summaryrefslogtreecommitdiff
path: root/libbb/procps.c
blob: 8d3aea3325c84a3dd8fb42ea6ad7429a196f18d9 (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
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright 1998 by Albert Cahalan; all rights reserved.
 * Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
 * SELinux support: (c) 2007 by Yuichi Nakamura <ynakam@hitachisoft.jp>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include "libbb.h"


typedef struct unsigned_to_name_map_t {
	unsigned id;
	char name[USERNAME_MAX_SIZE];
} unsigned_to_name_map_t;

typedef struct cache_t {
	unsigned_to_name_map_t *cache;
	int size;
} cache_t;

static cache_t username, groupname;

static void clear_cache(cache_t *cp)
{
	free(cp->cache);
	cp->cache = NULL;
	cp->size = 0;
}
void clear_username_cache(void)
{
	clear_cache(&username);
	clear_cache(&groupname);
}

#if 0 /* more generic, but we don't need that yet */
/* Returns -N-1 if not found. */
/* cp->cache[N] is allocated and must be filled in this case */
static int get_cached(cache_t *cp, unsigned id)
{
	int i;
	for (i = 0; i < cp->size; i++)
		if (cp->cache[i].id == id)
			return i;
	i = cp->size++;
	cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
	cp->cache[i++].id = id;
	return -i;
}
#endif

typedef char* ug_func(char *name, int bufsize, long uid);
static char* get_cached(cache_t *cp, unsigned id, ug_func* fp)
{
	int i;
	for (i = 0; i < cp->size; i++)
		if (cp->cache[i].id == id)
			return cp->cache[i].name;
	i = cp->size++;
	cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
	cp->cache[i].id = id;
	/* Never fails. Generates numeric string if name isn't found */
	fp(cp->cache[i].name, sizeof(cp->cache[i].name), id);
	return cp->cache[i].name;
}
const char* get_cached_username(uid_t uid)
{
	return get_cached(&username, uid, bb_getpwuid);
}
const char* get_cached_groupname(gid_t gid)
{
	return get_cached(&groupname, gid, bb_getgrgid);
}


#define PROCPS_BUFSIZE 1024

static int read_to_buf(const char *filename, void *buf)
{
	int fd;
	/* open_read_close() would do two reads, checking for EOF.
	 * When you have 10000 /proc/$NUM/stat to read, it isn't desirable */
	ssize_t ret = -1;
	fd = open(filename, O_RDONLY);
	if (fd >= 0) {
		ret = read(fd, buf, PROCPS_BUFSIZE-1);
		close(fd);
	}
	((char *)buf)[ret > 0 ? ret : 0] = '\0';
	return ret;
}

procps_status_t *alloc_procps_scan(int flags)
{
	unsigned n = getpagesize();
	procps_status_t* sp = xzalloc(sizeof(procps_status_t));
	sp->dir = xopendir("/proc");
	while (1) {
		n >>= 1;
		if (!n) break;
		sp->shift_pages_to_bytes++;
	}
	sp->shift_pages_to_kb = sp->shift_pages_to_bytes - 10;
	return sp;
}

void free_procps_scan(procps_status_t* sp)
{
	closedir(sp->dir);
	free(sp->argv0);
	USE_SELINUX(free(sp->context);)
	free(sp);
}

#if ENABLE_FEATURE_FAST_TOP
/* We cut a lot of corners here for speed */
static unsigned long fast_strtoul_10(char **endptr)
{
	char c;
	char *str = *endptr;
	unsigned long n = *str - '0';

	while ((c = *++str) != ' ')
		n = n*10 + (c - '0');

	*endptr = str + 1; /* We skip trailing space! */
	return n;
}
static char *skip_fields(char *str, int count)
{
	do {
		while (*str++ != ' ')
			continue;
		/* we found a space char, str points after it */
	} while (--count);
	return str;
}
#endif

void BUG_comm_size(void);
procps_status_t *procps_scan(procps_status_t* sp, int flags)
{
	struct dirent *entry;
	char buf[PROCPS_BUFSIZE];
	char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
	char *filename_tail;
	long tasknice;
	unsigned pid;
	int n;
	struct stat sb;

	if (!sp)
		sp = alloc_procps_scan(flags);

	for (;;) {
		entry = readdir(sp->dir);
		if (entry == NULL) {
			free_procps_scan(sp);
			return NULL;
		}
		pid = bb_strtou(entry->d_name, NULL, 10);
		if (errno)
			continue;

		/* After this point we have to break, not continue
		 * ("continue" would mean that current /proc/NNN
		 * is not a valid process info) */

		memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));

		sp->pid = pid;
		if (!(flags & ~PSSCAN_PID)) break;

#if ENABLE_SELINUX
		if (flags & PSSCAN_CONTEXT) {
			if (getpidcon(sp->pid, &sp->context) < 0)
				sp->context = NULL;
		}
#endif

		filename_tail = filename + sprintf(filename, "/proc/%d", pid);

		if (flags & PSSCAN_UIDGID) {
			if (stat(filename, &sb))
				break;
			/* Need comment - is this effective or real UID/GID? */
			sp->uid = sb.st_uid;
			sp->gid = sb.st_gid;
		}

		if (flags & PSSCAN_STAT) {
			char *cp, *comm1;
			int tty;
#if !ENABLE_FEATURE_FAST_TOP
			unsigned long vsz, rss;
#endif

			/* see proc(5) for some details on this */
			strcpy(filename_tail, "/stat");
			n = read_to_buf(filename, buf);
			if (n < 0)
				break;
			cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
			/*if (!cp || cp[1] != ' ')
				break;*/
			cp[0] = '\0';
			if (sizeof(sp->comm) < 16)
				BUG_comm_size();
			comm1 = strchr(buf, '(');
			/*if (comm1)*/
				safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));

#if !ENABLE_FEATURE_FAST_TOP
			n = sscanf(cp+2,
				"%c %u "               /* state, ppid */
				"%u %u %d %*s "        /* pgid, sid, tty, tpgid */
				"%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
				"%lu %lu "             /* utime, stime */
				"%*s %*s %*s "         /* cutime, cstime, priority */
				"%ld "                 /* nice */
				"%*s %*s %*s "         /* timeout, it_real_value, start_time */
				"%lu "                 /* vsize */
				"%lu "                 /* rss */
			/*	"%lu %lu %lu %lu %lu %lu " rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
			/*	"%u %u %u %u "         signal, blocked, sigignore, sigcatch */
			/*	"%lu %lu %lu"          wchan, nswap, cnswap */
				,
				sp->state, &sp->ppid,
				&sp->pgid, &sp->sid, &tty,
				&sp->utime, &sp->stime,
				&tasknice,
				&vsz,
				&rss);
			if (n != 10)
				break;
			/* vsz is in bytes and we want kb */
			sp->vsz = vsz >> 10;
			/* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
			sp->rss = rss << sp->shift_pages_to_kb;
			sp->tty_major = (tty >> 8) & 0xfff;
			sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
#else
/* This costs ~100 bytes more but makes top faster by 20%
 * If you run 10000 processes, this may be important for you */
			sp->state[0] = cp[2];
			cp += 4;
			sp->ppid = fast_strtoul_10(&cp);
			sp->pgid = fast_strtoul_10(&cp);
			sp->sid = fast_strtoul_10(&cp);
			tty = fast_strtoul_10(&cp);
			sp->tty_major = (tty >> 8) & 0xfff;
			sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
			cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
			sp->utime = fast_strtoul_10(&cp);
			sp->stime = fast_strtoul_10(&cp);
			cp = skip_fields(cp, 3); /* cutime, cstime, priority */
			tasknice = fast_strtoul_10(&cp);
			cp = skip_fields(cp, 3); /* timeout, it_real_value, start_time */
			/* vsz is in bytes and we want kb */
			sp->vsz = fast_strtoul_10(&cp) >> 10;
			/* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
			sp->rss = fast_strtoul_10(&cp) << sp->shift_pages_to_kb;
#endif

			if (sp->vsz == 0 && sp->state[0] != 'Z')
				sp->state[1] = 'W';
			else
				sp->state[1] = ' ';
			if (tasknice < 0)
				sp->state[2] = '<';
			else if (tasknice) /* > 0 */
				sp->state[2] = 'N';
			else
				sp->state[2] = ' ';

		}

#if 0 /* PSSCAN_CMD is not used */
		if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
			if (sp->argv0) {
				free(sp->argv0);
				sp->argv0 = NULL;
			}
			if (sp->cmd) {
				free(sp->cmd);
				sp->cmd = NULL;
			}
			strcpy(filename_tail, "/cmdline");
			/* TODO: to get rid of size limits, read into malloc buf,
			 * then realloc it down to real size. */
			n = read_to_buf(filename, buf);
			if (n <= 0)
				break;
			if (flags & PSSCAN_ARGV0)
				sp->argv0 = xstrdup(buf);
			if (flags & PSSCAN_CMD) {
				do {
					n--;
					if ((unsigned char)(buf[n]) < ' ')
						buf[n] = ' ';
				} while (n);
				sp->cmd = xstrdup(buf);
			}
		}
#else
		if (flags & PSSCAN_ARGV0) {
			if (sp->argv0) {
				free(sp->argv0);
				sp->argv0 = NULL;
			}
			strcpy(filename_tail, "/cmdline");
			n = read_to_buf(filename, buf);
			if (n <= 0)
				break;
			if (flags & PSSCAN_ARGV0)
				sp->argv0 = xstrdup(buf);
		}
#endif
		break;
	}
	return sp;
}

void read_cmdline(char *buf, int col, unsigned pid, const char *comm)
{
	ssize_t sz;
	char filename[sizeof("/proc//cmdline") + sizeof(int)*3];

	sprintf(filename, "/proc/%u/cmdline", pid);
	sz = open_read_close(filename, buf, col);
	if (sz > 0) {
		buf[sz] = '\0';
		while (--sz >= 0)
			if ((unsigned char)(buf[sz]) < ' ')
				buf[sz] = ' ';
	} else {
		snprintf(buf, col, "[%s]", comm);
	}
}

/* from kernel:
	//             pid comm S ppid pgid sid tty_nr tty_pgrp flg
	sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
%lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
%lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
		task->pid,
		tcomm,
		state,
		ppid,
		pgid,
		sid,
		tty_nr,
		tty_pgrp,
		task->flags,
		min_flt,
		cmin_flt,
		maj_flt,
		cmaj_flt,
		cputime_to_clock_t(utime),
		cputime_to_clock_t(stime),
		cputime_to_clock_t(cutime),
		cputime_to_clock_t(cstime),
		priority,
		nice,
		num_threads,
		// 0,
		start_time,
		vsize,
		mm ? get_mm_rss(mm) : 0,
		rsslim,
		mm ? mm->start_code : 0,
		mm ? mm->end_code : 0,
		mm ? mm->start_stack : 0,
		esp,
		eip,
the rest is some obsolete cruft
*/