network: tc: support teql

Closes systemd#14792.

Author: yuwata

man/systemd.network.xml

@@ -2677,6 +2677,31 @@
     </variablelist>
   </refsect1>
 
+  <refsect1>
+    <title>[TrivialLinkEqualizer] Section Options</title>
+    <para>The <literal>[TrivialLinkEqualizer]</literal> section manages the queueing discipline (qdisc) of
+    trivial link equalizer (teql).</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>Id=</varname></term>
+        <listitem>
+          <para>Specifies the interface ID <literal>N</literal> of teql. Defaults to <literal>0</literal>.
+          Note that when teql is used, currently, the module <constant>sch_teql</constant> with
+          <constant>max_equalizers=N+1</constant> option must be loaded before
+          <command>systemd-networkd</command> is started.</para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
   <refsect1>
     <title>[BridgeVLAN] Section Options</title>
       <para>The <literal>[BridgeVLAN]</literal> section manages the VLAN ID configuration of a bridge port and accepts

src/network/meson.build

@@ -123,6 +123,8 @@ sources = files('''
         tc/tbf.h
         tc/tc-util.c
         tc/tc-util.h
+        tc/teql.c
+        tc/teql.h
 '''.split())
 
 systemd_networkd_sources = files('networkd.c')

src/network/networkd-network-gperf.gperf

@@ -293,6 +293,8 @@ TokenBucketFilter.MTUBytes,                  config_parse_token_bucket_filter_si
 TokenBucketFilter.MPUBytes,                  config_parse_token_bucket_filter_size,                    QDISC_KIND_TBF,                0
 TokenBucketFilter.PeakRate,                  config_parse_token_bucket_filter_size,                    QDISC_KIND_TBF,                0
 TokenBucketFilter.LatencySec,                config_parse_token_bucket_filter_latency,                 QDISC_KIND_TBF,                0
+TrivialLinkEqualizer.Parent,                 config_parse_qdisc_parent,                                QDISC_KIND_TEQL,               0
+TrivialLinkEqualizer.Id,                     config_parse_trivial_link_equalizer_id,                   QDISC_KIND_TEQL,               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/networkd-network.c

@@ -488,7 +488,8 @@ int network_load_one(Manager *manager, OrderedHashmap **networks, const char *fi
                               "FairQueueingControlledDelay\0"
                               "NetworkEmulator\0"
                               "StochasticFairnessQueueing\0"
-                              "TokenBucketFilter\0",
+                              "TokenBucketFilter\0"
+                              "TrivialLinkEqualizer\0",
                               config_item_perf_lookup, network_network_gperf_lookup,
                               CONFIG_PARSE_WARN, network);
         if (r < 0)

src/network/tc/qdisc.c

@@ -20,6 +20,7 @@ const QDiscVTable * const qdisc_vtable[_QDISC_KIND_MAX] = {
         [QDISC_KIND_NETEM] = &netem_vtable,
         [QDISC_KIND_SFQ] = &sfq_vtable,
         [QDISC_KIND_TBF] = &tbf_vtable,
+        [QDISC_KIND_TEQL] = &teql_vtable,
 };
 
 static int qdisc_new(QDiscKind kind, QDisc **ret) {
@@ -176,13 +177,21 @@ int qdisc_configure(Link *link, QDisc *qdisc) {
         }
 
         if (QDISC_VTABLE(qdisc)) {
-                r = sd_netlink_message_append_string(req, TCA_KIND, QDISC_VTABLE(qdisc)->tca_kind);
-                if (r < 0)
-                        return log_link_error_errno(link, r, "Could not append TCA_KIND attribute: %m");
+                if (QDISC_VTABLE(qdisc)->fill_tca_kind) {
+                        r = QDISC_VTABLE(qdisc)->fill_tca_kind(link, qdisc, req);
+                        if (r < 0)
+                                return r;
+                } else {
+                        r = sd_netlink_message_append_string(req, TCA_KIND, QDISC_VTABLE(qdisc)->tca_kind);
+                        if (r < 0)
+                                return log_link_error_errno(link, r, "Could not append TCA_KIND attribute: %m");
+                }
 
-                r = QDISC_VTABLE(qdisc)->fill_message(link, qdisc, req);
-                if (r < 0)
-                        return r;
+                if (QDISC_VTABLE(qdisc)->fill_message) {
+                        r = QDISC_VTABLE(qdisc)->fill_message(link, qdisc, req);
+                        if (r < 0)
+                                return r;
+                }
         } else {
                 r = sd_netlink_message_append_string(req, TCA_KIND, qdisc->tca_kind);
                 if (r < 0)

src/network/tc/qdisc.h

@@ -14,6 +14,7 @@ typedef enum QDiscKind {
         QDISC_KIND_NETEM,
         QDISC_KIND_SFQ,
         QDISC_KIND_TBF,
+        QDISC_KIND_TEQL,
         _QDISC_KIND_MAX,
         _QDISC_KIND_INVALID = -1,
 } QDiscKind;
@@ -35,6 +36,7 @@ typedef struct QDiscVTable {
         const char *tca_kind;
         /* called in qdisc_new() */
         int (*init)(QDisc *qdisc);
+        int (*fill_tca_kind)(Link *link, QDisc *qdisc, sd_netlink_message *m);
         int (*fill_message)(Link *link, QDisc *qdisc, sd_netlink_message *m);
         int (*verify)(QDisc *qdisc);
 } QDiscVTable;
@@ -71,3 +73,4 @@ CONFIG_PARSER_PROTOTYPE(config_parse_qdisc_parent);
 #include "netem.h"
 #include "sfq.h"
 #include "tbf.h"
+#include "teql.h"

src/network/tc/teql.c

@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "macro.h"
+#include "netlink-util.h"
+#include "parse-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "teql.h"
+
+static int trivial_link_equalizer_fill_tca_kind(Link *link, QDisc *qdisc, sd_netlink_message *req) {
+        char kind[STRLEN("teql") + DECIMAL_STR_MAX(unsigned)];
+        TrivialLinkEqualizer *teql;
+        int r;
+
+        assert(link);
+        assert(qdisc);
+        assert(req);
+
+        teql = TEQL(qdisc);
+
+        xsprintf(kind, "teql%u", teql->id);
+        r = sd_netlink_message_append_string(req, TCA_KIND, kind);
+        if (r < 0)
+                return log_link_error_errno(link, r, "Could not append TCA_KIND attribute: %m");
+
+        return 0;
+}
+
+const QDiscVTable teql_vtable = {
+        .object_size = sizeof(TrivialLinkEqualizer),
+        .fill_tca_kind = trivial_link_equalizer_fill_tca_kind,
+};
+
+int config_parse_trivial_link_equalizer_id(
+                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;
+        TrivialLinkEqualizer *teql;
+        Network *network = data;
+        unsigned id;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        r = qdisc_new_static(QDISC_KIND_TEQL, 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");
+
+        teql = TEQL(qdisc);
+
+        if (isempty(rvalue)) {
+                teql->id = 0;
+
+                qdisc = NULL;
+                return 0;
+        }
+
+        r = safe_atou(rvalue, &id);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Failed to parse '%s=', ignoring assignment: %s",
+                           lvalue, rvalue);
+                return 0;
+        }
+        if (id > INT_MAX) {
+                log_syntax(unit, LOG_ERR, filename, line, 0,
+                           "'%s=' is too large, ignoring assignment: %s",
+                           lvalue, rvalue);
+        }
+
+        teql->id = id;
+
+        qdisc = NULL;
+        return 0;
+}

src/network/tc/teql.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "conf-parser.h"
+#include "qdisc.h"
+
+typedef struct TrivialLinkEqualizer {
+        QDisc meta;
+
+        unsigned id;
+} TrivialLinkEqualizer;
+
+DEFINE_QDISC_CAST(TEQL, TrivialLinkEqualizer);
+extern const QDiscVTable teql_vtable;
+
+CONFIG_PARSER_PROTOTYPE(config_parse_trivial_link_equalizer_id);

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

@@ -326,3 +326,6 @@ NetworkEmulatorDelayJitterSec=
 NetworkEmulatorLossRate=
 NetworkEmulatorDuplicateRate=
 NetworkEmulatorPacketLimit=
+[TrivialLinkEqualizer]
+Parent=
+Id=