Related issue:
https://github.com/uBlockOrigin/uBlock-issues/issues/3206
The main purpose is to bypass URLs designed to track whether a user
visited a specific URL, typically used in click-tracking links.
The `urlskip=` option ...
- ... is valid only when used in a trusted filter list
- ... is enforced only on top documents
- ... is enforced on both blocked and non-blocked documents
- ... is a modifier, i.e. it cannot be used along with other
modifier options in a single filter
The syntax is `urlskip=[steps]`, where steps is a space-separated
list of extraction directives detailing what action to perform on
the current URL.
The only supported directive in this first commit is `?name`,
which purpose is to extract the value of a named URL parameter
and use the result as the new URL. Example:
||example.com/path/to/tracker$urlskip=?url
The above filter will cause navigation to
https://example.com/path/to/tracker?url=https://example.org/
to automatically bypass navigation to `example.com` and navigate
directly to
https://example.org/
It is possible to recursively extract URL parameters by using
more than one directive, example:
||example.com/path/to/tracker$urlskip=?url ?to
More extraction capabilities may be added in the future.
DNR conversion module is a dev tool, no point loading it by
default. This was done this way because in a distant past uBO
had to be compatible with browsers not supporting dynamically
loaded modules.
Currently all supported browser versions support dynamically
loaded modules.
In Firefox-specific contentScripts API used to register
scriptlets. This could potentially occurs when there are
registrations pending during a reload of filter lists.
This commit makes the DNS resolution code better suited for both
filtering on cname and ip address. The change allows early availability
of ip address so that `ipaddress=` option can be matched at
onBeforeRequest time.
As a result, it is now possible to block root document using
`ipaddress=` option -- so long as an ip address can be extracted
before first onBeforeRequest() call.
Related issue:
https://github.com/uBlockOrigin/uBlock-issues/issues/2792
Caveat
------
the ip address used is the first one among the list of ip
addresses returned by dns.resolve() method. There is no way for uBO
to know which exact ip address will be used by the browser when
sending the request, so this is at most a best guess. The exact IP
address used by the browser is available at onHeadersReceived time,
and uBO will also filter according to this value, but by then the
network request has already been sent to the remote server.
Possibly a future improvement would make available the whole list
of ip addresses to the filtering engine, but even then it's impossible
to know with certainty which ip address will ultimately be used by the
browser -- it is entirely possible that the ip address used by the
browser might not be in the list received through dns.resolve().
If an IP address can be extracted from the hostname portion of
a URL, the IP address matching will be performed at onBeforeRequest()
time.
Regardless, IP address matching will subsequently always be performed
at onHeadersReceived() time as the request details at that point
contain a reliable IP address value on supported platforms (Firefox-
only as of now).
The `cap_ipaddress` now evaluates to `true` in Chromium-based
browsers. Even though these browsers are unable to provide reliable
IP address value at onHeadersReceived() time, they can still
perform IP address matching for IP address extracted from hostname
portion of a URL.
