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SubjectRe: [RFC] y2038: HCI_TIME_STAMP with time64
On Fri, Jan 10, 2020 at 4:44 PM Marcel Holtmann <> wrote:
> > I noticed earlier this week that the HCI_CMSG_TSTAMP/HCI_TIME_STAMP
> > interface has no time64 equivalent, as we apparently missed that when
> > converting the normal socket timestamps to support both time32 and time64
> > variants of the sockopt and cmsg data.
> > When using HCI_TIME_STAMP on a 32-bit system with a time64
> > libc, users will interpret the { s32 tv_sec; s32 tv_usec } layout of
> > the kernel as { s64 tv_sec; ... }, which puts complete garbage
> > into the timestamp regardless of whether this code runs before or
> > after y2038. From looking at, I found two
> > users of this: libpcap and hcidump. There are probably others that
> > are not part of Debian.
> > 3. Add support for the normal SO_TIMESTAMPNS_NEW sockopt in
> > HCI, providing timestamps in the unambiguous { long long tv_sec;
> > long long tv_nsec; } format to user space, and change applications
> > to use that if supported by the kernel.
> I have added SO_TIMESTAMP* to every Bluetooth socket a while back. And that should be used by the majority of the tools. One exception might by hcidump which has been replaced by btmon already anyway.
> So I would not bother with HCI_TIME_STAMP fixing. We can do 2) if someone really still wants to use that socket option. However I am under the impression that 3) should be already possible.

Ok, excellent, I had not realized this works already.

I have now also checked
which uses SO_TIMESTAMP and then should work. I guess this is similar
to what btmon does.

For libpcap that leaves

which needs a fairly simply fix on 32-bit architectures to copy the
two 32-bit fields
into the longer pkth.ts fields individually rather than using a memcpy.
I've added Guy Harris to Cc, he seems to be the maintainer for this file
according to the git history.

The same change is needed for
if there are any remaining users. I can send you a patch if you want.


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