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-rw-r--r--lib/port.c454
1 files changed, 454 insertions, 0 deletions
diff --git a/lib/port.c b/lib/port.c
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+++ b/lib/port.c
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+/*
+ * SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 1997, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2005 , Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2008 , Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <stdio.h>
+#include <ctype.h>
+#include <errno.h>
+#include "defines.h"
+#include "prototypes.h"
+#include "port.h"
+
+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 (('\0' != *pattern) && (*pattern == *port)) {
+ pattern++;
+ port++;
+ }
+
+ if (('\0' == *pattern) && ('\0' == *port)) {
+ return 0;
+ }
+ if (('S' == orig[0]) && ('U' == orig[1]) && ('\0' == orig[2])) {
+ 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 (NULL != 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 (NULL != ports) {
+ (void) 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 (NULL == ports) {
+ setportent ();
+ }
+
+ if (NULL == 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, (int) 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 (('\0' != *cp) && (':' != *cp) && (',' != *cp)) {
+ cp++;
+ }
+
+ if ('\0' == *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';
+ cp++;
+ 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';
+ cp++;
+ port.pt_users[j] = cp;
+ j++;
+ }
+ }
+ port.pt_users[j] = 0;
+ } else {
+ port.pt_users = 0;
+ }
+
+ if (':' != *cp) {
+ goto again;
+ }
+
+ *cp = '\0';
+ cp++;
+
+ /*
+ * 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 ('\0' == *cp) {
+ port.pt_times = 0;
+ return &port;
+ }
+
+ port.pt_times = ptimes;
+
+ /*
+ * Get the next comma separated entry
+ */
+
+ for (j = 0; ('\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;
+ ('\0' != cp[i]) && ('\0' != 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 (0 == i) {
+ 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; ('\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 = 0, i = 0;
+ ('\0' != cp[i]) && isdigit (cp[i]);
+ i++) {
+ dtime = dtime * 10 + cp[i] - '0';
+ }
+
+ if ( ((',' != cp[i]) && ('\0' != 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 ()) != NULL) {
+ if ( (0 == port->pt_names)
+ || (0 == port->pt_users)) {
+ continue;
+ }
+
+ for (i = 0; NULL != port->pt_names[i]; i++) {
+ if (portcmp (port->pt_names[i], tty) == 0) {
+ break;
+ }
+ }
+
+ if (port->pt_names[i] == 0) {
+ continue;
+ }
+
+ for (j = 0; NULL != 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.
+ */
+
+bool 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 plenty of ways to have an
+ * entry to match all users.
+ */
+
+ pp = getttyuser (port, id);
+ if (NULL == pp) {
+ return true;
+ }
+
+ /*
+ * The entry is there, but has no time entries - don't
+ * ever let them login.
+ */
+
+ if (0 == pp->pt_times) {
+ return false;
+ }
+
+ /*
+ * The current time is converted to HHMM format for
+ * comparison 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 comparison 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 true;
+ }
+ } else {
+ if ( (dtime >= pp->pt_times[i].t_start)
+ || (dtime <= pp->pt_times[i].t_end)) {
+ return true;
+ }
+ }
+ }
+
+ /*
+ * No matching time entry was found, user shouldn't
+ * be let in right now.
+ */
+
+ return false;
+}
+
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