plugins/omstdout/omstdout.c - main - githubmirror/rsyslog

plugins/omstdout/omstdout.c
358 строк11 KB
Rainer Gerhards
omprog/omstdout: guard empty template LF checks
28 июн 2026, 09:39
28 июн 2026, 09:393995f55
/* omstdout.c
 * send all output to stdout - this is primarily a test driver (but may
 * be used for weired use cases). Not tested for robustness!
 *
 * NOTE: read comments in module-template.h for more specifics!
 *
 * File begun on 2009-03-19 by RGerhards
 *
 * Copyright 2009-2017 Adiscon GmbH.
 *
 * This file is part of rsyslog.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *       -or-
 *       see COPYING.ASL20 in the source distribution
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "config.h"
#include "rsyslog.h"
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include "conf.h"
#include "syslogd-types.h"
#include "srUtils.h"
#include "template.h"
#include "module-template.h"
#include "errmsg.h"
#include "cfsysline.h"

MODULE_TYPE_OUTPUT;
MODULE_TYPE_NOKEEP;
MODULE_CNFNAME("omstdout")

static rsRetVal resetConfigVariables(uchar __attribute__((unused)) * pp, void __attribute__((unused)) * pVal);

/* static data */

/* internal structures
 */
DEF_OMOD_STATIC_DATA;

/* config variables */

typedef struct _instanceData {
    int bUseArrayInterface; /* uses action use array instead of string template interface? */
    int bEnsureLFEnding; /* ensure that a linefeed is written at the end of EACH
             record (test aid for nettester) */
    uchar *templateName;
} instanceData;

typedef struct wrkrInstanceData {
    instanceData *pData;
} wrkrInstanceData_t;

typedef struct configSettings_s {
    int bUseArrayInterface; /* shall action use array instead of string template interface? */
    int bEnsureLFEnding;
    int templateName;
} configSettings_t;
static configSettings_t cs;

/* tables for interfacing with the v6 config system */
/* action (instance) parameters */
static struct cnfparamdescr actpdescr[] = {{"ensurelfending", eCmdHdlrBinary, 0}, {"template", eCmdHdlrGetWord, 0}};
static struct cnfparamblk actpblk = {CNFPARAMBLK_VERSION, sizeof(actpdescr) / sizeof(struct cnfparamdescr), actpdescr};

struct modConfData_s {
    rsconf_t *pConf; /* our overall config object */
};

static modConfData_t *loadModConf = NULL; /* modConf ptr to use for the current load process */
static modConfData_t *runModConf = NULL; /* modConf ptr to use for the current exec process */


BEGINinitConfVars /* (re)set config variables to default values */
    CODESTARTinitConfVars;
    resetConfigVariables(NULL, NULL);
ENDinitConfVars

BEGINcreateInstance
    CODESTARTcreateInstance;
ENDcreateInstance


BEGINcreateWrkrInstance
    CODESTARTcreateWrkrInstance;
ENDcreateWrkrInstance


BEGINbeginCnfLoad
    CODESTARTbeginCnfLoad;
    loadModConf = pModConf;
    pModConf->pConf = pConf;
ENDbeginCnfLoad


BEGINendCnfLoad
    CODESTARTendCnfLoad;
    loadModConf = NULL; /* done loading */
ENDendCnfLoad

BEGINcheckCnf
    CODESTARTcheckCnf;
ENDcheckCnf

BEGINactivateCnf
    CODESTARTactivateCnf;
    runModConf = pModConf;
ENDactivateCnf

BEGINfreeCnf
    CODESTARTfreeCnf;
ENDfreeCnf


BEGINisCompatibleWithFeature
    CODESTARTisCompatibleWithFeature;
    if (eFeat == sFEATURERepeatedMsgReduction) iRet = RS_RET_OK;
ENDisCompatibleWithFeature


BEGINfreeInstance
    CODESTARTfreeInstance;
ENDfreeInstance


BEGINfreeWrkrInstance
    CODESTARTfreeWrkrInstance;
ENDfreeWrkrInstance


BEGINdbgPrintInstInfo
    CODESTARTdbgPrintInstInfo;
    dbgprintf("omstdout\n");
    dbgprintf("\tensureLFEnding='%d'\n", pData->bEnsureLFEnding);
    dbgprintf("\ttemplate='%s'\n", pData->templateName);
ENDdbgPrintInstInfo


BEGINtryResume
    CODESTARTtryResume;
ENDtryResume

BEGINdoAction
    char **szParams;
    char *toWrite;
    int iParamVal;
    int iParam;
    int iBuf;
    char szBuf[65564];
    size_t len;
    int r;
    CODESTARTdoAction;
    dbgprintf("omstdout: in doAction\n");
    if (pWrkrData->pData->bUseArrayInterface) {
        dbgprintf("omstdout: in ArrayInterface\n");
        /* if we use array passing, we need to put together a string
         * ourselves. At this point, please keep in mind that omstdout is
         * primarily a testing aid. Other modules may do different processing
         * if they would like to support downlevel versions which do not support
         * array-passing, but also use that interface on cores who do...
         * So this code here is also more or less an example of how to do that.
         * rgerhards, 2009-04-03
         */
        szParams = (char **)(void *)(ppString[0]);
        /* In array-passing mode, ppString[] contains a NULL-terminated array
         * of char *pointers.
         */
        iParam = 0;
        iBuf = 0;
        while (szParams[iParam] != NULL && iBuf < (int)sizeof(szBuf) - 1) {
            if (iParam > 0) szBuf[iBuf++] = ','; /* all but first need a delimiter */
            iParamVal = 0;
            while (szParams[iParam][iParamVal] != '\0' && iBuf < (int)sizeof(szBuf) - 1) {
                szBuf[iBuf++] = szParams[iParam][iParamVal++];
            }
            ++iParam;
        }
        szBuf[iBuf] = '\0';
        toWrite = szBuf;
    } else {
        dbgprintf("omstdout: in else\n");
        toWrite = (char *)ppString[0];
    }
    len = strlen(toWrite);
    /* the following if's are just to silence compiler warnings. If someone
     * actually intends to use this module in production (why???), this code
     * needs to be more solid. -- rgerhards, 2012-11-28
     */
    dbgprintf("omstdout: len: %d, toWrite: %s\n", (int)len, toWrite);
    if (len > 0 && (r = write(1, toWrite, len)) != (int)len) { /* 1 is stdout! */
        DBGPRINTF("omstdout: error %d writing to stdout[%zd]: %s\n", r, len, toWrite);
    }
    /* A rendered template may legitimately be empty. Treat that like any other
     * non-LF-terminated message; do not inspect toWrite[-1].
     */
    if (pWrkrData->pData->bEnsureLFEnding && (len == 0 || toWrite[len - 1] != '\n')) {
        if ((r = write(1, "\n", 1)) != 1) { /* write missing LF */
            DBGPRINTF("omstdout: error %d writing \\n to stdout\n", r);
        }
    }
ENDdoAction

static void setInstParamDefaults(instanceData *pData) {
    pData->bEnsureLFEnding = 1;
    pData->templateName = (uchar *)"RSYSLOG_FileFormat";
    pData->bUseArrayInterface = 0;
}


BEGINnewActInst
    struct cnfparamvals *pvals;
    int i;
    int bDestructPValsOnExit;
    uchar *tplToUse;
    CODESTARTnewActInst;
    DBGPRINTF("newActInst (omstdout)\n");

    bDestructPValsOnExit = 0;
    pvals = nvlstGetParams(lst, &actpblk, NULL);
    if (pvals == NULL) {
        LogError(0, RS_RET_MISSING_CNFPARAMS,
                 "omstdout: error reading "
                 "config parameters");
        ABORT_FINALIZE(RS_RET_MISSING_CNFPARAMS);
    }
    bDestructPValsOnExit = 1;

    if (Debug) {
        dbgprintf("action param blk in omstdout:\n");
        cnfparamsPrint(&actpblk, pvals);
    }

    CHKiRet(createInstance(&pData));
    setInstParamDefaults(pData);

    for (i = 0; i < actpblk.nParams; ++i) {
        if (!pvals[i].bUsed) {
            continue;
        } else if (!strcmp(actpblk.descr[i].name, "ensurelfending")) {
            pData->bEnsureLFEnding = (int)pvals[i].val.d.n;
        } else if (!strcmp(actpblk.descr[i].name, "template")) {
            CHKmalloc(pData->templateName = (uchar *)es_str2cstr(pvals[i].val.d.estr, NULL));
        } else {
            DBGPRINTF(
                "omstdout: program error, non-handled "
                "param '%s'\n",
                actpblk.descr[i].name);
        }
    }


    CODE_STD_STRING_REQUESTnewActInst(1);
    // TODO: make the template a parameter
    tplToUse = (uchar *)strdup((pData->templateName == NULL) ? "RSYSLOG_FileFormat" : (char *)pData->templateName);
    CHKiRet(OMSRsetEntry(*ppOMSR, 0, tplToUse, OMSR_NO_RQD_TPL_OPTS));
    CODE_STD_FINALIZERnewActInst;
    if (bDestructPValsOnExit) cnfparamvalsDestruct(pvals, &actpblk);
ENDnewActInst


BEGINparseSelectorAct
    int iTplOpts;
    CODESTARTparseSelectorAct;
    CODE_STD_STRING_REQUESTparseSelectorAct(1)
        /* first check if this config line is actually for us */
        if (strncmp((char *)p, ":omstdout:", sizeof(":omstdout:") - 1)) {
        ABORT_FINALIZE(RS_RET_CONFLINE_UNPROCESSED);
    }

    /* ok, if we reach this point, we have something for us */
    p += sizeof(":omstdout:") - 1; /* eat indicator sequence  (-1 because of '\0'!) */
    CHKiRet(createInstance(&pData));

    /* check if a non-standard template is to be applied */
    if (*(p - 1) == ';') --p;
    iTplOpts = (cs.bUseArrayInterface == 0) ? 0 : OMSR_TPL_AS_ARRAY;
    CHKiRet(cflineParseTemplateName(&p, *ppOMSR, 0, iTplOpts, (uchar *)"RSYSLOG_FileFormat"));
    pData->bUseArrayInterface = cs.bUseArrayInterface;
    pData->bEnsureLFEnding = cs.bEnsureLFEnding;
    CODE_STD_FINALIZERparseSelectorAct
ENDparseSelectorAct


BEGINmodExit
    CODESTARTmodExit;
ENDmodExit


BEGINqueryEtryPt
    CODESTARTqueryEtryPt;
    CODEqueryEtryPt_STD_OMOD_QUERIES;
    CODEqueryEtryPt_STD_OMOD8_QUERIES;
    CODEqueryEtryPt_STD_CONF2_CNFNAME_QUERIES;
    CODEqueryEtryPt_STD_CONF2_QUERIES;
    CODEqueryEtryPt_STD_CONF2_OMOD_QUERIES;
ENDqueryEtryPt


/* Reset config variables for this module to default values.
 */
static rsRetVal resetConfigVariables(uchar __attribute__((unused)) * pp, void __attribute__((unused)) * pVal) {
    DEFiRet;
    cs.bUseArrayInterface = 0;
    cs.bEnsureLFEnding = 1;
    RETiRet;
}


BEGINmodInit()
    rsRetVal localRet;
    rsRetVal (*pomsrGetSupportedTplOpts)(unsigned long *pOpts);
    unsigned long opts;
    int bArrayPassingSupported; /* does core support template passing as an array? */
    CODESTARTmodInit;
    INITLegCnfVars;
    *ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */
    CODEmodInit_QueryRegCFSLineHdlr
        /* check if the rsyslog core supports parameter passing code */
        bArrayPassingSupported = 0;
    localRet = pHostQueryEtryPt((uchar *)"OMSRgetSupportedTplOpts", &pomsrGetSupportedTplOpts);
    if (localRet == RS_RET_OK) {
        /* found entry point, so let's see if core supports array passing */
        CHKiRet((*pomsrGetSupportedTplOpts)(&opts));
        if (opts & OMSR_TPL_AS_ARRAY) bArrayPassingSupported = 1;
    } else if (localRet != RS_RET_ENTRY_POINT_NOT_FOUND) {
        ABORT_FINALIZE(localRet); /* Something else went wrong, what is not acceptable */
    }
    DBGPRINTF("omstdout: array-passing is %ssupported by rsyslog core.\n", bArrayPassingSupported ? "" : "not ");

    if (bArrayPassingSupported) {
        /* enable config comand only if core supports it */
        CHKiRet(omsdRegCFSLineHdlr((uchar *)"actionomstdoutarrayinterface", 0, eCmdHdlrBinary, NULL,
                                   &cs.bUseArrayInterface, STD_LOADABLE_MODULE_ID));
    }
    CHKiRet(omsdRegCFSLineHdlr((uchar *)"actionomstdoutensurelfending", 0, eCmdHdlrBinary, NULL, &cs.bEnsureLFEnding,
                               STD_LOADABLE_MODULE_ID));
    CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler, resetConfigVariables, NULL,
                               STD_LOADABLE_MODULE_ID));
ENDmodInit

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