top: TOPMEM feature - 's(how sizes)' command. +2.5k when enabled,
[people/mcb30/busybox.git] / libbb / procps.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Utility routines.
4  *
5  * Copyright 1998 by Albert Cahalan; all rights reserved.
6  * Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
7  * SELinux support: (c) 2007 by Yuichi Nakamura <ynakam@hitachisoft.jp>
8  *
9  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
10  */
11
12 #include "libbb.h"
13
14
15 typedef struct unsigned_to_name_map_t {
16         unsigned id;
17         char name[USERNAME_MAX_SIZE];
18 } unsigned_to_name_map_t;
19
20 typedef struct cache_t {
21         unsigned_to_name_map_t *cache;
22         int size;
23 } cache_t;
24
25 static cache_t username, groupname;
26
27 static void clear_cache(cache_t *cp)
28 {
29         free(cp->cache);
30         cp->cache = NULL;
31         cp->size = 0;
32 }
33 void clear_username_cache(void)
34 {
35         clear_cache(&username);
36         clear_cache(&groupname);
37 }
38
39 #if 0 /* more generic, but we don't need that yet */
40 /* Returns -N-1 if not found. */
41 /* cp->cache[N] is allocated and must be filled in this case */
42 static int get_cached(cache_t *cp, unsigned id)
43 {
44         int i;
45         for (i = 0; i < cp->size; i++)
46                 if (cp->cache[i].id == id)
47                         return i;
48         i = cp->size++;
49         cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
50         cp->cache[i++].id = id;
51         return -i;
52 }
53 #endif
54
55 typedef char* ug_func(char *name, int bufsize, long uid);
56 static char* get_cached(cache_t *cp, unsigned id, ug_func* fp)
57 {
58         int i;
59         for (i = 0; i < cp->size; i++)
60                 if (cp->cache[i].id == id)
61                         return cp->cache[i].name;
62         i = cp->size++;
63         cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
64         cp->cache[i].id = id;
65         /* Never fails. Generates numeric string if name isn't found */
66         fp(cp->cache[i].name, sizeof(cp->cache[i].name), id);
67         return cp->cache[i].name;
68 }
69 const char* get_cached_username(uid_t uid)
70 {
71         return get_cached(&username, uid, bb_getpwuid);
72 }
73 const char* get_cached_groupname(gid_t gid)
74 {
75         return get_cached(&groupname, gid, bb_getgrgid);
76 }
77
78
79 #define PROCPS_BUFSIZE 1024
80
81 static int read_to_buf(const char *filename, void *buf)
82 {
83         int fd;
84         /* open_read_close() would do two reads, checking for EOF.
85          * When you have 10000 /proc/$NUM/stat to read, it isn't desirable */
86         ssize_t ret = -1;
87         fd = open(filename, O_RDONLY);
88         if (fd >= 0) {
89                 ret = read(fd, buf, PROCPS_BUFSIZE-1);
90                 close(fd);
91         }
92         ((char *)buf)[ret > 0 ? ret : 0] = '\0';
93         return ret;
94 }
95
96 procps_status_t *alloc_procps_scan(int flags)
97 {
98         unsigned n = getpagesize();
99         procps_status_t* sp = xzalloc(sizeof(procps_status_t));
100         sp->dir = xopendir("/proc");
101         while (1) {
102                 n >>= 1;
103                 if (!n) break;
104                 sp->shift_pages_to_bytes++;
105         }
106         sp->shift_pages_to_kb = sp->shift_pages_to_bytes - 10;
107         return sp;
108 }
109
110 void free_procps_scan(procps_status_t* sp)
111 {
112         closedir(sp->dir);
113         free(sp->argv0);
114         USE_SELINUX(free(sp->context);)
115         free(sp);
116 }
117
118 #if ENABLE_FEATURE_TOPMEM
119 static unsigned long fast_strtoul_16(char **endptr)
120 {
121         unsigned char c;
122         char *str = *endptr;
123         unsigned long n = 0;
124
125         while ((c = *str++) != ' ') {
126                 c = ((c|0x20) - '0');
127                 if (c > 9)
128                         // c = c + '0' - 'a' + 10:
129                         c = c - ('a' - '0' - 10);
130                 n = n*16 + c;
131         }
132         *endptr = str; /* We skip trailing space! */
133         return n;
134 }
135 /* TOPMEM uses fast_strtoul_10, so... */
136 #undef ENABLE_FEATURE_FAST_TOP
137 #define ENABLE_FEATURE_FAST_TOP 1
138 #endif
139
140 #if ENABLE_FEATURE_FAST_TOP
141 /* We cut a lot of corners here for speed */
142 static unsigned long fast_strtoul_10(char **endptr)
143 {
144         char c;
145         char *str = *endptr;
146         unsigned long n = *str - '0';
147
148         while ((c = *++str) != ' ')
149                 n = n*10 + (c - '0');
150
151         *endptr = str + 1; /* We skip trailing space! */
152         return n;
153 }
154 static char *skip_fields(char *str, int count)
155 {
156         do {
157                 while (*str++ != ' ')
158                         continue;
159                 /* we found a space char, str points after it */
160         } while (--count);
161         return str;
162 }
163 #endif
164
165 void BUG_comm_size(void);
166 procps_status_t *procps_scan(procps_status_t* sp, int flags)
167 {
168         struct dirent *entry;
169         char buf[PROCPS_BUFSIZE];
170         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
171         char *filename_tail;
172         long tasknice;
173         unsigned pid;
174         int n;
175         struct stat sb;
176
177         if (!sp)
178                 sp = alloc_procps_scan(flags);
179
180         for (;;) {
181                 entry = readdir(sp->dir);
182                 if (entry == NULL) {
183                         free_procps_scan(sp);
184                         return NULL;
185                 }
186                 pid = bb_strtou(entry->d_name, NULL, 10);
187                 if (errno)
188                         continue;
189
190                 /* After this point we have to break, not continue
191                  * ("continue" would mean that current /proc/NNN
192                  * is not a valid process info) */
193
194                 memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
195
196                 sp->pid = pid;
197                 if (!(flags & ~PSSCAN_PID)) break;
198
199 #if ENABLE_SELINUX
200                 if (flags & PSSCAN_CONTEXT) {
201                         if (getpidcon(sp->pid, &sp->context) < 0)
202                                 sp->context = NULL;
203                 }
204 #endif
205
206                 filename_tail = filename + sprintf(filename, "/proc/%d", pid);
207
208                 if (flags & PSSCAN_UIDGID) {
209                         if (stat(filename, &sb))
210                                 break;
211                         /* Need comment - is this effective or real UID/GID? */
212                         sp->uid = sb.st_uid;
213                         sp->gid = sb.st_gid;
214                 }
215
216                 if (flags & PSSCAN_STAT) {
217                         char *cp, *comm1;
218                         int tty;
219 #if !ENABLE_FEATURE_FAST_TOP
220                         unsigned long vsz, rss;
221 #endif
222
223                         /* see proc(5) for some details on this */
224                         strcpy(filename_tail, "/stat");
225                         n = read_to_buf(filename, buf);
226                         if (n < 0)
227                                 break;
228                         cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
229                         /*if (!cp || cp[1] != ' ')
230                                 break;*/
231                         cp[0] = '\0';
232                         if (sizeof(sp->comm) < 16)
233                                 BUG_comm_size();
234                         comm1 = strchr(buf, '(');
235                         /*if (comm1)*/
236                                 safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));
237
238 #if !ENABLE_FEATURE_FAST_TOP
239                         n = sscanf(cp+2,
240                                 "%c %u "               /* state, ppid */
241                                 "%u %u %d %*s "        /* pgid, sid, tty, tpgid */
242                                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
243                                 "%lu %lu "             /* utime, stime */
244                                 "%*s %*s %*s "         /* cutime, cstime, priority */
245                                 "%ld "                 /* nice */
246                                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
247                                 "%lu "                 /* vsize */
248                                 "%lu "                 /* rss */
249                         /*      "%lu %lu %lu %lu %lu %lu " rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
250                         /*      "%u %u %u %u "         signal, blocked, sigignore, sigcatch */
251                         /*      "%lu %lu %lu"          wchan, nswap, cnswap */
252                                 ,
253                                 sp->state, &sp->ppid,
254                                 &sp->pgid, &sp->sid, &tty,
255                                 &sp->utime, &sp->stime,
256                                 &tasknice,
257                                 &vsz,
258                                 &rss);
259                         if (n != 10)
260                                 break;
261                         /* vsz is in bytes and we want kb */
262                         sp->vsz = vsz >> 10;
263                         /* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
264                         sp->rss = rss << sp->shift_pages_to_kb;
265                         sp->tty_major = (tty >> 8) & 0xfff;
266                         sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
267 #else
268 /* This costs ~100 bytes more but makes top faster by 20%
269  * If you run 10000 processes, this may be important for you */
270                         sp->state[0] = cp[2];
271                         cp += 4;
272                         sp->ppid = fast_strtoul_10(&cp);
273                         sp->pgid = fast_strtoul_10(&cp);
274                         sp->sid = fast_strtoul_10(&cp);
275                         tty = fast_strtoul_10(&cp);
276                         sp->tty_major = (tty >> 8) & 0xfff;
277                         sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
278                         cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
279                         sp->utime = fast_strtoul_10(&cp);
280                         sp->stime = fast_strtoul_10(&cp);
281                         cp = skip_fields(cp, 3); /* cutime, cstime, priority */
282                         tasknice = fast_strtoul_10(&cp);
283                         cp = skip_fields(cp, 3); /* timeout, it_real_value, start_time */
284                         /* vsz is in bytes and we want kb */
285                         sp->vsz = fast_strtoul_10(&cp) >> 10;
286                         /* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
287                         sp->rss = fast_strtoul_10(&cp) << sp->shift_pages_to_kb;
288 #endif
289
290                         if (sp->vsz == 0 && sp->state[0] != 'Z')
291                                 sp->state[1] = 'W';
292                         else
293                                 sp->state[1] = ' ';
294                         if (tasknice < 0)
295                                 sp->state[2] = '<';
296                         else if (tasknice) /* > 0 */
297                                 sp->state[2] = 'N';
298                         else
299                                 sp->state[2] = ' ';
300
301                 }
302
303 #if ENABLE_FEATURE_TOPMEM
304                 if (flags & (PSSCAN_SMAPS)) {
305                         FILE *file;
306
307                         strcpy(filename_tail, "/smaps");
308                         file = fopen(filename, "r");
309                         if (!file)
310                                 break;
311                         while (fgets(buf, sizeof(buf), file)) {
312                                 unsigned long sz;
313                                 char *tp;
314                                 char w;
315 #define SCAN(str, name) \
316         if (strncmp(buf, str, sizeof(str)-1) == 0) { \
317                 tp = skip_whitespace(buf + sizeof(str)-1); \
318                 sp->name += fast_strtoul_10(&tp); \
319                 continue; \
320         }
321                                 SCAN("Shared_Clean:" , shared_clean );
322                                 SCAN("Shared_Dirty:" , shared_dirty );
323                                 SCAN("Private_Clean:", private_clean);
324                                 SCAN("Private_Dirty:", private_dirty);
325 #undef SCAN
326                                 // f7d29000-f7d39000 rw-s ADR M:m OFS FILE
327                                 tp = strchr(buf, '-');
328                                 if (tp) {
329                                         *tp = ' ';
330                                         tp = buf;
331                                         sz = fast_strtoul_16(&tp); /* start */
332                                         sz = (fast_strtoul_16(&tp) - sz) >> 10; /* end - start */
333                                         // tp -> "rw-s" string
334                                         w = tp[1];
335                                         // skipping "rw-s ADR M:m OFS "
336                                         tp = skip_whitespace(skip_fields(tp, 4));
337                                         // filter out /dev/something (something != zero)
338                                         if (strncmp(tp, "/dev/", 5) != 0 || strcmp(tp, "/dev/zero\n") == 0) {
339                                                 if (w == 'w') {
340                                                         sp->mapped_rw += sz;
341                                                 } else if (w == '-') {
342                                                         sp->mapped_ro += sz;
343                                                 }
344                                         }
345 //else printf("DROPPING %s (%s)\n", buf, tp);
346                                         if (strcmp(tp, "[stack]\n") == 0)
347                                                 sp->stack += sz;
348                                 }
349                         }
350                         fclose(file);
351                 }
352 #endif /* TOPMEM */
353
354 #if 0 /* PSSCAN_CMD is not used */
355                 if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
356                         if (sp->argv0) {
357                                 free(sp->argv0);
358                                 sp->argv0 = NULL;
359                         }
360                         if (sp->cmd) {
361                                 free(sp->cmd);
362                                 sp->cmd = NULL;
363                         }
364                         strcpy(filename_tail, "/cmdline");
365                         /* TODO: to get rid of size limits, read into malloc buf,
366                          * then realloc it down to real size. */
367                         n = read_to_buf(filename, buf);
368                         if (n <= 0)
369                                 break;
370                         if (flags & PSSCAN_ARGV0)
371                                 sp->argv0 = xstrdup(buf);
372                         if (flags & PSSCAN_CMD) {
373                                 do {
374                                         n--;
375                                         if ((unsigned char)(buf[n]) < ' ')
376                                                 buf[n] = ' ';
377                                 } while (n);
378                                 sp->cmd = xstrdup(buf);
379                         }
380                 }
381 #else
382                 if (flags & PSSCAN_ARGV0) {
383                         if (sp->argv0) {
384                                 free(sp->argv0);
385                                 sp->argv0 = NULL;
386                         }
387                         strcpy(filename_tail, "/cmdline");
388                         n = read_to_buf(filename, buf);
389                         if (n <= 0)
390                                 break;
391                         if (flags & PSSCAN_ARGV0)
392                                 sp->argv0 = xstrdup(buf);
393                 }
394 #endif
395                 break;
396         }
397         return sp;
398 }
399
400 void read_cmdline(char *buf, int col, unsigned pid, const char *comm)
401 {
402         ssize_t sz;
403         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
404
405         sprintf(filename, "/proc/%u/cmdline", pid);
406         sz = open_read_close(filename, buf, col);
407         if (sz > 0) {
408                 buf[sz] = '\0';
409                 while (--sz >= 0)
410                         if ((unsigned char)(buf[sz]) < ' ')
411                                 buf[sz] = ' ';
412         } else {
413                 snprintf(buf, col, "[%s]", comm);
414         }
415 }
416
417 /* from kernel:
418         //             pid comm S ppid pgid sid tty_nr tty_pgrp flg
419         sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
420 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
421 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
422                 task->pid,
423                 tcomm,
424                 state,
425                 ppid,
426                 pgid,
427                 sid,
428                 tty_nr,
429                 tty_pgrp,
430                 task->flags,
431                 min_flt,
432                 cmin_flt,
433                 maj_flt,
434                 cmaj_flt,
435                 cputime_to_clock_t(utime),
436                 cputime_to_clock_t(stime),
437                 cputime_to_clock_t(cutime),
438                 cputime_to_clock_t(cstime),
439                 priority,
440                 nice,
441                 num_threads,
442                 // 0,
443                 start_time,
444                 vsize,
445                 mm ? get_mm_rss(mm) : 0,
446                 rsslim,
447                 mm ? mm->start_code : 0,
448                 mm ? mm->end_code : 0,
449                 mm ? mm->start_stack : 0,
450                 esp,
451                 eip,
452 the rest is some obsolete cruft
453 */