source: vbox/trunk/include/VBox/HostServices/GuestPropertySvc.h@ 13437

/** @file
 * Guest property service:
 * Common header for host service and guest clients.
 */

/*
 * Copyright (C) 2006-2007 Sun Microsystems, Inc.
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
 * VirtualBox OSE distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
 * Clara, CA 95054 USA or visit http://www.sun.com if you need
 * additional information or have any questions.
 */

#ifndef ___VBox_HostService_GuestPropertyService_h
#define ___VBox_HostService_GuestPropertyService_h

#include <VBox/types.h>
#include <VBox/VBoxGuest.h>
#include <VBox/hgcmsvc.h>
#include <VBox/log.h>
#include <iprt/assert.h>

#include <string.h>

#ifdef RT_OS_WINDOWS
# define strncasecmp strnicmp
#endif

/** Everything defined in this file lives in this namespace. */
namespace guestProp {

/******************************************************************************
* Typedefs, constants and inlines                                             *
******************************************************************************/

/** Maximum length for property names */
enum { MAX_NAME_LEN = 64 };
/** Maximum length for property values */
enum { MAX_VALUE_LEN = 128 };
/** Maximum number of properties per guest */
enum { MAX_PROPS = 256 };

/**
 * The guest property flag values which are currently accepted.
 */
enum ePropFlags
{
    NILFLAG    = 0,
    TRANSIENT  = RT_BIT(1),
    HOSTWRITE  = RT_BIT(2),
    GUESTWRITE = RT_BIT(3),
    READONLY   = RT_BIT(4)
};

/**
 * A structure to map the guest property flag values to names. I know it is
 * ugly to have constants inline, but it has to be accessible in different
 * modules and it does not seem reasonable to put it into its own library.
 */
const struct
{
    /** The flag value */
    uint32_t fFlag;
    /** And the name of the flag */
    const char *pcszName;
} flagNames[] =
{
    { TRANSIENT,  "TRANSIENT" },
    { HOSTWRITE,  "HOSTWRITE" },
    { GUESTWRITE, "GUESTWRITE" },
    { READONLY,   "READONLY" },
    { NILFLAG,    NULL }
};

/** Maximum length for the property flags field */
enum { MAX_FLAGS_LEN =   sizeof(flagNames[0]) + 2  /* + 2 for ", " */
                       + sizeof(flagNames[1]) + 2
                       + sizeof(flagNames[2]) + 2
                       + sizeof(flagNames[3])
     };

/**
 * Parse a guest properties flags string for the flags in flagNames.
 * @returns  IPRT status code
 * @returns  VERR_INVALID_PARAM if the flag string is not valid
 * @param    pcszFlags  the flag string to parse
 * @param    pfFlags    where to store the parse result.  May not be NULL.
 * @note     This function is also inline because it must be accessible from
 *           several modules and it does not seem reasonable to put it into
 *           its own library.
 */
DECLINLINE(int) validateFlags(const char *pcszFlags, uint32_t *pfFlags)
{
    const char *pcszNext = pcszFlags;
    int rc = VINF_SUCCESS;
    uint32_t fFlags = 0;
    AssertLogRelReturn(VALID_PTR(pfFlags), VERR_INVALID_POINTER);
    AssertLogRelReturn(VALID_PTR(pcszFlags), VERR_INVALID_POINTER);
    while (' ' == *pcszNext)
        ++pcszNext;
    while ((*pcszNext != '\0') && RT_SUCCESS(rc))
    {
        int i = 0;
        for (; flagNames[i].fFlag != NILFLAG; ++i)
            if (strncasecmp(pcszNext, flagNames[i].pcszName,
                            strlen(flagNames[i].pcszName)) == 0)
                break;
        if (NILFLAG == flagNames[i].fFlag)
            rc = VERR_INVALID_PARAMETER;
        else
        {
            fFlags |= flagNames[i].fFlag;
            pcszNext += strlen(flagNames[i].pcszName);
        }
        while (' ' == *pcszNext)
            ++pcszNext;
        if (',' == *pcszNext)
            ++pcszNext;
        while (' ' == *pcszNext)
            ++pcszNext;
    }
    if (RT_SUCCESS(rc))
        *pfFlags = fFlags;
    return rc;
}

/**
 * Write out flags to a string.
 * @returns  IPRT status code
 * @param    fFlags    the flags to write out
 * @param    pszFlags  where to write the flags string.  This must point to
 *                     a buffer of size (at least) MAX_FLAGS_LEN + 1.
 */
DECLINLINE(int) writeFlags(uint32_t fFlags, char *pszFlags)
{
    char *pszNext = pszFlags;
    int rc = VINF_SUCCESS;
    AssertLogRelReturn(VALID_PTR(pszFlags), VERR_INVALID_POINTER);
    int i = 0;
    for (; flagNames[i].fFlag != NILFLAG; ++i)
    {
        if (fFlags & flagNames[i].fFlag)
        {
            strcpy(pszNext, flagNames[i].pcszName);
            pszNext += strlen(flagNames[i].pcszName);
            fFlags &= ~flagNames[i].fFlag;
            if ((flagNames[i + 1].fFlag != NILFLAG) && (fFlags != NILFLAG))
            {
                strcpy(pszNext, ", ");
                pszNext += 2;
            }
        }
    }
    *pszNext = '\0';
    if (fFlags != NILFLAG)
        rc = VERR_INVALID_PARAMETER;  /* But pszFlags will still be set right. */
    return rc;
}

/*
 * The service functions which are callable by host.
 */
enum eHostFn
{
    /** Pass the address of the cfgm node used by the service as a database. */
    SET_CFGM_NODE = 1,
    /**
     * Get the value attached to a guest property
     * The parameter format matches that of GET_PROP.
     */
    GET_PROP_HOST = 2,
    /**
     * Set the value attached to a guest property
     * The parameter format matches that of SET_PROP.
     */
    SET_PROP_HOST = 3,
    /**
     * Set the value attached to a guest property
     * The parameter format matches that of SET_PROP_VALUE.
     */
    SET_PROP_VALUE_HOST = 4,
    /**
     * Remove a guest property.
     * The parameter format matches that of DEL_PROP.
     */
    DEL_PROP_HOST = 5,
    /**
     * Enumerate guest properties.
     * The parameter format matches that of ENUM_PROPS.
     */
    ENUM_PROPS_HOST = 6
};

/**
 * The service functions which are called by guest.  The numbers may not change,
 * so we hardcode them.
 */
enum eGuestFn
{
    /** Get a guest property */
    GET_PROP = 1,
    /** Set a guest property */
    SET_PROP = 2,
    /** Set just the value of a guest property */
    SET_PROP_VALUE = 3,
    /** Delete a guest property */
    DEL_PROP = 4,
    /** Enumerate guest properties */
    ENUM_PROPS = 5
};

/**
 * Data structure to pass to the service extension callback.  We use this to
 * notify the host of changes to properties.
 */
typedef struct _HOSTCALLBACKDATA
{
    /** Magic number to identify the structure */
    uint32_t u32Magic;
    /** The name of the property that was changed */
    const char *pcszName;
    /** The new property value, or NULL if the property was deleted */
    const char *pcszValue;
    /** The timestamp of the modification */
    uint64_t u64Timestamp;
    /** The flags field of the modified property */
    const char *pcszFlags;
} HOSTCALLBACKDATA, *PHOSTCALLBACKDATA;

enum
{
    /** Magic number for sanity checking the HOSTCALLBACKDATA structure */
    HOSTCALLBACKMAGIC = 0x69c87a78
};

/**
 * HGCM parameter structures.  Packing is explicitly defined as this is a wire format.
 */
#pragma pack (1)
/** The guest is requesting the value of a property */
typedef struct _GetProperty
{
    VBoxGuestHGCMCallInfo hdr;

    /**
     * The property name (IN pointer)
     * This must fit to a number of criteria, namely
     *  - Only Utf8 strings are allowed
     *  - Less than or equal to MAX_NAME_LEN bytes in length
     *  - Zero terminated
     */
    HGCMFunctionParameter name;

    /**
     * The returned string data will be placed here.  (OUT pointer)
     * This call returns two null-terminated strings which will be placed one
     * after another: value and flags.
     */
    HGCMFunctionParameter buffer;

    /**
     * The property timestamp.  (OUT uint64_t)
     */

    HGCMFunctionParameter timestamp;

    /**
     * If the buffer provided was large enough this will contain the size of
     * the returned data.  Otherwise it will contain the size of the buffer
     * needed to hold the data and VERR_BUFFER_OVERFLOW will be returned.
     * (OUT uint32_t)
     */
    HGCMFunctionParameter size;
} GetProperty;

/** The guest is requesting to change a property */
typedef struct _SetProperty
{
    VBoxGuestHGCMCallInfo hdr;

    /**
     * The property name.  (IN pointer)
     * This must fit to a number of criteria, namely
     *  - Only Utf8 strings are allowed
     *  - Less than or equal to MAX_NAME_LEN bytes in length
     *  - Zero terminated
     */
    HGCMFunctionParameter name;

    /**
     * The value of the property (IN pointer)
     * Criteria as for the name parameter, but with length less than or equal to
     * MAX_VALUE_LEN.  
     */
    HGCMFunctionParameter value;

    /**
     * The property flags (IN pointer)
     * This is a comma-separated list of the format flag=value
     * The length must be less than or equal to MAX_FLAGS_LEN and only
     * known flag names and values will be accepted.
     */
    HGCMFunctionParameter flags;
} SetProperty;

/** The guest is requesting to change the value of a property */
typedef struct _SetPropertyValue
{
    VBoxGuestHGCMCallInfo hdr;

    /**
     * The property name.  (IN pointer)
     * This must fit to a number of criteria, namely
     *  - Only Utf8 strings are allowed
     *  - Less than or equal to MAX_NAME_LEN bytes in length
     *  - Zero terminated
     */
    HGCMFunctionParameter name;

    /**
     * The value of the property (IN pointer)
     * Criteria as for the name parameter, but with length less than or equal to
     * MAX_VALUE_LEN.  
     */
    HGCMFunctionParameter value;
} SetPropertyValue;

/** The guest is requesting to remove a property */
typedef struct _DelProperty
{
    VBoxGuestHGCMCallInfo hdr;

    /**
     * The property name.  This must fit to a number of criteria, namely
     *  - Only Utf8 strings are allowed
     *  - Less than or equal to MAX_NAME_LEN bytes in length
     *  - Zero terminated
     */
    HGCMFunctionParameter name;
} DelProperty;

/** The guest is requesting to enumerate properties */
typedef struct _EnumProperties
{
    VBoxGuestHGCMCallInfo hdr;

    /**
     * Null-separated array of patterns to match the properties against.
     * (IN pointer)
     * If no patterns are given then return all.  The list is terminated by an
     * empty string.
     */
    HGCMFunctionParameter patterns;
    /**
     * On success, null-separated array of strings in which the properties are
     * returned.  (OUT pointer)
     * The number of strings in the array is always a multiple of four,
     * and in sequences of name, value, timestamp (hexadecimal string) and the
     * flags as a comma-separated list in the format "name=value".  The list
     * is terminated by an empty string after a "flags" entry (or at the
     * start).
     */
    HGCMFunctionParameter strings;
    /**
     * On success, the size of the returned data.  If the buffer provided is
     * too small, the size of buffer needed.  (OUT uint32_t)
     */
    HGCMFunctionParameter size;
} EnumProperties;
#pragma pack ()

} /* namespace guestProp */

#endif  /* ___VBox_HostService_GuestPropertySvc_h defined */