diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/xdp.h | 27 | ||||
| -rw-r--r-- | include/net/xdp_sock.h | 11 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 4 |
3 files changed, 39 insertions, 3 deletions
diff --git a/include/net/xdp.h b/include/net/xdp.h index 3cc6d5d84aa4..3094fccf5a88 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -6,6 +6,8 @@ #ifndef __LINUX_NET_XDP_H__ #define __LINUX_NET_XDP_H__ +#include <linux/skbuff.h> /* skb_shared_info */ + /** * DOC: XDP RX-queue information * @@ -70,13 +72,25 @@ struct xdp_buff { void *data_hard_start; unsigned long handle; struct xdp_rxq_info *rxq; + u32 frame_sz; /* frame size to deduce data_hard_end/reserved tailroom*/ }; +/* Reserve memory area at end-of data area. + * + * This macro reserves tailroom in the XDP buffer by limiting the + * XDP/BPF data access to data_hard_end. Notice same area (and size) + * is used for XDP_PASS, when constructing the SKB via build_skb(). + */ +#define xdp_data_hard_end(xdp) \ + ((xdp)->data_hard_start + (xdp)->frame_sz - \ + SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) + struct xdp_frame { void *data; u16 len; u16 headroom; - u16 metasize; + u32 metasize:8; + u32 frame_sz:24; /* Lifetime of xdp_rxq_info is limited to NAPI/enqueue time, * while mem info is valid on remote CPU. */ @@ -91,6 +105,10 @@ static inline void xdp_scrub_frame(struct xdp_frame *frame) frame->dev_rx = NULL; } +/* Avoids inlining WARN macro in fast-path */ +void xdp_warn(const char *msg, const char *func, const int line); +#define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__) + struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp); /* Convert xdp_buff to xdp_frame */ @@ -111,6 +129,12 @@ struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp) if (unlikely((headroom - metasize) < sizeof(*xdp_frame))) return NULL; + /* Catch if driver didn't reserve tailroom for skb_shared_info */ + if (unlikely(xdp->data_end > xdp_data_hard_end(xdp))) { + XDP_WARN("Driver BUG: missing reserved tailroom"); + return NULL; + } + /* Store info in top of packet */ xdp_frame = xdp->data_hard_start; @@ -118,6 +142,7 @@ struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp) xdp_frame->len = xdp->data_end - xdp->data; xdp_frame->headroom = headroom - sizeof(*xdp_frame); xdp_frame->metasize = metasize; + xdp_frame->frame_sz = xdp->frame_sz; /* rxq only valid until napi_schedule ends, convert to xdp_mem_info */ xdp_frame->mem = xdp->rxq->mem; diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index 67191ccaab85..abd72de25fa4 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -236,6 +236,12 @@ static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 address, else return address + offset; } + +static inline u32 xsk_umem_xdp_frame_sz(struct xdp_umem *umem) +{ + return umem->chunk_size_nohr + umem->headroom; +} + #else static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) { @@ -366,6 +372,11 @@ static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 handle, return 0; } +static inline u32 xsk_umem_xdp_frame_sz(struct xdp_umem *umem) +{ + return 0; +} + static inline int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) { return -EOPNOTSUPP; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 32cbf36c7729..b9b8a0f63b91 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2015,8 +2015,8 @@ union bpf_attr { * int bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta) * Description * Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is - * only possible to shrink the packet as of this writing, - * therefore *delta* must be a negative integer. + * possible to both shrink and grow the packet tail. + * Shrink done via *delta* being a negative integer. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers |