Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/780
New webext permission added: `dns`, which purpose is
to allow an extension to fetch the DNS record of
specific hostnames, reference documentation:
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/dns
The webext API `dns` is available in Firefox 60+ only.
The new API will enable uBO to "uncloak" the actual
hostname used in network requests. The ability is
currently disabled by default for now -- this is only
a first commit related to the above issue to allow
advanced users to immediately use the new ability.
Four advanced settings have been created to control the
uncloaking of actual hostnames:
cnameAliasList: a space-separated list of hostnames.
Default value: unset => empty list.
Special value: * => all hostnames.
A space-separated list of hostnames => this tells uBO
to "uncloak" the hostnames in the list will.
cnameIgnoreList: a space-separated list of hostnames.
Default value: unset => empty list.
Special value: * => all hostnames.
A space-separated list of hostnames => this tells uBO
to NOT re-run the network request through uBO's
filtering engine with the CNAME hostname. This is
useful to exclude commonly used actual hostnames
from being re-run through uBO's filtering engine, so
as to avoid pointless overhead.
cnameIgnore1stParty: boolean.
Default value: true.
Whether uBO should ignore to re-run a network request
through the filtering engine when the CNAME hostname
is 1st-party to the alias hostname.
cnameMaxTTL: number of minutes.
Default value: 120.
This tells uBO to clear its CNAME cache after the
specified time. For efficiency purpose, uBO will
cache alias=>CNAME associations for reuse so as
to reduce calls to `browser.dns.resolve`. All the
associations will be cleared after the specified time
to ensure the map does not grow too large and too
ensure uBO uses up to date CNAME information.
With the new PSL implementation, benchmarks do not show benefit
from caching the domain extracted from a hostname for later
reuse -- the caching seems to even add an overhead instead with
the new publicSuffixList implementation.
A new filtering class has been created: "static extended filtering".
This new class is an umbrella class for more specialized filtering
engines:
- Cosmetic filtering
- Scriptlet filtering
- HTML filtering
HTML filtering is available only on platforms which support modifying
the response body on the fly, so only Firefox 57+ at the moment.
With the ability to modify the response body, HTML filtering has
been introduced: removing elements from the DOM before the source
data has been parsed by the browser.
A consequence of HTML filtering ability is to bring back script tag
filtering feature.
A negative side-effect of not sorting properly the entries was to
cause raw filter lists to linger in memory due to v8's sliced-
string implementation, which caused the parent string (a whole
filter list possibly) to be kept around forever even though it was
no longer used by uBO (raw filter lists are compiled then discarded).
.jshintrc's otion-set is a personal choice, merely a suggestion.
Beside that, it includes some common globals for specific browsers, so
there's no need to set the globals in every .js file.
In order to force strict coding, "use strict" directive was added into
every .js file.
