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 struct xen_netif_tx_request {
  51     grant_ref_t gref;      /* Reference to buffer page */
  52     uint16_t offset;       /* Offset within buffer page */
  53     uint16_t flags;        /* XEN_NETTXF_* */
  54     uint16_t id;           /* Echoed in response message. */
  55     uint16_t size;         /* Packet size in bytes.       */
  56 };
  57
  58 /* Types of xen_netif_extra_info descriptors. */
  59 #define XEN_NETIF_EXTRA_TYPE_NONE       (0)  /* Never used - invalid */
  60 #define XEN_NETIF_EXTRA_TYPE_GSO        (1)  /* u.gso */
  61 #define XEN_NETIF_EXTRA_TYPE_MAX        (2)
  62
  63 /* xen_netif_extra_info flags. */
  64 #define _XEN_NETIF_EXTRA_FLAG_MORE      (0)
  65 #define  XEN_NETIF_EXTRA_FLAG_MORE      (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
  66
  67 /* GSO types - only TCPv4 currently supported. */
  68 #define XEN_NETIF_GSO_TYPE_TCPV4        (1)
  69
  70 /*
  71  * This structure needs to fit within both netif_tx_request and
  72  * netif_rx_response for compatibility.
  73  */
  74 struct xen_netif_extra_info {
  75         uint8_t type;  /* XEN_NETIF_EXTRA_TYPE_* */
  76         uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */
  77
  78         union {
  79                 struct {
  80                         /*
  81                          * Maximum payload size of each segment. For
  82                          * example, for TCP this is just the path MSS.
  83                          */
  84                         uint16_t size;
  85
  86                         /*
  87                          * GSO type. This determines the protocol of
  88                          * the packet and any extra features required
  89                          * to segment the packet properly.
  90                          */
  91                         uint8_t type; /* XEN_NETIF_GSO_TYPE_* */
  92
  93                         /* Future expansion. */
  94                         uint8_t pad;
  95
  96                         /*
  97                          * GSO features. This specifies any extra GSO
  98                          * features required to process this packet,
  99                          * such as ECN support for TCPv4.
 100                          */
 101                         uint16_t features; /* XEN_NETIF_GSO_FEAT_* */
 102                 } gso;
 103
 104                 uint16_t pad[3];
 105         } u;
 106 };
 107
 108 struct xen_netif_tx_response {
 109         uint16_t id;
 110         int16_t  status;       /* XEN_NETIF_RSP_* */
 111 };
 112
 113 struct xen_netif_rx_request {
 114         uint16_t    id;        /* Echoed in response message.        */
 115         grant_ref_t gref;      /* Reference to incoming granted frame */
 116 };
 117
 118 /* Packet data has been validated against protocol checksum. */
 119 #define _XEN_NETRXF_data_validated      (0)
 120 #define  XEN_NETRXF_data_validated      (1U<<_XEN_NETRXF_data_validated)
 121
 122 /* Protocol checksum field is blank in the packet (hardware offload)? */
 123 #define _XEN_NETRXF_csum_blank          (1)
 124 #define  XEN_NETRXF_csum_blank          (1U<<_XEN_NETRXF_csum_blank)
 125
 126 /* Packet continues in the next request descriptor. */
 127 #define _XEN_NETRXF_more_data           (2)
 128 #define  XEN_NETRXF_more_data           (1U<<_XEN_NETRXF_more_data)
 129
 130 /* Packet to be followed by extra descriptor(s). */
 131 #define _XEN_NETRXF_extra_info          (3)
 132 #define  XEN_NETRXF_extra_info          (1U<<_XEN_NETRXF_extra_info)
 133
 134 /* GSO Prefix descriptor. */
 135 #define _XEN_NETRXF_gso_prefix          (4)
 136 #define  XEN_NETRXF_gso_prefix          (1U<<_XEN_NETRXF_gso_prefix)
 137
 138 struct xen_netif_rx_response {
 139     uint16_t id;
 140     uint16_t offset;       /* Offset in page of start of received packet  */
 141     uint16_t flags;        /* XEN_NETRXF_* */
 142     int16_t  status;       /* -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */
 143 };
 144
 145 /*
 146  * Generate netif ring structures and types.
 147  */
 148
 149 DEFINE_RING_TYPES(xen_netif_tx,
 150                   struct xen_netif_tx_request,
 151                   struct xen_netif_tx_response);
 152 DEFINE_RING_TYPES(xen_netif_rx,
 153                   struct xen_netif_rx_request,
 154                   struct xen_netif_rx_response);
 155
 156 #define XEN_NETIF_RSP_DROPPED   -2
 157 #define XEN_NETIF_RSP_ERROR     -1
 158 #define XEN_NETIF_RSP_OKAY       0
 159 /* No response: used for auxiliary requests (e.g., xen_netif_extra_info). */
 160 #define XEN_NETIF_RSP_NULL       1
 161
 162 #endif