libbb/md5: code shrink
[oweals/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 source tree.
10  */
11
12 #include "libbb.h"
13
14
15 typedef struct unsigned_to_name_map_t {
16         long 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 FAST_FUNC 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_vector(cp->cache, 2, i);
50         cp->cache[i++].id = id;
51         return -i;
52 }
53 #endif
54
55 static char* get_cached(cache_t *cp, long id,
56                         char* FAST_FUNC x2x_utoa(long id))
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_vector(cp->cache, 2, i);
64         cp->cache[i].id = id;
65         /* Never fails. Generates numeric string if name isn't found */
66         safe_strncpy(cp->cache[i].name, x2x_utoa(id), sizeof(cp->cache[i].name));
67         return cp->cache[i].name;
68 }
69 const char* FAST_FUNC get_cached_username(uid_t uid)
70 {
71         return get_cached(&username, uid, uid2uname_utoa);
72 }
73 const char* FAST_FUNC get_cached_groupname(gid_t gid)
74 {
75         return get_cached(&groupname, gid, gid2group_utoa);
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 static procps_status_t* FAST_FUNC alloc_procps_scan(void)
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 FAST_FUNC free_procps_scan(procps_status_t* sp)
111 {
112         closedir(sp->dir);
113 #if ENABLE_FEATURE_SHOW_THREADS
114         if (sp->task_dir)
115                 closedir(sp->task_dir);
116 #endif
117         free(sp->argv0);
118         free(sp->exe);
119         IF_SELINUX(free(sp->context);)
120         free(sp);
121 }
122
123 #if ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
124 static unsigned long fast_strtoul_16(char **endptr)
125 {
126         unsigned char c;
127         char *str = *endptr;
128         unsigned long n = 0;
129
130         while ((c = *str++) != ' ') {
131                 c = ((c|0x20) - '0');
132                 if (c > 9)
133                         // c = c + '0' - 'a' + 10:
134                         c = c - ('a' - '0' - 10);
135                 n = n*16 + c;
136         }
137         *endptr = str; /* We skip trailing space! */
138         return n;
139 }
140 #endif
141
142 #if ENABLE_FEATURE_FAST_TOP || ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
143 /* We cut a lot of corners here for speed */
144 static unsigned long fast_strtoul_10(char **endptr)
145 {
146         char c;
147         char *str = *endptr;
148         unsigned long n = *str - '0';
149
150         while ((c = *++str) != ' ')
151                 n = n*10 + (c - '0');
152
153         *endptr = str + 1; /* We skip trailing space! */
154         return n;
155 }
156
157 static long fast_strtol_10(char **endptr)
158 {
159         if (**endptr != '-')
160                 return fast_strtoul_10(endptr);
161
162         (*endptr)++;
163         return - (long)fast_strtoul_10(endptr);
164 }
165
166 static char *skip_fields(char *str, int count)
167 {
168         do {
169                 while (*str++ != ' ')
170                         continue;
171                 /* we found a space char, str points after it */
172         } while (--count);
173         return str;
174 }
175 #endif
176
177 #if ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
178 int FAST_FUNC procps_read_smaps(pid_t pid, struct smaprec *total,
179                       void (*cb)(struct smaprec *, void *), void *data)
180 {
181         FILE *file;
182         struct smaprec currec;
183         char filename[sizeof("/proc/%u/smaps") + sizeof(int)*3];
184         char buf[PROCPS_BUFSIZE];
185 #if !ENABLE_PMAP
186         void (*cb)(struct smaprec *, void *) = NULL;
187         void *data = NULL;
188 #endif
189
190         sprintf(filename, "/proc/%u/smaps", (int)pid);
191
192         file = fopen_for_read(filename);
193         if (!file)
194                 return 1;
195
196         memset(&currec, 0, sizeof(currec));
197         while (fgets(buf, PROCPS_BUFSIZE, file)) {
198                 // Each mapping datum has this form:
199                 // f7d29000-f7d39000 rw-s ADR M:m OFS FILE
200                 // Size:                nnn kB
201                 // Rss:                 nnn kB
202                 // .....
203
204                 char *tp = buf, *p;
205
206 #define SCAN(S, X) \
207                 if (strncmp(tp, S, sizeof(S)-1) == 0) {              \
208                         tp = skip_whitespace(tp + sizeof(S)-1);      \
209                         total->X += currec.X = fast_strtoul_10(&tp); \
210                         continue;                                    \
211                 }
212                 if (cb) {
213                         SCAN("Pss:"  , smap_pss     );
214                         SCAN("Swap:" , smap_swap    );
215                 }
216                 SCAN("Private_Dirty:", private_dirty);
217                 SCAN("Private_Clean:", private_clean);
218                 SCAN("Shared_Dirty:" , shared_dirty );
219                 SCAN("Shared_Clean:" , shared_clean );
220 #undef SCAN
221                 tp = strchr(buf, '-');
222                 if (tp) {
223                         // We reached next mapping - the line of this form:
224                         // f7d29000-f7d39000 rw-s ADR M:m OFS FILE
225
226                         if (cb) {
227                                 /* If we have a previous record, there's nothing more
228                                  * for it, call the callback and clear currec
229                                  */
230                                 if (currec.smap_size)
231                                         cb(&currec, data);
232                                 free(currec.smap_name);
233                         }
234                         memset(&currec, 0, sizeof(currec));
235
236                         *tp = ' ';
237                         tp = buf;
238                         currec.smap_start = fast_strtoul_16(&tp);
239                         currec.smap_size = (fast_strtoul_16(&tp) - currec.smap_start) >> 10;
240
241                         strncpy(currec.smap_mode, tp, sizeof(currec.smap_mode)-1);
242
243                         // skipping "rw-s ADR M:m OFS "
244                         tp = skip_whitespace(skip_fields(tp, 4));
245                         // filter out /dev/something (something != zero)
246                         if (strncmp(tp, "/dev/", 5) != 0 || strcmp(tp, "/dev/zero\n") == 0) {
247                                 if (currec.smap_mode[1] == 'w') {
248                                         currec.mapped_rw = currec.smap_size;
249                                         total->mapped_rw += currec.smap_size;
250                                 } else if (currec.smap_mode[1] == '-') {
251                                         currec.mapped_ro = currec.smap_size;
252                                         total->mapped_ro += currec.smap_size;
253                                 }
254                         }
255
256                         if (strcmp(tp, "[stack]\n") == 0)
257                                 total->stack += currec.smap_size;
258                         if (cb) {
259                                 p = skip_non_whitespace(tp);
260                                 if (p == tp) {
261                                         currec.smap_name = xstrdup("  [ anon ]");
262                                 } else {
263                                         *p = '\0';
264                                         currec.smap_name = xstrdup(tp);
265                                 }
266                         }
267                         total->smap_size += currec.smap_size;
268                 }
269         }
270         fclose(file);
271
272         if (cb) {
273                 if (currec.smap_size)
274                         cb(&currec, data);
275                 free(currec.smap_name);
276         }
277
278         return 0;
279 }
280 #endif
281
282 void BUG_comm_size(void);
283 procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
284 {
285         struct dirent *entry;
286         char buf[PROCPS_BUFSIZE];
287         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
288         char *filename_tail;
289         long tasknice;
290         unsigned pid;
291         int n;
292         struct stat sb;
293
294         if (!sp)
295                 sp = alloc_procps_scan();
296
297         for (;;) {
298 #if ENABLE_FEATURE_SHOW_THREADS
299                 if ((flags & PSSCAN_TASKS) && sp->task_dir) {
300                         entry = readdir(sp->task_dir);
301                         if (entry)
302                                 goto got_entry;
303                         closedir(sp->task_dir);
304                         sp->task_dir = NULL;
305                 }
306 #endif
307                 entry = readdir(sp->dir);
308                 if (entry == NULL) {
309                         free_procps_scan(sp);
310                         return NULL;
311                 }
312  IF_FEATURE_SHOW_THREADS(got_entry:)
313                 pid = bb_strtou(entry->d_name, NULL, 10);
314                 if (errno)
315                         continue;
316 #if ENABLE_FEATURE_SHOW_THREADS
317                 if ((flags & PSSCAN_TASKS) && !sp->task_dir) {
318                         /* We found another /proc/PID. Do not use it,
319                          * there will be /proc/PID/task/PID (same PID!),
320                          * so just go ahead and dive into /proc/PID/task. */
321                         char task_dir[sizeof("/proc/%u/task") + sizeof(int)*3];
322                         sprintf(task_dir, "/proc/%u/task", pid);
323                         sp->task_dir = xopendir(task_dir);
324                         continue;
325                 }
326 #endif
327
328                 /* After this point we can:
329                  * "break": stop parsing, return the data
330                  * "continue": try next /proc/XXX
331                  */
332
333                 memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
334
335                 sp->pid = pid;
336                 if (!(flags & ~PSSCAN_PID))
337                         break; /* we needed only pid, we got it */
338
339 #if ENABLE_SELINUX
340                 if (flags & PSSCAN_CONTEXT) {
341                         if (getpidcon(sp->pid, &sp->context) < 0)
342                                 sp->context = NULL;
343                 }
344 #endif
345
346                 filename_tail = filename + sprintf(filename, "/proc/%u/", pid);
347
348                 if (flags & PSSCAN_UIDGID) {
349                         if (stat(filename, &sb))
350                                 continue; /* process probably exited */
351                         /* Effective UID/GID, not real */
352                         sp->uid = sb.st_uid;
353                         sp->gid = sb.st_gid;
354                 }
355
356                 if (flags & PSSCAN_STAT) {
357                         char *cp, *comm1;
358                         int tty;
359 #if !ENABLE_FEATURE_FAST_TOP
360                         unsigned long vsz, rss;
361 #endif
362                         /* see proc(5) for some details on this */
363                         strcpy(filename_tail, "stat");
364                         n = read_to_buf(filename, buf);
365                         if (n < 0)
366                                 continue; /* process probably exited */
367                         cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
368                         /*if (!cp || cp[1] != ' ')
369                                 continue;*/
370                         cp[0] = '\0';
371                         if (sizeof(sp->comm) < 16)
372                                 BUG_comm_size();
373                         comm1 = strchr(buf, '(');
374                         /*if (comm1)*/
375                                 safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));
376
377 #if !ENABLE_FEATURE_FAST_TOP
378                         n = sscanf(cp+2,
379                                 "%c %u "               /* state, ppid */
380                                 "%u %u %d %*s "        /* pgid, sid, tty, tpgid */
381                                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
382                                 "%lu %lu "             /* utime, stime */
383                                 "%*s %*s %*s "         /* cutime, cstime, priority */
384                                 "%ld "                 /* nice */
385                                 "%*s %*s "             /* timeout, it_real_value */
386                                 "%lu "                 /* start_time */
387                                 "%lu "                 /* vsize */
388                                 "%lu "                 /* rss */
389 # if ENABLE_FEATURE_TOP_SMP_PROCESS
390                                 "%*s %*s %*s %*s %*s %*s " /*rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
391                                 "%*s %*s %*s %*s "         /*signal, blocked, sigignore, sigcatch */
392                                 "%*s %*s %*s %*s "         /*wchan, nswap, cnswap, exit_signal */
393                                 "%d"                       /*cpu last seen on*/
394 # endif
395                                 ,
396                                 sp->state, &sp->ppid,
397                                 &sp->pgid, &sp->sid, &tty,
398                                 &sp->utime, &sp->stime,
399                                 &tasknice,
400                                 &sp->start_time,
401                                 &vsz,
402                                 &rss
403 # if ENABLE_FEATURE_TOP_SMP_PROCESS
404                                 , &sp->last_seen_on_cpu
405 # endif
406                                 );
407
408                         if (n < 11)
409                                 continue; /* bogus data, get next /proc/XXX */
410 # if ENABLE_FEATURE_TOP_SMP_PROCESS
411                         if (n < 11+15)
412                                 sp->last_seen_on_cpu = 0;
413 # endif
414
415                         /* vsz is in bytes and we want kb */
416                         sp->vsz = vsz >> 10;
417                         /* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
418                         sp->rss = rss << sp->shift_pages_to_kb;
419                         sp->tty_major = (tty >> 8) & 0xfff;
420                         sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
421 #else
422 /* This costs ~100 bytes more but makes top faster by 20%
423  * If you run 10000 processes, this may be important for you */
424                         sp->state[0] = cp[2];
425                         cp += 4;
426                         sp->ppid = fast_strtoul_10(&cp);
427                         sp->pgid = fast_strtoul_10(&cp);
428                         sp->sid = fast_strtoul_10(&cp);
429                         tty = fast_strtoul_10(&cp);
430                         sp->tty_major = (tty >> 8) & 0xfff;
431                         sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
432                         cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
433                         sp->utime = fast_strtoul_10(&cp);
434                         sp->stime = fast_strtoul_10(&cp);
435                         cp = skip_fields(cp, 3); /* cutime, cstime, priority */
436                         tasknice = fast_strtol_10(&cp);
437                         cp = skip_fields(cp, 2); /* timeout, it_real_value */
438                         sp->start_time = fast_strtoul_10(&cp);
439                         /* vsz is in bytes and we want kb */
440                         sp->vsz = fast_strtoul_10(&cp) >> 10;
441                         /* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
442                         sp->rss = fast_strtoul_10(&cp) << sp->shift_pages_to_kb;
443 # if ENABLE_FEATURE_TOP_SMP_PROCESS
444                         /* (6): rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
445                         /* (4): signal, blocked, sigignore, sigcatch */
446                         /* (4): wchan, nswap, cnswap, exit_signal */
447                         cp = skip_fields(cp, 14);
448 //FIXME: is it safe to assume this field exists?
449                         sp->last_seen_on_cpu = fast_strtoul_10(&cp);
450 # endif
451 #endif /* end of !ENABLE_FEATURE_TOP_SMP_PROCESS */
452
453 #if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
454                         sp->niceness = tasknice;
455 #endif
456
457                         if (sp->vsz == 0 && sp->state[0] != 'Z')
458                                 sp->state[1] = 'W';
459                         else
460                                 sp->state[1] = ' ';
461                         if (tasknice < 0)
462                                 sp->state[2] = '<';
463                         else if (tasknice) /* > 0 */
464                                 sp->state[2] = 'N';
465                         else
466                                 sp->state[2] = ' ';
467                 }
468
469 #if ENABLE_FEATURE_TOPMEM
470                 if (flags & PSSCAN_SMAPS)
471                         procps_read_smaps(pid, &sp->smaps, NULL, NULL);
472 #endif /* TOPMEM */
473 #if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
474                 if (flags & PSSCAN_RUIDGID) {
475                         FILE *file;
476
477                         strcpy(filename_tail, "status");
478                         file = fopen_for_read(filename);
479                         if (file) {
480                                 while (fgets(buf, sizeof(buf), file)) {
481                                         char *tp;
482 #define SCAN_TWO(str, name, statement) \
483         if (strncmp(buf, str, sizeof(str)-1) == 0) { \
484                 tp = skip_whitespace(buf + sizeof(str)-1); \
485                 sscanf(tp, "%u", &sp->name); \
486                 statement; \
487         }
488                                         SCAN_TWO("Uid:", ruid, continue);
489                                         SCAN_TWO("Gid:", rgid, break);
490 #undef SCAN_TWO
491                                 }
492                                 fclose(file);
493                         }
494                 }
495 #endif /* PS_ADDITIONAL_COLUMNS */
496                 if (flags & PSSCAN_EXE) {
497                         strcpy(filename_tail, "exe");
498                         free(sp->exe);
499                         sp->exe = xmalloc_readlink(filename);
500                 }
501                 /* Note: if /proc/PID/cmdline is empty,
502                  * code below "breaks". Therefore it must be
503                  * the last code to parse /proc/PID/xxx data
504                  * (we used to have /proc/PID/exe parsing after it
505                  * and were getting stale sp->exe).
506                  */
507 #if 0 /* PSSCAN_CMD is not used */
508                 if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
509                         free(sp->argv0);
510                         sp->argv0 = NULL;
511                         free(sp->cmd);
512                         sp->cmd = NULL;
513                         strcpy(filename_tail, "cmdline");
514                         /* TODO: to get rid of size limits, read into malloc buf,
515                          * then realloc it down to real size. */
516                         n = read_to_buf(filename, buf);
517                         if (n <= 0)
518                                 break;
519                         if (flags & PSSCAN_ARGV0)
520                                 sp->argv0 = xstrdup(buf);
521                         if (flags & PSSCAN_CMD) {
522                                 do {
523                                         n--;
524                                         if ((unsigned char)(buf[n]) < ' ')
525                                                 buf[n] = ' ';
526                                 } while (n);
527                                 sp->cmd = xstrdup(buf);
528                         }
529                 }
530 #else
531                 if (flags & (PSSCAN_ARGV0|PSSCAN_ARGVN)) {
532                         free(sp->argv0);
533                         sp->argv0 = NULL;
534                         strcpy(filename_tail, "cmdline");
535                         n = read_to_buf(filename, buf);
536                         if (n <= 0)
537                                 break;
538                         if (flags & PSSCAN_ARGVN) {
539                                 sp->argv_len = n;
540                                 sp->argv0 = xmalloc(n + 1);
541                                 memcpy(sp->argv0, buf, n + 1);
542                                 /* sp->argv0[n] = '\0'; - buf has it */
543                         } else {
544                                 sp->argv_len = 0;
545                                 sp->argv0 = xstrdup(buf);
546                         }
547                 }
548 #endif
549                 break;
550         } /* for (;;) */
551
552         return sp;
553 }
554
555 void FAST_FUNC read_cmdline(char *buf, int col, unsigned pid, const char *comm)
556 {
557         int sz;
558         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
559
560         sprintf(filename, "/proc/%u/cmdline", pid);
561         sz = open_read_close(filename, buf, col - 1);
562         if (sz > 0) {
563                 buf[sz] = '\0';
564                 while (--sz >= 0 && buf[sz] == '\0')
565                         continue;
566                 do {
567                         if ((unsigned char)(buf[sz]) < ' ')
568                                 buf[sz] = ' ';
569                 } while (--sz >= 0);
570         } else {
571                 snprintf(buf, col, "[%s]", comm);
572         }
573 }
574
575 /* from kernel:
576         //             pid comm S ppid pgid sid tty_nr tty_pgrp flg
577         sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
578 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
579 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
580                 task->pid,
581                 tcomm,
582                 state,
583                 ppid,
584                 pgid,
585                 sid,
586                 tty_nr,
587                 tty_pgrp,
588                 task->flags,
589                 min_flt,
590                 cmin_flt,
591                 maj_flt,
592                 cmaj_flt,
593                 cputime_to_clock_t(utime),
594                 cputime_to_clock_t(stime),
595                 cputime_to_clock_t(cutime),
596                 cputime_to_clock_t(cstime),
597                 priority,
598                 nice,
599                 num_threads,
600                 // 0,
601                 start_time,
602                 vsize,
603                 mm ? get_mm_rss(mm) : 0,
604                 rsslim,
605                 mm ? mm->start_code : 0,
606                 mm ? mm->end_code : 0,
607                 mm ? mm->start_stack : 0,
608                 esp,
609                 eip,
610 the rest is some obsolete cruft
611 */