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Diffstat (limited to 'tools/ompipe.c')
-rw-r--r-- | tools/ompipe.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/tools/ompipe.c b/tools/ompipe.c new file mode 100644 index 00000000..541b6552 --- /dev/null +++ b/tools/ompipe.c @@ -0,0 +1,240 @@ +/* ompipe.c + * This is the implementation of the build-in pipe output module. + * Note that this module stems back to the "old" (4.4.2 and below) + * omfile. There were some issues with the new omfile code and pipes + * (namely in regard to xconsole), so we took out the pipe code and moved + * that to a separate module. That a) immediately solves the issue for a + * less common use case and probably makes it much easier to enhance + * file and pipe support (now independently) in the future (we always + * needed to think about pipes in omfile so far, what we now no longer + * need to, hopefully resulting in reduction of complexity). + * + * NOTE: read comments in module-template.h to understand how this pipe + * works! + * + * Copyright 2007-2010 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 "rsyslog.h" +#include <stdio.h> +#include <stdarg.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> +#include <errno.h> +#include <unistd.h> +#include <sys/file.h> + +#include "syslogd.h" +#include "syslogd-types.h" +#include "srUtils.h" +#include "template.h" +#include "ompipe.h" +#include "omfile.h" /* for dirty trick: access to $ActionFileDefaultTemplate value */ +#include "cfsysline.h" +#include "module-template.h" +#include "conf.h" +#include "errmsg.h" + +MODULE_TYPE_OUTPUT + +/* internal structures + */ +DEF_OMOD_STATIC_DATA +DEFobjCurrIf(errmsg) + + +/* globals for default values */ +/* end globals for default values */ + + +typedef struct _instanceData { + uchar f_fname[MAXFNAME];/* pipe or template name (display only) */ + short fd; /* pipe descriptor for (current) pipe */ +} instanceData; + + +BEGINisCompatibleWithFeature +CODESTARTisCompatibleWithFeature + if(eFeat == sFEATURERepeatedMsgReduction) + iRet = RS_RET_OK; +ENDisCompatibleWithFeature + + +BEGINdbgPrintInstInfo +CODESTARTdbgPrintInstInfo + dbgprintf("pipe %s", pData->f_fname); + if (pData->fd == -1) + dbgprintf(" (unused)"); +ENDdbgPrintInstInfo + + +/* This is now shared code for all types of files. It simply prepares + * pipe access, which, among others, means the the pipe wil be opened + * and any directories in between will be created (based on config, of + * course). -- rgerhards, 2008-10-22 + * changed to iRet interface - 2009-03-19 + */ +static inline rsRetVal +preparePipe(instanceData *pData) +{ + DEFiRet; + pData->fd = open((char*) pData->f_fname, O_RDWR|O_NONBLOCK|O_CLOEXEC); + RETiRet; +} + + +/* rgerhards 2004-11-11: write to a pipe output. This + * will be called for all outputs using pipe semantics, + * for example also for pipes. + */ +static rsRetVal writePipe(uchar **ppString, instanceData *pData) +{ + int iLenWritten; + DEFiRet; + + ASSERT(pData != NULL); + + if(pData->fd == -1) { + rsRetVal iRetLocal; + iRetLocal = preparePipe(pData); + if((iRetLocal != RS_RET_OK) || (pData->fd == -1)) + ABORT_FINALIZE(RS_RET_SUSPENDED); /* whatever the failure was, we need to retry */ + } + + /* create the message based on format specified */ + iLenWritten = write(pData->fd, ppString[0], strlen((char*)ppString[0])); + if(iLenWritten < 0) { + int e = errno; + char errStr[1024]; + rs_strerror_r(errno, errStr, sizeof(errStr)); + DBGPRINTF("pipe (%d) write error %d: %s\n", pData->fd, e, errStr); + + /* If a named pipe is full, we suspend this action for a while */ + if(e == EAGAIN) + ABORT_FINALIZE(RS_RET_SUSPENDED); + + close(pData->fd); + pData->fd = -1; /* tell that fd is no longer open! */ + iRet = RS_RET_SUSPENDED; + errno = e; + errmsg.LogError(0, NO_ERRCODE, "%s", pData->f_fname); + } + +finalize_it: + RETiRet; +} + + +BEGINcreateInstance +CODESTARTcreateInstance + pData->fd = -1; +ENDcreateInstance + + +BEGINfreeInstance +CODESTARTfreeInstance + if(pData->fd != -1) + close(pData->fd); +ENDfreeInstance + + +BEGINtryResume +CODESTARTtryResume +ENDtryResume + +BEGINdoAction +CODESTARTdoAction + DBGPRINTF(" (%s)\n", pData->f_fname); + iRet = writePipe(ppString, pData); +ENDdoAction + + +BEGINparseSelectorAct +CODESTARTparseSelectorAct + /* yes, the if below is redundant, but I need it now. Will go away as + * the code further changes. -- rgerhards, 2007-07-25 + */ + if(*p == '|') { + if((iRet = createInstance(&pData)) != RS_RET_OK) { + ENDfunc + return iRet; /* this can not use RET_iRet! */ + } + } else { + /* this is not clean, but we need it for the time being + * TODO: remove when cleaning up modularization + */ + ENDfunc + return RS_RET_CONFLINE_UNPROCESSED; + } + + CODE_STD_STRING_REQUESTparseSelectorAct(1) + ++p; + /* rgerhards 2004-11-17: from now, we need to have different + * processing, because after the first comma, the template name + * to use is specified. So we need to scan for the first coma first + * and then look at the rest of the line. + */ + CHKiRet(cflineParseFileName(p, (uchar*) pData->f_fname, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS, + (pszFileDfltTplName == NULL) ? (uchar*)"RSYSLOG_FileFormat" : pszFileDfltTplName)); + + /* at this stage, we ignore the return value of preparePipe, this is taken + * care of in later steps. -- rgerhards, 2009-03-19 + */ + preparePipe(pData); + + if(pData->fd < 0 ) { + pData->fd = -1; + DBGPRINTF("Error opening log pipe: %s\n", pData->f_fname); + errmsg.LogError(0, RS_RET_NO_FILE_ACCESS, "Could no open output pipe '%s'", pData->f_fname); + } +CODE_STD_FINALIZERparseSelectorAct +ENDparseSelectorAct + + +BEGINdoHUP +CODESTARTdoHUP + if(pData->fd != -1) { + close(pData->fd); + pData->fd = -1; + } +ENDdoHUP + + +BEGINmodExit +CODESTARTmodExit +ENDmodExit + + +BEGINqueryEtryPt +CODESTARTqueryEtryPt +CODEqueryEtryPt_STD_OMOD_QUERIES +CODEqueryEtryPt_doHUP +ENDqueryEtryPt + + +BEGINmodInit(Pipe) +CODESTARTmodInit + *ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */ +CODEmodInit_QueryRegCFSLineHdlr + CHKiRet(objUse(errmsg, CORE_COMPONENT)); +ENDmodInit +/* vi:set ai: + */ |