Chapter 6 Writing Pre/Post-Operation Plug-Ins

This chapter explains how to write functions that the server calls before and after executing an LDAP operation. These functions are called pre-operation and post-operation plug-in functions.

• How Pre/Post-Operation Plug-Ins Work
• Writing Pre/Post-Operation Functions
• Registering Pre/Post-Operation Functions

• bind
• unbind
• search
• modify
• add
• delete
• modify RDN
• compare
• abandon

You can set up the Directory Server to call your own plug-in functions before and after executing these LDAP operations. For example, you can write a function that validates an entry before the server performs an LDAP add operation to add it to the directory. Or you can write a function that notifies a user whose entry has just been modified by an LDAP modify operation.

You can also set up the Directory Server to call your own plug-in functions before and after:

• sending an LDAP entry back to the client
• sending an LDAP result code back to the client
• sending an LDAP referral back to the client

Figure 6.1 How the server calls pre-operation and post-operation plug-in functions

Types of Pre-Operation Functions

Table 6.1 lists the Directory Server pre-operation functions and the purpose of each function.

Table 6.1 Functions called before the Directory Server executes an operation

ID in Parameter Block	Description
SLAPI_PLUGIN_PRE_BIND_FN	Specifies the function called before the Directory Server executes an LDAP bind operation. For information on writing this type of function, see "Processing an LDAP Bind Operation" on page  99.
SLAPI_PLUGIN_PRE_UNBIND_FN	Specifies the function called before the Directory Server executes an LDAP unbind operation. For information on writing this type of function, see "Processing an LDAP Unbind Operation" on page  101.
SLAPI_PLUGIN_PRE_SEARCH_FN	Specifies the function called before the Directory Server executes an LDAP search operation. For information on writing this type of function, see "Processing an LDAP Search Operation" on page  101.
SLAPI_PLUGIN_PRE_COMPARE_FN	Specifies the function called before the Directory Server executes an LDAP compare operation. For information on writing this type of function, see "Processing an LDAP Compare Operation" on page  105.
SLAPI_PLUGIN_PRE_ADD_FN	Specifies the function called before the Directory Server executes an LDAP add operation. For information on writing this type of function, see "Processing an LDAP Add Operation" on page  106.
SLAPI_PLUGIN_PRE_MODIFY_FN	Specifies the function called before the Directory Server executes an LDAP modify operation. For information on writing this type of function, see "Processing an LDAP Modify Operation" on page  108.
SLAPI_PLUGIN_PRE_MODRDN_FN	Specifies the function called before the Directory Server executes an LDAP modify RDN operation. For information on writing this type of function, see "Processing an LDAP Modify RDN Operation" on page  109.
SLAPI_PLUGIN_PRE_DELETE_FN	Specifies the function called before the Directory Server executes an LDAP delete operation. For information on writing this type of function, see "Processing an LDAP Delete Operation" on page  111.
SLAPI_PLUGIN_PRE_ABANDON_FN	Specifies the function called before the Directory Server executes an LDAP abandon operation. For information on writing this type of function, see "Processing an LDAP Abandon Operation" on page  112.
SLAPI_PLUGIN_PRE_ENTRY_FN	Specifies the function called before the Directory Server sends an entry back to the client (for example, when you call slapi_send_ldap_search_entry(), the pre-operation entry function is called before the entry is sent back to the client).
SLAPI_PLUGIN_PRE_REFERRAL_FN	Specifies the function called before the Directory Server sends a referral back to the client (for example, when you call slapi_send_ldap_referral(), the pre-operation referral function is called before the referral is sent back to the client).
SLAPI_PLUGIN_PRE_RESULT_FN	Specifies the function called before the Directory Server sends a result code back to the client (for example, when you call slapi_send_ldap_result(), the pre-operation result function is called before the result code is sent back to the client).

Types of Post-Operation Functions

Table 6.2 lists the Directory Server post-operation functions and the purpose of each function.

Table 6.2 Functions called after the Directory Server executes an operation

ID in Parameter Block	Description
SLAPI_PLUGIN_POST_BIND_FN	Specifies the function called after the Directory Server executes an LDAP bind operation. For information on writing this type of function, see "Processing an LDAP Bind Operation" on page  99.
SLAPI_PLUGIN_POST_UNBIND_FN	Specifies the function called after the Directory Server executes an LDAP unbind operation. For information on writing this type of function, see "Processing an LDAP Unbind Operation" on page  101.
SLAPI_PLUGIN_POST_SEARCH_FN	Specifies the function called after the Directory Server executes an LDAP search operation. For information on writing this type of function, see "Processing an LDAP Search Operation" on page  101.
SLAPI_PLUGIN_POST_COMPARE_FN	Specifies the function called after the Directory Server executes an LDAP compare operation. For information on writing this type of function, see "Processing an LDAP Compare Operation" on page  105.
SLAPI_PLUGIN_POST_ADD_FN	Specifies the function called after the Directory Server executes an LDAP add operation. For information on writing this type of function, see "Processing an LDAP Add Operation" on page  106.
SLAPI_PLUGIN_POST_MODIFY_FN	Specifies the function called after the Directory Server executes an LDAP modify operation. For information on writing this type of function, see "Processing an LDAP Modify Operation" on page  108.
SLAPI_PLUGIN_POST_MODRDN_FN	Specifies the function called after the Directory Server executes an LDAP modify RDN operation. For information on writing this type of function, see "Processing an LDAP Modify RDN Operation" on page  109.
SLAPI_PLUGIN_POST_DELETE_FN	Specifies the function called after the Directory Server executes an LDAP delete operation. For information on writing this type of function, see "Processing an LDAP Delete Operation" on page  111.
SLAPI_PLUGIN_POST_ABANDON_FN	Specifies the function called after the Directory Server executes an LDAP abandon operation. For information on writing this type of function, see "Processing an LDAP Abandon Operation" on page  112.
SLAPI_PLUGIN_POST_ENTRY_FN	Specifies the function called after the Directory Server sends an entry back to the client (for example, when you call slapi_send_ldap_search_entry(), the post-operation entry function is called after the entry is sent back to the client).
SLAPI_PLUGIN_POST_REFERRAL_FN	Specifies the function called after the Directory Server sends a referral back to the client (for example, when you call slapi_send_ldap_referral(), the pre-operation referral function is called after the referral is sent back to the client).
SLAPI_PLUGIN_POST_RESULT_FN	Specifies the function called after the Directory Server sends a result code back to the client (for example, when you call slapi_send_ldap_result(), the pre-operation result function is called after the result code is sent back to the client).

For details, follow the procedures outlined in "Writing an Initialization Function" on page  34 and "Configuring the Server" on page  39.

Note. Each pre-operation and post-operation plug-in is associated with a back-end. Make sure that the plugin directive that registers the plug-in is within the database section for that back-end in the slapd.conf file. (The plugin directive should be after the database directive and before the next database directive, if any.)