xref: /freebsd/usr.bin/fstat/fuser.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 __FBSDID("$FreeBSD$");
31 
32 #include <sys/queue.h>
33 #include <sys/stat.h>
34 #include <sys/sysctl.h>
35 #include <sys/user.h>
36 
37 #include <assert.h>
38 #include <ctype.h>
39 #include <err.h>
40 #include <fcntl.h>
41 #include <libprocstat.h>
42 #include <limits.h>
43 #include <paths.h>
44 #include <pwd.h>
45 #include <signal.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <sysexits.h>
50 #include <unistd.h>
51 
52 #include "functions.h"
53 
54 /*
55  * File access mode flags table.
56  */
57 static const struct {
58 	int	flag;
59 	char	ch;
60 } fflags[] = {
61 	{PS_FST_FFLAG_WRITE,	'w'},
62 	{PS_FST_FFLAG_APPEND,	'a'},
63 	{PS_FST_FFLAG_DIRECT,	'd'},
64 	{PS_FST_FFLAG_SHLOCK,	's'},
65 	{PS_FST_FFLAG_EXLOCK,	'e'}
66 };
67 #define	NFFLAGS	(sizeof(fflags) / sizeof(*fflags))
68 
69 /*
70  * Usage flags translation table.
71  */
72 static const struct {
73 	int	flag;
74 	char	ch;
75 } uflags[] = {
76 	{PS_FST_UFLAG_RDIR,	'r'},
77 	{PS_FST_UFLAG_CDIR,	'c'},
78 	{PS_FST_UFLAG_JAIL,	'j'},
79 	{PS_FST_UFLAG_TRACE,	't'},
80 	{PS_FST_UFLAG_TEXT,	'x'},
81 	{PS_FST_UFLAG_MMAP,	'm'},
82 	{PS_FST_UFLAG_CTTY,	'y'}
83 };
84 #define	NUFLAGS	(sizeof(uflags) / sizeof(*uflags))
85 
86 struct consumer {
87 	pid_t	pid;
88 	uid_t	uid;
89 	int	fd;
90 	int	flags;
91 	int	uflags;
92 	STAILQ_ENTRY(consumer)	next;
93 };
94 struct reqfile {
95 	dev_t		fsid;
96 	ino_t		fileid;
97 	const char	*name;
98 	STAILQ_HEAD(, consumer) consumers;
99 };
100 
101 /*
102  * Option flags.
103  */
104 #define	UFLAG	0x01	/* -u flag: show users				*/
105 #define	FFLAG	0x02	/* -f flag: specified files only		*/
106 #define	CFLAG	0x04	/* -c flag: treat as mpoints			*/
107 #define	MFLAG	0x10	/* -m flag: mmapped files too			*/
108 #define	KFLAG	0x20	/* -k flag: send signal (SIGKILL by default)	*/
109 
110 static int flags = 0;	/* Option flags. */
111 
112 static void	printflags(struct consumer *consumer);
113 static int	str2sig(const char *str);
114 static void	usage(void) __dead2;
115 static int	addfile(const char *path, struct reqfile *reqfile);
116 static void	dofiles(struct procstat *procstat, struct kinfo_proc *kp,
117     struct reqfile *reqfiles, size_t nfiles);
118 
119 static void
120 usage(void)
121 {
122 
123 	fprintf(stderr,
124 "usage: fuser [-cfhkmu] [-M core] [-N system] [-s signal] file ...\n");
125 	exit(EX_USAGE);
126 }
127 
128 static void
129 printflags(struct consumer *cons)
130 {
131 	unsigned int i;
132 
133 	assert(cons);
134 	for (i = 0; i < NUFLAGS; i++)
135 		if ((cons->uflags & uflags[i].flag) != 0)
136 			fputc(uflags[i].ch, stderr);
137 	for (i = 0; i < NFFLAGS; i++)
138 		if ((cons->flags & fflags[i].flag) != 0)
139 			fputc(fflags[i].ch, stderr);
140 }
141 
142 /*
143  * Add file to the list.
144  */
145 static int
146 addfile(const char *path, struct reqfile *reqfile)
147 {
148 	struct stat sb;
149 
150 	assert(path);
151 	if (stat(path, &sb) != 0) {
152 		warn("%s", path);
153 		return (1);
154 	}
155 	reqfile->fileid = sb.st_ino;
156 	reqfile->fsid = sb.st_dev;
157 	reqfile->name = path;
158 	STAILQ_INIT(&reqfile->consumers);
159 	return (0);
160 }
161 
162 int
163 do_fuser(int argc, char *argv[])
164 {
165 	struct consumer *consumer;
166 	struct kinfo_proc *p, *procs;
167 	struct procstat *procstat;
168 	struct reqfile *reqfiles;
169 	char *ep, *nlistf, *memf;
170 	int ch, cnt, sig;
171 	unsigned int i, nfiles;
172 
173 	sig = SIGKILL;	/* Default to kill. */
174 	nlistf = NULL;
175 	memf = NULL;
176 	while ((ch = getopt(argc, argv, "M:N:cfhkms:u")) != -1)
177 		switch(ch) {
178 		case 'f':
179 			if ((flags & CFLAG) != 0)
180 				usage();
181 			flags |= FFLAG;
182 			break;
183 		case 'c':
184 			if ((flags & FFLAG) != 0)
185 				usage();
186 			flags |= CFLAG;
187 			break;
188 		case 'N':
189 			nlistf = optarg;
190 			break;
191 		case 'M':
192 			memf = optarg;
193 			break;
194 		case 'u':
195 			flags |= UFLAG;
196 			break;
197 		case 'm':
198 			flags |= MFLAG;
199 			break;
200 		case 'k':
201 			flags |= KFLAG;
202 			break;
203 		case 's':
204 			if (isdigit(*optarg)) {
205 				sig = strtol(optarg, &ep, 10);
206 				if (*ep != '\0' || sig < 0 || sig >= sys_nsig)
207 					errx(EX_USAGE, "illegal signal number" ": %s",
208 					    optarg);
209 			} else {
210 				sig = str2sig(optarg);
211 				if (sig < 0)
212 					errx(EX_USAGE, "illegal signal name: "
213 					    "%s", optarg);
214 			}
215 			break;
216 		case 'h':
217 			/* PASSTHROUGH */
218 		default:
219 			usage();
220 			/* NORETURN */
221 		}
222 	argv += optind;
223 	argc -= optind;
224 
225 	assert(argc >= 0);
226 	if (argc == 0)
227 		usage();
228 		/* NORETURN */
229 
230 	/*
231 	 * Process named files.
232 	 */
233 	reqfiles = malloc(argc * sizeof(struct reqfile));
234 	if (reqfiles == NULL)
235 		err(EX_OSERR, "malloc()");
236 	nfiles = 0;
237 	while (argc--)
238 		if (!addfile(*(argv++), &reqfiles[nfiles]))
239 			nfiles++;
240 	if (nfiles == 0)
241 		errx(EX_IOERR, "files not accessible");
242 
243 	if (memf != NULL)
244 		procstat = procstat_open_kvm(nlistf, memf);
245 	else
246 		procstat = procstat_open_sysctl();
247 	if (procstat == NULL)
248 		errx(1, "procstat_open()");
249 	procs = procstat_getprocs(procstat, KERN_PROC_PROC, 0, &cnt);
250 	if (procs == NULL)
251 		 errx(1, "procstat_getprocs()");
252 
253 	/*
254 	 * Walk through process table and look for matching files.
255 	 */
256 	p = procs;
257 	while(cnt--)
258 		if (p->ki_stat != SZOMB)
259 			dofiles(procstat, p++, reqfiles, nfiles);
260 
261 	for (i = 0; i < nfiles; i++) {
262 		fprintf(stderr, "%s:", reqfiles[i].name);
263 		fflush(stderr);
264 		STAILQ_FOREACH(consumer, &reqfiles[i].consumers, next) {
265 			if (consumer->flags != 0) {
266 				fprintf(stdout, "%6d", consumer->pid);
267 				fflush(stdout);
268 				printflags(consumer);
269 				if ((flags & UFLAG) != 0)
270 					fprintf(stderr, "(%s)",
271 					    user_from_uid(consumer->uid, 0));
272 				if ((flags & KFLAG) != 0)
273 					kill(consumer->pid, sig);
274 				fflush(stderr);
275 			}
276 		}
277 		(void)fprintf(stderr, "\n");
278 	}
279 	procstat_freeprocs(procstat, procs);
280 	procstat_close(procstat);
281 	free(reqfiles);
282 	return (0);
283 }
284 
285 static void
286 dofiles(struct procstat *procstat, struct kinfo_proc *kp,
287     struct reqfile *reqfiles, size_t nfiles)
288 {
289 	struct vnstat vn;
290 	struct consumer *cons;
291 	struct filestat *fst;
292 	struct filestat_list *head;
293 	int error, match;
294 	unsigned int i;
295 	char errbuf[_POSIX2_LINE_MAX];
296 
297 	head = procstat_getfiles(procstat, kp, flags & MFLAG);
298 	if (head == NULL)
299 		return;
300 	STAILQ_FOREACH(fst, head, next) {
301 		if (fst->fs_type != PS_FST_TYPE_VNODE)
302 			continue;
303 		error = procstat_get_vnode_info(procstat, fst, &vn, errbuf);
304 		if (error != 0)
305 			continue;
306 		for (i = 0; i < nfiles; i++) {
307 			if (flags & CFLAG && reqfiles[i].fsid == vn.vn_fsid) {
308 				break;
309 			}
310 			else if (reqfiles[i].fsid == vn.vn_fsid &&
311 			    reqfiles[i].fileid == vn.vn_fileid) {
312 				break;
313 			}
314 			else if (!(flags & FFLAG) &&
315 			    (vn.vn_type == PS_FST_VTYPE_VCHR ||
316 			    vn.vn_type == PS_FST_VTYPE_VBLK) &&
317 			    vn.vn_fsid == reqfiles[i].fileid) {
318 				break;
319 			}
320 		}
321 		if (i == nfiles)
322 			continue;	/* No match. */
323 
324 		/*
325 		 * Look for existing entries.
326 		 */
327 		match = 0;
328 		STAILQ_FOREACH(cons, &reqfiles[i].consumers, next)
329 			if (cons->pid == kp->ki_pid) {
330 				match = 1;
331 				break;
332 			}
333 		if (match == 1) {	/* Use old entry. */
334 			cons->flags |= fst->fs_fflags;
335 			cons->uflags |= fst->fs_uflags;
336 		} else {
337 			/*
338 			 * Create new entry in the consumer chain.
339 			 */
340 			cons = calloc(1, sizeof(struct consumer));
341 			if (cons == NULL) {
342 				warn("malloc()");
343 				continue;
344 			}
345 			cons->uid = kp->ki_uid;
346 			cons->pid = kp->ki_pid;
347 			cons->uflags = fst->fs_uflags;
348 			cons->flags = fst->fs_fflags;
349 			STAILQ_INSERT_TAIL(&reqfiles[i].consumers, cons, next);
350 		}
351 	}
352 	procstat_freefiles(procstat, head);
353 }
354 
355 /*
356  * Returns signal number for it's string representation.
357  */
358 static int
359 str2sig(const char *str)
360 {
361 	int i;
362 
363 	if (!strncasecmp(str, "SIG", 3))
364 		str += 3;
365 	for (i = 1; i < sys_nsig; i++) {
366                 if (!strcasecmp(sys_signame[i], str))
367                         return (i);
368         }
369         return (-1);
370 }
371