-*- mode: text; -*- $Id: HACKING,v 1.21 2005/11/10 10:21:19 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 Id:, replacing 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 (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. The ChangeLog should provide: * The date, in YYYY-MM-DD format * The author's name and email. * a short description of each change made * file by file * function by function (use of "ditto" is allowed) (detailed discussion of non-obvious reasoning behind and/or implications of a change should be made in comments in the code concerned). The changelog optionally may have a (general) description, to provide a short description of the general intent of the patch. The reason for such itemised ChangeLogs is to encourage the author to self-review every line of the patch, as well as provide reviewers an index of which changes are intended, along with a short description for each. E.g.: 2012-05-29 Joe Bar * (general) Add a new DOWN state to the frob state machine to allow the barinator to detect loss of frob. * frob.h: (struct frob) Add DOWN state flag. * frob.c: (frob_change) set/clear DOWN appropriately on state change. * bar.c: (barinate) Check frob for DOWN state. 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 [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 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, prefixed with a category name (either the name of the daemon, the library component or the general topic) and a one-line short summary of the change as the first line, suitable for use as a Subject in an email. The ChangeLog entry should suffice as the body of the commit message, 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.) An example: ---------------------------------------------------------------- [frob] Defangulator needs to specify frob 2012-05-12 Joe Bar * frobinate.c: (frob_lookup) fix NULL dereference (defangulate) check whether frob is in state FROB_VALID before defangulating. ---------------------------------------------------------------- * 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