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  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   9  */
  10
  11 #include "libbb.h"
  12
  13
  14 typedef struct {
  15         uid_t uid;
  16         char username[12];
  17 } user_map_t;
  18
  19 static user_map_t *username_cache;
  20 static int username_cache_size;
  21
  22 void clear_username_cache(void)
  23 {
  24         free(username_cache);
  25         username_cache = NULL;
  26         username_cache_size = 0;
  27 }
  28
  29 const char* get_cached_username(uid_t uid)
  30 {
  31         int i;
  32         for (i = 0; i < username_cache_size; i++)
  33                 if (username_cache[i].uid == uid)
  34                         return username_cache[i].username;
  35         i = username_cache_size++;
  36         username_cache = xrealloc(username_cache, username_cache_size * sizeof(*username_cache));
  37         username_cache[i].uid = uid;
  38         bb_getpwuid(username_cache[i].username, uid, sizeof(username_cache[i].username));
  39         return username_cache[i].username;
  40 }
  41
  42
  43 #define PROCPS_BUFSIZE 1024
  44
  45 static int read_to_buf(const char *filename, void *buf)
  46 {
  47         ssize_t ret;
  48         ret = open_read_close(filename, buf, PROCPS_BUFSIZE-1);
  49         ((char *)buf)[ret > 0 ? ret : 0] = '\0';
  50         return ret;
  51 }
  52
  53 procps_status_t* alloc_procps_scan(int flags)
  54 {
  55         procps_status_t* sp = xzalloc(sizeof(procps_status_t));
  56         sp->dir = xopendir("/proc");
  57         return sp;
  58 }
  59
  60 void free_procps_scan(procps_status_t* sp)
  61 {
  62         closedir(sp->dir);
  63         free(sp->cmd);
  64         free(sp);
  65 }
  66
  67 void BUG_comm_size(void);
  68 procps_status_t* procps_scan(procps_status_t* sp, int flags)
  69 {
  70         struct dirent *entry;
  71         char buf[PROCPS_BUFSIZE];
  72         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
  73         char *filename_tail;
  74         long tasknice;
  75         unsigned pid;
  76         int n;
  77         struct stat sb;
  78
  79         if (!sp)
  80                 sp = alloc_procps_scan(flags);
  81
  82         for (;;) {
  83                 entry = readdir(sp->dir);
  84                 if (entry == NULL) {
  85                         free_procps_scan(sp);
  86                         return NULL;
  87                 }
  88                 if (safe_strtou(entry->d_name, &pid))
  89                         continue;
  90
  91                 /* After this point we have to break, not continue
  92                  * ("continue" would mean that current /proc/NNN
  93                  * is not a valid process info) */
  94
  95                 memset(&sp->rss, 0, sizeof(*sp) - offsetof(procps_status_t, rss));
  96
  97                 sp->pid = pid;
  98                 if (!(flags & ~PSSCAN_PID)) break;
  99
 100                 filename_tail = filename + sprintf(filename, "/proc/%d", pid);
 101
 102                 if (flags & PSSCAN_UIDGID) {
 103                         if (stat(filename, &sb))
 104                                 break;
 105                         /* Need comment - is this effective or read UID/GID? */
 106                         sp->uid = sb.st_uid;
 107                         sp->gid = sb.st_gid;
 108                 }
 109
 110                 if (flags & PSSCAN_STAT) {
 111                         char *cp;
 112                         /* see proc(5) for some details on this */
 113                         strcpy(filename_tail, "/stat");
 114                         n = read_to_buf(filename, buf);
 115                         if (n < 0)
 116                                 break;
 117                         cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
 118                         if (!cp || cp[1] != ' ')
 119                                 break;
 120                         cp[0] = '\0';
 121                         if (sizeof(sp->comm) < 16)
 122                                 BUG_comm_size();
 123                         sscanf(buf, "%*s (%15c", sp->comm);
 124                         n = sscanf(cp+2,
 125                                 "%c %u "               /* state, ppid */
 126                                 "%u %u %*s %*s "       /* pgid, sid, tty, tpgid */
 127                                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
 128                                 "%lu %lu "             /* utime, stime */
 129                                 "%*s %*s %*s "         /* cutime, cstime, priority */
 130                                 "%ld "                 /* nice */
 131                                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
 132                                 "%*s "                 /* vsize */
 133                                 "%lu",                 /* rss */
 134                                 sp->state, &sp->ppid,
 135                                 &sp->pgid, &sp->sid,
 136                                 &sp->utime, &sp->stime,
 137                                 &tasknice,
 138                                 &sp->rss);
 139                         if (n != 8)
 140                                 break;
 141
 142                         if (sp->rss == 0 && sp->state[0] != 'Z')
 143                                 sp->state[1] = 'W';
 144                         else
 145                                 sp->state[1] = ' ';
 146                         if (tasknice < 0)
 147                                 sp->state[2] = '<';
 148                         else if (tasknice > 0)
 149                                 sp->state[2] = 'N';
 150                         else
 151                                 sp->state[2] = ' ';
 152
 153 #ifdef PAGE_SHIFT
 154                         sp->rss <<= (PAGE_SHIFT - 10);     /* 2**10 = 1kb */
 155 #else
 156                         sp->rss *= (getpagesize() >> 10);     /* 2**10 = 1kb */
 157 #endif
 158                 }
 159
 160                 if (flags & PSSCAN_CMD) {
 161                         free(sp->cmd);
 162                         sp->cmd = NULL;
 163                         strcpy(filename_tail, "/cmdline");
 164                         n = read_to_buf(filename, buf);
 165                         if (n <= 0)
 166                                 break;
 167                         if (buf[n-1] == '\n') {
 168                                 if (!--n)
 169                                         break;
 170                                 buf[n] = '\0';
 171                         }
 172                         do {
 173                                 n--;
 174                                 if ((unsigned char)(buf[n]) < ' ')
 175                                         buf[n] = ' ';
 176                         } while (n);
 177                         sp->cmd = strdup(buf);
 178                 }
 179                 break;
 180         }
 181         return sp;
 182 }
 183 /* from kernel:
 184         //             pid comm S ppid pgid sid tty_nr tty_pgrp flg
 185         sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
 186 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
 187 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
 188                 task->pid,
 189                 tcomm,
 190                 state,
 191                 ppid,
 192                 pgid,
 193                 sid,
 194                 tty_nr,
 195                 tty_pgrp,
 196                 task->flags,
 197                 min_flt,
 198
 199                 cmin_flt,
 200                 maj_flt,
 201                 cmaj_flt,
 202                 cputime_to_clock_t(utime),
 203                 cputime_to_clock_t(stime),
 204                 cputime_to_clock_t(cutime),
 205                 cputime_to_clock_t(cstime),
 206                 priority,
 207                 nice,
 208                 num_threads,
 209         // 0,
 210                 start_time,
 211                 vsize,
 212                 mm ? get_mm_rss(mm) : 0,
 213                 rsslim,
 214                 mm ? mm->start_code : 0,
 215                 mm ? mm->end_code : 0,
 216                 mm ? mm->start_stack : 0,
 217                 esp,
 218                 eip,
 219 the rest is some obsolete cruft
 220 */