nmbd_winsserver.c

来自「samba-3.0.22.tar.gz 编译smb服务器的源码」· C语言 代码 · 共 2,043 行 · 第 1/5 页

		DEBUG( 3, ( "wins_process_multihomed_name_registration_request: Attempt \
to register name %s. Name already exists in WINS with source type %d.\n",
			nmb_namestr(question), namerec->data.source ));
		send_wins_name_registration_response(RFS_ERR, 0, p);
		return;
	}

	/*
	 * Reject if the name exists and is a GROUP name and is active.
	 */

	if((namerec != NULL) && NAME_GROUP(namerec) && WINS_STATE_ACTIVE(namerec)) {
		DEBUG(3,("wins_process_multihomed_name_registration_request: Attempt to register name %s. Name \
already exists in WINS as a GROUP name.\n", nmb_namestr(question) ));
		send_wins_name_registration_response(RFS_ERR, 0, p);
		return;
	} 

	/*
	 * From here on down we know that if the name exists in the WINS db it is
	 * a unique name, not a group name.
	 */

	/*
	 * If the name exists and is one of our names then check the
	 * registering IP address. If it's not one of ours then automatically
	 * reject without doing the query - we know we will reject it.
	 */

	if((namerec != NULL) && (is_myname(namerec->name.name)) ) {
		if(!ismyip(from_ip)) {
			DEBUG(3,("wins_process_multihomed_name_registration_request: Attempt to register name %s. Name \
is one of our (WINS server) names. Denying registration.\n", nmb_namestr(question) ));
			send_wins_name_registration_response(RFS_ERR, 0, p);
			return;
		} else {
			/*
			 * It's one of our names and one of our IP's. Ensure the IP is in the record and
			 *  update the ttl. Update the version ID to force replication.
			 */
			update_name_ttl(namerec, ttl);

			if(!find_ip_in_name_record(namerec, from_ip)) {
				get_global_id_and_update(&namerec->data.id, True);
				update_wins_owner(namerec, our_fake_ip);
				update_wins_flag(namerec, WINS_ACTIVE);

				add_ip_to_name_record(namerec, from_ip);
			}

			wins_hook("refresh", namerec, ttl);
			send_wins_name_registration_response(0, ttl, p);
			return;
		}
	}

	/*
	 * If the name exists and is active, check if the IP address is already registered
	 * to that name. If so then update the ttl and reply success.
	 */

	if((namerec != NULL) && find_ip_in_name_record(namerec, from_ip) && WINS_STATE_ACTIVE(namerec)) {
		update_name_ttl(namerec, ttl);

		/*
		 * If it's a replica, we need to become the wins owner
		 * to force the replication
		 */
		if (!ip_equal(namerec->data.wins_ip, our_fake_ip)) {
			get_global_id_and_update(&namerec->data.id, True);
			update_wins_owner(namerec, our_fake_ip);
			update_wins_flag(namerec, WINS_ACTIVE);
		}
    
		wins_hook("refresh", namerec, ttl);
		send_wins_name_registration_response(0, ttl, p);
		return;
	}

	/*
	 * If the name exists do a query to the owner
	 * to see if they still want the name.
	 */

	if(namerec != NULL) {
		long *ud[(sizeof(struct userdata_struct) + sizeof(struct packet_struct *))/sizeof(long *) + 1];
		struct userdata_struct *userdata = (struct userdata_struct *)ud;

		/*
		 * First send a WACK to the registering machine.
		 */

		send_wins_wack_response(60, p);

		/*
		 * When the reply comes back we need the original packet.
		 * Lock this so it won't be freed and then put it into
		 * the userdata structure.
		 */

		p->locked = True;

		userdata = (struct userdata_struct *)ud;

		userdata->copy_fn = NULL;
		userdata->free_fn = NULL;
		userdata->userdata_len = sizeof(struct packet_struct *);
		memcpy(userdata->data, (char *)&p, sizeof(struct packet_struct *) );

		/* 
		 * Use the new call to send a query directly to an IP address.
		 * This sends the query directly to the IP address, and ensures
		 * the recursion desired flag is not set (you were right Luke :-).
		 * This function should *only* be called from the WINS server
		 * code. JRA.
		 *
		 * Note that this packet is sent to the current owner of the name,
		 * not the person who sent the packet 
		 */

		pull_ascii_nstring( qname, sizeof(qname), question->name);
		query_name_from_wins_server( namerec->data.ip[0],
				qname,
				question->name_type, 
				wins_multihomed_register_query_success,
				wins_multihomed_register_query_fail,
				userdata );

		return;
	}

	/*
	 * Name did not exist - add it.
	 */

	pull_ascii_nstring( qname, sizeof(qname), question->name);
	add_name_to_subnet( subrec, qname, question->name_type,
			nb_flags, ttl, REGISTER_NAME, 1, &from_ip);

	if ((namerec = find_name_on_subnet(subrec, question, FIND_ANY_NAME))) {
		get_global_id_and_update(&namerec->data.id, True);
		update_wins_owner(namerec, our_fake_ip);
		update_wins_flag(namerec, WINS_ACTIVE);
		wins_hook("add", namerec, ttl);
	}

	send_wins_name_registration_response(0, ttl, p);
}

/***********************************************************************
 Deal with the special name query for *<1b>.
***********************************************************************/
   
static void process_wins_dmb_query_request(struct subnet_record *subrec,  
                                           struct packet_struct *p)
{  
	struct name_record *namerec = NULL;
	char *prdata;
	int num_ips;

	/*
	 * Go through all the ACTIVE names in the WINS db looking for those
	 * ending in <1b>. Use this to calculate the number of IP
	 * addresses we need to return.
	 */

	num_ips = 0;
	for( namerec = (struct name_record *)ubi_trFirst( subrec->namelist );
			namerec; namerec = (struct name_record *)ubi_trNext( namerec ) ) {
		if(WINS_STATE_ACTIVE(namerec) && namerec->name.name_type == 0x1b )
			num_ips += namerec->data.num_ips;
	}

	if(num_ips == 0) {
		/*
		 * There are no 0x1b names registered. Return name query fail.
		 */
		send_wins_name_query_response(NAM_ERR, p, NULL);
		return;
	}

	if((prdata = (char *)SMB_MALLOC( num_ips * 6 )) == NULL) {
		DEBUG(0,("process_wins_dmb_query_request: Malloc fail !.\n"));
		return;
	}

	/*
	 * Go through all the names again in the WINS db looking for those
	 * ending in <1b>. Add their IP addresses into the list we will
	 * return.
	 */ 

	num_ips = 0;
	for( namerec = (struct name_record *)ubi_trFirst( subrec->namelist );
			namerec; namerec = (struct name_record *)ubi_trNext( namerec ) ) {
		if(WINS_STATE_ACTIVE(namerec) && namerec->name.name_type == 0x1b) {
			int i;
			for(i = 0; i < namerec->data.num_ips; i++) {
				set_nb_flags(&prdata[num_ips * 6],namerec->data.nb_flags);
				putip((char *)&prdata[(num_ips * 6) + 2], &namerec->data.ip[i]);
				num_ips++;
			}
		}
	}

	/*
	 * Send back the reply containing the IP list.
	 */

	reply_netbios_packet(p,                                /* Packet to reply to. */
				0,                             /* Result code. */
				WINS_QUERY,                    /* nmbd type code. */
				NMB_NAME_QUERY_OPCODE,         /* opcode. */
				lp_min_wins_ttl(),             /* ttl. */
				prdata,                        /* data to send. */
				num_ips*6);                    /* data length. */

	SAFE_FREE(prdata);
}

/****************************************************************************
Send a WINS name query response.
**************************************************************************/

void send_wins_name_query_response(int rcode, struct packet_struct *p, 
                                          struct name_record *namerec)
{
	char rdata[6];
	char *prdata = rdata;
	int reply_data_len = 0;
	int ttl = 0;
	int i;

	memset(rdata,'\0',6);

	if(rcode == 0) {
		ttl = (namerec->data.death_time != PERMANENT_TTL) ?  namerec->data.death_time - p->timestamp : lp_max_wins_ttl();

		/* Copy all known ip addresses into the return data. */
		/* Optimise for the common case of one IP address so we don't need a malloc. */

		if( namerec->data.num_ips == 1 ) {
			prdata = rdata;
		} else {
			if((prdata = (char *)SMB_MALLOC( namerec->data.num_ips * 6 )) == NULL) {
				DEBUG(0,("send_wins_name_query_response: malloc fail !\n"));
				return;
			}
		}

		for(i = 0; i < namerec->data.num_ips; i++) {
			set_nb_flags(&prdata[i*6],namerec->data.nb_flags);
			putip((char *)&prdata[2+(i*6)], &namerec->data.ip[i]);
		}

		sort_query_replies(prdata, i, p->ip);
		reply_data_len = namerec->data.num_ips * 6;
	}

	reply_netbios_packet(p,                                /* Packet to reply to. */
				rcode,                         /* Result code. */
				WINS_QUERY,                    /* nmbd type code. */
				NMB_NAME_QUERY_OPCODE,         /* opcode. */
				ttl,                           /* ttl. */
				prdata,                        /* data to send. */
				reply_data_len);               /* data length. */

	if(prdata != rdata) {
		SAFE_FREE(prdata);
	}
}

/***********************************************************************
 Deal with a name query.
***********************************************************************/

void wins_process_name_query_request(struct subnet_record *subrec, 
                                     struct packet_struct *p)
{
	struct nmb_packet *nmb = &p->packet.nmb;
	struct nmb_name *question = &nmb->question.question_name;
	struct name_record *namerec = NULL;
	unstring qname;

	DEBUG(3,("wins_process_name_query: name query for name %s from IP %s\n", 
		nmb_namestr(question), inet_ntoa(p->ip) ));

	/*
	 * Special name code. If the queried name is *<1b> then search
	 * the entire WINS database and return a list of all the IP addresses
	 * registered to any <1b> name. This is to allow domain master browsers
	 * to discover other domains that may not have a presence on their subnet.
	 */

	pull_ascii_nstring(qname, sizeof(qname), question->name);
	if(strequal( qname, "*") && (question->name_type == 0x1b)) {
		process_wins_dmb_query_request( subrec, p);
		return;
	}

	namerec = find_name_on_subnet(subrec, question, FIND_ANY_NAME);

	if(namerec != NULL) {
		/*
		 * If the name is not anymore in active state then reply not found.
		 * it's fair even if we keep it in the cache for days.
		 */
		if (!WINS_STATE_ACTIVE(namerec)) {
			DEBUG(3,("wins_process_name_query: name query for name %s - name expired. Returning fail.\n",
				nmb_namestr(question) ));
			send_wins_name_query_response(NAM_ERR, p, namerec);
			return;
		}

		/* 
		 * If it's a DNSFAIL_NAME then reply name not found.
		 */

		if( namerec->data.source == DNSFAIL_NAME ) {
			DEBUG(3,("wins_process_name_query: name query for name %s returning DNS fail.\n",
				nmb_namestr(question) ));
			send_wins_name_query_response(NAM_ERR, p, namerec);
			return;
		}

		/*
		 * If the name has expired then reply name not found.
		 */

		if( (namerec->data.death_time != PERMANENT_TTL) && (namerec->data.death_time < p->timestamp) ) {
			DEBUG(3,("wins_process_name_query: name query for name %s - name expired. Returning fail.\n",
					nmb_namestr(question) ));
			send_wins_name_query_response(NAM_ERR, p, namerec);
			return;
		}

		DEBUG(3,("wins_process_name_query: name query for name %s returning first IP %s.\n",
				nmb_namestr(question), inet_ntoa(namerec->data.ip[0]) ));

		send_wins_name_query_response(0, p, namerec);
		return;
	}

	/* 
	 * Name not found in WINS - try a dns query if it's a 0x20 name.
	 */

	if(lp_dns_proxy() && ((question->name_type == 0x20) || question->name_type == 0)) {
		DEBUG(3,("wins_process_name_query: name query for name %s not found - doing dns lookup.\n",
				nmb_namestr(question) ));

		queue_dns_query(p, question, &namerec);
		return;
	}

	/*
	 * Name not found - return error.
	 */

	send_wins_name_query_response(NAM_ERR, p, NULL);
}

/****************************************************************************
Send a WINS name release response.
**************************************************************************/

static void send_wins_name_release_response(int rcode, struct packet_struct *p)
{
	struct nmb_packet *nmb = &p->packet.nmb;
	char rdata[6];

	memcpy(&rdata[0], &nmb->additional->rdata[0], 6);

	reply_netbios_packet(p,                               /* Packet to reply to. */
				rcode,                        /* Result code. */
				NMB_REL,                      /* nmbd type code. */
				NMB_NAME_RELEASE_OPCODE,      /* opcode. */
				0,                            /* ttl. */
				rdata,                        /* data to send. */
				6);                           /* data length. */
}

/***********************************************************************
 Deal with a name release.
***********************************************************************/

void wins_process_name_release_request(struct subnet_record *subrec,
                                       struct packet_struct *p)
{
	struct nmb_packet *nmb = &p->packet.nmb;
	struct nmb_name *question = &nmb->question.question_name;
	BOOL bcast = nmb->header.nm_flags.bcast;
	uint16 nb_flags = get_nb_flags(nmb->additional->rdata);
	struct name_record *namerec = NULL;
	struct in_addr from_ip;
	BOOL releasing_group_name = (nb_flags & NB_GROUP) ? True : False;;

	putip((char *)&from_ip,&nmb->additional->rdata[2]);

	if(bcast) {
		/*
		 * We should only get unicast name registration packets here.
		 * Anyone trying to register broadcast should not be going to a WINS
		 * server. Log an error here.
		 */

		DEBUG(0,("wins_process_name_release_request: broadcast name registration request \
received for name %s from IP %s on subnet %s. Error - should not be sent to WINS server\n",
			nmb_namestr(question), inet_ntoa(from_ip), subrec->subnet_name));