hush/libbb/procps.c
Denis Vlasenko 459e4d6cf7 replace /proc scanning code by more versatile one.
Use it where appropriate.
Stop scanning /etc/passwd *for every process*!!! (uid->username)
top: reduce memory usage - we won't save unneeded fields
from /proc info anymore. Downside: ~+250 bytes of code
2006-11-05 00:43:51 +00:00

221 lines
5.3 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright 1998 by Albert Cahalan; all rights reserved.
* Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
typedef struct {
uid_t uid;
char username[12];
} user_map_t;
static user_map_t *username_cache;
static int username_cache_size;
void clear_username_cache(void)
{
free(username_cache);
username_cache = NULL;
username_cache_size = 0;
}
const char* get_cached_username(uid_t uid)
{
int i;
for (i = 0; i < username_cache_size; i++)
if (username_cache[i].uid == uid)
return username_cache[i].username;
i = username_cache_size++;
username_cache = xrealloc(username_cache, username_cache_size * sizeof(*username_cache));
username_cache[i].uid = uid;
bb_getpwuid(username_cache[i].username, uid, sizeof(username_cache[i].username));
return username_cache[i].username;
}
#define PROCPS_BUFSIZE 1024
static int read_to_buf(const char *filename, void *buf)
{
ssize_t ret;
ret = open_read_close(filename, buf, PROCPS_BUFSIZE-1);
((char *)buf)[ret > 0 ? ret : 0] = '\0';
return ret;
}
procps_status_t* alloc_procps_scan(int flags)
{
procps_status_t* sp = xzalloc(sizeof(procps_status_t));
sp->dir = xopendir("/proc");
return sp;
}
void free_procps_scan(procps_status_t* sp)
{
closedir(sp->dir);
free(sp->cmd);
free(sp);
}
void BUG_comm_size(void);
procps_status_t* procps_scan(procps_status_t* sp, int flags)
{
struct dirent *entry;
char buf[PROCPS_BUFSIZE];
char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
char *filename_tail;
long tasknice;
unsigned pid;
int n;
struct stat sb;
if (!sp)
sp = alloc_procps_scan(flags);
for (;;) {
entry = readdir(sp->dir);
if (entry == NULL) {
free_procps_scan(sp);
return NULL;
}
if (safe_strtou(entry->d_name, &pid))
continue;
/* After this point we have to break, not continue
* ("continue" would mean that current /proc/NNN
* is not a valid process info) */
memset(&sp->rss, 0, sizeof(*sp) - offsetof(procps_status_t, rss));
sp->pid = pid;
if (!(flags & ~PSSCAN_PID)) break;
filename_tail = filename + sprintf(filename, "/proc/%d", pid);
if (flags & PSSCAN_UIDGID) {
if (stat(filename, &sb))
break;
/* Need comment - is this effective or read UID/GID? */
sp->uid = sb.st_uid;
sp->gid = sb.st_gid;
}
if (flags & PSSCAN_STAT) {
char *cp;
/* see proc(5) for some details on this */
strcpy(filename_tail, "/stat");
n = read_to_buf(filename, buf);
if (n < 0)
break;
cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
if (!cp || cp[1] != ' ')
break;
cp[0] = '\0';
if (sizeof(sp->comm) < 16)
BUG_comm_size();
sscanf(buf, "%*s (%15c", sp->comm);
n = sscanf(cp+2,
"%c %u " /* state, ppid */
"%u %u %*s %*s " /* pgid, sid, tty, tpgid */
"%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
"%lu %lu " /* utime, stime */
"%*s %*s %*s " /* cutime, cstime, priority */
"%ld " /* nice */
"%*s %*s %*s " /* timeout, it_real_value, start_time */
"%*s " /* vsize */
"%lu", /* rss */
sp->state, &sp->ppid,
&sp->pgid, &sp->sid,
&sp->utime, &sp->stime,
&tasknice,
&sp->rss);
if (n != 8)
break;
if (sp->rss == 0 && sp->state[0] != 'Z')
sp->state[1] = 'W';
else
sp->state[1] = ' ';
if (tasknice < 0)
sp->state[2] = '<';
else if (tasknice > 0)
sp->state[2] = 'N';
else
sp->state[2] = ' ';
#ifdef PAGE_SHIFT
sp->rss <<= (PAGE_SHIFT - 10); /* 2**10 = 1kb */
#else
sp->rss *= (getpagesize() >> 10); /* 2**10 = 1kb */
#endif
}
if (flags & PSSCAN_CMD) {
free(sp->cmd);
sp->cmd = NULL;
strcpy(filename_tail, "/cmdline");
n = read_to_buf(filename, buf);
if (n <= 0)
break;
if (buf[n-1] == '\n') {
if (!--n)
break;
buf[n] = '\0';
}
do {
n--;
if ((unsigned char)(buf[n]) < ' ')
buf[n] = ' ';
} while (n);
sp->cmd = strdup(buf);
}
break;
}
return sp;
}
/* from kernel:
// pid comm S ppid pgid sid tty_nr tty_pgrp flg
sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
%lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
%lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
task->pid,
tcomm,
state,
ppid,
pgid,
sid,
tty_nr,
tty_pgrp,
task->flags,
min_flt,
cmin_flt,
maj_flt,
cmaj_flt,
cputime_to_clock_t(utime),
cputime_to_clock_t(stime),
cputime_to_clock_t(cutime),
cputime_to_clock_t(cstime),
priority,
nice,
num_threads,
// 0,
start_time,
vsize,
mm ? get_mm_rss(mm) : 0,
rsslim,
mm ? mm->start_code : 0,
mm ? mm->end_code : 0,
mm ? mm->start_stack : 0,
esp,
eip,
the rest is some obsolete cruft
*/