And while we're at it, also provide a proper entry for this feature
in meson_options.txt, so that people who don't need it have a knob
to disable this feature.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 configure                     | 17 -----------------
 meson.build                   |  8 ++++++++
 meson_options.txt             |  2 ++
 net/meson.build               |  4 +++-
 scripts/meson-buildoptions.sh |  3 +++
 5 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/configure b/configure
index 8fe03b6230..170b1b237a 100755
--- a/configure
+++ b/configure
@@ -1907,20 +1907,6 @@ if test -z "$want_tools"; then
     fi
 fi
 
-##########################################
-# L2TPV3 probe
-
-cat > $TMPC <<EOF
-#include <sys/socket.h>
-#include <linux/ip.h>
-int main(void) { return sizeof(struct mmsghdr); }
-EOF
-if compile_prog "" "" ; then
-  l2tpv3=yes
-else
-  l2tpv3=no
-fi
-
 #########################################
 # vhost interdependencies and host support
 
@@ -3544,9 +3530,6 @@ if test "$slirp_smbd" = "yes" ; then
   echo "CONFIG_SLIRP_SMBD=y" >> $config_host_mak
   echo "CONFIG_SMBD_COMMAND=\"$smbd\"" >> $config_host_mak
 fi
-if test "$l2tpv3" = "yes" ; then
-  echo "CONFIG_L2TPV3=y" >> $config_host_mak
-fi
 if test "$gprof" = "yes" ; then
   echo "CONFIG_GPROF=y" >> $config_host_mak
 fi
diff --git a/meson.build b/meson.build
index 2c5b53cbe2..5bb6b901b0 100644
--- a/meson.build
+++ b/meson.build
@@ -1678,6 +1678,13 @@ config_host_data.set('HAVE_MLOCKALL', cc.links(gnu_source_prefix + '''
     return mlockall(MCL_FUTURE);
   }'''))
 
+have_l2tpv3 = false
+if not get_option('l2tpv3').disabled() and have_system
+  have_l2tpv3 = (cc.has_header_symbol('sys/socket.h', 'struct mmsghdr')
+                 and cc.has_header('linux/ip.h'))
+endif
+config_host_data.set('CONFIG_L2TPV3', have_l2tpv3)
+
 have_netmap = false
 if not get_option('netmap').disabled() and have_system
   have_netmap = cc.compiles('''
@@ -3394,6 +3401,7 @@ summary_info += {'JACK support':      jack}
 summary_info += {'brlapi support':    brlapi}
 summary_info += {'vde support':       vde}
 summary_info += {'netmap support':    have_netmap}
+summary_info += {'l2tpv3 support':    have_l2tpv3}
 summary_info += {'Linux AIO support': libaio}
 summary_info += {'Linux io_uring support': linux_io_uring}
 summary_info += {'ATTR/XATTR support': libattr}
diff --git a/meson_options.txt b/meson_options.txt
index 4ab4570125..e740dce2a5 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -141,6 +141,8 @@ option('u2f', type : 'feature', value : 'auto',
        description: 'U2F emulation support')
 option('usb_redir', type : 'feature', value : 'auto',
        description: 'libusbredir support')
+option('l2tpv3', type : 'feature', value : 'auto',
+       description: 'l2tpv3 network backend support')
 option('netmap', type : 'feature', value : 'auto',
        description: 'netmap network backend support')
 option('vde', type : 'feature', value : 'auto',
diff --git a/net/meson.build b/net/meson.build
index 94383e7460..847bc2ac85 100644
--- a/net/meson.build
+++ b/net/meson.build
@@ -18,7 +18,9 @@ softmmu_ss.add(files(
 
 softmmu_ss.add(when: 'CONFIG_TCG', if_true: files('filter-replay.c'))
 
-softmmu_ss.add(when: 'CONFIG_L2TPV3', if_true: files('l2tpv3.c'))
+if have_l2tpv3
+  softmmu_ss.add(files('l2tpv3.c'))
+endif
 softmmu_ss.add(when: slirp, if_true: files('slirp.c'))
 softmmu_ss.add(when: vde, if_true: files('vde.c'))
 if have_netmap
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index c795a13020..55b8a78560 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -49,6 +49,7 @@ meson_options_help() {
   printf "%s\n" '  iconv           Font glyph conversion support'
   printf "%s\n" '  jack            JACK sound support'
   printf "%s\n" '  kvm             KVM acceleration support'
+  printf "%s\n" '  l2tpv3          l2tpv3 network backend support'
   printf "%s\n" '  libdaxctl       libdaxctl support'
   printf "%s\n" '  libiscsi        libiscsi userspace initiator'
   printf "%s\n" '  libnfs          libnfs block device driver'
@@ -166,6 +167,8 @@ _meson_option_parse() {
     --disable-jack) printf "%s" -Djack=disabled ;;
     --enable-kvm) printf "%s" -Dkvm=enabled ;;
     --disable-kvm) printf "%s" -Dkvm=disabled ;;
+    --enable-l2tpv3) printf "%s" -Dl2tpv3=enabled ;;
+    --disable-l2tpv3) printf "%s" -Dl2tpv3=disabled ;;
     --enable-libdaxctl) printf "%s" -Dlibdaxctl=enabled ;;
     --disable-libdaxctl) printf "%s" -Dlibdaxctl=disabled ;;
     --enable-libiscsi) printf "%s" -Dlibiscsi=enabled ;;
-- 
2.27.0

On 28/10/21 20:59, Thomas Huth wrote:
> And while we're at it, also provide a proper entry for this feature
> in meson_options.txt, so that people who don't need it have a knob
> to disable this feature.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   configure                     | 17 -----------------
>   meson.build                   |  8 ++++++++
>   meson_options.txt             |  2 ++
>   net/meson.build               |  4 +++-
>   scripts/meson-buildoptions.sh |  3 +++
>   5 files changed, 16 insertions(+), 18 deletions(-)
> 
> diff --git a/configure b/configure
> index 8fe03b6230..170b1b237a 100755
> --- a/configure
> +++ b/configure
> @@ -1907,20 +1907,6 @@ if test -z "$want_tools"; then
>       fi
>   fi
>   
> -##########################################
> -# L2TPV3 probe
> -
> -cat > $TMPC <<EOF
> -#include <sys/socket.h>
> -#include <linux/ip.h>
> -int main(void) { return sizeof(struct mmsghdr); }
> -EOF
> -if compile_prog "" "" ; then
> -  l2tpv3=yes
> -else
> -  l2tpv3=no
> -fi
> -
>   #########################################
>   # vhost interdependencies and host support
>   
> @@ -3544,9 +3530,6 @@ if test "$slirp_smbd" = "yes" ; then
>     echo "CONFIG_SLIRP_SMBD=y" >> $config_host_mak
>     echo "CONFIG_SMBD_COMMAND=\"$smbd\"" >> $config_host_mak
>   fi
> -if test "$l2tpv3" = "yes" ; then
> -  echo "CONFIG_L2TPV3=y" >> $config_host_mak
> -fi
>   if test "$gprof" = "yes" ; then
>     echo "CONFIG_GPROF=y" >> $config_host_mak
>   fi
> diff --git a/meson.build b/meson.build
> index 2c5b53cbe2..5bb6b901b0 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1678,6 +1678,13 @@ config_host_data.set('HAVE_MLOCKALL', cc.links(gnu_source_prefix + '''
>       return mlockall(MCL_FUTURE);
>     }'''))
>   
> +have_l2tpv3 = false
> +if not get_option('l2tpv3').disabled() and have_system
> +  have_l2tpv3 = (cc.has_header_symbol('sys/socket.h', 'struct mmsghdr')
> +                 and cc.has_header('linux/ip.h'))
> +endif
> +config_host_data.set('CONFIG_L2TPV3', have_l2tpv3)
> +
>   have_netmap = false
>   if not get_option('netmap').disabled() and have_system
>     have_netmap = cc.compiles('''
> @@ -3394,6 +3401,7 @@ summary_info += {'JACK support':      jack}
>   summary_info += {'brlapi support':    brlapi}
>   summary_info += {'vde support':       vde}
>   summary_info += {'netmap support':    have_netmap}
> +summary_info += {'l2tpv3 support':    have_l2tpv3}
>   summary_info += {'Linux AIO support': libaio}
>   summary_info += {'Linux io_uring support': linux_io_uring}
>   summary_info += {'ATTR/XATTR support': libattr}
> diff --git a/meson_options.txt b/meson_options.txt
> index 4ab4570125..e740dce2a5 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -141,6 +141,8 @@ option('u2f', type : 'feature', value : 'auto',
>          description: 'U2F emulation support')
>   option('usb_redir', type : 'feature', value : 'auto',
>          description: 'libusbredir support')
> +option('l2tpv3', type : 'feature', value : 'auto',
> +       description: 'l2tpv3 network backend support')
>   option('netmap', type : 'feature', value : 'auto',
>          description: 'netmap network backend support')
>   option('vde', type : 'feature', value : 'auto',
> diff --git a/net/meson.build b/net/meson.build
> index 94383e7460..847bc2ac85 100644
> --- a/net/meson.build
> +++ b/net/meson.build
> @@ -18,7 +18,9 @@ softmmu_ss.add(files(
>   
>   softmmu_ss.add(when: 'CONFIG_TCG', if_true: files('filter-replay.c'))
>   
> -softmmu_ss.add(when: 'CONFIG_L2TPV3', if_true: files('l2tpv3.c'))
> +if have_l2tpv3
> +  softmmu_ss.add(files('l2tpv3.c'))
> +endif
>   softmmu_ss.add(when: slirp, if_true: files('slirp.c'))
>   softmmu_ss.add(when: vde, if_true: files('vde.c'))
>   if have_netmap
> diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
> index c795a13020..55b8a78560 100644
> --- a/scripts/meson-buildoptions.sh
> +++ b/scripts/meson-buildoptions.sh
> @@ -49,6 +49,7 @@ meson_options_help() {
>     printf "%s\n" '  iconv           Font glyph conversion support'
>     printf "%s\n" '  jack            JACK sound support'
>     printf "%s\n" '  kvm             KVM acceleration support'
> +  printf "%s\n" '  l2tpv3          l2tpv3 network backend support'
>     printf "%s\n" '  libdaxctl       libdaxctl support'
>     printf "%s\n" '  libiscsi        libiscsi userspace initiator'
>     printf "%s\n" '  libnfs          libnfs block device driver'
> @@ -166,6 +167,8 @@ _meson_option_parse() {
>       --disable-jack) printf "%s" -Djack=disabled ;;
>       --enable-kvm) printf "%s" -Dkvm=enabled ;;
>       --disable-kvm) printf "%s" -Dkvm=disabled ;;
> +    --enable-l2tpv3) printf "%s" -Dl2tpv3=enabled ;;
> +    --disable-l2tpv3) printf "%s" -Dl2tpv3=disabled ;;
>       --enable-libdaxctl) printf "%s" -Dlibdaxctl=enabled ;;
>       --disable-libdaxctl) printf "%s" -Dlibdaxctl=disabled ;;
>       --enable-libiscsi) printf "%s" -Dlibiscsi=enabled ;;
> 

Queued, thanks.

Paolo