1 /*
2  * Details of the "wire" protocol between Xen Store Daemon and client
3  * library or guest kernel.
4  * Copyright (C) 2005 Rusty Russell IBM Corporation
5  */
6 
7 #ifndef _XS_WIRE_H
8 #define _XS_WIRE_H
9 
10 enum xsd_sockmsg_type
11 {
12     XS_DEBUG,
13     XS_DIRECTORY,
14     XS_READ,
15     XS_GET_PERMS,
16     XS_WATCH,
17     XS_UNWATCH,
18     XS_TRANSACTION_START,
19     XS_TRANSACTION_END,
20     XS_INTRODUCE,
21     XS_RELEASE,
22     XS_GET_DOMAIN_PATH,
23     XS_WRITE,
24     XS_MKDIR,
25     XS_RM,
26     XS_SET_PERMS,
27     XS_WATCH_EVENT,
28     XS_ERROR,
29     XS_IS_DOMAIN_INTRODUCED,
30     XS_RESUME,
31     XS_SET_TARGET,
32     XS_RESTRICT
33 };
34 
35 #define XS_WRITE_NONE "NONE"
36 #define XS_WRITE_CREATE "CREATE"
37 #define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
38 
39 /* We hand errors as strings, for portability. */
40 struct xsd_errors
41 {
42     int errnum;
43     const char *errstring;
44 };
45 #define XSD_ERROR(x) { x, #x }
46 static struct xsd_errors xsd_errors[] __attribute__((unused)) = {
47     XSD_ERROR(EINVAL),
48     XSD_ERROR(EACCES),
49     XSD_ERROR(EEXIST),
50     XSD_ERROR(EISDIR),
51     XSD_ERROR(ENOENT),
52     XSD_ERROR(ENOMEM),
53     XSD_ERROR(ENOSPC),
54     XSD_ERROR(EIO),
55     XSD_ERROR(ENOTEMPTY),
56     XSD_ERROR(ENOSYS),
57     XSD_ERROR(EROFS),
58     XSD_ERROR(EBUSY),
59     XSD_ERROR(EAGAIN),
60     XSD_ERROR(EISCONN)
61 };
62 
63 struct xsd_sockmsg
64 {
65     uint32_t type;  /* XS_??? */
66     uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
67     uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
68     uint32_t len;   /* Length of data following this. */
69 
70     /* Generally followed by nul-terminated string(s). */
71 };
72 
73 enum xs_watch_type
74 {
75     XS_WATCH_PATH = 0,
76     XS_WATCH_TOKEN
77 };
78 
79 /* Inter-domain shared memory communications. */
80 #define XENSTORE_RING_SIZE 1024
81 typedef uint32_t XENSTORE_RING_IDX;
82 #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
83 struct xenstore_domain_interface {
84     char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
85     char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
86     XENSTORE_RING_IDX req_cons, req_prod;
87     XENSTORE_RING_IDX rsp_cons, rsp_prod;
88 };
89 
90 /* Violating this is very bad.  See docs/misc/xenstore.txt. */
91 #define XENSTORE_PAYLOAD_MAX 4096
92 
93 #endif /* _XS_WIRE_H */
94