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

364 lines
9.2 KiB
C

/* dhcpd.c
DHCP Server Daemon. */
/*
* Copyright (c) 1995, 1996, 1997, 1998, 1999
* 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 ocopyright[] =
"$Id: dhcpd.c,v 1.14 1999/08/24 03:25:33 enami Exp $ Copyright 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.";
#endif
static char copyright[] =
"Copyright 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.";
static char arr [] = "All rights reserved.";
static char message [] = "Internet Software Consortium DHCP Server V2.0b1pl27";
static char contrib [] = "Please contribute if you find this software useful.";
static char url [] = "For info, please visit http://www.isc.org/dhcp-contrib.html";
#include "dhcpd.h"
static void usage PROTO ((char *));
TIME cur_time;
struct group root_group;
struct iaddr server_identifier;
int server_identifier_matched;
u_int16_t local_port;
u_int16_t remote_port;
int log_priority;
#ifdef DEBUG
int log_perror = -1;
#else
int log_perror = 1;
#endif
char *path_dhcpd_conf = _PATH_DHCPD_CONF;
char *path_dhcpd_db = _PATH_DHCPD_DB;
char *path_dhcpd_pid = _PATH_DHCPD_PID;
int main (argc, argv, envp)
int argc;
char **argv, **envp;
{
int i, status;
struct servent *ent;
char *s, *appname;
int cftest = 0;
#ifndef DEBUG
int pidfilewritten = 0;
int pid;
char pbuf [20];
int daemon = 1;
#endif
int quiet = 0;
appname = strchr (argv [0], '/');
if (!appname)
appname = argv [0];
else
appname++;
/* Initially, log errors to stderr as well as to syslogd. */
#ifdef SYSLOG_4_2
openlog (appname, LOG_NDELAY);
log_priority = DHCPD_LOG_FACILITY;
#else
openlog (appname, LOG_NDELAY, DHCPD_LOG_FACILITY);
#endif
#ifndef DEBUG
#ifndef SYSLOG_4_2
#ifndef __CYGWIN32__ /* XXX */
setlogmask (LOG_UPTO (LOG_INFO));
#endif
#endif
#endif
for (i = 1; i < argc; i++) {
if (!strcmp (argv [i], "-p")) {
if (++i == argc)
usage (appname);
for (s = argv [i]; *s; s++)
if (!isdigit (*s))
error ("%s: not a valid UDP port",
argv [i]);
status = atoi (argv [i]);
if (status < 1 || status > 65535)
error ("%s: not a valid UDP port",
argv [i]);
local_port = htons (status);
debug ("binding to user-specified port %d",
ntohs (local_port));
} else if (!strcmp (argv [i], "-f")) {
#ifndef DEBUG
daemon = 0;
#endif
} else if (!strcmp (argv [i], "-d")) {
#ifndef DEBUG
daemon = 0;
#endif
log_perror = -1;
} else if (!strcmp (argv [i], "-cf")) {
if (++i == argc)
usage (appname);
path_dhcpd_conf = argv [i];
} else if (!strcmp (argv [i], "-pf")) {
if (++i == argc)
usage (appname);
path_dhcpd_pid = argv [i];
} else if (!strcmp (argv [i], "-lf")) {
if (++i == argc)
usage (appname);
path_dhcpd_db = argv [i];
} else if (!strcmp (argv [i], "-t")) {
/* test configurations only */
#ifndef DEBUG
daemon = 0;
#endif
cftest = 1;
log_perror = -1;
} else if (!strcmp (argv [i], "-q")) {
quiet = 1;
quiet_interface_discovery = 1;
} else if (argv [i][0] == '-') {
usage (appname);
} else {
struct interface_info *tmp =
((struct interface_info *)
dmalloc (sizeof *tmp, "get_interface_list"));
if (!tmp)
error ("Insufficient memory to %s %s",
"record interface", argv [i]);
memset (tmp, 0, sizeof *tmp);
strcpy (tmp -> name, argv [i]);
tmp -> next = interfaces;
tmp -> flags = INTERFACE_REQUESTED;
interfaces = tmp;
}
}
if (!quiet) {
note (message);
note (copyright);
note (arr);
note ("");
note (contrib);
note (url);
note ("");
}
/* Default to the DHCP/BOOTP port. */
if (!local_port)
{
ent = getservbyname ("dhcp", "udp");
if (!ent)
local_port = htons (67);
else
local_port = ent -> s_port;
#ifndef __CYGWIN32__ /* XXX */
endservent ();
#endif
}
remote_port = htons (ntohs (local_port) + 1);
/* Get the current time... */
GET_TIME (&cur_time);
/* Read the dhcpd.conf file... */
if (!readconf ())
error ("Configuration file errors encountered -- exiting");
/* test option should cause an early exit */
if (cftest)
exit(0);
/* Start up the database... */
db_startup ();
/* Discover all the network interfaces and initialize them. */
discover_interfaces (DISCOVER_SERVER);
/* Initialize icmp support... */
icmp_startup (1, lease_pinged);
#ifndef DEBUG
if (daemon) {
/* First part of becoming a daemon... */
if ((pid = fork ()) < 0)
error ("Can't fork daemon: %m");
else if (pid)
exit (0);
}
/* Read previous pid file. */
if ((i = open (path_dhcpd_pid, O_RDONLY)) >= 0) {
status = read (i, pbuf, (sizeof pbuf) - 1);
close (i);
pbuf [status] = 0;
pid = atoi (pbuf);
/* If the previous server process is not still running,
write a new pid file immediately. */
if (pid && (pid == getpid () || kill (pid, 0) < 0)) {
unlink (path_dhcpd_pid);
if ((i = open (path_dhcpd_pid,
O_WRONLY | O_CREAT, 0640)) >= 0) {
sprintf (pbuf, "%d\n", (int)getpid ());
write (i, pbuf, strlen (pbuf));
close (i);
pidfilewritten = 1;
}
} else
error ("There's already a DHCP server running.\n");
}
/* If we were requested to log to stdout on the command line,
keep doing so; otherwise, stop. */
if (log_perror == -1)
log_perror = 1;
else
log_perror = 0;
if (daemon) {
/* Become session leader and get pid... */
close (0);
close (1);
close (2);
pid = setsid ();
}
/* If we didn't write the pid file earlier because we found a
process running the logged pid, but we made it to here,
meaning nothing is listening on the bootp port, then write
the pid file out - what's in it now is bogus anyway. */
if (!pidfilewritten) {
unlink (path_dhcpd_pid);
if ((i = open (path_dhcpd_pid,
O_WRONLY | O_CREAT, 0640)) >= 0) {
sprintf (pbuf, "%d\n", (int)getpid ());
write (i, pbuf, strlen (pbuf));
close (i);
pidfilewritten = 1;
}
}
#endif /* !DEBUG */
/* Set up the bootp packet handler... */
bootp_packet_handler = do_packet;
/* Receive packets and dispatch them... */
dispatch (NULL);
/* Not reached */
return 0;
}
/* Print usage message. */
static void usage (appname)
char *appname;
{
note (message);
note (copyright);
note (arr);
note ("");
note (contrib);
note (url);
note ("");
warn ("Usage: %s [-p <UDP port #>] [-d] [-f] [-cf config-file]",
appname);
error(" [-lf lease-file] [-pf pidfile] [if0 [...ifN]]");
}
void cleanup ()
{
}
void lease_pinged (from, packet, length)
struct iaddr from;
u_int8_t *packet;
int length;
{
struct lease *lp;
/* Don't try to look up a pinged lease if we aren't trying to
ping one - otherwise somebody could easily make us churn by
just forging repeated ICMP EchoReply packets for us to look
up. */
if (!outstanding_pings)
return;
lp = find_lease_by_ip_addr (from);
if (!lp) {
note ("unexpected ICMP Echo Reply from %s", piaddr (from));
return;
}
if (!lp -> state) {
warn ("ICMP Echo Reply for %s arrived late or is spurious.\n",
piaddr (from));
return;
}
/* At this point it looks like we pinged a lease and got a
response, which shouldn't have happened. */
free_lease_state (lp -> state, "lease_pinged");
lp -> state = (struct lease_state *)0;
abandon_lease (lp, "pinged before offer");
cancel_timeout (lease_ping_timeout, lp);
--outstanding_pings;
}
void lease_ping_timeout (vlp)
void *vlp;
{
struct lease *lp = vlp;
--outstanding_pings;
dhcp_reply (lp);
}