1/*
2 * Details of the "wire" protocol between Xen Store Daemon and client
3 * library or guest kernel.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a copy
6 * of this software and associated documentation files (the "Software"), to
7 * deal in the Software without restriction, including without limitation the
8 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
9 * sell copies of the Software, and to permit persons to whom the Software is
10 * furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Copyright (C) 2005 Rusty Russell IBM Corporation
24 */
25
26#ifndef _XS_WIRE_H
27#define _XS_WIRE_H
28
29enum xsd_sockmsg_type
30{
31    XS_CONTROL,
32#define XS_DEBUG XS_CONTROL
33    XS_DIRECTORY,
34    XS_READ,
35    XS_GET_PERMS,
36    XS_WATCH,
37    XS_UNWATCH,
38    XS_TRANSACTION_START,
39    XS_TRANSACTION_END,
40    XS_INTRODUCE,
41    XS_RELEASE,
42    XS_GET_DOMAIN_PATH,
43    XS_WRITE,
44    XS_MKDIR,
45    XS_RM,
46    XS_SET_PERMS,
47    XS_WATCH_EVENT,
48    XS_ERROR,
49    XS_IS_DOMAIN_INTRODUCED,
50    XS_RESUME,
51    XS_SET_TARGET,
52    /* XS_RESTRICT has been removed */
53    XS_RESET_WATCHES = XS_SET_TARGET + 2,
54    XS_DIRECTORY_PART,
55
56    XS_TYPE_COUNT,      /* Number of valid types. */
57
58    XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */
59};
60
61#define XS_WRITE_NONE "NONE"
62#define XS_WRITE_CREATE "CREATE"
63#define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
64
65/* We hand errors as strings, for portability. */
66struct xsd_errors
67{
68    int errnum;
69    const char *errstring;
70};
71#ifdef EINVAL
72#define XSD_ERROR(x) { x, #x }
73/* LINTED: static unused */
74static struct xsd_errors xsd_errors[]
75#if defined(__GNUC__)
76__attribute__((unused))
77#endif
78    = {
79    XSD_ERROR(EINVAL),
80    XSD_ERROR(EACCES),
81    XSD_ERROR(EEXIST),
82    XSD_ERROR(EISDIR),
83    XSD_ERROR(ENOENT),
84    XSD_ERROR(ENOMEM),
85    XSD_ERROR(ENOSPC),
86    XSD_ERROR(EIO),
87    XSD_ERROR(ENOTEMPTY),
88    XSD_ERROR(ENOSYS),
89    XSD_ERROR(EROFS),
90    XSD_ERROR(EBUSY),
91    XSD_ERROR(EAGAIN),
92    XSD_ERROR(EISCONN),
93    XSD_ERROR(E2BIG)
94};
95#endif
96
97struct xsd_sockmsg
98{
99    uint32_t type;  /* XS_??? */
100    uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
101    uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
102    uint32_t len;   /* Length of data following this. */
103
104    /* Generally followed by nul-terminated string(s). */
105};
106
107enum xs_watch_type
108{
109    XS_WATCH_PATH = 0,
110    XS_WATCH_TOKEN
111};
112
113/*
114 * `incontents 150 xenstore_struct XenStore wire protocol.
115 *
116 * Inter-domain shared memory communications. */
117#define XENSTORE_RING_SIZE 1024
118typedef uint32_t XENSTORE_RING_IDX;
119#define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
120struct xenstore_domain_interface {
121    char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
122    char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
123    XENSTORE_RING_IDX req_cons, req_prod;
124    XENSTORE_RING_IDX rsp_cons, rsp_prod;
125    uint32_t server_features; /* Bitmap of features supported by the server */
126    uint32_t connection;
127};
128
129/* Violating this is very bad.  See docs/misc/xenstore.txt. */
130#define XENSTORE_PAYLOAD_MAX 4096
131
132/* Violating these just gets you an error back */
133#define XENSTORE_ABS_PATH_MAX 3072
134#define XENSTORE_REL_PATH_MAX 2048
135
136/* The ability to reconnect a ring */
137#define XENSTORE_SERVER_FEATURE_RECONNECTION 1
138
139/* Valid values for the connection field */
140#define XENSTORE_CONNECTED 0 /* the steady-state */
141#define XENSTORE_RECONNECT 1 /* guest has initiated a reconnect */
142
143#endif /* _XS_WIRE_H */
144
145/*
146 * Local variables:
147 * mode: C
148 * c-file-style: "BSD"
149 * c-basic-offset: 4
150 * tab-width: 4
151 * indent-tabs-mode: nil
152 * End:
153 */
154