release_notes

早期freebsd实现

	@(#)RELEASE_NOTES       [e-mail] (Eric Wassenaar) 930926

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
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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 <[e-mail]>.
	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 <[e-mail]>
	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
		<[e-mail]> and Paul Vixie <[e-mail]>
	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 <[e-mail]>.
	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 <[e-mail]>.
	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 <[e-mail]>
	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 <[e-mail]>.
		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.