From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/can/j1939/main.c | 429 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 429 insertions(+) create mode 100644 net/can/j1939/main.c (limited to 'net/can/j1939/main.c') 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 +// Copyright (c) 2010-2011 EIA Electronics, +// Kurt Van Dijck +// Copyright (c) 2018 Protonic, +// Robin van der Gracht +// Copyright (c) 2017-2019 Pengutronix, +// Marc Kleine-Budde +// Copyright (c) 2017-2019 Pengutronix, +// Oleksij Rempel + +/* Core of can-j1939 that links j1939 to CAN. */ + +#include +#include +#include +#include +#include + +#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); -- cgit v1.2.3