[LTP] [PATCH v1] tst_net.sh: Add more tst_require_cmds check

[Wei Gao]

On Fri, Jan 20, 2023 at 09:38:43AM +0100, Petr Vorel wrote:
> > On Tue, Jan 17, 2023 at 09:33:14AM +0100, Petr Vorel wrote:
> > > Hi Wei,
> 
> > > > More strict check for ns_xxx etc will help avoid following issue:
> > > > https://github.com/linux-test-project/ltp/issues/991
> 
> > > > Signed-off-by: Wei Gao <wegao@suse.com>
> > > > Suggested-by: Petr Vorel <pvorel@suse.cz>
> > > > ---
> > > >  testcases/lib/tst_net.sh | 2 ++
> > > >  1 file changed, 2 insertions(+)
> 
> > > > diff --git a/testcases/lib/tst_net.sh b/testcases/lib/tst_net.sh
> > > > index ceb45c98d..ec915ad74 100644
> > > > --- a/testcases/lib/tst_net.sh
> > > > +++ b/testcases/lib/tst_net.sh
> > > > @@ -205,6 +205,7 @@ tst_rhost_run()
> > > >  	sh_cmd="$pre_cmd $cmd $post_cmd"
> 
> > > >  	if [ -n "${TST_USE_NETNS:-}" ]; then
> > > > +		tst_require_cmds ip ns_create ns_exec ns_ifmove
> > > Why this? none of these commands is used here.
> > This line is the key to avoid wrong configuration(such as add ip inteface etc..) continue even ns_xxx not exist,
> > you can check following code, line 222 will execute ns_xxx with error but not exit test immediately, so if we add 
> > require_cmds here then we can avoid it. (line 222 $rcmd will contain command ns_xxx)
> 
> >  218                 tst_res_ TINFO "tst_rhost_run: cmd: $cmd"
> >  219                 tst_res_ TINFO "$use: $rcmd \"$sh_cmd\" $out 2>&1"
> >  220         fi
> >  221
> >  222         output=$($rcmd "$sh_cmd" $out 2>&1 || echo 'RTERR')
> >  223
> >  224         echo "$output" | grep -q 'RTERR$' && ret=1
> >  225         if [ $ret -eq 1 ]; then
> 
> Long time ago the first run code for netns was init_ltp_netspace.
> I added IPv6 check quite recently. (I originally submitted it as run after, but
> in the end it is run before it.)
> I need to have a deeper look how tst_net_detect_ipv6 rhost works, calling
> tst_rhost_run before init_ltp_netspace should not work (interfaces aren't
> configured yet).
> 
> But even if "ip ns_create ns_exec ns_ifmove" are needed to be checked to fix
> tst_rhost_run (not yet convinced), why to check them each time tst_rhost_run is
> called? It should be checked before first tst_rhost_run call to avoid useless
> repeating.

tst_rhost_run already be called everywhere so if you need check before call tst_rhost_run, means lot of place/cases maybe need review and update. 

Furthermore, check each time in tst_rhost_run can make this function more robust, the 
old code also do tst_require_cmds if go ssh logic in line 211 for example.

 205         sh_cmd="$pre_cmd $cmd $post_cmd"
 206
 207         if [ -n "${TST_USE_NETNS:-}" ]; then
 208                 use="NETNS"
 209                 rcmd="$LTP_NETNS sh -c"
 210         else
 211                 tst_require_cmds ssh
 212                 use="SSH"
 213                 rcmd="ssh -nq $user@$RHOST"
 214         fi



> 
> Kind regards,
> Petr
> 
> > > >  		use="NETNS"
> > > >  		rcmd="$LTP_NETNS sh -c"
> > > >  	else
> > > > @@ -1006,6 +1007,7 @@ IPV6_RHOST="${IPV6_RHOST:-fd00:1:1:1::1/64}"
> > > >  # tst_net_iface_prefix -h
> > > >  # tst_net_vars -h
> > > >  if [ -z "$_tst_net_parse_variables" ]; then
> > > > +	tst_require_cmds tst_net_ip_prefix
> > > This is correct.
> 
> > > Kind regards,
> > > Petr