Re: [Qemu-devel] vnc port selection

Re: [Qemu-devel] vnc port selection

[acue]

[-- Attachment #1: Type: text/plain, Size: 1793 bytes --]

Anthony Liguori wrote:
> Gerd Hoffmann wrote:
>>   Hi folks,
>>
>> Xen's qemu-dm version has a '-vncunused' command line switch which asks
>> the internal vnc server to pick any unused tcp port to listen on.  The
>> actual port is communicated to the outside world via xenstore.
>>
>> I'm looking for a reasonable way to implement that functionality in
>> upstream qemu.  First, I think it shouldn't be a separate command line
>> switch but an option for the existion -vnc switch.
>
> Maybe something like a to=N option.  So you would have:
>
> -vnc localhost:0,to=10
>
> That would try from displays 0 to 10 and select the first one it could 
> attach to.
>
>>   Second, we need a
>> way to communicate the port picked which isn't xen-specific.  Obvious
>> choice is a monitor info subcommand.
>>   
>
> There's already an info vnc.  It can be added to that.
>
> Regards,
>
> Anthony Liguori
>
>> Comments?  Other suggestions?
>>
>> cheers,
>>   Gerd
>>
>>   
>
>
>
>
Hello Gerd,
Even though currently it is a bash+awk solution the algorithm could be 
of interest for you.

It works on Linux+OpenBSD+Solaris and accepts MIN and MAX value for the 
port.
An aditional seed-value is added for slowly-released ports for immediate 
access.

I use different ranges particularly in order to distinguish 
displayforwarding and
"clientforwarding".
Thus one range for local vncviewer access by OpenSSH with "-X" option, 
another for
forwarded remote vncviewer access by OpenSSH tunnels with port-forwarding.

The files are available at http:/sourceforge.net/projects/ctys with the
directory path: ctys.01_07_001b04/plugins/VNC

Arno
 

-- 
----------------------------------------------------------------------------

                   Arno-Can Uestuensoez

                www.i4p.de  / www.i4p.com


[-- Attachment #2: getFirstFreeVNCPort.Linux.awk --]
[-- Type: text/plain, Size: 1202 bytes --]

########################################################################
#
#PROJECT:      Unified Sessions Manager
#AUTHOR:       Arno-Can Uestuensoez - acue@UnifiedSessionsManager.org
#MAINTAINER:   Arno-Can Uestuensoez - acue_sf1@sourceforge.net
#SHORT:        ctys
#CALLFULLNAME: Commutate To Your Session
#LICENCE:      GPL3
#VERSION:      01_06_001a10
#
########################################################################
#
# Copyright (C) 2007 Arno-Can Uestuensoez (UnifiedSessionsManager.org)
#
########################################################################

function ptrace(inp){
    if(!d){
        print line ":" inp | "cat 1>&2"
    }
}


BEGIN{
    ptrace("awk:getFirstFreeVNCPort");
    ptrace("min ="min);
    ptrace("max ="max);
    ptrace("seed="seed);
    chk[0]="";
}

{
    gsub("^[0-9.]*:+","",$4);
}

$4>min&&$4<max{
    idx=$4-min;
    chk[idx]=$4;
}

END{
    l=max-min;
    for(i=0;i<l;i++){
        if(chk[i]==""){
            if(seed==0){break;}
            seed--;
            ptrace("skip("seed")="i);
        }
    }
    if(i<max){
        ptrace("result="i);
        printf("%d",min+i);
    }else{
        ptrace("result exceeds maximum("max")="i);
    }
}

[-- Attachment #3: getFirstFreeVNCPort.OpenBSD.awk --]
[-- Type: text/plain, Size: 1202 bytes --]

########################################################################
#
#PROJECT:      Unified Sessions Manager
#AUTHOR:       Arno-Can Uestuensoez - acue@UnifiedSessionsManager.org
#MAINTAINER:   Arno-Can Uestuensoez - acue_sf1@sourceforge.net
#SHORT:        ctys
#CALLFULLNAME: Commutate To Your Session
#LICENCE:      GPL3
#VERSION:      01_06_001a10
#
########################################################################
#
# Copyright (C) 2007 Arno-Can Uestuensoez (UnifiedSessionsManager.org)
#
########################################################################

function ptrace(inp){
    if(!d){
        print line ":" inp | "cat 1>&2"
    }
}


BEGIN{
    ptrace("awk:getFirstFreeVNCPort");
    ptrace("min ="min);
    ptrace("max ="max);
    ptrace("seed="seed);
    chk[0]="";
}

{
    gsub("^[0-9.]*:+","",$4);
}

$4>min&&$4<max{
    idx=$4-min;
    chk[idx]=$4;
}

END{
    l=max-min;
    for(i=0;i<l;i++){
        if(chk[i]==""){
            if(seed==0){break;}
            seed--;
            ptrace("skip("seed")="i);
        }
    }
    if(i<max){
        ptrace("result="i);
        printf("%d",min+i);
    }else{
        ptrace("result exceeds maximum("max")="i);
    }
}

[-- Attachment #4: getFirstFreeVNCPort.SunOS.awk --]
[-- Type: text/plain, Size: 1202 bytes --]

########################################################################
#
#PROJECT:      Unified Sessions Manager
#AUTHOR:       Arno-Can Uestuensoez - acue@UnifiedSessionsManager.org
#MAINTAINER:   Arno-Can Uestuensoez - acue_sf1@sourceforge.net
#SHORT:        ctys
#CALLFULLNAME: Commutate To Your Session
#LICENCE:      GPL3
#VERSION:      01_06_001a10
#
########################################################################
#
# Copyright (C) 2007 Arno-Can Uestuensoez (UnifiedSessionsManager.org)
#
########################################################################

function ptrace(inp){
    if(!d){
        print line ":" inp | "cat 1>&2"
    }
}


BEGIN{
    ptrace("awk:getFirstFreeVNCPort");
    ptrace("min ="min);
    ptrace("max ="max);
    ptrace("seed="seed);
    chk[0]="";
}

{
    gsub("^[0-9.]*:+","",$4);
}

$4>min&&$4<max{
    idx=$4-min;
    chk[idx]=$4;
}

END{
    l=max-min;
    for(i=0;i<l;i++){
        if(chk[i]==""){
            if(seed==0){break;}
            seed--;
            ptrace("skip("seed")="i);
        }
    }
    if(i<max){
        ptrace("result="i);
        printf("%d",min+i);
    }else{
        ptrace("result exceeds maximum("max")="i);
    }
}

[-- Attachment #5: hook --]
[-- Type: text/plain, Size: 19056 bytes --]

#!/bin/bash

########################################################################
#
#PROJECT:      Unified Sessions Manager
#AUTHOR:       Arno-Can Uestuensoez - acue@UnifiedSessionsManager.org
#MAINTAINER:   Arno-Can Uestuensoez - acue_sf1@sourceforge.net
#SHORT:        ctys
#CALLFULLNAME: Commutate To Your Session
#LICENCE:      GPL3
#VERSION:      01_03_001b01
#
########################################################################
#
# Copyright (C) 2007 Arno-Can Uestuensoez (UnifiedSessionsManager.org)
#
########################################################################

VNC_MAGIC=VNC_GENERIC;
VNC_VERSTRING=;
VNC_STATE=DISABLED;
VNCSERVER_OPT=;
VNCVIEWER_OPT=;
VNC_PREREQ=;


export VNC_BASEPORT=${VNC_BASEPORT:-5900}

_myPKGNAME_VNC="${BASH_SOURCE}"
_myPKGVERS_VNC="01.02.001b01"
hookInfoAdd $_myPKGNAME_VNC $_myPKGVERS_VNC
_myPKGBASE_VNC="${_myPKGNAME_VNC%/hook}"


VNC_VERSTRING=${_myPKGVERS_VNC};
VNC_PREREQ="HOST-CAPABILITY:VNC-${VNC_VERSTRING}-${MYARCH}";


if [ -d "${HOME}/.ctys" -a -d "${HOME}/.ctys/vnc" ];then
    if [ -f "${HOME}/.ctys/vnc/vnc.conf.${MYOS}" ];then
	. "${HOME}/.ctys/vnc/vnc.conf.${MYOS}"
    fi
fi

if [ -d "${MYCONFPATH}" -a -d "${MYCONFPATH}/vnc" ];then
    if [ -f "${MYCONFPATH}/vnc/vnc.conf.${MYOS}" ];then
	. "${MYCONFPATH}/vnc/vnc.conf.${MYOS}"
    fi
fi



_waitcVNC=${VNC_INIT_WAITC:-2}
_waitsVNC=${VNC_INIT_WAITS:-2}



#FUNCBEG###############################################################
#NAME:
#  getFirstFreeVNCPort
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#  Gets the first free port above a given base, thus multiple regions
#  could be managed
#
#EXAMPLE:
#
#PARAMETERS:
#  $1: <MIN>
#  $2: [<MAX>]
#
#OUTPUT:
#  RETURN:
#  VALUES:
#    <first-port>
#
#FUNCEND###############################################################
function getFirstFreeVNCPort () {
    printDBG $S_LIB ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME:CALL=<${*}>"
    local MIN=${1:-$VNC_BASEPORT};
    local MAX=$2;
    [ -z "$MAX" ]&&let MAX=MIN+1000;
    local _seed=$((RANDOM%VNCPORTSEED));
    doDebug $S_XEN  ${D_MAINT} $LINENO $BASH_SOURCE
    local D=$?

    printDBG $S_LIB ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME:MIN=${MIN} MAX=${MAX} seed=${_seed}"
    case ${MYOS} in
	Linux)
	    local localClientAccess=`${CTYS_NETSTAT} -n -l -t|awk -v d="${D}" -v min="${MIN}" -v max="${MAX}" -v seed="${_seed}" -f ${_myPKGBASE_VNC}/getFirstFreeVNCPort.${MYOS}.awk`
	    ;;
	OpenBSD)
	    local localClientAccess=`${CTYS_NETSTAT} -n -l -t|awk -v d="${D}" -v min="${MIN}" -v max="${MAX}" -v seed="${_seed}" -f ${_myPKGBASE_VNC}/getFirstFreeVNCPort.${MYOS}.awk`
	    ;;
	SunOS)
	    local localClientAccess=`${CTYS_NETSTAT} -n -l -t|awk -v d="${D}" -v min="${MIN}" -v max="${MAX}" -v seed="${_seed}" -f ${_myPKGBASE_VNC}/getFirstFreeVNCPort.${MYOS}.awk`
	    ;;
    esac
    printDBG $S_LIB ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME:localClientAccess=<${localClientAccess}>"
    echo -n -e "${localClientAccess}";
}

#FUNCBEG###############################################################
#NAME:
#  getFirstFreeVNCDisplay
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#  Gets the first free display above a given base, thus multiple regions
#  could be managed
#
#EXAMPLE:
#
#PARAMETERS:
#  $1: <MIN>
#  $2: [<MAX>]
#
#OUTPUT:
#  RETURN:
#  VALUES:
#    <first-port>
#
#FUNCEND###############################################################
function getFirstFreeVNCDisplay () {
    printDBG $S_LIB ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME:CALL=<${*}>"
    local MIN=${1:-$VNC_BASEPORT};
    local MAX=$2;
    [ -z "$MAX" ]&&let MAX=VNC_PORT+1000;
    printDBG $S_LIB ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME:MIN=${MIN} MAX=${MAX}"
    local _myPort=`getFirstFreeVNCPort ${@}`
    local _myDisplay=$((_myPort-MIN));
    printDBG $S_LIB ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME:_myPort=<${_myPort}>"
    printDBG $S_LIB ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME:_myDisplay=<${_myDisplay}>"
    echo -n -e "${_myDisplay}";
}


#FUNCBEG###############################################################
#NAME:
#  serverRequireVNC
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#  Reports whether a server component has to be called for the current
#  action.
#
#EXAMPLE:
#
#PARAMETERS:
# $*: ${EXECCALL}|<options-list>
#     Generally a string containing an <options-list>, where the
#     first match is choosen. So only one type option is allowed to
#     be contained.
#
#OUTPUT:
#  RETURN:
#    INPUT, where required changes for destination are set.
#  VALUES:
#    0: true, required - output is valid.
#    1: false, not required - output is not valid.
#
#FUNCEND###############################################################
function serverRequireVNC () {
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME \$@=$@"
    local _ret=1;
    local _res=;

    local _S=`getSessionType ${*}`;_S=${_S:-$C_SESSIONTYPE};
    local _A=`getActionResulting ${*}`;
    case $_A in
	GETCLIENTPORT)
	    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "$FUNCNAME:_res=\"${*}\""
	    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "$FUNCNAME:_ret=\"0\""
	    echo -n "${*}";
	    return 0
	    ;;
    esac

    local _CS_SPLIT=${*};
    _CS_SPLIT=${_CS_SPLIT//CONNECTIONFORWARDING/SERVERONLY}
    _CS_SPLIT=${_CS_SPLIT//*LOCALONLY*/}
    _CS_SPLIT=${_CS_SPLIT//*CLIENTONLY*/}
    if [ -n "${_CS_SPLIT}" ];then
	_res="${_CS_SPLIT}";_ret=0;
    fi


    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "_CS_SPLIT=\"${_CS_SPLIT}\""
    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "_S=\"${_S}\""
    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "_A=\"${_A}\""

    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "$FUNCNAME:_res=\"${_res}\""
    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "$FUNCNAME:_ret=\"${_ret}\""
    echo -n "${_res}";
    return ${_ret};  
}



#FUNCBEG###############################################################
#NAME:
#  clientRequireVNC
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#  Reports whether a client component has to be called for the current
#  action.
#
#EXAMPLE:
#
#PARAMETERS:
# $*: ${EXECCALL}|<options-list>
#     Generally a string containing an <options-list>, where the
#     first match is choosen. So only one type option is allowed to
#     be contained.
#
#OUTPUT:
#  RETURN:
#    INPUT, where required changes for destination are set.
#  VALUES:
#    0: true, required - output is valid.
#    1: false, not required - output is not valid.
#
#FUNCEND###############################################################
function clientRequireVNC () {
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME \$@=$@"
    local _ret=1;
    local _res=;

    local _A=`getActionResulting ${*}`;

    local _S=`getSessionType ${*}`;_S=${_S:-$C_SESSIONTYPE};
    local _CS_SPLIT=${*};
    _CS_SPLIT=${_CS_SPLIT//*DISPLAYFORWARDING*/}
    _CS_SPLIT=${_CS_SPLIT//*SERVERONLY*/}
    if [ "${_CS_SPLIT}" == "${*}" ];then
	_res="${_CS_SPLIT}";_ret=0;
    fi
    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "_CS_SPLIT=\"${_CS_SPLIT}\""
    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "_S=\"${_S}\""
    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "_A=\"${_A}\""

    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "$FUNCNAME:_res=\"${_res}\""
    printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "$FUNCNAME:_ret=\"${_ret}\""
    echo -n "${_res}";
    return ${_ret};  
}






#FUNCBEG###############################################################
#NAME:
#  setVersionVNC
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#  Sets defaults and MAGIC-ID for local vmware version.
#
#EXAMPLE:
#
#PARAMETERS:
#
#
#OUTPUT:
#  GLOBALS:
#    VNC_MAGIC:  {VNC_REAL412|VNC_TIGHT129|...}
#      Value to be checked.
#
#    VMW_DEFAULTOPTS
#      Appropriate defaults.
#
#      -RealVNC  - 4.1.2 
#      -TightVNC - 1.2.9
#
#  RETURN:
#
#  VALUES:
#
#FUNCEND###############################################################
function setVersionVNC () {
    local _checkonly=;
    local _ret=0;
    if [ "$1" == "NOEXIT" ];then
	local _checkonly=1;        
    fi

    local _verstrg=;
    if [ -z "${VNCSEXE}" ];then
	ABORT=2;
	printERR $LINENO $BASH_SOURCE ${ABORT} "Missing executable for VNCserver"
	printERR $LINENO $BASH_SOURCE ${ABORT} "can not find:"
	printERR $LINENO $BASH_SOURCE ${ABORT} " -> vncserv"
	printERR $LINENO $BASH_SOURCE ${ABORT} ""
	printERR $LINENO $BASH_SOURCE ${ABORT} "Check your PATH"
	printERR $LINENO $BASH_SOURCE ${ABORT} " -> PATH=${PATH}"
	printERR $LINENO $BASH_SOURCE ${ABORT} ""
	if [ "${C_SESSIONTYPE}" == "VNC" -a -z "${_checkonly}" ];then
	    gotoHell ${ABORT}
	else
	    return ${ABORT}
	fi
	_ret=${ABORT};
    else
	local _vsexe=`${VNCSEXE} --help 2>&1|egrep '(Usage:|usage:)'`
	ABORT=2;
	if [ -n "$_vsexe" ];then
	    printDBG $S_LIB ${D_SYS} $LINENO "$BASH_SOURCE" "$FUNCNAME:`setSeverityColor TRY \"call(${VNCSEXE} --help)\"` => [ `setSeverityColor INF OK` ]"
	    _ret=0;
	else
	    printDBG $S_LIB ${D_SYS} $LINENO "$BASH_SOURCE" "$FUNCNAME:`setSeverityColor TRY \"call(${VNCSEXE} --help)\"` => [ `setSeverityColor ERR NOK` ]"
	    _ret=${ABORT};
	fi
    fi

    if [ -z "${VNCVEXE}" ];then
	ABORT=2
	printERR $LINENO $BASH_SOURCE ${ABORT} "Missing executable for VNCviewer"
	printERR $LINENO $BASH_SOURCE ${ABORT} "can not find:"
	printERR $LINENO $BASH_SOURCE ${ABORT} " -> vncviewer"
	printERR $LINENO $BASH_SOURCE ${ABORT} ""
	printERR $LINENO $BASH_SOURCE ${ABORT} "Check your PATH"
	printERR $LINENO $BASH_SOURCE ${ABORT} " -> PATH=${PATH}"
	printERR $LINENO $BASH_SOURCE ${ABORT} ""
	if [ "${C_SESSIONTYPE}" == "VNC" -a -z "${_checkonly}" ];then
	    gotoHell ${ABORT}
	else
	    return ${ABORT}
	fi
	_ret=${ABORT};
    fi


    if [ -n "`${VNCVEXE} --help 2>&1|egrep '(RealVNC)'`" ];then
#	_verstrg=`${VNCVEXE} --help 2>&1|awk '/VNC [Vv]iewer/{printf("%s\n",$5);}'`
	_verstrg=`${VNCVEXE} --help 2>&1|sed -n 's/VNC [Vv]iewer[^0-9]*\([0-9]*.[0-9]*.[0-9]*\).*/\1/p'`
	ABORT=2;
	if [ -n "$_verstrg" ];then
            _verstrg="RealVNC-${_verstrg}"
	    printDBG $S_LIB ${D_SYS} $LINENO "$BASH_SOURCE" "$FUNCNAME:`setSeverityColor TRY \"call(${VNCVEXE} -version)\"` => [ `setSeverityColor INF OK` ]"
	    _ret=0;
	else
	    printDBG $S_LIB ${D_SYS} $LINENO "$BASH_SOURCE" "$FUNCNAME:`setSeverityColor TRY \"call(${VNCVEXE} --version)\"` => [ `setSeverityColor ERR NOK` ]"
	    _ret=${ABORT};
	fi
    else
	if [ -n "`${VNCVEXE} --help 2>&1|egrep '(TightVNC)'`" ];then
	    _verstrg=`${VNCVEXE} --help 2>&1|awk -v a=${_allign} '/[vV]iewer [vV]ersion/{printf("%s\n",$4);}'`
	    ABORT=2;
	    if [ -n "$_verstrg" ];then
		_verstrg="TightVNC-${_verstrg}"
		printDBG $S_LIB ${D_SYS} $LINENO "$BASH_SOURCE" "$FUNCNAME:`setSeverityColor TRY \"call(${VNCVEXE} -version)\"` => [ `setSeverityColor INF OK` ]"
		_ret=0;
	    else
		printDBG $S_LIB ${D_SYS} $LINENO "$BASH_SOURCE" "$FUNCNAME:`setSeverityColor TRY \"call(${VNCVEXE} --version)\"` => [ `setSeverityColor ERR NOK` ]"
		_ret=${ABORT};
	    fi
	else
	    if [ -n "`${VNCVEXE} --help 2>&1|egrep '(open display:)'`" ];then
		printWNG 1 $LINENO $BASH_SOURCE 0  "DISPLAY is not available"
		printWNG 1 $LINENO $BASH_SOURCE 0  " 1. One common cause is the call of \"ssh\" without the \"-X\""
		printWNG 1 $LINENO $BASH_SOURCE 0  "    option. Even for the utilized check by \"vncviewer --help\" "
		printWNG 1 $LINENO $BASH_SOURCE 0  "    option a display is required."
  		_verstrg=GENERIC
		_ret=0;
	    else
		printWNG 1 $LINENO $BASH_SOURCE 0  "Can not evaluate version for \"which-ed\" vncviewer."
		printWNG 1 $LINENO $BASH_SOURCE 0  "."
		printWNG 1 $LINENO $BASH_SOURCE 0  " 1. One common cause is the call of \"ssh\" without the \"-X\""
		printWNG 1 $LINENO $BASH_SOURCE 0  "    option. Even for the utilized check by \"vncviewer --help\" "
		printWNG 1 $LINENO $BASH_SOURCE 0  "    option a display is required."
		printWNG 1 $LINENO $BASH_SOURCE 0  " 2. Another common cause for the initial usage is the missing "
		printWNG 1 $LINENO $BASH_SOURCE 0  "    permission \"X11Forwarding yes\" in \"/etc/ssh/sshd_conf\"."
  		_verstrg=GENERIC
		_ret=0;
	    fi
	fi
    fi

    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "VNC"
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "  _verstrg=${_verstrg}"


    #currently somewhat restrictive to specific versions.
    case ${_verstrg} in
	"TightVNC"*)
	    VNC_MAGIC=VNCT;
	    VNC_STATE=ENABLED;
	    VNC_PREREQ="${VNC_PREREQ}%${_verstrg}-${MYARCH} vncserver,vncviewer";
	    VNCSERVER_OPT="${VNCSERVER_OPT_TightVNC}";
	    VNCVIEWER_OPT="${VNCVIEWER_OPT_TightVNC}";
	    _ret=0;
	    ;;

	"RealVNC"*)
	    VNC_MAGIC=VNCR;
	    VNC_STATE=ENABLED;
	    VNC_PREREQ="${VNC_PREREQ}%${_verstrg}-${MYARCH} vncserver,vncviewer";
            VNCSERVER_OPT="${VNCSERVER_OPT_RealVNC}";
            VNCVIEWER_OPT="${VNCVIEWER_OPT_RealVNC}";
	    _ret=0;
	    ;;

         *)
	    VNC_MAGIC=VNCG;
            VNCSERVER_OPT="${VNCSERVER_OPT_GENERIC}";
            VNCVIEWER_OPT="${VNCVIEWER_OPT_GENERIC}";
	    VNC_PREREQ="${VNC_PREREQ}%${_verstrg}-${MYARCH}";
	    _ret=2;
	    ;;
    esac
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "VNC_MAGIC       = ${VNC_MAGIC}"
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "VNC_VERSTRING   = ${VNC_VERSTRING}"
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "VNC_STATE       = ${VNC_STATE}"
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "VNC_PREREQ      = ${VNC_PREREQ}"
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "VNCSERVER_OPT   = ${VNCSERVER_OPT}"
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "VNCVIEWER_OPT   = ${VNCVIEWER_OPT}"
    return $_ret;
}







#FUNCBEG###############################################################
#NAME:
#  noClientServerSplitSupportedMessageVNC
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#
#EXAMPLE:
#
#PARAMETERS:
#
#OUTPUT:
#  RETURN:
#  VALUES:
#
#FUNCEND###############################################################
function noClientServerSplitSupportedMessageVNC () {
    ABORT=2
    printERR $LINENO $BASH_SOURCE ${ABORT} "Unexpected ERROR!!!"
    printERR $LINENO $BASH_SOURCE ${ABORT} "VNC perfectly supports ClientServerSplit!!!"
    printERR $LINENO $BASH_SOURCE ${ABORT} "Check for process ownership, probably just missing permissions."
    printERR $LINENO $BASH_SOURCE ${ABORT} "On grave slow machines just a timeout may have occured."
    printERR $LINENO $BASH_SOURCE ${ABORT} "Try a following connect, if so adapt TIMEOUT value, but for this target only."
}



#FUNCBEG###############################################################
#NAME:
#  clientServerSplitSupportedVNC
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#  Checks whether the split of client and server is supported.
#  This is just a hardcoded attribute.
#
#EXAMPLE:
#
#PARAMETERS:
#
#OUTPUT:
#  RETURN:
#    0: If supported
#    1: else
#
#  VALUES:
#
#FUNCEND###############################################################
function clientServerSplitSupportedVNC () {
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME $1"
    case $1 in
	CREATE)return 0;;
	CANCEL)return 0;;
    esac
    return 1;
}



#FUNCBEG###############################################################
#NAME:
#  enumerateMySessionsVNC
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#  Not supported.
#
#EXAMPLE:
#
#PARAMETERS:
#
#OUTPUT:
#  RETURN:
#  VALUES:
#
#FUNCEND###############################################################
function enumerateMySessionsVNC () {
    printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "$FUNCNAME:\$@=${@}"
}


#
#Managed load of sub-packages gwhich are required in almost any case.
#On-demand-loads will be performed within requesting action.
#
hookPackage "${_myPKGBASE_VNC}/session"
hookPackage "${_myPKGBASE_VNC}/list"
hookPackage "${_myPKGBASE_VNC}/info"

if [ -d "${HOME}/.ctys" -a -d "${HOME}/.ctys/vnc" ];then
    #Source pre-set environment from user
    if [ -f "${HOME}/.ctys/vnc/vnc.conf" ];then
	. "${HOME}/.ctys/vnc/vnc.conf"
    fi

    #Source pre-set environment from installation 
    if [ -f "${MYCONFPATH}/vnc/vnc/cli.conf" ];then
	. "${MYCONFPATH}/conf/vnc/vnc.conf"
    fi
fi



#FUNCBEG###############################################################
#NAME:
#  handleVNC
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#
#EXAMPLE:
#
#PARAMETERS:
#  $1: <OPMODE>
#  $2: <ACTION>
#
#OUTPUT:
#  RETURN:
#
#  VALUES:
#
#FUNCEND###############################################################
function handleVNC () {
  printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "${FUNCNAME}:$*"
  local OPMODE=$1;shift
  local ACTION=$1;shift

  case ${ACTION} in

      CREATE) 
	  case ${OPMODE} in
              PROLOGUE)
		  ;;
              EPILOGUE)
		  ;;
	      CHECKPARAM|ASSEMBLE|EXECUTE)
		  hookPackage "${_myPKGBASE_VNC}/create"
		  createConnectVNC ${OPMODE} ${ACTION} 
		  ;;
	  esac
          ;;

      CANCEL)
	  case ${OPMODE} in
              PROLOGUE)
		  ;;
              EPILOGUE)
		  ;;
	      CHECKPARAM|ASSEMBLE|EXECUTE)
		  hookPackage "${_myPKGBASE_VNC}/cancel"
		  cutCancelSessionVNC ${OPMODE} ${ACTION} 
		  ;;
	  esac
          ;;


      GETCLIENTPORT)
	  case ${OPMODE} in
              PROLOGUE)
		  ;;
              EPILOGUE)
		  ;;
              CHECKPARAM)
		  if [ -n "$C_MODE_ARGS" ];then
                      printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "C_MODE_ARGS=$C_MODE_ARGS"
                      _C_GETCLIENTPORT=$C_MODE_ARGS
		  else
		      ABORT=1
		      printERR $LINENO $BASH_SOURCE ${ABORT} "Missing <session-label>|<session-id>"
		      gotoHell ${ABORT}
		  fi

                  ;;
	      EXECUTE)
		  printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "Remote command:C_MODE_ARGS=${C_MODE_ARGS}"
		  printDBG $S_VNC ${D_BULK} $LINENO $BASH_SOURCE "CLIENTPORT(VNC,${MYHOST},${_C_GETCLIENTPORT})=`getClientTPVNC ${_C_GETCLIENTPORT}`"
  		  echo "CLIENTPORT(VNC,${MYHOST},${_C_GETCLIENTPORT})=`getClientTPVNC ${_C_GETCLIENTPORT}`"
		  gotoHell 0
		  ;;
 	      ASSEMBLE)
   		  ;;
          esac
	  ;;

      *)
          #SUSPEND|RESUME|RESET
          ABORT=1;
          printERR $LINENO $BASH_SOURCE ${ABORT} "System Error, unsupported ACTION for VNC:ACTION=${ACTION} OPMODE=${OPMODE}"
          ;;
  esac

}


#FUNCBEG###############################################################
#NAME:
#  initVNC
#
#TYPE:
#  bash-function
#
#DESCRIPTION:
#
#EXAMPLE:
#
#PARAMETERS:
#
#OUTPUT:
#  RETURN:
#
#  VALUES:
#
#FUNCEND###############################################################
function initVNC () {
  local _curInit=$1;shift
  local _initConsequences=$1
  local ret=0;


  local _raise=$((INITSTATE<_curInit));

  printDBG $S_VNC ${D_MAINT} $LINENO $BASH_SOURCE "$FUNCNAME:${INITSTATE} -> ${_curInit} - ${_raise}"

  if [ "$_raise" == "1" ];then
      #for raise of INITSTATE do not touch the OS's decisions, just expand.

      case $_curInit in
	  0);;#NOP - Done by shell
	  1)  #add own help to searchlist for options
	      MYOPTSFILES="${MYOPTSFILES} ${MYHELPPATH}/010_vnc"
              setVersionVNC $_initConsequences

              ret=$?
	      ;;
	  2);;
	  3);;
	  4);;
	  5);;
	  6);;
      esac
  else
      case $_curInit in
	  *);;
      esac

  fi

  return $ret
}

[Qemu-devel] vnc port selection

[Gerd Hoffmann]

  Hi folks,

Xen's qemu-dm version has a '-vncunused' command line switch which asks
the internal vnc server to pick any unused tcp port to listen on.  The
actual port is communicated to the outside world via xenstore.

I'm looking for a reasonable way to implement that functionality in
upstream qemu.  First, I think it shouldn't be a separate command line
switch but an option for the existion -vnc switch.  Second, we need a
way to communicate the port picked which isn't xen-specific.  Obvious
choice is a monitor info subcommand.

Comments?  Other suggestions?

cheers,
  Gerd

-- 
http://kraxel.fedorapeople.org/xenner/

Re: [Qemu-devel] vnc port selection

[Anthony Liguori]

Gerd Hoffmann wrote:
>   Hi folks,
>
> Xen's qemu-dm version has a '-vncunused' command line switch which asks
> the internal vnc server to pick any unused tcp port to listen on.  The
> actual port is communicated to the outside world via xenstore.
>
> I'm looking for a reasonable way to implement that functionality in
> upstream qemu.  First, I think it shouldn't be a separate command line
> switch but an option for the existion -vnc switch.

Maybe something like a to=N option.  So you would have:

-vnc localhost:0,to=10

That would try from displays 0 to 10 and select the first one it could 
attach to.

>   Second, we need a
> way to communicate the port picked which isn't xen-specific.  Obvious
> choice is a monitor info subcommand.
>   

There's already an info vnc.  It can be added to that.

Regards,

Anthony Liguori

> Comments?  Other suggestions?
>
> cheers,
>   Gerd
>
>   

Re: [Qemu-devel] vnc port selection

[Avi Kivity]

Gerd Hoffmann wrote:
>   Hi folks,
>
> Xen's qemu-dm version has a '-vncunused' command line switch which asks
> the internal vnc server to pick any unused tcp port to listen on.  The
> actual port is communicated to the outside world via xenstore.
>
> I'm looking for a reasonable way to implement that functionality in
> upstream qemu.  First, I think it shouldn't be a separate command line
> switch but an option for the existion -vnc switch.  Second, we need a
> way to communicate the port picked which isn't xen-specific.  Obvious
> choice is a monitor info subcommand.
>
> Comments?  Other suggestions?
>
>   

Presumably -vncunused is passed by the management application, which 
knows about all domains.  Can't it figure out an unused port and pass it on?

Alternatively, have the management application pass an fd denoting the 
socket.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

Re: [Qemu-devel] vnc port selection

[Anthony Liguori]

Avi Kivity wrote:
> Gerd Hoffmann wrote:
>>   Hi folks,
>>
>> Xen's qemu-dm version has a '-vncunused' command line switch which asks
>> the internal vnc server to pick any unused tcp port to listen on.  The
>> actual port is communicated to the outside world via xenstore.
>>
>> I'm looking for a reasonable way to implement that functionality in
>> upstream qemu.  First, I think it shouldn't be a separate command line
>> switch but an option for the existion -vnc switch.  Second, we need a
>> way to communicate the port picked which isn't xen-specific.  Obvious
>> choice is a monitor info subcommand.
>>
>> Comments?  Other suggestions?
>>
>>   
>
> Presumably -vncunused is passed by the management application, which 
> knows about all domains.  Can't it figure out an unused port and pass 
> it on?

An argument for this sort of semantics is that if you just launch 
vncserver with no argument, it'll sit on the first unused port.  So 
people are sort of used to this behavior.

> Alternatively, have the management application pass an fd denoting the 
> socket.

If you are allocating the ports in the management tool, then just tell 
QEMU what port to open up.  I don't think you gain anything passing an fd.

Regards,

Anthony Liguori

Re: [Xen-devel] Re: [Qemu-devel] vnc port selection

[Daniel P. Berrange]

On Thu, Aug 21, 2008 at 09:30:21PM +0300, Avi Kivity wrote:
> Gerd Hoffmann wrote:
> >  Hi folks,
> >
> >Xen's qemu-dm version has a '-vncunused' command line switch which asks
> >the internal vnc server to pick any unused tcp port to listen on.  The
> >actual port is communicated to the outside world via xenstore.
> >
> >I'm looking for a reasonable way to implement that functionality in
> >upstream qemu.  First, I think it shouldn't be a separate command line
> >switch but an option for the existion -vnc switch.  Second, we need a
> >way to communicate the port picked which isn't xen-specific.  Obvious
> >choice is a monitor info subcommand.
> >
> >Comments?  Other suggestions?
> >
> >  
> 
> Presumably -vncunused is passed by the management application, which 
> knows about all domains.  Can't it figure out an unused port and pass it on?
>

Yes & no. Yes, we do this in libvirt, but it open a race condition
unless you pass the actual file descriptor to QEMU. In addition when
we add IPv6 support to QEMU, you will actally have multiple sockets
you need to listen on. It will make it far easier if we just do the
right thing in QEMU, based on a command line flag. 

Daniel
-- 
|: Red Hat, Engineering, London   -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org  -o-  http://virt-manager.org  -o-  http://ovirt.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-  F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|

Re: [Xen-devel] Re: [Qemu-devel] vnc port selection

[Daniel P. Berrange]

On Thu, Aug 21, 2008 at 01:35:57PM -0500, Anthony Liguori wrote:
> Avi Kivity wrote:
> >Gerd Hoffmann wrote:
> >>  Hi folks,
> >>
> >>Xen's qemu-dm version has a '-vncunused' command line switch which asks
> >>the internal vnc server to pick any unused tcp port to listen on.  The
> >>actual port is communicated to the outside world via xenstore.
> >>
> >>I'm looking for a reasonable way to implement that functionality in
> >>upstream qemu.  First, I think it shouldn't be a separate command line
> >>switch but an option for the existion -vnc switch.  Second, we need a
> >>way to communicate the port picked which isn't xen-specific.  Obvious
> >>choice is a monitor info subcommand.
> >>
> >>Comments?  Other suggestions?
> >>
> >>  
> >
> >Presumably -vncunused is passed by the management application, which 
> >knows about all domains.  Can't it figure out an unused port and pass 
> >it on?
> 
> An argument for this sort of semantics is that if you just launch 
> vncserver with no argument, it'll sit on the first unused port.  So 
> people are sort of used to this behavior.
> 
> >Alternatively, have the management application pass an fd denoting the 
> >socket.
> 
> If you are allocating the ports in the management tool, then just tell 
> QEMU what port to open up.  I don't think you gain anything passing an fd.

And it as I mentioned it'll make adding IPv6 support harder. 

Daniel
-- 
|: Red Hat, Engineering, London   -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org  -o-  http://virt-manager.org  -o-  http://ovirt.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-  F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|

Re: [Qemu-devel] vnc port selection

[Avi Kivity]

Anthony Liguori wrote:
>
>> Alternatively, have the management application pass an fd denoting 
>> the socket.
>
> If you are allocating the ports in the management tool, then just tell 
> QEMU what port to open up.  I don't think you gain anything passing an 
> fd.
>

It prevents races, allows listening on non-traditional sockets (vnc over 
unix-domain), and allows privilege separation.

-- 
error compiling committee.c: too many arguments to function

Re: [Qemu-devel] vnc port selection

[Jamie Lokier]

Avi Kivity wrote:
> Anthony Liguori wrote:
> >
> >>Alternatively, have the management application pass an fd denoting 
> >>the socket.
> >
> >If you are allocating the ports in the management tool, then just tell 
> >QEMU what port to open up.  I don't think you gain anything passing an 
> >fd.
> >
> 
> It prevents races, allows listening on non-traditional sockets (vnc over 
> unix-domain), and allows privilege separation.

Agreed: races are particularly irksome.

I have the same problem in another application, where one program
allocates a fee port, but another (SSH tunnel) opens it.  It's very
annoying that the second program fails from time to time, due to the
race.

-- Jamie

Re: [Xen-devel] Re: [Qemu-devel] vnc port selection

[Ian Jackson]

Anthony Liguori writes ("[Xen-devel] Re: [Qemu-devel] vnc port selection"):
> Avi Kivity wrote:
> > Presumably -vncunused is passed by the management application, which 
> > knows about all domains.  Can't it figure out an unused port and pass 
> > it on?
> 
> An argument for this sort of semantics is that if you just launch 
> vncserver with no argument, it'll sit on the first unused port.  So 
> people are sort of used to this behavior.

Exactly.  So that's why we need both the ability to do this, and the
ability to find out what port was eventually used.

> > Alternatively, have the management application pass an fd denoting the 
> > socket.
> 
> If you are allocating the ports in the management tool, then just tell 
> QEMU what port to open up.  I don't think you gain anything passing an fd.

That has a race, because you commit to the port before having
prevented another application from grabbing it.  I think the `pick
unused port' option is more sensible.

Ian.