diff options
| author | Jeff Morriss <jeff.morriss.ws@gmail.com> | 2012-10-25 22:26:52 +0000 |
|---|---|---|
| committer | Jeff Morriss <jeff.morriss.ws@gmail.com> | 2012-10-25 22:26:52 +0000 |
| commit | d97b4ec325830bee235568138ba4151edc253c54 (patch) | |
| tree | 837208043a832c28468bf2692f69433067ca30a6 /epan/dissectors/packet-ntp.c | |
| parent | 4518ece9f954ab0e86a7c4e54c566919bb5cd1c1 (diff) | |
Fix problem where NTP times with the high-bit set to 0 (which RFC 2030
chapter 3 has redefined to mean years *after* 2036) were being represented as
times prior to 1968.
This has been broken since r35840 (apparently not many people see NTP
timestamps beyond 2036 :-)): apparently I over-optimized packet-ntp's code
while copying it into proto.c: that temporary variable is necessary for the
unsigned math to happen correctly before assigning the result to the (signed)
time_t.
Leave a comment in the code indicating why the temporary variable is needed.
Copy that comment to packet-ntp.c.
Fix the same problem in ntp_to_nstime(): it also did not use the temporary variable.
svn path=/trunk/; revision=45790
Diffstat (limited to 'epan/dissectors/packet-ntp.c')
| -rw-r--r-- | epan/dissectors/packet-ntp.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/epan/dissectors/packet-ntp.c b/epan/dissectors/packet-ntp.c index 5d113c7eb1..e32a2693fa 100644 --- a/epan/dissectors/packet-ntp.c +++ b/epan/dissectors/packet-ntp.c @@ -644,6 +644,10 @@ tvb_ntp_fmt_ts(tvbuff_t *tvb, gint offset) return "NULL"; } + /* We need a temporary variable here so the unsigned math + * works correctly (for years > 2036 according to RFC 2030 + * chapter 3). + */ temptime = tempstmp - (guint32) NTP_BASETIME; bd = gmtime(&temptime); if(!bd){ @@ -666,9 +670,18 @@ tvb_ntp_fmt_ts(tvbuff_t *tvb, gint offset) void ntp_to_nstime(tvbuff_t *tvb, gint offset, nstime_t *nstime) { - nstime->secs = tvb_get_ntohl(tvb, offset); - if (nstime->secs) - nstime->secs -= NTP_BASETIME; + guint32 tempstmp; + + /* We need a temporary variable here so the unsigned math + * works correctly (for years > 2036 according to RFC 2030 + * chapter 3). + */ + tempstmp = tvb_get_ntohl(tvb, offset); + if (tempstmp) + nstime->secs = tempstmp - (guint32)NTP_BASETIME; + else + nstime->secs = tempstmp; /* 0 */ + nstime->nsecs = (int)(tvb_get_ntohl(tvb, offset+4)/(NTP_FLOAT_DENOM/1000000000.0)); } |