net-snmp/agent/helpers/serialize.c

117 lines
3.4 KiB
C

/*
* Portions of this file are subject to the following copyright(s). See
* the Net-SNMP's COPYING file for more details and other copyrights
* that may apply:
*
* Portions of this file are copyrighted by:
* Copyright (c) 2016 VMware, Inc. All rights reserved.
* Use is subject to license terms specified in the COPYING file
* distributed with the Net-SNMP package.
*/
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <net-snmp/agent/serialize.h>
/** @defgroup serialize serialize
* Calls sub handlers one request at a time.
* @ingroup utilities
* This functionally passes in one request at a time
* into lower handlers rather than a whole bunch of requests at once.
* This is useful for handlers that don't want to iterate through the
* request lists themselves. Generally, this is probably less
* efficient so use with caution. The serialize handler might be
* useable to dynamically fix handlers with broken looping code,
* however.
* @{
*/
/** returns a serialize handler that can be injected into a given
* handler chain.
*/
netsnmp_mib_handler *
netsnmp_get_serialize_handler(void)
{
return netsnmp_create_handler("serialize",
netsnmp_serialize_helper_handler);
}
/** functionally the same as calling netsnmp_register_handler() but also
* injects a serialize handler at the same time for you. */
int
netsnmp_register_serialize(netsnmp_handler_registration *reginfo)
{
netsnmp_mib_handler *handler = netsnmp_get_serialize_handler();
if (!handler ||
(netsnmp_inject_handler(reginfo, handler) != SNMPERR_SUCCESS)) {
snmp_log(LOG_ERR, "could not create serialize handler\n");
netsnmp_handler_free(handler);
netsnmp_handler_registration_free(reginfo);
return MIB_REGISTRATION_FAILED;
}
return netsnmp_register_handler(reginfo);
}
/** Implements the serial handler */
int
netsnmp_serialize_helper_handler(netsnmp_mib_handler *handler,
netsnmp_handler_registration *reginfo,
netsnmp_agent_request_info *reqinfo,
netsnmp_request_info *requests)
{
netsnmp_request_info *request, *requesttmp;
DEBUGMSGTL(("helper:serialize", "Got request\n"));
/*
* loop through requests
*/
for (request = requests; request; request = request->next) {
int ret;
/*
* store next pointer and delete it
*/
requesttmp = request->next;
request->next = NULL;
/*
* call the next handler
*/
ret =
netsnmp_call_next_handler(handler, reginfo, reqinfo, request);
/*
* restore original next pointer
*/
request->next = requesttmp;
if (ret != SNMP_ERR_NOERROR)
return ret;
}
return SNMP_ERR_NOERROR;
}
/**
* initializes the serialize helper which then registers a serialize
* handler as a run-time injectable handler for configuration file
* use.
*/
void
netsnmp_init_serialize(void)
{
netsnmp_mib_handler *handler = netsnmp_get_serialize_handler();
if (!handler) {
snmp_log(LOG_ERR, "could not create serialize handler\n");
return;
}
netsnmp_register_handler_by_name("serialize", handler);
}
/** @} */