Modernize usage of "restrict" keyword in ntp.conf

It is no longer necessary to specify a -4/-6 flag on any ntp.conf
keyword.  The address type is inferred from the address itself as
necessary.  "restrict default" statements always apply to both address
families regardless of any -4/-6 flag that may be present.

So this change just tidies up our default config by removing the redundant
restrict -6 statement and comment, and by removing the -6 flag from the
restrict keyword that allows access from localhost.

This change was inspired by the patches provided in PRs 201803 and 210245,
and included some contrib/ntp code inspection to verify that the -4/-6
keywords are basically no-ops in all contexts now.

PR:		201803 210245
Differential Revision:	https://reviews.freebsd.org/D15974
This commit is contained in:
Ian Lepore 2018-06-24 03:29:00 +00:00
parent 57ec63b396
commit 4b4a865284

View File

@ -62,15 +62,13 @@ pool 0.freebsd.pool.ntp.org iburst
# See http://support.ntp.org/bin/view/Support/AccessRestrictions
# for more information.
#
restrict default limited kod nomodify notrap noquery nopeer
restrict -6 default limited kod nomodify notrap noquery nopeer
restrict source limited kod nomodify notrap noquery
restrict default limited kod nomodify notrap noquery nopeer
restrict source limited kod nomodify notrap noquery
#
# Alternatively, the following rules would block all unauthorized access.
#
#restrict default ignore
#restrict -6 default ignore
#
# In this case, all remote NTP time servers also need to be explicitly
# allowed or they would not be able to exchange time information with
@ -85,7 +83,7 @@ restrict source limited kod nomodify notrap noquery
#
# The following settings allow unrestricted access from the localhost
restrict 127.0.0.1
restrict -6 ::1
restrict ::1
#
# If a server loses sync with all upstream servers, NTP clients