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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> | |
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" | |
6299b669 | 61 | static __initconst const char banner[] = |
c1aabdf3 OH |
62 | KERN_INFO "can: netlink gateway (rev " CAN_GW_VERSION ")\n"; |
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"); | |
68 | ||
a75afd47 | 69 | static HLIST_HEAD(cgw_list); |
c1aabdf3 OH |
70 | static struct notifier_block notifier; |
71 | ||
72 | static struct kmem_cache *cgw_cache __read_mostly; | |
73 | ||
74 | /* structure that contains the (on-the-fly) CAN frame modifications */ | |
75 | struct 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 | */ | |
109 | struct 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 */ | |
116 | struct 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 | ||
143 | MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id) | |
144 | MODFUNC(mod_and_dlc, cf->can_dlc &= mod->modframe.and.can_dlc) | |
145 | MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data) | |
146 | MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id) | |
147 | MODFUNC(mod_or_dlc, cf->can_dlc |= mod->modframe.or.can_dlc) | |
148 | MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data) | |
149 | MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id) | |
150 | MODFUNC(mod_xor_dlc, cf->can_dlc ^= mod->modframe.xor.can_dlc) | |
151 | MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data) | |
152 | MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id) | |
153 | MODFUNC(mod_set_dlc, cf->can_dlc = mod->modframe.set.can_dlc) | |
154 | MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data) | |
155 | ||
156 | static 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 | ||
169 | static 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 | ||
188 | static 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 | ||
196 | static 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 | ||
218 | static 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 | ||
229 | static 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 | ||
240 | static 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 | ||
279 | static 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 | ||
306 | static 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 */ | |
334 | static 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 | ||
404 | static 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 | ||
411 | static 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 | ||
417 | static 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 | ||
1da0faa3 TG |
447 | static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type, |
448 | u32 pid, u32 seq, int flags) | |
c1aabdf3 OH |
449 | { |
450 | struct cgw_frame_mod mb; | |
451 | struct rtcanmsg *rtcan; | |
1da0faa3 TG |
452 | struct nlmsghdr *nlh; |
453 | ||
454 | nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags); | |
c1aabdf3 OH |
455 | if (!nlh) |
456 | return -EMSGSIZE; | |
457 | ||
458 | rtcan = nlmsg_data(nlh); | |
459 | rtcan->can_family = AF_CAN; | |
460 | rtcan->gwtype = gwj->gwtype; | |
461 | rtcan->flags = gwj->flags; | |
462 | ||
463 | /* add statistics if available */ | |
464 | ||
465 | if (gwj->handled_frames) { | |
466 | if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0) | |
467 | goto cancel; | |
c1aabdf3 OH |
468 | } |
469 | ||
470 | if (gwj->dropped_frames) { | |
471 | if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0) | |
472 | goto cancel; | |
c1aabdf3 OH |
473 | } |
474 | ||
475 | /* check non default settings of attributes */ | |
476 | ||
477 | if (gwj->mod.modtype.and) { | |
478 | memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf)); | |
479 | mb.modtype = gwj->mod.modtype.and; | |
480 | if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0) | |
481 | goto cancel; | |
c1aabdf3 OH |
482 | } |
483 | ||
484 | if (gwj->mod.modtype.or) { | |
485 | memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf)); | |
486 | mb.modtype = gwj->mod.modtype.or; | |
487 | if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0) | |
488 | goto cancel; | |
c1aabdf3 OH |
489 | } |
490 | ||
491 | if (gwj->mod.modtype.xor) { | |
492 | memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf)); | |
493 | mb.modtype = gwj->mod.modtype.xor; | |
494 | if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0) | |
495 | goto cancel; | |
c1aabdf3 OH |
496 | } |
497 | ||
498 | if (gwj->mod.modtype.set) { | |
499 | memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf)); | |
500 | mb.modtype = gwj->mod.modtype.set; | |
501 | if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0) | |
502 | goto cancel; | |
c1aabdf3 OH |
503 | } |
504 | ||
505 | if (gwj->mod.csumfunc.crc8) { | |
506 | if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN, | |
507 | &gwj->mod.csum.crc8) < 0) | |
508 | goto cancel; | |
c1aabdf3 OH |
509 | } |
510 | ||
511 | if (gwj->mod.csumfunc.xor) { | |
512 | if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN, | |
513 | &gwj->mod.csum.xor) < 0) | |
514 | goto cancel; | |
c1aabdf3 OH |
515 | } |
516 | ||
517 | if (gwj->gwtype == CGW_TYPE_CAN_CAN) { | |
518 | ||
519 | if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) { | |
520 | if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter), | |
521 | &gwj->ccgw.filter) < 0) | |
522 | goto cancel; | |
c1aabdf3 OH |
523 | } |
524 | ||
525 | if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0) | |
526 | goto cancel; | |
c1aabdf3 OH |
527 | |
528 | if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0) | |
529 | goto cancel; | |
c1aabdf3 OH |
530 | } |
531 | ||
6eaf53ca | 532 | return nlmsg_end(skb, nlh); |
c1aabdf3 OH |
533 | |
534 | cancel: | |
535 | nlmsg_cancel(skb, nlh); | |
536 | return -EMSGSIZE; | |
537 | } | |
538 | ||
539 | /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */ | |
540 | static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb) | |
541 | { | |
542 | struct cgw_job *gwj = NULL; | |
543 | struct hlist_node *n; | |
544 | int idx = 0; | |
545 | int s_idx = cb->args[0]; | |
546 | ||
547 | rcu_read_lock(); | |
548 | hlist_for_each_entry_rcu(gwj, n, &cgw_list, list) { | |
549 | if (idx < s_idx) | |
550 | goto cont; | |
551 | ||
15e47304 | 552 | if (cgw_put_job(skb, gwj, RTM_NEWROUTE, NETLINK_CB(cb->skb).portid, |
1da0faa3 | 553 | cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0) |
c1aabdf3 OH |
554 | break; |
555 | cont: | |
556 | idx++; | |
557 | } | |
558 | rcu_read_unlock(); | |
559 | ||
560 | cb->args[0] = idx; | |
561 | ||
562 | return skb->len; | |
563 | } | |
564 | ||
732d35fd TG |
565 | static const struct nla_policy cgw_policy[CGW_MAX+1] = { |
566 | [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) }, | |
567 | [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) }, | |
568 | [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) }, | |
569 | [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) }, | |
570 | [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) }, | |
571 | [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) }, | |
572 | [CGW_SRC_IF] = { .type = NLA_U32 }, | |
573 | [CGW_DST_IF] = { .type = NLA_U32 }, | |
574 | [CGW_FILTER] = { .len = sizeof(struct can_filter) }, | |
575 | }; | |
576 | ||
c1aabdf3 OH |
577 | /* check for common and gwtype specific attributes */ |
578 | static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, | |
579 | u8 gwtype, void *gwtypeattr) | |
580 | { | |
581 | struct nlattr *tb[CGW_MAX+1]; | |
582 | struct cgw_frame_mod mb; | |
583 | int modidx = 0; | |
584 | int err = 0; | |
585 | ||
586 | /* initialize modification & checksum data space */ | |
587 | memset(mod, 0, sizeof(*mod)); | |
588 | ||
732d35fd TG |
589 | err = nlmsg_parse(nlh, sizeof(struct rtcanmsg), tb, CGW_MAX, |
590 | cgw_policy); | |
c1aabdf3 OH |
591 | if (err < 0) |
592 | return err; | |
593 | ||
594 | /* check for AND/OR/XOR/SET modifications */ | |
595 | ||
732d35fd | 596 | if (tb[CGW_MOD_AND]) { |
c1aabdf3 OH |
597 | nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN); |
598 | ||
599 | canframecpy(&mod->modframe.and, &mb.cf); | |
600 | mod->modtype.and = mb.modtype; | |
601 | ||
602 | if (mb.modtype & CGW_MOD_ID) | |
603 | mod->modfunc[modidx++] = mod_and_id; | |
604 | ||
605 | if (mb.modtype & CGW_MOD_DLC) | |
606 | mod->modfunc[modidx++] = mod_and_dlc; | |
607 | ||
608 | if (mb.modtype & CGW_MOD_DATA) | |
609 | mod->modfunc[modidx++] = mod_and_data; | |
610 | } | |
611 | ||
732d35fd | 612 | if (tb[CGW_MOD_OR]) { |
c1aabdf3 OH |
613 | nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN); |
614 | ||
615 | canframecpy(&mod->modframe.or, &mb.cf); | |
616 | mod->modtype.or = mb.modtype; | |
617 | ||
618 | if (mb.modtype & CGW_MOD_ID) | |
619 | mod->modfunc[modidx++] = mod_or_id; | |
620 | ||
621 | if (mb.modtype & CGW_MOD_DLC) | |
622 | mod->modfunc[modidx++] = mod_or_dlc; | |
623 | ||
624 | if (mb.modtype & CGW_MOD_DATA) | |
625 | mod->modfunc[modidx++] = mod_or_data; | |
626 | } | |
627 | ||
732d35fd | 628 | if (tb[CGW_MOD_XOR]) { |
c1aabdf3 OH |
629 | nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN); |
630 | ||
631 | canframecpy(&mod->modframe.xor, &mb.cf); | |
632 | mod->modtype.xor = mb.modtype; | |
633 | ||
634 | if (mb.modtype & CGW_MOD_ID) | |
635 | mod->modfunc[modidx++] = mod_xor_id; | |
636 | ||
637 | if (mb.modtype & CGW_MOD_DLC) | |
638 | mod->modfunc[modidx++] = mod_xor_dlc; | |
639 | ||
640 | if (mb.modtype & CGW_MOD_DATA) | |
641 | mod->modfunc[modidx++] = mod_xor_data; | |
642 | } | |
643 | ||
732d35fd | 644 | if (tb[CGW_MOD_SET]) { |
c1aabdf3 OH |
645 | nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN); |
646 | ||
647 | canframecpy(&mod->modframe.set, &mb.cf); | |
648 | mod->modtype.set = mb.modtype; | |
649 | ||
650 | if (mb.modtype & CGW_MOD_ID) | |
651 | mod->modfunc[modidx++] = mod_set_id; | |
652 | ||
653 | if (mb.modtype & CGW_MOD_DLC) | |
654 | mod->modfunc[modidx++] = mod_set_dlc; | |
655 | ||
656 | if (mb.modtype & CGW_MOD_DATA) | |
657 | mod->modfunc[modidx++] = mod_set_data; | |
658 | } | |
659 | ||
660 | /* check for checksum operations after CAN frame modifications */ | |
661 | if (modidx) { | |
662 | ||
732d35fd | 663 | if (tb[CGW_CS_CRC8]) { |
5d91efa8 | 664 | struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]); |
c1aabdf3 OH |
665 | |
666 | err = cgw_chk_csum_parms(c->from_idx, c->to_idx, | |
667 | c->result_idx); | |
668 | if (err) | |
669 | return err; | |
670 | ||
671 | nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8], | |
672 | CGW_CS_CRC8_LEN); | |
673 | ||
674 | /* | |
675 | * select dedicated processing function to reduce | |
676 | * runtime operations in receive hot path. | |
677 | */ | |
678 | if (c->from_idx < 0 || c->to_idx < 0 || | |
679 | c->result_idx < 0) | |
680 | mod->csumfunc.crc8 = cgw_csum_crc8_rel; | |
681 | else if (c->from_idx <= c->to_idx) | |
682 | mod->csumfunc.crc8 = cgw_csum_crc8_pos; | |
683 | else | |
684 | mod->csumfunc.crc8 = cgw_csum_crc8_neg; | |
685 | } | |
686 | ||
732d35fd | 687 | if (tb[CGW_CS_XOR]) { |
5d91efa8 | 688 | struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]); |
c1aabdf3 OH |
689 | |
690 | err = cgw_chk_csum_parms(c->from_idx, c->to_idx, | |
691 | c->result_idx); | |
692 | if (err) | |
693 | return err; | |
694 | ||
695 | nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR], | |
696 | CGW_CS_XOR_LEN); | |
697 | ||
698 | /* | |
699 | * select dedicated processing function to reduce | |
700 | * runtime operations in receive hot path. | |
701 | */ | |
702 | if (c->from_idx < 0 || c->to_idx < 0 || | |
703 | c->result_idx < 0) | |
704 | mod->csumfunc.xor = cgw_csum_xor_rel; | |
705 | else if (c->from_idx <= c->to_idx) | |
706 | mod->csumfunc.xor = cgw_csum_xor_pos; | |
707 | else | |
708 | mod->csumfunc.xor = cgw_csum_xor_neg; | |
709 | } | |
710 | } | |
711 | ||
712 | if (gwtype == CGW_TYPE_CAN_CAN) { | |
713 | ||
714 | /* check CGW_TYPE_CAN_CAN specific attributes */ | |
715 | ||
716 | struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr; | |
717 | memset(ccgw, 0, sizeof(*ccgw)); | |
718 | ||
719 | /* check for can_filter in attributes */ | |
732d35fd | 720 | if (tb[CGW_FILTER]) |
c1aabdf3 OH |
721 | nla_memcpy(&ccgw->filter, tb[CGW_FILTER], |
722 | sizeof(struct can_filter)); | |
723 | ||
724 | err = -ENODEV; | |
725 | ||
726 | /* specifying two interfaces is mandatory */ | |
727 | if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF]) | |
728 | return err; | |
729 | ||
732d35fd TG |
730 | ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]); |
731 | ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]); | |
c1aabdf3 OH |
732 | |
733 | /* both indices set to 0 for flushing all routing entries */ | |
734 | if (!ccgw->src_idx && !ccgw->dst_idx) | |
735 | return 0; | |
736 | ||
737 | /* only one index set to 0 is an error */ | |
738 | if (!ccgw->src_idx || !ccgw->dst_idx) | |
739 | return err; | |
740 | } | |
741 | ||
742 | /* add the checks for other gwtypes here */ | |
743 | ||
744 | return 0; | |
745 | } | |
746 | ||
747 | static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, | |
748 | void *arg) | |
749 | { | |
750 | struct rtcanmsg *r; | |
751 | struct cgw_job *gwj; | |
752 | int err = 0; | |
753 | ||
dfc47ef8 EB |
754 | if (!capable(CAP_NET_ADMIN)) |
755 | return -EPERM; | |
756 | ||
c1aabdf3 OH |
757 | if (nlmsg_len(nlh) < sizeof(*r)) |
758 | return -EINVAL; | |
759 | ||
760 | r = nlmsg_data(nlh); | |
761 | if (r->can_family != AF_CAN) | |
762 | return -EPFNOSUPPORT; | |
763 | ||
764 | /* so far we only support CAN -> CAN routings */ | |
765 | if (r->gwtype != CGW_TYPE_CAN_CAN) | |
766 | return -EINVAL; | |
767 | ||
768 | gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL); | |
769 | if (!gwj) | |
770 | return -ENOMEM; | |
771 | ||
772 | gwj->handled_frames = 0; | |
773 | gwj->dropped_frames = 0; | |
774 | gwj->flags = r->flags; | |
775 | gwj->gwtype = r->gwtype; | |
776 | ||
777 | err = cgw_parse_attr(nlh, &gwj->mod, CGW_TYPE_CAN_CAN, &gwj->ccgw); | |
778 | if (err < 0) | |
779 | goto out; | |
780 | ||
781 | err = -ENODEV; | |
782 | ||
783 | /* ifindex == 0 is not allowed for job creation */ | |
784 | if (!gwj->ccgw.src_idx || !gwj->ccgw.dst_idx) | |
785 | goto out; | |
786 | ||
787 | gwj->src.dev = dev_get_by_index(&init_net, gwj->ccgw.src_idx); | |
788 | ||
789 | if (!gwj->src.dev) | |
790 | goto out; | |
791 | ||
792 | /* check for CAN netdev not using header_ops - see gw_rcv() */ | |
793 | if (gwj->src.dev->type != ARPHRD_CAN || gwj->src.dev->header_ops) | |
794 | goto put_src_out; | |
795 | ||
796 | gwj->dst.dev = dev_get_by_index(&init_net, gwj->ccgw.dst_idx); | |
797 | ||
798 | if (!gwj->dst.dev) | |
799 | goto put_src_out; | |
800 | ||
801 | /* check for CAN netdev not using header_ops - see gw_rcv() */ | |
802 | if (gwj->dst.dev->type != ARPHRD_CAN || gwj->dst.dev->header_ops) | |
803 | goto put_src_dst_out; | |
804 | ||
805 | ASSERT_RTNL(); | |
806 | ||
807 | err = cgw_register_filter(gwj); | |
808 | if (!err) | |
809 | hlist_add_head_rcu(&gwj->list, &cgw_list); | |
810 | ||
811 | put_src_dst_out: | |
812 | dev_put(gwj->dst.dev); | |
813 | put_src_out: | |
814 | dev_put(gwj->src.dev); | |
815 | out: | |
816 | if (err) | |
817 | kmem_cache_free(cgw_cache, gwj); | |
818 | ||
819 | return err; | |
820 | } | |
821 | ||
822 | static void cgw_remove_all_jobs(void) | |
823 | { | |
824 | struct cgw_job *gwj = NULL; | |
825 | struct hlist_node *n, *nx; | |
826 | ||
827 | ASSERT_RTNL(); | |
828 | ||
829 | hlist_for_each_entry_safe(gwj, n, nx, &cgw_list, list) { | |
830 | hlist_del(&gwj->list); | |
831 | cgw_unregister_filter(gwj); | |
832 | kfree(gwj); | |
833 | } | |
834 | } | |
835 | ||
836 | static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) | |
837 | { | |
838 | struct cgw_job *gwj = NULL; | |
839 | struct hlist_node *n, *nx; | |
840 | struct rtcanmsg *r; | |
841 | struct cf_mod mod; | |
842 | struct can_can_gw ccgw; | |
843 | int err = 0; | |
844 | ||
dfc47ef8 EB |
845 | if (!capable(CAP_NET_ADMIN)) |
846 | return -EPERM; | |
847 | ||
c1aabdf3 OH |
848 | if (nlmsg_len(nlh) < sizeof(*r)) |
849 | return -EINVAL; | |
850 | ||
851 | r = nlmsg_data(nlh); | |
852 | if (r->can_family != AF_CAN) | |
853 | return -EPFNOSUPPORT; | |
854 | ||
855 | /* so far we only support CAN -> CAN routings */ | |
856 | if (r->gwtype != CGW_TYPE_CAN_CAN) | |
857 | return -EINVAL; | |
858 | ||
859 | err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw); | |
860 | if (err < 0) | |
861 | return err; | |
862 | ||
863 | /* two interface indices both set to 0 => remove all entries */ | |
864 | if (!ccgw.src_idx && !ccgw.dst_idx) { | |
865 | cgw_remove_all_jobs(); | |
866 | return 0; | |
867 | } | |
868 | ||
869 | err = -EINVAL; | |
870 | ||
871 | ASSERT_RTNL(); | |
872 | ||
873 | /* remove only the first matching entry */ | |
874 | hlist_for_each_entry_safe(gwj, n, nx, &cgw_list, list) { | |
875 | ||
876 | if (gwj->flags != r->flags) | |
877 | continue; | |
878 | ||
879 | if (memcmp(&gwj->mod, &mod, sizeof(mod))) | |
880 | continue; | |
881 | ||
882 | /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */ | |
883 | if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) | |
884 | continue; | |
885 | ||
886 | hlist_del(&gwj->list); | |
887 | cgw_unregister_filter(gwj); | |
888 | kfree(gwj); | |
889 | err = 0; | |
890 | break; | |
891 | } | |
892 | ||
893 | return err; | |
894 | } | |
895 | ||
896 | static __init int cgw_module_init(void) | |
897 | { | |
898 | printk(banner); | |
899 | ||
900 | cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job), | |
901 | 0, 0, NULL); | |
902 | ||
903 | if (!cgw_cache) | |
904 | return -ENOMEM; | |
905 | ||
906 | /* set notifier */ | |
907 | notifier.notifier_call = cgw_notifier; | |
908 | register_netdevice_notifier(¬ifier); | |
909 | ||
910 | if (__rtnl_register(PF_CAN, RTM_GETROUTE, NULL, cgw_dump_jobs, NULL)) { | |
911 | unregister_netdevice_notifier(¬ifier); | |
912 | kmem_cache_destroy(cgw_cache); | |
913 | return -ENOBUFS; | |
914 | } | |
915 | ||
916 | /* Only the first call to __rtnl_register can fail */ | |
917 | __rtnl_register(PF_CAN, RTM_NEWROUTE, cgw_create_job, NULL, NULL); | |
918 | __rtnl_register(PF_CAN, RTM_DELROUTE, cgw_remove_job, NULL, NULL); | |
919 | ||
920 | return 0; | |
921 | } | |
922 | ||
923 | static __exit void cgw_module_exit(void) | |
924 | { | |
925 | rtnl_unregister_all(PF_CAN); | |
926 | ||
927 | unregister_netdevice_notifier(¬ifier); | |
928 | ||
929 | rtnl_lock(); | |
930 | cgw_remove_all_jobs(); | |
931 | rtnl_unlock(); | |
932 | ||
933 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ | |
934 | ||
935 | kmem_cache_destroy(cgw_cache); | |
936 | } | |
937 | ||
938 | module_init(cgw_module_init); | |
939 | module_exit(cgw_module_exit); |