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-rw-r--r--net/can/j1939/main.c429
1 files changed, 429 insertions, 0 deletions
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
new file mode 100644
index 000000000..ecff1c947
--- /dev/null
+++ b/net/can/j1939/main.c
@@ -0,0 +1,429 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+// Pieter Beyens <pieter.beyens@eia.be>
+// Copyright (c) 2010-2011 EIA Electronics,
+// Kurt Van Dijck <kurt.van.dijck@eia.be>
+// Copyright (c) 2018 Protonic,
+// Robin van der Gracht <robin@protonic.nl>
+// Copyright (c) 2017-2019 Pengutronix,
+// Marc Kleine-Budde <kernel@pengutronix.de>
+// Copyright (c) 2017-2019 Pengutronix,
+// Oleksij Rempel <kernel@pengutronix.de>
+
+/* Core of can-j1939 that links j1939 to CAN. */
+
+#include <linux/can/can-ml.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/if_arp.h>
+#include <linux/module.h>
+
+#include "j1939-priv.h"
+
+MODULE_DESCRIPTION("PF_CAN SAE J1939");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("EIA Electronics (Kurt Van Dijck & Pieter Beyens)");
+MODULE_ALIAS("can-proto-" __stringify(CAN_J1939));
+
+/* LOWLEVEL CAN interface */
+
+/* CAN_HDR: #bytes before can_frame data part */
+#define J1939_CAN_HDR (offsetof(struct can_frame, data))
+
+/* CAN_FTR: #bytes beyond data part */
+#define J1939_CAN_FTR (sizeof(struct can_frame) - J1939_CAN_HDR - \
+ sizeof(((struct can_frame *)0)->data))
+
+/* lowest layer */
+static void j1939_can_recv(struct sk_buff *iskb, void *data)
+{
+ struct j1939_priv *priv = data;
+ struct sk_buff *skb;
+ struct j1939_sk_buff_cb *skcb, *iskcb;
+ struct can_frame *cf;
+
+ /* make sure we only get Classical CAN frames */
+ if (!can_is_can_skb(iskb))
+ return;
+
+ /* create a copy of the skb
+ * j1939 only delivers the real data bytes,
+ * the header goes into sockaddr.
+ * j1939 may not touch the incoming skb in such way
+ */
+ skb = skb_clone(iskb, GFP_ATOMIC);
+ if (!skb)
+ return;
+
+ j1939_priv_get(priv);
+ can_skb_set_owner(skb, iskb->sk);
+
+ /* get a pointer to the header of the skb
+ * the skb payload (pointer) is moved, so that the next skb_data
+ * returns the actual payload
+ */
+ cf = (void *)skb->data;
+ skb_pull(skb, J1939_CAN_HDR);
+
+ /* fix length, set to dlc, with 8 maximum */
+ skb_trim(skb, min_t(uint8_t, cf->len, 8));
+
+ /* set addr */
+ skcb = j1939_skb_to_cb(skb);
+ memset(skcb, 0, sizeof(*skcb));
+
+ iskcb = j1939_skb_to_cb(iskb);
+ skcb->tskey = iskcb->tskey;
+ skcb->priority = (cf->can_id >> 26) & 0x7;
+ skcb->addr.sa = cf->can_id;
+ skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
+ /* set default message type */
+ skcb->addr.type = J1939_TP;
+
+ if (!j1939_address_is_valid(skcb->addr.sa)) {
+ netdev_err_once(priv->ndev, "%s: sa is broadcast address, ignoring!\n",
+ __func__);
+ goto done;
+ }
+
+ if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
+ /* Type 1: with destination address */
+ skcb->addr.da = skcb->addr.pgn;
+ /* normalize pgn: strip dst address */
+ skcb->addr.pgn &= 0x3ff00;
+ } else {
+ /* set broadcast address */
+ skcb->addr.da = J1939_NO_ADDR;
+ }
+
+ /* update localflags */
+ read_lock_bh(&priv->lock);
+ if (j1939_address_is_unicast(skcb->addr.sa) &&
+ priv->ents[skcb->addr.sa].nusers)
+ skcb->flags |= J1939_ECU_LOCAL_SRC;
+ if (j1939_address_is_unicast(skcb->addr.da) &&
+ priv->ents[skcb->addr.da].nusers)
+ skcb->flags |= J1939_ECU_LOCAL_DST;
+ read_unlock_bh(&priv->lock);
+
+ /* deliver into the j1939 stack ... */
+ j1939_ac_recv(priv, skb);
+
+ if (j1939_tp_recv(priv, skb))
+ /* this means the transport layer processed the message */
+ goto done;
+
+ j1939_simple_recv(priv, skb);
+ j1939_sk_recv(priv, skb);
+ done:
+ j1939_priv_put(priv);
+ kfree_skb(skb);
+}
+
+/* NETDEV MANAGEMENT */
+
+/* values for can_rx_(un)register */
+#define J1939_CAN_ID CAN_EFF_FLAG
+#define J1939_CAN_MASK (CAN_EFF_FLAG | CAN_RTR_FLAG)
+
+static DEFINE_MUTEX(j1939_netdev_lock);
+
+static struct j1939_priv *j1939_priv_create(struct net_device *ndev)
+{
+ struct j1939_priv *priv;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return NULL;
+
+ rwlock_init(&priv->lock);
+ INIT_LIST_HEAD(&priv->ecus);
+ priv->ndev = ndev;
+ kref_init(&priv->kref);
+ kref_init(&priv->rx_kref);
+ dev_hold(ndev);
+
+ netdev_dbg(priv->ndev, "%s : 0x%p\n", __func__, priv);
+
+ return priv;
+}
+
+static inline void j1939_priv_set(struct net_device *ndev,
+ struct j1939_priv *priv)
+{
+ struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
+
+ can_ml->j1939_priv = priv;
+}
+
+static void __j1939_priv_release(struct kref *kref)
+{
+ struct j1939_priv *priv = container_of(kref, struct j1939_priv, kref);
+ struct net_device *ndev = priv->ndev;
+
+ netdev_dbg(priv->ndev, "%s: 0x%p\n", __func__, priv);
+
+ WARN_ON_ONCE(!list_empty(&priv->active_session_list));
+ WARN_ON_ONCE(!list_empty(&priv->ecus));
+ WARN_ON_ONCE(!list_empty(&priv->j1939_socks));
+
+ dev_put(ndev);
+ kfree(priv);
+}
+
+void j1939_priv_put(struct j1939_priv *priv)
+{
+ kref_put(&priv->kref, __j1939_priv_release);
+}
+
+void j1939_priv_get(struct j1939_priv *priv)
+{
+ kref_get(&priv->kref);
+}
+
+static int j1939_can_rx_register(struct j1939_priv *priv)
+{
+ struct net_device *ndev = priv->ndev;
+ int ret;
+
+ j1939_priv_get(priv);
+ ret = can_rx_register(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
+ j1939_can_recv, priv, "j1939", NULL);
+ if (ret < 0) {
+ j1939_priv_put(priv);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void j1939_can_rx_unregister(struct j1939_priv *priv)
+{
+ struct net_device *ndev = priv->ndev;
+
+ can_rx_unregister(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
+ j1939_can_recv, priv);
+
+ /* The last reference of priv is dropped by the RCU deferred
+ * j1939_sk_sock_destruct() of the last socket, so we can
+ * safely drop this reference here.
+ */
+ j1939_priv_put(priv);
+}
+
+static void __j1939_rx_release(struct kref *kref)
+ __releases(&j1939_netdev_lock)
+{
+ struct j1939_priv *priv = container_of(kref, struct j1939_priv,
+ rx_kref);
+
+ j1939_can_rx_unregister(priv);
+ j1939_ecu_unmap_all(priv);
+ j1939_priv_set(priv->ndev, NULL);
+ mutex_unlock(&j1939_netdev_lock);
+}
+
+/* get pointer to priv without increasing ref counter */
+static inline struct j1939_priv *j1939_ndev_to_priv(struct net_device *ndev)
+{
+ struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
+
+ return can_ml->j1939_priv;
+}
+
+static struct j1939_priv *j1939_priv_get_by_ndev_locked(struct net_device *ndev)
+{
+ struct j1939_priv *priv;
+
+ lockdep_assert_held(&j1939_netdev_lock);
+
+ priv = j1939_ndev_to_priv(ndev);
+ if (priv)
+ j1939_priv_get(priv);
+
+ return priv;
+}
+
+static struct j1939_priv *j1939_priv_get_by_ndev(struct net_device *ndev)
+{
+ struct j1939_priv *priv;
+
+ mutex_lock(&j1939_netdev_lock);
+ priv = j1939_priv_get_by_ndev_locked(ndev);
+ mutex_unlock(&j1939_netdev_lock);
+
+ return priv;
+}
+
+struct j1939_priv *j1939_netdev_start(struct net_device *ndev)
+{
+ struct j1939_priv *priv, *priv_new;
+ int ret;
+
+ mutex_lock(&j1939_netdev_lock);
+ priv = j1939_priv_get_by_ndev_locked(ndev);
+ if (priv) {
+ kref_get(&priv->rx_kref);
+ mutex_unlock(&j1939_netdev_lock);
+ return priv;
+ }
+ mutex_unlock(&j1939_netdev_lock);
+
+ priv = j1939_priv_create(ndev);
+ if (!priv)
+ return ERR_PTR(-ENOMEM);
+
+ j1939_tp_init(priv);
+ spin_lock_init(&priv->j1939_socks_lock);
+ INIT_LIST_HEAD(&priv->j1939_socks);
+
+ mutex_lock(&j1939_netdev_lock);
+ priv_new = j1939_priv_get_by_ndev_locked(ndev);
+ if (priv_new) {
+ /* Someone was faster than us, use their priv and roll
+ * back our's.
+ */
+ kref_get(&priv_new->rx_kref);
+ mutex_unlock(&j1939_netdev_lock);
+ dev_put(ndev);
+ kfree(priv);
+ return priv_new;
+ }
+ j1939_priv_set(ndev, priv);
+
+ ret = j1939_can_rx_register(priv);
+ if (ret < 0)
+ goto out_priv_put;
+
+ mutex_unlock(&j1939_netdev_lock);
+ return priv;
+
+ out_priv_put:
+ j1939_priv_set(ndev, NULL);
+ mutex_unlock(&j1939_netdev_lock);
+
+ dev_put(ndev);
+ kfree(priv);
+
+ return ERR_PTR(ret);
+}
+
+void j1939_netdev_stop(struct j1939_priv *priv)
+{
+ kref_put_mutex(&priv->rx_kref, __j1939_rx_release, &j1939_netdev_lock);
+ j1939_priv_put(priv);
+}
+
+int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb)
+{
+ int ret, dlc;
+ canid_t canid;
+ struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+ struct can_frame *cf;
+
+ /* apply sanity checks */
+ if (j1939_pgn_is_pdu1(skcb->addr.pgn))
+ skcb->addr.pgn &= J1939_PGN_PDU1_MAX;
+ else
+ skcb->addr.pgn &= J1939_PGN_MAX;
+
+ if (skcb->priority > 7)
+ skcb->priority = 6;
+
+ ret = j1939_ac_fixup(priv, skb);
+ if (unlikely(ret))
+ goto failed;
+ dlc = skb->len;
+
+ /* re-claim the CAN_HDR from the SKB */
+ cf = skb_push(skb, J1939_CAN_HDR);
+
+ /* initialize header structure */
+ memset(cf, 0, J1939_CAN_HDR);
+
+ /* make it a full can frame again */
+ skb_put(skb, J1939_CAN_FTR + (8 - dlc));
+
+ canid = CAN_EFF_FLAG |
+ (skcb->priority << 26) |
+ (skcb->addr.pgn << 8) |
+ skcb->addr.sa;
+ if (j1939_pgn_is_pdu1(skcb->addr.pgn))
+ canid |= skcb->addr.da << 8;
+
+ cf->can_id = canid;
+ cf->len = dlc;
+
+ return can_send(skb, 1);
+
+ failed:
+ kfree_skb(skb);
+ return ret;
+}
+
+static int j1939_netdev_notify(struct notifier_block *nb,
+ unsigned long msg, void *data)
+{
+ struct net_device *ndev = netdev_notifier_info_to_dev(data);
+ struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
+ struct j1939_priv *priv;
+
+ if (!can_ml)
+ goto notify_done;
+
+ priv = j1939_priv_get_by_ndev(ndev);
+ if (!priv)
+ goto notify_done;
+
+ switch (msg) {
+ case NETDEV_DOWN:
+ j1939_cancel_active_session(priv, NULL);
+ j1939_sk_netdev_event_netdown(priv);
+ j1939_ecu_unmap_all(priv);
+ break;
+ }
+
+ j1939_priv_put(priv);
+
+notify_done:
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block j1939_netdev_notifier = {
+ .notifier_call = j1939_netdev_notify,
+};
+
+/* MODULE interface */
+static __init int j1939_module_init(void)
+{
+ int ret;
+
+ pr_info("can: SAE J1939\n");
+
+ ret = register_netdevice_notifier(&j1939_netdev_notifier);
+ if (ret)
+ goto fail_notifier;
+
+ ret = can_proto_register(&j1939_can_proto);
+ if (ret < 0) {
+ pr_err("can: registration of j1939 protocol failed\n");
+ goto fail_sk;
+ }
+
+ return 0;
+
+ fail_sk:
+ unregister_netdevice_notifier(&j1939_netdev_notifier);
+ fail_notifier:
+ return ret;
+}
+
+static __exit void j1939_module_exit(void)
+{
+ can_proto_unregister(&j1939_can_proto);
+
+ unregister_netdevice_notifier(&j1939_netdev_notifier);
+}
+
+module_init(j1939_module_init);
+module_exit(j1939_module_exit);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 06:45:56 +0000