baby_steps.c

snmp的源代码,已经在我的ubuntu下编译通过

        }

#ifdef BABY_STEPS_NEXT_MODE
        /*
         * I can't remember why I wanted the next mode in the request,
         * but it's not used anywhere, so don't use this code. saved,
         * in case I remember why I thought needed it. - rstory 040911
         */
        if((BABY_STEPS_PER_MODE_MAX - 1) == i)
            reqinfo->next_mode_ok = BABY_STEP_NONE;
        else {
            if(BSTEP_USE_ORIGINAL == mode_map_ptr[i+1])
                reqinfo->next_mode_ok = save_mode;
            else
                reqinfo->next_mode_ok = mode_map_ptr[i+1];
        }
#endif

        /*
         * call handlers for baby step
         */
        rc = netsnmp_call_next_handler(handler, reginfo, reqinfo,
                                       requests);

        /*
         * check for error calling handler (unlikely, but...)
         */
        if(rc) {
            DEBUGMSGTL(("baby_steps", "   ERROR:handler error\n"));
            break;
        }

        /*
         * check for errors in any of the requests for GET-like, reserve1,
         * reserve2 and action. (there is no recovery from errors
         * in commit, free or undo.)
         */
        if (MODE_IS_GET(save_mode)
            || (save_mode < SNMP_MSG_INTERNAL_SET_COMMIT)) {
            rc = netsnmp_check_requests_error(requests);
            if(rc) {
                DEBUGMSGTL(("baby_steps", "   ERROR:request error\n"));
                break;
            }
        }
    }

    /*
     * restore original mode
     */
    reqinfo->mode = save_mode;

    
    return rc;
}

/** initializes the baby_steps helper which then registers a baby_steps
 *  handler as a run-time injectable handler for configuration file
 *  use.
 */
void
netsnmp_baby_steps_handler_init(void)
{
    netsnmp_register_handler_by_name("baby_steps",
                                     netsnmp_baby_steps_handler_get(BABY_STEP_ALL));
}

/** @} */

/** @defgroup baby_steps baby_steps_access_multiplexer: calls individual access methods based on baby_step mode.
 *  @ingroup handler
 *  @{
 */

/** returns a baby_steps handler that can be injected into a given
 *  handler chain.
 */
netsnmp_mib_handler *
netsnmp_baby_steps_access_multiplexer_get(netsnmp_baby_steps_access_methods *am)
{
    netsnmp_mib_handler *mh;

    mh = netsnmp_create_handler("baby_steps_mux",
                                _baby_steps_access_multiplexer);
    if(!mh)
        return NULL;

    mh->myvoid = am;
    mh->flags |= MIB_HANDLER_AUTO_NEXT;
    
    return mh;
}

/** @internal Implements the baby_steps handler */
static int
_baby_steps_access_multiplexer(netsnmp_mib_handler *handler,
                               netsnmp_handler_registration *reginfo,
                               netsnmp_agent_request_info *reqinfo,
                               netsnmp_request_info *requests)
{
    void *temp_void;
    Netsnmp_Node_Handler *method = NULL;
    netsnmp_baby_steps_access_methods *access_methods;
    int rc = SNMP_ERR_NOERROR;

    /** call handlers should enforce these */
    netsnmp_assert((handler!=NULL) && (reginfo!=NULL) && (reqinfo!=NULL) &&
                   (requests!=NULL));

    DEBUGMSGT(("baby_steps_mux", "mode %s\n",
               se_find_label_in_slist("babystep_mode",reqinfo->mode)));

    access_methods = (netsnmp_baby_steps_access_methods *)handler->myvoid;
    if(!access_methods) {
        snmp_log(LOG_ERR,"baby_steps_access_multiplexer has no methods\n");
        return SNMPERR_GENERR;
    }

    switch(reqinfo->mode) {
        
    case MODE_BSTEP_PRE_REQUEST:
        if( access_methods->pre_request )
            method = access_methods->pre_request;
        break;
        
    case MODE_BSTEP_OBJECT_LOOKUP:
        if( access_methods->object_lookup )
            method = access_methods->object_lookup;
        break;

    case SNMP_MSG_GET:
    case SNMP_MSG_GETNEXT:
        if( access_methods->get_values )
            method = access_methods->get_values;
        break;
        
    case MODE_BSTEP_CHECK_VALUE:
        if( access_methods->object_syntax_checks )
            method = access_methods->object_syntax_checks;
        break;

    case MODE_BSTEP_ROW_CREATE:
        if( access_methods->row_creation )
            method = access_methods->row_creation;
        break;

    case MODE_BSTEP_UNDO_SETUP:
        if( access_methods->undo_setup )
            method = access_methods->undo_setup;
        break;

    case MODE_BSTEP_SET_VALUE:
        if( access_methods->set_values )
            method = access_methods->set_values;
        break;

    case MODE_BSTEP_CHECK_CONSISTENCY:
        if( access_methods->consistency_checks )
            method = access_methods->consistency_checks;
        break;

    case MODE_BSTEP_UNDO_SET:
        if( access_methods->undo_sets )
            method = access_methods->undo_sets;
        break;

    case MODE_BSTEP_COMMIT:
        if( access_methods->commit )
            method = access_methods->commit;
        break;

    case MODE_BSTEP_UNDO_COMMIT:
        if( access_methods->undo_commit )
            method = access_methods->undo_commit;
        break;

    case MODE_BSTEP_IRREVERSIBLE_COMMIT:
        if( access_methods->irreversible_commit )
            method = access_methods->irreversible_commit;
        break;

    case MODE_BSTEP_UNDO_CLEANUP:
        if( access_methods->undo_cleanup )
            method = access_methods->undo_cleanup;
        break;
        
    case MODE_BSTEP_POST_REQUEST:
        if( access_methods->post_request )
            method = access_methods->post_request;
        break;

    default:
        snmp_log(LOG_ERR,"unknown mode %d\n", reqinfo->mode);
        return SNMP_ERR_GENERR;
    }

    /*
     * if method exists, set up handler void and call method.
     */
    if(NULL != method) {
        temp_void = handler->myvoid;
        handler->myvoid = access_methods->my_access_void;
        rc = (*method)(handler, reginfo, reqinfo, requests);
        handler->myvoid = temp_void;
    }
    else {
        rc = SNMP_ERR_GENERR;
        snmp_log(LOG_ERR,"baby steps multiplexer handler called for a mode "
                 "with no handler\n");
        netsnmp_assert(NULL != method);
    }

    /*
     * don't call any lower handlers, it will be done for us 
     * since we set MIB_HANDLER_AUTO_NEXT
     */

    return rc;
}

/*
 * give a baby step mode, return the flag for that mode
 */
int
netsnmp_baby_step_mode2flag( u_int mode )
{
    switch( mode ) {
        case MODE_BSTEP_OBJECT_LOOKUP:
            return BABY_STEP_OBJECT_LOOKUP;
        case MODE_BSTEP_SET_VALUE:
            return BABY_STEP_SET_VALUE;
        case MODE_BSTEP_IRREVERSIBLE_COMMIT:
            return BABY_STEP_IRREVERSIBLE_COMMIT;
        case MODE_BSTEP_CHECK_VALUE:
            return BABY_STEP_CHECK_VALUE;
        case MODE_BSTEP_PRE_REQUEST:
            return BABY_STEP_PRE_REQUEST;
        case MODE_BSTEP_POST_REQUEST:
            return BABY_STEP_POST_REQUEST;
        case MODE_BSTEP_UNDO_SETUP:
            return BABY_STEP_UNDO_SETUP;
        case MODE_BSTEP_UNDO_CLEANUP:
            return BABY_STEP_UNDO_CLEANUP;
        case MODE_BSTEP_UNDO_SET:
            return BABY_STEP_UNDO_SET;
        case MODE_BSTEP_ROW_CREATE:
            return BABY_STEP_ROW_CREATE;
        case MODE_BSTEP_CHECK_CONSISTENCY:
            return BABY_STEP_CHECK_CONSISTENCY;
        case MODE_BSTEP_COMMIT:
            return BABY_STEP_COMMIT;
        case MODE_BSTEP_UNDO_COMMIT:
            return BABY_STEP_UNDO_COMMIT;
        default:
            netsnmp_assert("unknown flag");
            break;
    }
    return 0;
}