--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/components/net-snmp/sun/sdk/demo/demo_module_9/demo_module_9.c Fri May 20 12:17:45 2011 +0530
@@ -0,0 +1,301 @@
+/*
+ * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ *
+ * U.S. Government Rights - Commercial software. Government users are subject
+ * to the Sun Microsystems, Inc. standard license agreement and applicable
+ * provisions of the FAR and its supplements.
+ *
+ *
+ * This distribution may include materials developed by third parties. Sun,
+ * Sun Microsystems, the Sun logo and Solaris are trademarks or registered
+ * trademarks of Sun Microsystems, Inc. in the U.S. and other countries.
+ *
+ */
+
+/* @example demo_module_9.c
+ *
+ *
+ * This example demonstrates how to implement objects that normally would
+ * block the agent as it waits for external events in such a way that the
+ * agent can continue responding to other requests while this implementation waits.
+ *
+ * This example uses the following features of SMA:
+ *
+ * - Use of the instance helper, which registers an exact OID such that GENEXT requests
+ * are handled entirely by the helper.
+ *
+ * - Setting the delegated member of the requests structure to 1 to indicate to the
+ * agent that this request should be delayed. The agent queues this request
+ * to be handled later and then is available to handle other requests. The
+ * agent is not blocked by this request.
+ *
+ * - Registering an SNMP alarm to update the results at a later time.
+ *
+ */
+
+#include <net-snmp/net-snmp-config.h>
+#include <net-snmp/net-snmp-includes.h>
+#include <net-snmp/agent/net-snmp-agent-includes.h>
+#include "demo_module_9.h"
+
+// default delay time for SNMP alarm
+static u_long delay_time = 1;
+
+void
+init_demo_module_9(void)
+{
+ static oid my_delayed_oid[] =
+ { 1, 3, 6, 1, 4, 1,42, 2, 2, 4, 4, 9, 1, 1, 0 };
+
+ /*
+ * Creates a registration handler, my_test, and passes
+ * the pointer it returns to the netsnmp_register_instance
+ * helper function.
+ */
+ netsnmp_handler_registration *my_test;
+ DEBUGMSGTL(("demo_module_9", "Initializing\n"));
+ my_test =
+ netsnmp_create_handler_registration("delayed_instance_example",
+ delayed_instance_handler,
+ my_delayed_oid,
+ OID_LENGTH(my_delayed_oid),
+ HANDLER_CAN_RWRITE);
+
+ netsnmp_register_instance(my_test);
+}
+
+#define DELAYED_INSTANCE_SET_NAME "test_delayed"
+
+int
+delayed_instance_handler(netsnmp_mib_handler *handler,
+ netsnmp_handler_registration *reginfo,
+ netsnmp_agent_request_info *reqinfo,
+ netsnmp_request_info *requests)
+{
+ /*
+ This handler is called to handle SNMP GET and SNMP SET
+ requests for the my_delayed_oid object. If it is called to
+ handle SNMP GET requests, the handler does not need to
+ handle a GETNEXT if it is registered as an instance handler.
+ Instance handlers only deliver one request at a time, so we
+ do not need to loop over a list of requests. */
+
+ DEBUGMSGTL(("demo_module_9", "Handler got request, mode = %d:\n",
+ reqinfo->mode));
+
+ switch (reqinfo->mode) {
+ /*
+ * here we merely mention that we'll answer this request
+ * later. we don't actually care about the mode type in this
+ * example, but for certain cases you may, so I'll leave in the
+ * otherwise useless switch and case statements
+ */
+
+ default:
+ /*
+ * Mark this variable as something that cannot be handled now
+ * by setting the delegated member of the requests structure
+ * to 1. The agent queues the request to be handled at a later
+ * time and continues responding to other client requests.
+ *
+ */
+ requests->delegated = 1;
+ DEBUGMSGTL(("demo_module_9", "Delegated is %d\n",
+ requests->delegated));
+
+ /*
+ * Register an alarm to update the results at a later
+ * time. Normally, we might have to query something else
+ * (like an external request sent to a different network
+ * or system socket, etc), but for this example we'll do
+ * something really simply and just insert an alarm for a
+ * certain period of time.
+ */
+ DEBUGMSGTL(("demo_module_9", "Delay is %d\n",
+ delay_time));
+ snmp_alarm_register(delay_time, /* seconds */
+ 0, /* dont repeat. */
+ return_delayed_response, /* the function
+ * to call */
+ /*
+ * Create a "cache" of useful
+ * information that can be retrieved
+ * at a later time. This argument is
+ * passed back to the module in the callback
+ * function for an alarm.
+ */
+ (void *)
+ netsnmp_create_delegated_cache(handler,
+ reginfo,
+ reqinfo,
+ requests,
+ NULL));
+ break;
+
+ }
+
+ return SNMP_ERR_NOERROR;
+}
+
+void
+return_delayed_response(unsigned int clientreg, void *clientarg)
+{
+ /*
+ * Extract the cache from the passed argument.
+ */
+ netsnmp_delegated_cache *cache = (netsnmp_delegated_cache *) clientarg;
+
+ netsnmp_request_info *requests;
+ netsnmp_agent_request_info *reqinfo;
+ u_long *delay_time_cache = NULL;
+
+ /*
+ * Make sure the cache created earlier is still
+ * valid. If not, the request timed out for some reason and we
+ * do not need to keep processing things. Should never happen, but
+ * this double checks.
+ */
+ cache = netsnmp_handler_check_cache(cache);
+
+ if (!cache) {
+ snmp_log(LOG_ERR, "illegal call to return delayed response\n");
+ return;
+ }
+
+ /*
+ * Re-establish the previous pointers,
+ */
+ reqinfo = cache->reqinfo;
+ requests = cache->requests;
+
+ DEBUGMSGTL(("demo_module_9",
+ "continuing delayed request, mode = %d\n",
+ cache->reqinfo->mode));
+
+
+ /*
+ * Set delegated to zero to indicate that the request is no longer
+ * delegated and answer the query.
+ */
+ requests->delegated = 0;
+
+ DEBUGMSGTL(("demo_module_9", "Set delegated to %d\n",
+ requests->delegated));
+
+
+ switch (cache->reqinfo->mode) {
+ /*
+ * Registering as an instance means we do not need to deal with
+ * GETNEXT processing, so we do not handle it here at all.
+ *
+ * However, since the instance handler already reset the mode
+ * back to GETNEXT from the GET mode, we need to do the
+ * same thing in both cases.
+ *
+ */
+
+ case MODE_GET:
+ case MODE_GETNEXT:
+ /*
+ * Return the current delay time
+ */
+ DEBUGMSGTL(("demo_module_9", "Got to MODE_GETNEXT\n"));
+
+ snmp_set_var_typed_value(cache->requests->requestvb,
+ ASN_INTEGER,
+ (u_char *) & delay_time,
+ sizeof(delay_time));
+ DEBUGMSGTL(("demo_module_9",
+ "Got delay time = %d\n",
+ delay_time));
+ break;
+
+ case MODE_SET_RESERVE1:
+ DEBUGMSGTL(("demo_module_9", "Got to MODE_SET_RESERVE1\n"));
+
+ /*
+ * check type
+ */
+ if (requests->requestvb->type != ASN_INTEGER) {
+ /*
+ * If not an integer, return SNMP error.
+ */
+ netsnmp_set_request_error(reqinfo, requests,
+ SNMP_ERR_WRONGTYPE);
+ /*
+ * Free cache. It is no longer needed.
+ */
+ netsnmp_free_delegated_cache(cache);
+ return;
+ }
+ break;
+
+ case MODE_SET_RESERVE2:
+ DEBUGMSGTL(("demo_module_9", "Got to MODE_SET_RESERVE2\n"));
+ /*
+ * Store old value for UNDO support in the future.
+ */
+ memdup((u_char **) & delay_time_cache,
+ (u_char *) & delay_time, sizeof(delay_time));
+
+ /*
+ * malloc failed
+ */
+ if (delay_time_cache == NULL) {
+ netsnmp_set_request_error(reqinfo, requests,
+ SNMP_ERR_RESOURCEUNAVAILABLE);
+ netsnmp_free_delegated_cache(cache);
+ return;
+ }
+
+ /*
+ * Add our temporary information to the request itself.
+ * This is then retrivable later. The free function
+ * passed auto-frees it when the request is later
+ * deleted.
+ */
+ netsnmp_request_add_list_data(requests,
+ netsnmp_create_data_list
+ (DELAYED_INSTANCE_SET_NAME,
+ delay_time_cache, free));
+ break;
+
+ case MODE_SET_ACTION:
+ DEBUGMSGTL(("demo_module_9", "Got to MODE_SET_ACTION\n"));
+ /*
+ * Update current value.
+ */
+ delay_time = *(requests->requestvb->val.integer);
+ DEBUGMSGTL(("demo_module_9", "updated delay_time -> %d\n",
+ delay_time));
+ break;
+
+ case MODE_SET_UNDO:
+ DEBUGMSGTL(("demo_module_9", "Got to MODE_SET_UNDO\n"));
+
+ /*
+ * A failure occurred. Reset to the
+ * previously value by extracting the previosuly
+ * stored information from the request.
+ */
+ delay_time =
+ *((u_long *) netsnmp_request_get_list_data(requests,
+ DELAYED_INSTANCE_SET_NAME));
+ break;
+
+ case MODE_SET_COMMIT:
+ case MODE_SET_FREE:
+ DEBUGMSGTL(("demo_module_9", "Got to MODE_SET_UNDO\n"));
+ /*
+ * The only thing to do here is free the old memdup'ed
+ * value, but it's auto-freed by the datalist recovery, so
+ * we don't have anything to actually do here
+ */
+ break;
+ }
+
+ /*
+ * free the information cache
+ */
+ netsnmp_free_delegated_cache(cache);
+}