Currently when both ipv4ll and dhcp are enabled, ipv4ll
address (if one has been claimed) is removed when dhcp
address is aquired. This is not the best thing to do
since there might be clients unaware of the removal
trying to communicate.
This patch provides a smooth transition between ipv4ll
and dhcp. If ipv4ll address was claimed [1] before dhcp,
address is marked as deprecated. Deprecated address is still
a valid address and packets can be received on it but address
cannot be selected as a source address. If dhcp lease cannot
be extended, then ipv4ll address is marked as valid again.
[1] If there is no collision, claiming IPv4LL takes between 4 to
7 seconds.
tcpwrap is legacy code, that is barely maintained upstream. It's APIs
are awful, and the feature set it exposes (such as DNS and IDENT
access control) questionnable. We should not support this natively in
systemd.
Hence, let's remove the code. If people want to continue making use of
this, they can do so by plugging in "tcpd" for the processes they start.
With that scheme things are as well or badly supported as they were from
traditional inetd, hence no functionality is really lost.
If you allocate a message with bus==NULL and then unref the main bus,
it will free your message underneath and your program will go boom!
To fix that, we really need to figure out what the semantics for
self-references (m->bus) should be and when/where/what accesses are
actually allowed.
Same is true for the pseudo-thread-safety we employ..
Increase the chance of using the same link local address between reboots. The
pseudo random sequence of addresses we attempt is now seeded with data that is
very likely to stay the same between reboots, but at the same time be unique
to the specific machine/nic.
First we try to use the ID_NET_NAME_* data from the udev db combined with the
machin-id, which is guaranteed to be unique and persistent, if available. If
that is not possible (e.g., in containers where we don't have access to the
udev db) we fallback to using the MAC address of the interface, which is
guaranteed to be unique, and likely to be persistent.
[tomegun: three minor changes:
- don't expose HASH_KEY in the siphash24 header
- get rid of some compile-warnings (and some casts at the same time),
by using uint8_t[8] rather than uint64_t in the api
- added commit message]
Implements IPv4LL with respect to RFC 3927
(http://tools.ietf.org/rfc/rfc3927.txt) and integrates it
with networkd. Majority of the IPv4LL state machine is
taken from avahi (http://avahi.org/) project's autoip.
IPv4LL can be enabled by IPv4LL=yes under [Network]
section of .network file.
IPv4LL works independent of DHCP but if DHCP lease is
aquired, then LL address will be dropped.
[tomegun: removed a trailing newline and a compiler warning]
This adds the host side of the veth link to the given bridge.
Also refactor the creation of the veth interfaces a bit to set it up
from the host rather than the container. This simplifies the addition
to the bridge, but otherwise the behavior is unchanged.
We cannot remove CAP_SYS_ADMIN, which basically makes removing all other
capabilities useless. Anyhow, still wouldn't hurt checking whether stuff
like CAP_KILL can be dropped from logind.
This way we have four kinds of properties:
a) those which are constant as long as an object exists
b) those which can change and PropertiesChange messages with contents are generated
c) those which can change and where the PropertesChange merely includes invalidation
d) those which can change but for which no events are generated
Clients (through code generators run on the introspection XML) can thus
aggressively cache a, b, c, with only d excluded.
Uevents are events of the host, which should not leak into a container.
Containers do not support hotplug at the moment, and devices and uevents
are not namespace aware.
The pattern of unreffing an IO event source and then closing its fd is
frequently seen in even source callbacks. Previously this likely
resultet in us removing the fd from the epoll after it was closed which
is problematic, since while we were dispatching we always kept an extra
reference to event source objects because we might still need it later.
With this change a failing event source handler will not cause the
entire event loop to fail. Instead, we just disable the specific event
source, log a message at debug level and go on.
This also introduces a new concept of "exit code" which can be stored in
the event loop and is returned by sd_event_loop(). We also rename "quit"
to "exit" everywhere else.
Altogether this should make things more robus and keep errors local
while still providing a way to return event loop errors in a clear way.