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                         free(sp->argv0);
 357                         sp->argv0 = NULL;
 358                         free(sp->cmd);
 359                         sp->cmd = NULL;
 360                         strcpy(filename_tail, "/cmdline");
 361                         /* TODO: to get rid of size limits, read into malloc buf,
 362                          * then realloc it down to real size. */
 363                         n = read_to_buf(filename, buf);
 364                         if (n <= 0)
 365                                 break;
 366                         if (flags & PSSCAN_ARGV0)
 367                                 sp->argv0 = xstrdup(buf);
 368                         if (flags & PSSCAN_CMD) {
 369                                 do {
 370                                         n--;
 371                                         if ((unsigned char)(buf[n]) < ' ')
 372                                                 buf[n] = ' ';
 373                                 } while (n);
 374                                 sp->cmd = xstrdup(buf);
 375                         }
 376                 }
 377 #else
 378                 if (flags & (PSSCAN_ARGV0|PSSCAN_ARGVN)) {
 379                         free(sp->argv0);
 380                         sp->argv0 = NULL;
 381                         strcpy(filename_tail, "/cmdline");
 382                         n = read_to_buf(filename, buf);
 383                         if (n <= 0)
 384                                 break;
 385 #if ENABLE_PGREP || ENABLE_PKILL
 386                         if (flags & PSSCAN_ARGVN) {
 387                                 do {
 388                                         n--;
 389                                         if (buf[n] == '\0')
 390                                                 buf[n] = ' ';
 391                                 } while (n);
 392                         }
 393 #endif
 394                         sp->argv0 = xstrdup(buf);
 395                 }
 396 #endif
 397                 break;
 398         }
 399         return sp;
 400 }
 401
 402 void read_cmdline(char *buf, int col, unsigned pid, const char *comm)
 403 {
 404         ssize_t sz;
 405         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
 406
 407         sprintf(filename, "/proc/%u/cmdline", pid);
 408         sz = open_read_close(filename, buf, col);
 409         if (sz > 0) {
 410                 buf[sz] = '\0';
 411                 while (--sz >= 0)
 412                         if ((unsigned char)(buf[sz]) < ' ')
 413                                 buf[sz] = ' ';
 414         } else {
 415                 snprintf(buf, col, "[%s]", comm);
 416         }
 417 }
 418
 419 /* from kernel:
 420         //             pid comm S ppid pgid sid tty_nr tty_pgrp flg
 421         sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
 422 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
 423 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
 424                 task->pid,
 425                 tcomm,
 426                 state,
 427                 ppid,
 428                 pgid,
 429                 sid,
 430                 tty_nr,
 431                 tty_pgrp,
 432                 task->flags,
 433                 min_flt,
 434                 cmin_flt,
 435                 maj_flt,
 436                 cmaj_flt,
 437                 cputime_to_clock_t(utime),
 438                 cputime_to_clock_t(stime),
 439                 cputime_to_clock_t(cutime),
 440                 cputime_to_clock_t(cstime),
 441                 priority,
 442                 nice,
 443                 num_threads,
 444                 // 0,
 445                 start_time,
 446                 vsize,
 447                 mm ? get_mm_rss(mm) : 0,
 448                 rsslim,
 449                 mm ? mm->start_code : 0,
 450                 mm ? mm->end_code : 0,
 451                 mm ? mm->start_stack : 0,
 452                 esp,
 453                 eip,
 454 the rest is some obsolete cruft
 455 */