NOTES.y2kfixes revision 290001 
1Name of the Application: xntp
2
3Version Number:  4.0.91
4
5Download Size: 4541953 bytes
6
7Downloaded from: http://www.eecis.udel.edu/~ntp/
8
9Operating Systems Supported: many
10
11Operating Systems Tested: unix
12
13Testing
14
15Dates tested (CPU clock set)
16
17	1999-12-31
18	2000-01-01
19	2000-02-29
20
21	Critical fragments of code tested with other dates by special
22	algorithms.
23
24Hardware Platform: Sun Sparc
25
26OS: Solaris 2.6
27
28Compiler: gcc
29
30Version: 2.8.1
31
32Repairs:  9
33
34No. of files Repaired: 13
35
36
37Compilation of Patches Required: yes
38
39Results Description:
40
411)	Tested suspicious code.
42
432)	Repaired problem code and added documentation to ntp.h.
44
453)	Verified ntpd works on critical Y2K dates.
46
47
48Comments:
49
501)	Errors were found in improper use of tm_year within struct tm,
51	calculations that did not support year 2000 as a leap year
52	(it truly is, despite any unchanged comments remaining in 
53	the NTP source), and some incorrect date calculations, while
54	not traditional Y2K errors, would break in the year 2000.
55
562)	include/ntpd.h
57    	Added some definitions and documentation about the right way
58        of doing things.  Definitions used by most, if not all, of
59        the Y2K repairs.
60
61Cautions:
62
631)	Some of the Y2K repairs were to reference clock drivers that
64	we did not have the local hardware to test.  While I believe
65	the changes are sound, they really need to be tested.
66	This includes:
67
68		refclock_arc.c
69		refclock_heath.c
70		refclock_hpgps.c
71
72	Also, parseutil/dcfd.c is another hardware dependent module that
73	was repaired without live testing.
74
75Non-Y2K Problems Observed:
76
771)	Inconsistent casts of variables containing time values may
78	make expansion to 64 bit integer values in a portable manner
79	difficult.
80
812)	libntp/caltontp.c:
82        Has logic I believe will fail starting in year 2100 or so.
83        Left unchanged/untested as it works well beyond basic NTP 2036 
84	limit checked by check_y2k.c.
85        If NTP is implemented on 64-bit machines, this should be fixed
86
873)	ntpd/refclock_acts.c:
88	ACTS time format has changed somewhat since the code was written.
89	In particular the '*' '#' character switch no longer occurs...
90	only '*' is typed.
91
92      NOTE: Author (falsely) stated Y2K is NOT a leap year when it 
93      really is.
94
95      TRUTH: ACTS will go beyond Y2K: it uses FourDigitYear % 100 values
96      for year so year 2000 will revert to "00".
97
98
994)     ntpd/refclock_oncore.c
100       Some very strange logic in manipulating year values:
101       1122         instance->pp->year = buf[6]*256+buf[7];
102       Multiply by 256????
103 
104    Response from PHK:
105       The entire protocol is binary, the year is a 16 bit quantity 
106       which according to the manual can have the range 1998-2018. 
107 
108