It can only be set on a "--internal" network, and the only difference is
that no address is assigned to the bridge. So, there's no route to a
host address.
Signed-off-by: Rob Murray <rob.murray@docker.com>
Prior to release 25.0.0, the bridge in an internal network was assigned
an IP address - making the internal network accessible from the host,
giving containers on the network access to anything listening on the
bridge's address (or INADDR_ANY on the host).
This change restores that behaviour. It does not restore the default
route that was configured in the container, because packets sent outside
the internal network's subnet have always been dropped. So, a 'connect()'
to an address outside the subnet will still fail fast.
Signed-off-by: Rob Murray <rob.murray@docker.com>
Calculate the IPv6 addreesses needed on a bridge, then reconcile them
with the addresses on an existing bridge by deleting then adding as
required.
(Previously, required addresses were added one-by-one, then unwanted
addresses were removed. This meant the daemon failed to start if, for
example, an existing bridge had address '2000:db8::/64' and the config
was changed to '2000:db8::/80'.)
IPv6 addresses are now calculated and applied in one go, so there's no
need for setupVerifyAndReconcile() to check the set of IPv6 addresses on
the bridge. And, it was guarded by !config.InhibitIPv4, which can't have
been right. So, removed its IPv6 parts, and added IPv4 to its name.
Link local addresses, the example given in the original ticket, are now
released when containers are stopped. Not releasing them meant that
when using an LL subnet on the default bridge, no container could be
started after a container was stopped (because the calculated address
could not be re-allocated). In non-default bridge networks using an
LL subnet, addresses leaked.
Linux always uses the standard 'fe80::/64' LL network. So, if a bridge
is configured with an LL subnet prefix that overlaps with it, a config
error is reported. Non-overlapping LL subnet prefixes are allowed.
Signed-off-by: Rob Murray <rob.murray@docker.com>
The github.com/containerd/containerd/log package was moved to a separate
module, which will also be used by upcoming (patch) releases of containerd.
This patch moves our own uses of the package to use the new module.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
So far, internal networks were only isolated from the host by iptables
DROP rules. As a consequence, outbound connections from containers would
timeout instead of being "rejected" through an immediate ICMP dest/port
unreachable, a TCP RST or a failing `connect` syscall.
This was visible when internal containers were trying to resolve a
domain that don't match any container on the same network (be it a truly
"external" domain, or a container that don't exist/is dead). In that
case, the embedded resolver would try to forward DNS queries for the
different values of resolv.conf `search` option, making DNS resolution
slow to return an error, and the slowness being exacerbated by some libc
implementations.
This change makes `connect` syscall to return ENETUNREACH, and thus
solves the broader issue of failing fast when external connections are
attempted.
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
This makes it easier to spot if code is only used on Linux. Note that "all of"
the bridge driver is Linux-only.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
