netif.h revision 181624 
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_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;         /* Packet size in bytes.       */
74};
75typedef struct netif_tx_request netif_tx_request_t;
76
77/* Types of netif_extra_info descriptors. */
78#define XEN_NETIF_EXTRA_TYPE_NONE  (0)  /* Never used - invalid */
79#define XEN_NETIF_EXTRA_TYPE_GSO   (1)  /* u.gso */
80#define XEN_NETIF_EXTRA_TYPE_MAX   (2)
81
82/* netif_extra_info flags. */
83#define _XEN_NETIF_EXTRA_FLAG_MORE (0)
84#define XEN_NETIF_EXTRA_FLAG_MORE  (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
85
86/* GSO types - only TCPv4 currently supported. */
87#define XEN_NETIF_GSO_TYPE_TCPV4        (1)
88
89/*
90 * This structure needs to fit within both netif_tx_request and
91 * netif_rx_response for compatibility.
92 */
93struct netif_extra_info {
94    uint8_t type;  /* XEN_NETIF_EXTRA_TYPE_* */
95    uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */
96
97    union {
98        struct {
99            /*
100             * Maximum payload size of each segment. For example, for TCP this
101             * is just the path MSS.
102             */
103            uint16_t size;
104
105            /*
106             * GSO type. This determines the protocol of the packet and any
107             * extra features required to segment the packet properly.
108             */
109            uint8_t type; /* XEN_NETIF_GSO_TYPE_* */
110
111            /* Future expansion. */
112            uint8_t pad;
113
114            /*
115             * GSO features. This specifies any extra GSO features required
116             * to process this packet, such as ECN support for TCPv4.
117             */
118            uint16_t features; /* XEN_NETIF_GSO_FEAT_* */
119        } gso;
120
121        uint16_t pad[3];
122    } u;
123};
124
125struct netif_tx_response {
126    uint16_t id;
127    int16_t  status;       /* NETIF_RSP_* */
128};
129typedef struct netif_tx_response netif_tx_response_t;
130
131struct netif_rx_request {
132    uint16_t    id;        /* Echoed in response message.        */
133    grant_ref_t gref;      /* Reference to incoming granted frame */
134};
135typedef struct netif_rx_request netif_rx_request_t;
136
137/* Packet data has been validated against protocol checksum. */
138#define _NETRXF_data_validated (0)
139#define  NETRXF_data_validated (1U<<_NETRXF_data_validated)
140
141/* Protocol checksum field is blank in the packet (hardware offload)? */
142#define _NETRXF_csum_blank     (1)
143#define  NETRXF_csum_blank     (1U<<_NETRXF_csum_blank)
144
145/* Packet continues in the next request descriptor. */
146#define _NETRXF_more_data      (2)
147#define  NETRXF_more_data      (1U<<_NETRXF_more_data)
148
149/* Packet to be followed by extra descriptor(s). */
150#define _NETRXF_extra_info     (3)
151#define  NETRXF_extra_info     (1U<<_NETRXF_extra_info)
152
153struct netif_rx_response {
154    uint16_t id;
155    uint16_t offset;       /* Offset in page of start of received packet  */
156    uint16_t flags;        /* NETRXF_* */
157    int16_t  status;       /* -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */
158};
159typedef struct netif_rx_response netif_rx_response_t;
160
161/*
162 * Generate netif ring structures and types.
163 */
164
165DEFINE_RING_TYPES(netif_tx, struct netif_tx_request, struct netif_tx_response);
166DEFINE_RING_TYPES(netif_rx, struct netif_rx_request, struct netif_rx_response);
167
168#define NETIF_RSP_DROPPED         -2
169#define NETIF_RSP_ERROR           -1
170#define NETIF_RSP_OKAY             0
171/* No response: used for auxiliary requests (e.g., netif_tx_extra). */
172#define NETIF_RSP_NULL             1
173
174#endif
175
176/*
177 * Local variables:
178 * mode: C
179 * c-set-style: "BSD"
180 * c-basic-offset: 4
181 * tab-width: 4
182 * indent-tabs-mode: nil
183 * End:
184 */
185