2 * gw.c - CAN frame Gateway/Router/Bridge with netlink interface
4 * Copyright (c) 2002-2010 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
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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
40 * Send feedback to <socketcan-users@lists.berlios.de>
44 #include <linux/module.h>
45 #include <linux/version.h>
46 #include <linux/init.h>
47 #include <linux/types.h>
48 #include <linux/list.h>
49 #include <linux/spinlock.h>
50 #include <linux/rcupdate.h>
51 #include <linux/net.h>
52 #include <linux/netdevice.h>
53 #include <linux/if_arp.h>
54 #include <linux/skbuff.h>
55 #include <socketcan/can.h>
56 #include <socketcan/can/core.h>
57 #include <socketcan/can/gw.h>
58 #include <net/rtnetlink.h>
59 #include <net/net_namespace.h>
61 #include <socketcan/can/version.h> /* for RCSID. Removed by mkpatch script */
64 #define CAN_GW_VERSION "20100222"
65 static __initdata const char banner[] =
66 KERN_INFO "can: netlink gateway (rev " CAN_GW_VERSION ")\n";
68 MODULE_DESCRIPTION("PF_CAN netlink gateway");
69 MODULE_LICENSE("Dual BSD/GPL");
70 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
72 HLIST_HEAD(can_gw_list);
73 static DEFINE_SPINLOCK(can_gw_list_lock);
74 static struct notifier_block notifier;
76 static struct kmem_cache *gw_cache __read_mostly;
78 #define GW_SK_MAGIC ((void *)(¬ifier))
81 * So far we just support CAN -> CAN routing and frame modifications.
83 * The internal can_can_gw structure contains optional attributes for
84 * a CAN -> CAN gateway job.
87 struct can_filter filter;
100 void (*modfunc[MAX_MODFUNCTIONS])(struct can_frame *cf,
101 struct can_can_gw *mod);
104 /* list entry for CAN gateways jobs */
106 struct hlist_node list;
108 struct net_device *src_dev;
109 struct net_device *dst_dev;
114 struct can_can_gw ccgw;
119 /* content of u32 gwjob.flags */
120 #define CAN_TX_ECHO 0x00000001
121 #define CAN_TX_SRC_TSTAMP 0x00000002
123 /* modification functions that are invoked in the hot path in gw_rcv */
124 void mod_and_id (struct can_frame *cf, struct can_can_gw *mod) {
125 cf->can_id &= mod->modframe.and.can_id;
127 void mod_and_dlc (struct can_frame *cf, struct can_can_gw *mod) {
128 cf->can_dlc &= mod->modframe.and.can_dlc;
130 void mod_and_data (struct can_frame *cf, struct can_can_gw *mod) {
131 *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data;
133 void mod_or_id (struct can_frame *cf, struct can_can_gw *mod) {
134 cf->can_id |= mod->modframe.or.can_id;
136 void mod_or_dlc (struct can_frame *cf, struct can_can_gw *mod) {
137 cf->can_dlc |= mod->modframe.or.can_dlc;
139 void mod_or_data (struct can_frame *cf, struct can_can_gw *mod) {
140 *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data;
142 void mod_xor_id (struct can_frame *cf, struct can_can_gw *mod) {
143 cf->can_id ^= mod->modframe.xor.can_id;
145 void mod_xor_dlc (struct can_frame *cf, struct can_can_gw *mod) {
146 cf->can_dlc ^= mod->modframe.xor.can_dlc;
148 void mod_xor_data (struct can_frame *cf, struct can_can_gw *mod) {
149 *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data;
151 void mod_set_id (struct can_frame *cf, struct can_can_gw *mod) {
152 cf->can_id = mod->modframe.set.can_id;
154 void mod_set_dlc (struct can_frame *cf, struct can_can_gw *mod) {
155 cf->can_dlc = mod->modframe.set.can_dlc;
157 void mod_set_data (struct can_frame *cf, struct can_can_gw *mod) {
158 *(u64 *)cf->data = *(u64 *)mod->modframe.set.data;
161 static inline void canframecpy(struct can_frame *dst, struct can_frame *src)
164 * Copy the struct members separately to ensure that no uninitialized
165 * data are copied in the 3 bytes hole of the struct. This is needed
166 * to make easy compares of the data in the struct can_can_gw.
169 dst->can_id = src->can_id;
170 dst->can_dlc = src->can_dlc;
171 *(u64 *)dst->data = *(u64 *)src->data;
174 /* the receive & process & send function */
175 static void gw_rcv(struct sk_buff *skb, void *data)
177 struct gw_job *gwj = (struct gw_job *)data;
178 struct can_frame *cf;
179 struct sk_buff *nskb;
182 /* do not handle already routed frames */
183 if (skb->sk == GW_SK_MAGIC)
186 if (!(gwj->dst_dev->flags & IFF_UP)) {
187 gwj->dropped_frames++;
192 * clone the given skb, which has not been done in can_rcv()
194 * When there is at least one modification function activated,
195 * we need to copy the skb as we want to modify skb->data.
197 if (gwj->ccgw.modfunc[0])
198 nskb = skb_copy(skb, GFP_ATOMIC);
200 nskb = skb_clone(skb, GFP_ATOMIC);
203 gwj->dropped_frames++;
207 /* mark routed frames with a 'special' sk value */
208 nskb->sk = GW_SK_MAGIC;
209 nskb->dev = gwj->dst_dev;
211 /* pointer to modifiable CAN frame */
212 cf = (struct can_frame *)nskb->data;
214 /* perform preprocessed modification functions if there are any */
215 while (modidx < MAX_MODFUNCTIONS && gwj->ccgw.modfunc[modidx])
216 (*gwj->ccgw.modfunc[modidx++])(cf, &gwj->ccgw);
218 /* clear the skb timestamp if not configured the other way */
219 if (!(gwj->flags & CAN_TX_SRC_TSTAMP))
220 nskb->tstamp.tv64 = 0;
222 /* send to netdevice */
223 if (can_send(nskb, gwj->flags & CAN_TX_ECHO))
224 gwj->dropped_frames++;
226 gwj->handled_frames++;
229 static inline int can_gw_register_filter(struct gw_job *gwj)
231 return can_rx_register(gwj->src_dev, gwj->ccgw.filter.can_id,
232 gwj->ccgw.filter.can_mask, gw_rcv, gwj, "gw");
235 static inline void can_gw_unregister_filter(struct gw_job *gwj)
237 can_rx_unregister(gwj->src_dev, gwj->ccgw.filter.can_id,
238 gwj->ccgw.filter.can_mask, gw_rcv, gwj);
241 static int gw_notifier(struct notifier_block *nb,
242 unsigned long msg, void *data)
244 struct net_device *dev = (struct net_device *)data;
246 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
247 if (!net_eq(dev_net(dev), &init_net))
249 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
250 if (dev->nd_net != &init_net)
253 if (dev->type != ARPHRD_CAN)
256 if (msg == NETDEV_UNREGISTER) {
258 struct gw_job *gwj = NULL;
259 struct hlist_node *n, *nx;
261 spin_lock(&can_gw_list_lock);
263 hlist_for_each_entry_safe(gwj, n, nx, &can_gw_list, list) {
265 if (gwj->src_dev == dev || gwj->dst_dev == dev) {
266 hlist_del(&gwj->list);
267 can_gw_unregister_filter(gwj);
272 spin_unlock(&can_gw_list_lock);
278 static int gw_put_job(struct sk_buff *skb, struct gw_job *gwj)
283 } __attribute__((packed)) mb;
285 struct rtcanmsg *rtcan;
286 struct nlmsghdr *nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*rtcan), 0);
290 rtcan = nlmsg_data(nlh);
291 rtcan->can_family = AF_CAN;
292 rtcan->src_ifindex = gwj->src_dev->ifindex;
293 rtcan->dst_ifindex = gwj->dst_dev->ifindex;
294 rtcan->can_txflags = 0;
296 if (gwj->flags & CAN_TX_ECHO)
297 rtcan->can_txflags |= CAN_GW_TXFLAGS_ECHO;
299 if (gwj->flags & CAN_TX_SRC_TSTAMP)
300 rtcan->can_txflags |= CAN_GW_TXFLAGS_SRC_TSTAMP;
302 /* check non default settings of attributes */
303 if (gwj->handled_frames) {
304 if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
307 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(u32));
310 if (gwj->dropped_frames) {
311 if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
314 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(u32));
317 if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
318 if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
319 &gwj->ccgw.filter) < 0)
322 nlh->nlmsg_len += NLA_HDRLEN +
323 NLA_ALIGN(sizeof(struct can_filter));
326 if (gwj->ccgw.modtype.and) {
327 memcpy(&mb.cf, &gwj->ccgw.modframe.and, sizeof(mb.cf));
328 mb.modtype = gwj->ccgw.modtype.and;
329 if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
332 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(mb));
335 if (gwj->ccgw.modtype.or) {
336 memcpy(&mb.cf, &gwj->ccgw.modframe.or, sizeof(mb.cf));
337 mb.modtype = gwj->ccgw.modtype.or;
338 if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
341 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(mb));
344 if (gwj->ccgw.modtype.xor) {
345 memcpy(&mb.cf, &gwj->ccgw.modframe.xor, sizeof(mb.cf));
346 mb.modtype = gwj->ccgw.modtype.xor;
347 if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
350 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(mb));
353 if (gwj->ccgw.modtype.set) {
354 memcpy(&mb.cf, &gwj->ccgw.modframe.set, sizeof(mb.cf));
355 mb.modtype = gwj->ccgw.modtype.set;
356 if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
359 nlh->nlmsg_len += NLA_HDRLEN + NLA_ALIGN(sizeof(mb));
365 nlmsg_cancel(skb, nlh);
369 /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
370 static int gw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
372 struct gw_job *gwj = NULL;
373 struct hlist_node *n;
378 hlist_for_each_entry_rcu(gwj, n, &can_gw_list, list) {
379 if (idx >= cb->args[0]) {
380 ret = gw_put_job(skb, gwj);
392 /* check for attributes / filters for the CAN->CAN gateway */
393 static int can_can_parse_attr(struct nlmsghdr *nlh, struct can_can_gw *ccgw)
395 struct nlattr *tb[CGW_MAX+1];
402 } __attribute__((packed)) mb;
404 BUILD_BUG_ON(sizeof(mb) != CGW_MODATTR_LEN);
406 memset(ccgw, 0, sizeof(*ccgw));
408 err = nlmsg_parse(nlh, sizeof(struct rtcanmsg), tb, CGW_MAX, NULL);
412 /* check for can_filter in attributes */
413 if (tb[CGW_FILTER] &&
414 nla_len(tb[CGW_FILTER]) == sizeof(struct can_filter))
415 nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
416 sizeof(struct can_filter));
418 /* check for AND/OR/XOR/SET modifications */
419 if (tb[CGW_MOD_AND] &&
420 nla_len(tb[CGW_MOD_AND]) == CGW_MODATTR_LEN) {
421 nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
423 canframecpy(&ccgw->modframe.and, &mb.cf);
424 ccgw->modtype.and = mb.modtype;
426 if (mb.modtype & CGW_MOD_ID)
427 ccgw->modfunc[modidx++] = mod_and_id;
429 if (mb.modtype & CGW_MOD_DLC)
430 ccgw->modfunc[modidx++] = mod_and_dlc;
432 if (mb.modtype & CGW_MOD_DATA)
433 ccgw->modfunc[modidx++] = mod_and_data;
436 if (tb[CGW_MOD_OR] &&
437 nla_len(tb[CGW_MOD_OR]) == CGW_MODATTR_LEN) {
438 nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
440 canframecpy(&ccgw->modframe.or, &mb.cf);
441 ccgw->modtype.or = mb.modtype;
443 if (mb.modtype & CGW_MOD_ID)
444 ccgw->modfunc[modidx++] = mod_or_id;
446 if (mb.modtype & CGW_MOD_DLC)
447 ccgw->modfunc[modidx++] = mod_or_dlc;
449 if (mb.modtype & CGW_MOD_DATA)
450 ccgw->modfunc[modidx++] = mod_or_data;
453 if (tb[CGW_MOD_XOR] &&
454 nla_len(tb[CGW_MOD_XOR]) == CGW_MODATTR_LEN) {
455 nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
457 canframecpy(&ccgw->modframe.xor, &mb.cf);
458 ccgw->modtype.xor = mb.modtype;
460 if (mb.modtype & CGW_MOD_ID)
461 ccgw->modfunc[modidx++] = mod_xor_id;
463 if (mb.modtype & CGW_MOD_DLC)
464 ccgw->modfunc[modidx++] = mod_xor_dlc;
466 if (mb.modtype & CGW_MOD_DATA)
467 ccgw->modfunc[modidx++] = mod_xor_data;
470 if (tb[CGW_MOD_SET] &&
471 nla_len(tb[CGW_MOD_SET]) == CGW_MODATTR_LEN) {
472 nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
474 canframecpy(&ccgw->modframe.set, &mb.cf);
475 ccgw->modtype.set = mb.modtype;
477 if (mb.modtype & CGW_MOD_ID)
478 ccgw->modfunc[modidx++] = mod_set_id;
480 if (mb.modtype & CGW_MOD_DLC)
481 ccgw->modfunc[modidx++] = mod_set_dlc;
483 if (mb.modtype & CGW_MOD_DATA)
484 ccgw->modfunc[modidx++] = mod_set_data;
490 static int gw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
496 if (nlmsg_len(nlh) < sizeof(*r))
500 if (r->can_family != AF_CAN)
501 return -EPFNOSUPPORT;
503 gwj = kmem_cache_alloc(gw_cache, GFP_KERNEL);
507 gwj->src_dev = dev_get_by_index(&init_net, r->src_ifindex);
513 /* for now the source device needs to be a CAN device */
514 if (gwj->src_dev->type != ARPHRD_CAN) {
519 gwj->dst_dev = dev_get_by_index(&init_net, r->dst_ifindex);
525 /* for now the destination device needs to be a CAN device */
526 if (gwj->dst_dev->type != ARPHRD_CAN) {
528 goto put_src_dst_fail;
531 gwj->handled_frames = 0;
532 gwj->dropped_frames = 0;
535 if (r->can_txflags & CAN_GW_TXFLAGS_ECHO)
536 gwj->flags |= CAN_TX_ECHO;
538 if (r->can_txflags & CAN_GW_TXFLAGS_SRC_TSTAMP)
539 gwj->flags |= CAN_TX_SRC_TSTAMP;
541 err = can_can_parse_attr(nlh, &gwj->ccgw);
543 goto put_src_dst_fail;
545 spin_lock(&can_gw_list_lock);
547 err = can_gw_register_filter(gwj);
549 hlist_add_head_rcu(&gwj->list, &can_gw_list);
551 spin_unlock(&can_gw_list_lock);
553 dev_put(gwj->src_dev);
554 dev_put(gwj->dst_dev);
562 dev_put(gwj->dst_dev);
564 dev_put(gwj->src_dev);
566 kmem_cache_free(gw_cache, gwj);
570 static int gw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
572 struct gw_job *gwj = NULL;
573 struct hlist_node *n, *nx;
575 struct can_can_gw ccgw;
579 if (nlmsg_len(nlh) < sizeof(*r))
583 if (r->can_family != AF_CAN)
584 return -EPFNOSUPPORT;
586 if (r->can_txflags & CAN_GW_TXFLAGS_ECHO)
587 flags |= CAN_TX_ECHO;
589 if (r->can_txflags & CAN_GW_TXFLAGS_SRC_TSTAMP)
590 flags |= CAN_TX_SRC_TSTAMP;
592 err = can_can_parse_attr(nlh, &ccgw);
598 spin_lock(&can_gw_list_lock);
600 /* remove only the first matching entry */
601 hlist_for_each_entry_safe(gwj, n, nx, &can_gw_list, list) {
603 if (gwj->dst_dev->ifindex != r->dst_ifindex)
606 if (gwj->src_dev->ifindex != r->src_ifindex)
609 if (gwj->flags != flags)
612 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
615 hlist_del(&gwj->list);
616 can_gw_unregister_filter(gwj);
622 spin_unlock(&can_gw_list_lock);
627 static __init int gw_module_init(void)
631 gw_cache = kmem_cache_create("can_gw", sizeof(struct gw_job),
638 notifier.notifier_call = gw_notifier;
639 register_netdevice_notifier(¬ifier);
641 if (__rtnl_register(PF_CAN, RTM_GETROUTE, NULL, gw_dump_jobs)) {
642 unregister_netdevice_notifier(¬ifier);
643 kmem_cache_destroy(gw_cache);
647 /* Only the first call to __rtnl_register can fail */
648 __rtnl_register(PF_CAN, RTM_NEWROUTE, gw_create_job, NULL);
649 __rtnl_register(PF_CAN, RTM_DELROUTE, gw_remove_job, NULL);
654 static __exit void gw_module_exit(void)
656 struct gw_job *gwj = NULL;
657 struct hlist_node *n, *nx;
659 rtnl_unregister_all(PF_CAN);
661 unregister_netdevice_notifier(¬ifier);
663 spin_lock(&can_gw_list_lock);
665 hlist_for_each_entry_safe(gwj, n, nx, &can_gw_list, list) {
666 hlist_del(&gwj->list);
667 can_gw_unregister_filter(gwj);
671 spin_unlock(&can_gw_list_lock);
673 rcu_barrier(); /* Wait for completion of call_rcu()'s */
675 kmem_cache_destroy(gw_cache);
678 module_init(gw_module_init);
679 module_exit(gw_module_exit);