It's pretty useful to be able to access the bytes generically, without
acknowledging a specific family, hence let's a third way to access an
in_addr_union.
In subsequent commits, calls to if_nametoindex() will be replaced by a wrapper
that falls back to alternative name resolution over netlink. netlink support
requires libsystemd (for sd-netlink), and we don't want to add any functions
that require netlink in basic/. So stuff that calls if_nametoindex() for user
supplied interface names, and everything that depends on that, needs to be
moved.
The DHCP client should not pre-filter addresses beyond what RFC
requires. If a client's user (like networkd) wishes to skip/filter
certain addresses, it's their responsibility.
The point of this is that the DHCP library does not hide/abstract
information that might be relevant for certain users. For example,
NetworkManager exposes DHCP options in its API. When doing that, the
options should be close to the actual lease.
This is related to commit d9ec2e632d
(dhcp4: filter bogus DNS/NTP server addresses silently).
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Let's rename all our functions that process IPv4 in_addr structures
in4_addr_xyz(), following the already establishing naming logic for
this.
Leave the in_addr_xyz() prefix for functions that process the IPv4/IPv6
in_addr_union union instead.
This adds in4_addr_is_localhost() and in4_addr_is_link_local() that only take
an IPv4 "struct in_addr", to match in_addr_is_localhost() and
in_addr_is_link_local() that that a "union in_addr_union".
This matches the existing in4_addr_is_null() call that already exists.
For IPv6 glibc already exports a set of macros, hence we don't add similar
functions in6_addr_is_localhost(). We also drop in6_addr_is_null() as
IN6_IS_ADDR_UNSPECIFIED() already provides that.
Make sure we can parse DNS server addresses that use the "zone id" syntax for
local link addresses, i.e. "fe80::c256:27ff:febb:12f%wlp3s0", when reading
/etc/resolv.conf.
Also make sure we spit this out correctly again when writing /etc/resolv.conf
and via the bus.
Fixes: #3359
This is useful for alternative network management solutions (such as NetworkManager) to push DNS configuration data
into resolved.
The calls will fail should networkd already have taken possesion of a link, so that the bus API is only available if
we don't get the data from networkd.
