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 unsigned_to_name_map_t {
  15         unsigned id;
  16         char name[USERNAME_MAX_SIZE];
  17 } unsigned_to_name_map_t;
  18
  19 typedef struct cache_t {
  20         unsigned_to_name_map_t *cache;
  21         int size;
  22 } cache_t;
  23
  24 static cache_t username, groupname;
  25
  26 static void clear_cache(cache_t *cp)
  27 {
  28         free(cp->cache);
  29         cp->cache = NULL;
  30         cp->size = 0;
  31 }
  32 void clear_username_cache(void)
  33 {
  34         clear_cache(&username);
  35         clear_cache(&groupname);
  36 }
  37
  38 #if 0 /* more generic, but we don't need that yet */
  39 /* Returns -N-1 if not found. */
  40 /* cp->cache[N] is allocated and must be filled in this case */
  41 static int get_cached(cache_t *cp, unsigned id)
  42 {
  43         int i;
  44         for (i = 0; i < cp->size; i++)
  45                 if (cp->cache[i].id == id)
  46                         return i;
  47         i = cp->size++;
  48         cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
  49         cp->cache[i++].id = id;
  50         return -i;
  51 }
  52 #endif
  53
  54 typedef char* ug_func(char *name, long uid, int bufsize);
  55 static char* get_cached(cache_t *cp, unsigned id, ug_func* fp)
  56 {
  57         int i;
  58         for (i = 0; i < cp->size; i++)
  59                 if (cp->cache[i].id == id)
  60                         return cp->cache[i].name;
  61         i = cp->size++;
  62         cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
  63         cp->cache[i].id = id;
  64         fp(cp->cache[i].name, id, sizeof(cp->cache[i].name));
  65         return cp->cache[i].name;
  66 }
  67 const char* get_cached_username(uid_t uid)
  68 {
  69         return get_cached(&username, uid, bb_getpwuid);
  70 }
  71 const char* get_cached_groupname(gid_t gid)
  72 {
  73         return get_cached(&groupname, gid, bb_getgrgid);
  74 }
  75
  76
  77 #define PROCPS_BUFSIZE 1024
  78
  79 static int read_to_buf(const char *filename, void *buf)
  80 {
  81         ssize_t ret;
  82         ret = open_read_close(filename, buf, PROCPS_BUFSIZE-1);
  83         ((char *)buf)[ret > 0 ? ret : 0] = '\0';
  84         return ret;
  85 }
  86
  87 procps_status_t* alloc_procps_scan(int flags)
  88 {
  89         procps_status_t* sp = xzalloc(sizeof(procps_status_t));
  90         sp->dir = xopendir("/proc");
  91         return sp;
  92 }
  93
  94 void free_procps_scan(procps_status_t* sp)
  95 {
  96         closedir(sp->dir);
  97         free(sp->cmd);
  98         free(sp);
  99 }
 100
 101 void BUG_comm_size(void);
 102 procps_status_t* procps_scan(procps_status_t* sp, int flags)
 103 {
 104         struct dirent *entry;
 105         char buf[PROCPS_BUFSIZE];
 106         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
 107         char *filename_tail;
 108         long tasknice;
 109         unsigned pid;
 110         int n;
 111         struct stat sb;
 112
 113         if (!sp)
 114                 sp = alloc_procps_scan(flags);
 115
 116         for (;;) {
 117                 entry = readdir(sp->dir);
 118                 if (entry == NULL) {
 119                         free_procps_scan(sp);
 120                         return NULL;
 121                 }
 122                 pid = bb_strtou(entry->d_name, NULL, 10);
 123                 if (errno)
 124                         continue;
 125
 126                 /* After this point we have to break, not continue
 127                  * ("continue" would mean that current /proc/NNN
 128                  * is not a valid process info) */
 129
 130                 memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
 131
 132                 sp->pid = pid;
 133                 if (!(flags & ~PSSCAN_PID)) break;
 134
 135                 filename_tail = filename + sprintf(filename, "/proc/%d", pid);
 136
 137                 if (flags & PSSCAN_UIDGID) {
 138                         if (stat(filename, &sb))
 139                                 break;
 140                         /* Need comment - is this effective or real UID/GID? */
 141                         sp->uid = sb.st_uid;
 142                         sp->gid = sb.st_gid;
 143                 }
 144
 145                 if (flags & PSSCAN_STAT) {
 146                         char *cp;
 147                         /* see proc(5) for some details on this */
 148                         strcpy(filename_tail, "/stat");
 149                         n = read_to_buf(filename, buf);
 150                         if (n < 0)
 151                                 break;
 152                         cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
 153                         if (!cp || cp[1] != ' ')
 154                                 break;
 155                         cp[0] = '\0';
 156                         if (sizeof(sp->comm) < 16)
 157                                 BUG_comm_size();
 158                         sscanf(buf, "%*s (%15c", sp->comm);
 159                         n = sscanf(cp+2,
 160                                 "%c %u "               /* state, ppid */
 161                                 "%u %u %*s %*s "       /* pgid, sid, tty, tpgid */
 162                                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
 163                                 "%lu %lu "             /* utime, stime */
 164                                 "%*s %*s %*s "         /* cutime, cstime, priority */
 165                                 "%ld "                 /* nice */
 166                                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
 167                                 "%lu ",                /* vsize */
 168                                 sp->state, &sp->ppid,
 169                                 &sp->pgid, &sp->sid,
 170                                 &sp->utime, &sp->stime,
 171                                 &tasknice,
 172                                 &sp->vsz);
 173                         if (n != 8)
 174                                 break;
 175
 176                         if (sp->vsz == 0 && sp->state[0] != 'Z')
 177                                 sp->state[1] = 'W';
 178                         else
 179                                 sp->state[1] = ' ';
 180                         if (tasknice < 0)
 181                                 sp->state[2] = '<';
 182                         else if (tasknice > 0)
 183                                 sp->state[2] = 'N';
 184                         else
 185                                 sp->state[2] = ' ';
 186
 187                         sp->vsz >>= 10; /* vsize is in bytes and we want kb */
 188                 }
 189
 190                 if (flags & PSSCAN_CMD) {
 191                         free(sp->cmd);
 192                         sp->cmd = NULL;
 193                         strcpy(filename_tail, "/cmdline");
 194                         n = read_to_buf(filename, buf);
 195                         if (n <= 0)
 196                                 break;
 197                         if (buf[n-1] == '\n') {
 198                                 if (!--n)
 199                                         break;
 200                                 buf[n] = '\0';
 201                         }
 202                         do {
 203                                 n--;
 204                                 if ((unsigned char)(buf[n]) < ' ')
 205                                         buf[n] = ' ';
 206                         } while (n);
 207                         sp->cmd = xstrdup(buf);
 208                 }
 209                 break;
 210         }
 211         return sp;
 212 }
 213 /* from kernel:
 214         //             pid comm S ppid pgid sid tty_nr tty_pgrp flg
 215         sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
 216 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
 217 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
 218                 task->pid,
 219                 tcomm,
 220                 state,
 221                 ppid,
 222                 pgid,
 223                 sid,
 224                 tty_nr,
 225                 tty_pgrp,
 226                 task->flags,
 227                 min_flt,
 228                 cmin_flt,
 229                 maj_flt,
 230                 cmaj_flt,
 231                 cputime_to_clock_t(utime),
 232                 cputime_to_clock_t(stime),
 233                 cputime_to_clock_t(cutime),
 234                 cputime_to_clock_t(cstime),
 235                 priority,
 236                 nice,
 237                 num_threads,
 238                 // 0,
 239                 start_time,
 240                 vsize,
 241                 mm ? get_mm_rss(mm) : 0,
 242                 rsslim,
 243                 mm ? mm->start_code : 0,
 244                 mm ? mm->end_code : 0,
 245                 mm ? mm->start_stack : 0,
 246                 esp,
 247                 eip,
 248 the rest is some obsolete cruft
 249 */