include/xen/interface/io/xs_wire.h

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