| /* |
| * DisMan Expression MIB: |
| * Implementation of the expValueTable MIB interface |
| * See 'expValue.c' for active evaluation of expressions. |
| * |
| * (Based roughly on mib2c.raw-table.conf output) |
| */ |
| |
| #include <net-snmp/net-snmp-config.h> |
| #include <net-snmp/net-snmp-includes.h> |
| #include <net-snmp/agent/net-snmp-agent-includes.h> |
| #include "expValue.h" |
| #include "expValueTable.h" |
| |
| /** Initializes the expValueTable module */ |
| void |
| init_expValueTable(void) |
| { |
| static oid expValueTable_oid[] = { 1, 3, 6, 1, 2, 1, 90, 1, 3, 1 }; |
| size_t expValueTable_oid_len = OID_LENGTH(expValueTable_oid); |
| netsnmp_handler_registration *reg; |
| netsnmp_table_registration_info *table_info; |
| |
| reg = |
| netsnmp_create_handler_registration("expValueTable", |
| expValueTable_handler, |
| expValueTable_oid, |
| expValueTable_oid_len, |
| HANDLER_CAN_RONLY); |
| |
| table_info = SNMP_MALLOC_TYPEDEF(netsnmp_table_registration_info); |
| netsnmp_table_helper_add_indexes(table_info, |
| ASN_OCTET_STR, /* expExpressionOwner */ |
| ASN_OCTET_STR, /* expExpressionName */ |
| /* expValueInstance */ |
| ASN_PRIV_IMPLIED_OBJECT_ID, |
| 0); |
| |
| table_info->min_column = COLUMN_EXPVALUECOUNTER32VAL; |
| table_info->max_column = COLUMN_EXPVALUECOUNTER64VAL; |
| |
| netsnmp_register_table(reg, table_info); |
| DEBUGMSGTL(("disman:expr:init", "Expression Value Table\n")); |
| } |
| |
| |
| netsnmp_variable_list * |
| expValueTable_getEntry(netsnmp_variable_list * indexes, |
| int mode, unsigned int colnum) |
| { |
| struct expExpression *exp; |
| netsnmp_variable_list *res, *vp, *vp2; |
| oid nullInstance[] = {0, 0, 0}; |
| int plen; |
| size_t len; |
| unsigned int type = colnum-1; /* column object subIDs and type |
| enumerations are off by one. */ |
| |
| if (!indexes || !indexes->next_variable || |
| !indexes->next_variable->next_variable ) { |
| /* XXX - Shouldn't happen! */ |
| return NULL; |
| } |
| |
| DEBUGMSGTL(( "disman:expr:val", "get (%d) entry (%s, %s, ", mode, |
| indexes->val.string, indexes->next_variable->val.string)); |
| DEBUGMSGOID(("disman:expr:val", |
| indexes->next_variable->next_variable->val.objid, |
| indexes->next_variable->next_variable->val_len/sizeof(oid))); |
| DEBUGMSG(( "disman:expr:val", ")\n")); |
| |
| /* |
| * Locate the expression that we've been asked to evaluate |
| */ |
| if (!indexes->val_len || !indexes->next_variable->val_len ) { |
| /* |
| * Incomplete expression specification |
| */ |
| if (mode == MODE_GETNEXT || mode == MODE_GETBULK) { |
| exp = expExpression_getFirstEntry(); |
| DEBUGMSGTL(( "disman:expr:val", "first entry (%p)\n", exp )); |
| } else { |
| DEBUGMSGTL(( "disman:expr:val", "incomplete request\n" )); |
| return NULL; /* No match */ |
| } |
| } else { |
| exp = expExpression_getEntry( (char*)indexes->val.string, |
| (char*)indexes->next_variable->val.string); |
| DEBUGMSGTL(( "disman:expr:val", "using entry (%p)\n", exp )); |
| } |
| |
| /* |
| * We know what type of value was requested, |
| * so ignore any non-matching expressions. |
| */ |
| while (exp && exp->expValueType != type) { |
| if (mode != MODE_GETNEXT && mode != MODE_GETBULK) { |
| DEBUGMSGTL(( "disman:expr:val", "wrong type (%d != %ld)\n", |
| type, (exp ? exp->expValueType : 0 ))); |
| return NULL; /* Wrong type */ |
| } |
| NEXT_EXP: |
| exp = expExpression_getNextEntry( exp->expOwner, exp->expName ); |
| DEBUGMSGTL(( "disman:expr:val", "using next entry (%p)\n", exp )); |
| } |
| if (!exp) { |
| DEBUGMSGTL(( "disman:expr:val", "no more entries\n")); |
| return NULL; /* No match (of the required type) */ |
| } |
| |
| |
| /* |
| * Now consider which instance of the chosen expression is needed |
| */ |
| vp = indexes->next_variable->next_variable; |
| if ( mode == MODE_GET ) { |
| /* |
| * For a GET request, check that the specified value instance |
| * is valid, and evaluate the expression using this. |
| */ |
| if ( !vp || !vp->val_len ) { |
| DEBUGMSGTL(( "disman:expr:val", "no instance index\n")); |
| return NULL; /* No instance provided */ |
| } |
| if ( vp->val.objid[0] != 0 ) { |
| DEBUGMSGTL(( "disman:expr:val", |
| "non-zero instance (%" NETSNMP_PRIo "d)\n", vp->val.objid[0])); |
| return NULL; /* Invalid instance */ |
| } |
| |
| if (exp->expPrefix_len == 0 ) { |
| /* |
| * The only valid instance for a non-wildcarded |
| * expression is .0.0.0 |
| */ |
| if ( vp->val_len != 3*sizeof(oid) || |
| vp->val.objid[1] != 0 || |
| vp->val.objid[2] != 0 ) { |
| DEBUGMSGTL(( "disman:expr:val", "invalid scalar instance\n")); |
| return NULL; |
| } |
| res = expValue_evaluateExpression( exp, NULL, 0 ); |
| DEBUGMSGTL(( "disman:expr:val", "scalar get returned (%p)\n", res)); |
| } else { |
| /* |
| * Otherwise, skip the leading '.0' and use |
| * the remaining instance subidentifiers. |
| */ |
| res = expValue_evaluateExpression( exp, vp->val.objid+1, |
| vp->val_len/sizeof(oid)-1); |
| DEBUGMSGTL(( "disman:expr:val", "w/card get returned (%p)\n", res)); |
| } |
| } else { |
| /* |
| * For a GETNEXT request, identify the appropriate next |
| * value instance, and evaluate the expression using |
| * that, updating the index list appropriately. |
| */ |
| if ( vp->val_len > 0 && vp->val.objid[0] != 0 ) { |
| DEBUGMSGTL(( "disman:expr:val", |
| "non-zero next instance (%" NETSNMP_PRIo "d)\n", vp->val.objid[0])); |
| return NULL; /* All valid instances start with .0 */ |
| } |
| plen = exp->expPrefix_len; |
| if (plen == 0 ) { |
| /* |
| * The only valid instances for GETNEXT on a |
| * non-wildcarded expression are .0 and .0.0 |
| * Anything else is too late. |
| */ |
| if ((vp->val_len > 2*sizeof(oid)) || |
| (vp->val_len == 2*sizeof(oid) && |
| vp->val.objid[1] != 0)) { |
| DEBUGMSGTL(( "disman:expr:val", "invalid scalar next instance\n")); |
| return NULL; /* Invalid instance */ |
| } |
| |
| /* |
| * Make sure the index varbind list refers to the |
| * (only) valid instance of this expression, |
| * and evaluate it. |
| */ |
| snmp_set_var_typed_value( indexes, ASN_OCTET_STR, |
| (u_char*)exp->expOwner, strlen(exp->expOwner)); |
| snmp_set_var_typed_value( indexes->next_variable, ASN_OCTET_STR, |
| (u_char*)exp->expName, strlen(exp->expName)); |
| snmp_set_var_typed_value( vp, ASN_PRIV_IMPLIED_OBJECT_ID, |
| (u_char*)nullInstance, 3*sizeof(oid)); |
| res = expValue_evaluateExpression( exp, NULL, 0 ); |
| DEBUGMSGTL(( "disman:expr:val", "scalar next returned (%p)\n", res)); |
| } else { |
| /* |
| * Now comes the interesting case - finding the |
| * appropriate instance of a wildcarded expression. |
| */ |
| if ( vp->val_len == 0 ) { |
| if ( !exp->pvars ) { |
| DEBUGMSGTL(( "disman:expr:val", "no instances\n")); |
| goto NEXT_EXP; |
| } |
| DEBUGMSGTL(( "disman:expr:val", "using first instance\n")); |
| vp2 = exp->pvars; |
| } else { |
| /* |
| * Search the list of instances for the (first) greater one |
| * XXX - This comparison relies on the OID of the prefix |
| * object being the same length as the wildcarded |
| * parameter objects. It ain't necessarily so. |
| */ |
| for ( vp2 = exp->pvars; vp2; vp2 = vp2->next_variable ) { |
| if ( snmp_oid_compare( vp2->name + plen, |
| vp2->name_length - plen, |
| vp->name, |
| vp->name_length) < 0 ) { |
| DEBUGMSGTL(( "disman:expr:val", "next instance ")); |
| DEBUGMSGOID(("disman:expr:val", vp2->name, vp2->name_length )); |
| DEBUGMSG(( "disman:expr:val", "\n")); |
| break; |
| } |
| } |
| if (!vp2) { |
| DEBUGMSGTL(( "disman:expr:val", "no next instance\n")); |
| goto NEXT_EXP; |
| } |
| } |
| snmp_set_var_typed_value( indexes, ASN_OCTET_STR, |
| (u_char*)exp->expOwner, strlen(exp->expOwner)); |
| snmp_set_var_typed_value( indexes->next_variable, ASN_OCTET_STR, |
| (u_char*)exp->expName, strlen(exp->expName)); |
| if (vp2) { |
| len = vp2->name_length - exp->expPrefix_len; |
| snmp_set_var_typed_value( vp, ASN_PRIV_IMPLIED_OBJECT_ID, |
| (u_char*)(vp2->name+exp->expPrefix_len), len); |
| } else { |
| len = 1; |
| } |
| res = expValue_evaluateExpression( exp, vp->val.objid+1, len-1); |
| DEBUGMSGTL(( "disman:expr:val", "w/card next returned (%p)\n", res)); |
| } |
| } |
| return res; |
| } |
| |
| /** handles requests for the expValueTable table */ |
| int |
| expValueTable_handler(netsnmp_mib_handler *handler, |
| netsnmp_handler_registration *reginfo, |
| netsnmp_agent_request_info *reqinfo, |
| netsnmp_request_info *requests) |
| { |
| |
| netsnmp_request_info *request; |
| netsnmp_table_request_info *tinfo; |
| netsnmp_variable_list *value; |
| oid expValueOID[] = { 1, 3, 6, 1, 2, 1, 90, 1, 3, 1, 1, 99 }; |
| size_t expValueOID_len = OID_LENGTH(expValueOID); |
| oid name_buf[ MAX_OID_LEN ]; |
| size_t name_buf_len = MAX_OID_LEN; |
| |
| DEBUGMSGTL(("disman:expr:mib", "Expression Value Table handler (%d)\n", |
| reqinfo->mode)); |
| switch (reqinfo->mode) { |
| case MODE_GET: |
| case MODE_GETNEXT: |
| for (request = requests; request; request = request->next) { |
| tinfo = netsnmp_extract_table_info(request); |
| value = expValueTable_getEntry(tinfo->indexes, |
| reqinfo->mode, |
| tinfo->colnum); |
| if (!value || !value->val.integer) { |
| netsnmp_set_request_error(reqinfo, request, |
| (reqinfo->mode == MODE_GET) ? |
| SNMP_NOSUCHINSTANCE : |
| SNMP_ENDOFMIBVIEW); |
| continue; |
| } |
| if ( reqinfo->mode == MODE_GETNEXT ) { |
| /* |
| * Need to update the request varbind OID |
| * to match the instance just evaluated. |
| * (XXX - Is this the appropriate mechanism?) |
| */ |
| build_oid_noalloc( name_buf, MAX_OID_LEN, &name_buf_len, |
| expValueOID, expValueOID_len, tinfo->indexes ); |
| name_buf[ expValueOID_len -1 ] = tinfo->colnum; |
| snmp_set_var_objid(request->requestvb, name_buf, name_buf_len); |
| } |
| |
| switch (tinfo->colnum) { |
| case COLUMN_EXPVALUECOUNTER32VAL: |
| snmp_set_var_typed_integer(request->requestvb, ASN_COUNTER, |
| *value->val.integer); |
| break; |
| case COLUMN_EXPVALUEUNSIGNED32VAL: |
| snmp_set_var_typed_integer(request->requestvb, ASN_UNSIGNED, |
| *value->val.integer); |
| break; |
| case COLUMN_EXPVALUETIMETICKSVAL: |
| snmp_set_var_typed_integer(request->requestvb, ASN_TIMETICKS, |
| *value->val.integer); |
| break; |
| case COLUMN_EXPVALUEINTEGER32VAL: |
| snmp_set_var_typed_integer(request->requestvb, ASN_INTEGER, |
| *value->val.integer); |
| break; |
| case COLUMN_EXPVALUEIPADDRESSVAL: |
| snmp_set_var_typed_integer(request->requestvb, ASN_IPADDRESS, |
| *value->val.integer); |
| break; |
| case COLUMN_EXPVALUEOCTETSTRINGVAL: |
| snmp_set_var_typed_value( request->requestvb, ASN_OCTET_STR, |
| value->val.string, value->val_len); |
| break; |
| case COLUMN_EXPVALUEOIDVAL: |
| snmp_set_var_typed_value( request->requestvb, ASN_OBJECT_ID, |
| (u_char *)value->val.objid, value->val_len); |
| break; |
| case COLUMN_EXPVALUECOUNTER64VAL: |
| snmp_set_var_typed_value( request->requestvb, ASN_COUNTER64, |
| (u_char *)value->val.counter64, value->val_len); |
| break; |
| } |
| } |
| break; |
| |
| } |
| DEBUGMSGTL(("disman:expr:mib", "Expression Value handler - done \n")); |
| return SNMP_ERR_NOERROR; |
| } |
