The Valve Component

Introduction

A Valve element represents a component that will be inserted into the request processing pipeline for the associated Catalina container (Engine, Host, or Context). Individual Valves have distinct processing capabilities, and are described individually below.

The description below uses the variable name $CATALINA_HOME to refer to the directory into which you have installed JBoss Web, and is the base directory against which most relative paths are resolved. However, if you have configured JBoss Web for multiple instances by setting a CATALINA_BASE directory, you should use $CATALINA_BASE instead of $CATALINA_HOME for each of these references.

Access Log Valve

Introduction

The Access Log Valve creates log files in the same format as those created by standard web servers. These logs can later be analyzed by standard log analysis tools to track page hit counts, user session activity, and so on. The files produces by this Valve are rolled over nightly at midnight. This Valve may be associated with any Catalina container (Context, Host, or Engine), and will record ALL requests processed by that container.

Attributes

The Access Log Valve supports the following configuration attributes:

Attribute	Description
className	Java class name of the implementation to use. This MUST be set to org.apache.catalina.valves.AccessLogValve to use the default access log valve.
directory	Absolute or relative pathname of a directory in which log files created by this valve will be placed. If a relative path is specified, it is interpreted as relative to $CATALINA_HOME. If no directory attribute is specified, the default value is "logs" (relative to $CATALINA_HOME).
pattern	A formatting layout identifying the various information fields from the request and response to be logged, or the word common or combined to select a standard format. See below for more information on configuring this attribute. Note that the optimized access does only support common and combined as the value for this attribute.
prefix	The prefix added to the start of each log file's name. If not specified, the default value is "access_log.". To specify no prefix, use a zero-length string.
resolveHosts	Set to true to convert the IP address of the remote host into the corresponding host name via a DNS lookup. Set to false to skip this lookup, and report the remote IP address instead.
suffix	The suffix added to the end of each log file's name. If not specified, the default value is "". To specify no suffix, use a zero-length string.
rotatable	Deafult true. Flag to determine if log rotation should occur. If set to false, then this file is never rotated and fileDateFormat is ignored. Use with caution!
condition	Turns on conditional logging. If set, requests will be logged only if ServletRequest.getAttribute() is null. For example, if this value is set to junk, then a particular request will only be logged if ServletRequest.getAttribute("junk") == null. The use of Filters is an easy way to set/unset the attribute in the ServletRequest on many different requests.
fileDateFormat	Allows a customized date format in the access log file name. The date format also decides how often the file is rotated. If you wish to rotate every hour, then set this value to: yyyy-MM-dd.HH
buffered	Deafult true. Flag to determine if logging will be buffered. If set to false, then access logging will be written after each request.

Values for the pattern attribute are made up of literal text strings, combined with pattern identifiers prefixed by the "%" character to cause replacement by the corresponding variable value from the current request and response. The following pattern codes are supported:

• %a - Remote IP address
• %A - Local IP address
• %b - Bytes sent, excluding HTTP headers, or '-' if zero
• %B - Bytes sent, excluding HTTP headers
• %h - Remote host name (or IP address if resolveHosts is false)
• %H - Request protocol
• %l - Remote logical username from identd (always returns '-')
• %m - Request method (GET, POST, etc.)
• %p - Local port on which this request was received
• %q - Query string (prepended with a '?' if it exists)
• %r - First line of the request (method and request URI)
• %s - HTTP status code of the response
• %S - User session ID
• %t - Date and time, in Common Log Format
• %u - Remote user that was authenticated (if any), else '-'
• %U - Requested URL path
• %v - Local server name
• %D - Time taken to process the request, in millis
• %T - Time taken to process the request, in seconds
• %I - current request thread name (can compare later with stacktraces)

There is also support to write information from the cookie, incoming header, the Session or something else in the ServletRequest. It is modeled after the apache syntax:

• %{xxx}i for incoming headers
• %{xxx}o for outgoing response headers
• %{xxx}c for a specific cookie
• %{xxx}r xxx is an attribute in the ServletRequest
• %{xxx}s xxx is an attribute in the HttpSession

The shorthand pattern name common (which is also the default) corresponds to '%h %l %u %t "%r" %s %b'.

The shorthand pattern name combined appends the values of the Referer and User-Agent headers, each in double quotes, to the common pattern described in the previous paragraph.

Remote Address Filter

Introduction

The Remote Address Filter allows you to compare the IP address of the client that submitted this request against one or more regular expressions, and either allow the request to continue or refuse to process the request from this client. A Remote Address Filter can be associated with any Catalina container (Engine, Host, or Context), and must accept any request presented to this container for processing before it will be passed on.

The syntax for regular expressions is different than that for 'standard' wildcard matching. JBoss Web uses the java.util.regex package. Please consult the Java documentation for details of the expressions supported.

Attributes

The Remote Address Filter supports the following configuration attributes:

Attribute	Description
className	Java class name of the implementation to use. This MUST be set to org.apache.catalina.valves.RemoteAddrValve.
allow	A comma-separated list of regular expression patterns that the remote client's IP address is compared to. If this attribute is specified, the remote address MUST match for this request to be accepted. If this attribute is not specified, all requests will be accepted UNLESS the remote address matches a deny pattern.
deny	A comma-separated list of regular expression patterns that the remote client's IP address is compared to. If this attribute is specified, the remote address MUST NOT match for this request to be accepted. If this attribute is not specified, request acceptance is governed solely by the accept attribute.

Remote Host Filter

Introduction

The Remote Host Filter allows you to compare the hostname of the client that submitted this request against one or more regular expressions, and either allow the request to continue or refuse to process the request from this client. A Remote Host Filter can be associated with any Catalina container (Engine, Host, or Context), and must accept any request presented to this container for processing before it will be passed on.

The syntax for regular expressions is different than that for 'standard' wildcard matching. JBoss Web uses the java.util.regex package. Please consult the Java documentation for details of the expressions supported.

Attributes

The Remote Host Filter supports the following configuration attributes:

Attribute	Description
className	Java class name of the implementation to use. This MUST be set to org.apache.catalina.valves.RemoteHostValve.
allow	A comma-separated list of regular expression patterns that the remote client's hostname is compared to. If this attribute is specified, the remote hostname MUST match for this request to be accepted. If this attribute is not specified, all requests will be accepted UNLESS the remote hostname matches a deny pattern.
deny	A comma-separated list of regular expression patterns that the remote client's hostname is compared to. If this attribute is specified, the remote hostname MUST NOT match for this request to be accepted. If this attribute is not specified, request acceptance is governed solely by the accept attribute.

Request Dumper Valve

Introduction

The Request Dumper Valve is a useful tool in debugging interactions with a client application (or browser) that is sending HTTP requests to your JBoss Web-based server. When configured, it causes details about each request processed by its associated Engine, Host, or Context to be logged according to the logging configuration for that container.

WARNING: Using this valve has side-effects. The output from this valve includes any parameters included with the request. The parameters will be decoded using the default platform encoding. Any subsequent calls to request.setCharacterEncoding() within the web application will have no effect.

Attributes

The Request Dumper Valve supports the following configuration attributes:

Attribute	Description
className	Java class name of the implementation to use. This MUST be set to org.apache.catalina.valves.RequestDumperValve.

Single Sign On Valve

Introduction

The Single Sign On Vale is utilized when you wish to give users the ability to sign on to any one of the web applications associated with your virtual host, and then have their identity recognized by all other web applications on the same virtual host.

See the Single Sign On special feature on the Host element for more information.

Attributes

The Single Sign On Valve supports the following configuration attributes:

Attribute	Description
className	Java class name of the implementation to use. This MUST be set to org.apache.catalina.authenticator.SingleSignOn.
requireReauthentication	Default false. Flag to determine whether each request needs to be reauthenticated to the security Realm. If "true", this Valve uses cached security credentials (username and password) to reauthenticate to the Realm each request associated with an SSO session. If "false", the Valve can itself authenticate requests based on the presence of a valid SSO cookie, without rechecking with the Realm.
cookieDomain	Sets the host domain to be used for sso cookies.

Form Authenticator Valve

Introduction

The Form Authenticator Valve is automatically added to any Context that is configured to use FORM authentication.

If any non-default settings are required, the valve may be configured within Context element with the required values.

Attributes

The Form Authenticator Valve supports the following configuration attributes:

Attribute	Description
className	Java class name of the implementation to use. This MUST be set to org.apache.catalina.authenticator.FormAuthenticator.
characterEncoding	Character encoding to use to read the username and password parameters from the request. If not set, the encoding of the request body will be used.

Remote IP Valve

Introduction

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 may be used at the Engine, Host or Context level as required. Normally, this Valve would be used at the Engine level.

If used in conjunction with Remote Address/Host valves then this valve should be defined first to ensure that the correct client IP address is presented to the Remote Address/Host valves.

Attributes

The Remote IP Valve supports the following configuration attributes:

Attribute	Description
className	Java class name of the implementation to use. This MUST be set to org.apache.catalina.valves.RemoteIpValve.
remoteIPHeader	Name of the HTTP Header read by this valve that holds the list of traversed IP addresses starting from the requesting client. If not specified, the default of x-forwarded-for is used.
internalProxies	List of internal proxies' IP addresses as comma separated regular expressions. If they appear in the remoteIpHeader value, they will be trusted and will not appear in the proxiesHeader value. If not specified the default value of 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} will be used.
proxiesHeader	Name of the HTTP header created by this valve to hold the list of proxies that have been processed in the incoming remoteIpHeader. If not specified, the default of x-forwarded-by is used.
trustedProxies	List of trusted proxies' IP addresses as comma separated regular expressions. If they appear in the remoteIpHeader value, they will be trusted and will appear in the proxiesHeader value. If not specified, no proxies will be trusted.
protocolHeader	Name of the HTTP Header read by this valve that holds the protocol used by the client to connect to the proxy. If not specified, the default of null is used.
protocolHeaderHttpsValue	Value of the protocolHeader to indicate that it is an HTTPS request. If not specified, the default of https is used.