Previously when creating a new rule we followed these steps:
- Create a new protobuf Rule object from the ruleseditor or the
pop-ups.
- If the rule contained more than one operator, we converted the
list of operators to a JSON string.
- This JSON string was sent back to the daemon, and saved to the
DB.
- The list of operators were never expanded on the GUI, i.e., they
were not saved as a list of protobuf Operator objects.
- Once received in the daemon, the JSON string was parsed and
converted to a protobuf Operator list of objects.
Both, the JSON string and the list of protobuf Operator objects were
saved to disk, but the JSON string was ignored when loading the
rules.
Saving the list of operators as a JSON string was a problem if you
wanted to create or modify rules without the GUI.
Now when creating or modifying rules from the GUI, the list of operators
is no longer converted to JSON string. Instead the list is sent to the
daemon as a list of protobuf Operators, and saved as JSON objects.
Notes:
- The JSON string is no longer saved to disk as part of the rules.
- The list of operators is still saved as JSON string to the DB.
- About not enabled rules:
Previously, not enabled rules only had the list of operators as JSON
string, with the field list:[] empty.
Now the list of operators is saved as JSON objects, but if the rule
is not enabled, it won't be parsed/loaded.
Closes#1047
Now you can create rules to filter processes by checksum. Only md5 is
available at the moment.
There's a global configuration option that you can use to enable or
disable this feature, from the config file or from the Preferences
dialog.
As part of this feature there have been more changes:
- New proc monitor method (PROCESS CONNECTOR) that listens for
exec/exit events from the kernel.
This feature depends on CONFIG_PROC_EVENTS kernel option.
- Only one cache of active processes for ebpf and proc monitor
methods.
More info and details: #413.
When blocking a connection via libnetfilter-queue using NF_DROP the
connection is discarded. If the blocked connection is a DNS query, the app
that initiated it will wait until it times out, which is ~30s.
This behaviour can for example cause slowdowns loading web pages: #481
This change adds the option to reject connections by killing the socket
that initiated them.
Denying:
$ time telnet 1.1.1.1 22
Trying 1.1.1.1...
telnet: Unable to connect to remote host: Connection timed out
real 2m10,039s
Rejecting:
$ time telnet 1.1.1.1 22
Trying 1.1.1.1...
telnet: Unable to connect to remote host: Software caused connection abort
real 0m0,005s
When the Duration of a rule changed (from 1h to 5m, from 5m to until
restart, etc), the timer of the old rule was fired, causing deleting the
rule from the list.
This erroneous behaviour could be one of the reasons of #429
- Delete lists of domains if the rule about to change is of type Lists.
- Monitor the lists of domains, and reload them if they're modified.
- Delete rules from disk when the Duration changes from
Always (saved on disk) to !Always (temporary).
- After the above operation a fsnotify Remove event is fired. Don't
delete the rule from memory if it's temporary.
- Rules are only compiled if they're enabled, avoiding unnecessary
allocations.
Any rule changed on disk caused reloading of all rules, usually
up to three times. This caused some problems.
- Don't compile Operators if the rule is disabled.
- Empty lists of domains if the user disables the rule.
- Delete rule from disk if the duration is not Always anymore.
There're some situations where we need to delete loaded lists:
- When an enabled rule of type Lists is disabled (after changed on
disk, or when configured from the GUI).
- When an enabled rule of type List with an Operator of type Lists is
disabled.
Initial support to filter connections using lists of domains.
The lists must be in hosts format:
- 0.0.0.0 www.domain.com
- 127.0.0.1 www.domain.com
From the rules editor, create a new rule, and select
[x] To this lists of domains
Select a directory with files in hosts format, select [x] Priority rule,
select [x] Deny and click on Apply.
An example of a list in hosts format:
https://www.github.developerdan.com/hosts/lists/ads-and-tracking-extended.txt
Note: you can also add a list of domains to allow, not only domains to
block.
TODOs:
- support for URLs besides directories (local lists).
- support for scheduled updates of the above URLs.
related #298
Every rule has an entry point besides a constructor, which configures
all it needs to match connections, based on user defined criteria (ip,
regexp, etc).
This only needs to be done the first time we load a rule, because the
fields of a rule are static. However for rules of type "lists" we were
iniatializing each rule of this type once per connection that it
matched.
- Rules are checked in alphabetical order.
- Deny and Priority rules must take precedence.
- If a rule matches and it's Allow-NoPriority, then return the rule.
- Otherwise we'll return nil.
If a rule has the priority flag set, no others rules will be checked.
So if you name the rule as 000-allow-xx and set the priority flag, the
rule wil lbe the only one that will be checked if it matches a
connection.
See #36 to know more on this feature.
Sort rules by name, so they're checked in alphabetical order.
This way, you can place deny rules at the top of the list to get better
performance, since it won't check the rest of the rules.
Discussion: #36
Added 30s, 5m, 15m, 30m and 1h timeout options to deny or allow
connections.
It helps to avoid repetitive new connection dialogs, while at the same
time it allows you to deny/allow a connection for a short period of time,
and apply the default for the rest.
