1/******************************************************************************
2 * netif.h
3 *
4 * Unified network-device I/O interface for Xen guest OSes.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 *
24 * Copyright (c) 2003-2004, Keir Fraser
25 */
26
27#ifndef __XEN_PUBLIC_IO_NETIF_H__
28#define __XEN_PUBLIC_IO_NETIF_H__
29
30#include "ring.h"
31#include "../grant_table.h"
32
33/*
34 * Notifications after enqueuing any type of message should be conditional on
35 * the appropriate req_event or rsp_event field in the shared ring.
36 * If the client sends notification for rx requests then it should specify
37 * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume
38 * that it cannot safely queue packets (as it may not be kicked to send them).
39 */
40
41/*
42 * This is the 'wire' format for packets:
43 *  Request 1: netif_tx_request -- NETTXF_* (any flags)
44 * [Request 2: netif_tx_extra] (only if request 1 has NETTXF_extra_info)
45 * [Request 3: netif_tx_extra] (only if request 2 has XEN_NETIF_EXTRA_FLAG_MORE)
46 *  Request 4: netif_tx_request -- NETTXF_more_data
47 *  Request 5: netif_tx_request -- NETTXF_more_data
48 *  ...
49 *  Request N: netif_tx_request -- 0
50 */
51
52/* Protocol checksum field is blank in the packet (hardware offload)? */
53#define _NETTXF_csum_blank     (0)
54#define  NETTXF_csum_blank     (1U<<_NETTXF_csum_blank)
55
56/* Packet data has been validated against protocol checksum. */
57#define _NETTXF_data_validated (1)
58#define  NETTXF_data_validated (1U<<_NETTXF_data_validated)
59
60/* Packet continues in the next request descriptor. */
61#define _NETTXF_more_data      (2)
62#define  NETTXF_more_data      (1U<<_NETTXF_more_data)
63
64/* Packet to be followed by extra descriptor(s). */
65#define _NETTXF_extra_info     (3)
66#define  NETTXF_extra_info     (1U<<_NETTXF_extra_info)
67
68struct netif_tx_request {
69    grant_ref_t gref;      /* Reference to buffer page */
70    uint16_t offset;       /* Offset within buffer page */
71    uint16_t flags;        /* NETTXF_* */
72    uint16_t id;           /* Echoed in response message. */
73    uint16_t size;         /* For the first request in a packet, the packet
74			      size in bytes.  For subsequent requests, the
75			      size of that request's associated data in bytes*/
76};
77typedef struct netif_tx_request netif_tx_request_t;
78
79/* Types of netif_extra_info descriptors. */
80#define XEN_NETIF_EXTRA_TYPE_NONE      (0)  /* Never used - invalid */
81#define XEN_NETIF_EXTRA_TYPE_GSO       (1)  /* u.gso */
82#define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2)  /* u.mcast */
83#define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3)  /* u.mcast */
84#define XEN_NETIF_EXTRA_TYPE_MAX       (4)
85
86/* netif_extra_info flags. */
87#define _XEN_NETIF_EXTRA_FLAG_MORE (0)
88#define XEN_NETIF_EXTRA_FLAG_MORE  (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
89
90/* GSO types - only TCPv4 currently supported. */
91#define XEN_NETIF_GSO_TYPE_TCPV4        (1)
92
93/*
94 * This structure needs to fit within both netif_tx_request and
95 * netif_rx_response for compatibility.
96 */
97struct netif_extra_info {
98    uint8_t type;  /* XEN_NETIF_EXTRA_TYPE_* */
99    uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */
100
101    union {
102        /*
103         * XEN_NETIF_EXTRA_TYPE_GSO:
104         */
105        struct {
106            /*
107             * Maximum payload size of each segment. For example, for TCP this
108             * is just the path MSS.
109             */
110            uint16_t size;
111
112            /*
113             * GSO type. This determines the protocol of the packet and any
114             * extra features required to segment the packet properly.
115             */
116            uint8_t type; /* XEN_NETIF_GSO_TYPE_* */
117
118            /* Future expansion. */
119            uint8_t pad;
120
121            /*
122             * GSO features. This specifies any extra GSO features required
123             * to process this packet, such as ECN support for TCPv4.
124             */
125            uint16_t features; /* XEN_NETIF_GSO_FEAT_* */
126        } gso;
127
128        /*
129         * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}:
130         * Backend advertises availability via 'feature-multicast-control'
131         * xenbus node containing value '1'.
132         * Frontend requests this feature by advertising
133         * 'request-multicast-control' xenbus node containing value '1'.
134         * If multicast control is requested then multicast flooding is
135         * disabled and the frontend must explicitly register its interest
136         * in multicast groups using dummy transmit requests containing
137         * MCAST_{ADD,DEL} extra-info fragments.
138         */
139        struct {
140            uint8_t addr[6]; /* Address to add/remove. */
141        } mcast;
142
143        uint16_t pad[3];
144    } u;
145};
146typedef struct netif_extra_info netif_extra_info_t;
147
148struct netif_tx_response {
149    uint16_t id;
150    int16_t  status;       /* NETIF_RSP_* */
151};
152typedef struct netif_tx_response netif_tx_response_t;
153
154struct netif_rx_request {
155    uint16_t    id;        /* Echoed in response message.        */
156    grant_ref_t gref;      /* Reference to incoming granted frame */
157};
158typedef struct netif_rx_request netif_rx_request_t;
159
160/* Packet data has been validated against protocol checksum. */
161#define _NETRXF_data_validated (0)
162#define  NETRXF_data_validated (1U<<_NETRXF_data_validated)
163
164/* Protocol checksum field is blank in the packet (hardware offload)? */
165#define _NETRXF_csum_blank     (1)
166#define  NETRXF_csum_blank     (1U<<_NETRXF_csum_blank)
167
168/* Packet continues in the next request descriptor. */
169#define _NETRXF_more_data      (2)
170#define  NETRXF_more_data      (1U<<_NETRXF_more_data)
171
172/* Packet to be followed by extra descriptor(s). */
173#define _NETRXF_extra_info     (3)
174#define  NETRXF_extra_info     (1U<<_NETRXF_extra_info)
175
176/* GSO Prefix descriptor. */
177#define _NETRXF_gso_prefix     (4)
178#define  NETRXF_gso_prefix     (1U<<_NETRXF_gso_prefix)
179
180struct netif_rx_response {
181    uint16_t id;
182    uint16_t offset;       /* Offset in page of start of received packet  */
183    uint16_t flags;        /* NETRXF_* */
184    int16_t  status;       /* -ve: NETIF_RSP_* ; +ve: Rx'ed response size. */
185};
186typedef struct netif_rx_response netif_rx_response_t;
187
188/*
189 * Generate netif ring structures and types.
190 */
191
192DEFINE_RING_TYPES(netif_tx, struct netif_tx_request, struct netif_tx_response);
193DEFINE_RING_TYPES(netif_rx, struct netif_rx_request, struct netif_rx_response);
194
195#define NETIF_RSP_DROPPED         -2
196#define NETIF_RSP_ERROR           -1
197#define NETIF_RSP_OKAY             0
198/* No response: used for auxiliary requests (e.g., netif_tx_extra). */
199#define NETIF_RSP_NULL             1
200
201#endif
202
203/*
204 * Local variables:
205 * mode: C
206 * c-set-style: "BSD"
207 * c-basic-offset: 4
208 * tab-width: 4
209 * indent-tabs-mode: nil
210 * End:
211 */
212