348 lines
8.6 KiB
C
348 lines
8.6 KiB
C
/* dhcpd.c
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DHCP Server Daemon. */
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/*
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* Copyright (c) 1995, 1996, 1997 The Internet Software Consortium.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of The Internet Software Consortium nor the names
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* of its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
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* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This software has been written for the Internet Software Consortium
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* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
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* Enterprises. To learn more about the Internet Software Consortium,
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* see ``http://www.vix.com/isc''. To learn more about Vixie
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* Enterprises, see ``http://www.vix.com''.
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*/
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#ifndef lint
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static char ocopyright[] =
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"$Id: dhcpd.c,v 1.1.1.6 1997/11/22 09:14:37 mellon Exp $ Copyright 1995, 1996 The Internet Software Consortium.";
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#endif
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static char copyright[] =
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"Copyright 1995, 1996 The Internet Software Consortium.";
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static char arr [] = "All rights reserved.";
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static char message [] = "Internet Software Consortium DHCPD $Name: $";
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#include "dhcpd.h"
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static void usage PROTO ((void));
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TIME cur_time;
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struct group root_group;
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struct iaddr server_identifier;
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int server_identifier_matched;
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#ifdef USE_FALLBACK
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struct interface_info fallback_interface;
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#endif
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u_int16_t local_port;
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u_int16_t remote_port;
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int log_priority;
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#ifdef DEBUG
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int log_perror = -1;
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#else
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int log_perror = 1;
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#endif
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char *path_dhcpd_conf = _PATH_DHCPD_CONF;
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char *path_dhcpd_db = _PATH_DHCPD_DB;
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char *path_dhcpd_pid = _PATH_DHCPD_PID;
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int main (argc, argv, envp)
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int argc;
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char **argv, **envp;
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{
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int i, status;
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struct servent *ent;
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char *s;
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int cftest = 0;
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#ifndef DEBUG
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int pidfilewritten = 0;
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int pid;
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char pbuf [20];
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int daemon = 1;
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#endif
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int quiet = 0;
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/* Initially, log errors to stderr as well as to syslogd. */
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#ifdef SYSLOG_4_2
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openlog ("dhcpd", LOG_NDELAY);
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log_priority = DHCPD_LOG_FACILITY;
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#else
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openlog ("dhcpd", LOG_NDELAY, DHCPD_LOG_FACILITY);
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#endif
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#ifndef DEBUG
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#ifndef SYSLOG_4_2
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#ifndef __CYGWIN32__ /* XXX */
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setlogmask (LOG_UPTO (LOG_INFO));
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#endif
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#endif
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#endif
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for (i = 1; i < argc; i++) {
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if (!strcmp (argv [i], "-p")) {
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if (++i == argc)
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usage ();
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for (s = argv [i]; *s; s++)
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if (!isdigit (*s))
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error ("%s: not a valid UDP port",
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argv [i]);
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status = atoi (argv [i]);
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if (status < 1 || status > 65535)
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error ("%s: not a valid UDP port",
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argv [i]);
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local_port = htons (status);
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debug ("binding to user-specified port %d",
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ntohs (local_port));
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} else if (!strcmp (argv [i], "-f")) {
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#ifndef DEBUG
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daemon = 0;
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#endif
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} else if (!strcmp (argv [i], "-d")) {
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#ifndef DEBUG
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daemon = 0;
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#endif
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log_perror = -1;
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} else if (!strcmp (argv [i], "-cf")) {
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if (++i == argc)
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usage ();
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path_dhcpd_conf = argv [i];
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} else if (!strcmp (argv [i], "-lf")) {
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if (++i == argc)
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usage ();
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path_dhcpd_db = argv [i];
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} else if (!strcmp (argv [i], "-t")) {
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/* test configurations only */
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#ifndef DEBUG
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daemon = 0;
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#endif
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cftest = 1;
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log_perror = -1;
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} else if (!strcmp (argv [i], "-q")) {
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quiet = 1;
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quiet_interface_discovery = 1;
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} else if (argv [i][0] == '-') {
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usage ();
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} else {
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struct interface_info *tmp =
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((struct interface_info *)
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dmalloc (sizeof *tmp, "get_interface_list"));
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if (!tmp)
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error ("Insufficient memory to %s %s",
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"record interface", argv [i]);
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memset (tmp, 0, sizeof *tmp);
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strcpy (tmp -> name, argv [i]);
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tmp -> next = interfaces;
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tmp -> flags = INTERFACE_REQUESTED;
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interfaces = tmp;
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}
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}
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if (!quiet) {
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note (message);
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note (copyright);
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note (arr);
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}
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/* Default to the DHCP/BOOTP port. */
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if (!local_port)
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{
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ent = getservbyname ("dhcp", "udp");
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if (!ent)
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local_port = htons (67);
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else
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local_port = ent -> s_port;
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#ifndef __CYGWIN32__ /* XXX */
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endservent ();
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#endif
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}
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remote_port = htons (ntohs (local_port) + 1);
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/* Get the current time... */
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GET_TIME (&cur_time);
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/* Initialize DNS support... */
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dns_startup ();
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/* Read the dhcpd.conf file... */
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if (!readconf ())
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error ("Configuration file errors encountered -- exiting");
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/* test option should cause an early exit */
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if (cftest)
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exit(0);
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/* Start up the database... */
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db_startup ();
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/* Discover all the network interfaces and initialize them. */
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discover_interfaces (1);
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/* Initialize icmp support... */
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icmp_startup (1, lease_pinged);
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#ifndef DEBUG
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if (daemon) {
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/* First part of becoming a daemon... */
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if ((pid = fork ()) < 0)
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error ("Can't fork daemon: %m");
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else if (pid)
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exit (0);
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}
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/* Read previous pid file. */
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if ((i = open (path_dhcpd_pid, O_RDONLY)) >= 0) {
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status = read (i, pbuf, (sizeof pbuf) - 1);
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close (i);
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pbuf [status] = 0;
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pid = atoi (pbuf);
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/* If the previous server process is not still running,
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write a new pid file immediately. */
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if (pid && kill (pid, 0) < 0) {
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unlink (path_dhcpd_pid);
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if ((i = open (path_dhcpd_pid,
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O_WRONLY | O_CREAT, 0640)) >= 0) {
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sprintf (pbuf, "%d\n", (int)getpid ());
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write (i, pbuf, strlen (pbuf));
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close (i);
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pidfilewritten = 1;
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}
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}
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}
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/* If we were requested to log to stdout on the command line,
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keep doing so; otherwise, stop. */
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if (log_perror == -1)
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log_perror = 1;
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else
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log_perror = 0;
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if (daemon) {
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/* Become session leader and get pid... */
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close (0);
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close (1);
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close (2);
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pid = setsid ();
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}
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/* If we didn't write the pid file earlier because we found a
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process running the logged pid, but we made it to here,
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meaning nothing is listening on the bootp port, then write
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the pid file out - what's in it now is bogus anyway. */
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if (!pidfilewritten) {
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unlink (path_dhcpd_pid);
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if ((i = open (path_dhcpd_pid,
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O_WRONLY | O_CREAT, 0640)) >= 0) {
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sprintf (pbuf, "%d\n", (int)getpid ());
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write (i, pbuf, strlen (pbuf));
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close (i);
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pidfilewritten = 1;
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}
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}
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#endif /* !DEBUG */
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/* Set up the bootp packet handler... */
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bootp_packet_handler = do_packet;
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/* Receive packets and dispatch them... */
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dispatch ();
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/* Not reached */
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return 0;
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}
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/* Print usage message. */
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static void usage ()
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{
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note (message);
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note (copyright);
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note (arr);
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error ("Usage: dhcpd [-p <UDP port #>] [-d] [-f] [-cf config-file]%s",
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"\n [-lf lease-file] [if0 [...ifN]]");
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}
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void cleanup ()
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{
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}
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void lease_pinged (from, packet, length)
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struct iaddr from;
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u_int8_t *packet;
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int length;
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{
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struct lease *lp;
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/* Don't try to look up a pinged lease if we aren't trying to
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ping one - otherwise somebody could easily make us churn by
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just forging repeated ICMP EchoReply packets for us to look
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up. */
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if (!outstanding_pings)
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return;
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lp = find_lease_by_ip_addr (from);
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if (!lp) {
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note ("unexpected ICMP Echo Reply from %s", piaddr (from));
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return;
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}
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if (!lp -> state) {
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warn ("ICMP Echo Reply for %s arrived late or is spurious.\n",
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piaddr (from));
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return;
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}
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/* At this point it looks like we pinged a lease and got a
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response, which shouldn't have happened. */
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free_lease_state (lp -> state, "lease_pinged");
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lp -> state = (struct lease_state *)0;
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abandon_lease (lp, "pinged before offer");
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cancel_timeout (lease_ping_timeout, lp);
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--outstanding_pings;
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}
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void lease_ping_timeout (vlp)
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void *vlp;
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{
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struct lease *lp = vlp;
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--outstanding_pings;
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dhcp_reply (lp);
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}
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