[Qemu-devel] [PATCH] block/ssh: Require libssh2 >= 1.2.8.

[Qemu-devel] [PATCH] block/ssh: Require libssh2 >= 1.2.8.

[Richard W.M. Jones]

From: "Richard W.M. Jones" <rjones@redhat.com>

libssh2 >= 1.2.8 is required to enable this block device (because
that version introduced the libssh2_session_handshake call).

Change the test to use pkg-config exclusively.  If the user requests
--enable-libssh2 and the minimum version is not available, then the
following error is displayed:

  $ ./configure --enable-libssh2

  ERROR: libssh2 >= 1.2.8 required for --enable-libssh2

If --enable-libssh2 is not specified, then the feature is silently
disabled if sufficiently new libssh2 is not available.
---
 configure | 24 ++++--------------------
 1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/configure b/configure
index ed49f91..4ec6eaa 100755
--- a/configure
+++ b/configure
@@ -2353,35 +2353,19 @@ fi
 
 ##########################################
 # libssh2 probe
+min_libssh2_version=1.2.8
 if test "$libssh2" != "no" ; then
-  cat > $TMPC <<EOF
-#include <stdio.h>
-#include <libssh2.h>
-#include <libssh2_sftp.h>
-int main(void) {
-    LIBSSH2_SESSION *session;
-    session = libssh2_session_init ();
-    (void) libssh2_sftp_init (session);
-    return 0;
-}
-EOF
-
-  if $pkg_config libssh2 --modversion >/dev/null 2>&1; then
+  if $pkg_config --atleast-version=$min_libssh2_version libssh2 >/dev/null 2>&1
+  then
     libssh2_cflags=`$pkg_config libssh2 --cflags`
     libssh2_libs=`$pkg_config libssh2 --libs`
-  else
-    libssh2_cflags=
-    libssh2_libs="-lssh2"
-  fi
-
-  if compile_prog "$libssh2_cflags" "$libssh2_libs" ; then
     libssh2=yes
     libs_tools="$libssh2_libs $libs_tools"
     libs_softmmu="$libssh2_libs $libs_softmmu"
     QEMU_CFLAGS="$QEMU_CFLAGS $libssh2_cflags"
   else
     if test "$libssh2" = "yes" ; then
-      feature_not_found "libssh2"
+      error_exit "libssh2 >= $min_libssh2_version required for --enable-libssh2"
     fi
     libssh2=no
   fi
-- 
1.8.1.4

Re: [Qemu-devel] [PATCH] block/ssh: Require libssh2 >= 1.2.8.

[Stefan Hajnoczi]

On Fri, Apr 19, 2013 at 09:16:39AM +0100, Richard W.M. Jones wrote:
> From: "Richard W.M. Jones" <rjones@redhat.com>
> 
> libssh2 >= 1.2.8 is required to enable this block device (because
> that version introduced the libssh2_session_handshake call).
> 
> Change the test to use pkg-config exclusively.  If the user requests
> --enable-libssh2 and the minimum version is not available, then the
> following error is displayed:
> 
>   $ ./configure --enable-libssh2
> 
>   ERROR: libssh2 >= 1.2.8 required for --enable-libssh2
> 
> If --enable-libssh2 is not specified, then the feature is silently
> disabled if sufficiently new libssh2 is not available.
> ---
>  configure | 24 ++++--------------------
>  1 file changed, 4 insertions(+), 20 deletions(-)

Two comments:

1. This patch also drops non-pkgconfig support.  I guess this is okay.

2. RHEL 5 and Debian stable do not have libssh2 1.2.8.  Since this is a
   new feature for the QEMU 1.5 release, no one is expecting it to be
   available for old distros.  Therefore, not a problem.

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan