[PATCH iproute2-next v2 0/8] Introduce new dcb-rewr subcommand

[PATCH iproute2-next v2 0/8] Introduce new dcb-rewr subcommand

[Daniel Machon]

========================================================================               
Introduction:
========================================================================

This series introduces a new DCB subcommand: rewr, which is used to
configure the in-kernel DCB rewrite table [1].

Rewrite support is added as a separate DCB subcommand, rather than an
APP opt-in flag or similar. This goes in line with what we did to dcbnl,
where rewrite is a separate object.  Obviously this requires a bit more
code to implement the new command, but much of the existing dcb-app code
(especially the bookkeeping code) can be reused. In some cases a little
adaptation is needed.

========================================================================
dcb-rewr parameters:
========================================================================

Initially, I have only made support for the prio-pcp and prio-dscp
parameters, as DSCP and PCP  are the only selectors that currently have
a user [2] and to be honest, I am not even sure it makes sense to add
dgram, stream, ethtype rewrite support - At least the rewriter of Sparx5
does not support this. Any input here is much appreciated!

Examples:

Rewrite DSCP to 63 for packets with priority 1
$ dcb rewr add dev eth0 prio-dscp 1:63

Rewrite PCP 7 and DEI to 1 for packets with priority 1
$ dcb rewr add dev eth0 prio-pcp 1:7de

A new manpage has been added, to cover the new dcb-rewr subcommand, and
its parameters. Also I took the liberty to clean up a few things in the
dcb-app manpage.

========================================================================               
Patch overview:
========================================================================

Patch #1 Adds a new field 'attr' to the dcb_app_table struct, which is
         used to distinguish app and rewrite tables.

Patch #2 Modifies existing dcb-app print functions for reuse by
         dcb-rewr.

Patch #3 Modifies existing dcb-app function dcb_app_table_remove_replaced 
         for reuse by dcb-rewr

Patch #4 Modifies existing dcb-app function dcb_app_parse_mapping_cb for
         reuse by dcb-rewr.

Patch #5 Adds the new dcb-rewr subcommand with initial support for
         prio-pcp and prio-dscp rewrite.

Patch #6 Adds the dcb-rewr.8 manpage
Patch #7 Adds references to dcb-apptrust and dcb-rewr in the dcb.8
         manpage.

Patch #8 Cleans up the dcb-app.8 manpage.

[1] https://elixir.bootlin.com/linux/v6.4-rc1/source/net/dcb/dcbnl.c#L181
[2] https://elixir.bootlin.com/linux/v6.4-rc1/source/drivers/net/ethernet/microchip/sparx5/sparx5_dcb.c#L380

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
Changes in v2:
- Got rid of patch #1 that introduced dcb_app.h - expose in individual patches. 
- Changed to callbacks for printing APP and rewrite entries. Also fixed %d to be %u.
- Changed to callbacks for removing replaced table entries for APP and rewrite.
- Changed to callbacks for pushing APP and rewrite entries to the table.
- Got rid of extra spaces in dcb-rewr helps, and reordered some parameters for dcb_parse_mapping.
- Rephrased 'that that' sentence in dcb-app.8 and dcb-rewr.8
- Link to v1: https://lore.kernel.org/r/20230510-dcb-rewr-v1-0-83adc1f93356@microchip.com

---
Daniel Machon (8):
      dcb: app: add new dcbnl attribute field
      dcb: app: modify dcb-app print functions for dcb-rewr reuse
      dcb: app: modify dcb_app_table_remove_replaced() for dcb-rewr reuse
      dcb: app: modify dcb_app_parse_mapping_cb for dcb-rewr reuse
      dcb: rewr: add new dcb-rewr subcommand
      man: dcb-rewr: add new manpage for dcb-rewr
      man: dcb: add additional references under 'SEE ALSO'
      man: dcb-app: clean up a few mistakes

 dcb/Makefile        |   3 +-
 dcb/dcb.c           |   4 +-
 dcb/dcb.h           |  58 +++++++++
 dcb/dcb_app.c       | 167 +++++++++++++-----------
 dcb/dcb_rewr.c      | 355 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 man/man8/dcb-app.8  |  10 +-
 man/man8/dcb-rewr.8 | 206 ++++++++++++++++++++++++++++++
 man/man8/dcb.8      |   4 +-
 8 files changed, 727 insertions(+), 80 deletions(-)
---
base-commit: 9c7bdc9f3328fb3fd5e7b77eb7b86f6c62538143
change-id: 20230510-dcb-rewr-534b7ab637eb

Best regards,
-- 
Daniel Machon <daniel.machon@microchip.com>

[PATCH iproute2-next v2 1/8] dcb: app: add new dcbnl attribute field

[Daniel Machon]

Add a new field 'attr' to the dcb_app_table struct, in order to inject
different dcbnl get/set attributes for APP and rewrite.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
 dcb/dcb_app.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
index eeb78e70f63f..8073415ad084 100644
--- a/dcb/dcb_app.c
+++ b/dcb/dcb_app.c
@@ -71,6 +71,7 @@ static void dcb_app_help(void)
 struct dcb_app_table {
 	struct dcb_app *apps;
 	size_t n_apps;
+	int attr;
 };
 
 enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector)
@@ -583,7 +584,7 @@ static int dcb_app_get(struct dcb *dcb, const char *dev, struct dcb_app_table *t
 	void *payload;
 	int ret;
 
-	ret = dcb_get_attribute_va(dcb, dev, DCB_ATTR_IEEE_APP_TABLE, &payload, &payload_len);
+	ret = dcb_get_attribute_va(dcb, dev, tab->attr, &payload, &payload_len);
 	if (ret != 0)
 		return ret;
 
@@ -606,7 +607,7 @@ static int dcb_app_add_del_cb(struct dcb *dcb, struct nlmsghdr *nlh, void *data)
 	struct nlattr *nest;
 	size_t i;
 
-	nest = mnl_attr_nest_start(nlh, DCB_ATTR_IEEE_APP_TABLE);
+	nest = mnl_attr_nest_start(nlh, add_del->tab->attr);
 
 	for (i = 0; i < add_del->tab->n_apps; i++) {
 		const struct dcb_app *app = &add_del->tab->apps[i];
@@ -715,7 +716,7 @@ static int dcb_cmd_app_parse_add_del(struct dcb *dcb, const char *dev,
 
 static int dcb_cmd_app_add(struct dcb *dcb, const char *dev, int argc, char **argv)
 {
-	struct dcb_app_table tab = {};
+	struct dcb_app_table tab = { .attr = DCB_ATTR_IEEE_APP_TABLE };
 	int ret;
 
 	ret = dcb_cmd_app_parse_add_del(dcb, dev, argc, argv, &tab);
@@ -729,7 +730,7 @@ static int dcb_cmd_app_add(struct dcb *dcb, const char *dev, int argc, char **ar
 
 static int dcb_cmd_app_del(struct dcb *dcb, const char *dev, int argc, char **argv)
 {
-	struct dcb_app_table tab = {};
+	struct dcb_app_table tab = { .attr = DCB_ATTR_IEEE_APP_TABLE };
 	int ret;
 
 	ret = dcb_cmd_app_parse_add_del(dcb, dev, argc, argv, &tab);
@@ -743,7 +744,7 @@ static int dcb_cmd_app_del(struct dcb *dcb, const char *dev, int argc, char **ar
 
 static int dcb_cmd_app_show(struct dcb *dcb, const char *dev, int argc, char **argv)
 {
-	struct dcb_app_table tab = {};
+	struct dcb_app_table tab = { .attr = DCB_ATTR_IEEE_APP_TABLE };
 	int ret;
 
 	ret = dcb_app_get(dcb, dev, &tab);
@@ -795,7 +796,7 @@ out:
 
 static int dcb_cmd_app_flush(struct dcb *dcb, const char *dev, int argc, char **argv)
 {
-	struct dcb_app_table tab = {};
+	struct dcb_app_table tab = { .attr = DCB_ATTR_IEEE_APP_TABLE };
 	int ret;
 
 	ret = dcb_app_get(dcb, dev, &tab);
@@ -848,9 +849,9 @@ out:
 
 static int dcb_cmd_app_replace(struct dcb *dcb, const char *dev, int argc, char **argv)
 {
-	struct dcb_app_table orig = {};
-	struct dcb_app_table tab = {};
-	struct dcb_app_table new = {};
+	struct dcb_app_table orig = { .attr = DCB_ATTR_IEEE_APP_TABLE };
+	struct dcb_app_table tab = { .attr = DCB_ATTR_IEEE_APP_TABLE };
+	struct dcb_app_table new = { .attr = DCB_ATTR_IEEE_APP_TABLE };
 	int ret;
 
 	ret = dcb_app_get(dcb, dev, &orig);

-- 
2.34.1

[PATCH iproute2-next v2 2/8] dcb: app: modify dcb-app print functions for dcb-rewr reuse

[Daniel Machon]

Where dcb-app requires protocol to be the printed key, dcb-rewr requires
it to be the priority. Adapt existing dcb-app print functions for this.

dcb_app_print_filtered() has been modified, to take two callbacks; one
for printing the entire string (pid and prio), and one for the pid type
(dec, hex, dscp, pcp). This saves us for making one dedicated function
for each pid type for both app and rewr.

dcb_app_print_key_*() functions have been renamed to
dcb_app_print_pid_*() to align with new situation. Also, none of them
will print the colon anymore.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
 dcb/dcb_app.c | 58 ++++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 36 insertions(+), 22 deletions(-)

diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
index 8073415ad084..1e36541bec61 100644
--- a/dcb/dcb_app.c
+++ b/dcb/dcb_app.c
@@ -403,38 +403,39 @@ static bool dcb_app_is_port(const struct dcb_app *app)
 	return app->selector == IEEE_8021QAZ_APP_SEL_ANY;
 }
 
-static int dcb_app_print_key_dec(__u16 protocol)
+static int dcb_app_print_pid_dec(__u16 protocol)
 {
-	return print_uint(PRINT_ANY, NULL, "%d:", protocol);
+	return print_uint(PRINT_ANY, NULL, "%u", protocol);
 }
 
-static int dcb_app_print_key_hex(__u16 protocol)
+static int dcb_app_print_pid_hex(__u16 protocol)
 {
-	return print_uint(PRINT_ANY, NULL, "%x:", protocol);
+	return print_uint(PRINT_ANY, NULL, "%x", protocol);
 }
 
-static int dcb_app_print_key_dscp(__u16 protocol)
+static int dcb_app_print_pid_dscp(__u16 protocol)
 {
 	const char *name = rtnl_dsfield_get_name(protocol << 2);
 
-
 	if (!is_json_context() && name != NULL)
-		return print_string(PRINT_FP, NULL, "%s:", name);
-	return print_uint(PRINT_ANY, NULL, "%d:", protocol);
+		return print_string(PRINT_FP, NULL, "%s", name);
+	return print_uint(PRINT_ANY, NULL, "%u", protocol);
 }
 
-static int dcb_app_print_key_pcp(__u16 protocol)
+static int dcb_app_print_pid_pcp(__u16 protocol)
 {
 	/* Print in numerical form, if protocol value is out-of-range */
 	if (protocol > DCB_APP_PCP_MAX)
-		return print_uint(PRINT_ANY, NULL, "%d:", protocol);
+		return print_uint(PRINT_ANY, NULL, "%u", protocol);
 
-	return print_string(PRINT_ANY, NULL, "%s:", pcp_names[protocol]);
+	return print_string(PRINT_ANY, NULL, "%s", pcp_names[protocol]);
 }
 
 static void dcb_app_print_filtered(const struct dcb_app_table *tab,
 				   bool (*filter)(const struct dcb_app *),
-				   int (*print_key)(__u16 protocol),
+				   void (*print_pid_prio)(int (*print_pid)(__u16),
+							  const struct dcb_app *),
+				   int (*print_pid)(__u16 protocol),
 				   const char *json_name,
 				   const char *fp_name)
 {
@@ -453,8 +454,8 @@ static void dcb_app_print_filtered(const struct dcb_app_table *tab,
 		}
 
 		open_json_array(PRINT_JSON, NULL);
-		print_key(app->protocol);
-		print_uint(PRINT_ANY, NULL, "%d ", app->priority);
+		print_pid_prio(print_pid, app);
+		print_string(PRINT_ANY, NULL, "%s", " ");
 		close_json_array(PRINT_JSON, NULL);
 	}
 
@@ -464,9 +465,17 @@ static void dcb_app_print_filtered(const struct dcb_app_table *tab,
 	}
 }
 
+static void dcb_app_print_pid_prio(int (*print_pid)(__u16 protocol),
+				   const struct dcb_app *app)
+{
+	print_pid(app->protocol);
+	print_uint(PRINT_ANY, NULL, ":%u", app->priority);
+}
+
 static void dcb_app_print_ethtype_prio(const struct dcb_app_table *tab)
 {
-	dcb_app_print_filtered(tab, dcb_app_is_ethtype,  dcb_app_print_key_hex,
+	dcb_app_print_filtered(tab, dcb_app_is_ethtype,
+			       dcb_app_print_pid_prio, dcb_app_print_pid_hex,
 			       "ethtype_prio", "ethtype-prio");
 }
 
@@ -474,8 +483,9 @@ static void dcb_app_print_pcp_prio(const struct dcb *dcb,
 				   const struct dcb_app_table *tab)
 {
 	dcb_app_print_filtered(tab, dcb_app_is_pcp,
-			       dcb->numeric ? dcb_app_print_key_dec
-					    : dcb_app_print_key_pcp,
+			       dcb_app_print_pid_prio,
+			       dcb->numeric ? dcb_app_print_pid_dec :
+					      dcb_app_print_pid_pcp,
 			       "pcp_prio", "pcp-prio");
 }
 
@@ -483,26 +493,30 @@ static void dcb_app_print_dscp_prio(const struct dcb *dcb,
 				    const struct dcb_app_table *tab)
 {
 	dcb_app_print_filtered(tab, dcb_app_is_dscp,
-			       dcb->numeric ? dcb_app_print_key_dec
-					    : dcb_app_print_key_dscp,
+			       dcb_app_print_pid_prio,
+			       dcb->numeric ? dcb_app_print_pid_dec :
+					      dcb_app_print_pid_dscp,
 			       "dscp_prio", "dscp-prio");
 }
 
 static void dcb_app_print_stream_port_prio(const struct dcb_app_table *tab)
 {
-	dcb_app_print_filtered(tab, dcb_app_is_stream_port, dcb_app_print_key_dec,
+	dcb_app_print_filtered(tab, dcb_app_is_stream_port,
+			       dcb_app_print_pid_prio, dcb_app_print_pid_dec,
 			       "stream_port_prio", "stream-port-prio");
 }
 
 static void dcb_app_print_dgram_port_prio(const struct dcb_app_table *tab)
 {
-	dcb_app_print_filtered(tab, dcb_app_is_dgram_port, dcb_app_print_key_dec,
+	dcb_app_print_filtered(tab, dcb_app_is_dgram_port,
+			       dcb_app_print_pid_prio, dcb_app_print_pid_dec,
 			       "dgram_port_prio", "dgram-port-prio");
 }
 
 static void dcb_app_print_port_prio(const struct dcb_app_table *tab)
 {
-	dcb_app_print_filtered(tab, dcb_app_is_port, dcb_app_print_key_dec,
+	dcb_app_print_filtered(tab, dcb_app_is_port,
+			       dcb_app_print_pid_prio, dcb_app_print_pid_dec,
 			       "port_prio", "port-prio");
 }
 

-- 
2.34.1

Re: [PATCH iproute2-next v2 2/8] dcb: app: modify dcb-app print functions for dcb-rewr reuse

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

> Where dcb-app requires protocol to be the printed key, dcb-rewr requires
> it to be the priority. Adapt existing dcb-app print functions for this.
>
> dcb_app_print_filtered() has been modified, to take two callbacks; one
> for printing the entire string (pid and prio), and one for the pid type
> (dec, hex, dscp, pcp). This saves us for making one dedicated function
> for each pid type for both app and rewr.
>
> dcb_app_print_key_*() functions have been renamed to
> dcb_app_print_pid_*() to align with new situation. Also, none of them
> will print the colon anymore.
>
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>

There are about four patches included in this one patch: the %d->%u
change, the colon shenanigans, the renaming, and prototype change of
dcb_app_print_filtered().

I think the code is OK, but I would appreciate splitting into a patch
per feature.

Re: [PATCH iproute2-next v2 2/8] dcb: app: modify dcb-app print functions for dcb-rewr reuse

[Daniel Machon]

 > > Where dcb-app requires protocol to be the printed key, dcb-rewr requires
> > it to be the priority. Adapt existing dcb-app print functions for this.
> >
> > dcb_app_print_filtered() has been modified, to take two callbacks; one
> > for printing the entire string (pid and prio), and one for the pid type
> > (dec, hex, dscp, pcp). This saves us for making one dedicated function
> > for each pid type for both app and rewr.
> >
> > dcb_app_print_key_*() functions have been renamed to
> > dcb_app_print_pid_*() to align with new situation. Also, none of them
> > will print the colon anymore.
> >
> > Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> 
> There are about four patches included in this one patch: the %d->%u
> change, the colon shenanigans, the renaming, and prototype change of
> dcb_app_print_filtered().
> 
> I think the code is OK, but I would appreciate splitting into a patch
> per feature.

Sure I can split those changes up.

Re: [PATCH iproute2-next v2 2/8] dcb: app: modify dcb-app print functions for dcb-rewr reuse

[Daniel Machon]

> Daniel Machon <daniel.machon@microchip.com> writes:
> 
> > Where dcb-app requires protocol to be the printed key, dcb-rewr requires
> > it to be the priority. Adapt existing dcb-app print functions for this.
> >
> > dcb_app_print_filtered() has been modified, to take two callbacks; one
> > for printing the entire string (pid and prio), and one for the pid type
> > (dec, hex, dscp, pcp). This saves us for making one dedicated function
> > for each pid type for both app and rewr.
> >
> > dcb_app_print_key_*() functions have been renamed to
> > dcb_app_print_pid_*() to align with new situation. Also, none of them
> > will print the colon anymore.
> >
> > Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> 
> There are about four patches included in this one patch: the %d->%u
> change, the colon shenanigans, the renaming, and prototype change of
> dcb_app_print_filtered().
> 
> I think the code is OK, but I would appreciate splitting into a patch
> per feature.

Actually, IMHO, the 'colon shenanigans' does not make much sense in a
patch of its own, since its not really a standalone feature, but rather
some change that is required for the prototype change of
dcb_app_print_filtered? 

Re: [PATCH iproute2-next v2 2/8] dcb: app: modify dcb-app print functions for dcb-rewr reuse

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

>> Daniel Machon <daniel.machon@microchip.com> writes:
>> 
>> > Where dcb-app requires protocol to be the printed key, dcb-rewr requires
>> > it to be the priority. Adapt existing dcb-app print functions for this.
>> >
>> > dcb_app_print_filtered() has been modified, to take two callbacks; one
>> > for printing the entire string (pid and prio), and one for the pid type
>> > (dec, hex, dscp, pcp). This saves us for making one dedicated function
>> > for each pid type for both app and rewr.
>> >
>> > dcb_app_print_key_*() functions have been renamed to
>> > dcb_app_print_pid_*() to align with new situation. Also, none of them
>> > will print the colon anymore.
>> >
>> > Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
>> 
>> There are about four patches included in this one patch: the %d->%u
>> change, the colon shenanigans, the renaming, and prototype change of
>> dcb_app_print_filtered().
>> 
>> I think the code is OK, but I would appreciate splitting into a patch
>> per feature.
>
> Actually, IMHO, the 'colon shenanigans' does not make much sense in a
> patch of its own, since its not really a standalone feature, but rather
> some change that is required for the prototype change of
> dcb_app_print_filtered? 

It doesn't make sense on its own, but it also does not get sent on its
own, but together with the following patches. Its role is to set stage.

dcb_app_print_filtered() should first stop assuming the callback prints
a colon. So you have one patch where the colon moves from the callback
to _print_filtered(). That's a clean, behavior-neutral change that
should be trivial to review. Then next patch introduces the callback.
Which at that point should likewise be tidy, focused and easy to review,
because it will only deal with the new callback.

Re: [PATCH iproute2-next v2 2/8] dcb: app: modify dcb-app print functions for dcb-rewr reuse

[David Ahern]

On 5/31/23 5:26 AM, Petr Machata wrote:
> It doesn't make sense on its own, but it also does not get sent on its
> own, but together with the following patches. Its role is to set stage.
> 
> dcb_app_print_filtered() should first stop assuming the callback prints
> a colon. So you have one patch where the colon moves from the callback
> to _print_filtered(). That's a clean, behavior-neutral change that
> should be trivial to review. Then next patch introduces the callback.
> Which at that point should likewise be tidy, focused and easy to review,
> because it will only deal with the new callback.

agreed. code should evolve in a way that makes it easy to review.

[PATCH iproute2-next v2 3/8] dcb: app: modify dcb_app_table_remove_replaced() for dcb-rewr reuse

[Daniel Machon]

When doing a replace command, entries are checked against selector and
protocol. Rewrite requires the check to be against selector and
priority.

Adapt the existing dcb_app_table_remove_replace function for this, by
using callback functions for selector, pid and prio checks.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
 dcb/dcb.h     | 14 ++++++++++++++
 dcb/dcb_app.c | 32 ++++++++++++++++++++------------
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/dcb/dcb.h b/dcb/dcb.h
index d40664f29dad..84ce95d5c1b2 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -56,11 +56,25 @@ void dcb_print_array_kw(const __u8 *array, size_t array_size,
 
 /* dcb_app.c */
 
+struct dcb_app_table {
+	struct dcb_app *apps;
+	size_t n_apps;
+	int attr;
+};
+
 int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
 enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
 bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
 bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
 
+bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
+bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
+
+void dcb_app_table_remove_replaced(struct dcb_app_table *a,
+				   const struct dcb_app_table *b,
+				   bool (*key_eq)(const struct dcb_app *aa,
+						  const struct dcb_app *ab));
+
 /* dcb_apptrust.c */
 
 int dcb_cmd_apptrust(struct dcb *dcb, int argc, char **argv);
diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
index 1e36541bec61..4cd175a0623b 100644
--- a/dcb/dcb_app.c
+++ b/dcb/dcb_app.c
@@ -68,12 +68,6 @@ static void dcb_app_help(void)
 	dcb_app_help_add();
 }
 
-struct dcb_app_table {
-	struct dcb_app *apps;
-	size_t n_apps;
-	int attr;
-};
-
 enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector)
 {
 	switch (selector) {
@@ -153,8 +147,22 @@ static void dcb_app_table_remove_existing(struct dcb_app_table *a,
 	a->n_apps = ja;
 }
 
-static void dcb_app_table_remove_replaced(struct dcb_app_table *a,
-					  const struct dcb_app_table *b)
+bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab)
+{
+	return aa->selector == ab->selector &&
+	       aa->protocol == ab->protocol;
+}
+
+bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab)
+{
+	return aa->selector == ab->selector &&
+	       aa->priority == ab->priority;
+}
+
+void dcb_app_table_remove_replaced(struct dcb_app_table *a,
+				   const struct dcb_app_table *b,
+				   bool (*key_eq)(const struct dcb_app *aa,
+						  const struct dcb_app *ab))
 {
 	size_t ia, ja;
 	size_t ib;
@@ -167,13 +175,13 @@ static void dcb_app_table_remove_replaced(struct dcb_app_table *a,
 		for (ib = 0; ib < b->n_apps; ib++) {
 			const struct dcb_app *ab = &b->apps[ib];
 
-			if (aa->selector == ab->selector &&
-			    aa->protocol == ab->protocol)
+			if (key_eq(aa, ab))
 				present = true;
 			else
 				continue;
 
-			if (aa->priority == ab->priority) {
+			if (aa->protocol == ab->protocol &&
+			    aa->priority == ab->priority) {
 				found = true;
 				break;
 			}
@@ -891,7 +899,7 @@ static int dcb_cmd_app_replace(struct dcb *dcb, const char *dev, int argc, char
 	}
 
 	/* Remove the obsolete entries. */
-	dcb_app_table_remove_replaced(&orig, &tab);
+	dcb_app_table_remove_replaced(&orig, &tab, dcb_app_pid_eq);
 	ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &orig, NULL);
 	if (ret != 0) {
 		fprintf(stderr, "Could not remove replaced APP entries\n");

-- 
2.34.1

Re: [PATCH iproute2-next v2 3/8] dcb: app: modify dcb_app_table_remove_replaced() for dcb-rewr reuse

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

> When doing a replace command, entries are checked against selector and
> protocol. Rewrite requires the check to be against selector and
> priority.
>
> Adapt the existing dcb_app_table_remove_replace function for this, by
> using callback functions for selector, pid and prio checks.
>
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> ---
>  dcb/dcb.h     | 14 ++++++++++++++
>  dcb/dcb_app.c | 32 ++++++++++++++++++++------------
>  2 files changed, 34 insertions(+), 12 deletions(-)
>
> diff --git a/dcb/dcb.h b/dcb/dcb.h
> index d40664f29dad..84ce95d5c1b2 100644
> --- a/dcb/dcb.h
> +++ b/dcb/dcb.h
> @@ -56,11 +56,25 @@ void dcb_print_array_kw(const __u8 *array, size_t array_size,
>  
>  /* dcb_app.c */
>  
> +struct dcb_app_table {
> +	struct dcb_app *apps;
> +	size_t n_apps;
> +	int attr;
> +};
> +
>  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
>  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
>  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
>  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
>  
> +bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
> +bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);

This function isn't necessary until 5/8, that's when it should be added.

> +
> +void dcb_app_table_remove_replaced(struct dcb_app_table *a,
> +				   const struct dcb_app_table *b,
> +				   bool (*key_eq)(const struct dcb_app *aa,
> +						  const struct dcb_app *ab));
> +

This is conflating publication with prototype change. It would be best
to separate. I think the publication could be done at the point when you
actually need the function, i.e. 5/8 as well. I would keep here just the
prototype change.

>  /* dcb_apptrust.c */
>  
>  int dcb_cmd_apptrust(struct dcb *dcb, int argc, char **argv);
> diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
> index 1e36541bec61..4cd175a0623b 100644
> --- a/dcb/dcb_app.c
> +++ b/dcb/dcb_app.c
> @@ -68,12 +68,6 @@ static void dcb_app_help(void)
>  	dcb_app_help_add();
>  }
>  
> -struct dcb_app_table {
> -	struct dcb_app *apps;
> -	size_t n_apps;
> -	int attr;
> -};
> -
>  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector)
>  {
>  	switch (selector) {
> @@ -153,8 +147,22 @@ static void dcb_app_table_remove_existing(struct dcb_app_table *a,
>  	a->n_apps = ja;
>  }
>  
> -static void dcb_app_table_remove_replaced(struct dcb_app_table *a,
> -					  const struct dcb_app_table *b)
> +bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab)
> +{
> +	return aa->selector == ab->selector &&
> +	       aa->protocol == ab->protocol;
> +}
> +
> +bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab)
> +{
> +	return aa->selector == ab->selector &&
> +	       aa->priority == ab->priority;
> +}
> +
> +void dcb_app_table_remove_replaced(struct dcb_app_table *a,
> +				   const struct dcb_app_table *b,
> +				   bool (*key_eq)(const struct dcb_app *aa,
> +						  const struct dcb_app *ab))
>  {
>  	size_t ia, ja;
>  	size_t ib;
> @@ -167,13 +175,13 @@ static void dcb_app_table_remove_replaced(struct dcb_app_table *a,
>  		for (ib = 0; ib < b->n_apps; ib++) {
>  			const struct dcb_app *ab = &b->apps[ib];
>  
> -			if (aa->selector == ab->selector &&
> -			    aa->protocol == ab->protocol)
> +			if (key_eq(aa, ab))
>  				present = true;
>  			else
>  				continue;
>  
> -			if (aa->priority == ab->priority) {
> +			if (aa->protocol == ab->protocol &&
> +			    aa->priority == ab->priority) {
>  				found = true;
>  				break;
>  			}
> @@ -891,7 +899,7 @@ static int dcb_cmd_app_replace(struct dcb *dcb, const char *dev, int argc, char
>  	}
>  
>  	/* Remove the obsolete entries. */
> -	dcb_app_table_remove_replaced(&orig, &tab);
> +	dcb_app_table_remove_replaced(&orig, &tab, dcb_app_pid_eq);
>  	ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &orig, NULL);
>  	if (ret != 0) {
>  		fprintf(stderr, "Could not remove replaced APP entries\n");

Re: [PATCH iproute2-next v2 3/8] dcb: app: modify dcb_app_table_remove_replaced() for dcb-rewr reuse

[Daniel Machon]

> > When doing a replace command, entries are checked against selector and
> > protocol. Rewrite requires the check to be against selector and
> > priority.
> >
> > Adapt the existing dcb_app_table_remove_replace function for this, by
> > using callback functions for selector, pid and prio checks.
> >
> > Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> > ---
> >  dcb/dcb.h     | 14 ++++++++++++++
> >  dcb/dcb_app.c | 32 ++++++++++++++++++++------------
> >  2 files changed, 34 insertions(+), 12 deletions(-)
> >
> > diff --git a/dcb/dcb.h b/dcb/dcb.h
> > index d40664f29dad..84ce95d5c1b2 100644
> > --- a/dcb/dcb.h
> > +++ b/dcb/dcb.h
> > @@ -56,11 +56,25 @@ void dcb_print_array_kw(const __u8 *array, size_t array_size,
> >
> >  /* dcb_app.c */
> >
> > +struct dcb_app_table {
> > +     struct dcb_app *apps;
> > +     size_t n_apps;
> > +     int attr;
> > +};
> > +
> >  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
> >  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
> >  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
> >  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
> >
> > +bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
> > +bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
> 
> This function isn't necessary until 5/8, that's when it should be added.
> 
> > +
> > +void dcb_app_table_remove_replaced(struct dcb_app_table *a,
> > +                                const struct dcb_app_table *b,
> > +                                bool (*key_eq)(const struct dcb_app *aa,
> > +                                               const struct dcb_app *ab));
> > +
> 
> This is conflating publication with prototype change. It would be best
> to separate. I think the publication could be done at the point when you
> actually need the function, i.e. 5/8 as well. I would keep here just the
> prototype change.
> 

Sounds OK to me. Will change in next v.
 

Re: [PATCH iproute2-next v2 3/8] dcb: app: modify dcb_app_table_remove_replaced() for dcb-rewr reuse

[Petr Machata]

Petr Machata <petrm@nvidia.com> writes:

> Daniel Machon <daniel.machon@microchip.com> writes:
>
>> diff --git a/dcb/dcb.h b/dcb/dcb.h
>> index d40664f29dad..84ce95d5c1b2 100644
>> --- a/dcb/dcb.h
>> +++ b/dcb/dcb.h
>> @@ -56,11 +56,25 @@ void dcb_print_array_kw(const __u8 *array, size_t array_size,
>>  
>>  /* dcb_app.c */
>>  
>> +struct dcb_app_table {
>> +	struct dcb_app *apps;
>> +	size_t n_apps;
>> +	int attr;
>> +};
>> +
>>  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
>>  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
>>  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
>>  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
>>  
>> +bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);

And I suspect this one does not need to be public at all?

>> +bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>
> This function isn't necessary until 5/8, that's when it should be added.

[PATCH iproute2-next v2 4/8] dcb: app: modify dcb_app_parse_mapping_cb for dcb-rewr reuse

[Daniel Machon]

When parsing APP table entries, priority and protocol is assigned from
value and key, respectively. Rewrite requires it opposite.

Adapt the existing dcb_app_parse_mapping_cb for this, by using callbacks
for pushing app or rewr entries to the table.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
 dcb/dcb.h     | 12 ++++++++++++
 dcb/dcb_app.c | 23 ++++++++++++-----------
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/dcb/dcb.h b/dcb/dcb.h
index 84ce95d5c1b2..b3bc30cd02c5 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -62,7 +62,16 @@ struct dcb_app_table {
 	int attr;
 };
 
+struct dcb_app_parse_mapping {
+	__u8 selector;
+	struct dcb_app_table *tab;
+	int (*push)(struct dcb_app_table *tab,
+		    __u8 selector, __u32 key, __u64 value);
+	int err;
+};
+
 int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
+
 enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
 bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
 bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
@@ -70,11 +79,14 @@ bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
 bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
 bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
 
+int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app);
 void dcb_app_table_remove_replaced(struct dcb_app_table *a,
 				   const struct dcb_app_table *b,
 				   bool (*key_eq)(const struct dcb_app *aa,
 						  const struct dcb_app *ab));
 
+void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data);
+
 /* dcb_apptrust.c */
 
 int dcb_cmd_apptrust(struct dcb *dcb, int argc, char **argv);
diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
index 4cd175a0623b..97cba658aa6b 100644
--- a/dcb/dcb_app.c
+++ b/dcb/dcb_app.c
@@ -105,7 +105,7 @@ static void dcb_app_table_fini(struct dcb_app_table *tab)
 	free(tab->apps);
 }
 
-static int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
+int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
 {
 	struct dcb_app *apps = realloc(tab->apps, (tab->n_apps + 1) * sizeof(*tab->apps));
 
@@ -231,25 +231,25 @@ static void dcb_app_table_sort(struct dcb_app_table *tab)
 	qsort(tab->apps, tab->n_apps, sizeof(*tab->apps), dcb_app_cmp_cb);
 }
 
-struct dcb_app_parse_mapping {
-	__u8 selector;
-	struct dcb_app_table *tab;
-	int err;
-};
-
-static void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
+static int dcb_app_push(struct dcb_app_table *tab,
+			__u8 selector, __u32 key, __u64 value)
 {
-	struct dcb_app_parse_mapping *pm = data;
 	struct dcb_app app = {
-		.selector = pm->selector,
+		.selector = selector,
 		.priority = value,
 		.protocol = key,
 	};
+	return dcb_app_table_push(tab, &app);
+}
+
+void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
+{
+	struct dcb_app_parse_mapping *pm = data;
 
 	if (pm->err)
 		return;
 
-	pm->err = dcb_app_table_push(pm->tab, &app);
+	pm->err = pm->push(pm->tab, pm->selector, key, value);
 }
 
 static int dcb_app_parse_mapping_ethtype_prio(__u32 key, char *value, void *data)
@@ -663,6 +663,7 @@ static int dcb_cmd_app_parse_add_del(struct dcb *dcb, const char *dev,
 {
 	struct dcb_app_parse_mapping pm = {
 		.tab = tab,
+		.push = dcb_app_push,
 	};
 	int ret;
 

-- 
2.34.1

Re: [PATCH iproute2-next v2 4/8] dcb: app: modify dcb_app_parse_mapping_cb for dcb-rewr reuse

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

> When parsing APP table entries, priority and protocol is assigned from
> value and key, respectively. Rewrite requires it opposite.
>
> Adapt the existing dcb_app_parse_mapping_cb for this, by using callbacks
> for pushing app or rewr entries to the table.
>
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> ---
>  dcb/dcb.h     | 12 ++++++++++++
>  dcb/dcb_app.c | 23 ++++++++++++-----------
>  2 files changed, 24 insertions(+), 11 deletions(-)
>
> diff --git a/dcb/dcb.h b/dcb/dcb.h
> index 84ce95d5c1b2..b3bc30cd02c5 100644
> --- a/dcb/dcb.h
> +++ b/dcb/dcb.h
> @@ -62,7 +62,16 @@ struct dcb_app_table {
>  	int attr;
>  };
>  
> +struct dcb_app_parse_mapping {
> +	__u8 selector;
> +	struct dcb_app_table *tab;
> +	int (*push)(struct dcb_app_table *tab,
> +		    __u8 selector, __u32 key, __u64 value);
> +	int err;
> +};
> +
>  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
> +
>  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
>  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
>  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
> @@ -70,11 +79,14 @@ bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
>  bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>  bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>  
> +int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app);
>  void dcb_app_table_remove_replaced(struct dcb_app_table *a,
>  				   const struct dcb_app_table *b,
>  				   bool (*key_eq)(const struct dcb_app *aa,
>  						  const struct dcb_app *ab));
>  
> +void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data);
> +
>  /* dcb_apptrust.c */
>  
>  int dcb_cmd_apptrust(struct dcb *dcb, int argc, char **argv);
> diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
> index 4cd175a0623b..97cba658aa6b 100644
> --- a/dcb/dcb_app.c
> +++ b/dcb/dcb_app.c
> @@ -105,7 +105,7 @@ static void dcb_app_table_fini(struct dcb_app_table *tab)
>  	free(tab->apps);
>  }
>  
> -static int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
> +int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
>  {
>  	struct dcb_app *apps = realloc(tab->apps, (tab->n_apps + 1) * sizeof(*tab->apps));
>  
> @@ -231,25 +231,25 @@ static void dcb_app_table_sort(struct dcb_app_table *tab)
>  	qsort(tab->apps, tab->n_apps, sizeof(*tab->apps), dcb_app_cmp_cb);
>  }
>  
> -struct dcb_app_parse_mapping {
> -	__u8 selector;
> -	struct dcb_app_table *tab;
> -	int err;
> -};
> -
> -static void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
> +static int dcb_app_push(struct dcb_app_table *tab,
> +			__u8 selector, __u32 key, __u64 value)
>  {
> -	struct dcb_app_parse_mapping *pm = data;
>  	struct dcb_app app = {
> -		.selector = pm->selector,
> +		.selector = selector,
>  		.priority = value,
>  		.protocol = key,
>  	};
> +	return dcb_app_table_push(tab, &app);
> +}
> +
> +void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
> +{
> +	struct dcb_app_parse_mapping *pm = data;
>  
>  	if (pm->err)
>  		return;
>  
> -	pm->err = dcb_app_table_push(pm->tab, &app);
> +	pm->err = pm->push(pm->tab, pm->selector, key, value);
>  }
>  
>  static int dcb_app_parse_mapping_ethtype_prio(__u32 key, char *value, void *data)
> @@ -663,6 +663,7 @@ static int dcb_cmd_app_parse_add_del(struct dcb *dcb, const char *dev,
>  {
>  	struct dcb_app_parse_mapping pm = {
>  		.tab = tab,
> +		.push = dcb_app_push,
>  	};
>  	int ret;

I think I misunderstood your code. Since you are adding new functions
for parsing the PRIO-DSCP and PRIO-PCP mappings, which have their own
dcb_parse_mapping() invocations, couldn't you just copy over the
dcb_app_parse_mapping_cb() from APP and adapt it to do the right thing
for REWR? Then the push callback is not even necessary
dcb_app_parse_mapping_cb() does not need to be public.

Re: [PATCH iproute2-next v2 4/8] dcb: app: modify dcb_app_parse_mapping_cb for dcb-rewr reuse

[Daniel Machon]

> Daniel Machon <daniel.machon@microchip.com> writes:
> 
> > When parsing APP table entries, priority and protocol is assigned from
> > value and key, respectively. Rewrite requires it opposite.
> >
> > Adapt the existing dcb_app_parse_mapping_cb for this, by using callbacks
> > for pushing app or rewr entries to the table.
> >
> > Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> > ---
> >  dcb/dcb.h     | 12 ++++++++++++
> >  dcb/dcb_app.c | 23 ++++++++++++-----------
> >  2 files changed, 24 insertions(+), 11 deletions(-)
> >
> > diff --git a/dcb/dcb.h b/dcb/dcb.h
> > index 84ce95d5c1b2..b3bc30cd02c5 100644
> > --- a/dcb/dcb.h
> > +++ b/dcb/dcb.h
> > @@ -62,7 +62,16 @@ struct dcb_app_table {
> >       int attr;
> >  };
> >
> > +struct dcb_app_parse_mapping {
> > +     __u8 selector;
> > +     struct dcb_app_table *tab;
> > +     int (*push)(struct dcb_app_table *tab,
> > +                 __u8 selector, __u32 key, __u64 value);
> > +     int err;
> > +};
> > +
> >  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
> > +
> >  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
> >  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
> >  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
> > @@ -70,11 +79,14 @@ bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
> >  bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
> >  bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
> >
> > +int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app);
> >  void dcb_app_table_remove_replaced(struct dcb_app_table *a,
> >                                  const struct dcb_app_table *b,
> >                                  bool (*key_eq)(const struct dcb_app *aa,
> >                                                 const struct dcb_app *ab));
> >
> > +void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data);
> > +
> >  /* dcb_apptrust.c */
> >
> >  int dcb_cmd_apptrust(struct dcb *dcb, int argc, char **argv);
> > diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
> > index 4cd175a0623b..97cba658aa6b 100644
> > --- a/dcb/dcb_app.c
> > +++ b/dcb/dcb_app.c
> > @@ -105,7 +105,7 @@ static void dcb_app_table_fini(struct dcb_app_table *tab)
> >       free(tab->apps);
> >  }
> >
> > -static int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
> > +int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
> >  {
> >       struct dcb_app *apps = realloc(tab->apps, (tab->n_apps + 1) * sizeof(*tab->apps));
> >
> > @@ -231,25 +231,25 @@ static void dcb_app_table_sort(struct dcb_app_table *tab)
> >       qsort(tab->apps, tab->n_apps, sizeof(*tab->apps), dcb_app_cmp_cb);
> >  }
> >
> > -struct dcb_app_parse_mapping {
> > -     __u8 selector;
> > -     struct dcb_app_table *tab;
> > -     int err;
> > -};
> > -
> > -static void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
> > +static int dcb_app_push(struct dcb_app_table *tab,
> > +                     __u8 selector, __u32 key, __u64 value)
> >  {
> > -     struct dcb_app_parse_mapping *pm = data;
> >       struct dcb_app app = {
> > -             .selector = pm->selector,
> > +             .selector = selector,
> >               .priority = value,
> >               .protocol = key,
> >       };
> > +     return dcb_app_table_push(tab, &app);
> > +}
> > +
> > +void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
> > +{
> > +     struct dcb_app_parse_mapping *pm = data;
> >
> >       if (pm->err)
> >               return;
> >
> > -     pm->err = dcb_app_table_push(pm->tab, &app);
> > +     pm->err = pm->push(pm->tab, pm->selector, key, value);
> >  }
> >
> >  static int dcb_app_parse_mapping_ethtype_prio(__u32 key, char *value, void *data)
> > @@ -663,6 +663,7 @@ static int dcb_cmd_app_parse_add_del(struct dcb *dcb, const char *dev,
> >  {
> >       struct dcb_app_parse_mapping pm = {
> >               .tab = tab,
> > +             .push = dcb_app_push,
> >       };
> >       int ret;
> 
> I think I misunderstood your code. Since you are adding new functions
> for parsing the PRIO-DSCP and PRIO-PCP mappings, which have their own
> dcb_parse_mapping() invocations, couldn't you just copy over the
> dcb_app_parse_mapping_cb() from APP and adapt it to do the right thing
> for REWR? Then the push callback is not even necessary
> dcb_app_parse_mapping_cb() does not need to be public.

It is always a balance of when to do what. So far, patches #2, #3 and #4
tries to modify the existing dcb-app functions for dcb-rewr reuse. They
all deal with the prio:pid, pid:prio problem (printing, pushing and
replacing entries). What you suggest now is to copy
dcb_app_parse_mapping_cb() entirely, just for changing that order. It
can be done, but then it could also be done for #2 and #3, which would
then result in more boilerplate code.

Whatever we choose, I think we should stay consistent?

Re: [PATCH iproute2-next v2 4/8] dcb: app: modify dcb_app_parse_mapping_cb for dcb-rewr reuse

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

>> Daniel Machon <daniel.machon@microchip.com> writes:
>> 
>> > When parsing APP table entries, priority and protocol is assigned from
>> > value and key, respectively. Rewrite requires it opposite.
>> >
>> > Adapt the existing dcb_app_parse_mapping_cb for this, by using callbacks
>> > for pushing app or rewr entries to the table.
>> >
>> > Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
>> > ---
>> >  dcb/dcb.h     | 12 ++++++++++++
>> >  dcb/dcb_app.c | 23 ++++++++++++-----------
>> >  2 files changed, 24 insertions(+), 11 deletions(-)
>> >
>> > diff --git a/dcb/dcb.h b/dcb/dcb.h
>> > index 84ce95d5c1b2..b3bc30cd02c5 100644
>> > --- a/dcb/dcb.h
>> > +++ b/dcb/dcb.h
>> > @@ -62,7 +62,16 @@ struct dcb_app_table {
>> >       int attr;
>> >  };
>> >
>> > +struct dcb_app_parse_mapping {
>> > +     __u8 selector;
>> > +     struct dcb_app_table *tab;
>> > +     int (*push)(struct dcb_app_table *tab,
>> > +                 __u8 selector, __u32 key, __u64 value);
>> > +     int err;
>> > +};
>> > +
>> >  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
>> > +
>> >  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
>> >  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
>> >  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
>> > @@ -70,11 +79,14 @@ bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
>> >  bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>> >  bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>> >
>> > +int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app);
>> >  void dcb_app_table_remove_replaced(struct dcb_app_table *a,
>> >                                  const struct dcb_app_table *b,
>> >                                  bool (*key_eq)(const struct dcb_app *aa,
>> >                                                 const struct dcb_app *ab));
>> >
>> > +void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data);
>> > +
>> >  /* dcb_apptrust.c */
>> >
>> >  int dcb_cmd_apptrust(struct dcb *dcb, int argc, char **argv);
>> > diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
>> > index 4cd175a0623b..97cba658aa6b 100644
>> > --- a/dcb/dcb_app.c
>> > +++ b/dcb/dcb_app.c
>> > @@ -105,7 +105,7 @@ static void dcb_app_table_fini(struct dcb_app_table *tab)
>> >       free(tab->apps);
>> >  }
>> >
>> > -static int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
>> > +int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
>> >  {
>> >       struct dcb_app *apps = realloc(tab->apps, (tab->n_apps + 1) * sizeof(*tab->apps));
>> >
>> > @@ -231,25 +231,25 @@ static void dcb_app_table_sort(struct dcb_app_table *tab)
>> >       qsort(tab->apps, tab->n_apps, sizeof(*tab->apps), dcb_app_cmp_cb);
>> >  }
>> >
>> > -struct dcb_app_parse_mapping {
>> > -     __u8 selector;
>> > -     struct dcb_app_table *tab;
>> > -     int err;
>> > -};
>> > -
>> > -static void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
>> > +static int dcb_app_push(struct dcb_app_table *tab,
>> > +                     __u8 selector, __u32 key, __u64 value)
>> >  {
>> > -     struct dcb_app_parse_mapping *pm = data;
>> >       struct dcb_app app = {
>> > -             .selector = pm->selector,
>> > +             .selector = selector,
>> >               .priority = value,
>> >               .protocol = key,
>> >       };
>> > +     return dcb_app_table_push(tab, &app);
>> > +}
>> > +
>> > +void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
>> > +{
>> > +     struct dcb_app_parse_mapping *pm = data;
>> >
>> >       if (pm->err)
>> >               return;
>> >
>> > -     pm->err = dcb_app_table_push(pm->tab, &app);
>> > +     pm->err = pm->push(pm->tab, pm->selector, key, value);
>> >  }
>> >
>> >  static int dcb_app_parse_mapping_ethtype_prio(__u32 key, char *value, void *data)
>> > @@ -663,6 +663,7 @@ static int dcb_cmd_app_parse_add_del(struct dcb *dcb, const char *dev,
>> >  {
>> >       struct dcb_app_parse_mapping pm = {
>> >               .tab = tab,
>> > +             .push = dcb_app_push,
>> >       };
>> >       int ret;
>> 
>> I think I misunderstood your code. Since you are adding new functions
>> for parsing the PRIO-DSCP and PRIO-PCP mappings, which have their own
>> dcb_parse_mapping() invocations, couldn't you just copy over the
>> dcb_app_parse_mapping_cb() from APP and adapt it to do the right thing
>> for REWR? Then the push callback is not even necessary
>> dcb_app_parse_mapping_cb() does not need to be public.
>
> It is always a balance of when to do what. So far, patches #2, #3 and #4
> tries to modify the existing dcb-app functions for dcb-rewr reuse. They
> all deal with the prio:pid, pid:prio problem (printing, pushing and
> replacing entries). What you suggest now is to copy
> dcb_app_parse_mapping_cb() entirely, just for changing that order. It
> can be done, but then it could also be done for #2 and #3, which would
> then result in more boilerplate code.
>
> Whatever we choose, I think we should stay consistent?

I mean, where do you put the threshold? Because what currently gets
reused is this:

void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data)
{
	struct dcb_app_parse_mapping *pm = data;

	if (pm->err)
		return;

	pm->err = pm->push(pm->tab, pm->selector, key, value);
}

(OK, that, and the helper data structure)

IMHO the ceremony around the declaration, it not being near where it's
used, the extra callback to make it generic, etc., is more expensive
than what the reuse saves us.

Like, similarly we could talk about reusing dcb_cmd_app() for
dcb_rewr_app() or whatever. But we shamelessly duplicate, because
making it reusable is more expensive than what it brings.

If anything, I would reuse the data structure, and copy the callback.

[PATCH iproute2-next v2 5/8] dcb: rewr: add new dcb-rewr subcommand

[Daniel Machon]

Add a new subcommand 'rewr' for configuring the in-kernel DCB rewrite
table. The rewr-table of the kernel is similar to the APP-table, and so
is this new subcommand. Therefore, much of the existing bookkeeping code
from dcb-app, can be reused in the dcb-rewr implementation.

Initially, only support for configuring PCP and DSCP-based rewrite has
been added.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
 dcb/Makefile   |   3 +-
 dcb/dcb.c      |   4 +-
 dcb/dcb.h      |  32 ++++++
 dcb/dcb_app.c  |  49 ++++----
 dcb/dcb_rewr.c | 355 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 416 insertions(+), 27 deletions(-)

diff --git a/dcb/Makefile b/dcb/Makefile
index dd41a559a0c8..10794c9dc19f 100644
--- a/dcb/Makefile
+++ b/dcb/Makefile
@@ -8,7 +8,8 @@ DCBOBJ = dcb.o \
          dcb_ets.o \
          dcb_maxrate.o \
          dcb_pfc.o \
-         dcb_apptrust.o
+         dcb_apptrust.o \
+         dcb_rewr.o
 TARGETS += dcb
 LDLIBS += -lm
 
diff --git a/dcb/dcb.c b/dcb/dcb.c
index 9b996abac529..fe0a0f04143d 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -470,7 +470,7 @@ static void dcb_help(void)
 	fprintf(stderr,
 		"Usage: dcb [ OPTIONS ] OBJECT { COMMAND | help }\n"
 		"       dcb [ -f | --force ] { -b | --batch } filename [ -n | --netns ] netnsname\n"
-		"where  OBJECT := { app | apptrust | buffer | dcbx | ets | maxrate | pfc }\n"
+		"where  OBJECT := { app | apptrust | buffer | dcbx | ets | maxrate | pfc | rewr }\n"
 		"       OPTIONS := [ -V | --Version | -i | --iec | -j | --json\n"
 		"                  | -N | --Numeric | -p | --pretty\n"
 		"                  | -s | --statistics | -v | --verbose]\n");
@@ -485,6 +485,8 @@ static int dcb_cmd(struct dcb *dcb, int argc, char **argv)
 		return dcb_cmd_app(dcb, argc - 1, argv + 1);
 	} else if (strcmp(*argv, "apptrust") == 0) {
 		return dcb_cmd_apptrust(dcb, argc - 1, argv + 1);
+	} else if (strcmp(*argv, "rewr") == 0) {
+		return dcb_cmd_rewr(dcb, argc - 1, argv + 1);
 	} else if (matches(*argv, "buffer") == 0) {
 		return dcb_cmd_buffer(dcb, argc - 1, argv + 1);
 	} else if (matches(*argv, "dcbx") == 0) {
diff --git a/dcb/dcb.h b/dcb/dcb.h
index b3bc30cd02c5..092dc90e8358 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -54,6 +54,10 @@ void dcb_print_array_on_off(const __u8 *array, size_t size);
 void dcb_print_array_kw(const __u8 *array, size_t array_size,
 			const char *const kw[], size_t kw_size);
 
+/* dcp_rewr.c */
+
+int dcb_cmd_rewr(struct dcb *dcb, int argc, char **argv);
+
 /* dcb_app.c */
 
 struct dcb_app_table {
@@ -70,8 +74,29 @@ struct dcb_app_parse_mapping {
 	int err;
 };
 
+#define DCB_APP_PCP_MAX 15
+#define DCB_APP_DSCP_MAX 63
+
 int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
 
+int dcb_app_get(struct dcb *dcb, const char *dev, struct dcb_app_table *tab);
+int dcb_app_add_del(struct dcb *dcb, const char *dev, int command,
+		    const struct dcb_app_table *tab,
+		    bool (*filter)(const struct dcb_app *));
+
+bool dcb_app_is_dscp(const struct dcb_app *app);
+bool dcb_app_is_pcp(const struct dcb_app *app);
+
+int dcb_app_print_pid_dscp(__u16 protocol);
+int dcb_app_print_pid_pcp(__u16 protocol);
+int dcb_app_print_pid_dec(__u16 protocol);
+void dcb_app_print_filtered(const struct dcb_app_table *tab,
+			    bool (*filter)(const struct dcb_app *),
+			    void (*print_pid_prio)(int (*print_pid)(__u16),
+						   const struct dcb_app *),
+			    int (*print_pid)(__u16 protocol),
+			    const char *json_name, const char *fp_name);
+
 enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
 bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
 bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
@@ -80,11 +105,18 @@ bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
 bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
 
 int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app);
+int dcb_app_table_copy(struct dcb_app_table *a, const struct dcb_app_table *b);
+void dcb_app_table_sort(struct dcb_app_table *tab);
+void dcb_app_table_fini(struct dcb_app_table *tab);
+void dcb_app_table_remove_existing(struct dcb_app_table *a,
+				   const struct dcb_app_table *b);
 void dcb_app_table_remove_replaced(struct dcb_app_table *a,
 				   const struct dcb_app_table *b,
 				   bool (*key_eq)(const struct dcb_app *aa,
 						  const struct dcb_app *ab));
 
+int dcb_app_parse_pcp(__u32 *key, const char *arg);
+int dcb_app_parse_dscp(__u32 *key, const char *arg);
 void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data);
 
 /* dcb_apptrust.c */
diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
index 97cba658aa6b..3cb1bb302ed6 100644
--- a/dcb/dcb_app.c
+++ b/dcb/dcb_app.c
@@ -100,7 +100,7 @@ bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector)
 	return dcb_app_attr_type_get(selector) == type;
 }
 
-static void dcb_app_table_fini(struct dcb_app_table *tab)
+void dcb_app_table_fini(struct dcb_app_table *tab)
 {
 	free(tab->apps);
 }
@@ -119,8 +119,8 @@ int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app)
 	return 0;
 }
 
-static void dcb_app_table_remove_existing(struct dcb_app_table *a,
-					  const struct dcb_app_table *b)
+void dcb_app_table_remove_existing(struct dcb_app_table *a,
+				   const struct dcb_app_table *b)
 {
 	size_t ia, ja;
 	size_t ib;
@@ -198,8 +198,7 @@ void dcb_app_table_remove_replaced(struct dcb_app_table *a,
 	a->n_apps = ja;
 }
 
-static int dcb_app_table_copy(struct dcb_app_table *a,
-			      const struct dcb_app_table *b)
+int dcb_app_table_copy(struct dcb_app_table *a, const struct dcb_app_table *b)
 {
 	size_t i;
 	int ret;
@@ -226,7 +225,7 @@ static int dcb_app_cmp_cb(const void *a, const void *b)
 	return dcb_app_cmp(a, b);
 }
 
-static void dcb_app_table_sort(struct dcb_app_table *tab)
+void dcb_app_table_sort(struct dcb_app_table *tab)
 {
 	qsort(tab->apps, tab->n_apps, sizeof(*tab->apps), dcb_app_cmp_cb);
 }
@@ -269,7 +268,7 @@ static int dcb_app_parse_mapping_ethtype_prio(__u32 key, char *value, void *data
 				 dcb_app_parse_mapping_cb, data);
 }
 
-static int dcb_app_parse_pcp(__u32 *key, const char *arg)
+int dcb_app_parse_pcp(__u32 *key, const char *arg)
 {
 	int i;
 
@@ -295,7 +294,7 @@ static int dcb_app_parse_mapping_pcp_prio(__u32 key, char *value, void *data)
 				 dcb_app_parse_mapping_cb, data);
 }
 
-static int dcb_app_parse_dscp(__u32 *key, const char *arg)
+int dcb_app_parse_dscp(__u32 *key, const char *arg)
 {
 	if (parse_mapping_num_all(key, arg) == 0)
 		return 0;
@@ -320,7 +319,7 @@ static int dcb_app_parse_mapping_dscp_prio(__u32 key, char *value, void *data)
 	if (get_u8(&prio, value, 0))
 		return -EINVAL;
 
-	return dcb_parse_mapping("DSCP", key, 63,
+	return dcb_parse_mapping("DSCP", key, DCB_APP_DSCP_MAX,
 				 "PRIO", prio, IEEE_8021QAZ_MAX_TCS - 1,
 				 dcb_app_parse_mapping_cb, data);
 }
@@ -386,12 +385,12 @@ static bool dcb_app_is_default(const struct dcb_app *app)
 	       app->protocol == 0;
 }
 
-static bool dcb_app_is_dscp(const struct dcb_app *app)
+bool dcb_app_is_dscp(const struct dcb_app *app)
 {
 	return app->selector == IEEE_8021QAZ_APP_SEL_DSCP;
 }
 
-static bool dcb_app_is_pcp(const struct dcb_app *app)
+bool dcb_app_is_pcp(const struct dcb_app *app)
 {
 	return app->selector == DCB_APP_SEL_PCP;
 }
@@ -411,7 +410,7 @@ static bool dcb_app_is_port(const struct dcb_app *app)
 	return app->selector == IEEE_8021QAZ_APP_SEL_ANY;
 }
 
-static int dcb_app_print_pid_dec(__u16 protocol)
+int dcb_app_print_pid_dec(__u16 protocol)
 {
 	return print_uint(PRINT_ANY, NULL, "%u", protocol);
 }
@@ -421,7 +420,7 @@ static int dcb_app_print_pid_hex(__u16 protocol)
 	return print_uint(PRINT_ANY, NULL, "%x", protocol);
 }
 
-static int dcb_app_print_pid_dscp(__u16 protocol)
+int dcb_app_print_pid_dscp(__u16 protocol)
 {
 	const char *name = rtnl_dsfield_get_name(protocol << 2);
 
@@ -430,7 +429,7 @@ static int dcb_app_print_pid_dscp(__u16 protocol)
 	return print_uint(PRINT_ANY, NULL, "%u", protocol);
 }
 
-static int dcb_app_print_pid_pcp(__u16 protocol)
+int dcb_app_print_pid_pcp(__u16 protocol)
 {
 	/* Print in numerical form, if protocol value is out-of-range */
 	if (protocol > DCB_APP_PCP_MAX)
@@ -439,13 +438,13 @@ static int dcb_app_print_pid_pcp(__u16 protocol)
 	return print_string(PRINT_ANY, NULL, "%s", pcp_names[protocol]);
 }
 
-static void dcb_app_print_filtered(const struct dcb_app_table *tab,
-				   bool (*filter)(const struct dcb_app *),
-				   void (*print_pid_prio)(int (*print_pid)(__u16),
-							  const struct dcb_app *),
-				   int (*print_pid)(__u16 protocol),
-				   const char *json_name,
-				   const char *fp_name)
+void dcb_app_print_filtered(const struct dcb_app_table *tab,
+			    bool (*filter)(const struct dcb_app *),
+			    void (*print_pid_prio)(int (*print_pid)(__u16),
+						   const struct dcb_app *),
+			    int (*print_pid)(__u16 protocol),
+			    const char *json_name,
+			    const char *fp_name)
 {
 	bool first = true;
 	size_t i;
@@ -600,7 +599,7 @@ static int dcb_app_get_table_attr_cb(const struct nlattr *attr, void *data)
 	return MNL_CB_OK;
 }
 
-static int dcb_app_get(struct dcb *dcb, const char *dev, struct dcb_app_table *tab)
+int dcb_app_get(struct dcb *dcb, const char *dev, struct dcb_app_table *tab)
 {
 	uint16_t payload_len;
 	void *payload;
@@ -643,9 +642,9 @@ static int dcb_app_add_del_cb(struct dcb *dcb, struct nlmsghdr *nlh, void *data)
 	return 0;
 }
 
-static int dcb_app_add_del(struct dcb *dcb, const char *dev, int command,
-			   const struct dcb_app_table *tab,
-			   bool (*filter)(const struct dcb_app *))
+int dcb_app_add_del(struct dcb *dcb, const char *dev, int command,
+		    const struct dcb_app_table *tab,
+		    bool (*filter)(const struct dcb_app *))
 {
 	struct dcb_app_add_del add_del = {
 		.tab = tab,
diff --git a/dcb/dcb_rewr.c b/dcb/dcb_rewr.c
new file mode 100644
index 000000000000..37372465cae0
--- /dev/null
+++ b/dcb/dcb_rewr.c
@@ -0,0 +1,355 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <errno.h>
+#include <linux/dcbnl.h>
+#include <stdio.h>
+
+#include "dcb.h"
+#include "utils.h"
+
+static void dcb_rewr_help_add(void)
+{
+	fprintf(stderr,
+		"Usage: dcb rewr { add | del | replace } dev STRING\n"
+		"           [ prio-pcp PRIO:PCP ]\n"
+		"           [ prio-dscp PRIO:DSCP ]\n"
+		"\n"
+		" where PRIO := { 0 .. 7 }\n"
+		"       PCP  := { 0(nd/de) .. 7(nd/de) }\n"
+		"       DSCP := { 0 .. 63 }\n"
+		"\n"
+	);
+}
+
+static void dcb_rewr_help_show_flush(void)
+{
+	fprintf(stderr,
+		"Usage: dcb rewr { show | flush } dev STRING\n"
+		"           [ prio-pcp ]\n"
+		"           [ prio-dscp ]\n"
+		"\n"
+	);
+}
+
+static void dcb_rewr_help(void)
+{
+	fprintf(stderr,
+		"Usage: dcb rewr help\n"
+		"\n"
+	);
+	dcb_rewr_help_show_flush();
+	dcb_rewr_help_add();
+}
+
+static int dcb_rewr_parse_mapping_prio_pcp(__u32 key, char *value, void *data)
+{
+	__u32 pcp;
+
+	if (dcb_app_parse_pcp(&pcp, value))
+		return -EINVAL;
+
+	return dcb_parse_mapping("PRIO", key, IEEE_8021QAZ_MAX_TCS - 1,
+				 "PCP", pcp, DCB_APP_PCP_MAX,
+				 dcb_app_parse_mapping_cb, data);
+}
+
+static int dcb_rewr_parse_mapping_prio_dscp(__u32 key, char *value, void *data)
+{
+	__u32 dscp;
+
+	if (dcb_app_parse_dscp(&dscp, value))
+		return -EINVAL;
+
+	return dcb_parse_mapping("PRIO", key, IEEE_8021QAZ_MAX_TCS - 1,
+				 "DSCP", dscp, DCB_APP_DSCP_MAX,
+				 dcb_app_parse_mapping_cb, data);
+}
+
+static void dcb_rewr_print_prio_pid(int (*print_pid)(__u16 protocol),
+				    const struct dcb_app *app)
+{
+	print_uint(PRINT_ANY, NULL, "%u:", app->priority);
+	print_pid(app->protocol);
+}
+
+static void dcb_rewr_print_prio_pcp(const struct dcb *dcb,
+				    const struct dcb_app_table *tab)
+{
+	dcb_app_print_filtered(tab, dcb_app_is_pcp,
+			       dcb_rewr_print_prio_pid,
+			       dcb->numeric ? dcb_app_print_pid_dec :
+					      dcb_app_print_pid_pcp,
+			       "prio_pcp", "prio-pcp");
+}
+
+static void dcb_rewr_print_prio_dscp(const struct dcb *dcb,
+				     const struct dcb_app_table *tab)
+{
+	dcb_app_print_filtered(tab, dcb_app_is_dscp,
+			       dcb_rewr_print_prio_pid,
+			       dcb->numeric ? dcb_app_print_pid_dec :
+					      dcb_app_print_pid_dscp,
+			       "prio_dscp", "prio-dscp");
+}
+
+static void dcb_rewr_print(const struct dcb *dcb,
+			   const struct dcb_app_table *tab)
+{
+	dcb_rewr_print_prio_pcp(dcb, tab);
+	dcb_rewr_print_prio_dscp(dcb, tab);
+}
+
+static int dcb_rewr_push(struct dcb_app_table *tab,
+			 __u8 selector, __u32 key, __u64 value)
+{
+	struct dcb_app app = {
+		.selector = selector,
+		.priority = key,
+		.protocol = value,
+	};
+	return dcb_app_table_push(tab, &app);
+}
+
+static int dcb_cmd_rewr_parse_add_del(struct dcb *dcb, const char *dev,
+				      int argc, char **argv,
+				      struct dcb_app_table *tab)
+{
+	struct dcb_app_parse_mapping pm = {
+		.tab = tab,
+		.push = dcb_rewr_push,
+	};
+	int ret;
+
+	if (!argc) {
+		dcb_rewr_help_add();
+		return 0;
+	}
+
+	do {
+		if (strcmp(*argv, "help") == 0) {
+			dcb_rewr_help_add();
+			return 0;
+		} else if (strcmp(*argv, "prio-pcp") == 0) {
+			NEXT_ARG();
+			pm.selector = DCB_APP_SEL_PCP;
+			ret = parse_mapping(&argc, &argv, false,
+					    &dcb_rewr_parse_mapping_prio_pcp,
+					    &pm);
+		} else if (strcmp(*argv, "prio-dscp") == 0) {
+			NEXT_ARG();
+			pm.selector = IEEE_8021QAZ_APP_SEL_DSCP;
+			ret = parse_mapping(&argc, &argv, false,
+					    &dcb_rewr_parse_mapping_prio_dscp,
+					    &pm);
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			dcb_rewr_help_add();
+			return -EINVAL;
+		}
+
+		if (ret != 0) {
+			fprintf(stderr, "Invalid mapping %s\n", *argv);
+			return ret;
+		}
+		if (pm.err)
+			return pm.err;
+	} while (argc > 0);
+
+	return 0;
+}
+
+static int dcb_cmd_rewr_add(struct dcb *dcb, const char *dev, int argc,
+			    char **argv)
+{
+	struct dcb_app_table tab = { .attr = DCB_ATTR_DCB_REWR_TABLE };
+	int ret;
+
+	ret = dcb_cmd_rewr_parse_add_del(dcb, dev, argc, argv, &tab);
+	if (ret != 0)
+		return ret;
+
+	ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_SET, &tab, NULL);
+	dcb_app_table_fini(&tab);
+	return ret;
+}
+
+static int dcb_cmd_rewr_del(struct dcb *dcb, const char *dev, int argc,
+			    char **argv)
+{
+	struct dcb_app_table tab = { .attr = DCB_ATTR_DCB_REWR_TABLE };
+	int ret;
+
+	ret = dcb_cmd_rewr_parse_add_del(dcb, dev, argc, argv, &tab);
+	if (ret != 0)
+		return ret;
+
+	ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &tab, NULL);
+	dcb_app_table_fini(&tab);
+	return ret;
+}
+
+static int dcb_cmd_rewr_replace(struct dcb *dcb, const char *dev, int argc,
+				char **argv)
+{
+	struct dcb_app_table orig = { .attr = DCB_ATTR_DCB_REWR_TABLE };
+	struct dcb_app_table tab = { .attr = DCB_ATTR_DCB_REWR_TABLE };
+	struct dcb_app_table new = { .attr = DCB_ATTR_DCB_REWR_TABLE };
+	int ret;
+
+	ret = dcb_app_get(dcb, dev, &orig);
+	if (ret != 0)
+		return ret;
+
+	ret = dcb_cmd_rewr_parse_add_del(dcb, dev, argc, argv, &tab);
+	if (ret != 0)
+		goto out;
+
+	/* Attempts to add an existing entry would be rejected, so drop
+	 * these entries from tab.
+	 */
+	ret = dcb_app_table_copy(&new, &tab);
+	if (ret != 0)
+		goto out;
+	dcb_app_table_remove_existing(&new, &orig);
+
+	ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_SET, &new, NULL);
+	if (ret != 0) {
+		fprintf(stderr, "Could not add new rewrite entries\n");
+		goto out;
+	}
+
+	/* Remove the obsolete entries. */
+	dcb_app_table_remove_replaced(&orig, &tab, dcb_app_prio_eq);
+	ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &orig, NULL);
+	if (ret != 0) {
+		fprintf(stderr, "Could not remove replaced rewrite entries\n");
+		goto out;
+	}
+
+out:
+	dcb_app_table_fini(&new);
+	dcb_app_table_fini(&tab);
+	dcb_app_table_fini(&orig);
+	return 0;
+}
+
+
+static int dcb_cmd_rewr_show(struct dcb *dcb, const char *dev, int argc,
+			     char **argv)
+{
+	struct dcb_app_table tab = { .attr = DCB_ATTR_DCB_REWR_TABLE };
+	int ret;
+
+	ret = dcb_app_get(dcb, dev, &tab);
+	if (ret != 0)
+		return ret;
+
+	dcb_app_table_sort(&tab);
+
+	open_json_object(NULL);
+
+	if (!argc) {
+		dcb_rewr_print(dcb, &tab);
+		goto out;
+	}
+
+	do {
+		if (strcmp(*argv, "help") == 0) {
+			dcb_rewr_help_show_flush();
+			goto out;
+		} else if (strcmp(*argv, "prio-pcp") == 0) {
+			dcb_rewr_print_prio_pcp(dcb, &tab);
+		} else if (strcmp(*argv, "prio-dscp") == 0) {
+			dcb_rewr_print_prio_dscp(dcb, &tab);
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			dcb_rewr_help_show_flush();
+			ret = -EINVAL;
+			goto out;
+		}
+
+		NEXT_ARG_FWD();
+	} while (argc > 0);
+
+out:
+	close_json_object();
+	dcb_app_table_fini(&tab);
+	return ret;
+}
+
+static int dcb_cmd_rewr_flush(struct dcb *dcb, const char *dev, int argc,
+			      char **argv)
+{
+	struct dcb_app_table tab = { .attr = DCB_ATTR_DCB_REWR_TABLE };
+	int ret;
+
+	ret = dcb_app_get(dcb, dev, &tab);
+	if (ret != 0)
+		return ret;
+
+	if (!argc) {
+		ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &tab,
+				      NULL);
+		goto out;
+	}
+
+	do {
+		if (strcmp(*argv, "help") == 0) {
+			dcb_rewr_help_show_flush();
+			goto out;
+		} else if (strcmp(*argv, "prio-pcp") == 0) {
+			ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &tab,
+					      &dcb_app_is_pcp);
+			if (ret != 0)
+				goto out;
+		} else if (strcmp(*argv, "prio-dscp") == 0) {
+			ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &tab,
+					      &dcb_app_is_dscp);
+			if (ret != 0)
+				goto out;
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			dcb_rewr_help_show_flush();
+			ret = -EINVAL;
+			goto out;
+		}
+
+		NEXT_ARG_FWD();
+	} while (argc > 0);
+
+out:
+	dcb_app_table_fini(&tab);
+	return ret;
+}
+
+int dcb_cmd_rewr(struct dcb *dcb, int argc, char **argv)
+{
+	if (!argc || strcmp(*argv, "help") == 0) {
+		dcb_rewr_help();
+		return 0;
+	} else if (strcmp(*argv, "show") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv, dcb_cmd_rewr_show,
+					 dcb_rewr_help_show_flush);
+	} else if (strcmp(*argv, "flush") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv, dcb_cmd_rewr_flush,
+					 dcb_rewr_help_show_flush);
+	} else if (strcmp(*argv, "add") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv, dcb_cmd_rewr_add,
+					 dcb_rewr_help_add);
+	} else if (strcmp(*argv, "del") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv, dcb_cmd_rewr_del,
+					 dcb_rewr_help_add);
+	} else if (strcmp(*argv, "replace") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv, dcb_cmd_rewr_replace,
+					 dcb_rewr_help_add);
+	} else {
+		fprintf(stderr, "What is \"%s\"?\n", *argv);
+		dcb_rewr_help();
+		return -EINVAL;
+	}
+}

-- 
2.34.1

Re: [PATCH iproute2-next v2 5/8] dcb: rewr: add new dcb-rewr subcommand

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

> Add a new subcommand 'rewr' for configuring the in-kernel DCB rewrite
> table. The rewr-table of the kernel is similar to the APP-table, and so
> is this new subcommand. Therefore, much of the existing bookkeeping code
> from dcb-app, can be reused in the dcb-rewr implementation.
>
> Initially, only support for configuring PCP and DSCP-based rewrite has
> been added.
>
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>

Looks good overall, barring the comment about dcb_app_parse_mapping_cb()
that I made in the other patch, and a handful of nits below.

> ---
>  dcb/Makefile   |   3 +-
>  dcb/dcb.c      |   4 +-
>  dcb/dcb.h      |  32 ++++++
>  dcb/dcb_app.c  |  49 ++++----
>  dcb/dcb_rewr.c | 355 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  5 files changed, 416 insertions(+), 27 deletions(-)

> diff --git a/dcb/dcb.h b/dcb/dcb.h
> index b3bc30cd02c5..092dc90e8358 100644
> --- a/dcb/dcb.h
> +++ b/dcb/dcb.h
> @@ -54,6 +54,10 @@ void dcb_print_array_on_off(const __u8 *array, size_t size);
>  void dcb_print_array_kw(const __u8 *array, size_t array_size,
>  			const char *const kw[], size_t kw_size);
>  
> +/* dcp_rewr.c */
> +
> +int dcb_cmd_rewr(struct dcb *dcb, int argc, char **argv);
> +
>  /* dcb_app.c */
>  
>  struct dcb_app_table {
> @@ -70,8 +74,29 @@ struct dcb_app_parse_mapping {
>  	int err;
>  };
>  
> +#define DCB_APP_PCP_MAX 15

This should be removed from dcb_app.c as well.

> +#define DCB_APP_DSCP_MAX 63

DCB_APP_DSCP_MAX should be introduced in a separate patch together with
the s/63/DCB_APP_DSCP_MAX/ of the existing code, instead of including it
all here. It's a concern separate from the main topic of the patch.

> +
>  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
>  
> +int dcb_app_get(struct dcb *dcb, const char *dev, struct dcb_app_table *tab);
> +int dcb_app_add_del(struct dcb *dcb, const char *dev, int command,
> +		    const struct dcb_app_table *tab,
> +		    bool (*filter)(const struct dcb_app *));
> +
> +bool dcb_app_is_dscp(const struct dcb_app *app);
> +bool dcb_app_is_pcp(const struct dcb_app *app);
> +
> +int dcb_app_print_pid_dscp(__u16 protocol);
> +int dcb_app_print_pid_pcp(__u16 protocol);
> +int dcb_app_print_pid_dec(__u16 protocol);
> +void dcb_app_print_filtered(const struct dcb_app_table *tab,
> +			    bool (*filter)(const struct dcb_app *),
> +			    void (*print_pid_prio)(int (*print_pid)(__u16),
> +						   const struct dcb_app *),
> +			    int (*print_pid)(__u16 protocol),
> +			    const char *json_name, const char *fp_name);
> +
>  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
>  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
>  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
> @@ -80,11 +105,18 @@ bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>  bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
>  
>  int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app);
> +int dcb_app_table_copy(struct dcb_app_table *a, const struct dcb_app_table *b);
> +void dcb_app_table_sort(struct dcb_app_table *tab);
> +void dcb_app_table_fini(struct dcb_app_table *tab);
> +void dcb_app_table_remove_existing(struct dcb_app_table *a,
> +				   const struct dcb_app_table *b);
>  void dcb_app_table_remove_replaced(struct dcb_app_table *a,
>  				   const struct dcb_app_table *b,
>  				   bool (*key_eq)(const struct dcb_app *aa,
>  						  const struct dcb_app *ab));
>  
> +int dcb_app_parse_pcp(__u32 *key, const char *arg);
> +int dcb_app_parse_dscp(__u32 *key, const char *arg);
>  void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data);
>  
>  /* dcb_apptrust.c */
> diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
> index 97cba658aa6b..3cb1bb302ed6 100644
> --- a/dcb/dcb_app.c
> +++ b/dcb/dcb_app.c

> @@ -643,9 +642,9 @@ static int dcb_app_add_del_cb(struct dcb *dcb, struct nlmsghdr *nlh, void *data)

> +static int dcb_cmd_rewr_replace(struct dcb *dcb, const char *dev, int argc,
> +				char **argv)
> +{

[...]

> +}
> +
> +

Two blank lines.

> +static int dcb_cmd_rewr_show(struct dcb *dcb, const char *dev, int argc,
> +			     char **argv)
> +{

Re: [PATCH iproute2-next v2 5/8] dcb: rewr: add new dcb-rewr subcommand

[Daniel Machon]

 > Daniel Machon <daniel.machon@microchip.com> writes:
> 
> > Add a new subcommand 'rewr' for configuring the in-kernel DCB rewrite
> > table. The rewr-table of the kernel is similar to the APP-table, and so
> > is this new subcommand. Therefore, much of the existing bookkeeping code
> > from dcb-app, can be reused in the dcb-rewr implementation.
> >
> > Initially, only support for configuring PCP and DSCP-based rewrite has
> > been added.
> >
> > Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> 
> Looks good overall, barring the comment about dcb_app_parse_mapping_cb()
> that I made in the other patch, and a handful of nits below.
> 
> > ---
> >  dcb/Makefile   |   3 +-
> >  dcb/dcb.c      |   4 +-
> >  dcb/dcb.h      |  32 ++++++
> >  dcb/dcb_app.c  |  49 ++++----
> >  dcb/dcb_rewr.c | 355 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  5 files changed, 416 insertions(+), 27 deletions(-)
> 
> > diff --git a/dcb/dcb.h b/dcb/dcb.h
> > index b3bc30cd02c5..092dc90e8358 100644
> > --- a/dcb/dcb.h
> > +++ b/dcb/dcb.h
> > @@ -54,6 +54,10 @@ void dcb_print_array_on_off(const __u8 *array, size_t size);
> >  void dcb_print_array_kw(const __u8 *array, size_t array_size,
> >                       const char *const kw[], size_t kw_size);
> >
> > +/* dcp_rewr.c */
> > +
> > +int dcb_cmd_rewr(struct dcb *dcb, int argc, char **argv);
> > +
> >  /* dcb_app.c */
> >
> >  struct dcb_app_table {
> > @@ -70,8 +74,29 @@ struct dcb_app_parse_mapping {
> >       int err;
> >  };
> >
> > +#define DCB_APP_PCP_MAX 15
> 
> This should be removed from dcb_app.c as well.
> 
> > +#define DCB_APP_DSCP_MAX 63
> 
> DCB_APP_DSCP_MAX should be introduced in a separate patch together with
> the s/63/DCB_APP_DSCP_MAX/ of the existing code, instead of including it
> all here. It's a concern separate from the main topic of the patch.

Ack.

> 
> > +
> >  int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
> >
> > +int dcb_app_get(struct dcb *dcb, const char *dev, struct dcb_app_table *tab);
> > +int dcb_app_add_del(struct dcb *dcb, const char *dev, int command,
> > +                 const struct dcb_app_table *tab,
> > +                 bool (*filter)(const struct dcb_app *));
> > +
> > +bool dcb_app_is_dscp(const struct dcb_app *app);
> > +bool dcb_app_is_pcp(const struct dcb_app *app);
> > +
> > +int dcb_app_print_pid_dscp(__u16 protocol);
> > +int dcb_app_print_pid_pcp(__u16 protocol);
> > +int dcb_app_print_pid_dec(__u16 protocol);
> > +void dcb_app_print_filtered(const struct dcb_app_table *tab,
> > +                         bool (*filter)(const struct dcb_app *),
> > +                         void (*print_pid_prio)(int (*print_pid)(__u16),
> > +                                                const struct dcb_app *),
> > +                         int (*print_pid)(__u16 protocol),
> > +                         const char *json_name, const char *fp_name);
> > +
> >  enum ieee_attrs_app dcb_app_attr_type_get(__u8 selector);
> >  bool dcb_app_attr_type_validate(enum ieee_attrs_app type);
> >  bool dcb_app_selector_validate(enum ieee_attrs_app type, __u8 selector);
> > @@ -80,11 +105,18 @@ bool dcb_app_pid_eq(const struct dcb_app *aa, const struct dcb_app *ab);
> >  bool dcb_app_prio_eq(const struct dcb_app *aa, const struct dcb_app *ab);
> >
> >  int dcb_app_table_push(struct dcb_app_table *tab, struct dcb_app *app);
> > +int dcb_app_table_copy(struct dcb_app_table *a, const struct dcb_app_table *b);
> > +void dcb_app_table_sort(struct dcb_app_table *tab);
> > +void dcb_app_table_fini(struct dcb_app_table *tab);
> > +void dcb_app_table_remove_existing(struct dcb_app_table *a,
> > +                                const struct dcb_app_table *b);
> >  void dcb_app_table_remove_replaced(struct dcb_app_table *a,
> >                                  const struct dcb_app_table *b,
> >                                  bool (*key_eq)(const struct dcb_app *aa,
> >                                                 const struct dcb_app *ab));
> >
> > +int dcb_app_parse_pcp(__u32 *key, const char *arg);
> > +int dcb_app_parse_dscp(__u32 *key, const char *arg);
> >  void dcb_app_parse_mapping_cb(__u32 key, __u64 value, void *data);
> >
> >  /* dcb_apptrust.c */
> > diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
> > index 97cba658aa6b..3cb1bb302ed6 100644
> > --- a/dcb/dcb_app.c
> > +++ b/dcb/dcb_app.c
> 
> > @@ -643,9 +642,9 @@ static int dcb_app_add_del_cb(struct dcb *dcb, struct nlmsghdr *nlh, void *data)
> 
> > +static int dcb_cmd_rewr_replace(struct dcb *dcb, const char *dev, int argc,
> > +                             char **argv)
> > +{
> 
> [...]
> 
> > +}
> > +
> > +
> 
> Two blank lines.
> 
> > +static int dcb_cmd_rewr_show(struct dcb *dcb, const char *dev, int argc,
> > +                          char **argv)
> > +{

[PATCH iproute2-next v2 6/8] man: dcb-rewr: add new manpage for dcb-rewr

[Daniel Machon]

Add a new manpage for dcb-rewr. Most of the content is copied over from
dcb-app, as the same set of commands and parameters (in reverse) applies
to dcb-rewr.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
 man/man8/dcb-rewr.8 | 206 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 206 insertions(+)

diff --git a/man/man8/dcb-rewr.8 b/man/man8/dcb-rewr.8
new file mode 100644
index 000000000000..03b59cf4837c
--- /dev/null
+++ b/man/man8/dcb-rewr.8
@@ -0,0 +1,206 @@
+.TH DCB-REWR 8 "15 may 2023" "iproute2" "Linux"
+.SH NAME
+dcb-rewr \- show / manipulate the rewrite table of
+the DCB (Data Center Bridging) subsystem
+.SH SYNOPSIS
+.sp
+.ad l
+.in +8
+
+.ti -8
+.B dcb
+.RI "[ " OPTIONS " ] "
+.B rewr
+.RI "{ " COMMAND " | " help " }"
+.sp
+
+.ti -8
+.B dcb rewr " { " show " | " flush " } " dev
+.RI DEV
+.RB "[ " prio-dscp " ]"
+.RB "[ " prio-pcp " ]"
+
+.ti -8
+.B dcb rewr " { " add " | " del " | " replace " } " dev
+.RI DEV
+.RB "[ " prio-dscp " " \fIDSCP-MAP\fB " ]"
+.RB "[ " prio-pcp " " \fIPCP-MAP\fB " ]"
+
+.ti -8
+.IR DSCP-MAP " := [ " DSCP-MAP " ] " DSCP-MAPPING
+
+.ti -8
+.IR DSCP-MAPPING " := " \fIPRIO \fB:\fR "{ " DSCP " | " \fBall\fR " }"
+
+.ti -8
+.IR PCP-MAP " := [ " PCP-MAP " ] " PCP-MAPPING
+
+.ti -8
+.IR PCP-MAPPING " := " \fIPRIO \fB:\fR PCP\fR
+
+.ti -8
+.IR DSCP " := { " \fB0\fR " .. " \fB63\fR " }"
+
+.ti -8
+.IR PCP " := { " \fB0(nd/de)\fR " .. " \fB7(nd/de)\fR " }"
+
+.ti -8
+.IR PRIO " := { " \fB0\fR " .. " \fB7\fR " }"
+
+.SH DESCRIPTION
+
+.B dcb rewr
+is used to configure the rewrite table, in the DCB (Data Center Bridging)
+subsystem.  The rewrite table is used to rewrite certain values in the packet
+headers, based on packet priority.
+
+DCB rewrite entries are, like DCB APP entries, 3-tuples of selector, protocol
+ID, and priority. Selector is an enumeration that picks one of the
+prioritization namespaces. Currently, only the DSCP and PCP selector namespaces
+are supported by dcb rewr.
+
+The rewrite table is a list of DCB rewrite rules, that applies to packets
+with matching priority.  Notably, it is valid to have conflicting rewrite
+assignment for the same selector and priority. For example, the set of two
+rewrite entries (DSCP, 10, 1) and (DSCP, 11, 1), where packets with priority 1
+should have its DSCP value rewritten to both 10 and 11, form a well-defined
+rewrite table.
+.B dcb rewr
+tool allows low-level management of the rewrite table by adding and deleting
+individual rewrite 3-tuples through
+.B add
+and
+.B del
+commands. On the other hand, the command
+.B replace
+does what one would typically want in this situation--first adds the new
+configuration, and then removes the obsolete one, so that only one
+rewrite rule is in effect for a given selector and priority.
+
+.SH COMMANDS
+
+.TP
+.B show
+Display all entries with a given selector. When no selector is given, shows all
+rewrite table entries categorized per selector.
+
+.TP
+.B flush
+Remove all entries with a given selector. When no selector is given, removes all
+rewrite table entries.
+
+.TP
+.B add
+.TQ
+.B del
+Add and, respectively, remove individual rewrite 3-tuples to and from the DCB
+rewrite table.
+
+.TP
+.B replace
+Take the list of entries mentioned as parameter, and add those that are not
+present in the rewrite table yet. Then remove those entries, whose selector and
+priority have been mentioned as parameter, but not with the exact same
+protocol ID. This has the effect of, for the given selector and priority,
+causing that the table only contains the protocol ID (or ID's) given as
+parameter.
+
+.SH PARAMETERS
+
+The following table shows parameters in a way that they would be used with
+\fBadd\fR, \fBdel\fR and \fBreplace\fR commands. For \fBshow\fR and
+\fBflush\fR, the parameter name is to be used as a simple keyword without
+further arguments.
+
+.TP
+.B prio-dscp \fIDSCP-MAP
+\fIDSCP-MAP\fR uses the array parameter syntax, see
+.BR dcb (8)
+for details. Keys are priorities, values are DSCP points for traffic
+with matching priority. DSCP points can be written either directly as numeric
+values, or using symbolic names specified in
+.B /etc/iproute2/rt_dsfield
+(however note that the file specifies full 8-bit dsfield values, whereas
+.B dcb rewr
+will only use the higher six bits).
+.B dcb rewr show
+will similarly format DSCP values as symbolic names if possible. The
+command line option
+.B -N
+turns the show translation off.
+
+.TP
+.B prio-pcp \fIPCP-MAP
+\fIPCP-MAP\fR uses the array parameter syntax, see
+.BR dcb (8)
+for details. Keys are priorities. Values are PCP/DEI for traffic with
+matching priority. PCP/DEI values are written as a combination of numeric- and
+symbolic values, to accommodate for both. PCP always in numeric form e.g 0 ..
+7 and DEI in symbolic form e.g 'de' (drop-eligible), indicating that the DEI
+bit is 1 or 'nd' (not-drop-eligible), indicating that the DEI bit is 0.  In
+combination 1:2de translates to a mapping of priority 1 to PCP=2 and DEI=1.
+
+.SH EXAMPLE & USAGE
+
+Add a rule to rewrite DSCP to 0, 24 and 48 for traffic with priority 0, 3 and
+6, respectively:
+.P
+# dcb rewr add dev eth0 prio-dscp 0:0 3:24 6:48
+
+Add a rule to rewrite DSCP to 25 for traffic with priority 3:
+.P
+# dcb rewr add dev eth0 prio-dscp 3:25
+.br
+# dcb rewr show dev eth0 prio-dscp
+.br
+prio-dscp 0:0 3:CS3 3:25 6:CS6
+.br
+# dcb -N rewr show dev eth0 prio-dscp
+.br
+prio-dscp 0:0 3:24 3:25 6:48
+
+Reconfigure the table so that only one rule exists for rewriting traffic with
+priority 3.
+
+.P
+# dcb rewr replace dev eth0 prio-dscp 3:26
+.br
+# dcb rewr -N show dev eth0 prio-dscp
+.br
+prio-dscp 0:0 3:26 6:48
+
+Flush all DSCP rules:
+
+.P
+# dcb rewr flush dev eth0 prio-dscp
+.br
+# dcb rewr show dev eth0 prio-dscp
+.br
+(nothing)
+
+Add a rule to rewrite PCP to 1 and DEI to 0 for traffic with priority 1 and a
+rule to rewrite PCP to 2 and DEI to 1 for traffic with priority 2:
+
+.P
+# dcb rewr add dev eth0 prio-pcp 1:1nd 2:2de
+.br
+# dcb rewr show dev eth0 prio-pcp
+.br
+prio-pcp 1:1nd 2:2de
+
+.SH EXIT STATUS
+Exit status is 0 if command was successful or a positive integer upon failure.
+
+.SH SEE ALSO
+.BR dcb (8)
+.BR dcb-app (8)
+.BR dcb-apptrust (8)
+
+.SH REPORTING BUGS
+Report any bugs to the Network Developers mailing list
+.B <netdev@vger.kernel.org>
+where the development and maintenance is primarily done.  You do not have to be
+subscribed to the list to send a message there.
+
+.SH AUTHOR
+Daniel Machon <daniel.machon@microchip.com>

-- 
2.34.1

Re: [PATCH iproute2-next v2 6/8] man: dcb-rewr: add new manpage for dcb-rewr

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

> Add a new manpage for dcb-rewr. Most of the content is copied over from
> dcb-app, as the same set of commands and parameters (in reverse) applies
> to dcb-rewr.
>
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>

Reviewed-by: Petr Machata <me@pmachata.org>

[PATCH iproute2-next v2 7/8] man: dcb: add additional references under 'SEE ALSO'

[Daniel Machon]

Add dcb-apptrust and dcb-rewr to the 'SEE ALSO' section of the dcb
manpage.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
 man/man8/dcb.8 | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/man/man8/dcb.8 b/man/man8/dcb.8
index 24944b73816b..a1d6505e93b4 100644
--- a/man/man8/dcb.8
+++ b/man/man8/dcb.8
@@ -140,10 +140,12 @@ Exit status is 0 if command was successful or a positive integer upon failure.
 
 .SH SEE ALSO
 .BR dcb-app (8),
+.BR dcb-apptrust (8),
 .BR dcb-buffer (8),
 .BR dcb-ets (8),
 .BR dcb-maxrate (8),
-.BR dcb-pfc (8)
+.BR dcb-pfc (8),
+.BR dcb-rewr (8)
 .br
 
 .SH REPORTING BUGS

-- 
2.34.1

Re: [PATCH iproute2-next v2 7/8] man: dcb: add additional references under 'SEE ALSO'

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

> Add dcb-apptrust and dcb-rewr to the 'SEE ALSO' section of the dcb
> manpage.

Hmm, yeah, apptrust was left behind the last time around.

> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>

Reviewed-by: Petr Machata <me@pmachata.org>

[PATCH iproute2-next v2 8/8] man: dcb-app: clean up a few mistakes

[Daniel Machon]

While referencing the dcb-app manpage, I spotted a few mistakes. Lets
fix them.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
 man/man8/dcb-app.8 | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/man/man8/dcb-app.8 b/man/man8/dcb-app.8
index ecb38591168e..be505a0be308 100644
--- a/man/man8/dcb-app.8
+++ b/man/man8/dcb-app.8
@@ -1,4 +1,4 @@
-.TH DCB-ETS 8 "6 December 2020" "iproute2" "Linux"
+.TH DCB-APP 8 "6 December 2020" "iproute2" "Linux"
 .SH NAME
 dcb-app \- show / manipulate application priority table of
 the DCB (Data Center Bridging) subsystem
@@ -26,7 +26,7 @@ the DCB (Data Center Bridging) subsystem
 .RB "[ " pcp-prio " ]"
 
 .ti -8
-.B dcb ets " { " add " | " del " | " replace " } " dev
+.B dcb app " { " add " | " del " | " replace " } " dev
 .RI DEV
 .RB "[ " default-prio " " \fIPRIO-LIST\fB " ]"
 .RB "[ " ethtype-prio " " \fIET-MAP\fB " ]"
@@ -106,7 +106,7 @@ individual APP 3-tuples through
 .B add
 and
 .B del
-commands. On the other other hand, the command
+commands. On the other hand, the command
 .B replace
 does what one would typically want in this situation--first adds the new
 configuration, and then removes the obsolete one, so that only one
@@ -184,7 +184,7 @@ for details. Keys are DSCP points, values are priorities assigned to
 traffic with matching DSCP. DSCP points can be written either directly as
 numeric values, or using symbolic names specified in
 .B /etc/iproute2/rt_dsfield
-(however note that that file specifies full 8-bit dsfield values, whereas
+(however note that the file specifies full 8-bit dsfield values, whereas
 .B dcb app
 will only use the higher six bits).
 .B dcb app show
@@ -230,7 +230,7 @@ priority 4:
 .P
 # dcb app replace dev eth0 dscp-prio 24:4
 .br
-# dcb app show dev eth0 dscp-prio
+# dcb app -N show dev eth0 dscp-prio
 .br
 dscp-prio 0:0 24:4 48:6
 

-- 
2.34.1

Re: [PATCH iproute2-next v2 8/8] man: dcb-app: clean up a few mistakes

[Petr Machata]

Daniel Machon <daniel.machon@microchip.com> writes:

> While referencing the dcb-app manpage, I spotted a few mistakes. Lets
> fix them.
>
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>

Reviewed-by: Petr Machata <me@pmachata.org>