Initializing the Extended Operation Plug-In

As for other plug-in types, extended operation plug-ins include an initialization function that registers other functions in the plug-in with Directory Server. For extended operation plug-ins, this initialization function also registers the OIDs handled by the plug-in. The function registers OIDs by setting SLAPI_PLUGIN_EXT_OP_OIDLIST in the parameter block Directory Server, which the function passes to the initialization function.

Example 10–1 Registering Plug-In Functions and OIDs (testextendedop.c)

This example demonstrates how the OID list is built and registered.

#include "slapi-plugin.h"

Slapi_PluginDesc expdesc = {
    "test-extendedop",                 /* plug-in identifier       */
    "Sun Microsystems, Inc.",          /* vendor name              */
    "6.0",                             /* plug-in revision number  */
    "Sample extended operation plug-in"/* plug-in description      */
};

#ifdef _WIN32
__declspec(dllexport)
#endif
int
testexop_init(Slapi_PBlock * pb)
{
    char ** argv;                      /* Args from configuration  */
    int     argc;                      /* entry for plug-in.       */
    char ** oid_list;                  /* OIDs supported           */
    int     rc = 0;                    /* 0 means success          */
    int     i;

    /* Get the arguments from the configuration entry.             */
    rc |= slapi_pblock_get(pb, SLAPI_PLUGIN_ARGV, &argv);
    rc |= slapi_pblock_get(pb, SLAPI_PLUGIN_ARGC, &argc);
    if (rc != 0) {
        slapi_log_info_ex(
            SLAPI_LOG_INFO_AREA_PLUGIN,
            SLAPI_LOG_INFO_LEVEL_DEFAULT,
            SLAPI_LOG_NO_MSGID,
            SLAPI_LOG_NO_CONNID,
            SLAPI_LOG_NO_OPID,
            "testexop_init in test-extendedop plug-in",
            "Could not get plug-in arguments.\n"
        );
        return (rc);
    }

    /* Extended operation plug-ins may handle a range of OIDs.     */
    oid_list = (char **)slapi_ch_malloc((argc + 1) * sizeof(char *));
    for (i = 0; i < argc; ++i) {
        oid_list[i] = slapi_ch_strdup(argv[i]);
        slapi_log_info_ex(
            SLAPI_LOG_INFO_AREA_PLUGIN,
            SLAPI_LOG_INFO_LEVEL_DEFAULT,
            SLAPI_LOG_NO_MSGID,
            SLAPI_LOG_NO_CONNID,
            SLAPI_LOG_NO_OPID,
            "testexop_init in test-extendedop plug-in",
            "Registering plug-in for extended operation %s.\n",
            oid_list[i]
        );
    }
    oid_list[argc] = NULL;
        
    rc |= slapi_pblock_set(            /* Plug-in API version      */
        pb,
        SLAPI_PLUGIN_VERSION,
        SLAPI_PLUGIN_CURRENT_VERSION
    );
    rc |= slapi_pblock_set(            /* Plug-in description      */
        pb,
        SLAPI_PLUGIN_DESCRIPTION,
        (void *) &expdesc
    );
    rc |= slapi_pblock_set(            /* Extended op. handler     */
        pb,
        SLAPI_PLUGIN_EXT_OP_FN,
        (void *) test_extendedop
    );
    rc |= slapi_pblock_set(            /* List of OIDs handled     */
        pb,
        SLAPI_PLUGIN_EXT_OP_OIDLIST,
        oid_list
    );
    return (rc);
}

Notice that you extract OIDs from the arguments passed by Directory Server. Directory Server passes the arguments from the configuration entry to the parameter block, by using slapi_ch_strdup() on each argv[] element. The OID list is then built by allocating space for the array by using slapi_ch_malloc() and placing the OIDs in each oid_list[] element. You then register the plug-in OID list by using SLAPI_PLUGIN_EXT_OP_OIDLIST. You register the extended operation handler function, test_extendedop(), using SLAPI_PLUGIN_EXT_OP_FN as shown.

Refer to Part II, Directory Server Plug-In API Reference for details about parameter block arguments and plug-in API functions.