xref: /netbsd-src/lib/libperfuse/perfuse.c (revision 46f5119e40af2e51998f686b2fdcc76b5488f7f3)
1 /*  $NetBSD: perfuse.c,v 1.13 2011/05/12 10:32:41 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/un.h>
38 #include <machine/vmparam.h>
39 
40 #define LIBPERFUSE
41 #include "perfuse.h"
42 #include "perfuse_if.h"
43 #include "perfuse_priv.h"
44 
45 int perfuse_diagflags = 0; /* global used only in DPRINTF/DERR/DWARN */
46 extern char **environ;
47 
48 static struct perfuse_state *init_state(void);
49 static int get_fd(const char *);
50 
51 
52 static struct perfuse_state *
53 init_state(void)
54 {
55 	struct perfuse_state *ps;
56 	char opts[1024];
57 
58 	if ((ps = malloc(sizeof(*ps))) == NULL)
59 		DERR(EX_OSERR, "malloc failed");
60 
61 	(void)memset(ps, 0, sizeof(*ps));
62 	ps->ps_max_write = UINT_MAX;
63 	ps->ps_max_readahead = UINT_MAX;
64 
65 	/*
66 	 * Most of the time, access() is broken because the filesystem
67 	 * performs the check with root privileges. glusterfs will do that
68 	 * if the Linux-specific setfsuid() is missing, for instance.
69 	 */
70 	ps->ps_flags |= PS_NO_ACCESS;
71 
72 	/*
73 	 * This is a temporary way to toggle access and creat usage.
74 	 * It would be nice if that could be provided as mount options,
75 	 * but that will not be obvious to do.
76  	 */
77 	if (getenv_r("PERFUSE_OPTIONS", opts, sizeof(opts)) != -1) {
78 		char *optname;
79 		char *last;
80 
81 		 for ((optname = strtok_r(opts, ",", &last));
82 		      optname != NULL;
83 		      (optname = strtok_r(NULL, ",", &last))) {
84 			if (strcmp(optname, "enable_access") == 0)
85 				ps->ps_flags &= ~PS_NO_ACCESS;
86 
87 			if (strcmp(optname, "disable_access") == 0)
88 				ps->ps_flags |= PS_NO_ACCESS;
89 
90 			if (strcmp(optname, "enable_creat") == 0)
91 				ps->ps_flags &= ~PS_NO_CREAT;
92 
93 			if (strcmp(optname, "disable_creat") == 0)
94 				ps->ps_flags |= PS_NO_CREAT;
95 		}
96 	}
97 
98 
99 	return ps;
100 }
101 
102 
103 static int
104 get_fd(data)
105 	const char *data;
106 {
107 	char *string;
108 	const char fdopt[] = "fd=";
109 	char *lastp;
110 	char *opt;
111 	int fd = -1;
112 
113 	if ((string = strdup(data)) == NULL)
114 		return -1;
115 
116 	for (opt = strtok_r(string, ",", &lastp);
117 	     opt != NULL;
118 	     opt = strtok_r(NULL, ",", &lastp)) {
119 		if (strncmp(opt, fdopt, strlen(fdopt)) == 0) {
120 			fd =  atoi(opt + strlen(fdopt));
121 			break;
122 		}
123 	}
124 
125 	/*
126 	 * No file descriptor found
127 	 */
128 	if (fd == -1)
129 		errno = EINVAL;
130 
131 	free(string);
132 	return fd;
133 
134 }
135 
136 int
137 perfuse_open(path, flags, mode)
138 	const char *path;
139 	int flags;
140 	mode_t mode;
141 {
142 	int sv[2];
143 	struct sockaddr_un sun;
144 	struct sockaddr *sa;
145 	char progname[] = _PATH_PERFUSED;
146 	char minus_i[] = "-i";
147 	char fdstr[16];
148 	char *const argv[] = { progname, minus_i, fdstr, NULL};
149 	uint32_t opt;
150 	uint32_t optlen;
151 
152 	if (strcmp(path, _PATH_FUSE) != 0)
153 		return open(path, flags, mode);
154 
155 	if ((sv[0] = socket(PF_LOCAL, SOCK_DGRAM, 0)) == -1) {
156 #ifdef PERFUSE_DEBUG
157 		DWARN("%s:%d socket failed: %s", __func__, __LINE__);
158 #endif
159 		return -1;
160 	}
161 
162 	/*
163 	 * Set a buffer lentgh large enough so that any FUSE packet
164 	 * will fit.
165 	 */
166 	opt = FUSE_BUFSIZE;
167 	optlen = sizeof(opt);
168 	if (setsockopt(sv[0], SOL_SOCKET, SO_SNDBUF, &opt, optlen) != 0)
169 		DWARN("%s: setsockopt SO_SNDBUF to %d failed", __func__, opt);
170 
171 	opt = FUSE_BUFSIZE;
172 	optlen = sizeof(opt);
173 	if (setsockopt(sv[0], SOL_SOCKET, SO_RCVBUF, &opt, optlen) != 0)
174 		DWARN("%s: setsockopt SO_RCVBUF to %d failed", __func__, opt);
175 
176 	sa = (struct sockaddr *)(void *)&sun;
177 	sun.sun_len = sizeof(sun);
178 	sun.sun_family = AF_LOCAL;
179 	(void)strcpy(sun.sun_path, path);
180 
181 	if (connect(sv[0], sa, (socklen_t)sun.sun_len) == 0)
182 		return sv[0];
183 
184 
185 	/*
186 	 * Attempt to run perfused on our own
187 	 * if it does not run yet; In that case
188 	 * we will talk using a socketpair
189 	 * instead of /dev/fuse.
190 	 */
191 	if (socketpair(PF_LOCAL, SOCK_DGRAM, 0, sv) != 0) {
192 		DWARN("%s:%d: socketpair failed", __func__, __LINE__);
193 		return -1;
194 	}
195 
196 	/*
197 	 * Set a buffer lentgh large enough so that any FUSE packet
198 	 * will fit.
199 	 */
200 	opt = FUSE_BUFSIZE;
201 	optlen = sizeof(opt);
202 	if (setsockopt(sv[0], SOL_SOCKET, SO_SNDBUF, &opt, optlen) != 0)
203 		DWARN("%s: setsockopt SO_SNDBUF to %d failed", __func__, opt);
204 
205 	opt = FUSE_BUFSIZE;
206 	optlen = sizeof(opt);
207 	if (setsockopt(sv[0], SOL_SOCKET, SO_RCVBUF, &opt, optlen) != 0)
208 		DWARN("%s: setsockopt SO_RCVBUF to %d failed", __func__, opt);
209 
210 	opt = FUSE_BUFSIZE;
211 	optlen = sizeof(opt);
212 	if (setsockopt(sv[1], SOL_SOCKET, SO_SNDBUF, &opt, optlen) != 0)
213 		DWARN("%s: setsockopt SO_SNDBUF to %d failed", __func__, opt);
214 
215 	opt = FUSE_BUFSIZE;
216 	optlen = sizeof(opt);
217 	if (setsockopt(sv[1], SOL_SOCKET, SO_RCVBUF, &opt, optlen) != 0)
218 		DWARN("%s: setsockopt SO_RCVBUF to %d failed", __func__, opt);
219 
220 	/*
221 	 * Request peer credentials. This musr be done before first
222 	 * frame is sent.
223 	 */
224 	opt = 1;
225 	optlen = sizeof(opt);
226 	if (setsockopt(sv[1], 0, LOCAL_CREDS, &opt, optlen) != 0)
227 		DWARN("%s: setsockopt LOCAL_CREDS failed", __func__);
228 
229 	(void)sprintf(fdstr, "%d", sv[1]);
230 
231 	switch(fork()) {
232 	case -1:
233 #ifdef PERFUSE_DEBUG
234 		DWARN("%s:%d: fork failed", __func__, __LINE__);
235 #endif
236 		return -1;
237 		/* NOTREACHED */
238 		break;
239 	case 0:
240 		(void)execve(argv[0], argv, environ);
241 #ifdef PERFUSE_DEBUG
242 		DWARN("%s:%d: execve failed", __func__, __LINE__);
243 #endif
244 		return -1;
245 		/* NOTREACHED */
246 		break;
247 	default:
248 		break;
249 	}
250 
251 	return sv[0];
252 }
253 
254 int
255 perfuse_mount(source, target, filesystemtype, mountflags, data)
256 	const char *source;
257 	const char *target;
258 	const char *filesystemtype;
259 	long mountflags;
260 	const void *data;
261 {
262 	int s;
263 	size_t len;
264 	struct perfuse_mount_out *pmo;
265 	struct sockaddr_storage ss;
266 	struct sockaddr_un *sun;
267 	struct sockaddr *sa;
268 	socklen_t sa_len;
269 	size_t sock_len;
270 	char *frame;
271 	char *cp;
272 
273 #ifdef PERFUSE_DEBUG
274 	if (perfuse_diagflags & PDF_MISC)
275 		DPRINTF("%s(\"%s\", \"%s\", \"%s\", 0x%lx, \"%s\")\n",
276 			__func__, source, target, filesystemtype,
277 			mountflags, (const char *)data);
278 #endif
279 
280 	if ((s = get_fd(data)) == -1)
281 		return -1;
282 
283 	/*
284 	 * If we are connected to /dev/fuse, we need a second
285 	 * socket to get replies from perfused.
286 	 * XXX This socket is not removed at exit time yet
287 	 */
288 	sock_len = 0;
289 	sa = (struct sockaddr *)(void *)&ss;
290 	sun = (struct sockaddr_un *)(void *)&ss;
291 	sa_len = sizeof(ss);
292 	if ((getpeername(s, sa, &sa_len) == 0) &&
293 	    (sa->sa_family = AF_LOCAL) &&
294 	    (strcmp(sun->sun_path, _PATH_FUSE) == 0)) {
295 
296 		sun->sun_len = sizeof(*sun);
297 		sun->sun_family = AF_LOCAL;
298 		(void)sprintf(sun->sun_path, "%s/%s-%d",
299 			      _PATH_TMP, getprogname(), getpid());
300 
301 		if (bind(s, sa, (socklen_t)sa->sa_len) != 0)
302 			DERR(EX_OSERR, "%s:%d bind to \"%s\" failed",
303 			     __func__, __LINE__, sun->sun_path);
304 
305 		sock_len = strlen(sun->sun_path) + 1;
306 	}
307 
308 	len = sizeof(*pmo);
309 	len += source ? (uint32_t)strlen(source) + 1 : 0;
310 	len += target ? (uint32_t)strlen(target) + 1 : 0;
311 	len += filesystemtype ? (uint32_t)strlen(filesystemtype) + 1 : 0;
312 	len += data ? (uint32_t)strlen(data) + 1 : 0;
313 	len += sock_len;
314 
315 	if ((frame = malloc(len)) == NULL) {
316 #ifdef PERFUSE_DEBUG
317 		if (perfuse_diagflags & PDF_MISC)
318 			DWARN("%s:%d malloc failed", __func__, __LINE__);
319 #endif
320 		return -1;
321 	}
322 
323 	pmo = (struct perfuse_mount_out *)(void *)frame;
324 	pmo->pmo_len = (uint32_t)len;
325 	pmo->pmo_error = 0;
326 	pmo->pmo_unique = (uint64_t)-1;
327 	(void)strcpy(pmo->pmo_magic, PERFUSE_MOUNT_MAGIC);
328 
329 	pmo->pmo_source_len = source ? (uint32_t)strlen(source) + 1 : 0;
330 	pmo->pmo_target_len = target ? (uint32_t)strlen(target) + 1: 0;
331 	pmo->pmo_filesystemtype_len =
332 	    filesystemtype ? (uint32_t)strlen(filesystemtype) + 1 : 0;
333 	pmo->pmo_mountflags = (uint32_t)mountflags;
334 	pmo->pmo_data_len = data ? (uint32_t)strlen(data) + 1 : 0;
335 	pmo->pmo_sock_len = (uint32_t)sock_len;
336 
337 	cp = (char *)(void *)(pmo + 1);
338 
339 	if (source) {
340 		(void)strcpy(cp, source);
341 		cp += pmo->pmo_source_len;
342 	}
343 
344 	if (target) {
345 		(void)strcpy(cp, target);
346 		cp += pmo->pmo_target_len;
347 	}
348 
349 	if (filesystemtype) {
350 		(void)strcpy(cp, filesystemtype);
351 		cp += pmo->pmo_filesystemtype_len;
352 	}
353 
354 	if (data) {
355 		(void)strcpy(cp, data);
356 		cp += pmo->pmo_data_len;
357 	}
358 
359 	if (sock_len != 0) {
360 		(void)strcpy(cp, sun->sun_path);
361 		cp += pmo->pmo_sock_len;
362 	}
363 
364 	if (send(s, frame, len, MSG_NOSIGNAL) != (ssize_t)len) {
365 #ifdef PERFUSE_DEBUG
366 		DWARN("%s:%d sendto failed", __func__, __LINE__);
367 #endif
368 		return -1;
369 	}
370 
371 	return 0;
372 }
373 
374 
375 uint64_t
376 perfuse_next_unique(pu)
377 	struct puffs_usermount *pu;
378 {
379 	struct perfuse_state *ps;
380 
381 	ps = puffs_getspecific(pu);
382 
383 	return ps->ps_unique++;
384 }
385 
386 struct puffs_usermount *
387 perfuse_init(pc, pmi)
388 	struct perfuse_callbacks *pc;
389 	struct perfuse_mount_info *pmi;
390 {
391 	struct perfuse_state *ps;
392 	struct puffs_usermount *pu;
393 	struct puffs_ops *pops;
394 	const char *source = _PATH_PUFFS;
395 	char *fstype;
396 	unsigned int puffs_flags;
397 	struct puffs_node *pn_root;
398 	struct puffs_pathobj *po_root;
399 
400 	ps = init_state();
401 	ps->ps_owner_uid = pmi->pmi_uid;
402 
403 	if (pmi->pmi_source) {
404 		if ((ps->ps_source = strdup(pmi->pmi_source)) == NULL)
405 			DERR(EX_OSERR, "strdup failed");
406 
407 		source = ps->ps_source;
408 	}
409 
410 	if (pmi->pmi_filesystemtype) {
411 		size_t len;
412 
413 		ps->ps_filesystemtype = strdup(pmi->pmi_filesystemtype);
414 		if (ps->ps_filesystemtype == NULL)
415 			DERR(EX_OSERR, "strdup failed");
416 
417 		len = sizeof("perfuse|") + strlen(ps->ps_filesystemtype) + 1;
418 		if ((fstype = malloc(len)) == NULL)
419 			DERR(EX_OSERR, "malloc failed");
420 
421 		(void)sprintf(fstype, "perfuse|%s", ps->ps_filesystemtype);
422 	} else {
423 		if ((fstype = strdup("perfuse")) == NULL)
424 			DERR(EX_OSERR, "strdup failed");
425 	}
426 
427 	if ((ps->ps_target = strdup(pmi->pmi_target)) == NULL)
428 		DERR(EX_OSERR, "strdup failed");
429 
430 	ps->ps_mountflags = pmi->pmi_mountflags;
431 
432 	/*
433 	 * Some options are forbidden for non root users
434 	 */
435 	if (ps->ps_owner_uid != 0)
436 	    ps->ps_mountflags |= MNT_NOSUID|MNT_NODEV;
437 
438 	PUFFSOP_INIT(pops);
439 	PUFFSOP_SET(pops, perfuse, fs, unmount);
440 	PUFFSOP_SET(pops, perfuse, fs, statvfs);
441 	PUFFSOP_SET(pops, perfuse, fs, sync);
442 	PUFFSOP_SET(pops, perfuse, node, lookup);
443 	PUFFSOP_SET(pops, perfuse, node, create);
444 	PUFFSOP_SET(pops, perfuse, node, mknod);
445 	PUFFSOP_SET(pops, perfuse, node, open);
446 	PUFFSOP_SET(pops, perfuse, node, close);
447 	PUFFSOP_SET(pops, perfuse, node, access);
448 	PUFFSOP_SET(pops, perfuse, node, getattr);
449 	PUFFSOP_SET(pops, perfuse, node, setattr);
450 	PUFFSOP_SET(pops, perfuse, node, poll);
451 #if 0
452 	PUFFSOP_SET(pops, perfuse, node, mmap);
453 #endif
454 	PUFFSOP_SET(pops, perfuse, node, fsync);
455 	PUFFSOP_SET(pops, perfuse, node, seek);
456 	PUFFSOP_SET(pops, perfuse, node, remove);
457 	PUFFSOP_SET(pops, perfuse, node, link);
458 	PUFFSOP_SET(pops, perfuse, node, rename);
459 	PUFFSOP_SET(pops, perfuse, node, mkdir);
460 	PUFFSOP_SET(pops, perfuse, node, rmdir);
461 	PUFFSOP_SET(pops, perfuse, node, symlink);
462 	PUFFSOP_SET(pops, perfuse, node, readdir);
463 	PUFFSOP_SET(pops, perfuse, node, readlink);
464 	PUFFSOP_SET(pops, perfuse, node, reclaim);
465 	PUFFSOP_SET(pops, perfuse, node, inactive);
466 	PUFFSOP_SET(pops, perfuse, node, print);
467 	PUFFSOP_SET(pops, perfuse, node, advlock);
468 	PUFFSOP_SET(pops, perfuse, node, read);
469 	PUFFSOP_SET(pops, perfuse, node, write);
470 
471 	puffs_flags = PUFFS_KFLAG_WTCACHE;
472 
473 	if (perfuse_diagflags & PDF_PUFFS)
474 		puffs_flags |= PUFFS_FLAG_OPDUMP;
475 
476 	if ((pu = puffs_init(pops, source, fstype, ps, puffs_flags)) == NULL)
477 		DERR(EX_OSERR, "puffs_init failed");
478 
479 	ps->ps_pu = pu;
480 
481 	/*
482 	 * Setup filesystem root
483 	 */
484 	pn_root = perfuse_new_pn(pu, "", NULL);
485 	PERFUSE_NODE_DATA(pn_root)->pnd_ino = FUSE_ROOT_ID;
486 	PERFUSE_NODE_DATA(pn_root)->pnd_parent = pn_root;
487 	puffs_setroot(pu, pn_root);
488 	ps->ps_fsid = pn_root->pn_va.va_fsid;
489 
490 	po_root = puffs_getrootpathobj(pu);
491 	if ((po_root->po_path = strdup("/")) == NULL)
492 		DERRX(EX_OSERR, "perfuse_mount_start() failed");
493 
494 	po_root->po_len = 1;
495 	puffs_path_buildhash(pu, po_root);
496 
497 	puffs_vattr_null(&pn_root->pn_va);
498 	pn_root->pn_va.va_type = VDIR;
499 	pn_root->pn_va.va_mode = 0755;
500 
501 	ps->ps_root = pn_root;
502 
503 	/*
504 	 *  Callbacks
505 	 */
506 	ps->ps_new_msg = pc->pc_new_msg;
507 	ps->ps_xchg_msg = pc->pc_xchg_msg;
508 	ps->ps_destroy_msg = pc->pc_destroy_msg;
509 	ps->ps_get_inhdr = pc->pc_get_inhdr;
510 	ps->ps_get_inpayload = pc->pc_get_inpayload;
511 	ps->ps_get_outhdr = pc->pc_get_outhdr;
512 	ps->ps_get_outpayload = pc->pc_get_outpayload;
513 
514 	return pu;
515 }
516 
517 void
518 perfuse_setspecific(pu, priv)
519 	struct puffs_usermount *pu;
520 	void *priv;
521 {
522 	struct perfuse_state *ps;
523 
524 	ps = puffs_getspecific(pu);
525 	ps->ps_private = priv;
526 
527 	return;
528 }
529 
530 void *
531 perfuse_getspecific(pu)
532 	struct puffs_usermount *pu;
533 {
534 	struct perfuse_state *ps;
535 
536 	ps = puffs_getspecific(pu);
537 
538 	return ps->ps_private;
539 }
540 
541 int
542 perfuse_inloop(pu)
543 	struct puffs_usermount *pu;
544 {
545 	struct perfuse_state *ps;
546 
547 	ps = puffs_getspecific(pu);
548 
549 	return ps->ps_flags & PS_INLOOP;
550 }
551 
552 int
553 perfuse_mainloop(pu)
554 	struct puffs_usermount *pu;
555 {
556 	struct perfuse_state *ps;
557 
558 	ps = puffs_getspecific(pu);
559 
560 	ps->ps_flags |= PS_INLOOP;
561 	if (puffs_mainloop(ps->ps_pu) != 0)
562 		DERR(EX_OSERR, "puffs_mainloop failed");
563 	DERR(EX_OSERR, "puffs_mainloop exit");
564 
565 	/* NOTREACHED */
566 	return -1;
567 }
568 
569 /* ARGSUSED0 */
570 uint64_t
571 perfuse_get_ino(pu, opc)
572 	struct puffs_usermount *pu;
573 	puffs_cookie_t opc;
574 {
575 	return PERFUSE_NODE_DATA(opc)->pnd_ino;
576 }
577 
578 int
579 perfuse_unmount(pu)
580 	struct puffs_usermount *pu;
581 {
582 	struct perfuse_state *ps;
583 
584 	ps = puffs_getspecific(pu);
585 
586 	return unmount(ps->ps_target, MNT_FORCE);
587 }
588