network tc: inroduce FQ - Fair Queue traffic policing

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

man/systemd.network.xml

@@ -2450,6 +2450,14 @@
         </listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term><varname>FairQueueTrafficPolicingPacketLimit=</varname></term>
+        <listitem>
+          <para>Specifies the hard limit on the real queue size. When this limit is reached, incoming packets are
+          dropped. Defaults to unset and kernel's default is used.</para>
+        </listitem>
+      </varlistentry>
+
     </variablelist>
   </refsect1>
 

src/network/meson.build

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

src/network/networkd-network-gperf.gperf

@@ -259,6 +259,7 @@ TrafficControlQueueingDiscipline.TokenBufferFilterPeakRate,                  con
 TrafficControlQueueingDiscipline.TokenBufferFilterLatencySec,                config_parse_tc_token_buffer_filter_latency,                 0, 0
 TrafficControlQueueingDiscipline.StochasticFairnessQueueingPerturbPeriodSec, config_parse_tc_stochastic_fairness_queueing_perturb_period, 0, 0
 TrafficControlQueueingDiscipline.FairQueuingControlledDelayPacketLimit,      config_parse_tc_fair_queuing_controlled_delay_limit,         0, 0
+TrafficControlQueueingDiscipline.FairQueueTrafficPolicingPacketLimit,        config_parse_tc_fair_queue_traffic_policing_packet_limit,    0, 0
 /* backwards compatibility: do not add new entries to this section */
 Network.IPv4LL,                         config_parse_ipv4ll,                             0,                             offsetof(Network, link_local)
 DHCP.ClientIdentifier,                  config_parse_dhcp_client_identifier,             0,                             offsetof(Network, dhcp_client_identifier)

src/network/tc/fq.c

@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: LGPL-2.1+
+ * Copyright © 2019 VMware, Inc. */
+
+#include <linux/pkt_sched.h>
+
+#include "alloc-util.h"
+#include "conf-parser.h"
+#include "fq.h"
+#include "netlink-util.h"
+#include "parse-util.h"
+#include "string-util.h"
+
+static int fair_queue_traffic_policing_fill_message(Link *link, QDisc *qdisc, sd_netlink_message *req) {
+        FairQueueTrafficPolicing *fq;
+        int r;
+
+        assert(link);
+        assert(qdisc);
+        assert(req);
+
+        fq = FQ(qdisc);
+
+        r = sd_netlink_message_open_container_union(req, TCA_OPTIONS, "fq");
+        if (r < 0)
+                return log_link_error_errno(link, r, "Could not open container TCA_OPTIONS: %m");
+
+        r = sd_netlink_message_append_u32(req, TCA_FQ_PLIMIT, fq->limit);
+        if (r < 0)
+                return log_link_error_errno(link, r, "Could not append TCA_FQ_PLIMIT 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_tc_fair_queue_traffic_policing_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;
+        FairQueueTrafficPolicing *fq;
+        Network *network = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        r = qdisc_new_static(QDISC_KIND_FQ, 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");
+
+        fq = FQ(qdisc);
+
+        if (isempty(rvalue)) {
+                fq->limit = 0;
+
+                qdisc = NULL;
+                return 0;
+        }
+
+        r = safe_atou32(rvalue, &fq->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 fq_vtable = {
+        .object_size = sizeof(FairQueueTrafficPolicing),
+        .tca_kind = "fq",
+        .fill_message = fair_queue_traffic_policing_fill_message,
+};

src/network/tc/fq.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: LGPL-2.1+
+ * Copyright © 2019 VMware, Inc. */
+#pragma once
+
+#include "conf-parser.h"
+#include "qdisc.h"
+
+typedef struct FairQueueTrafficPolicing {
+        QDisc meta;
+
+        uint32_t limit;
+} FairQueueTrafficPolicing;
+
+DEFINE_QDISC_CAST(FQ, FairQueueTrafficPolicing);
+extern const QDiscVTable fq_vtable;
+
+CONFIG_PARSER_PROTOTYPE(config_parse_tc_fair_queue_traffic_policing_packet_limit);

src/network/tc/qdisc.c

@@ -14,6 +14,7 @@
 #include "string-util.h"
 
 const QDiscVTable * const qdisc_vtable[_QDISC_KIND_MAX] = {
+        [QDISC_KIND_FQ] = &fq_vtable,
         [QDISC_KIND_FQ_CODEL] = &fq_codel_vtable,
         [QDISC_KIND_NETEM] = &netem_vtable,
         [QDISC_KIND_SFQ] = &sfq_vtable,

src/network/tc/qdisc.h

@@ -8,6 +8,7 @@
 #include "networkd-util.h"
 
 typedef enum QDiscKind {
+        QDISC_KIND_FQ,
         QDISC_KIND_FQ_CODEL,
         QDISC_KIND_NETEM,
         QDISC_KIND_SFQ,
@@ -62,6 +63,7 @@ DEFINE_NETWORK_SECTION_FUNCTIONS(QDisc, qdisc_free);
 CONFIG_PARSER_PROTOTYPE(config_parse_tc_qdiscs_parent);
 
 #include "fq-codel.h"
+#include "fq.h"
 #include "netem.h"
 #include "sfq.h"
 #include "tbf.h"

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

@@ -279,3 +279,4 @@ TokenBufferFilterPeakRate=
 TokenBufferFilterLatencySec=
 StochasticFairnessQueueingPerturbPeriodSec=
 FairQueuingControlledDelayPacketLimit=
+FairQueueTrafficPolicingPacketLimit=