diff options
| -rw-r--r-- | Makefile.am | 2 | ||||
| -rw-r--r-- | rsyslog.h | 1 | ||||
| -rw-r--r-- | vm.c | 221 | ||||
| -rw-r--r-- | vm.h | 59 | ||||
| -rw-r--r-- | vmop.h | 3 |
5 files changed, 285 insertions, 1 deletions
diff --git a/Makefile.am b/Makefile.am index bbccb8a5..179c53f0 100644 --- a/Makefile.am +++ b/Makefile.am @@ -5,6 +5,8 @@ rfc3195d_SOURCES = rfc3195d.c rsyslog.h rsyslogd_SOURCES = \ syslogd.c \ syslogd.h \ + vm.c \ + vm.h \ vmstk.c \ vmstk.h \ vmprg.c \ @@ -130,6 +130,7 @@ enum rsRetVal_ /** return value. All methods return this if not specified oth RS_RET_INTERFACE_NOT_SUPPORTED = -2054, /**< interface not supported */ RS_RET_OUT_OF_STACKSPACE = -2055, /**< a stack data structure is exhausted and can not be grown */ RS_RET_STACK_EMPTY = -2056, /**< a pop was requested on a stack, but the stack was already empty */ + RS_RET_INVALID_VMOP = -2057, /**< invalid virtual machine instruction */ RS_RET_OK_DELETE_LISTENTRY = 1, /**< operation successful, but callee requested the deletion of an entry (special state) */ RS_RET_TERMINATE_NOW = 2, /**< operation successful, function is requested to terminate (mostly used with threads) */ RS_RET_NO_RUN = 3, /**< operation successful, but function does not like to be executed */ @@ -0,0 +1,221 @@ +/* vm.c - the arithmetic stack of a virtual machine. + * + * Module begun 2008-02-22 by Rainer Gerhards + * + * Copyright 2008 Rainer Gerhards and Adiscon GmbH. + * + * This file is part of rsyslog. + * + * Rsyslog is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * Rsyslog is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with Rsyslog. If not, see <http://www.gnu.org/licenses/>. + * + * A copy of the GPL can be found in the file "COPYING" in this distribution. + */ + +#include "config.h" +#include <stdlib.h> +#include <assert.h> + +#include "rsyslog.h" +#include "obj.h" +#include "vm.h" + +/* static data */ +DEFobjStaticHelpers +DEFobjCurrIf(vmstk) + + +/* ------------------------------ instruction set implementation ------------------------------ * + * The following functions implement the VM's instruction set. + */ +#define BEGINop(instruction) \ + static rsRetVal op##instruction(vm_t *pThis, vmop_t *pOp) \ + { \ + DEFiRet; + +#define CODESTARTop(instruction) \ + ISOBJ_TYPE_assert(pThis, vm); \ + ISOBJ_TYPE_assert(pOp, vmop); + +#define ENDop(instruction) \ + RETiRet; \ + } + +BEGINop(OR) /* remember to set the instruction also in the ENDop macro! */ + // var_t *pVar[2]; + var_t *operand1; + var_t *operand2; +CODESTARTop(OR) + // Pop(2, &pVar); --> should also do the conversion outlined below + vmstk.Pop(pThis->pStk, &operand1); + vmstk.Pop(pThis->pStk, &operand2); + // TODO: implement + /* We must check data types and find out on which data type the + * operation needs to be performed. This may result in some data types + * being converted. + * + * Current school of thought: + * op1 op2 operation data type + * string string string + * string number number if op1 can be converted to number, string else + * date string date if op1 can be converted to date, string else + * number number number + * date number string (maybe we can do better?) + * date date date + * + * If a boolean value is required, we need to have a number inside the + * operand. If it is not, conversion rules to number apply. Once we + * have a number, things get easy: 0 is false, anything else is true. + * Please note that due to this conversion rules, "0" becomes false + * while "-4712" becomes true. Using a date as boolen is not a good + * idea. Depending on the ultimate conversion rules, it may always + * become true or false. As such, using dates as booleans is + * prohibited and the result defined to be undefined. + */ + vmstk.Push(pThis->pStk, operand1); /* result */ +ENDop(OR) + +BEGINop(AND) /* remember to set the instruction also in the ENDop macro! */ + var_t *operand1; + var_t *operand2; +CODESTARTop(AND) + vmstk.Pop(pThis->pStk, &operand1); + vmstk.Pop(pThis->pStk, &operand2); + // TODO: implement + vmstk.Push(pThis->pStk, operand1); /* result */ +ENDop(AND) + +BEGINop(POP) /* remember to set the instruction also in the ENDop macro! */ +CODESTARTop(POP) +/* TODO: implement */ +ENDop(POP) + +BEGINop(PUSHCONSTANT) /* remember to set the instruction also in the ENDop macro! */ +CODESTARTop(PUSHCONSTANT) + vmstk.Push(pThis->pStk, pOp->operand.pVar); +ENDop(PUSHCONSTANT) + + +/* ------------------------------ end instruction set implementation ------------------------------ */ + + +/* Standard-Constructor + */ +BEGINobjConstruct(vm) /* be sure to specify the object type also in END macro! */ +ENDobjConstruct(vm) + + +/* ConstructionFinalizer + * rgerhards, 2008-01-09 + */ +static rsRetVal +vmConstructFinalize(vm_t __attribute__((unused)) *pThis) +{ + DEFiRet; + ISOBJ_TYPE_assert(pThis, vm); + RETiRet; +} + + +/* destructor for the vm object */ +BEGINobjDestruct(vm) /* be sure to specify the object type also in END and CODESTART macros! */ +CODESTARTobjDestruct(vm) +ENDobjDestruct(vm) + + +/* debugprint for the vm object */ +BEGINobjDebugPrint(vm) /* be sure to specify the object type also in END and CODESTART macros! */ +CODESTARTobjDebugPrint(vm) + dbgoprint((obj_t*) pThis, "rsyslog virtual machine, currently no state info available\n"); +ENDobjDebugPrint(vm) + + +/* execute a program + */ +static rsRetVal +execProg(vm_t *pThis, vmprg_t *pProg) +{ + DEFiRet; + vmop_t *pCurrOp; /* virtual instruction pointer */ + + ISOBJ_TYPE_assert(pThis, vm); + ISOBJ_TYPE_assert(pProg, vmprg); + +#define doOP(OP) case opcode_##OP: CHKiRet(op##OP(pThis, pCurrOp)); break + pCurrOp = pProg->vmopRoot; /* TODO: do this via a method! */ + while(pCurrOp != NULL && pCurrOp->opcode != opcode_END_PROG) { + switch(pCurrOp->opcode) { + doOP(OR); + doOP(AND); + doOP(POP); + doOP(PUSHCONSTANT); + default: + ABORT_FINALIZE(RS_RET_INVALID_VMOP); + dbgoprint((obj_t*) pThis, "invalid instruction %d in vmprg\n", pCurrOp->opcode); + break; + } + /* so far, we have plain sequential execution, so on to next... */ + pCurrOp = pCurrOp->pNext; + } +#undef doOP + + /* if we reach this point, our program has intintionally terminated + * (no error state). + */ + +finalize_it: + RETiRet; +} + + + +/* queryInterface function + * rgerhards, 2008-02-21 + */ +BEGINobjQueryInterface(vm) +CODESTARTobjQueryInterface(vm) + if(pIf->ifVersion != vmCURR_IF_VERSION) { /* check for current version, increment on each change */ + ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED); + } + + /* ok, we have the right interface, so let's fill it + * Please note that we may also do some backwards-compatibility + * work here (if we can support an older interface version - that, + * of course, also affects the "if" above). + */ + pIf->oID = OBJvm; + + pIf->Construct = vmConstruct; + pIf->ConstructFinalize = vmConstructFinalize; + pIf->Destruct = vmDestruct; + pIf->DebugPrint = vmDebugPrint; + pIf->ExecProg = execProg; +finalize_it: +ENDobjQueryInterface(vm) + + +/* Initialize the vm class. Must be called as the very first method + * before anything else is called inside this class. + * rgerhards, 2008-02-19 + */ +BEGINObjClassInit(vm, 1) /* class, version */ + /* request objects we use */ + CHKiRet(objUse(vmstk)); + + /* set our own handlers */ + OBJSetMethodHandler(objMethod_DEBUGPRINT, vmDebugPrint); + OBJSetMethodHandler(objMethod_CONSTRUCTION_FINALIZER, vmConstructFinalize); +ENDObjClassInit(vm) + +/* vi:set ai: + */ @@ -0,0 +1,59 @@ +/* The vm object. + * + * This implements the rsyslog virtual machine. The initial implementation is + * done to support complex user-defined expressions, but it may evolve into a + * much more useful thing over time. + * + * The virtual machine uses rsyslog variables as its memory storage system. + * All computation is done on a stack (vmstk). The vm supports a given + * instruction set and executes programs of type vmprg, which consist of + * single operations defined in vmop (which hold the instruction and the + * data). + * + * Copyright 2008 Rainer Gerhards and Adiscon GmbH. + * + * This file is part of rsyslog. + * + * Rsyslog is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * Rsyslog is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with Rsyslog. If not, see <http://www.gnu.org/licenses/>. + * + * A copy of the GPL can be found in the file "COPYING" in this distribution. + */ +#ifndef INCLUDED_VM_H +#define INCLUDED_VM_H + +#include "vmstk.h" +#include "vmprg.h" + +/* the vm object */ +typedef struct vm_s { + BEGINobjInstance; /* Data to implement generic object - MUST be the first data element! */ + vmstk_t *pStk; /* The stack */ +} vm_t; + + +/* interfaces */ +BEGINinterface(vm) /* name must also be changed in ENDinterface macro! */ + INTERFACEObjDebugPrint(vm); + rsRetVal (*Construct)(vm_t **ppThis); + rsRetVal (*ConstructFinalize)(vm_t __attribute__((unused)) *pThis); + rsRetVal (*Destruct)(vm_t **ppThis); + rsRetVal (*ExecProg)(vm_t *pThis, vmprg_t *pProg); +ENDinterface(vm) +#define vmCURR_IF_VERSION 1 /* increment whenever you change the interface structure! */ + + +/* prototypes */ +PROTOTYPEObj(vm); + +#endif /* #ifndef INCLUDED_VM_H */ @@ -51,7 +51,8 @@ typedef enum { /* do NOT start at 0 to detect uninitialized types after calloc( opcode_PUSHSYSVAR = 1001, /* requires var operand */ opcode_PUSHMSGVAR = 1002, /* requires var operand */ opcode_PUSHCONSTANT = 1003, /* requires var operand */ - opcode_UNARY_MINUS = 1010 + opcode_UNARY_MINUS = 1010, + opcode_END_PROG = 1011 } opcode_t; |