Skip to content

Commit

Permalink
Add proxy support to obtain a connection
Browse files Browse the repository at this point in the history 
This is a further incremental step toward making it possible to properly layer WebSocket connections on top of this primitive (see #1243).

WebTransport PR: w3c/webtransport#351.
  • Loading branch information
@annevk
annevk authored Sep 9, 2021
1 parent 4c1c5b0 commit b2f04e2
Showing 1 changed file with 64 additions and 41 deletions.
105 changes: 64 additions & 41 deletions fetch.bs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2244,9 +2244,6 @@ be used as part of the cache key.
<li><p>If <var>origin</var>'s <a for=origin>host</a> is an <a for=/>IP address</a>, then return
« <var>origin</var>'s <a for=origin>host</a> ».

<li><p>If the user agent is configured to use a proxy that resolves domains on its own, then return
« <var>origin</var>'s <a for=origin>host</a> ».

<li><p>Return the result of running <a>resolve a domain</a> given <var>key</var> and
<var>origin</var>'s <a for=origin>host</a>.
</ol>
Expand Down Expand Up @@ -2324,23 +2321,25 @@ steps:

<hr>

<p>A <dfn>new connection setting</dfn> is "<code>no</code>", "<code>yes</code>", or
"<code>yes-and-dedicated</code>".

<p>To <dfn export id=concept-connection-obtain>obtain a connection</dfn>, given a
<a>network partition key</a> <var>key</var>, <a for=/>origin</a> <var>origin</var>, boolean
<var>credentials</var>, an optional boolean <var>forceNew</var> (default false), an optional boolean
<dfn export for="obtain a connection"><var>http3Only</var></dfn> (default false), and an optional
boolean <dfn export for="obtain a connection"><var>dedicated</var></dfn> (default false), run these
steps:
<!-- http3Only and dedicated have been added for WebTransport -->
<a>network partition key</a> <var>key</var>, <a for=/>URL</a> <var>url</var>, boolean
<var>credentials</var>, an optional <a>new connection setting</a> <var>new</var> (default
"<code>no</code>"), and an optional boolean
<dfn export for="obtain a connection"><var>http3Only</var></dfn> (default false), run these steps:
<!-- new's "yes-and-dedicated" and http3Only have been added for WebTransport -->

<ol>
<li>
<p>If <var>forceNew</var> is false or <var>dedicated</var> is false, then:
<p>If <var>new</var> is "<code>no</code>", then:

<ol>
<li><p>Let <var>connections</var> be a set of <a>connections</a> in the user agent's
<a>connection pool</a> whose <a for=connection>key</a> is <var>key</var>,
<a for=connection>origin</a> is <var>origin</var>, and <a for=connection>credentials</a> is
<var>credentials</var>.
<a for=connection>origin</a> is <var>url</var>'s <a for=url>origin</a>, and
<a for=connection>credentials</a> is <var>credentials</var>.

<li><p>If <var>connections</var> is not empty and <var>http3Only</var> is false, then return
one of <var>connections</var>.
Expand All @@ -2349,38 +2348,59 @@ steps:
<a>connection</a>.
</ol>

<li>
<p>Let <var>proxies</var> be the result of finding proxies for <var>url</var> in an
<a>implementation-defined</a> manner. If there are no proxies, let <var>proxies</var> be
« "<code>DIRECT</code>" ».

<p class=note>This is where non-standard technology such as
<a href="https://en.wikipedia.org/wiki/Web_Proxy_Auto-Discovery_Protocol">Web Proxy Auto-Discovery Protocol (WPAD)</a>
and <a href="https://en.wikipedia.org/wiki/Proxy_auto-config">proxy auto-config (PAC)</a> come
into play. The "<code>DIRECT</code>" value means to not use a proxy for this particular
<var>url</var>.

<li><p>Let <var>timingInfo</var> be a new <a for=/>connection timing info</a>.

<li><p>Set <var>timingInfo</var>'s <a for="connection timing info">domain lookup start time</a> to
the <a for=/>unsafe shared current time</a>.
<li>
<p><a for=list>For each</a> <var>proxy</var> of <var>proxies</var>:

<ol>
<li><p>Set <var>timingInfo</var>'s <a for="connection timing info">domain lookup start time</a>
to the <a for=/>unsafe shared current time</a>.

<li><p>Let <var>hosts</var> be the result of running <a>resolve an origin</a> given <var>key</var>
and <var>origin</var>.
<li><p>Let <var>hosts</var> be « <var>origin</var>'s <a for=origin>host</a> ».

<li><p>If <var>hosts</var> is failure, then return failure.
<li><p>If <var>proxy</var> is "<code>DIRECT</code>", then set <var>hosts</var> to the result of
running <a>resolve an origin</a> given <var>key</var> and <var>url</var>'s <a for=url>origin</a>.

<li><p>Set <var>timingInfo</var>'s <a for="connection timing info">domain lookup end time</a> to
the <a for=/>unsafe shared current time</a>.
<li><p>If <var>hosts</var> is failure, then <a for=iteration>continue</a>.

<li>
<p>Let <var>connection</var> be the result of running this step: run <a>create a connection</a>
given <var>key</var>, <var>origin</var>, <var>credentials</var>, an <a>implementation-defined</a>
<a for=/>host</a> from <var>hosts</var>, <var>timingInfo</var>, and <var>http3Only</var> an
<a>implementation-defined</a> number of times, <a>in parallel</a> from each other, and wait for at
least 1 to return a value. In an <a>implementation-defined</a> manner, select a value to return
from the returned values and return it. Any other returned values that are <a>connections</a> may
be closed.
<li><p>Set <var>timingInfo</var>'s <a for="connection timing info">domain lookup end time</a> to
the <a for=/>unsafe shared current time</a>.

<p class=note>Essentially this allows an implementation to pick one or more
<a for=/>IP addresses</a> from the return value of <a>resolve a domain</a> (assuming no proxy) and
race them against each other, favor <a for=/>IPv6 addresses</a>, retry in case of a timeout, etc.
<li>
<p>Let <var>connection</var> be the result of running this step: run <a>create a connection</a>
given <var>key</var>, <var>url</var>'s <a for=url>origin</a>, <var>credentials</var>,
<var>proxy</var>, an <a>implementation-defined</a> <a for=/>host</a> from <var>hosts</var>,
<var>timingInfo</var>, and <var>http3Only</var> an <a>implementation-defined</a> number of
times, <a>in parallel</a> from each other, and wait for at least 1 to return a value. In an
<a>implementation-defined</a> manner, select a value to return from the returned values and
return it. Any other returned values that are <a>connections</a> may be closed.

<li><p>If <var>connection</var> is failure, then return failure.
<p class=note>Essentially this allows an implementation to pick one or more
<a for=/>IP addresses</a> from the return value of <a>resolve a domain</a> (assuming
<var>proxy</var> is "<code>DIRECT</code>") and race them against each other, favor
<a for=/>IPv6 addresses</a>, retry in case of a timeout, etc.

<li><p>If <var>dedicated</var> is false, then <a for=set>append</a> <var>connection</var> to the
user agent's <a>connection pool</a>.
<li><p>If <var>connection</var> is failure, then <a for=iteration>continue</a>.

<li><p>Return <var>connection</var>.
<li><p>If <var>new</var> is not "<code>yes-and-dedicated</code>", then <a for=set>append</a>
<var>connection</var> to the user agent's <a>connection pool</a>.

<li><p>Return <var>connection</var>.
</ol>

<li><p>Return failure.
</ol>

<p class=note>This is intentionally a little vague as there are a lot of nuances to connection
Expand All @@ -2393,9 +2413,9 @@ reused across <a>connections</a> whose <a for=connection>credentials</a> are fal
<hr>

<p>To <dfn>create a connection</dfn>, given a <a for=/>network partition key</a> <var>key</var>,
<a for=/>origin</a> <var>origin</var>, boolean <var>credentials</var>, <a for=/>host</a>
<var>host</var>, <a for=/>connection timing info</a> <var>timingInfo</var>, and boolean
<var>http3Only</var>, run these steps:
<a for=/>origin</a> <var>origin</var>, boolean <var>credentials</var>, string <var>proxy</var>,
<a for=/>host</a> <var>host</var>, <a for=/>connection timing info</a> <var>timingInfo</var>, and
boolean <var>http3Only</var>, run these steps:

<ol>
<li><p>Set <var>timingInfo</var>'s <a for="connection timing info">connection start time</a> to the
Expand All @@ -2407,8 +2427,8 @@ reused across <a>connections</a> whose <a for=connection>credentials</a> are fal
<a for=connection>credentials</a> is <var>credentials</var>, and <a for=connection>timing info</a>
is <var>timingInfo</var>. <a for=/>Record connection timing info</a> given <var>connection</var>
and use <var>connection</var> to establish an HTTP connection to <var>host</var>, taking
<var>origin</var> into account. [[!HTTP]] [[!HTTP-SEMANTICS]] [[!HTTP-COND]] [[!HTTP-CACHING]]
[[!HTTP-AUTH]] [[!TLS]]
<var>proxy</var> and <var>origin</var> into account. [[!HTTP]] [[!HTTP-SEMANTICS]] [[!HTTP-COND]]
[[!HTTP-CACHING]] [[!HTTP-AUTH]] [[!TLS]]

<p>If <var>http3Only</var> is true, then establish an HTTP/3 connection. [[!HTTP3]]

Expand Down Expand Up @@ -5155,6 +5175,9 @@ optional boolean <var>forceNewConnection</var> (default false), run these steps:
<li><p>Let <var>networkPartitionKey</var> be the result of
<a for=request>determining the network partition key</a> given <var>request</var>.

<li><p>Let <var>newConnection</var> be "<code>yes</code>" if <var>forceNewConnection</var> is true;
otherwise "<code>no</code>".

<li>
<p>Switch on <var>request</var>'s <a for=request>mode</a>:

Expand All @@ -5167,8 +5190,8 @@ optional boolean <var>forceNewConnection</var> (default false), run these steps:
<dt>Otherwise
<dd><p>Let <var>connection</var> be the result of
<a lt="obtain a connection">obtaining a connection</a>, given <var>networkPartitionKey</var>,
<var>request</var>'s <a for=request>current URL</a>'s <a for=url>origin</a>,
<var>includeCredentials</var>, and <var>forceNewConnection</var>.
<var>request</var>'s <a for=request>current URL</a>, <var>includeCredentials</var>, and
<var>newConnection</var>.
</dl>

<li>
Expand Down

0 comments on commit b2f04e2

Please sign in to comment.