Libreswan on Debian Wheezy

Executive Summary

# enable workarounds and compile:
echo USE_GLIBC_KERN_FLIP_HEADERS=true >> Makefile.inc.local
echo "USE_SYSTEMD_WATCHDOG=false" >> Makefile.inc.local
echo "USE_DNSSEC=false" >> Makefile.inc.local
echo "USE_NIC_OFFLOAD=false" >>  Makefile.inc.local
make deb

Details about the issues of libreswan on Debian Wheezy

You need 3 workarounds to compile on Debian Wheezy. The workaround #1 is very specific to Wheezy (libc < 2.19 and kernel < 3.12). Later distributions fixed issues #1 and #2. #3 is because libunbound is too old.

conflict between netinet/in.h and linux/in6.h

It got worse by commit 07a01d3 to xfrm.in in libreswan. The issue has a long history. It is partly due to UAPI ABI out of sync and partly due to updating local copy of xfrm.h with commit 07a01d3 while supporting nic-offload for Mellanox cards. We could have worked around 07a01d3, however, it was easy to keep xfrm.h in sync with kernel UAPI copy 4.12 which seemed to work in most cases(glibc 2.19+ kernel 3.12+); except Wheezy!

                -c /home/build/libreswan/programs/pluto/kernel_netlink.c
/bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)
In file included from
/home/build/libreswan/programs/pluto/linux-copy/linux/xfrm.h:4:0,
                 from
/home/build/libreswan/programs/pluto/kernel_netlink.c:52:
/usr/include/linux/in6.h:30:8: error: redefinition of 'struct in6_addr'
In file included from /home/build/libreswan/linux/include/libreswan.h:212:0,
                 from
/home/build/libreswan/programs/pluto/kernel_netlink.c:51:
/usr/include/netinet/in.h:198:8: note: originally defined here

dpkg -S linux/in6.h
linux-libc-dev:amd64: /usr/include/linux/in.h

dpkg -S netinet/in.h
libc6-dev:amd64: /usr/include/netinet/in.h

Package: libc6-dev
Source: eglibc
Version: 2.13-38+deb7u10

The local copy
programs/pluto/linux-copy/linux/xfrm.h is updated linux kernel 4.12

Workaround : enable header files workaround

echo USE_GLIBC_KERN_FLIP_HEADERS=true >> Makefile.inc.local

Details about the conflict

glibc 2.19+

https://sourceware.org/bugzilla/show_bug.cgi?id=15850 If you have glibc 2.19+ you may have flip the two lines in programs/pluto/kernel_netlink.c

52 #include "linux/xfrm.h" /* local (if configured) or system copy */
51 #include "libreswan.h" /* before xfrm.h otherwise break on F22 */

Why not commit this

We default to ensure newer systems compile properly. If there is a conflict with older systems, we write workarounds for the older code. Ideally, we get to remove ancient workarounds after a long long time without the need to keep old version workarounds forever.

How does this work on RHEL/CentOS 7.3 or even 6.8

Most likely they have backports to fix this. 7.3 has kernel 3.10 and glibc 2.17

With kernel 3.12 and libc-dev 2.19+ =

Kernel made more efforts fix this issue https://github.com/torvalds/linux/commit/cfd280c91253cc28e4919e349fa7a813b63e71e8

Can't link with libsystemd

This error is with debian.

/usr/bin/ld: cannot find -lsystemd 
collect2: error: ld returned 1 exit status
 
 Package: libsystemd-daemon-dev
 Source: systemd
 Version: 44-11+deb7u5

Workaround: USE_SYSTEMD_WATCHDOG=false

in libreswan src directory

echo "USE_SYSTEMD_WATCHDOG=false" >> Makefile.inc.local

FYI: debian stretch seems to have proper libsystemd-dev

Wheezy libunbound2 (1.4.17) do not support libevent

(NOTE: this is not re-compiling issue, you need > 1.5x)

/home/build/libreswan/lib/libswan/unbound.c:187: undefined reference to
`ub_ctx_create_event'
collect2: error: ld returned 1 exit status

apt-cache show libunbound2
Package: libunbound2
Source: unbound
Version: 1.4.17-3+deb7u2

Workaround : USE_DNSSEC=false

echo "USE_DNSSEC=false" >> Makefile.inc.local

If you have libunbound version less than 1.5.0 disable is the only way. libunbound2 1.5.0 above should be compiled with --with-libevent --enable-event-api

NOTE: to compile libunbound2 + libevent on Wheezy your best bet is upstream. unbound-1.6.0 from jessie-backports has unmet dependencies on Wheeezy. Strech package is not dowards compaitable.

Fixed in.h/in6.h conflict in #master

If you have have master with commit a7d8a0bbb9cff171b9d0ba5ee36293f92a1b1eba on Debian Wheezy disable NIC Offload and use system's xfrm.h. Then you can compile.

nic-offload disable commit to v3.21

git clone https://github.com/libreswan/libreswan 
cd libreswan 
git checkout v3.21
git cherry-pick a7d8a0bbb9cff171b9d0ba5ee36293f92a1b1eba

echo USE_XFRM_HEADER_COPY=false >>  Makefile.inc.local
echo USE_NIC_OFFLOAD=false >>  Makefile.inc.local
echo USE_DNSSEC=false >> Makefile.inc.local
echo USE_SYSTEMD_WATCHDOG=false >> Makefile.inc.local

https://github.com/libreswan/libreswan/commit/a7d8a0bbb9cff171b9d0ba5ee36293f92a1b1eba

Kernel headers 4.16 later : uapi/if_ether.h error: redefinition of 'struct in6_addr' struct in6_addr

Kernel 4.16 got a fix that could cause error:

In file included from /<<PKGBUILDDIR>>/programs/pluto/linux-copy/linux/xfrm.h:4:0,
                 from /<<PKGBUILDDIR>>/programs/pluto/kernel_netlink.c:55:
/usr/include/linux/in6.h:33:8: error: redefinition of 'struct in6_addr'  struct in6_addr {
           ^~~~~~~~
In file included from /<<PKGBUILDDIR>>/linux/include/libreswan.h:76:0,
                  from /<<PKGBUILDDIR>>/programs/pluto/kernel_netlink.c:54:
/usr/include/netinet/in.h:211:8: note: originally defined here  struct in6_addr
         ^~~~~~~~

https://www.spinics.net/lists/stable/msg215023.html