Re: [Qemu-devel] [PATCH 07/10] block: convert quorum blockdrv to use crypto APIs

[Gonglei <arei.gonglei@huawei.com>]

On 2015/5/21 18:56, Daniel P. Berrange wrote:
> 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>
> ---
>  block/Makefile.objs |  2 +-
>  block/quorum.c      | 38 +++++++++++++++++++-------------------
>  configure           | 39 ---------------------------------------
>  3 files changed, 20 insertions(+), 59 deletions(-)
> 
> diff --git a/block/Makefile.objs b/block/Makefile.objs
> index 0d8c2a4..8f908d9 100644
> --- a/block/Makefile.objs
> +++ b/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
> diff --git a/block/quorum.c b/block/quorum.c
> index f91ef75..4193f30 100644
> --- a/block/quorum.c
> +++ b/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"
> @@ -23,6 +21,9 @@
>  #include "qapi/qmp/qlist.h"
>  #include "qapi/qmp/qstring.h"
>  #include "qapi-event.h"
> +#include "crypto/hash.h"
> +
> +#include <glib/gi18n.h>
>  
>  #define HASH_LENGTH 32
>  
> @@ -33,7 +34,7 @@
>  
>  /* 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;
>  
> @@ -427,25 +428,18 @@ 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;
> -
> -    ret = gnutls_hash_init(&dig, GNUTLS_DIG_SHA256);
> -
> -    if (ret < 0) {
> -        return ret;
> +    size_t len = sizeof(hash->h);
> +    uint8_t *data = hash->h;
> +
> +    if (qcrypto_hash_bytesv(QCRYPTO_HASH_ALG_SHA256,
> +                            qiov->iov, qiov->niov,
> +                            &data, &len,
> +                            NULL) < 0) {

The last argument should not be NULL, maybe miss error message.

Regards,
-Gonglei

> +        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)
> @@ -872,6 +866,12 @@ 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, "%s",
> +                   _("SHA256 hash support is required for quorum device"));
> +        return -EINVAL;
> +    }
> +
>      qdict_flatten(options);
>      qdict_extract_subqdict(options, &sub, "children.");
>      qdict_array_split(sub, &list);
> diff --git a/configure b/configure
> index a48aa90..cc60f0b 100755
> --- a/configure
> +++ b/configure
> @@ -336,7 +336,6 @@ vte=""
>  tpm="yes"
>  libssh2=""
>  vhdx=""
> -quorum=""
>  numa=""
>  tcmalloc="no"
>  
> @@ -1133,10 +1132,6 @@ for opt do
>    ;;
>    --disable-vhdx) vhdx="no"
>    ;;
> -  --disable-quorum) quorum="no"
> -  ;;
> -  --enable-quorum) quorum="yes"
> -  ;;
>    --disable-numa) numa="no"
>    ;;
>    --enable-numa) numa="yes"
> @@ -1416,8 +1411,6 @@ Advanced options (experts only):
>    --enable-libssh2         enable ssh block device support
>    --disable-vhdx           disable support for the Microsoft VHDX image format
>    --enable-vhdx            enable support for the Microsoft VHDX image format
> -  --disable-quorum         disable quorum block filter support
> -  --enable-quorum          enable quorum block filter support
>    --disable-numa           disable libnuma support
>    --enable-numa            enable libnuma support
>    --disable-tcmalloc       disable tcmalloc support
> @@ -2414,33 +2407,6 @@ EOF
>  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
>    cat > $TMPC <<EOF
> @@ -4562,7 +4528,6 @@ 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     $bzip2"
> @@ -5038,10 +5003,6 @@ if test "$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
>