]>
Commit | Line | Data |
---|---|---|
c1aabdf3 OH |
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 | * | |
c1aabdf3 OH |
40 | */ |
41 | ||
42 | #include <linux/module.h> | |
43 | #include <linux/init.h> | |
44 | #include <linux/types.h> | |
be286baf | 45 | #include <linux/kernel.h> |
c1aabdf3 OH |
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> | |
d904d3ed | 56 | #include <linux/can/skb.h> |
c1aabdf3 OH |
57 | #include <linux/can/gw.h> |
58 | #include <net/rtnetlink.h> | |
59 | #include <net/net_namespace.h> | |
60 | #include <net/sock.h> | |
61 | ||
be286baf OH |
62 | #define CAN_GW_VERSION "20130117" |
63 | #define CAN_GW_NAME "can-gw" | |
c1aabdf3 OH |
64 | |
65 | MODULE_DESCRIPTION("PF_CAN netlink gateway"); | |
66 | MODULE_LICENSE("Dual BSD/GPL"); | |
67 | MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); | |
be286baf OH |
68 | MODULE_ALIAS(CAN_GW_NAME); |
69 | ||
70 | #define CGW_MIN_HOPS 1 | |
71 | #define CGW_MAX_HOPS 6 | |
72 | #define CGW_DEFAULT_HOPS 1 | |
73 | ||
74 | static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS; | |
75 | module_param(max_hops, uint, S_IRUGO); | |
76 | MODULE_PARM_DESC(max_hops, | |
77 | "maximum " CAN_GW_NAME " routing hops for CAN frames " | |
78 | "(valid values: " __stringify(CGW_MIN_HOPS) "-" | |
79 | __stringify(CGW_MAX_HOPS) " hops, " | |
80 | "default: " __stringify(CGW_DEFAULT_HOPS) ")"); | |
c1aabdf3 | 81 | |
a75afd47 | 82 | static HLIST_HEAD(cgw_list); |
c1aabdf3 OH |
83 | static struct notifier_block notifier; |
84 | ||
85 | static struct kmem_cache *cgw_cache __read_mostly; | |
86 | ||
87 | /* structure that contains the (on-the-fly) CAN frame modifications */ | |
88 | struct cf_mod { | |
89 | struct { | |
90 | struct can_frame and; | |
91 | struct can_frame or; | |
92 | struct can_frame xor; | |
93 | struct can_frame set; | |
94 | } modframe; | |
95 | struct { | |
96 | u8 and; | |
97 | u8 or; | |
98 | u8 xor; | |
99 | u8 set; | |
100 | } modtype; | |
101 | void (*modfunc[MAX_MODFUNCTIONS])(struct can_frame *cf, | |
102 | struct cf_mod *mod); | |
103 | ||
104 | /* CAN frame checksum calculation after CAN frame modifications */ | |
105 | struct { | |
106 | struct cgw_csum_xor xor; | |
107 | struct cgw_csum_crc8 crc8; | |
108 | } csum; | |
109 | struct { | |
110 | void (*xor)(struct can_frame *cf, struct cgw_csum_xor *xor); | |
111 | void (*crc8)(struct can_frame *cf, struct cgw_csum_crc8 *crc8); | |
112 | } csumfunc; | |
113 | }; | |
114 | ||
115 | ||
116 | /* | |
117 | * So far we just support CAN -> CAN routing and frame modifications. | |
118 | * | |
119 | * The internal can_can_gw structure contains data and attributes for | |
120 | * a CAN -> CAN gateway job. | |
121 | */ | |
122 | struct can_can_gw { | |
123 | struct can_filter filter; | |
124 | int src_idx; | |
125 | int dst_idx; | |
126 | }; | |
127 | ||
128 | /* list entry for CAN gateways jobs */ | |
129 | struct cgw_job { | |
130 | struct hlist_node list; | |
131 | struct rcu_head rcu; | |
132 | u32 handled_frames; | |
133 | u32 dropped_frames; | |
e6afa00a | 134 | u32 deleted_frames; |
c1aabdf3 OH |
135 | struct cf_mod mod; |
136 | union { | |
137 | /* CAN frame data source */ | |
138 | struct net_device *dev; | |
139 | } src; | |
140 | union { | |
141 | /* CAN frame data destination */ | |
142 | struct net_device *dev; | |
143 | } dst; | |
144 | union { | |
145 | struct can_can_gw ccgw; | |
146 | /* tbc */ | |
147 | }; | |
148 | u8 gwtype; | |
391ac128 | 149 | u8 limit_hops; |
c1aabdf3 OH |
150 | u16 flags; |
151 | }; | |
152 | ||
153 | /* modification functions that are invoked in the hot path in can_can_gw_rcv */ | |
154 | ||
155 | #define MODFUNC(func, op) static void func(struct can_frame *cf, \ | |
156 | struct cf_mod *mod) { op ; } | |
157 | ||
158 | MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id) | |
159 | MODFUNC(mod_and_dlc, cf->can_dlc &= mod->modframe.and.can_dlc) | |
160 | MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data) | |
161 | MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id) | |
162 | MODFUNC(mod_or_dlc, cf->can_dlc |= mod->modframe.or.can_dlc) | |
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_dlc, cf->can_dlc ^= mod->modframe.xor.can_dlc) | |
166 | MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data) | |
167 | MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id) | |
168 | MODFUNC(mod_set_dlc, cf->can_dlc = mod->modframe.set.can_dlc) | |
169 | MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data) | |
170 | ||
171 | static inline void canframecpy(struct can_frame *dst, struct can_frame *src) | |
172 | { | |
173 | /* | |
174 | * Copy the struct members separately to ensure that no uninitialized | |
175 | * data are copied in the 3 bytes hole of the struct. This is needed | |
176 | * to make easy compares of the data in the struct cf_mod. | |
177 | */ | |
178 | ||
179 | dst->can_id = src->can_id; | |
180 | dst->can_dlc = src->can_dlc; | |
181 | *(u64 *)dst->data = *(u64 *)src->data; | |
182 | } | |
183 | ||
184 | static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re) | |
185 | { | |
186 | /* | |
187 | * absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0] | |
188 | * relative to received dlc -1 .. -8 : | |
189 | * e.g. for received dlc = 8 | |
190 | * -1 => index = 7 (data[7]) | |
191 | * -3 => index = 5 (data[5]) | |
192 | * -8 => index = 0 (data[0]) | |
193 | */ | |
194 | ||
195 | if (fr > -9 && fr < 8 && | |
196 | to > -9 && to < 8 && | |
197 | re > -9 && re < 8) | |
198 | return 0; | |
199 | else | |
200 | return -EINVAL; | |
201 | } | |
202 | ||
203 | static inline int calc_idx(int idx, int rx_dlc) | |
204 | { | |
205 | if (idx < 0) | |
206 | return rx_dlc + idx; | |
207 | else | |
208 | return idx; | |
209 | } | |
210 | ||
211 | static void cgw_csum_xor_rel(struct can_frame *cf, struct cgw_csum_xor *xor) | |
212 | { | |
213 | int from = calc_idx(xor->from_idx, cf->can_dlc); | |
214 | int to = calc_idx(xor->to_idx, cf->can_dlc); | |
215 | int res = calc_idx(xor->result_idx, cf->can_dlc); | |
216 | u8 val = xor->init_xor_val; | |
217 | int i; | |
218 | ||
219 | if (from < 0 || to < 0 || res < 0) | |
220 | return; | |
221 | ||
222 | if (from <= to) { | |
223 | for (i = from; i <= to; i++) | |
224 | val ^= cf->data[i]; | |
225 | } else { | |
226 | for (i = from; i >= to; i--) | |
227 | val ^= cf->data[i]; | |
228 | } | |
229 | ||
230 | cf->data[res] = val; | |
231 | } | |
232 | ||
233 | static void cgw_csum_xor_pos(struct can_frame *cf, struct cgw_csum_xor *xor) | |
234 | { | |
235 | u8 val = xor->init_xor_val; | |
236 | int i; | |
237 | ||
238 | for (i = xor->from_idx; i <= xor->to_idx; i++) | |
239 | val ^= cf->data[i]; | |
240 | ||
241 | cf->data[xor->result_idx] = val; | |
242 | } | |
243 | ||
244 | static void cgw_csum_xor_neg(struct can_frame *cf, struct cgw_csum_xor *xor) | |
245 | { | |
246 | u8 val = xor->init_xor_val; | |
247 | int i; | |
248 | ||
249 | for (i = xor->from_idx; i >= xor->to_idx; i--) | |
250 | val ^= cf->data[i]; | |
251 | ||
252 | cf->data[xor->result_idx] = val; | |
253 | } | |
254 | ||
255 | static void cgw_csum_crc8_rel(struct can_frame *cf, struct cgw_csum_crc8 *crc8) | |
256 | { | |
257 | int from = calc_idx(crc8->from_idx, cf->can_dlc); | |
258 | int to = calc_idx(crc8->to_idx, cf->can_dlc); | |
259 | int res = calc_idx(crc8->result_idx, cf->can_dlc); | |
260 | u8 crc = crc8->init_crc_val; | |
261 | int i; | |
262 | ||
263 | if (from < 0 || to < 0 || res < 0) | |
264 | return; | |
265 | ||
266 | if (from <= to) { | |
267 | for (i = crc8->from_idx; i <= crc8->to_idx; i++) | |
268 | crc = crc8->crctab[crc^cf->data[i]]; | |
269 | } else { | |
270 | for (i = crc8->from_idx; i >= crc8->to_idx; i--) | |
271 | crc = crc8->crctab[crc^cf->data[i]]; | |
272 | } | |
273 | ||
274 | switch (crc8->profile) { | |
275 | ||
276 | case CGW_CRC8PRF_1U8: | |
277 | crc = crc8->crctab[crc^crc8->profile_data[0]]; | |
278 | break; | |
279 | ||
280 | case CGW_CRC8PRF_16U8: | |
281 | crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]]; | |
282 | break; | |
283 | ||
284 | case CGW_CRC8PRF_SFFID_XOR: | |
285 | crc = crc8->crctab[crc^(cf->can_id & 0xFF)^ | |
286 | (cf->can_id >> 8 & 0xFF)]; | |
287 | break; | |
288 | ||
289 | } | |
290 | ||
291 | cf->data[crc8->result_idx] = crc^crc8->final_xor_val; | |
292 | } | |
293 | ||
294 | static void cgw_csum_crc8_pos(struct can_frame *cf, struct cgw_csum_crc8 *crc8) | |
295 | { | |
296 | u8 crc = crc8->init_crc_val; | |
297 | int i; | |
298 | ||
299 | for (i = crc8->from_idx; i <= crc8->to_idx; i++) | |
300 | crc = crc8->crctab[crc^cf->data[i]]; | |
301 | ||
302 | switch (crc8->profile) { | |
303 | ||
304 | case CGW_CRC8PRF_1U8: | |
305 | crc = crc8->crctab[crc^crc8->profile_data[0]]; | |
306 | break; | |
307 | ||
308 | case CGW_CRC8PRF_16U8: | |
309 | crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]]; | |
310 | break; | |
311 | ||
312 | case CGW_CRC8PRF_SFFID_XOR: | |
313 | crc = crc8->crctab[crc^(cf->can_id & 0xFF)^ | |
314 | (cf->can_id >> 8 & 0xFF)]; | |
315 | break; | |
316 | } | |
317 | ||
318 | cf->data[crc8->result_idx] = crc^crc8->final_xor_val; | |
319 | } | |
320 | ||
321 | static void cgw_csum_crc8_neg(struct can_frame *cf, struct cgw_csum_crc8 *crc8) | |
322 | { | |
323 | u8 crc = crc8->init_crc_val; | |
324 | int i; | |
325 | ||
326 | for (i = crc8->from_idx; i >= crc8->to_idx; i--) | |
327 | crc = crc8->crctab[crc^cf->data[i]]; | |
328 | ||
329 | switch (crc8->profile) { | |
330 | ||
331 | case CGW_CRC8PRF_1U8: | |
332 | crc = crc8->crctab[crc^crc8->profile_data[0]]; | |
333 | break; | |
334 | ||
335 | case CGW_CRC8PRF_16U8: | |
336 | crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]]; | |
337 | break; | |
338 | ||
339 | case CGW_CRC8PRF_SFFID_XOR: | |
340 | crc = crc8->crctab[crc^(cf->can_id & 0xFF)^ | |
341 | (cf->can_id >> 8 & 0xFF)]; | |
342 | break; | |
343 | } | |
344 | ||
345 | cf->data[crc8->result_idx] = crc^crc8->final_xor_val; | |
346 | } | |
347 | ||
348 | /* the receive & process & send function */ | |
349 | static void can_can_gw_rcv(struct sk_buff *skb, void *data) | |
350 | { | |
351 | struct cgw_job *gwj = (struct cgw_job *)data; | |
352 | struct can_frame *cf; | |
353 | struct sk_buff *nskb; | |
354 | int modidx = 0; | |
355 | ||
be286baf OH |
356 | /* |
357 | * Do not handle CAN frames routed more than 'max_hops' times. | |
358 | * In general we should never catch this delimiter which is intended | |
359 | * to cover a misconfiguration protection (e.g. circular CAN routes). | |
360 | * | |
361 | * The Controller Area Network controllers only accept CAN frames with | |
362 | * correct CRCs - which are not visible in the controller registers. | |
363 | * According to skbuff.h documentation the csum_start element for IP | |
364 | * checksums is undefined/unsued when ip_summed == CHECKSUM_UNNECESSARY. | |
365 | * Only CAN skbs can be processed here which already have this property. | |
366 | */ | |
367 | ||
368 | #define cgw_hops(skb) ((skb)->csum_start) | |
369 | ||
370 | BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY); | |
371 | ||
e6afa00a OH |
372 | if (cgw_hops(skb) >= max_hops) { |
373 | /* indicate deleted frames due to misconfiguration */ | |
374 | gwj->deleted_frames++; | |
c1aabdf3 | 375 | return; |
e6afa00a | 376 | } |
c1aabdf3 OH |
377 | |
378 | if (!(gwj->dst.dev->flags & IFF_UP)) { | |
379 | gwj->dropped_frames++; | |
380 | return; | |
381 | } | |
382 | ||
d904d3ed OH |
383 | /* is sending the skb back to the incoming interface not allowed? */ |
384 | if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) && | |
2bf3440d | 385 | can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex) |
d904d3ed OH |
386 | return; |
387 | ||
c1aabdf3 OH |
388 | /* |
389 | * clone the given skb, which has not been done in can_rcv() | |
390 | * | |
391 | * When there is at least one modification function activated, | |
392 | * we need to copy the skb as we want to modify skb->data. | |
393 | */ | |
394 | if (gwj->mod.modfunc[0]) | |
395 | nskb = skb_copy(skb, GFP_ATOMIC); | |
396 | else | |
397 | nskb = skb_clone(skb, GFP_ATOMIC); | |
398 | ||
399 | if (!nskb) { | |
400 | gwj->dropped_frames++; | |
401 | return; | |
402 | } | |
403 | ||
be286baf OH |
404 | /* put the incremented hop counter in the cloned skb */ |
405 | cgw_hops(nskb) = cgw_hops(skb) + 1; | |
391ac128 OH |
406 | |
407 | /* first processing of this CAN frame -> adjust to private hop limit */ | |
408 | if (gwj->limit_hops && cgw_hops(nskb) == 1) | |
409 | cgw_hops(nskb) = max_hops - gwj->limit_hops + 1; | |
410 | ||
c1aabdf3 OH |
411 | nskb->dev = gwj->dst.dev; |
412 | ||
413 | /* pointer to modifiable CAN frame */ | |
414 | cf = (struct can_frame *)nskb->data; | |
415 | ||
416 | /* perform preprocessed modification functions if there are any */ | |
417 | while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx]) | |
418 | (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod); | |
419 | ||
420 | /* check for checksum updates when the CAN frame has been modified */ | |
421 | if (modidx) { | |
422 | if (gwj->mod.csumfunc.crc8) | |
423 | (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8); | |
424 | ||
425 | if (gwj->mod.csumfunc.xor) | |
426 | (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor); | |
427 | } | |
428 | ||
429 | /* clear the skb timestamp if not configured the other way */ | |
430 | if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP)) | |
431 | nskb->tstamp.tv64 = 0; | |
432 | ||
433 | /* send to netdevice */ | |
434 | if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO)) | |
435 | gwj->dropped_frames++; | |
436 | else | |
437 | gwj->handled_frames++; | |
438 | } | |
439 | ||
440 | static inline int cgw_register_filter(struct cgw_job *gwj) | |
441 | { | |
442 | return can_rx_register(gwj->src.dev, gwj->ccgw.filter.can_id, | |
443 | gwj->ccgw.filter.can_mask, can_can_gw_rcv, | |
444 | gwj, "gw"); | |
445 | } | |
446 | ||
447 | static inline void cgw_unregister_filter(struct cgw_job *gwj) | |
448 | { | |
449 | can_rx_unregister(gwj->src.dev, gwj->ccgw.filter.can_id, | |
450 | gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj); | |
451 | } | |
452 | ||
453 | static int cgw_notifier(struct notifier_block *nb, | |
351638e7 | 454 | unsigned long msg, void *ptr) |
c1aabdf3 | 455 | { |
351638e7 | 456 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
c1aabdf3 OH |
457 | |
458 | if (!net_eq(dev_net(dev), &init_net)) | |
459 | return NOTIFY_DONE; | |
460 | if (dev->type != ARPHRD_CAN) | |
461 | return NOTIFY_DONE; | |
462 | ||
463 | if (msg == NETDEV_UNREGISTER) { | |
464 | ||
465 | struct cgw_job *gwj = NULL; | |
b67bfe0d | 466 | struct hlist_node *nx; |
c1aabdf3 OH |
467 | |
468 | ASSERT_RTNL(); | |
469 | ||
b67bfe0d | 470 | hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) { |
c1aabdf3 OH |
471 | |
472 | if (gwj->src.dev == dev || gwj->dst.dev == dev) { | |
473 | hlist_del(&gwj->list); | |
474 | cgw_unregister_filter(gwj); | |
3480a212 | 475 | kmem_cache_free(cgw_cache, gwj); |
c1aabdf3 OH |
476 | } |
477 | } | |
478 | } | |
479 | ||
480 | return NOTIFY_DONE; | |
481 | } | |
482 | ||
1da0faa3 TG |
483 | static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type, |
484 | u32 pid, u32 seq, int flags) | |
c1aabdf3 OH |
485 | { |
486 | struct cgw_frame_mod mb; | |
487 | struct rtcanmsg *rtcan; | |
1da0faa3 TG |
488 | struct nlmsghdr *nlh; |
489 | ||
490 | nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags); | |
c1aabdf3 OH |
491 | if (!nlh) |
492 | return -EMSGSIZE; | |
493 | ||
494 | rtcan = nlmsg_data(nlh); | |
495 | rtcan->can_family = AF_CAN; | |
496 | rtcan->gwtype = gwj->gwtype; | |
497 | rtcan->flags = gwj->flags; | |
498 | ||
499 | /* add statistics if available */ | |
500 | ||
501 | if (gwj->handled_frames) { | |
502 | if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0) | |
503 | goto cancel; | |
c1aabdf3 OH |
504 | } |
505 | ||
506 | if (gwj->dropped_frames) { | |
507 | if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0) | |
508 | goto cancel; | |
c1aabdf3 OH |
509 | } |
510 | ||
e6afa00a OH |
511 | if (gwj->deleted_frames) { |
512 | if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0) | |
513 | goto cancel; | |
514 | } | |
515 | ||
c1aabdf3 OH |
516 | /* check non default settings of attributes */ |
517 | ||
391ac128 OH |
518 | if (gwj->limit_hops) { |
519 | if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0) | |
520 | goto cancel; | |
521 | } | |
522 | ||
c1aabdf3 OH |
523 | if (gwj->mod.modtype.and) { |
524 | memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf)); | |
525 | mb.modtype = gwj->mod.modtype.and; | |
526 | if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0) | |
527 | goto cancel; | |
c1aabdf3 OH |
528 | } |
529 | ||
530 | if (gwj->mod.modtype.or) { | |
531 | memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf)); | |
532 | mb.modtype = gwj->mod.modtype.or; | |
533 | if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0) | |
534 | goto cancel; | |
c1aabdf3 OH |
535 | } |
536 | ||
537 | if (gwj->mod.modtype.xor) { | |
538 | memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf)); | |
539 | mb.modtype = gwj->mod.modtype.xor; | |
540 | if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0) | |
541 | goto cancel; | |
c1aabdf3 OH |
542 | } |
543 | ||
544 | if (gwj->mod.modtype.set) { | |
545 | memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf)); | |
546 | mb.modtype = gwj->mod.modtype.set; | |
547 | if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0) | |
548 | goto cancel; | |
c1aabdf3 OH |
549 | } |
550 | ||
551 | if (gwj->mod.csumfunc.crc8) { | |
552 | if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN, | |
553 | &gwj->mod.csum.crc8) < 0) | |
554 | goto cancel; | |
c1aabdf3 OH |
555 | } |
556 | ||
557 | if (gwj->mod.csumfunc.xor) { | |
558 | if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN, | |
559 | &gwj->mod.csum.xor) < 0) | |
560 | goto cancel; | |
c1aabdf3 OH |
561 | } |
562 | ||
563 | if (gwj->gwtype == CGW_TYPE_CAN_CAN) { | |
564 | ||
565 | if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) { | |
566 | if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter), | |
567 | &gwj->ccgw.filter) < 0) | |
568 | goto cancel; | |
c1aabdf3 OH |
569 | } |
570 | ||
571 | if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0) | |
572 | goto cancel; | |
c1aabdf3 OH |
573 | |
574 | if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0) | |
575 | goto cancel; | |
c1aabdf3 OH |
576 | } |
577 | ||
6eaf53ca | 578 | return nlmsg_end(skb, nlh); |
c1aabdf3 OH |
579 | |
580 | cancel: | |
581 | nlmsg_cancel(skb, nlh); | |
582 | return -EMSGSIZE; | |
583 | } | |
584 | ||
585 | /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */ | |
586 | static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb) | |
587 | { | |
588 | struct cgw_job *gwj = NULL; | |
c1aabdf3 OH |
589 | int idx = 0; |
590 | int s_idx = cb->args[0]; | |
591 | ||
592 | rcu_read_lock(); | |
b67bfe0d | 593 | hlist_for_each_entry_rcu(gwj, &cgw_list, list) { |
c1aabdf3 OH |
594 | if (idx < s_idx) |
595 | goto cont; | |
596 | ||
15e47304 | 597 | if (cgw_put_job(skb, gwj, RTM_NEWROUTE, NETLINK_CB(cb->skb).portid, |
1da0faa3 | 598 | cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0) |
c1aabdf3 OH |
599 | break; |
600 | cont: | |
601 | idx++; | |
602 | } | |
603 | rcu_read_unlock(); | |
604 | ||
605 | cb->args[0] = idx; | |
606 | ||
607 | return skb->len; | |
608 | } | |
609 | ||
732d35fd TG |
610 | static const struct nla_policy cgw_policy[CGW_MAX+1] = { |
611 | [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) }, | |
612 | [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) }, | |
613 | [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) }, | |
614 | [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) }, | |
615 | [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) }, | |
616 | [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) }, | |
617 | [CGW_SRC_IF] = { .type = NLA_U32 }, | |
618 | [CGW_DST_IF] = { .type = NLA_U32 }, | |
619 | [CGW_FILTER] = { .len = sizeof(struct can_filter) }, | |
391ac128 | 620 | [CGW_LIM_HOPS] = { .type = NLA_U8 }, |
732d35fd TG |
621 | }; |
622 | ||
c1aabdf3 OH |
623 | /* check for common and gwtype specific attributes */ |
624 | static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, | |
391ac128 | 625 | u8 gwtype, void *gwtypeattr, u8 *limhops) |
c1aabdf3 OH |
626 | { |
627 | struct nlattr *tb[CGW_MAX+1]; | |
628 | struct cgw_frame_mod mb; | |
629 | int modidx = 0; | |
630 | int err = 0; | |
631 | ||
632 | /* initialize modification & checksum data space */ | |
633 | memset(mod, 0, sizeof(*mod)); | |
634 | ||
732d35fd TG |
635 | err = nlmsg_parse(nlh, sizeof(struct rtcanmsg), tb, CGW_MAX, |
636 | cgw_policy); | |
c1aabdf3 OH |
637 | if (err < 0) |
638 | return err; | |
639 | ||
391ac128 OH |
640 | if (tb[CGW_LIM_HOPS]) { |
641 | *limhops = nla_get_u8(tb[CGW_LIM_HOPS]); | |
642 | ||
643 | if (*limhops < 1 || *limhops > max_hops) | |
644 | return -EINVAL; | |
645 | } | |
646 | ||
c1aabdf3 OH |
647 | /* check for AND/OR/XOR/SET modifications */ |
648 | ||
732d35fd | 649 | if (tb[CGW_MOD_AND]) { |
c1aabdf3 OH |
650 | nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN); |
651 | ||
652 | canframecpy(&mod->modframe.and, &mb.cf); | |
653 | mod->modtype.and = mb.modtype; | |
654 | ||
655 | if (mb.modtype & CGW_MOD_ID) | |
656 | mod->modfunc[modidx++] = mod_and_id; | |
657 | ||
658 | if (mb.modtype & CGW_MOD_DLC) | |
659 | mod->modfunc[modidx++] = mod_and_dlc; | |
660 | ||
661 | if (mb.modtype & CGW_MOD_DATA) | |
662 | mod->modfunc[modidx++] = mod_and_data; | |
663 | } | |
664 | ||
732d35fd | 665 | if (tb[CGW_MOD_OR]) { |
c1aabdf3 OH |
666 | nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN); |
667 | ||
668 | canframecpy(&mod->modframe.or, &mb.cf); | |
669 | mod->modtype.or = mb.modtype; | |
670 | ||
671 | if (mb.modtype & CGW_MOD_ID) | |
672 | mod->modfunc[modidx++] = mod_or_id; | |
673 | ||
674 | if (mb.modtype & CGW_MOD_DLC) | |
675 | mod->modfunc[modidx++] = mod_or_dlc; | |
676 | ||
677 | if (mb.modtype & CGW_MOD_DATA) | |
678 | mod->modfunc[modidx++] = mod_or_data; | |
679 | } | |
680 | ||
732d35fd | 681 | if (tb[CGW_MOD_XOR]) { |
c1aabdf3 OH |
682 | nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN); |
683 | ||
684 | canframecpy(&mod->modframe.xor, &mb.cf); | |
685 | mod->modtype.xor = mb.modtype; | |
686 | ||
687 | if (mb.modtype & CGW_MOD_ID) | |
688 | mod->modfunc[modidx++] = mod_xor_id; | |
689 | ||
690 | if (mb.modtype & CGW_MOD_DLC) | |
691 | mod->modfunc[modidx++] = mod_xor_dlc; | |
692 | ||
693 | if (mb.modtype & CGW_MOD_DATA) | |
694 | mod->modfunc[modidx++] = mod_xor_data; | |
695 | } | |
696 | ||
732d35fd | 697 | if (tb[CGW_MOD_SET]) { |
c1aabdf3 OH |
698 | nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN); |
699 | ||
700 | canframecpy(&mod->modframe.set, &mb.cf); | |
701 | mod->modtype.set = mb.modtype; | |
702 | ||
703 | if (mb.modtype & CGW_MOD_ID) | |
704 | mod->modfunc[modidx++] = mod_set_id; | |
705 | ||
706 | if (mb.modtype & CGW_MOD_DLC) | |
707 | mod->modfunc[modidx++] = mod_set_dlc; | |
708 | ||
709 | if (mb.modtype & CGW_MOD_DATA) | |
710 | mod->modfunc[modidx++] = mod_set_data; | |
711 | } | |
712 | ||
713 | /* check for checksum operations after CAN frame modifications */ | |
714 | if (modidx) { | |
715 | ||
732d35fd | 716 | if (tb[CGW_CS_CRC8]) { |
5d91efa8 | 717 | struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]); |
c1aabdf3 OH |
718 | |
719 | err = cgw_chk_csum_parms(c->from_idx, c->to_idx, | |
720 | c->result_idx); | |
721 | if (err) | |
722 | return err; | |
723 | ||
724 | nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8], | |
725 | CGW_CS_CRC8_LEN); | |
726 | ||
727 | /* | |
728 | * select dedicated processing function to reduce | |
729 | * runtime operations in receive hot path. | |
730 | */ | |
731 | if (c->from_idx < 0 || c->to_idx < 0 || | |
732 | c->result_idx < 0) | |
733 | mod->csumfunc.crc8 = cgw_csum_crc8_rel; | |
734 | else if (c->from_idx <= c->to_idx) | |
735 | mod->csumfunc.crc8 = cgw_csum_crc8_pos; | |
736 | else | |
737 | mod->csumfunc.crc8 = cgw_csum_crc8_neg; | |
738 | } | |
739 | ||
732d35fd | 740 | if (tb[CGW_CS_XOR]) { |
5d91efa8 | 741 | struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]); |
c1aabdf3 OH |
742 | |
743 | err = cgw_chk_csum_parms(c->from_idx, c->to_idx, | |
744 | c->result_idx); | |
745 | if (err) | |
746 | return err; | |
747 | ||
748 | nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR], | |
749 | CGW_CS_XOR_LEN); | |
750 | ||
751 | /* | |
752 | * select dedicated processing function to reduce | |
753 | * runtime operations in receive hot path. | |
754 | */ | |
755 | if (c->from_idx < 0 || c->to_idx < 0 || | |
756 | c->result_idx < 0) | |
757 | mod->csumfunc.xor = cgw_csum_xor_rel; | |
758 | else if (c->from_idx <= c->to_idx) | |
759 | mod->csumfunc.xor = cgw_csum_xor_pos; | |
760 | else | |
761 | mod->csumfunc.xor = cgw_csum_xor_neg; | |
762 | } | |
763 | } | |
764 | ||
765 | if (gwtype == CGW_TYPE_CAN_CAN) { | |
766 | ||
767 | /* check CGW_TYPE_CAN_CAN specific attributes */ | |
768 | ||
769 | struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr; | |
770 | memset(ccgw, 0, sizeof(*ccgw)); | |
771 | ||
772 | /* check for can_filter in attributes */ | |
732d35fd | 773 | if (tb[CGW_FILTER]) |
c1aabdf3 OH |
774 | nla_memcpy(&ccgw->filter, tb[CGW_FILTER], |
775 | sizeof(struct can_filter)); | |
776 | ||
777 | err = -ENODEV; | |
778 | ||
779 | /* specifying two interfaces is mandatory */ | |
780 | if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF]) | |
781 | return err; | |
782 | ||
732d35fd TG |
783 | ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]); |
784 | ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]); | |
c1aabdf3 OH |
785 | |
786 | /* both indices set to 0 for flushing all routing entries */ | |
787 | if (!ccgw->src_idx && !ccgw->dst_idx) | |
788 | return 0; | |
789 | ||
790 | /* only one index set to 0 is an error */ | |
791 | if (!ccgw->src_idx || !ccgw->dst_idx) | |
792 | return err; | |
793 | } | |
794 | ||
795 | /* add the checks for other gwtypes here */ | |
796 | ||
797 | return 0; | |
798 | } | |
799 | ||
661d2967 | 800 | static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh) |
c1aabdf3 OH |
801 | { |
802 | struct rtcanmsg *r; | |
803 | struct cgw_job *gwj; | |
391ac128 | 804 | u8 limhops = 0; |
c1aabdf3 OH |
805 | int err = 0; |
806 | ||
dfc47ef8 EB |
807 | if (!capable(CAP_NET_ADMIN)) |
808 | return -EPERM; | |
809 | ||
c1aabdf3 OH |
810 | if (nlmsg_len(nlh) < sizeof(*r)) |
811 | return -EINVAL; | |
812 | ||
813 | r = nlmsg_data(nlh); | |
814 | if (r->can_family != AF_CAN) | |
815 | return -EPFNOSUPPORT; | |
816 | ||
817 | /* so far we only support CAN -> CAN routings */ | |
818 | if (r->gwtype != CGW_TYPE_CAN_CAN) | |
819 | return -EINVAL; | |
820 | ||
821 | gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL); | |
822 | if (!gwj) | |
823 | return -ENOMEM; | |
824 | ||
825 | gwj->handled_frames = 0; | |
826 | gwj->dropped_frames = 0; | |
e6afa00a | 827 | gwj->deleted_frames = 0; |
c1aabdf3 OH |
828 | gwj->flags = r->flags; |
829 | gwj->gwtype = r->gwtype; | |
830 | ||
391ac128 OH |
831 | err = cgw_parse_attr(nlh, &gwj->mod, CGW_TYPE_CAN_CAN, &gwj->ccgw, |
832 | &limhops); | |
c1aabdf3 OH |
833 | if (err < 0) |
834 | goto out; | |
835 | ||
836 | err = -ENODEV; | |
837 | ||
838 | /* ifindex == 0 is not allowed for job creation */ | |
839 | if (!gwj->ccgw.src_idx || !gwj->ccgw.dst_idx) | |
840 | goto out; | |
841 | ||
842 | gwj->src.dev = dev_get_by_index(&init_net, gwj->ccgw.src_idx); | |
843 | ||
844 | if (!gwj->src.dev) | |
845 | goto out; | |
846 | ||
c0ebbdd6 | 847 | if (gwj->src.dev->type != ARPHRD_CAN) |
c1aabdf3 OH |
848 | goto put_src_out; |
849 | ||
850 | gwj->dst.dev = dev_get_by_index(&init_net, gwj->ccgw.dst_idx); | |
851 | ||
852 | if (!gwj->dst.dev) | |
853 | goto put_src_out; | |
854 | ||
c0ebbdd6 | 855 | if (gwj->dst.dev->type != ARPHRD_CAN) |
c1aabdf3 OH |
856 | goto put_src_dst_out; |
857 | ||
391ac128 OH |
858 | gwj->limit_hops = limhops; |
859 | ||
c1aabdf3 OH |
860 | ASSERT_RTNL(); |
861 | ||
862 | err = cgw_register_filter(gwj); | |
863 | if (!err) | |
864 | hlist_add_head_rcu(&gwj->list, &cgw_list); | |
865 | ||
866 | put_src_dst_out: | |
867 | dev_put(gwj->dst.dev); | |
868 | put_src_out: | |
869 | dev_put(gwj->src.dev); | |
870 | out: | |
871 | if (err) | |
872 | kmem_cache_free(cgw_cache, gwj); | |
873 | ||
874 | return err; | |
875 | } | |
876 | ||
877 | static void cgw_remove_all_jobs(void) | |
878 | { | |
879 | struct cgw_job *gwj = NULL; | |
b67bfe0d | 880 | struct hlist_node *nx; |
c1aabdf3 OH |
881 | |
882 | ASSERT_RTNL(); | |
883 | ||
b67bfe0d | 884 | hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) { |
c1aabdf3 OH |
885 | hlist_del(&gwj->list); |
886 | cgw_unregister_filter(gwj); | |
3480a212 | 887 | kmem_cache_free(cgw_cache, gwj); |
c1aabdf3 OH |
888 | } |
889 | } | |
890 | ||
391ac128 | 891 | static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh) |
c1aabdf3 OH |
892 | { |
893 | struct cgw_job *gwj = NULL; | |
b67bfe0d | 894 | struct hlist_node *nx; |
c1aabdf3 OH |
895 | struct rtcanmsg *r; |
896 | struct cf_mod mod; | |
897 | struct can_can_gw ccgw; | |
391ac128 | 898 | u8 limhops = 0; |
c1aabdf3 OH |
899 | int err = 0; |
900 | ||
dfc47ef8 EB |
901 | if (!capable(CAP_NET_ADMIN)) |
902 | return -EPERM; | |
903 | ||
c1aabdf3 OH |
904 | if (nlmsg_len(nlh) < sizeof(*r)) |
905 | return -EINVAL; | |
906 | ||
907 | r = nlmsg_data(nlh); | |
908 | if (r->can_family != AF_CAN) | |
909 | return -EPFNOSUPPORT; | |
910 | ||
911 | /* so far we only support CAN -> CAN routings */ | |
912 | if (r->gwtype != CGW_TYPE_CAN_CAN) | |
913 | return -EINVAL; | |
914 | ||
391ac128 | 915 | err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); |
c1aabdf3 OH |
916 | if (err < 0) |
917 | return err; | |
918 | ||
919 | /* two interface indices both set to 0 => remove all entries */ | |
920 | if (!ccgw.src_idx && !ccgw.dst_idx) { | |
921 | cgw_remove_all_jobs(); | |
922 | return 0; | |
923 | } | |
924 | ||
925 | err = -EINVAL; | |
926 | ||
927 | ASSERT_RTNL(); | |
928 | ||
929 | /* remove only the first matching entry */ | |
b67bfe0d | 930 | hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) { |
c1aabdf3 OH |
931 | |
932 | if (gwj->flags != r->flags) | |
933 | continue; | |
934 | ||
391ac128 OH |
935 | if (gwj->limit_hops != limhops) |
936 | continue; | |
937 | ||
c1aabdf3 OH |
938 | if (memcmp(&gwj->mod, &mod, sizeof(mod))) |
939 | continue; | |
940 | ||
941 | /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */ | |
942 | if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) | |
943 | continue; | |
944 | ||
945 | hlist_del(&gwj->list); | |
946 | cgw_unregister_filter(gwj); | |
3480a212 | 947 | kmem_cache_free(cgw_cache, gwj); |
c1aabdf3 OH |
948 | err = 0; |
949 | break; | |
950 | } | |
951 | ||
952 | return err; | |
953 | } | |
954 | ||
955 | static __init int cgw_module_init(void) | |
956 | { | |
be286baf OH |
957 | /* sanitize given module parameter */ |
958 | max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS); | |
959 | ||
960 | pr_info("can: netlink gateway (rev " CAN_GW_VERSION ") max_hops=%d\n", | |
961 | max_hops); | |
c1aabdf3 OH |
962 | |
963 | cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job), | |
964 | 0, 0, NULL); | |
965 | ||
966 | if (!cgw_cache) | |
967 | return -ENOMEM; | |
968 | ||
969 | /* set notifier */ | |
970 | notifier.notifier_call = cgw_notifier; | |
971 | register_netdevice_notifier(¬ifier); | |
972 | ||
973 | if (__rtnl_register(PF_CAN, RTM_GETROUTE, NULL, cgw_dump_jobs, NULL)) { | |
974 | unregister_netdevice_notifier(¬ifier); | |
975 | kmem_cache_destroy(cgw_cache); | |
976 | return -ENOBUFS; | |
977 | } | |
978 | ||
979 | /* Only the first call to __rtnl_register can fail */ | |
980 | __rtnl_register(PF_CAN, RTM_NEWROUTE, cgw_create_job, NULL, NULL); | |
981 | __rtnl_register(PF_CAN, RTM_DELROUTE, cgw_remove_job, NULL, NULL); | |
982 | ||
983 | return 0; | |
984 | } | |
985 | ||
986 | static __exit void cgw_module_exit(void) | |
987 | { | |
988 | rtnl_unregister_all(PF_CAN); | |
989 | ||
990 | unregister_netdevice_notifier(¬ifier); | |
991 | ||
992 | rtnl_lock(); | |
993 | cgw_remove_all_jobs(); | |
994 | rtnl_unlock(); | |
995 | ||
996 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ | |
997 | ||
998 | kmem_cache_destroy(cgw_cache); | |
999 | } | |
1000 | ||
1001 | module_init(cgw_module_init); | |
1002 | module_exit(cgw_module_exit); |