[mpls-linux-devel] quagga-ldp successful build

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Many people here have reported problems with quagga compilation with
mpld/ldp support. AFAIK the developer Vasu Dasari submitted a patch for both
the quagga-tree and ldp-portable tree, but only the ldp-portable patch were
added to the git repo. This may be what breaked the build-system.
So applying Vasu's path (link below) manually to the mpls-quagga tree and
following the traditional steps did it.

Vasu's patch for quagga:
http://sourceforge.net/mailarchive/attachment.php?list_name=mpls-linux-devel&message_id=65d0eee90906110946q36579ee7l1b9b1e15ef255ba6%40mail.gmail.com&counter=2

Compilation how-to (debian approach):

1)
//download and extract the quagga-mpls and quagga-ldp-portable trees:
$ git clone git://repo.or.cz/mpls-quagga.git
$ git clone git://repo.or.cz/mpls-ldp-portable.git
//applying "git archive master | bzip2 > ./mpls-xxx.tar.bz2" is not strictly
necessary

//apply the Vasu's patch for quagga:
$ cd mpls-quagga
$ patch -p1 < ../0001-Quagga-MPLS-fixes-and-improvements.patch

2)
//compilations requirements
# apt-get install gawk
# apt-get install libreadline-dev
# apt-get install build-essential autoconf libtool
//to convert .dia doc files to .png
# apt-get install dia texinfo

3)
//another point now is that the build-system will look at "/usr/include" by
default
//to search for the mpls-linux headers, but our mpls-kernel includes should
be at
//something like "/usr/src/linux-2.6.27.24/include"
//I dont know how to fix it but there is a workaround:

First, open the configure.ac script and add "-I
/usr/src/kernel-2.6.27.24/include" (or whatever is your dir) to the gcc
cflags (line 123).
Now gcc will correctly include the mpls headers, but the configure script
will continue to look on /usr/include, so we have to edit the configure.ac:

Change...
<i>dnl ----------
dnl MPLS check
dnl ----------
MPLS_METHOD=""
AC_MSG_CHECKING(whether this OS has MPLS stack)
AM_CONDITIONAL(MPLS_ENABLED, test "x${enable_mpls}" != "xno")
if test "${enable_mpls}" = "no"; then
  enable_ldpd="no"
  enable_rsvpd="no"
  AC_MSG_RESULT(disabled)
else
  if test "x${enable_mpls}" = "xnull"; then
    AC_DEFINE(HAVE_MPLS,1,Enable MPLS)
    MPLS_METHOD="mpls_null.o"
    AC_MSG_RESULT(MPLS Null)
  else
    AC_EGREP_CPP(yes, [
    #include <linux/mpls.h>
    #if MPLS_LINUX_VERSION
    yes
    #endif],
    [AC_DEFINE(HAVE_MPLS,1,Enable MPLS)
     AC_DEFINE(LINUX_MPLS,1,Linux MPLS)
     MPLS_METHOD="mpls_netlink.o"
     AC_MSG_RESULT(MPLS Linux)],
    [enable_ldpd="no"
     enable_rsvpd="no"
     AC_MSG_RESULT(no)]
    )
  fi
fi
AC_SUBST(MPLS_METHOD)</i>

to...
<i>
dnl ----------
dnl MPLS check
dnl ----------
MPLS_METHOD=""
AC_MSG_CHECKING(whether this OS has MPLS stack)
AM_CONDITIONAL(MPLS_ENABLED, test "x${enable_mpls}" != "xno")
if test "${enable_mpls}" = "no"; then
  enable_ldpd="no"
  enable_rsvpd="no"
  AC_MSG_RESULT(disabled)
else
  if test "x${enable_mpls}" = "xnull"; then
    AC_DEFINE(HAVE_MPLS,1,Enable MPLS)
    MPLS_METHOD="mpls_null.o"
    AC_MSG_RESULT(MPLS Null)
  else
#    AC_EGREP_CPP(yes, [
#    #include <linux/mpls.h>
#    #if MPLS_LINUX_VERSION
#    yes
#    #endif],
#    [
    AC_DEFINE(HAVE_MPLS,1,Enable MPLS)
     AC_DEFINE(LINUX_MPLS,1,Linux MPLS)
     MPLS_METHOD="mpls_netlink.o"
     AC_MSG_RESULT(MPLS Linux)
#                ],
#    [enable_ldpd="no"
#     enable_rsvpd="no"
#     AC_MSG_RESULT(no)]
#   )
  fi
fi
AC_SUBST(MPLS_METHOD)
</i>

4)
$ cd mpls-quagga/ldpd
$ nano ./create-links
//now modify 'create-links' to point DEFSRC to the ldp-portable folder
$ ./create-links
$ cd ..
$ autoreconf -i
$ ./configure --sysconfdir=/usr/local/quagga
--localstatedir=/usr/local/quagga --enable-vtysh --enable-netlink
--enable-mpls --enable-ldpd --disable-rsvpd

//memtypes.h and route_types.h are defined as targets on the makefiles but
for
//some reason they are not been processed by awk, so we have to make it
manually
//this have been corrected on the quagga 0.99.13 release
$ gawk -f ./lib/memtypes.awk ./lib/memtypes.c > ./lib/memtypes.h
$ gawk -f ./lib/route_types.awk ./lib/route_types.txt > ./lib/route_types.h

5)
$ make
# mkdir /usr/local/quagga
# make install

6)
# adduser quagga
# chown quagga:quagga /usr/local/quagga
$ cd /usr/local/quagga/
# cp zebra.conf.sample zebra.conf
# touch ldpd.conf

7)
//sometimes we have the dev files but not the lib itself
# apt-get install libcap2-bin

//type "ldd /usr/local/sbin/zebra"
//if appears "libzebra.so.0 => not found", then:
# cp /usr/local/lib/libzebra.* /lib/

8)
//now...
$ zebra -d -A 127.0.0.1
$ ldpd -d -A 127.0.0.1
$ vtysh

//inside vtysh you can play a little
lsr#mpls show forwarding
lsr#conf t
lsr(config)#mpls static 0
lsr(config)#label-map ...

-----x--------

Despite the successful compilation, i had some problems. MPLS/LDP commands
were available on the quagga CLI but some of them dont work as expected. I
will list some issues i've faced:

1 - It's not possible to build the quagga with mpls support if the
'--disable-ipv6' flag is given to the configure script. Actually the
build-system isn't very good at all, if we enable mpls and disable ldp, for
example, the ldp commands are still available on the zebra daemon. This
should be fixed.

2 - Mpls "show" commands are ok but sometimes when I try to change some
configuration the following error comes up:
Warning: closing connection to zebra because of an I/O error! (btw this
should be a error not a warning!)
Using strace its possible to see that this happens at a 'read' system call
which should return one file descriptor but returns 0. The fix of this error
is hard and requires a good knowledge of the quagga/zebra framewok.

3 - After enabling LDP, I can't see any "LDP Hello Messages" on wireshark.

4 - After typing the following:
lsr(config)# mpls static 0
lsr(config-ls)# label-map gen 16 swap gen 17 nexthop eth1 192.168.3.1

The 'mpls ilm/nhlfe/xc show' still empty, maybe I'm missing something?

5 - Changing any configuration on zebra causes the daemon to starts
consuming about 99% of the CPU!

6 - The software is very unstable, vtysh freezes frequently and I need to
"killall -9 zebra; killall vtysh" to come back.

I'm working to port the mpls+ldp code to the quagga 0.99.15, many bug fixes
were made on the quagga tree and maybe this may help to we have more luck
next time! Any help would be appreciated.

(sorry for my english)

Regards,
Renato Westphal