xref: /netbsd-src/usr.sbin/perfused/perfused.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*  $NetBSD: perfused.c,v 1.7 2010/09/07 02:11:04 manu Exp $ */
2 
3 /*-
4  *  Copyright (c) 2010 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 <syslog.h>
33 #include <ctype.h>
34 #include <paths.h>
35 #include <stdarg.h>
36 #include <err.h>
37 #include <errno.h>
38 #include <string.h>
39 #include <sysexits.h>
40 #include <signal.h>
41 #include <puffs.h>
42 #include <sys/wait.h>
43 #include <sys/param.h>
44 #include <sys/queue.h>
45 #include <sys/uio.h>
46 #include <sys/socket.h>
47 #include <sys/un.h>
48 #include <machine/vmparam.h>
49 
50 #include "../../lib/libperfuse/perfuse_if.h"
51 #include "perfused.h"
52 
53 static int getpeerid(int, pid_t *, uid_t *, gid_t *);
54 static int access_mount(const char *, uid_t, int);
55 static void new_mount(int, int);
56 static int parse_debug(char *);
57 static void siginfo_handler(int);
58 static int parse_options(int, char **);
59 static void get_mount_info(int, struct perfuse_mount_info *);
60 int main(int, char **);
61 
62 /*
63  * Flags for new_mount()
64  */
65 #define  PMNT_DEVFUSE	0x0	/* We use /dev/fuse */
66 #define  PMNT_SOCKPAIR	0x1	/* We use socketpair */
67 
68 
69 static int
70 getpeerid(s, pidp, uidp, gidp)
71 	int s;
72 	pid_t *pidp;
73 	uid_t *uidp;
74 	gid_t *gidp;
75 {
76 	struct unpcbid unp;
77 	socklen_t len;
78 	int error;
79 
80 	len = sizeof(unp);
81 	error = getsockopt(s, 0, LOCAL_PEEREID, &unp, &len);
82 	if (error != 0)
83 		return error;
84 
85 	if (pidp != NULL)
86 		*pidp = unp.unp_pid;
87 
88 	if (uidp != NULL)
89 		*uidp = unp.unp_euid;
90 
91 	if (gidp != NULL)
92 		*gidp = unp.unp_egid;
93 
94 	return 0;
95 }
96 
97 static int
98 access_mount(mnt, uid, ro)
99 	const char *mnt;
100 	uid_t uid;
101 	int ro;
102 {
103 	struct stat st;
104 	mode_t mode;
105 
106 	if (uid == 0)
107 		return 0;
108 
109 	if (stat(mnt, &st) == -1)
110 		return -1;
111 
112 	if (st.st_uid != uid)
113 		return -1;
114 
115 	mode = S_IRUSR;
116 	if (!ro)
117 		mode |= S_IWUSR;
118 
119 	if ((st.st_mode & mode) == mode)
120 		return 0;
121 
122 	return -1;
123 }
124 
125 static void
126 get_mount_info(fd, pmi)
127 	int fd;
128 	struct perfuse_mount_info *pmi;
129 {
130 	struct perfuse_mount_out *pmo;
131 	char *source = NULL;
132 	char *target = NULL;
133 	char *filesystemtype = NULL;
134 	long mountflags = 0;
135 	void *data;
136 	size_t len;
137 
138 	pmo = (struct perfuse_mount_out *)perfuse_recv_early(fd, sizeof(*pmo));
139 	if (pmo == NULL) {
140 		if (shutdown(fd, SHUT_RDWR) != 0)
141 			DERR(EX_OSERR, "shutdown failed");
142 		exit(EX_PROTOCOL);
143 	}
144 
145 #ifdef PERFUSE_DEBUG
146 	if (perfuse_diagflags & PDF_MISC)
147 		DPRINTF("perfuse lengths: source = %"PRId32", "
148 			"target = %"PRId32", filesystemtype = %"PRId32", "
149 			"data = %"PRId32"\n", pmo->pmo_source_len,
150 			pmo->pmo_target_len, pmo->pmo_filesystemtype_len,
151 			pmo->pmo_data_len);
152 #endif
153 	len = pmo->pmo_source_len;
154 	source = perfuse_recv_early(fd, len);
155 
156 	len = pmo->pmo_target_len;
157 	target = perfuse_recv_early(fd, len);
158 
159 	len = pmo->pmo_filesystemtype_len;
160 	filesystemtype = perfuse_recv_early(fd, len);
161 
162 	mountflags = pmo->pmo_mountflags;
163 
164 	len = pmo->pmo_data_len;
165 	data = perfuse_recv_early(fd, len);
166 
167 #ifdef PERFUSE_DEBUG
168 	if (perfuse_diagflags & PDF_MISC)
169 		DPRINTF("%s(\"%s\", \"%s\", \"%s\", 0x%lx, \"%s\")\n",
170 		__func__, source, target, filesystemtype,
171 		mountflags, (const char *)data);
172 #endif
173 	pmi->pmi_source = source;
174 	pmi->pmi_target = target;
175 	pmi->pmi_filesystemtype = filesystemtype;
176 	pmi->pmi_mountflags = (int)mountflags;
177 	pmi->pmi_data = data;
178 
179 	return;
180 }
181 
182 static void
183 new_mount(fd, pmnt_flags)
184 	int fd;
185 	int pmnt_flags;
186 {
187 	struct puffs_usermount *pu;
188 	struct perfuse_mount_info pmi;
189 	struct perfuse_callbacks pc;
190 	int ro_flag;
191 	pid_t pid;
192 	int flags;
193 
194 
195 	pid = (perfuse_diagflags & PDF_FOREGROUND) ? 0 : fork();
196 	switch(pid) {
197 	case -1:
198 		DERR(EX_OSERR, "cannot fork");
199 		break;
200 	case 0:
201 		break;
202 	default:
203 		return;
204 		/* NOTREACHED */
205 		break;
206 	}
207 
208 	/*
209 	 * Mount information (source, target, mount flags...)
210 	 */
211 	get_mount_info(fd, &pmi);
212 
213 	/*
214 	 * Get peer identity. If we use socketpair (-i option),
215 	 * peer identity if the same as us.
216 	 */
217 	if (pmnt_flags & PMNT_SOCKPAIR) {
218 		pmi.pmi_uid = getuid();
219 	} else {
220 		if (getpeerid(fd, NULL, &pmi.pmi_uid, NULL) != 0) {
221 			DWARNX("Unable to retreive peer identity");
222 			pmi.pmi_uid = (uid_t)-1;
223 		}
224 	}
225 
226 	/*
227 	 * Check that peer owns mountpoint and read (and write) on it?
228 	 */
229 	ro_flag = pmi.pmi_mountflags & MNT_RDONLY;
230 	if (access_mount(pmi.pmi_target, pmi.pmi_uid, ro_flag) != 0)
231 		DERRX(EX_NOPERM, "insuficient privileges to mount on %s",
232 		      pmi.pmi_target);
233 
234 
235 	/*
236 	 * Initialize libperfuse, which will initialize libpuffs
237 	 */
238 	pc.pc_new_msg = perfuse_new_pb;
239 	pc.pc_xchg_msg = perfuse_xchg_pb;
240 	pc.pc_destroy_msg = (perfuse_destroy_msg_fn)puffs_framebuf_destroy;
241 	pc.pc_get_inhdr = perfuse_get_inhdr;
242 	pc.pc_get_inpayload = perfuse_get_inpayload;
243 	pc.pc_get_outhdr = perfuse_get_outhdr;
244 	pc.pc_get_outpayload = perfuse_get_outpayload;
245 
246 	pu = perfuse_init(&pc, &pmi);
247 
248 	puffs_framev_init(pu, perfuse_readframe, perfuse_writeframe,
249 			  perfuse_cmpframe, perfuse_gotframe, perfuse_fdnotify);
250 
251 	if (puffs_framev_addfd(pu, fd, PUFFS_FBIO_READ|PUFFS_FBIO_WRITE) == -1)
252 		DERR(EX_SOFTWARE, "puffs_framev_addfd failed");
253 
254 	perfuse_setspecific(pu, (void *)(long)fd);
255 
256 	setproctitle("perfused %s", pmi.pmi_target);
257 	(void)kill(getpid(), SIGINFO);		/* This is for -s option */
258 
259 	perfuse_fs_init(pu);
260 
261 	/*
262 	 * Non blocking I/O on /dev/fuse
263 	 * This must be done after perfuse_fs_init
264 	 */
265 	if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
266 		DERR(EX_OSERR, "fcntl failed");
267 	if (fcntl(fd, F_SETFL, flags|O_NONBLOCK) != 0)
268 		DERR(EX_OSERR, "fcntl failed");
269 
270 	/*
271 	 * Hand over control to puffs main loop.
272 	 */
273 	(void)perfuse_mainloop(pu);
274 
275 	DERRX(EX_SOFTWARE, "perfuse_mainloop exit");
276 
277 	/* NOTREACHED */
278 	return;
279 }
280 
281 static int
282 parse_debug(optstr)
283 	char *optstr;
284 {
285 	int retval = PDF_SYSLOG;
286 	char *opt;
287 	char *lastp;
288 
289 	for (opt = strtok_r(optstr, ",", &lastp);
290 	     opt;
291 	     opt = strtok_r(NULL, ",", &lastp)) {
292 		if (strcmp(opt, "fuse") == 0)
293 			retval |= PDF_FUSE;
294 		else if (strcmp(opt, "puffs") == 0)
295 			retval |= PDF_PUFFS;
296 		else if (strcmp(opt, "dump") == 0)
297 			retval |= PDF_DUMP;
298 		else if (strcmp(opt, "fh") == 0)
299 			retval |= PDF_FH;
300 		else if (strcmp(opt, "readdir") == 0)
301 			retval |= PDF_READDIR;
302 		else if (strcmp(opt, "reclaim") == 0)
303 			retval |= PDF_RECLAIM;
304 		else if (strcmp(opt, "requeue") == 0)
305 			retval |= PDF_REQUEUE;
306 		else if (strcmp(opt, "sync") == 0)
307 			retval |= PDF_SYNC;
308 		else if (strcmp(opt, "misc") == 0)
309 			retval |= PDF_MISC;
310 		else
311 			DERRX(EX_USAGE, "unknown debug flag \"%s\"", opt);
312 	}
313 
314 	return retval;
315 }
316 
317 /* ARGSUSED0 */
318 static void
319 siginfo_handler(sig)
320 	int sig;
321 {
322 	static int old_flags = 0;
323 	int swap;
324 
325 	swap = perfuse_diagflags;
326 	perfuse_diagflags = old_flags;
327 	old_flags = swap;
328 
329 	DWARNX("debug %sabled", old_flags == 0 ? "en" : "dis");
330 
331 	return;
332 }
333 
334 static int
335 parse_options(argc, argv)
336 	int argc;
337 	char **argv;
338 {
339 	int ch;
340 	int foreground = 0;
341 	int retval = -1;
342 
343 	perfuse_diagflags = PDF_FOREGROUND | PDF_SYSLOG;
344 
345 	while ((ch = getopt(argc, argv, "d:fsi:")) != -1) {
346 		switch (ch) {
347 		case 'd':
348 			perfuse_diagflags |= parse_debug(optarg);
349 			break;
350 		case 's':
351 			if (signal(SIGINFO, siginfo_handler) != 0)
352 				DERR(EX_OSERR, "signal failed");
353 			break;
354 		case 'f':
355 			foreground = 1;
356 			perfuse_diagflags |= PDF_MISC;
357 			break;
358 		case 'i':
359 			retval = atoi(optarg);
360 			foreground = 1;
361 			break;
362 		default:
363 			DERR(EX_USAGE, "%s [-fs] [-d level] [-i fd]", argv[0]);
364 			break;
365 		}
366 	}
367 
368 	if (!foreground)
369 		perfuse_diagflags &= ~PDF_FOREGROUND;
370 
371 	return retval;
372 }
373 
374 int
375 main(argc, argv)
376 	int argc;
377 	char **argv;
378 {
379 	int s;
380 
381 	s = parse_options(argc, argv);
382 
383 	if (perfuse_diagflags & PDF_SYSLOG)
384 		openlog("perfused", 0, LOG_DAEMON);
385 
386 	if (!(perfuse_diagflags & PDF_FOREGROUND))
387 		if (daemon(0, 0) != 0)
388 			DERR(EX_OSERR, "daemon failed");
389 
390 	if (s != -1) {
391 		new_mount(s, PMNT_SOCKPAIR);
392 		DERRX(EX_SOFTWARE, "new_mount exit while -i is used");
393 	}
394 
395 	s = perfuse_open_sock();
396 
397 	do {
398 		struct sockaddr *sa;
399 		struct sockaddr_storage ss;
400 		socklen_t ss_len;
401 		int fd;
402 
403 #ifdef PERFUSE_DEBUG
404 		if (perfuse_diagflags & PDF_MISC)
405 			DPRINTF("waiting connexion\n");
406 #endif
407 		sa = (struct sockaddr *)(void *)&ss;
408 		ss_len = sizeof(ss);
409 		if ((fd = accept(s, sa, &ss_len)) == -1)
410 			DERR(EX_OSERR,  "accept failed");
411 #ifdef PERFUSE_DEBUG
412 		if (perfuse_diagflags & PDF_MISC)
413 			DPRINTF("connexion accepted\n");
414 #endif
415 		new_mount(fd, PMNT_DEVFUSE);
416 	} while (1 /* CONSTCOND */);
417 
418 	/* NOTREACHED */
419 	return 0;
420 }
421