include/xen/interface/io/netif.h

   1 /******************************************************************************
   2  * netif.h
   3  *
   4  * Unified network-device I/O interface for Xen guest OSes.
   5  *
   6  * Copyright (c) 2003-2004, Keir Fraser
   7  */
   8
   9 #ifndef __XEN_PUBLIC_IO_NETIF_H__
  10 #define __XEN_PUBLIC_IO_NETIF_H__
  11
  12 #include <xen/interface/io/ring.h>
  13 #include <xen/interface/grant_table.h>
  14
  15 /*
  16  * Notifications after enqueuing any type of message should be conditional on
  17  * the appropriate req_event or rsp_event field in the shared ring.
  18  * If the client sends notification for rx requests then it should specify
  19  * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume
  20  * that it cannot safely queue packets (as it may not be kicked to send them).
  21  */
  22
  23 /*
  24  * This is the 'wire' format for packets:
  25  *  Request 1: xen_netif_tx_request  -- XEN_NETTXF_* (any flags)
  26  * [Request 2: xen_netif_extra_info]    (only if request 1 has XEN_NETTXF_extra_info)
  27  * [Request 3: xen_netif_extra_info]    (only if request 2 has XEN_NETIF_EXTRA_MORE)
  28  *  Request 4: xen_netif_tx_request  -- XEN_NETTXF_more_data
  29  *  Request 5: xen_netif_tx_request  -- XEN_NETTXF_more_data
  30  *  ...
  31  *  Request N: xen_netif_tx_request  -- 0
  32  */
  33
  34 /* Protocol checksum field is blank in the packet (hardware offload)? */
  35 #define _XEN_NETTXF_csum_blank          (0)
  36 #define  XEN_NETTXF_csum_blank          (1U<<_XEN_NETTXF_csum_blank)
  37
  38 /* Packet data has been validated against protocol checksum. */
  39 #define _XEN_NETTXF_data_validated      (1)
  40 #define  XEN_NETTXF_data_validated      (1U<<_XEN_NETTXF_data_validated)
  41
  42 /* Packet continues in the next request descriptor. */
  43 #define _XEN_NETTXF_more_data           (2)
  44 #define  XEN_NETTXF_more_data           (1U<<_XEN_NETTXF_more_data)
  45
  46 /* Packet to be followed by extra descriptor(s). */
  47 #define _XEN_NETTXF_extra_info          (3)
  48 #define  XEN_NETTXF_extra_info          (1U<<_XEN_NETTXF_extra_info)
  49
  50 #define XEN_NETIF_MAX_TX_SIZE 0xFFFF
  51 struct xen_netif_tx_request {
  52     grant_ref_t gref;      /* Reference to buffer page */
  53     uint16_t offset;       /* Offset within buffer page */
  54     uint16_t flags;        /* XEN_NETTXF_* */
  55     uint16_t id;           /* Echoed in response message. */
  56     uint16_t size;         /* Packet size in bytes.       */
  57 };
  58
  59 /* Types of xen_netif_extra_info descriptors. */
  60 #define XEN_NETIF_EXTRA_TYPE_NONE       (0)  /* Never used - invalid */
  61 #define XEN_NETIF_EXTRA_TYPE_GSO        (1)  /* u.gso */
  62 #define XEN_NETIF_EXTRA_TYPE_MAX        (2)
  63
  64 /* xen_netif_extra_info flags. */
  65 #define _XEN_NETIF_EXTRA_FLAG_MORE      (0)
  66 #define  XEN_NETIF_EXTRA_FLAG_MORE      (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
  67
  68 /* GSO types - only TCPv4 currently supported. */
  69 #define XEN_NETIF_GSO_TYPE_TCPV4        (1)
  70
  71 /*
  72  * This structure needs to fit within both netif_tx_request and
  73  * netif_rx_response for compatibility.
  74  */
  75 struct xen_netif_extra_info {
  76         uint8_t type;  /* XEN_NETIF_EXTRA_TYPE_* */
  77         uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */
  78
  79         union {
  80                 struct {
  81                         /*
  82                          * Maximum payload size of each segment. For
  83                          * example, for TCP this is just the path MSS.
  84                          */
  85                         uint16_t size;
  86
  87                         /*
  88                          * GSO type. This determines the protocol of
  89                          * the packet and any extra features required
  90                          * to segment the packet properly.
  91                          */
  92                         uint8_t type; /* XEN_NETIF_GSO_TYPE_* */
  93
  94                         /* Future expansion. */
  95                         uint8_t pad;
  96
  97                         /*
  98                          * GSO features. This specifies any extra GSO
  99                          * features required to process this packet,
 100                          * such as ECN support for TCPv4.
 101                          */
 102                         uint16_t features; /* XEN_NETIF_GSO_FEAT_* */
 103                 } gso;
 104
 105                 uint16_t pad[3];
 106         } u;
 107 };
 108
 109 struct xen_netif_tx_response {
 110         uint16_t id;
 111         int16_t  status;       /* XEN_NETIF_RSP_* */
 112 };
 113
 114 struct xen_netif_rx_request {
 115         uint16_t    id;        /* Echoed in response message.        */
 116         grant_ref_t gref;      /* Reference to incoming granted frame */
 117 };
 118
 119 /* Packet data has been validated against protocol checksum. */
 120 #define _XEN_NETRXF_data_validated      (0)
 121 #define  XEN_NETRXF_data_validated      (1U<<_XEN_NETRXF_data_validated)
 122
 123 /* Protocol checksum field is blank in the packet (hardware offload)? */
 124 #define _XEN_NETRXF_csum_blank          (1)
 125 #define  XEN_NETRXF_csum_blank          (1U<<_XEN_NETRXF_csum_blank)
 126
 127 /* Packet continues in the next request descriptor. */
 128 #define _XEN_NETRXF_more_data           (2)
 129 #define  XEN_NETRXF_more_data           (1U<<_XEN_NETRXF_more_data)
 130
 131 /* Packet to be followed by extra descriptor(s). */
 132 #define _XEN_NETRXF_extra_info          (3)
 133 #define  XEN_NETRXF_extra_info          (1U<<_XEN_NETRXF_extra_info)
 134
 135 /* GSO Prefix descriptor. */
 136 #define _XEN_NETRXF_gso_prefix          (4)
 137 #define  XEN_NETRXF_gso_prefix          (1U<<_XEN_NETRXF_gso_prefix)
 138
 139 struct xen_netif_rx_response {
 140     uint16_t id;
 141     uint16_t offset;       /* Offset in page of start of received packet  */
 142     uint16_t flags;        /* XEN_NETRXF_* */
 143     int16_t  status;       /* -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */
 144 };
 145
 146 /*
 147  * Generate netif ring structures and types.
 148  */
 149
 150 DEFINE_RING_TYPES(xen_netif_tx,
 151                   struct xen_netif_tx_request,
 152                   struct xen_netif_tx_response);
 153 DEFINE_RING_TYPES(xen_netif_rx,
 154                   struct xen_netif_rx_request,
 155                   struct xen_netif_rx_response);
 156
 157 #define XEN_NETIF_RSP_DROPPED   -2
 158 #define XEN_NETIF_RSP_ERROR     -1
 159 #define XEN_NETIF_RSP_OKAY       0
 160 /* No response: used for auxiliary requests (e.g., xen_netif_extra_info). */
 161 #define XEN_NETIF_RSP_NULL       1
 162
 163 #endif