/* 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 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 1.1.1.3 1997/06/08 04:55:15 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 %2.2x", lease -> uid [0]); if (errno) { ++errors; } for (i = 1; i < lease -> uid_len; i++) { errno = 0; fprintf (db_file, ":%2.2x", 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; }