WAF防火墙数据接入 ES最佳实践（下）

在数据处理中，我们用得最多的是 grok 插件，grok 是 logstash 最重要的插件。

一、Logstash介绍

1. logstash插件说明

1.1 Filter配置

• Grok

在数据处理中，我们用得最多的是 grok 插件，grok 是 logstash 最重要的插件。我们可以在 grok 里直接使用或应用预定义的表达式名称。

grok匹配模式语法为：%{SYNTAX:SEMANTIC:TYPE}

• SYNTAX: 正则表达式、预定义的正则表达式名称
• SEMANTIC: 标识符，标识匹配之后要放的字段名字（自定义或随心所欲，只要自己能认识区分的）
• TYPE: 可选的类型，目前支持int、float

例如 NUMBER 可以匹配3.44，IP可以匹配 192.168.21.2

所以这上面这两个值可以用 %{NUMBER:duration} %{IP:client} 来匹配。

官方提供了很多可以直接使用的表达式，以下面这两个预定义 grok 表达式为例。

USERNAME [a-zA-Z0-9._-]+
USER %{
   USERNAME}

第一列是正则grok表达式的名称，可直接使用；第二列是普通的正则表达式； 第一行，用普通的正则表达式来定义一个 grok 表达式；第二行，简单来说，名字和表达式，可嵌套使用

Grok正则截取

grok正则表达式：

(?<temMsg>(.*)(?=Report)/?) 获取Report之前的字符作为temMsg字段的值

grok正则表达式：

(?<temMsg>(?=Report)(.*)/?) 获取Report之后的字符作为temMsg字段的值

grok{
   
        match => {
    
                 #截取<Report>之前的字符作为temMsg字段的值
                "message" => "(?<temMsg>(.*)(?=Report)/?)" 
            }
    }

这个是截取特定的字符集日志，要日志中包含了"Report"关键字，关键字根据实际替换即可。

注：表达式中(?=Report)中的等于"="符号如果换成"<="这表示就不包含本身了，例如：

(?<temMsg>(.*)(?=Report)/?) 可以写成 (?<temMsg>(.*)(?<=Report)/?)

这样输出的结果就不包含Report了，同理下面的一样。

其他样例：

grok正则表达式，截取report和msg之间的值，不包含report和msg本身：

(?<temMsg>(?<=report).*?(?=msg))

grok正则表达式，截取 包含report但不包含msg：

(?<temMsg>(report).*?(?=msg))

grok正则表达式，截取 不包含report但包含msg：

(?<temMsg>(?<=report).*?(msg))

grok正则表达式，输出以report开头，以msg或者以request结尾的所有包含头尾信息：

(?<temMsg>(report).*?(msg|request))

grok正则表达式，输出以report开头，以msg或者以request结尾的不包含头尾信息：

(?<temMsg>(report).*?(?=(msg|request)))

grok{
   
        match => {
    
                 #截取<Report>之后的和<msg>之前的值作为temMsg字段的值
                "message" => "(?<temMsg>(?<=report).*?(?=msg))" 
            }
    }

这个是截取特定的字符集日志，要日志中包含了【report和msg和request】关键字

之间的表达式只要替换一下就可以使用了

（注：这个表达式中出现异常，在单个的字符串中可以将小括号【()】去掉，例如：(report).?(?=msg) 可以写成report.?(?=msg)）

grok正则表达式：(?<MYELF>([\s\S]{
   500}))
 grok{
   
       match => {
   
              #截取日志500个字符 作为MYELF的值
              "message" => "(?<MYELF>([\s\S]{500}))"  
             }
     }

测试匹配规则我们可以使用 Kiabna 的Dev Tools里的Grok Debug来实现，如下图：

Demo举例

(1) 我们虚构的一个http请求日志：

114.114.114.114 GET /index.html 15824 0.043

可以使用如下grok pattern来匹配这种记录：

%{
   IP:client} %{
   WORD:method} %{
   URIPATHPARAM:request} %{
   NUMBER:bytes} %{
   NUMBER:duration}

返回：

{
   
  "duration": "0.043",
  "request": "/index.html",
  "method": "GET",
  "bytes": "15824",
  "client": "114.114.114.114"
}

（2）我们想要得到下面日志里前面的时间 2020-03-18 以及 日志的级别 INFO

2020-03-18 14:04:23.944 [DubboServerHandler-10.50.245.25:63046-thread-168] INFO  c.f.l.d.LogTraceDubboProviderFilter - c79b0905-03c7-4e54-a5a6-ff1b34058cdf CALLEE_IN dubbo:EstatePriceService.listCellPrice

解决如下:

\s*%{
   TIMESTAMP_ISO8601:timestamp} \s*\[%{
   DATA:current_thread}\]\s*%{
   LOGLEVEL:loglevel}\s*(?<class_info>([\S+]*))

过滤结果显示如下：

{
   
  "current_thread": "DubboServerHandler-10.50.245.25:63046-thread-168",
  "loglevel": "INFO",
  "class_info": "c.f.l.d.LogTraceDubboProviderFilter",
  "timestamp": "2020-03-18 14:04:23.944"
}

（3）我们再看一看另外一个完整的nginx的access日志，样本文件如下，我们需要通过grok方式来输出json。

10.0.16.138 - - [18/Aug/2020:16:21:05 +0800] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.87 Safari/537.36" "-"

grok 语法规则如下：

^%{
   IPV4:remote_addr} - (%{
   USERNAME:remote_user}|-) \[%{
   HTTPDATE:time_local}\] \"%{WORD:method} %{DATA:request} HTTP/%{NUMBER:httpversion}\" %{NUMBER:status:int} %{NUMBER:body_sent:int} "%{
   NOTSPACE:http_user_agent}\" %{
   QS:http_referer} %{
   NOTSPACE:http_user_agent}

返回内容如下：

{
   
  "remote_addr": "10.0.16.138",
  "request": "/",
  "method": "GET",
  "time_local": "18/Aug/2020:16:21:05 +0800",
  "http_user_agent": "-",
  "remote_user": "-",
  "http_referer": "\"Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.87 Safari/537.36\"",
  "httpversion": "1.1",
  "body_sent": 0,
  "status": 304
}

（4）Java日志内容

2020-12-04 14:16:30.003  INFO 19095 --- [pool-4-thread-1] com.yck.laochangzhang.task.EndorseTask   : 平台发起结束

Grok 配置如下：

(?<datetime>\d{
   4}-\d{
   2}-\d{
   2}\s\d{
   2}:\d{
   2}:\d{
   2}\.\d{
   3})\s+(?<level>\w+)\s+\d+\s+-+\s\[[^\[\]]+\]\s+(?<handler>\S+)\s+:(?<msg>.*)

返回内容如下：

{
   
  "msg": "平台发起结束"
  "handler":"com.yck.laochangzhang.task.EndorseTask""datetime": "2020-12-84 14:16:38.883"
  "level":"INFO"
}

二、需求实现

1. DLP日志接入

原始日志（已经过全量严格脱敏）：

2022-07-21T07:15:13.150Z 10.13.1.74 <6>Jul 21 15:15:34 [主机名] CEF:0|SkyGuard|Data Security|[ID]|DLP Incident Syslog| serialId=[ID] transactionId=[替换transactionId] incidentTime=2022-07-21 14:57:23 detectTime=2022-07-21 14:55:27 policyGroupNames=默认策略组 policyNames=[替换]-客户数据-信息 statusType=新 severityType=信息 maxMatches=16 transactionSize=116.87 KB detectAgent=Endpoint(MacBook-Pro.local) analyzeAgent=Content Analysis Engine(MacBook-Pro.local) tagContent=N/A ignoreStatus=未忽略 breachContents=[邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址]; [邮箱地址] totalMatches=16 classificationNames=N/A classificationLevelNames=N/A tagNames=N/A policyUuid=[替换policyUuid] ruleUuid=[替换ruleUuid] ruleName=邮件地址(16) sourceName=[替换姓名]-seti destinationNames=[域名] channelType=HTTP actionType=放行 attachmentNames=N/A details=http://[域名]/function/proto/json-to-proto-json-to-proto/proxy workModeType=阻断 sourceGroups=N/A sourceOu=[替换OU],OU=[替换OU],OU=[替换OU],OU=[替换OU],OU=[替换OU],DC=[替换DC],DC=[替换DC] sourceIp=[替换IP],[替换IP] destinationIps=[替换IP] sourceMail=[邮箱地址] sourceManagers=N/A sourceDepartment=N/A urlCategories=N/A destinationCountries=N/A destinationCities=N/A destinationLocations=N/A riskLevel=N/A sourceTitle=N/A sourceMobile=N/A sourceTelephone=N/A sourceEmployeeID=N/A sourceOffice=N/A sourceUuid=[替换ID] sourceLogonName=seti sourceDomain=N/A destinationUuid=N/A destinationLogonName=N/A destinationMail=N/A destinationDomain=[域名] messageId=N/A deviceType=笔记本 corporateType=公司内部 operationSystem=macOS hostname=[主机名] dmDeviceName=sec-dlp-lite-1 sourceMacAddress=[MAC地址] dataMethod=N/A

filter 规则如下：

filter{
   
    grok {
   
      match => {
   
        "message" => "%{TIMESTAMP_ISO8601:messageTime} %{IP:clientIp} (?<logTime>\<.*?\>%{MONTH}%{SPACE}%{MONTHDAY}%{SPACE}%{TIME}) (?<logName>.*?\-.*?\-.*?\-.*?\-.*?) (?<logTag>.*?\|.*?\|.*?\|.*?\|.*?\|) %{GREEDYDATA:logContents}"
      }
    }

    # 移除内容里的空格
    mutate {
    
        gsub => ["logContents", "; ", ";"]
    }

    # 解析kv
    kv {
   
        source => "logContents"
        field_split => " "
        value_split => "="
    }

    # 还原内容里的空格
    mutate {
    
        gsub => ["breachContents", ";", "; "]
    }

    # 匹配ISO8601
    date {
   
        match => ["messageTime", "ISO8601"]
        target => "@timestamp"
    }

    # 移除字段
    mutate {
   
        remove_field => ["logContents", "message"]
    }
}

2. 网络认证日志接入

原始日志（已经过全量严格脱敏）：

{
   
  "severity": 0,
  "priority": 0,
  "facility_label": "kernel",
  "type": "clearpass_syslog",
  "host": "[脱敏后的IP地址]",
  "severity_label": "Emergency",
  "message": "<143>Nov 29 2022 11:23:56 [脱敏后的IP地址] CEF:0|Aruba Networks|ClearPass|6.10.6.186545|1000|RADIUS Authentications|1|cat=Insight Logs dvc=[脱敏后的IP地址] duser=[脱敏后的用户名] dmac=[脱敏后的MAC地址] cs2=[脱敏后的值] cs2Label=Authentication Protocol src=[脱敏后的IP地址] cs4=[脱敏后的值] cs4Label=Login Status destinationServiceName=[脱敏后的值] cs3=[脱敏后的值] cs3Label=Authentication Source dpriv=[脱敏后的值]|[脱敏后的值] cs5=[脱敏后的值] cs5Label=Enforcement Profiles\n",
  "facility": 0
}

filter 规则如下：

filter {
   
    grok {
   
        match => {
   
          "message" => "<%{NUMBER:message_type_id}>(?<message_time>%{MONTH}%{SPACE}%{MONTHDAY}%{SPACE}%{YEAR}%{SPACE}%{TIME})%{SPACE}%{IP:message_ip}%{SPACE}(?<message_cef>.*?\|)(?<networks>.*?\|)(?<message_type>.*?\|)(?<message_info>.*?\|)(?<message_number>.*?\|)(?<message_logged>.*?\|)(?<message_flag>.*?\|)%{GREEDYDATA:logContents}"
        }
    }

    # 移除外层分隔符
    mutate {
   
        gsub => ["message_cef", "\|", "",
                 "message_number", "\|", "",
                 "message_type", "\|", "",
                 "networks", "\|", "",
                 "message_info", "\|", "",
                 "message_flag", "\|", "",
                 "message_logged", "\|", ""
                ]
    }

    # 移除末尾回车
    mutate {
   
        gsub => ["logContents", "\\n", ""]
    }

    # 解析kv
    kv {
   
        source => "logContents"
        field_split => " "
        value_split => "="
    }

    # 补全因空格分隔符造成value丢失的数据
    mutate {
   
        gsub => ["cat", "Session", "Session Logs",
                 "cat", "Insight", "Insight Logs",
                 "cs1Label", "Login", "Login Status",
                 "cs2Label", "Authentication", "Authentication Protocol",
                 "cs4Label", "Login", "Login Status",
                 "cs3Label", "Authentication", "Authentication Source",
                 "cs5Label", "Enforcement", "Enforcement Profiles",
                 "dpriv", "\[Guest\]\|\[User", "Guest|User Authenticated"
                ]
    }

    # 移除字段
    mutate {
   
        remove_field => ["severity","severity_label","type","priority","host","facility","facility_label"]
    }
}

3. 终端日志接入

原始日志（已经过全量严格脱敏）：

2022-06-06T00:56:25.042Z [脱敏] <6>2022-06-06T08:56:25+08:00 [脱敏] HRESS[2100]: {
   "center_version":"1.0.37.0","event":{
   "time":1654476985,"client_id":3412,"hostname":"[脱敏]","group_name":"[脱敏]","class":1,"rule_name":"IE首页项","action":4,"proc_path":"C:\Program Files (x86)\Tencent\QQPCMgr\13.5.20525.234\QQPCTray.exe","cmdline":""C:\Program Files (x86)\Tencent\QQPCMgr\13.5.20525.234\QQPCTray.exe" /elevated /regrun","res_path":"HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Start Page","res_val":"https://hao.qq.com/?unc=Af31026\u0026s=o400493_1","treatment":131075},"event_type":"系统加固"}
2022-06-07T11:03:25.000Z [脱敏] {
   "center_version":"1.0.37.0","event":{
   "time":1654599805,"client_id":71,"hostname":"[脱敏]","group_name":"[脱敏]","class":"rogue","domain":"[脱敏]"},"event_type":"恶意网站拦截"}
2022-06-07T10:57:25.000Z [脱敏] {
   "center_version":"1.0.37.0","event":{
   "time":1654599445,"client_id":1835,"hostname":"[脱敏]","group_name":"[脱敏]","software_name":"搜狗输入法","proc_path":"C:\Program Files\Google\Chrome\Application\chrome.exe","file_path":"C:\Users\linsu\Downloads\sogou_pinyin_121b.exe","treatment":0},"event_type":"软件安装拦截"}
2022-06-08T01:34:25.000Z [脱敏] {
   "center_version":"1.0.37.0","event":{
   "time":1654652065,"client_id":3178,"hostname":"[脱敏]","group_name":"[脱敏]","kbid":"5005260","desc":"现已确认 Microsoft 软件产品中存在可能会影响您的系统的安全问题。您可以通过安装本 Microsoft 更新程序来保护您的系统不受侵害。有关本更新程序中所含问题的完整列表，请参阅相关 Microsoft 知识库文章。安装本更新程序之后，可能需要重新启动系统。","level":0,"state":7},"event_type":"漏洞修复"}
2022-06-08T01:50:25.000Z [脱敏] {
   "center_version":"1.0.37.0","event":{
   "time":1654653025,"client_id":2925,"hostname":"[脱敏]","group_name":"[脱敏]","software_name":"360画报","proc_path":"C:\360浏览器\360se6\Application\components\sesvc\sesvc.exe","file_path":"C:\360浏览器\360se6\Application\components\huabao\13.0.42.0\360hb_inst.exe","treatment":3},"event_type":"软件安装拦截"}

filter 规则如下：

filter {
   
  ruby {
   
    code => 'event.set("space_num", event.get("message").split("{")[0].count(" "))'
  }

  if [space_num] == 5 {
   
    grok {
   
      match => {
   "message" => "%{TIMESTAMP_ISO8601:message_time} %{IP:client_ip} (\<.*?\>%{TIMESTAMP_ISO8601:data_time}) (%{DATA:logsource}) %{DATA:program} %{GREEDYDATA:HRESS2100}"}
    }
  }

  if [space_num] == 2 {
   
    grok {
   
      match => {
   "message" => "%{TIMESTAMP_ISO8601:message_time} %{IP:client_ip} %{GREEDYDATA:HRESS2100}"}
    }
  }

  if [space_num] == 0 {
   
    grok {
   
      match => {
   "message" => "%{GREEDYDATA:HRESS2100}"}
    }
  }

  json {
   
    source => "HRESS2100"
  }

  mutate {
   
    add_field => {
   "@event" => "%{event}"}
  }

  json {
   
    source => "@event"  #再进行解析
  }

  mutate {
   
    # 修改字段类型
    convert => ["time", "string"]
    convert => ["client_id", "string"]
    convert => ["priority", "string"] 
    convert => ["severity", "string"] 
    convert => ["facility", "string"]
  }

  date {
   
    match => ["time", "UNIX"]
    target => "@timestamp"
  }

  # 移除字段
  mutate {
   
    remove_field => [ "HRESS2100" , "message", "@event", "event", "space_num"]
  }
}

附录

官方提供的预定义 grok 表达式

USERNAME [a-zA-Z0-9._-]+
USER %{
   USERNAME}
EMAILLOCALPART [a-zA-Z][a-zA-Z0-9_.+-=:]+
EMAILADDRESS %{
   EMAILLOCALPART}@%{
   HOSTNAME}
INT (?:[+-]?(?:[0-9]+))
BASE10NUM (?<![0-9.+-])(?>[+-]?(?:(?:[0-9]+(?:\.[0-9]+)?)|(?:\.[0-9]+)))
NUMBER (?:%{
   BASE10NUM})
BASE16NUM (?<![0-9A-Fa-f])(?:[+-]?(?:0x)?(?:[0-9A-Fa-f]+))
BASE16FLOAT \b(?<![0-9A-Fa-f.])(?:[+-]?(?:0x)?(?:(?:[0-9A-Fa-f]+(?:\.[0-9A-Fa-f]*)?)|(?:\.[0-9A-Fa-f]+)))\b

POSINT \b(?:[1-9][0-9]*)\b
NONNEGINT \b(?:[0-9]+)\b
WORD \b\w+\b
NOTSPACE \S+
SPACE \s*
DATA .*?
GREEDYDATA .*
QUOTEDSTRING (?>(?<!\\)(?>"(?>\\.|[^\\"]+)+"|""|(?>'(?>\\.|[^\\']+)+')|''|(?>`(?>\\.|[^\\`]+)+`)|``))
UUID [A-Fa-f0-9]{
   8}-(?:[A-Fa-f0-9]{
   4}-){
   3}[A-Fa-f0-9]{
   12}
# URN, allowing use of RFC 2141 section 2.3 reserved characters
URN urn:[0-9A-Za-z][0-9A-Za-z-]{
   0,31}:(?:%[0-9a-fA-F]{
   2}|[0-9A-Za-z()+,.:=@;$_!*'/?#-])+

# Networking
MAC (?:%{
   CISCOMAC}|%{
   WINDOWSMAC}|%{
   COMMONMAC})
CISCOMAC (?:(?:[A-Fa-f0-9]{
   4}\.){
   2}[A-Fa-f0-9]{
   4})
WINDOWSMAC (?:(?:[A-Fa-f0-9]{
   2}-){
   5}[A-Fa-f0-9]{
   2})
COMMONMAC (?:(?:[A-Fa-f0-9]{
   2}:){
   5}[A-Fa-f0-9]{
   2})
IPV6 ((([0-9A-Fa-f]{
   1,4}:){
   7}([0-9A-Fa-f]{
   1,4}|:))|(([0-9A-Fa-f]{
   1,4}:){
   6}(:[0-9A-Fa-f]{
   1,4}|((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){
   3})|:))|(([0-9A-Fa-f]{
   1,4}:){
   5}(((:[0-9A-Fa-f]{
   1,4}){
   1,2})|:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){
   3})|:))|(([0-9A-Fa-f]{
   1,4}:){
   4}(((:[0-9A-Fa-f]{
   1,4}){
   1,3})|((:[0-9A-Fa-f]{
   1,4})?:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){
   3}))|:))|(([0-9A-Fa-f]{
   1,4}:){
   3}(((:[0-9A-Fa-f]{
   1,4}){
   1,4})|((:[0-9A-Fa-f]{
   1,4}){
   0,2}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){
   3}))|:))|(([0-9A-Fa-f]{
   1,4}:){
   2}(((:[0-9A-Fa-f]{
   1,4}){
   1,5})|((:[0-9A-Fa-f]{
   1,4}){
   0,3}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){
   3}))|:))|(([0-9A-Fa-f]{
   1,4}:){
   1}(((:[0-9A-Fa-f]{
   1,4}){
   1,6})|((:[0-9A-Fa-f]{
   1,4}){
   0,4}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){
   3}))|:))|(:(((:[0-9A-Fa-f]{
   1,4}){
   1,7})|((:[0-9A-Fa-f]{
   1,4}){
   0,5}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){
   3}))|:)))(%.+)?
IPV4 (?<![0-9])(?:(?:[0-1]?[0-9]{
   1,2}|2[0-4][0-9]|25[0-5])[.](?:[0-1]?[0-9]{
   1,2}|2[0-4][0-9]|25[0-5])[.](?:[0-1]?[0-9]{
   1,2}|2[0-4][0-9]|25[0-5])[.](?:[0-1]?[0-9]{
   1,2}|2[0-4][0-9]|25[0-5]))(?![0-9])
IP (?:%{
   IPV6}|%{
   IPV4})
HOSTNAME \b(?:[0-9A-Za-z][0-9A-Za-z-]{
   0,62})(?:\.(?:[0-9A-Za-z][0-9A-Za-z-]{
   0,62}))*(\.?|\b)
IPORHOST (?:%{
   IP}|%{
   HOSTNAME})
HOSTPORT %{
   IPORHOST}:%{
   POSINT}

# paths
PATH (?:%{
   UNIXPATH}|%{
   WINPATH})
UNIXPATH (/([\w_%!$@:.,+~-]+|\\.)*)+
TTY (?:/dev/(pts|tty([pq])?)(\w+)?/?(?:[0-9]+))
WINPATH (?>[A-Za-z]+:|\\)(?:\\[^\\?*]*)+
URIPROTO [A-Za-z]([A-Za-z0-9+\-.]+)+
URIHOST %{
   IPORHOST}(?::%{
   POSINT:port})?
# uripath comes loosely from RFC1738, but mostly from what Firefox
# doesn't turn into %XX
URIPATH (?:/[A-Za-z0-9$.+!*'(){
   },~:;=@#%&_\-]*)+
#URIPARAM \?(?:[A-Za-z0-9]+(?:=(?:[^&]*))?(?:&(?:[A-Za-z0-9]+(?:=(?:[^&]*))?)?)*)?
URIPARAM \?[A-Za-z0-9$.+!*'|(){
   },~@#%&/=:;_?\-\[\]<>]*
URIPATHPARAM %{
   URIPATH}(?:%{
   URIPARAM})?
URI %{
   URIPROTO}://(?:%{
   USER}(?::[^@]*)?@)?(?:%{
   URIHOST})?(?:%{
   URIPATHPARAM})?

# Months: January, Feb, 3, 03, 12, December
MONTH \b(?:[Jj]an(?:uary|uar)?|[Ff]eb(?:ruary|ruar)?|[Mm](?:a|ä)?r(?:ch|z)?|[Aa]pr(?:il)?|[Mm]a(?:y|i)?|[Jj]un(?:e|i)?|[Jj]ul(?:y)?|[Aa]ug(?:ust)?|[Ss]ep(?:tember)?|[Oo](?:c|k)?t(?:ober)?|[Nn]ov(?:ember)?|[Dd]e(?:c|z)(?:ember)?)\b
MONTHNUM (?:0?[1-9]|1[0-2])
MONTHNUM2 (?:0[1-9]|1[0-2])
MONTHDAY (?:(?:0[1-9])|(?:[12][0-9])|(?:3[01])|[1-9])

# Days: Monday, Tue, Thu, etc...
DAY (?:Mon(?:day)?|Tue(?:sday)?|Wed(?:nesday)?|Thu(?:rsday)?|Fri(?:day)?|Sat(?:urday)?|Sun(?:day)?)

# Years?
YEAR (?>\d\d){
   1,2}
HOUR (?:2[0123]|[01]?[0-9])
MINUTE (?:[0-5][0-9])
# '60' is a leap second in most time standards and thus is valid.
SECOND (?:(?:[0-5]?[0-9]|60)(?:[:.,][0-9]+)?)
TIME (?!<[0-9])%{
   HOUR}:%{
   MINUTE}(?::%{
   SECOND})(?![0-9])
# datestamp is YYYY/MM/DD-HH:MM:SS.UUUU (or something like it)
DATE_US %{
   MONTHNUM}[/-]%{
   MONTHDAY}[/-]%{
   YEAR}
DATE_EU %{
   MONTHDAY}[./-]%{
   MONTHNUM}[./-]%{
   YEAR}
ISO8601_TIMEZONE (?:Z|[+-]%{
   HOUR}(?::?%{
   MINUTE}))
ISO8601_SECOND (?:%{
   SECOND}|60)
TIMESTAMP_ISO8601 %{
   YEAR}-%{
   MONTHNUM}-%{
   MONTHDAY}[T ]%{
   HOUR}:?%{
   MINUTE}(?::?%{
   SECOND})?%{
   ISO8601_TIMEZONE}?
DATE %{
   DATE_US}|%{
   DATE_EU}
DATESTAMP %{
   DATE}[- ]%{
   TIME}
TZ (?:[APMCE][SD]T|UTC)
DATESTAMP_RFC822 %{
   DAY} %{
   MONTH} %{
   MONTHDAY} %{
   YEAR} %{
   TIME} %{
   TZ}
DATESTAMP_RFC2822 %{
   DAY}, %{
   MONTHDAY} %{
   MONTH} %{
   YEAR} %{
   TIME} %{
   ISO8601_TIMEZONE}
DATESTAMP_OTHER %{
   DAY} %{
   MONTH} %{
   MONTHDAY} %{
   TIME} %{
   TZ} %{
   YEAR}
DATESTAMP_EVENTLOG %{
   YEAR}%{
   MONTHNUM2}%{
   MONTHDAY}%{
   HOUR}%{
   MINUTE}%{
   SECOND}

# Syslog Dates: Month Day HH:MM:SS
SYSLOGTIMESTAMP %{
   MONTH} +%{
   MONTHDAY} %{
   TIME}
PROG [\x21-\x5a\x5c\x5e-\x7e]+
SYSLOGPROG %{
   PROG:program}(?:\[%{
   POSINT:pid}\])?
SYSLOGHOST %{
   IPORHOST}
SYSLOGFACILITY <%{
   NONNEGINT:facility}.%{
   NONNEGINT:priority}>
HTTPDATE %{
   MONTHDAY}/%{
   MONTH}/%{
   YEAR}:%{
   TIME} %{
   INT}

# Shortcuts
QS %{
   QUOTEDSTRING}

# Log formats
SYSLOGBASE %{
   SYSLOGTIMESTAMP:timestamp} (?:%{
   SYSLOGFACILITY} )?%{
   SYSLOGHOST:logsource} %{
   SYSLOGPROG}:

# Log Levels
LOGLEVEL ([Aa]lert|ALERT|[Tt]race|TRACE|[Dd]ebug|DEBUG|[Nn]otice|NOTICE|[Ii]nfo|INFO|[Ww]arn?(?:ing)?|WARN?(?:ING)?|[Ee]rr?(?:or)?|ERR?(?:OR)?|[Cc]rit?(?:ical)?|CRIT?(?:ICAL)?|[Ff]atal|FATAL|[Ss]evere|SEVERE|EMERG(?:ENCY)?|[Ee]merg(?:ency)?)