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| <modulesynopsis metafile="mod_remoteip.xml.meta"> |
| |
| <name>mod_remoteip</name> |
| <description>Replaces the original client IP address for the connection |
| with the useragent IP address list presented by a proxies or a load balancer |
| via the request headers. |
| </description> |
| |
| <status>Base</status> |
| <sourcefile>mod_remoteip.c</sourcefile> |
| <identifier>remoteip_module</identifier> |
| |
| <summary> |
| <p>This module is used to treat the useragent which initiated the |
| request as the originating useragent as identified by httpd for the |
| purposes of authorization and logging, even where that useragent is |
| behind a load balancer, front end server, or proxy server.</p> |
| |
| <p>The module overrides the client IP address for the connection |
| with the useragent IP address reported in the request header configured |
| with the <directive module="mod_remoteip">RemoteIPHeader</directive> directive.</p> |
| |
| <p>Once replaced as instructed, this overridden useragent IP address is |
| then used for the <module>mod_authz_host</module> |
| <directive module="mod_authz_core" name="require">Require ip</directive> |
| feature, is reported by <module>mod_status</module>, and is recorded by |
| <module>mod_log_config</module> <code>%a</code> and <module>core</module> |
| <code>%a</code> format strings. The underlying client IP of the connection |
| is available in the <code>%{c}a</code> format string.</p> |
| |
| <note type="warning">It is critical to only enable this behavior from |
| intermediate hosts (proxies, etc) which are trusted by this server, since |
| it is trivial for the remote useragent to impersonate another |
| useragent.</note> |
| </summary> |
| |
| <seealso><module>mod_authz_host</module></seealso> |
| <seealso><module>mod_status</module></seealso> |
| <seealso><module>mod_log_config</module></seealso> |
| |
| <section id="processing"><title>Remote IP Processing</title> |
| |
| <p>Apache by default identifies the useragent with the connection's |
| client_ip value, and the connection remote_host and remote_logname are |
| derived from this value. These fields play a role in authentication, |
| authorization and logging and other purposes by other loadable |
| modules.</p> |
| |
| <p>mod_remoteip overrides the client IP of the connection with the |
| advertised useragent IP as provided by a proxy or load balancer, for |
| the duration of the request. A load balancer might establish a long |
| lived keepalive connection with the server, and each request will |
| have the correct useragent IP, even though the underlying client IP |
| address of the load balancer remains unchanged.</p> |
| |
| <p>When multiple, comma delimited useragent IP addresses are listed in the |
| header value, they are processed in Right-to-Left order. Processing |
| halts when a given useragent IP address is not trusted to present the |
| preceding IP address. The header field is updated to this remaining |
| list of unconfirmed IP addresses, or if all IP addresses were trusted, |
| this header is removed from the request altogether.</p> |
| |
| <p>In overriding the client IP, the module stores the list of intermediate |
| hosts in a remoteip-proxy-ip-list note, which <module>mod_log_config</module> |
| can record using the <code>%{remoteip-proxy-ip-list}n</code> format token. |
| If the administrator needs to store this as an additional header, this |
| same value can also be recording as a header using the directive |
| <directive module="mod_remoteip">RemoteIPProxiesHeader</directive>.</p> |
| |
| <note><title>IPv4-over-IPv6 Mapped Addresses</title> |
| As with httpd in general, any IPv4-over-IPv6 mapped addresses are recorded |
| in their IPv4 representation.</note> |
| |
| <note><title>Internal (Private) Addresses</title> |
| All internal addresses 10/8, 172.16/12, 192.168/16, 169.254/16 and 127/8 |
| blocks (and IPv6 addresses outside of the public 2000::/3 block) are only |
| evaluated by mod_remoteip when <directive module="mod_remoteip">RemoteIPInternalProxy</directive> |
| internal (intranet) proxies are registered.</note> |
| |
| </section> |
| |
| <directivesynopsis> |
| <name>RemoteIPHeader</name> |
| <description>Declare the header field which should be parsed for useragent IP addresses</description> |
| <syntax>RemoteIPHeader <var>header-field</var></syntax> |
| <contextlist><context>server config</context><context>virtual host</context></contextlist> |
| |
| <usage> |
| <p>The <directive module="mod_remoteip">RemoteIPHeader</directive> directive triggers |
| <module>mod_remoteip</module> to treat the value of the specified |
| <var>header-field</var> header as the useragent IP address, or list |
| of intermediate useragent IP addresses, subject to further configuration |
| of the <directive module="mod_remoteip">RemoteIPInternalProxy</directive> and |
| <directive module="mod_remoteip">RemoteIPTrustedProxy</directive> directives. Unless these |
| other directives are used, <module>mod_remoteip</module> will trust all |
| hosts presenting a <directive module="mod_remoteip">RemoteIPHeader</directive> IP value.</p> |
| |
| <example><title>Internal (Load Balancer) Example</title> |
| <highlight language="config"> |
| RemoteIPHeader X-Client-IP |
| </highlight> |
| </example> |
| |
| <example><title>Proxy Example</title> |
| <highlight language="config"> |
| RemoteIPHeader X-Forwarded-For |
| </highlight> |
| </example> |
| </usage> |
| </directivesynopsis> |
| |
| <directivesynopsis> |
| <name>RemoteIPInternalProxy</name> |
| <description>Declare client intranet IP addresses trusted to present the RemoteIPHeader value</description> |
| <syntax>RemoteIPInternalProxy <var>proxy-ip</var>|<var>proxy-ip/subnet</var>|<var>hostname</var> ...</syntax> |
| <contextlist><context>server config</context><context>virtual host</context></contextlist> |
| |
| <usage> |
| <p>The <directive module="mod_remoteip">RemoteIPInternalProxy</directive> directive adds one |
| or more addresses (or address blocks) to trust as presenting a valid |
| RemoteIPHeader value of the useragent IP. Unlike the |
| <directive module="mod_remoteip">RemoteIPTrustedProxy</directive> directive, any IP address |
| presented in this header, including private intranet addresses, are |
| trusted when passed from these proxies.</p> |
| |
| <example><title>Internal (Load Balancer) Example</title> |
| <highlight language="config"> |
| RemoteIPHeader X-Client-IP |
| RemoteIPInternalProxy 10.0.2.0/24 |
| RemoteIPInternalProxy gateway.localdomain |
| </highlight> |
| </example> |
| </usage> |
| </directivesynopsis> |
| |
| <directivesynopsis> |
| <name>RemoteIPInternalProxyList</name> |
| <description>Declare client intranet IP addresses trusted to present the RemoteIPHeader value</description> |
| <syntax>RemoteIPInternalProxyList <var>filename</var></syntax> |
| <contextlist><context>server config</context><context>virtual host</context></contextlist> |
| |
| <usage> |
| <p>The <directive module="mod_remoteip">RemoteIPInternalProxyList</directive> directive specifies |
| a file parsed at startup, and builds a list of addresses (or address blocks) |
| to trust as presenting a valid RemoteIPHeader value of the useragent IP.</p> |
| |
| <p>The '<code>#</code>' hash character designates a comment line, otherwise |
| each whitespace or newline separated entry is processed identically to |
| the <directive module="mod_remoteip">RemoteIPInternalProxy</directive> directive.</p> |
| |
| <example><title>Internal (Load Balancer) Example</title> |
| <highlight language="config"> |
| RemoteIPHeader X-Client-IP |
| RemoteIPInternalProxyList conf/trusted-proxies.lst |
| </highlight> |
| </example> |
| |
| <example><title>conf/trusted-proxies.lst contents</title> |
| <pre> |
| # Our internally trusted proxies; |
| 10.0.2.0/24 #Everyone in the testing group |
| gateway.localdomain #The front end balancer |
| </pre> |
| </example> |
| </usage> |
| </directivesynopsis> |
| |
| <directivesynopsis> |
| <name>RemoteIPProxiesHeader</name> |
| <description>Declare the header field which will record all intermediate IP addresses</description> |
| <syntax>RemoteIPProxiesHeader <var>HeaderFieldName</var></syntax> |
| <contextlist><context>server config</context><context>virtual host</context></contextlist> |
| |
| <usage> |
| <p>The <directive module="mod_remoteip">RemoteIPProxiesHeader</directive> directive specifies |
| a header into which <module>mod_remoteip</module> will collect a list of |
| all of the intermediate client IP addresses trusted to resolve the useragent |
| IP of the request. Note that intermediate |
| <directive module="mod_remoteip">RemoteIPTrustedProxy</directive> addresses are recorded in |
| this header, while any intermediate |
| <directive module="mod_remoteip">RemoteIPInternalProxy</directive> addresses are discarded.</p> |
| |
| <example><title>Example</title> |
| <highlight language="config"> |
| RemoteIPHeader X-Forwarded-For |
| RemoteIPProxiesHeader X-Forwarded-By |
| </highlight> |
| </example> |
| </usage> |
| </directivesynopsis> |
| |
| <directivesynopsis> |
| <name>RemoteIPTrustedProxy</name> |
| <description>Declare client intranet IP addresses trusted to present the RemoteIPHeader value</description> |
| <syntax>RemoteIPTrustedProxy <var>proxy-ip</var>|<var>proxy-ip/subnet</var>|<var>hostname</var> ...</syntax> |
| <contextlist><context>server config</context><context>virtual host</context></contextlist> |
| |
| <usage> |
| <p>The <directive module="mod_remoteip">RemoteIPTrustedProxy</directive> directive adds one |
| or more addresses (or address blocks) to trust as presenting a valid |
| RemoteIPHeader value of the useragent IP. Unlike the |
| <directive module="mod_remoteip">RemoteIPInternalProxy</directive> directive, any intranet |
| or private IP address reported by such proxies, including the 10/8, 172.16/12, |
| 192.168/16, 169.254/16 and 127/8 blocks (or outside of the IPv6 public |
| 2000::/3 block) are not trusted as the useragent IP, and are left in the |
| <directive module="mod_remoteip">RemoteIPHeader</directive> header's value.</p> |
| |
| <example><title>Trusted (Load Balancer) Example</title> |
| <highlight language="config"> |
| RemoteIPHeader X-Forwarded-For |
| RemoteIPTrustedProxy 10.0.2.16/28 |
| RemoteIPTrustedProxy proxy.example.com |
| </highlight> |
| </example> |
| </usage> |
| </directivesynopsis> |
| |
| <directivesynopsis> |
| <name>RemoteIPTrustedProxyList</name> |
| <description>Declare client intranet IP addresses trusted to present the RemoteIPHeader value</description> |
| <syntax>RemoteIPTrustedProxyList <var>filename</var></syntax> |
| <contextlist><context>server config</context><context>virtual host</context></contextlist> |
| |
| <usage> |
| <p>The <directive module="mod_remoteip">RemoteIPTrustedProxyList</directive> directive specifies |
| a file parsed at startup, and builds a list of addresses (or address blocks) |
| to trust as presenting a valid RemoteIPHeader value of the useragent IP.</p> |
| |
| <p>The '<code>#</code>' hash character designates a comment line, otherwise |
| each whitespace or newline separated entry is processed identically to |
| the <directive module="mod_remoteip">RemoteIPTrustedProxy</directive> directive.</p> |
| |
| <example><title>Trusted (Load Balancer) Example</title> |
| <highlight language="config"> |
| RemoteIPHeader X-Forwarded-For |
| RemoteIPTrustedProxyList conf/trusted-proxies.lst |
| </highlight> |
| </example> |
| |
| <example><title>conf/trusted-proxies.lst contents</title> |
| # Identified external proxies;<br/> |
| 192.0.2.16/28 #wap phone group of proxies<br/> |
| proxy.isp.example.com #some well known ISP |
| </example> |
| </usage> |
| </directivesynopsis> |
| |
| |
| </modulesynopsis> |