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-rw-r--r--net/can/gw.c1260
1 files changed, 1260 insertions, 0 deletions
diff --git a/net/can/gw.c b/net/can/gw.c
new file mode 100644
index 000000000..cbb46d3aa
--- /dev/null
+++ b/net/can/gw.c
@@ -0,0 +1,1260 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* gw.c - CAN frame Gateway/Router/Bridge with netlink interface
+ *
+ * Copyright (c) 2019 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/can.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/can/gw.h>
+#include <net/rtnetlink.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#define CAN_GW_NAME "can-gw"
+
+MODULE_DESCRIPTION("PF_CAN netlink gateway");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
+MODULE_ALIAS(CAN_GW_NAME);
+
+#define CGW_MIN_HOPS 1
+#define CGW_MAX_HOPS 6
+#define CGW_DEFAULT_HOPS 1
+
+static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS;
+module_param(max_hops, uint, 0444);
+MODULE_PARM_DESC(max_hops,
+ "maximum " CAN_GW_NAME " routing hops for CAN frames "
+ "(valid values: " __stringify(CGW_MIN_HOPS) "-"
+ __stringify(CGW_MAX_HOPS) " hops, "
+ "default: " __stringify(CGW_DEFAULT_HOPS) ")");
+
+static struct notifier_block notifier;
+static struct kmem_cache *cgw_cache __read_mostly;
+
+/* structure that contains the (on-the-fly) CAN frame modifications */
+struct cf_mod {
+ struct {
+ struct canfd_frame and;
+ struct canfd_frame or;
+ struct canfd_frame xor;
+ struct canfd_frame set;
+ } modframe;
+ struct {
+ u8 and;
+ u8 or;
+ u8 xor;
+ u8 set;
+ } modtype;
+ void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf,
+ struct cf_mod *mod);
+
+ /* CAN frame checksum calculation after CAN frame modifications */
+ struct {
+ struct cgw_csum_xor xor;
+ struct cgw_csum_crc8 crc8;
+ } csum;
+ struct {
+ void (*xor)(struct canfd_frame *cf,
+ struct cgw_csum_xor *xor);
+ void (*crc8)(struct canfd_frame *cf,
+ struct cgw_csum_crc8 *crc8);
+ } csumfunc;
+ u32 uid;
+};
+
+/* So far we just support CAN -> CAN routing and frame modifications.
+ *
+ * The internal can_can_gw structure contains data and attributes for
+ * a CAN -> CAN gateway job.
+ */
+struct can_can_gw {
+ struct can_filter filter;
+ int src_idx;
+ int dst_idx;
+};
+
+/* list entry for CAN gateways jobs */
+struct cgw_job {
+ struct hlist_node list;
+ struct rcu_head rcu;
+ u32 handled_frames;
+ u32 dropped_frames;
+ u32 deleted_frames;
+ struct cf_mod mod;
+ union {
+ /* CAN frame data source */
+ struct net_device *dev;
+ } src;
+ union {
+ /* CAN frame data destination */
+ struct net_device *dev;
+ } dst;
+ union {
+ struct can_can_gw ccgw;
+ /* tbc */
+ };
+ u8 gwtype;
+ u8 limit_hops;
+ u16 flags;
+};
+
+/* modification functions that are invoked in the hot path in can_can_gw_rcv */
+
+#define MODFUNC(func, op) static void func(struct canfd_frame *cf, \
+ struct cf_mod *mod) { op ; }
+
+MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
+MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len)
+MODFUNC(mod_and_flags, cf->flags &= mod->modframe.and.flags)
+MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
+MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
+MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len)
+MODFUNC(mod_or_flags, cf->flags |= mod->modframe.or.flags)
+MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
+MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
+MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len)
+MODFUNC(mod_xor_flags, cf->flags ^= mod->modframe.xor.flags)
+MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
+MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
+MODFUNC(mod_set_len, cf->len = mod->modframe.set.len)
+MODFUNC(mod_set_flags, cf->flags = mod->modframe.set.flags)
+MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
+
+static void mod_and_fddata(struct canfd_frame *cf, struct cf_mod *mod)
+{
+ int i;
+
+ for (i = 0; i < CANFD_MAX_DLEN; i += 8)
+ *(u64 *)(cf->data + i) &= *(u64 *)(mod->modframe.and.data + i);
+}
+
+static void mod_or_fddata(struct canfd_frame *cf, struct cf_mod *mod)
+{
+ int i;
+
+ for (i = 0; i < CANFD_MAX_DLEN; i += 8)
+ *(u64 *)(cf->data + i) |= *(u64 *)(mod->modframe.or.data + i);
+}
+
+static void mod_xor_fddata(struct canfd_frame *cf, struct cf_mod *mod)
+{
+ int i;
+
+ for (i = 0; i < CANFD_MAX_DLEN; i += 8)
+ *(u64 *)(cf->data + i) ^= *(u64 *)(mod->modframe.xor.data + i);
+}
+
+static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod)
+{
+ memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN);
+}
+
+static void canframecpy(struct canfd_frame *dst, struct can_frame *src)
+{
+ /* Copy the struct members separately to ensure that no uninitialized
+ * data are copied in the 3 bytes hole of the struct. This is needed
+ * to make easy compares of the data in the struct cf_mod.
+ */
+
+ dst->can_id = src->can_id;
+ dst->len = src->can_dlc;
+ *(u64 *)dst->data = *(u64 *)src->data;
+}
+
+static void canfdframecpy(struct canfd_frame *dst, struct canfd_frame *src)
+{
+ /* Copy the struct members separately to ensure that no uninitialized
+ * data are copied in the 2 bytes hole of the struct. This is needed
+ * to make easy compares of the data in the struct cf_mod.
+ */
+
+ dst->can_id = src->can_id;
+ dst->flags = src->flags;
+ dst->len = src->len;
+ memcpy(dst->data, src->data, CANFD_MAX_DLEN);
+}
+
+static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re, struct rtcanmsg *r)
+{
+ s8 dlen = CAN_MAX_DLEN;
+
+ if (r->flags & CGW_FLAGS_CAN_FD)
+ dlen = CANFD_MAX_DLEN;
+
+ /* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
+ * relative to received dlc -1 .. -8 :
+ * e.g. for received dlc = 8
+ * -1 => index = 7 (data[7])
+ * -3 => index = 5 (data[5])
+ * -8 => index = 0 (data[0])
+ */
+
+ if (fr >= -dlen && fr < dlen &&
+ to >= -dlen && to < dlen &&
+ re >= -dlen && re < dlen)
+ return 0;
+ else
+ return -EINVAL;
+}
+
+static inline int calc_idx(int idx, int rx_len)
+{
+ if (idx < 0)
+ return rx_len + idx;
+ else
+ return idx;
+}
+
+static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor)
+{
+ int from = calc_idx(xor->from_idx, cf->len);
+ int to = calc_idx(xor->to_idx, cf->len);
+ int res = calc_idx(xor->result_idx, cf->len);
+ u8 val = xor->init_xor_val;
+ int i;
+
+ if (from < 0 || to < 0 || res < 0)
+ return;
+
+ if (from <= to) {
+ for (i = from; i <= to; i++)
+ val ^= cf->data[i];
+ } else {
+ for (i = from; i >= to; i--)
+ val ^= cf->data[i];
+ }
+
+ cf->data[res] = val;
+}
+
+static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor)
+{
+ u8 val = xor->init_xor_val;
+ int i;
+
+ for (i = xor->from_idx; i <= xor->to_idx; i++)
+ val ^= cf->data[i];
+
+ cf->data[xor->result_idx] = val;
+}
+
+static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor)
+{
+ u8 val = xor->init_xor_val;
+ int i;
+
+ for (i = xor->from_idx; i >= xor->to_idx; i--)
+ val ^= cf->data[i];
+
+ cf->data[xor->result_idx] = val;
+}
+
+static void cgw_csum_crc8_rel(struct canfd_frame *cf,
+ struct cgw_csum_crc8 *crc8)
+{
+ int from = calc_idx(crc8->from_idx, cf->len);
+ int to = calc_idx(crc8->to_idx, cf->len);
+ int res = calc_idx(crc8->result_idx, cf->len);
+ u8 crc = crc8->init_crc_val;
+ int i;
+
+ if (from < 0 || to < 0 || res < 0)
+ return;
+
+ if (from <= to) {
+ for (i = crc8->from_idx; i <= crc8->to_idx; i++)
+ crc = crc8->crctab[crc ^ cf->data[i]];
+ } else {
+ for (i = crc8->from_idx; i >= crc8->to_idx; i--)
+ crc = crc8->crctab[crc ^ cf->data[i]];
+ }
+
+ switch (crc8->profile) {
+ case CGW_CRC8PRF_1U8:
+ crc = crc8->crctab[crc ^ crc8->profile_data[0]];
+ break;
+
+ case CGW_CRC8PRF_16U8:
+ crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
+ break;
+
+ case CGW_CRC8PRF_SFFID_XOR:
+ crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
+ (cf->can_id >> 8 & 0xFF)];
+ break;
+ }
+
+ cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
+}
+
+static void cgw_csum_crc8_pos(struct canfd_frame *cf,
+ struct cgw_csum_crc8 *crc8)
+{
+ u8 crc = crc8->init_crc_val;
+ int i;
+
+ for (i = crc8->from_idx; i <= crc8->to_idx; i++)
+ crc = crc8->crctab[crc ^ cf->data[i]];
+
+ switch (crc8->profile) {
+ case CGW_CRC8PRF_1U8:
+ crc = crc8->crctab[crc ^ crc8->profile_data[0]];
+ break;
+
+ case CGW_CRC8PRF_16U8:
+ crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
+ break;
+
+ case CGW_CRC8PRF_SFFID_XOR:
+ crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
+ (cf->can_id >> 8 & 0xFF)];
+ break;
+ }
+
+ cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
+}
+
+static void cgw_csum_crc8_neg(struct canfd_frame *cf,
+ struct cgw_csum_crc8 *crc8)
+{
+ u8 crc = crc8->init_crc_val;
+ int i;
+
+ for (i = crc8->from_idx; i >= crc8->to_idx; i--)
+ crc = crc8->crctab[crc ^ cf->data[i]];
+
+ switch (crc8->profile) {
+ case CGW_CRC8PRF_1U8:
+ crc = crc8->crctab[crc ^ crc8->profile_data[0]];
+ break;
+
+ case CGW_CRC8PRF_16U8:
+ crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
+ break;
+
+ case CGW_CRC8PRF_SFFID_XOR:
+ crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
+ (cf->can_id >> 8 & 0xFF)];
+ break;
+ }
+
+ cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
+}
+
+/* the receive & process & send function */
+static void can_can_gw_rcv(struct sk_buff *skb, void *data)
+{
+ struct cgw_job *gwj = (struct cgw_job *)data;
+ struct canfd_frame *cf;
+ struct sk_buff *nskb;
+ int modidx = 0;
+
+ /* process strictly Classic CAN or CAN FD frames */
+ if (gwj->flags & CGW_FLAGS_CAN_FD) {
+ if (skb->len != CANFD_MTU)
+ return;
+ } else {
+ if (skb->len != CAN_MTU)
+ return;
+ }
+
+ /* Do not handle CAN frames routed more than 'max_hops' times.
+ * In general we should never catch this delimiter which is intended
+ * to cover a misconfiguration protection (e.g. circular CAN routes).
+ *
+ * The Controller Area Network controllers only accept CAN frames with
+ * correct CRCs - which are not visible in the controller registers.
+ * According to skbuff.h documentation the csum_start element for IP
+ * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY.
+ * Only CAN skbs can be processed here which already have this property.
+ */
+
+#define cgw_hops(skb) ((skb)->csum_start)
+
+ BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY);
+
+ if (cgw_hops(skb) >= max_hops) {
+ /* indicate deleted frames due to misconfiguration */
+ gwj->deleted_frames++;
+ return;
+ }
+
+ if (!(gwj->dst.dev->flags & IFF_UP)) {
+ gwj->dropped_frames++;
+ return;
+ }
+
+ /* is sending the skb back to the incoming interface not allowed? */
+ if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
+ can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex)
+ return;
+
+ /* clone the given skb, which has not been done in can_rcv()
+ *
+ * When there is at least one modification function activated,
+ * we need to copy the skb as we want to modify skb->data.
+ */
+ if (gwj->mod.modfunc[0])
+ nskb = skb_copy(skb, GFP_ATOMIC);
+ else
+ nskb = skb_clone(skb, GFP_ATOMIC);
+
+ if (!nskb) {
+ gwj->dropped_frames++;
+ return;
+ }
+
+ /* put the incremented hop counter in the cloned skb */
+ cgw_hops(nskb) = cgw_hops(skb) + 1;
+
+ /* first processing of this CAN frame -> adjust to private hop limit */
+ if (gwj->limit_hops && cgw_hops(nskb) == 1)
+ cgw_hops(nskb) = max_hops - gwj->limit_hops + 1;
+
+ nskb->dev = gwj->dst.dev;
+
+ /* pointer to modifiable CAN frame */
+ cf = (struct canfd_frame *)nskb->data;
+
+ /* perform preprocessed modification functions if there are any */
+ while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
+ (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod);
+
+ /* Has the CAN frame been modified? */
+ if (modidx) {
+ /* get available space for the processed CAN frame type */
+ int max_len = nskb->len - offsetof(struct canfd_frame, data);
+
+ /* dlc may have changed, make sure it fits to the CAN frame */
+ if (cf->len > max_len) {
+ /* delete frame due to misconfiguration */
+ gwj->deleted_frames++;
+ kfree_skb(nskb);
+ return;
+ }
+
+ /* check for checksum updates */
+ if (gwj->mod.csumfunc.crc8)
+ (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
+
+ if (gwj->mod.csumfunc.xor)
+ (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
+ }
+
+ /* clear the skb timestamp if not configured the other way */
+ if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
+ nskb->tstamp = 0;
+
+ /* send to netdevice */
+ if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
+ gwj->dropped_frames++;
+ else
+ gwj->handled_frames++;
+}
+
+static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
+{
+ return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
+ gwj->ccgw.filter.can_mask, can_can_gw_rcv,
+ gwj, "gw", NULL);
+}
+
+static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
+{
+ can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
+ gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
+}
+
+static int cgw_notifier(struct notifier_block *nb,
+ unsigned long msg, void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct net *net = dev_net(dev);
+
+ if (dev->type != ARPHRD_CAN)
+ return NOTIFY_DONE;
+
+ if (msg == NETDEV_UNREGISTER) {
+ struct cgw_job *gwj = NULL;
+ struct hlist_node *nx;
+
+ ASSERT_RTNL();
+
+ hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
+ if (gwj->src.dev == dev || gwj->dst.dev == dev) {
+ hlist_del(&gwj->list);
+ cgw_unregister_filter(net, gwj);
+ synchronize_rcu();
+ kmem_cache_free(cgw_cache, gwj);
+ }
+ }
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
+ u32 pid, u32 seq, int flags)
+{
+ struct rtcanmsg *rtcan;
+ struct nlmsghdr *nlh;
+
+ nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ rtcan = nlmsg_data(nlh);
+ rtcan->can_family = AF_CAN;
+ rtcan->gwtype = gwj->gwtype;
+ rtcan->flags = gwj->flags;
+
+ /* add statistics if available */
+
+ if (gwj->handled_frames) {
+ if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
+ goto cancel;
+ }
+
+ if (gwj->dropped_frames) {
+ if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
+ goto cancel;
+ }
+
+ if (gwj->deleted_frames) {
+ if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0)
+ goto cancel;
+ }
+
+ /* check non default settings of attributes */
+
+ if (gwj->limit_hops) {
+ if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0)
+ goto cancel;
+ }
+
+ if (gwj->flags & CGW_FLAGS_CAN_FD) {
+ struct cgw_fdframe_mod mb;
+
+ if (gwj->mod.modtype.and) {
+ memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
+ mb.modtype = gwj->mod.modtype.and;
+ if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0)
+ goto cancel;
+ }
+
+ if (gwj->mod.modtype.or) {
+ memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
+ mb.modtype = gwj->mod.modtype.or;
+ if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0)
+ goto cancel;
+ }
+
+ if (gwj->mod.modtype.xor) {
+ memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
+ mb.modtype = gwj->mod.modtype.xor;
+ if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0)
+ goto cancel;
+ }
+
+ if (gwj->mod.modtype.set) {
+ memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
+ mb.modtype = gwj->mod.modtype.set;
+ if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0)
+ goto cancel;
+ }
+ } else {
+ struct cgw_frame_mod mb;
+
+ if (gwj->mod.modtype.and) {
+ memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
+ mb.modtype = gwj->mod.modtype.and;
+ if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
+ goto cancel;
+ }
+
+ if (gwj->mod.modtype.or) {
+ memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
+ mb.modtype = gwj->mod.modtype.or;
+ if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
+ goto cancel;
+ }
+
+ if (gwj->mod.modtype.xor) {
+ memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
+ mb.modtype = gwj->mod.modtype.xor;
+ if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
+ goto cancel;
+ }
+
+ if (gwj->mod.modtype.set) {
+ memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
+ mb.modtype = gwj->mod.modtype.set;
+ if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
+ goto cancel;
+ }
+ }
+
+ if (gwj->mod.uid) {
+ if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0)
+ goto cancel;
+ }
+
+ if (gwj->mod.csumfunc.crc8) {
+ if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
+ &gwj->mod.csum.crc8) < 0)
+ goto cancel;
+ }
+
+ if (gwj->mod.csumfunc.xor) {
+ if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN,
+ &gwj->mod.csum.xor) < 0)
+ goto cancel;
+ }
+
+ if (gwj->gwtype == CGW_TYPE_CAN_CAN) {
+ if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
+ if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
+ &gwj->ccgw.filter) < 0)
+ goto cancel;
+ }
+
+ if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0)
+ goto cancel;
+
+ if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0)
+ goto cancel;
+ }
+
+ nlmsg_end(skb, nlh);
+ return 0;
+
+cancel:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+/* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
+static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct net *net = sock_net(skb->sk);
+ struct cgw_job *gwj = NULL;
+ int idx = 0;
+ int s_idx = cb->args[0];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) {
+ if (idx < s_idx)
+ goto cont;
+
+ if (cgw_put_job(skb, gwj, RTM_NEWROUTE,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0)
+ break;
+cont:
+ idx++;
+ }
+ rcu_read_unlock();
+
+ cb->args[0] = idx;
+
+ return skb->len;
+}
+
+static const struct nla_policy cgw_policy[CGW_MAX + 1] = {
+ [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) },
+ [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) },
+ [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) },
+ [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) },
+ [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) },
+ [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) },
+ [CGW_SRC_IF] = { .type = NLA_U32 },
+ [CGW_DST_IF] = { .type = NLA_U32 },
+ [CGW_FILTER] = { .len = sizeof(struct can_filter) },
+ [CGW_LIM_HOPS] = { .type = NLA_U8 },
+ [CGW_MOD_UID] = { .type = NLA_U32 },
+ [CGW_FDMOD_AND] = { .len = sizeof(struct cgw_fdframe_mod) },
+ [CGW_FDMOD_OR] = { .len = sizeof(struct cgw_fdframe_mod) },
+ [CGW_FDMOD_XOR] = { .len = sizeof(struct cgw_fdframe_mod) },
+ [CGW_FDMOD_SET] = { .len = sizeof(struct cgw_fdframe_mod) },
+};
+
+/* check for common and gwtype specific attributes */
+static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
+ u8 gwtype, void *gwtypeattr, u8 *limhops)
+{
+ struct nlattr *tb[CGW_MAX + 1];
+ struct rtcanmsg *r = nlmsg_data(nlh);
+ int modidx = 0;
+ int err = 0;
+
+ /* initialize modification & checksum data space */
+ memset(mod, 0, sizeof(*mod));
+
+ err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb,
+ CGW_MAX, cgw_policy, NULL);
+ if (err < 0)
+ return err;
+
+ if (tb[CGW_LIM_HOPS]) {
+ *limhops = nla_get_u8(tb[CGW_LIM_HOPS]);
+
+ if (*limhops < 1 || *limhops > max_hops)
+ return -EINVAL;
+ }
+
+ /* check for AND/OR/XOR/SET modifications */
+ if (r->flags & CGW_FLAGS_CAN_FD) {
+ struct cgw_fdframe_mod mb;
+
+ if (tb[CGW_FDMOD_AND]) {
+ nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN);
+
+ canfdframecpy(&mod->modframe.and, &mb.cf);
+ mod->modtype.and = mb.modtype;
+
+ if (mb.modtype & CGW_MOD_ID)
+ mod->modfunc[modidx++] = mod_and_id;
+
+ if (mb.modtype & CGW_MOD_LEN)
+ mod->modfunc[modidx++] = mod_and_len;
+
+ if (mb.modtype & CGW_MOD_FLAGS)
+ mod->modfunc[modidx++] = mod_and_flags;
+
+ if (mb.modtype & CGW_MOD_DATA)
+ mod->modfunc[modidx++] = mod_and_fddata;
+ }
+
+ if (tb[CGW_FDMOD_OR]) {
+ nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN);
+
+ canfdframecpy(&mod->modframe.or, &mb.cf);
+ mod->modtype.or = mb.modtype;
+
+ if (mb.modtype & CGW_MOD_ID)
+ mod->modfunc[modidx++] = mod_or_id;
+
+ if (mb.modtype & CGW_MOD_LEN)
+ mod->modfunc[modidx++] = mod_or_len;
+
+ if (mb.modtype & CGW_MOD_FLAGS)
+ mod->modfunc[modidx++] = mod_or_flags;
+
+ if (mb.modtype & CGW_MOD_DATA)
+ mod->modfunc[modidx++] = mod_or_fddata;
+ }
+
+ if (tb[CGW_FDMOD_XOR]) {
+ nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN);
+
+ canfdframecpy(&mod->modframe.xor, &mb.cf);
+ mod->modtype.xor = mb.modtype;
+
+ if (mb.modtype & CGW_MOD_ID)
+ mod->modfunc[modidx++] = mod_xor_id;
+
+ if (mb.modtype & CGW_MOD_LEN)
+ mod->modfunc[modidx++] = mod_xor_len;
+
+ if (mb.modtype & CGW_MOD_FLAGS)
+ mod->modfunc[modidx++] = mod_xor_flags;
+
+ if (mb.modtype & CGW_MOD_DATA)
+ mod->modfunc[modidx++] = mod_xor_fddata;
+ }
+
+ if (tb[CGW_FDMOD_SET]) {
+ nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN);
+
+ canfdframecpy(&mod->modframe.set, &mb.cf);
+ mod->modtype.set = mb.modtype;
+
+ if (mb.modtype & CGW_MOD_ID)
+ mod->modfunc[modidx++] = mod_set_id;
+
+ if (mb.modtype & CGW_MOD_LEN)
+ mod->modfunc[modidx++] = mod_set_len;
+
+ if (mb.modtype & CGW_MOD_FLAGS)
+ mod->modfunc[modidx++] = mod_set_flags;
+
+ if (mb.modtype & CGW_MOD_DATA)
+ mod->modfunc[modidx++] = mod_set_fddata;
+ }
+ } else {
+ struct cgw_frame_mod mb;
+
+ if (tb[CGW_MOD_AND]) {
+ nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
+
+ canframecpy(&mod->modframe.and, &mb.cf);
+ mod->modtype.and = mb.modtype;
+
+ if (mb.modtype & CGW_MOD_ID)
+ mod->modfunc[modidx++] = mod_and_id;
+
+ if (mb.modtype & CGW_MOD_LEN)
+ mod->modfunc[modidx++] = mod_and_len;
+
+ if (mb.modtype & CGW_MOD_DATA)
+ mod->modfunc[modidx++] = mod_and_data;
+ }
+
+ if (tb[CGW_MOD_OR]) {
+ nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
+
+ canframecpy(&mod->modframe.or, &mb.cf);
+ mod->modtype.or = mb.modtype;
+
+ if (mb.modtype & CGW_MOD_ID)
+ mod->modfunc[modidx++] = mod_or_id;
+
+ if (mb.modtype & CGW_MOD_LEN)
+ mod->modfunc[modidx++] = mod_or_len;
+
+ if (mb.modtype & CGW_MOD_DATA)
+ mod->modfunc[modidx++] = mod_or_data;
+ }
+
+ if (tb[CGW_MOD_XOR]) {
+ nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
+
+ canframecpy(&mod->modframe.xor, &mb.cf);
+ mod->modtype.xor = mb.modtype;
+
+ if (mb.modtype & CGW_MOD_ID)
+ mod->modfunc[modidx++] = mod_xor_id;
+
+ if (mb.modtype & CGW_MOD_LEN)
+ mod->modfunc[modidx++] = mod_xor_len;
+
+ if (mb.modtype & CGW_MOD_DATA)
+ mod->modfunc[modidx++] = mod_xor_data;
+ }
+
+ if (tb[CGW_MOD_SET]) {
+ nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
+
+ canframecpy(&mod->modframe.set, &mb.cf);
+ mod->modtype.set = mb.modtype;
+
+ if (mb.modtype & CGW_MOD_ID)
+ mod->modfunc[modidx++] = mod_set_id;
+
+ if (mb.modtype & CGW_MOD_LEN)
+ mod->modfunc[modidx++] = mod_set_len;
+
+ if (mb.modtype & CGW_MOD_DATA)
+ mod->modfunc[modidx++] = mod_set_data;
+ }
+ }
+
+ /* check for checksum operations after CAN frame modifications */
+ if (modidx) {
+ if (tb[CGW_CS_CRC8]) {
+ struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]);
+
+ err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
+ c->result_idx, r);
+ if (err)
+ return err;
+
+ nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8],
+ CGW_CS_CRC8_LEN);
+
+ /* select dedicated processing function to reduce
+ * runtime operations in receive hot path.
+ */
+ if (c->from_idx < 0 || c->to_idx < 0 ||
+ c->result_idx < 0)
+ mod->csumfunc.crc8 = cgw_csum_crc8_rel;
+ else if (c->from_idx <= c->to_idx)
+ mod->csumfunc.crc8 = cgw_csum_crc8_pos;
+ else
+ mod->csumfunc.crc8 = cgw_csum_crc8_neg;
+ }
+
+ if (tb[CGW_CS_XOR]) {
+ struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]);
+
+ err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
+ c->result_idx, r);
+ if (err)
+ return err;
+
+ nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR],
+ CGW_CS_XOR_LEN);
+
+ /* select dedicated processing function to reduce
+ * runtime operations in receive hot path.
+ */
+ if (c->from_idx < 0 || c->to_idx < 0 ||
+ c->result_idx < 0)
+ mod->csumfunc.xor = cgw_csum_xor_rel;
+ else if (c->from_idx <= c->to_idx)
+ mod->csumfunc.xor = cgw_csum_xor_pos;
+ else
+ mod->csumfunc.xor = cgw_csum_xor_neg;
+ }
+
+ if (tb[CGW_MOD_UID])
+ nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32));
+ }
+
+ if (gwtype == CGW_TYPE_CAN_CAN) {
+ /* check CGW_TYPE_CAN_CAN specific attributes */
+ struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr;
+
+ memset(ccgw, 0, sizeof(*ccgw));
+
+ /* check for can_filter in attributes */
+ if (tb[CGW_FILTER])
+ nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
+ sizeof(struct can_filter));
+
+ err = -ENODEV;
+
+ /* specifying two interfaces is mandatory */
+ if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF])
+ return err;
+
+ ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]);
+ ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]);
+
+ /* both indices set to 0 for flushing all routing entries */
+ if (!ccgw->src_idx && !ccgw->dst_idx)
+ return 0;
+
+ /* only one index set to 0 is an error */
+ if (!ccgw->src_idx || !ccgw->dst_idx)
+ return err;
+ }
+
+ /* add the checks for other gwtypes here */
+
+ return 0;
+}
+
+static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ struct rtcanmsg *r;
+ struct cgw_job *gwj;
+ struct cf_mod mod;
+ struct can_can_gw ccgw;
+ u8 limhops = 0;
+ int err = 0;
+
+ if (!netlink_capable(skb, CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (nlmsg_len(nlh) < sizeof(*r))
+ return -EINVAL;
+
+ r = nlmsg_data(nlh);
+ if (r->can_family != AF_CAN)
+ return -EPFNOSUPPORT;
+
+ /* so far we only support CAN -> CAN routings */
+ if (r->gwtype != CGW_TYPE_CAN_CAN)
+ return -EINVAL;
+
+ err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
+ if (err < 0)
+ return err;
+
+ if (mod.uid) {
+ ASSERT_RTNL();
+
+ /* check for updating an existing job with identical uid */
+ hlist_for_each_entry(gwj, &net->can.cgw_list, list) {
+ if (gwj->mod.uid != mod.uid)
+ continue;
+
+ /* interfaces & filters must be identical */
+ if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
+ return -EINVAL;
+
+ /* update modifications with disabled softirq & quit */
+ local_bh_disable();
+ memcpy(&gwj->mod, &mod, sizeof(mod));
+ local_bh_enable();
+ return 0;
+ }
+ }
+
+ /* ifindex == 0 is not allowed for job creation */
+ if (!ccgw.src_idx || !ccgw.dst_idx)
+ return -ENODEV;
+
+ gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL);
+ if (!gwj)
+ return -ENOMEM;
+
+ gwj->handled_frames = 0;
+ gwj->dropped_frames = 0;
+ gwj->deleted_frames = 0;
+ gwj->flags = r->flags;
+ gwj->gwtype = r->gwtype;
+ gwj->limit_hops = limhops;
+
+ /* insert already parsed information */
+ memcpy(&gwj->mod, &mod, sizeof(mod));
+ memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw));
+
+ err = -ENODEV;
+
+ gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx);
+
+ if (!gwj->src.dev)
+ goto out;
+
+ if (gwj->src.dev->type != ARPHRD_CAN)
+ goto out;
+
+ gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx);
+
+ if (!gwj->dst.dev)
+ goto out;
+
+ if (gwj->dst.dev->type != ARPHRD_CAN)
+ goto out;
+
+ ASSERT_RTNL();
+
+ err = cgw_register_filter(net, gwj);
+ if (!err)
+ hlist_add_head_rcu(&gwj->list, &net->can.cgw_list);
+out:
+ if (err)
+ kmem_cache_free(cgw_cache, gwj);
+
+ return err;
+}
+
+static void cgw_remove_all_jobs(struct net *net)
+{
+ struct cgw_job *gwj = NULL;
+ struct hlist_node *nx;
+
+ ASSERT_RTNL();
+
+ hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
+ hlist_del(&gwj->list);
+ cgw_unregister_filter(net, gwj);
+ synchronize_rcu();
+ kmem_cache_free(cgw_cache, gwj);
+ }
+}
+
+static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ struct cgw_job *gwj = NULL;
+ struct hlist_node *nx;
+ struct rtcanmsg *r;
+ struct cf_mod mod;
+ struct can_can_gw ccgw;
+ u8 limhops = 0;
+ int err = 0;
+
+ if (!netlink_capable(skb, CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (nlmsg_len(nlh) < sizeof(*r))
+ return -EINVAL;
+
+ r = nlmsg_data(nlh);
+ if (r->can_family != AF_CAN)
+ return -EPFNOSUPPORT;
+
+ /* so far we only support CAN -> CAN routings */
+ if (r->gwtype != CGW_TYPE_CAN_CAN)
+ return -EINVAL;
+
+ err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
+ if (err < 0)
+ return err;
+
+ /* two interface indices both set to 0 => remove all entries */
+ if (!ccgw.src_idx && !ccgw.dst_idx) {
+ cgw_remove_all_jobs(net);
+ return 0;
+ }
+
+ err = -EINVAL;
+
+ ASSERT_RTNL();
+
+ /* remove only the first matching entry */
+ hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
+ if (gwj->flags != r->flags)
+ continue;
+
+ if (gwj->limit_hops != limhops)
+ continue;
+
+ /* we have a match when uid is enabled and identical */
+ if (gwj->mod.uid || mod.uid) {
+ if (gwj->mod.uid != mod.uid)
+ continue;
+ } else {
+ /* no uid => check for identical modifications */
+ if (memcmp(&gwj->mod, &mod, sizeof(mod)))
+ continue;
+ }
+
+ /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */
+ if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
+ continue;
+
+ hlist_del(&gwj->list);
+ cgw_unregister_filter(net, gwj);
+ synchronize_rcu();
+ kmem_cache_free(cgw_cache, gwj);
+ err = 0;
+ break;
+ }
+
+ return err;
+}
+
+static int __net_init cangw_pernet_init(struct net *net)
+{
+ INIT_HLIST_HEAD(&net->can.cgw_list);
+ return 0;
+}
+
+static void __net_exit cangw_pernet_exit(struct net *net)
+{
+ rtnl_lock();
+ cgw_remove_all_jobs(net);
+ rtnl_unlock();
+}
+
+static struct pernet_operations cangw_pernet_ops = {
+ .init = cangw_pernet_init,
+ .exit = cangw_pernet_exit,
+};
+
+static __init int cgw_module_init(void)
+{
+ int ret;
+
+ /* sanitize given module parameter */
+ max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS);
+
+ pr_info("can: netlink gateway - max_hops=%d\n", max_hops);
+
+ ret = register_pernet_subsys(&cangw_pernet_ops);
+ if (ret)
+ return ret;
+
+ ret = -ENOMEM;
+ cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
+ 0, 0, NULL);
+ if (!cgw_cache)
+ goto out_cache_create;
+
+ /* set notifier */
+ notifier.notifier_call = cgw_notifier;
+ ret = register_netdevice_notifier(&notifier);
+ if (ret)
+ goto out_register_notifier;
+
+ ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE,
+ NULL, cgw_dump_jobs, 0);
+ if (ret)
+ goto out_rtnl_register1;
+
+ ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE,
+ cgw_create_job, NULL, 0);
+ if (ret)
+ goto out_rtnl_register2;
+ ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE,
+ cgw_remove_job, NULL, 0);
+ if (ret)
+ goto out_rtnl_register3;
+
+ return 0;
+
+out_rtnl_register3:
+ rtnl_unregister(PF_CAN, RTM_NEWROUTE);
+out_rtnl_register2:
+ rtnl_unregister(PF_CAN, RTM_GETROUTE);
+out_rtnl_register1:
+ unregister_netdevice_notifier(&notifier);
+out_register_notifier:
+ kmem_cache_destroy(cgw_cache);
+out_cache_create:
+ unregister_pernet_subsys(&cangw_pernet_ops);
+
+ return ret;
+}
+
+static __exit void cgw_module_exit(void)
+{
+ rtnl_unregister_all(PF_CAN);
+
+ unregister_netdevice_notifier(&notifier);
+
+ unregister_pernet_subsys(&cangw_pernet_ops);
+ rcu_barrier(); /* Wait for completion of call_rcu()'s */
+
+ kmem_cache_destroy(cgw_cache);
+}
+
+module_init(cgw_module_init);
+module_exit(cgw_module_exit);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 04:31:28 +0000