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Merge tag 'aspeed-5.14-devicetree-2' of git://git.kernel.org/pub/scm/linux/kernel...
[mirror_ubuntu-jammy-kernel.git] / net / can / gw.c
1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /* gw.c - CAN frame Gateway/Router/Bridge with netlink interface
3 *
4 * Copyright (c) 2019 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42 #include <linux/module.h>
43 #include <linux/init.h>
44 #include <linux/types.h>
45 #include <linux/kernel.h>
46 #include <linux/list.h>
47 #include <linux/spinlock.h>
48 #include <linux/rcupdate.h>
49 #include <linux/rculist.h>
50 #include <linux/net.h>
51 #include <linux/netdevice.h>
52 #include <linux/if_arp.h>
53 #include <linux/skbuff.h>
54 #include <linux/can.h>
55 #include <linux/can/core.h>
56 #include <linux/can/skb.h>
57 #include <linux/can/gw.h>
58 #include <net/rtnetlink.h>
59 #include <net/net_namespace.h>
60 #include <net/sock.h>
61
62 #define CAN_GW_NAME "can-gw"
63
64 MODULE_DESCRIPTION("PF_CAN netlink gateway");
65 MODULE_LICENSE("Dual BSD/GPL");
66 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
67 MODULE_ALIAS(CAN_GW_NAME);
68
69 #define CGW_MIN_HOPS 1
70 #define CGW_MAX_HOPS 6
71 #define CGW_DEFAULT_HOPS 1
72
73 static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS;
74 module_param(max_hops, uint, 0444);
75 MODULE_PARM_DESC(max_hops,
76 "maximum " CAN_GW_NAME " routing hops for CAN frames "
77 "(valid values: " __stringify(CGW_MIN_HOPS) "-"
78 __stringify(CGW_MAX_HOPS) " hops, "
79 "default: " __stringify(CGW_DEFAULT_HOPS) ")");
80
81 static struct notifier_block notifier;
82 static struct kmem_cache *cgw_cache __read_mostly;
83
84 /* structure that contains the (on-the-fly) CAN frame modifications */
85 struct cf_mod {
86 struct {
87 struct canfd_frame and;
88 struct canfd_frame or;
89 struct canfd_frame xor;
90 struct canfd_frame set;
91 } modframe;
92 struct {
93 u8 and;
94 u8 or;
95 u8 xor;
96 u8 set;
97 } modtype;
98 void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf,
99 struct cf_mod *mod);
100
101 /* CAN frame checksum calculation after CAN frame modifications */
102 struct {
103 struct cgw_csum_xor xor;
104 struct cgw_csum_crc8 crc8;
105 } csum;
106 struct {
107 void (*xor)(struct canfd_frame *cf,
108 struct cgw_csum_xor *xor);
109 void (*crc8)(struct canfd_frame *cf,
110 struct cgw_csum_crc8 *crc8);
111 } csumfunc;
112 u32 uid;
113 };
114
115 /* So far we just support CAN -> CAN routing and frame modifications.
116 *
117 * The internal can_can_gw structure contains data and attributes for
118 * a CAN -> CAN gateway job.
119 */
120 struct can_can_gw {
121 struct can_filter filter;
122 int src_idx;
123 int dst_idx;
124 };
125
126 /* list entry for CAN gateways jobs */
127 struct cgw_job {
128 struct hlist_node list;
129 struct rcu_head rcu;
130 u32 handled_frames;
131 u32 dropped_frames;
132 u32 deleted_frames;
133 struct cf_mod mod;
134 union {
135 /* CAN frame data source */
136 struct net_device *dev;
137 } src;
138 union {
139 /* CAN frame data destination */
140 struct net_device *dev;
141 } dst;
142 union {
143 struct can_can_gw ccgw;
144 /* tbc */
145 };
146 u8 gwtype;
147 u8 limit_hops;
148 u16 flags;
149 };
150
151 /* modification functions that are invoked in the hot path in can_can_gw_rcv */
152
153 #define MODFUNC(func, op) static void func(struct canfd_frame *cf, \
154 struct cf_mod *mod) { op ; }
155
156 MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
157 MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len)
158 MODFUNC(mod_and_flags, cf->flags &= mod->modframe.and.flags)
159 MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
160 MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
161 MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len)
162 MODFUNC(mod_or_flags, cf->flags |= mod->modframe.or.flags)
163 MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
164 MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
165 MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len)
166 MODFUNC(mod_xor_flags, cf->flags ^= mod->modframe.xor.flags)
167 MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
168 MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
169 MODFUNC(mod_set_len, cf->len = mod->modframe.set.len)
170 MODFUNC(mod_set_flags, cf->flags = mod->modframe.set.flags)
171 MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
172
173 static void mod_and_fddata(struct canfd_frame *cf, struct cf_mod *mod)
174 {
175 int i;
176
177 for (i = 0; i < CANFD_MAX_DLEN; i += 8)
178 *(u64 *)(cf->data + i) &= *(u64 *)(mod->modframe.and.data + i);
179 }
180
181 static void mod_or_fddata(struct canfd_frame *cf, struct cf_mod *mod)
182 {
183 int i;
184
185 for (i = 0; i < CANFD_MAX_DLEN; i += 8)
186 *(u64 *)(cf->data + i) |= *(u64 *)(mod->modframe.or.data + i);
187 }
188
189 static void mod_xor_fddata(struct canfd_frame *cf, struct cf_mod *mod)
190 {
191 int i;
192
193 for (i = 0; i < CANFD_MAX_DLEN; i += 8)
194 *(u64 *)(cf->data + i) ^= *(u64 *)(mod->modframe.xor.data + i);
195 }
196
197 static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod)
198 {
199 memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN);
200 }
201
202 /* retrieve valid CC DLC value and store it into 'len' */
203 static void mod_retrieve_ccdlc(struct canfd_frame *cf)
204 {
205 struct can_frame *ccf = (struct can_frame *)cf;
206
207 /* len8_dlc is only valid if len == CAN_MAX_DLEN */
208 if (ccf->len != CAN_MAX_DLEN)
209 return;
210
211 /* do we have a valid len8_dlc value from 9 .. 15 ? */
212 if (ccf->len8_dlc > CAN_MAX_DLEN && ccf->len8_dlc <= CAN_MAX_RAW_DLC)
213 ccf->len = ccf->len8_dlc;
214 }
215
216 /* convert valid CC DLC value in 'len' into struct can_frame elements */
217 static void mod_store_ccdlc(struct canfd_frame *cf)
218 {
219 struct can_frame *ccf = (struct can_frame *)cf;
220
221 /* clear potential leftovers */
222 ccf->len8_dlc = 0;
223
224 /* plain data length 0 .. 8 - that was easy */
225 if (ccf->len <= CAN_MAX_DLEN)
226 return;
227
228 /* potentially broken values are caught in can_can_gw_rcv() */
229 if (ccf->len > CAN_MAX_RAW_DLC)
230 return;
231
232 /* we have a valid dlc value from 9 .. 15 in ccf->len */
233 ccf->len8_dlc = ccf->len;
234 ccf->len = CAN_MAX_DLEN;
235 }
236
237 static void mod_and_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
238 {
239 mod_retrieve_ccdlc(cf);
240 mod_and_len(cf, mod);
241 mod_store_ccdlc(cf);
242 }
243
244 static void mod_or_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
245 {
246 mod_retrieve_ccdlc(cf);
247 mod_or_len(cf, mod);
248 mod_store_ccdlc(cf);
249 }
250
251 static void mod_xor_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
252 {
253 mod_retrieve_ccdlc(cf);
254 mod_xor_len(cf, mod);
255 mod_store_ccdlc(cf);
256 }
257
258 static void mod_set_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
259 {
260 mod_set_len(cf, mod);
261 mod_store_ccdlc(cf);
262 }
263
264 static void canframecpy(struct canfd_frame *dst, struct can_frame *src)
265 {
266 /* Copy the struct members separately to ensure that no uninitialized
267 * data are copied in the 3 bytes hole of the struct. This is needed
268 * to make easy compares of the data in the struct cf_mod.
269 */
270
271 dst->can_id = src->can_id;
272 dst->len = src->len;
273 *(u64 *)dst->data = *(u64 *)src->data;
274 }
275
276 static void canfdframecpy(struct canfd_frame *dst, struct canfd_frame *src)
277 {
278 /* Copy the struct members separately to ensure that no uninitialized
279 * data are copied in the 2 bytes hole of the struct. This is needed
280 * to make easy compares of the data in the struct cf_mod.
281 */
282
283 dst->can_id = src->can_id;
284 dst->flags = src->flags;
285 dst->len = src->len;
286 memcpy(dst->data, src->data, CANFD_MAX_DLEN);
287 }
288
289 static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re, struct rtcanmsg *r)
290 {
291 s8 dlen = CAN_MAX_DLEN;
292
293 if (r->flags & CGW_FLAGS_CAN_FD)
294 dlen = CANFD_MAX_DLEN;
295
296 /* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
297 * relative to received dlc -1 .. -8 :
298 * e.g. for received dlc = 8
299 * -1 => index = 7 (data[7])
300 * -3 => index = 5 (data[5])
301 * -8 => index = 0 (data[0])
302 */
303
304 if (fr >= -dlen && fr < dlen &&
305 to >= -dlen && to < dlen &&
306 re >= -dlen && re < dlen)
307 return 0;
308 else
309 return -EINVAL;
310 }
311
312 static inline int calc_idx(int idx, int rx_len)
313 {
314 if (idx < 0)
315 return rx_len + idx;
316 else
317 return idx;
318 }
319
320 static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor)
321 {
322 int from = calc_idx(xor->from_idx, cf->len);
323 int to = calc_idx(xor->to_idx, cf->len);
324 int res = calc_idx(xor->result_idx, cf->len);
325 u8 val = xor->init_xor_val;
326 int i;
327
328 if (from < 0 || to < 0 || res < 0)
329 return;
330
331 if (from <= to) {
332 for (i = from; i <= to; i++)
333 val ^= cf->data[i];
334 } else {
335 for (i = from; i >= to; i--)
336 val ^= cf->data[i];
337 }
338
339 cf->data[res] = val;
340 }
341
342 static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor)
343 {
344 u8 val = xor->init_xor_val;
345 int i;
346
347 for (i = xor->from_idx; i <= xor->to_idx; i++)
348 val ^= cf->data[i];
349
350 cf->data[xor->result_idx] = val;
351 }
352
353 static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor)
354 {
355 u8 val = xor->init_xor_val;
356 int i;
357
358 for (i = xor->from_idx; i >= xor->to_idx; i--)
359 val ^= cf->data[i];
360
361 cf->data[xor->result_idx] = val;
362 }
363
364 static void cgw_csum_crc8_rel(struct canfd_frame *cf,
365 struct cgw_csum_crc8 *crc8)
366 {
367 int from = calc_idx(crc8->from_idx, cf->len);
368 int to = calc_idx(crc8->to_idx, cf->len);
369 int res = calc_idx(crc8->result_idx, cf->len);
370 u8 crc = crc8->init_crc_val;
371 int i;
372
373 if (from < 0 || to < 0 || res < 0)
374 return;
375
376 if (from <= to) {
377 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
378 crc = crc8->crctab[crc ^ cf->data[i]];
379 } else {
380 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
381 crc = crc8->crctab[crc ^ cf->data[i]];
382 }
383
384 switch (crc8->profile) {
385 case CGW_CRC8PRF_1U8:
386 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
387 break;
388
389 case CGW_CRC8PRF_16U8:
390 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
391 break;
392
393 case CGW_CRC8PRF_SFFID_XOR:
394 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
395 (cf->can_id >> 8 & 0xFF)];
396 break;
397 }
398
399 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
400 }
401
402 static void cgw_csum_crc8_pos(struct canfd_frame *cf,
403 struct cgw_csum_crc8 *crc8)
404 {
405 u8 crc = crc8->init_crc_val;
406 int i;
407
408 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
409 crc = crc8->crctab[crc ^ cf->data[i]];
410
411 switch (crc8->profile) {
412 case CGW_CRC8PRF_1U8:
413 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
414 break;
415
416 case CGW_CRC8PRF_16U8:
417 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
418 break;
419
420 case CGW_CRC8PRF_SFFID_XOR:
421 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
422 (cf->can_id >> 8 & 0xFF)];
423 break;
424 }
425
426 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
427 }
428
429 static void cgw_csum_crc8_neg(struct canfd_frame *cf,
430 struct cgw_csum_crc8 *crc8)
431 {
432 u8 crc = crc8->init_crc_val;
433 int i;
434
435 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
436 crc = crc8->crctab[crc ^ cf->data[i]];
437
438 switch (crc8->profile) {
439 case CGW_CRC8PRF_1U8:
440 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
441 break;
442
443 case CGW_CRC8PRF_16U8:
444 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
445 break;
446
447 case CGW_CRC8PRF_SFFID_XOR:
448 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
449 (cf->can_id >> 8 & 0xFF)];
450 break;
451 }
452
453 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
454 }
455
456 /* the receive & process & send function */
457 static void can_can_gw_rcv(struct sk_buff *skb, void *data)
458 {
459 struct cgw_job *gwj = (struct cgw_job *)data;
460 struct canfd_frame *cf;
461 struct sk_buff *nskb;
462 int modidx = 0;
463
464 /* process strictly Classic CAN or CAN FD frames */
465 if (gwj->flags & CGW_FLAGS_CAN_FD) {
466 if (skb->len != CANFD_MTU)
467 return;
468 } else {
469 if (skb->len != CAN_MTU)
470 return;
471 }
472
473 /* Do not handle CAN frames routed more than 'max_hops' times.
474 * In general we should never catch this delimiter which is intended
475 * to cover a misconfiguration protection (e.g. circular CAN routes).
476 *
477 * The Controller Area Network controllers only accept CAN frames with
478 * correct CRCs - which are not visible in the controller registers.
479 * According to skbuff.h documentation the csum_start element for IP
480 * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY.
481 * Only CAN skbs can be processed here which already have this property.
482 */
483
484 #define cgw_hops(skb) ((skb)->csum_start)
485
486 BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY);
487
488 if (cgw_hops(skb) >= max_hops) {
489 /* indicate deleted frames due to misconfiguration */
490 gwj->deleted_frames++;
491 return;
492 }
493
494 if (!(gwj->dst.dev->flags & IFF_UP)) {
495 gwj->dropped_frames++;
496 return;
497 }
498
499 /* is sending the skb back to the incoming interface not allowed? */
500 if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
501 can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex)
502 return;
503
504 /* clone the given skb, which has not been done in can_rcv()
505 *
506 * When there is at least one modification function activated,
507 * we need to copy the skb as we want to modify skb->data.
508 */
509 if (gwj->mod.modfunc[0])
510 nskb = skb_copy(skb, GFP_ATOMIC);
511 else
512 nskb = skb_clone(skb, GFP_ATOMIC);
513
514 if (!nskb) {
515 gwj->dropped_frames++;
516 return;
517 }
518
519 /* put the incremented hop counter in the cloned skb */
520 cgw_hops(nskb) = cgw_hops(skb) + 1;
521
522 /* first processing of this CAN frame -> adjust to private hop limit */
523 if (gwj->limit_hops && cgw_hops(nskb) == 1)
524 cgw_hops(nskb) = max_hops - gwj->limit_hops + 1;
525
526 nskb->dev = gwj->dst.dev;
527
528 /* pointer to modifiable CAN frame */
529 cf = (struct canfd_frame *)nskb->data;
530
531 /* perform preprocessed modification functions if there are any */
532 while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
533 (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod);
534
535 /* Has the CAN frame been modified? */
536 if (modidx) {
537 /* get available space for the processed CAN frame type */
538 int max_len = nskb->len - offsetof(struct canfd_frame, data);
539
540 /* dlc may have changed, make sure it fits to the CAN frame */
541 if (cf->len > max_len) {
542 /* delete frame due to misconfiguration */
543 gwj->deleted_frames++;
544 kfree_skb(nskb);
545 return;
546 }
547
548 /* check for checksum updates */
549 if (gwj->mod.csumfunc.crc8)
550 (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
551
552 if (gwj->mod.csumfunc.xor)
553 (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
554 }
555
556 /* clear the skb timestamp if not configured the other way */
557 if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
558 nskb->tstamp = 0;
559
560 /* send to netdevice */
561 if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
562 gwj->dropped_frames++;
563 else
564 gwj->handled_frames++;
565 }
566
567 static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
568 {
569 return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
570 gwj->ccgw.filter.can_mask, can_can_gw_rcv,
571 gwj, "gw", NULL);
572 }
573
574 static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
575 {
576 can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
577 gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
578 }
579
580 static int cgw_notifier(struct notifier_block *nb,
581 unsigned long msg, void *ptr)
582 {
583 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
584 struct net *net = dev_net(dev);
585
586 if (dev->type != ARPHRD_CAN)
587 return NOTIFY_DONE;
588
589 if (msg == NETDEV_UNREGISTER) {
590 struct cgw_job *gwj = NULL;
591 struct hlist_node *nx;
592
593 ASSERT_RTNL();
594
595 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
596 if (gwj->src.dev == dev || gwj->dst.dev == dev) {
597 hlist_del(&gwj->list);
598 cgw_unregister_filter(net, gwj);
599 synchronize_rcu();
600 kmem_cache_free(cgw_cache, gwj);
601 }
602 }
603 }
604
605 return NOTIFY_DONE;
606 }
607
608 static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
609 u32 pid, u32 seq, int flags)
610 {
611 struct rtcanmsg *rtcan;
612 struct nlmsghdr *nlh;
613
614 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags);
615 if (!nlh)
616 return -EMSGSIZE;
617
618 rtcan = nlmsg_data(nlh);
619 rtcan->can_family = AF_CAN;
620 rtcan->gwtype = gwj->gwtype;
621 rtcan->flags = gwj->flags;
622
623 /* add statistics if available */
624
625 if (gwj->handled_frames) {
626 if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
627 goto cancel;
628 }
629
630 if (gwj->dropped_frames) {
631 if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
632 goto cancel;
633 }
634
635 if (gwj->deleted_frames) {
636 if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0)
637 goto cancel;
638 }
639
640 /* check non default settings of attributes */
641
642 if (gwj->limit_hops) {
643 if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0)
644 goto cancel;
645 }
646
647 if (gwj->flags & CGW_FLAGS_CAN_FD) {
648 struct cgw_fdframe_mod mb;
649
650 if (gwj->mod.modtype.and) {
651 memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
652 mb.modtype = gwj->mod.modtype.and;
653 if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0)
654 goto cancel;
655 }
656
657 if (gwj->mod.modtype.or) {
658 memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
659 mb.modtype = gwj->mod.modtype.or;
660 if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0)
661 goto cancel;
662 }
663
664 if (gwj->mod.modtype.xor) {
665 memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
666 mb.modtype = gwj->mod.modtype.xor;
667 if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0)
668 goto cancel;
669 }
670
671 if (gwj->mod.modtype.set) {
672 memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
673 mb.modtype = gwj->mod.modtype.set;
674 if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0)
675 goto cancel;
676 }
677 } else {
678 struct cgw_frame_mod mb;
679
680 if (gwj->mod.modtype.and) {
681 memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
682 mb.modtype = gwj->mod.modtype.and;
683 if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
684 goto cancel;
685 }
686
687 if (gwj->mod.modtype.or) {
688 memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
689 mb.modtype = gwj->mod.modtype.or;
690 if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
691 goto cancel;
692 }
693
694 if (gwj->mod.modtype.xor) {
695 memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
696 mb.modtype = gwj->mod.modtype.xor;
697 if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
698 goto cancel;
699 }
700
701 if (gwj->mod.modtype.set) {
702 memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
703 mb.modtype = gwj->mod.modtype.set;
704 if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
705 goto cancel;
706 }
707 }
708
709 if (gwj->mod.uid) {
710 if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0)
711 goto cancel;
712 }
713
714 if (gwj->mod.csumfunc.crc8) {
715 if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
716 &gwj->mod.csum.crc8) < 0)
717 goto cancel;
718 }
719
720 if (gwj->mod.csumfunc.xor) {
721 if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN,
722 &gwj->mod.csum.xor) < 0)
723 goto cancel;
724 }
725
726 if (gwj->gwtype == CGW_TYPE_CAN_CAN) {
727 if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
728 if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
729 &gwj->ccgw.filter) < 0)
730 goto cancel;
731 }
732
733 if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0)
734 goto cancel;
735
736 if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0)
737 goto cancel;
738 }
739
740 nlmsg_end(skb, nlh);
741 return 0;
742
743 cancel:
744 nlmsg_cancel(skb, nlh);
745 return -EMSGSIZE;
746 }
747
748 /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
749 static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
750 {
751 struct net *net = sock_net(skb->sk);
752 struct cgw_job *gwj = NULL;
753 int idx = 0;
754 int s_idx = cb->args[0];
755
756 rcu_read_lock();
757 hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) {
758 if (idx < s_idx)
759 goto cont;
760
761 if (cgw_put_job(skb, gwj, RTM_NEWROUTE,
762 NETLINK_CB(cb->skb).portid,
763 cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0)
764 break;
765 cont:
766 idx++;
767 }
768 rcu_read_unlock();
769
770 cb->args[0] = idx;
771
772 return skb->len;
773 }
774
775 static const struct nla_policy cgw_policy[CGW_MAX + 1] = {
776 [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) },
777 [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) },
778 [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) },
779 [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) },
780 [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) },
781 [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) },
782 [CGW_SRC_IF] = { .type = NLA_U32 },
783 [CGW_DST_IF] = { .type = NLA_U32 },
784 [CGW_FILTER] = { .len = sizeof(struct can_filter) },
785 [CGW_LIM_HOPS] = { .type = NLA_U8 },
786 [CGW_MOD_UID] = { .type = NLA_U32 },
787 [CGW_FDMOD_AND] = { .len = sizeof(struct cgw_fdframe_mod) },
788 [CGW_FDMOD_OR] = { .len = sizeof(struct cgw_fdframe_mod) },
789 [CGW_FDMOD_XOR] = { .len = sizeof(struct cgw_fdframe_mod) },
790 [CGW_FDMOD_SET] = { .len = sizeof(struct cgw_fdframe_mod) },
791 };
792
793 /* check for common and gwtype specific attributes */
794 static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
795 u8 gwtype, void *gwtypeattr, u8 *limhops)
796 {
797 struct nlattr *tb[CGW_MAX + 1];
798 struct rtcanmsg *r = nlmsg_data(nlh);
799 int modidx = 0;
800 int err = 0;
801
802 /* initialize modification & checksum data space */
803 memset(mod, 0, sizeof(*mod));
804
805 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb,
806 CGW_MAX, cgw_policy, NULL);
807 if (err < 0)
808 return err;
809
810 if (tb[CGW_LIM_HOPS]) {
811 *limhops = nla_get_u8(tb[CGW_LIM_HOPS]);
812
813 if (*limhops < 1 || *limhops > max_hops)
814 return -EINVAL;
815 }
816
817 /* check for AND/OR/XOR/SET modifications */
818 if (r->flags & CGW_FLAGS_CAN_FD) {
819 struct cgw_fdframe_mod mb;
820
821 if (tb[CGW_FDMOD_AND]) {
822 nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN);
823
824 canfdframecpy(&mod->modframe.and, &mb.cf);
825 mod->modtype.and = mb.modtype;
826
827 if (mb.modtype & CGW_MOD_ID)
828 mod->modfunc[modidx++] = mod_and_id;
829
830 if (mb.modtype & CGW_MOD_LEN)
831 mod->modfunc[modidx++] = mod_and_len;
832
833 if (mb.modtype & CGW_MOD_FLAGS)
834 mod->modfunc[modidx++] = mod_and_flags;
835
836 if (mb.modtype & CGW_MOD_DATA)
837 mod->modfunc[modidx++] = mod_and_fddata;
838 }
839
840 if (tb[CGW_FDMOD_OR]) {
841 nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN);
842
843 canfdframecpy(&mod->modframe.or, &mb.cf);
844 mod->modtype.or = mb.modtype;
845
846 if (mb.modtype & CGW_MOD_ID)
847 mod->modfunc[modidx++] = mod_or_id;
848
849 if (mb.modtype & CGW_MOD_LEN)
850 mod->modfunc[modidx++] = mod_or_len;
851
852 if (mb.modtype & CGW_MOD_FLAGS)
853 mod->modfunc[modidx++] = mod_or_flags;
854
855 if (mb.modtype & CGW_MOD_DATA)
856 mod->modfunc[modidx++] = mod_or_fddata;
857 }
858
859 if (tb[CGW_FDMOD_XOR]) {
860 nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN);
861
862 canfdframecpy(&mod->modframe.xor, &mb.cf);
863 mod->modtype.xor = mb.modtype;
864
865 if (mb.modtype & CGW_MOD_ID)
866 mod->modfunc[modidx++] = mod_xor_id;
867
868 if (mb.modtype & CGW_MOD_LEN)
869 mod->modfunc[modidx++] = mod_xor_len;
870
871 if (mb.modtype & CGW_MOD_FLAGS)
872 mod->modfunc[modidx++] = mod_xor_flags;
873
874 if (mb.modtype & CGW_MOD_DATA)
875 mod->modfunc[modidx++] = mod_xor_fddata;
876 }
877
878 if (tb[CGW_FDMOD_SET]) {
879 nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN);
880
881 canfdframecpy(&mod->modframe.set, &mb.cf);
882 mod->modtype.set = mb.modtype;
883
884 if (mb.modtype & CGW_MOD_ID)
885 mod->modfunc[modidx++] = mod_set_id;
886
887 if (mb.modtype & CGW_MOD_LEN)
888 mod->modfunc[modidx++] = mod_set_len;
889
890 if (mb.modtype & CGW_MOD_FLAGS)
891 mod->modfunc[modidx++] = mod_set_flags;
892
893 if (mb.modtype & CGW_MOD_DATA)
894 mod->modfunc[modidx++] = mod_set_fddata;
895 }
896 } else {
897 struct cgw_frame_mod mb;
898
899 if (tb[CGW_MOD_AND]) {
900 nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
901
902 canframecpy(&mod->modframe.and, &mb.cf);
903 mod->modtype.and = mb.modtype;
904
905 if (mb.modtype & CGW_MOD_ID)
906 mod->modfunc[modidx++] = mod_and_id;
907
908 if (mb.modtype & CGW_MOD_DLC)
909 mod->modfunc[modidx++] = mod_and_ccdlc;
910
911 if (mb.modtype & CGW_MOD_DATA)
912 mod->modfunc[modidx++] = mod_and_data;
913 }
914
915 if (tb[CGW_MOD_OR]) {
916 nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
917
918 canframecpy(&mod->modframe.or, &mb.cf);
919 mod->modtype.or = mb.modtype;
920
921 if (mb.modtype & CGW_MOD_ID)
922 mod->modfunc[modidx++] = mod_or_id;
923
924 if (mb.modtype & CGW_MOD_DLC)
925 mod->modfunc[modidx++] = mod_or_ccdlc;
926
927 if (mb.modtype & CGW_MOD_DATA)
928 mod->modfunc[modidx++] = mod_or_data;
929 }
930
931 if (tb[CGW_MOD_XOR]) {
932 nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
933
934 canframecpy(&mod->modframe.xor, &mb.cf);
935 mod->modtype.xor = mb.modtype;
936
937 if (mb.modtype & CGW_MOD_ID)
938 mod->modfunc[modidx++] = mod_xor_id;
939
940 if (mb.modtype & CGW_MOD_DLC)
941 mod->modfunc[modidx++] = mod_xor_ccdlc;
942
943 if (mb.modtype & CGW_MOD_DATA)
944 mod->modfunc[modidx++] = mod_xor_data;
945 }
946
947 if (tb[CGW_MOD_SET]) {
948 nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
949
950 canframecpy(&mod->modframe.set, &mb.cf);
951 mod->modtype.set = mb.modtype;
952
953 if (mb.modtype & CGW_MOD_ID)
954 mod->modfunc[modidx++] = mod_set_id;
955
956 if (mb.modtype & CGW_MOD_DLC)
957 mod->modfunc[modidx++] = mod_set_ccdlc;
958
959 if (mb.modtype & CGW_MOD_DATA)
960 mod->modfunc[modidx++] = mod_set_data;
961 }
962 }
963
964 /* check for checksum operations after CAN frame modifications */
965 if (modidx) {
966 if (tb[CGW_CS_CRC8]) {
967 struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]);
968
969 err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
970 c->result_idx, r);
971 if (err)
972 return err;
973
974 nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8],
975 CGW_CS_CRC8_LEN);
976
977 /* select dedicated processing function to reduce
978 * runtime operations in receive hot path.
979 */
980 if (c->from_idx < 0 || c->to_idx < 0 ||
981 c->result_idx < 0)
982 mod->csumfunc.crc8 = cgw_csum_crc8_rel;
983 else if (c->from_idx <= c->to_idx)
984 mod->csumfunc.crc8 = cgw_csum_crc8_pos;
985 else
986 mod->csumfunc.crc8 = cgw_csum_crc8_neg;
987 }
988
989 if (tb[CGW_CS_XOR]) {
990 struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]);
991
992 err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
993 c->result_idx, r);
994 if (err)
995 return err;
996
997 nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR],
998 CGW_CS_XOR_LEN);
999
1000 /* select dedicated processing function to reduce
1001 * runtime operations in receive hot path.
1002 */
1003 if (c->from_idx < 0 || c->to_idx < 0 ||
1004 c->result_idx < 0)
1005 mod->csumfunc.xor = cgw_csum_xor_rel;
1006 else if (c->from_idx <= c->to_idx)
1007 mod->csumfunc.xor = cgw_csum_xor_pos;
1008 else
1009 mod->csumfunc.xor = cgw_csum_xor_neg;
1010 }
1011
1012 if (tb[CGW_MOD_UID])
1013 nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32));
1014 }
1015
1016 if (gwtype == CGW_TYPE_CAN_CAN) {
1017 /* check CGW_TYPE_CAN_CAN specific attributes */
1018 struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr;
1019
1020 memset(ccgw, 0, sizeof(*ccgw));
1021
1022 /* check for can_filter in attributes */
1023 if (tb[CGW_FILTER])
1024 nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
1025 sizeof(struct can_filter));
1026
1027 err = -ENODEV;
1028
1029 /* specifying two interfaces is mandatory */
1030 if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF])
1031 return err;
1032
1033 ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]);
1034 ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]);
1035
1036 /* both indices set to 0 for flushing all routing entries */
1037 if (!ccgw->src_idx && !ccgw->dst_idx)
1038 return 0;
1039
1040 /* only one index set to 0 is an error */
1041 if (!ccgw->src_idx || !ccgw->dst_idx)
1042 return err;
1043 }
1044
1045 /* add the checks for other gwtypes here */
1046
1047 return 0;
1048 }
1049
1050 static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh,
1051 struct netlink_ext_ack *extack)
1052 {
1053 struct net *net = sock_net(skb->sk);
1054 struct rtcanmsg *r;
1055 struct cgw_job *gwj;
1056 struct cf_mod mod;
1057 struct can_can_gw ccgw;
1058 u8 limhops = 0;
1059 int err = 0;
1060
1061 if (!netlink_capable(skb, CAP_NET_ADMIN))
1062 return -EPERM;
1063
1064 if (nlmsg_len(nlh) < sizeof(*r))
1065 return -EINVAL;
1066
1067 r = nlmsg_data(nlh);
1068 if (r->can_family != AF_CAN)
1069 return -EPFNOSUPPORT;
1070
1071 /* so far we only support CAN -> CAN routings */
1072 if (r->gwtype != CGW_TYPE_CAN_CAN)
1073 return -EINVAL;
1074
1075 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
1076 if (err < 0)
1077 return err;
1078
1079 if (mod.uid) {
1080 ASSERT_RTNL();
1081
1082 /* check for updating an existing job with identical uid */
1083 hlist_for_each_entry(gwj, &net->can.cgw_list, list) {
1084 if (gwj->mod.uid != mod.uid)
1085 continue;
1086
1087 /* interfaces & filters must be identical */
1088 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
1089 return -EINVAL;
1090
1091 /* update modifications with disabled softirq & quit */
1092 local_bh_disable();
1093 memcpy(&gwj->mod, &mod, sizeof(mod));
1094 local_bh_enable();
1095 return 0;
1096 }
1097 }
1098
1099 /* ifindex == 0 is not allowed for job creation */
1100 if (!ccgw.src_idx || !ccgw.dst_idx)
1101 return -ENODEV;
1102
1103 gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL);
1104 if (!gwj)
1105 return -ENOMEM;
1106
1107 gwj->handled_frames = 0;
1108 gwj->dropped_frames = 0;
1109 gwj->deleted_frames = 0;
1110 gwj->flags = r->flags;
1111 gwj->gwtype = r->gwtype;
1112 gwj->limit_hops = limhops;
1113
1114 /* insert already parsed information */
1115 memcpy(&gwj->mod, &mod, sizeof(mod));
1116 memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw));
1117
1118 err = -ENODEV;
1119
1120 gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx);
1121
1122 if (!gwj->src.dev)
1123 goto out;
1124
1125 if (gwj->src.dev->type != ARPHRD_CAN)
1126 goto out;
1127
1128 gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx);
1129
1130 if (!gwj->dst.dev)
1131 goto out;
1132
1133 if (gwj->dst.dev->type != ARPHRD_CAN)
1134 goto out;
1135
1136 ASSERT_RTNL();
1137
1138 err = cgw_register_filter(net, gwj);
1139 if (!err)
1140 hlist_add_head_rcu(&gwj->list, &net->can.cgw_list);
1141 out:
1142 if (err)
1143 kmem_cache_free(cgw_cache, gwj);
1144
1145 return err;
1146 }
1147
1148 static void cgw_remove_all_jobs(struct net *net)
1149 {
1150 struct cgw_job *gwj = NULL;
1151 struct hlist_node *nx;
1152
1153 ASSERT_RTNL();
1154
1155 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
1156 hlist_del(&gwj->list);
1157 cgw_unregister_filter(net, gwj);
1158 synchronize_rcu();
1159 kmem_cache_free(cgw_cache, gwj);
1160 }
1161 }
1162
1163 static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
1164 struct netlink_ext_ack *extack)
1165 {
1166 struct net *net = sock_net(skb->sk);
1167 struct cgw_job *gwj = NULL;
1168 struct hlist_node *nx;
1169 struct rtcanmsg *r;
1170 struct cf_mod mod;
1171 struct can_can_gw ccgw;
1172 u8 limhops = 0;
1173 int err = 0;
1174
1175 if (!netlink_capable(skb, CAP_NET_ADMIN))
1176 return -EPERM;
1177
1178 if (nlmsg_len(nlh) < sizeof(*r))
1179 return -EINVAL;
1180
1181 r = nlmsg_data(nlh);
1182 if (r->can_family != AF_CAN)
1183 return -EPFNOSUPPORT;
1184
1185 /* so far we only support CAN -> CAN routings */
1186 if (r->gwtype != CGW_TYPE_CAN_CAN)
1187 return -EINVAL;
1188
1189 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
1190 if (err < 0)
1191 return err;
1192
1193 /* two interface indices both set to 0 => remove all entries */
1194 if (!ccgw.src_idx && !ccgw.dst_idx) {
1195 cgw_remove_all_jobs(net);
1196 return 0;
1197 }
1198
1199 err = -EINVAL;
1200
1201 ASSERT_RTNL();
1202
1203 /* remove only the first matching entry */
1204 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
1205 if (gwj->flags != r->flags)
1206 continue;
1207
1208 if (gwj->limit_hops != limhops)
1209 continue;
1210
1211 /* we have a match when uid is enabled and identical */
1212 if (gwj->mod.uid || mod.uid) {
1213 if (gwj->mod.uid != mod.uid)
1214 continue;
1215 } else {
1216 /* no uid => check for identical modifications */
1217 if (memcmp(&gwj->mod, &mod, sizeof(mod)))
1218 continue;
1219 }
1220
1221 /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */
1222 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
1223 continue;
1224
1225 hlist_del(&gwj->list);
1226 cgw_unregister_filter(net, gwj);
1227 synchronize_rcu();
1228 kmem_cache_free(cgw_cache, gwj);
1229 err = 0;
1230 break;
1231 }
1232
1233 return err;
1234 }
1235
1236 static int __net_init cangw_pernet_init(struct net *net)
1237 {
1238 INIT_HLIST_HEAD(&net->can.cgw_list);
1239 return 0;
1240 }
1241
1242 static void __net_exit cangw_pernet_exit(struct net *net)
1243 {
1244 rtnl_lock();
1245 cgw_remove_all_jobs(net);
1246 rtnl_unlock();
1247 }
1248
1249 static struct pernet_operations cangw_pernet_ops = {
1250 .init = cangw_pernet_init,
1251 .exit = cangw_pernet_exit,
1252 };
1253
1254 static __init int cgw_module_init(void)
1255 {
1256 int ret;
1257
1258 /* sanitize given module parameter */
1259 max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS);
1260
1261 pr_info("can: netlink gateway - max_hops=%d\n", max_hops);
1262
1263 ret = register_pernet_subsys(&cangw_pernet_ops);
1264 if (ret)
1265 return ret;
1266
1267 ret = -ENOMEM;
1268 cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
1269 0, 0, NULL);
1270 if (!cgw_cache)
1271 goto out_cache_create;
1272
1273 /* set notifier */
1274 notifier.notifier_call = cgw_notifier;
1275 ret = register_netdevice_notifier(&notifier);
1276 if (ret)
1277 goto out_register_notifier;
1278
1279 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE,
1280 NULL, cgw_dump_jobs, 0);
1281 if (ret)
1282 goto out_rtnl_register1;
1283
1284 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE,
1285 cgw_create_job, NULL, 0);
1286 if (ret)
1287 goto out_rtnl_register2;
1288 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE,
1289 cgw_remove_job, NULL, 0);
1290 if (ret)
1291 goto out_rtnl_register3;
1292
1293 return 0;
1294
1295 out_rtnl_register3:
1296 rtnl_unregister(PF_CAN, RTM_NEWROUTE);
1297 out_rtnl_register2:
1298 rtnl_unregister(PF_CAN, RTM_GETROUTE);
1299 out_rtnl_register1:
1300 unregister_netdevice_notifier(&notifier);
1301 out_register_notifier:
1302 kmem_cache_destroy(cgw_cache);
1303 out_cache_create:
1304 unregister_pernet_subsys(&cangw_pernet_ops);
1305
1306 return ret;
1307 }
1308
1309 static __exit void cgw_module_exit(void)
1310 {
1311 rtnl_unregister_all(PF_CAN);
1312
1313 unregister_netdevice_notifier(&notifier);
1314
1315 unregister_pernet_subsys(&cangw_pernet_ops);
1316 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1317
1318 kmem_cache_destroy(cgw_cache);
1319 }
1320
1321 module_init(cgw_module_init);
1322 module_exit(cgw_module_exit);
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