1 // SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
2 /* gw.c - CAN frame Gateway/Router/Bridge with netlink interface
4 * Copyright (c) 2017 Volkswagen Group Electronic Research
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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.
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.
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
42 #include <linux/module.h>
43 #include <linux/init.h>
44 #include <linux/types.h>
45 #include <linux/kernel.h>
46 #include <linux/list.h>
47 #include <linux/spinlock.h>
48 #include <linux/rcupdate.h>
49 #include <linux/rculist.h>
50 #include <linux/net.h>
51 #include <linux/netdevice.h>
52 #include <linux/if_arp.h>
53 #include <linux/skbuff.h>
54 #include <linux/can.h>
55 #include <linux/can/core.h>
56 #include <linux/can/skb.h>
57 #include <linux/can/gw.h>
58 #include <net/rtnetlink.h>
59 #include <net/net_namespace.h>
62 #define CAN_GW_VERSION "20170425"
63 #define CAN_GW_NAME "can-gw"
65 MODULE_DESCRIPTION("PF_CAN netlink gateway");
66 MODULE_LICENSE("Dual BSD/GPL");
67 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
68 MODULE_ALIAS(CAN_GW_NAME);
70 #define CGW_MIN_HOPS 1
71 #define CGW_MAX_HOPS 6
72 #define CGW_DEFAULT_HOPS 1
74 static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS;
75 module_param(max_hops, uint, 0444);
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) ")");
82 static struct notifier_block notifier;
83 static struct kmem_cache *cgw_cache __read_mostly;
85 /* structure that contains the (on-the-fly) CAN frame modifications */
99 void (*modfunc[MAX_MODFUNCTIONS])(struct can_frame *cf,
102 /* CAN frame checksum calculation after CAN frame modifications */
104 struct cgw_csum_xor xor;
105 struct cgw_csum_crc8 crc8;
108 void (*xor)(struct can_frame *cf, struct cgw_csum_xor *xor);
109 void (*crc8)(struct can_frame *cf, struct cgw_csum_crc8 *crc8);
114 /* So far we just support CAN -> CAN routing and frame modifications.
116 * The internal can_can_gw structure contains data and attributes for
117 * a CAN -> CAN gateway job.
120 struct can_filter filter;
125 /* list entry for CAN gateways jobs */
127 struct hlist_node list;
134 /* CAN frame data source */
135 struct net_device *dev;
138 /* CAN frame data destination */
139 struct net_device *dev;
142 struct can_can_gw ccgw;
150 /* modification functions that are invoked in the hot path in can_can_gw_rcv */
152 #define MODFUNC(func, op) static void func(struct can_frame *cf, \
153 struct cf_mod *mod) { op ; }
155 MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
156 MODFUNC(mod_and_dlc, cf->can_dlc &= mod->modframe.and.can_dlc)
157 MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
158 MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
159 MODFUNC(mod_or_dlc, cf->can_dlc |= mod->modframe.or.can_dlc)
160 MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
161 MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
162 MODFUNC(mod_xor_dlc, cf->can_dlc ^= mod->modframe.xor.can_dlc)
163 MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
164 MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
165 MODFUNC(mod_set_dlc, cf->can_dlc = mod->modframe.set.can_dlc)
166 MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
168 static inline void canframecpy(struct can_frame *dst, struct can_frame *src)
170 /* Copy the struct members separately to ensure that no uninitialized
171 * data are copied in the 3 bytes hole of the struct. This is needed
172 * to make easy compares of the data in the struct cf_mod.
175 dst->can_id = src->can_id;
176 dst->can_dlc = src->can_dlc;
177 *(u64 *)dst->data = *(u64 *)src->data;
180 static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re)
182 /* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
183 * relative to received dlc -1 .. -8 :
184 * e.g. for received dlc = 8
185 * -1 => index = 7 (data[7])
186 * -3 => index = 5 (data[5])
187 * -8 => index = 0 (data[0])
190 if (fr > -9 && fr < 8 &&
198 static inline int calc_idx(int idx, int rx_dlc)
206 static void cgw_csum_xor_rel(struct can_frame *cf, struct cgw_csum_xor *xor)
208 int from = calc_idx(xor->from_idx, cf->can_dlc);
209 int to = calc_idx(xor->to_idx, cf->can_dlc);
210 int res = calc_idx(xor->result_idx, cf->can_dlc);
211 u8 val = xor->init_xor_val;
214 if (from < 0 || to < 0 || res < 0)
218 for (i = from; i <= to; i++)
221 for (i = from; i >= to; i--)
228 static void cgw_csum_xor_pos(struct can_frame *cf, struct cgw_csum_xor *xor)
230 u8 val = xor->init_xor_val;
233 for (i = xor->from_idx; i <= xor->to_idx; i++)
236 cf->data[xor->result_idx] = val;
239 static void cgw_csum_xor_neg(struct can_frame *cf, struct cgw_csum_xor *xor)
241 u8 val = xor->init_xor_val;
244 for (i = xor->from_idx; i >= xor->to_idx; i--)
247 cf->data[xor->result_idx] = val;
250 static void cgw_csum_crc8_rel(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
252 int from = calc_idx(crc8->from_idx, cf->can_dlc);
253 int to = calc_idx(crc8->to_idx, cf->can_dlc);
254 int res = calc_idx(crc8->result_idx, cf->can_dlc);
255 u8 crc = crc8->init_crc_val;
258 if (from < 0 || to < 0 || res < 0)
262 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
263 crc = crc8->crctab[crc ^ cf->data[i]];
265 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
266 crc = crc8->crctab[crc ^ cf->data[i]];
269 switch (crc8->profile) {
270 case CGW_CRC8PRF_1U8:
271 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
274 case CGW_CRC8PRF_16U8:
275 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
278 case CGW_CRC8PRF_SFFID_XOR:
279 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
280 (cf->can_id >> 8 & 0xFF)];
284 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
287 static void cgw_csum_crc8_pos(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
289 u8 crc = crc8->init_crc_val;
292 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
293 crc = crc8->crctab[crc ^ cf->data[i]];
295 switch (crc8->profile) {
296 case CGW_CRC8PRF_1U8:
297 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
300 case CGW_CRC8PRF_16U8:
301 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
304 case CGW_CRC8PRF_SFFID_XOR:
305 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
306 (cf->can_id >> 8 & 0xFF)];
310 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
313 static void cgw_csum_crc8_neg(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
315 u8 crc = crc8->init_crc_val;
318 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
319 crc = crc8->crctab[crc ^ cf->data[i]];
321 switch (crc8->profile) {
322 case CGW_CRC8PRF_1U8:
323 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
326 case CGW_CRC8PRF_16U8:
327 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
330 case CGW_CRC8PRF_SFFID_XOR:
331 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
332 (cf->can_id >> 8 & 0xFF)];
336 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
339 /* the receive & process & send function */
340 static void can_can_gw_rcv(struct sk_buff *skb, void *data)
342 struct cgw_job *gwj = (struct cgw_job *)data;
343 struct can_frame *cf;
344 struct sk_buff *nskb;
347 /* Do not handle CAN frames routed more than 'max_hops' times.
348 * In general we should never catch this delimiter which is intended
349 * to cover a misconfiguration protection (e.g. circular CAN routes).
351 * The Controller Area Network controllers only accept CAN frames with
352 * correct CRCs - which are not visible in the controller registers.
353 * According to skbuff.h documentation the csum_start element for IP
354 * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY.
355 * Only CAN skbs can be processed here which already have this property.
358 #define cgw_hops(skb) ((skb)->csum_start)
360 BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY);
362 if (cgw_hops(skb) >= max_hops) {
363 /* indicate deleted frames due to misconfiguration */
364 gwj->deleted_frames++;
368 if (!(gwj->dst.dev->flags & IFF_UP)) {
369 gwj->dropped_frames++;
373 /* is sending the skb back to the incoming interface not allowed? */
374 if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
375 can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex)
378 /* clone the given skb, which has not been done in can_rcv()
380 * When there is at least one modification function activated,
381 * we need to copy the skb as we want to modify skb->data.
383 if (gwj->mod.modfunc[0])
384 nskb = skb_copy(skb, GFP_ATOMIC);
386 nskb = skb_clone(skb, GFP_ATOMIC);
389 gwj->dropped_frames++;
393 /* put the incremented hop counter in the cloned skb */
394 cgw_hops(nskb) = cgw_hops(skb) + 1;
396 /* first processing of this CAN frame -> adjust to private hop limit */
397 if (gwj->limit_hops && cgw_hops(nskb) == 1)
398 cgw_hops(nskb) = max_hops - gwj->limit_hops + 1;
400 nskb->dev = gwj->dst.dev;
402 /* pointer to modifiable CAN frame */
403 cf = (struct can_frame *)nskb->data;
405 /* perform preprocessed modification functions if there are any */
406 while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
407 (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod);
409 /* Has the CAN frame been modified? */
411 /* get available space for the processed CAN frame type */
412 int max_len = nskb->len - offsetof(struct can_frame, data);
414 /* dlc may have changed, make sure it fits to the CAN frame */
415 if (cf->can_dlc > max_len)
418 /* check for checksum updates in classic CAN length only */
419 if (gwj->mod.csumfunc.crc8) {
423 (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
426 if (gwj->mod.csumfunc.xor) {
430 (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
434 /* clear the skb timestamp if not configured the other way */
435 if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
438 /* send to netdevice */
439 if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
440 gwj->dropped_frames++;
442 gwj->handled_frames++;
447 /* delete frame due to misconfiguration */
448 gwj->deleted_frames++;
452 static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
454 return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
455 gwj->ccgw.filter.can_mask, can_can_gw_rcv,
459 static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
461 can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
462 gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
465 static int cgw_notifier(struct notifier_block *nb,
466 unsigned long msg, void *ptr)
468 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
469 struct net *net = dev_net(dev);
471 if (dev->type != ARPHRD_CAN)
474 if (msg == NETDEV_UNREGISTER) {
475 struct cgw_job *gwj = NULL;
476 struct hlist_node *nx;
480 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
481 if (gwj->src.dev == dev || gwj->dst.dev == dev) {
482 hlist_del(&gwj->list);
483 cgw_unregister_filter(net, gwj);
484 kmem_cache_free(cgw_cache, gwj);
492 static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
493 u32 pid, u32 seq, int flags)
495 struct cgw_frame_mod mb;
496 struct rtcanmsg *rtcan;
497 struct nlmsghdr *nlh;
499 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags);
503 rtcan = nlmsg_data(nlh);
504 rtcan->can_family = AF_CAN;
505 rtcan->gwtype = gwj->gwtype;
506 rtcan->flags = gwj->flags;
508 /* add statistics if available */
510 if (gwj->handled_frames) {
511 if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
515 if (gwj->dropped_frames) {
516 if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
520 if (gwj->deleted_frames) {
521 if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0)
525 /* check non default settings of attributes */
527 if (gwj->limit_hops) {
528 if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0)
532 if (gwj->mod.modtype.and) {
533 memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
534 mb.modtype = gwj->mod.modtype.and;
535 if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
539 if (gwj->mod.modtype.or) {
540 memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
541 mb.modtype = gwj->mod.modtype.or;
542 if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
546 if (gwj->mod.modtype.xor) {
547 memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
548 mb.modtype = gwj->mod.modtype.xor;
549 if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
553 if (gwj->mod.modtype.set) {
554 memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
555 mb.modtype = gwj->mod.modtype.set;
556 if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
561 if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0)
565 if (gwj->mod.csumfunc.crc8) {
566 if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
567 &gwj->mod.csum.crc8) < 0)
571 if (gwj->mod.csumfunc.xor) {
572 if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN,
573 &gwj->mod.csum.xor) < 0)
577 if (gwj->gwtype == CGW_TYPE_CAN_CAN) {
578 if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
579 if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
580 &gwj->ccgw.filter) < 0)
584 if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0)
587 if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0)
595 nlmsg_cancel(skb, nlh);
599 /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
600 static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
602 struct net *net = sock_net(skb->sk);
603 struct cgw_job *gwj = NULL;
605 int s_idx = cb->args[0];
608 hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) {
612 if (cgw_put_job(skb, gwj, RTM_NEWROUTE,
613 NETLINK_CB(cb->skb).portid,
614 cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0)
626 static const struct nla_policy cgw_policy[CGW_MAX + 1] = {
627 [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) },
628 [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) },
629 [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) },
630 [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) },
631 [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) },
632 [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) },
633 [CGW_SRC_IF] = { .type = NLA_U32 },
634 [CGW_DST_IF] = { .type = NLA_U32 },
635 [CGW_FILTER] = { .len = sizeof(struct can_filter) },
636 [CGW_LIM_HOPS] = { .type = NLA_U8 },
637 [CGW_MOD_UID] = { .type = NLA_U32 },
640 /* check for common and gwtype specific attributes */
641 static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
642 u8 gwtype, void *gwtypeattr, u8 *limhops)
644 struct nlattr *tb[CGW_MAX + 1];
645 struct cgw_frame_mod mb;
649 /* initialize modification & checksum data space */
650 memset(mod, 0, sizeof(*mod));
652 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb,
653 CGW_MAX, cgw_policy, NULL);
657 if (tb[CGW_LIM_HOPS]) {
658 *limhops = nla_get_u8(tb[CGW_LIM_HOPS]);
660 if (*limhops < 1 || *limhops > max_hops)
664 /* check for AND/OR/XOR/SET modifications */
666 if (tb[CGW_MOD_AND]) {
667 nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
669 canframecpy(&mod->modframe.and, &mb.cf);
670 mod->modtype.and = mb.modtype;
672 if (mb.modtype & CGW_MOD_ID)
673 mod->modfunc[modidx++] = mod_and_id;
675 if (mb.modtype & CGW_MOD_DLC)
676 mod->modfunc[modidx++] = mod_and_dlc;
678 if (mb.modtype & CGW_MOD_DATA)
679 mod->modfunc[modidx++] = mod_and_data;
682 if (tb[CGW_MOD_OR]) {
683 nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
685 canframecpy(&mod->modframe.or, &mb.cf);
686 mod->modtype.or = mb.modtype;
688 if (mb.modtype & CGW_MOD_ID)
689 mod->modfunc[modidx++] = mod_or_id;
691 if (mb.modtype & CGW_MOD_DLC)
692 mod->modfunc[modidx++] = mod_or_dlc;
694 if (mb.modtype & CGW_MOD_DATA)
695 mod->modfunc[modidx++] = mod_or_data;
698 if (tb[CGW_MOD_XOR]) {
699 nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
701 canframecpy(&mod->modframe.xor, &mb.cf);
702 mod->modtype.xor = mb.modtype;
704 if (mb.modtype & CGW_MOD_ID)
705 mod->modfunc[modidx++] = mod_xor_id;
707 if (mb.modtype & CGW_MOD_DLC)
708 mod->modfunc[modidx++] = mod_xor_dlc;
710 if (mb.modtype & CGW_MOD_DATA)
711 mod->modfunc[modidx++] = mod_xor_data;
714 if (tb[CGW_MOD_SET]) {
715 nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
717 canframecpy(&mod->modframe.set, &mb.cf);
718 mod->modtype.set = mb.modtype;
720 if (mb.modtype & CGW_MOD_ID)
721 mod->modfunc[modidx++] = mod_set_id;
723 if (mb.modtype & CGW_MOD_DLC)
724 mod->modfunc[modidx++] = mod_set_dlc;
726 if (mb.modtype & CGW_MOD_DATA)
727 mod->modfunc[modidx++] = mod_set_data;
730 /* check for checksum operations after CAN frame modifications */
732 if (tb[CGW_CS_CRC8]) {
733 struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]);
735 err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
740 nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8],
743 /* select dedicated processing function to reduce
744 * runtime operations in receive hot path.
746 if (c->from_idx < 0 || c->to_idx < 0 ||
748 mod->csumfunc.crc8 = cgw_csum_crc8_rel;
749 else if (c->from_idx <= c->to_idx)
750 mod->csumfunc.crc8 = cgw_csum_crc8_pos;
752 mod->csumfunc.crc8 = cgw_csum_crc8_neg;
755 if (tb[CGW_CS_XOR]) {
756 struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]);
758 err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
763 nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR],
766 /* select dedicated processing function to reduce
767 * runtime operations in receive hot path.
769 if (c->from_idx < 0 || c->to_idx < 0 ||
771 mod->csumfunc.xor = cgw_csum_xor_rel;
772 else if (c->from_idx <= c->to_idx)
773 mod->csumfunc.xor = cgw_csum_xor_pos;
775 mod->csumfunc.xor = cgw_csum_xor_neg;
779 nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32));
782 if (gwtype == CGW_TYPE_CAN_CAN) {
783 /* check CGW_TYPE_CAN_CAN specific attributes */
784 struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr;
786 memset(ccgw, 0, sizeof(*ccgw));
788 /* check for can_filter in attributes */
790 nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
791 sizeof(struct can_filter));
795 /* specifying two interfaces is mandatory */
796 if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF])
799 ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]);
800 ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]);
802 /* both indices set to 0 for flushing all routing entries */
803 if (!ccgw->src_idx && !ccgw->dst_idx)
806 /* only one index set to 0 is an error */
807 if (!ccgw->src_idx || !ccgw->dst_idx)
811 /* add the checks for other gwtypes here */
816 static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh,
817 struct netlink_ext_ack *extack)
819 struct net *net = sock_net(skb->sk);
823 struct can_can_gw ccgw;
827 if (!netlink_capable(skb, CAP_NET_ADMIN))
830 if (nlmsg_len(nlh) < sizeof(*r))
834 if (r->can_family != AF_CAN)
835 return -EPFNOSUPPORT;
837 /* so far we only support CAN -> CAN routings */
838 if (r->gwtype != CGW_TYPE_CAN_CAN)
841 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
848 /* check for updating an existing job with identical uid */
849 hlist_for_each_entry(gwj, &net->can.cgw_list, list) {
850 if (gwj->mod.uid != mod.uid)
853 /* interfaces & filters must be identical */
854 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
857 /* update modifications with disabled softirq & quit */
859 memcpy(&gwj->mod, &mod, sizeof(mod));
865 /* ifindex == 0 is not allowed for job creation */
866 if (!ccgw.src_idx || !ccgw.dst_idx)
869 gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL);
873 gwj->handled_frames = 0;
874 gwj->dropped_frames = 0;
875 gwj->deleted_frames = 0;
876 gwj->flags = r->flags;
877 gwj->gwtype = r->gwtype;
878 gwj->limit_hops = limhops;
880 /* insert already parsed information */
881 memcpy(&gwj->mod, &mod, sizeof(mod));
882 memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw));
886 gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx);
891 if (gwj->src.dev->type != ARPHRD_CAN)
894 gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx);
899 if (gwj->dst.dev->type != ARPHRD_CAN)
904 err = cgw_register_filter(net, gwj);
906 hlist_add_head_rcu(&gwj->list, &net->can.cgw_list);
909 kmem_cache_free(cgw_cache, gwj);
914 static void cgw_remove_all_jobs(struct net *net)
916 struct cgw_job *gwj = NULL;
917 struct hlist_node *nx;
921 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
922 hlist_del(&gwj->list);
923 cgw_unregister_filter(net, gwj);
924 kmem_cache_free(cgw_cache, gwj);
928 static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
929 struct netlink_ext_ack *extack)
931 struct net *net = sock_net(skb->sk);
932 struct cgw_job *gwj = NULL;
933 struct hlist_node *nx;
936 struct can_can_gw ccgw;
940 if (!netlink_capable(skb, CAP_NET_ADMIN))
943 if (nlmsg_len(nlh) < sizeof(*r))
947 if (r->can_family != AF_CAN)
948 return -EPFNOSUPPORT;
950 /* so far we only support CAN -> CAN routings */
951 if (r->gwtype != CGW_TYPE_CAN_CAN)
954 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
958 /* two interface indices both set to 0 => remove all entries */
959 if (!ccgw.src_idx && !ccgw.dst_idx) {
960 cgw_remove_all_jobs(net);
968 /* remove only the first matching entry */
969 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
970 if (gwj->flags != r->flags)
973 if (gwj->limit_hops != limhops)
976 /* we have a match when uid is enabled and identical */
977 if (gwj->mod.uid || mod.uid) {
978 if (gwj->mod.uid != mod.uid)
981 /* no uid => check for identical modifications */
982 if (memcmp(&gwj->mod, &mod, sizeof(mod)))
986 /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */
987 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
990 hlist_del(&gwj->list);
991 cgw_unregister_filter(net, gwj);
992 kmem_cache_free(cgw_cache, gwj);
1000 static int __net_init cangw_pernet_init(struct net *net)
1002 INIT_HLIST_HEAD(&net->can.cgw_list);
1006 static void __net_exit cangw_pernet_exit(struct net *net)
1009 cgw_remove_all_jobs(net);
1013 static struct pernet_operations cangw_pernet_ops = {
1014 .init = cangw_pernet_init,
1015 .exit = cangw_pernet_exit,
1018 static __init int cgw_module_init(void)
1022 /* sanitize given module parameter */
1023 max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS);
1025 pr_info("can: netlink gateway (rev " CAN_GW_VERSION ") max_hops=%d\n",
1028 ret = register_pernet_subsys(&cangw_pernet_ops);
1033 cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
1036 goto out_cache_create;
1039 notifier.notifier_call = cgw_notifier;
1040 ret = register_netdevice_notifier(¬ifier);
1042 goto out_register_notifier;
1044 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE,
1045 NULL, cgw_dump_jobs, 0);
1047 goto out_rtnl_register1;
1049 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE,
1050 cgw_create_job, NULL, 0);
1052 goto out_rtnl_register2;
1053 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE,
1054 cgw_remove_job, NULL, 0);
1056 goto out_rtnl_register3;
1061 rtnl_unregister(PF_CAN, RTM_NEWROUTE);
1063 rtnl_unregister(PF_CAN, RTM_GETROUTE);
1065 unregister_netdevice_notifier(¬ifier);
1066 out_register_notifier:
1067 kmem_cache_destroy(cgw_cache);
1069 unregister_pernet_subsys(&cangw_pernet_ops);
1074 static __exit void cgw_module_exit(void)
1076 rtnl_unregister_all(PF_CAN);
1078 unregister_netdevice_notifier(¬ifier);
1080 unregister_pernet_subsys(&cangw_pernet_ops);
1081 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1083 kmem_cache_destroy(cgw_cache);
1086 module_init(cgw_module_init);
1087 module_exit(cgw_module_exit);