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, long uid, int bufsize);
  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         fp(cp->cache[i].name, id, sizeof(cp->cache[i].name));
  66         return cp->cache[i].name;
  67 }
  68 const char* get_cached_username(uid_t uid)
  69 {
  70         return get_cached(&username, uid, bb_getpwuid);
  71 }
  72 const char* get_cached_groupname(gid_t gid)
  73 {
  74         return get_cached(&groupname, gid, bb_getgrgid);
  75 }
  76
  77
  78 #define PROCPS_BUFSIZE 1024
  79
  80 static int read_to_buf(const char *filename, void *buf)
  81 {
  82         ssize_t ret;
  83         ret = open_read_close(filename, buf, PROCPS_BUFSIZE-1);
  84         ((char *)buf)[ret > 0 ? ret : 0] = '\0';
  85         return ret;
  86 }
  87
  88 procps_status_t* alloc_procps_scan(int flags)
  89 {
  90         procps_status_t* sp = xzalloc(sizeof(procps_status_t));
  91         sp->dir = xopendir("/proc");
  92         return sp;
  93 }
  94
  95 void free_procps_scan(procps_status_t* sp)
  96 {
  97         closedir(sp->dir);
  98         free(sp->cmd);
  99         USE_SELINUX(free(sp->context);)
 100         free(sp);
 101 }
 102
 103 void BUG_comm_size(void);
 104 procps_status_t* procps_scan(procps_status_t* sp, int flags)
 105 {
 106         struct dirent *entry;
 107         char buf[PROCPS_BUFSIZE];
 108         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
 109         char *filename_tail;
 110         long tasknice;
 111         unsigned pid;
 112         int n;
 113         struct stat sb;
 114
 115         if (!sp)
 116                 sp = alloc_procps_scan(flags);
 117
 118         for (;;) {
 119                 entry = readdir(sp->dir);
 120                 if (entry == NULL) {
 121                         free_procps_scan(sp);
 122                         return NULL;
 123                 }
 124                 pid = bb_strtou(entry->d_name, NULL, 10);
 125                 if (errno)
 126                         continue;
 127
 128                 /* After this point we have to break, not continue
 129                  * ("continue" would mean that current /proc/NNN
 130                  * is not a valid process info) */
 131
 132                 memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
 133
 134                 sp->pid = pid;
 135                 if (!(flags & ~PSSCAN_PID)) break;
 136
 137 #if ENABLE_SELINUX
 138                 if (flags & PSSCAN_CONTEXT) {
 139                         if (getpidcon(sp->pid, &sp->context) < 0)
 140                                 sp->context = NULL;
 141                 }
 142 #endif
 143
 144                 filename_tail = filename + sprintf(filename, "/proc/%d", pid);
 145
 146                 if (flags & PSSCAN_UIDGID) {
 147                         if (stat(filename, &sb))
 148                                 break;
 149                         /* Need comment - is this effective or real UID/GID? */
 150                         sp->uid = sb.st_uid;
 151                         sp->gid = sb.st_gid;
 152                 }
 153
 154                 if (flags & PSSCAN_STAT) {
 155                         char *cp;
 156                         unsigned long vsz, rss;
 157                         int tty;
 158
 159                         /* see proc(5) for some details on this */
 160                         strcpy(filename_tail, "/stat");
 161                         n = read_to_buf(filename, buf);
 162                         if (n < 0)
 163                                 break;
 164                         cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
 165                         if (!cp || cp[1] != ' ')
 166                                 break;
 167                         cp[0] = '\0';
 168                         if (sizeof(sp->comm) < 16)
 169                                 BUG_comm_size();
 170                         sscanf(buf, "%*s (%15c", sp->comm);
 171                         n = sscanf(cp+2,
 172                                 "%c %u "               /* state, ppid */
 173                                 "%u %u %d %*s "        /* pgid, sid, tty, tpgid */
 174                                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
 175                                 "%lu %lu "             /* utime, stime */
 176                                 "%*s %*s %*s "         /* cutime, cstime, priority */
 177                                 "%ld "                 /* nice */
 178                                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
 179                                 "%lu "                 /* vsize */
 180                                 "%lu "                 /* rss */
 181                         /*      "%lu %lu %lu %lu %lu %lu " rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
 182                         /*      "%u %u %u %u "         signal, blocked, sigignore, sigcatch */
 183                         /*      "%lu %lu %lu"          wchan, nswap, cnswap */
 184                                 ,
 185                                 sp->state, &sp->ppid,
 186                                 &sp->pgid, &sp->sid, &tty,
 187                                 &sp->utime, &sp->stime,
 188                                 &tasknice,
 189                                 &vsz,
 190                                 &rss);
 191                         if (n != 10)
 192                                 break;
 193
 194                         sp->tty_str[0] = '?';
 195                         /* sp->tty_str[1] = '\0'; - done by memset */
 196                         if (tty) /* tty field of "0" means "no tty" */
 197                                 snprintf(sp->tty_str, sizeof(sp->tty_str), "%u,%u",
 198                                         (tty >> 8) & 0xfff, /* major */
 199                                         (tty & 0xff) | ((tty >> 12) & 0xfff00));
 200                         if (sp->vsz == 0 && sp->state[0] != 'Z')
 201                                 sp->state[1] = 'W';
 202                         else
 203                                 sp->state[1] = ' ';
 204                         if (tasknice < 0)
 205                                 sp->state[2] = '<';
 206                         else if (tasknice) /* > 0 */
 207                                 sp->state[2] = 'N';
 208                         else
 209                                 sp->state[2] = ' ';
 210
 211                         sp->vsz = vsz >> 10; /* vsize is in bytes and we want kb */
 212                         sp->rss = rss >> 10;
 213                 }
 214
 215                 if (flags & PSSCAN_CMD) {
 216                         free(sp->cmd);
 217                         sp->cmd = NULL;
 218                         strcpy(filename_tail, "/cmdline");
 219                         n = read_to_buf(filename, buf);
 220                         if (n <= 0)
 221                                 break;
 222                         if (buf[n-1] == '\n') {
 223                                 if (!--n)
 224                                         break;
 225                                 buf[n] = '\0';
 226                         }
 227                         do {
 228                                 n--;
 229                                 if ((unsigned char)(buf[n]) < ' ')
 230                                         buf[n] = ' ';
 231                         } while (n);
 232                         sp->cmd = xstrdup(buf);
 233                 }
 234                 break;
 235         }
 236         return sp;
 237 }
 238 /* from kernel:
 239         //             pid comm S ppid pgid sid tty_nr tty_pgrp flg
 240         sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
 241 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
 242 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
 243                 task->pid,
 244                 tcomm,
 245                 state,
 246                 ppid,
 247                 pgid,
 248                 sid,
 249                 tty_nr,
 250                 tty_pgrp,
 251                 task->flags,
 252                 min_flt,
 253                 cmin_flt,
 254                 maj_flt,
 255                 cmaj_flt,
 256                 cputime_to_clock_t(utime),
 257                 cputime_to_clock_t(stime),
 258                 cputime_to_clock_t(cutime),
 259                 cputime_to_clock_t(cstime),
 260                 priority,
 261                 nice,
 262                 num_threads,
 263                 // 0,
 264                 start_time,
 265                 vsize,
 266                 mm ? get_mm_rss(mm) : 0,
 267                 rsslim,
 268                 mm ? mm->start_code : 0,
 269                 mm ? mm->end_code : 0,
 270                 mm ? mm->start_stack : 0,
 271                 esp,
 272                 eip,
 273 the rest is some obsolete cruft
 274 */