openwrt/package/utils/busybox
Baptiste Jonglez c3068a5b26 busybox: disable PREFER_IPV4_ADDRESS
PREFER_IPV4_ADDRESS is broken on IPv6-only hosts, as it causes busybox
utilities (ping, traceroute, ntpd) to forcibly use the A record instead of
the AAAA record when resolving a DNS name.  This obviously fails when
there is no IPv4 connectivity.  Since IPv6-only hosts or routers will only
become more common over time, disable PREFER_IPV4_ADDRESS to support this
use-case.

As a side-effect, disabling PREFER_IPV4_ADDRESS changes the default
resolution behaviour of busybox utilities on dual-stack hosts.  Busybox
utilities now simply use the order given by getaddrinfo(), so they will
now prefer IPv6 addresses when resolving a name with both A and AAAA
records if there is IPv6 connectivity.  This is in line with RFC 6724.

PREFER_IPV4_ADDRESS was likely intended to work around naive
implementations of getaddrinfo() that could return AAAA records first,
even on an IPv4-only host.  But both musl (since 1.1.3) and glibc
correctly implement RFC 6724 for getaddrinfo() and check connectivity to
determine the correct order in which to return records.  On IPv4-only
hosts, getaddrinfo() will return A records first, so there is no need for
the PREFER_IPV4_ADDRESS hack.

See also: https://bugs.busybox.net/show_bug.cgi?id=12381

Fixes: FS#84
Fixes: FS#2608
References: https://github.com/openwrt/openwrt/pull/4167
Signed-off-by: Alexander Traud <pabstraud@compuserve.com>
Signed-off-by: Baptiste Jonglez <git@bitsofnetworks.org>
Signed-off-by: maurerr <mariusd84@gmail.com>
2021-09-01 08:08:05 +00:00
..
config busybox: update to 1.33 2021-09-01 08:07:35 +00:00
files busybox: sysntpd: option to bind server to iface 2021-09-01 08:07:43 +00:00
patches busybox: update to 1.33.1 2021-09-01 08:08:05 +00:00
Config-defaults.in busybox: disable PREFER_IPV4_ADDRESS 2021-09-01 08:08:05 +00:00
Config.in busybox: add selinux variant 2021-09-01 08:06:53 +00:00
convert_defaults.pl
convert_menuconfig.pl
Makefile build: introduce $(MKHASH) 2021-09-01 08:08:05 +00:00
selinux.config busybox: add selinux variant 2021-09-01 08:06:53 +00:00