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added created and tridge comments on first revision first kick-off in
revision history.
lkcl
(This used to be commit 70d3d3bbf0)
101 lines
3.8 KiB
Plaintext
101 lines
3.8 KiB
Plaintext
/*
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Unix SMB/Netbios documentation.
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Version 0.1
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Copyright (C) Luke Leighton Andrew Tridgell 1996
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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Document name: namedbresp.doc
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Revision History:
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0.0 - 02jul96 : lkcl@pires.co.uk
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created
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0.1 - 22jul96 Andrew.Tridgell@anu.edu.au
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tridge's comments on first revision
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*/
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module namedbresp deals with the maintenance of the list of expected
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responses - creating, finding and removal.
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module nameresp deals with the initial transmission, re-transmission
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and time-out of netbios response records.
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/*************************************************************************
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find_response_record()
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*************************************************************************/
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this function is responsible for matching the unique response transaction
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id with an expected response record. as a side-effect of this search,
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it will find the subnet (or the WINS pseudo-subnet) that samba expected
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the response to come from.
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/*************************************************************************
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make_response_queue_record()
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*************************************************************************/
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this function is responsible for creating a response record, which will
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be queued awaiting a response.
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the number of retries is set to 3, and the retry period set to 1 second.
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if no response is received, then the packet is re-transmitted, which is
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why so much information is stored in the response record.
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the number of expected responses queued is kept, so listen_for_packets()
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knows it must time-out after 1 second if one or more responses are
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expected.
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/*************************************************************************
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remove_response_record()
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*************************************************************************/
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this function is responsible for removing a response record from the
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expected response queue. the number of expected responses is decreased.
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/*************************************************************************
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add_response_record()
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*************************************************************************/
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this function is responsible for adding the response record created by
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make_response_queue_record() into the appropriate response record queue.
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-----------------
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NOTE FROM TRIDGE:
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namedbresp.c is interesting because it implements a novel way of
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getting most of the advantages of a multi-threaded nmbd daemon without
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the portability problems.
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The NBT specs (rfc1001/1002) talk about the 16 bit IDs in the packets
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as being used to ensure that packets are unique, and to stop packets
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from being confused. It suggests incrementing the ID by 1 each time.
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Instead Luke uses these IDs to identify individual threads of control
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in nmbd. So when nmbd sends out a NBT packet as part of some complex
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processing, it adds to a linked list the information required to
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continue the processing when the reply comes in (or it times
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out). When a reply arrives this list can be searched to find the
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matching query and the next step in the processing can be carried out.
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This is really good stuff, and allows for much more complex behaviour
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than was possible with the old nmbd.
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----------------
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