nmbd_incomingdgrams.c

来自「samba-3.0.22.tar.gz 编译smb服务器的源码」· C语言 代码 · 共 845 行 · 第 1/2 页

/* 
   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 1994-1998
   
   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"

extern BOOL found_lm_clients;

#if 0

/* XXXX note: This function is currently unsuitable for use, as it
   does not properly check that a server is in a fit state to become
   a backup browser before asking it to be one.
   The code is left here to be worked on at a later date.
*/

/****************************************************************************
Tell a server to become a backup browser
**************************************************************************/

void tell_become_backup(void)
{
  struct subnet_record *subrec;
  for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
  {
    struct work_record *work;
    for (work = subrec->workgrouplist; work; work = work->next)
    {
      struct server_record *servrec;
      int num_servers = 0;
      int num_backups = 0;
	  
      for (servrec = work->serverlist; servrec; servrec = servrec->next)
      {
        num_servers++;
	      
        if (is_myname(servrec->serv.name))
          continue;
	      
        if (servrec->serv.type & SV_TYPE_BACKUP_BROWSER) 
        {
          num_backups++;
          continue;
        }
	      
        if (servrec->serv.type & SV_TYPE_MASTER_BROWSER)
          continue;
	      
        if (!(servrec->serv.type & SV_TYPE_POTENTIAL_BROWSER))
          continue;
	      
        DEBUG(3,("num servers: %d num backups: %d\n", 
              num_servers, num_backups));
	      
        /* make first server a backup server. thereafter make every
           tenth server a backup server */
        if (num_backups != 0 && (num_servers+9) / num_backups > 10)
          continue;
	      
        DEBUG(2,("sending become backup to %s %s for %s\n",
             servrec->serv.name, inet_ntoa(subrec->bcast_ip),
             work->work_group));
	      
        /* type 11 request from MYNAME(20) to WG(1e) for SERVER */
        do_announce_request(servrec->serv.name, work->work_group,
              ANN_BecomeBackup, 0x20, 0x1e, subrec->bcast_ip);
      }
    }
  }
}
#endif

/*******************************************************************
  Process an incoming host announcement packet.
*******************************************************************/

void process_host_announce(struct subnet_record *subrec, struct packet_struct *p, char *buf)
{
	struct dgram_packet *dgram = &p->packet.dgram;
	int ttl = IVAL(buf,1)/1000;
	unstring announce_name;
	uint32 servertype = IVAL(buf,23);
	fstring comment;
	struct work_record *work;
	struct server_record *servrec;
	unstring work_name;
	unstring source_name;

	START_PROFILE(host_announce);

	pull_ascii_fstring(comment, buf+31);
	comment[42] = 0;
  
	pull_ascii_nstring(announce_name, sizeof(announce_name), buf+5);
	pull_ascii_nstring(source_name, sizeof(source_name), dgram->source_name.name);

	DEBUG(3,("process_host_announce: from %s<%02x> IP %s to \
%s for server %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
			nmb_namestr(&dgram->dest_name),announce_name));

	DEBUG(5,("process_host_announce: ttl=%d server type=%08x comment=%s\n",
		ttl, servertype,comment));

	/* Filter servertype to remove impossible bits. */
	servertype &= ~(SV_TYPE_LOCAL_LIST_ONLY|SV_TYPE_DOMAIN_ENUM);

	/* A host announcement must be sent to the name WORKGROUP<1d>. */
	if(dgram->dest_name.name_type != 0x1d) {
		DEBUG(2,("process_host_announce: incorrect name type for destination from IP %s \
(was %02x) should be 0x1d. Allowing packet anyway.\n",
			inet_ntoa(p->ip), dgram->dest_name.name_type));
		/* Change it so it was. */
		dgram->dest_name.name_type = 0x1d;
	}

	/* For a host announce the workgroup name is the destination name. */
	pull_ascii_nstring(work_name, sizeof(work_name), dgram->dest_name.name);

	/*
	 * Syntax servers version 5.1 send HostAnnounce packets to
	 * *THE WRONG NAME*. They send to LOCAL_MASTER_BROWSER_NAME<00>
	 * instead of WORKGROUP<1d> name. So to fix this we check if
	 * the workgroup name is our own name, and if so change it
	 * to be our primary workgroup name.
	 */

	if(strequal(work_name, global_myname()))
		unstrcpy(work_name,lp_workgroup());

	/*
	 * We are being very agressive here in adding a workgroup
	 * name on the basis of a host announcing itself as being
	 * in that workgroup. Maybe we should wait for the workgroup
	 * announce instead ? JRA.
	 */

	work = find_workgroup_on_subnet(subrec, work_name);

	if(servertype != 0) {
		if (work ==NULL ) {
			/* We have no record of this workgroup. Add it. */
			if((work = create_workgroup_on_subnet(subrec, work_name, ttl))==NULL)
				goto done;
		}
  
		if((servrec = find_server_in_workgroup( work, announce_name))==NULL) {
			/* If this server is not already in the workgroup, add it. */
			create_server_on_workgroup(work, announce_name, 
				servertype|SV_TYPE_LOCAL_LIST_ONLY, 
				ttl, comment);
		} else {
			/* Update the record. */
			servrec->serv.type = servertype|SV_TYPE_LOCAL_LIST_ONLY;
			update_server_ttl( servrec, ttl);
			fstrcpy(servrec->serv.comment,comment);
		}
	} else {
		/*
		 * This server is announcing it is going down. Remove it from the 
		 * workgroup.
		 */
		if(!is_myname(announce_name) && (work != NULL) &&
				((servrec = find_server_in_workgroup( work, announce_name))!=NULL)) {
			remove_server_from_workgroup( work, servrec);
		}
	}

	subrec->work_changed = True;
done:

	END_PROFILE(host_announce);
}

/*******************************************************************
  Process an incoming WORKGROUP announcement packet.
*******************************************************************/

void process_workgroup_announce(struct subnet_record *subrec, struct packet_struct *p, char *buf)
{
	struct dgram_packet *dgram = &p->packet.dgram;
	int ttl = IVAL(buf,1)/1000;
	unstring workgroup_announce_name;
	unstring master_name;
	uint32 servertype = IVAL(buf,23);
	struct work_record *work;
	unstring source_name;
	unstring dest_name;

	START_PROFILE(workgroup_announce);

	pull_ascii_nstring(workgroup_announce_name,sizeof(workgroup_announce_name),buf+5);
	pull_ascii_nstring(master_name,sizeof(master_name),buf+31);
	pull_ascii_nstring(source_name,sizeof(source_name),dgram->source_name.name);
	pull_ascii_nstring(dest_name,sizeof(dest_name),dgram->dest_name.name);

	DEBUG(3,("process_workgroup_announce: from %s<%02x> IP %s to \
%s for workgroup %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
			nmb_namestr(&dgram->dest_name),workgroup_announce_name));

	DEBUG(5,("process_workgroup_announce: ttl=%d server type=%08x master browser=%s\n",
		ttl, servertype, master_name));

	/* Workgroup announcements must only go to the MSBROWSE name. */
	if (!strequal(dest_name, MSBROWSE) || (dgram->dest_name.name_type != 0x1)) {
		DEBUG(0,("process_workgroup_announce: from IP %s should be to __MSBROWSE__<0x01> not %s\n",
			inet_ntoa(p->ip), nmb_namestr(&dgram->dest_name)));
		goto done;
	}

	if ((work = find_workgroup_on_subnet(subrec, workgroup_announce_name))==NULL) {
		/* We have no record of this workgroup. Add it. */
		if((work = create_workgroup_on_subnet(subrec, workgroup_announce_name, ttl))==NULL)
			goto done;
	} else {
		/* Update the workgroup death_time. */
		update_workgroup_ttl(work, ttl);
	}

	if(*work->local_master_browser_name == '\0') {
		/* Set the master browser name. */
		set_workgroup_local_master_browser_name( work, master_name );
	}

	subrec->work_changed = True;

done:

	END_PROFILE(workgroup_announce);
}

/*******************************************************************
  Process an incoming local master browser announcement packet.
*******************************************************************/

void process_local_master_announce(struct subnet_record *subrec, struct packet_struct *p, char *buf)
{
	struct dgram_packet *dgram = &p->packet.dgram;
	int ttl = IVAL(buf,1)/1000;
	unstring server_name;
	uint32 servertype = IVAL(buf,23);
	fstring comment;
	unstring work_name;
	struct work_record *work;
	struct server_record *servrec;
	unstring source_name;

	START_PROFILE(local_master_announce);

	pull_ascii_nstring(server_name,sizeof(server_name),buf+5);
	pull_ascii_fstring(comment, buf+31);
	comment[42] = 0;
	pull_ascii_nstring(source_name, sizeof(source_name), dgram->source_name.name);
	pull_ascii_nstring(work_name, sizeof(work_name), dgram->dest_name.name);

	DEBUG(3,("process_local_master_announce: from %s<%02x> IP %s to \
%s for server %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
		nmb_namestr(&dgram->dest_name),server_name));

	DEBUG(5,("process_local_master_announce: ttl=%d server type=%08x comment=%s\n",
		ttl, servertype, comment));

	/* A local master announcement must be sent to the name WORKGROUP<1e>. */
	if(dgram->dest_name.name_type != 0x1e) {
		DEBUG(0,("process_local_master_announce: incorrect name type for destination from IP %s \
(was %02x) should be 0x1e. Ignoring packet.\n",
			inet_ntoa(p->ip), dgram->dest_name.name_type));
		goto done;
	}

	/* Filter servertype to remove impossible bits. */
	servertype &= ~(SV_TYPE_LOCAL_LIST_ONLY|SV_TYPE_DOMAIN_ENUM);

	/* For a local master announce the workgroup name is the destination name. */

	if ((work = find_workgroup_on_subnet(subrec, work_name))==NULL) {
		/* Don't bother adding if it's a local master release announce. */
		if(servertype == 0)
			goto done;

		/* We have no record of this workgroup. Add it. */
		if((work = create_workgroup_on_subnet(subrec, work_name, ttl))==NULL)
			goto done;
	}

	/* If we think we're the local master browser for this workgroup,
		we should never have got this packet. We don't see our own
		packets.
	*/
	if(AM_LOCAL_MASTER_BROWSER(work)) {
		DEBUG(0,("process_local_master_announce: Server %s at IP %s is announcing itself as \
a local master browser for workgroup %s and we think we are master. Forcing election.\n",
			server_name, inet_ntoa(p->ip), work_name));

		/* Samba nmbd versions 1.9.17 to 1.9.17p4 have a bug in that when
		 they have become a local master browser once, they will never
		 stop sending local master announcements. To fix this we send
		 them a reset browser packet, with level 0x2 on the __SAMBA__
		 name that only they should be listening to. */
   
		send_browser_reset( 0x2, "__SAMBA__" , 0x20, p->ip);

		/* We should demote ourself and force an election. */

		unbecome_local_master_browser( subrec, work, True);

		/* The actual election requests are handled in nmbd_election.c */
		goto done;
	}  

	/* Find the server record on this workgroup. If it doesn't exist, add it. */

	if(servertype != 0) {
		if((servrec = find_server_in_workgroup( work, server_name))==NULL) {
			/* If this server is not already in the workgroup, add it. */
			create_server_on_workgroup(work, server_name, 
				servertype|SV_TYPE_LOCAL_LIST_ONLY, 
				ttl, comment);
		} else {
			/* Update the record. */
			servrec->serv.type = servertype|SV_TYPE_LOCAL_LIST_ONLY;
			update_server_ttl(servrec, ttl);
			fstrcpy(servrec->serv.comment,comment);
		}
	
		set_workgroup_local_master_browser_name( work, server_name );
	} else {
		/*
		 * This server is announcing it is going down. Remove it from the
		 * workgroup.
		 */
		if(!is_myname(server_name) && (work != NULL) &&
				((servrec = find_server_in_workgroup( work, server_name))!=NULL)) {
			remove_server_from_workgroup( work, servrec);
		}
	}

	subrec->work_changed = True;
done:

	END_PROFILE(local_master_announce);
}

/*******************************************************************
  Process a domain master announcement frame.
  Domain master browsers receive these from local masters. The Domain
  master should then issue a sync with the local master, asking for
  that machines local server list.
******************************************************************/

void process_master_browser_announce(struct subnet_record *subrec, 
                                     struct packet_struct *p,char *buf)
{
	unstring local_master_name;
	struct work_record *work;
	struct browse_cache_record *browrec;

	START_PROFILE(master_browser_announce);

	pull_ascii_nstring(local_master_name,sizeof(local_master_name),buf);
  
	DEBUG(3,("process_master_browser_announce: Local master announce from %s IP %s.\n",
		local_master_name, inet_ntoa(p->ip)));
  
	if (!lp_domain_master()) {
		DEBUG(0,("process_master_browser_announce: Not configured as domain \
master - ignoring master announce.\n"));
		goto done;
	}
  
	if((work = find_workgroup_on_subnet(subrec, lp_workgroup())) == NULL) {
		DEBUG(0,("process_master_browser_announce: Cannot find workgroup %s on subnet %s\n",
			lp_workgroup(), subrec->subnet_name));
		goto done;
	}

	if(!AM_DOMAIN_MASTER_BROWSER(work)) {
		DEBUG(0,("process_master_browser_announce: Local master announce made to us from \
%s IP %s and we are not a domain master browser.\n", local_master_name, inet_ntoa(p->ip)));
		goto done;
	}

	/* Add this host as a local master browser entry on the browse lists.
		This causes a sync request to be made to it at a later date.
	*/

	if((browrec = find_browser_in_lmb_cache( local_master_name )) == NULL) {
		/* Add it. */
		create_browser_in_lmb_cache( work->work_group, local_master_name, p->ip);
	} else {
		update_browser_death_time(browrec);
	}

done:

	END_PROFILE(master_browser_announce);
}

/*******************************************************************
  Process an incoming LanMan host announcement packet.
*******************************************************************/

void process_lm_host_announce(struct subnet_record *subrec, struct packet_struct *p, char *buf)
{
	struct dgram_packet *dgram = &p->packet.dgram;