xref: /illumos-gate/usr/src/uts/common/xen/public/io/netif.h (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 
68 struct 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 };
75 typedef 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  */
93 struct 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 
125 struct netif_tx_response {
126     uint16_t id;
127     int16_t  status;       /* NETIF_RSP_* */
128 };
129 typedef struct netif_tx_response netif_tx_response_t;
130 
131 struct netif_rx_request {
132     uint16_t    id;        /* Echoed in response message.        */
133     grant_ref_t gref;      /* Reference to incoming granted frame */
134 };
135 typedef 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 
153 struct 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 };
159 typedef struct netif_rx_response netif_rx_response_t;
160 
161 /*
162  * Generate netif ring structures and types.
163  */
164 
165 DEFINE_RING_TYPES(netif_tx, struct netif_tx_request, struct netif_tx_response);
166 DEFINE_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