Re: HTTP 1.1 issue 15: 14.23 Host

jg@pa.dec.com (Jim Gettys) writes:

>Actually, Roy, I see Ross's point here: it says "on the Internet". Some
>might misinterpret this on a LAN or intranet.  I agree there should be
>no reference to TCP or other transport protocols in this paragraph, of
>course, for the reasons you give.

Right.

>So I think striking the two phrases "on the Internet", and the word
>"Internet-based"  from the paragraph will reduce the wriggle room of
>implementers to get it wrong.  The result would be:
>
>
>   "A client MUST include a Host header field in all HTTP/1.1 request
>   messages (i.e., on any message corresponding to a
>   request for a URL which includes an Internet host address for the
>   service being requested). If the Host field is not already
>   present, an HTTP/1.1 proxy MUST add a Host field to the request
>   message prior to forwarding it. All
>   HTTP/1.1 servers MUST respond with a 400 (Bad Request) status code
>   to any HTTP/1.1 request message which lacks a Host header field."

That's clearer, and jibes with the MUST in section 9.

>I don't think that any arguments to allow the host header to be dropped
>for PDA use are compelling enough to relax this requirement in this way.

Indeed, one could argue that a PDA if RF/infrared/whatever communication
with its base station should send Host headers if the URL includes a
host address for the base station (e.g., running IP-on-the-air ala
AMPRNet).  By the same argument, if the URL requested by the PDA doesn't
include a host address, no Host header is required (although that
violates section 9).

Ross Patterson
VM Software Division
Sterling Software, Inc.