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         int fd;
  83         /* open_read_close() would do two reads, checking for EOF.
  84          * When you have 10000 /proc/$NUM/stat to read, it isn't desirable */
  85         ssize_t ret = -1;
  86         fd = open(filename, O_RDONLY);
  87         if (fd >= 0) {
  88                 ret = read(fd, buf, PROCPS_BUFSIZE-1);
  89                 close(fd);
  90         }
  91         ((char *)buf)[ret > 0 ? ret : 0] = '\0';
  92         return ret;
  93 }
  94
  95 procps_status_t* alloc_procps_scan(int flags)
  96 {
  97         procps_status_t* sp = xzalloc(sizeof(procps_status_t));
  98         sp->dir = xopendir("/proc");
  99         return sp;
 100 }
 101
 102 void free_procps_scan(procps_status_t* sp)
 103 {
 104         closedir(sp->dir);
 105         free(sp->cmd);
 106         USE_SELINUX(free(sp->context);)
 107         free(sp);
 108 }
 109
 110 void BUG_comm_size(void);
 111 procps_status_t* procps_scan(procps_status_t* sp, int flags)
 112 {
 113         struct dirent *entry;
 114         char buf[PROCPS_BUFSIZE];
 115         char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
 116         char *filename_tail;
 117         long tasknice;
 118         unsigned pid;
 119         int n;
 120         struct stat sb;
 121
 122         if (!sp)
 123                 sp = alloc_procps_scan(flags);
 124
 125         for (;;) {
 126                 entry = readdir(sp->dir);
 127                 if (entry == NULL) {
 128                         free_procps_scan(sp);
 129                         return NULL;
 130                 }
 131                 pid = bb_strtou(entry->d_name, NULL, 10);
 132                 if (errno)
 133                         continue;
 134
 135                 /* After this point we have to break, not continue
 136                  * ("continue" would mean that current /proc/NNN
 137                  * is not a valid process info) */
 138
 139                 memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
 140
 141                 sp->pid = pid;
 142                 if (!(flags & ~PSSCAN_PID)) break;
 143
 144 #if ENABLE_SELINUX
 145                 if (flags & PSSCAN_CONTEXT) {
 146                         if (getpidcon(sp->pid, &sp->context) < 0)
 147                                 sp->context = NULL;
 148                 }
 149 #endif
 150
 151                 filename_tail = filename + sprintf(filename, "/proc/%d", pid);
 152
 153                 if (flags & PSSCAN_UIDGID) {
 154                         if (stat(filename, &sb))
 155                                 break;
 156                         /* Need comment - is this effective or real UID/GID? */
 157                         sp->uid = sb.st_uid;
 158                         sp->gid = sb.st_gid;
 159                 }
 160
 161                 if (flags & PSSCAN_STAT) {
 162                         char *cp;
 163                         unsigned long vsz, rss;
 164                         int tty;
 165
 166                         /* see proc(5) for some details on this */
 167                         strcpy(filename_tail, "/stat");
 168                         n = read_to_buf(filename, buf);
 169                         if (n < 0)
 170                                 break;
 171                         cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
 172                         if (!cp || cp[1] != ' ')
 173                                 break;
 174                         cp[0] = '\0';
 175                         if (sizeof(sp->comm) < 16)
 176                                 BUG_comm_size();
 177                         sscanf(buf, "%*s (%15c", sp->comm);
 178                         n = sscanf(cp+2,
 179                                 "%c %u "               /* state, ppid */
 180                                 "%u %u %d %*s "        /* pgid, sid, tty, tpgid */
 181                                 "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
 182                                 "%lu %lu "             /* utime, stime */
 183                                 "%*s %*s %*s "         /* cutime, cstime, priority */
 184                                 "%ld "                 /* nice */
 185                                 "%*s %*s %*s "         /* timeout, it_real_value, start_time */
 186                                 "%lu "                 /* vsize */
 187                                 "%lu "                 /* rss */
 188                         /*      "%lu %lu %lu %lu %lu %lu " rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
 189                         /*      "%u %u %u %u "         signal, blocked, sigignore, sigcatch */
 190                         /*      "%lu %lu %lu"          wchan, nswap, cnswap */
 191                                 ,
 192                                 sp->state, &sp->ppid,
 193                                 &sp->pgid, &sp->sid, &tty,
 194                                 &sp->utime, &sp->stime,
 195                                 &tasknice,
 196                                 &vsz,
 197                                 &rss);
 198                         if (n != 10)
 199                                 break;
 200
 201                         sp->tty_str[0] = '?';
 202                         /* sp->tty_str[1] = '\0'; - done by memset */
 203                         if (tty) /* tty field of "0" means "no tty" */
 204                                 snprintf(sp->tty_str, sizeof(sp->tty_str), "%u,%u",
 205                                         (tty >> 8) & 0xfff, /* major */
 206                                         (tty & 0xff) | ((tty >> 12) & 0xfff00));
 207                         if (sp->vsz == 0 && sp->state[0] != 'Z')
 208                                 sp->state[1] = 'W';
 209                         else
 210                                 sp->state[1] = ' ';
 211                         if (tasknice < 0)
 212                                 sp->state[2] = '<';
 213                         else if (tasknice) /* > 0 */
 214                                 sp->state[2] = 'N';
 215                         else
 216                                 sp->state[2] = ' ';
 217
 218                         sp->vsz = vsz >> 10; /* vsize is in bytes and we want kb */
 219                         sp->rss = rss >> 10;
 220                 }
 221
 222                 if (flags & PSSCAN_CMD) {
 223                         free(sp->cmd);
 224                         sp->cmd = NULL;
 225                         strcpy(filename_tail, "/cmdline");
 226                         n = read_to_buf(filename, buf);
 227                         if (n <= 0)
 228                                 break;
 229                         if (buf[n-1] == '\n') {
 230                                 if (!--n)
 231                                         break;
 232                                 buf[n] = '\0';
 233                         }
 234                         do {
 235                                 n--;
 236                                 if ((unsigned char)(buf[n]) < ' ')
 237                                         buf[n] = ' ';
 238                         } while (n);
 239                         sp->cmd = xstrdup(buf);
 240                 }
 241                 break;
 242         }
 243         return sp;
 244 }
 245 /* from kernel:
 246         //             pid comm S ppid pgid sid tty_nr tty_pgrp flg
 247         sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
 248 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
 249 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
 250                 task->pid,
 251                 tcomm,
 252                 state,
 253                 ppid,
 254                 pgid,
 255                 sid,
 256                 tty_nr,
 257                 tty_pgrp,
 258                 task->flags,
 259                 min_flt,
 260                 cmin_flt,
 261                 maj_flt,
 262                 cmaj_flt,
 263                 cputime_to_clock_t(utime),
 264                 cputime_to_clock_t(stime),
 265                 cputime_to_clock_t(cutime),
 266                 cputime_to_clock_t(cstime),
 267                 priority,
 268                 nice,
 269                 num_threads,
 270                 // 0,
 271                 start_time,
 272                 vsize,
 273                 mm ? get_mm_rss(mm) : 0,
 274                 rsslim,
 275                 mm ? mm->start_code : 0,
 276                 mm ? mm->end_code : 0,
 277                 mm ? mm->start_stack : 0,
 278                 esp,
 279                 eip,
 280 the rest is some obsolete cruft
 281 */