163 строки
4.5 KiB
C
163 строки
4.5 KiB
C
/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
|
|
/*
|
|
* linux/can/skb.h
|
|
*
|
|
* Definitions for the CAN network socket buffer
|
|
*
|
|
* Copyright (C) 2012 Oliver Hartkopp <socketcan@hartkopp.net>
|
|
*
|
|
*/
|
|
|
|
#ifndef _CAN_SKB_H
|
|
#define _CAN_SKB_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/can.h>
|
|
#include <net/sock.h>
|
|
|
|
void can_flush_echo_skb(struct net_device *dev);
|
|
int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
|
|
unsigned int idx, unsigned int frame_len);
|
|
struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
|
|
u8 *len_ptr, unsigned int *frame_len_ptr);
|
|
unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx,
|
|
unsigned int *frame_len_ptr);
|
|
void can_free_echo_skb(struct net_device *dev, unsigned int idx,
|
|
unsigned int *frame_len_ptr);
|
|
struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
|
|
struct sk_buff *alloc_canfd_skb(struct net_device *dev,
|
|
struct canfd_frame **cfd);
|
|
struct sk_buff *alloc_can_err_skb(struct net_device *dev,
|
|
struct can_frame **cf);
|
|
|
|
/*
|
|
* The struct can_skb_priv is used to transport additional information along
|
|
* with the stored struct can(fd)_frame that can not be contained in existing
|
|
* struct sk_buff elements.
|
|
* N.B. that this information must not be modified in cloned CAN sk_buffs.
|
|
* To modify the CAN frame content or the struct can_skb_priv content
|
|
* skb_copy() needs to be used instead of skb_clone().
|
|
*/
|
|
|
|
/**
|
|
* struct can_skb_priv - private additional data inside CAN sk_buffs
|
|
* @ifindex: ifindex of the first interface the CAN frame appeared on
|
|
* @skbcnt: atomic counter to have an unique id together with skb pointer
|
|
* @frame_len: length of CAN frame in data link layer
|
|
* @cf: align to the following CAN frame at skb->data
|
|
*/
|
|
struct can_skb_priv {
|
|
int ifindex;
|
|
int skbcnt;
|
|
unsigned int frame_len;
|
|
struct can_frame cf[];
|
|
};
|
|
|
|
static inline struct can_skb_priv *can_skb_prv(struct sk_buff *skb)
|
|
{
|
|
return (struct can_skb_priv *)(skb->head);
|
|
}
|
|
|
|
static inline void can_skb_reserve(struct sk_buff *skb)
|
|
{
|
|
skb_reserve(skb, sizeof(struct can_skb_priv));
|
|
}
|
|
|
|
static inline void can_skb_set_owner(struct sk_buff *skb, struct sock *sk)
|
|
{
|
|
/* If the socket has already been closed by user space, the
|
|
* refcount may already be 0 (and the socket will be freed
|
|
* after the last TX skb has been freed). So only increase
|
|
* socket refcount if the refcount is > 0.
|
|
*/
|
|
if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
|
|
skb->destructor = sock_efree;
|
|
skb->sk = sk;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* returns an unshared skb owned by the original sock to be echo'ed back
|
|
*/
|
|
static inline struct sk_buff *can_create_echo_skb(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *nskb;
|
|
|
|
nskb = skb_clone(skb, GFP_ATOMIC);
|
|
if (unlikely(!nskb)) {
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
|
|
can_skb_set_owner(nskb, skb->sk);
|
|
consume_skb(skb);
|
|
return nskb;
|
|
}
|
|
|
|
/* Check for outgoing skbs that have not been created by the CAN subsystem */
|
|
static inline bool can_skb_headroom_valid(struct net_device *dev,
|
|
struct sk_buff *skb)
|
|
{
|
|
/* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */
|
|
if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv)))
|
|
return false;
|
|
|
|
/* af_packet does not apply CAN skb specific settings */
|
|
if (skb->ip_summed == CHECKSUM_NONE) {
|
|
/* init headroom */
|
|
can_skb_prv(skb)->ifindex = dev->ifindex;
|
|
can_skb_prv(skb)->skbcnt = 0;
|
|
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
|
|
/* perform proper loopback on capable devices */
|
|
if (dev->flags & IFF_ECHO)
|
|
skb->pkt_type = PACKET_LOOPBACK;
|
|
else
|
|
skb->pkt_type = PACKET_HOST;
|
|
|
|
skb_reset_mac_header(skb);
|
|
skb_reset_network_header(skb);
|
|
skb_reset_transport_header(skb);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
|
|
static inline bool can_dropped_invalid_skb(struct net_device *dev,
|
|
struct sk_buff *skb)
|
|
{
|
|
const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
|
|
|
|
if (skb->protocol == htons(ETH_P_CAN)) {
|
|
if (unlikely(skb->len != CAN_MTU ||
|
|
cfd->len > CAN_MAX_DLEN))
|
|
goto inval_skb;
|
|
} else if (skb->protocol == htons(ETH_P_CANFD)) {
|
|
if (unlikely(skb->len != CANFD_MTU ||
|
|
cfd->len > CANFD_MAX_DLEN))
|
|
goto inval_skb;
|
|
} else
|
|
goto inval_skb;
|
|
|
|
if (!can_skb_headroom_valid(dev, skb))
|
|
goto inval_skb;
|
|
|
|
return false;
|
|
|
|
inval_skb:
|
|
kfree_skb(skb);
|
|
dev->stats.tx_dropped++;
|
|
return true;
|
|
}
|
|
|
|
static inline bool can_is_canfd_skb(const struct sk_buff *skb)
|
|
{
|
|
/* the CAN specific type of skb is identified by its data length */
|
|
return skb->len == CANFD_MTU;
|
|
}
|
|
|
|
#endif /* !_CAN_SKB_H */
|