Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/911
Since cname-uncloaking is available only on Firefox
at the moment, the fix is relevant only to Firefox.
By default uBO will no longer cname-uncloak when it
detects that network requests are being being proxied.
This default behavior can be overriden by setting the
new advanced setting `cnameUncloakProxied` to `true`.
The new setting default to `false`, i.e. cname-uncloaking
is disabled when uBO detects that a proxy is in use.
This new advanced setting may disappear once the
following Firefox issue is fixed:
- https://bugzilla.mozilla.org/show_bug.cgi?id=1618271
Advanced setting `cnameAliasList` has been removed.
New advanced settings:
cnameUncloak:
Boolean
Default value:
true
Description:
Whether to CNAME-uncloak hostnames.
cnameIgnoreExceptions:
Boolean
Default value:
true
Description:
Whether to bypass the uncloaking of network requests
which were excepted by filters/rules. This is
necessary so as to avoid undue breakage by having
exception filters being rendered useless as a result
of CNAME-uncloaking.
For example, `google-analytics.com` uncloaks to
`www-google-analytics.l.google.com` and both hostnames
appear in Peter Lowe's list, which means exception
filters for `google-analytics.com` (to fix site
breakage) would be rendered useless as the uncloaking
would cause the network request to be ultimately
blocked.
Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/780
Related commit:
- https://github.com/gorhill/uBlock/commit/3a564c199260
This adds two new advanced settings:
- cnameIgnoreRootDocument
- Default to `true`
- Tells uBO to skip CNAME-lookup for root document.
- cnameReplayFullURL
- Default to `false`
- Tells uBO whether to replay the whole URL or just
the origin part of it.
Replaying only the origin part is meant to lower
undue breakage and improve performance by avoiding
repeating the pattern-matching of the whole URL --
which pattern-matching was most likely already
accomplished with the original request.
This commit is meant to explore enabling CNAME-lookup
by default for the next stable release while:
- Eliminating a development burden by removing the
need to create a new filtering syntax to deal with
undesirable CNAME-cloaked hostnames
- Eliminating a filter list maintainer burden by
removing the need to find/deal with all base
domains which engage in undesirable CNAME-cloaked
hostnames
The hope is that the approach implemented in this
commit should require at most a few unbreak rules
with no further need for special filtering syntax
or filter list maintance efforts.
This fixes the ability to block when a hostname
had to be cname-resolved the first time it was
encountered. The result being cached allowed
the subsequent requests to be correctly blockable.
Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/780
- Handle DNS lookup failure
- Skip DNS lookup for non network-based URLs
- Benchmark code to be able to provide an estimate
based on objective measurements regarding added
overhead when DNS lookup is enabled
(quick answer: a complete non-issue)
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.
Tabless network requests were bypassing uBO's
onBeforeRequest's listener when in suspended
mode. Suspend mode occurs during the time the
filter lists are all reloaded.
Regression from:
- 1dfdc40e09 (diff-d04c15ee6bff6a6269c6aee25a7c7522R1122)
This works only for platforms supporting the return of
Promise by network listeners, i.e. only Firefox at this
point.
When filter lists are reloaded[1], there is a small
time window in which some network requests which should
have normally been blocked are not being blocked
because the static network filtering engine may not
have yet loaded all the filters in memory
This is now addressed by suspending the network request
handler when filter lists are reloaded -- again, this
works only on supported platforms.
[1] Examples: when a filter list update session
completes; when user filters change, when
adding/removing filter lists.
Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/407
Both flavors will be stitched together into a single
`vapi-qebrequest.js` file.
The decision of which flavor to use will be made at runtime,
according to the browser environment.
