OpenBSD-4.6/usr.sbin/dhcpd/db.c
/* $OpenBSD: db.c,v 1.10 2004/09/16 18:35:42 deraadt Exp $ */
/*
* 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''.
*/
#include "dhcpd.h"
FILE *db_file;
static int counting = 0;
static int count = 0;
time_t write_time;
/*
* Write the specified lease to the current lease database file.
*/
int
write_lease(struct lease *lease)
{
struct tm *t;
char tbuf[64];
int errors = 0;
int i;
if (counting)
++count;
errno = 0;
fprintf(db_file, "lease %s {\n", piaddr(lease->ip_addr));
if (errno)
++errors;
t = gmtime(&lease->starts);
snprintf(tbuf, sizeof(tbuf), "%d %d/%02d/%02d %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);
snprintf(tbuf, sizeof(tbuf), "%d %d/%02d/%02d %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 j;
errno = 0;
fprintf(db_file, "\n\tuid %2.2x", lease->uid[0]);
if (errno)
++errors;
for (j = 1; j < lease->uid_len; j++) {
errno = 0;
fprintf(db_file, ":%2.2x", lease->uid[j]);
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) {
for (i = 0; lease->client_hostname[i]; i++)
if (lease->client_hostname[i] < 33 ||
lease->client_hostname[i] > 126)
goto bad_client_hostname;
errno = 0;
fprintf(db_file, "\n\tclient-hostname \"%s\";",
lease->client_hostname);
if (errno)
++errors;
}
bad_client_hostname:
if (lease->hostname) {
for (i = 0; lease->hostname[i]; i++)
if (lease->hostname[i] < 33 ||
lease->hostname[i] > 126)
goto bad_hostname;
errno = 0;
fprintf(db_file, "\n\thostname \"%s\";",
lease->hostname);
if (errno)
++errors;
}
bad_hostname:
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(void)
{
/*
* 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)) == -1) {
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(void)
{
int db_fd;
/* open lease file. once we dropped privs it has to stay open */
db_fd = open(path_dhcpd_db, O_WRONLY|O_CREAT, 0664);
if (db_fd == -1)
error("Can't create new lease file: %m");
if ((db_file = fdopen(db_fd, "w")) == NULL)
error("Can't fdopen new lease file!");
/* Read in the existing lease file... */
read_leases();
time(&write_time);
new_lease_file();
}
void
new_lease_file(void)
{
fflush(db_file);
rewind(db_file);
/*
* Write an introduction so people don't complain about time being off.
*/
fprintf(db_file, "# All times in this file are in UTC (GMT), "
"not your local timezone.\n");
fprintf(db_file, "# The format of this file is documented in "
"the dhcpd.leases(5) manual page.\n\n");
/* Write out all the leases that we know of... */
counting = 0;
write_leases();
fflush(db_file);
ftruncate(fileno(db_file), ftello(db_file));
fsync(fileno(db_file));
counting = 1;
}