network: TC - introduce HHF

Please see https://lwn.net/Articles/577208/

man/systemd.network.xml

@@ -3246,7 +3246,38 @@
           is used.</para>
         </listitem>
       </varlistentry>
+    </variablelist>
+  </refsect1>
 
+  <refsect1>
+    <title>[HeavyHitterFilter] Section Options</title>
+    <para>The <literal>[HeavyHitterFilter]</literal> section manages the queueing discipline
+    (qdisc) of Heavy Hitter Filter (hhf).</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> or <literal>ingress</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>PacketLimit=</varname></term>
+        <listitem>
+          <para>Specifies the hard limit on the queue size in number of packets. When this limit is reached, 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>
 

src/network/meson.build

@@ -121,6 +121,8 @@ sources = files('''
         tc/fq-codel.h
         tc/gred.c
         tc/gred.h
+        tc/hhf.c
+        tc/hhf.h
         tc/htb.c
         tc/htb.h
         tc/netem.c

src/network/networkd-network-gperf.gperf

@@ -311,6 +311,9 @@ GenericRandomEarlyDetection.Handle,          config_parse_qdisc_handle,
 GenericRandomEarlyDetection.VirtualQueues,   config_parse_generic_random_early_detection_u32,          QDISC_KIND_GRED,               0
 GenericRandomEarlyDetection.DefaultVirtualQueue, config_parse_generic_random_early_detection_u32,      QDISC_KIND_GRED,               0
 GenericRandomEarlyDetection.GenericRIO,      config_parse_generic_random_early_detection_bool,         QDISC_KIND_GRED,               0
+HeavyHitterFilter.Parent,                    config_parse_qdisc_parent,                                QDISC_KIND_HHF,                0
+HeavyHitterFilter.Handle,                    config_parse_qdisc_handle,                                QDISC_KIND_HHF,                0
+HeavyHitterFilter.PacketLimit,               config_parse_heavy_hitter_filter_packet_limit,            QDISC_KIND_HHF,                0
 HierarchyTokenBucket.Parent,                 config_parse_qdisc_parent,                                QDISC_KIND_HTB,                0
 HierarchyTokenBucket.Handle,                 config_parse_qdisc_handle,                                QDISC_KIND_HTB,                0
 HierarchyTokenBucket.DefaultClass,           config_parse_hierarchy_token_bucket_default_class,        QDISC_KIND_HTB,                0

src/network/networkd-network.c

@@ -497,6 +497,7 @@ int network_load_one(Manager *manager, OrderedHashmap **networks, const char *fi
                               "FairQueueing\0"
                               "FairQueueingControlledDelay\0"
                               "GenericRandomEarlyDetection\0"
+                              "HeavyHitterFilter\0"
                               "HierarchyTokenBucket\0"
                               "HierarchyTokenBucketClass\0"
                               "NetworkEmulator\0"

src/network/tc/hhf.c

@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: LGPL-2.1+
+ * Copyright © 2020 VMware, Inc. */
+
+#include <linux/pkt_sched.h>
+
+#include "alloc-util.h"
+#include "conf-parser.h"
+#include "hhf.h"
+#include "netlink-util.h"
+#include "parse-util.h"
+#include "string-util.h"
+#include "util.h"
+
+static int heavy_hitter_filter_fill_message(Link *link, QDisc *qdisc, sd_netlink_message *req) {
+        HeavyHitterFilter *hhf;
+        int r;
+
+        assert(link);
+        assert(qdisc);
+        assert(req);
+
+        hhf = HHF(qdisc);
+
+        r = sd_netlink_message_open_container_union(req, TCA_OPTIONS, "hhf");
+        if (r < 0)
+                return log_link_error_errno(link, r, "Could not open container TCA_OPTIONS: %m");
+
+        if (hhf->packet_limit > 0) {
+                r = sd_netlink_message_append_u32(req, TCA_HHF_BACKLOG_LIMIT, hhf->packet_limit);
+                if (r < 0)
+                        return log_link_error_errno(link, r, "Could not append TCA_HHF_BACKLOG_LIMIT 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_heavy_hitter_filter_packet_limit(
+                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;
+        HeavyHitterFilter *hhf;
+        Network *network = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        r = qdisc_new_static(QDISC_KIND_HHF, 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");
+
+        hhf = HHF(qdisc);
+
+        if (isempty(rvalue)) {
+                hhf->packet_limit = 0;
+
+                qdisc = NULL;
+                return 0;
+        }
+
+        r = safe_atou32(rvalue, &hhf->packet_limit);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Failed to parse '%s=', ignoring assignment: %s",
+                           lvalue, rvalue);
+                return 0;
+        }
+
+        qdisc = NULL;
+
+        return 0;
+}
+
+const QDiscVTable hhf_vtable = {
+        .object_size = sizeof(HeavyHitterFilter),
+        .tca_kind = "hhf",
+        .fill_message = heavy_hitter_filter_fill_message,
+};

src/network/tc/hhf.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: LGPL-2.1+
+ * Copyright © 2020 VMware, Inc. */
+#pragma once
+
+#include "conf-parser.h"
+#include "qdisc.h"
+
+typedef struct HeavyHitterFilter {
+        QDisc meta;
+
+        uint32_t packet_limit;
+} HeavyHitterFilter;
+
+DEFINE_QDISC_CAST(HHF, HeavyHitterFilter);
+extern const QDiscVTable hhf_vtable;
+
+CONFIG_PARSER_PROTOTYPE(config_parse_heavy_hitter_filter_packet_limit);

src/network/tc/qdisc.c

@@ -23,6 +23,7 @@ const QDiscVTable * const qdisc_vtable[_QDISC_KIND_MAX] = {
         [QDISC_KIND_FQ] = &fq_vtable,
         [QDISC_KIND_FQ_CODEL] = &fq_codel_vtable,
         [QDISC_KIND_GRED] = &gred_vtable,
+        [QDISC_KIND_HHF] = &hhf_vtable,
         [QDISC_KIND_HTB] = &htb_vtable,
         [QDISC_KIND_NETEM] = &netem_vtable,
         [QDISC_KIND_PIE] = &pie_vtable,

src/network/tc/qdisc.h

@@ -16,6 +16,7 @@ typedef enum QDiscKind {
         QDISC_KIND_FQ,
         QDISC_KIND_FQ_CODEL,
         QDISC_KIND_GRED,
+        QDISC_KIND_HHF,
         QDISC_KIND_HTB,
         QDISC_KIND_NETEM,
         QDISC_KIND_PFIFO,
@@ -89,6 +90,7 @@ CONFIG_PARSER_PROTOTYPE(config_parse_qdisc_handle);
 #include "fq-codel.h"
 #include "fq.h"
 #include "gred.h"
+#include "hhf.h"
 #include "htb.h"
 #include "pie.h"
 #include "netem.h"

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

@@ -392,3 +392,7 @@ Handle=
 Parent=
 ClassId=
 Quantum=
+[HeavyHitterFilter]
+Parent=
+Handle=
+PacketLimit=