nmbd_nameregister.c

samba-3.0.22.tar.gz 编译smb服务器的源码

/* 
   Unix SMB/CIFS implementation.
   NBT netbios routines and daemon - version 2
   Copyright (C) Andrew Tridgell 1994-1998
   Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   Copyright (C) Jeremy Allison 1994-2003
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   
*/

#include "includes.h"

/* forward declarations */
static void wins_next_registration(struct response_record *rrec);


/****************************************************************************
 Deal with a response packet when registering one of our names.
****************************************************************************/

static void register_name_response(struct subnet_record *subrec,
                       struct response_record *rrec, struct packet_struct *p)
{
	/* 
	 * If we are registering broadcast, then getting a response is an
	 * error - we do not have the name. If we are registering unicast,
	 * then we expect to get a response.
	 */

	struct nmb_packet *nmb = &p->packet.nmb;
	BOOL bcast = nmb->header.nm_flags.bcast;
	BOOL success = True;
	struct nmb_name *question_name = &rrec->packet->packet.nmb.question.question_name;
	struct nmb_name *answer_name = &nmb->answers->rr_name;
	struct nmb_packet *sent_nmb = &rrec->packet->packet.nmb;
	int ttl = 0;
	uint16 nb_flags = 0;
	struct in_addr register_ip;
	fstring reg_name;
	
	putip(&register_ip,&sent_nmb->additional->rdata[2]);
	fstrcpy(reg_name, inet_ntoa(register_ip));
	
	if (subrec == unicast_subnet) {
		/* we know that this wins server is definately alive - for the moment! */
		wins_srv_alive(rrec->packet->ip, register_ip);
	}

	/* Sanity check. Ensure that the answer name in the incoming packet is the
	   same as the requested name in the outgoing packet. */

	if(!question_name || !answer_name) {
		DEBUG(0,("register_name_response: malformed response (%s is NULL).\n",
			 question_name ? "question_name" : "answer_name" ));
		return;
	}

	if(!nmb_name_equal(question_name, answer_name)) {
		DEBUG(0,("register_name_response: Answer name %s differs from question name %s.\n", 
			 nmb_namestr(answer_name), nmb_namestr(question_name)));
		return;
	}

	if(bcast) {
		/*
		 * Special hack to cope with old Samba nmbd's.
		 * Earlier versions of Samba (up to 1.9.16p11) respond 
		 * to a broadcast name registration of WORKGROUP<1b> when 
		 * they should not. Hence, until these versions are gone, 
		 * we should treat such errors as success for this particular
		 * case only. [e-mail].
		 */
		
#if 1 /* OLD_SAMBA_SERVER_HACK */
		unstring ans_name;
		pull_ascii_nstring(ans_name, sizeof(ans_name), answer_name->name);
		if((nmb->header.rcode == ACT_ERR) && strequal(lp_workgroup(), ans_name) &&
		   (answer_name->name_type == 0x1b)) {
			/* Pretend we did not get this. */
			rrec->num_msgs--;

			DEBUG(5,("register_name_response: Ignoring broadcast response to registration of name %s due to old Samba server bug.\n", 
				 nmb_namestr(answer_name)));
			return;
		}
#endif /* OLD_SAMBA_SERVER_HACK */

		/* Someone else has the name. Log the problem. */
		DEBUG(1,("register_name_response: Failed to register name %s IP %s on subnet %s via broadcast. Error code was %d. Reject came from IP %s\n", 
			 nmb_namestr(answer_name), 
			 reg_name,
			 subrec->subnet_name, nmb->header.rcode, inet_ntoa(p->ip)));
		success = False;
	} else {
		/* Unicast - check to see if the response allows us to have the name. */
		if (nmb->header.opcode == NMB_WACK_OPCODE) {
			/* WINS server is telling us to wait. Pretend we didn't get
			   the response but don't send out any more register requests. */

			DEBUG(5,("register_name_response: WACK from WINS server %s in registering name %s IP %s\n", 
				 inet_ntoa(p->ip), nmb_namestr(answer_name), reg_name));

			rrec->repeat_count = 0;
			/* How long we should wait for. */
			rrec->repeat_time = p->timestamp + nmb->answers->ttl;
			rrec->num_msgs--;
			return;
		} else if (nmb->header.rcode != 0) {
			/* Error code - we didn't get the name. */
			success = False;

			DEBUG(0,("register_name_response: %sserver at IP %s rejected our name registration of %s IP %s with error code %d.\n", 
				 subrec==unicast_subnet?"WINS ":"",
				 inet_ntoa(p->ip), 
				 nmb_namestr(answer_name), 
				 reg_name,
				 nmb->header.rcode));
		} else {
			success = True;
			/* Get the data we need to pass to the success function. */
			nb_flags = get_nb_flags(nmb->answers->rdata);
			ttl = nmb->answers->ttl;

			/* send off a registration for the next IP, if any */
			wins_next_registration(rrec);
		}
	} 

	DEBUG(5,("register_name_response: %s in registering %sname %s IP %s with %s.\n",
		 success ? "success" : "failure", 
		 subrec==unicast_subnet?"WINS ":"",
		 nmb_namestr(answer_name), 
		 reg_name,
		 inet_ntoa(rrec->packet->ip)));

	if(success) {
		/* Enter the registered name into the subnet name database before calling
		   the success function. */
		standard_success_register(subrec, rrec->userdata, answer_name, nb_flags, ttl, register_ip);
		if( rrec->success_fn)
			(*(register_name_success_function)rrec->success_fn)(subrec, rrec->userdata, answer_name, nb_flags, ttl, register_ip);
	} else {
		if( rrec->fail_fn)
			(*(register_name_fail_function)rrec->fail_fn)(subrec, rrec, question_name);
		/* Remove the name. */
		standard_fail_register( subrec, rrec, question_name);
	}

	/* Ensure we don't retry. */
	remove_response_record(subrec, rrec);
}

/****************************************************************************
 Deal with a timeout of a WINS registration request
****************************************************************************/

static void wins_registration_timeout(struct subnet_record *subrec,
				      struct response_record *rrec)
{
	struct userdata_struct *userdata = rrec->userdata;
	struct nmb_packet *sent_nmb = &rrec->packet->packet.nmb;
	struct nmb_name *nmbname = &sent_nmb->question.question_name;
	struct in_addr register_ip;
	fstring src_addr;

	putip(&register_ip,&sent_nmb->additional->rdata[2]);

	fstrcpy(src_addr, inet_ntoa(register_ip));

	DEBUG(2,("wins_registration_timeout: WINS server %s timed out registering IP %s\n", 
		 inet_ntoa(rrec->packet->ip), src_addr));

	/* mark it temporarily dead for this source address */
	wins_srv_died(rrec->packet->ip, register_ip);

	/* if we have some userdata then use that to work out what
	   wins server to try next */
	if (userdata) {
		const char *tag = (const char *)userdata->data;

		/* try the next wins server in our failover list for
		   this tag */
		rrec->packet->ip = wins_srv_ip_tag(tag, register_ip);
	}

	/* if we have run out of wins servers for this tag then they
	   must all have timed out. We treat this as *success*, not
	   failure, and go into our standard name refresh mode. This
	   copes with all the wins servers being down */
	if (wins_srv_is_dead(rrec->packet->ip, register_ip)) {
		uint16 nb_flags = get_nb_flags(sent_nmb->additional->rdata);
		int ttl = sent_nmb->additional->ttl;

		standard_success_register(subrec, userdata, nmbname, nb_flags, ttl, register_ip);
		if(rrec->success_fn) {
			(*(register_name_success_function)rrec->success_fn)(subrec, 
									    rrec->userdata, 
									    nmbname, 
									    nb_flags, 
									    ttl, 
									    register_ip);
		}

		/* send off a registration for the next IP, if any */
		wins_next_registration(rrec);

		/* don't need to send this packet any more */
		remove_response_record(subrec, rrec);
		return;
	}
	
	/* we will be moving to the next WINS server for this group,
	   send it immediately */
	rrec->repeat_count = 2;
	rrec->repeat_time = time(NULL) + 1;
	rrec->in_expiration_processing = False;

	DEBUG(6,("Retrying register of name %s IP %s with WINS server %s\n",
		 nmb_namestr(nmbname), src_addr, inet_ntoa(rrec->packet->ip)));

	/* notice that we don't remove the response record. This keeps
	   us trying to register with each of our failover wins servers */
}

/****************************************************************************
 Deal with a timeout when registering one of our names.
****************************************************************************/

static void register_name_timeout_response(struct subnet_record *subrec,
					   struct response_record *rrec)
{
	/*
	 * If we are registering unicast, then NOT getting a response is an
	 * error - we do not have the name. If we are registering broadcast,
	 * then we don't expect to get a response.
	 */

	struct nmb_packet *sent_nmb = &rrec->packet->packet.nmb;
	BOOL bcast = sent_nmb->header.nm_flags.bcast;
	BOOL success = False;
	struct nmb_name *question_name = &sent_nmb->question.question_name;
	uint16 nb_flags = 0;
	int ttl = 0;
	struct in_addr registered_ip;
	
	if (bcast) {
		if(rrec->num_msgs == 0) {
			/* Not receiving a message is success for broadcast registration. */
			success = True; 

			/* Pull the success values from the original request packet. */
			nb_flags = get_nb_flags(sent_nmb->additional->rdata);
			ttl = sent_nmb->additional->ttl;
			putip(&registered_ip,&sent_nmb->additional->rdata[2]);
		}
	} else {