xref: /netbsd-src/usr.sbin/perfused/perfused.c (revision 179b12252ecaf3553d9c2b7458ce62b6a2203d0c)
1 /*  $NetBSD: perfused.c,v 1.3 2010/08/27 09:58:17 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);
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 static int
64 getpeerid(s, pidp, uidp, gidp)
65 	int s;
66 	pid_t *pidp;
67 	uid_t *uidp;
68 	gid_t *gidp;
69 {
70 	struct unpcbid unp;
71 	socklen_t len;
72 	int error;
73 
74 	len = sizeof(unp);
75 	error = getsockopt(s, 0, LOCAL_PEEREID, &unp, &len);
76 	if (error != 0)
77 		return error;
78 
79 	if (pidp != NULL)
80 		*pidp = unp.unp_pid;
81 
82 	if (uidp != NULL)
83 		*uidp = unp.unp_euid;
84 
85 	if (gidp != NULL)
86 		*gidp = unp.unp_egid;
87 
88 	return 0;
89 }
90 
91 static int
92 access_mount(mnt, uid, ro)
93 	const char *mnt;
94 	uid_t uid;
95 	int ro;
96 {
97 	struct stat st;
98 	mode_t mode;
99 
100 	if (uid == 0)
101 		return 0;
102 
103 	if (stat(mnt, &st) == -1)
104 		return -1;
105 
106 	if (st.st_uid != uid)
107 		return -1;
108 
109 	mode = S_IRUSR;
110 	if (!ro)
111 		mode |= S_IWUSR;
112 
113 	if ((st.st_mode & mode) == mode)
114 		return 0;
115 
116 	return -1;
117 }
118 
119 static void
120 get_mount_info(fd, pmi)
121 	int fd;
122 	struct perfuse_mount_info *pmi;
123 {
124 	struct perfuse_mount_out *pmo;
125 	char *source = NULL;
126 	char *target = NULL;
127 	char *filesystemtype = NULL;
128 	long mountflags = 0;
129 	void *data;
130 	size_t len;
131 
132 	pmo = (struct perfuse_mount_out *)perfuse_recv_early(fd, sizeof(*pmo));
133 	if (pmo == NULL) {
134 		if (shutdown(fd, SHUT_RDWR) != 0)
135 			DERR(EX_OSERR, "shutdown failed");
136 		exit(EX_PROTOCOL);
137 	}
138 
139 #ifdef PERFUSE_DEBUG
140 	DPRINTF("perfuse lengths: source = %d, target = %d, "
141 	       "filesystemtype = %d, data = %d\n",
142 		pmo->pmo_source_len,
143 		pmo->pmo_target_len,
144 		pmo->pmo_filesystemtype_len,
145 		pmo->pmo_data_len);
146 #endif
147 	len = pmo->pmo_source_len;
148 	source = perfuse_recv_early(fd, len);
149 
150 	len = pmo->pmo_target_len;
151 	target = perfuse_recv_early(fd, len);
152 
153 	len = pmo->pmo_filesystemtype_len;
154 	filesystemtype = perfuse_recv_early(fd, len);
155 
156 	mountflags = pmo->pmo_mountflags;
157 
158 	len = pmo->pmo_data_len;
159 	data = perfuse_recv_early(fd, len);
160 
161 #ifdef PERFUSE_DEBUG
162 	DPRINTF("%s(\"%s\", \"%s\", \"%s\", 0x%lx, \"%s\")\n", __func__,
163 	       source, target, filesystemtype, mountflags, (const char *)data);
164 #endif
165 	pmi->pmi_source = source;
166 	pmi->pmi_target = target;
167 	pmi->pmi_filesystemtype = filesystemtype;
168 	pmi->pmi_mountflags = mountflags;
169 	pmi->pmi_data = data;
170 
171 	return;
172 }
173 
174 static void
175 new_mount(fd)
176 	int fd;
177 {
178 	struct puffs_usermount *pu;
179 	struct perfuse_mount_info pmi;
180 	struct perfuse_callbacks pc;
181 	int ro_flag;
182 	pid_t pid;
183 	int flags;
184 
185 
186 	pid = (perfuse_diagflags & PDF_FOREGROUND) ? 0 : fork();
187 	switch(pid) {
188 	case -1:
189 		DERR(EX_OSERR, "cannot fork");
190 		break;
191 	case 0:
192 		break;
193 	default:
194 		return;
195 		/* NOTREACHED */
196 		break;
197 	}
198 
199 	/*
200 	 * Mount information (source, target, mount flags...)
201 	 */
202 	get_mount_info(fd, &pmi);
203 
204 	/*
205 	 * Get peer identity
206 	 */
207 	if (getpeerid(fd, NULL, &pmi.pmi_uid, NULL) != 0)
208 		DWARNX("Unable to retreive peer identity");
209 
210 	/*
211 	 * Check that peer owns mountpoint and read (and write) on it?
212 	 */
213 	ro_flag = pmi.pmi_mountflags & MNT_RDONLY;
214 	if (access_mount(pmi.pmi_target, pmi.pmi_uid, ro_flag) != 0)
215 		DERRX(EX_NOPERM, "insuficient privvileges to mount %s",
216 		      pmi.pmi_target);
217 
218 
219 	/*
220 	 * Initialize libperfuse, which will initialize libpuffs
221 	 */
222 	pc.pc_new_msg = perfuse_new_pb;
223 	pc.pc_xchg_msg = perfuse_xchg_pb;
224 	pc.pc_destroy_msg = (perfuse_destroy_msg_fn)puffs_framebuf_destroy;
225 	pc.pc_get_inhdr = perfuse_get_inhdr;
226 	pc.pc_get_inpayload = perfuse_get_inpayload;
227 	pc.pc_get_outhdr = perfuse_get_outhdr;
228 	pc.pc_get_outpayload = perfuse_get_outpayload;
229 
230 	pu = perfuse_init(&pc, &pmi);
231 
232 	puffs_framev_init(pu, perfuse_readframe, perfuse_writeframe,
233 			  perfuse_cmpframe, perfuse_gotframe, perfuse_fdnotify);
234 
235 	if (puffs_framev_addfd(pu, fd, PUFFS_FBIO_READ|PUFFS_FBIO_WRITE) == -1)
236 		DERR(EX_SOFTWARE, "puffs_framev_addfd failed");
237 
238 	perfuse_setspecific(pu, (void *)fd);
239 
240 	setproctitle("perfused %s", pmi.pmi_target);
241 	(void)kill(getpid(), SIGINFO);		/* This is for -s option */
242 
243 	perfuse_fs_init(pu);
244 
245 	/*
246 	 * Non blocking I/O on /dev/fuse
247 	 * This must be done after perfuse_fs_init
248 	 */
249 	if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
250 		DERR(EX_OSERR, "fcntl failed");
251 	if (fcntl(fd, F_SETFL, flags|O_NONBLOCK) != 0)
252 		DERR(EX_OSERR, "fcntl failed");
253 
254 	/*
255 	 * Hand over control to puffs main loop.
256 	 */
257 	(void)perfuse_mainloop(pu);
258 
259 	DERRX(EX_SOFTWARE, "perfuse_mainloop exit");
260 
261 	/* NOTREACHED */
262 	return;
263 }
264 
265 static int
266 parse_debug(optstr)
267 	char *optstr;
268 {
269 	int retval = PDF_SYSLOG;
270 	char *opt;
271 	char *lastp;
272 
273 	for (opt = strtok_r(optstr, ",", &lastp);
274 	     opt;
275 	     opt = strtok_r(NULL, ",", &lastp)) {
276 		if (strcmp(opt, "fuse") == 0)
277 			retval |= PDF_FUSE;
278 		else if (strcmp(opt, "puffs") == 0)
279 			retval |= PDF_PUFFS;
280 		else if (strcmp(opt, "dump") == 0)
281 			retval |= PDF_DUMP;
282 		else if (strcmp(opt, "fh") == 0)
283 			retval |= PDF_FH;
284 		else if (strcmp(opt, "readdir") == 0)
285 			retval |= PDF_READDIR;
286 		else if (strcmp(opt, "reclaim") == 0)
287 			retval |= PDF_RECLAIM;
288 		else if (strcmp(opt, "requeue") == 0)
289 			retval |= PDF_REQUEUE;
290 		else if (strcmp(opt, "sync") == 0)
291 			retval |= PDF_SYNC;
292 		else if (strcmp(opt, "misc") == 0)
293 			retval |= PDF_MISC;
294 		else
295 			DERRX(EX_USAGE, "unknown debug flag \"%s\"", opt);
296 	}
297 
298 	return retval;
299 }
300 
301 /* ARGSUSED0 */
302 static void
303 siginfo_handler(sig)
304 	int sig;
305 {
306 	static int old_flags = 0;
307 	int swap;
308 
309 	swap = perfuse_diagflags;
310 	perfuse_diagflags = old_flags;
311 	old_flags = swap;
312 
313 	DWARNX("debug %sabled", old_flags == 0 ? "en" : "dis");
314 
315 	return;
316 }
317 
318 static int
319 parse_options(argc, argv)
320 	int argc;
321 	char **argv;
322 {
323 	int ch;
324 	int foreground = 0;
325 	int retval = -1;
326 
327 	perfuse_diagflags = PDF_FOREGROUND | PDF_SYSLOG;
328 
329 	while ((ch = getopt(argc, argv, "d:fsi:")) != -1) {
330 		switch (ch) {
331 		case 'd':
332 			perfuse_diagflags |= parse_debug(optarg);
333 			break;
334 		case 's':
335 			if (signal(SIGINFO, siginfo_handler) != 0)
336 				DERR(EX_OSERR, "signal failed");
337 			break;
338 		case 'f':
339 			foreground = 1;
340 			break;
341 		case 'i':
342 			retval = atoi(optarg);
343 			foreground = 1;
344 			break;
345 		default:
346 			DERR(EX_USAGE, "%s [-d level] [-s] [-f] [-i fd]", argv[0]);
347 			break;
348 		}
349 	}
350 
351 	if (!foreground)
352 		perfuse_diagflags &= ~PDF_FOREGROUND;
353 
354 	return retval;
355 }
356 
357 int
358 main(argc, argv)
359 	int argc;
360 	char **argv;
361 {
362 	int s;
363 
364 	s = parse_options(argc, argv);
365 
366 	if (perfuse_diagflags & PDF_SYSLOG)
367 		openlog("perfused", 0, LOG_DAEMON);
368 
369 	if (!(perfuse_diagflags & PDF_FOREGROUND))
370 		if (daemon(0, 0) != 0)
371 			DERR(EX_OSERR, "daemon failed");
372 
373 	if (s != -1) {
374 		new_mount(s);
375 		DERRX(EX_SOFTWARE, "new_mount exit while -i is used");
376 	}
377 
378 	s = perfuse_open_sock();
379 
380 	do {
381 		struct sockaddr *sa;
382 		struct sockaddr_storage ss;
383 		socklen_t ss_len;
384 		int fd;
385 
386 #ifdef PERFUSE_DEBUG
387 		if (perfuse_diagflags & PDF_MISC)
388 			DPRINTF("waiting connexion\n");
389 #endif
390 		sa = (struct sockaddr *)(void *)&ss;
391 		ss_len = sizeof(ss);
392 		if ((fd = accept(s, sa, &ss_len)) == -1)
393 			DERR(EX_OSERR,  "accept failed");
394 #ifdef PERFUSE_DEBUG
395 		if (perfuse_diagflags & PDF_MISC)
396 			DPRINTF("connexion accepted\n");
397 #endif
398 		new_mount(fd);
399 	} while (1 /* CONSTCOND */);
400 
401 	/* NOTREACHED */
402 	return 0;
403 }
404