Re: [PATCH] sslh: Update to version 1.20

[ummeegge <ummeegge@ipfire.org>]

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Hi Michael and thanks for looking into this.

On Mi, 2019-04-24 at 12:04 +0100, Michael Tremer wrote:
> Hi,
> 
> Thanks for working on this. I have a couple of questions and remarks.
> 
> > On 23 Apr 2019, at 08:06, Erik Kapfer <ummeegge(a)ipfire.org> wrote:
> > 
> > - Added USELIBCAP=1 to enable the possibility for transparent
> > option.
> > - Wrote configuration directives in initscript into variable for
> > better overview.
> > - Introduce chroot directive in start parameter.
> > - Added new user and group sslh (will be deleted if uninstall).
> > - Changed EXTERNAL_IP_FUNCT to serve data also for configuration
> > block but use it also as check as before.
> > - Added symlinks in sslh paks since the initscripts LFS do not
> > serves it in old installation (a reboot does not started sslh
> > again).
> > - Deleted sslh symlinks in initscripts LFS since they are served
> > via sslh paks and are not needed anymore.
> > 
> > Signed-off-by: Erik Kapfer <ummeegge(a)ipfire.org>
> > ---
> > lfs/initscripts               |  3 --
> > lfs/sslh                      | 12 ++++----
> > src/initscripts/packages/sslh | 65
> > +++++++++++++++++++++++++++++++++----------
> > src/paks/sslh/install.sh      | 13 +++++++++
> > src/paks/sslh/uninstall.sh    |  9 ++++++
> > 5 files changed, 79 insertions(+), 23 deletions(-)
> > 
> > diff --git a/lfs/initscripts b/lfs/initscripts
> > index 055e106d0..3173a04e4 100644
> > --- a/lfs/initscripts
> > +++ b/lfs/initscripts
> > @@ -136,9 +136,6 @@ $(TARGET) :
> > 	ln -sf ../init.d/client175   /etc/rc.d/rc0.d/K34client175
> > 	ln -sf ../init.d/client175   /etc/rc.d/rc3.d/S66client175
> > 	ln -sf ../init.d/client175   /etc/rc.d/rc6.d/K34client175
> > -	ln -sf ../init.d/sslh        /etc/rc.d/rc3.d/S98sslh
> > -	ln -sf ../init.d/sslh        /etc/rc.d/rc0.d/K02sslh
> > -	ln -sf ../init.d/sslh        /etc/rc.d/rc6.d/K02sslh
> > 	ln -sf ../init.d/vdradmin    /etc/rc.d/rc3.d/S99vdradmin
> > 	ln -sf ../init.d/vdradmin    /etc/rc.d/rc0.d/K01vdradmin
> > 	ln -sf ../init.d/vdradmin    /etc/rc.d/rc6.d/K01vdradmin
> > diff --git a/lfs/sslh b/lfs/sslh
> > index 100cec065..dedd10272 100644
> > --- a/lfs/sslh
> > +++ b/lfs/sslh
> > @@ -1,7 +1,7 @@
> > ###################################################################
> > ############
> > #                                                                  
> >            #
> > # IPFire.org - A linux based
> > firewall                                         #
> > -# Copyright (C) 2007-2018  IPFire Team  <info(a)ipfire.org>         
> >             #
> > +# Copyright (C) 2007-2019  IPFire Team  <info(a)ipfire.org>         
> >             #
> > #                                                                  
> >            #
> > # This program is free software: you can redistribute it and/or
> > modify        #
> > # it under the terms of the GNU General Public License as published
> > by        #
> > @@ -24,7 +24,7 @@
> > 
> > include Config
> > 
> > -VER        = 1.7a
> > +VER        = 1.20
> > 
> > THISAPP    = sslh-$(VER)
> > DL_FILE    = $(THISAPP).tar.gz
> > @@ -32,7 +32,7 @@ DL_FROM    = $(URL_IPFIRE)
> > DIR_APP    = $(DIR_SRC)/$(THISAPP)
> > TARGET     = $(DIR_INFO)/$(THISAPP)
> > PROG       = sslh
> > -PAK_VER    = 5
> > +PAK_VER    = 6
> > 
> > DEPS       = ""
> > 
> > @@ -44,7 +44,7 @@ objects = $(DL_FILE)
> > 
> > $(DL_FILE) = $(DL_FROM)/$(DL_FILE)
> > 
> > -$(DL_FILE)_MD5 = ee124654412198a5e11fe28acf10634d
> > +$(DL_FILE)_MD5 = 0db26ed2825b1ef6c83959a988279912
> > 
> > install : $(TARGET)
> > 
> > @@ -77,8 +77,8 @@ $(subst %,%_MD5,$(objects)) :
> > $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
> > 	@$(PREBUILD)
> > 	@rm -rf $(DIR_APP) && cd $(DIR_SRC) && tar zxf
> > $(DIR_DL)/$(DL_FILE)
> > -	cd $(DIR_APP) && make CFLAGS="$(CFLAGS)" $(MAKETUNING)
> > USELIBWRAP=
> > -	cd $(DIR_APP) && install -v -m 755 sslh /usr/sbin
> > +	cd $(DIR_APP) && make CFLAGS="$(CFLAGS)" $(MAKETUNING)
> > USELIBCAP=1 USELIBWRAP=
> > +	cd $(DIR_APP) && install -v -m 755 sslh-fork /usr/sbin/sslh
> > 
> > 	#install initscripts
> > 	$(call INSTALL_INITSCRIPT,sslh)
> 
> It looks all fine up to this point.
> 
> > diff --git a/src/initscripts/packages/sslh
> > b/src/initscripts/packages/sslh
> > index 43e58f392..0935b1114 100644
> > --- a/src/initscripts/packages/sslh
> > +++ b/src/initscripts/packages/sslh
> > @@ -3,31 +3,68 @@
> > 
> > # Based on sysklogd script from LFS-3.1 and earlier.
> > # Rewritten by Gerard Beekmans  - gerard(a)linuxfromscratch.org
> > +#
> > +# $LastChangedBy: ummeegge - ummeegge(a)ipfire.org $
> > +# $Date: 2019-04-04 04:35:09 -0500 (Thu, 04 Apr 2019) $
> > +#
> > +#############################################################
> > +#
> 
> You do not need to include authorship headers because Git will take
> care of this.
Done.

> 
> > 
> > . /etc/sysconfig/rc
> > . $rc_functions
> > 
> > +DAEMON="/usr/sbin/sslh"
> > +
> > +# Check for external IP address and provide it to listening option
> > +EXTERNAL_IP_ADDRESS="$(</var/ipfire/red/local-ipaddress)"
> > +EXTERNAL_IP_FUNCT() {
> > +        if [ -z "${EXTERNAL_IP_ADDRESS}" ]; then
> > +                echo_failure
> > +                boot_mesg -n "FAILURE:\n\nCould not determine"
> > ${FAILURE}
> > +                boot_mesg -n " your external IP address."
> > +                boot_mesg "" ${NORMAL}
> > +                exit 1
> > +        fi
> > +}
> 
> Although you are starting the service rather late in the boot
> process, it might indeed happen that this goes wrong. How do we
> recover from this? The service should be started eventually when RED
> comes up.
I tried to leave the most options pretty much the same as they where
before whereby the numbers of the symlinks are a part of this the
testings did not delivered problems with this but better to stay save
there.
The network initscript starts at 'S20' where i think RED will be
started too what you think is a good starting point for sslh ?

> 
> What if the IP address on RED changes? How is sslh notified?
I think it won´t currently. Have seen some configurations which uses
0.0.0.0 for the --listen option but this can cause bigger troubles if
'443' is the --listen port here i think. As far as i can see only a
restart of sslh would fix this currently.
May you have an idea here ?


> 
> > +
> > +# Loopback interface
> > +LO="127.0.0.1"
> > +# Used TCP ports
> > +LISTENPORT="443"
> > +SSHPORT="222"
> > +TLSPORT="444"
> > +OPENVPNPORT=“1194"
> 
> Can we use hard-coded port numbers here?
Here arises also some more questions for me.
We can grep for them in the configuration files but also may a check
for the correct usage can be made since e.g. OpenVPN needs to run with
TCP for example.
Should we really provide TCP 444 in here for external access ? I think
also SSH might be more secure via VPN but may a little more acceptable
if no VPN is in usage?!
The main topic in the tests we made in the forum where mainly for LAN
instances on seperated machines (mostly webservers) where those
questions may be not that critical?!

> 
> > +
> > +# Configuration options
> > +DAEMON_OPTS="
> > +--user sslh
> > +--listen ${EXTERNAL_IP_ADDRESS}:${LISTENPORT}
> > +--ssh ${LO}:${SSHPORT}
> > +--tls ${LO}:${TLSPORT}
> > +--openvpn ${LO}:${OPENVPNPORT}
> > +--pidfile /var/run/sslh.pid
> > +-C /var/empty
> > +"
> > +
> > +# Check for binary
> > +if ! [ -x "$(command -v ${DAEMON})" ]; then
> > +	echo "Error: could not find ${DAEMON}" >&2
> > +	exit 1
> > +fi
> 
> No need for this check really. We don’t have it anywhere else.
Done.

> 
> > +
> > +# Check for external IP
> > +EXTERNAL_IP_FUNCT
> 
> This does not really need to be a function because the if statement
> above isn’t either.
> 
> And it should not be evaluated in the stop case. If the system is not
> online, this service can never be stopped.
> 
> I think it is best for this code to have it in the start section
> where is was before - unless I missed something here.
Have externalised the investigation of the RED address to provide it
also for the --listen option in the configuration block. To keep the
start) case also a little cleaner have decided to set the external IP
check completely outside of the start) case and set the check before
but this is fast changed.

> 
> > +
> > case "$1" in
> > 	start)
> > 		boot_mesg "Starting SSLH Deamon..."
> > -
> > -		LOCAL_IP_ADDRESS="$(</var/ipfire/red/local-ipaddress)"
> > -		if [ -z "${LOCAL_IP_ADDRESS}" ]; then
> > -			echo_failure
> > -			boot_mesg -n "FAILURE:\n\nCould not determine"
> > ${FAILURE}
> > -			boot_mesg -n " your external IP address."
> > -			boot_mesg "" ${NORMAL}
> > -			exit 1
> > -		fi
> > -
> > -		loadproc /usr/sbin/sslh -u nobody \
> > -			-p "${LOCAL_IP_ADDRESS}:443" -s localhost:222
> > -l localhost:444
> > +		loadproc ${DAEMON} ${DAEMON_OPTS}
> > 		evaluate_retval
> > 		;;
> > 
> > 	stop)
> > 		boot_mesg "Stopping SSLH Deamon..."
> > -		killproc /usr/sbin/sslh
> > +		killproc ${DAEMON}
> > 		evaluate_retval
> > 		;;
> > 
> > @@ -38,7 +75,7 @@ case "$1" in
> > 		;;
> > 
> > 	status)
> > -		statusproc /usr/sbin/sslh
> > +		statusproc ${DAEMON}
> > 		;;
> > 
> > 	*)
> > diff --git a/src/paks/sslh/install.sh b/src/paks/sslh/install.sh
> > index 626884bdd..df7cafc78 100644
> > --- a/src/paks/sslh/install.sh
> > +++ b/src/paks/sslh/install.sh
> > @@ -23,5 +23,18 @@
> > #
> > . /opt/pakfire/lib/functions.sh
> > extract_files
> > +
> > +# Add user and group for sslh if not already done
> > +if ! grep -q sslh /etc/passwd; then
> > +    groupadd sslh;
> > +    useradd -g sslh -M -s /sbin/nologin sslh
> > +fi
> 
> Can you change this to use getent? There are a couple of examples in
> some other scripts (e.g. tor).
Done.

> 
> You should also check if the group existed already.
I think the getent solution -->
if ! getent group sslh &>/dev/null; then
...
will do this.

> 
> > +
> > ln -s /etc/init.d/sslh /etc/rc.d/init.d/networking/red.up/50-sslh
> 
> Why is this link not in the package?
You mean in the LFS ? This is also a part of the old implementation,
might it be an idea to have it in the initscript (incl. deletion of the
symlink) ?

> 
> Should we not check if the service is running and only then restart? 
Via pgrep check in start) ?

> What happens when the service is disabled at boot time?
You mean disabled via WUI ?

> 
> > +
> > +# Set symlink for runlevels
> > +ln -svf ../init.d/sslh /etc/rc.d/rc0.d/K02sslh
> > +ln -svf ../init.d/sslh /etc/rc.d/rc3.d/S98sslh
> > +ln -svf ../init.d/sslh /etc/rc.d/rc6.d/K02sslh
> > +
> > start_service --background ${NAME}
> > diff --git a/src/paks/sslh/uninstall.sh
> > b/src/paks/sslh/uninstall.sh
> > index dca34ccbd..05bb27945 100644
> > --- a/src/paks/sslh/uninstall.sh
> > +++ b/src/paks/sslh/uninstall.sh
> > @@ -23,5 +23,14 @@
> > #
> > . /opt/pakfire/lib/functions.sh
> > stop_service ${NAME}
> > +
> > +# Delete user and group sslh
> > +if grep -q sslh /etc/passwd; then
> > +	userdel sslh
> > +	groupdel sslh
> > +fi
> 
> We don’t delete users. This will cause that log files or so will have
> no owner any more.
> 
> This won’t be an issue because we check if the user exists in the
> install script and if it does we are not trying to create it any
> more.
Done.

> 
> > +
> > remove_files
> > rm -f /etc/rc.d/init.d/networking/red.up/50-sslh
> > +# Delete initscript symlinks
> > +rm -f /etc/rc.d/rc?.d/???sslh
> > -- 
> > 2.12.2
> > 
> 
> Overall this looks good and makes this a better add-on. It looks like
> many things to change, but they are all small and should not take too
> long.
This Addon is really a old one and i was not sure if it should be
updated again or if it would be dropped since stunnel do a similar job
i think. But am happy if it can be a better one and the time to bring
it back to life was not wasted.

> 
> Best,
> -Michael
> 

Best,

Erik