summaryrefslogtreecommitdiff
path: root/net/can/j1939/j1939-priv.h
blob: 16af1a7f80f60e18b5526c973f66e98821786a78 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
/* SPDX-License-Identifier: GPL-2.0 */
// Copyright (c) 2010-2011 EIA Electronics,
//                         Kurt Van Dijck <kurt.van.dijck@eia.be>
// Copyright (c) 2017-2019 Pengutronix,
//                         Marc Kleine-Budde <kernel@pengutronix.de>
// Copyright (c) 2017-2019 Pengutronix,
//                         Oleksij Rempel <kernel@pengutronix.de>

#ifndef _J1939_PRIV_H_
#define _J1939_PRIV_H_

#include <linux/can/j1939.h>
#include <net/sock.h>

/* Timeout to receive the abort signal over loop back. In case CAN
 * bus is open, the timeout should be triggered.
 */
#define J1939_XTP_ABORT_TIMEOUT_MS 500
#define J1939_SIMPLE_ECHO_TIMEOUT_MS (10 * 1000)

struct j1939_session;
enum j1939_sk_errqueue_type {
	J1939_ERRQUEUE_TX_ACK,
	J1939_ERRQUEUE_TX_SCHED,
	J1939_ERRQUEUE_TX_ABORT,
	J1939_ERRQUEUE_RX_RTS,
	J1939_ERRQUEUE_RX_DPO,
	J1939_ERRQUEUE_RX_ABORT,
};

/* j1939 devices */
struct j1939_ecu {
	struct list_head list;
	name_t name;
	u8 addr;

	/* indicates that this ecu successfully claimed @sa as its address */
	struct hrtimer ac_timer;
	struct kref kref;
	struct j1939_priv *priv;

	/* count users, to help transport protocol decide for interaction */
	int nusers;
};

struct j1939_priv {
	struct list_head ecus;
	/* local list entry in priv
	 * These allow irq (& softirq) context lookups on j1939 devices
	 * This approach (separate lists) is done as the other 2 alternatives
	 * are not easier or even wrong
	 * 1) using the pure kobject methods involves mutexes, which are not
	 *    allowed in irq context.
	 * 2) duplicating data structures would require a lot of synchronization
	 *    code
	 * usage:
	 */

	/* segments need a lock to protect the above list */
	rwlock_t lock;

	struct net_device *ndev;

	/* list of 256 ecu ptrs, that cache the claimed addresses.
	 * also protected by the above lock
	 */
	struct j1939_addr_ent {
		struct j1939_ecu *ecu;
		/* count users, to help transport protocol */
		int nusers;
	} ents[256];

	struct kref kref;

	/* List of active sessions to prevent start of conflicting
	 * one.
	 *
	 * Do not start two sessions of same type, addresses and
	 * direction.
	 */
	struct list_head active_session_list;

	/* protects active_session_list */
	spinlock_t active_session_list_lock;

	unsigned int tp_max_packet_size;

	/* lock for j1939_socks list */
	spinlock_t j1939_socks_lock;
	struct list_head j1939_socks;

	struct kref rx_kref;
	u32 rx_tskey;
};

void j1939_ecu_put(struct j1939_ecu *ecu);

/* keep the cache of what is local */
int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa);
void j1939_local_ecu_put(struct j1939_priv *priv, name_t name, u8 sa);

static inline bool j1939_address_is_unicast(u8 addr)
{
	return addr <= J1939_MAX_UNICAST_ADDR;
}

static inline bool j1939_address_is_idle(u8 addr)
{
	return addr == J1939_IDLE_ADDR;
}

static inline bool j1939_address_is_valid(u8 addr)
{
	return addr != J1939_NO_ADDR;
}

static inline bool j1939_pgn_is_pdu1(pgn_t pgn)
{
	/* ignore dp & res bits for this */
	return (pgn & 0xff00) < 0xf000;
}

/* utility to correctly unmap an ECU */
void j1939_ecu_unmap_locked(struct j1939_ecu *ecu);
void j1939_ecu_unmap(struct j1939_ecu *ecu);

u8 j1939_name_to_addr(struct j1939_priv *priv, name_t name);
struct j1939_ecu *j1939_ecu_find_by_addr_locked(struct j1939_priv *priv,
						u8 addr);
struct j1939_ecu *j1939_ecu_get_by_addr(struct j1939_priv *priv, u8 addr);
struct j1939_ecu *j1939_ecu_get_by_addr_locked(struct j1939_priv *priv,
					       u8 addr);
struct j1939_ecu *j1939_ecu_get_by_name(struct j1939_priv *priv, name_t name);
struct j1939_ecu *j1939_ecu_get_by_name_locked(struct j1939_priv *priv,
					       name_t name);

enum j1939_transfer_type {
	J1939_TP,
	J1939_ETP,
	J1939_SIMPLE,
};

struct j1939_addr {
	name_t src_name;
	name_t dst_name;
	pgn_t pgn;

	u8 sa;
	u8 da;

	u8 type;
};

/* control buffer of the sk_buff */
struct j1939_sk_buff_cb {
	/* Offset in bytes within one ETP session */
	u32 offset;

	/* for tx, MSG_SYN will be used to sync on sockets */
	u32 msg_flags;
	u32 tskey;

	struct j1939_addr addr;

	/* Flags for quick lookups during skb processing.
	 * These are set in the receive path only.
	 */
#define J1939_ECU_LOCAL_SRC BIT(0)
#define J1939_ECU_LOCAL_DST BIT(1)
	u8 flags;

	priority_t priority;
};

static inline
struct j1939_sk_buff_cb *j1939_skb_to_cb(const struct sk_buff *skb)
{
	BUILD_BUG_ON(sizeof(struct j1939_sk_buff_cb) > sizeof(skb->cb));

	return (struct j1939_sk_buff_cb *)skb->cb;
}

int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb);
void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb);
bool j1939_sk_recv_match(struct j1939_priv *priv,
			 struct j1939_sk_buff_cb *skcb);
void j1939_sk_send_loop_abort(struct sock *sk, int err);
void j1939_sk_errqueue(struct j1939_session *session,
		       enum j1939_sk_errqueue_type type);
void j1939_sk_queue_activate_next(struct j1939_session *session);

/* stack entries */
struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
				    struct sk_buff *skb, size_t size);
int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb);
int j1939_ac_fixup(struct j1939_priv *priv, struct sk_buff *skb);
void j1939_ac_recv(struct j1939_priv *priv, struct sk_buff *skb);
void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb);

/* network management */
struct j1939_ecu *j1939_ecu_create_locked(struct j1939_priv *priv, name_t name);

void j1939_ecu_timer_start(struct j1939_ecu *ecu);
void j1939_ecu_timer_cancel(struct j1939_ecu *ecu);
void j1939_ecu_unmap_all(struct j1939_priv *priv);

struct j1939_priv *j1939_netdev_start(struct net_device *ndev);
void j1939_netdev_stop(struct j1939_priv *priv);

void j1939_priv_put(struct j1939_priv *priv);
void j1939_priv_get(struct j1939_priv *priv);

/* notify/alert all j1939 sockets bound to ifindex */
void j1939_sk_netdev_event_netdown(struct j1939_priv *priv);
int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk);
void j1939_tp_init(struct j1939_priv *priv);

/* decrement pending skb for a j1939 socket */
void j1939_sock_pending_del(struct sock *sk);

enum j1939_session_state {
	J1939_SESSION_NEW,
	J1939_SESSION_ACTIVE,
	/* waiting for abort signal on the bus */
	J1939_SESSION_WAITING_ABORT,
	J1939_SESSION_ACTIVE_MAX,
	J1939_SESSION_DONE,
};

struct j1939_session {
	struct j1939_priv *priv;
	struct list_head active_session_list_entry;
	struct list_head sk_session_queue_entry;
	struct kref kref;
	struct sock *sk;

	/* ifindex, src, dst, pgn define the session block
	 * the are _never_ modified after insertion in the list
	 * this decreases locking problems a _lot_
	 */
	struct j1939_sk_buff_cb skcb;
	struct sk_buff_head skb_queue;

	/* all tx related stuff (last_txcmd, pkt.tx)
	 * is protected (modified only) with the txtimer hrtimer
	 * 'total' & 'block' are never changed,
	 * last_cmd, last & block are protected by ->lock
	 * this means that the tx may run after cts is received that should
	 * have stopped tx, but this time discrepancy is never avoided anyhow
	 */
	u8 last_cmd, last_txcmd;
	bool transmission;
	bool extd;
	/* Total message size, number of bytes */
	unsigned int total_message_size;
	/* Total number of bytes queue from socket to the session */
	unsigned int total_queued_size;
	unsigned int tx_retry;

	int err;
	u32 tskey;
	enum j1939_session_state state;

	/* Packets counters for a (extended) transfer session. The packet is
	 * maximal of 7 bytes.
	 */
	struct {
		/* total - total number of packets for this session */
		unsigned int total;
		/* last - last packet of a transfer block after which
		 * responder should send ETP.CM_CTS and originator
		 * ETP.CM_DPO
		 */
		unsigned int last;
		/* tx - number of packets send by originator node.
		 * this counter can be set back if responder node
		 * didn't received all packets send by originator.
		 */
		unsigned int tx;
		unsigned int tx_acked;
		/* rx - number of packets received */
		unsigned int rx;
		/* block - amount of packets expected in one block */
		unsigned int block;
		/* dpo - ETP.CM_DPO, Data Packet Offset */
		unsigned int dpo;
	} pkt;
	struct hrtimer txtimer, rxtimer;
};

struct j1939_sock {
	struct sock sk; /* must be first to skip with memset */
	struct j1939_priv *priv;
	struct list_head list;

#define J1939_SOCK_BOUND BIT(0)
#define J1939_SOCK_CONNECTED BIT(1)
#define J1939_SOCK_PROMISC BIT(2)
#define J1939_SOCK_ERRQUEUE BIT(3)
	int state;

	int ifindex;
	struct j1939_addr addr;
	struct j1939_filter *filters;
	int nfilters;
	pgn_t pgn_rx_filter;

	/* j1939 may emit equal PGN (!= equal CAN-id's) out of order
	 * when transport protocol comes in.
	 * To allow emitting in order, keep a 'pending' nr. of packets
	 */
	atomic_t skb_pending;
	wait_queue_head_t waitq;

	/* lock for the sk_session_queue list */
	spinlock_t sk_session_queue_lock;
	struct list_head sk_session_queue;
};

static inline struct j1939_sock *j1939_sk(const struct sock *sk)
{
	return container_of(sk, struct j1939_sock, sk);
}

void j1939_session_get(struct j1939_session *session);
void j1939_session_put(struct j1939_session *session);
void j1939_session_skb_queue(struct j1939_session *session,
			     struct sk_buff *skb);
int j1939_session_activate(struct j1939_session *session);
void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec);
void j1939_session_timers_cancel(struct j1939_session *session);

#define J1939_MIN_TP_PACKET_SIZE 9
#define J1939_MAX_TP_PACKET_SIZE (7 * 0xff)
#define J1939_MAX_ETP_PACKET_SIZE (7 * 0x00ffffff)

#define J1939_REGULAR 0
#define J1939_EXTENDED 1

/* CAN protocol */
extern const struct can_proto j1939_can_proto;

#endif /* _J1939_PRIV_H_ */