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.
All those uses were correct, but I think it's better to be explicit.
Using implicit errno is too error prone, and with this change we can require
(in the sense of a style guideline) that the code is always specified.
Helpful query: git grep -n -P 'log_[^s][a-z]+\(.*%m'
The compiler warning is a false positive, since n_addresses is always
initialised on the success path from parse_argv(), but the compiler
obviously can’t work that out.
Fixes:
src/test/test-nss.c:426:9: warning: 'n_addresses' may be used uninitialized in this function [-Wmaybe-uninitialized]
When building without resolved and/or myhostname, test-nss.c failed to build
with
src/test/test-nss.c: In function 'main':
src/test/test-nss.c:417:32: error: 'MODULE1' undeclared (first use in this function)
NULSTR_FOREACH(module, MODULE1 MODULE2 MODULE3 MODULE4) {
^
Ensure that all MODULEx are always defined, and empty if the module is not
available (so that it will be a no-op in the string concatenation).
Zbigniew Jędrzejewski-Szmek