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_FAST_TOP
 119 /* We cut a lot of corners here for speed */
 120 static unsigned long fast_strtoul_10(char **endptr)
 121 {
 122         char c;
 123         char *str = *endptr;
 124         unsigned long n = *str - '0';
 125
 126         while ((c = *++str) != ' ')
 127                 n = n*10 + (c - '0');
 128
 129         *endptr = str + 1; /* We skip trailing space! */
 130         return n;
 131 }
 132 static char *skip_fields(char *str, int count)
 133 {
 134         do {
 135                 while (*str++ != ' ')
 136                         continue;
 137                 /* we found a space char, str points after it */
 138         } while (--count);
 139         return str;
 140 }
 141 #endif
 142
 143 void BUG_comm_size(void);
 144 procps_status_t *procps_scan(procps_status_t* sp, int flags)
 145 {
 146         struct dirent *entry;
 147         char buf[PROCPS_BUFSIZE];
 148         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
 149         char *filename_tail;
 150         long tasknice;
 151         unsigned pid;
 152         int n;
 153         struct stat sb;
 154
 155         if (!sp)
 156                 sp = alloc_procps_scan(flags);
 157
 158         for (;;) {
 159                 entry = readdir(sp->dir);
 160                 if (entry == NULL) {
 161                         free_procps_scan(sp);
 162                         return NULL;
 163                 }
 164                 pid = bb_strtou(entry->d_name, NULL, 10);
 165                 if (errno)
 166                         continue;
 167
 168                 /* After this point we have to break, not continue
 169                  * ("continue" would mean that current /proc/NNN
 170                  * is not a valid process info) */
 171
 172                 memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
 173
 174                 sp->pid = pid;
 175                 if (!(flags & ~PSSCAN_PID)) break;
 176
 177 #if ENABLE_SELINUX
 178                 if (flags & PSSCAN_CONTEXT) {
 179                         if (getpidcon(sp->pid, &sp->context) < 0)
 180                                 sp->context = NULL;
 181                 }
 182 #endif
 183
 184                 filename_tail = filename + sprintf(filename, "/proc/%d", pid);
 185
 186                 if (flags & PSSCAN_UIDGID) {
 187                         if (stat(filename, &sb))
 188                                 break;
 189                         /* Need comment - is this effective or real UID/GID? */
 190                         sp->uid = sb.st_uid;
 191                         sp->gid = sb.st_gid;
 192                 }
 193
 194                 if (flags & PSSCAN_STAT) {
 195                         char *cp, *comm1;
 196                         int tty;
 197 #if !ENABLE_FEATURE_FAST_TOP
 198                         unsigned long vsz, rss;
 199 #endif
 200
 201                         /* see proc(5) for some details on this */
 202                         strcpy(filename_tail, "/stat");
 203                         n = read_to_buf(filename, buf);
 204                         if (n < 0)
 205                                 break;
 206                         cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
 207                         /*if (!cp || cp[1] != ' ')
 208                                 break;*/
 209                         cp[0] = '\0';
 210                         if (sizeof(sp->comm) < 16)
 211                                 BUG_comm_size();
 212                         comm1 = strchr(buf, '(');
 213                         /*if (comm1)*/
 214                                 safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));
 215
 216 #if !ENABLE_FEATURE_FAST_TOP
 217                         n = sscanf(cp+2,
 218                                 "%c %u "               /* state, ppid */
 219                                 "%u %u %d %*s "        /* pgid, sid, tty, tpgid */
 220                                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
 221                                 "%lu %lu "             /* utime, stime */
 222                                 "%*s %*s %*s "         /* cutime, cstime, priority */
 223                                 "%ld "                 /* nice */
 224                                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
 225                                 "%lu "                 /* vsize */
 226                                 "%lu "                 /* rss */
 227                         /*      "%lu %lu %lu %lu %lu %lu " rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
 228                         /*      "%u %u %u %u "         signal, blocked, sigignore, sigcatch */
 229                         /*      "%lu %lu %lu"          wchan, nswap, cnswap */
 230                                 ,
 231                                 sp->state, &sp->ppid,
 232                                 &sp->pgid, &sp->sid, &tty,
 233                                 &sp->utime, &sp->stime,
 234                                 &tasknice,
 235                                 &vsz,
 236                                 &rss);
 237                         if (n != 10)
 238                                 break;
 239                         /* vsz is in bytes and we want kb */
 240                         sp->vsz = vsz >> 10;
 241                         /* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
 242                         sp->rss = rss << sp->shift_pages_to_kb;
 243                         sp->tty_major = (tty >> 8) & 0xfff;
 244                         sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
 245 #else
 246 /* This costs ~100 bytes more but makes top faster by 20%
 247  * If you run 10000 processes, this may be important for you */
 248                         sp->state[0] = cp[2];
 249                         cp += 4;
 250                         sp->ppid = fast_strtoul_10(&cp);
 251                         sp->pgid = fast_strtoul_10(&cp);
 252                         sp->sid = fast_strtoul_10(&cp);
 253                         tty = fast_strtoul_10(&cp);
 254                         sp->tty_major = (tty >> 8) & 0xfff;
 255                         sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
 256                         cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
 257                         sp->utime = fast_strtoul_10(&cp);
 258                         sp->stime = fast_strtoul_10(&cp);
 259                         cp = skip_fields(cp, 3); /* cutime, cstime, priority */
 260                         tasknice = fast_strtoul_10(&cp);
 261                         cp = skip_fields(cp, 3); /* timeout, it_real_value, start_time */
 262                         /* vsz is in bytes and we want kb */
 263                         sp->vsz = fast_strtoul_10(&cp) >> 10;
 264                         /* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
 265                         sp->rss = fast_strtoul_10(&cp) << sp->shift_pages_to_kb;
 266 #endif
 267
 268                         if (sp->vsz == 0 && sp->state[0] != 'Z')
 269                                 sp->state[1] = 'W';
 270                         else
 271                                 sp->state[1] = ' ';
 272                         if (tasknice < 0)
 273                                 sp->state[2] = '<';
 274                         else if (tasknice) /* > 0 */
 275                                 sp->state[2] = 'N';
 276                         else
 277                                 sp->state[2] = ' ';
 278
 279                 }
 280
 281 #if 0 /* PSSCAN_CMD is not used */
 282                 if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
 283                         if (sp->argv0) {
 284                                 free(sp->argv0);
 285                                 sp->argv0 = NULL;
 286                         }
 287                         if (sp->cmd) {
 288                                 free(sp->cmd);
 289                                 sp->cmd = NULL;
 290                         }
 291                         strcpy(filename_tail, "/cmdline");
 292                         /* TODO: to get rid of size limits, read into malloc buf,
 293                          * then realloc it down to real size. */
 294                         n = read_to_buf(filename, buf);
 295                         if (n <= 0)
 296                                 break;
 297                         if (flags & PSSCAN_ARGV0)
 298                                 sp->argv0 = xstrdup(buf);
 299                         if (flags & PSSCAN_CMD) {
 300                                 do {
 301                                         n--;
 302                                         if ((unsigned char)(buf[n]) < ' ')
 303                                                 buf[n] = ' ';
 304                                 } while (n);
 305                                 sp->cmd = xstrdup(buf);
 306                         }
 307                 }
 308 #else
 309                 if (flags & PSSCAN_ARGV0) {
 310                         if (sp->argv0) {
 311                                 free(sp->argv0);
 312                                 sp->argv0 = NULL;
 313                         }
 314                         strcpy(filename_tail, "/cmdline");
 315                         n = read_to_buf(filename, buf);
 316                         if (n <= 0)
 317                                 break;
 318                         if (flags & PSSCAN_ARGV0)
 319                                 sp->argv0 = xstrdup(buf);
 320                 }
 321 #endif
 322                 break;
 323         }
 324         return sp;
 325 }
 326
 327 void read_cmdline(char *buf, int col, unsigned pid, const char *comm)
 328 {
 329         ssize_t sz;
 330         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
 331
 332         sprintf(filename, "/proc/%u/cmdline", pid);
 333         sz = open_read_close(filename, buf, col);
 334         if (sz > 0) {
 335                 buf[sz] = '\0';
 336                 while (--sz >= 0)
 337                         if ((unsigned char)(buf[sz]) < ' ')
 338                                 buf[sz] = ' ';
 339         } else {
 340                 snprintf(buf, col, "[%s]", comm);
 341         }
 342 }
 343
 344 /* from kernel:
 345         //             pid comm S ppid pgid sid tty_nr tty_pgrp flg
 346         sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
 347 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
 348 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
 349                 task->pid,
 350                 tcomm,
 351                 state,
 352                 ppid,
 353                 pgid,
 354                 sid,
 355                 tty_nr,
 356                 tty_pgrp,
 357                 task->flags,
 358                 min_flt,
 359                 cmin_flt,
 360                 maj_flt,
 361                 cmaj_flt,
 362                 cputime_to_clock_t(utime),
 363                 cputime_to_clock_t(stime),
 364                 cputime_to_clock_t(cutime),
 365                 cputime_to_clock_t(cstime),
 366                 priority,
 367                 nice,
 368                 num_threads,
 369                 // 0,
 370                 start_time,
 371                 vsize,
 372                 mm ? get_mm_rss(mm) : 0,
 373                 rsslim,
 374                 mm ? mm->start_code : 0,
 375                 mm ? mm->end_code : 0,
 376                 mm ? mm->start_stack : 0,
 377                 esp,
 378                 eip,
 379 the rest is some obsolete cruft
 380 */