sys/arch/xen/include/xen3-public/io/netif.h

   1 /* $NetBSD: netif.h,v 1.5 2007/10/17 19:58:31 garbled Exp $ */
   2 /******************************************************************************
   3  * netif.h
   4  *
   5  * Unified network-device I/O interface for Xen guest OSes.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to
   9  * deal in the Software without restriction, including without limitation the
  10  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  11  * sell copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23  * DEALINGS IN THE SOFTWARE.
  24  *
  25  * Copyright (c) 2003-2004, Keir Fraser
  26  */
  27
  28 #ifndef __XEN_PUBLIC_IO_NETIF_H__
  29 #define __XEN_PUBLIC_IO_NETIF_H__
  30
  31 #include "ring.h"
  32 #include "../grant_table.h"
  33
  34 /*
  35  * Notifications after enqueuing any type of message should be conditional on
  36  * the appropriate req_event or rsp_event field in the shared ring.
  37  * If the client sends notification for rx requests then it should specify
  38  * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume
  39  * that it cannot safely queue packets (as it may not be kicked to send them).
  40  */
  41
  42 /*
  43  * This is the 'wire' format for packets:
  44  *  Request 1: netif_tx_request -- NETTXF_* (any flags)
  45  * [Request 2: netif_tx_extra]  (only if request 1 has NETTXF_extra_info)
  46  * [Request 3: netif_tx_extra]  (only if request 2 has XEN_NETIF_EXTRA_MORE)
  47  *  Request 4: netif_tx_request -- NETTXF_more_data
  48  *  Request 5: netif_tx_request -- NETTXF_more_data
  49  *  ...
  50  *  Request N: netif_tx_request -- 0
  51  */
  52
  53 /* Protocol checksum field is blank in the packet (hardware offload)? */
  54 #define _NETTXF_csum_blank     (0)
  55 #define  NETTXF_csum_blank     (1U<<_NETTXF_csum_blank)
  56
  57 /* Packet data has been validated against protocol checksum. */
  58 #define _NETTXF_data_validated (1)
  59 #define  NETTXF_data_validated (1U<<_NETTXF_data_validated)
  60
  61 /* Packet continues in the next request descriptor. */
  62 #define _NETTXF_more_data      (2)
  63 #define  NETTXF_more_data      (1U<<_NETTXF_more_data)
  64
  65 /* Packet to be followed by extra descriptor(s). */
  66 #define _NETTXF_extra_info     (3)
  67 #define  NETTXF_extra_info     (1U<<_NETTXF_extra_info)
  68
  69 struct netif_tx_request {
  70     grant_ref_t gref;      /* Reference to buffer page */
  71     uint16_t offset;       /* Offset within buffer page */
  72     uint16_t flags;        /* NETTXF_* */
  73     uint16_t id;           /* Echoed in response message. */
  74     uint16_t size;         /* Packet size in bytes.       */
  75 };
  76 typedef struct netif_tx_request netif_tx_request_t;
  77
  78 /* Types of netif_extra_info descriptors. */
  79 #define XEN_NETIF_EXTRA_TYPE_NONE      (0)  /* Never used - invalid */
  80 #define XEN_NETIF_EXTRA_TYPE_GSO       (1)  /* u.gso */
  81 #define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2)  /* u.mcast */
  82 #define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3)  /* u.mcast */
  83 #define XEN_NETIF_EXTRA_TYPE_MAX       (4)
  84
  85 /* netif_extra_info flags. */
  86 #define _XEN_NETIF_EXTRA_FLAG_MORE (0)
  87 #define XEN_NETIF_EXTRA_FLAG_MORE  (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
  88
  89 /* GSO types - only TCPv4 currently supported. */
  90 #define XEN_NETIF_GSO_TYPE_TCPV4        (1)
  91
  92 /*
  93  * This structure needs to fit within both netif_tx_request and
  94  * netif_rx_response for compatibility.
  95  */
  96 struct netif_extra_info {
  97     uint8_t type;  /* XEN_NETIF_EXTRA_TYPE_* */
  98     uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */
  99
 100     union {
 101         /*
 102          * XEN_NETIF_EXTRA_TYPE_GSO:
 103          */
 104         struct {
 105             /*
 106              * Maximum payload size of each segment. For example, for TCP this
 107              * is just the path MSS.
 108              */
 109             uint16_t size;
 110
 111             /*
 112              * GSO type. This determines the protocol of the packet and any
 113              * extra features required to segment the packet properly.
 114              */
 115             uint8_t type; /* XEN_NETIF_GSO_TYPE_* */
 116
 117             /* Future expansion. */
 118             uint8_t pad;
 119
 120             /*
 121              * GSO features. This specifies any extra GSO features required
 122              * to process this packet, such as ECN support for TCPv4.
 123              */
 124             uint16_t features; /* XEN_NETIF_GSO_FEAT_* */
 125         } gso;
 126
 127         /*
 128          * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}:
 129          * Backend advertises availability via 'feature-multicast-control'
 130          * xenbus node containing value '1'.
 131          * Frontend requests this feature by advertising
 132          * 'request-multicast-control' xenbus node containing value '1'.
 133          * If multicast control is requested then multicast flooding is
 134          * disabled and the frontend must explicitly register its interest
 135          * in multicast groups using dummy transmit requests containing
 136          * MCAST_{ADD,DEL} extra-info fragments.
 137          */
 138         struct {
 139             uint8_t addr[6]; /* Address to add/remove. */
 140         } mcast;
 141
 142         uint16_t pad[3];
 143     } u;
 144 };
 145 typedef struct netif_extra_info netif_extra_info_t;
 146
 147 struct netif_tx_response {
 148     uint16_t id;
 149     int16_t  status;       /* NETIF_RSP_* */
 150 };
 151 typedef struct netif_tx_response netif_tx_response_t;
 152
 153 struct netif_rx_request {
 154     uint16_t    id;        /* Echoed in response message.        */
 155     grant_ref_t gref;      /* Reference to incoming granted frame */
 156 };
 157 typedef struct netif_rx_request netif_rx_request_t;
 158
 159 /* Packet data has been validated against protocol checksum. */
 160 #define _NETRXF_data_validated (0)
 161 #define  NETRXF_data_validated (1U<<_NETRXF_data_validated)
 162
 163 /* Protocol checksum field is blank in the packet (hardware offload)? */
 164 #define _NETRXF_csum_blank     (1)
 165 #define  NETRXF_csum_blank     (1U<<_NETRXF_csum_blank)
 166
 167 /* Packet continues in the next request descriptor. */
 168 #define _NETRXF_more_data      (2)
 169 #define  NETRXF_more_data      (1U<<_NETRXF_more_data)
 170
 171 /* Packet to be followed by extra descriptor(s). */
 172 #define _NETRXF_extra_info     (3)
 173 #define  NETRXF_extra_info     (1U<<_NETRXF_extra_info)
 174
 175 struct netif_rx_response {
 176     uint16_t id;
 177     uint16_t offset;       /* Offset in page of start of received packet  */
 178     uint16_t flags;        /* NETRXF_* */
 179     int16_t  status;       /* -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */
 180 };
 181 typedef struct netif_rx_response netif_rx_response_t;
 182
 183 /*
 184  * Generate netif ring structures and types.
 185  */
 186
 187 DEFINE_RING_TYPES(netif_tx, struct netif_tx_request, struct netif_tx_response);
 188 DEFINE_RING_TYPES(netif_rx, struct netif_rx_request, struct netif_rx_response);
 189
 190 #define NETIF_RSP_DROPPED         -2
 191 #define NETIF_RSP_ERROR           -1
 192 #define NETIF_RSP_OKAY             0
 193 /* No response: used for auxiliary requests (e.g., netif_tx_extra). */
 194 #define NETIF_RSP_NULL             1
 195
 196 #endif
 197
 198 /*
 199  * Local variables:
 200  * mode: C
 201  * c-set-style: "BSD"
 202  * c-basic-offset: 4
 203  * tab-width: 4
 204  * indent-tabs-mode: nil
 205  * End:
 206  */