include/xen/interface/io/xs_wire.h

   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 */