu;
537 	void *priv;
538 {
539 	struct perfuse_state *ps;
540 
541 	ps = puffs_getspecific(pu);
542 	ps->ps_private = priv;
543 
544 	return;
545 }
546 
547 void *
548 perfuse_getspecific(pu)
549 	struct puffs_usermount *pu;
550 {
551 	struct perfuse_state *ps;
552 
553 	ps = puffs_getspecific(pu);
554 
555 	return ps->ps_private;
556 }
557 
558 int
559 perfuse_inloop(pu)
560 	struct puffs_usermount *pu;
561 {
562 	struct perfuse_state *ps;
563 
564 	ps = puffs_getspecific(pu);
565 
566 	return ps->ps_flags & PS_INLOOP;
567 }
568 
569 int
570 perfuse_mainloop(pu)
571 	struct puffs_usermount *pu;
572 {
573 	struct perfuse_state *ps;
574 
575 	ps = puffs_getspecific(pu);
576 
577 	ps->ps_flags |= PS_INLOOP;
578 	if (puffs_mainloop(ps->ps_pu) != 0) {
579 		DERR(EX_OSERR, "puffs_mainloop failed");
580 		return -1;
581 	}
582 
583 	/*
584 	 * Normal exit after unmount
585 	 */
586 	return 0;
587 }
588 
589 /* ARGSUSED0 */
590 uint64_t
591 perfuse_get_ino(pu, opc)
592 	struct puffs_usermount *pu;
593 	puffs_cookie_t opc;
594 {
595 	return PERFUSE_NODE_DATA(opc)->pnd_ino;
596 }
597 
598 int
599 perfuse_unmount(pu)
600 	struct puffs_usermount *pu;
601 {
602 	struct perfuse_state *ps;
603 
604 	ps = puffs_getspecific(pu);
605 
606 	return unmount(ps->ps_target, MNT_FORCE);
607 }
608