--- /dev/null
+/*
+ * gw.c - CAN frame Gateway/Router/Bridge with netlink interface
+ *
+ * Copyright (c) 2002-2010 Volkswagen Group Electronic Research
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Volkswagen nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <socketcan/can.h>
+#include <socketcan/can/core.h>
+#include <socketcan/can/gw.h>
+#include <net/rtnetlink.h>
+#include <net/net_namespace.h>
+
+#include <socketcan/can/version.h> /* for RCSID. Removed by mkpatch script */
+RCSID("$Id$");
+
+#define CAN_GW_VERSION "20100218"
+static __initdata const char banner[] =
+ KERN_INFO "can: netlink gateway (rev " CAN_GW_VERSION ")\n";
+
+MODULE_DESCRIPTION("PF_CAN netlink gateway");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
+
+HLIST_HEAD(can_gw_list);
+static DEFINE_SPINLOCK(can_gw_list_lock);
+static struct notifier_block notifier;
+
+static struct kmem_cache *gw_cache __read_mostly;
+
+#define GW_SK_MAGIC ((void *)(¬ifier))
+
+/*
+ * So far we just support CAN -> CAN routing and frame modifications.
+ *
+ * The internal can_can_gw structure contains optional attributes for
+ * a CAN -> CAN gateway job.
+ */
+struct can_can_gw {
+ struct can_filter filter;
+ struct {
+ struct can_frame and;
+ struct can_frame or;
+ struct can_frame xor;
+ struct can_frame set;
+ } modframe;
+ void (*modfunc[MAX_MODFUNCTIONS])(struct can_frame *cf,
+ struct can_can_gw *mod);
+};
+
+/* list entry for CAN gateways jobs */
+struct gw_job {
+ struct hlist_node list;
+ struct rcu_head rcu;
+ struct net_device *src_dev;
+ struct net_device *dst_dev;
+ u32 flags;
+ u32 handled_frames;
+ u32 dropped_frames;
+ union {
+ struct can_can_gw ccgw;
+ /* tbc */
+ };
+};
+
+/* content of u32 gwjob.flags */
+#define CAN_TX_LOOPBACK 0x00000001
+
+/* modification functions that are invoked in the hot path in gw_rcv */
+void mod_and_id (struct can_frame *cf, struct can_can_gw *mod) {
+ cf->can_id &= mod->modframe.and.can_id;
+}
+void mod_and_dlc (struct can_frame *cf, struct can_can_gw *mod) {
+ cf->can_dlc &= mod->modframe.and.can_dlc;
+}
+void mod_and_data (struct can_frame *cf, struct can_can_gw *mod) {
+ *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data;
+}
+void mod_or_id (struct can_frame *cf, struct can_can_gw *mod) {
+ cf->can_id |= mod->modframe.or.can_id;
+}
+void mod_or_dlc (struct can_frame *cf, struct can_can_gw *mod) {
+ cf->can_dlc |= mod->modframe.or.can_dlc;
+}
+void mod_or_data (struct can_frame *cf, struct can_can_gw *mod) {
+ *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data;
+}
+void mod_xor_id (struct can_frame *cf, struct can_can_gw *mod) {
+ cf->can_id ^= mod->modframe.xor.can_id;
+}
+void mod_xor_dlc (struct can_frame *cf, struct can_can_gw *mod) {
+ cf->can_dlc ^= mod->modframe.xor.can_dlc;
+}
+void mod_xor_data (struct can_frame *cf, struct can_can_gw *mod) {
+ *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data;
+}
+void mod_set_id (struct can_frame *cf, struct can_can_gw *mod) {
+ cf->can_id = mod->modframe.set.can_id;
+}
+void mod_set_dlc (struct can_frame *cf, struct can_can_gw *mod) {
+ cf->can_dlc = mod->modframe.set.can_dlc;
+}
+void mod_set_data (struct can_frame *cf, struct can_can_gw *mod) {
+ *(u64 *)cf->data = *(u64 *)mod->modframe.set.data;
+}
+
+
+/* the receive & process & send function */
+static void gw_rcv(struct sk_buff *skb, void *data)
+{
+ struct gw_job *gwj = (struct gw_job *)data;
+ struct can_frame *cf;
+ struct sk_buff *nskb;
+ int modidx = 0;
+
+ /* do not handle already routed frames */
+ if (skb->sk == GW_SK_MAGIC)
+ return;
+
+ if (!netif_running(gwj->dst_dev)) {
+ gwj->dropped_frames++;
+ return;
+ }
+
+ /*
+ * clone the given skb, which has not been done in can_rv()
+ *
+ * When there is at least one modification function activated,
+ * we need to copy the skb as we want to modify skb->data.
+ */
+ if (gwj->ccgw.modfunc[0])
+ nskb = skb_copy(skb, GFP_ATOMIC);
+ else
+ nskb = skb_clone(skb, GFP_ATOMIC);
+
+ if (!nskb) {
+ gwj->dropped_frames++;
+ return;
+ }
+
+ gwj->handled_frames++;
+
+ /* mark routed frames with a 'special' sk value */
+ nskb->sk = GW_SK_MAGIC;
+ nskb->dev = gwj->dst_dev;
+
+ /* pointer to modifiable CAN frame */
+ cf = (struct can_frame *)nskb->data;
+
+ /* perform preprocessed modification functions if there are any */
+ while (modidx < MAX_MODFUNCTIONS && gwj->ccgw.modfunc[modidx])
+ (*gwj->ccgw.modfunc[modidx++])(cf, &gwj->ccgw);
+
+ /* send to netdevice */
+ if (can_send(nskb, gwj->flags & CAN_TX_LOOPBACK))
+ gwj->dropped_frames++;
+}
+
+static inline int can_gw_register_filter(struct gw_job *gwj)
+{
+ return can_rx_register(gwj->src_dev, gwj->ccgw.filter.can_id,
+ gwj->ccgw.filter.can_mask, gw_rcv, gwj, "gw");
+}
+
+static inline void can_gw_unregister_filter(struct gw_job *gwj)
+{
+ can_rx_unregister(gwj->src_dev, gwj->ccgw.filter.can_id,
+ gwj->ccgw.filter.can_mask, gw_rcv, gwj);
+}
+
+static int gw_notifier(struct notifier_block *nb,
+ unsigned long msg, void *data)
+{
+ struct net_device *dev = (struct net_device *)data;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
+ if (!net_eq(dev_net(dev), &init_net))
+ return NOTIFY_DONE;
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
+ if (dev->nd_net != &init_net)
+ return NOTIFY_DONE;
+#endif
+ if (dev->type != ARPHRD_CAN)
+ return NOTIFY_DONE;
+
+ if (msg == NETDEV_UNREGISTER) {
+
+ struct gw_job *gwj = NULL;
+ struct hlist_node *n, *nx;
+
+ spin_lock(&can_gw_list_lock);
+
+ hlist_for_each_entry_safe(gwj, n, nx, &can_gw_list, list) {
+
+ if (gwj->src_dev == dev || gwj->dst_dev == dev) {
+ hlist_del(&gwj->list);
+ can_gw_unregister_filter(gwj);
+ kfree(gwj);
+ }
+ }
+
+ spin_unlock(&can_gw_list_lock);
+ }
+
+ return NOTIFY_DONE;
+}
+
+/*
+ * Dump information about all ports, in response to GETROUTE
+ */
+static int gw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ printk(KERN_INFO "%s (TODO)\n", __FUNCTION__);
+
+ return 0;
+}
+
+static int gw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
+{
+
+ struct rtcanmsg *r;
+ struct nlattr *tb[CGW_MAX+1];
+ struct gw_job *gwj;
+ u8 buf[CGW_MODATTR_LEN];
+ int modidx = 0;
+ int err = 0;
+
+ printk(KERN_INFO "%s: len %d attrlen %d\n", __FUNCTION__,
+ nlmsg_len(nlh), nlmsg_attrlen(nlh, sizeof(*r)));
+
+ if (nlmsg_len(nlh) < sizeof(*r))
+ return -EINVAL;
+
+ r = nlmsg_data(nlh);
+ if (r->can_family != AF_CAN)
+ return -EPFNOSUPPORT;
+
+ gwj = kmem_cache_alloc(gw_cache, GFP_KERNEL);
+ if (!gwj)
+ return -ENOMEM;
+
+ gwj->src_dev = dev_get_by_index(&init_net, r->src_ifindex);
+ if (!gwj->src_dev) {
+ err = -ENODEV;
+ goto fail;
+ }
+
+ /* for now the source device needs to be a CAN device */
+ if (gwj->src_dev->type != ARPHRD_CAN) {
+ err = -ENODEV;
+ goto put_src_fail;
+ }
+
+ gwj->dst_dev = dev_get_by_index(&init_net, r->dst_ifindex);
+ if (!gwj->dst_dev) {
+ err = -ENODEV;
+ goto put_src_fail;
+ }
+
+ /* for now the destination device needs to be a CAN device */
+ if (gwj->dst_dev->type != ARPHRD_CAN) {
+ err = -ENODEV;
+ goto put_src_dst_fail;
+ }
+
+ gwj->flags = 0;
+
+ if (r->can_txflags & CAN_GW_TXFLAGS_LOOPBACK)
+ gwj->flags |= CAN_TX_LOOPBACK;
+
+ memset(&gwj->ccgw, 0, sizeof(gwj->ccgw));
+
+ /* check for additional attributes / filters here */
+
+ err = nlmsg_parse(nlh, sizeof(*r), tb, CGW_MAX, NULL);
+ if (err < 0)
+ goto put_src_dst_fail;
+
+ /* check for can_filter in attributes */
+ if (tb[CGW_FILTER] &&
+ nla_len(tb[CGW_FILTER]) == sizeof(struct can_filter))
+ nla_memcpy(&gwj->ccgw.filter, tb[CGW_FILTER],
+ sizeof(struct can_filter));
+
+ /* check for AND/OR/XOR/SET modifications */
+ if (tb[CGW_MOD_AND] &&
+ nla_len(tb[CGW_MOD_AND]) == CGW_MODATTR_LEN) {
+ nla_memcpy(&buf, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
+
+ memcpy(&gwj->ccgw.modframe.and, &buf[1],
+ sizeof(struct can_frame));
+
+ if (buf[0] & CGW_MOD_ID)
+ gwj->ccgw.modfunc[modidx++] = mod_and_id;
+
+ if (buf[0] & CGW_MOD_DLC)
+ gwj->ccgw.modfunc[modidx++] = mod_and_dlc;
+
+ if (buf[0] & CGW_MOD_DATA)
+ gwj->ccgw.modfunc[modidx++] = mod_and_data;
+ }
+
+ if (tb[CGW_MOD_OR] &&
+ nla_len(tb[CGW_MOD_OR]) == CGW_MODATTR_LEN) {
+ nla_memcpy(&buf, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
+
+ memcpy(&gwj->ccgw.modframe.or, &buf[1],
+ sizeof(struct can_frame));
+
+ if (buf[0] & CGW_MOD_ID)
+ gwj->ccgw.modfunc[modidx++] = mod_or_id;
+
+ if (buf[0] & CGW_MOD_DLC)
+ gwj->ccgw.modfunc[modidx++] = mod_or_dlc;
+
+ if (buf[0] & CGW_MOD_DATA)
+ gwj->ccgw.modfunc[modidx++] = mod_or_data;
+ }
+
+ if (tb[CGW_MOD_XOR] &&
+ nla_len(tb[CGW_MOD_XOR]) == CGW_MODATTR_LEN) {
+ nla_memcpy(&buf, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
+
+ memcpy(&gwj->ccgw.modframe.xor, &buf[1],
+ sizeof(struct can_frame));
+
+ if (buf[0] & CGW_MOD_ID)
+ gwj->ccgw.modfunc[modidx++] = mod_xor_id;
+
+ if (buf[0] & CGW_MOD_DLC)
+ gwj->ccgw.modfunc[modidx++] = mod_xor_dlc;
+
+ if (buf[0] & CGW_MOD_DATA)
+ gwj->ccgw.modfunc[modidx++] = mod_xor_data;
+ }
+
+ if (tb[CGW_MOD_SET] &&
+ nla_len(tb[CGW_MOD_SET]) == CGW_MODATTR_LEN) {
+ nla_memcpy(&buf, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
+
+ memcpy(&gwj->ccgw.modframe.set, &buf[1],
+ sizeof(struct can_frame));
+
+ if (buf[0] & CGW_MOD_ID)
+ gwj->ccgw.modfunc[modidx++] = mod_set_id;
+
+ if (buf[0] & CGW_MOD_DLC)
+ gwj->ccgw.modfunc[modidx++] = mod_set_dlc;
+
+ if (buf[0] & CGW_MOD_DATA)
+ gwj->ccgw.modfunc[modidx++] = mod_set_data;
+ }
+
+ spin_lock(&can_gw_list_lock);
+
+ err = can_gw_register_filter(gwj);
+ if (!err)
+ hlist_add_head_rcu(&gwj->list, &can_gw_list);
+
+ spin_unlock(&can_gw_list_lock);
+
+ dev_put(gwj->src_dev);
+ dev_put(gwj->dst_dev);
+
+ if (!err)
+ return 0;
+
+put_src_dst_fail:
+ dev_put(gwj->dst_dev);
+put_src_fail:
+ dev_put(gwj->src_dev);
+fail:
+ kmem_cache_free(gw_cache, gwj);
+ return err;
+}
+
+static int gw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
+{
+ printk(KERN_INFO "%s (TODO)\n", __FUNCTION__);
+
+ return 0;
+}
+
+static __init int gw_module_init(void)
+{
+ printk(banner);
+
+ gw_cache = kmem_cache_create("can_gw", sizeof(struct gw_job),
+ 0, 0, NULL);
+
+ if (!gw_cache)
+ return -ENOMEM;
+
+ /* set notifier */
+ notifier.notifier_call = gw_notifier;
+ register_netdevice_notifier(¬ifier);
+
+ if (__rtnl_register(PF_CAN, RTM_GETROUTE, NULL, gw_dump_jobs)) {
+ unregister_netdevice_notifier(¬ifier);
+ kmem_cache_destroy(gw_cache);
+ return -ENOBUFS;
+ }
+
+ /* Only the first call to __rtnl_register can fail */
+ __rtnl_register(PF_CAN, RTM_NEWROUTE, gw_create_job, NULL);
+ __rtnl_register(PF_CAN, RTM_DELROUTE, gw_remove_job, NULL);
+
+ return 0;
+}
+
+static __exit void gw_module_exit(void)
+{
+ struct gw_job *gwj = NULL;
+ struct hlist_node *n, *nx;
+
+ rtnl_unregister_all(PF_CAN);
+
+ unregister_netdevice_notifier(¬ifier);
+
+ spin_lock(&can_gw_list_lock);
+
+ hlist_for_each_entry_safe(gwj, n, nx, &can_gw_list, list) {
+ hlist_del(&gwj->list);
+ can_gw_unregister_filter(gwj);
+ kfree(gwj);
+ }
+
+ spin_unlock(&can_gw_list_lock);
+
+ rcu_barrier(); /* Wait for completion of call_rcu()'s */
+
+ kmem_cache_destroy(gw_cache);
+}
+
+module_init(gw_module_init);
+module_exit(gw_module_exit);
--- /dev/null
+/*
+ * A real quick'n'dirty hack to add a netlink CAN gateway entry.
+ *
+ * Parts of this code were taken from the iproute source and the original
+ * vcan.c from Urs Thuermann.
+ *
+ * Oliver Hartkopp 2010-02-18
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <net/if.h>
+
+#include <asm/types.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <socketcan/can/gw.h>
+
+#include <linux/if_link.h>
+
+#define NLMSG_TAIL(nmsg) \
+ ((struct rtattr *)(((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
+
+int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
+ int alen)
+{
+ int len = RTA_LENGTH(alen);
+ struct rtattr *rta;
+
+ if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
+ fprintf(stderr, "addattr_l: message exceeded bound of %d\n",
+ maxlen);
+ return -1;
+ }
+ rta = NLMSG_TAIL(n);
+ rta->rta_type = type;
+ rta->rta_len = len;
+ memcpy(RTA_DATA(rta), data, alen);
+ n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ int s;
+ int err = 0;
+
+ struct {
+ struct nlmsghdr n;
+ struct rtcanmsg r;
+ char buf[1000];
+
+ } req;
+
+ static struct can_frame modframe;
+ struct can_filter filter;
+ struct sockaddr_nl nladdr;
+ char modbuf[CGW_MODATTR_LEN];
+
+ s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+
+ memset(&req, 0, sizeof(req));
+
+ req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtcanmsg));
+ req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
+ req.n.nlmsg_type = RTM_NEWROUTE;
+ req.n.nlmsg_seq = 0;
+
+ req.r.can_family = AF_CAN;
+ req.r.src_ifindex = if_nametoindex("vcan2");
+ req.r.dst_ifindex = if_nametoindex("vcan3");
+ req.r.can_txflags = CAN_GW_TXFLAGS_LOOPBACK;
+
+ /* add new attributes here */
+
+ filter.can_id = 0x400;
+ filter.can_mask = 0x700;
+
+ addattr_l(&req.n, sizeof(req), CGW_FILTER, &filter, sizeof(filter));
+ modframe.can_id = 0x555;
+ modframe.can_dlc = 5;
+ *(unsigned long long *)modframe.data = 0x5555555555555555ULL;
+
+ modbuf[0] = CGW_MOD_ID;
+ memcpy(&modbuf[1], &modframe, sizeof(struct can_frame));
+
+ addattr_l(&req.n, sizeof(req), CGW_MOD_SET, modbuf, CGW_MODATTR_LEN);
+
+ modbuf[0] = CGW_MOD_DLC;
+ memcpy(&modbuf[1], &modframe, sizeof(struct can_frame));
+
+ addattr_l(&req.n, sizeof(req), CGW_MOD_AND, modbuf, CGW_MODATTR_LEN);
+
+ modbuf[0] = CGW_MOD_DATA;
+ memcpy(&modbuf[1], &modframe, sizeof(struct can_frame));
+
+ addattr_l(&req.n, sizeof(req), CGW_MOD_XOR, modbuf, CGW_MODATTR_LEN);
+
+
+ memset(&nladdr, 0, sizeof(nladdr));
+ nladdr.nl_family = AF_NETLINK;
+ nladdr.nl_pid = 0;
+ nladdr.nl_groups = 0;
+
+ err = sendto(s, &req, req.n.nlmsg_len, 0,
+ (struct sockaddr*)&nladdr, sizeof(nladdr));
+
+ perror("netlink says ");
+ close(s);
+
+ return 0;
+}
+
projects / socketcan-devel.git / commitdiff