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| author | vorlon <vorlon@alioth.debian.org> | 2008-03-24 08:23:36 +0000 |
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| committer | vorlon <vorlon@alioth.debian.org> | 2008-03-24 08:23:36 +0000 |
| commit | bba625b04e0d12c2c03a345554d98b8575f4f380 (patch) | |
| tree | 1333f979a7278d10b7c56c4f0b34fa6d3e75b2e1 /docs/htmldocs/Samba3-Developers-Guide/modules.html | |
| parent | 74a2535fdc9252584a2ca4256431b28b20ed4f58 (diff) | |
| download | samba-bba625b04e0d12c2c03a345554d98b8575f4f380.tar.gz | |
Load samba-3.2.0pre2 into branches/samba/upstream-3.2.upstream/3.2.0_pre2
git-svn-id: svn://svn.debian.org/svn/pkg-samba/branches/samba/upstream-3.2@1780 fc4039ab-9d04-0410-8cac-899223bdd6b0
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diff --git a/docs/htmldocs/Samba3-Developers-Guide/modules.html b/docs/htmldocs/Samba3-Developers-Guide/modules.html new file mode 100644 index 0000000000..c7593f6761 --- /dev/null +++ b/docs/htmldocs/Samba3-Developers-Guide/modules.html @@ -0,0 +1,70 @@ +<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 8. Modules</title><link rel="stylesheet" href="samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.72.0"><link rel="start" href="index.html" title="SAMBA Developers Guide"><link rel="up" href="pt02.html" title="Part II. Samba Basics"><link rel="prev" href="contributing.html" title="Chapter 7. Contributing code"><link rel="next" href="pt03.html" title="Part III. Samba Subsystems"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 8. Modules</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="contributing.html">Prev</a> </td><th width="60%" align="center">Part II. Samba Basics</th><td width="20%" align="right"> <a accesskey="n" href="pt03.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="modules"></a>Chapter 8. Modules</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Jelmer</span> <span class="surname">Vernooij</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email"><<a href="mailto:jelmer@samba.org">jelmer@samba.org</a>></code></p></div></div></div></div><div><p class="pubdate"> 19 March 2003 </p></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="modules.html#id331748">Advantages</a></span></dt><dt><span class="sect1"><a href="modules.html#id331783">Loading modules</a></span></dt><dd><dl><dt><span class="sect2"><a href="modules.html#id331806">Static modules</a></span></dt><dt><span class="sect2"><a href="modules.html#id331836">Shared modules</a></span></dt></dl></dd><dt><span class="sect1"><a href="modules.html#id331855">Writing modules</a></span></dt><dd><dl><dt><span class="sect2"><a href="modules.html#id331898">Static/Shared selection in configure.in</a></span></dt></dl></dd></dl></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id331748"></a>Advantages</h2></div></div></div><p> +The new modules system has the following advantages: +</p><table class="simplelist" border="0" summary="Simple list"><tr><td>Transparent loading of static and shared modules (no need +for a subsystem to know about modules)</td></tr><tr><td>Simple selection between shared and static modules at configure time</td></tr><tr><td>"preload modules" option for increasing performance for stable modules</td></tr><tr><td>No nasty #define stuff anymore</td></tr><tr><td>All backends are available as plugin now (including pdb_ldap and pdb_tdb)</td></tr></table></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id331783"></a>Loading modules</h2></div></div></div><p> +Some subsystems in samba use different backends. These backends can be +either statically linked in to samba or available as a plugin. A subsystem +should have a function that allows a module to register itself. For example, +the passdb subsystem has: +</p><pre class="programlisting"> +NTSTATUS smb_register_passdb(int version, const char *name, pdb_init_function init); +</pre><p> +This function will be called by the initialisation function of the module to +register itself. +</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id331806"></a>Static modules</h3></div></div></div><p> +The modules system compiles a list of initialisation functions for the +static modules of each subsystem. This is a define. For example, +it is here currently (from <code class="filename">include/config.h</code>): +</p><pre class="programlisting"> +/* Static init functions */ +#define static_init_pdb { pdb_mysql_init(); pdb_ldap_init(); pdb_smbpasswd_init(); pdb_tdbsam_init(); pdb_guest_init();} +</pre><p> +These functions should be called before the subsystem is used. That +should be done when the subsystem is initialised or first used. +</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id331836"></a>Shared modules</h3></div></div></div><p> +If a subsystem needs a certain backend, it should check if it has +already been registered. If the backend hasn't been registered already, +the subsystem should call smb_probe_module(char *subsystem, char *backend). +This function tries to load the correct module from a certain path +($LIBDIR/subsystem/backend.so). If the first character in 'backend' +is a slash, smb_probe_module() tries to load the module from the +absolute path specified in 'backend'. +</p><p>After smb_probe_module() has been executed, the subsystem +should check again if the module has been registered. +</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id331855"></a>Writing modules</h2></div></div></div><p> +Each module has an initialisation function. For modules that are +included with samba this name is '<em class="replaceable"><code>subsystem</code></em>_<em class="replaceable"><code>backend</code></em>_init'. For external modules (that will never be built-in, but only available as a module) this name is always 'init_module'. (In the case of modules included with samba, the configure system will add a #define subsystem_backend_init() init_module()). +The prototype for these functions is: +</p><pre class="programlisting"> +NTSTATUS init_module(void); +</pre><p>This function should call one or more +registration functions. The function should return NT_STATUS_OK on success and +NT_STATUS_UNSUCCESSFUL or a more useful nt error code on failure.</p><p>For example, pdb_ldap_init() contains: </p><pre class="programlisting"> +NTSTATUS pdb_ldap_init(void) +{ +smb_register_passdb(PASSDB_INTERFACE_VERSION, "ldapsam", pdb_init_ldapsam); +smb_register_passdb(PASSDB_INTERFACE_VERSION, "ldapsam_nua", pdb_init_ldapsam_nua); + return NT_STATUS_OK; +} +</pre><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id331898"></a>Static/Shared selection in configure.in</h3></div></div></div><p> +Some macros in configure.in generate the various defines and substs that +are necessary for the system to work correct. All modules that should +be built by default have to be added to the variable 'default_modules'. +For example, if ldap is found, pdb_ldap is added to this variable. +</p><p> +On the bottom of configure.in, SMB_MODULE() should be called +for each module and SMB_SUBSYSTEM() for each subsystem. +</p><p>Syntax:</p><pre class="programlisting"> +SMB_MODULE(<em class="replaceable"><code>subsystem</code></em>_<em class="replaceable"><code>backend</code></em>, <em class="replaceable"><code>object files</code></em>, <em class="replaceable"><code>plugin name</code></em>, <em class="replaceable"><code>subsystem name</code></em>, <em class="replaceable"><code>static_action</code></em>, <em class="replaceable"><code>shared_action</code></em>) +SMB_SUBSYSTEM(<em class="replaceable"><code>subsystem</code></em>,<em class="replaceable"><code>depfile</code></em>) +</pre><p>The depfile for a certain subsystem is the file that calls the +initialisation functions for the statically built in modules.</p><p> +<em class="replaceable"><code>@SUBSYSTEM_MODULES@</code></em> in Makefile.in will +be replaced with the names of the plugins to build. +</p><p>You must make sure all .c files that contain defines that can +be changed by ./configure are rebuilded in the 'modules_clean' make target. +Practically, this means all c files that contain <code class="literal">static_init_subsystem;</code> calls need to be rebuilded. +</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> +There currently also is a configure.in command called SMB_MODULE_PROVIVES(). +This is used for modules that register multiple things. It should not +be used as probing will most likely disappear in the future.</p></div></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="contributing.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="pt02.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="pt03.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 7. Contributing code </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Part III. Samba Subsystems</td></tr></table></div></body></html> |