There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
a) drop handling of obsolete or unused DHCP options time_offset,
mtu_aging_timeout, policy filter, mdr, ttl, ip forwarding settings.
Should this become useful one day we can readd support for this.
b) For subnet mask and broadcast it is not always clear whether 0 or
255.255.255.255 might be valid, hence maintain a boolean indicating
validity next to it.
c) serialize/deserialize broadcast address, lifetime, T1 and T2 together
with the rest of the fields in dhcp_lease_save() and
dhcp_lease_load().
d) consistently return ENODATA from getter functions for data that is
missing in the lease.
e) add missing getter calls for broadcast, lifetime, T1, T2.
f) when decoding DHCP options, generate debug messages on parse
failures, but try to proceed if possible.
g) Similar, when deserializing a lease in dhcp_lease_load(), make sure
we deal nicely with unparsable fields, to provide upgrade compat.
h) fix some memory allocations
In our API design, getter-functions don't ref objects. Calls like
foo_get_bar() will not ref 'bar'. We never do that and there is no real
reason to do it in single threaded APIs. If you need a ref-count, you
better take it yourself *BEFORE* doing anything else on the parent object
(as this might invalidate your pointer).
Right now, sd_dhcp?_get_lease() refs the lease it returns. A lot of
code-paths in systemd do not expect this and thus leak the lease
reference. Fix this by changing the API to not ref returned objects.
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
In addition to the benefits listed in the RFC, this allows DHCP to work also in
case several interfaces share the same MAC address on the same link (IPVLAN).
Note that this will make the ClientID (so probably the assigned IP address)
change on upgrades. If it is desired to avoid that we would have to remember and
write back the ID (which the library supports, but networkd currently does not).
The client identifier can be in many different formats, not just
the one that systemd creates from the Ethernet MAC address. Non-
ethernet interfaces may have different client IDs formats. Users
may also have custom client IDs that the wish to use to preserve
lease options delivered by servers configured with the existing
client ID.
client->secs wasn't getting set in the REBOOT state, causing
an assertion. REBOOT should work the same way as INIT, per
RFC 2131:
secs 2 Filled in by client, seconds elapsed since client
began address acquisition or renewal process.
REBOOT is necessary because some DHCP servers (eg on
home routers) do not hand back the same IP address unless the
'ciaddr' field is filled with that address, which DISCOVER
cannot do per the RFCs. This leads to multiple leases
on machine reboot or DHCP client restart.
The raw socket sd_event_source used for DHCP server solicitations
was simply dropped on the floor when creating the new UDP socket
after a lease has been acquired. Clean it up properly so we're
not still listening and responding to events on it.
Like Infiniband. See RFC 4390 section 2.1 for details on DHCP
and Infiniband; chaddr is zeroed, hlen is set to 0, and htype
is set to ARPHRD_INFINIBAND because IB hardware addresses
are 20 bytes in length.
The timeouts in the networking library (DHCP lease timeouts and similar) should not be affected
by suspend. In the cases where CLOCK_BOOTTIME is not implemented, it is still safe to fallback to
CLOCK_MONOTONIC, as the consumers of the library (i.e., networkd) _should_ renew the leases when
coming out of suspend.
It appears there is no good way to decide whether or not broadcasts should be enabled,
there is hardware that must have broadcast, and there are networks that only allow
unicast. So we give up and make this configurable.
By default, unicast is used, but if the kernel were to inform us abotu certain
interfaces requiring broadcast, we could change this to opt-in by default in
those cases.
Vendor Class Identifier be used by DHCP clients to identify
their vendor type and configuration. When using this option,
vendors can define their own specific identifier values, such
as to convey a particular hardware or operating system
configuration or other identifying information.
Vendor-specified DHCP options—features that let administrators assign
separate options to clients with similar configuration requirements.
For example, if DHCP-aware clients for example we want to separate
different gateway and option for different set of people
(dev/test/hr/finance) in a org or devices for example web/database
servers or let's say in a embedded device etc and require a different
default gateway or DNS server than the rest of clients.
Check that received DHCP packets actually include our MAC address in
chaddr field. BPF interpreter has 32 bit wide registers but MAC address
is 48 bits long so we have to do check in two steps.
Send hostname (option 12) in DISCOVER and REQUEST messages so the
DHCP server could use it to register with dynamic DNS and such.
To opt-out of this behaviour set SendHostname to false in [DHCP]
section of .network file
[tomegun: rebased, made sure a failing set_hostname is a noop and moved
config from DHCPv4 to DHCP]
Even if we cannot renew the lease at T1, we will likely succeed at T2, so warn and ignore the failure.
This could happen if for whatever reason the received address is not yet configured, or it has
been lost.
Let's keep this behavior consistent across our libraries.
In order to keep the refcounting working, a DONT_DESTROY macro similar
to the one in sd-bus was introduced.
static int client_send_request(...) in
./src/libsystemd-network/sd-dhcp-client.c tries to initialize
"request" by calling client_message_init(...), which has atleast
5 error cases where it can return without that happening.
This leads to the function finishing without "request" being initialized.
On systems which cannot receive unicast packets until its IP stack has been configured
we need to request broadcast packets. We are currently not able to reliably detect when
this is necessary, so set it unconditionally for now.
This is set on all packets, but the DHCP server will only broadcast the packets that are
necessary, and unicast the rest.
For more information please refer to this thread in CoreOS: https://github.com/coreos/bugs/issues/12
[tomegun: rephrased commit message]
