NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service (DDoS) attacks. Please also take this opportunity to defeat denial-of-service attacks by implementing Ingress and Egress filtering through BCP38.

ntp-4.2.8p15 was released on 23 June 2020. It addresses 1 medium-severity security issue in ntpd, and provides 13 non-security bugfixes over 4.2.8p13.

Please see the NTP Security Notice for vulnerability and mitigation details.

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Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.

Parsing ntp.conf - the config file for ntpd

Needed Tools

We process ntpd/ntp_parser.y with bison because we get much better error messages that way, and we also get a useful table of token symbolic names.

We used to allow building with yacc, but we stopped when we discovered we needed the token symbolic name tables.

What files are involved

• ntpd/ntp_parser.y
  • ntpd/ntp_parser.c
• ntpd/keyword-gen.c (see comments at top)
  • ntpd/ntp_keyword.h
  • ntpd/keyword-get-utd
• ntpd/ntp_config.c

Indented files are derived from the file above.

-- HarlanStenn - 2011-03-06