block: convert quorum blockdrv to use crypto APIs

Get rid of direct use of gnutls APIs in quorum blockdrv in
favour of using the crypto APIs. This avoids the need to
do conditional compilation of the quorum driver. It can
simply report an error at file open file instead if the
required hash algorithm isn't supported by QEMU.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-8-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

block/Makefile.objs

@@ -3,7 +3,7 @@ block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-c
 block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
 block-obj-y += qed-check.o
 block-obj-$(CONFIG_VHDX) += vhdx.o vhdx-endian.o vhdx-log.o
-block-obj-$(CONFIG_QUORUM) += quorum.o
+block-obj-y += quorum.o
 block-obj-y += parallels.o blkdebug.o blkverify.o
 block-obj-y += block-backend.o snapshot.o qapi.o
 block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o

block/quorum.c

@@ -13,8 +13,6 @@
  * See the COPYING file in the top-level directory.
  */
 
-#include <gnutls/gnutls.h>
-#include <gnutls/crypto.h>
 #include "block/block_int.h"
 #include "qapi/qmp/qbool.h"
 #include "qapi/qmp/qdict.h"
@@ -24,6 +22,7 @@
 #include "qapi/qmp/qlist.h"
 #include "qapi/qmp/qstring.h"
 #include "qapi-event.h"
+#include "crypto/hash.h"
 
 #define HASH_LENGTH 32
 
@@ -34,7 +33,7 @@
 
 /* This union holds a vote hash value */
 typedef union QuorumVoteValue {
-    char h[HASH_LENGTH];       /* SHA-256 hash */
+    uint8_t h[HASH_LENGTH];    /* SHA-256 hash */
     int64_t l;                 /* simpler 64 bits hash */
 } QuorumVoteValue;
 
@@ -428,25 +427,21 @@ static void quorum_free_vote_list(QuorumVotes *votes)
 
 static int quorum_compute_hash(QuorumAIOCB *acb, int i, QuorumVoteValue *hash)
 {
-    int j, ret;
-    gnutls_hash_hd_t dig;
     QEMUIOVector *qiov = &acb->qcrs[i].qiov;
+    size_t len = sizeof(hash->h);
+    uint8_t *data = hash->h;
 
-    ret = gnutls_hash_init(&dig, GNUTLS_DIG_SHA256);
-
-    if (ret < 0) {
-        return ret;
+    /* XXX - would be nice if we could pass in the Error **
+     * and propagate that back, but this quorum code is
+     * restricted to just errno values currently */
+    if (qcrypto_hash_bytesv(QCRYPTO_HASH_ALG_SHA256,
+                            qiov->iov, qiov->niov,
+                            &data, &len,
+                            NULL) < 0) {
+        return -EINVAL;
     }
 
-    for (j = 0; j < qiov->niov; j++) {
-        ret = gnutls_hash(dig, qiov->iov[j].iov_base, qiov->iov[j].iov_len);
-        if (ret < 0) {
-            break;
-        }
-    }
-
-    gnutls_hash_deinit(dig, (void *) hash);
-    return ret;
+    return 0;
 }
 
 static QuorumVoteVersion *quorum_get_vote_winner(QuorumVotes *votes)
@@ -870,6 +865,12 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
     int i;
     int ret = 0;
 
+    if (!qcrypto_hash_supports(QCRYPTO_HASH_ALG_SHA256)) {
+        error_setg(errp,
+                   "SHA256 hash support is required for quorum device");
+        return -EINVAL;
+    }
+
     qdict_flatten(options);
 
     /* count how many different children are present */

configure

@@ -336,7 +336,6 @@ vte=""
 tpm="yes"
 libssh2=""
 vhdx=""
-quorum=""
 numa=""
 tcmalloc="no"
 
@@ -1146,10 +1145,6 @@ for opt do
   ;;
   --disable-vhdx) vhdx="no"
   ;;
-  --disable-quorum) quorum="no"
-  ;;
-  --enable-quorum) quorum="yes"
-  ;;
   --disable-numa) numa="no"
   ;;
   --enable-numa) numa="yes"
@@ -1382,7 +1377,6 @@ disabled with --disable-FEATURE, default is enabled if available:
   tpm             TPM support
   libssh2         ssh block device support
   vhdx            support for the Microsoft VHDX image format
-  quorum          quorum block filter support
   numa            libnuma support
   tcmalloc        tcmalloc support
 
@@ -2377,33 +2371,6 @@ EOF
   fi
 fi
 
-##########################################
-# Quorum probe (check for gnutls)
-if test "$quorum" != "no" ; then
-cat > $TMPC <<EOF
-#include <gnutls/gnutls.h>
-#include <gnutls/crypto.h>
-int main(void) {char data[4096], digest[32];
-gnutls_hash_fast(GNUTLS_DIG_SHA256, data, 4096, digest);
-return 0;
-}
-EOF
-quorum_tls_cflags=`$pkg_config --cflags gnutls 2> /dev/null`
-quorum_tls_libs=`$pkg_config --libs gnutls 2> /dev/null`
-if compile_prog "$quorum_tls_cflags" "$quorum_tls_libs" ; then
-  qcow_tls=yes
-  libs_softmmu="$quorum_tls_libs $libs_softmmu"
-  libs_tools="$quorum_tls_libs $libs_softmmu"
-  QEMU_CFLAGS="$QEMU_CFLAGS $quorum_tls_cflags"
-  quorum="yes"
-else
-  if test "$quorum" = "yes"; then
-    feature_not_found "gnutls" "gnutls > 2.10.0 required to compile Quorum"
-  fi
-  quorum="no"
-fi
-fi
-
 ##########################################
 # VNC SASL detection
 if test "$vnc" = "yes" -a "$vnc_sasl" != "no" ; then
@@ -4592,7 +4559,6 @@ echo "libssh2 support   $libssh2"
 echo "TPM passthrough   $tpm_passthrough"
 echo "QOM debugging     $qom_cast_debug"
 echo "vhdx              $vhdx"
-echo "Quorum            $quorum"
 echo "lzo support       $lzo"
 echo "snappy support    $snappy"
 echo "bzip2 support     $bzip2"
@@ -5074,10 +5040,6 @@ if test "$libssh2" = "yes" ; then
   echo "LIBSSH2_LIBS=$libssh2_libs" >> $config_host_mak
 fi
 
-if test "$quorum" = "yes" ; then
-  echo "CONFIG_QUORUM=y" >> $config_host_mak
-fi
-
 if test "$vhdx" = "yes" ; then
   echo "CONFIG_VHDX=y" >> $config_host_mak
 fi