Apache Tomcat 7.0.42

## 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

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

Regular expression that matches the IP addresses of internal proxies. If they appear in the `remoteIpHeader` value, they will be trusted and will not appear in the `proxiesHeader` value

RemoteIPInternalProxy

Regular expression (in the syntax supported by `java.util.regex`)

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` | proxiesHeader | Compliant http header name | x-forwarded-by
trustedProxies | Regular expression that matches the IP addresses of trusted proxies. If they appear in the `remoteIpHeader` value, they will be trusted and will appear in the `proxiesHeader` value | RemoteIPTrustedProxy | Regular expression (in the syntax supported by `java.util.regex`) |
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"
       proxiesHeader="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"
       proxiesHeader="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"
       proxiesHeader="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"
       proxiesHeader="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

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

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

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

Constructor Summary
`RemoteIpValve()` Default constructor that ensures `ValveBase.ValveBase(boolean)` is called with `true`.

Method Summary
`protected static String[]` `commaDelimitedListToStringArray(String commaDelimitedStrings)` Convert a given comma delimited String into an array of String
`int` `getHttpServerPort()`
`int` `getHttpsServerPort()`
`String` `getInfo()` Return descriptive information about this Valve implementation.
`String` `getInternalProxies()`
`String` `getPortHeader()` Obtain the name of the HTTP header used to override the value returned by `Request.getServerPort()` and (optionally depending on {link `isChangeLocalPort()` `Request.getLocalPort()`.
`String` `getProtocolHeader()`
`String` `getProtocolHeaderHttpsValue()`
`String` `getProxiesHeader()`
`String` `getRemoteIpHeader()`
`boolean` `getRequestAttributesEnabled()`
`String` `getTrustedProxies()`
`void` `invoke(Request request, Response response)` The implementation-specific logic represented by this Valve.
`boolean` `isChangeLocalPort()`
`protected static String` `listToCommaDelimitedString(List<String> stringList)` Convert an array of strings in a comma delimited string
`void` `setChangeLocalPort(boolean changeLocalPort)`
`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 internalProxies)` Regular expression that defines the internal proxies.
`void` `setPortHeader(String portHeader)` Set the name of the HTTP header used to override the value returned by `Request.getServerPort()` and (optionally depending on {link `isChangeLocalPort()` `Request.getLocalPort()`.
`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` `setRequestAttributesEnabled(boolean requestAttributesEnabled)` Should this valve set request attributes for IP address, Hostname, protocol and port used for the request?
`void` `setTrustedProxies(String trustedProxies)` Regular expression defining 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`

Constructor Detail

### RemoteIpValve

    public RemoteIpValve()

  Default constructor that ensures `ValveBase.ValveBase(boolean)` is called with `true`.

Method Detail

### commaDelimitedListToStringArray

    protected static String[] commaDelimitedListToStringArray(String commaDelimitedStrings)

  Convert a given comma delimited String into an array of String

  Returns:
    array of String (non `null`)

### listToCommaDelimitedString

    protected static String listToCommaDelimitedString(List<String> stringList)

  Convert an array of strings in a comma delimited string

### getHttpsServerPort

    public int getHttpsServerPort()

### getHttpServerPort

    public int getHttpServerPort()

### isChangeLocalPort

    public boolean isChangeLocalPort()

### setChangeLocalPort

    public void setChangeLocalPort(boolean changeLocalPort)

### getPortHeader

    public String getPortHeader()

  Obtain the name of the HTTP header used to override the value returned by `Request.getServerPort()` and (optionally depending on {link `isChangeLocalPort()` `Request.getLocalPort()`.

  Returns:
    The HTTP header name

### setPortHeader

    public void setPortHeader(String portHeader)

  Set the name of the HTTP header used to override the value returned by `Request.getServerPort()` and (optionally depending on {link `isChangeLocalPort()` `Request.getLocalPort()`.

  Parameters:
    `portHeader` - The HTTP header name

### 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:
    Regular expression that defines the 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)`

### getRequestAttributesEnabled

    public boolean getRequestAttributesEnabled()

  Returns:
    `true` if the attributes will be logged, otherwise `false`
  See Also:
    `setRequestAttributesEnabled(boolean)`

### getTrustedProxies

    public String getTrustedProxies()

  Returns:
    Regular expression that defines the 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 internalProxies)

  Regular expression that defines the internal proxies.

  Default value : 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}

### 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` -

### setRequestAttributesEnabled

    public void setRequestAttributesEnabled(boolean requestAttributesEnabled)

  Should this valve set request attributes for IP address, Hostname, protocol and port used for the request? This are typically used in conjunction with the `AccessLog` which will otherwise log the original values. Default is `true`. The attributes set are:
  - org.apache.catalina.AccessLog.RemoteAddr
  - org.apache.catalina.AccessLog.RemoteHost
  - org.apache.catalina.AccessLog.Protocol
  - org.apache.catalina.AccessLog.ServerPort

  Parameters:
    `requestAttributesEnabled` - `true` causes the attributes to be set, `false` disables the setting of the attributes.

### setTrustedProxies

    public void setTrustedProxies(String trustedProxies)

  Regular expression defining proxies that are trusted when they appear in the `remoteIpHeader` header.

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

Apache Tomcat 7.0.42

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