Extending the Modify Operation

This section shows how to develop functionality called by Directory Server after a client modify operation. A preoperation plug-in, not demonstrated here, can be found in install-path/examples/testpreop.c. Refer to install-path/examples/testpostop.c for the source code discussed here.

Before using the plug-in function as described here, set up Directory Server as described in Logging the Entry to Add, making sure to add Quentin’s entry.

The testpostop_mod() function logs the DN of the modified entry and also writes the entry to a log managed by the plug-in, changelog.txt. The location of changelog.txt depends on the platform, as shown in the source code.

The following example shows the code that performs the logging.

Example 5-15 Tracking Modified Entries (testpostop.c)

#include "slapi-plugin.h"

int
testpostop_mod(Slapi_PBlock * pb)
{
    char    *  dn;                     /* DN of entry to modify      */
    LDAPMod ** mods;                   /* Modifications to apply     */
    int        is_repl = 0;            /* Is this replication?       */
    int        connId, opId, rc = 0;
    long       msgId;

    rc |= slapi_pblock_get(pb, SLAPI_MODIFY_TARGET,           &dn);
    rc |= slapi_pblock_get(pb, SLAPI_MODIFY_MODS,             &mods);
    rc |= slapi_pblock_get(pb, SLAPI_OPERATION_MSGID,         &msgId);
    rc |= slapi_pblock_get(pb, SLAPI_CONN_ID,                 &connId);
    rc |= slapi_pblock_get(pb, SLAPI_OPERATION_ID,            &opId);
    rc |= slapi_pblock_get(pb, SLAPI_IS_REPLICATED_OPERATION, &is_repl);
    
    if (rc != 0) return (rc);
    slapi_log_info_ex(
        SLAPI_LOG_INFO_AREA_PLUGIN,
        SLAPI_LOG_INFO_LEVEL_DEFAULT,
        msgId,
        connId,
        opId,
        "testpostop_mod in test-postop plug-in",
        "Modified entry (%s)\n", dn
    );

    /* In general, do not interfere in replication operations.       */
    /* Log the DN and the modifications made to the change log file. */
    if (!is_repl) write_changelog(_MOD, dn, (void *) mods, 0);

    return (rc);
}

First, check that Quentin’s entry is in the directory.

Example 5-16 Checking the Directory for an Entry

$ ldapsearch -h localhost -p 1389 -b dc=example,dc=com uid=qcubbins
version: 1
dn: uid=qcubbins,ou=People,dc=example,dc=com
objectClass: top
objectClass: person
objectClass: organizationalPerson
objectClass: inetOrgPerson
uid: qcubbins
givenName: Quentin
sn: Cubbins
cn: Quentin Cubbins
mail: qcubbins@example.com
secretary: uid=bjensen,ou=People,dc=example,dc=com

After the plug-in is activated in Directory Server, modify Quentin’s mail address.

Example 5-17 Modifying a Mail Address

$ ldapmodify -h localhost -p 1389 \
 -D uid=kvaughan,ou=people,dc=example,dc=com -w bribery
dn: uid=qcubbins,ou=People,dc=example,dc=com
changetype: modify
replace: mail
mail: quentin@example.com
^D

Search instance-path/logs/errors for the log message. If you ignore housekeeping information, you get the following message:

Modified entry (uid=qcubbins,ou=people,dc=example,dc=com)

Notice also the information logged to changelog.txt as shown in the following example.

Example 5-18 Example changelog.txt After Modification

time: 21120506181305
dn: uid=qcubbins,ou=people,dc=example,dc=com
changetype: modify
replace: mail
mail: quentin@example.com
-
replace: modifiersname
modifiersname: cn=Directory Manager
-
replace: modifytimestamp
modifytimestamp: 21120506161305Z
-