Package: libc6
Version: 2.24-8
Severity: normal
Tags: upstream
Hello,
quoting getaddrinfo(3):
According to POSIX.1-2001, specifying hints as NULL should cause
ai_flags to be assumed as 0. The GNU C library instead assumes a value
of (AI_V4MAPPED | AI_ADDRCONFIG) for this case, since this value is
considered an improvement on the specification.
On an offline host trying to connect a service via 127.0.0.1 (or ::1)
should work. If however the application uses
getaddrinfo("127.0.0.1", "http", NULL, ...);
it fails to connect because of the above "improvement", while it would
just work if getaddrinfo implemented the POSIX specification.
(Note, currently this is not a problem because of a bug in
getaddrinfo(), see https://bugs.debian.org/854301.)
Best regards
Uwe
-- System Information:
Debian Release: 9.0
APT prefers testing
APT policy: (800, 'testing'), (600, 'unstable'), (500, 'testing-debug'),
(500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 4.9.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
