network: tc: introduce cake

CAKE (Common Applications Kept Enhanced)

Please see http://man7.org/linux/man-pages/man8/tc-cake.8.html

man/systemd.network.xml

@@ -2562,7 +2562,49 @@
           incoming packets are dropped. An unsigned integer ranges 0 to 4294967294. Defaults to unset and kernel's default is used.</para>
         </listitem>
       </varlistentry>
+    </variablelist>
+  </refsect1>
 
+  <refsect1>
+    <title>[CAKE] Section Options</title>
+    <para>The <literal>[CAKE]</literal> section manages the queueing discipline (qdisc) of
+    Common Applications Kept Enhanced (CAKE).</para>
+
+    <variablelist class='network-directives'>
+      <varlistentry>
+        <term><varname>Parent=</varname></term>
+        <listitem>
+          <para>Specifies the parent Queueing Discipline (qdisc). Takes one of <literal>root</literal>,
+          <literal>clsact</literal>, <literal>ingress</literal> or a class id. The class id takes the
+          major and minor number in hexadecimal ranges 1 to ffff separated with a colon
+          (<literal>major:minor</literal>). Defaults to <literal>root</literal>.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><varname>Handle=</varname></term>
+        <listitem>
+          <para>Specifies the major number of unique identifier of the qdisc, known as the handle.
+          Takes a number in hexadecimal ranges 1 to ffff. Defaults to unset.</para>
+        </listitem>
+      </varlistentry>
+
+       <varlistentry>
+        <term><varname>Overhead=</varname></term>
+        <listitem>
+          <para>Specifies that bytes to be addeded to the size of each packet. Bytes may be negative.
+          Takes an integer ranges -64 to 256. Defaults to unset and kernel's default is used.</para>
+        </listitem>
+       </varlistentry>
+
+      <varlistentry>
+        <term><varname>Bandwidth=</varname></term>
+        <listitem>
+          <para>Specifies the shaper bandwidth. When suffixed with K, M, or G, the specified size is
+          parsed as Kilobits, Megabits, or Gigabits, respectively, to the base of 1000. Defaults to
+          unset and kernel's default is used.</para>
+        </listitem>
+      </varlistentry>
     </variablelist>
   </refsect1>
 

src/libsystemd/sd-netlink/netlink-types.c

@@ -745,6 +745,12 @@ static const NLTypeSystem rtnl_nexthop_type_system = {
        .types = rtnl_nexthop_types,
 };
 
+static const NLType rtnl_tca_option_data_cake_types[] = {
+        [TCA_CAKE_BASE_RATE64] = { .type = NETLINK_TYPE_U64 },
+        [TCA_CAKE_OVERHEAD]    = { .type = NETLINK_TYPE_S32 },
+        [TCA_CAKE_MPU]         = { .type = NETLINK_TYPE_U32 },
+};
+
 static const NLType rtnl_tca_option_data_codel_types[] = {
         [TCA_CODEL_TARGET]        = { .type = NETLINK_TYPE_U32 },
         [TCA_CODEL_LIMIT]         = { .type = NETLINK_TYPE_U32 },
@@ -808,6 +814,7 @@ static const NLType rtnl_tca_option_data_tbf_types[] = {
 };
 
 static const char* const nl_union_tca_option_data_table[] = {
+        [NL_UNION_TCA_OPTION_DATA_CAKE] = "cake",
         [NL_UNION_TCA_OPTION_DATA_CODEL] = "codel",
         [NL_UNION_TCA_OPTION_DATA_FQ] = "fq",
         [NL_UNION_TCA_OPTION_DATA_FQ_CODEL] = "fq_codel",
@@ -820,6 +827,8 @@ static const char* const nl_union_tca_option_data_table[] = {
 DEFINE_STRING_TABLE_LOOKUP(nl_union_tca_option_data, NLUnionTCAOptionData);
 
 static const NLTypeSystem rtnl_tca_option_data_type_systems[] = {
+        [NL_UNION_TCA_OPTION_DATA_CAKE] =        { .count = ELEMENTSOF(rtnl_tca_option_data_cake_types),
+                                                   .types = rtnl_tca_option_data_cake_types },
         [NL_UNION_TCA_OPTION_DATA_CODEL] =       { .count = ELEMENTSOF(rtnl_tca_option_data_codel_types),
                                                    .types = rtnl_tca_option_data_codel_types },
         [NL_UNION_TCA_OPTION_DATA_FQ] =          { .count = ELEMENTSOF(rtnl_tca_option_data_fq_types),

src/libsystemd/sd-netlink/netlink-types.h

@@ -96,6 +96,7 @@ const char *nl_union_link_info_data_to_string(NLUnionLinkInfoData p) _const_;
 NLUnionLinkInfoData nl_union_link_info_data_from_string(const char *p) _pure_;
 
 typedef enum NLUnionTCAOptionData {
+        NL_UNION_TCA_OPTION_DATA_CAKE,
         NL_UNION_TCA_OPTION_DATA_CODEL,
         NL_UNION_TCA_OPTION_DATA_FQ,
         NL_UNION_TCA_OPTION_DATA_FQ_CODEL,

src/network/meson.build

@@ -107,6 +107,8 @@ sources = files('''
         networkd-util.h
         networkd-wifi.c
         networkd-wifi.h
+        tc/cake.c
+        tc/cake.h
         tc/codel.c
         tc/codel.h
         tc/fifo.c

src/network/networkd-network-gperf.gperf

@@ -254,6 +254,10 @@ CAN.RestartSec,                              config_parse_sec,
 CAN.TripleSampling,                          config_parse_tristate,                                    0,                             offsetof(Network, can_triple_sampling)
 QDisc.Parent,                                config_parse_qdisc_parent,                                _QDISC_KIND_INVALID,           0
 QDisc.Handle,                                config_parse_qdisc_handle,                                _QDISC_KIND_INVALID,           0
+CAKE.Parent,                                 config_parse_qdisc_parent,                                QDISC_KIND_CAKE,               0
+CAKE.Handle,                                 config_parse_qdisc_handle,                                QDISC_KIND_CAKE,               0
+CAKE.Bandwidth,                              config_parse_cake_bandwidth,                              QDISC_KIND_CAKE,               0
+CAKE.Overhead,                               config_parse_cake_overhead,                               QDISC_KIND_CAKE,               0
 ControlledDelay.Parent,                      config_parse_qdisc_parent,                                QDISC_KIND_CODEL,              0
 ControlledDelay.Handle,                      config_parse_qdisc_handle,                                QDISC_KIND_CODEL,              0
 ControlledDelay.PacketLimit,                 config_parse_controlled_delay_u32,                        QDISC_KIND_CODEL,              0

src/network/networkd-network.c

@@ -484,6 +484,7 @@ int network_load_one(Manager *manager, OrderedHashmap **networks, const char *fi
                               "TrafficControlQueueingDiscipline\0"
                               "CAN\0"
                               "QDisc\0"
+                              "CAKE\0"
                               "ControlledDelay\0"
                               "PFIFO\0"
                               "FairQueueing\0"

src/network/tc/cake.c

@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: LGPL-2.1+
+ * Copyright © 2020 VMware, Inc. */
+
+#include <linux/pkt_sched.h>
+
+#include "alloc-util.h"
+#include "cake.h"
+#include "conf-parser.h"
+#include "netlink-util.h"
+#include "parse-util.h"
+#include "qdisc.h"
+#include "string-util.h"
+
+static int cake_fill_message(Link *link, QDisc *qdisc, sd_netlink_message *req) {
+        CommonApplicationsKeptEnhanced *c;
+        int r;
+
+        assert(link);
+        assert(qdisc);
+        assert(req);
+
+        c = CAKE(qdisc);
+
+        r = sd_netlink_message_open_container_union(req, TCA_OPTIONS, "cake");
+        if (r < 0)
+                return log_link_error_errno(link, r, "Could not open container TCA_OPTIONS: %m");
+
+        if (c->bandwidth > 0) {
+                r = sd_netlink_message_append_u64(req, TCA_CAKE_BASE_RATE64, c->bandwidth);
+                if (r < 0)
+                        return log_link_error_errno(link, r, "Could not append TCA_CAKE_BASE_RATE64 attribute: %m");
+        }
+
+        r = sd_netlink_message_append_s32(req, TCA_CAKE_OVERHEAD, c->overhead);
+        if (r < 0)
+                return log_link_error_errno(link, r, "Could not append TCA_CAKE_OVERHEAD attribute: %m");
+
+        r = sd_netlink_message_close_container(req);
+        if (r < 0)
+                return log_link_error_errno(link, r, "Could not close container TCA_OPTIONS: %m");
+
+        return 0;
+}
+
+int config_parse_cake_bandwidth(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        _cleanup_(qdisc_free_or_set_invalidp) QDisc *qdisc = NULL;
+        CommonApplicationsKeptEnhanced *c;
+        Network *network = data;
+        uint64_t k;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        r = qdisc_new_static(QDISC_KIND_CAKE, network, filename, section_line, &qdisc);
+        if (r == -ENOMEM)
+                return log_oom();
+        if (r < 0)
+                return log_syntax(unit, LOG_ERR, filename, line, r,
+                                  "More than one kind of queueing discipline, ignoring assignment: %m");
+
+        c = CAKE(qdisc);
+
+        if (isempty(rvalue)) {
+                c->bandwidth = 0;
+
+                qdisc = NULL;
+                return 0;
+        }
+
+        r = parse_size(rvalue, 1000, &k);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Failed to parse '%s=', ignoring assignment: %s",
+                           lvalue, rvalue);
+                return 0;
+        }
+
+        c->bandwidth = k/8;
+        qdisc = NULL;
+
+        return 0;
+}
+
+int config_parse_cake_overhead(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        _cleanup_(qdisc_free_or_set_invalidp) QDisc *qdisc = NULL;
+        CommonApplicationsKeptEnhanced *c;
+        Network *network = data;
+        int32_t v;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        r = qdisc_new_static(QDISC_KIND_CAKE, network, filename, section_line, &qdisc);
+        if (r == -ENOMEM)
+                return log_oom();
+        if (r < 0)
+                return log_syntax(unit, LOG_ERR, filename, line, r,
+                                  "More than one kind of queueing discipline, ignoring assignment: %m");
+
+        c = CAKE(qdisc);
+
+        if (isempty(rvalue)) {
+                c->overhead = 0;
+                qdisc = NULL;
+                return 0;
+        }
+
+        r = safe_atoi32(rvalue, &v);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Failed to parse 'Overhead=', ignoring assignment: %s",
+                           rvalue);
+                return 0;
+        }
+        if (v < -64 || v > 256) {
+                log_syntax(unit, LOG_ERR, filename, line, 0,
+                           "Invalid 'Overhead=', ignoring assignment: %s",
+                           rvalue);
+                return 0;
+        }
+
+        c->overhead = v;
+        qdisc = NULL;
+        return 0;
+}
+
+const QDiscVTable cake_vtable = {
+        .object_size = sizeof(CommonApplicationsKeptEnhanced),
+        .tca_kind = "cake",
+        .fill_message = cake_fill_message,
+};

src/network/tc/cake.h

@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: LGPL-2.1+
+ * Copyright © 2020 VMware, Inc. */
+#pragma once
+
+#include "conf-parser.h"
+#include "qdisc.h"
+
+typedef struct CommonApplicationsKeptEnhanced {
+        QDisc meta;
+
+        int overhead;
+        uint64_t bandwidth;
+
+} CommonApplicationsKeptEnhanced;
+
+DEFINE_QDISC_CAST(CAKE, CommonApplicationsKeptEnhanced);
+extern const QDiscVTable cake_vtable;
+
+CONFIG_PARSER_PROTOTYPE(config_parse_cake_bandwidth);
+CONFIG_PARSER_PROTOTYPE(config_parse_cake_overhead);

src/network/tc/qdisc.c

@@ -16,6 +16,7 @@
 #include "tc-util.h"
 
 const QDiscVTable * const qdisc_vtable[_QDISC_KIND_MAX] = {
+        [QDISC_KIND_CAKE] = &cake_vtable,
         [QDISC_KIND_CODEL] = &codel_vtable,
         [QDISC_KIND_FQ] = &fq_vtable,
         [QDISC_KIND_FQ_CODEL] = &fq_codel_vtable,

src/network/tc/qdisc.h

@@ -9,6 +9,7 @@
 #include "tc.h"
 
 typedef enum QDiscKind {
+        QDISC_KIND_CAKE,
         QDISC_KIND_CODEL,
         QDISC_KIND_FQ,
         QDISC_KIND_FQ_CODEL,
@@ -77,6 +78,7 @@ DEFINE_TC_CAST(QDISC, QDisc);
 CONFIG_PARSER_PROTOTYPE(config_parse_qdisc_parent);
 CONFIG_PARSER_PROTOTYPE(config_parse_qdisc_handle);
 
+#include "cake.h"
 #include "codel.h"
 #include "fifo.h"
 #include "fq-codel.h"

test/fuzz/fuzz-network-parser/directives.network

@@ -326,6 +326,11 @@ TargetSec=
 IntervalSec=
 CEThresholdSec=
 ECN=
+[CAKE]
+Parent=
+Handle=
+Bandwidth=
+Overhead=
 [TrafficControlQueueingDiscipline]
 Parent=
 NetworkEmulatorDelaySec=