The filer supports the HTTP/1.0 protocol, which is documented
in the Internet Engineering Task Force (IETF) RFC1945 titled "HyperText Transfer Protocol --HTTP/1.0."
HTTP is the primary Internet protocol used for transferring
documents on the World Wide Web. It is a simple ASCII
text request/response protocol. An HTTP request consists
of a method, a target Web address or URL (Uniform Resource
Locator), a protocol version identifier, and a set of
headers. The method specifies the type of operation. For
example, the GET method is used to retrieve a document.
The POST method is used to submit a form. Headers contain
additional information to the request in the form of simple
name-value pairs. The HTTP header section is similar
to Multipurpose Internet Mail Extensions (MIME).
The GET method is the most commonly used HTTP method. GET
is used to retrieve a single resource, for example, an
HTML document, image file, or other type of object, or
part of it. By appending an If-modified-since header to
the GET request, the document is retrieved conditionally,
based on whether it has been modified since the date specified
in the header.
An HTTP response consists of a protocol version identifier,
a status code, a text response status line, response
headers, and the contents of the requested document.
Access for http can be restricted by the optionshttpd.access command. Please see na_protocolaccess(8) for
details.