network: can: add support for bus error reporting

Enhance systemd-networkd to be able to control a CAN device's berr-reporting
flag via the new boolean directive BusErrorReporting= to be used in network
files.

6 files changed, 20 insertions, 0 deletions

diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 422268b0f7..5a6613ab60 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -2743,6 +2743,16 @@ IPv6Token=prefixstable:2002:da8:1::</programlisting></para>
           </listitem>
         </varlistentry>
         <varlistentry>
+          <term><varname>BusErrorReporting=</varname></term>
+          <listitem>
+            <para>Takes a boolean. When <literal>yes</literal>, reporting of CAN bus errors is activated
+            (those include single bit, frame format, and bit stuffing errors, unable to send dominant bit,
+            unable to send recessive bit, bus overload, active error announcement, error occurred on
+            transmission). When unset, the kernel's default will be used. Note: in case of a CAN bus with a
+            single CAN device, sending a CAN frame may result in a huge number of CAN bus errors.</para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
           <term><varname>ListenOnly=</varname></term>
           <listitem>
             <para>Takes a boolean. When <literal>yes</literal>, listen-only mode is enabled. When the
diff --git a/src/network/networkd-can.c b/src/network/networkd-can.c
index d3aefe1970..c0018c306f 100644
--- a/src/network/networkd-can.c
+++ b/src/network/networkd-can.c
@@ -211,6 +211,12 @@ static int link_set_can(Link *link) {
                 log_link_debug(link, "Setting triple-sampling to '%s'.", yes_no(link->network->can_triple_sampling));
         }
 
+        if (link->network->can_berr_reporting >= 0) {
+                cm.mask |= CAN_CTRLMODE_BERR_REPORTING;
+                SET_FLAG(cm.flags, CAN_CTRLMODE_BERR_REPORTING, link->network->can_berr_reporting);
+                log_link_debug(link, "Setting bus error reporting to '%s'.", yes_no(link->network->can_berr_reporting));
+        }
+
         if (link->network->can_listen_only >= 0) {
                 cm.mask |= CAN_CTRLMODE_LISTENONLY;
                 SET_FLAG(cm.flags, CAN_CTRLMODE_LISTENONLY, link->network->can_listen_only);
diff --git a/src/network/networkd-network-gperf.gperf b/src/network/networkd-network-gperf.gperf
index 444c6c78bc..55c404a19b 100644
--- a/src/network/networkd-network-gperf.gperf
+++ b/src/network/networkd-network-gperf.gperf
@@ -320,6 +320,7 @@ CAN.FDMode,                                  config_parse_tristate,
 CAN.FDNonISO,                                config_parse_tristate,                                    0,                             offsetof(Network, can_non_iso)
 CAN.RestartSec,                              config_parse_sec,                                         0,                             offsetof(Network, can_restart_us)
 CAN.TripleSampling,                          config_parse_tristate,                                    0,                             offsetof(Network, can_triple_sampling)
+CAN.BusErrorReporting,                       config_parse_tristate,                                    0,                             offsetof(Network, can_berr_reporting)
 CAN.Termination,                             config_parse_tristate,                                    0,                             offsetof(Network, can_termination)
 CAN.ListenOnly,                              config_parse_tristate,                                    0,                             offsetof(Network, can_listen_only)
 QDisc.Parent,                                config_parse_qdisc_parent,                                _QDISC_KIND_INVALID,           0
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 6f1afed091..6b7c9aaa3f 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -415,6 +415,7 @@ int network_load_one(Manager *manager, OrderedHashmap **networks, const char *fi
                 .ipv6_accept_ra_start_dhcp6_client = IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES,
 
                 .can_triple_sampling = -1,
+                .can_berr_reporting = -1,
                 .can_termination = -1,
                 .can_listen_only = -1,
                 .can_fd_mode = -1,
diff --git a/src/network/networkd-network.h b/src/network/networkd-network.h
index 762dc971db..2b7dc4e94b 100644
--- a/src/network/networkd-network.h
+++ b/src/network/networkd-network.h
@@ -231,6 +231,7 @@ struct Network {
         unsigned can_data_sample_point;
         usec_t can_restart_us;
         int can_triple_sampling;
+        int can_berr_reporting;
         int can_termination;
         int can_listen_only;
         int can_fd_mode;
diff --git a/test/fuzz/fuzz-network-parser/directives.network b/test/fuzz/fuzz-network-parser/directives.network
index e7860702c6..a8324b3b01 100644
--- a/test/fuzz/fuzz-network-parser/directives.network
+++ b/test/fuzz/fuzz-network-parser/directives.network
@@ -246,6 +246,7 @@ FDMode=
 FDNonISO=
 RestartSec=
 TripleSampling=
+BusErrorReporting=
 Termination=
 ListenOnly=
 [Address]