HACKING - quagga - Gitiles

 -*- mode: text; -*-
 $Id: HACKING,v 1.20 2005/04/25 00:37:03 paul Exp $

 GUIDELINES FOR HACKING ON QUAGGA

 [this is a draft in progress]

 GNU coding standards apply.  Indentation follows the result of
 invoking GNU indent (as of 2.2.8a) with no arguments.  Note that this
 uses tabs instead of spaces where possible for leading whitespace, and
 assumes that tabs are every 8 columns.  Do not attempt to redefine the
 location of tab stops.  Note also that some indentation does not
 follow GNU style.  This is a historical accident, and we generally
 only clean up whitespace when code is unmaintainable due to whitespace
 issues, as fewer changes from zebra lead to easier merges.

 For GNU emacs, use indentation style "gnu".

 For Vim, use the following lines (note that tabs are at 8, and that
 softtabstop sets the indentation level):

 set tabstop=8
 set softtabstop=2
 set shiftwidth=2
 set noexpandtab

 Be particularly careful not to break platforms/protocols that you
 cannot test.

 New code should have good comments, and changes to existing code
 should in many cases upgrade the comments when necessary for a
 reviewer to conclude that the change has no unintended consequences.

 Each file in CVS should have the RCS keyword Id, somewhere very near
 the top, commented out appropriately for the file type.  Just add
 <dollar>Id:<dollar>, replacing <dollar> with $.  See line 2 of HACKING
 for an example; on checkout :$ is expanded to include the value.

 Please document fully the proper use of a new function in the header file
 in which it is declared.  And please consult existing headers for
 documentation on how to use existing functions.  In particular, please consult
 these header files:

   lib/log.h	logging levels and usage guidance
   [more to be added]

 If changing an exported interface, please try to deprecate the interface in
 an orderly manner. If at all possible, try to retain the old deprecated
 interface as is, or functionally equivalent. Make a note of when the
 interface was deprecated and guard the deprecated interface definitions in
 the header file, ie:

 /* Deprecated: 20050406 */
 #if !defined(QUAGGA_NO_DEPRECATED_INTERFACES)
 #warning "Using deprecated <libname> (interface(s)|function(s))"
 ...
 #endif /* QUAGGA_NO_DEPRECATED_INTERFACES */

 To ensure that the core Quagga sources do not use the deprecated interfaces
 (you should update Quagga sources to use new interfaces, if applicable)
 while allowing external sources to continue to build. Deprecated interfaces
 should be excised in the next unstable cycle.

 Note: If you wish, you can test for GCC and use a function
 marked with the 'deprecated' attribute. However, you must provide the
 #warning for other compilers.

 If changing or removing a command definition, *ensure* that you properly
 deprecate it - use the _DEPRECATED form of the appropriate DEFUN macro. This
 is *critical*. Even if the command can no longer function, you *must* still
 implement it as a do-nothing stub. Failure to follow this causes grief for
 systems administrators. Deprecated commands should be excised in the next
 unstable cycle. A list of deprecated commands should be collated for each
 release.

 See also below regarding SHARED LIBRARY VERSIONING.


 CHANGELOG

 Add a ChangeLog entry whenever changing code, except for minor fixes
 to a commit (with a ChangeLog entry) within the last few days.

 Most directories have a ChangeLog file; changes to code in that
 directory should go in the per-directory ChangeLog.  Global or
 structural changes should also be mentioned in the top-level
 ChangeLog.

 Certain directories do not contain project code, but contain project
 meta-data, eg packaging information, changes to files in these directory may
 not require the global ChangeLog to be updated (at the discretion of the
 maintainer who usually maintains that meta-data). Also, CVS meta-data such
 as cvsignore files do not require ChangeLog updates, just a sane commit
 message.


 HACKING THE BUILD SYSTEM

 If you change or add to the build system (configure.ac, any Makefile.am,
 etc.), try to check that the following things still work:

 	- make dist
 	- resulting dist tarball builds
 	- out-of-tree builds

 The quagga.net site relies on make dist to work to generate snapshots. It
 must work. Commong problems are to forget to have some additional file
 included in the dist, or to have a make rule refer to a source file without
 using the srcdir variable.

 RELEASE PROCEDURE

   Tag the repository with release tag (follow existing conventions).
   [This enables recreating the release, and is just good CM practice.]

   Check out the tag, and do a test build.

   In an empty directory, do a fresh checkout with -r <release-tag>
   [This makes the dates in the tarball be the modified dates in CVS.]

   ./configure
   make dist

 If any errors occur, move tags as needed and start over from the fresh
 checkouts.  Do not append to tarballs, as this has produced
 non-standards-conforming tarballs in the past.

 [TODO: collation of a list of deprecated commands. Possibly can be scripted
 to extract from vtysh/vtysh_cmd.c]


 TOOL VERSIONS

 Require versions of support tools are listed in INSTALL.quagga.txt.
 Required versions should only be done with due deliberation, as it can
 cause environments to no longer be able to compile quagga.


 SHARED LIBRARY VERSIONING

 [this section is at the moment just gdt's opinion]

 Quagga builds several shared libaries (lib/libzebra, ospfd/libospf,
 ospfclient/libsopfapiclient).  These may be used by external programs,
 e.g. a new routing protocol that works with the zebra daemon, or
 ospfapi clients.  The libtool info pages (node Versioning) explain
 when major and minor version numbers should be changed.  These values
 are set in Makefile.am near the definition of the library.  If you
 make a change that requires changing the shared library version,
 please update Makefile.am.

 libospf exports far more than it should, and is needed by ospfapi
 clients.  Only bump libospf for changes to functions for which it is
 reasonable for a user of ospfapi to call, and please err on the side
 of not bumping.

 There is no support intended for installing part of zebra.  The core
 library libzebra and the included daemons should always be built and
 installed together.


 PATCH SUBMISSION

 * Send a clean diff against the head of CVS in unified diff format, eg by:
   cvs <cvs opts> diff -upwb ....

 * Include ChangeLog and NEWS entries as appropriate before the patch
   (or in it if you are 100% up to date). A good ChangeLog makes it easier to
   review a patch, hence failure to include a good ChangeLog is prejudicial
   to proper review of the patch, and hence the possibility of inclusion.

 * Include only one semantic change or group of changes per patch.

 * Do not make gratuitous changes to whitespace. See the w and b arguments
   to diff.

 * State on which platforms and with what daemons the patch has been
   tested.  Understand that if the set of testing locations is small,
   and the patch might have unforeseen or hard to fix consequences that
   there may be a call for testers on quagga-dev, and that the patch
   may be blocked until test results appear.

   If there are no users for a platform on quagga-dev who are able and
   willing to verify -current occasionally, that platform may be
   dropped from the "should be checked" list.


 PATCH APPLICATION TO CVS

 * Only apply patches that meet the submission guidelines.

 * If a patch is large (perhaps more than 100 new/changed lines), tag
   the repository before and after the change with e.g. before-foo-fix
   and after-foo-fix.

 * If the patch might break something, issue a call for testing on the
   mailinglist.

 * Give an appropriate commit message, eg the ChangeLog entry should suffice,
   if it does not, then the ChangeLog entry itself needs to be corrected. The
   commit message text should be identical to that added to the ChangeLog
   message. (One suggestion: when commiting, use your editor to read in the
   ChangeLog and delete all previous ChangeLogs.)

 * By committing a patch, you are responsible for fixing problems
   resulting from it (or backing it out).


 STABLE PLATFORMS AND DAEMONS

 The list of platforms that should be tested follow.  This is a list
 derived from what quagga is thought to run on and for which
 maintainers can test or there are people on quagga-dev who are able
 and willing to verify that -current does or does not work correctly.

   BSD (Free, Net or Open, any platform) # without capabilities
   GNU/Linux (any distribution, i386)
   Solaris (strict alignment, any platform)
   [future: NetBSD/sparc64]

 The list of daemons that are thought to be stable and that should be
 tested are:

   zebra
   bgpd
   ripd
   ospfd
   ripngd

 Daemons which are in a testing phase are

   ospf6d
   isisd
   watchquagga


 IMPORT OR UPDATE VENDOR SPECIFIC ROUTING PROTOCOLS

 The source code of Quagga is based on two vendors:

    zebra_org (http://www.zebra.org/)
    isisd_sf (http://isisd.sf.net/)

 [20041105: Is isisd.sf.netf still where isisd word is happening, or is
 the quagga repo now the canonical place?  The last tarball on sf is
 two years old.  --gdt]

 In order to import source code, the following procedure should be used:

 * Tag the Current Quagga CVS repository:

     cvs tag import_isisd_sf_20031223

 * Import the source code into the Quagga's framework. You must not modified
   this source code. It will be merged later.

     cd dir_isisd
     export CVSROOT=:pserver:LOGIN@anoncvs.quagga.net:/var/cvsroot
     cvs import quagga/isisd isisd_sf isisd_sf_20031223
   ---COMMENTS---
     Vendor: [isisd_sf] Sampo's ISISd from Sourceforge
     Tag: [isisd_sf_20031217] Current CVS release
   ---

 * Update your Quagga's directory:

     cd dir_quagga
     cvs update -dP

   or

     cvs co -d quagga_isisd quagga

 * Merge the code, then commit:

     cvs commit
	-- mode: text; --
	$Id: HACKING,v 1.20 2005/04/25 00:37:03 paul Exp $

	GUIDELINES FOR HACKING ON QUAGGA

	[this is a draft in progress]

	GNU coding standards apply. Indentation follows the result of
	invoking GNU indent (as of 2.2.8a) with no arguments. Note that this
	uses tabs instead of spaces where possible for leading whitespace, and
	assumes that tabs are every 8 columns. Do not attempt to redefine the
	location of tab stops. Note also that some indentation does not
	follow GNU style. This is a historical accident, and we generally
	only clean up whitespace when code is unmaintainable due to whitespace
	issues, as fewer changes from zebra lead to easier merges.

	For GNU emacs, use indentation style "gnu".

	For Vim, use the following lines (note that tabs are at 8, and that
	softtabstop sets the indentation level):

	set tabstop=8
	set softtabstop=2
	set shiftwidth=2
	set noexpandtab

	Be particularly careful not to break platforms/protocols that you
	cannot test.

	New code should have good comments, and changes to existing code
	should in many cases upgrade the comments when necessary for a
	reviewer to conclude that the change has no unintended consequences.

	Each file in CVS should have the RCS keyword Id, somewhere very near
	the top, commented out appropriately for the file type. Just add
	<dollar>Id:<dollar>, replacing <dollar> with $. See line 2 of HACKING
	for an example; on checkout :$ is expanded to include the value.

	Please document fully the proper use of a new function in the header file
	in which it is declared. And please consult existing headers for
	documentation on how to use existing functions. In particular, please consult
	these header files:

	lib/log.h logging levels and usage guidance
	[more to be added]

	If changing an exported interface, please try to deprecate the interface in
	an orderly manner. If at all possible, try to retain the old deprecated
	interface as is, or functionally equivalent. Make a note of when the
	interface was deprecated and guard the deprecated interface definitions in
	the header file, ie:

	/* Deprecated: 20050406 */
	#if !defined(QUAGGA_NO_DEPRECATED_INTERFACES)
	#warning "Using deprecated <libname> (interface(s)\|function(s))"
	...
	#endif /* QUAGGA_NO_DEPRECATED_INTERFACES */

	To ensure that the core Quagga sources do not use the deprecated interfaces
	(you should update Quagga sources to use new interfaces, if applicable)
	while allowing external sources to continue to build. Deprecated interfaces
	should be excised in the next unstable cycle.

	Note: If you wish, you can test for GCC and use a function
	marked with the 'deprecated' attribute. However, you must provide the
	#warning for other compilers.

	If changing or removing a command definition, ensure that you properly
	deprecate it - use the _DEPRECATED form of the appropriate DEFUN macro. This
	is critical. Even if the command can no longer function, you must still
	implement it as a do-nothing stub. Failure to follow this causes grief for
	systems administrators. Deprecated commands should be excised in the next
	unstable cycle. A list of deprecated commands should be collated for each
	release.

	See also below regarding SHARED LIBRARY VERSIONING.


	CHANGELOG

	Add a ChangeLog entry whenever changing code, except for minor fixes
	to a commit (with a ChangeLog entry) within the last few days.

	Most directories have a ChangeLog file; changes to code in that
	directory should go in the per-directory ChangeLog. Global or
	structural changes should also be mentioned in the top-level
	ChangeLog.

	Certain directories do not contain project code, but contain project
	meta-data, eg packaging information, changes to files in these directory may
	not require the global ChangeLog to be updated (at the discretion of the
	maintainer who usually maintains that meta-data). Also, CVS meta-data such
	as cvsignore files do not require ChangeLog updates, just a sane commit
	message.


	HACKING THE BUILD SYSTEM

	If you change or add to the build system (configure.ac, any Makefile.am,
	etc.), try to check that the following things still work:

	- make dist
	- resulting dist tarball builds
	- out-of-tree builds

	The quagga.net site relies on make dist to work to generate snapshots. It
	must work. Commong problems are to forget to have some additional file
	included in the dist, or to have a make rule refer to a source file without
	using the srcdir variable.

	RELEASE PROCEDURE

	Tag the repository with release tag (follow existing conventions).
	[This enables recreating the release, and is just good CM practice.]

	Check out the tag, and do a test build.

	In an empty directory, do a fresh checkout with -r <release-tag>
	[This makes the dates in the tarball be the modified dates in CVS.]

	./configure
	make dist

	If any errors occur, move tags as needed and start over from the fresh
	checkouts. Do not append to tarballs, as this has produced
	non-standards-conforming tarballs in the past.

	[TODO: collation of a list of deprecated commands. Possibly can be scripted
	to extract from vtysh/vtysh_cmd.c]


	TOOL VERSIONS

	Require versions of support tools are listed in INSTALL.quagga.txt.
	Required versions should only be done with due deliberation, as it can
	cause environments to no longer be able to compile quagga.


	SHARED LIBRARY VERSIONING

	[this section is at the moment just gdt's opinion]

	Quagga builds several shared libaries (lib/libzebra, ospfd/libospf,
	ospfclient/libsopfapiclient). These may be used by external programs,
	e.g. a new routing protocol that works with the zebra daemon, or
	ospfapi clients. The libtool info pages (node Versioning) explain
	when major and minor version numbers should be changed. These values
	are set in Makefile.am near the definition of the library. If you
	make a change that requires changing the shared library version,
	please update Makefile.am.

	libospf exports far more than it should, and is needed by ospfapi
	clients. Only bump libospf for changes to functions for which it is
	reasonable for a user of ospfapi to call, and please err on the side
	of not bumping.

	There is no support intended for installing part of zebra. The core
	library libzebra and the included daemons should always be built and
	installed together.


	PATCH SUBMISSION

	* Send a clean diff against the head of CVS in unified diff format, eg by:
	cvs <cvs opts> diff -upwb ....

	* Include ChangeLog and NEWS entries as appropriate before the patch
	(or in it if you are 100% up to date). A good ChangeLog makes it easier to
	review a patch, hence failure to include a good ChangeLog is prejudicial
	to proper review of the patch, and hence the possibility of inclusion.

	* Include only one semantic change or group of changes per patch.

	* Do not make gratuitous changes to whitespace. See the w and b arguments
	to diff.

	* State on which platforms and with what daemons the patch has been
	tested. Understand that if the set of testing locations is small,
	and the patch might have unforeseen or hard to fix consequences that
	there may be a call for testers on quagga-dev, and that the patch
	may be blocked until test results appear.

	If there are no users for a platform on quagga-dev who are able and
	willing to verify -current occasionally, that platform may be
	dropped from the "should be checked" list.


	PATCH APPLICATION TO CVS

	* Only apply patches that meet the submission guidelines.

	* If a patch is large (perhaps more than 100 new/changed lines), tag
	the repository before and after the change with e.g. before-foo-fix
	and after-foo-fix.

	* If the patch might break something, issue a call for testing on the
	mailinglist.

	* Give an appropriate commit message, eg the ChangeLog entry should suffice,
	if it does not, then the ChangeLog entry itself needs to be corrected. The
	commit message text should be identical to that added to the ChangeLog
	message. (One suggestion: when commiting, use your editor to read in the
	ChangeLog and delete all previous ChangeLogs.)

	* By committing a patch, you are responsible for fixing problems
	resulting from it (or backing it out).


	STABLE PLATFORMS AND DAEMONS

	The list of platforms that should be tested follow. This is a list
	derived from what quagga is thought to run on and for which
	maintainers can test or there are people on quagga-dev who are able
	and willing to verify that -current does or does not work correctly.

	BSD (Free, Net or Open, any platform) # without capabilities
	GNU/Linux (any distribution, i386)
	Solaris (strict alignment, any platform)
	[future: NetBSD/sparc64]

	The list of daemons that are thought to be stable and that should be
	tested are:

	zebra
	bgpd
	ripd
	ospfd
	ripngd

	Daemons which are in a testing phase are

	ospf6d
	isisd
	watchquagga


	IMPORT OR UPDATE VENDOR SPECIFIC ROUTING PROTOCOLS

	The source code of Quagga is based on two vendors:

	zebra_org (http://www.zebra.org/)
	isisd_sf (http://isisd.sf.net/)

	[20041105: Is isisd.sf.netf still where isisd word is happening, or is
	the quagga repo now the canonical place? The last tarball on sf is
	two years old. --gdt]

	In order to import source code, the following procedure should be used:

	* Tag the Current Quagga CVS repository:

	cvs tag import_isisd_sf_20031223

	* Import the source code into the Quagga's framework. You must not modified
	this source code. It will be merged later.

	cd dir_isisd
	export CVSROOT=:pserver:LOGIN@anoncvs.quagga.net:/var/cvsroot
	cvs import quagga/isisd isisd_sf isisd_sf_20031223
	---COMMENTS---
	Vendor: [isisd_sf] Sampo's ISISd from Sourceforge
	Tag: [isisd_sf_20031217] Current CVS release
	---

	* Update your Quagga's directory:

	cd dir_quagga
	cvs update -dP

	or

	cvs co -d quagga_isisd quagga

	* Merge the code, then commit:

	cvs commit