vquic: add support for GnuTLS backend of ngtcp2

Currently, the TLS backend used by vquic/ngtcp2.c is selected at compile
time. Therefore OpenSSL support needs to be explicitly disabled.

Signed-off-by: Daiki Ueno <dueno@redhat.com>
Closes #5148

1 files changed, 56 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index 90a678ec8..889617ffa 100755
--- a/configure.ac
+++ b/configure.ac
@@ -3528,7 +3528,7 @@ if test X"$want_tcp2" != Xno; then
 
 fi
 
-if test "x$NGTCP2_ENABLED" = "x1"; then
+if test "x$NGTCP2_ENABLED" = "x1" -a "x$OPENSSL_ENABLED" = "x1"; then
   dnl backup the pre-ngtcp2_crypto_openssl variables
   CLEANLDFLAGS="$LDFLAGS"
   CLEANCPPFLAGS="$CPPFLAGS"
@@ -3583,6 +3583,61 @@ if test "x$NGTCP2_ENABLED" = "x1"; then
   fi
 fi
 
+if test "x$NGTCP2_ENABLED" = "x1" -a "x$GNUTLS_ENABLED" = "x1"; then
+  dnl backup the pre-ngtcp2_crypto_gnutls variables
+  CLEANLDFLAGS="$LDFLAGS"
+  CLEANCPPFLAGS="$CPPFLAGS"
+  CLEANLIBS="$LIBS"
+
+  CURL_CHECK_PKGCONFIG(libngtcp2_crypto_gnutls, $want_tcp2_path)
+
+  if test "$PKGCONFIG" != "no" ; then
+    LIB_NGTCP2_CRYPTO_GNUTLS=`CURL_EXPORT_PCDIR([$want_tcp2_path])
+      $PKGCONFIG --libs-only-l libngtcp2_crypto_gnutls`
+    AC_MSG_NOTICE([-l is $LIB_NGTCP2_CRYPTO_GNUTLS])
+
+    CPP_NGTCP2_CRYPTO_GNUTLS=`CURL_EXPORT_PCDIR([$want_tcp2_path]) dnl
+      $PKGCONFIG --cflags-only-I libngtcp2_crypto_gnutls`
+    AC_MSG_NOTICE([-I is $CPP_NGTCP2_CRYPTO_GNUTLS])
+
+    LD_NGTCP2_CRYPTO_GNUTLS=`CURL_EXPORT_PCDIR([$want_tcp2_path])
+      $PKGCONFIG --libs-only-L libngtcp2_crypto_gnutls`
+    AC_MSG_NOTICE([-L is $LD_NGTCP2_CRYPTO_GNUTLS])
+
+    LDFLAGS="$LDFLAGS $LD_NGTCP2_CRYPTO_GNUTLS"
+    CPPFLAGS="$CPPFLAGS $CPP_NGTCP2_CRYPTO_GNUTLS"
+    LIBS="$LIB_NGTCP2_CRYPTO_GNUTLS $LIBS"
+
+    if test "x$cross_compiling" != "xyes"; then
+      DIR_NGTCP2_CRYPTO_GNUTLS=`echo $LD_NGTCP2_CRYPTO_GNUTLS | $SED -e 's/-L//'`
+    fi
+    AC_CHECK_LIB(ngtcp2_crypto_gnutls, ngtcp2_crypto_ctx_initial,
+      [
+       AC_CHECK_HEADERS(ngtcp2/ngtcp2_crypto.h,
+          NGTCP2_ENABLED=1
+          AC_DEFINE(USE_NGTCP2_CRYPTO_GNUTLS, 1, [if ngtcp2_crypto_gnutls is in use])
+          AC_SUBST(USE_NGTCP2_CRYPTO_GNUTLS, [1])
+          CURL_LIBRARY_PATH="$CURL_LIBRARY_PATH:$DIR_NGTCP2_CRYPTO_GNUTLS"
+          export CURL_LIBRARY_PATH
+          AC_MSG_NOTICE([Added $DIR_NGTCP2_CRYPTO_GNUTLS to CURL_LIBRARY_PATH])
+       )
+      ],
+        dnl not found, revert back to clean variables
+        LDFLAGS=$CLEANLDFLAGS
+        CPPFLAGS=$CLEANCPPFLAGS
+        LIBS=$CLEANLIBS
+    )
+
+  else
+    dnl no ngtcp2_crypto_gnutls pkg-config found, deal with it
+    if test X"$want_tcp2" != Xdefault; then
+      dnl To avoid link errors, we do not allow --with-ngtcp2 without
+      dnl a pkgconfig file
+      AC_MSG_ERROR([--with-ngtcp2 was specified but could not find ngtcp2_crypto_gnutls pkg-config file.])
+    fi
+  fi
+fi
+
 dnl **********************************************************************
 dnl Check for nghttp3 (HTTP/3 with ngtcp2)
 dnl **********************************************************************