HACKING

   1 -*- mode: text; -*-
   2 $Id: HACKING,v 1.19 2005/04/07 07:30:20 paul Exp $
   3
   4 GUIDELINES FOR HACKING ON QUAGGA
   5
   6 [this is a draft in progress]
   7
   8 GNU coding standards apply.  Indentation follows the result of
   9 invoking GNU indent (as of 2.2.8a) with no arguments.  Note that this
  10 uses tabs instead of spaces where possible for leading whitespace, and
  11 assumes that tabs are every 8 columns.  Do not attempt to redefine the
  12 location of tab stops.  Note also that some indentation does not
  13 follow GNU style.  This is a historical accident, and we generally
  14 only clean up whitespace when code is unmaintainable due to whitespace
  15 issues, as fewer changes from zebra lead to easier merges.
  16
  17 For GNU emacs, use indentation style "gnu".
  18
  19 For Vim, use the following lines (note that tabs are at 8, and that
  20 softtabstop sets the indentation level):
  21
  22 set tabstop=8
  23 set softtabstop=2
  24 set shiftwidth=2
  25 set noexpandtab
  26
  27 Be particularly careful not to break platforms/protocols that you
  28 cannot test.
  29
  30 New code should have good comments, and changes to existing code
  31 should in many cases upgrade the comments when necessary for a
  32 reviewer to conclude that the change has no unintended consequences.
  33
  34 Each file in CVS should have the RCS keyword Id, somewhere very near
  35 the top, commented out appropriately for the file type.  Just add
  36 <dollar>Id:<dollar>, replacing <dollar> with $.  See line 2 of HACKING
  37 for an example; on checkout :$ is expanded to include the value.
  38
  39 Please document fully the proper use of a new function in the header file
  40 in which it is declared.  And please consult existing headers for
  41 documentation on how to use existing functions.  In particular, please consult
  42 these header files:
  43
  44   lib/log.h     logging levels and usage guidance
  45   [more to be added]
  46
  47 If changing an exported interface, please try to deprecate the interface in
  48 an orderly manner. If at all possible, try to retain the old deprecated
  49 interface as is, or functionally equivalent. Make a note of when the
  50 interface was deprecated and guard the deprecated interface definitions in
  51 the header file, ie:
  52
  53 /* Deprecated: 20050406 */
  54 #if !defined(QUAGGA_NO_DEPRECATED_INTERFACES)
  55 #warning "Using deprecated <libname> (interface(s)|function(s))"
  56 ...
  57 #endif /* QUAGGA_NO_DEPRECATED_INTERFACES */
  58
  59 To ensure that the core Quagga sources do not use the deprecated interfaces
  60 (you should update Quagga sources to use new interfaces, if applicable)
  61 while allowing external sources to continue to build. Deprecated interfaces
  62 should be excised in the next unstable cycle.
  63
  64 If changing or removing a command definition, *ensure* that you properly
  65 deprecate it - use the _DEPRECATED form of the appropriate DEFUN macro. This
  66 is *critical*. Even if the command can no longer function, you *must* still
  67 implement it as a do-nothing stub. Failure to follow this causes grief for
  68 systems administrators. Deprecated commands should be excised in the next
  69 unstable cycle. A list of deprecated commands should be collated for each
  70 release.
  71
  72 See also below regarding SHARED LIBRARY VERSIONING.
  73
  74 CHANGELOG
  75
  76 Add a ChangeLog entry whenever changing code, except for minor fixes
  77 to a commit (with a ChangeLog entry) within the last few days.
  78
  79 Most directories have a ChangeLog file; changes to code in that
  80 directory should go in the per-directory ChangeLog.  Global or
  81 structural changes should also be mentioned in the top-level
  82 ChangeLog.
  83
  84 Certain directories do not contain project code, but contain project
  85 meta-data, eg packaging information, changes to files in these directory may
  86 not require the global ChangeLog to be updated (at the discretion of the
  87 maintainer who usually maintains that meta-data). Also, CVS meta-data such
  88 as cvsignore files do not require ChangeLog updates, just a sane commit
  89 message.
  90
  91 RELEASE PROCEDURE
  92
  93   Tag the repository with release tag (follow existing conventions).
  94   [This enables recreating the release, and is just good CM practice.]
  95
  96   Check out the tag, and do a test build.
  97
  98   In an empty directory, do a fresh checkout with -r <release-tag>
  99   [This makes the dates in the tarball be the modified dates in CVS.]
 100
 101   ./configure
 102   make dist
 103
 104 If any errors occur, move tags as needed and start over from the fresh
 105 checkouts.  Do not append to tarballs, as this has produced
 106 non-standards-conforming tarballs in the past.
 107
 108 [TODO: collation of a list of deprecated commands. Possibly can be scripted
 109 to extract from vtysh/vtysh_cmd.c]
 110
 111 TOOL VERSIONS
 112
 113 Require versions of support tools are listed in INSTALL.quagga.txt.
 114 Required versions should only be done with due deliberation, as it can
 115 cause environments to no longer be able to compile quagga.
 116
 117 SHARED LIBRARY VERSIONING
 118
 119 [this section is at the moment just gdt's opinion]
 120
 121 Quagga builds several shared libaries (lib/libzebra, ospfd/libospf,
 122 ospfclient/libsopfapiclient).  These may be used by external programs,
 123 e.g. a new routing protocol that works with the zebra daemon, or
 124 ospfapi clients.  The libtool info pages (node Versioning) explain
 125 when major and minor version numbers should be changed.  These values
 126 are set in Makefile.am near the definition of the library.  If you
 127 make a change that requires changing the shared library version,
 128 please update Makefile.am.
 129
 130 libospf exports far more than it should, and is needed by ospfapi
 131 clients.  Only bump libospf for changes to functions for which it is
 132 reasonable for a user of ospfapi to call, and please err on the side
 133 of not bumping.
 134
 135 There is no support intended for installing part of zebra.  The core
 136 library libzebra and the included daemons should always be built and
 137 installed together.
 138
 139 PATCH SUBMISSION
 140
 141 * Send a clean diff against the head of CVS in unified diff format, eg by:
 142   cvs <cvs opts> diff -upwb ....
 143
 144 * Include ChangeLog and NEWS entries as appropriate before the patch
 145   (or in it if you are 100% up to date). A good ChangeLog makes it easier to
 146   review a patch, hence failure to include a good ChangeLog is prejudicial
 147   to proper review of the patch, and hence the possibility of inclusion.
 148
 149 * Include only one semantic change or group of changes per patch.
 150
 151 * Do not make gratuitous changes to whitespace. See the w and b arguments
 152   to diff.
 153
 154 * State on which platforms and with what daemons the patch has been
 155   tested.  Understand that if the set of testing locations is small,
 156   and the patch might have unforeseen or hard to fix consequences that
 157   there may be a call for testers on quagga-dev, and that the patch
 158   may be blocked until test results appear.
 159
 160   If there are no users for a platform on quagga-dev who are able and
 161   willing to verify -current occasionally, that platform may be
 162   dropped from the "should be checked" list.
 163
 164 PATCH APPLICATION TO CVS
 165
 166 * Only apply patches that meet the submission guidelines.
 167
 168 * If a patch is large (perhaps more than 100 new/changed lines), tag
 169   the repository before and after the change with e.g. before-foo-fix
 170   and after-foo-fix.
 171
 172 * If the patch might break something, issue a call for testing on the
 173   mailinglist.
 174
 175 * Give an appropriate commit message, eg the ChangeLog entry should suffice,
 176   if it does not, then the ChangeLog entry itself needs to be corrected. The
 177   commit message text should be identical to that added to the ChangeLog
 178   message. (One suggestion: when commiting, use your editor to read in the
 179   ChangeLog and delete all previous ChangeLogs.)
 180
 181 * By committing a patch, you are responsible for fixing problems
 182   resulting from it (or backing it out).
 183
 184 STABLE PLATFORMS AND DAEMONS
 185
 186 The list of platforms that should be tested follow.  This is a list
 187 derived from what quagga is thought to run on and for which
 188 maintainers can test or there are people on quagga-dev who are able
 189 and willing to verify that -current does or does not work correctly.
 190
 191   BSD (Free, Net or Open, any platform) # without capabilities
 192   GNU/Linux (any distribution, i386)
 193   Solaris (strict alignment, any platform)
 194   [future: NetBSD/sparc64]
 195
 196 The list of daemons that are thought to be stable and that should be
 197 tested are:
 198
 199   zebra
 200   bgpd
 201   ripd
 202   ospfd
 203   ripngd
 204
 205 Daemons which are in a testing phase are
 206
 207   ospf6d
 208   isisd
 209   watchquagga
 210
 211 IMPORT OR UPDATE VENDOR SPECIFIC ROUTING PROTOCOLS
 212
 213 The source code of Quagga is based on two vendors:
 214
 215    zebra_org (http://www.zebra.org/)
 216    isisd_sf (http://isisd.sf.net/)
 217
 218 [20041105: Is isisd.sf.netf still where isisd word is happening, or is
 219 the quagga repo now the canonical place?  The last tarball on sf is
 220 two years old.  --gdt]
 221
 222 In order to import source code, the following procedure should be used:
 223
 224 * Tag the Current Quagga CVS repository:
 225
 226     cvs tag import_isisd_sf_20031223
 227
 228 * Import the source code into the Quagga's framework. You must not modified
 229   this source code. It will be merged later.
 230
 231     cd dir_isisd
 232     export CVSROOT=:pserver:LOGIN@anoncvs.quagga.net:/var/cvsroot
 233     cvs import quagga/isisd isisd_sf isisd_sf_20031223
 234   ---COMMENTS---
 235     Vendor: [isisd_sf] Sampo's ISISd from Sourceforge
 236     Tag: [isisd_sf_20031217] Current CVS release
 237   ---
 238
 239 * Update your Quagga's directory:
 240
 241     cd dir_quagga
 242     cvs update -dP
 243
 244   or
 245
 246     cvs co -d quagga_isisd quagga
 247
 248 * Merge the code, then commit:
 249
 250     cvs commit
 251