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  1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
  3 * Copyright (C) 2006 Andrey Volkov, Varma Electronics
  4 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
  5 */
  6
  7#include <linux/can/dev.h>
  8#include <net/rtnetlink.h>
  9
 10static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
 11	[IFLA_CAN_STATE] = { .type = NLA_U32 },
 12	[IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
 13	[IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
 14	[IFLA_CAN_RESTART] = { .type = NLA_U32 },
 15	[IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
 16	[IFLA_CAN_BITTIMING_CONST] = { .len = sizeof(struct can_bittiming_const) },
 17	[IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
 18	[IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
 19	[IFLA_CAN_DATA_BITTIMING] = { .len = sizeof(struct can_bittiming) },
 20	[IFLA_CAN_DATA_BITTIMING_CONST]	= { .len = sizeof(struct can_bittiming_const) },
 21	[IFLA_CAN_TERMINATION] = { .type = NLA_U16 },
 22};
 23
 24static int can_validate(struct nlattr *tb[], struct nlattr *data[],
 25			struct netlink_ext_ack *extack)
 26{
 27	bool is_can_fd = false;
 28
 29	/* Make sure that valid CAN FD configurations always consist of
 30	 * - nominal/arbitration bittiming
 31	 * - data bittiming
 32	 * - control mode with CAN_CTRLMODE_FD set
 33	 */
 34
 35	if (!data)
 36		return 0;
 37
 38	if (data[IFLA_CAN_CTRLMODE]) {
 39		struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 40
 41		is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
 42	}
 43
 44	if (is_can_fd) {
 45		if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
 46			return -EOPNOTSUPP;
 47	}
 48
 49	if (data[IFLA_CAN_DATA_BITTIMING]) {
 50		if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
 51			return -EOPNOTSUPP;
 52	}
 53
 54	return 0;
 55}
 56
 57static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 58			  struct nlattr *data[],
 59			  struct netlink_ext_ack *extack)
 60{
 61	struct can_priv *priv = netdev_priv(dev);
 62	int err;
 63
 64	/* We need synchronization with dev->stop() */
 65	ASSERT_RTNL();
 66
 67	if (data[IFLA_CAN_BITTIMING]) {
 68		struct can_bittiming bt;
 69
 70		/* Do not allow changing bittiming while running */
 71		if (dev->flags & IFF_UP)
 72			return -EBUSY;
 73
 74		/* Calculate bittiming parameters based on
 75		 * bittiming_const if set, otherwise pass bitrate
 76		 * directly via do_set_bitrate(). Bail out if neither
 77		 * is given.
 78		 */
 79		if (!priv->bittiming_const && !priv->do_set_bittiming)
 80			return -EOPNOTSUPP;
 81
 82		memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
 83		err = can_get_bittiming(dev, &bt,
 84					priv->bittiming_const,
 85					priv->bitrate_const,
 86					priv->bitrate_const_cnt);
 87		if (err)
 88			return err;
 89
 90		if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
 91			netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
 92				   priv->bitrate_max);
 93			return -EINVAL;
 94		}
 95
 96		memcpy(&priv->bittiming, &bt, sizeof(bt));
 97
 98		if (priv->do_set_bittiming) {
 99			/* Finally, set the bit-timing registers */
100			err = priv->do_set_bittiming(dev);
101			if (err)
102				return err;
103		}
104	}
105
106	if (data[IFLA_CAN_CTRLMODE]) {
107		struct can_ctrlmode *cm;
108		u32 ctrlstatic;
109		u32 maskedflags;
110
111		/* Do not allow changing controller mode while running */
112		if (dev->flags & IFF_UP)
113			return -EBUSY;
114		cm = nla_data(data[IFLA_CAN_CTRLMODE]);
115		ctrlstatic = priv->ctrlmode_static;
116		maskedflags = cm->flags & cm->mask;
117
118		/* check whether provided bits are allowed to be passed */
119		if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
120			return -EOPNOTSUPP;
121
122		/* do not check for static fd-non-iso if 'fd' is disabled */
123		if (!(maskedflags & CAN_CTRLMODE_FD))
124			ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
125
126		/* make sure static options are provided by configuration */
127		if ((maskedflags & ctrlstatic) != ctrlstatic)
128			return -EOPNOTSUPP;
129
130		/* clear bits to be modified and copy the flag values */
131		priv->ctrlmode &= ~cm->mask;
132		priv->ctrlmode |= maskedflags;
133
134		/* CAN_CTRLMODE_FD can only be set when driver supports FD */
135		if (priv->ctrlmode & CAN_CTRLMODE_FD)
136			dev->mtu = CANFD_MTU;
137		else
138			dev->mtu = CAN_MTU;
139	}
140
141	if (data[IFLA_CAN_RESTART_MS]) {
142		/* Do not allow changing restart delay while running */
143		if (dev->flags & IFF_UP)
144			return -EBUSY;
145		priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
146	}
147
148	if (data[IFLA_CAN_RESTART]) {
149		/* Do not allow a restart while not running */
150		if (!(dev->flags & IFF_UP))
151			return -EINVAL;
152		err = can_restart_now(dev);
153		if (err)
154			return err;
155	}
156
157	if (data[IFLA_CAN_DATA_BITTIMING]) {
158		struct can_bittiming dbt;
159
160		/* Do not allow changing bittiming while running */
161		if (dev->flags & IFF_UP)
162			return -EBUSY;
163
164		/* Calculate bittiming parameters based on
165		 * data_bittiming_const if set, otherwise pass bitrate
166		 * directly via do_set_bitrate(). Bail out if neither
167		 * is given.
168		 */
169		if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
170			return -EOPNOTSUPP;
171
172		memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
173		       sizeof(dbt));
174		err = can_get_bittiming(dev, &dbt,
175					priv->data_bittiming_const,
176					priv->data_bitrate_const,
177					priv->data_bitrate_const_cnt);
178		if (err)
179			return err;
180
181		if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
182			netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
183				   priv->bitrate_max);
184			return -EINVAL;
185		}
186
187		memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
188
189		can_calc_tdco(dev);
190
191		if (priv->do_set_data_bittiming) {
192			/* Finally, set the bit-timing registers */
193			err = priv->do_set_data_bittiming(dev);
194			if (err)
195				return err;
196		}
197	}
198
199	if (data[IFLA_CAN_TERMINATION]) {
200		const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
201		const unsigned int num_term = priv->termination_const_cnt;
202		unsigned int i;
203
204		if (!priv->do_set_termination)
205			return -EOPNOTSUPP;
206
207		/* check whether given value is supported by the interface */
208		for (i = 0; i < num_term; i++) {
209			if (termval == priv->termination_const[i])
210				break;
211		}
212		if (i >= num_term)
213			return -EINVAL;
214
215		/* Finally, set the termination value */
216		err = priv->do_set_termination(dev, termval);
217		if (err)
218			return err;
219
220		priv->termination = termval;
221	}
222
223	return 0;
224}
225
226static size_t can_get_size(const struct net_device *dev)
227{
228	struct can_priv *priv = netdev_priv(dev);
229	size_t size = 0;
230
231	if (priv->bittiming.bitrate)				/* IFLA_CAN_BITTIMING */
232		size += nla_total_size(sizeof(struct can_bittiming));
233	if (priv->bittiming_const)				/* IFLA_CAN_BITTIMING_CONST */
234		size += nla_total_size(sizeof(struct can_bittiming_const));
235	size += nla_total_size(sizeof(struct can_clock));	/* IFLA_CAN_CLOCK */
236	size += nla_total_size(sizeof(u32));			/* IFLA_CAN_STATE */
237	size += nla_total_size(sizeof(struct can_ctrlmode));	/* IFLA_CAN_CTRLMODE */
238	size += nla_total_size(sizeof(u32));			/* IFLA_CAN_RESTART_MS */
239	if (priv->do_get_berr_counter)				/* IFLA_CAN_BERR_COUNTER */
240		size += nla_total_size(sizeof(struct can_berr_counter));
241	if (priv->data_bittiming.bitrate)			/* IFLA_CAN_DATA_BITTIMING */
242		size += nla_total_size(sizeof(struct can_bittiming));
243	if (priv->data_bittiming_const)				/* IFLA_CAN_DATA_BITTIMING_CONST */
244		size += nla_total_size(sizeof(struct can_bittiming_const));
245	if (priv->termination_const) {
246		size += nla_total_size(sizeof(priv->termination));		/* IFLA_CAN_TERMINATION */
247		size += nla_total_size(sizeof(*priv->termination_const) *	/* IFLA_CAN_TERMINATION_CONST */
248				       priv->termination_const_cnt);
249	}
250	if (priv->bitrate_const)				/* IFLA_CAN_BITRATE_CONST */
251		size += nla_total_size(sizeof(*priv->bitrate_const) *
252				       priv->bitrate_const_cnt);
253	if (priv->data_bitrate_const)				/* IFLA_CAN_DATA_BITRATE_CONST */
254		size += nla_total_size(sizeof(*priv->data_bitrate_const) *
255				       priv->data_bitrate_const_cnt);
256	size += sizeof(priv->bitrate_max);			/* IFLA_CAN_BITRATE_MAX */
257
258	return size;
259}
260
261static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
262{
263	struct can_priv *priv = netdev_priv(dev);
264	struct can_ctrlmode cm = {.flags = priv->ctrlmode};
265	struct can_berr_counter bec = { };
266	enum can_state state = priv->state;
267
268	if (priv->do_get_state)
269		priv->do_get_state(dev, &state);
270
271	if ((priv->bittiming.bitrate &&
272	     nla_put(skb, IFLA_CAN_BITTIMING,
273		     sizeof(priv->bittiming), &priv->bittiming)) ||
274
275	    (priv->bittiming_const &&
276	     nla_put(skb, IFLA_CAN_BITTIMING_CONST,
277		     sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
278
279	    nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
280	    nla_put_u32(skb, IFLA_CAN_STATE, state) ||
281	    nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
282	    nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
283
284	    (priv->do_get_berr_counter &&
285	     !priv->do_get_berr_counter(dev, &bec) &&
286	     nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
287
288	    (priv->data_bittiming.bitrate &&
289	     nla_put(skb, IFLA_CAN_DATA_BITTIMING,
290		     sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
291
292	    (priv->data_bittiming_const &&
293	     nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
294		     sizeof(*priv->data_bittiming_const),
295		     priv->data_bittiming_const)) ||
296
297	    (priv->termination_const &&
298	     (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
299	      nla_put(skb, IFLA_CAN_TERMINATION_CONST,
300		      sizeof(*priv->termination_const) *
301		      priv->termination_const_cnt,
302		      priv->termination_const))) ||
303
304	    (priv->bitrate_const &&
305	     nla_put(skb, IFLA_CAN_BITRATE_CONST,
306		     sizeof(*priv->bitrate_const) *
307		     priv->bitrate_const_cnt,
308		     priv->bitrate_const)) ||
309
310	    (priv->data_bitrate_const &&
311	     nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
312		     sizeof(*priv->data_bitrate_const) *
313		     priv->data_bitrate_const_cnt,
314		     priv->data_bitrate_const)) ||
315
316	    (nla_put(skb, IFLA_CAN_BITRATE_MAX,
317		     sizeof(priv->bitrate_max),
318		     &priv->bitrate_max))
319	    )
320
321		return -EMSGSIZE;
322
323	return 0;
324}
325
326static size_t can_get_xstats_size(const struct net_device *dev)
327{
328	return sizeof(struct can_device_stats);
329}
330
331static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
332{
333	struct can_priv *priv = netdev_priv(dev);
334
335	if (nla_put(skb, IFLA_INFO_XSTATS,
336		    sizeof(priv->can_stats), &priv->can_stats))
337		goto nla_put_failure;
338	return 0;
339
340nla_put_failure:
341	return -EMSGSIZE;
342}
343
344static int can_newlink(struct net *src_net, struct net_device *dev,
345		       struct nlattr *tb[], struct nlattr *data[],
346		       struct netlink_ext_ack *extack)
347{
348	return -EOPNOTSUPP;
349}
350
351static void can_dellink(struct net_device *dev, struct list_head *head)
352{
353}
354
355struct rtnl_link_ops can_link_ops __read_mostly = {
356	.kind		= "can",
357	.netns_refund	= true,
358	.maxtype	= IFLA_CAN_MAX,
359	.policy		= can_policy,
360	.setup		= can_setup,
361	.validate	= can_validate,
362	.newlink	= can_newlink,
363	.changelink	= can_changelink,
364	.dellink	= can_dellink,
365	.get_size	= can_get_size,
366	.fill_info	= can_fill_info,
367	.get_xstats_size = can_get_xstats_size,
368	.fill_xstats	= can_fill_xstats,
369};
370
371int can_netlink_register(void)
372{
373	return rtnl_link_register(&can_link_ops);
374}
375
376void can_netlink_unregister(void)
377{
378	rtnl_link_unregister(&can_link_ops);
379}