1 /* SPDX-License-Identifier: GPL-2.0 */
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_DEBUG,
14     XS_DIRECTORY,
15     XS_READ,
16     XS_GET_PERMS,
17     XS_WATCH,
18     XS_UNWATCH,
19     XS_TRANSACTION_START,
20     XS_TRANSACTION_END,
21     XS_INTRODUCE,
22     XS_RELEASE,
23     XS_GET_DOMAIN_PATH,
24     XS_WRITE,
25     XS_MKDIR,
26     XS_RM,
27     XS_SET_PERMS,
28     XS_WATCH_EVENT,
29     XS_ERROR,
30     XS_IS_DOMAIN_INTRODUCED,
31     XS_RESUME,
32     XS_SET_TARGET,
33     XS_RESTRICT,
34     XS_RESET_WATCHES,
35 };
36 
37 #define XS_WRITE_NONE "NONE"
38 #define XS_WRITE_CREATE "CREATE"
39 #define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
40 
41 /* We hand errors as strings, for portability. */
42 struct xsd_errors
43 {
44     int errnum;
45     const char *errstring;
46 };
47 #define XSD_ERROR(x) { x, #x }
48 static struct xsd_errors xsd_errors[] __attribute__((unused)) = {
49     XSD_ERROR(EINVAL),
50     XSD_ERROR(EACCES),
51     XSD_ERROR(EEXIST),
52     XSD_ERROR(EISDIR),
53     XSD_ERROR(ENOENT),
54     XSD_ERROR(ENOMEM),
55     XSD_ERROR(ENOSPC),
56     XSD_ERROR(EIO),
57     XSD_ERROR(ENOTEMPTY),
58     XSD_ERROR(ENOSYS),
59     XSD_ERROR(EROFS),
60     XSD_ERROR(EBUSY),
61     XSD_ERROR(EAGAIN),
62     XSD_ERROR(EISCONN)
63 };
64 
65 struct xsd_sockmsg
66 {
67     uint32_t type;  /* XS_??? */
68     uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
69     uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
70     uint32_t len;   /* Length of data following this. */
71 
72     /* Generally followed by nul-terminated string(s). */
73 };
74 
75 enum xs_watch_type
76 {
77     XS_WATCH_PATH = 0,
78     XS_WATCH_TOKEN
79 };
80 
81 /* Inter-domain shared memory communications. */
82 #define XENSTORE_RING_SIZE 1024
83 typedef uint32_t XENSTORE_RING_IDX;
84 #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
85 struct xenstore_domain_interface {
86     char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
87     char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
88     XENSTORE_RING_IDX req_cons, req_prod;
89     XENSTORE_RING_IDX rsp_cons, rsp_prod;
90 };
91 
92 /* Violating this is very bad.  See docs/misc/xenstore.txt. */
93 #define XENSTORE_PAYLOAD_MAX 4096
94 
95 #endif /* _XS_WIRE_H */
96