[PATCH iproute2] dcb: fix broken "show default-prio"

[PATCH iproute2] dcb: fix broken "show default-prio"

[Vladimir Oltean]

Although "dcb app show dev eth0 default-prio" is documented as a valid
command in the help text, it doesn't work because the parser for the
"show" command doesn't parse "default-prio". Fix this by establishing
the linkage between the sub-command parsing code and
dcb_app_print_default_prio() - which was previously only called from
dcb_app_print().

Fixes: 8e9bed1493f5 ("dcb: Add a subtool for the DCB APP object")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 dcb/dcb_app.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
index 6bd64bbed0cc..c135e73acb76 100644
--- a/dcb/dcb_app.c
+++ b/dcb/dcb_app.c
@@ -646,6 +646,8 @@ static int dcb_cmd_app_show(struct dcb *dcb, const char *dev, int argc, char **a
 		if (matches(*argv, "help") == 0) {
 			dcb_app_help_show_flush();
 			goto out;
+		} else if (matches(*argv, "default-prio") == 0) {
+			dcb_app_print_default_prio(&tab);
 		} else if (matches(*argv, "ethtype-prio") == 0) {
 			dcb_app_print_ethtype_prio(&tab);
 		} else if (matches(*argv, "dscp-prio") == 0) {
-- 
2.25.1

Re: [PATCH iproute2] dcb: fix broken "show default-prio"

[Stephen Hemminger]

On Fri, 25 Feb 2022 19:12:58 +0200
Vladimir Oltean <vladimir.oltean@nxp.com> wrote:

> Although "dcb app show dev eth0 default-prio" is documented as a valid
> command in the help text, it doesn't work because the parser for the
> "show" command doesn't parse "default-prio". Fix this by establishing
> the linkage between the sub-command parsing code and
> dcb_app_print_default_prio() - which was previously only called from
> dcb_app_print().
> 
> Fixes: 8e9bed1493f5 ("dcb: Add a subtool for the DCB APP object")
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
>  dcb/dcb_app.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
> index 6bd64bbed0cc..c135e73acb76 100644
> --- a/dcb/dcb_app.c
> +++ b/dcb/dcb_app.c
> @@ -646,6 +646,8 @@ static int dcb_cmd_app_show(struct dcb *dcb, const char *dev, int argc, char **a
>  		if (matches(*argv, "help") == 0) {
>  			dcb_app_help_show_flush();
>  			goto out;
> +		} else if (matches(*argv, "default-prio") == 0) {
> +			dcb_app_print_default_prio(&tab);
>  		} else if (matches(*argv, "ethtype-prio") == 0) {
>  			dcb_app_print_ethtype_prio(&tab);
>  		} else if (matches(*argv, "dscp-prio") == 0) {

This is an example of why matches() sucks.
If we add this patch, then the result of command where *argv == "d"
will change.

All those argument handling should be using strcmp() instead.
Should have required that before merging dcb. David and I should
have caught that, too late now.

Re: [PATCH iproute2] dcb: fix broken "show default-prio"

[Petr Machata]

Stephen Hemminger <stephen@networkplumber.org> writes:

> On Fri, 25 Feb 2022 19:12:58 +0200
> Vladimir Oltean <vladimir.oltean@nxp.com> wrote:
>
>> diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
>> index 6bd64bbed0cc..c135e73acb76 100644
>> --- a/dcb/dcb_app.c
>> +++ b/dcb/dcb_app.c
>> @@ -646,6 +646,8 @@ static int dcb_cmd_app_show(struct dcb *dcb, const char *dev, int argc, char **a
>>  		if (matches(*argv, "help") == 0) {
>>  			dcb_app_help_show_flush();
>>  			goto out;
>> +		} else if (matches(*argv, "default-prio") == 0) {
>> +			dcb_app_print_default_prio(&tab);
>>  		} else if (matches(*argv, "ethtype-prio") == 0) {
>>  			dcb_app_print_ethtype_prio(&tab);
>>  		} else if (matches(*argv, "dscp-prio") == 0) {

A fix along these lines got merged recently:

    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=924f6b4a5d2b

> This is an example of why matches() sucks.
> If we add this patch, then the result of command where *argv == "d"
> will change.

To further drive this point, I made the exact same mistake in v1 of my
patch.

Re: [PATCH iproute2] dcb: fix broken "show default-prio"

[Vladimir Oltean]

On Fri, Feb 25, 2022 at 10:30:38PM +0100, Petr Machata wrote:
> 
> Stephen Hemminger <stephen@networkplumber.org> writes:
> 
> > On Fri, 25 Feb 2022 19:12:58 +0200
> > Vladimir Oltean <vladimir.oltean@nxp.com> wrote:
> >
> >> diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
> >> index 6bd64bbed0cc..c135e73acb76 100644
> >> --- a/dcb/dcb_app.c
> >> +++ b/dcb/dcb_app.c
> >> @@ -646,6 +646,8 @@ static int dcb_cmd_app_show(struct dcb *dcb, const char *dev, int argc, char **a
> >>  		if (matches(*argv, "help") == 0) {
> >>  			dcb_app_help_show_flush();
> >>  			goto out;
> >> +		} else if (matches(*argv, "default-prio") == 0) {
> >> +			dcb_app_print_default_prio(&tab);
> >>  		} else if (matches(*argv, "ethtype-prio") == 0) {
> >>  			dcb_app_print_ethtype_prio(&tab);
> >>  		} else if (matches(*argv, "dscp-prio") == 0) {
> 
> A fix along these lines got merged recently:
> 
>     https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=924f6b4a5d2b

Ah, ok, I was on iproute2-next, this makes sense. Sorry.