![YueHaibing](/assets/img/avatar_default.png)
This patch add error path for cgw_module_init to avoid possible crash if
some error occurs.
Fixes: c1aabdf379
("can-gw: add netlink based CAN routing")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
1109 lines
27 KiB
C
1109 lines
27 KiB
C
/*
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* gw.c - CAN frame Gateway/Router/Bridge with netlink interface
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*
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* Copyright (c) 2017 Volkswagen Group Electronic Research
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Volkswagen nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* Alternatively, provided that this notice is retained in full, this
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* software may be distributed under the terms of the GNU General
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* Public License ("GPL") version 2, in which case the provisions of the
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* GPL apply INSTEAD OF those given above.
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*
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* The provided data structures and external interfaces from this code
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* are not restricted to be used by modules with a GPL compatible license.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/rculist.h>
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#include <linux/net.h>
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#include <linux/netdevice.h>
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#include <linux/if_arp.h>
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#include <linux/skbuff.h>
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#include <linux/can.h>
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#include <linux/can/core.h>
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#include <linux/can/skb.h>
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#include <linux/can/gw.h>
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#include <net/rtnetlink.h>
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#include <net/net_namespace.h>
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#include <net/sock.h>
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#define CAN_GW_VERSION "20170425"
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#define CAN_GW_NAME "can-gw"
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MODULE_DESCRIPTION("PF_CAN netlink gateway");
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MODULE_LICENSE("Dual BSD/GPL");
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MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
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MODULE_ALIAS(CAN_GW_NAME);
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#define CGW_MIN_HOPS 1
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#define CGW_MAX_HOPS 6
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#define CGW_DEFAULT_HOPS 1
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static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS;
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module_param(max_hops, uint, 0444);
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MODULE_PARM_DESC(max_hops,
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"maximum " CAN_GW_NAME " routing hops for CAN frames "
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"(valid values: " __stringify(CGW_MIN_HOPS) "-"
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__stringify(CGW_MAX_HOPS) " hops, "
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"default: " __stringify(CGW_DEFAULT_HOPS) ")");
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static struct notifier_block notifier;
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static struct kmem_cache *cgw_cache __read_mostly;
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/* structure that contains the (on-the-fly) CAN frame modifications */
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struct cf_mod {
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struct {
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struct can_frame and;
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struct can_frame or;
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struct can_frame xor;
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struct can_frame set;
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} modframe;
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struct {
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u8 and;
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u8 or;
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u8 xor;
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u8 set;
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} modtype;
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void (*modfunc[MAX_MODFUNCTIONS])(struct can_frame *cf,
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struct cf_mod *mod);
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/* CAN frame checksum calculation after CAN frame modifications */
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struct {
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struct cgw_csum_xor xor;
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struct cgw_csum_crc8 crc8;
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} csum;
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struct {
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void (*xor)(struct can_frame *cf, struct cgw_csum_xor *xor);
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void (*crc8)(struct can_frame *cf, struct cgw_csum_crc8 *crc8);
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} csumfunc;
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u32 uid;
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};
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/*
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* So far we just support CAN -> CAN routing and frame modifications.
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*
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* The internal can_can_gw structure contains data and attributes for
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* a CAN -> CAN gateway job.
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*/
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struct can_can_gw {
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struct can_filter filter;
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int src_idx;
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int dst_idx;
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};
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/* list entry for CAN gateways jobs */
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struct cgw_job {
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struct hlist_node list;
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struct rcu_head rcu;
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u32 handled_frames;
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u32 dropped_frames;
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u32 deleted_frames;
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struct cf_mod mod;
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union {
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/* CAN frame data source */
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struct net_device *dev;
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} src;
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union {
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/* CAN frame data destination */
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struct net_device *dev;
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} dst;
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union {
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struct can_can_gw ccgw;
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/* tbc */
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};
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u8 gwtype;
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u8 limit_hops;
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u16 flags;
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};
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/* modification functions that are invoked in the hot path in can_can_gw_rcv */
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#define MODFUNC(func, op) static void func(struct can_frame *cf, \
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struct cf_mod *mod) { op ; }
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MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
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MODFUNC(mod_and_dlc, cf->can_dlc &= mod->modframe.and.can_dlc)
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MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
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MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
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MODFUNC(mod_or_dlc, cf->can_dlc |= mod->modframe.or.can_dlc)
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MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
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MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
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MODFUNC(mod_xor_dlc, cf->can_dlc ^= mod->modframe.xor.can_dlc)
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MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
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MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
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MODFUNC(mod_set_dlc, cf->can_dlc = mod->modframe.set.can_dlc)
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MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
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static inline void canframecpy(struct can_frame *dst, struct can_frame *src)
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{
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/*
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* Copy the struct members separately to ensure that no uninitialized
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* data are copied in the 3 bytes hole of the struct. This is needed
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* to make easy compares of the data in the struct cf_mod.
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*/
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dst->can_id = src->can_id;
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dst->can_dlc = src->can_dlc;
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*(u64 *)dst->data = *(u64 *)src->data;
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}
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static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re)
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{
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/*
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* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
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* relative to received dlc -1 .. -8 :
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* e.g. for received dlc = 8
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* -1 => index = 7 (data[7])
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* -3 => index = 5 (data[5])
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* -8 => index = 0 (data[0])
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*/
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if (fr > -9 && fr < 8 &&
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to > -9 && to < 8 &&
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re > -9 && re < 8)
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return 0;
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else
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return -EINVAL;
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}
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static inline int calc_idx(int idx, int rx_dlc)
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{
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if (idx < 0)
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return rx_dlc + idx;
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else
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return idx;
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}
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static void cgw_csum_xor_rel(struct can_frame *cf, struct cgw_csum_xor *xor)
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{
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int from = calc_idx(xor->from_idx, cf->can_dlc);
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int to = calc_idx(xor->to_idx, cf->can_dlc);
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int res = calc_idx(xor->result_idx, cf->can_dlc);
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u8 val = xor->init_xor_val;
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int i;
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if (from < 0 || to < 0 || res < 0)
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return;
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if (from <= to) {
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for (i = from; i <= to; i++)
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val ^= cf->data[i];
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} else {
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for (i = from; i >= to; i--)
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val ^= cf->data[i];
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}
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cf->data[res] = val;
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}
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static void cgw_csum_xor_pos(struct can_frame *cf, struct cgw_csum_xor *xor)
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{
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u8 val = xor->init_xor_val;
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int i;
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for (i = xor->from_idx; i <= xor->to_idx; i++)
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val ^= cf->data[i];
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cf->data[xor->result_idx] = val;
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}
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static void cgw_csum_xor_neg(struct can_frame *cf, struct cgw_csum_xor *xor)
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{
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u8 val = xor->init_xor_val;
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int i;
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for (i = xor->from_idx; i >= xor->to_idx; i--)
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val ^= cf->data[i];
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cf->data[xor->result_idx] = val;
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}
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static void cgw_csum_crc8_rel(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
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{
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int from = calc_idx(crc8->from_idx, cf->can_dlc);
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int to = calc_idx(crc8->to_idx, cf->can_dlc);
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int res = calc_idx(crc8->result_idx, cf->can_dlc);
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u8 crc = crc8->init_crc_val;
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int i;
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if (from < 0 || to < 0 || res < 0)
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return;
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if (from <= to) {
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for (i = crc8->from_idx; i <= crc8->to_idx; i++)
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crc = crc8->crctab[crc^cf->data[i]];
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} else {
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for (i = crc8->from_idx; i >= crc8->to_idx; i--)
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crc = crc8->crctab[crc^cf->data[i]];
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}
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switch (crc8->profile) {
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case CGW_CRC8PRF_1U8:
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crc = crc8->crctab[crc^crc8->profile_data[0]];
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break;
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case CGW_CRC8PRF_16U8:
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crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]];
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break;
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case CGW_CRC8PRF_SFFID_XOR:
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crc = crc8->crctab[crc^(cf->can_id & 0xFF)^
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(cf->can_id >> 8 & 0xFF)];
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break;
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}
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cf->data[crc8->result_idx] = crc^crc8->final_xor_val;
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}
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static void cgw_csum_crc8_pos(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
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{
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u8 crc = crc8->init_crc_val;
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int i;
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for (i = crc8->from_idx; i <= crc8->to_idx; i++)
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crc = crc8->crctab[crc^cf->data[i]];
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switch (crc8->profile) {
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case CGW_CRC8PRF_1U8:
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crc = crc8->crctab[crc^crc8->profile_data[0]];
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break;
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case CGW_CRC8PRF_16U8:
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crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]];
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break;
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case CGW_CRC8PRF_SFFID_XOR:
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crc = crc8->crctab[crc^(cf->can_id & 0xFF)^
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(cf->can_id >> 8 & 0xFF)];
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break;
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}
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cf->data[crc8->result_idx] = crc^crc8->final_xor_val;
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}
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static void cgw_csum_crc8_neg(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
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{
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u8 crc = crc8->init_crc_val;
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int i;
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for (i = crc8->from_idx; i >= crc8->to_idx; i--)
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crc = crc8->crctab[crc^cf->data[i]];
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switch (crc8->profile) {
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case CGW_CRC8PRF_1U8:
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crc = crc8->crctab[crc^crc8->profile_data[0]];
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break;
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case CGW_CRC8PRF_16U8:
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crc = crc8->crctab[crc^crc8->profile_data[cf->data[1] & 0xF]];
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break;
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case CGW_CRC8PRF_SFFID_XOR:
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crc = crc8->crctab[crc^(cf->can_id & 0xFF)^
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(cf->can_id >> 8 & 0xFF)];
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break;
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}
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cf->data[crc8->result_idx] = crc^crc8->final_xor_val;
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}
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/* the receive & process & send function */
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static void can_can_gw_rcv(struct sk_buff *skb, void *data)
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{
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struct cgw_job *gwj = (struct cgw_job *)data;
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struct can_frame *cf;
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struct sk_buff *nskb;
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int modidx = 0;
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/*
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* Do not handle CAN frames routed more than 'max_hops' times.
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* In general we should never catch this delimiter which is intended
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* to cover a misconfiguration protection (e.g. circular CAN routes).
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*
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* The Controller Area Network controllers only accept CAN frames with
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* correct CRCs - which are not visible in the controller registers.
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* According to skbuff.h documentation the csum_start element for IP
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* checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY.
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* Only CAN skbs can be processed here which already have this property.
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*/
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#define cgw_hops(skb) ((skb)->csum_start)
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BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY);
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if (cgw_hops(skb) >= max_hops) {
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/* indicate deleted frames due to misconfiguration */
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gwj->deleted_frames++;
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return;
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}
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if (!(gwj->dst.dev->flags & IFF_UP)) {
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gwj->dropped_frames++;
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return;
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}
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/* is sending the skb back to the incoming interface not allowed? */
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if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
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can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex)
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return;
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/*
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* clone the given skb, which has not been done in can_rcv()
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*
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* When there is at least one modification function activated,
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* we need to copy the skb as we want to modify skb->data.
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*/
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if (gwj->mod.modfunc[0])
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nskb = skb_copy(skb, GFP_ATOMIC);
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else
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nskb = skb_clone(skb, GFP_ATOMIC);
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if (!nskb) {
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gwj->dropped_frames++;
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return;
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}
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/* put the incremented hop counter in the cloned skb */
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cgw_hops(nskb) = cgw_hops(skb) + 1;
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/* first processing of this CAN frame -> adjust to private hop limit */
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if (gwj->limit_hops && cgw_hops(nskb) == 1)
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cgw_hops(nskb) = max_hops - gwj->limit_hops + 1;
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nskb->dev = gwj->dst.dev;
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/* pointer to modifiable CAN frame */
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cf = (struct can_frame *)nskb->data;
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/* perform preprocessed modification functions if there are any */
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while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
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(*gwj->mod.modfunc[modidx++])(cf, &gwj->mod);
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/* Has the CAN frame been modified? */
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if (modidx) {
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/* get available space for the processed CAN frame type */
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int max_len = nskb->len - offsetof(struct can_frame, data);
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/* dlc may have changed, make sure it fits to the CAN frame */
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if (cf->can_dlc > max_len)
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goto out_delete;
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/* check for checksum updates in classic CAN length only */
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if (gwj->mod.csumfunc.crc8) {
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if (cf->can_dlc > 8)
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goto out_delete;
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(*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
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}
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if (gwj->mod.csumfunc.xor) {
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if (cf->can_dlc > 8)
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goto out_delete;
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(*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
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}
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}
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/* clear the skb timestamp if not configured the other way */
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if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
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nskb->tstamp = 0;
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|
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/* send to netdevice */
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if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
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gwj->dropped_frames++;
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else
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gwj->handled_frames++;
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return;
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out_delete:
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/* delete frame due to misconfiguration */
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gwj->deleted_frames++;
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kfree_skb(nskb);
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return;
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}
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|
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static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
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{
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return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
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gwj->ccgw.filter.can_mask, can_can_gw_rcv,
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gwj, "gw", NULL);
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}
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|
|
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);
|
|
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 cgw_frame_mod mb;
|
|
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->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 },
|
|
};
|
|
|
|
/* 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 cgw_frame_mod mb;
|
|
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 (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_DLC)
|
|
mod->modfunc[modidx++] = mod_and_dlc;
|
|
|
|
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_DLC)
|
|
mod->modfunc[modidx++] = mod_or_dlc;
|
|
|
|
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_DLC)
|
|
mod->modfunc[modidx++] = mod_xor_dlc;
|
|
|
|
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_DLC)
|
|
mod->modfunc[modidx++] = mod_set_dlc;
|
|
|
|
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);
|
|
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);
|
|
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);
|
|
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);
|
|
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 (rev " CAN_GW_VERSION ") 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(¬ifier);
|
|
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(¬ifier);
|
|
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(¬ifier);
|
|
|
|
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);
|