/* The systemd journal import module
 *
 * To test under Linux:
 * emmit log message into systemd journal
 *
 * Copyright (C) 2008-2012 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 <assert.h>
#include <string.h>
#include <stdarg.h>
#include <ctype.h>
#include <stdlib.h>
#include <time.h>
#include <sys/socket.h>

#include "dirty.h"
#include "cfsysline.h"
#include "obj.h"
#include "msg.h"
#include "module-template.h"
#include "datetime.h"
#include "imjournal.h"
#include "net.h"
#include "glbl.h"
#include "prop.h"
#include "errmsg.h"
#include "unicode-helper.h"
#include <systemd/sd-journal.h>

MODULE_TYPE_INPUT
MODULE_TYPE_NOKEEP
MODULE_CNFNAME("imjournal")

/* Module static data */
DEF_IMOD_STATIC_DATA
DEFobjCurrIf(datetime)
DEFobjCurrIf(glbl)
DEFobjCurrIf(prop)
DEFobjCurrIf(net)
DEFobjCurrIf(errmsg)

static int bLegacyCnfModGlobalsPermitted;/* are legacy module-global config parameters permitted? */

static prop_t *pInputName = NULL;	/* there is only one global inputName for all messages generated by this module */
static prop_t *pLocalHostIP = NULL;	/* a pseudo-constant propterty for 127.0.0.1 */

static sd_journal *j;

/* enqueue the the journal message into the message queue.
 * The provided msg string is not freed - thus must be done
 * by the caller.
 */
static rsRetVal
enqMsg(uchar *msg, uchar *pszTag, int iFacility, int iSeverity, struct timeval *tp, struct json_object *json)
{
	struct syslogTime st;
	msg_t *pMsg;
	DEFiRet;

	assert(msg != NULL);
	assert(pszTag != NULL);

	if(tp == NULL) {
		CHKiRet(msgConstruct(&pMsg));
	} else {
		datetime.timeval2syslogTime(tp, &st);
		CHKiRet(msgConstructWithTime(&pMsg, &st, tp->tv_sec));
	}
	MsgSetFlowControlType(pMsg, eFLOWCTL_LIGHT_DELAY);
	MsgSetInputName(pMsg, pInputName);
	MsgSetRawMsgWOSize(pMsg, (char*)msg);
	MsgSetMSGoffs(pMsg, 0);	/* we do not have a header... */
	MsgSetRcvFrom(pMsg, glbl.GetLocalHostNameProp());
	MsgSetRcvFromIP(pMsg, pLocalHostIP);
	MsgSetHOSTNAME(pMsg, glbl.GetLocalHostName(), ustrlen(glbl.GetLocalHostName()));
	MsgSetTAG(pMsg, pszTag, ustrlen(pszTag));
	pMsg->iFacility = iFacility;
	pMsg->iSeverity = iSeverity;

	if(json != NULL) {
		msgAddJSON(pMsg, (uchar*)"!", json);
	}

	CHKiRet(submitMsg(pMsg));

finalize_it:
	RETiRet;
}


/* Read journal log while data are available, each read() reads one
 * record of printk buffer.
 */
static rsRetVal
readjournal() {
	DEFiRet;

	struct timeval tv;
	uint64_t timestamp;

	struct json_object *json = NULL;
	json = json_object_new_object();

	/* Information from messages */
	char *message;
	char *sys_iden;
	char *sys_iden_help;

	const void *get;
	uchar *parse;
	char *get2;
	size_t length;

	const void *equal_sign;
	struct json_object *jval;
	char *data;
	char *name;
	size_t l;

	long prefixlen = 0;

	int priority = 0;
	int facility = 0;

	/* Get next journal message, if there is none, wait a second */
	if (sd_journal_next(j) == 0) {
		sleep(1);
		iRet = RS_RET_OK;
		goto ret;
	}

	/* Get message text */
	if (sd_journal_get_data(j, "MESSAGE", &get, &length) < 0) {
		logmsgInternal(NO_ERRCODE, LOG_SYSLOG|LOG_INFO, (uchar *)"log message from journal doesn't have MESSAGE", 0);
		iRet = RS_RET_OK;
		goto ret;
	}
	message = strndup(get+8, length-8);
	if (message == NULL) {
		iRet = RS_RET_OUT_OF_MEMORY;
		goto ret;
	}

	/* Get message priority */
	if (sd_journal_get_data(j, "PRIORITY", &get, &length) >= 0) {
		get2 = strndup(get, length);
		priority = ((char *)get2)[9] - '0';
		free (get2);
	}

	/* Get syslog facility */
	if (sd_journal_get_data(j, "SYSLOG_FACILITY", &get, &length) >= 0) {
		get2 = strndup(get, length);
		char f = ((char *)get2)[16];
		if (f >= '0' && f <= '9') {
			facility += f - '0';
		}
		f = ((char *)get2)[17];
		if (f >= '0' && f <= '9') {
			facility *= 10;
			facility += (f - '0');
		}
		free (get2);
	} else {
		/* message is missing facility -> internal systemd journal msg, drop */
		iRet = RS_RET_OK;
		goto free_message;
	}

	/* Get message identifier and add ':' */
	if (sd_journal_get_data(j, "SYSLOG_IDENTIFIER", &get, &length) >= 0) {
		sys_iden = strndup(get+18, length-18);
	} else {
		sys_iden = strdup("journal");
	}
	if (sys_iden == NULL) {
		iRet = RS_RET_OUT_OF_MEMORY;
		goto free_message;
	}

	asprintf(&sys_iden_help, "%s:", sys_iden);
	if (sys_iden_help == NULL) {
		iRet = RS_RET_OUT_OF_MEMORY;
		goto finalize_it;
	}
	free (sys_iden);


	SD_JOURNAL_FOREACH_DATA(j, get, l) {
		/* locate equal sign, this is always present */
		equal_sign = memchr(get, '=', l);
		assert (equal_sign != NULL);

		/* get length of journal data prefix */
		prefixlen = ((char *)equal_sign - (char *)get);

		/* translate name fields to lumberjack names */
		parse = (uchar *)get;

		switch (*parse)
		{
		case '_':
			++parse;
			if (*parse == 'P') {
				name = strdup("pid");
			} else if (*parse == 'G') {
				name = strdup("gid");
			} else if (*parse == 'U') {
				name = strdup("uid");
			} else if (*parse == 'E') {
				name = strdup("exe");
			} else if (*parse == 'C') {
				parse++;
				if (*parse == 'O') {
					name = strdup("appname");
				} else if (*parse == 'M') {
					name = strdup("cmd");
				} else {
					name = strndup(get, prefixlen);
				}
			} else {
				name = strndup(get, prefixlen);
			}
			break;

		default:
			name = strndup(get, prefixlen);
			break;
		}

		if (name == NULL) {
			iRet = RS_RET_OUT_OF_MEMORY;
			goto ret;
		}

		prefixlen++; /* remove '=' */

		data = strndup(get + prefixlen, l - prefixlen);
		if (data == NULL) {
			iRet = RS_RET_OUT_OF_MEMORY;
			free (name);
			goto ret;
		}

		/* and save them to json object */
		jval = json_object_new_string((char *)data);
		json_object_object_add(json, name, jval);
		free (data);
		free (name);
	}

	/* calculate timestamp */
	if (sd_journal_get_realtime_usec(j, &timestamp) >= 0) {
		tv.tv_sec = timestamp / 1000000;
		tv.tv_usec = timestamp % 1000000;
	}

	/* submit message */
	enqMsg((uchar *)message, (uchar *) sys_iden_help, facility, priority, &tv, json);

finalize_it:
	free(sys_iden_help);
free_message:
	free(message);
ret:
	RETiRet;
}


BEGINrunInput
CODESTARTrunInput
	/* this is an endless loop - it is terminated when the thread is
	 * signalled to do so. This, however, is handled by the framework,
	 * right into the sleep below.
	 */
	while(!pThrd->bShallStop) {
          CHKiRet(readjournal());
	}
finalize_it:
ENDrunInput


BEGINbeginCnfLoad
CODESTARTbeginCnfLoad
	bLegacyCnfModGlobalsPermitted = 1;
ENDbeginCnfLoad


BEGINendCnfLoad
CODESTARTendCnfLoad
ENDendCnfLoad


BEGINcheckCnf
CODESTARTcheckCnf
ENDcheckCnf


BEGINactivateCnf
CODESTARTactivateCnf
ENDactivateCnf


BEGINfreeCnf
CODESTARTfreeCnf
ENDfreeCnf

/* open journal */
BEGINwillRun
CODESTARTwillRun
	int ret;
	ret = sd_journal_open(&j, SD_JOURNAL_LOCAL_ONLY);
	if (ret < 0) {
		iRet = RS_RET_IO_ERROR;
	}
ENDwillRun

/* close journal */
BEGINafterRun
CODESTARTafterRun
	sd_journal_close(j);
ENDafterRun


BEGINmodExit
CODESTARTmodExit
	if(pInputName != NULL)
		prop.Destruct(&pInputName);
	if(pLocalHostIP != NULL)
		prop.Destruct(&pLocalHostIP);

	/* release objects we used */
	objRelease(glbl, CORE_COMPONENT);
	objRelease(net, CORE_COMPONENT);
	objRelease(datetime, CORE_COMPONENT);
	objRelease(prop, CORE_COMPONENT);
	objRelease(errmsg, CORE_COMPONENT);
ENDmodExit


BEGINqueryEtryPt
CODESTARTqueryEtryPt
CODEqueryEtryPt_STD_IMOD_QUERIES
CODEqueryEtryPt_STD_CONF2_QUERIES
ENDqueryEtryPt


BEGINmodInit()
CODESTARTmodInit
	*ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */
CODEmodInit_QueryRegCFSLineHdlr
	CHKiRet(objUse(datetime, CORE_COMPONENT));
	CHKiRet(objUse(glbl, CORE_COMPONENT));
	CHKiRet(objUse(prop, CORE_COMPONENT));
	CHKiRet(objUse(net, CORE_COMPONENT));
	CHKiRet(objUse(errmsg, CORE_COMPONENT));

	/* we need to create the inputName property (only once during our lifetime) */
	CHKiRet(prop.CreateStringProp(&pInputName, UCHAR_CONSTANT("imjournal"), sizeof("imjournal") - 1));
	CHKiRet(prop.CreateStringProp(&pLocalHostIP, UCHAR_CONSTANT("127.0.0.1"), sizeof("127.0.0.1") - 1));

	/* init legacy config settings */

ENDmodInit
/* vim:set ai:
 */