+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <net/if.h>
+#include <linux/can/netlink.h>
+
+#include "netlink-util.h"
+#include "networkd-can.h"
+#include "networkd-link.h"
+#include "networkd-manager.h"
+#include "string-util.h"
+
+static int link_up_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
+ int r;
+
+ assert(link);
+
+ if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
+ return 1;
+
+ r = sd_netlink_message_get_errno(m);
+ if (r < 0)
+ /* we warn but don't fail the link, as it may be brought up later */
+ log_link_warning_errno(link, r, "Could not bring up interface: %m");
+
+ return 1;
+}
+
+static int link_up_can(Link *link) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
+ int r;
+
+ assert(link);
+
+ log_link_debug(link, "Bringing CAN link up");
+
+ r = sd_rtnl_message_new_link(link->manager->rtnl, &req, RTM_SETLINK, link->ifindex);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not allocate RTM_SETLINK message: %m");
+
+ r = sd_rtnl_message_link_set_flags(req, IFF_UP, IFF_UP);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not set link flags: %m");
+
+ r = netlink_call_async(link->manager->rtnl, NULL, req, link_up_handler,
+ link_netlink_destroy_callback, link);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not send rtnetlink message: %m");
+
+ link_ref(link);
+
+ return 0;
+}
+
+static int link_set_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
+ int r;
+
+ assert(link);
+
+ log_link_debug(link, "Set link");
+
+ r = sd_netlink_message_get_errno(m);
+ if (r < 0 && r != -EEXIST) {
+ log_link_error_errno(link, r, "Failed to configure CAN link: %m");
+ link_enter_failed(link);
+ }
+
+ return 1;
+}
+
+static int link_set_can(Link *link) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r;
+
+ assert(link);
+ assert(link->network);
+ assert(link->manager);
+ assert(link->manager->rtnl);
+
+ log_link_debug(link, "Configuring CAN link.");
+
+ r = sd_rtnl_message_new_link(link->manager->rtnl, &m, RTM_NEWLINK, link->ifindex);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Failed to allocate netlink message: %m");
+
+ r = sd_netlink_message_set_flags(m, NLM_F_REQUEST | NLM_F_ACK);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not set netlink flags: %m");
+
+ r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Failed to open netlink container: %m");
+
+ r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, link->kind);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not append IFLA_INFO_DATA attribute: %m");
+
+ if (link->network->can_bitrate > 0 || link->network->can_sample_point > 0) {
+ struct can_bittiming bt = {
+ .bitrate = link->network->can_bitrate,
+ .sample_point = link->network->can_sample_point,
+ };
+
+ if (link->network->can_bitrate > UINT32_MAX) {
+ log_link_error(link, "bitrate (%zu) too big.", link->network->can_bitrate);
+ return -ERANGE;
+ }
+
+ log_link_debug(link, "Setting bitrate = %d bit/s", bt.bitrate);
+ if (link->network->can_sample_point > 0)
+ log_link_debug(link, "Setting sample point = %d.%d%%", bt.sample_point / 10, bt.sample_point % 10);
+ else
+ log_link_debug(link, "Using default sample point");
+
+ r = sd_netlink_message_append_data(m, IFLA_CAN_BITTIMING, &bt, sizeof(bt));
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not append IFLA_CAN_BITTIMING attribute: %m");
+ }
+
+ if (link->network->can_restart_us > 0) {
+ char time_string[FORMAT_TIMESPAN_MAX];
+ uint64_t restart_ms;
+
+ if (link->network->can_restart_us == USEC_INFINITY)
+ restart_ms = 0;
+ else
+ restart_ms = DIV_ROUND_UP(link->network->can_restart_us, USEC_PER_MSEC);
+
+ format_timespan(time_string, FORMAT_TIMESPAN_MAX, restart_ms * 1000, MSEC_PER_SEC);
+
+ if (restart_ms > UINT32_MAX) {
+ log_link_error(link, "restart timeout (%s) too big.", time_string);
+ return -ERANGE;
+ }
+
+ log_link_debug(link, "Setting restart = %s", time_string);
+
+ r = sd_netlink_message_append_u32(m, IFLA_CAN_RESTART_MS, restart_ms);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not append IFLA_CAN_RESTART_MS attribute: %m");
+ }
+
+ if (link->network->can_triple_sampling >= 0) {
+ struct can_ctrlmode cm = {
+ .mask = CAN_CTRLMODE_3_SAMPLES,
+ .flags = link->network->can_triple_sampling ? CAN_CTRLMODE_3_SAMPLES : 0,
+ };
+
+ log_link_debug(link, "%sabling triple-sampling", link->network->can_triple_sampling ? "En" : "Dis");
+
+ r = sd_netlink_message_append_data(m, IFLA_CAN_CTRLMODE, &cm, sizeof(cm));
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not append IFLA_CAN_CTRLMODE attribute: %m");
+ }
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Failed to close netlink container: %m");
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Failed to close netlink container: %m");
+
+ r = netlink_call_async(link->manager->rtnl, NULL, m, link_set_handler,
+ link_netlink_destroy_callback, link);
+ if (r < 0)
+ return log_link_error_errno(link, r, "Could not send rtnetlink message: %m");
+
+ link_ref(link);
+
+ if (!(link->flags & IFF_UP))
+ return link_up_can(link);
+
+ return 0;
+}
+
+static int link_down_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
+ int r;
+
+ assert(link);
+
+ if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
+ return 1;
+
+ r = sd_netlink_message_get_errno(m);
+ if (r < 0) {
+ log_link_warning_errno(link, r, "Could not bring down interface: %m");
+ link_enter_failed(link);
+ return 1;
+ }
+
+ r = link_set_can(link);
+ if (r < 0)
+ link_enter_failed(link);
+
+ return 1;
+}
+
+int link_configure_can(Link *link) {
+ int r;
+
+ if (streq_ptr(link->kind, "can")) {
+ /* The CAN interface must be down to configure bitrate, etc... */
+ if ((link->flags & IFF_UP)) {
+ r = link_down(link, link_down_handler);
+ if (r < 0) {
+ link_enter_failed(link);
+ return r;
+ }
+ } else {
+ r = link_set_can(link);
+ if (r < 0) {
+ link_enter_failed(link);
+ return r;
+ }
+ }
+
+ return 0;
+ }
+
+ if (!(link->flags & IFF_UP)) {
+ r = link_up_can(link);
+ if (r < 0) {
+ link_enter_failed(link);
+ return r;
+ }
+ }
+
+ return 0;
+}