Y2038 problem with date-and-time

[awesomenode]

Hi,

On 32-bit platforms the date-and-time type from ietf-yang-types cannot handle dates properly after year 2038.
For example when I try to set clock through "/ietf-system:set-current-datetime" RPC to year 2040,
the subscribed rpc callback receives year 1970 in the input values.

I attached an example application to reproduce it:
reprod.zip

$ ./reprod  
Setting date-time to 2040-02-23T15:14:35Z 


========== RPC "/ietf-system:set-current-datetime" RECEIVED: ======================= 

/ietf-system:set-current-datetime/current-datetime = 1970-01-01T00:59:59+01:00

libyang version: 2.1.159
sysrepo version: 2.2.155

Thank you in advance!

[michalvasko]

So I have tested it and reproduced, the cause is timgm() returning -1 (without setting errno for some reason). And based on what I read about this, it seems it is a "feature" of 32b systems so I am not sure what you expect from libyang to make it work.

[jktjkt]

In case you can recompile everything (and I mean it, everything, since this is obviously a huge ABI change), and you're already on kernel 5.1+ and glibc 2.34+, then you can set -D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64 and you're good to go. Beware, though, that you might face some nasty surprises if you have, say, a time_t in some binary on-disk file. If you're using a system such as Buildroot, there's a config option for this already, BR2_TIME_BITS_64.

TL;DR: this fix IMHO belongs to the "system library", not into libyang.

[awesomenode]

Thank you for the answers!