network: TC introduce PFIFO

man/systemd.network.xml

@@ -2500,6 +2500,40 @@
     </variablelist>
   </refsect1>
 
+  <refsect1>
+    <title>[PFIFO] Section Options</title>
+    <para>The <literal>[PFIFO]</literal> section manages the queueing discipline (qdisc) of
+    Packet First In First Out (pfifo).</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 FIFO size in number of packets. The size limit (a buffer size) to prevent it
+          from overflowing in case it is unable to dequeue packets as quickly as it receives them. 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>
+
   <refsect1>
     <title>[ControlledDelay] Section Options</title>
     <para>The <literal>[ControlledDelay]</literal> section manages the queueing discipline (qdisc) of

src/network/meson.build

@@ -109,6 +109,8 @@ sources = files('''
         networkd-wifi.h
         tc/codel.c
         tc/codel.h
+        tc/fifo.c
+        tc/fifo.h
         tc/fq.c
         tc/fq.h
         tc/fq-codel.c

src/network/networkd-network-gperf.gperf

@@ -261,6 +261,9 @@ ControlledDelay.TargetSec,                   config_parse_controlled_delay_usec,
 ControlledDelay.IntervalSec,                 config_parse_controlled_delay_usec,                       QDISC_KIND_CODEL,              0
 ControlledDelay.CEThresholdSec,              config_parse_controlled_delay_usec,                       QDISC_KIND_CODEL,              0
 ControlledDelay.ECN,                         config_parse_controlled_delay_bool,                       QDISC_KIND_CODEL,              0
+PFIFO.Parent,                                config_parse_qdisc_parent,                                QDISC_KIND_PFIFO,              0
+PFIFO.Handle,                                config_parse_qdisc_handle,                                QDISC_KIND_PFIFO,              0
+PFIFO.PacketLimit,                           config_parse_fifo_size,                                   QDISC_KIND_PFIFO,              0
 FairQueueing.Parent,                         config_parse_qdisc_parent,                                QDISC_KIND_FQ,                 0
 FairQueueing.Handle,                         config_parse_qdisc_handle,                                QDISC_KIND_FQ,                 0
 FairQueueing.PacketLimit,                    config_parse_fair_queueing_u32,                           QDISC_KIND_FQ,                 0

src/network/networkd-network.c

@@ -485,6 +485,7 @@ int network_load_one(Manager *manager, OrderedHashmap **networks, const char *fi
                               "CAN\0"
                               "QDisc\0"
                               "ControlledDelay\0"
+                              "PFIFO\0"
                               "FairQueueing\0"
                               "FairQueueingControlledDelay\0"
                               "HierarchyTokenBucket\0"

src/network/tc/fifo.c

@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: LGPL-2.1+
+ * Copyright © 2020 VMware, Inc. */
+
+#include <linux/pkt_sched.h>
+
+#include "alloc-util.h"
+#include "conf-parser.h"
+#include "fifo.h"
+#include "netlink-util.h"
+#include "parse-util.h"
+#include "string-util.h"
+
+static int fifo_fill_message(Link *link, QDisc *qdisc, sd_netlink_message *req) {
+        struct tc_fifo_qopt opt = {};
+        FirstInFirstOut *fifo;
+        int r;
+
+        assert(link);
+        assert(qdisc);
+        assert(req);
+
+        fifo = PFIFO(qdisc);
+
+        opt.limit = fifo->limit;
+
+        r = sd_netlink_message_append_data(req, TCA_OPTIONS, &opt, sizeof(struct tc_fifo_qopt));
+        if (r < 0)
+                return log_link_error_errno(link, r, "Could not append TCA_OPTIONS attribute: %m");
+
+        return 0;
+}
+
+int config_parse_fifo_size(
+                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;
+        Network *network = data;
+        FirstInFirstOut *fifo;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        r = qdisc_new_static(QDISC_KIND_PFIFO, 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");
+
+        fifo = PFIFO(qdisc);
+
+        if (isempty(rvalue)) {
+                fifo->limit = 0;
+
+                qdisc = NULL;
+                return 0;
+        }
+
+        r = safe_atou32(rvalue, &fifo->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 pfifo_vtable = {
+        .object_size = sizeof(FirstInFirstOut),
+        .tca_kind = "pfifo",
+        .fill_message = fifo_fill_message,
+};

src/network/tc/fifo.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 FirstInFirstOut {
+        QDisc meta;
+
+        uint32_t limit;
+} FirstInFirstOut;
+
+DEFINE_QDISC_CAST(PFIFO, FirstInFirstOut);
+extern const QDiscVTable pfifo_vtable;
+
+CONFIG_PARSER_PROTOTYPE(config_parse_fifo_size);

src/network/tc/qdisc.c

@@ -21,6 +21,7 @@ const QDiscVTable * const qdisc_vtable[_QDISC_KIND_MAX] = {
         [QDISC_KIND_FQ_CODEL] = &fq_codel_vtable,
         [QDISC_KIND_HTB] = &htb_vtable,
         [QDISC_KIND_NETEM] = &netem_vtable,
+        [QDISC_KIND_PFIFO] = &pfifo_vtable,
         [QDISC_KIND_SFQ] = &sfq_vtable,
         [QDISC_KIND_TBF] = &tbf_vtable,
         [QDISC_KIND_TEQL] = &teql_vtable,

src/network/tc/qdisc.h

@@ -14,6 +14,7 @@ typedef enum QDiscKind {
         QDISC_KIND_FQ_CODEL,
         QDISC_KIND_HTB,
         QDISC_KIND_NETEM,
+        QDISC_KIND_PFIFO,
         QDISC_KIND_SFQ,
         QDISC_KIND_TBF,
         QDISC_KIND_TEQL,
@@ -75,6 +76,7 @@ CONFIG_PARSER_PROTOTYPE(config_parse_qdisc_parent);
 CONFIG_PARSER_PROTOTYPE(config_parse_qdisc_handle);
 
 #include "codel.h"
+#include "fifo.h"
 #include "fq-codel.h"
 #include "fq.h"
 #include "htb.h"

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

@@ -347,3 +347,7 @@ ClassId=
 Priority=
 Rate=
 CeilRate=
+[PFIFO]
+Parent=
+Handle=
+PacketLimit=