/* $Id: VBoxGuestR3LibSharedFolders.cpp $ */
/** @file
 * VBoxGuestR3Lib - Ring-3 Support Library for VirtualBox guest additions, shared folders.
 */

/*
 * Copyright (C) 2010-2020 Oracle Corporation
 *
 * 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.
 */


/*********************************************************************************************************************************
*   Header Files                                                                                                                 *
*********************************************************************************************************************************/
#include <iprt/string.h>
#include <iprt/mem.h>
#include <iprt/assert.h>
#include <iprt/cpp/autores.h>
#include <iprt/stdarg.h>
#include <VBox/log.h>
#include <VBox/shflsvc.h> /** @todo File should be moved to VBox/HostServices/SharedFolderSvc.h */

#include "VBoxGuestR3LibInternal.h"


/**
 * Connects to the shared folder service.
 *
 * @returns VBox status code
 * @param   pidClient       Where to put the client id on success. The client id
 *                          must be passed to all the other calls to the service.
 */
VBGLR3DECL(int) VbglR3SharedFolderConnect(HGCMCLIENTID *pidClient)
{
    return VbglR3HGCMConnect("VBoxSharedFolders", pidClient);
}


/**
 * Disconnect from the shared folder service.
 *
 * @returns VBox status code.
 * @param   idClient        The client id returned by VbglR3InfoSvcConnect().
 */
VBGLR3DECL(int) VbglR3SharedFolderDisconnect(HGCMCLIENTID idClient)
{
    return VbglR3HGCMDisconnect(idClient);
}


/**
 * Checks whether a shared folder share exists or not.
 *
 * @returns True if shared folder exists, false if not.
 * @param   idClient        The client id returned by VbglR3InfoSvcConnect().
 * @param   pszShareName    Shared folder name to check.
 */
VBGLR3DECL(bool) VbglR3SharedFolderExists(HGCMCLIENTID idClient, const char *pszShareName)
{
    AssertPtr(pszShareName);

    uint32_t cMappings;
    VBGLR3SHAREDFOLDERMAPPING *paMappings;

    /** @todo Use some caching here? */
    bool fFound = false;
    int rc = VbglR3SharedFolderGetMappings(idClient, true /* Only process auto-mounted folders */, &paMappings, &cMappings);
    if (RT_SUCCESS(rc))
    {
        for (uint32_t i = 0; i < cMappings && !fFound; i++)
        {
            char *pszName = NULL;
            rc = VbglR3SharedFolderGetName(idClient, paMappings[i].u32Root, &pszName);
            if (   RT_SUCCESS(rc)
                && *pszName)
            {
                if (RTStrICmp(pszName, pszShareName) == 0)
                    fFound = true;
                RTStrFree(pszName);
            }
        }
        VbglR3SharedFolderFreeMappings(paMappings);
    }
    return fFound;
}


/**
 * Get the list of available shared folders.
 *
 * @returns VBox status code.
 * @param   idClient        The client id returned by VbglR3SharedFolderConnect().
 * @param   fAutoMountOnly  Flag whether only auto-mounted shared folders
 *                          should be reported.
 * @param   ppaMappings     Allocated array which will retrieve the mapping info.  Needs
 *                          to be freed with VbglR3SharedFolderFreeMappings() later.
 * @param   pcMappings      The number of mappings returned in @a ppaMappings.
 */
VBGLR3DECL(int) VbglR3SharedFolderGetMappings(HGCMCLIENTID idClient, bool fAutoMountOnly,
                                              PVBGLR3SHAREDFOLDERMAPPING *ppaMappings, uint32_t *pcMappings)
{
    AssertPtrReturn(pcMappings, VERR_INVALID_PARAMETER);
    AssertPtrReturn(ppaMappings, VERR_INVALID_PARAMETER);

    *pcMappings = 0;
    *ppaMappings = NULL;

    VBoxSFQueryMappings Msg;
    VBGL_HGCM_HDR_INIT(&Msg.callInfo, idClient, SHFL_FN_QUERY_MAPPINGS, 3);

    /* Set the mapping flags. */
    uint32_t u32Flags = 0; /** @todo SHFL_MF_UTF8 is not implemented yet. */
    if (fAutoMountOnly) /* We only want the mappings which get auto-mounted. */
        u32Flags |= SHFL_MF_AUTOMOUNT;
    VbglHGCMParmUInt32Set(&Msg.flags, u32Flags);

    /*
     * Prepare and get the actual mappings from the host service.
     */
    int rc = VINF_SUCCESS;
    uint32_t cMappings = 8; /* Should be a good default value. */
    uint32_t cbSize = cMappings * sizeof(VBGLR3SHAREDFOLDERMAPPING);
    VBGLR3SHAREDFOLDERMAPPING *ppaMappingsTemp = (PVBGLR3SHAREDFOLDERMAPPING)RTMemAllocZ(cbSize);
    if (!ppaMappingsTemp)
        return VERR_NO_MEMORY;

    do
    {
        VbglHGCMParmUInt32Set(&Msg.numberOfMappings, cMappings);
        VbglHGCMParmPtrSet(&Msg.mappings, ppaMappingsTemp, cbSize);

        rc = VbglR3HGCMCall(&Msg.callInfo, sizeof(Msg));
        if (RT_SUCCESS(rc))
        {
            VbglHGCMParmUInt32Get(&Msg.numberOfMappings, pcMappings);

            /* Do we have more mappings than we have allocated space for? */
            if (rc == VINF_BUFFER_OVERFLOW)
            {
                cMappings = *pcMappings;
                cbSize = cMappings * sizeof(VBGLR3SHAREDFOLDERMAPPING);
                void *pvNew = RTMemRealloc(ppaMappingsTemp, cbSize);
                AssertPtrBreakStmt(pvNew, rc = VERR_NO_MEMORY);
                ppaMappingsTemp = (PVBGLR3SHAREDFOLDERMAPPING)pvNew;
            }
        }
    } while (rc == VINF_BUFFER_OVERFLOW); /** @todo r=bird: This won't happen because the weird host code never returns it. */

    if (   RT_FAILURE(rc)
        || !*pcMappings)
    {
        RTMemFree(ppaMappingsTemp);
        ppaMappingsTemp = NULL;
    }

    /* In this case, just return success with 0 mappings */
    if (   rc == VERR_INVALID_PARAMETER
        && fAutoMountOnly)
        rc = VINF_SUCCESS;

    *ppaMappings = ppaMappingsTemp;

    return rc;
}


/**
 * Frees the shared folder mappings allocated by
 * VbglR3SharedFolderGetMappings() before.
 *
 * @param   paMappings     What
 */
VBGLR3DECL(void) VbglR3SharedFolderFreeMappings(PVBGLR3SHAREDFOLDERMAPPING paMappings)
{
    if (paMappings)
        RTMemFree(paMappings);
}


/**
 * Get the real name of a shared folder.
 *
 * @returns VBox status code.
 * @param   idClient        The client id returned by VbglR3InvsSvcConnect().
 * @param   u32Root         Root ID of shared folder to get the name for.
 * @param   ppszName        Where to return the name string.  This shall be
 *                          freed by calling RTStrFree.
 */
VBGLR3DECL(int) VbglR3SharedFolderGetName(HGCMCLIENTID idClient, uint32_t u32Root, char **ppszName)
{
    AssertPtr(ppszName);

    VBoxSFQueryMapName Msg;
    VBGL_HGCM_HDR_INIT(&Msg.callInfo, idClient, SHFL_FN_QUERY_MAP_NAME, 2);

    int         rc;
    uint32_t    cbString = SHFLSTRING_HEADER_SIZE + SHFL_MAX_LEN * sizeof(RTUTF16);
    PSHFLSTRING pString = (PSHFLSTRING)RTMemAlloc(cbString);
    if (pString)
    {
        if (!ShflStringInitBuffer(pString, cbString))
        {
            RTMemFree(pString);
            return VERR_INVALID_PARAMETER;
        }

        VbglHGCMParmUInt32Set(&Msg.root, u32Root);
        VbglHGCMParmPtrSet(&Msg.name, pString, cbString);

        rc = VbglR3HGCMCall(&Msg.callInfo, sizeof(Msg));
        if (RT_SUCCESS(rc))
        {
            *ppszName = NULL;
            rc = RTUtf16ToUtf8(&pString->String.ucs2[0], ppszName);
        }
        RTMemFree(pString);
    }
    else
        rc = VERR_NO_MEMORY;
    return rc;
}


/**
 * Queries information about a shared folder.
 *
 * @returns VBox status code.
 *
 * @param   idClient        The client ID.
 * @param   idRoot          The root ID of the folder to query information for.
 * @param   fQueryFlags     SHFL_MIQF_XXX.
 * @param   ppszName        Where to return the pointer to the name.
 *                          Free using RTStrFree.  Optional.
 * @param   ppszMountPoint  Where to return the pointer to the auto mount point.
 *                          Free using RTStrFree.  Optional.
 * @param   pfFlags         Where to return the flags (SHFL_MIF_XXX).  Optional.
 * @param   puRootIdVersion where to return the root ID version.  Optional.
 *                          This helps detecting root-id reuse.
 *
 * @remarks ASSUMES UTF-16 connection to host.
 */
VBGLR3DECL(int) VbglR3SharedFolderQueryFolderInfo(HGCMCLIENTID idClient, uint32_t idRoot, uint64_t fQueryFlags,
                                                  char **ppszName, char **ppszMountPoint,
                                                  uint64_t *pfFlags, uint32_t *puRootIdVersion)
{
    AssertReturn(!(fQueryFlags & ~(SHFL_MIQF_DRIVE_LETTER | SHFL_MIQF_PATH)), VERR_INVALID_FLAGS);

    /*
     * Allocate string buffers first.
     */
    int rc;
    PSHFLSTRING pNameBuf    = (PSHFLSTRING)RTMemAlloc(SHFLSTRING_HEADER_SIZE + (SHFL_MAX_LEN + 1) * sizeof(RTUTF16));
    PSHFLSTRING pMountPoint = (PSHFLSTRING)RTMemAlloc(SHFLSTRING_HEADER_SIZE + (260          + 1) * sizeof(RTUTF16));
    if (pNameBuf && pMountPoint)
    {
        ShflStringInitBuffer(pNameBuf,    SHFLSTRING_HEADER_SIZE + (SHFL_MAX_LEN + 1) * sizeof(RTUTF16));
        ShflStringInitBuffer(pMountPoint, SHFLSTRING_HEADER_SIZE + (260          + 1) * sizeof(RTUTF16));

        /*
         * Make the call.
         */
        VBoxSFQueryMapInfo Msg;
        VBGL_HGCM_HDR_INIT(&Msg.callInfo, idClient, SHFL_FN_QUERY_MAP_INFO, 5);
        VbglHGCMParmUInt32Set(&Msg.root, idRoot);
        VbglHGCMParmPtrSet(&Msg.name, pNameBuf, SHFLSTRING_HEADER_SIZE + pNameBuf->u16Size);
        VbglHGCMParmPtrSet(&Msg.mountPoint, pMountPoint, SHFLSTRING_HEADER_SIZE + pMountPoint->u16Size);
        VbglHGCMParmUInt64Set(&Msg.flags, fQueryFlags);
        VbglHGCMParmUInt32Set(&Msg.rootIdVersion, 0);

        rc = VbglR3HGCMCall(&Msg.callInfo, sizeof(Msg));
        if (RT_SUCCESS(rc))
        {
            /*
             * Copy out the results.
             */
            if (puRootIdVersion)
                *puRootIdVersion = Msg.rootIdVersion.u.value64;

            if (pfFlags)
                *pfFlags = Msg.flags.u.value64;

            if (ppszName)
            {
                *ppszName = NULL;
                rc = RTUtf16ToUtf8Ex(pNameBuf->String.utf16, pNameBuf->u16Length / sizeof(RTUTF16), ppszName, 0, NULL);
            }

            if (ppszMountPoint && RT_SUCCESS(rc))
            {
                *ppszMountPoint = NULL;
                rc = RTUtf16ToUtf8Ex(pMountPoint->String.utf16, pMountPoint->u16Length / sizeof(RTUTF16), ppszMountPoint, 0, NULL);
                if (RT_FAILURE(rc) && ppszName)
                {
                    RTStrFree(*ppszName);
                    *ppszName = NULL;
                }
            }
        }
    }
    else
        rc = VERR_NO_MEMORY;
    RTMemFree(pMountPoint);
    RTMemFree(pNameBuf);
    return rc;
}


/**
 * Waits for changes to the mappings (add, remove, restore).
 *
 * @returns VBox status code.
 * @retval  VINF_SUCCESS on change
 * @retval  VINF_TRY_AGAIN on restore.
 * @retval  VERR_OUT_OF_RESOURCES if there are too many guys waiting.
 *
 * @param   idClient        The client ID.
 * @param   uPrevVersion    The mappings config version number returned the last
 *                          time around.  Use UINT32_MAX for the first call.
 * @param   puCurVersion    Where to return the current mappings config version.
 */
VBGLR3DECL(int) VbglR3SharedFolderWaitForMappingsChanges(HGCMCLIENTID idClient, uint32_t uPrevVersion, uint32_t *puCurVersion)
{
    VBoxSFWaitForMappingsChanges Msg;
    VBGL_HGCM_HDR_INIT(&Msg.callInfo, idClient, SHFL_FN_WAIT_FOR_MAPPINGS_CHANGES, 1);
    VbglHGCMParmUInt32Set(&Msg.version, uPrevVersion);

    int rc = VbglR3HGCMCall(&Msg.callInfo, sizeof(Msg));

    *puCurVersion = Msg.version.u.value32;
    return rc;
}


/**
 * Cancels all threads currently waiting for changes for this client.
 *
 * @returns VBox status code.
 * @param   idClient        The client ID.
 */
VBGLR3DECL(int) VbglR3SharedFolderCancelMappingsChangesWaits(HGCMCLIENTID idClient)
{
    VBGLIOCHGCMCALL CallInfo;
    VBGL_HGCM_HDR_INIT(&CallInfo, idClient, SHFL_FN_CANCEL_MAPPINGS_CHANGES_WAITS, 0);

    return VbglR3HGCMCall(&CallInfo, sizeof(CallInfo));
}


/**
 * Retrieves the prefix for a shared folder mount point.  If no prefix
 * is set in the guest properties "sf_" is returned.
 *
 * @returns VBox status code.
 * @param   ppszPrefix      Where to return the prefix string.  This shall be
 *                          freed by calling RTStrFree.
 */
VBGLR3DECL(int) VbglR3SharedFolderGetMountPrefix(char **ppszPrefix)
{
    AssertPtrReturn(ppszPrefix, VERR_INVALID_POINTER);
    int rc;
#ifdef VBOX_WITH_GUEST_PROPS
    HGCMCLIENTID idClientGuestProp;
    rc = VbglR3GuestPropConnect(&idClientGuestProp);
    if (RT_SUCCESS(rc))
    {
        rc = VbglR3GuestPropReadValueAlloc(idClientGuestProp, "/VirtualBox/GuestAdd/SharedFolders/MountPrefix", ppszPrefix);
        if (rc == VERR_NOT_FOUND) /* No prefix set? Then set the default. */
        {
#endif
/** @todo r=bird: Inconsistent! VbglR3SharedFolderGetMountDir does not return a default. */
            rc = RTStrDupEx(ppszPrefix, "sf_");
#ifdef VBOX_WITH_GUEST_PROPS
        }
        VbglR3GuestPropDisconnect(idClientGuestProp);
    }
#endif
    return rc;
}


/**
 * Retrieves the mount root directory for auto-mounted shared
 * folders. mount point. If no string is set (VERR_NOT_FOUND)
 * it's up on the caller (guest) to decide where to mount.
 *
 * @returns VBox status code.
 * @param   ppszDir         Where to return the directory
 *                          string. This shall be freed by
 *                          calling RTStrFree.
 */
VBGLR3DECL(int) VbglR3SharedFolderGetMountDir(char **ppszDir)
{
    AssertPtrReturn(ppszDir, VERR_INVALID_POINTER);
    int rc = VERR_NOT_FOUND;
#ifdef VBOX_WITH_GUEST_PROPS
    HGCMCLIENTID idClientGuestProp;
    rc = VbglR3GuestPropConnect(&idClientGuestProp);
    if (RT_SUCCESS(rc))
    {
        rc = VbglR3GuestPropReadValueAlloc(idClientGuestProp, "/VirtualBox/GuestAdd/SharedFolders/MountDir", ppszDir);
        VbglR3GuestPropDisconnect(idClientGuestProp);
    }
#endif
    return rc;
}

