/*
* Details of the "wire" protocol between Xen Store Daemon and client
* library or guest kernel.
* Copyright (C) 2005 Rusty Russell IBM Corporation
*/

#ifndef _XS_WIRE_H
#define _XS_WIRE_H

enum xsd_sockmsg_type
{
XS_DEBUG,
XS_DIRECTORY,
XS_READ,
XS_GET_PERMS,
XS_WATCH,
XS_UNWATCH,
XS_TRANSACTION_START,
XS_TRANSACTION_END,
XS_INTRODUCE,
XS_RELEASE,
XS_GET_DOMAIN_PATH,
XS_WRITE,
XS_MKDIR,
XS_RM,
XS_SET_PERMS,
XS_WATCH_EVENT,
XS_ERROR,
XS_IS_DOMAIN_INTRODUCED,
XS_RESUME,
XS_SET_TARGET,
XS_RESTRICT,
XS_RESET_WATCHES,
};

#define XS_WRITE_NONE "NONE"
#define XS_WRITE_CREATE "CREATE"
#define XS_WRITE_CREATE_EXCL "CREATE|EXCL"

/* We hand errors as strings, for portability. */
struct xsd_errors
{
int errnum;
const char *errstring;
};
#define XSD_ERROR(x) { x, #x }
static struct xsd_errors xsd_errors[] __attribute__((unused)) = {
XSD_ERROR(EINVAL),
XSD_ERROR(EACCES),
XSD_ERROR(EEXIST),
XSD_ERROR(EISDIR),
XSD_ERROR(ENOENT),
XSD_ERROR(ENOMEM),
XSD_ERROR(ENOSPC),
XSD_ERROR(EIO),
XSD_ERROR(ENOTEMPTY),
XSD_ERROR(ENOSYS),
XSD_ERROR(EROFS),
XSD_ERROR(EBUSY),
XSD_ERROR(EAGAIN),
XSD_ERROR(EISCONN)
};

struct xsd_sockmsg
{
uint32_t type; /* XS_??? */
uint32_t req_id;/* Request identifier, echoed in daemon's response. */
uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
uint32_t len; /* Length of data following this. */

/* Generally followed by nul-terminated string(s). */
};

enum xs_watch_type
{
XS_WATCH_PATH = 0,
XS_WATCH_TOKEN
};

/* Inter-domain shared memory communications. */
#define XENSTORE_RING_SIZE 1024
typedef uint32_t XENSTORE_RING_IDX;
#define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
struct xenstore_domain_interface {
char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
XENSTORE_RING_IDX req_cons, req_prod;
XENSTORE_RING_IDX rsp_cons, rsp_prod;
};

/* Violating this is very bad. See docs/misc/xenstore.txt. */
#define XENSTORE_PAYLOAD_MAX 4096

#endif /* _XS_WIRE_H */