Both block and filter actions write responses to the client based upon
the source IP address of the UDP packet containing the query. An
attacker spoofing the source IP address to that of their target, can
elicit a response to be sent to the victim host, known as DNS
Reflection. If an attacker is able to elicit a large response from a
relatively small query, with a spoofed source IP address, they are able
to increase the amount of data sent to the victim, known as DNS
Amplification. Scaling this from one to many queries allows an attacker
to perform an effective Denial of Service (DoS) attack against their
target.
Adding the drop action enables CoreDNS to ignore queries of a given
type or network range from being processed and a response written,
where an operator knows ahead of time, should not originate or be
destined to.
Signed-off-by: rsclarke <hey@rsclarke.dev>
Signed-off-by: rsclarke <hey@rsclarke.dev>
* plugin/acl : add support for Extended DNS Errors
Signed-off-by: Ondřej Benkovský <ondrej.benkovsky@jamf.com>
* fixup! plugin/acl : add support for Extended DNS Errors
Signed-off-by: Ondřej Benkovský <ondrej.benkovsky@jamf.com>
* Fixing #5376 by adding a check to parse out Zone information
Signed-off-by: Tintin <samrath.sodi@gmail.com>
* using IndexByte instead of strings.Split()
Signed-off-by: Tintin <samrath.sodi@gmail.com>
* using plugin logger for logging parsing failure
Signed-off-by: Tintin <samrath.sodi@gmail.com>
* using var keywork instead of short declaration operator
Signed-off-by: Tintin <samrath.sodi@gmail.com>
* reordering imports
Signed-off-by: Tintin <samrath.sodi@gmail.com>
* Update ACL plugin's README to capture the edge case
This PR adds a note in ACL plugin's README to capture the edge case
where source ip of the client may be different from the source ip
observed by coredns server (in situations such as Source NAT).
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
* Update plugin/acl/README.md
Co-authored-by: Chris O'Haver <cohaver@infoblox.com>
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
* Update plugin/acl/README.md
Co-authored-by: Chris O'Haver <cohaver@infoblox.com>
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Co-authored-by: Chris O'Haver <cohaver@infoblox.com>
Make normalize return multiple "hosts" (= reverse zones) when a
non-octet boundary cidr is given.
Added pkg/cidr package that holds the cidr calculation routines; felt
they didn't really fit dnsutil.
This change means the IPNet return parameter isn't needed, the hosts are
all correct. The tests that tests this is also removed: TestSplitHostPortReverse
The fallout was that zoneAddr _also_ doesn't need the IPNet member, that
in turn make it visible that zoneAddr in address.go duplicated a bunch
of stuff from register.go; removed/refactored that too.
Created a plugin.OriginsFromArgsOrServerBlock to help plugins do the
right things, by consuming ZONE arguments; this now expands reverse
zones correctly. This is mostly mechanical.
Remove the reverse test in plugin/kubernetes which is a copy-paste from
a core test (which has since been fixed).
Remove MustNormalize as it has no plugin users.
This change is not backwards compatible to plugins that have a ZONE
argument that they parse in the setup util.
All in-tree plugins have been updated.
Signed-off-by: Miek Gieben <miek@miek.nl>
Currently ACLs only allow for allow and block, however it isn't
always desirable to set the status code to REFUSED. Often times
you want to completely hide the fact that those records even exist.
Adding the ability to acl to filter results makes it significantly
harder for a third party to know that the records are being masked.
Signed-off-by: George Shammas <george@shamm.as>
* For caddy v1 in our org
This RP changes all imports for caddyserver/caddy to coredns/caddy. This
is the v1 code of caddy.
For the coredns/caddy repo the following changes have been made:
* anything not needed by us is deleted
* all `telemetry` stuff is deleted
* all its import paths are also changed to point to coredns/caddy
* the v1 branch has been moved to the master branch
* a v1.1.0 tag has been added to signal the latest release
Signed-off-by: Miek Gieben <miek@miek.nl>
* Fix imports
Signed-off-by: Miek Gieben <miek@miek.nl>
* Group coredns/caddy with out plugins
Signed-off-by: Miek Gieben <miek@miek.nl>
* remove this file
Signed-off-by: Miek Gieben <miek@miek.nl>
* Relax import ordering
github.com/coredns is now also a coredns dep, this makes
github.com/coredns/caddy fit more natural in the list.
Signed-off-by: Miek Gieben <miek@miek.nl>
* Fix final import
Signed-off-by: Miek Gieben <miek@miek.nl>
The subsystem of a metric must be it's plugin name. "dns" is reserved
for the core. Use a const convention to avoid copy-paste mistakes in
naming.
Fix dns64 and acl plugin.
Signed-off-by: Ben Kochie <superq@gmail.com>
Cleanup a variety of metric issues.
* Eliminate department of redundancy "count_total" naming.
* Use the plural of the unit when appropriate. (ex, "requests")
* Remove label names from metric names where appropriate. (ex, "rcode")
* Simplify request metrics by consolidating type label in to the base
request counter.
* Re-generate man pages.
Signed-off-by: Ben Kochie <superq@gmail.com>
Co-authored-by: Ben Kochie <superq@gmail.com>
* Fix acl page
It must have a Name section.
Fixes: https://github.com/coredns/coredns.io/issues/177
Signed-off-by: Miek Gieben <miek@miek.nl>
* generate
Signed-off-by: Miek Gieben <miek@miek.nl>
* Move to CODEOWNERS
No change in who own what; just a move to CODEOWNERS. This allows
dreck cleanups.
Added .dreck.yaml for alias and exec.
Fixes: #3486
Signed-off-by: Miek Gieben <miek@miek.nl>
* stickler bot
Signed-off-by: Miek Gieben <miek@miek.nl>
* sort the file
Signed-off-by: Miek Gieben <miek@miek.nl>
* Run gostaticheck
Run gostaticcheck on the codebase and fix almost all flagged items.
Only keep
* coremain/run.go:192:2: var appVersion is unused (U1000)
* plugin/chaos/setup.go:54:3: the surrounding loop is unconditionally terminated (SA4004)
* plugin/etcd/setup.go:103:3: the surrounding loop is unconditionally terminated (SA4004)
* plugin/pkg/replacer/replacer.go:274:13: argument should be pointer-like to avoid allocations (SA6002)
* plugin/route53/setup.go:124:28: session.New is deprecated: Use NewSession functions to create sessions instead. NewSession has the same functionality as New except an error can be returned when the func is called instead of waiting to receive an error until a request is made. (SA1019)
* test/grpc_test.go:25:69: grpc.WithTimeout is deprecated: use DialContext and context.WithTimeout instead. Will be supported throughout 1.x. (SA1019)
The first one isn't true, as this is set via ldflags. The rest is
minor. The deprecation should be fixed at some point; I'll file some
issues.
Signed-off-by: Miek Gieben <miek@miek.nl>
* Make sure to plug in the plugins
import the plugins, that file that did this was removed, put it in the
reload test as this requires an almost complete coredns server.
Signed-off-by: Miek Gieben <miek@miek.nl>
Abstract the caddy call and make it simpler.
See #3261 for some part of the discussion.
Go from:
~~~ go
func init() {
caddy.RegisterPlugin("any", caddy.Plugin{
ServerType: "dns",
Action: setup,
})
}
~~~
To:
~~~ go
func init() { plugin.Register("any", setup) }
~~~
This requires some external documents in coredns.io to be updated as
well; the old way still works, so it's backwards compatible.
Signed-off-by: Miek Gieben <miek@miek.nl>
OWNERS file was padded, remove empty lines. Fix code block in README,
and set codeblock type to 'corefile' without the upper case C.
Signed-off-by: Miek Gieben <miek@miek.nl>
* Add plugin ACL for source ip filtering
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Allow all arguments to be optional and support multiple qtypes in a single policy
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Add newline before third party imports
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Use camel instead of underscore in method name
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Start with an upper case letter in t.Errorf()
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Use the qtype parse logic in miekg/dns
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Use third party trie implementation as the ip filter
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Update based on rdrozhdzh's comment
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Change the type of action to int
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Add IPv6 support
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Update plugin.cfg
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Remove file functionality
Signed-off-by: An Xiao <hac@zju.edu.cn>
* Update
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Update README
Signed-off-by: Xiao An <hac@zju.edu.cn>
* remove comments
Signed-off-by: Xiao An <hac@zju.edu.cn>
* update
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Update dependency
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Update
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Update test
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Add OWNERS
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Refactor shouldBlock and skip useless check
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Introduce ActionNone
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Update label name
Signed-off-by: Xiao An <hac@zju.edu.cn>
* Avoid capitalizing private types
Signed-off-by: Xiao An <hac@zju.edu.cn>
