RemoteIpValve (Apache Tomcat 7.0.4 API Documentation)

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Apache Tomcat 7.0.4

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org.apache.catalina.valves
Class RemoteIpValve

java.lang.Object
  org.apache.catalina.util.LifecycleBase
      org.apache.catalina.util.LifecycleMBeanBase
          org.apache.catalina.valves.ValveBase
              org.apache.catalina.valves.RemoteIpValve

All Implemented Interfaces:: MBeanRegistration, Contained, Lifecycle, Valve

public class RemoteIpValve
extends ValveBase
extends ValveBase

Tomcat port of mod_remoteip, this valve replaces the apparent client remote IP address and hostname for the request with the IP address list presented by a proxy or a load balancer via a request headers (e.g. "X-Forwarded-For").

Another feature of this valve is to replace the apparent scheme (http/https) and server port with the scheme presented by a proxy or a load balancer via a request header (e.g. "X-Forwarded-Proto").

This valve proceeds as follows:

If the incoming request.getRemoteAddr() matches the valve's list of internal proxies :

Loop on the comma delimited list of IPs and hostnames passed by the preceding load balancer or proxy in the given request's Http header named $remoteIpHeader (default value x-forwarded-for). Values are processed in right-to-left order.
For each ip/host of the list:
- if it matches the internal proxies list, the ip/host is swallowed
- if it matches the trusted proxies list, the ip/host is added to the created proxies header
- otherwise, the ip/host is declared to be the remote ip and looping is stopped.
If the request http header named $protocolHeader (e.g. x-forwarded-for) equals to the value of protocolHeaderHttpsValue configuration parameter (default https) then request.isSecure = true, request.scheme = https and request.serverPort = 443. Note that 443 can be overwritten with the $httpsServerPort configuration parameter.

Configuration parameters:

RemoteIpValve property	Description	Equivalent mod_remoteip directive	Format	Default Value
remoteIpHeader	Name of the Http Header read by this valve that holds the list of traversed IP addresses starting from the requesting client	RemoteIPHeader	Compliant http header name	x-forwarded-for
internalProxies	List of internal proxies ip adress. If they appear in the `remoteIpHeader` value, they will be trusted and will not appear in the `proxiesHeader` value	RemoteIPInternalProxy	Comma delimited list of regular expressions (in the syntax supported by the `Pattern` library)	10\.\d{1,3}\.\d{1,3}\.\d{1,3}, 192\.168\.\d{1,3}\.\d{1,3}, 169\.254\.\d{1,3}\.\d{1,3}, 127\.\d{1,3}\.\d{1,3}\.\d{1,3} By default, 10/8, 192.168/16, 169.254/16 and 127/8 are allowed ; 172.16/12 has not been enabled by default because it is complex to describe with regular expressions
proxiesHeader	Name of the http header created by this valve to hold the list of proxies that have been processed in the incoming `remoteIpHeader`	RemoteIPProxiesHeader	Compliant http header name	x-forwarded-by
trustedProxies	List of trusted proxies ip adress. If they appear in the `remoteIpHeader` value, they will be trusted and will appear in the `proxiesHeader` value	RemoteIPTrustedProxy	Comma delimited list of regular expressions (in the syntax supported by the `Pattern` library)
protocolHeader	Name of the http header read by this valve that holds the flag that this request	N/A	Compliant http header name like `X-Forwarded-Proto`, `X-Forwarded-Ssl` or `Front-End-Https`	`null`
protocolHeaderHttpsValue	Value of the `protocolHeader` to indicate that it is an Https request	N/A	String like `https` or `ON`	`https`
httpServerPort	Value returned by `ServletRequest.getServerPort()` when the `protocolHeader` indicates `http` protocol	N/A	integer	80
httpsServerPort	Value returned by `ServletRequest.getServerPort()` when the `protocolHeader` indicates `https` protocol	N/A	integer	443

This Valve may be attached to any Container, depending on the granularity of the filtering you wish to perform.

Regular expression vs. IP address blocks: mod_remoteip allows to use address blocks (e.g. 192.168/16) to configure RemoteIPInternalProxy and RemoteIPTrustedProxy ; as Tomcat doesn't have a library similar to apr_ipsubnet_test, RemoteIpValve uses regular expression to configure internalProxies and trustedProxies in the same fashion as RequestFilterValve does.

Sample with internal proxies

RemoteIpValve configuration:

 <Valve 
   className="org.apache.catalina.valves.RemoteIpValve"
   internalProxies="192\.168\.0\.10, 192\.168\.0\.11"
   remoteIpHeader="x-forwarded-for"
   remoteIpProxiesHeader="x-forwarded-by"
   protocolHeader="x-forwarded-proto"
   />

Request values:

property	Value Before RemoteIpValve	Value After RemoteIpValve
request.remoteAddr	192.168.0.10	140.211.11.130
request.header['x-forwarded-for']	140.211.11.130, 192.168.0.10	null
request.header['x-forwarded-by']	null	null
request.header['x-forwarded-proto']	https	https
request.scheme	http	https
request.secure	false	true
request.serverPort	80	443

Note : x-forwarded-by header is null because only internal proxies as been traversed by the request. x-forwarded-by is null because all the proxies are trusted or internal.

Sample with trusted proxies

RemoteIpValve configuration:

 <Valve 
   className="org.apache.catalina.valves.RemoteIpValve"
   internalProxies="192\.168\.0\.10, 192\.168\.0\.11"
   remoteIpHeader="x-forwarded-for"
   remoteIpProxiesHeader="x-forwarded-by"
   trustedProxies="proxy1, proxy2"
   />

Request values:

property	Value Before RemoteIpValve	Value After RemoteIpValve
request.remoteAddr	192.168.0.10	140.211.11.130
request.header['x-forwarded-for']	140.211.11.130, proxy1, proxy2	null
request.header['x-forwarded-by']	null	proxy1, proxy2

Note : proxy1 and proxy2 are both trusted proxies that come in x-forwarded-for header, they both are migrated in x-forwarded-by header. x-forwarded-by is null because all the proxies are trusted or internal.

Sample with internal and trusted proxies

RemoteIpValve configuration:

 <Valve 
   className="org.apache.catalina.valves.RemoteIpValve"
   internalProxies="192\.168\.0\.10, 192\.168\.0\.11"
   remoteIpHeader="x-forwarded-for"
   remoteIpProxiesHeader="x-forwarded-by"
   trustedProxies="proxy1, proxy2"
   />

Request values:

property	Value Before RemoteIpValve	Value After RemoteIpValve
request.remoteAddr	192.168.0.10	140.211.11.130
request.header['x-forwarded-for']	140.211.11.130, proxy1, proxy2, 192.168.0.10	null
request.header['x-forwarded-by']	null	proxy1, proxy2

Note : proxy1 and proxy2 are both trusted proxies that come in x-forwarded-for header, they both are migrated in x-forwarded-by header. As 192.168.0.10 is an internal proxy, it does not appear in x-forwarded-by. x-forwarded-by is null because all the proxies are trusted or internal.

Sample with an untrusted proxy

RemoteIpValve configuration:

 <Valve 
   className="org.apache.catalina.valves.RemoteIpValve"
   internalProxies="192\.168\.0\.10, 192\.168\.0\.11"
   remoteIpHeader="x-forwarded-for"
   remoteIpProxiesHeader="x-forwarded-by"
   trustedProxies="proxy1, proxy2"
   />

Request values:

property	Value Before RemoteIpValve	Value After RemoteIpValve
request.remoteAddr	192.168.0.10	untrusted-proxy
request.header['x-forwarded-for']	140.211.11.130, untrusted-proxy, proxy1	140.211.11.130
request.header['x-forwarded-by']	null	proxy1

Note : x-forwarded-by holds the trusted proxy proxy1. x-forwarded-by holds 140.211.11.130 because untrusted-proxy is not trusted and thus, we can not trust that untrusted-proxy is the actual remote ip. request.remoteAddr is untrusted-proxy that is an IP verified by proxy1.

Field Summary
`protected static StringManager`	`sm` The StringManager for this package.

Fields inherited from class org.apache.catalina.valves.ValveBase
`asyncSupported, container, containerLog, next`

Fields inherited from class org.apache.catalina.util.LifecycleMBeanBase
`mserver`

Fields inherited from interface org.apache.catalina.Lifecycle
`AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, DESTROY_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT`

Constructor Summary
`RemoteIpValve()`

Method Summary
`protected static Pattern[]`	`commaDelimitedListToPatternArray(String commaDelimitedPatterns)` Convert a given comma delimited list of regular expressions into an array of compiled `Pattern`
`protected static String[]`	`commaDelimitedListToStringArray(String commaDelimitedStrings)` Convert a given comma delimited list of regular expressions into an array of String
`int`	`getHttpServerPort()`
`int`	`getHttpsServerPort()`
`String`	`getInfo()` Return descriptive information about this Valve implementation.
`String`	`getInternalProxies()`
`String`	`getProtocolHeader()`
`String`	`getProtocolHeaderHttpsValue()`
`String`	`getProxiesHeader()`
`String`	`getRemoteIpHeader()`
`String`	`getTrustedProxies()`
`void`	`invoke(Request request, Response response)` The implementation-specific logic represented by this Valve.
`protected static String`	`listToCommaDelimitedString(List<String> stringList)` Convert an array of strings in a comma delimited string
`protected static boolean`	`matchesOne(String str, Pattern... patterns)` Return `true` if the given `str` matches at least one of the given `patterns`.
`void`	`setHttpServerPort(int httpServerPort)` Server Port value if the `protocolHeader` is not `null` and does not indicate HTTP Default value : 80
`void`	`setHttpsServerPort(int httpsServerPort)` Server Port value if the `protocolHeader` indicates HTTPS Default value : 443
`void`	`setInternalProxies(String commaDelimitedInternalProxies)` Comma delimited list of internal proxies.
`void`	`setProtocolHeader(String protocolHeader)` Header that holds the incoming protocol, usally named `X-Forwarded-Proto`.
`void`	`setProtocolHeaderHttpsValue(String protocolHeaderHttpsValue)` Case insensitive value of the protocol header to indicate that the incoming http request uses SSL.
`void`	`setProxiesHeader(String proxiesHeader)` The proxiesHeader directive specifies a header into which mod_remoteip will collect a list of all of the intermediate client IP addresses trusted to resolve the actual remote IP.
`void`	`setRemoteIpHeader(String remoteIpHeader)` Name of the http header from which the remote ip is extracted.
`void`	`setTrustedProxies(String commaDelimitedTrustedProxies)` Comma delimited list of proxies that are trusted when they appear in the `remoteIpHeader` header.

Methods inherited from class org.apache.catalina.valves.ValveBase
`backgroundProcess, event, getContainer, getDomainInternal, getNext, getObjectNameKeyProperties, initInternal, isAsyncSupported, setAsyncSupported, setContainer, setNext, startInternal, stopInternal, toString`

Methods inherited from class org.apache.catalina.util.LifecycleMBeanBase
`destroyInternal, getDomain, getObjectName, postDeregister, postRegister, preDeregister, preRegister, register, setDomain, unregister`

Methods inherited from class org.apache.catalina.util.LifecycleBase
`addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, getStateName, init, removeLifecycleListener, setState, setState, start, stop`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Field Detail

sm

protected static final StringManager sm

The StringManager for this package.

Constructor Detail

RemoteIpValve

public RemoteIpValve()

Method Detail

commaDelimitedListToPatternArray

protected static Pattern[] commaDelimitedListToPatternArray(String commaDelimitedPatterns)

Convert a given comma delimited list of regular expressions into an array of compiled Pattern

Returns:: array of patterns (not null)

commaDelimitedListToStringArray

protected static String[] commaDelimitedListToStringArray(String commaDelimitedStrings)

Convert a given comma delimited list of regular expressions into an array of String

Returns:: array of patterns (non null)

listToCommaDelimitedString

protected static String listToCommaDelimitedString(List<String> stringList)

Convert an array of strings in a comma delimited string

matchesOne

protected static boolean matchesOne(String str,
                                    Pattern... patterns)

Return true if the given str matches at least one of the given patterns.

getHttpsServerPort

public int getHttpsServerPort()

getHttpServerPort

public int getHttpServerPort()

getInfo

public String getInfo()

Return descriptive information about this Valve implementation.

Specified by:: getInfo in interface Valve
Overrides:: getInfo in class ValveBase

getInternalProxies

public String getInternalProxies()

Returns:: comma delimited list of internal proxies
See Also:: setInternalProxies(String)

getProtocolHeader

public String getProtocolHeader()

Returns:: the protocol header (e.g. "X-Forwarded-Proto")
See Also:: setProtocolHeader(String)

getProtocolHeaderHttpsValue

public String getProtocolHeaderHttpsValue()

Returns:: the value of the protocol header for incoming https request (e.g. "https")
See Also:: setProtocolHeaderHttpsValue(String)

getProxiesHeader

public String getProxiesHeader()

Returns:: the proxies header name (e.g. "X-Forwarded-By")
See Also:: setProxiesHeader(String)

getRemoteIpHeader

public String getRemoteIpHeader()

Returns:: the remote IP header name (e.g. "X-Forwarded-For")
See Also:: setRemoteIpHeader(String)

getTrustedProxies

public String getTrustedProxies()

Returns:: comma delimited list of trusted proxies
See Also:: setTrustedProxies(String)

invoke

public void invoke(Request request,
                   Response response)
            throws IOException,
                   ServletException

The implementation-specific logic represented by this Valve. See the Valve description for the normal design patterns for this method.

This method MUST be provided by a subclass.

Specified by:: invoke in interface Valve
Specified by:: invoke in class ValveBase

Parameters:: request - The servlet request to be processed; response - The servlet response to be created
Throws:: IOException - if an input/output error occurs; ServletException - if a servlet error occurs

setHttpServerPort

public void setHttpServerPort(int httpServerPort)

Server Port value if the protocolHeader is not null and does not indicate HTTP

Default value : 80

setHttpsServerPort

public void setHttpsServerPort(int httpsServerPort)

Server Port value if the protocolHeader indicates HTTPS

Default value : 443

setInternalProxies

public void setInternalProxies(String commaDelimitedInternalProxies)

Comma delimited list of internal proxies. Can be expressed with regular expressions.

Default value : 10\.\d{1,3}\.\d{1,3}\.\d{1,3}, 192\.168\.\d{1,3}\.\d{1,3}, 127\.\d{1,3}\.\d{1,3}\.\d{1,3}

setProtocolHeader

public void setProtocolHeader(String protocolHeader)

Header that holds the incoming protocol, usally named X-Forwarded-Proto. If null, request.scheme and request.secure will not be modified.

Default value : null

setProtocolHeaderHttpsValue

public void setProtocolHeaderHttpsValue(String protocolHeaderHttpsValue)

Case insensitive value of the protocol header to indicate that the incoming http request uses SSL.

Default value : https

setProxiesHeader

public void setProxiesHeader(String proxiesHeader)

The proxiesHeader directive specifies a header into which mod_remoteip will collect a list of all of the intermediate client IP addresses trusted to resolve the actual remote IP. Note that intermediate RemoteIPTrustedProxy addresses are recorded in this header, while any intermediate RemoteIPInternalProxy addresses are discarded.

Name of the http header that holds the list of trusted proxies that has been traversed by the http request.

The value of this header can be comma delimited.

Default value : X-Forwarded-By

setRemoteIpHeader

public void setRemoteIpHeader(String remoteIpHeader)

Name of the http header from which the remote ip is extracted.

The value of this header can be comma delimited.

Default value : X-Forwarded-For

Parameters:: remoteIpHeader -

setTrustedProxies

public void setTrustedProxies(String commaDelimitedTrustedProxies)

Comma delimited list of proxies that are trusted when they appear in the remoteIpHeader header. Can be expressed as a regular expression.

Default value : empty list, no external proxy is trusted.

Overview

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Apache Tomcat 7.0.4

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org.apache.catalina.valves Class RemoteIpValve

sm

RemoteIpValve

commaDelimitedListToPatternArray

commaDelimitedListToStringArray

listToCommaDelimitedString

matchesOne

getHttpsServerPort

getHttpServerPort

getInfo

getInternalProxies

getProtocolHeader

getProtocolHeaderHttpsValue

getProxiesHeader

getRemoteIpHeader

getTrustedProxies

invoke

setHttpServerPort

setHttpsServerPort

setInternalProxies

setProtocolHeader

setProtocolHeaderHttpsValue

setProxiesHeader

setRemoteIpHeader

setTrustedProxies

org.apache.catalina.valves
Class RemoteIpValve