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shadow/lib/port.c

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/*
* Copyright 1989 - 1994, Julianne Frances Haugh
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Julianne F. Haugh nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <config.h>
#include "rcsid.h"
RCSID ("$Id: port.c,v 1.4 2005/03/31 05:14:49 kloczek Exp $")
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include "defines.h"
#include "port.h"
extern int errno;
static FILE *ports;
/*
* portcmp - compare the name of a port to a /etc/porttime entry
*
* portcmp works like strcmp, except that if the last character
* in a failing match is a '*', the match is considered to have
* passed. The "*" match is suppressed whenever the port is "SU",
* which is the token the "su" command uses to validate access.
* A match returns 0, failure returns non-zero.
*/
static int portcmp (const char *pattern, const char *port)
{
const char *orig = port;
while (*pattern && *pattern == *port)
pattern++, port++;
if (*pattern == 0 && *port == 0)
return 0;
if (orig[0] == 'S' && orig[1] == 'U' && orig[2] == '\0')
return 1;
return *pattern == '*' ? 0 : 1;
}
/*
* setportent - open /etc/porttime file or rewind
*
* the /etc/porttime file is rewound if already open, or
* opened for reading.
*/
static void setportent (void)
{
if (ports)
rewind (ports);
else
ports = fopen (PORTS, "r");
}
/*
* endportent - close the /etc/porttime file
*
* the /etc/porttime file is closed and the ports variable set
* to NULL to indicate that the /etc/porttime file is no longer
* open.
*/
static void endportent (void)
{
if (ports)
fclose (ports);
ports = (FILE *) 0;
}
/*
* getportent - read a single entry from /etc/porttime
*
* the next line in /etc/porttime is converted to a (struct port)
* and a pointer to a static (struct port) is returned to the
* invoker. NULL is returned on either EOF or error. errno is
* set to EINVAL on error to distinguish the two conditions.
*/
static struct port *getportent (void)
{
static struct port port; /* static struct to point to */
static char buf[BUFSIZ]; /* some space for stuff */
static char *ttys[PORT_TTY + 1]; /* some pointers to tty names */
static char *users[PORT_IDS + 1]; /* some pointers to user ids */
static struct pt_time ptimes[PORT_TIMES + 1]; /* time ranges */
char *cp; /* pointer into line */
int dtime; /* scratch time of day */
int i, j;
int saveerr = errno; /* errno value on entry */
/*
* If the ports file is not open, open the file. Do not rewind
* since we want to search from the beginning each time.
*/
if (!ports)
setportent ();
if (!ports) {
errno = saveerr;
return 0;
}
/*
* Common point for beginning a new line -
*
* - read a line, and NUL terminate
* - skip lines which begin with '#'
* - parse off the tty names
* - parse off a list of user names
* - parse off a list of days and times
*/
again:
/*
* Get the next line and remove the last character, which
* is a '\n'. Lines which begin with '#' are all ignored.
*/
if (fgets (buf, sizeof buf, ports) == 0) {
errno = saveerr;
return 0;
}
if (buf[0] == '#')
goto again;
/*
* Get the name of the TTY device. It is the first colon
* separated field, and is the name of the TTY with no
* leading "/dev". The entry '*' is used to specify all
* TTY devices.
*/
buf[strlen (buf) - 1] = 0;
port.pt_names = ttys;
for (cp = buf, j = 0; j < PORT_TTY; j++) {
port.pt_names[j] = cp;
while (*cp && *cp != ':' && *cp != ',')
cp++;
if (!*cp)
goto again; /* line format error */
if (*cp == ':') /* end of tty name list */
break;
if (*cp == ',') /* end of current tty name */
*cp++ = '\0';
}
*cp++ = 0;
port.pt_names[j + 1] = (char *) 0;
/*
* Get the list of user names. It is the second colon
* separated field, and is a comma separated list of user
* names. The entry '*' is used to specify all usernames.
* The last entry in the list is a (char *) 0 pointer.
*/
if (*cp != ':') {
port.pt_users = users;
port.pt_users[0] = cp;
for (j = 1; *cp != ':'; cp++) {
if (*cp == ',' && j < PORT_IDS) {
*cp++ = 0;
port.pt_users[j++] = cp;
}
}
port.pt_users[j] = 0;
} else
port.pt_users = 0;
if (*cp != ':')
goto again;
*cp++ = 0;
/*
* Get the list of valid times. The times field is the third
* colon separated field and is a list of days of the week and
* times during which this port may be used by this user. The
* valid days are 'Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', and 'Sa'.
*
* In addition, the value 'Al' represents all 7 days, and 'Wk'
* represents the 5 weekdays.
*
* Times are given as HHMM-HHMM. The ending time may be before
* the starting time. Days are presumed to wrap at 0000.
*/
if (*cp == '\0') {
port.pt_times = 0;
return &port;
}
port.pt_times = ptimes;
/*
* Get the next comma separated entry
*/
for (j = 0; *cp && j < PORT_TIMES; j++) {
/*
* Start off with no days of the week
*/
port.pt_times[j].t_days = 0;
/*
* Check each two letter sequence to see if it is
* one of the abbreviations for the days of the
* week or the other two values.
*/
for (i = 0; cp[i] && cp[i + 1] && isalpha (cp[i]); i += 2) {
switch ((cp[i] << 8) | (cp[i + 1])) {
case ('S' << 8) | 'u':
port.pt_times[j].t_days |= 01;
break;
case ('M' << 8) | 'o':
port.pt_times[j].t_days |= 02;
break;
case ('T' << 8) | 'u':
port.pt_times[j].t_days |= 04;
break;
case ('W' << 8) | 'e':
port.pt_times[j].t_days |= 010;
break;
case ('T' << 8) | 'h':
port.pt_times[j].t_days |= 020;
break;
case ('F' << 8) | 'r':
port.pt_times[j].t_days |= 040;
break;
case ('S' << 8) | 'a':
port.pt_times[j].t_days |= 0100;
break;
case ('W' << 8) | 'k':
port.pt_times[j].t_days |= 076;
break;
case ('A' << 8) | 'l':
port.pt_times[j].t_days |= 0177;
break;
default:
errno = EINVAL;
return 0;
}
}
/*
* The default is 'Al' if no days were seen.
*/
if (i == 0)
port.pt_times[j].t_days = 0177;
/*
* The start and end times are separated from each
* other by a '-'. The times are four digit numbers
* representing the times of day.
*/
for (dtime = 0; cp[i] && isdigit (cp[i]); i++)
dtime = dtime * 10 + cp[i] - '0';
if (cp[i] != '-' || dtime > 2400 || dtime % 100 > 59)
goto again;
port.pt_times[j].t_start = dtime;
cp = cp + i + 1;
for (dtime = i = 0; cp[i] && isdigit (cp[i]); i++)
dtime = dtime * 10 + cp[i] - '0';
if ((cp[i] != ',' && cp[i]) || dtime > 2400 || dtime % 100 > 59)
goto again;
port.pt_times[j].t_end = dtime;
cp = cp + i + 1;
}
/*
* The end of the list is indicated by a pair of -1's for the
* start and end times.
*/
port.pt_times[j].t_start = port.pt_times[j].t_end = -1;
return &port;
}
/*
* getttyuser - get ports information for user and tty
*
* getttyuser() searches the ports file for an entry with a TTY
* and user field both of which match the supplied TTY and
* user name. The file is searched from the beginning, so the
* entries are treated as an ordered list.
*/
static struct port *getttyuser (const char *tty, const char *user)
{
int i, j;
struct port *port;
setportent ();
while ((port = getportent ())) {
if (port->pt_names == 0 || port->pt_users == 0)
continue;
for (i = 0; port->pt_names[i]; i++)
if (portcmp (port->pt_names[i], tty) == 0)
break;
if (port->pt_names[i] == 0)
continue;
for (j = 0; port->pt_users[j]; j++)
if (strcmp (user, port->pt_users[j]) == 0 ||
strcmp (port->pt_users[j], "*") == 0)
break;
if (port->pt_users[j] != 0)
break;
}
endportent ();
return port;
}
/*
* isttytime - tell if a given user may login at a particular time
*
* isttytime searches the ports file for an entry which matches
* the user name and TTY given.
*/
int isttytime (const char *id, const char *port, time_t when)
{
int i;
int dtime;
struct port *pp;
struct tm *tm;
/*
* Try to find a matching entry for this user. Default to
* letting the user in - there are pleny of ways to have an
* entry to match all users.
*/
if (!(pp = getttyuser (port, id)))
return 1;
/*
* The entry is there, but has no time entries - don't
* ever let them login.
*/
if (pp->pt_times == 0)
return 0;
/*
* The current time is converted to HHMM format for
* comparision against the time values in the TTY entry.
*/
tm = localtime (&when);
dtime = tm->tm_hour * 100 + tm->tm_min;
/*
* Each time entry is compared against the current
* time. For entries with the start after the end time,
* the comparision is made so that the time is between
* midnight and either the start or end time.
*/
for (i = 0; pp->pt_times[i].t_start != -1; i++) {
if (!(pp->pt_times[i].t_days & PORT_DAY (tm->tm_wday)))
continue;
if (pp->pt_times[i].t_start <= pp->pt_times[i].t_end) {
if (dtime >= pp->pt_times[i].t_start &&
dtime <= pp->pt_times[i].t_end)
return 1;
} else {
if (dtime >= pp->pt_times[i].t_start ||
dtime <= pp->pt_times[i].t_end)
return 1;
}
}
/*
* No matching time entry was found, user shouldn't
* be let in right now.
*/
return 0;
}
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