include/uapi/linux/if_xdp.h

   1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2 /*
   3  * if_xdp: XDP socket user-space interface
   4  * Copyright(c) 2018 Intel Corporation.
   5  *
   6  * Author(s): Björn Töpel <bjorn.topel@intel.com>
   7  *            Magnus Karlsson <magnus.karlsson@intel.com>
   8  */
   9
  10 #ifndef _LINUX_IF_XDP_H
  11 #define _LINUX_IF_XDP_H
  12
  13 #include <linux/types.h>
  14
  15 /* Options for the sxdp_flags field */
  16 #define XDP_SHARED_UMEM (1 << 0)
  17 #define XDP_COPY        (1 << 1) /* Force copy-mode */
  18 #define XDP_ZEROCOPY    (1 << 2) /* Force zero-copy mode */
  19 /* If this option is set, the driver might go sleep and in that case
  20  * the XDP_RING_NEED_WAKEUP flag in the fill and/or Tx rings will be
  21  * set. If it is set, the application need to explicitly wake up the
  22  * driver with a poll() (Rx and Tx) or sendto() (Tx only). If you are
  23  * running the driver and the application on the same core, you should
  24  * use this option so that the kernel will yield to the user space
  25  * application.
  26  */
  27 #define XDP_USE_NEED_WAKEUP (1 << 3)
  28 /* By setting this option, userspace application indicates that it can
  29  * handle multiple descriptors per packet thus enabling AF_XDP to split
  30  * multi-buffer XDP frames into multiple Rx descriptors. Without this set
  31  * such frames will be dropped.
  32  */
  33 #define XDP_USE_SG      (1 << 4)
  34
  35 /* Flags for xsk_umem_config flags */
  36 #define XDP_UMEM_UNALIGNED_CHUNK_FLAG   (1 << 0)
  37
  38 /* Force checksum calculation in software. Can be used for testing or
  39  * working around potential HW issues. This option causes performance
  40  * degradation and only works in XDP_COPY mode.
  41  */
  42 #define XDP_UMEM_TX_SW_CSUM             (1 << 1)
  43
  44 /* Request to reserve tx_metadata_len bytes of per-chunk metadata.
  45  */
  46 #define XDP_UMEM_TX_METADATA_LEN        (1 << 2)
  47
  48 struct sockaddr_xdp {
  49         __u16 sxdp_family;
  50         __u16 sxdp_flags;
  51         __u32 sxdp_ifindex;
  52         __u32 sxdp_queue_id;
  53         __u32 sxdp_shared_umem_fd;
  54 };
  55
  56 /* XDP_RING flags */
  57 #define XDP_RING_NEED_WAKEUP (1 << 0)
  58
  59 struct xdp_ring_offset {
  60         __u64 producer;
  61         __u64 consumer;
  62         __u64 desc;
  63         __u64 flags;
  64 };
  65
  66 struct xdp_mmap_offsets {
  67         struct xdp_ring_offset rx;
  68         struct xdp_ring_offset tx;
  69         struct xdp_ring_offset fr; /* Fill */
  70         struct xdp_ring_offset cr; /* Completion */
  71 };
  72
  73 /* XDP socket options */
  74 #define XDP_MMAP_OFFSETS                1
  75 #define XDP_RX_RING                     2
  76 #define XDP_TX_RING                     3
  77 #define XDP_UMEM_REG                    4
  78 #define XDP_UMEM_FILL_RING              5
  79 #define XDP_UMEM_COMPLETION_RING        6
  80 #define XDP_STATISTICS                  7
  81 #define XDP_OPTIONS                     8
  82
  83 struct xdp_umem_reg {
  84         __u64 addr; /* Start of packet data area */
  85         __u64 len; /* Length of packet data area */
  86         __u32 chunk_size;
  87         __u32 headroom;
  88         __u32 flags;
  89         __u32 tx_metadata_len;
  90 };
  91
  92 struct xdp_statistics {
  93         __u64 rx_dropped; /* Dropped for other reasons */
  94         __u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
  95         __u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
  96         __u64 rx_ring_full; /* Dropped due to rx ring being full */
  97         __u64 rx_fill_ring_empty_descs; /* Failed to retrieve item from fill ring */
  98         __u64 tx_ring_empty_descs; /* Failed to retrieve item from tx ring */
  99 };
 100
 101 struct xdp_options {
 102         __u32 flags;
 103 };
 104
 105 /* Flags for the flags field of struct xdp_options */
 106 #define XDP_OPTIONS_ZEROCOPY (1 << 0)
 107
 108 /* Pgoff for mmaping the rings */
 109 #define XDP_PGOFF_RX_RING                         0
 110 #define XDP_PGOFF_TX_RING                0x80000000
 111 #define XDP_UMEM_PGOFF_FILL_RING        0x100000000ULL
 112 #define XDP_UMEM_PGOFF_COMPLETION_RING  0x180000000ULL
 113
 114 /* Masks for unaligned chunks mode */
 115 #define XSK_UNALIGNED_BUF_OFFSET_SHIFT 48
 116 #define XSK_UNALIGNED_BUF_ADDR_MASK \
 117         ((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
 118
 119 /* Request transmit timestamp. Upon completion, put it into tx_timestamp
 120  * field of struct xsk_tx_metadata.
 121  */
 122 #define XDP_TXMD_FLAGS_TIMESTAMP                (1 << 0)
 123
 124 /* Request transmit checksum offload. Checksum start position and offset
 125  * are communicated via csum_start and csum_offset fields of struct
 126  * xsk_tx_metadata.
 127  */
 128 #define XDP_TXMD_FLAGS_CHECKSUM                 (1 << 1)
 129
 130 /* AF_XDP offloads request. 'request' union member is consumed by the driver
 131  * when the packet is being transmitted. 'completion' union member is
 132  * filled by the driver when the transmit completion arrives.
 133  */
 134 struct xsk_tx_metadata {
 135         __u64 flags;
 136
 137         union {
 138                 struct {
 139                         /* XDP_TXMD_FLAGS_CHECKSUM */
 140
 141                         /* Offset from desc->addr where checksumming should start. */
 142                         __u16 csum_start;
 143                         /* Offset from csum_start where checksum should be stored. */
 144                         __u16 csum_offset;
 145                 } request;
 146
 147                 struct {
 148                         /* XDP_TXMD_FLAGS_TIMESTAMP */
 149                         __u64 tx_timestamp;
 150                 } completion;
 151         };
 152 };
 153
 154 /* Rx/Tx descriptor */
 155 struct xdp_desc {
 156         __u64 addr;
 157         __u32 len;
 158         __u32 options;
 159 };
 160
 161 /* UMEM descriptor is __u64 */
 162
 163 /* Flag indicating that the packet continues with the buffer pointed out by the
 164  * next frame in the ring. The end of the packet is signalled by setting this
 165  * bit to zero. For single buffer packets, every descriptor has 'options' set
 166  * to 0 and this maintains backward compatibility.
 167  */
 168 #define XDP_PKT_CONTD (1 << 0)
 169
 170 /* TX packet carries valid metadata. */
 171 #define XDP_TX_METADATA (1 << 1)
 172
 173 #endif /* _LINUX_IF_XDP_H */