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-rw-r--r--net/can/gw.c957
1 files changed, 957 insertions, 0 deletions
diff --git a/net/can/gw.c b/net/can/gw.c
new file mode 100644
index 000000000000..3d79b127881e
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+++ b/net/can/gw.c
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1/*
2 * gw.c - CAN frame Gateway/Router/Bridge with netlink interface
3 *
4 * Copyright (c) 2011 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/list.h>
46#include <linux/spinlock.h>
47#include <linux/rcupdate.h>
48#include <linux/rculist.h>
49#include <linux/net.h>
50#include <linux/netdevice.h>
51#include <linux/if_arp.h>
52#include <linux/skbuff.h>
53#include <linux/can.h>
54#include <linux/can/core.h>
55#include <linux/can/gw.h>
56#include <net/rtnetlink.h>
57#include <net/net_namespace.h>
58#include <net/sock.h>
59
60#define CAN_GW_VERSION "20101209"
61static __initdata const char banner[] =
62 KERN_INFO "can: netlink gateway (rev " CAN_GW_VERSION ")\n";
63
64MODULE_DESCRIPTION("PF_CAN netlink gateway");
65MODULE_LICENSE("Dual BSD/GPL");
66MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
67MODULE_ALIAS("can-gw");
68
69HLIST_HEAD(cgw_list);
70static struct notifier_block notifier;
71
72static struct kmem_cache *cgw_cache __read_mostly;
73
74/* structure that contains the (on-the-fly) CAN frame modifications */
75struct cf_mod {
76 struct {
77 struct can_frame and;
78 struct can_frame or;
79 struct can_frame xor;
80 struct can_frame set;
81 } modframe;
82 struct {
83 u8 and;
84 u8 or;
85 u8 xor;
86 u8 set;
87 } modtype;
88 void (*modfunc[MAX_MODFUNCTIONS])(struct can_frame *cf,
89 struct cf_mod *mod);
90
91 /* CAN frame checksum calculation after CAN frame modifications */
92 struct {
93 struct cgw_csum_xor xor;
94 struct cgw_csum_crc8 crc8;
95 } csum;
96 struct {
97 void (*xor)(struct can_frame *cf, struct cgw_csum_xor *xor);
98 void (*crc8)(struct can_frame *cf, struct cgw_csum_crc8 *crc8);
99 } csumfunc;
100};
101
102
103/*
104 * So far we just support CAN -> CAN routing and frame modifications.
105 *
106 * The internal can_can_gw structure contains data and attributes for
107 * a CAN -> CAN gateway job.
108 */
109struct can_can_gw {
110 struct can_filter filter;
111 int src_idx;
112 int dst_idx;
113};
114
115/* list entry for CAN gateways jobs */
116struct cgw_job {
117 struct hlist_node list;
118 struct rcu_head rcu;
119 u32 handled_frames;
120 u32 dropped_frames;
121 struct cf_mod mod;
122 union {
123 /* CAN frame data source */
124 struct net_device *dev;
125 } src;
126 union {
127 /* CAN frame data destination */
128 struct net_device *dev;
129 } dst;
130 union {
131 struct can_can_gw ccgw;
132 /* tbc */
133 };
134 u8 gwtype;
135 u16 flags;
136};
137
138/* modification functions that are invoked in the hot path in can_can_gw_rcv */
139
140#define MODFUNC(func, op) static void func(struct can_frame *cf, \
141 struct cf_mod *mod) { op ; }
142
143MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
144MODFUNC(mod_and_dlc, cf->can_dlc &= mod->modframe.and.can_dlc)
145MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
146MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
147MODFUNC(mod_or_dlc, cf->can_dlc |= mod->modframe.or.can_dlc)
148MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
149MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
150MODFUNC(mod_xor_dlc, cf->can_dlc ^= mod->modframe.xor.can_dlc)
151MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
152MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
153MODFUNC(mod_set_dlc, cf->can_dlc = mod->modframe.set.can_dlc)
154MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
155
156static inline void canframecpy(struct can_frame *dst, struct can_frame *src)
157{
158 /*
159 * Copy the struct members separately to ensure that no uninitialized
160 * data are copied in the 3 bytes hole of the struct. This is needed
161 * to make easy compares of the data in the struct cf_mod.
162 */
163
164 dst->can_id = src->can_id;
165 dst->can_dlc = src->can_dlc;
166 *(u64 *)dst->data = *(u64 *)src->data;
167}
168
169static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re)
170{
171 /*
172 * absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
173 * relative to received dlc -1 .. -8 :
174 * e.g. for received dlc = 8
175 * -1 => index = 7 (data[7])
176 * -3 => index = 5 (data[5])
177 * -8 => index = 0 (data[0])
178 */
179
180 if (fr > -9 && fr < 8 &&
181 to > -9 && to < 8 &&
182 re > -9 && re < 8)
183 return 0;
184 else
185 return -EINVAL;
186}
187
188static inline int calc_idx(int idx, int rx_dlc)
189{
190 if (idx < 0)
191 return rx_dlc + idx;
192 else
193 return idx;
194}
195
196static void cgw_csum_xor_rel(struct can_frame *cf, struct cgw_csum_xor *xor)
197{
198 int from = calc_idx(xor->from_idx, cf->can_dlc);
199 int to = calc_idx(xor->to_idx, cf->can_dlc);
200 int res = calc_idx(xor->result_idx, cf->can_dlc);
201 u8 val = xor->init_xor_val;
202 int i;
203
204 if (from < 0 || to < 0 || res < 0)
205 return;
206
207 if (from <= to) {
208 for (i = from; i <= to; i++)
209 val ^= cf->data[i];
210 } else {
211 for (i = from; i >= to; i--)
212 val ^= cf->data[i];
213 }
214
215 cf->data[res] = val;
216}
217
218static void cgw_csum_xor_pos(struct can_frame *cf, struct cgw_csum_xor *xor)
219{
220 u8 val = xor->init_xor_val;
221 int i;
222
223 for (i = xor->from_idx; i <= xor->to_idx; i++)
224 val ^= cf->data[i];
225
226 cf->data[xor->result_idx] = val;
227}
228
229static void cgw_csum_xor_neg(struct can_frame *cf, struct cgw_csum_xor *xor)
230{
231 u8 val = xor->init_xor_val;
232 int i;
233
234 for (i = xor->from_idx; i >= xor->to_idx; i--)
235 val ^= cf->data[i];
236
237 cf->data[xor->result_idx] = val;
238}
239
240static void cgw_csum_crc8_rel(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
241{
242 int from = calc_idx(crc8->from_idx, cf->can_dlc);
243 int to = calc_idx(crc8->to_idx, cf->can_dlc);
244 int res = calc_idx(crc8->result_idx, cf->can_dlc);
245 u8 crc = crc8->init_crc_val;
246 int i;
247
248 if (from < 0 || to < 0 || res < 0)
249 return;
250
251 if (from <= to) {
252 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
253 crc = crc8->crctab[crc^cf->data[i]];
254 } else {
255 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
256 crc = crc8->crctab[crc^cf->data[i]];
257 }
258
259 switch (crc8->profile) {
260
261 case CGW_CRC8PRF_1U8:
262 crc = crc8->crctab[crc^crc8->profile_data[0]];
263 break;
264
265 case CGW_CRC8PRF_16U8:
266 crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]];
267 break;
268
269 case CGW_CRC8PRF_SFFID_XOR:
270 crc = crc8->crctab[crc^(cf->can_id & 0xFF)^
271 (cf->can_id >> 8 & 0xFF)];
272 break;
273
274 }
275
276 cf->data[crc8->result_idx] = crc^crc8->final_xor_val;
277}
278
279static void cgw_csum_crc8_pos(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
280{
281 u8 crc = crc8->init_crc_val;
282 int i;
283
284 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
285 crc = crc8->crctab[crc^cf->data[i]];
286
287 switch (crc8->profile) {
288
289 case CGW_CRC8PRF_1U8:
290 crc = crc8->crctab[crc^crc8->profile_data[0]];
291 break;
292
293 case CGW_CRC8PRF_16U8:
294 crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]];
295 break;
296
297 case CGW_CRC8PRF_SFFID_XOR:
298 crc = crc8->crctab[crc^(cf->can_id & 0xFF)^
299 (cf->can_id >> 8 & 0xFF)];
300 break;
301 }
302
303 cf->data[crc8->result_idx] = crc^crc8->final_xor_val;
304}
305
306static void cgw_csum_crc8_neg(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
307{
308 u8 crc = crc8->init_crc_val;
309 int i;
310
311 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
312 crc = crc8->crctab[crc^cf->data[i]];
313
314 switch (crc8->profile) {
315
316 case CGW_CRC8PRF_1U8:
317 crc = crc8->crctab[crc^crc8->profile_data[0]];
318 break;
319
320 case CGW_CRC8PRF_16U8:
321 crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]];
322 break;
323
324 case CGW_CRC8PRF_SFFID_XOR:
325 crc = crc8->crctab[crc^(cf->can_id & 0xFF)^
326 (cf->can_id >> 8 & 0xFF)];
327 break;
328 }
329
330 cf->data[crc8->result_idx] = crc^crc8->final_xor_val;
331}
332
333/* the receive & process & send function */
334static void can_can_gw_rcv(struct sk_buff *skb, void *data)
335{
336 struct cgw_job *gwj = (struct cgw_job *)data;
337 struct can_frame *cf;
338 struct sk_buff *nskb;
339 int modidx = 0;
340
341 /* do not handle already routed frames - see comment below */
342 if (skb_mac_header_was_set(skb))
343 return;
344
345 if (!(gwj->dst.dev->flags & IFF_UP)) {
346 gwj->dropped_frames++;
347 return;
348 }
349
350 /*
351 * clone the given skb, which has not been done in can_rcv()
352 *
353 * When there is at least one modification function activated,
354 * we need to copy the skb as we want to modify skb->data.
355 */
356 if (gwj->mod.modfunc[0])
357 nskb = skb_copy(skb, GFP_ATOMIC);
358 else
359 nskb = skb_clone(skb, GFP_ATOMIC);
360
361 if (!nskb) {
362 gwj->dropped_frames++;
363 return;
364 }
365
366 /*
367 * Mark routed frames by setting some mac header length which is
368 * not relevant for the CAN frames located in the skb->data section.
369 *
370 * As dev->header_ops is not set in CAN netdevices no one is ever
371 * accessing the various header offsets in the CAN skbuffs anyway.
372 * E.g. using the packet socket to read CAN frames is still working.
373 */
374 skb_set_mac_header(nskb, 8);
375 nskb->dev = gwj->dst.dev;
376
377 /* pointer to modifiable CAN frame */
378 cf = (struct can_frame *)nskb->data;
379
380 /* perform preprocessed modification functions if there are any */
381 while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
382 (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod);
383
384 /* check for checksum updates when the CAN frame has been modified */
385 if (modidx) {
386 if (gwj->mod.csumfunc.crc8)
387 (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
388
389 if (gwj->mod.csumfunc.xor)
390 (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
391 }
392
393 /* clear the skb timestamp if not configured the other way */
394 if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
395 nskb->tstamp.tv64 = 0;
396
397 /* send to netdevice */
398 if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
399 gwj->dropped_frames++;
400 else
401 gwj->handled_frames++;
402}
403
404static inline int cgw_register_filter(struct cgw_job *gwj)
405{
406 return can_rx_register(gwj->src.dev, gwj->ccgw.filter.can_id,
407 gwj->ccgw.filter.can_mask, can_can_gw_rcv,
408 gwj, "gw");
409}
410
411static inline void cgw_unregister_filter(struct cgw_job *gwj)
412{
413 can_rx_unregister(gwj->src.dev, gwj->ccgw.filter.can_id,
414 gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
415}
416
417static int cgw_notifier(struct notifier_block *nb,
418 unsigned long msg, void *data)
419{
420 struct net_device *dev = (struct net_device *)data;
421
422 if (!net_eq(dev_net(dev), &init_net))
423 return NOTIFY_DONE;
424 if (dev->type != ARPHRD_CAN)
425 return NOTIFY_DONE;
426
427 if (msg == NETDEV_UNREGISTER) {
428
429 struct cgw_job *gwj = NULL;
430 struct hlist_node *n, *nx;
431
432 ASSERT_RTNL();
433
434 hlist_for_each_entry_safe(gwj, n, nx, &cgw_list, list) {
435
436 if (gwj->src.dev == dev || gwj->dst.dev == dev) {
437 hlist_del(&gwj->list);
438 cgw_unregister_filter(gwj);
439 kfree(gwj);
440 }
441 }
442 }
443
444 return NOTIFY_DONE;
445}
446
447static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj)
448{
449 struct cgw_frame_mod mb;
450 struct rtcanmsg *rtcan;
451 struct nlmsghdr *nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*rtcan), 0);
452 if (!nlh)
453 return -EMSGSIZE;
454
455 rtcan = nlmsg_data(nlh);
456 rtcan->can_family = AF_CAN;
457 rtcan->gwtype = gwj->gwtype;
458 rtcan->flags = gwj->flags;
459
460 /* add statistics if available */
461
462 if (gwj->handled_frames) {
463 if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
464 goto cancel;
465 else
466 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(u32));
467 }
468
469 if (gwj->dropped_frames) {
470 if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
471 goto cancel;
472 else
473 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(u32));
474 }
475
476 /* check non default settings of attributes */
477
478 if (gwj->mod.modtype.and) {
479 memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
480 mb.modtype = gwj->mod.modtype.and;
481 if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
482 goto cancel;
483 else
484 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(mb));
485 }
486
487 if (gwj->mod.modtype.or) {
488 memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
489 mb.modtype = gwj->mod.modtype.or;
490 if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
491 goto cancel;
492 else
493 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(mb));
494 }
495
496 if (gwj->mod.modtype.xor) {
497 memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
498 mb.modtype = gwj->mod.modtype.xor;
499 if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
500 goto cancel;
501 else
502 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(mb));
503 }
504
505 if (gwj->mod.modtype.set) {
506 memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
507 mb.modtype = gwj->mod.modtype.set;
508 if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
509 goto cancel;
510 else
511 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(mb));
512 }
513
514 if (gwj->mod.csumfunc.crc8) {
515 if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
516 &gwj->mod.csum.crc8) < 0)
517 goto cancel;
518 else
519 nlh->nlmsg_len += NLA_HDRLEN + \
520 NLA_ALIGN(CGW_CS_CRC8_LEN);
521 }
522
523 if (gwj->mod.csumfunc.xor) {
524 if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN,
525 &gwj->mod.csum.xor) < 0)
526 goto cancel;
527 else
528 nlh->nlmsg_len += NLA_HDRLEN + \
529 NLA_ALIGN(CGW_CS_XOR_LEN);
530 }
531
532 if (gwj->gwtype == CGW_TYPE_CAN_CAN) {
533
534 if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
535 if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
536 &gwj->ccgw.filter) < 0)
537 goto cancel;
538 else
539 nlh->nlmsg_len += NLA_HDRLEN +
540 NLA_ALIGN(sizeof(struct can_filter));
541 }
542
543 if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0)
544 goto cancel;
545 else
546 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(u32));
547
548 if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0)
549 goto cancel;
550 else
551 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(u32));
552 }
553
554 return skb->len;
555
556cancel:
557 nlmsg_cancel(skb, nlh);
558 return -EMSGSIZE;
559}
560
561/* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
562static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
563{
564 struct cgw_job *gwj = NULL;
565 struct hlist_node *n;
566 int idx = 0;
567 int s_idx = cb->args[0];
568
569 rcu_read_lock();
570 hlist_for_each_entry_rcu(gwj, n, &cgw_list, list) {
571 if (idx < s_idx)
572 goto cont;
573
574 if (cgw_put_job(skb, gwj) < 0)
575 break;
576cont:
577 idx++;
578 }
579 rcu_read_unlock();
580
581 cb->args[0] = idx;
582
583 return skb->len;
584}
585
586/* check for common and gwtype specific attributes */
587static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
588 u8 gwtype, void *gwtypeattr)
589{
590 struct nlattr *tb[CGW_MAX+1];
591 struct cgw_frame_mod mb;
592 int modidx = 0;
593 int err = 0;
594
595 /* initialize modification & checksum data space */
596 memset(mod, 0, sizeof(*mod));
597
598 err = nlmsg_parse(nlh, sizeof(struct rtcanmsg), tb, CGW_MAX, NULL);
599 if (err < 0)
600 return err;
601
602 /* check for AND/OR/XOR/SET modifications */
603
604 if (tb[CGW_MOD_AND] &&
605 nla_len(tb[CGW_MOD_AND]) == CGW_MODATTR_LEN) {
606 nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
607
608 canframecpy(&mod->modframe.and, &mb.cf);
609 mod->modtype.and = mb.modtype;
610
611 if (mb.modtype & CGW_MOD_ID)
612 mod->modfunc[modidx++] = mod_and_id;
613
614 if (mb.modtype & CGW_MOD_DLC)
615 mod->modfunc[modidx++] = mod_and_dlc;
616
617 if (mb.modtype & CGW_MOD_DATA)
618 mod->modfunc[modidx++] = mod_and_data;
619 }
620
621 if (tb[CGW_MOD_OR] &&
622 nla_len(tb[CGW_MOD_OR]) == CGW_MODATTR_LEN) {
623 nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
624
625 canframecpy(&mod->modframe.or, &mb.cf);
626 mod->modtype.or = mb.modtype;
627
628 if (mb.modtype & CGW_MOD_ID)
629 mod->modfunc[modidx++] = mod_or_id;
630
631 if (mb.modtype & CGW_MOD_DLC)
632 mod->modfunc[modidx++] = mod_or_dlc;
633
634 if (mb.modtype & CGW_MOD_DATA)
635 mod->modfunc[modidx++] = mod_or_data;
636 }
637
638 if (tb[CGW_MOD_XOR] &&
639 nla_len(tb[CGW_MOD_XOR]) == CGW_MODATTR_LEN) {
640 nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
641
642 canframecpy(&mod->modframe.xor, &mb.cf);
643 mod->modtype.xor = mb.modtype;
644
645 if (mb.modtype & CGW_MOD_ID)
646 mod->modfunc[modidx++] = mod_xor_id;
647
648 if (mb.modtype & CGW_MOD_DLC)
649 mod->modfunc[modidx++] = mod_xor_dlc;
650
651 if (mb.modtype & CGW_MOD_DATA)
652 mod->modfunc[modidx++] = mod_xor_data;
653 }
654
655 if (tb[CGW_MOD_SET] &&
656 nla_len(tb[CGW_MOD_SET]) == CGW_MODATTR_LEN) {
657 nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
658
659 canframecpy(&mod->modframe.set, &mb.cf);
660 mod->modtype.set = mb.modtype;
661
662 if (mb.modtype & CGW_MOD_ID)
663 mod->modfunc[modidx++] = mod_set_id;
664
665 if (mb.modtype & CGW_MOD_DLC)
666 mod->modfunc[modidx++] = mod_set_dlc;
667
668 if (mb.modtype & CGW_MOD_DATA)
669 mod->modfunc[modidx++] = mod_set_data;
670 }
671
672 /* check for checksum operations after CAN frame modifications */
673 if (modidx) {
674
675 if (tb[CGW_CS_CRC8] &&
676 nla_len(tb[CGW_CS_CRC8]) == CGW_CS_CRC8_LEN) {
677
678 struct cgw_csum_crc8 *c = (struct cgw_csum_crc8 *)\
679 nla_data(tb[CGW_CS_CRC8]);
680
681 err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
682 c->result_idx);
683 if (err)
684 return err;
685
686 nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8],
687 CGW_CS_CRC8_LEN);
688
689 /*
690 * select dedicated processing function to reduce
691 * runtime operations in receive hot path.
692 */
693 if (c->from_idx < 0 || c->to_idx < 0 ||
694 c->result_idx < 0)
695 mod->csumfunc.crc8 = cgw_csum_crc8_rel;
696 else if (c->from_idx <= c->to_idx)
697 mod->csumfunc.crc8 = cgw_csum_crc8_pos;
698 else
699 mod->csumfunc.crc8 = cgw_csum_crc8_neg;
700 }
701
702 if (tb[CGW_CS_XOR] &&
703 nla_len(tb[CGW_CS_XOR]) == CGW_CS_XOR_LEN) {
704
705 struct cgw_csum_xor *c = (struct cgw_csum_xor *)\
706 nla_data(tb[CGW_CS_XOR]);
707
708 err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
709 c->result_idx);
710 if (err)
711 return err;
712
713 nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR],
714 CGW_CS_XOR_LEN);
715
716 /*
717 * select dedicated processing function to reduce
718 * runtime operations in receive hot path.
719 */
720 if (c->from_idx < 0 || c->to_idx < 0 ||
721 c->result_idx < 0)
722 mod->csumfunc.xor = cgw_csum_xor_rel;
723 else if (c->from_idx <= c->to_idx)
724 mod->csumfunc.xor = cgw_csum_xor_pos;
725 else
726 mod->csumfunc.xor = cgw_csum_xor_neg;
727 }
728 }
729
730 if (gwtype == CGW_TYPE_CAN_CAN) {
731
732 /* check CGW_TYPE_CAN_CAN specific attributes */
733
734 struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr;
735 memset(ccgw, 0, sizeof(*ccgw));
736
737 /* check for can_filter in attributes */
738 if (tb[CGW_FILTER] &&
739 nla_len(tb[CGW_FILTER]) == sizeof(struct can_filter))
740 nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
741 sizeof(struct can_filter));
742
743 err = -ENODEV;
744
745 /* specifying two interfaces is mandatory */
746 if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF])
747 return err;
748
749 if (nla_len(tb[CGW_SRC_IF]) == sizeof(u32))
750 nla_memcpy(&ccgw->src_idx, tb[CGW_SRC_IF],
751 sizeof(u32));
752
753 if (nla_len(tb[CGW_DST_IF]) == sizeof(u32))
754 nla_memcpy(&ccgw->dst_idx, tb[CGW_DST_IF],
755 sizeof(u32));
756
757 /* both indices set to 0 for flushing all routing entries */
758 if (!ccgw->src_idx && !ccgw->dst_idx)
759 return 0;
760
761 /* only one index set to 0 is an error */
762 if (!ccgw->src_idx || !ccgw->dst_idx)
763 return err;
764 }
765
766 /* add the checks for other gwtypes here */
767
768 return 0;
769}
770
771static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh,
772 void *arg)
773{
774 struct rtcanmsg *r;
775 struct cgw_job *gwj;
776 int err = 0;
777
778 if (nlmsg_len(nlh) < sizeof(*r))
779 return -EINVAL;
780
781 r = nlmsg_data(nlh);
782 if (r->can_family != AF_CAN)
783 return -EPFNOSUPPORT;
784
785 /* so far we only support CAN -> CAN routings */
786 if (r->gwtype != CGW_TYPE_CAN_CAN)
787 return -EINVAL;
788
789 gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL);
790 if (!gwj)
791 return -ENOMEM;
792
793 gwj->handled_frames = 0;
794 gwj->dropped_frames = 0;
795 gwj->flags = r->flags;
796 gwj->gwtype = r->gwtype;
797
798 err = cgw_parse_attr(nlh, &gwj->mod, CGW_TYPE_CAN_CAN, &gwj->ccgw);
799 if (err < 0)
800 goto out;
801
802 err = -ENODEV;
803
804 /* ifindex == 0 is not allowed for job creation */
805 if (!gwj->ccgw.src_idx || !gwj->ccgw.dst_idx)
806 goto out;
807
808 gwj->src.dev = dev_get_by_index(&init_net, gwj->ccgw.src_idx);
809
810 if (!gwj->src.dev)
811 goto out;
812
813 /* check for CAN netdev not using header_ops - see gw_rcv() */
814 if (gwj->src.dev->type != ARPHRD_CAN || gwj->src.dev->header_ops)
815 goto put_src_out;
816
817 gwj->dst.dev = dev_get_by_index(&init_net, gwj->ccgw.dst_idx);
818
819 if (!gwj->dst.dev)
820 goto put_src_out;
821
822 /* check for CAN netdev not using header_ops - see gw_rcv() */
823 if (gwj->dst.dev->type != ARPHRD_CAN || gwj->dst.dev->header_ops)
824 goto put_src_dst_out;
825
826 ASSERT_RTNL();
827
828 err = cgw_register_filter(gwj);
829 if (!err)
830 hlist_add_head_rcu(&gwj->list, &cgw_list);
831
832put_src_dst_out:
833 dev_put(gwj->dst.dev);
834put_src_out:
835 dev_put(gwj->src.dev);
836out:
837 if (err)
838 kmem_cache_free(cgw_cache, gwj);
839
840 return err;
841}
842
843static void cgw_remove_all_jobs(void)
844{
845 struct cgw_job *gwj = NULL;
846 struct hlist_node *n, *nx;
847
848 ASSERT_RTNL();
849
850 hlist_for_each_entry_safe(gwj, n, nx, &cgw_list, list) {
851 hlist_del(&gwj->list);
852 cgw_unregister_filter(gwj);
853 kfree(gwj);
854 }
855}
856
857static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
858{
859 struct cgw_job *gwj = NULL;
860 struct hlist_node *n, *nx;
861 struct rtcanmsg *r;
862 struct cf_mod mod;
863 struct can_can_gw ccgw;
864 int err = 0;
865
866 if (nlmsg_len(nlh) < sizeof(*r))
867 return -EINVAL;
868
869 r = nlmsg_data(nlh);
870 if (r->can_family != AF_CAN)
871 return -EPFNOSUPPORT;
872
873 /* so far we only support CAN -> CAN routings */
874 if (r->gwtype != CGW_TYPE_CAN_CAN)
875 return -EINVAL;
876
877 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw);
878 if (err < 0)
879 return err;
880
881 /* two interface indices both set to 0 => remove all entries */
882 if (!ccgw.src_idx && !ccgw.dst_idx) {
883 cgw_remove_all_jobs();
884 return 0;
885 }
886
887 err = -EINVAL;
888
889 ASSERT_RTNL();
890
891 /* remove only the first matching entry */
892 hlist_for_each_entry_safe(gwj, n, nx, &cgw_list, list) {
893
894 if (gwj->flags != r->flags)
895 continue;
896
897 if (memcmp(&gwj->mod, &mod, sizeof(mod)))
898 continue;
899
900 /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */
901 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
902 continue;
903
904 hlist_del(&gwj->list);
905 cgw_unregister_filter(gwj);
906 kfree(gwj);
907 err = 0;
908 break;
909 }
910
911 return err;
912}
913
914static __init int cgw_module_init(void)
915{
916 printk(banner);
917
918 cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
919 0, 0, NULL);
920
921 if (!cgw_cache)
922 return -ENOMEM;
923
924 /* set notifier */
925 notifier.notifier_call = cgw_notifier;
926 register_netdevice_notifier(&notifier);
927
928 if (__rtnl_register(PF_CAN, RTM_GETROUTE, NULL, cgw_dump_jobs, NULL)) {
929 unregister_netdevice_notifier(&notifier);
930 kmem_cache_destroy(cgw_cache);
931 return -ENOBUFS;
932 }
933
934 /* Only the first call to __rtnl_register can fail */
935 __rtnl_register(PF_CAN, RTM_NEWROUTE, cgw_create_job, NULL, NULL);
936 __rtnl_register(PF_CAN, RTM_DELROUTE, cgw_remove_job, NULL, NULL);
937
938 return 0;
939}
940
941static __exit void cgw_module_exit(void)
942{
943 rtnl_unregister_all(PF_CAN);
944
945 unregister_netdevice_notifier(&notifier);
946
947 rtnl_lock();
948 cgw_remove_all_jobs();
949 rtnl_unlock();
950
951 rcu_barrier(); /* Wait for completion of call_rcu()'s */
952
953 kmem_cache_destroy(cgw_cache);
954}
955
956module_init(cgw_module_init);
957module_exit(cgw_module_exit);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-29 08:07:51 -0500