By default, Nebula replies to packets it has no tunnel for with a `recv_error` packet. This packet helps speed up re-connection
in the case that Nebula on either side did not shut down cleanly. This response can be abused as a way to discover if Nebula is running
on a host though. This option lets you configure if you want to send `recv_error` packets always, never, or only to private network remotes.
valid values: always, never, private
This setting is reloadable with SIGHUP.
When running in `-test` mode, `tun` is set to nil. So we should move the
defer into the `!configTest` if block.
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x54855c]
goroutine 1 [running]:
github.com/slackhq/nebula.Main.func3(0x4000135e80, {0x0, 0x0})
github.com/slackhq/nebula/main.go:176 +0x2c
github.com/slackhq/nebula.Main(0x400022e060, 0x1, {0x76faa0, 0x5}, 0x4000230000, 0x0)
github.com/slackhq/nebula/main.go:316 +0x2414
main.main()
github.com/slackhq/nebula/cmd/nebula/main.go:54 +0x540
This allows you to configure remote allow lists specific to different
subnets of the inside CIDR. Example:
remote_allow_ranges:
10.42.42.0/24:
192.168.0.0/16: true
This would only allow hosts with a VPN IP in the 10.42.42.0/24 range to
have private IPs (and thus don't connect over public IPs).
The PR also refactors AllowList into RemoteAllowList and LocalAllowList to make it clearer which methods are allowed on which allow list.
This is how Prometheus recommends you do it, and how they do it
themselves in their client. This makes it easy to see which versions you
have deployed in your fleet, and query over it too.
* Do not allow someone to run a nebula lighthouse with an ephemeral port
* derp - we discover the port so we have to check the config setting
* No context needed for this error
* gofmt yourself
* Revert "gofmt yourself"
This reverts commit c01423498e.
* Revert "No context needed for this error"
This reverts commit 6792af6846.
* snip snap snip snap
Previously, every packet we see gets a lock on the conntrack table and updates it. When running with multiple routines, this can cause heavy lock contention and limit our ability for the threads to run independently. This change caches reads from the conntrack table for a very short period of time to reduce this lock contention. This cache will currently default to disabled unless you are running with multiple routines, in which case the default cache delay will be 1 second. This means that entries in the conntrack table may be up to 1 second out of date and remain in a routine local cache for up to 1 second longer than the global table.
Instead of calling time.Now() for every packet, this cache system relies on a tick thread that updates the current cache "version" each tick. Every packet we check if the cache version is out of date, and reset the cache if so.
This change allows a server running with `tun.disabled: true` (usually
a lighthouse) to still reply to ICMP EchoRequest packets. This allows
you to "ping" the lighthouse Nebula IP as a quick check to make sure the
tunnel is up, even when running with tun.disabled.
This is still gated by allowing `icmp` packets in the inbound firewall
rules.
This change is for Linux only.
Previously, when running with multiple tun.routines, we would only have one file descriptor. This change instead sets IFF_MULTI_QUEUE and opens a file descriptor for each routine. This allows us to process with multiple threads while preventing out of order packet reception issues.
To attempt to distribute the flows across the queues, we try to write to the tun/UDP queue that corresponds with the one we read from. So if we read a packet from tun queue "2", we will write the outgoing encrypted packet to UDP queue "2". Because of the nature of how multi queue works with flows, a given host tunnel will be sticky to a given routine (so if you try to performance benchmark by only using one tunnel between two hosts, you are only going to be using a max of one thread for each direction).
Because this system works much better when we can correlate flows between the tun and udp routines, we are deprecating the undocumented "tun.routines" and "listen.routines" parameters and introducing a new "routines" parameter that sets the value for both. If you use the old undocumented parameters, the max of the values will be used and a warning logged.
Co-authored-by: Nate Brown <nbrown.us@gmail.com>
This commit adds support for Nebula to be started without creating
a tun device. A node started in this mode still has a full "control
plane", but no effective "data plane". Its use is suited to a
lighthouse that has no need to partake in the mesh VPN.
Consequently, creation of the tun device is the only reason nebula
neesd to be started with elevated privileged, so this example
lighthouse can also be run as a non-root user.
Currently, we wait until the next timer tick to act on the lighthouse's
reply to our HostQuery. This means we can easily add hundreds of
milliseconds of unnecessary delay to the handshake. To fix this, we
can introduce a channel to trigger an outbound handshake without waiting
for the next timer tick.
A few samples of cold ping time between two hosts that require a
lighthouse lookup:
before (v1.2.0):
time=156 ms
time=252 ms
time=12.6 ms
time=301 ms
time=352 ms
time=49.4 ms
time=150 ms
time=13.5 ms
time=8.24 ms
time=161 ms
time=355 ms
after:
time=3.53 ms
time=3.14 ms
time=3.08 ms
time=3.92 ms
time=7.78 ms
time=3.59 ms
time=3.07 ms
time=3.22 ms
time=3.12 ms
time=3.08 ms
time=8.04 ms
I recommend reviewing this PR by looking at each commit individually, as
some refactoring was required that makes the diff a bit confusing when
combined together.
* enforce the use of goimports
Instead of enforcing `gofmt`, enforce `goimports`, which also asserts
a separate section for non-builtin packages.
* run `goimports` everywhere
* exclude generated .pb.go files
This change add more metrics around "meta" (non "message" type packets).
For lighthouse packets, we also record statistics around the specific
lighthouse meta type.
We don't keep statistics for the "message" type so that we don't slow
down the fast path (and you can just look at metrics on the tun
interface to find that information).
These settings make it possible to blacklist / whitelist IP addresses
that are used for remote connections.
`lighthouse.remoteAllowList` filters which remote IPs are allow when
fetching from the lighthouse (or, if you are the lighthouse, which IPs
you store and forward to querying hosts). By default, any remote IPs are
allowed. You can provide CIDRs here with `true` to allow and `false` to
deny. The most specific CIDR rule applies to each remote. If all rules
are "allow", the default will be "deny", and vice-versa. If both "allow"
and "deny" rules are present, then you MUST set a rule for "0.0.0.0/0"
as the default.
lighthouse:
remoteAllowList:
# Example to block IPs from this subnet from being used for remote IPs.
"172.16.0.0/12": false
# A more complicated example, allow public IPs but only private IPs from a specific subnet
"0.0.0.0/0": true
"10.0.0.0/8": false
"10.42.42.0/24": true
`lighthouse.localAllowList` has the same logic as above, but it applies
to the local addresses we advertise to the lighthouse. Additionally, you
can specify an `interfaces` map of regular expressions to match against
interface names. The regexp must match the entire name. All interface
rules must be either true or false (and the default rule will be the
inverse). CIDR rules are matched after interface name rules.
Default is all local IP addresses.
lighthouse:
localAllowList:
# Example to blacklist docker interfaces.
interfaces:
'docker.*': false
# Example to only advertise IPs in this subnet to the lighthouse.
"10.0.0.0/8": true
* Better config test
Previously, when using the config test option `-test`, we quit fairly
earlier in the process and would not catch a variety of additional
parsing errors (such as lighthouse IP addresses, local_range, the new
check to make sure static hosts are in the certificate's subnet, etc).
* run config test as part of smoke test
* don't need privileges for configtest
Co-authored-by: Nathan Brown <nate@slack-corp.com>
* add configurable punching delay because of race-condition-y conntracks
* add changelog
* fix tests
* only do one punch per query
* Coalesce punchy config
* It is not is not set
* Add tests
Co-authored-by: Nate Brown <nbrown.us@gmail.com>
This change exposes the current constants we have defined for the handshake
manager as configuration options. This will allow us to test and tweak
with different intervals and wait rotations.
# Handshake Manger Settings
handshakes:
# Total time to try a handshake = sequence of `try_interval * retries`
# With 100ms interval and 20 retries it is 23.5 seconds
try_interval: 100ms
retries: 20
# wait_rotation is the number of handshake attempts to do before starting to try non-local IP addresses
wait_rotation: 5
Validate all lighthouse.hosts and static_host_map VPN IPs are in the
subnet defined in our cert. Exit with a fatal error if they are not in
our subnet, as this is an invalid configuration (we will not have the
proper routes set up to communicate with these hosts).
This error case could occur for the following invalid example:
nebula-cert sign -name "lighthouse" -ip "10.0.1.1/24"
nebula-cert sign -name "host" -ip "10.0.2.1/24"
config.yaml:
static_host_map:
"10.0.1.1": ["lighthouse.local:4242"]
lighthouse:
hosts:
- "10.0.1.1"
We will now return a fatal error for this config, since `10.0.1.1` is
not in the host cert's subnet of `10.0.2.1/24`
Nate Brown