libsystemd-network provides the public function
sd_dhcp6_client_set_request_option() to enable the request of a given
DHCP option. However the enum defining such options is defined in the
internal header dhcp6-protocol.h. Move the enum definition to the
public header sd-dhcp6-client.h and properly namespace values.
libsystemd-network provides the public function
sd_dhcp_client_set_request_option() to enable the request of a given
DHCP option. However the enum defining such options is defined in the
internal header dhcp-protocol.h. Move the enum definition to the
public header sd-dhcp-client.h and properly namespace values.
At the moment sd_dhcp_lease_get_routes() returns an array of structs
which are not defined in public headers. Instead, change the function
to return an array of pointers to opaque sd_dhcp_route objects.
Merge separate two error handling statements into two nested ifs.
This looks cleaner, and avoids a gcc warning about *prefix being
uninitialized.
While at it, fix identation of logging statements elsewhere in the
file.
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.
With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.
The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).
This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.
Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:
#define _cleanup_(function) __attribute__((cleanup(function)))
Or similar, to make the gcc feature easier to use.
Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.
See #2008.
The new dns_label_escape() call now operates on a buffer passed in,
similar to dns_label_unescape(). This should make decoding a bit faster,
and nicer.
Let's change the return value to bool. If we encounter an error while
parsing, return "false" instead of the actual parsing error, after all
the specified hostname does not qualify for what the function is
supposed to test.
Dealing with the additional error codes was always cumbersome, and
easily misused, like for example in the DHCP code.
Let's also rename the functions from dns_name_root() to
dns_name_is_root(), to indicate that this function checks something and
returns a bool. Similar for dns_name_is_signal_label().
If a client sends a DECLINE or a server sends a NAK, they can include
a string with a message to explain the error. Parse this and print it
at debug level.
See https://tools.ietf.org/html/rfc4861#section-4.2. Some routers (dnsmasq) will send packets
from global addresses, which would break the default route setup, so ignore those.
This is also what the kernel does.
This adds support for the Client Fully Qualified Domain Name (FQDN)
option [RFC 4702] to libsystemd-network. The option can be used to
exchange information about a DHCPv4 client's fully qualified domain
name and about responsibility for updating the DNS RR related to the
client's address assignment.
Other popular DHCP clients (dhclient, dhcpcd) support this option and
it would be useful to have it in networkd too.
Rather than passing a pointer to return the result, return it directly
from the function calls.
Also, return the result in native endianess, and let the callers care
about the conversion. For hash tables and bloom filters, we don't care,
but in order to keep MAC addresses and DHCP client IDs stable, we
explicitly convert to LE.
Change the "out" parameter from uint8_t[8] to uint64_t. On architectures which
enforce pointer alignment this fixes crashes when we previously cast an
unaligned array to uint64_t*, and on others this should at least improve
performance as the compiler now aligns these properly.
This also simplifies the code in most cases by getting rid of typecasts. The
only place which we can't change is struct duid's en.id, as that is _packed_
and public API, so we can't enforce alignment of the "id" field and have to
use memcpy instead.
Router Discovery is a core part of IPv6, which by default is handled by the kernel.
However, the kernel implementation is meant as a fall-back, and to fully support
the protocol a userspace implementation is desired.
The protocol essentially listens for Router Advertisement packets from routers
on the local link and use these to configure the client automatically. The four
main pieces of information are: what kind (if any) of DHCPv6 configuration should
be performed; a default gateway; the prefixes that should be considered to be on
the local link; and the prefixes with which we can preform SLAAC in order to pick
a global IPv6 address.
A lot of additional information is also available, which we do not yet fully
support, but which will eventually allow us to avoid the need for DHCPv6 in the
common case.
Short-term, the reason for wanting this is in userspace was the desire to fully
track all the addresses on links we manage, and that is not possible for addresses
managed by the kernel (as the kernel does not expose to us the fact that it
manages these addresses). Moreover, we would like to support stable privacy
addresses, which will soon be mandated and the legacy MAC-based global addresses
deprecated, to do this well we need to handle the generation in userspace. Lastly,
more long-term we wish to support more RA options than what the kernel exposes.
As the data passed is very different, we introduce four different callbacks:
- Generic - router discovery timed out or state machine stopped
- Router - router and link configuration received
- Prefix onlink - configuration for an onlink prefix received
- Prefix autonomous - configuration for to configure a SLAAC address for a prefix received
