libtrap: multi-file read errors --> `strncpy` misuse?

[rickhg12hs]

https://github.com/CESNET/Nemea-Framework/blob/a57307a0fa7ec230e48177f54b213cfa552dafd6/libtrap/src/ifc_file.c#L378

For reading multiple files from a directory by globbing, won't this miss the null termination when a shorter filename follows a longer filename? Ref: CESNET/LiST#10

From strncpy(3) man page:

Warning: If there is no null byte among the first n bytes of src, the string placed in dest will not be null-terminated.

[rickhg12hs]

From https://github.com/CESNET/LiST/issues/10:

There seems to be a problem reading multiple files in directory. For example

[vagrant@list-vagrant sf_vboxsf]$ ll my_UniRecs/
total 40
drwxrwx---. 1 root vboxsf 4096 Dec 12 16:49 ./
drwxrwx---. 1 root vboxsf 4096 Dec 12 16:42 ../
-rwxrwx---. 1 root vboxsf 3146 Nov  2  2018 lan_basic.201711261310*
-rwxrwx---. 1 root vboxsf 1485 Nov  2  2018 lan_dns.201711261310*
-rwxrwx---. 1 root vboxsf  787 Nov  2  2018 lan_http.201711261310*
-rwxrwx---. 1 root vboxsf 8913 Nov  2  2018 wan_basic.201711261310*
-rwxrwx---. 1 root vboxsf 1861 Nov  2  2018 wan_dns.201711261310*
-rwxrwx---. 1 root vboxsf  917 Nov  2  2018 wan_http.201711261310*

[vagrant@list-vagrant sf_vboxsf]$ traffic_repeater -v -i f:my_UniRecs/*,f:/dev/null
Info: Initializing traffic repeater...
VERBOSE: --------------- STATS --------------- 
VERBOSE: ------------- INPUT IFC ------------- 
VERBOSE: IFC[0]: recv buf: 1, msg: 37.
VERBOSE: ------------- OUTPUT IFC ------------ 
VERBOSE: IFC[0]: sent buf: 0, msg: 37, drop msg: 0, flush: 0.
VERBOSE: ------------------------------------- 
ERROR: FILE IFC[0]: unable to open file "my_UniRecs/lan_dns.20171126131010" in mode "r". Possible reasons: non-existing file, bad permission, file can not be opened in this mode.
Error: trap_recv() returned 14 (INPUT FILE IFC[0]: Unable to open next file.)
Info: Flows received:                36
Info: Flows sent:                    36
Info: Timeouts:                       0
Info: Time elapsed:               0.013s
VERBOSE: Output ifc 0: Setting autoflush timeout to 18446744073709551615.
VERBOSE: Output ifc 0: Setting timeout to 100000.

It appears that part of the file globbing isn't null terminating a string somewhere.

[vagrant@list-vagrant sf_vboxsf]$ \ls -1 my_UniRecs/
lan_basic.201711261310
lan_dns.201711261310
lan_http.201711261310
wan_basic.201711261310
wan_dns.201711261310
wan_http.201711261310

See how the second filename got trashed?

Also, ...

[vagrant@list-vagrant sf_vboxsf]$ traffic_repeater -v -i f:my_UniRecs/lan_basic.201711261310,f:/dev/null
Info: Initializing traffic repeater...
Info: Final record received, terminating repeater...
Info: Flows received:                37
Info: Flows sent:                    37
Info: Timeouts:                       0
Info: Time elapsed:               0.016s
VERBOSE: Output ifc 0: Setting autoflush timeout to 18446744073709551615.
VERBOSE: Output ifc 0: Setting timeout to 100000.

Why are the flows received/sent +1 from the example above? Where did the extra flow come from?

[havraji6]

I can confirm there was a misuse of a strncpy function. That should be fixed in #153.

The reason flow counts differs is because null termination record was not provided by libtrap, but was removed from statistics anyway.