/* omfile.c
 * This is the implementation of the build-in file output module.
 *
 * Handles: eTypeCONSOLE, eTypeTTY, eTypeFILE, eTypePIPE
 *
 * NOTE: read comments in module-template.h to understand how this file
 *       works!
 *
 * File begun on 2007-07-21 by RGerhards (extracted from syslogd.c)
 * This file is under development and has not yet arrived at being fully
 * self-contained and a real object. So far, it is mostly an excerpt
 * of the "old" message code without any modifications. However, it
 * helps to have things at the right place one we go to the meat of it.
 *
 * A large re-write of this file was done in June, 2009. The focus was
 * to introduce many more features (like zipped writing), clean up the code
 * and make it more reliable. In short, that rewrite tries to provide a new
 * solid basis for the next three to five years to come. During it, bugs
 * may have been introduced ;) -- rgerhards, 2009-06-04
 *
 * Copyright 2007-2009 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 <time.h>
#include <assert.h>
#include <errno.h>
#include <ctype.h>
#include <libgen.h>
#include <unistd.h>
#include <sys/file.h>

#ifdef OS_SOLARIS
#	include <fcntl.h>
#endif

#include "conf.h"
#include "syslogd-types.h"
#include "srUtils.h"
#include "template.h"
#include "outchannel.h"
#include "omfile.h"
#include "cfsysline.h"
#include "module-template.h"
#include "errmsg.h"
#include "stream.h"
#include "unicode-helper.h"
#include "atomic.h"

MODULE_TYPE_OUTPUT

/* internal structures
 */
DEF_OMOD_STATIC_DATA
DEFobjCurrIf(errmsg)
DEFobjCurrIf(strm)

/* The following structure is a dynafile name cache entry.
 */
struct s_dynaFileCacheEntry {
	uchar *pName;		/* name currently open, if dynamic name */
	strm_t	*pStrm;		/* our output stream */
	time_t	lastUsed;	/* for LRU - last access */ // TODO: perforamcne change to counter (see other comment!) 
};
typedef struct s_dynaFileCacheEntry dynaFileCacheEntry;


#define IOBUF_DFLT_SIZE 1024	/* default size for io buffers */
#define FLUSH_INTRVL_DFLT 1 	/* default buffer flush interval (in seconds) */

/* globals for default values */
static int iDynaFileCacheSize = 10; /* max cache for dynamic files */
static int fCreateMode = 0644; /* mode to use when creating files */
static int fDirCreateMode = 0700; /* mode to use when creating files */
static int	bFailOnChown;	/* fail if chown fails? */
static uid_t	fileUID;	/* UID to be used for newly created files */
static uid_t	fileGID;	/* GID to be used for newly created files */
static uid_t	dirUID;		/* UID to be used for newly created directories */
static uid_t	dirGID;		/* GID to be used for newly created directories */
static int	bCreateDirs;	/* auto-create directories for dynaFiles: 0 - no, 1 - yes */
static int	bEnableSync = 0;/* enable syncing of files (no dash in front of pathname in conf): 0 - no, 1 - yes */
static int	iZipLevel = 0;	/* zip compression mode (0..9 as usual) */
static bool	bFlushOnTXEnd = 1;/* flush write buffers when transaction has ended? */
static int64	iIOBufSize = IOBUF_DFLT_SIZE;	/* size of an io buffer */
static int	iFlushInterval = FLUSH_INTRVL_DFLT; 	/* how often flush the output buffer on inactivity? */
static uchar	*pszTplName = NULL; /* name of the default template to use */
/* end globals for default values */


typedef struct _instanceData {
	uchar	f_fname[MAXFNAME];/* file or template name (display only) */
	strm_t	*pStrm;		/* our output stream */
	char	bDynamicName;	/* 0 - static name, 1 - dynamic name (with properties) */
	int	fCreateMode;	/* file creation mode for open() */
	int	fDirCreateMode;	/* creation mode for mkdir() */
	int	bCreateDirs;	/* auto-create directories? */
	int	bSyncFile;	/* should the file by sync()'ed? 1- yes, 0- no */
	uid_t	fileUID;	/* IDs for creation */
	uid_t	dirUID;
	gid_t	fileGID;
	gid_t	dirGID;
	int	bFailOnChown;	/* fail creation if chown fails? */
	int	iCurrElt;	/* currently active cache element (-1 = none) */
	int	iCurrCacheSize;	/* currently cache size (1-based) */
	int	iDynaFileCacheSize; /* size of file handle cache */
	/* The cache is implemented as an array. An empty element is indicated
	 * by a NULL pointer. Memory is allocated as needed. The following
	 * pointer points to the overall structure.
	 */
	dynaFileCacheEntry **dynCache;
	off_t	iSizeLimit;		/* file size limit, 0 = no limit */
	uchar	*pszSizeLimitCmd;	/* command to carry out when size limit is reached */
	int 	iZipLevel;		/* zip mode to use for this selector */
	int	iIOBufSize;		/* size of associated io buffer */
	int	iFlushInterval;		/* how fast flush buffer on inactivity? */
	bool	bFlushOnTXEnd;		/* flush write buffers when transaction has ended? */
} instanceData;


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


BEGINdbgPrintInstInfo
CODESTARTdbgPrintInstInfo
	if(pData->bDynamicName) {
		dbgprintf("[dynamic]\n\ttemplate='%s'"
		       "\tfile cache size=%d\n"
		       "\tcreate directories: %s\n"
		       "\tfile owner %d, group %d\n"
		       "\tdirectory owner %d, group %d\n"
		       "\tdir create mode 0%3.3o, file create mode 0%3.3o\n"
		       "\tfail if owner/group can not be set: %s\n",
		        pData->f_fname,
			pData->iDynaFileCacheSize,
			pData->bCreateDirs ? "yes" : "no",
			pData->fileUID, pData->fileGID,
			pData->dirUID, pData->dirGID,
			pData->fDirCreateMode, pData->fCreateMode,
			pData->bFailOnChown ? "yes" : "no"
			);
	} else { /* regular file */
		dbgprintf("%s", pData->f_fname);
		if (pData->pStrm == NULL)
			dbgprintf(" (unused)");
	}
ENDdbgPrintInstInfo


/* set the dynaFile cache size. Does some limit checking.
 * rgerhards, 2007-07-31
 */
rsRetVal setDynaFileCacheSize(void __attribute__((unused)) *pVal, int iNewVal)
{
	DEFiRet;
	uchar errMsg[128];	/* for dynamic error messages */

	if(iNewVal < 1) {
		snprintf((char*) errMsg, sizeof(errMsg)/sizeof(uchar),
		         "DynaFileCacheSize must be greater 0 (%d given), changed to 1.", iNewVal);
		errno = 0;
		errmsg.LogError(0, RS_RET_VAL_OUT_OF_RANGE, "%s", errMsg);
		iRet = RS_RET_VAL_OUT_OF_RANGE;
		iNewVal = 1;
	} else if(iNewVal > 1000) {
		snprintf((char*) errMsg, sizeof(errMsg)/sizeof(uchar),
		         "DynaFileCacheSize maximum is 1,000 (%d given), changed to 1,000.", iNewVal);
		errno = 0;
		errmsg.LogError(0, RS_RET_VAL_OUT_OF_RANGE, "%s", errMsg);
		iRet = RS_RET_VAL_OUT_OF_RANGE;
		iNewVal = 1000;
	}

	iDynaFileCacheSize = iNewVal;
	DBGPRINTF("DynaFileCacheSize changed to %d.\n", iNewVal);

	RETiRet;
}


/* Helper to cfline(). Parses a output channel name up until the first
 * comma and then looks for the template specifier. Tries
 * to find that template. Maps the output channel to the 
 * proper filed structure settings. Everything is stored in the
 * filed struct. Over time, the dependency on filed might be
 * removed.
 * rgerhards 2005-06-21
 */
static rsRetVal cflineParseOutchannel(instanceData *pData, uchar* p, omodStringRequest_t *pOMSR, int iEntry, int iTplOpts)
{
	DEFiRet;
	size_t i;
	struct outchannel *pOch;
	char szBuf[128];	/* should be more than sufficient */

	++p; /* skip '$' */
	i = 0;
	/* get outchannel name */
	while(*p && *p != ';' && *p != ' ' &&
	      i < sizeof(szBuf) / sizeof(char)) {
	      szBuf[i++] = *p++;
	}
	szBuf[i] = '\0';

	/* got the name, now look up the channel... */
	pOch = ochFind(szBuf, i);

	if(pOch == NULL) {
		char errMsg[128];
		errno = 0;
		snprintf(errMsg, sizeof(errMsg)/sizeof(char),
			 "outchannel '%s' not found - ignoring action line",
			 szBuf);
		errmsg.LogError(0, RS_RET_NOT_FOUND, "%s", errMsg);
		ABORT_FINALIZE(RS_RET_NOT_FOUND);