1  /* SPDX-License-Identifier: GPL-2.0 */
2  // Copyright (c) 2010-2011 EIA Electronics,
3  //                         Kurt Van Dijck <kurt.van.dijck@eia.be>
4  // Copyright (c) 2017-2019 Pengutronix,
5  //                         Marc Kleine-Budde <kernel@pengutronix.de>
6  // Copyright (c) 2017-2019 Pengutronix,
7  //                         Oleksij Rempel <kernel@pengutronix.de>
8  
9  #ifndef _J1939_PRIV_H_
10  #define _J1939_PRIV_H_
11  
12  #include <linux/can/j1939.h>
13  #include <net/sock.h>
14  
15  /* Timeout to receive the abort signal over loop back. In case CAN
16   * bus is open, the timeout should be triggered.
17   */
18  #define J1939_XTP_ABORT_TIMEOUT_MS 500
19  #define J1939_SIMPLE_ECHO_TIMEOUT_MS (10 * 1000)
20  
21  struct j1939_session;
22  enum j1939_sk_errqueue_type {
23  	J1939_ERRQUEUE_TX_ACK,
24  	J1939_ERRQUEUE_TX_SCHED,
25  	J1939_ERRQUEUE_TX_ABORT,
26  	J1939_ERRQUEUE_RX_RTS,
27  	J1939_ERRQUEUE_RX_DPO,
28  	J1939_ERRQUEUE_RX_ABORT,
29  };
30  
31  /* j1939 devices */
32  struct j1939_ecu {
33  	struct list_head list;
34  	name_t name;
35  	u8 addr;
36  
37  	/* indicates that this ecu successfully claimed @sa as its address */
38  	struct hrtimer ac_timer;
39  	struct kref kref;
40  	struct j1939_priv *priv;
41  
42  	/* count users, to help transport protocol decide for interaction */
43  	int nusers;
44  };
45  
46  struct j1939_priv {
47  	struct list_head ecus;
48  	/* local list entry in priv
49  	 * These allow irq (& softirq) context lookups on j1939 devices
50  	 * This approach (separate lists) is done as the other 2 alternatives
51  	 * are not easier or even wrong
52  	 * 1) using the pure kobject methods involves mutexes, which are not
53  	 *    allowed in irq context.
54  	 * 2) duplicating data structures would require a lot of synchronization
55  	 *    code
56  	 * usage:
57  	 */
58  
59  	/* segments need a lock to protect the above list */
60  	rwlock_t lock;
61  
62  	struct net_device *ndev;
63  
64  	/* list of 256 ecu ptrs, that cache the claimed addresses.
65  	 * also protected by the above lock
66  	 */
67  	struct j1939_addr_ent {
68  		struct j1939_ecu *ecu;
69  		/* count users, to help transport protocol */
70  		int nusers;
71  	} ents[256];
72  
73  	struct kref kref;
74  
75  	/* List of active sessions to prevent start of conflicting
76  	 * one.
77  	 *
78  	 * Do not start two sessions of same type, addresses and
79  	 * direction.
80  	 */
81  	struct list_head active_session_list;
82  
83  	/* protects active_session_list */
84  	spinlock_t active_session_list_lock;
85  
86  	unsigned int tp_max_packet_size;
87  
88  	/* lock for j1939_socks list */
89  	spinlock_t j1939_socks_lock;
90  	struct list_head j1939_socks;
91  
92  	struct kref rx_kref;
93  	u32 rx_tskey;
94  };
95  
96  void j1939_ecu_put(struct j1939_ecu *ecu);
97  
98  /* keep the cache of what is local */
99  int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa);
100  void j1939_local_ecu_put(struct j1939_priv *priv, name_t name, u8 sa);
101  
j1939_address_is_unicast(u8 addr)102  static inline bool j1939_address_is_unicast(u8 addr)
103  {
104  	return addr <= J1939_MAX_UNICAST_ADDR;
105  }
106  
j1939_address_is_idle(u8 addr)107  static inline bool j1939_address_is_idle(u8 addr)
108  {
109  	return addr == J1939_IDLE_ADDR;
110  }
111  
j1939_address_is_valid(u8 addr)112  static inline bool j1939_address_is_valid(u8 addr)
113  {
114  	return addr != J1939_NO_ADDR;
115  }
116  
j1939_pgn_is_pdu1(pgn_t pgn)117  static inline bool j1939_pgn_is_pdu1(pgn_t pgn)
118  {
119  	/* ignore dp & res bits for this */
120  	return (pgn & 0xff00) < 0xf000;
121  }
122  
123  /* utility to correctly unmap an ECU */
124  void j1939_ecu_unmap_locked(struct j1939_ecu *ecu);
125  void j1939_ecu_unmap(struct j1939_ecu *ecu);
126  
127  u8 j1939_name_to_addr(struct j1939_priv *priv, name_t name);
128  struct j1939_ecu *j1939_ecu_find_by_addr_locked(struct j1939_priv *priv,
129  						u8 addr);
130  struct j1939_ecu *j1939_ecu_get_by_addr(struct j1939_priv *priv, u8 addr);
131  struct j1939_ecu *j1939_ecu_get_by_addr_locked(struct j1939_priv *priv,
132  					       u8 addr);
133  struct j1939_ecu *j1939_ecu_get_by_name(struct j1939_priv *priv, name_t name);
134  struct j1939_ecu *j1939_ecu_get_by_name_locked(struct j1939_priv *priv,
135  					       name_t name);
136  
137  enum j1939_transfer_type {
138  	J1939_TP,
139  	J1939_ETP,
140  	J1939_SIMPLE,
141  };
142  
143  struct j1939_addr {
144  	name_t src_name;
145  	name_t dst_name;
146  	pgn_t pgn;
147  
148  	u8 sa;
149  	u8 da;
150  
151  	u8 type;
152  };
153  
154  /* control buffer of the sk_buff */
155  struct j1939_sk_buff_cb {
156  	/* Offset in bytes within one ETP session */
157  	u32 offset;
158  
159  	/* for tx, MSG_SYN will be used to sync on sockets */
160  	u32 msg_flags;
161  	u32 tskey;
162  
163  	struct j1939_addr addr;
164  
165  	/* Flags for quick lookups during skb processing.
166  	 * These are set in the receive path only.
167  	 */
168  #define J1939_ECU_LOCAL_SRC BIT(0)
169  #define J1939_ECU_LOCAL_DST BIT(1)
170  	u8 flags;
171  
172  	priority_t priority;
173  };
174  
175  static inline
j1939_skb_to_cb(const struct sk_buff * skb)176  struct j1939_sk_buff_cb *j1939_skb_to_cb(const struct sk_buff *skb)
177  {
178  	BUILD_BUG_ON(sizeof(struct j1939_sk_buff_cb) > sizeof(skb->cb));
179  
180  	return (struct j1939_sk_buff_cb *)skb->cb;
181  }
182  
183  int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb);
184  void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb);
185  bool j1939_sk_recv_match(struct j1939_priv *priv,
186  			 struct j1939_sk_buff_cb *skcb);
187  void j1939_sk_send_loop_abort(struct sock *sk, int err);
188  void j1939_sk_errqueue(struct j1939_session *session,
189  		       enum j1939_sk_errqueue_type type);
190  void j1939_sk_queue_activate_next(struct j1939_session *session);
191  
192  /* stack entries */
193  struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
194  				    struct sk_buff *skb, size_t size);
195  int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb);
196  int j1939_ac_fixup(struct j1939_priv *priv, struct sk_buff *skb);
197  void j1939_ac_recv(struct j1939_priv *priv, struct sk_buff *skb);
198  void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb);
199  
200  /* network management */
201  struct j1939_ecu *j1939_ecu_create_locked(struct j1939_priv *priv, name_t name);
202  
203  void j1939_ecu_timer_start(struct j1939_ecu *ecu);
204  void j1939_ecu_timer_cancel(struct j1939_ecu *ecu);
205  void j1939_ecu_unmap_all(struct j1939_priv *priv);
206  
207  struct j1939_priv *j1939_netdev_start(struct net_device *ndev);
208  void j1939_netdev_stop(struct j1939_priv *priv);
209  
210  void j1939_priv_put(struct j1939_priv *priv);
211  void j1939_priv_get(struct j1939_priv *priv);
212  
213  /* notify/alert all j1939 sockets bound to ifindex */
214  void j1939_sk_netdev_event_netdown(struct j1939_priv *priv);
215  int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk);
216  void j1939_tp_init(struct j1939_priv *priv);
217  
218  /* decrement pending skb for a j1939 socket */
219  void j1939_sock_pending_del(struct sock *sk);
220  
221  enum j1939_session_state {
222  	J1939_SESSION_NEW,
223  	J1939_SESSION_ACTIVE,
224  	/* waiting for abort signal on the bus */
225  	J1939_SESSION_WAITING_ABORT,
226  	J1939_SESSION_ACTIVE_MAX,
227  	J1939_SESSION_DONE,
228  };
229  
230  struct j1939_session {
231  	struct j1939_priv *priv;
232  	struct list_head active_session_list_entry;
233  	struct list_head sk_session_queue_entry;
234  	struct kref kref;
235  	struct sock *sk;
236  
237  	/* ifindex, src, dst, pgn define the session block
238  	 * the are _never_ modified after insertion in the list
239  	 * this decreases locking problems a _lot_
240  	 */
241  	struct j1939_sk_buff_cb skcb;
242  	struct sk_buff_head skb_queue;
243  
244  	/* all tx related stuff (last_txcmd, pkt.tx)
245  	 * is protected (modified only) with the txtimer hrtimer
246  	 * 'total' & 'block' are never changed,
247  	 * last_cmd, last & block are protected by ->lock
248  	 * this means that the tx may run after cts is received that should
249  	 * have stopped tx, but this time discrepancy is never avoided anyhow
250  	 */
251  	u8 last_cmd, last_txcmd;
252  	bool transmission;
253  	bool extd;
254  	/* Total message size, number of bytes */
255  	unsigned int total_message_size;
256  	/* Total number of bytes queue from socket to the session */
257  	unsigned int total_queued_size;
258  	unsigned int tx_retry;
259  
260  	int err;
261  	u32 tskey;
262  	enum j1939_session_state state;
263  
264  	/* Packets counters for a (extended) transfer session. The packet is
265  	 * maximal of 7 bytes.
266  	 */
267  	struct {
268  		/* total - total number of packets for this session */
269  		unsigned int total;
270  		/* last - last packet of a transfer block after which
271  		 * responder should send ETP.CM_CTS and originator
272  		 * ETP.CM_DPO
273  		 */
274  		unsigned int last;
275  		/* tx - number of packets send by originator node.
276  		 * this counter can be set back if responder node
277  		 * didn't received all packets send by originator.
278  		 */
279  		unsigned int tx;
280  		unsigned int tx_acked;
281  		/* rx - number of packets received */
282  		unsigned int rx;
283  		/* block - amount of packets expected in one block */
284  		unsigned int block;
285  		/* dpo - ETP.CM_DPO, Data Packet Offset */
286  		unsigned int dpo;
287  	} pkt;
288  	struct hrtimer txtimer, rxtimer;
289  };
290  
291  struct j1939_sock {
292  	struct sock sk; /* must be first to skip with memset */
293  	struct j1939_priv *priv;
294  	struct list_head list;
295  
296  #define J1939_SOCK_BOUND BIT(0)
297  #define J1939_SOCK_CONNECTED BIT(1)
298  #define J1939_SOCK_PROMISC BIT(2)
299  #define J1939_SOCK_ERRQUEUE BIT(3)
300  	int state;
301  
302  	int ifindex;
303  	struct j1939_addr addr;
304  	struct j1939_filter *filters;
305  	int nfilters;
306  	pgn_t pgn_rx_filter;
307  
308  	/* j1939 may emit equal PGN (!= equal CAN-id's) out of order
309  	 * when transport protocol comes in.
310  	 * To allow emitting in order, keep a 'pending' nr. of packets
311  	 */
312  	atomic_t skb_pending;
313  	wait_queue_head_t waitq;
314  
315  	/* lock for the sk_session_queue list */
316  	spinlock_t sk_session_queue_lock;
317  	struct list_head sk_session_queue;
318  };
319  
j1939_sk(const struct sock * sk)320  static inline struct j1939_sock *j1939_sk(const struct sock *sk)
321  {
322  	return container_of(sk, struct j1939_sock, sk);
323  }
324  
325  void j1939_session_get(struct j1939_session *session);
326  void j1939_session_put(struct j1939_session *session);
327  void j1939_session_skb_queue(struct j1939_session *session,
328  			     struct sk_buff *skb);
329  int j1939_session_activate(struct j1939_session *session);
330  void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec);
331  void j1939_session_timers_cancel(struct j1939_session *session);
332  
333  #define J1939_MIN_TP_PACKET_SIZE 9
334  #define J1939_MAX_TP_PACKET_SIZE (7 * 0xff)
335  #define J1939_MAX_ETP_PACKET_SIZE (7 * 0x00ffffff)
336  
337  #define J1939_REGULAR 0
338  #define J1939_EXTENDED 1
339  
340  /* CAN protocol */
341  extern const struct can_proto j1939_can_proto;
342  
343  #endif /* _J1939_PRIV_H_ */
344