summaryrefslogtreecommitdiff
path: root/procps/fuser.c
blob: 7465d455499641f05a0e064d27e6091d80c5558a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
/* vi: set sw=4 ts=4: */
/*
 * tiny fuser implementation
 *
 * Copyright 2004 Tony J. White
 *
 * Licensed under GPLv2, see file LICENSE in this tarball for details.
 */

#include "libbb.h"

#define MAX_LINE 255

#define OPTION_STRING "mks64"
enum {
	OPT_MOUNT  = (1 << 0),
	OPT_KILL   = (1 << 1),
	OPT_SILENT = (1 << 2),
	OPT_IP6    = (1 << 3),
	OPT_IP4    = (1 << 4),
};

typedef struct inode_list {
	struct inode_list *next;
	ino_t inode;
	dev_t dev;
} inode_list;

typedef struct pid_list {
	struct pid_list *next;
	pid_t pid;
} pid_list;


struct globals {
	pid_list *pid_list_head;
	inode_list *inode_list_head;
};
#define G (*(struct globals*)&bb_common_bufsiz1)
#define INIT_G() do { } while (0)


static dev_t find_socket_dev(void)
{
	int fd = socket(AF_INET, SOCK_DGRAM, 0);
	if (fd >= 0) {
		struct stat buf;
		int r = fstat(fd, &buf);
		close(fd);
		if (r == 0)
			return buf.st_dev;
	}
	return 0;
}

static char *parse_net_arg(const char *arg, unsigned *port)
{
	char path[20], tproto[5];

	if (sscanf(arg, "%u/%4s", port, tproto) != 2)
		return NULL;
	sprintf(path, "/proc/net/%s", tproto);
	if (access(path, R_OK) != 0)
		return NULL;
	return xstrdup(path);
}

static void add_pid(const pid_t pid)
{
	pid_list **curr = &G.pid_list_head;

	while (*curr) {
		if ((*curr)->pid == pid)
			return;
		curr = &(*curr)->next;
	}

	*curr = xzalloc(sizeof(pid_list));
	(*curr)->pid = pid;
}

static void add_inode(const struct stat *st)
{
	inode_list **curr = &G.inode_list_head;

	while (*curr) {
		if ((*curr)->dev == st->st_dev
		 && (*curr)->inode == st->st_ino
		) {
			return;
		}
		curr = &(*curr)->next;
	}

	*curr = xzalloc(sizeof(inode_list));
	(*curr)->dev = st->st_dev;
	(*curr)->inode = st->st_ino;
}

static void scan_proc_net(const char *path, unsigned port)
{
	char line[MAX_LINE + 1];
	long long uint64_inode;
	unsigned tmp_port;
	FILE *f;
	struct stat st;

	st.st_dev = find_socket_dev();

	f = fopen_for_read(path);
	if (!f)
		return;

	while (fgets(line, MAX_LINE, f)) {
		char addr[68];
		if (sscanf(line, "%*d: %64[0-9A-Fa-f]:%x %*x:%*x %*x %*x:%*x "
				"%*x:%*x %*x %*d %*d %llu",
				addr, &tmp_port, &uint64_inode) == 3
		) {
			int len = strlen(addr);
			if (len == 8 && (option_mask32 & OPT_IP6))
				continue;
			if (len > 8 && (option_mask32 & OPT_IP4))
				continue;
			if (tmp_port == port) {
				st.st_ino = uint64_inode;
				add_inode(&st);
			}
		}
	}
	fclose(f);
}

static int search_dev_inode(const struct stat *st)
{
	inode_list *ilist = G.inode_list_head;

	while (ilist) {
		if (ilist->dev == st->st_dev) {
			if (option_mask32 & OPT_MOUNT)
				return 1;
			if (ilist->inode == st->st_ino)
				return 1;
		}
		ilist = ilist->next;
	}
	return 0;
}

static void scan_pid_maps(const char *fname, pid_t pid)
{
	FILE *file;
	char line[MAX_LINE + 1];
	int major, minor;
	long long uint64_inode;
	struct stat st;

	file = fopen_for_read(fname);
	if (!file)
		return;

	while (fgets(line, MAX_LINE, file)) {
		if (sscanf(line, "%*s %*s %*s %x:%x %llu", &major, &minor, &uint64_inode) != 3)
			continue;
		st.st_ino = uint64_inode;
		if (major == 0 && minor == 0 && st.st_ino == 0)
			continue;
		st.st_dev = makedev(major, minor);
		if (search_dev_inode(&st))
			add_pid(pid);
	}
	fclose(file);
}

static void scan_link(const char *lname, pid_t pid)
{
	struct stat st;

	if (stat(lname, &st) >= 0) {
		if (search_dev_inode(&st))
			add_pid(pid);
	}
}

static void scan_dir_links(const char *dname, pid_t pid)
{
	DIR *d;
	struct dirent *de;
	char *lname;

	d = opendir(dname);
	if (!d)
		return;

	while ((de = readdir(d)) != NULL) {
		lname = concat_subpath_file(dname, de->d_name);
		if (lname == NULL)
			continue;
		scan_link(lname, pid);
		free(lname);
	}
	closedir(d);
}

/* NB: does chdir internally */
static void scan_proc_pids(void)
{
	DIR *d;
	struct dirent *de;
	pid_t pid;

	xchdir("/proc");
	d = opendir("/proc");
	if (!d)
		return;

	while ((de = readdir(d)) != NULL) {
		pid = (pid_t)bb_strtou(de->d_name, NULL, 10);
		if (errno)
			continue;
		if (chdir(de->d_name) < 0)
			continue;
		scan_link("cwd", pid);
		scan_link("exe", pid);
		scan_link("root", pid);

		scan_dir_links("fd", pid);
		scan_dir_links("lib", pid);
		scan_dir_links("mmap", pid);

		scan_pid_maps("maps", pid);
		xchdir("/proc");
	}
	closedir(d);
}

int fuser_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fuser_main(int argc UNUSED_PARAM, char **argv)
{
	pid_list *plist;
	pid_t mypid;
	char **pp;
	struct stat st;
	unsigned port;
	int opt;
	int exitcode;
	int killsig;
/*
fuser [OPTIONS] FILE or PORT/PROTO
Find processes which use FILEs or PORTs
        -m      Find processes which use same fs as FILEs
        -4      Search only IPv4 space
        -6      Search only IPv6 space
        -s      Don't display PIDs
        -k      Kill found processes
        -SIGNAL Signal to send (default: KILL)
*/
	/* Handle -SIGNAL. Oh my... */
	killsig = SIGKILL; /* yes, the default is not SIGTERM */
	pp = argv;
	while (*++pp) {
		char *arg = *pp;
		if (arg[0] != '-')
			continue;
		if (arg[1] == '-' && arg[2] == '\0') /* "--" */
			break;
		if ((arg[1] == '4' || arg[1] == '6') && arg[2] == '\0')
			continue; /* it's "-4" or "-6" */
		opt = get_signum(&arg[1]);
		if (opt < 0)
			continue;
		/* "-SIGNAL" option found. Remove it and bail out */
		killsig = opt;
		do {
			pp[0] = arg = pp[1];
			pp++;
		} while (arg);
		break;
	}

	opt_complementary = "-1"; /* at least one param */
	opt = getopt32(argv, OPTION_STRING);
	argv += optind;

	pp = argv;
	while (*pp) {
		char *path = parse_net_arg(*pp, &port);
		if (path) { /* PORT/PROTO */
			scan_proc_net(path, port);
			free(path);
		} else { /* FILE */
			xstat(*pp, &st);
			add_inode(&st);
		}
		pp++;
	}

	scan_proc_pids(); /* changes dir to "/proc" */

	mypid = getpid();
	plist = G.pid_list_head;
	while (1) {
		if (!plist)
			return EXIT_FAILURE;
		if (plist->pid != mypid)
			break;
		plist = plist->next;
	}

	exitcode = EXIT_SUCCESS;
	do {
		if (plist->pid != mypid) {
			if (opt & OPT_KILL) {
				if (kill(plist->pid, killsig) != 0) {
					bb_perror_msg("kill pid %u", (unsigned)plist->pid);
					exitcode = EXIT_FAILURE;
				}
			}
			if (!(opt & OPT_SILENT)) {
				printf("%u ", (unsigned)plist->pid);
			}
		}
		plist = plist->next;
	} while (plist);

	if (!(opt & (OPT_SILENT))) {
		bb_putchar('\n');
	}

	return exitcode;
}