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 rwlock_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
102 static inline bool j1939_address_is_unicast(u8 addr)
103 {
104 return addr <= J1939_MAX_UNICAST_ADDR;
105 }
106
107 static inline bool j1939_address_is_idle(u8 addr)
108 {
109 return addr == J1939_IDLE_ADDR;
110 }
111
112 static inline bool j1939_address_is_valid(u8 addr)
113 {
114 return addr != J1939_NO_ADDR;
115 }
116
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
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 spinlock_t filters_lock;
305 struct j1939_filter *filters;
306 int nfilters;
307 pgn_t pgn_rx_filter;
308
309 /* j1939 may emit equal PGN (!= equal CAN-id's) out of order
310 * when transport protocol comes in.
311 * To allow emitting in order, keep a 'pending' nr. of packets
312 */
313 atomic_t skb_pending;
314 wait_queue_head_t waitq;
315
316 /* lock for the sk_session_queue list */
317 spinlock_t sk_session_queue_lock;
318 struct list_head sk_session_queue;
319 };
320
321 static inline struct j1939_sock *j1939_sk(const struct sock *sk)
322 {
323 return container_of(sk, struct j1939_sock, sk);
324 }
325
326 void j1939_session_get(struct j1939_session *session);
327 void j1939_session_put(struct j1939_session *session);
328 void j1939_session_skb_queue(struct j1939_session *session,
329 struct sk_buff *skb);
330 int j1939_session_activate(struct j1939_session *session);
331 void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec);
332 void j1939_session_timers_cancel(struct j1939_session *session);
333
334 #define J1939_MIN_TP_PACKET_SIZE 9
335 #define J1939_MAX_TP_PACKET_SIZE (7 * 0xff)
336 #define J1939_MAX_ETP_PACKET_SIZE (7 * 0x00ffffff)
337
338 #define J1939_REGULAR 0
339 #define J1939_EXTENDED 1
340
341 /* CAN protocol */
342 extern const struct can_proto j1939_can_proto;
343
344 #endif /* _J1939_PRIV_H_ */
345
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