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_DEBUG,
32    XS_DIRECTORY,
33    XS_READ,
34    XS_GET_PERMS,
35    XS_WATCH,
36    XS_UNWATCH,
37    XS_TRANSACTION_START,
38    XS_TRANSACTION_END,
39    XS_INTRODUCE,
40    XS_RELEASE,
41    XS_GET_DOMAIN_PATH,
42    XS_WRITE,
43    XS_MKDIR,
44    XS_RM,
45    XS_SET_PERMS,
46    XS_WATCH_EVENT,
47    XS_ERROR,
48    XS_IS_DOMAIN_INTRODUCED,
49    XS_RESUME,
50    XS_SET_TARGET,
51    XS_RESTRICT,
52    XS_RESET_WATCHES,
53
54    XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */
55};
56
57#define XS_WRITE_NONE "NONE"
58#define XS_WRITE_CREATE "CREATE"
59#define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
60
61/* We hand errors as strings, for portability. */
62struct xsd_errors
63{
64    int errnum;
65    const char *errstring;
66};
67#ifdef EINVAL
68#define XSD_ERROR(x) { x, #x }
69/* LINTED: static unused */
70static struct xsd_errors xsd_errors[]
71#if defined(__GNUC__)
72__attribute__((unused))
73#endif
74    = {
75    XSD_ERROR(EINVAL),
76    XSD_ERROR(EACCES),
77    XSD_ERROR(EEXIST),
78    XSD_ERROR(EISDIR),
79    XSD_ERROR(ENOENT),
80    XSD_ERROR(ENOMEM),
81    XSD_ERROR(ENOSPC),
82    XSD_ERROR(EIO),
83    XSD_ERROR(ENOTEMPTY),
84    XSD_ERROR(ENOSYS),
85    XSD_ERROR(EROFS),
86    XSD_ERROR(EBUSY),
87    XSD_ERROR(EAGAIN),
88    XSD_ERROR(EISCONN),
89    XSD_ERROR(E2BIG)
90};
91#endif
92
93struct xsd_sockmsg
94{
95    uint32_t type;  /* XS_??? */
96    uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
97    uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
98    uint32_t len;   /* Length of data following this. */
99
100    /* Generally followed by nul-terminated string(s). */
101};
102
103enum xs_watch_type
104{
105    XS_WATCH_PATH = 0,
106    XS_WATCH_TOKEN
107};
108
109/*
110 * `incontents 150 xenstore_struct XenStore wire protocol.
111 *
112 * Inter-domain shared memory communications. */
113#define XENSTORE_RING_SIZE 1024
114typedef uint32_t XENSTORE_RING_IDX;
115#define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
116struct xenstore_domain_interface {
117    char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
118    char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
119    XENSTORE_RING_IDX req_cons, req_prod;
120    XENSTORE_RING_IDX rsp_cons, rsp_prod;
121    uint32_t server_features; /* Bitmap of features supported by the server */
122    uint32_t connection;
123};
124
125/* Violating this is very bad.  See docs/misc/xenstore.txt. */
126#define XENSTORE_PAYLOAD_MAX 4096
127
128/* Violating these just gets you an error back */
129#define XENSTORE_ABS_PATH_MAX 3072
130#define XENSTORE_REL_PATH_MAX 2048
131
132/* The ability to reconnect a ring */
133#define XENSTORE_SERVER_FEATURE_RECONNECTION 1
134
135/* Valid values for the connection field */
136#define XENSTORE_CONNECTED 0 /* the steady-state */
137#define XENSTORE_RECONNECT 1 /* guest has initiated a reconnect */
138
139#endif /* _XS_WIRE_H */
140
141/*
142 * Local variables:
143 * mode: C
144 * c-file-style: "BSD"
145 * c-basic-offset: 4
146 * tab-width: 4
147 * indent-tabs-mode: nil
148 * End:
149 */
150