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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 "ring.h"
13#include "../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
50struct 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 */
74struct 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
108struct xen_netif_tx_response {
109 uint16_t id;
110 int16_t status; /* XEN_NETIF_RSP_* */
111};
112
113struct 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
138struct 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
149DEFINE_RING_TYPES(xen_netif_tx,
150 struct xen_netif_tx_request,
151 struct xen_netif_tx_response);
152DEFINE_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
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 * Older implementation of Xen network frontend / backend has an
17 * implicit dependency on the MAX_SKB_FRAGS as the maximum number of
18 * ring slots a skb can use. Netfront / netback may not work as
19 * expected when frontend and backend have different MAX_SKB_FRAGS.
20 *
21 * A better approach is to add mechanism for netfront / netback to
22 * negotiate this value. However we cannot fix all possible
23 * frontends, so we need to define a value which states the minimum
24 * slots backend must support.
25 *
26 * The minimum value derives from older Linux kernel's MAX_SKB_FRAGS
27 * (18), which is proved to work with most frontends. Any new backend
28 * which doesn't negotiate with frontend should expect frontend to
29 * send a valid packet using slots up to this value.
30 */
31#define XEN_NETIF_NR_SLOTS_MIN 18
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 * "feature-split-event-channels" is introduced to separate guest TX
43 * and RX notificaion. Backend either doesn't support this feature or
44 * advertise it via xenstore as 0 (disabled) or 1 (enabled).
45 *
46 * To make use of this feature, frontend should allocate two event
47 * channels for TX and RX, advertise them to backend as
48 * "event-channel-tx" and "event-channel-rx" respectively. If frontend
49 * doesn't want to use this feature, it just writes "event-channel"
50 * node as before.
51 */
52
53/*
54 * "feature-no-csum-offload" should be used to turn IPv4 TCP/UDP checksum
55 * offload off or on. If it is missing then the feature is assumed to be on.
56 * "feature-ipv6-csum-offload" should be used to turn IPv6 TCP/UDP checksum
57 * offload on or off. If it is missing then the feature is assumed to be off.
58 */
59
60/*
61 * "feature-gso-tcpv4" and "feature-gso-tcpv6" advertise the capability to
62 * handle large TCP packets (in IPv4 or IPv6 form respectively). Neither
63 * frontends nor backends are assumed to be capable unless the flags are
64 * present.
65 */
66
67/*
68 * This is the 'wire' format for packets:
69 * Request 1: xen_netif_tx_request -- XEN_NETTXF_* (any flags)
70 * [Request 2: xen_netif_extra_info] (only if request 1 has XEN_NETTXF_extra_info)
71 * [Request 3: xen_netif_extra_info] (only if request 2 has XEN_NETIF_EXTRA_MORE)
72 * Request 4: xen_netif_tx_request -- XEN_NETTXF_more_data
73 * Request 5: xen_netif_tx_request -- XEN_NETTXF_more_data
74 * ...
75 * Request N: xen_netif_tx_request -- 0
76 */
77
78/* Protocol checksum field is blank in the packet (hardware offload)? */
79#define _XEN_NETTXF_csum_blank (0)
80#define XEN_NETTXF_csum_blank (1U<<_XEN_NETTXF_csum_blank)
81
82/* Packet data has been validated against protocol checksum. */
83#define _XEN_NETTXF_data_validated (1)
84#define XEN_NETTXF_data_validated (1U<<_XEN_NETTXF_data_validated)
85
86/* Packet continues in the next request descriptor. */
87#define _XEN_NETTXF_more_data (2)
88#define XEN_NETTXF_more_data (1U<<_XEN_NETTXF_more_data)
89
90/* Packet to be followed by extra descriptor(s). */
91#define _XEN_NETTXF_extra_info (3)
92#define XEN_NETTXF_extra_info (1U<<_XEN_NETTXF_extra_info)
93
94#define XEN_NETIF_MAX_TX_SIZE 0xFFFF
95struct xen_netif_tx_request {
96 grant_ref_t gref; /* Reference to buffer page */
97 uint16_t offset; /* Offset within buffer page */
98 uint16_t flags; /* XEN_NETTXF_* */
99 uint16_t id; /* Echoed in response message. */
100 uint16_t size; /* Packet size in bytes. */
101};
102
103/* Types of xen_netif_extra_info descriptors. */
104#define XEN_NETIF_EXTRA_TYPE_NONE (0) /* Never used - invalid */
105#define XEN_NETIF_EXTRA_TYPE_GSO (1) /* u.gso */
106#define XEN_NETIF_EXTRA_TYPE_MAX (2)
107
108/* xen_netif_extra_info flags. */
109#define _XEN_NETIF_EXTRA_FLAG_MORE (0)
110#define XEN_NETIF_EXTRA_FLAG_MORE (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
111
112/* GSO types */
113#define XEN_NETIF_GSO_TYPE_NONE (0)
114#define XEN_NETIF_GSO_TYPE_TCPV4 (1)
115#define XEN_NETIF_GSO_TYPE_TCPV6 (2)
116
117/*
118 * This structure needs to fit within both netif_tx_request and
119 * netif_rx_response for compatibility.
120 */
121struct xen_netif_extra_info {
122 uint8_t type; /* XEN_NETIF_EXTRA_TYPE_* */
123 uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */
124
125 union {
126 struct {
127 /*
128 * Maximum payload size of each segment. For
129 * example, for TCP this is just the path MSS.
130 */
131 uint16_t size;
132
133 /*
134 * GSO type. This determines the protocol of
135 * the packet and any extra features required
136 * to segment the packet properly.
137 */
138 uint8_t type; /* XEN_NETIF_GSO_TYPE_* */
139
140 /* Future expansion. */
141 uint8_t pad;
142
143 /*
144 * GSO features. This specifies any extra GSO
145 * features required to process this packet,
146 * such as ECN support for TCPv4.
147 */
148 uint16_t features; /* XEN_NETIF_GSO_FEAT_* */
149 } gso;
150
151 uint16_t pad[3];
152 } u;
153};
154
155struct xen_netif_tx_response {
156 uint16_t id;
157 int16_t status; /* XEN_NETIF_RSP_* */
158};
159
160struct xen_netif_rx_request {
161 uint16_t id; /* Echoed in response message. */
162 grant_ref_t gref; /* Reference to incoming granted frame */
163};
164
165/* Packet data has been validated against protocol checksum. */
166#define _XEN_NETRXF_data_validated (0)
167#define XEN_NETRXF_data_validated (1U<<_XEN_NETRXF_data_validated)
168
169/* Protocol checksum field is blank in the packet (hardware offload)? */
170#define _XEN_NETRXF_csum_blank (1)
171#define XEN_NETRXF_csum_blank (1U<<_XEN_NETRXF_csum_blank)
172
173/* Packet continues in the next request descriptor. */
174#define _XEN_NETRXF_more_data (2)
175#define XEN_NETRXF_more_data (1U<<_XEN_NETRXF_more_data)
176
177/* Packet to be followed by extra descriptor(s). */
178#define _XEN_NETRXF_extra_info (3)
179#define XEN_NETRXF_extra_info (1U<<_XEN_NETRXF_extra_info)
180
181/* GSO Prefix descriptor. */
182#define _XEN_NETRXF_gso_prefix (4)
183#define XEN_NETRXF_gso_prefix (1U<<_XEN_NETRXF_gso_prefix)
184
185struct xen_netif_rx_response {
186 uint16_t id;
187 uint16_t offset; /* Offset in page of start of received packet */
188 uint16_t flags; /* XEN_NETRXF_* */
189 int16_t status; /* -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */
190};
191
192/*
193 * Generate netif ring structures and types.
194 */
195
196DEFINE_RING_TYPES(xen_netif_tx,
197 struct xen_netif_tx_request,
198 struct xen_netif_tx_response);
199DEFINE_RING_TYPES(xen_netif_rx,
200 struct xen_netif_rx_request,
201 struct xen_netif_rx_response);
202
203#define XEN_NETIF_RSP_DROPPED -2
204#define XEN_NETIF_RSP_ERROR -1
205#define XEN_NETIF_RSP_OKAY 0
206/* No response: used for auxiliary requests (e.g., xen_netif_extra_info). */
207#define XEN_NETIF_RSP_NULL 1
208
209#endif