Hi Peter, > Older toolchains need to include sys/types.h and sys/socket.h before > linux/if.h, RTA_PREF was introduces with linux-4.1.x. sounds like these are two separate fixes. > > Fixes: > > In file included from ell/rtnl.c:28:0: > .../host/arm-buildroot-linux-gnueabi/sysroot/usr/include/linux/if.h:185:19: error: field 'ifru_addr' has incomplete type > .../host/arm-buildroot-linux-gnueabi/sysroot/usr/include/linux/if.h:186:19: error: field 'ifru_dstaddr' has incomplete type > .../host/arm-buildroot-linux-gnueabi/sysroot/usr/include/linux/if.h:187:19: error: field 'ifru_broadaddr' has incomplete type > .../host/arm-buildroot-linux-gnueabi/sysroot/usr/include/linux/if.h:188:19: error: field 'ifru_netmask' has incomplete type > .../arm-buildroot-linux-gnueabi/sysroot/usr/include/linux/if.h:189:20: error: field 'ifru_hwaddr' has incomplete type > ell/rtnl.c: In function 'l_rtnl_route_extract': > ell/rtnl.c:120:8: error: 'RTA_PREF' undeclared (first use in this function) > --- > configure.ac | 2 ++ > ell/rtnl.c | 7 ++++++- > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/configure.ac b/configure.ac > index 0351f89..3be35a4 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -113,6 +113,8 @@ AC_CHECK_LIB(dl, dlopen, dummy=yes, > > AC_CHECK_HEADERS(linux/types.h linux/if_alg.h) > > +AC_CHECK_DECLS([RTA_PREF], [], [], [[#include <linux/rtnetlink.h>]]) > + > AC_ARG_ENABLE(glib, AC_HELP_STRING([--enable-glib], > [enable ell/glib main loop example]), > [enable_glib=${enableval}]) > diff --git a/ell/rtnl.c b/ell/rtnl.c > index dc83937..3493d34 100644 > --- a/ell/rtnl.c > +++ b/ell/rtnl.c > @@ -25,8 +25,9 @@ > #endif > > #define _GNU_SOURCE > -#include <linux/if.h> > +#include <sys/types.h> > #include <sys/socket.h> > +#include <linux/if.h> > #include <arpa/inet.h> > > #include "util.h" > @@ -35,6 +36,10 @@ > #include "rtnl.h" > #include "private.h" > > +#if defined HAVE_DECL_RTA_PREF && !HAVE_DECL_RTA_PREF > +#define RTA_PREF 20 > +#endif > + Do we actually care about such an ancient kernel? And I don’t get the if check above.

Regards Marcel