1 /* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
5 * Definitions for the CAN network socket buffer
7 * Copyright (C) 2012 Oliver Hartkopp <socketcan@hartkopp.net>
14 #include <linux/types.h>
15 #include <linux/skbuff.h>
16 #include <linux/can.h>
19 void can_flush_echo_skb(struct net_device *dev);
20 int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
21 unsigned int idx, unsigned int frame_len);
22 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
23 u8 *len_ptr, unsigned int *frame_len_ptr);
24 unsigned int __must_check can_get_echo_skb(struct net_device *dev,
26 unsigned int *frame_len_ptr);
27 void can_free_echo_skb(struct net_device *dev, unsigned int idx,
28 unsigned int *frame_len_ptr);
29 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
30 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
31 struct canfd_frame **cfd);
32 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
33 struct can_frame **cf);
34 bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb);
37 * The struct can_skb_priv is used to transport additional information along
38 * with the stored struct can(fd)_frame that can not be contained in existing
39 * struct sk_buff elements.
40 * N.B. that this information must not be modified in cloned CAN sk_buffs.
41 * To modify the CAN frame content or the struct can_skb_priv content
42 * skb_copy() needs to be used instead of skb_clone().
46 * struct can_skb_priv - private additional data inside CAN sk_buffs
47 * @ifindex: ifindex of the first interface the CAN frame appeared on
48 * @skbcnt: atomic counter to have an unique id together with skb pointer
49 * @frame_len: length of CAN frame in data link layer
50 * @cf: align to the following CAN frame at skb->data
55 unsigned int frame_len;
56 struct can_frame cf[];
59 static inline struct can_skb_priv *can_skb_prv(struct sk_buff *skb)
61 return (struct can_skb_priv *)(skb->head);
64 static inline void can_skb_reserve(struct sk_buff *skb)
66 skb_reserve(skb, sizeof(struct can_skb_priv));
69 static inline void can_skb_set_owner(struct sk_buff *skb, struct sock *sk)
71 /* If the socket has already been closed by user space, the
72 * refcount may already be 0 (and the socket will be freed
73 * after the last TX skb has been freed). So only increase
74 * socket refcount if the refcount is > 0.
76 if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
77 skb->destructor = sock_efree;
83 * returns an unshared skb owned by the original sock to be echo'ed back
85 static inline struct sk_buff *can_create_echo_skb(struct sk_buff *skb)
89 nskb = skb_clone(skb, GFP_ATOMIC);
90 if (unlikely(!nskb)) {
95 can_skb_set_owner(nskb, skb->sk);
100 static inline bool can_is_can_skb(const struct sk_buff *skb)
102 struct can_frame *cf = (struct can_frame *)skb->data;
104 /* the CAN specific type of skb is identified by its data length */
105 return (skb->len == CAN_MTU && cf->len <= CAN_MAX_DLEN);
108 static inline bool can_is_canfd_skb(const struct sk_buff *skb)
110 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
112 /* the CAN specific type of skb is identified by its data length */
113 return (skb->len == CANFD_MTU && cfd->len <= CANFD_MAX_DLEN);
116 #endif /* !_CAN_SKB_H */