procps/proc/whattime.c
Qualys Security Advisory 00ab5f0b32 proc/whattime.c: Always initialize buf.
In the human_readable case; otherwise the strcat() that follows may
append bytes to the previous contents of buf.

Also, slightly enlarge buf, as it was a bit too tight.

Could also replace all sprintf()s with snprintf()s, but all the calls
here output a limited number of characters, so they should be safe.
2018-05-19 07:32:21 +10:00

163 lines
4.5 KiB
C

/*
* This is a trivial uptime program. I hereby release this program
* into the public domain. I disclaim any responsibility for this
* program --- use it at your own risk. (as if there were any.. ;-)
* -michaelkjohnson (johnsonm@sunsite.unc.edu)
*
* Modified by Larry Greenfield to give a more traditional output,
* count users, etc. (greenfie@gauss.rutgers.edu)
*
* Modified by mkj again to fix a few tiny buglies.
*
* Modified by J. Cowley to add printing the uptime message to a
* string (for top) and to optimize file handling. 19 Mar 1993.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <utmp.h>
#include <sys/ioctl.h>
#include "whattime.h"
#include "sysinfo.h"
static char buf[256];
static double av[3];
char *sprint_uptime(int human_readable) {
struct utmp *utmpstruct;
int upminutes, uphours, updays, upweeks, upyears, updecades;
int pos;
int comma;
struct tm *realtime;
time_t realseconds;
int numuser;
double uptime_secs, idle_secs;
/* first get the current time */
if (!human_readable) {
time(&realseconds);
realtime = localtime(&realseconds);
pos = sprintf(buf, " %02d:%02d:%02d ",
realtime->tm_hour, realtime->tm_min, realtime->tm_sec);
} else {
pos = 0;
buf[0] = '\0';
}
/* read and calculate the amount of uptime */
uptime(&uptime_secs, &idle_secs);
if (human_readable) {
updecades = (int) uptime_secs / (60*60*24*365*10);
upyears = ((int) uptime_secs / (60*60*24*365)) % 10;
upweeks = ((int) uptime_secs / (60*60*24*7)) % 52;
updays = ((int) uptime_secs / (60*60*24)) % 7;
}
else
updays = (int) uptime_secs / (60*60*24);
strcat (buf, "up ");
pos += 3;
if (!human_readable) {
if (updays)
pos += sprintf(buf + pos, "%d day%s, ", updays, (updays != 1) ? "s" : "");
}
upminutes = (int) uptime_secs / 60;
uphours = upminutes / 60;
uphours = uphours % 24;
upminutes = upminutes % 60;
if (!human_readable) {
if(uphours)
pos += sprintf(buf + pos, "%2d:%02d, ", uphours, upminutes);
else
pos += sprintf(buf + pos, "%d min, ", upminutes);
/* count the number of users */
numuser = 0;
setutent();
while ((utmpstruct = getutent())) {
if ((utmpstruct->ut_type == USER_PROCESS) &&
(utmpstruct->ut_name[0] != '\0'))
numuser++;
}
endutent();
pos += sprintf(buf + pos, "%2d user%s, ", numuser, numuser == 1 ? "" : "s");
loadavg(&av[0], &av[1], &av[2]);
pos += sprintf(buf + pos, " load average: %.2f, %.2f, %.2f",
av[0], av[1], av[2]);
}
if (human_readable) {
comma = 0;
if (updecades) {
pos += sprintf(buf + pos, "%d %s", updecades,
updecades > 1 ? "decades" : "decade");
comma += 1;
}
if (upyears) {
pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", upyears,
upyears > 1 ? "years" : "year");
comma += 1;
}
if (upweeks) {
pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", upweeks,
upweeks > 1 ? "weeks" : "week");
comma += 1;
}
if (updays) {
pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", updays,
updays > 1 ? "days" : "day");
comma += 1;
}
if (uphours) {
pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", uphours,
uphours > 1 ? "hours" : "hour");
comma += 1;
}
if (upminutes || (!upminutes && uptime_secs < 60)) {
pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", upminutes,
upminutes != 1 ? "minutes" : "minute");
comma += 1;
}
}
return buf;
}
void print_uptime(int human_readable) {
printf("%s\n", sprint_uptime(human_readable));
}