Intercepting Information Sent to the Client

This section demonstrates functionality called by Directory Server before sending a result code, a referral, or an entry to the client application. Refer to install-path/examples/testpreop.c for the source code discussed here.

The following example shows the code that logs the operation number and user DN.

Example 5-24 Logging and Responding to the Client (testpreop.c)

#include "slapi-plugin.h"

int
testpreop_send(Slapi_PBlock * pb)
{
    Slapi_Operation * op;              /* Operation in progress   */
    char            * connDn;          /* Get DN from connection  */
    int               connId, opId, rc = 0;
    long              msgId;

    rc |= slapi_pblock_get(pb, SLAPI_OPERATION,       &op);
    rc |= slapi_pblock_get(pb, SLAPI_CONN_DN,         &connDn);
    rc |= slapi_pblock_get(pb, SLAPI_CONN_ID,         &connId);
    rc |= slapi_pblock_get(pb, SLAPI_OPERATION_MSGID, &msgId);
    rc |= slapi_pblock_get(pb, SLAPI_OPERATION_ID,    &opId);
    if (rc == 0) {
        slapi_log_info_ex(
            SLAPI_LOG_INFO_AREA_PLUGIN,
            SLAPI_LOG_INFO_LEVEL_DEFAULT,
            msgId,
            connId,
            opId,
            "testpreop_send in test-preop plug-in",
            "Operation: %d\tUser: %s\n", slapi_op_get_type(op), connDn
        );
    }
    slapi_ch_free_string(&connDn);

    return (rc);
}

Operation identifiers are defined in the plug-in header file install-path/include/slapi-plugin.h. Search for SLAPI_OPERATION_*.

Before using the plug-in function as described here, set up the example suffix and register the plug-in. See Extending the Bind Operation and “To register the Plug-in”, as described previously.

With the plug-in activated in Directory Server, perform a search as Kirsten Vaughan:

$ ldapsearch -h localhost -p 1389 -b dc=example,dc=com \
 -D uid=kvaughan,ou=people,dc=example,dc=com -w bribery \
 uid=bcubbins

Search instance-path/logs/errors for the log messages. Minus housekeeping information, the first message reflects the bind result:

Operation: 1 User: uid=kvaughan,ou=people,dc=example,dc=com

The next message reflects the search:

Operation: 4 User: uid=kvaughan,ou=people,dc=example,dc=com

Inside plug-in functions, use slapi_op_get_type() to determine the type of an operation. Refer to Part II, Directory Server Plug-In API Reference for info about slapi_op_get_type(), or see the plug-in header file install-path/include/slapi-plugin.h for a list of operation types.