xref: /freebsd/usr.bin/fstat/fuser.c (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005-2009 Stanislav Sedov <stas@FreeBSD.org>
5  * All rights reserved.
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 <sys/cdefs.h>
30 #include <sys/queue.h>
31 #include <sys/stat.h>
32 #include <sys/sysctl.h>
33 #include <sys/user.h>
34 
35 #include <assert.h>
36 #include <ctype.h>
37 #include <err.h>
38 #include <fcntl.h>
39 #include <libprocstat.h>
40 #include <limits.h>
41 #include <paths.h>
42 #include <pwd.h>
43 #include <signal.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <sysexits.h>
48 #include <unistd.h>
49 
50 #include "functions.h"
51 
52 /*
53  * File access mode flags table.
54  */
55 static const struct {
56 	int	flag;
57 	char	ch;
58 } fflags[] = {
59 	{PS_FST_FFLAG_WRITE,	'w'},
60 	{PS_FST_FFLAG_APPEND,	'a'},
61 	{PS_FST_FFLAG_DIRECT,	'd'},
62 	{PS_FST_FFLAG_SHLOCK,	's'},
63 	{PS_FST_FFLAG_EXLOCK,	'e'}
64 };
65 #define	NFFLAGS	(sizeof(fflags) / sizeof(*fflags))
66 
67 /*
68  * Usage flags translation table.
69  */
70 static const struct {
71 	int	flag;
72 	char	ch;
73 } uflags[] = {
74 	{PS_FST_UFLAG_RDIR,	'r'},
75 	{PS_FST_UFLAG_CDIR,	'c'},
76 	{PS_FST_UFLAG_JAIL,	'j'},
77 	{PS_FST_UFLAG_TRACE,	't'},
78 	{PS_FST_UFLAG_TEXT,	'x'},
79 	{PS_FST_UFLAG_MMAP,	'm'},
80 	{PS_FST_UFLAG_CTTY,	'y'}
81 };
82 #define	NUFLAGS	(sizeof(uflags) / sizeof(*uflags))
83 
84 struct consumer {
85 	pid_t	pid;
86 	uid_t	uid;
87 	int	fd;
88 	int	flags;
89 	int	uflags;
90 	STAILQ_ENTRY(consumer)	next;
91 };
92 struct reqfile {
93 	dev_t		fsid;
94 	ino_t		fileid;
95 	const char	*name;
96 	STAILQ_HEAD(, consumer) consumers;
97 };
98 
99 /*
100  * Option flags.
101  */
102 #define	UFLAG	0x01	/* -u flag: show users				*/
103 #define	FFLAG	0x02	/* -f flag: specified files only		*/
104 #define	CFLAG	0x04	/* -c flag: treat as mpoints			*/
105 #define	MFLAG	0x10	/* -m flag: mmapped files too			*/
106 #define	KFLAG	0x20	/* -k flag: send signal (SIGKILL by default)	*/
107 
108 static int flags = 0;	/* Option flags. */
109 
110 static void	printflags(struct consumer *consumer);
111 static int	str2sig(const char *str);
112 static void	usage(void) __dead2;
113 static int	addfile(const char *path, struct reqfile *reqfile);
114 static void	dofiles(struct procstat *procstat, struct kinfo_proc *kp,
115     struct reqfile *reqfiles, size_t nfiles);
116 
117 static void
118 usage(void)
119 {
120 
121 	fprintf(stderr,
122 "usage: fuser [-cfhkmu] [-M core] [-N system] [-s signal] file ...\n");
123 	exit(EX_USAGE);
124 }
125 
126 static void
127 printflags(struct consumer *cons)
128 {
129 	unsigned int i;
130 
131 	assert(cons);
132 	for (i = 0; i < NUFLAGS; i++)
133 		if ((cons->uflags & uflags[i].flag) != 0)
134 			fputc(uflags[i].ch, stderr);
135 	for (i = 0; i < NFFLAGS; i++)
136 		if ((cons->flags & fflags[i].flag) != 0)
137 			fputc(fflags[i].ch, stderr);
138 }
139 
140 /*
141  * Add file to the list.
142  */
143 static int
144 addfile(const char *path, struct reqfile *reqfile)
145 {
146 	struct stat sb;
147 
148 	assert(path);
149 	if (stat(path, &sb) != 0) {
150 		warn("%s", path);
151 		return (1);
152 	}
153 	reqfile->fileid = sb.st_ino;
154 	reqfile->fsid = sb.st_dev;
155 	reqfile->name = path;
156 	STAILQ_INIT(&reqfile->consumers);
157 	return (0);
158 }
159 
160 int
161 do_fuser(int argc, char *argv[])
162 {
163 	struct consumer *consumer;
164 	struct kinfo_proc *procs;
165 	struct procstat *procstat;
166 	struct reqfile *reqfiles;
167 	char *ep, *nlistf, *memf;
168 	int ch, sig;
169 	unsigned int i, cnt, nfiles;
170 
171 	sig = SIGKILL;	/* Default to kill. */
172 	nlistf = NULL;
173 	memf = NULL;
174 	while ((ch = getopt(argc, argv, "M:N:cfhkms:u")) != -1)
175 		switch(ch) {
176 		case 'f':
177 			if ((flags & CFLAG) != 0)
178 				usage();
179 			flags |= FFLAG;
180 			break;
181 		case 'c':
182 			if ((flags & FFLAG) != 0)
183 				usage();
184 			flags |= CFLAG;
185 			break;
186 		case 'N':
187 			nlistf = optarg;
188 			break;
189 		case 'M':
190 			memf = optarg;
191 			break;
192 		case 'u':
193 			flags |= UFLAG;
194 			break;
195 		case 'm':
196 			flags |= MFLAG;
197 			break;
198 		case 'k':
199 			flags |= KFLAG;
200 			break;
201 		case 's':
202 			if (isdigit(*optarg)) {
203 				sig = strtol(optarg, &ep, 10);
204 				if (*ep != '\0' || sig < 0 || sig >= sys_nsig)
205 					errx(EX_USAGE, "illegal signal number" ": %s",
206 					    optarg);
207 			} else {
208 				sig = str2sig(optarg);
209 				if (sig < 0)
210 					errx(EX_USAGE, "illegal signal name: "
211 					    "%s", optarg);
212 			}
213 			break;
214 		case 'h':
215 			/* PASSTHROUGH */
216 		default:
217 			usage();
218 			/* NORETURN */
219 		}
220 	argv += optind;
221 	argc -= optind;
222 
223 	assert(argc >= 0);
224 	if (argc == 0)
225 		usage();
226 		/* NORETURN */
227 
228 	/*
229 	 * Process named files.
230 	 */
231 	reqfiles = malloc(argc * sizeof(struct reqfile));
232 	if (reqfiles == NULL)
233 		err(EX_OSERR, "malloc()");
234 	nfiles = 0;
235 	while (argc--)
236 		if (!addfile(*(argv++), &reqfiles[nfiles]))
237 			nfiles++;
238 	if (nfiles == 0)
239 		errx(EX_IOERR, "files not accessible");
240 
241 	if (memf != NULL)
242 		procstat = procstat_open_kvm(nlistf, memf);
243 	else
244 		procstat = procstat_open_sysctl();
245 	if (procstat == NULL)
246 		errx(1, "procstat_open()");
247 	procs = procstat_getprocs(procstat, KERN_PROC_PROC, 0, &cnt);
248 	if (procs == NULL)
249 		 errx(1, "procstat_getprocs()");
250 
251 	/*
252 	 * Walk through process table and look for matching files.
253 	 */
254 	for (i = 0; i < cnt; i++)
255 		if (procs[i].ki_stat != SZOMB)
256 			dofiles(procstat, &procs[i], reqfiles, nfiles);
257 
258 	for (i = 0; i < nfiles; i++) {
259 		fprintf(stderr, "%s:", reqfiles[i].name);
260 		fflush(stderr);
261 		STAILQ_FOREACH(consumer, &reqfiles[i].consumers, next) {
262 			if (consumer->flags != 0) {
263 				fprintf(stdout, "%6d", consumer->pid);
264 				fflush(stdout);
265 				printflags(consumer);
266 				if ((flags & UFLAG) != 0)
267 					fprintf(stderr, "(%s)",
268 					    user_from_uid(consumer->uid, 0));
269 				if ((flags & KFLAG) != 0)
270 					kill(consumer->pid, sig);
271 				fflush(stderr);
272 			}
273 		}
274 		(void)fprintf(stderr, "\n");
275 	}
276 	procstat_freeprocs(procstat, procs);
277 	procstat_close(procstat);
278 	free(reqfiles);
279 	return (0);
280 }
281 
282 static void
283 dofiles(struct procstat *procstat, struct kinfo_proc *kp,
284     struct reqfile *reqfiles, size_t nfiles)
285 {
286 	struct vnstat vn;
287 	struct consumer *cons;
288 	struct filestat *fst;
289 	struct filestat_list *head;
290 	int error, match;
291 	unsigned int i;
292 	char errbuf[_POSIX2_LINE_MAX];
293 
294 	head = procstat_getfiles(procstat, kp, flags & MFLAG);
295 	if (head == NULL)
296 		return;
297 	STAILQ_FOREACH(fst, head, next) {
298 		if (fst->fs_type != PS_FST_TYPE_VNODE)
299 			continue;
300 		error = procstat_get_vnode_info(procstat, fst, &vn, errbuf);
301 		if (error != 0)
302 			continue;
303 		for (i = 0; i < nfiles; i++) {
304 			if (flags & CFLAG && reqfiles[i].fsid == vn.vn_fsid) {
305 				break;
306 			}
307 			else if (reqfiles[i].fsid == vn.vn_fsid &&
308 			    reqfiles[i].fileid == vn.vn_fileid) {
309 				break;
310 			}
311 			else if (!(flags & FFLAG) &&
312 			    (vn.vn_type == PS_FST_VTYPE_VCHR ||
313 			    vn.vn_type == PS_FST_VTYPE_VBLK) &&
314 			    vn.vn_fsid == reqfiles[i].fileid) {
315 				break;
316 			}
317 		}
318 		if (i == nfiles)
319 			continue;	/* No match. */
320 
321 		/*
322 		 * Look for existing entries.
323 		 */
324 		match = 0;
325 		STAILQ_FOREACH(cons, &reqfiles[i].consumers, next)
326 			if (cons->pid == kp->ki_pid) {
327 				match = 1;
328 				break;
329 			}
330 		if (match == 1) {	/* Use old entry. */
331 			cons->flags |= fst->fs_fflags;
332 			cons->uflags |= fst->fs_uflags;
333 		} else {
334 			/*
335 			 * Create new entry in the consumer chain.
336 			 */
337 			cons = calloc(1, sizeof(struct consumer));
338 			if (cons == NULL) {
339 				warn("malloc()");
340 				continue;
341 			}
342 			cons->uid = kp->ki_uid;
343 			cons->pid = kp->ki_pid;
344 			cons->uflags = fst->fs_uflags;
345 			cons->flags = fst->fs_fflags;
346 			STAILQ_INSERT_TAIL(&reqfiles[i].consumers, cons, next);
347 		}
348 	}
349 	procstat_freefiles(procstat, head);
350 }
351 
352 /*
353  * Returns signal number for it's string representation.
354  */
355 static int
356 str2sig(const char *str)
357 {
358 	int i;
359 
360 	if (!strncasecmp(str, "SIG", 3))
361 		str += 3;
362 	for (i = 1; i < sys_nsig; i++) {
363                 if (!strcasecmp(sys_signame[i], str))
364                         return (i);
365         }
366         return (-1);
367 }
368