1 | /* SPDX-License-Identifier: MIT */ |
2 | /* |
3 | * Details of the "wire" protocol between Xen Store Daemon and client |
4 | * library or guest kernel. |
5 | * Copyright (C) 2005 Rusty Russell IBM Corporation |
6 | */ |
7 | |
8 | #ifndef _XS_WIRE_H |
9 | #define _XS_WIRE_H |
10 | |
11 | enum xsd_sockmsg_type |
12 | { |
13 | XS_CONTROL, |
14 | #define XS_DEBUG XS_CONTROL |
15 | XS_DIRECTORY, |
16 | XS_READ, |
17 | XS_GET_PERMS, |
18 | XS_WATCH, |
19 | XS_UNWATCH, |
20 | XS_TRANSACTION_START, |
21 | XS_TRANSACTION_END, |
22 | XS_INTRODUCE, |
23 | XS_RELEASE, |
24 | XS_GET_DOMAIN_PATH, |
25 | XS_WRITE, |
26 | XS_MKDIR, |
27 | XS_RM, |
28 | XS_SET_PERMS, |
29 | XS_WATCH_EVENT, |
30 | XS_ERROR, |
31 | XS_IS_DOMAIN_INTRODUCED, |
32 | XS_RESUME, |
33 | XS_SET_TARGET, |
34 | /* XS_RESTRICT has been removed */ |
35 | XS_RESET_WATCHES = XS_SET_TARGET + 2, |
36 | XS_DIRECTORY_PART, |
37 | |
38 | XS_TYPE_COUNT, /* Number of valid types. */ |
39 | |
40 | XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */ |
41 | }; |
42 | |
43 | #define XS_WRITE_NONE "NONE" |
44 | #define XS_WRITE_CREATE "CREATE" |
45 | #define XS_WRITE_CREATE_EXCL "CREATE|EXCL" |
46 | |
47 | /* We hand errors as strings, for portability. */ |
48 | struct xsd_errors |
49 | { |
50 | int errnum; |
51 | const char *errstring; |
52 | }; |
53 | #define XSD_ERROR(x) { x, #x } |
54 | static struct xsd_errors xsd_errors[] __attribute__((unused)) = { |
55 | XSD_ERROR(EINVAL), |
56 | XSD_ERROR(EACCES), |
57 | XSD_ERROR(EEXIST), |
58 | XSD_ERROR(EISDIR), |
59 | XSD_ERROR(ENOENT), |
60 | XSD_ERROR(ENOMEM), |
61 | XSD_ERROR(ENOSPC), |
62 | XSD_ERROR(EIO), |
63 | XSD_ERROR(ENOTEMPTY), |
64 | XSD_ERROR(ENOSYS), |
65 | XSD_ERROR(EROFS), |
66 | XSD_ERROR(EBUSY), |
67 | XSD_ERROR(EAGAIN), |
68 | XSD_ERROR(EISCONN), |
69 | XSD_ERROR(E2BIG) |
70 | }; |
71 | |
72 | struct xsd_sockmsg |
73 | { |
74 | uint32_t type; /* XS_??? */ |
75 | uint32_t req_id;/* Request identifier, echoed in daemon's response. */ |
76 | uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */ |
77 | uint32_t len; /* Length of data following this. */ |
78 | |
79 | /* Generally followed by nul-terminated string(s). */ |
80 | }; |
81 | |
82 | enum xs_watch_type |
83 | { |
84 | XS_WATCH_PATH = 0, |
85 | XS_WATCH_TOKEN |
86 | }; |
87 | |
88 | /* Inter-domain shared memory communications. */ |
89 | #define XENSTORE_RING_SIZE 1024 |
90 | typedef uint32_t XENSTORE_RING_IDX; |
91 | #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1)) |
92 | struct xenstore_domain_interface { |
93 | char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */ |
94 | char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */ |
95 | XENSTORE_RING_IDX req_cons, req_prod; |
96 | XENSTORE_RING_IDX rsp_cons, rsp_prod; |
97 | uint32_t server_features; /* Bitmap of features supported by the server */ |
98 | uint32_t connection; |
99 | uint32_t error; |
100 | }; |
101 | |
102 | /* Violating this is very bad. See docs/misc/xenstore.txt. */ |
103 | #define XENSTORE_PAYLOAD_MAX 4096 |
104 | |
105 | /* Violating these just gets you an error back */ |
106 | #define XENSTORE_ABS_PATH_MAX 3072 |
107 | #define XENSTORE_REL_PATH_MAX 2048 |
108 | |
109 | /* The ability to reconnect a ring */ |
110 | #define XENSTORE_SERVER_FEATURE_RECONNECTION 1 |
111 | /* The presence of the "error" field in the ring page */ |
112 | #define XENSTORE_SERVER_FEATURE_ERROR 2 |
113 | |
114 | /* Valid values for the connection field */ |
115 | #define XENSTORE_CONNECTED 0 /* the steady-state */ |
116 | #define XENSTORE_RECONNECT 1 /* guest has initiated a reconnect */ |
117 | |
118 | /* Valid values for the error field */ |
119 | #define XENSTORE_ERROR_NONE 0 /* No error */ |
120 | #define XENSTORE_ERROR_COMM 1 /* Communication problem */ |
121 | #define XENSTORE_ERROR_RINGIDX 2 /* Invalid ring index */ |
122 | #define XENSTORE_ERROR_PROTO 3 /* Protocol violation (payload too long) */ |
123 | |
124 | #endif /* _XS_WIRE_H */ |
125 | |