NetBSD/usr.sbin/dhcp/server/db.c

237 lines
6.2 KiB
C

/* db.c
Persistent database management routines for DHCPD... */
/*
* Copyright (c) 1995, 1996 The Internet Software Consortium.
* 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 The Internet Software Consortium 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 THE INTERNET SOFTWARE CONSORTIUM 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 THE INTERNET SOFTWARE CONSORTIUM 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.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
* Enterprises. To learn more about the Internet Software Consortium,
* see ``http://www.vix.com/isc''. To learn more about Vixie
* Enterprises, see ``http://www.vix.com''.
*/
#ifndef lint
static char copyright[] =
"$Id: db.c,v 1.1.1.2 1997/06/03 02:49:55 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
FILE *db_file;
static int counting = 0;
static int count = 0;
TIME write_time;
/* Write the specified lease to the current lease database file. */
int write_lease (lease)
struct lease *lease;
{
struct tm *t;
char tbuf [64];
int errors = 0;
if (counting)
++count;
errno = 0;
fprintf (db_file, "lease %s {\n", piaddr (lease -> ip_addr));
if (errno) {
++errors;
}
t = gmtime (&lease -> starts);
sprintf (tbuf, "%d %d/%d/%d %02d:%02d:%02d;",
t -> tm_wday, t -> tm_year + 1900,
t -> tm_mon + 1, t -> tm_mday,
t -> tm_hour, t -> tm_min, t -> tm_sec);
errno = 0;
fprintf (db_file, "\tstarts %s\n", tbuf);
if (errno) {
++errors;
}
t = gmtime (&lease -> ends);
sprintf (tbuf, "%d %d/%d/%d %02d:%02d:%02d;",
t -> tm_wday, t -> tm_year + 1900,
t -> tm_mon + 1, t -> tm_mday,
t -> tm_hour, t -> tm_min, t -> tm_sec);
errno = 0;
fprintf (db_file, "\tends %s", tbuf);
if (errno) {
++errors;
}
if (lease -> hardware_addr.hlen) {
errno = 0;
fprintf (db_file, "\n\thardware %s %s;",
hardware_types [lease -> hardware_addr.htype],
print_hw_addr (lease -> hardware_addr.htype,
lease -> hardware_addr.hlen,
lease -> hardware_addr.haddr));
if (errno) {
++errors;
}
}
if (lease -> uid_len) {
int i;
errno = 0;
fprintf (db_file, "\n\tuid %x", lease -> uid [0]);
if (errno) {
++errors;
}
for (i = 1; i < lease -> uid_len; i++) {
errno = 0;
fprintf (db_file, ":%x", lease -> uid [i]);
if (errno) {
++errors;
}
}
putc (';', db_file);
}
if (lease -> flags & BOOTP_LEASE) {
errno = 0;
fprintf (db_file, "\n\tdynamic-bootp;");
if (errno) {
++errors;
}
}
if (lease -> flags & ABANDONED_LEASE) {
errno = 0;
fprintf (db_file, "\n\tabandoned;");
if (errno) {
++errors;
}
}
if (lease -> client_hostname) {
errno = 0;
fprintf (db_file, "\n\tclient-hostname %s;",
lease -> client_hostname);
if (errno) {
++errors;
}
}
if (lease -> hostname) {
errno = 0;
fprintf (db_file, "\n\thostname %s;",
lease -> client_hostname);
if (errno) {
++errors;
}
}
errno = 0;
fputs ("\n}\n", db_file);
if (errno) {
++errors;
}
if (errors)
note ("write_lease: unable to write lease %s",
piaddr (lease -> ip_addr));
return !errors;
}
/* Commit any leases that have been written out... */
int commit_leases ()
{
/* Commit any outstanding writes to the lease database file.
We need to do this even if we're rewriting the file below,
just in case the rewrite fails. */
if (fflush (db_file) == EOF) {
note ("commit_leases: unable to commit: %m");
return 0;
}
if (fsync (fileno (db_file)) < 0) {
note ("commit_leases: unable to commit: %m");
return 0;
}
/* If we've written more than a thousand leases or if
we haven't rewritten the lease database in over an
hour, rewrite it now. */
if (count > 1000 || (count && cur_time - write_time > 3600)) {
count = 0;
write_time = cur_time;
new_lease_file ();
}
return 1;
}
void db_startup ()
{
/* Read in the existing lease file... */
read_leases ();
GET_TIME (&write_time);
new_lease_file ();
}
void new_lease_file ()
{
char newfname [512];
char backfname [512];
TIME t;
/* If we already have an open database, close it. */
if (db_file) {
fclose (db_file);
}
/* Make a temporary lease file... */
GET_TIME (&t);
sprintf (newfname, "%s.%d", path_dhcpd_db, (int)t);
if ((db_file = fopen (newfname, "w")) == NULL) {
error ("Can't start new lease file: %m");
}
/* Write out all the leases that we know of... */
counting = 0;
write_leases ();
/* Get the old database out of the way... */
sprintf (backfname, "%s~", path_dhcpd_db);
if (unlink (backfname) < 0 && errno != ENOENT)
error ("Can't remove old lease database backup %s: %m",
backfname);
if (link (path_dhcpd_db, backfname) < 0)
error ("Can't backup lease database %s to %s: %m",
path_dhcpd_db, backfname);
/* Move in the new file... */
if (rename (newfname, path_dhcpd_db) < 0)
error ("Can't install new lease database %s to %s: %m",
newfname, path_dhcpd_db);
counting = 1;
}