dhcpd.c

DHCP服务器源码

/* dhcpd.c

   DHCP Server Daemon. */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1996-2003 by Internet Software Consortium
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *   Internet Systems Consortium, Inc.
 *   950 Charter Street
 *   Redwood City, CA 94063
 *   <[e-mail]>
 *   http://www.isc.org/
 *
 * This software has been written for Internet Systems Consortium
 * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
 * To learn more about Internet Systems Consortium, see
 * ``http://www.isc.org/''.  To learn more about Vixie Enterprises,
 * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 * ``http://www.nominum.com''.
 */

#ifndef lint
static char ocopyright[] =
"$Id: dhcpd.c,v 1.115.2.12 2004/07/10 00:11:18 dhankins Exp $ Copyright 2004 Internet Systems Consortium.";
#endif

  static char copyright[] =
"Copyright 2004 Internet Systems Consortium.";
static char arr [] = "All rights reserved.";
static char message [] = "Internet Systems Consortium DHCP Server";
static char url [] = "For info, please visit http://www.isc.org/sw/dhcp/";

#include "dhcpd.h"
#include "version.h"
#include <omapip/omapip_p.h>

static void usage PROTO ((void));

struct iaddr server_identifier;
int server_identifier_matched;

#if defined (NSUPDATE)

/* This stuff is always executed to figure the default values for certain
   ddns variables. */

char std_nsupdate [] = "						    \n\
option server.ddns-hostname =						    \n\
  pick (option fqdn.hostname, option host-name);			    \n\
option server.ddns-domainname =	config-option domain-name;		    \n\
option server.ddns-ttl = encode-int(lease-time / 2, 32);		    \n\
option server.ddns-rev-domainname = \"in-addr.arpa.\";";

/* This is the old-style name service updater that is executed
   whenever a lease is committed.  It does not follow the DHCP-DNS
   draft at all. */

char old_nsupdate [] = "						    \n\
on commit {								    \n\
  if (not static and							    \n\
      ((config-option server.ddns-updates = null) or			    \n\
       (config-option server.ddns-updates != 0))) {			    \n\
    set new-ddns-fwd-name =						    \n\
      concat (pick (config-option server.ddns-hostname,			    \n\
		    option host-name), \".\",				    \n\
	      pick (config-option server.ddns-domainname,		    \n\
		    config-option domain-name));			    \n\
    if (defined (ddns-fwd-name) and ddns-fwd-name != new-ddns-fwd-name) {   \n\
      switch (ns-update (delete (IN, A, ddns-fwd-name, leased-address))) {  \n\
      case NOERROR:							    \n\
	unset ddns-fwd-name;						    \n\
	on expiry or release {						    \n\
	}								    \n\
      }									    \n\
    }									    \n\
									    \n\
    if (not defined (ddns-fwd-name)) {					    \n\
      set ddns-fwd-name = new-ddns-fwd-name;				    \n\
      if defined (ddns-fwd-name) {					    \n\
	switch (ns-update (not exists (IN, A, ddns-fwd-name, null),	    \n\
			   add (IN, A, ddns-fwd-name, leased-address,	    \n\
				lease-time / 2))) {			    \n\
	default:							    \n\
	  unset ddns-fwd-name;						    \n\
	  break;							    \n\
									    \n\
	case NOERROR:							    \n\
	  set ddns-rev-name =						    \n\
	    concat (binary-to-ascii (10, 8, \".\",			    \n\
				     reverse (1,			    \n\
					      leased-address)), \".\",	    \n\
		    pick (config-option server.ddns-rev-domainname,	    \n\
			  \"in-addr.arpa.\"));				    \n\
	  switch (ns-update (delete (IN, PTR, ddns-rev-name, null),	    \n\
			     add (IN, PTR, ddns-rev-name, ddns-fwd-name,    \n\
				  lease-time / 2)))			    \n\
	    {								    \n\
	    default:							    \n\
	      unset ddns-rev-name;					    \n\
	      on release or expiry {					    \n\
		switch (ns-update (delete (IN, A, ddns-fwd-name,	    \n\
					   leased-address))) {		    \n\
		case NOERROR:						    \n\
		  unset ddns-fwd-name;					    \n\
		  break;						    \n\
		}							    \n\
		on release or expiry;					    \n\
	      }								    \n\
	      break;							    \n\
									    \n\
	    case NOERROR:						    \n\
	      on release or expiry {					    \n\
		switch (ns-update (delete (IN, PTR, ddns-rev-name, null))) {\n\
		case NOERROR:						    \n\
		  unset ddns-rev-name;					    \n\
		  break;						    \n\
		}							    \n\
		switch (ns-update (delete (IN, A, ddns-fwd-name,	    \n\
					   leased-address))) {		    \n\
		case NOERROR:						    \n\
		  unset ddns-fwd-name;					    \n\
		  break;						    \n\
		}							    \n\
		on release or expiry;					    \n\
	      }								    \n\
	    }								    \n\
	}								    \n\
      }									    \n\
    }									    \n\
    unset new-ddns-fwd-name;						    \n\
  }									    \n\
}";

int ddns_update_style;
#endif /* NSUPDATE */

const char *path_dhcpd_conf = _PATH_DHCPD_CONF;
const char *path_dhcpd_db = _PATH_DHCPD_DB;
const char *path_dhcpd_pid = _PATH_DHCPD_PID;

int dhcp_max_agent_option_packet_length = DHCP_MTU_MAX;

static omapi_auth_key_t *omapi_key = (omapi_auth_key_t *)0;
int omapi_port;

#if defined (TRACING)
trace_type_t *trace_srandom;
#endif

static isc_result_t verify_addr (omapi_object_t *l, omapi_addr_t *addr) {
	return ISC_R_SUCCESS;
}

static isc_result_t verify_auth (omapi_object_t *p, omapi_auth_key_t *a) {
	if (a != omapi_key)
		return ISC_R_INVALIDKEY;
	return ISC_R_SUCCESS;
}

static void omapi_listener_start (void *foo)
{
	omapi_object_t *listener;
	isc_result_t result;

	listener = (omapi_object_t *)0;
	result = omapi_generic_new (&listener, MDL);
	if (result != ISC_R_SUCCESS)
		log_fatal ("Can't allocate new generic object: %s",
			   isc_result_totext (result));
	result = omapi_protocol_listen (listener,
					(unsigned)omapi_port, 1);
	if (result == ISC_R_SUCCESS && omapi_key)
		result = omapi_protocol_configure_security
			(listener, verify_addr, verify_auth);
	if (result != ISC_R_SUCCESS) {
		log_error ("Can't start OMAPI protocol: %s",
			   isc_result_totext (result));
		add_timeout (cur_time + 5, omapi_listener_start, 0, 0, 0);
	}
	omapi_object_dereference (&listener, MDL);
}

int main (argc, argv, envp)
	int argc;
	char **argv, **envp;
{
	int i, status;
	struct servent *ent;
	char *s;
	int cftest = 0;
	int lftest = 0;
#ifndef DEBUG
	int pidfilewritten = 0;
	int pid;
	char pbuf [20];
	int daemon = 1;
#endif
	int quiet = 0;
	char *server = (char *)0;
	isc_result_t result;
	unsigned seed;
	struct interface_info *ip;
	struct parse *parse;
	int lose;
	omapi_object_t *auth;
	struct tsig_key *key;
	omapi_typed_data_t *td;
	int no_dhcpd_conf = 0;
	int no_dhcpd_db = 0;
	int no_dhcpd_pid = 0;
#if defined (TRACING)
	char *traceinfile = (char *)0;
	char *traceoutfile = (char *)0;
#endif

	/* Make sure we have stdin, stdout and stderr. */
	status = open ("/dev/null", O_RDWR);
	if (status == 0)
		status = open ("/dev/null", O_RDWR);
	if (status == 1) {
		status = open ("/dev/null", O_RDWR);
		log_perror = 0; /* No sense logging to /dev/null. */
	} else if (status != -1)
		close (status);

	/* Set up the client classification system. */
	classification_setup ();

	/* Initialize the omapi system. */
	result = omapi_init ();
	if (result != ISC_R_SUCCESS)
		log_fatal ("Can't initialize OMAPI: %s",
			   isc_result_totext (result));

	/* Set up the OMAPI wrappers for common objects. */
	dhcp_db_objects_setup ();
	/* Set up the OMAPI wrappers for various server database internal
	   objects. */
	dhcp_common_objects_setup ();

	/* Initially, log errors to stderr as well as to syslogd. */
#ifdef SYSLOG_4_2
	openlog ("dhcpd", LOG_NDELAY);
	log_priority = DHCPD_LOG_FACILITY;
#else
	openlog ("dhcpd", LOG_NDELAY, DHCPD_LOG_FACILITY);
#endif

	for (i = 1; i < argc; i++) {
		if (!strcmp (argv [i], "-p")) {
			if (++i == argc)
				usage ();
			for (s = argv [i]; *s; s++)
				if (!isdigit (*s))
					log_fatal ("%s: not a valid UDP port",
					       argv [i]);
			status = atoi (argv [i]);
			if (status < 1 || status > 65535)
				log_fatal ("%s: not a valid UDP port",
				       argv [i]);
			local_port = htons (status);
			log_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], "-s")) {
			if (++i == argc)
				usage ();
			server = argv [i];
		} else if (!strcmp (argv [i], "-cf")) {
			if (++i == argc)
				usage ();
			path_dhcpd_conf = argv [i];
			no_dhcpd_conf = 1;
		} else if (!strcmp (argv [i], "-lf")) {
			if (++i == argc)
				usage ();
			path_dhcpd_db = argv [i];
			no_dhcpd_db = 1;
		} else if (!strcmp (argv [i], "-pf")) {
			if (++i == argc)
				usage ();
			path_dhcpd_pid = argv [i];
			no_dhcpd_pid = 1;
                } else if (!strcmp (argv [i], "-t")) {
			/* test configurations only */
#ifndef DEBUG
			daemon = 0;
#endif
			cftest = 1;
			log_perror = -1;
                } else if (!strcmp (argv [i], "-T")) {
			/* test configurations and lease file only */
#ifndef DEBUG
			daemon = 0;
#endif
			cftest = 1;
			lftest = 1;
			log_perror = -1;
		} else if (!strcmp (argv [i], "-q")) {
			quiet = 1;
			quiet_interface_discovery = 1;
		} else if (!strcmp (argv [i], "--version")) {
			log_info ("isc-dhcpd-%s", DHCP_VERSION);
			exit (0);
#if defined (TRACING)
		} else if (!strcmp (argv [i], "-tf")) {
			if (++i == argc)
				usage ();
			traceoutfile = argv [i];
		} else if (!strcmp (argv [i], "-play")) {
			if (++i == argc)
				usage ();
			traceinfile = argv [i];
			trace_replay_init ();
#endif /* TRACING */
		} else if (argv [i][0] == '-') {
			usage ();
		} else {
			struct interface_info *tmp =
				(struct interface_info *)0;
			result = interface_allocate (&tmp, MDL);
			if (result != ISC_R_SUCCESS)
				log_fatal ("Insufficient memory to %s %s: %s",
					   "record interface", argv [i],
					   isc_result_totext (result));
			strcpy (tmp -> name, argv [i]);
			if (interfaces) {
				interface_reference (&tmp -> next,
						     interfaces, MDL);
				interface_dereference (&interfaces, MDL);
			}
			interface_reference (&interfaces, tmp, MDL);
			tmp -> flags = INTERFACE_REQUESTED;
		}
	}

	if (!no_dhcpd_conf && (s = getenv ("PATH_DHCPD_CONF"))) {
		path_dhcpd_conf = s;
	}
	if (!no_dhcpd_db && (s = getenv ("PATH_DHCPD_DB"))) {
		path_dhcpd_db = s;
	}
	if (!no_dhcpd_pid && (s = getenv ("PATH_DHCPD_PID"))) {
		path_dhcpd_pid = s;
	}

	if (!quiet) {
		log_info ("%s %s", message, DHCP_VERSION);
		log_info (copyright);
		log_info (arr);
		log_info (url);
	} else {
		quiet = 0;
		log_perror = 0;
	}

#if defined (TRACING)
	trace_init (set_time, MDL);
	if (traceoutfile)
		trace_begin (traceoutfile, MDL);
	interface_trace_setup ();
	parse_trace_setup ();
	trace_srandom = trace_type_register ("random-seed", (void *)0,
					     trace_seed_input,
					     trace_seed_stop, MDL);
#endif