This changes the symbolic name for the default gateway from "gateway" to
"_gateway". A new configuration option -Dcompat-gateway-hostname=true|false
is added. If it is set, the old name is also supported, but the new name
is used as the canonical name in either case. This is intended as a temporary
measure to make the transition easier, and the option should be removed
after a few releases, at which point only the new name will be used.
The old "gateway" name mostly works OK, but hasn't gained widespread acceptance
because of the following (potential) conflicts:
- it is completely legal to have a host called "gateway"
- there is no guarantee that "gateway" will not be registered as a TLD, even
though this currently seems unlikely. (Even then, there would be no
conflict except for the case when the top-level domain itself was being resolved.
The "gateway" or "_gateway" labels have only special meaning when the
whole name consists of a single label, so resolution of any subdomain
of the hypothetical gateway. TLD would still work OK. )
Moving to "_gateway" avoids those issues because underscores are not allowed
in host names (RFC 1123, §2.1) and avoids potential conflicts with local or
global names.
v2:
- simplify the logic to hardcode "_gateway" and allow
-Dcompat-gateway-hostname=true as a temporary measure.
Currently, if the hostname is not set gethostname_malloc() defaults to
the "sysname", which is "linux" on Linux. Let's change that to also
honour the compile-time fallback hostname as specified on the configure
command line.
Rework 17eb9a9ddb a bit.
Let's make sure we don't clobber the input parameter args[1], following our
coding style to not clobber parameters unless explicitly indicated. (in
particular, as we don't want to have our changes appear in the command line
shown in "ps"...)
No functional change.
".localdomain" is not a reserved suffix (or prefix). I'm not aware of any
product expecting *.localdomain to resolve to localhost, however I am aware of
at least one product that defaults to ".localdomain" as its DNS suffix provided
via DHCP (pfSense). This leads to unexpected results when attempting to access
a host that's offline (or a host that's online, when nsswitch.conf is
[mis-]configured to have myhostname ahead of DNS).
Operate on:
localhost (and localhost.)
*.localhost (and *.localhost.)
localhost.localdomain (and localhost.localdomain.)
*.localhost.localdomain (and *.localhost.localdomain.)
We should not cover:
*.localdomain (nor *.localdomain.)
localdomain (nor localdomain.)
Throughout the tree there's spurious use of spaces separating ++ and --
operators from their respective operands. Make ++ and -- operator
consistent with the majority of existing uses; discard the spaces.
Let's add some minimalistic LLDP sender support. The idea is that this is
either on or off, and all fields determined automatically rather than
configured explicitly.
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.
This moves is_gateway() from nss-myhostname into the basic APIs, and
makes it more like is_localhost(). Also, we rename it to
is_gateway_hostname() to make it more expressive.
Sharing this function in src/basic/ allows us to reuse the function for
routing name requests in resolved (in a later commit).
Tests are modified to check behaviour with relax and without relax.
New tests are added for hostname_cleanup().
Tests are moved a new file (test-hostname-util) because there's
now a bunch of them.
New parameter is not used anywhere, except in tests, so there should
be no observable change.
Zbigniew Jędrzejewski-Szmek