[PATCH iproute2-next 0/9] dcb: Support APP, DCBX objects

[PATCH iproute2-next 0/9] dcb: Support APP, DCBX objects

[Petr Machata]

Add support to the dcb tool for the following two DCB objects:

- APP, which allows configuration of traffic prioritization rules based on
  several possible packet headers.

- DCBX, which is a 1-byte bitfield of flags that configure whether the DCBX
  protocol is implemented in the device or in the host, and which version
  of the protocol should be used.

Patches #1 and #2 fix issues in the current DCB code.

Patch #3 adds a new helper for finding a name of a given dsfield value.
This is useful for APP DSCP-to-priority rules, which can use human-readable
DSCP names.

Patches #4, #5 and #6 extend existing interfaces for, respectively, parsing
of the X:Y mappings, for setting a DCB object, and for getting a DCB
object.

In patch #7, support for the command line argument -n / --no-nice-names is
added. The APP tool later uses it to decide whether to format DSCP values
as human-readable strings or as plain numbers.

Patches #8 and #9 add the subtools themselves and their man pages.

Petr Machata (9):
  dcb: Set values with RTM_SETDCB type
  dcb: Plug a leaking DCB socket buffer
  lib: rt_names: Add rtnl_dsfield_get_name()
  lib: Generalize parse_mapping()
  dcb: Generalize dcb_set_attribute()
  dcb: Generalize dcb_get_attribute()
  dcb: Support -n to suppress translation to nice names
  dcb: Add a subtool for the DCB APP object
  dcb: Add a subtool for the DCBX object

 dcb/Makefile        |   8 +-
 dcb/dcb.c           | 194 +++++++++--
 dcb/dcb.h           |  20 ++
 dcb/dcb_app.c       | 796 ++++++++++++++++++++++++++++++++++++++++++++
 dcb/dcb_dcbx.c      | 192 +++++++++++
 include/rt_names.h  |   1 +
 include/utils.h     |   5 +
 lib/rt_names.c      |  20 +-
 lib/utils.c         |  37 +-
 man/man8/dcb-app.8  | 237 +++++++++++++
 man/man8/dcb-dcbx.8 | 108 ++++++
 man/man8/dcb.8      |  12 +-
 12 files changed, 1592 insertions(+), 38 deletions(-)
 create mode 100644 dcb/dcb_app.c
 create mode 100644 dcb/dcb_dcbx.c
 create mode 100644 man/man8/dcb-app.8
 create mode 100644 man/man8/dcb-dcbx.8

-- 
2.25.1

[PATCH iproute2-next 1/9] dcb: Set values with RTM_SETDCB type

[Petr Machata]

dcb currently sends all netlink messages with a type RTM_GETDCB, even the
set ones. Change to the appropriate type.

Signed-off-by: Petr Machata <me@pmachata.org>
---
 dcb/dcb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dcb/dcb.c b/dcb/dcb.c
index adec57476e1d..f5c62790e27e 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -177,7 +177,7 @@ int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr, const void *da
 	struct nlattr *nest;
 	int ret;
 
-	nlh = dcb_prepare(dcb, dev, RTM_GETDCB, DCB_CMD_IEEE_SET);
+	nlh = dcb_prepare(dcb, dev, RTM_SETDCB, DCB_CMD_IEEE_SET);
 
 	nest = mnl_attr_nest_start(nlh, DCB_ATTR_IEEE);
 	mnl_attr_put(nlh, attr, data_len, data);
-- 
2.25.1

[PATCH iproute2-next 2/9] dcb: Plug a leaking DCB socket buffer

[Petr Machata]

DCB socket buffer is allocated in dcb_init(), but never freed(). Free it
in dcb_fini().

Signed-off-by: Petr Machata <me@pmachata.org>
---
 dcb/dcb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dcb/dcb.c b/dcb/dcb.c
index f5c62790e27e..0e3c87484f2a 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -38,6 +38,7 @@ static void dcb_fini(struct dcb *dcb)
 {
 	delete_json_obj_plain();
 	mnl_socket_close(dcb->nl);
+	free(dcb->buf);
 }
 
 static struct dcb *dcb_alloc(void)
-- 
2.25.1

[PATCH iproute2-next 3/9] lib: rt_names: Add rtnl_dsfield_get_name()

[Petr Machata]

For formatting DSCP (not full dsfield), it would be handy to be able to
just get the name from the name table, and not get any of the remaining
cruft related to formatting. Add a new entry point to just fetch the
name table string uninterpreted. Use it from rtnl_dsfield_n2a().

Signed-off-by: Petr Machata <me@pmachata.org>
---
 include/rt_names.h |  1 +
 lib/rt_names.c     | 20 ++++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/include/rt_names.h b/include/rt_names.h
index 990ed7f22e69..1835f3be2bed 100644
--- a/include/rt_names.h
+++ b/include/rt_names.h
@@ -9,6 +9,7 @@ const char *rtnl_rtscope_n2a(int id, char *buf, int len);
 const char *rtnl_rttable_n2a(__u32 id, char *buf, int len);
 const char *rtnl_rtrealm_n2a(int id, char *buf, int len);
 const char *rtnl_dsfield_n2a(int id, char *buf, int len);
+const char *rtnl_dsfield_get_name(int id);
 const char *rtnl_group_n2a(int id, char *buf, int len);
 
 int rtnl_rtprot_a2n(__u32 *id, const char *arg);
diff --git a/lib/rt_names.c b/lib/rt_names.c
index ca0680a12150..b976471d7979 100644
--- a/lib/rt_names.c
+++ b/lib/rt_names.c
@@ -479,18 +479,30 @@ static void rtnl_rtdsfield_initialize(void)
 
 const char *rtnl_dsfield_n2a(int id, char *buf, int len)
 {
+	const char *name;
+
 	if (id < 0 || id >= 256) {
 		snprintf(buf, len, "%d", id);
 		return buf;
 	}
+	if (!numeric) {
+		name = rtnl_dsfield_get_name(id);
+		if (name != NULL)
+			return name;
+	}
+	snprintf(buf, len, "0x%02x", id);
+	return buf;
+}
+
+const char *rtnl_dsfield_get_name(int id)
+{
+	if (id < 0 || id >= 256)
+		return NULL;
 	if (!rtnl_rtdsfield_tab[id]) {
 		if (!rtnl_rtdsfield_init)
 			rtnl_rtdsfield_initialize();
 	}
-	if (!numeric && rtnl_rtdsfield_tab[id])
-		return rtnl_rtdsfield_tab[id];
-	snprintf(buf, len, "0x%02x", id);
-	return buf;
+	return rtnl_rtdsfield_tab[id];
 }
 
 
-- 
2.25.1

[PATCH iproute2-next 4/9] lib: Generalize parse_mapping()

[Petr Machata]

The function parse_mapping() assumes the key is a number, with a single
configurable exception, which is using "all" to mean "all possible keys".
If a caller wishes to use symbolic names instead of numbers, they cannot
reuse this function.

To facilitate reuse in these situations, convert parse_mapping() into a
helper, parse_mapping_gen(), which instead of an allow-all boolean takes a
generic key-parsing callback. Rewrite parse_mapping() in terms of this
newly-added helper and add a pair of key parsers, one for just numbers,
another for numbers and the keyword "all". Publish the latter as well.

Signed-off-by: Petr Machata <me@pmachata.org>
---
 include/utils.h |  5 +++++
 lib/utils.c     | 37 +++++++++++++++++++++++++++++++------
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/include/utils.h b/include/utils.h
index 1704392525a2..f1403f7306a0 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -331,6 +331,11 @@ int parse_one_of(const char *msg, const char *realval, const char * const *list,
 		 size_t len, int *p_err);
 bool parse_on_off(const char *msg, const char *realval, int *p_err);
 
+int parse_mapping_num_all(__u32 *keyp, const char *key);
+int parse_mapping_gen(int *argcp, char ***argvp,
+		      int (*key_cb)(__u32 *keyp, const char *key),
+		      int (*mapping_cb)(__u32 key, char *value, void *data),
+		      void *mapping_cb_data);
 int parse_mapping(int *argcp, char ***argvp, bool allow_all,
 		  int (*mapping_cb)(__u32 key, char *value, void *data),
 		  void *mapping_cb_data);
diff --git a/lib/utils.c b/lib/utils.c
index de875639c608..90e58fa309d5 100644
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -1878,9 +1878,10 @@ bool parse_on_off(const char *msg, const char *realval, int *p_err)
 	return parse_one_of(msg, realval, values_on_off, ARRAY_SIZE(values_on_off), p_err);
 }
 
-int parse_mapping(int *argcp, char ***argvp, bool allow_all,
-		  int (*mapping_cb)(__u32 key, char *value, void *data),
-		  void *mapping_cb_data)
+int parse_mapping_gen(int *argcp, char ***argvp,
+		      int (*key_cb)(__u32 *keyp, const char *key),
+		      int (*mapping_cb)(__u32 key, char *value, void *data),
+		      void *mapping_cb_data)
 {
 	int argc = *argcp;
 	char **argv = *argvp;
@@ -1894,9 +1895,7 @@ int parse_mapping(int *argcp, char ***argvp, bool allow_all,
 			break;
 		*colon = '\0';
 
-		if (allow_all && matches(*argv, "all") == 0) {
-			key = (__u32) -1;
-		} else if (get_u32(&key, *argv, 0)) {
+		if (key_cb(&key, *argv)) {
 			ret = 1;
 			break;
 		}
@@ -1912,3 +1911,29 @@ int parse_mapping(int *argcp, char ***argvp, bool allow_all,
 	*argvp = argv;
 	return ret;
 }
+
+static int parse_mapping_num(__u32 *keyp, const char *key)
+{
+	return get_u32(keyp, key, 0);
+}
+
+int parse_mapping_num_all(__u32 *keyp, const char *key)
+{
+	if (matches(key, "all") == 0) {
+		*keyp = (__u32) -1;
+		return 0;
+	}
+	return parse_mapping_num(keyp, key);
+}
+
+int parse_mapping(int *argcp, char ***argvp, bool allow_all,
+		  int (*mapping_cb)(__u32 key, char *value, void *data),
+		  void *mapping_cb_data)
+{
+	if (allow_all)
+		return parse_mapping_gen(argcp, argvp, parse_mapping_num_all,
+					 mapping_cb, mapping_cb_data);
+	else
+		return parse_mapping_gen(argcp, argvp, parse_mapping_num,
+					 mapping_cb, mapping_cb_data);
+}
-- 
2.25.1

[PATCH iproute2-next 5/9] dcb: Generalize dcb_set_attribute()

[Petr Machata]

The function dcb_set_attribute() takes a fully-formed payload as an
argument. For callers that need to build a nested attribute, such as is the
case for DCB APP table, this is not great, because with libmnl, they would
need to construct a separate netlink message just to pluck out the payload
and hand it over to this function.

Currently, dcb_set_attribute() also always wraps the payload in an
DCB_ATTR_IEEE container, because that is what all the dcb subtools so far
needed. But that is not appropriate for DCBX in particular, and in fact a
handful other attributes, as well as any CEE payloads.

Instead, generalize this code by adding parameters for constructing a
custom payload and for fetching the response from a custom response
attribute. Then add dcb_set_attribute_va(), which takes a callback to
invoke in the right place for the nest to be built, and
dcb_set_attribute_bare(), which is similar to dcb_set_attribute(), but does
not encapsulate the payload in an IEEE container. Rewrite
dcb_set_attribute() compatibly in terms of the new functions.

Signed-off-by: Petr Machata <me@pmachata.org>
---
 dcb/dcb.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
 dcb/dcb.h |  7 ++++
 2 files changed, 98 insertions(+), 8 deletions(-)

diff --git a/dcb/dcb.c b/dcb/dcb.c
index 0e3c87484f2a..547c226280c1 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -94,12 +94,17 @@ static int dcb_get_attribute_cb(const struct nlmsghdr *nlh, void *data)
 	return mnl_attr_parse(nlh, sizeof(struct dcbmsg), dcb_get_attribute_attr_cb, data);
 }
 
+struct dcb_set_attribute_response {
+	int response_attr;
+};
+
 static int dcb_set_attribute_attr_cb(const struct nlattr *attr, void *data)
 {
+	struct dcb_set_attribute_response *resp = data;
 	uint16_t len;
 	uint8_t err;
 
-	if (mnl_attr_get_type(attr) != DCB_ATTR_IEEE)
+	if (mnl_attr_get_type(attr) != resp->response_attr)
 		return MNL_CB_OK;
 
 	len = mnl_attr_get_payload_len(attr);
@@ -172,19 +177,23 @@ int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr, void *data, si
 	return 0;
 }
 
-int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr, const void *data, size_t data_len)
+static int __dcb_set_attribute(struct dcb *dcb, int command, const char *dev,
+			       int (*cb)(struct dcb *, struct nlmsghdr *, void *),
+			       void *data, int response_attr)
 {
+	struct dcb_set_attribute_response resp = {
+		.response_attr = response_attr,
+	};
 	struct nlmsghdr *nlh;
-	struct nlattr *nest;
 	int ret;
 
-	nlh = dcb_prepare(dcb, dev, RTM_SETDCB, DCB_CMD_IEEE_SET);
+	nlh = dcb_prepare(dcb, dev, RTM_SETDCB, command);
 
-	nest = mnl_attr_nest_start(nlh, DCB_ATTR_IEEE);
-	mnl_attr_put(nlh, attr, data_len, data);
-	mnl_attr_nest_end(nlh, nest);
+	ret = cb(dcb, nlh, data);
+	if (ret)
+		return ret;
 
-	ret = dcb_talk(dcb, nlh, dcb_set_attribute_cb, NULL);
+	ret = dcb_talk(dcb, nlh, dcb_set_attribute_cb, &resp);
 	if (ret) {
 		perror("Attribute write");
 		return ret;
@@ -192,6 +201,80 @@ int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr, const void *da
 	return 0;
 }
 
+struct dcb_set_attribute_ieee_cb {
+	int (*cb)(struct dcb *dcb, struct nlmsghdr *nlh, void *data);
+	void *data;
+};
+
+static int dcb_set_attribute_ieee_cb(struct dcb *dcb, struct nlmsghdr *nlh, void *data)
+{
+	struct dcb_set_attribute_ieee_cb *ieee_data = data;
+	struct nlattr *nest;
+	int ret;
+
+	nest = mnl_attr_nest_start(nlh, DCB_ATTR_IEEE);
+	ret = ieee_data->cb(dcb, nlh, ieee_data->data);
+	if (ret)
+		return ret;
+	mnl_attr_nest_end(nlh, nest);
+
+	return 0;
+}
+
+int dcb_set_attribute_va(struct dcb *dcb, int command, const char *dev,
+			 int (*cb)(struct dcb *dcb, struct nlmsghdr *nlh, void *data),
+			 void *data)
+{
+	struct dcb_set_attribute_ieee_cb ieee_data = {
+		.cb = cb,
+		.data = data,
+	};
+
+	return __dcb_set_attribute(dcb, command, dev,
+				   &dcb_set_attribute_ieee_cb, &ieee_data,
+				   DCB_ATTR_IEEE);
+}
+
+struct dcb_set_attribute {
+	int attr;
+	const void *data;
+	size_t data_len;
+};
+
+static int dcb_set_attribute_put(struct dcb *dcb, struct nlmsghdr *nlh, void *data)
+{
+	struct dcb_set_attribute *dsa = data;
+
+	mnl_attr_put(nlh, dsa->attr, dsa->data_len, dsa->data);
+	return 0;
+}
+
+int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr, const void *data, size_t data_len)
+{
+	struct dcb_set_attribute dsa = {
+		.attr = attr,
+		.data = data,
+		.data_len = data_len,
+	};
+
+	return dcb_set_attribute_va(dcb, DCB_CMD_IEEE_SET, dev,
+				    &dcb_set_attribute_put, &dsa);
+}
+
+int dcb_set_attribute_bare(struct dcb *dcb, int command, const char *dev,
+			   int attr, const void *data, size_t data_len,
+			   int response_attr)
+{
+	struct dcb_set_attribute dsa = {
+		.attr = attr,
+		.data = data,
+		.data_len = data_len,
+	};
+
+	return __dcb_set_attribute(dcb, command, dev,
+				   &dcb_set_attribute_put, &dsa, response_attr);
+}
+
 void dcb_print_array_u8(const __u8 *array, size_t size)
 {
 	SPRINT_BUF(b);
diff --git a/dcb/dcb.h b/dcb/dcb.h
index 388a4204b95c..da14937c8925 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -2,6 +2,7 @@
 #ifndef __DCB_H__
 #define __DCB_H__ 1
 
+#include <libmnl/libmnl.h>
 #include <stdbool.h>
 #include <stddef.h>
 
@@ -32,6 +33,12 @@ int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr,
 		      void *data, size_t data_len);
 int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr,
 		      const void *data, size_t data_len);
+int dcb_set_attribute_va(struct dcb *dcb, int command, const char *dev,
+			 int (*cb)(struct dcb *dcb, struct nlmsghdr *nlh, void *data),
+			 void *data);
+int dcb_set_attribute_bare(struct dcb *dcb, int command, const char *dev,
+			   int attr, const void *data, size_t data_len,
+			   int response_attr);
 
 void dcb_print_named_array(const char *json_name, const char *fp_name,
 			   const __u8 *array, size_t size,
-- 
2.25.1

[PATCH iproute2-next 6/9] dcb: Generalize dcb_get_attribute()

[Petr Machata]

The function dcb_get_attribute() assumes that the caller knows the exact
size of the looked-for payload. It also assumes that the response comes
wrapped in an DCB_ATTR_IEEE nest. The former assumption does not hold for
the IEEE APP table, which has variable size. The latter one does not hold
for DCBX, which is not IEEE-nested, and also for any CEE attributes, which
would come CEE-nested.

Factor out the payload extractor from the current dcb_get_attribute() code,
and put into a helper. Then rewrite dcb_get_attribute() compatibly in terms
of the new function. Introduce dcb_get_attribute_va() as a thin wrapper for
IEEE-nested access, and dcb_get_attribute_bare() for access to attributes
that are not nested.

Rewrite dcb_get_attribute() in terms of the new dcb_get_attribute_va().

Signed-off-by: Petr Machata <me@pmachata.org>
---
 dcb/dcb.c | 79 ++++++++++++++++++++++++++++++++++++++++++++-----------
 dcb/dcb.h |  4 +++
 2 files changed, 68 insertions(+), 15 deletions(-)

diff --git a/dcb/dcb.c b/dcb/dcb.c
index 547c226280c1..a59b63ac9159 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -59,25 +59,19 @@ static void dcb_free(struct dcb *dcb)
 struct dcb_get_attribute {
 	struct dcb *dcb;
 	int attr;
-	void *data;
-	size_t data_len;
+	void *payload;
+	__u16 payload_len;
 };
 
 static int dcb_get_attribute_attr_ieee_cb(const struct nlattr *attr, void *data)
 {
 	struct dcb_get_attribute *ga = data;
-	uint16_t len;
 
 	if (mnl_attr_get_type(attr) != ga->attr)
 		return MNL_CB_OK;
 
-	len = mnl_attr_get_payload_len(attr);
-	if (len != ga->data_len) {
-		fprintf(stderr, "Wrong len %d, expected %zd\n", len, ga->data_len);
-		return MNL_CB_ERROR;
-	}
-
-	memcpy(ga->data, mnl_attr_get_payload(attr), ga->data_len);
+	ga->payload = mnl_attr_get_payload(attr);
+	ga->payload_len = mnl_attr_get_payload_len(attr);
 	return MNL_CB_STOP;
 }
 
@@ -94,6 +88,16 @@ static int dcb_get_attribute_cb(const struct nlmsghdr *nlh, void *data)
 	return mnl_attr_parse(nlh, sizeof(struct dcbmsg), dcb_get_attribute_attr_cb, data);
 }
 
+static int dcb_get_attribute_bare_cb(const struct nlmsghdr *nlh, void *data)
+{
+	/* Bare attributes (e.g. DCB_ATTR_DCBX) are not wrapped inside an IEEE
+	 * container, so this does not have to go through unpacking in
+	 * dcb_get_attribute_attr_cb().
+	 */
+	return mnl_attr_parse(nlh, sizeof(struct dcbmsg),
+			      dcb_get_attribute_attr_ieee_cb, data);
+}
+
 struct dcb_set_attribute_response {
 	int response_attr;
 };
@@ -155,25 +159,70 @@ static struct nlmsghdr *dcb_prepare(struct dcb *dcb, const char *dev,
 	return nlh;
 }
 
-int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr, void *data, size_t data_len)
+static int __dcb_get_attribute(struct dcb *dcb, int command,
+			       const char *dev, int attr,
+			       void **payload_p, __u16 *payload_len_p,
+			       int (*get_attribute_cb)(const struct nlmsghdr *nlh,
+						       void *data))
 {
 	struct dcb_get_attribute ga;
 	struct nlmsghdr *nlh;
 	int ret;
 
-	nlh = dcb_prepare(dcb, dev, RTM_GETDCB, DCB_CMD_IEEE_GET);
+	nlh = dcb_prepare(dcb, dev, RTM_GETDCB, command);
 
 	ga = (struct dcb_get_attribute) {
 		.dcb = dcb,
 		.attr = attr,
-		.data = data,
-		.data_len = data_len,
+		.payload = NULL,
 	};
-	ret = dcb_talk(dcb, nlh, dcb_get_attribute_cb, &ga);
+	ret = dcb_talk(dcb, nlh, get_attribute_cb, &ga);
 	if (ret) {
 		perror("Attribute read");
 		return ret;
 	}
+	if (ga.payload == NULL) {
+		perror("Attribute not found");
+		return -ENOENT;
+	}
+
+	*payload_p = ga.payload;
+	*payload_len_p = ga.payload_len;
+	return 0;
+}
+
+int dcb_get_attribute_va(struct dcb *dcb, const char *dev, int attr,
+			 void **payload_p, __u16 *payload_len_p)
+{
+	return __dcb_get_attribute(dcb, DCB_CMD_IEEE_GET, dev, attr,
+				   payload_p, payload_len_p,
+				   dcb_get_attribute_cb);
+}
+
+int dcb_get_attribute_bare(struct dcb *dcb, int cmd, const char *dev, int attr,
+			   void **payload_p, __u16 *payload_len_p)
+{
+	return __dcb_get_attribute(dcb, cmd, dev, attr,
+				   payload_p, payload_len_p,
+				   dcb_get_attribute_bare_cb);
+}
+
+int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr, void *data, size_t data_len)
+{
+	__u16 payload_len;
+	void *payload;
+	int ret;
+
+	ret = dcb_get_attribute_va(dcb, dev, attr, &payload, &payload_len);
+	if (ret)
+		return ret;
+
+	if (payload_len != data_len) {
+		fprintf(stderr, "Wrong len %d, expected %zd\n", payload_len, data_len);
+		return -EINVAL;
+	}
+
+	memcpy(data, payload, data_len);
 	return 0;
 }
 
diff --git a/dcb/dcb.h b/dcb/dcb.h
index da14937c8925..8c7327a43588 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -33,9 +33,13 @@ int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr,
 		      void *data, size_t data_len);
 int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr,
 		      const void *data, size_t data_len);
+int dcb_get_attribute_va(struct dcb *dcb, const char *dev, int attr,
+			 void **payload_p, __u16 *payload_len_p);
 int dcb_set_attribute_va(struct dcb *dcb, int command, const char *dev,
 			 int (*cb)(struct dcb *dcb, struct nlmsghdr *nlh, void *data),
 			 void *data);
+int dcb_get_attribute_bare(struct dcb *dcb, int cmd, const char *dev, int attr,
+			   void **payload_p, __u16 *payload_len_p);
 int dcb_set_attribute_bare(struct dcb *dcb, int command, const char *dev,
 			   int attr, const void *data, size_t data_len,
 			   int response_attr);
-- 
2.25.1

[PATCH iproute2-next 7/9] dcb: Support -n to suppress translation to nice names

[Petr Machata]

Some DSCP values can be translated to symbolic names. That may not be
always desirable. Introduce a command-line option similar to other
tools, -n or --no-nice-names, to suppress this translation.

Signed-off-by: Petr Machata <me@pmachata.org>
---
 dcb/dcb.c      | 9 +++++++--
 dcb/dcb.h      | 1 +
 man/man8/dcb.8 | 5 +++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/dcb/dcb.c b/dcb/dcb.c
index a59b63ac9159..e6cda7337924 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -467,7 +467,8 @@ static void dcb_help(void)
 		"       dcb [ -f | --force ] { -b | --batch } filename [ -N | --Netns ] netnsname\n"
 		"where  OBJECT := { buffer | ets | maxrate | pfc }\n"
 		"       OPTIONS := [ -V | --Version | -i | --iec | -j | --json\n"
-		"                  | -p | --pretty | -s | --statistics | -v | --verbose]\n");
+		"                  | -n | --no-nice-names | -p | --pretty\n"
+		"                  | -s | --statistics | -v | --verbose]\n");
 }
 
 static int dcb_cmd(struct dcb *dcb, int argc, char **argv)
@@ -509,6 +510,7 @@ int main(int argc, char **argv)
 		{ "batch",		required_argument,	NULL, 'b' },
 		{ "iec",		no_argument,		NULL, 'i' },
 		{ "json",		no_argument,		NULL, 'j' },
+		{ "no-nice-names",	no_argument,		NULL, 'n' },
 		{ "pretty",		no_argument,		NULL, 'p' },
 		{ "statistics",		no_argument,		NULL, 's' },
 		{ "Netns",		required_argument,	NULL, 'N' },
@@ -528,7 +530,7 @@ int main(int argc, char **argv)
 		return EXIT_FAILURE;
 	}
 
-	while ((opt = getopt_long(argc, argv, "b:fhijpsvN:V",
+	while ((opt = getopt_long(argc, argv, "b:fhijnpsvN:V",
 				  long_options, NULL)) >= 0) {
 
 		switch (opt) {
@@ -545,6 +547,9 @@ int main(int argc, char **argv)
 		case 'j':
 			dcb->json_output = true;
 			break;
+		case 'n':
+			dcb->no_nice_names = true;
+			break;
 		case 'p':
 			pretty = true;
 			break;
diff --git a/dcb/dcb.h b/dcb/dcb.h
index 8c7327a43588..f1d089257867 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -14,6 +14,7 @@ struct dcb {
 	bool json_output;
 	bool stats;
 	bool use_iec;
+	bool no_nice_names;
 };
 
 int dcb_parse_mapping(const char *what_key, __u32 key, __u32 max_key,
diff --git a/man/man8/dcb.8 b/man/man8/dcb.8
index 5964f25d386d..46c7a31410b7 100644
--- a/man/man8/dcb.8
+++ b/man/man8/dcb.8
@@ -52,6 +52,11 @@ the 1000-based ones (K, M, B).
 .BR "\-j" , " --json"
 Generate JSON output.
 
+.TP
+.BR "\-n" , " --no-nice-names"
+If the subtool in question translates numbers to symbolic names in some way,
+suppress this translation.
+
 .TP
 .BR "\-p" , " --pretty"
 When combined with -j generate a pretty JSON output.
-- 
2.25.1

[PATCH iproute2-next 8/9] dcb: Add a subtool for the DCB APP object

[Petr Machata]

DCB APP interfaces are standardized in 802.1q-2018, and allow configuration
of traffic prioritization rules based on several possible headers.

Add a dcb subtool for maintenance and display of the APP table. For
example:

    # dcb app add dev eni1np1 dscp-prio 0:0 CS3:3 CS6:6
    # dcb app show dev eni1np1
    dscp-prio 0:0 CS3:3 CS6:6
    # dcb app add dev eni1np1 dscp-prio CS3:4
    # dcb app show dev eni1np1
    dscp-prio 0:0 CS3:3 CS3:4 CS6:6
    # dcb app replace dev eni1np1 dscp-prio CS3:5
    # dcb app show dev eni1np1
    dscp-prio 0:0 CS3:5 CS6:6

Signed-off-by: Petr Machata <me@pmachata.org>
---
 dcb/Makefile       |   7 +-
 dcb/dcb.c          |   4 +-
 dcb/dcb.h          |   4 +
 dcb/dcb_app.c      | 796 +++++++++++++++++++++++++++++++++++++++++++++
 man/man8/dcb-app.8 | 237 ++++++++++++++
 man/man8/dcb.8     |   7 +-
 6 files changed, 1052 insertions(+), 3 deletions(-)
 create mode 100644 dcb/dcb_app.c
 create mode 100644 man/man8/dcb-app.8

diff --git a/dcb/Makefile b/dcb/Makefile
index 4add954b4bba..13d45f2b96b1 100644
--- a/dcb/Makefile
+++ b/dcb/Makefile
@@ -5,7 +5,12 @@ TARGETS :=
 
 ifeq ($(HAVE_MNL),y)
 
-DCBOBJ = dcb.o dcb_buffer.o dcb_ets.o dcb_maxrate.o dcb_pfc.o
+DCBOBJ = dcb.o \
+         dcb_app.o \
+         dcb_buffer.o \
+         dcb_ets.o \
+         dcb_maxrate.o \
+         dcb_pfc.o
 TARGETS += dcb
 
 endif
diff --git a/dcb/dcb.c b/dcb/dcb.c
index e6cda7337924..85e40a7e0d0b 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -465,7 +465,7 @@ 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 := { buffer | ets | maxrate | pfc }\n"
+		"where  OBJECT := { app | buffer | ets | maxrate | pfc }\n"
 		"       OPTIONS := [ -V | --Version | -i | --iec | -j | --json\n"
 		"                  | -n | --no-nice-names | -p | --pretty\n"
 		"                  | -s | --statistics | -v | --verbose]\n");
@@ -476,6 +476,8 @@ static int dcb_cmd(struct dcb *dcb, int argc, char **argv)
 	if (!argc || matches(*argv, "help") == 0) {
 		dcb_help();
 		return 0;
+	} else if (matches(*argv, "app") == 0) {
+		return dcb_cmd_app(dcb, argc - 1, argv + 1);
 	} else if (matches(*argv, "buffer") == 0) {
 		return dcb_cmd_buffer(dcb, argc - 1, argv + 1);
 	} else if (matches(*argv, "ets") == 0) {
diff --git a/dcb/dcb.h b/dcb/dcb.h
index f1d089257867..c4993d689656 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);
 
+/* dcb_app.c */
+
+int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
+
 /* dcb_buffer.c */
 
 int dcb_cmd_buffer(struct dcb *dcb, int argc, char **argv);
diff --git a/dcb/dcb_app.c b/dcb/dcb_app.c
new file mode 100644
index 000000000000..791abaa62cec
--- /dev/null
+++ b/dcb/dcb_app.c
@@ -0,0 +1,796 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <libmnl/libmnl.h>
+#include <linux/dcbnl.h>
+
+#include "dcb.h"
+#include "utils.h"
+#include "rt_names.h"
+
+static void dcb_app_help_add(void)
+{
+	fprintf(stderr,
+		"Usage: dcb app { add | del | replace } dev STRING\n"
+		"           [ default-prio PRIO ]\n"
+		"           [ ethtype-prio ET:PRIO ]\n"
+		"           [ stream-port-prio PORT:PRIO ]\n"
+		"           [ dgram-port-prio PORT:PRIO ]\n"
+		"           [ port-prio PORT:PRIO ]\n"
+		"           [ dscp-prio INTEGER:PRIO ]\n"
+		"\n"
+		" where PRIO := { 0 .. 7 }\n"
+		"       ET := { 0x600 .. 0xffff }\n"
+		"       PORT := { 1 .. 65535 }\n"
+		"       DSCP := { 0 .. 63 }\n"
+		"\n"
+	);
+}
+
+static void dcb_app_help_show_flush(void)
+{
+	fprintf(stderr,
+		"Usage: dcb app { show | flush } dev STRING\n"
+		"           [ default-prio ]\n"
+		"           [ ethtype-prio ]\n"
+		"           [ stream-port-prio ]\n"
+		"           [ dgram-port-prio ]\n"
+		"           [ port-prio ]\n"
+		"           [ dscp-prio ]\n"
+		"\n"
+	);
+}
+
+static void dcb_app_help(void)
+{
+	fprintf(stderr,
+		"Usage: dcb app help\n"
+		"\n"
+	);
+	dcb_app_help_show_flush();
+	dcb_app_help_add();
+}
+
+struct dcb_app_table {
+	struct dcb_app *apps;
+	size_t n_apps;
+};
+
+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)
+{
+	struct dcb_app *apps = reallocarray(tab->apps, tab->n_apps + 1,
+					    sizeof(*tab->apps));
+
+	if (apps == NULL) {
+		perror("Cannot allocate APP table");
+		return -ENOMEM;
+	}
+
+	tab->apps = apps;
+	tab->apps[tab->n_apps++] = *app;
+	return 0;
+}
+
+static void dcb_app_table_remove_existing(struct dcb_app_table *a,
+					  const struct dcb_app_table *b)
+{
+	size_t ia, ja;
+	size_t ib;
+
+	for (ia = 0, ja = 0; ia < a->n_apps; ia++) {
+		struct dcb_app *aa = &a->apps[ia];
+		bool found = false;
+
+		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 &&
+			    aa->priority == ab->priority) {
+				found = true;
+				break;
+			}
+		}
+
+		if (!found)
+			a->apps[ja++] = *aa;
+	}
+
+	a->n_apps = ja;
+}
+
+static void dcb_app_table_remove_replaced(struct dcb_app_table *a,
+					  const struct dcb_app_table *b)
+{
+	size_t ia, ja;
+	size_t ib;
+
+	for (ia = 0, ja = 0; ia < a->n_apps; ia++) {
+		struct dcb_app *aa = &a->apps[ia];
+		bool present = false;
+		bool found = false;
+
+		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)
+				present = true;
+			else
+				continue;
+
+			if (aa->priority == ab->priority) {
+				found = true;
+				break;
+			}
+		}
+
+		/* Entries that remain in A will be removed, so keep in the
+		 * table only APP entries whose sel/pid is mentioned in B,
+		 * but that do not have the full sel/pid/prio match.
+		 */
+		if (present && !found)
+			a->apps[ja++] = *aa;
+	}
+
+	a->n_apps = ja;
+}
+
+static int dcb_app_table_copy(struct dcb_app_table *a,
+			      const struct dcb_app_table *b)
+{
+	size_t i;
+	int ret;
+
+	for (i = 0; i < b->n_apps; i++) {
+		ret = dcb_app_table_push(a, &b->apps[i]);
+		if (ret != 0)
+			return ret;
+	}
+	return 0;
+}
+
+static int dcb_app_cmp(const struct dcb_app *a, const struct dcb_app *b)
+{
+	if (a->protocol < b->protocol)
+		return -1;
+	if (a->protocol > b->protocol)
+		return 1;
+	return a->priority - b->priority;
+}
+
+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)
+{
+	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)
+{
+	struct dcb_app_parse_mapping *pm = data;
+	struct dcb_app app = {
+		.selector = pm->selector,
+		.priority = value,
+		.protocol = key,
+	};
+
+	if (pm->err)
+		return;
+
+	pm->err = dcb_app_table_push(pm->tab, &app);
+}
+
+static int dcb_app_parse_mapping_ethtype_prio(__u32 key, char *value, void *data)
+{
+	__u8 prio;
+
+	if (key < 0x600) {
+		fprintf(stderr, "Protocol IDs < 0x600 are reserved for EtherType\n");
+		return -EINVAL;
+	}
+
+	if (get_u8(&prio, value, 0))
+		return -EINVAL;
+
+	return dcb_parse_mapping("ETHTYPE", key, 0xffff,
+				 "PRIO", prio, IEEE_8021QAZ_MAX_TCS - 1,
+				 dcb_app_parse_mapping_cb, data);
+}
+
+static int dcb_app_parse_dscp(__u32 *key, const char *arg)
+{
+	if (parse_mapping_num_all(key, arg) == 0)
+		return 0;
+
+	if (rtnl_dsfield_a2n(key, arg) != 0)
+		return -1;
+
+	if (*key & 0x03) {
+		fprintf(stderr, "The values `%s' uses non-DSCP bits.\n", arg);
+		return -1;
+	}
+
+	/* Unshift the value to convert it from dsfield to DSCP. */
+	*key >>= 2;
+	return 0;
+}
+
+static int dcb_app_parse_mapping_dscp_prio(__u32 key, char *value, void *data)
+{
+	__u8 prio;
+
+	if (get_u8(&prio, value, 0))
+		return -EINVAL;
+
+	return dcb_parse_mapping("DSCP", key, 63,
+				 "PRIO", prio, IEEE_8021QAZ_MAX_TCS - 1,
+				 dcb_app_parse_mapping_cb, data);
+}
+
+static int dcb_app_parse_mapping_port_prio(__u32 key, char *value, void *data)
+{
+	__u8 prio;
+
+	if (key == 0) {
+		fprintf(stderr, "Port ID of 0 is invalid\n");
+		return -EINVAL;
+	}
+
+	if (get_u8(&prio, value, 0))
+		return -EINVAL;
+
+	return dcb_parse_mapping("PORT", key, 0xffff,
+				 "PRIO", prio, IEEE_8021QAZ_MAX_TCS - 1,
+				 dcb_app_parse_mapping_cb, data);
+}
+
+static int dcb_app_parse_default_prio(int *argcp, char ***argvp, struct dcb_app_table *tab)
+{
+	int argc = *argcp;
+	char **argv = *argvp;
+	int ret = 0;
+
+	while (argc > 0) {
+		struct dcb_app app;
+		__u8 prio;
+
+		if (get_u8(&prio, *argv, 0)) {
+			ret = 1;
+			break;
+		}
+
+		app = (struct dcb_app){
+			.selector = IEEE_8021QAZ_APP_SEL_ETHERTYPE,
+			.protocol = 0,
+			.priority = prio,
+		};
+		ret = dcb_app_table_push(tab, &app);
+		if (ret != 0)
+			break;
+
+		argc--, argv++;
+	}
+
+	*argcp = argc;
+	*argvp = argv;
+	return ret;
+}
+
+static bool dcb_app_is_ethtype(const struct dcb_app *app)
+{
+	return app->selector == IEEE_8021QAZ_APP_SEL_ETHERTYPE &&
+	       app->protocol != 0;
+}
+
+static bool dcb_app_is_default(const struct dcb_app *app)
+{
+	return app->selector == IEEE_8021QAZ_APP_SEL_ETHERTYPE &&
+	       app->protocol == 0;
+}
+
+static bool dcb_app_is_dscp(const struct dcb_app *app)
+{
+	return app->selector == IEEE_8021QAZ_APP_SEL_DSCP;
+}
+
+static bool dcb_app_is_stream_port(const struct dcb_app *app)
+{
+	return app->selector == IEEE_8021QAZ_APP_SEL_STREAM;
+}
+
+static bool dcb_app_is_dgram_port(const struct dcb_app *app)
+{
+	return app->selector == IEEE_8021QAZ_APP_SEL_DGRAM;
+}
+
+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)
+{
+	return print_uint(PRINT_ANY, NULL, "%d:", protocol);
+}
+
+static int dcb_app_print_key_hex(__u16 protocol)
+{
+	return print_uint(PRINT_ANY, NULL, "%x:", protocol);
+}
+
+static int dcb_app_print_key_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);
+}
+
+static void dcb_app_print_filtered(const struct dcb_app_table *tab,
+				   bool (*filter)(const struct dcb_app *),
+				   int (*print_key)(__u16 protocol),
+				   const char *json_name,
+				   const char *fp_name)
+{
+	bool first = true;
+	size_t i;
+
+	for (i = 0; i < tab->n_apps; i++) {
+		struct dcb_app *app = &tab->apps[i];
+
+		if (!filter(app))
+			continue;
+		if (first) {
+			open_json_array(PRINT_JSON, json_name);
+			print_string(PRINT_FP, NULL, "%s ", fp_name);
+			first = false;
+		}
+
+		open_json_array(PRINT_JSON, NULL);
+		print_key(app->protocol);
+		print_uint(PRINT_ANY, NULL, "%d ", app->priority);
+		close_json_array(PRINT_JSON, NULL);
+	}
+
+	if (!first) {
+		close_json_array(PRINT_JSON, json_name);
+		print_nl();
+	}
+}
+
+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,
+			       "ethtype_prio", "ethtype-prio");
+}
+
+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->no_nice_names ? dcb_app_print_key_dec
+						  : dcb_app_print_key_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,
+			       "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,
+			       "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,
+			       "port_prio", "port-prio");
+}
+
+static void dcb_app_print_default_prio(const struct dcb_app_table *tab)
+{
+	bool first = true;
+	size_t i;
+
+	for (i = 0; i < tab->n_apps; i++) {
+		if (!dcb_app_is_default(&tab->apps[i]))
+			continue;
+		if (first) {
+			open_json_array(PRINT_JSON, "default_prio");
+			print_string(PRINT_FP, NULL, "default-prio ", NULL);
+			first = false;
+		}
+		print_uint(PRINT_ANY, NULL, "%d ", tab->apps[i].priority);
+	}
+
+	if (!first) {
+		close_json_array(PRINT_JSON, "default_prio");
+		print_nl();
+	}
+}
+
+static void dcb_app_print(const struct dcb *dcb, const struct dcb_app_table *tab)
+{
+	dcb_app_print_ethtype_prio(tab);
+	dcb_app_print_default_prio(tab);
+	dcb_app_print_dscp_prio(dcb, tab);
+	dcb_app_print_stream_port_prio(tab);
+	dcb_app_print_dgram_port_prio(tab);
+	dcb_app_print_port_prio(tab);
+}
+
+static int dcb_app_get_table_attr_cb(const struct nlattr *attr, void *data)
+{
+	struct dcb_app_table *tab = data;
+	struct dcb_app *app;
+	int ret;
+
+	if (mnl_attr_get_type(attr) != DCB_ATTR_IEEE_APP) {
+		fprintf(stderr, "Unknown attribute in DCB_ATTR_IEEE_APP_TABLE: %d\n",
+			mnl_attr_get_type(attr));
+		return MNL_CB_OK;
+	}
+	if (mnl_attr_get_payload_len(attr) < sizeof(struct dcb_app)) {
+		fprintf(stderr, "DCB_ATTR_IEEE_APP payload expected to have size %zd, not %d\n",
+			sizeof(struct dcb_app), mnl_attr_get_payload_len(attr));
+		return MNL_CB_OK;
+	}
+
+	app = mnl_attr_get_payload(attr);
+	ret = dcb_app_table_push(tab, app);
+	if (ret != 0)
+		return MNL_CB_ERROR;
+
+	return MNL_CB_OK;
+}
+
+static int dcb_app_get(struct dcb *dcb, const char *dev, struct dcb_app_table *tab)
+{
+	uint16_t payload_len;
+	void *payload;
+	int ret;
+
+	ret = dcb_get_attribute_va(dcb, dev, DCB_ATTR_IEEE_APP_TABLE, &payload, &payload_len);
+	if (ret != 0)
+		return ret;
+
+	ret = mnl_attr_parse_payload(payload, payload_len, dcb_app_get_table_attr_cb, tab);
+	if (ret != MNL_CB_OK)
+		return -EINVAL;
+
+	return 0;
+}
+
+struct dcb_app_add_del {
+	const struct dcb_app_table *tab;
+	bool (*filter)(const struct dcb_app *app);
+};
+
+static int dcb_app_add_del_cb(struct dcb *dcb, struct nlmsghdr *nlh, void *data)
+{
+	struct dcb_app_add_del *add_del = data;
+	struct nlattr *nest;
+	size_t i;
+
+	nest = mnl_attr_nest_start(nlh, DCB_ATTR_IEEE_APP_TABLE);
+
+	for (i = 0; i < add_del->tab->n_apps; i++) {
+		const struct dcb_app *app = &add_del->tab->apps[i];
+
+		if (add_del->filter == NULL || add_del->filter(app))
+			mnl_attr_put(nlh, DCB_ATTR_IEEE_APP, sizeof(*app), app);
+	}
+
+	mnl_attr_nest_end(nlh, nest);
+	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 *))
+{
+	struct dcb_app_add_del add_del = {
+		.tab = tab,
+		.filter = filter,
+	};
+
+	if (tab->n_apps == 0)
+		return 0;
+
+	return dcb_set_attribute_va(dcb, command, dev, dcb_app_add_del_cb, &add_del);
+}
+
+static int dcb_cmd_app_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,
+	};
+	int ret;
+
+	if (!argc) {
+		dcb_app_help_add();
+		return 0;
+	}
+
+	do {
+		if (matches(*argv, "help") == 0) {
+			dcb_app_help_add();
+			return 0;
+		} else if (matches(*argv, "ethtype-prio") == 0) {
+			NEXT_ARG();
+			pm.selector = IEEE_8021QAZ_APP_SEL_ETHERTYPE;
+			ret = parse_mapping(&argc, &argv, false,
+					    &dcb_app_parse_mapping_ethtype_prio,
+					    &pm);
+		} else if (matches(*argv, "default-prio") == 0) {
+			NEXT_ARG();
+			ret = dcb_app_parse_default_prio(&argc, &argv, pm.tab);
+			if (ret != 0) {
+				fprintf(stderr, "Invalid default priority %s\n", *argv);
+				return ret;
+			}
+		} else if (matches(*argv, "dscp-prio") == 0) {
+			NEXT_ARG();
+			pm.selector = IEEE_8021QAZ_APP_SEL_DSCP;
+			ret = parse_mapping_gen(&argc, &argv,
+						&dcb_app_parse_dscp,
+						&dcb_app_parse_mapping_dscp_prio,
+						&pm);
+		} else if (matches(*argv, "stream-port-prio") == 0) {
+			NEXT_ARG();
+			pm.selector = IEEE_8021QAZ_APP_SEL_STREAM;
+			ret = parse_mapping(&argc, &argv, false,
+					    &dcb_app_parse_mapping_port_prio,
+					    &pm);
+		} else if (matches(*argv, "dgram-port-prio") == 0) {
+			NEXT_ARG();
+			pm.selector = IEEE_8021QAZ_APP_SEL_DGRAM;
+			ret = parse_mapping(&argc, &argv, false,
+					    &dcb_app_parse_mapping_port_prio,
+					    &pm);
+		} else if (matches(*argv, "port-prio") == 0) {
+			NEXT_ARG();
+			pm.selector = IEEE_8021QAZ_APP_SEL_ANY;
+			ret = parse_mapping(&argc, &argv, false,
+					    &dcb_app_parse_mapping_port_prio,
+					    &pm);
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			dcb_app_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_app_add(struct dcb *dcb, const char *dev, int argc, char **argv)
+{
+	struct dcb_app_table tab = {};
+	int ret;
+
+	ret = dcb_cmd_app_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_app_del(struct dcb *dcb, const char *dev, int argc, char **argv)
+{
+	struct dcb_app_table tab = {};
+	int ret;
+
+	ret = dcb_cmd_app_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_app_show(struct dcb *dcb, const char *dev, int argc, char **argv)
+{
+	struct dcb_app_table tab = {};
+	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_app_print(dcb, &tab);
+		goto out;
+	}
+
+	do {
+		if (matches(*argv, "help") == 0) {
+			dcb_app_help_show_flush();
+			goto out;
+		} else if (matches(*argv, "ethtype-prio") == 0) {
+			dcb_app_print_ethtype_prio(&tab);
+		} else if (matches(*argv, "dscp-prio") == 0) {
+			dcb_app_print_dscp_prio(dcb, &tab);
+		} else if (matches(*argv, "stream-port-prio") == 0) {
+			dcb_app_print_stream_port_prio(&tab);
+		} else if (matches(*argv, "dgram-port-prio") == 0) {
+			dcb_app_print_dgram_port_prio(&tab);
+		} else if (matches(*argv, "port-prio") == 0) {
+			dcb_app_print_port_prio(&tab);
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			dcb_app_help_show_flush();
+			ret = -EINVAL;
+			goto out;
+		}
+
+		NEXT_ARG_FWD();
+	} while (argc > 0);
+
+out:
+	close_json_object();
+	dcb_app_table_fini(&tab);
+	return 0;
+}
+
+static int dcb_cmd_app_flush(struct dcb *dcb, const char *dev, int argc, char **argv)
+{
+	struct dcb_app_table tab = {};
+	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 (matches(*argv, "help") == 0) {
+			dcb_app_help_show_flush();
+			goto out;
+		} else if (matches(*argv, "ethtype-prio") == 0) {
+			ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &tab,
+					      &dcb_app_is_ethtype);
+			if (ret != 0)
+				goto out;
+		} else if (matches(*argv, "default-prio") == 0) {
+			ret = dcb_app_add_del(dcb, dev, DCB_CMD_IEEE_DEL, &tab,
+					      &dcb_app_is_default);
+			if (ret != 0)
+				goto out;
+		} else if (matches(*argv, "dscp-prio") == 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_app_help_show_flush();
+			ret = -EINVAL;
+			goto out;
+		}
+
+		NEXT_ARG_FWD();
+	} while (argc > 0);
+
+out:
+	dcb_app_table_fini(&tab);
+	return ret;
+}
+
+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 = {};
+	int ret;
+
+	ret = dcb_app_get(dcb, dev, &orig);
+	if (ret != 0)
+		return ret;
+
+	ret = dcb_cmd_app_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 APP entries\n");
+		goto out;
+	}
+
+	/* Remove the obsolete entries. */
+	dcb_app_table_remove_replaced(&orig, &tab);
+	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");
+		goto out;
+	}
+
+out:
+	dcb_app_table_fini(&new);
+	dcb_app_table_fini(&tab);
+	dcb_app_table_fini(&orig);
+	return 0;
+}
+
+int dcb_cmd_app(struct dcb *dcb, int argc, char **argv)
+{
+	if (!argc || matches(*argv, "help") == 0) {
+		dcb_app_help();
+		return 0;
+	} else if (matches(*argv, "show") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv,
+					 dcb_cmd_app_show, dcb_app_help_show_flush);
+	} else if (matches(*argv, "flush") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv,
+					 dcb_cmd_app_flush, dcb_app_help_show_flush);
+	} else if (matches(*argv, "add") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv,
+					 dcb_cmd_app_add, dcb_app_help_add);
+	} else if (matches(*argv, "del") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv,
+					 dcb_cmd_app_del, dcb_app_help_add);
+	} else if (matches(*argv, "replace") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv,
+					 dcb_cmd_app_replace, dcb_app_help_add);
+	} else {
+		fprintf(stderr, "What is \"%s\"?\n", *argv);
+		dcb_app_help();
+		return -EINVAL;
+	}
+}
diff --git a/man/man8/dcb-app.8 b/man/man8/dcb-app.8
new file mode 100644
index 000000000000..6a5f267489bc
--- /dev/null
+++ b/man/man8/dcb-app.8
@@ -0,0 +1,237 @@
+.TH DCB-ETS 8 "6 December 2020" "iproute2" "Linux"
+.SH NAME
+dcb-app \- show / manipulate application priority table of
+the DCB (Data Center Bridging) subsystem
+.SH SYNOPSIS
+.sp
+.ad l
+.in +8
+
+.ti -8
+.B dcb
+.RI "[ " OPTIONS " ] "
+.B app
+.RI "{ " COMMAND " | " help " }"
+.sp
+
+.ti -8
+.B dcb app " { " show " | " flush " } " dev
+.RI DEV
+.RB "[ " default-prio " ]"
+.RB "[ " ethtype-prio " ]"
+.RB "[ " stream-port-prio " ]"
+.RB "[ " dgram-port-prio " ]"
+.RB "[ " port-prio " ]"
+.RB "[ " dscp-prio " ]"
+
+.ti -8
+.B dcb ets " { " add " | " del " | " replace " } " dev
+.RI DEV
+.RB "[ " default-prio " " \fIPRIO-LIST\fB " ]"
+.RB "[ " ethtype-prio " " \fIET-MAP\fB " ]"
+.RB "[ " stream-port-prio " " \fIPORT-MAP\fB " ]"
+.RB "[ " dgram-port-prio " " \fIPORT-MAP\fB " ]"
+.RB "[ " port-prio " " \fIPORT-MAP\fB " ]"
+.RB "[ " dscp-prio " " \fIDSCP-MAP\fB " ]"
+
+.ti -8
+.IR PRIO-LIST " := [ " PRIO-LIST " ] " PRIO
+
+.ti -8
+.IR ET-MAP " := [ " ET-MAP " ] " ET-MAPPING
+
+.ti -8
+.IR ET-MAPPING " := " ET\fB:\fIPRIO\fR
+
+.ti -8
+.IR PORT-MAP " := [ " PORT-MAP " ] " PORT-MAPPING
+
+.ti -8
+.IR PORT-MAPPING " := " PORT\fB:\fIPRIO\fR
+
+.ti -8
+.IR DSCP-MAP " := [ " DSCP-MAP " ] " DSCP-MAPPING
+
+.ti -8
+.IR DSCP-MAPPING " := { " DSCP " | " \fBall " }" \fB:\fIPRIO\fR
+
+.ti -8
+.IR ET " := { " \fB0x600\fR " .. " \fB0xffff\fR " }"
+
+.ti -8
+.IR PORT " := { " \fB1\fR " .. " \fB65535\fR " }"
+
+.ti -8
+.IR DSCP " := { " \fB0\fR " .. " \fB63\fR " }"
+
+.ti -8
+.IR PRIO " := { " \fB0\fR " .. " \fB7\fR " }"
+
+.SH DESCRIPTION
+
+.B dcb app
+is used to configure APP table, or application priority table in the DCB (Data
+Center Bridging) subsystem. The APP table is used to assign priority to traffic
+based on value in one of several headers: EtherType, L4 destination port, or
+DSCP. It also allows configuration of port-default priority that is chosen if no
+other prioritization rule applies.
+
+DCB APP entries are 3-tuples of selector, protocol ID, and priority. Selector is
+an enumeration that picks one of the prioritization namespaces. Currently it
+mostly corresponds to configurable parameters described below. Protocol ID is a
+value in the selector namespace. E.g. for EtherType selector, protocol IDs are
+the individual EtherTypes, for DSCP they are individual code points. The
+priority is the priority that should be assigned to traffic that matches the
+selector and protocol ID.
+
+The APP table is a set of DCB APP entries. The only requirement is that
+duplicate entries are not added. Notably, it is valid to have conflicting
+priority assignment for the same selector and protocol ID. For example, the set
+of two APP entries (DSCP, 10, 1) and (DSCP, 10, 2), where packets with DSCP of
+10 should get priority of both 1 and 2, form a well-defined APP table. The
+.B dcb app
+tool allows low-level management of the app table by adding and deleting
+individual APP 3-tuples through
+.B add
+and
+.B del
+commands. On the other 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
+prioritization is in effect for a given selector and protocol ID.
+
+.SH COMMANDS
+
+.TP
+.B show
+Display all entries with a given selector. When no selector is given, shows all
+APP table entries categorized per selector.
+
+.TP
+.B flush
+Remove all entries with a given selector. When no selector is given, removes all
+APP table entries.
+
+.TP
+.B add
+.TQ
+.B del
+Add and, respectively, remove individual APP 3-tuples to and from the DCB APP
+table.
+
+.TP
+.B replace
+Take the list of entries mentioned as parameter, and add those that are not
+present in the APP table yet. Then remove those entries, whose selector and
+protocol ID have been mentioned as parameter, but not with the exact same
+priority. This has the effect of, for the given selector and protocol ID,
+causing that the table only contains the priority (or priorities) 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 default-prio \fIPRIO-LIST
+The priority to be used for traffic the priority of which is otherwise
+unspecified. The argument is a list of individual priorities. Note that
+.B default-prio
+rules are configured as triplets (\fBEtherType\fR, \fB0\fR, \fIPRIO\fR).
+.B dcb app
+translates these rules to the symbolic name
+.B default-prio
+and back.
+
+.TP
+.B ethtype-prio \fIET-MAP
+\fIET-MAP\fR uses the array parameter syntax, see
+.BR dcb (8)
+for details. Keys are EtherType values. Values are priorities to be assigned to
+traffic with the matching EtherType.
+
+.TP
+.B stream-port-prio \fIPORT-MAP
+.TQ
+.B dgram-port-prio \fIPORT-MAP
+.TQ
+.B port-prio \fIPORT-MAP
+\fIPORT-MAP\fR uses the array parameter syntax, see
+.BR dcb (8)
+for details. Keys are L4 destination port numbers that match on, respectively,
+TCP and SCTP traffic, UDP and DCCP traffic, and either of those. Values are
+priorities that should be assigned to matching traffic.
+
+.TP
+.B dscp-prio \fIDSCP-MAP
+\fIDSCP-MAP\fR uses the array parameter syntax, see
+.BR dcb (8)
+for details. Keys are DSCP points, values are priorities assigned to
+traffic with matching DSCP. DSCP points can be written either direcly 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
+.B dcb app
+will only use the higher six bits).
+.B dcb app show
+will similarly format DSCP values as symbolic names if possible. The
+command line option
+.B -n
+turns the show translation off.
+
+.SH EXAMPLE & USAGE
+
+Prioritize traffic with DSCP 0 to priority 0, 24 to 3 and 48 to 6:
+
+.P
+# dcb app add dev eth0 dscp-prio 0:0 24:3 48:6
+
+Add another rule to configure DSCP 24 to priority 2 and show the result:
+
+.P
+# dcb app add dev eth0 dscp-prio 24:2
+.br
+# dcb app show dev eth0 dscp-prio
+.br
+dscp-prio 0:0 CS3:2 CS3:3 CS6:6
+.br
+# dcb -n app show dev eth0 dscp-prio
+.br
+dscp-prio 0:0 24:2 24:3 48:6
+
+Reconfigure the table so that the only rule for DSCP 24 is for assignment of
+priority 4:
+
+.P
+# dcb app replace dev eth0 dscp-prio 24:4
+.br
+# dcb app show dev eth0 dscp-prio
+.br
+dscp-prio 0:0 24:4 48:6
+
+Flush all DSCP rules:
+
+.P
+# dcb app flush dev eth0 dscp-prio
+.br
+# dcb app show dev eth0 dscp-prio
+.br
+(nothing)
+
+.SH EXIT STATUS
+Exit status is 0 if command was successful or a positive integer upon failure.
+
+.SH SEE ALSO
+.BR dcb (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
+Petr Machata <me@pmachata.org>
diff --git a/man/man8/dcb.8 b/man/man8/dcb.8
index 46c7a31410b7..78be104e0b3b 100644
--- a/man/man8/dcb.8
+++ b/man/man8/dcb.8
@@ -9,7 +9,7 @@ dcb \- show / manipulate DCB (Data Center Bridging) settings
 .ti -8
 .B dcb
 .RI "[ " OPTIONS " ] "
-.RB "{ " buffer " | " ets " | " maxrate " | " pfc " }"
+.RB "{ " app " | " buffer " | " ets " | " maxrate " | " pfc " }"
 .RI "{ " COMMAND " | " help " }"
 .sp
 
@@ -68,6 +68,10 @@ part of the "show" output.
 
 .SH OBJECTS
 
+.TP
+.B app
+- Configuration of application priority table
+
 .TP
 .B buffer
 - Configuration of port buffers
@@ -128,6 +132,7 @@ other values:
 Exit status is 0 if command was successful or a positive integer upon failure.
 
 .SH SEE ALSO
+.BR dcb-app (8),
 .BR dcb-buffer (8),
 .BR dcb-ets (8),
 .BR dcb-maxrate (8),
-- 
2.25.1

[PATCH iproute2-next 9/9] dcb: Add a subtool for the DCBX object

[Petr Machata]

The Linux DCBX object is a 1-byte bitfield of flags that configure whether
the DCBX protocol is implemented in the device or in the host, and which
version of the protocol should be used. Add a tool to access the per-port
Linux DCBX object.

For example:

	# dcb dcbx set dev eni1np1 host ieee
	# dcb dcbx show dev eni1np1
	host ieee

Signed-off-by: Petr Machata <me@pmachata.org>
---
 dcb/Makefile        |   1 +
 dcb/dcb.c           |   4 +-
 dcb/dcb.h           |   4 +
 dcb/dcb_dcbx.c      | 192 ++++++++++++++++++++++++++++++++++++++++++++
 man/man8/dcb-dcbx.8 | 108 +++++++++++++++++++++++++
 5 files changed, 308 insertions(+), 1 deletion(-)
 create mode 100644 dcb/dcb_dcbx.c
 create mode 100644 man/man8/dcb-dcbx.8

diff --git a/dcb/Makefile b/dcb/Makefile
index 13d45f2b96b1..02d5d044cf09 100644
--- a/dcb/Makefile
+++ b/dcb/Makefile
@@ -8,6 +8,7 @@ ifeq ($(HAVE_MNL),y)
 DCBOBJ = dcb.o \
          dcb_app.o \
          dcb_buffer.o \
+         dcb_dcbx.o \
          dcb_ets.o \
          dcb_maxrate.o \
          dcb_pfc.o
diff --git a/dcb/dcb.c b/dcb/dcb.c
index 85e40a7e0d0b..264b553c4b26 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -465,7 +465,7 @@ 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 | buffer | ets | maxrate | pfc }\n"
+		"where  OBJECT := { app | buffer | dcbx | ets | maxrate | pfc }\n"
 		"       OPTIONS := [ -V | --Version | -i | --iec | -j | --json\n"
 		"                  | -n | --no-nice-names | -p | --pretty\n"
 		"                  | -s | --statistics | -v | --verbose]\n");
@@ -480,6 +480,8 @@ static int dcb_cmd(struct dcb *dcb, int argc, char **argv)
 		return dcb_cmd_app(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) {
+		return dcb_cmd_dcbx(dcb, argc - 1, argv + 1);
 	} else if (matches(*argv, "ets") == 0) {
 		return dcb_cmd_ets(dcb, argc - 1, argv + 1);
 	} else if (matches(*argv, "maxrate") == 0) {
diff --git a/dcb/dcb.h b/dcb/dcb.h
index c4993d689656..e5829682c32a 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -62,6 +62,10 @@ int dcb_cmd_app(struct dcb *dcb, int argc, char **argv);
 
 int dcb_cmd_buffer(struct dcb *dcb, int argc, char **argv);
 
+/* dcb_dcbx.c */
+
+int dcb_cmd_dcbx(struct dcb *dcb, int argc, char **argv);
+
 /* dcb_ets.c */
 
 int dcb_cmd_ets(struct dcb *dcb, int argc, char **argv);
diff --git a/dcb/dcb_dcbx.c b/dcb/dcb_dcbx.c
new file mode 100644
index 000000000000..244b671b893b
--- /dev/null
+++ b/dcb/dcb_dcbx.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <linux/dcbnl.h>
+
+#include "dcb.h"
+#include "utils.h"
+
+static void dcb_dcbx_help_set(void)
+{
+	fprintf(stderr,
+		"Usage: dcb dcbx set dev STRING\n"
+		"           [ host | lld-managed ]\n"
+		"           [ cee | ieee ] [ static ]\n"
+		"\n"
+	);
+}
+
+static void dcb_dcbx_help_show(void)
+{
+	fprintf(stderr,
+		"Usage: dcb dcbx show dev STRING\n"
+		"\n"
+	);
+}
+
+static void dcb_dcbx_help(void)
+{
+	fprintf(stderr,
+		"Usage: dcb dcbx help\n"
+		"\n"
+	);
+	dcb_dcbx_help_show();
+	dcb_dcbx_help_set();
+}
+
+struct dcb_dcbx_flag {
+	__u8 value;
+	const char *key_fp;
+	const char *key_json;
+};
+
+static struct dcb_dcbx_flag dcb_dcbx_flags[] = {
+	{DCB_CAP_DCBX_HOST, "host"},
+	{DCB_CAP_DCBX_LLD_MANAGED, "lld-managed", "lld_managed"},
+	{DCB_CAP_DCBX_VER_CEE, "cee"},
+	{DCB_CAP_DCBX_VER_IEEE, "ieee"},
+	{DCB_CAP_DCBX_STATIC, "static"},
+};
+
+static void dcb_dcbx_print(__u8 dcbx)
+{
+	int bit;
+	int i;
+
+	while ((bit = ffs(dcbx))) {
+		bool found = false;
+
+		bit--;
+		for (i = 0; i < ARRAY_SIZE(dcb_dcbx_flags); i++) {
+			struct dcb_dcbx_flag *flag = &dcb_dcbx_flags[i];
+
+			if (flag->value == 1 << bit) {
+				print_bool(PRINT_JSON, flag->key_json ?: flag->key_fp,
+					   NULL, true);
+				print_string(PRINT_FP, NULL, "%s ", flag->key_fp);
+				found = true;
+				break;
+			}
+		}
+
+		if (!found)
+			fprintf(stderr, "Unknown DCBX bit %#x.\n", 1 << bit);
+
+		dcbx &= ~(1 << bit);
+	}
+
+	print_nl();
+}
+
+static int dcb_dcbx_get(struct dcb *dcb, const char *dev, __u8 *dcbx)
+{
+	__u16 payload_len;
+	void *payload;
+	int err;
+
+	err = dcb_get_attribute_bare(dcb, DCB_CMD_IEEE_GET, dev, DCB_ATTR_DCBX,
+				     &payload, &payload_len);
+	if (err != 0)
+		return err;
+
+	if (payload_len != 1) {
+		fprintf(stderr, "DCB_ATTR_DCBX payload has size %d, expected 1.\n",
+			payload_len);
+		return -EINVAL;
+	}
+	*dcbx = *(__u8 *) payload;
+	return 0;
+}
+
+static int dcb_dcbx_set(struct dcb *dcb, const char *dev, __u8 dcbx)
+{
+	return dcb_set_attribute_bare(dcb, DCB_CMD_SDCBX, dev, DCB_ATTR_DCBX,
+				      &dcbx, 1, DCB_ATTR_DCBX);
+}
+
+static int dcb_cmd_dcbx_set(struct dcb *dcb, const char *dev, int argc, char **argv)
+{
+	__u8 dcbx = 0;
+	__u8 i;
+
+	if (!argc) {
+		dcb_dcbx_help_set();
+		return 0;
+	}
+
+	do {
+		if (matches(*argv, "help") == 0) {
+			dcb_dcbx_help_set();
+			return 0;
+		}
+
+		for (i = 0; i < ARRAY_SIZE(dcb_dcbx_flags); i++) {
+			struct dcb_dcbx_flag *flag = &dcb_dcbx_flags[i];
+
+			if (matches(*argv, flag->key_fp) == 0) {
+				dcbx |= flag->value;
+				NEXT_ARG_FWD();
+				goto next;
+			}
+		}
+
+		fprintf(stderr, "What is \"%s\"?\n", *argv);
+		dcb_dcbx_help_set();
+		return -EINVAL;
+
+next:
+		;
+	} while (argc > 0);
+
+	return dcb_dcbx_set(dcb, dev, dcbx);
+}
+
+static int dcb_cmd_dcbx_show(struct dcb *dcb, const char *dev, int argc, char **argv)
+{
+	__u8 dcbx;
+	int ret;
+
+	ret = dcb_dcbx_get(dcb, dev, &dcbx);
+	if (ret != 0)
+		return ret;
+
+	while (argc > 0) {
+		if (matches(*argv, "help") == 0) {
+			dcb_dcbx_help_show();
+			return 0;
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			dcb_dcbx_help_show();
+			return -EINVAL;
+		}
+
+		NEXT_ARG_FWD();
+	}
+
+	open_json_object(NULL);
+	dcb_dcbx_print(dcbx);
+	close_json_object();
+	return 0;
+}
+
+int dcb_cmd_dcbx(struct dcb *dcb, int argc, char **argv)
+{
+	if (!argc || matches(*argv, "help") == 0) {
+		dcb_dcbx_help();
+		return 0;
+	} else if (matches(*argv, "show") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv,
+					 dcb_cmd_dcbx_show, dcb_dcbx_help_show);
+	} else if (matches(*argv, "set") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv,
+					 dcb_cmd_dcbx_set, dcb_dcbx_help_set);
+	} else {
+		fprintf(stderr, "What is \"%s\"?\n", *argv);
+		dcb_dcbx_help();
+		return -EINVAL;
+	}
+}
diff --git a/man/man8/dcb-dcbx.8 b/man/man8/dcb-dcbx.8
new file mode 100644
index 000000000000..52133e348a70
--- /dev/null
+++ b/man/man8/dcb-dcbx.8
@@ -0,0 +1,108 @@
+.TH DCB-DCBX 8 "13 December 2020" "iproute2" "Linux"
+.SH NAME
+dcb-dcbx \- show / manipulate port DCBX (Data Center Bridging eXchange)
+.SH SYNOPSIS
+.sp
+.ad l
+.in +8
+
+.ti -8
+.B dcb
+.RI "[ " OPTIONS " ] "
+.B dcbx
+.RI "{ " COMMAND " | " help " }"
+.sp
+
+.ti -8
+.B dcb dcbx show dev
+.RI DEV
+
+.ti -8
+.B dcb dcbx set dev
+.RI DEV
+.RB "[ " host " ]"
+.RB "[ " lld-managed " ]"
+.RB "[ " cee " ]"
+.RB "[ " ieee " ]"
+.RB "[ " static " ]"
+
+.SH DESCRIPTION
+
+Data Center Bridging eXchange (DCBX) is a protocol used by DCB devices to
+exchange configuration information with directly connected peers. The Linux DCBX
+object is a 1-byte bitfield of flags that configure whether DCBX is implemented
+in the device or in the host, and which version of the protocol should be used.
+.B dcb dcbx
+is used to access the per-port Linux DCBX object.
+
+There are two principal modes of operation: in
+.B host
+mode, DCBX protocol is implemented by the host LLDP agent, and the DCB
+interfaces are used to propagate the negotiate parameters to capable devices. In
+.B lld-managed
+mode, the configuration is handled by the device, and DCB interfaces are used
+for inspection of negotiated parameters, and can also be used to set initial
+parameters.
+
+.SH PARAMETERS
+
+When used with
+.B dcb dcbx set,
+the following keywords enable the corresponding configuration. The keywords that
+are not mentioned on the command line are considered disabled. When used with
+.B show,
+each enabled feature is shown by its corresponding keyword.
+
+.TP
+.B host
+.TQ
+.B lld-managed
+The device is in the host mode of operation and, respectively, the lld-managed
+mode of operation, as described above. In principle these two keywords are
+mutually exclusive, but
+.B dcb dcbx
+allows setting both and lets the driver handle it as appropriate.
+
+.TP
+.B cee
+.TQ
+.B ieee
+The device supports CEE (Converged Enhanced Ethernet) and, respecively, IEEE
+version of the DCB specification. Typically only one of these will be set, but
+.B dcb dcbx
+does not mandate this.
+
+.TP
+.B static
+indicates the engine supports static configuration. No actual negotiation is
+performed, negotiated parameters are always the initial configuration.
+
+.SH EXAMPLE & USAGE
+
+Put the DCB engine into the "host" mode of operation, and use IEEE-standardized
+DCB interfaces:
+
+.P
+# dcb dcbx set dev eth0 host ieee
+
+Show what was set:
+
+.P
+# dcb dcbx show dev eth0
+.br
+host ieee
+
+.SH EXIT STATUS
+Exit status is 0 if command was successful or a positive integer upon failure.
+
+.SH SEE ALSO
+.BR dcb (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
+Petr Machata <me@pmachata.org>
-- 
2.25.1

Re: [PATCH iproute2-next 7/9] dcb: Support -n to suppress translation to nice names

[David Ahern]

On 12/23/20 11:25 AM, Petr Machata wrote:
> diff --git a/dcb/dcb.c b/dcb/dcb.c
> index a59b63ac9159..e6cda7337924 100644
> --- a/dcb/dcb.c
> +++ b/dcb/dcb.c
> @@ -467,7 +467,8 @@ static void dcb_help(void)
>  		"       dcb [ -f | --force ] { -b | --batch } filename [ -N | --Netns ] netnsname\n"
>  		"where  OBJECT := { buffer | ets | maxrate | pfc }\n"
>  		"       OPTIONS := [ -V | --Version | -i | --iec | -j | --json\n"
> -		"                  | -p | --pretty | -s | --statistics | -v | --verbose]\n");
> +		"                  | -n | --no-nice-names | -p | --pretty\n"


iproute2 commands really should have a consistent user interface.
Unfortunately -N and -n are inconsistent with the newer commands like
devlink. dcb has not been released yet so time to fix this.

devlink is the only one using the horribly named 'no-nice-names', and we
should avoid propagating that to dcb. At a minimum it should be
'numeric' which is consistent with the others.

My preference is also to have dcb follow ip and tc (vs ss) with '-n' to
mean -netns and -N' to mean numeric.

Re: [PATCH iproute2-next 7/9] dcb: Support -n to suppress translation to nice names

[Petr Machata]

David Ahern <dsahern@gmail.com> writes:

> On 12/23/20 11:25 AM, Petr Machata wrote:
>> diff --git a/dcb/dcb.c b/dcb/dcb.c
>> index a59b63ac9159..e6cda7337924 100644
>> --- a/dcb/dcb.c
>> +++ b/dcb/dcb.c
>> @@ -467,7 +467,8 @@ static void dcb_help(void)
>>  		"       dcb [ -f | --force ] { -b | --batch } filename [ -N | --Netns ] netnsname\n"
>>  		"where  OBJECT := { buffer | ets | maxrate | pfc }\n"
>>  		"       OPTIONS := [ -V | --Version | -i | --iec | -j | --json\n"
>> -		"                  | -p | --pretty | -s | --statistics | -v | --verbose]\n");
>> +		"                  | -n | --no-nice-names | -p | --pretty\n"
>
>
> iproute2 commands really should have a consistent user interface.
> Unfortunately -N and -n are inconsistent with the newer commands like
> devlink. dcb has not been released yet so time to fix this.
>
> devlink is the only one using the horribly named 'no-nice-names', and we
> should avoid propagating that to dcb. At a minimum it should be
> 'numeric' which is consistent with the others.
>
> My preference is also to have dcb follow ip and tc (vs ss) with '-n' to
> mean -netns and -N' to mean numeric.

Agreed on all counts.