diff options
Diffstat (limited to 'include/linux/can/skb.h')
| -rw-r--r-- | include/linux/can/skb.h | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h new file mode 100644 index 000000000..1abc25a8d --- /dev/null +++ b/include/linux/can/skb.h @@ -0,0 +1,159 @@ +/* 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, + unsigned int *len_ptr, + unsigned int *frame_len_ptr); +unsigned int __must_check 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_canxl_skb(struct net_device *dev, + struct canxl_frame **cxl, + unsigned int data_len); +struct sk_buff *alloc_can_err_skb(struct net_device *dev, + struct can_frame **cf); +bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb); + +/* + * 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; +} + +static inline bool can_is_can_skb(const struct sk_buff *skb) +{ + struct can_frame *cf = (struct can_frame *)skb->data; + + /* the CAN specific type of skb is identified by its data length */ + return (skb->len == CAN_MTU && cf->len <= CAN_MAX_DLEN); +} + +static inline bool can_is_canfd_skb(const struct sk_buff *skb) +{ + struct canfd_frame *cfd = (struct canfd_frame *)skb->data; + + /* the CAN specific type of skb is identified by its data length */ + return (skb->len == CANFD_MTU && cfd->len <= CANFD_MAX_DLEN); +} + +static inline bool can_is_canxl_skb(const struct sk_buff *skb) +{ + const struct canxl_frame *cxl = (struct canxl_frame *)skb->data; + + if (skb->len < CANXL_HDR_SIZE + CANXL_MIN_DLEN || skb->len > CANXL_MTU) + return false; + + /* this also checks valid CAN XL data length boundaries */ + if (skb->len != CANXL_HDR_SIZE + cxl->len) + return false; + + return cxl->flags & CANXL_XLF; +} + +/* get length element value from can[|fd|xl]_frame structure */ +static inline unsigned int can_skb_get_len_val(struct sk_buff *skb) +{ + const struct canxl_frame *cxl = (struct canxl_frame *)skb->data; + const struct canfd_frame *cfd = (struct canfd_frame *)skb->data; + + if (can_is_canxl_skb(skb)) + return cxl->len; + + return cfd->len; +} + +/* get needed data length inside CAN frame for all frame types (RTR aware) */ +static inline unsigned int can_skb_get_data_len(struct sk_buff *skb) +{ + unsigned int len = can_skb_get_len_val(skb); + const struct can_frame *cf = (struct can_frame *)skb->data; + + /* RTR frames have an actual length of zero */ + if (can_is_can_skb(skb) && cf->can_id & CAN_RTR_FLAG) + return 0; + + return len; +} + +#endif /* !_CAN_SKB_H */ |