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 
29 enum 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 };
52 
53 #define XS_WRITE_NONE "NONE"
54 #define XS_WRITE_CREATE "CREATE"
55 #define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
56 
57 /* We hand errors as strings, for portability. */
58 struct xsd_errors
59 {
60     int errnum;
61     const char *errstring;
62 };
63 #define XSD_ERROR(x) { x, #x }
64 /* LINTED: static unused */
65 static struct xsd_errors xsd_errors[]
66 #if defined(__GNUC__)
67 __attribute__((unused))
68 #endif
69     = {
70     XSD_ERROR(EINVAL),
71     XSD_ERROR(EACCES),
72     XSD_ERROR(EEXIST),
73     XSD_ERROR(EISDIR),
74     XSD_ERROR(ENOENT),
75     XSD_ERROR(ENOMEM),
76     XSD_ERROR(ENOSPC),
77     XSD_ERROR(EIO),
78     XSD_ERROR(ENOTEMPTY),
79     XSD_ERROR(ENOSYS),
80     XSD_ERROR(EROFS),
81     XSD_ERROR(EBUSY),
82     XSD_ERROR(EAGAIN),
83     XSD_ERROR(EISCONN)
84 };
85 
86 struct xsd_sockmsg
87 {
88     uint32_t type;  /* XS_??? */
89     uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
90     uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
91     uint32_t len;   /* Length of data following this. */
92 
93     /* Generally followed by nul-terminated string(s). */
94 };
95 
96 enum xs_watch_type
97 {
98     XS_WATCH_PATH = 0,
99     XS_WATCH_TOKEN
100 };
101 
102 /* Inter-domain shared memory communications. */
103 #define XENSTORE_RING_SIZE 1024
104 typedef uint32_t XENSTORE_RING_IDX;
105 #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
106 struct xenstore_domain_interface {
107     char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
108     char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
109     XENSTORE_RING_IDX req_cons, req_prod;
110     XENSTORE_RING_IDX rsp_cons, rsp_prod;
111 };
112 
113 /* Violating this is very bad.  See docs/misc/xenstore.txt. */
114 #define XENSTORE_PAYLOAD_MAX 4096
115 
116 /* Violating these just gets you an error back */
117 #define XENSTORE_ABS_PATH_MAX 3072
118 #define XENSTORE_REL_PATH_MAX 2048
119 
120 #endif /* _XS_WIRE_H */
121 
122 /*
123  * Local variables:
124  * mode: C
125  * c-set-style: "BSD"
126  * c-basic-offset: 4
127  * tab-width: 4
128  * indent-tabs-mode: nil
129  * End:
130  */
131