@@ -55,7 +55,7 @@ WFLAGS += -Wmissing-declarations -Wold-style-definition -Wformat=2
CFLAGS := $(WFLAGS) $(CCOPTS) -I../include -I../include/uapi $(DEFINES) $(CFLAGS)
YACCFLAGS = -d -t -v
-SUBDIRS=lib ip tc bridge misc netem genl tipc devlink rdma man
+SUBDIRS=lib ip tc bridge misc netem genl tipc devlink rdma dcb man
LIBNETLINK=../lib/libutil.a ../lib/libnetlink.a
LDLIBS += $(LIBNETLINK)
new file mode 100644
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+include ../config.mk
+
+TARGETS :=
+
+ifeq ($(HAVE_MNL),y)
+
+DCBOBJ = dcb.o
+TARGETS += dcb
+
+endif
+
+all: $(TARGETS) $(LIBS)
+
+dcb: $(DCBOBJ) $(LIBNETLINK)
+ $(QUIET_LINK)$(CC) $^ $(LDFLAGS) $(LDLIBS) -o $@
+
+install: all
+ for i in $(TARGETS); \
+ do install -m 0755 $$i $(DESTDIR)$(SBINDIR); \
+ done
+
+clean:
+ rm -f $(DCBOBJ) $(TARGETS)
new file mode 100644
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <stdio.h>
+#include <linux/dcbnl.h>
+#include <libmnl/libmnl.h>
+#include <getopt.h>
+
+#include "dcb.h"
+#include "mnl_utils.h"
+#include "namespace.h"
+#include "utils.h"
+#include "version.h"
+
+static int dcb_init(struct dcb *dcb)
+{
+ dcb->buf = malloc(MNL_SOCKET_BUFFER_SIZE);
+ if (dcb->buf == NULL) {
+ perror("Netlink buffer allocation");
+ return -1;
+ }
+
+ dcb->nl = mnlu_socket_open(NETLINK_ROUTE);
+ if (dcb->nl == NULL) {
+ perror("Open netlink socket");
+ goto err_socket_open;
+ }
+
+ new_json_obj_plain(dcb->json_output);
+ return 0;
+
+err_socket_open:
+ free(dcb->buf);
+ return -1;
+}
+
+static void dcb_fini(struct dcb *dcb)
+{
+ delete_json_obj_plain();
+ mnl_socket_close(dcb->nl);
+}
+
+static struct dcb *dcb_alloc(void)
+{
+ struct dcb *dcb;
+
+ dcb = calloc(1, sizeof(*dcb));
+ if (!dcb)
+ return NULL;
+ return dcb;
+}
+
+static void dcb_free(struct dcb *dcb)
+{
+ free(dcb);
+}
+
+struct dcb_get_attribute {
+ struct dcb *dcb;
+ int attr;
+ void *data;
+ size_t data_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);
+ return MNL_CB_STOP;
+}
+
+static int dcb_get_attribute_attr_cb(const struct nlattr *attr, void *data)
+{
+ if (mnl_attr_get_type(attr) != DCB_ATTR_IEEE)
+ return MNL_CB_OK;
+
+ return mnl_attr_parse_nested(attr, dcb_get_attribute_attr_ieee_cb, data);
+}
+
+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_set_attribute_attr_cb(const struct nlattr *attr, void *data)
+{
+ uint16_t len;
+ uint8_t err;
+
+ if (mnl_attr_get_type(attr) != DCB_ATTR_IEEE)
+ return MNL_CB_OK;
+
+ len = mnl_attr_get_payload_len(attr);
+ if (len != 1) {
+ fprintf(stderr, "Response attribute expected to have size 1, not %d\n", len);
+ return MNL_CB_ERROR;
+ }
+
+ err = mnl_attr_get_u8(attr);
+ if (err) {
+ fprintf(stderr, "Error when attempting to set attribute: %s\n",
+ strerror(err));
+ return MNL_CB_ERROR;
+ }
+
+ return MNL_CB_STOP;
+}
+
+static int dcb_set_attribute_cb(const struct nlmsghdr *nlh, void *data)
+{
+ return mnl_attr_parse(nlh, sizeof(struct dcbmsg), dcb_set_attribute_attr_cb, data);
+}
+
+static int dcb_talk(struct dcb *dcb, struct nlmsghdr *nlh, mnl_cb_t cb, void *data)
+{
+ int ret;
+
+ ret = mnl_socket_sendto(dcb->nl, nlh, nlh->nlmsg_len);
+ if (ret < 0) {
+ perror("mnl_socket_sendto");
+ return -1;
+ }
+
+ return mnlu_socket_recv_run(dcb->nl, nlh->nlmsg_seq, dcb->buf, MNL_SOCKET_BUFFER_SIZE,
+ cb, data);
+}
+
+static struct nlmsghdr *dcb_prepare(struct dcb *dcb, const char *dev,
+ uint32_t nlmsg_type, uint8_t dcb_cmd)
+{
+ struct dcbmsg dcbm = {
+ .cmd = dcb_cmd,
+ };
+ struct nlmsghdr *nlh;
+
+ nlh = mnlu_msg_prepare(dcb->buf, nlmsg_type, NLM_F_REQUEST, &dcbm, sizeof(dcbm));
+ mnl_attr_put_strz(nlh, DCB_ATTR_IFNAME, dev);
+ return nlh;
+}
+
+int dcb_get_attribute(struct dcb *dcb, const char *dev, int attr, void *data, size_t data_len)
+{
+ struct dcb_get_attribute ga;
+ struct nlmsghdr *nlh;
+ int ret;
+
+ nlh = dcb_prepare(dcb, dev, RTM_GETDCB, DCB_CMD_IEEE_GET);
+
+ ga = (struct dcb_get_attribute) {
+ .dcb = dcb,
+ .attr = attr,
+ .data = data,
+ .data_len = data_len,
+ };
+ ret = dcb_talk(dcb, nlh, dcb_get_attribute_cb, &ga);
+ if (ret) {
+ perror("Attribute read");
+ return ret;
+ }
+ return 0;
+}
+
+int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr, const void *data, size_t data_len)
+{
+ struct nlmsghdr *nlh;
+ struct nlattr *nest;
+ int ret;
+
+ nlh = dcb_prepare(dcb, dev, RTM_GETDCB, DCB_CMD_IEEE_SET);
+
+ nest = mnl_attr_nest_start(nlh, DCB_ATTR_IEEE);
+ mnl_attr_put(nlh, attr, data_len, data);
+ mnl_attr_nest_end(nlh, nest);
+
+ ret = dcb_talk(dcb, nlh, dcb_set_attribute_cb, NULL);
+ if (ret) {
+ perror("Attribute write");
+ return ret;
+ }
+ return 0;
+}
+
+void dcb_print_array_num(FILE *fp, const __u8 *array, size_t size)
+{
+ SPRINT_BUF(b1);
+ SPRINT_BUF(b2);
+ size_t i;
+
+ for (i = 0; i < size; i++) {
+ snprintf(b1, sizeof(b1), "%zd", i);
+ snprintf(b2, sizeof(b2), "%zd:%%d ", i);
+ print_uint(PRINT_ANY, b1, b2, array[i]);
+ }
+}
+
+void dcb_print_array_kw(FILE *fp, const __u8 *array, size_t array_size,
+ const char *const kw[], size_t kw_size)
+{
+ SPRINT_BUF(b1);
+ SPRINT_BUF(b2);
+ size_t i;
+
+ for (i = 0; i < array_size; i++) {
+ __u8 emt = array[i];
+
+ snprintf(b1, sizeof(b1), "%zd", i);
+ snprintf(b2, sizeof(b2), "%zd:%%s ", i);
+ if (emt < kw_size && kw[emt])
+ print_string(PRINT_ANY, b1, b2, kw[emt]);
+ else
+ print_string(PRINT_ANY, b1, b2, "???");
+ }
+}
+
+void dcb_print_named_array(FILE *fp, const char *name, const __u8 *array, size_t size,
+ void (*print_array)(FILE *, const __u8 *, size_t))
+{
+ open_json_object(name);
+ print_string(PRINT_FP, NULL, "%s ", name);
+ print_array(fp, array, size);
+ close_json_object();
+}
+
+int dcb_cmd_parse_dev(struct dcb *dcb, int argc, char **argv,
+ int (*and_then)(struct dcb *dcb, const char *dev,
+ int argc, char **argv),
+ void (*help)(void))
+{
+ const char *dev;
+
+ if (!argc || matches(*argv, "help") == 0) {
+ help();
+ return 0;
+ } else if (matches(*argv, "dev") == 0) {
+ NEXT_ARG();
+ dev = *argv;
+ if (check_ifname(dev)) {
+ invarg("not a valid ifname", *argv);
+ return -EINVAL;
+ }
+ NEXT_ARG_FWD();
+ return and_then(dcb, dev, argc, argv);
+ } else {
+ fprintf(stderr, "Expected `dev DEV', not `%s'", *argv);
+ help();
+ return -EINVAL;
+ }
+}
+
+static void dcb_help(void)
+{
+ fprintf(stderr,
+ "Usage: dcb [ OPTIONS ] OBJECT { COMMAND | help }\n"
+ " dcb [ -f[orce] ] -b[atch] filename -N[etns] netnsname\n"
+ "where OBJECT :=\n"
+ " OPTIONS := { -V[ersion] | -j[son] | -p[retty] | -v[erbose] }\n");
+}
+
+static int dcb_cmd(struct dcb *dcb, int argc, char **argv)
+{
+ if (!argc || matches(*argv, "help") == 0) {
+ dcb_help();
+ return 0;
+ }
+
+ fprintf(stderr, "Object \"%s\" is unknown\n", *argv);
+ return -ENOENT;
+}
+
+static int dcb_batch_cmd(int argc, char *argv[], void *data)
+{
+ struct dcb *dcb = data;
+
+ return dcb_cmd(dcb, argc, argv);
+}
+
+static int dcb_batch(struct dcb *dcb, const char *name, bool force)
+{
+ return do_batch(name, force, dcb_batch_cmd, dcb);
+}
+
+int main(int argc, char **argv)
+{
+ static const struct option long_options[] = {
+ { "Version", no_argument, NULL, 'V' },
+ { "force", no_argument, NULL, 'f' },
+ { "batch", required_argument, NULL, 'b' },
+ { "json", no_argument, NULL, 'j' },
+ { "pretty", no_argument, NULL, 'p' },
+ { "Netns", required_argument, NULL, 'N' },
+ { NULL, 0, NULL, 0 }
+ };
+ const char *batch_file = NULL;
+ bool force = false;
+ struct dcb *dcb;
+ int opt;
+ int err;
+ int ret;
+
+ dcb = dcb_alloc();
+ if (!dcb) {
+ fprintf(stderr, "Failed to allocate memory for dcb\n");
+ return EXIT_FAILURE;
+ }
+
+ while ((opt = getopt_long(argc, argv, "Vfb:njpvsN:",
+ long_options, NULL)) >= 0) {
+
+ switch (opt) {
+ case 'V':
+ printf("dcb utility, iproute2-%s\n", version);
+ ret = EXIT_SUCCESS;
+ goto dcb_free;
+ case 'f':
+ force = true;
+ break;
+ case 'b':
+ batch_file = optarg;
+ break;
+ case 'j':
+ dcb->json_output = true;
+ break;
+ case 'p':
+ pretty = true;
+ break;
+ case 'N':
+ if (netns_switch(optarg)) {
+ ret = EXIT_FAILURE;
+ goto dcb_free;
+ }
+ break;
+ default:
+ fprintf(stderr, "Unknown option.\n");
+ dcb_help();
+ ret = EXIT_FAILURE;
+ goto dcb_free;
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ err = dcb_init(dcb);
+ if (err) {
+ ret = EXIT_FAILURE;
+ goto dcb_free;
+ }
+
+ if (batch_file)
+ err = dcb_batch(dcb, batch_file, force);
+ else
+ err = dcb_cmd(dcb, argc, argv);
+
+ if (err) {
+ ret = EXIT_FAILURE;
+ goto dcb_fini;
+ }
+
+ ret = EXIT_SUCCESS;
+
+dcb_fini:
+ dcb_fini(dcb);
+dcb_free:
+ dcb_free(dcb);
+
+ return ret;
+}
new file mode 100644
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __DCB_H__
+#define __DCB_H__ 1
+
+#include <stdbool.h>
+#include <stddef.h>
+
+/* dcb.c */
+
+struct dcb {
+ char *buf;
+ struct mnl_socket *nl;
+ bool json_output;
+};
+
+int dcb_cmd_parse_dev(struct dcb *dcb, int argc, char **argv,
+ int (*and_then)(struct dcb *dcb, const char *dev,
+ int argc, char **argv),
+ void (*help)(void));
+
+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);
+
+void dcb_print_named_array(FILE *fp, const char *name, const __u8 *array, size_t size,
+ void (*print_array)(FILE *, const __u8 *, size_t));
+void dcb_print_array_num(FILE *fp, const __u8 *array, size_t size);
+void dcb_print_array_kw(FILE *fp, const __u8 *array, size_t array_size,
+ const char *const kw[], size_t kw_size);
+
+#endif /* __DCB_H__ */
new file mode 100644
@@ -0,0 +1,103 @@
+.TH DCB 8 "19 October 2020" "iproute2" "Linux"
+.SH NAME
+dcb \- show / manipulate DCB (Data Center Bridging) settings
+.SH SYNOPSIS
+.sp
+.ad l
+.in +8
+
+.ti -8
+.B dcb
+.RB "[ " -force " ] "
+.BI "-batch " filename
+.sp
+
+.ti -8
+.B dcb
+.RI "[ " OPTIONS " ] "
+.B help
+.sp
+
+.SH OPTIONS
+
+.TP
+.BR "\-V" , " --Version"
+Print the version of the
+.B dcb
+utility and exit.
+
+.TP
+.BR "\-b", " \-batch " <FILENAME>
+Read commands from provided file or standard input and invoke them. First
+failure will cause termination of dcb.
+
+.TP
+.B \-force
+Don't terminate dcb on errors in batch mode. If there were any errors during
+execution of the commands, the application return code will be non zero.
+
+.TP
+.BR "\-j" , " --json"
+Generate JSON output.
+
+.TP
+.BR "\-p" , " --pretty"
+When combined with -j generate a pretty JSON output.
+
+.SH OBJECTS
+
+.SH COMMANDS
+
+A \fICOMMAND\fR specifies the action to perform on the object. The set of
+possible actions depends on the object type. As a rule, it is possible to
+.B show
+objects and to invoke topical
+.B help,
+which prints a list of available commands and argument syntax conventions.
+
+.SH ARRAY PARAMETERS
+
+Like commands, specification of parameters is in the domain of individual
+objects (and their commands) as well. However, much of the DCB interface
+revolves around arrays of fixed size that specify one value per some key, such
+as per traffic class or per priority. There is therefore a single syntax for
+adjusting elements of these arrays. It consists of a series of
+\fIKEY\fB:\fIVALUE\fR pairs, where the meaning of the individual keys and values
+depends on the parameter.
+
+The elements are evaluated in order from left to right, and the latter ones
+override the earlier ones. The elements that are not specified on the command
+line are queried from the kernel and their current value is retained.
+
+As an example, take a made-up parameter tc-juju, which can be set to charm
+traffic in a given TC with either good luck or bad luck. \fIKEY\fR can therefore
+be 0..7 (as is usual for TC numbers in DCB), and \fIVALUE\fR either of
+\fBnone\fR, \fBgood\fR, and \fBbad\fR. An example of changing a juju value of
+TCs 0 and 7, while leaving all other intact, would then be:
+
+.P
+# dcb foo set dev eth0 tc-juju 0:good 7:bad
+
+A special key, \fBall\fR, is recognized which sets the same value to all array
+elements. This can be combined with the usual single-element syntax. E.g. in the
+following, the juju or all keys is set to \fBnone\fR, except 0 and 7, which have
+other values:
+
+.P
+# dcb foo set dev eth0 tc-juju all:none 0:good 7:bad
+
+.SH EXIT STATUS
+Exit status is 0 if command was successful or a positive integer upon failure.
+
+.SH SEE ALSO
+.BR dcb-ets (8)
+.br
+
+.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>
The Linux DCB interface allows configuration of a broad range of hardware-specific attributes, such as TC scheduling, flow control, per-port buffer configuration, TC rate, etc. Add a new tool to show that configuration and tweak it. DCB allows configuration of several objects, and possibly could expand to pre-standard CEE interfaces. Therefore the tool itself is a lean shell that dispatches to subtools each dedicated to one of the objects. Signed-off-by: Petr Machata <me@pmachata.org> --- Makefile | 2 +- dcb/Makefile | 24 ++++ dcb/dcb.c | 377 +++++++++++++++++++++++++++++++++++++++++++++++++ dcb/dcb.h | 32 +++++ man/man8/dcb.8 | 103 ++++++++++++++ 5 files changed, 537 insertions(+), 1 deletion(-) create mode 100644 dcb/Makefile create mode 100644 dcb/dcb.c create mode 100644 dcb/dcb.h create mode 100644 man/man8/dcb.8