From 046f98d0753872b1e3189689da16c68e1f6c78c2 Mon Sep 17 00:00:00 2001 From: Daniel P. Berrangé Date: Fri, 4 Mar 2022 19:36:00 +0000 Subject: block: pass desired TLS hostname through from block driver client In commit a71d597b989fd701b923f09b3c20ac4fcaa55e81 Author: Vladimir Sementsov-Ogievskiy Date: Thu Jun 10 13:08:00 2021 +0300 block/nbd: reuse nbd_co_do_establish_connection() in nbd_open() the use of the 'hostname' field from the BDRVNBDState struct was lost, and 'nbd_connect' just hardcoded it to match the IP socket address. This was a harmless bug at the time since we block use with anything other than IP sockets. Shortly though, we want to allow the caller to override the hostname used in the TLS certificate checks. This is to allow for TLS when doing port forwarding or tunneling. Thus we need to reinstate the passing along of the 'hostname'. Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrangé Message-Id: <20220304193610.3293146-3-berrange@redhat.com> Signed-off-by: Eric Blake --- block/nbd.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'block') diff --git a/block/nbd.c b/block/nbd.c index 146d25660e..f046349055 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -92,7 +92,7 @@ typedef struct BDRVNBDState { SocketAddress *saddr; char *export, *tlscredsid; QCryptoTLSCreds *tlscreds; - const char *hostname; + const char *tlshostname; char *x_dirty_bitmap; bool alloc_depth; @@ -1836,7 +1836,7 @@ static int nbd_process_options(BlockDriverState *bs, QDict *options, error_setg(errp, "TLS only supported over IP sockets"); goto error; } - s->hostname = s->saddr->u.inet.host; + s->tlshostname = s->saddr->u.inet.host; } s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); @@ -1876,7 +1876,8 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, } s->conn = nbd_client_connection_new(s->saddr, true, s->export, - s->x_dirty_bitmap, s->tlscreds); + s->x_dirty_bitmap, s->tlscreds, + s->tlshostname); if (s->open_timeout) { nbd_client_connection_enable_retry(s->conn); -- cgit v1.2.3-55-g7522 From a0cd6d297283bedffafce939dce38f3d06f3e2cd Mon Sep 17 00:00:00 2001 From: Daniel P. Berrangé Date: Fri, 4 Mar 2022 19:36:01 +0000 Subject: block/nbd: support override of hostname for TLS certificate validation When connecting to an NBD server with TLS and x509 credentials, the client must validate the hostname it uses for the connection, against that published in the server's certificate. If the client is tunnelling its connection over some other channel, however, the hostname it uses may not match the info reported in the server's certificate. In such a case, the user needs to explicitly set an override for the hostname to use for certificate validation. This is achieved by adding a 'tls-hostname' property to the NBD block driver. Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrangé Message-Id: <20220304193610.3293146-4-berrange@redhat.com> Signed-off-by: Eric Blake --- block/nbd.c | 18 +++++++++++++++--- qapi/block-core.json | 3 +++ 2 files changed, 18 insertions(+), 3 deletions(-) (limited to 'block') diff --git a/block/nbd.c b/block/nbd.c index f046349055..0a9b6cde5b 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -90,9 +90,10 @@ typedef struct BDRVNBDState { uint32_t reconnect_delay; uint32_t open_timeout; SocketAddress *saddr; - char *export, *tlscredsid; + char *export; + char *tlscredsid; QCryptoTLSCreds *tlscreds; - const char *tlshostname; + char *tlshostname; char *x_dirty_bitmap; bool alloc_depth; @@ -121,6 +122,8 @@ static void nbd_clear_bdrvstate(BlockDriverState *bs) s->export = NULL; g_free(s->tlscredsid); s->tlscredsid = NULL; + g_free(s->tlshostname); + s->tlshostname = NULL; g_free(s->x_dirty_bitmap); s->x_dirty_bitmap = NULL; } @@ -1765,6 +1768,11 @@ static QemuOptsList nbd_runtime_opts = { .type = QEMU_OPT_STRING, .help = "ID of the TLS credentials to use", }, + { + .name = "tls-hostname", + .type = QEMU_OPT_STRING, + .help = "Override hostname for validating TLS x509 certificate", + }, { .name = "x-dirty-bitmap", .type = QEMU_OPT_STRING, @@ -1836,7 +1844,10 @@ static int nbd_process_options(BlockDriverState *bs, QDict *options, error_setg(errp, "TLS only supported over IP sockets"); goto error; } - s->tlshostname = s->saddr->u.inet.host; + s->tlshostname = g_strdup(qemu_opt_get(opts, "tls-hostname")); + if (!s->tlshostname) { + s->tlshostname = g_strdup(s->saddr->u.inet.host); + } } s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); @@ -2038,6 +2049,7 @@ static const char *const nbd_strong_runtime_opts[] = { "port", "export", "tls-creds", + "tls-hostname", "server.", NULL diff --git a/qapi/block-core.json b/qapi/block-core.json index f13b5ff942..e89f2dfb5b 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -4079,6 +4079,8 @@ # # @tls-creds: TLS credentials ID # +# @tls-hostname: TLS hostname override for certificate validation (Since 7.0) +# # @x-dirty-bitmap: A metadata context name such as "qemu:dirty-bitmap:NAME" # or "qemu:allocation-depth" to query in place of the # traditional "base:allocation" block status (see @@ -4109,6 +4111,7 @@ 'data': { 'server': 'SocketAddress', '*export': 'str', '*tls-creds': 'str', + '*tls-hostname': 'str', '*x-dirty-bitmap': { 'type': 'str', 'features': [ 'unstable' ] }, '*reconnect-delay': 'uint32', '*open-timeout': 'uint32' } } -- cgit v1.2.3-55-g7522 From e8ae8b1a75e8f6420c37be31797bd13aa7e95778 Mon Sep 17 00:00:00 2001 From: Daniel P. Berrangé Date: Fri, 4 Mar 2022 19:36:03 +0000 Subject: block/nbd: don't restrict TLS usage to IP sockets The TLS usage for NBD was restricted to IP sockets because validating x509 certificates requires knowledge of the hostname that the client is connecting to. TLS does not have to use x509 certificates though, as PSK (pre-shared keys) provide an alternative credential option. These have no requirement for a hostname and can thus be trivially used for UNIX sockets. Furthermore, with the ability to overide the default hostname for TLS validation in the previous patch, it is now also valid to want to use x509 certificates with FD passing and UNIX sockets. Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrangé Message-Id: <20220304193610.3293146-6-berrange@redhat.com> Signed-off-by: Eric Blake --- block/nbd.c | 8 ++------ blockdev-nbd.c | 6 ------ qemu-nbd.c | 8 +++----- 3 files changed, 5 insertions(+), 17 deletions(-) (limited to 'block') diff --git a/block/nbd.c b/block/nbd.c index 0a9b6cde5b..34b9429de3 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -1839,13 +1839,9 @@ static int nbd_process_options(BlockDriverState *bs, QDict *options, goto error; } - /* TODO SOCKET_ADDRESS_KIND_FD where fd has AF_INET or AF_INET6 */ - if (s->saddr->type != SOCKET_ADDRESS_TYPE_INET) { - error_setg(errp, "TLS only supported over IP sockets"); - goto error; - } s->tlshostname = g_strdup(qemu_opt_get(opts, "tls-hostname")); - if (!s->tlshostname) { + if (!s->tlshostname && + s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { s->tlshostname = g_strdup(s->saddr->u.inet.host); } } diff --git a/blockdev-nbd.c b/blockdev-nbd.c index bdfa7ed3a5..9840d25a82 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -148,12 +148,6 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, if (!nbd_server->tlscreds) { goto error; } - - /* TODO SOCKET_ADDRESS_TYPE_FD where fd has AF_INET or AF_INET6 */ - if (addr->type != SOCKET_ADDRESS_TYPE_INET) { - error_setg(errp, "TLS is only supported with IPv4/IPv6"); - goto error; - } } nbd_server->tlsauthz = g_strdup(tls_authz); diff --git a/qemu-nbd.c b/qemu-nbd.c index 18d281aba3..713e7557a9 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -808,7 +808,9 @@ int main(int argc, char **argv) socket_activation = check_socket_activation(); if (socket_activation == 0) { - setup_address_and_port(&bindto, &port); + if (!sockpath) { + setup_address_and_port(&bindto, &port); + } } else { /* Using socket activation - check user didn't use -p etc. */ const char *err_msg = socket_activation_validate_opts(device, sockpath, @@ -829,10 +831,6 @@ int main(int argc, char **argv) } if (tlscredsid) { - if (sockpath) { - error_report("TLS is only supported with IPv4/IPv6"); - exit(EXIT_FAILURE); - } if (device) { error_report("TLS is not supported with a host device"); exit(EXIT_FAILURE); -- cgit v1.2.3-55-g7522