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
21struct j1939_session;
22enum j1939_sk_errqueue_type {
23	J1939_ERRQUEUE_ACK,
24	J1939_ERRQUEUE_SCHED,
25	J1939_ERRQUEUE_ABORT,
26};
27
28/* j1939 devices */
29struct j1939_ecu {
30	struct list_head list;
31	name_t name;
32	u8 addr;
33
34	/* indicates that this ecu successfully claimed @sa as its address */
35	struct hrtimer ac_timer;
36	struct kref kref;
37	struct j1939_priv *priv;
38
39	/* count users, to help transport protocol decide for interaction */
40	int nusers;
41};
42
43struct j1939_priv {
44	struct list_head ecus;
45	/* local list entry in priv
46	 * These allow irq (& softirq) context lookups on j1939 devices
47	 * This approach (separate lists) is done as the other 2 alternatives
48	 * are not easier or even wrong
49	 * 1) using the pure kobject methods involves mutexes, which are not
50	 *    allowed in irq context.
51	 * 2) duplicating data structures would require a lot of synchronization
52	 *    code
53	 * usage:
54	 */
55
56	/* segments need a lock to protect the above list */
57	rwlock_t lock;
58
59	struct net_device *ndev;
60
61	/* list of 256 ecu ptrs, that cache the claimed addresses.
62	 * also protected by the above lock
63	 */
64	struct j1939_addr_ent {
65		struct j1939_ecu *ecu;
66		/* count users, to help transport protocol */
67		int nusers;
68	} ents[256];
69
70	struct kref kref;
71
72	/* List of active sessions to prevent start of conflicting
73	 * one.
74	 *
75	 * Do not start two sessions of same type, addresses and
76	 * direction.
77	 */
78	struct list_head active_session_list;
79
80	/* protects active_session_list */
81	spinlock_t active_session_list_lock;
82
83	unsigned int tp_max_packet_size;
84
85	/* lock for j1939_socks list */
86	spinlock_t j1939_socks_lock;
87	struct list_head j1939_socks;
88
89	struct kref rx_kref;
90};
91
92void j1939_ecu_put(struct j1939_ecu *ecu);
93
94/* keep the cache of what is local */
95int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa);
96void j1939_local_ecu_put(struct j1939_priv *priv, name_t name, u8 sa);
97
98static inline bool j1939_address_is_unicast(u8 addr)
99{
100	return addr <= J1939_MAX_UNICAST_ADDR;
101}
102
103static inline bool j1939_address_is_idle(u8 addr)
104{
105	return addr == J1939_IDLE_ADDR;
106}
107
108static inline bool j1939_address_is_valid(u8 addr)
109{
110	return addr != J1939_NO_ADDR;
111}
112
113static inline bool j1939_pgn_is_pdu1(pgn_t pgn)
114{
115	/* ignore dp & res bits for this */
116	return (pgn & 0xff00) < 0xf000;
117}
118
119/* utility to correctly unmap an ECU */
120void j1939_ecu_unmap_locked(struct j1939_ecu *ecu);
121void j1939_ecu_unmap(struct j1939_ecu *ecu);
122
123u8 j1939_name_to_addr(struct j1939_priv *priv, name_t name);
124struct j1939_ecu *j1939_ecu_find_by_addr_locked(struct j1939_priv *priv,
125						u8 addr);
126struct j1939_ecu *j1939_ecu_get_by_addr(struct j1939_priv *priv, u8 addr);
127struct j1939_ecu *j1939_ecu_get_by_addr_locked(struct j1939_priv *priv,
128					       u8 addr);
129struct j1939_ecu *j1939_ecu_get_by_name(struct j1939_priv *priv, name_t name);
130struct j1939_ecu *j1939_ecu_get_by_name_locked(struct j1939_priv *priv,
131					       name_t name);
132
133enum j1939_transfer_type {
134	J1939_TP,
135	J1939_ETP,
136	J1939_SIMPLE,
137};
138
139struct j1939_addr {
140	name_t src_name;
141	name_t dst_name;
142	pgn_t pgn;
143
144	u8 sa;
145	u8 da;
146
147	u8 type;
148};
149
150/* control buffer of the sk_buff */
151struct j1939_sk_buff_cb {
152	/* Offset in bytes within one ETP session */
153	u32 offset;
154
155	/* for tx, MSG_SYN will be used to sync on sockets */
156	u32 msg_flags;
157	u32 tskey;
158
159	struct j1939_addr addr;
160
161	/* Flags for quick lookups during skb processing.
162	 * These are set in the receive path only.
163	 */
164#define J1939_ECU_LOCAL_SRC BIT(0)
165#define J1939_ECU_LOCAL_DST BIT(1)
166	u8 flags;
167
168	priority_t priority;
169};
170
171static inline
172struct j1939_sk_buff_cb *j1939_skb_to_cb(const struct sk_buff *skb)
173{
174	BUILD_BUG_ON(sizeof(struct j1939_sk_buff_cb) > sizeof(skb->cb));
175
176	return (struct j1939_sk_buff_cb *)skb->cb;
177}
178
179int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb);
180void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb);
181bool j1939_sk_recv_match(struct j1939_priv *priv,
182			 struct j1939_sk_buff_cb *skcb);
183void j1939_sk_send_loop_abort(struct sock *sk, int err);
184void j1939_sk_errqueue(struct j1939_session *session,
185		       enum j1939_sk_errqueue_type type);
186void j1939_sk_queue_activate_next(struct j1939_session *session);
187
188/* stack entries */
189struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
190				    struct sk_buff *skb, size_t size);
191int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb);
192int j1939_ac_fixup(struct j1939_priv *priv, struct sk_buff *skb);
193void j1939_ac_recv(struct j1939_priv *priv, struct sk_buff *skb);
194void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb);
195
196/* network management */
197struct j1939_ecu *j1939_ecu_create_locked(struct j1939_priv *priv, name_t name);
198
199void j1939_ecu_timer_start(struct j1939_ecu *ecu);
200void j1939_ecu_timer_cancel(struct j1939_ecu *ecu);
201void j1939_ecu_unmap_all(struct j1939_priv *priv);
202
203struct j1939_priv *j1939_netdev_start(struct net_device *ndev);
204void j1939_netdev_stop(struct j1939_priv *priv);
205
206void j1939_priv_put(struct j1939_priv *priv);
207void j1939_priv_get(struct j1939_priv *priv);
208
209/* notify/alert all j1939 sockets bound to ifindex */
210void j1939_sk_netdev_event_netdown(struct j1939_priv *priv);
211int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk);
212void j1939_tp_init(struct j1939_priv *priv);
213
214/* decrement pending skb for a j1939 socket */
215void j1939_sock_pending_del(struct sock *sk);
216
217enum j1939_session_state {
218	J1939_SESSION_NEW,
219	J1939_SESSION_ACTIVE,
220	/* waiting for abort signal on the bus */
221	J1939_SESSION_WAITING_ABORT,
222	J1939_SESSION_ACTIVE_MAX,
223	J1939_SESSION_DONE,
224};
225
226struct j1939_session {
227	struct j1939_priv *priv;
228	struct list_head active_session_list_entry;
229	struct list_head sk_session_queue_entry;
230	struct kref kref;
231	struct sock *sk;
232
233	/* ifindex, src, dst, pgn define the session block
234	 * the are _never_ modified after insertion in the list
235	 * this decreases locking problems a _lot_
236	 */
237	struct j1939_sk_buff_cb skcb;
238	struct sk_buff_head skb_queue;
239
240	/* all tx related stuff (last_txcmd, pkt.tx)
241	 * is protected (modified only) with the txtimer hrtimer
242	 * 'total' & 'block' are never changed,
243	 * last_cmd, last & block are protected by ->lock
244	 * this means that the tx may run after cts is received that should
245	 * have stopped tx, but this time discrepancy is never avoided anyhow
246	 */
247	u8 last_cmd, last_txcmd;
248	bool transmission;
249	bool extd;
250	/* Total message size, number of bytes */
251	unsigned int total_message_size;
252	/* Total number of bytes queue from socket to the session */
253	unsigned int total_queued_size;
254	unsigned int tx_retry;
255
256	int err;
257	u32 tskey;
258	enum j1939_session_state state;
259
260	/* Packets counters for a (extended) transfer session. The packet is
261	 * maximal of 7 bytes.
262	 */
263	struct {
264		/* total - total number of packets for this session */
265		unsigned int total;
266		/* last - last packet of a transfer block after which
267		 * responder should send ETP.CM_CTS and originator
268		 * ETP.CM_DPO
269		 */
270		unsigned int last;
271		/* tx - number of packets send by originator node.
272		 * this counter can be set back if responder node
273		 * didn't received all packets send by originator.
274		 */
275		unsigned int tx;
276		unsigned int tx_acked;
277		/* rx - number of packets received */
278		unsigned int rx;
279		/* block - amount of packets expected in one block */
280		unsigned int block;
281		/* dpo - ETP.CM_DPO, Data Packet Offset */
282		unsigned int dpo;
283	} pkt;
284	struct hrtimer txtimer, rxtimer;
285};
286
287struct j1939_sock {
288	struct sock sk; /* must be first to skip with memset */
289	struct j1939_priv *priv;
290	struct list_head list;
291
292#define J1939_SOCK_BOUND BIT(0)
293#define J1939_SOCK_CONNECTED BIT(1)
294#define J1939_SOCK_PROMISC BIT(2)
295#define J1939_SOCK_ERRQUEUE BIT(3)
296	int state;
297
298	int ifindex;
299	struct j1939_addr addr;
300	spinlock_t filters_lock;
301	struct j1939_filter *filters;
302	int nfilters;
303	pgn_t pgn_rx_filter;
304
305	/* j1939 may emit equal PGN (!= equal CAN-id's) out of order
306	 * when transport protocol comes in.
307	 * To allow emitting in order, keep a 'pending' nr. of packets
308	 */
309	atomic_t skb_pending;
310	wait_queue_head_t waitq;
311
312	/* lock for the sk_session_queue list */
313	spinlock_t sk_session_queue_lock;
314	struct list_head sk_session_queue;
315};
316
317static inline struct j1939_sock *j1939_sk(const struct sock *sk)
318{
319	return container_of(sk, struct j1939_sock, sk);
320}
321
322void j1939_session_get(struct j1939_session *session);
323void j1939_session_put(struct j1939_session *session);
324void j1939_session_skb_queue(struct j1939_session *session,
325			     struct sk_buff *skb);
326int j1939_session_activate(struct j1939_session *session);
327void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec);
328void j1939_session_timers_cancel(struct j1939_session *session);
329
330#define J1939_MIN_TP_PACKET_SIZE 9
331#define J1939_MAX_TP_PACKET_SIZE (7 * 0xff)
332#define J1939_MAX_ETP_PACKET_SIZE (7 * 0x00ffffff)
333
334#define J1939_REGULAR 0
335#define J1939_EXTENDED 1
336
337/* CAN protocol */
338extern const struct can_proto j1939_can_proto;
339
340#endif /* _J1939_PRIV_H_ */
341