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: http://neptun.sai.msu.su/manual/mod/mod_access.html
Дата изменения: Thu May 20 13:01:37 2004 Дата индексирования: Mon Oct 1 20:04:23 2012 Кодировка: Поисковые слова: movie |
This module provides access control based on client hostname, IP address, or other characteristics of the client request.
Status: Base
Source File: mod_access.c
Module Identifier:
access_module
The directives provided by mod_access are used in <Directory>, <Files>,
and <Location>
sections
as well as .htaccess
files to
control access to particular parts of the server. Access can be
controlled based on the client hostname, IP address, or other
characteristics of the client request, as captured in environment variables. The
Allow
and Deny
directives are used to
specify which clients are or are not allowed access to the
server, while the Order
directive sets the default
access state, and configures how the Allow
and
Deny
directives interact with each other.
Both host-based access restrictions and password-based authentication may be implemented simultaneously. In that case, the Satisfy directive is used to determine how the two sets of restrictions interact.
In general, access restriction directives apply to all
access methods (GET
, PUT
,
POST
, etc). This is the desired behavior in most
cases. However, it is possible to restrict some methods, while
leaving other methods unrestricted, by enclosing the directives
in a <Limit> section.
Syntax: Allow from
all|host|env=env-variable
[host|env=env-variable] ...
Context: directory,
.htaccess
Override: Limit
Status: Base
Module: mod_access
The Allow
directive affects which hosts can
access an area of the server. Access can be controlled by
hostname, IP Address, IP Address range, or by other
characteristics of the client request captured in environment
variables.
The first argument to this directive is always
from
. The subsequent arguments can take three
different forms. If Allow from all
is specified,
then all hosts are allowed access, subject to the configuration
of the Deny
and Order
directives as
discussed below. To allow only particular hosts or groups of
hosts to access the server, the host can be specified
in any of the following formats:
Allow from apache.org
foo.apache.org
but it will
not match fooapache.org
. This configuration will
cause the server to perform a double reverse DNS lookup on the
client IP address, regardless of the setting of the HostnameLookups
directive. It will do a reverse DNS lookup on the IP address to
find the associated hostname, and then do a forward lookup on
the hostname to assure that it matches the original IP address.
Only if the forward and reverse DNS are consistent and the
hostname matches will access be allowed.Allow from 10.1.2.3
Allow from 10.1
Allow from
10.1.0.0/255.255.0.0
Allow from 10.1.0.0/16
Note that the last three examples above match exactly the same set of hosts.
The third format of the arguments to the Allow
directive allows access to the server to be controlled based on
the existence of an environment
variable. When Allow from
env=
env-variable is specified, then the request
is allowed access if the environment variable
env-variable exists. The server provides the ability
to set environment variables in a flexible way based on
characteristics of the client request using the directives
provided by mod_setenvif.
Therefore, this directive can be used to allow access based on
such factors as the clients User-Agent
(browser
type), Referer
, or other HTTP request header
fields.
Example:
SetEnvIf User-Agent ^KnockKnock/2\.0 let_me_in <Directory /docroot> Order Deny,Allow Deny from all Allow from env=let_me_in </Directory>
In this case, browsers with a user-agent string beginning with KnockKnock/2.0 will be allowed access, and all others will be denied.
See also Deny, Order and SetEnvIf.
Syntax: Deny from
all|host|env=env-variable
[host|env=env-variable] ...
Context: directory,
.htaccess
Override: Limit
Status: Base
Module: mod_access
This directive allows access to the server to be restricted
based on hostname, IP address, or environment variables. The
arguments for the Deny
directive are identical to
the arguments for the Allow directive.
See also Allow, Order and SetEnvIf.
Syntax: Order
ordering
Default: Order
Deny,Allow
Context: directory,
.htaccess
Override: Limit
Status: Base
Module: mod_access
The Order
directive controls the default access
state and the order in which Allow and Deny directives are evaluated.
Ordering is one of
Deny
directives are evaluated before the
Allow
directives. Access is allowed by default.
Any client which does not match a Deny
directive
or does match an Allow
directive will be allowed
access to the server.Allow
directives are evaluated before
the Deny
directives. Access is denied by
default. Any client which does not match an
Allow
directive or does match a
Deny
directive will be denied access to the
server.Allow
list and do not appear on the Deny
list are
granted access. This ordering has the same effect as
Order Allow,Deny
and is deprecated in favor of
that configuration.Keywords may only be separated by a comma; no whitespace is
allowed between them. Note that in all cases every
Allow
and Deny
statement is
evaluated.
In the following example, all hosts in the apache.org domain are allowed access; all other hosts are denied access.
Order Deny,Allow
Deny from all
Allow from apache.org
In the next example, all hosts in the apache.org domain are allowed access, except for the hosts which are in the foo.apache.org subdomain, who are denied access. All hosts not in the apache.org domain are denied access because the default state is to deny access to the server.
Order Allow,Deny
Allow from apache.org
Deny from foo.apache.org
On the other hand, if the Order
in the last
example is changed to Deny,Allow
, all hosts will
be allowed access. This happens because, regardless of the
actual ordering of the directives in the configuration file,
the Allow from apache.org
will be evaluated last
and will override the Deny from foo.apache.org
.
All hosts not in the apache.org
domain will also
be allowed access because the default state will change to
allow.
The presence of an Order
directive can affect
access to a part of the server even in the absence of
accompanying Allow
and Deny
directives because of its effect on the default access state.
For example,
<Directory /www>
Order Allow,Deny
</Directory>
will deny all access to the /www
directory
because the default access state will be set to
deny.
The Order
directive controls the order of
access directive processing only within each phase of the
server's configuration processing. This implies, for example,
that an Allow
or Deny
directive
occurring in a <Location> section will always be
evaluated after an Allow
or Deny
directive occurring in a <Directory> section or
.htaccess
file, regardless of the setting of the
Order
directive. For details on the merging of
configuration sections, see the documentation on How Directory, Location and Files
sections work.