[Qemu-block] [PATCH v4 00/14] Implement TLS support to QEMU NBD server & client

[Daniel P. Berrange]

This is an update of the series previously posted:

  v1: https://lists.gnu.org/archive/html/qemu-devel/2015-11/msg06126.html
  v2: https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg01580.html
  v3: https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg03440.html

This series of patches implements support for TLS in the QEMU NBD
server and client code.

It is implementing the NBD_OPT_STARTTLS option that was previously
discussed here:

  https://www.redhat.com/archives/libvir-list/2014-October/msg00506.html

And is also described in the NBD spec here:

  https://github.com/yoe/nbd/blob/master/doc/proto.md

To ensure that clients always get a suitable error message from the
NBD server when it is configured with TLS, a client speaking the
new style protocol will always send NBD_OPT_LIST as the first thing
it does, so that we can see the NBD_REP_ERR_TLS_REQD response. This
should all be backwards & forwards compatible with previous QEMU
impls of NBD

Usage of TLS is described in the commit messages for each patch,
but for sake of people who don't want to explore the series, here's
the summary

Starting QEMU system emulator with a disk backed by an TLS encrypted
NBD export

  $ qemu-system-x86_64 \
     -object 
tls-creds-x509,id=tls0,endpoint=client,dir=/home/berrange/security/qemutls \
     -drive driver=nbd,host=localhost,port=9000,tls-creds=tls0

Starting a standalone NBD server providing a TLS encrypted NBD export

  $ qemu-nbd \
     --object 
tls-creds-x509,id=tls0,endpoint=server,dir=/home/berrange/security/qemutls
     --tls-creds tls0 \
     --export-name default \
     $IMAGEFILE

The --export-name is optional, if omitted, the default "" will
be used.

Starting a QEMU system emulator built-in NBD server

  $ qemu-system-x86_64 \
     -qmp unix:/tmp/qmp,server \
     -hda /home/berrange/Fedora-Server-netinst-x86_64-23.iso \
     -object 
tls-creds-x509,id=tls0,dir=/home/berrange/security/qemutls,endpoint=server

  $ qmp-shell /tmp/qmp
    (qmp) nbd-server-start addr={"host":"localhost","port":"9000"} 
tls-creds=tls0
    (qmp) nbd-server-add device=ide0-hd0

This series depends on this bug fix I recently sent:

  https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg03406.html

And the qemu-nbd/etc command line options work

  https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg03381.html

The first 4 patches are the conversion to the I/O channels
framework.

The next 6 patches are general tweaks to QEMU's impl of the
NBD protocol for better compliance and/or future proofing.

The next patch provides the NBD protocol TLS implementation.

The final 3 patches allow TLS to be enabled in the QEMU NBD
client and servers.

Changed in v4:

 - Don't pick the first export name in the list if no export
   name is provided (Paolo)
 - Set client requested export name to "" if none is provided
   by the user (Paolo)
 - Set server advertized export name to "" if TLS is enabled
   and none is provided by the user (Paolo)
 - Rename qemu-nbd --exportname to --export-name (Paolo)
 - Use iov_discard_front() to simplify iov handling (Paolo)

Changed in v3:

 - Rebase to resolve conflicts with recently merged NBD patches

Changed in v2:

 - Fix error codes used during NBD TLS option negotiate
 - Update patch with helpers for UserCreatable object types

Daniel P. Berrange (14):
  nbd: convert block client to use I/O channels for connection setup
  nbd: convert qemu-nbd server to use I/O channels for connection setup
  nbd: convert blockdev NBD server to use I/O channels for connection
    setup
  nbd: convert to using I/O channels for actual socket I/O
  nbd: invert client logic for negotiating protocol version
  nbd: make server compliant with fixed newstyle spec
  nbd: make client request fixed new style if advertized
  nbd: allow setting of an export name for qemu-nbd server
  nbd: always query export list in fixed new style protocol
  nbd: use "" as a default export name if none provided
  nbd: implement TLS support in the protocol negotiation
  nbd: enable use of TLS with NBD block driver
  nbd: enable use of TLS with qemu-nbd server
  nbd: enable use of TLS with nbd-server-start command

 Makefile            |   6 +-
 block/nbd-client.c  |  91 +++++++----
 block/nbd-client.h  |  10 +-
 block/nbd.c         | 105 ++++++++++---
 blockdev-nbd.c      | 131 +++++++++++++---
 hmp.c               |   2 +-
 include/block/nbd.h |  28 +++-
 nbd/client.c        | 440 +++++++++++++++++++++++++++++++++++++++++++++-------
 nbd/common.c        |  83 ++++++----
 nbd/nbd-internal.h  |  32 ++--
 nbd/server.c        | 334 ++++++++++++++++++++++++++++-----------
 qapi/block.json     |   4 +-
 qemu-nbd.c          | 159 ++++++++++++++-----
 qemu-nbd.texi       |   7 +
 qmp-commands.hx     |   2 +-
 tests/Makefile      |   2 +-
 16 files changed, 1123 insertions(+), 313 deletions(-)

-- 
2.5.0