stash_to_next.c

00001 #include <net-snmp/net-snmp-config.h>
00002 
00003 #include <net-snmp/net-snmp-includes.h>
00004 #include <net-snmp/agent/net-snmp-agent-includes.h>
00005 
00006 #include <net-snmp/agent/stash_to_next.h>
00007 
00008 #include <net-snmp/agent/stash_cache.h>
00009 
00022 netsnmp_mib_handler *
00023 netsnmp_get_stash_to_next_handler(void)
00024 {
00025     netsnmp_mib_handler *handler =
00026         netsnmp_create_handler("stash_to_next",
00027                                netsnmp_stash_to_next_helper);
00028 
00029     if (NULL != handler)
00030         handler->flags |= MIB_HANDLER_AUTO_NEXT;
00031 
00032     return handler;
00033 }
00034 
00036 int
00037 netsnmp_stash_to_next_helper(netsnmp_mib_handler *handler,
00038                             netsnmp_handler_registration *reginfo,
00039                             netsnmp_agent_request_info *reqinfo,
00040                             netsnmp_request_info *requests)
00041 {
00042 
00043     int             ret = SNMP_ERR_NOERROR;
00044     int             namelen;
00045     int             finished = 0;
00046     netsnmp_oid_stash_node **cinfo;
00047     netsnmp_variable_list   *vb;
00048     netsnmp_request_info    *reqtmp;
00049 
00050     /*
00051      * this code depends on AUTO_NEXT being set
00052      */
00053     netsnmp_assert(handler->flags & MIB_HANDLER_AUTO_NEXT);
00054 
00055     /*
00056      * Don't do anything for any modes except GET_STASH. Just return,
00057      * and the agent will call the next handler (AUTO_NEXT).
00058      *
00059      * If the handler chain already supports GET_STASH, we don't
00060      * need to do anything here either.  Once again, we just return
00061      * and the agent will call the next handler (AUTO_NEXT).
00062      *
00063      * Otherwise, we munge the mode to GET_NEXT, and call the
00064      * next handler ourselves, repeatedly until we've retrieved the
00065      * full contents of the table or subtree.
00066      *   Then restore the mode and return to the calling handler 
00067      * (setting AUTO_NEXT_OVERRRIDE so the agent knows what we did).
00068      */
00069     if (MODE_GET_STASH == reqinfo->mode) {
00070         if ( reginfo->modes & HANDLER_CAN_STASH ) {
00071             return ret;
00072         }
00073         cinfo  = netsnmp_extract_stash_cache( reqinfo );
00074         reqtmp = SNMP_MALLOC_TYPEDEF(netsnmp_request_info);
00075         vb = reqtmp->requestvb = SNMP_MALLOC_TYPEDEF( netsnmp_variable_list );
00076         vb->type = ASN_NULL;
00077         snmp_set_var_objid( vb, reginfo->rootoid, reginfo->rootoid_len );
00078 
00079         reqinfo->mode = MODE_GETNEXT;
00080         while (!finished) {
00081             ret = netsnmp_call_next_handler(handler, reginfo, reqinfo, reqtmp);
00082             namelen = SNMP_MIN(vb->name_length, reginfo->rootoid_len);
00083             if ( !snmp_oid_compare( reginfo->rootoid, reginfo->rootoid_len,
00084                                    vb->name, namelen) &&
00085                  vb->type != ASN_NULL && vb->type != SNMP_ENDOFMIBVIEW ) {
00086                 /*
00087                  * This result is relevant so save it, and prepare
00088                  * the request varbind for the next query.
00089                  */
00090                 netsnmp_oid_stash_add_data( cinfo, vb->name, vb->name_length,
00091                                             snmp_clone_varbind( vb ));
00092                     /*
00093                      * Tidy up the response structure,
00094                      *  ready for retrieving the next entry
00095                      */
00096                 netsnmp_free_all_list_data(reqtmp->parent_data);
00097                 reqtmp->parent_data = NULL;
00098                 reqtmp->processed = 0;
00099                 vb->type = ASN_NULL;
00100             } else {
00101                 finished = 1;
00102             }
00103         }
00104         reqinfo->mode = MODE_GET_STASH;
00105 
00106         /*
00107          * let the handler chain processing know that we've already
00108          * called the next handler
00109          */
00110         handler->flags |= MIB_HANDLER_AUTO_NEXT_OVERRIDE_ONCE;
00111     }
00112 
00113     return ret;
00114 }