dcb: Add a subtool for the DCB ETS object

ETS, for "Enhanced Transmission Selection", is a set of configurations that
permit configuration of mapping of priorities to traffic classes, traffic
selection algorithm to use per traffic class, bandwidth allocation, etc.

Add a dcb subtool to allow showing and tweaking of individual ETS
configuration options. For example:

    # dcb ets show dev eni1np1
    willing on ets_cap 8 cbs off
    tc-bw 0:0 1:0 2:0 3:0 4:100 5:0 6:0 7:0
    pg-bw 0:0 1:0 2:0 3:0 4:0 5:0 6:0 7:0
    tc-tsa 0:strict 1:strict 2:strict 3:strict 4:ets 5:strict 6:strict 7:strict
    prio-tc 0:1 1:3 2:5 3:0 4:0 5:0 6:0 7:0
    reco-tc-bw 0:0 1:0 2:0 3:0 4:0 5:0 6:0 7:0
    reco-tc-tsa 0:strict 1:strict 2:strict 3:strict 4:strict 5:strict 6:strict 7:strict
    reco-prio-tc 0:0 1:0 2:0 3:0 4:0 5:0 6:0 7:0

Signed-off-by: Petr Machata <me@pmachata.org>
Signed-off-by: David Ahern <dsahern@gmail.com>

4 files changed, 443 insertions, 2 deletions

diff --git a/dcb/Makefile b/dcb/Makefile
index 9966c8f0..89581716 100644
--- a/dcb/Makefile
+++ b/dcb/Makefile
@@ -5,7 +5,7 @@ TARGETS :=
 
 ifeq ($(HAVE_MNL),y)
 
-DCBOBJ = dcb.o
+DCBOBJ = dcb.o dcb_ets.o
 TARGETS += dcb
 
 endif
diff --git a/dcb/dcb.c b/dcb/dcb.c
index 1ec8c24e..dc1e9fe0 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -295,7 +295,7 @@ 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 :=\n"
+		"where  OBJECT := ets\n"
 		"       OPTIONS := [ -V | --Version | -j | --json | -p | --pretty | -v | --verbose ]\n");
 }
 
@@ -304,6 +304,8 @@ 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, "ets") == 0) {
+		return dcb_cmd_ets(dcb, argc - 1, argv + 1);
 	}
 
 	fprintf(stderr, "Object \"%s\" is unknown\n", *argv);
diff --git a/dcb/dcb.h b/dcb/dcb.h
index a09d102a..6f135ed0 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -36,4 +36,8 @@ void dcb_print_array_u8(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_ets.c */
+
+int dcb_cmd_ets(struct dcb *dcb, int argc, char **argv);
+
 #endif /* __DCB_H__ */
diff --git a/dcb/dcb_ets.c b/dcb/dcb_ets.c
new file mode 100644
index 00000000..1735885a
--- /dev/null
+++ b/dcb/dcb_ets.c
@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <errno.h>
+#include <stdio.h>
+#include <linux/dcbnl.h>
+
+#include "dcb.h"
+#include "utils.h"
+
+static void dcb_ets_help_set(void)
+{
+	fprintf(stderr,
+		"Usage: dcb ets set dev STRING\n"
+		"           [ willing { on | off } ]\n"
+		"           [ { tc-tsa | reco-tc-tsa } TSA-MAP ]\n"
+		"           [ { pg-bw | tc-bw | reco-tc-bw } BW-MAP ]\n"
+		"           [ { prio-tc | reco-prio-tc } PRIO-MAP ]\n"
+		"\n"
+		" where TSA-MAP := [ TSA-MAP ] TSA-MAPPING\n"
+		"       TSA-MAPPING := { all | TC }:{ strict | cbs | ets | vendor }\n"
+		"       BW-MAP := [ BW-MAP ] BW-MAPPING\n"
+		"       BW-MAPPING := { all | TC }:INTEGER\n"
+		"       PRIO-MAP := [ PRIO-MAP ] PRIO-MAPPING\n"
+		"       PRIO-MAPPING := { all | PRIO }:TC\n"
+		"       TC := { 0 .. 7 }\n"
+		"       PRIO := { 0 .. 7 }\n"
+		"\n"
+	);
+}
+
+static void dcb_ets_help_show(void)
+{
+	fprintf(stderr,
+		"Usage: dcb ets show dev STRING\n"
+		"           [ willing | ets-cap | cbs | tc-tsa | reco-tc-tsa |\n"
+		"             pg-bw | tc-bw | reco-tc-bw | prio-tc |\n"
+		"             reco-prio-tc ]\n"
+		"\n"
+	);
+}
+
+static void dcb_ets_help(void)
+{
+	fprintf(stderr,
+		"Usage: dcb ets help\n"
+		"\n"
+	);
+	dcb_ets_help_show();
+	dcb_ets_help_set();
+}
+
+static const char *const tsa_names[] = {
+	[IEEE_8021QAZ_TSA_STRICT] = "strict",
+	[IEEE_8021QAZ_TSA_CB_SHAPER] = "cbs",
+	[IEEE_8021QAZ_TSA_ETS] = "ets",
+	[IEEE_8021QAZ_TSA_VENDOR] = "vendor",
+};
+
+static int dcb_ets_parse_mapping_tc_tsa(__u32 key, char *value, void *data)
+{
+	__u8 tsa;
+	int ret;
+
+	tsa = parse_one_of("TSA", value, tsa_names, ARRAY_SIZE(tsa_names), &ret);
+	if (ret)
+		return ret;
+
+	return dcb_parse_mapping("TC", key, IEEE_8021QAZ_MAX_TCS - 1,
+				 "TSA", tsa, -1U,
+				 dcb_set_u8, data);
+}
+
+static int dcb_ets_parse_mapping_tc_bw(__u32 key, char *value, void *data)
+{
+	__u8 bw;
+
+	if (get_u8(&bw, value, 0))
+		return -EINVAL;
+
+	return dcb_parse_mapping("TC", key, IEEE_8021QAZ_MAX_TCS - 1,
+				 "BW", bw, 100,
+				 dcb_set_u8, data);
+}
+
+static int dcb_ets_parse_mapping_prio_tc(unsigned int key, char *value, void *data)
+{
+	__u8 tc;
+
+	if (get_u8(&tc, value, 0))
+		return -EINVAL;
+
+	return dcb_parse_mapping("PRIO", key, IEEE_8021QAZ_MAX_TCS - 1,
+				 "TC", tc, IEEE_8021QAZ_MAX_TCS - 1,
+				 dcb_set_u8, data);
+}
+
+static void dcb_print_array_tsa(const __u8 *array, size_t size)
+{
+	dcb_print_array_kw(array, size, tsa_names, ARRAY_SIZE(tsa_names));
+}
+
+static void dcb_ets_print_willing(const struct ieee_ets *ets)
+{
+	print_on_off(PRINT_ANY, "willing", "willing %s ", ets->willing);
+}
+
+static void dcb_ets_print_ets_cap(const struct ieee_ets *ets)
+{
+	print_uint(PRINT_ANY, "ets_cap", "ets-cap %d ", ets->ets_cap);
+}
+
+static void dcb_ets_print_cbs(const struct ieee_ets *ets)
+{
+	print_on_off(PRINT_ANY, "cbs", "cbs %s ", ets->cbs);
+}
+
+static void dcb_ets_print_tc_bw(const struct ieee_ets *ets)
+{
+	dcb_print_named_array("tc_bw", "tc-bw",
+			      ets->tc_tx_bw, ARRAY_SIZE(ets->tc_tx_bw),
+			      dcb_print_array_u8);
+}
+
+static void dcb_ets_print_pg_bw(const struct ieee_ets *ets)
+{
+	dcb_print_named_array("pg_bw", "pg-bw",
+			      ets->tc_rx_bw, ARRAY_SIZE(ets->tc_rx_bw),
+			      dcb_print_array_u8);
+}
+
+static void dcb_ets_print_tc_tsa(const struct ieee_ets *ets)
+{
+	dcb_print_named_array("tc_tsa", "tc-tsa",
+			      ets->tc_tsa, ARRAY_SIZE(ets->tc_tsa),
+			      dcb_print_array_tsa);
+}
+
+static void dcb_ets_print_prio_tc(const struct ieee_ets *ets)
+{
+	dcb_print_named_array("prio_tc", "prio-tc",
+			      ets->prio_tc, ARRAY_SIZE(ets->prio_tc),
+			      dcb_print_array_u8);
+}
+
+static void dcb_ets_print_reco_tc_bw(const struct ieee_ets *ets)
+{
+	dcb_print_named_array("reco_tc_bw", "reco-tc-bw",
+			      ets->tc_reco_bw, ARRAY_SIZE(ets->tc_reco_bw),
+			      dcb_print_array_u8);
+}
+
+static void dcb_ets_print_reco_tc_tsa(const struct ieee_ets *ets)
+{
+	dcb_print_named_array("reco_tc_tsa", "reco-tc-tsa",
+			      ets->tc_reco_tsa, ARRAY_SIZE(ets->tc_reco_tsa),
+			      dcb_print_array_tsa);
+}
+
+static void dcb_ets_print_reco_prio_tc(const struct ieee_ets *ets)
+{
+	dcb_print_named_array("reco_prio_tc", "reco-prio-tc",
+			      ets->reco_prio_tc, ARRAY_SIZE(ets->reco_prio_tc),
+			      dcb_print_array_u8);
+}
+
+static void dcb_ets_print(const struct ieee_ets *ets)
+{
+	dcb_ets_print_willing(ets);
+	dcb_ets_print_ets_cap(ets);
+	dcb_ets_print_cbs(ets);
+	print_nl();
+
+	dcb_ets_print_tc_bw(ets);
+	print_nl();
+
+	dcb_ets_print_pg_bw(ets);
+	print_nl();
+
+	dcb_ets_print_tc_tsa(ets);
+	print_nl();
+
+	dcb_ets_print_prio_tc(ets);
+	print_nl();
+
+	dcb_ets_print_reco_tc_bw(ets);
+	print_nl();
+
+	dcb_ets_print_reco_tc_tsa(ets);
+	print_nl();
+
+	dcb_ets_print_reco_prio_tc(ets);
+	print_nl();
+}
+
+static int dcb_ets_get(struct dcb *dcb, const char *dev, struct ieee_ets *ets)
+{
+	return dcb_get_attribute(dcb, dev, DCB_ATTR_IEEE_ETS, ets, sizeof(*ets));
+}
+
+static int dcb_ets_validate_bw(const __u8 bw[], const __u8 tsa[], const char *what)
+{
+	bool has_ets = false;
+	unsigned int total = 0;
+	unsigned int tc;
+
+	for (tc = 0; tc < IEEE_8021QAZ_MAX_TCS; tc++) {
+		if (tsa[tc] == IEEE_8021QAZ_TSA_ETS) {
+			has_ets = true;
+			break;
+		}
+	}
+
+	/* TC bandwidth is only intended for ETS, but 802.1Q-2018 only requires
+	 * that the sum be 100, and individual entries 0..100. It explicitly
+	 * notes that non-ETS TCs can have non-0 TC bandwidth during
+	 * reconfiguration.
+	 */
+	for (tc = 0; tc < IEEE_8021QAZ_MAX_TCS; tc++) {
+		if (bw[tc] > 100) {
+			fprintf(stderr, "%d%% for TC %d of %s is not a valid bandwidth percentage, expected 0..100%%\n",
+				bw[tc], tc, what);
+			return -EINVAL;
+		}
+		total += bw[tc];
+	}
+
+	/* This is what 802.1Q-2018 requires. */
+	if (total == 100)
+		return 0;
+
+	/* But this requirement does not make sense for all-strict
+	 * configurations. Anything else than 0 does not make sense: either BW
+	 * has not been reconfigured for the all-strict allocation yet, at which
+	 * point we expect sum of 100. Or it has already been reconfigured, at
+	 * which point accept 0.
+	 */
+	if (!has_ets && total == 0)
+		return 0;
+
+	fprintf(stderr, "Bandwidth percentages in %s sum to %d%%, expected %d%%\n",
+		what, total, has_ets ? 100 : 0);
+	return -EINVAL;
+}
+
+static int dcb_ets_set(struct dcb *dcb, const char *dev, const struct ieee_ets *ets)
+{
+	/* Do not validate pg-bw, which is not standard and has unclear
+	 * meaning.
+	 */
+	if (dcb_ets_validate_bw(ets->tc_tx_bw, ets->tc_tsa, "tc-bw") ||
+	    dcb_ets_validate_bw(ets->tc_reco_bw, ets->tc_reco_tsa, "reco-tc-bw"))
+		return -EINVAL;
+
+	return dcb_set_attribute(dcb, dev, DCB_ATTR_IEEE_ETS, ets, sizeof(*ets));
+}
+
+static int dcb_cmd_ets_set(struct dcb *dcb, const char *dev, int argc, char **argv)
+{
+	struct ieee_ets ets;
+	int ret;
+
+	if (!argc) {
+		dcb_ets_help_set();
+		return 1;
+	}
+
+	ret = dcb_ets_get(dcb, dev, &ets);
+	if (ret)
+		return ret;
+
+	do {
+		if (matches(*argv, "help") == 0) {
+			dcb_ets_help_set();
+			return 0;
+		} else if (matches(*argv, "willing") == 0) {
+			NEXT_ARG();
+			ets.willing = parse_on_off("willing", *argv, &ret);
+			if (ret)
+				return ret;
+		} else if (matches(*argv, "tc-tsa") == 0) {
+			NEXT_ARG();
+			ret = parse_mapping(&argc, &argv, true, &dcb_ets_parse_mapping_tc_tsa,
+					    ets.tc_tsa);
+			if (ret) {
+				fprintf(stderr, "Invalid tc-tsa mapping %s\n", *argv);
+				return ret;
+			}
+			continue;
+		} else if (matches(*argv, "reco-tc-tsa") == 0) {
+			NEXT_ARG();
+			ret = parse_mapping(&argc, &argv, true, &dcb_ets_parse_mapping_tc_tsa,
+					    ets.tc_reco_tsa);
+			if (ret) {
+				fprintf(stderr, "Invalid reco-tc-tsa mapping %s\n", *argv);
+				return ret;
+			}
+			continue;
+		} else if (matches(*argv, "tc-bw") == 0) {
+			NEXT_ARG();
+			ret = parse_mapping(&argc, &argv, true, &dcb_ets_parse_mapping_tc_bw,
+					    ets.tc_tx_bw);
+			if (ret) {
+				fprintf(stderr, "Invalid tc-bw mapping %s\n", *argv);
+				return ret;
+			}
+			continue;
+		} else if (matches(*argv, "pg-bw") == 0) {
+			NEXT_ARG();
+			ret = parse_mapping(&argc, &argv, true, &dcb_ets_parse_mapping_tc_bw,
+					    ets.tc_rx_bw);
+			if (ret) {
+				fprintf(stderr, "Invalid pg-bw mapping %s\n", *argv);
+				return ret;
+			}
+			continue;
+		} else if (matches(*argv, "reco-tc-bw") == 0) {
+			NEXT_ARG();
+			ret = parse_mapping(&argc, &argv, true, &dcb_ets_parse_mapping_tc_bw,
+					    ets.tc_reco_bw);
+			if (ret) {
+				fprintf(stderr, "Invalid reco-tc-bw mapping %s\n", *argv);
+				return ret;
+			}
+			continue;
+		} else if (matches(*argv, "prio-tc") == 0) {
+			NEXT_ARG();
+			ret = parse_mapping(&argc, &argv, true, &dcb_ets_parse_mapping_prio_tc,
+					    ets.prio_tc);
+			if (ret) {
+				fprintf(stderr, "Invalid prio-tc mapping %s\n", *argv);
+				return ret;
+			}
+			continue;
+		} else if (matches(*argv, "reco-prio-tc") == 0) {
+			NEXT_ARG();
+			ret = parse_mapping(&argc, &argv, true, &dcb_ets_parse_mapping_prio_tc,
+					    ets.reco_prio_tc);
+			if (ret) {
+				fprintf(stderr, "Invalid reco-prio-tc mapping %s\n", *argv);
+				return ret;
+			}
+			continue;
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			dcb_ets_help_set();
+			return -EINVAL;
+		}
+
+		NEXT_ARG_FWD();
+	} while (argc > 0);
+
+	return dcb_ets_set(dcb, dev, &ets);
+}
+
+static int dcb_cmd_ets_show(struct dcb *dcb, const char *dev, int argc, char **argv)
+{
+	struct ieee_ets ets;
+	int ret;
+
+	ret = dcb_ets_get(dcb, dev, &ets);
+	if (ret)
+		return ret;
+
+	open_json_object(NULL);
+
+	if (!argc) {
+		dcb_ets_print(&ets);
+		goto out;
+	}
+
+	do {
+		if (matches(*argv, "help") == 0) {
+			dcb_ets_help();
+			return 0;
+		} else if (matches(*argv, "willing") == 0) {
+			dcb_ets_print_willing(&ets);
+			print_nl();
+		} else if (matches(*argv, "ets-cap") == 0) {
+			dcb_ets_print_ets_cap(&ets);
+			print_nl();
+		} else if (matches(*argv, "cbs") == 0) {
+			dcb_ets_print_cbs(&ets);
+			print_nl();
+		} else if (matches(*argv, "tc-tsa") == 0) {
+			dcb_ets_print_tc_tsa(&ets);
+			print_nl();
+		} else if (matches(*argv, "reco-tc-tsa") == 0) {
+			dcb_ets_print_reco_tc_tsa(&ets);
+			print_nl();
+		} else if (matches(*argv, "tc-bw") == 0) {
+			dcb_ets_print_tc_bw(&ets);
+			print_nl();
+		} else if (matches(*argv, "pg-bw") == 0) {
+			dcb_ets_print_pg_bw(&ets);
+			print_nl();
+		} else if (matches(*argv, "reco-tc-bw") == 0) {
+			dcb_ets_print_reco_tc_bw(&ets);
+			print_nl();
+		} else if (matches(*argv, "prio-tc") == 0) {
+			dcb_ets_print_prio_tc(&ets);
+			print_nl();
+		} else if (matches(*argv, "reco-prio-tc") == 0) {
+			dcb_ets_print_reco_prio_tc(&ets);
+			print_nl();
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			dcb_ets_help();
+			return -EINVAL;
+		}
+
+		NEXT_ARG_FWD();
+	} while (argc > 0);
+
+out:
+	close_json_object();
+	return 0;
+}
+
+int dcb_cmd_ets(struct dcb *dcb, int argc, char **argv)
+{
+	if (!argc || matches(*argv, "help") == 0) {
+		dcb_ets_help();
+		return 0;
+	} else if (matches(*argv, "show") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv, dcb_cmd_ets_show, dcb_ets_help_show);
+	} else if (matches(*argv, "set") == 0) {
+		NEXT_ARG_FWD();
+		return dcb_cmd_parse_dev(dcb, argc, argv, dcb_cmd_ets_set, dcb_ets_help_set);
+	} else {
+		fprintf(stderr, "What is \"%s\"?\n", *argv);
+		dcb_ets_help();
+		return -EINVAL;
+	}
+}