diff options
Diffstat (limited to 'source/namebrowse.doc')
| -rw-r--r-- | source/namebrowse.doc | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/source/namebrowse.doc b/source/namebrowse.doc new file mode 100644 index 00000000000..82713d85708 --- /dev/null +++ b/source/namebrowse.doc @@ -0,0 +1,149 @@ +/* + Unix SMB/Netbios documentation. + Version 0.1 + Copyright (C) Luke Leighton Andrew Tridgell 1996 + + 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. + + Document name: namebrowse.doc + + Revision History: + + 0.0 - 02jul96 : lkcl@pires.co.uk + created + + 0.1 - 22jul96 Andrew.Tridgell@anu.edu.au + tridge's comments on first revision +*/ + +this module deals with queueing servers that samba must sync browse +lists with. it will always issue a name query immediately before +actually carrying out the NetServerEnum call, to ensure that time +is not wasted by a remote server's failure. + +this module was created to minimise the amount of NetServerEnum calls +that samba may be asked to perform, by maintaining the name of a server +for up to a minute after the NetServerEnum call was issued, and +disallowing further NetServerEnum calls to this remote server until +the entry is removed. + +samba can ask for a NetServerEnum call to be issued to grab a remote +server's list of servers and workgroups either in its capacity as +a domain master browser, as a local master browser. + +samba does not deal with becoming a backup master browser properly +at present. + +------------- +NOTE FROM TRIDGE: + +Yes, samba can send these either in its capacity as a DMB or as a +MB. There are only two situations: + +- If samba is a DMB then it should sync with the "local only" bit set +with any master browser that has sent it a "master announce". + +- if samba is not a DMB then it can only sync with the DMB, and should +not set the "local only" bit. + +Note that samba should never sync with other non-DMB servers when it +is not a DMB. + +Try to do a sync under any other circumstances is dangerous without a +multi-threaded nmbd. I have a print server at home that knows some SMB +and NBT, but if you try to sync browse lists with it then it clogs up, +and also clogs up nmbd while it times out the connection. If we +follow the above two rules then we can't get into this sort of +trouble as: + +- if we are a DMB and a master browser sends us a "master announce" +then it is expecting to receive a NetServerEnum SMB connection soon, +and must be capabable of handling it. + +- if we are not a DMB then we will only sync with the DMB, which must +be capable of doing this stuff or things are really in a mess :-) +-------------- + + +/************************************************************************* + do_browser_lists() + *************************************************************************/ + +this function is responsible for finding an appropriate entry in the +sync browser cache, initiating a name query (which results in a +NetServerEnum call if there is a positive response), and then +removing all entries that have been actioned and have been around +for over a minute. + + +/************************************************************************* + start_sync_browse_entry() + *************************************************************************/ + +this function is responsible for initiating a name query. if a +positive response is received, then this will result in a +NetServerEnum api call. + +samba will only initiate this process if it is a master browser +for this workgroup. + +----------- +NOTE FROM TRIDGE: + +I'd actually prefer to skip the name query completely if we can +resolve the DMBs name via gethostbyname(). For the name query to work +we either have to have WINS working, or we need to know the broadcast +address of the network that the DMB is on. This makes us too dependent +on too many thing being right. + +If the gethostbyname() fails then sure, go for a normal name query, +but if it works then we have saved ourselves a lot of trouble and +gained a lot of robustness. + +This is best handled by a generic "resolve netbios name" routine that +tries DNS first then resorts to WINS or bcast if that fails. It also +needs to cache the results. +------------- + + +/************************************************************************* + add_browser_entry() + *************************************************************************/ + +this function is responsible for adding a browser into the list of +servers to sync browse lists with. if the server entry has already +been added and syncing browse lists has already been initiated, it +will not be added again. + + +/************************************************************************* + expire_browse_cache() + *************************************************************************/ + +this function is responsible for removing entries that have had the +sync browse list initiated (whether that succeeded or not is beyond +this function's scope) and have been in the cache for a while. + + +/************************************************************************* + add_browse_entry() + *************************************************************************/ + +this function is responsible for adding a new entry into the list +of servers to sync browse lists with at some point in the near future. + + + + |