	@(#)RELEASE_NOTES       e07@nikhef.nl (Eric Wassenaar) 940623

yymmdd		Description of changes per release
TODO		Things that still need to be done
WISHLIST	Wishes expressed by various people
NOTES		Important issues to keep in mind
MISC		Miscellaneous reminders

# ----------------------------------------------------------------------
# Description of changes per release
# ----------------------------------------------------------------------

940623
	Revise res_send() strategy.
		Mark bad server status for certain conditions which make
		it unlikely that we will succeed during the next try.
		Operating system failures are not in this category.
		Nameserver unreachable status is now reported in a more
		reliable fashion. A second try would sometimes timeout.
		(May be useful for monitoring the upcoming summer 1994
		reshuffling of EBONE/EuropaNET/NSFnet interconnections).
	Facelift for socket I/O routines.
		Systematically use _res_close() to close a connection.
		Include the answer packet length in debug printout.
	Extend resolver initialization.
		Set initial query ID to some arbitrary number.
	Various speedup fixes.
		Avoid unnecessary strlen() calls during zone listings.
		Check whether the resource record data must be printed
		outside the print routine to avoid unnecessary overhead.
		Use bcopy() instead of sprintf() in obvious cases.
	Better output format control.
		In non-verbose and non-debug mode, only pure resource
		record output is written to stdout.
		Add new -Z option to force resource record output to be
		in full zone listing format, including trailing dot in
		domain names, plus ttl value and class indicator.
	Rearrange include files.
		Define resource record structures in rrec.h.
		Function declarations moved to defs.h.

940615
	Various portability changes.
		Avoid use of sizeof() for all entities that have a fixed
		field width, and use predefined constants instead. This
		is necessary for systems without 16 or 32 bit integers.
		Fix use of ipaddr_t and struct in_addr appropriately.
		All this makes the utility portable to e.g. Cray.
	Save and restore state during recursive lookup.
		Error codes could be clobbered during MAILB tracing.
	Miscellaneous minor code cleanup.

940603
	Fix implementation for -F option properly.
		Exchanging the role of stdout and the logfile now works
		on all platforms. Asked by Artur Romao <artur@dns.pt>

940526
	Combine explicit server and -p option.
		If both are specified, the explicit server is contacted
		to retrieve the desired servers for the given zone
		during zone listing/checking modes. This is useful for
		checking zones that have not been registered yet.
		Requested by Geert Jan de Groot <geertj@ripe.net>
	Rudimentary support for NSAP records.
		This is still very experimental. It is unclear how an
		NSAP address should be encoded in the resource record,
		and how its hierarchical structure is decided.
		Inspired by the 4.9 diffs from cisco.com.

940317
	Print SOA serial always as an unsigned value.
		Warn about ``extraordinary'' serial if high bit is set.
	Reset errno to avoid stale values.
		Could happen when doing multiple gethostbyaddr() calls
		in extended mode when the BIND res_send() is linked in.
		Problem noted by <Piete.Brooks@cl.cam.ac.uk>
	Solaris portability fix.
		For solaris 2.x use res_gethostby{addr,name} modules
		to force dns lookups. The __switch_gethostby{addr,name}
		modules have disappeared in solaris 2.3.

930926
	Extend -I option with argument containing allowed chars.
		This string specifies formally illegal, but silently
		allowed characters when checking illegal domain names.
		The -I option is still necessary to enable checking.
		Still done only for resource record names in listings.
		Note that some hesiod names contain the '/' character.
		Indicated by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.
	Additional SOA record checks.
		Check hostmaster field for illegal chars, such as '@'
		(needed as long as data field names are not checked).
	Revised SOA record checks.
		Check primary field against list of known nameservers.
		Issue warning if not among the authoritative servers.
		This may be intentional in special cases, however.
		Required some code reshuffling.
	Add new -M option to list mailable subdomains in a zone.
		This is a new variant of the zone listing specials.
		A zone transfer is done (without listing anything by
		default) to determine the available delegated zones.
		For each of these zones, the MX records are printed.
		Experimental, undocumented. Insufficient too: you
		really want to see also the domains for which only
		an MX record exist.
	Cleanup terminology in the code documentation.
		Remove the word 'subdomain' and cleanup the confusion
		between 'domain' versus 'zone'.
	Update manual page.
		Use terminology that is technically more correct.
		Explain various things that were still missing.

930919
	Print actual name that was queried in error messages.
		Formerly, only the (possibly abbreviated) queryname
		as specified on the command line was printed. 
		Special care must be given if domain search is enabled,
		especially in the enforced BIND compatibility mode.
		Looks much better. Asked by <Piete.Brooks@cl.cam.ac.uk>
	Some more SOA record tests.
		Some records have the name of the zone specified in the
		field that should contain the name of the primary server.
	Miscellaneous minor changes.
		Slightly modify the nameserver name printout during -C.
		Set proper h_errno when answer buffer counts are corrupt.
	Add new -V option to print version number.
		Define version in separate vers.c
	Use class mnemonics as defined in RFC 1035.
		Print 'CH' instead of 'CHAOS'. Anyone using this ?
		Recognize obsolete 'CS' or 'CSNET'. Pretty useless.
		Just for ultimate completeness.
	Check for invalid characters in domain names.
		Only alphanumeric characters and hyphen '-' are valid.
		Unfortunately, the use of underscore '_' is widespread,
		so issuing a warning by default is unrealistic. Therefore:
	Add new -I option to warn about illegal domain names.
		Currently done only for resource record names during zone
		listing. Could be extended to domain names in data fields.
		Perhaps a warning by default in case illegal other than
		underscore. Option is still undocumented as the semantics
		are subject to change.

930915
	Add -R option to always first try search domains.
		Normally querynames are assumed to be fully qualified
		and are tried as such, unless it is a single name which
		is always tried, and only once, in the default domain.
		This option sets RES_DNSRCH and simulates the default
		BIND behaviour, with the exception that NO_DATA status
		terminates the search immediately.
		With the additional otherwise undocumented -B option the
		BIND behaviour is fully enforced and the search continues.
		Added only for testing purposes, not for general use.
	Few more BIND 4.9 compatibility changes.
		Some resolver routines have gotten new argument types.
	Adapt Makefile to BIND conventions.
		The Makefile can be used completely stand-alone,
		or can be invoked from the master BIND Makefile.
		Affects names of various (inherited) make variables.
		Change BIND_RES_SEND to HOST_RES_SEND with opposite
		meaning. Default is HOST_RES_SEND in case stand-alone.

930911
	Extension of user interface.
		Allow multiple arguments on command line or from stdin.
		Requires new syntax for specifying explicit server.
		New options -x and '-X server' indicate extended syntax.
		Quite a lot reshuffling of code. Urgently requested by
		<Piete.Brooks@cl.cam.ac.uk> and Paul Vixie <paul@vix.com>
	Configurable default options.
		Use an environment variable HOST_DEFAULTS to pre-define
		default options and parameters. These are interpolated
		in front of the command line arguments before scanning.
		Syntax is the same as the command line syntax.
	Fix bug when querying single name without dot.
		Not only the default domain, but also the eventual other
		search domains would be tried, although DNSRCH is off.
		This is a long-standing bug. Very important fix.

930908
	Various declaration changes for portability.
	Print TXT/HINFO/UINFO strings within double quotes.
		It is done both in regular and zone listing output.
		This is conforming the syntax for zone input files.
	Add trailing dot to domain names in zone listing.
		This is conforming the syntax for zone input files.
		The trailing dot is not added in regular output.
	Define exit codes in new exit.h header file.
		This avoids the need to include /usr/ucbinclude when
		running in non-BSD mode on solaris 2.x platforms.
	Attempt to diagnose lame delegations.
		Error messages about lame delegations are given during
		zone listings and when checking SOA records (but only when
		the contacted servers are supposed to be authoritative).
		Also in case servers from NS records turn out not to exist.
		This may need some refinement for special cases.
	Perform some extra checks during zone listings.
		Check for unexpected error status in packets. Only the
		very first packet in response to a transfer query can
		have an error status.
	Issue warning if only a single nameserver found.
		Not an error per se, but not much redundancy then.
		Suggested by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.
	Check for anomalous empty zone transfers.
		Transfers consisting of only SOA records could occur if
		we queried the victim of a lame delegation which happened
		to have the SOA record present. Fake an error that will
		result in a lame delegation message.
		Mentioned by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.
	Indicate list/check failure/success via exit code.
		Failure status is returned in case any error has been
		reported via errmsg or pr_error (not pr_warning).
		For Ruediger Volk <rv@deins.informatik.uni-dortmund.de>
	Add -o option to suppress rr output to stdout.
		Can be used in combination with -f to separate rr output
		from verbose comments and error output.
	Perform some SOA timer consistency checks.
		Check timer values for anomalies, such as (retry > refresh)
		or (refresh + retry > expire).
		Suggested by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.
		Also compare all values instead of just serial.
	More accurate reporting of zones processed.
		Print total number of successful zone transfers versus the
		number of attempted transfers. Print count of zones which
		were successfully processed (transferred or -C checked)
		versus the number of zones requested to be processed.
		From this we can deduce the number of transfers that failed
		and the number of times we couldn't find any nameservers.

930901
	Increase MAXNSNAME from 12 to 16.
		This is conforming NSMAX in ns.h
	Don't accumulate statistics if not necessary.
		Skip the costly host count scan in case nothing would
		be reported at all according to the command line options.
	Add some extra checks during zone listings.
		Check for invalid nonzero nscount and arcount.
	Special handling for non-authoritative answers.
		We had already NO_RREC for non-authoritative NO_DATA, but
		non-authoritative HOST_NOT_FOUND would yield TRY_AGAIN.
		Change this to NO_HOST to issue a separate error message.
		This identifies some special cases, e.g. queries for a
		non-existing name using class C_ANY when the nameserver
		is authoritative only for one specific class.
		Use TRY_AGAIN in both cases during zone listing errors.
	Minor declaration changes for portability.
	Add -F option to exchange role of stdout and logfile.
		The '-F file' is the same as '-f file' but all stdout
		output goes to the logfile, and stdout only gets the extra
		resource record output (so that it can be used in pipes).
		Implementation is inherently unportable. Supported only on
		a few platforms where it happens to work.
	Explain status messages in the manual page.
 	Include address and name of server in perror messages.
		This gives a lot more information in case stderr and stdout
		are differently redirected.

930830
	Make error checking in some routines uniform.
	Miscellaneous declaration changes.
	Filter resource record class appropriately.
		In zone listings records of different class can show up,
		e.g. HS records are mixed with IN records. Only records
		of the requested class should be processed. This fixes
		problems with recursive zone traversals and inaccurate
		statistics. Pointed out by <Yves.Devillers@inria.fr>
		and <Piet.Beertema@EU.net>. Important fix.
	Include record class, if special, in some output.
		Show the class if it is not the default IN class.
	Include address of duplicate hosts in message.
		This may help to locate the problem.
	Properly concatenate long TXT strings that are split.
		Long TXT strings (>255) are split as of BIND 4.8.3.
		They were displayed incorrectly with TAB separators.
		Problem noted by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.
	Cleanup some DNS terminology in output messages.
		Fix some confusion between '(sub)domain' and 'zone'. Only
		done in the output of host, not yet in the documentation.
		Pointed out by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.
	Implement host address list as hashed list.
		The linear list is replaced with a hashed list, using the
		low-order address bits as the key. This may dramatically
		speed up recursive zone listings. Very important fix.
		Suggested by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.
	Miscellaneous portability hooks.
		Add new port.h header file.
	Change u_long to u_int for resource record fields.
		These are fixed 32-bit quantities.
		Note that BIND 4.9 uses u_int32_t for these, but still uses
		(inconsistently) u_short instead of u_int16_t.
		Necessary for port to alpha and BIND 4.9.
	Change u_long to ipaddr_t for 32-bit address fields.
		For the time being, make this identical to u_long for non-
		alpha machines with pre-BIND 4.9 to avoid lint warnings.
		Note that BIND 4.9 uses u_int32_t for these.
		Necessary for port to alpha and BIND 4.9.
	Introduce new typedef for 'struct state'.
		Necessary for BIND 4.9.
	Make all arguments to vararg routines same type.
		No more mixing of arbitrary pointers and ints. Only number
		of arguments is variable. Requires few silly interfaces.
		Necessary for port to alpha.
	Add the RELEASE_NOTES file to explain changes.

930209
	Lookup server name with default resolver values.
	Check SOA records without nameserver recursion.
	Implement new RR types from RFC 1183 and 1348.

921005
	Anticipate ultrix specific resolv.h
	Miscellaneous declaration changes.
	Some reshuffling of code.

920702
	Recognize alternative program call names.
	Distinguish between auth and non-auth NO_DATA.

920624
	Lookup server name before changing nameserver address.
	Handle possible truncation in zone transfers.
	Provide private simplified version of res_send().
	Add -u option to force virtual circuit connections.
	Move all socket I/O routines to separate send.c.

920616
	Allocate list of zonenames dynamically, not statically.
	Move and slightly modify the test for fake hosts.
	Suppress host count statistics during inverse listing.
	Miscellaneous documentation updates.

920315
	Improve counting of hosts within domain.
	Discard glue records not directly within domain.
	Keep track of hosts with duplicate address.
	Add -D option to list duplicate hosts.
	Add -E option to list extrazone hosts.
	Miscellaneous casting and typing cleanup.
	Increase (static) number of possible subdomains.

911201
	Option -T also prints MX preference value.
	Save name of longest hostname found (just for fun).
	Undocumented option -g to select long names (fun).

911010
	Don't recurse on cnames if querytype is cname.

910923
	Count gateway hosts (with multiple addresses).
	Add -G option to list gateway hosts.

910905
	Improve counting of hosts within domain.
	Allow hosts not directly within domain.
	Increase (static) maximum number of hosts.

910415
	Improve finding of subdomain names.
	Allow subdomains not directly within domain.
	Check for unauthoritative glue records.
	Add -T option to print ttl when non-verbose.
	Improve connect timeout handling.
	Improve dotted quad parsing.
	Minimum ttl is now called default ttl.

910129
	Maintain count of hosts during domain listings.
	Check for hosts with same name as subdomain.
	Add -H option for special host count mode.
	Recognize obsolete T_MAILA.

# ----------------------------------------------------------------------
# TODO
# ----------------------------------------------------------------------

	Documentation changes.
		References to BIND 4.9, not only 4.8.

# ----------------------------------------------------------------------
# WISHLIST
# ----------------------------------------------------------------------

	TTL consistency checks.
		Multiple records of same name/type/class should have the
		same ttl value in zone listings.
	Skip printing of second SOA in zone listing.
		Asked by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.

# ----------------------------------------------------------------------
# NOTES
# ----------------------------------------------------------------------

	Include files and resolver library.
		If you are linking this utility with an explicit resolver
		library, make sure you will be compiling with the same
		include files that were used to build the resolver library.
		The BIND 4.9 include file <resolv.h> is incompatible with
		the BIND 4.8 version. This utility can handle both versions,
		but you cannot link with an 4.9 library after compilation
		with the 4.8 include files, and vice versa.
	Old resolver libraries.
		The res_mkquery() routine in the SUN-supplied resolver
		library on SunOS <= 4.1.3 adds the default domain to given
		single names if REF_DEFNAMES is set. This is not correct and
		leads to undesired results if you query about toplevel domains.
		It may be a pre-BIND 4.8.2 problem.
		The same behaviour is reported in the default ultrix resolver.
		This will not be fixed in host. The documentation states that
		you need BIND 4.8.2 or higher.
		Problem noted by Peter Koch <pk@TechFak.Uni-Bielefeld.DE>.
	Vendor-specific resolver libraries.
		Some vendors supply resolver libraries with configurable
		lookup strategies for gethostbyname/gethostbyaddr, e.g. to
		consult DNS, NIS, /etc/hosts, or other databases, in specific
		order. Such libraries are to be avoided when linking host.
		It is meant to query the DNS and DNS only.
	SUN's resolver library on solaris 2.x
		If you are on solaris 2.x and you don't have a proper BIND
		resolver library to link with, but have to use the broken
		default library, you can define NO_YP_LOOKUP in the Makefile
		to prevent gethostbyname/gethostbyaddr querying the YP/NIS.

# ----------------------------------------------------------------------
# MISC
# ----------------------------------------------------------------------

	Port to DEC/Alpha with OSF/1.
		Requested by various people.
		This requires basically two adaptations:
		- sizeof(u_long) is 64 bits instead of 32 bits.
		  Affects ip address fields and some fixed fields in the
		  nameserver query/answer buffers.
		- pointers in C subroutine arguments are 64 bit quantities.
		  Affects the varargs modules.
		Suggestions by Dietrich Wiegandt <dietrich@dxcern.cern.ch>
		and David Cherkus <cherkus@zk3.dec.com>.
	Compatibility with BIND 4.9.
		Don't use the u_long types any more.
		The 'struct state' is now 'struct __res_state'.
		New resolver library has various hooks for 'dig'.
		New resolver library prints to stdout with leading ";" but
		unfortunately not everywhere. It prints to stderr sometimes
		also with ";" but does not so in the perror() messages.
		BIND 4.9 prints FQDN with trailing dot.
		BIND 4.9 prints TXT strings within double quotes.
	New features of BIND 4.9.3.
		Don't use sizeof() for u_int, u_short, struct in_addr, and
		HEADER, but use predefined constants for entities that have
		a fixed field width.
		A new parameter _res.ndots has been defined.
		The res_search() module may query the given name ``as_is''.
		The res_search() module retries after SERVFAIL.
		The res_send() module marks a bad server status for almost
		every error condition.
		Extra checks are carried out to ensure that a reply packet
		really is the answer to a query: nameserver addresses and
		query fields are compared.

