[Qemu-block] [PATCH v3 11/19] nbd/client: Split out nbd_receive_one_meta_context()
Extract portions of nbd_negotiate_simple_meta_context() to
a new function nbd_receive_one_meta_context() that copies the
pattern of nbd_receive_list() for performing the argument
validation of one reply. The error message when the server
replies with more than one context changes slightly, but
that shouldn't happen in the common case.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-15-ebl...@redhat.com>
---
v3: rebase, without changing into a loop
---
nbd/client.c | 148 +--
nbd/trace-events | 2 +-
2 files changed, 92 insertions(+), 58 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 3c716be2719..22505199d3b 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -672,7 +672,86 @@ static int nbd_send_one_meta_context(QIOChannel *ioc,
return ret;
}
-/* nbd_negotiate_simple_meta_context:
+/*
+ * nbd_receive_one_meta_context:
+ * Called in a loop to receive and trace one set/list meta context reply.
+ * Pass non-NULL @name or @id to collect results back to the caller, which
+ * must eventually call g_free().
+ * return 1 if name is set and iteration must continue,
+ *0 if iteration is complete (including if option is unsupported),
+ *-1 with errp set for any error
+ */
+static int nbd_receive_one_meta_context(QIOChannel *ioc,
+uint32_t opt,
+char **name,
+uint32_t *id,
+Error **errp)
+{
+int ret;
+NBDOptionReply reply;
+char *local_name = NULL;
+uint32_t local_id;
+
+if (nbd_receive_option_reply(ioc, opt, , errp) < 0) {
+return -1;
+}
+
+ret = nbd_handle_reply_err(ioc, , errp);
+if (ret <= 0) {
+return ret;
+}
+
+if (reply.type == NBD_REP_ACK) {
+if (reply.length != 0) {
+error_setg(errp, "Unexpected length to ACK response");
+nbd_send_opt_abort(ioc);
+return -1;
+}
+return 0;
+} else if (reply.type != NBD_REP_META_CONTEXT) {
+error_setg(errp, "Unexpected reply type %u (%s), expected %u (%s)",
+ reply.type, nbd_rep_lookup(reply.type),
+ NBD_REP_META_CONTEXT, nbd_rep_lookup(NBD_REP_META_CONTEXT));
+nbd_send_opt_abort(ioc);
+return -1;
+}
+
+if (reply.length <= sizeof(local_id) ||
+reply.length > NBD_MAX_BUFFER_SIZE) {
+error_setg(errp, "Failed to negotiate meta context, server "
+ "answered with unexpected length %" PRIu32,
+ reply.length);
+nbd_send_opt_abort(ioc);
+return -1;
+}
+
+if (nbd_read(ioc, _id, sizeof(local_id), errp) < 0) {
+return -1;
+}
+local_id = be32_to_cpu(local_id);
+
+reply.length -= sizeof(local_id);
+local_name = g_malloc(reply.length + 1);
+if (nbd_read(ioc, local_name, reply.length, errp) < 0) {
+g_free(local_name);
+return -1;
+}
+local_name[reply.length] = '\0';
+trace_nbd_opt_meta_reply(nbd_opt_lookup(opt), local_name, local_id);
+
+if (name) {
+*name = local_name;
+} else {
+g_free(local_name);
+}
+if (id) {
+*id = local_id;
+}
+return 1;
+}
+
+/*
+ * nbd_negotiate_simple_meta_context:
* Request the server to set the meta context for export @info->name
* using @info->x_dirty_bitmap with a fallback to "base:allocation",
* setting @info->context_id to the resulting id. Fail if the server
@@ -693,50 +772,21 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
* function should lose the term _simple.
*/
int ret;
-NBDOptionReply reply;
const char *context = info->x_dirty_bitmap ?: "base:allocation";
bool received = false;
+char *name = NULL;
if (nbd_send_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
info->name, context, errp) < 0) {
return -1;
}
-if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, ,
- errp) < 0)
-{
+ret = nbd_receive_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
+ , >context_id, errp);
+if (ret < 0) {
return -1;
}
-
-ret = nbd_handle_reply_err(ioc, , errp);
-if (ret <= 0) {
-return ret;
-}
-
-if (reply.type == NBD_REP_META_CONTEXT) {
-char *name;
-
-if (reply.length != sizeof(info->context_id) + strlen(context)) {
-error_setg(errp, "Failed to negotiate meta context '%s', server "
- "answered with unexpected length %" PRIu32, context,
- reply.length);
-nbd_send_opt_abort(ioc);
-return -1;
-}
-
-if (nbd_read(ioc, >context_id, sizeof(info->context_id),
- errp) < 0) {
-return
[Qemu-block] [PATCH v3 18/19] nbd/client: Work around 3.0 bug for listing meta contexts
Commit 3d068aff forgot to advertise available qemu: contexts
when the client requests a list with 0 queries. Furthermore,
3.0 shipped with a qemu-img hack of x-dirty-bitmap (commit
216ee365) that _silently_ acts as though the entire image is
clean if a requested bitmap is not present. Both bugs have
been recently fixed, so that a modern qemu server gives full
context output right away, and the client refuses a
connection if a requested x-dirty-bitmap was not found.
Still, it is likely that there will be users that have to
work with a mix of old and new qemu versions, depending on
which features get backported where, at which point being
able to rely on 'qemu-img --list' output to know for sure
whether a given NBD export has the desired dirty bitmap is
much nicer than blindly connecting and risking that the
entire image may appear clean. We can make our --list code
smart enough to work around buggy servers by tracking
whether we've seen any qemu: replies in the original 0-query
list; if not, repeat with a single query on "qemu:" (which
may still have no replies, but then we know for sure we
didn't trip up on the server bug).
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-22-ebl...@redhat.com>
---
nbd/client.c | 19 +++
1 file changed, 19 insertions(+)
diff --git a/nbd/client.c b/nbd/client.c
index 2001e6e8160..64f3e45edd4 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -21,6 +21,7 @@
#include "qapi/error.h"
#include "trace.h"
#include "nbd-internal.h"
+#include "qemu/cutils.h"
/* Definitions for opaque data types */
@@ -828,6 +829,8 @@ static int nbd_list_meta_contexts(QIOChannel *ioc,
Error **errp)
{
int ret;
+int seen_any = false;
+int seen_qemu = false;
if (nbd_send_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
info->name, NULL, errp) < 0) {
@@ -839,9 +842,25 @@ static int nbd_list_meta_contexts(QIOChannel *ioc,
ret = nbd_receive_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
, NULL, errp);
+if (ret == 0 && seen_any && !seen_qemu) {
+/*
+ * Work around qemu 3.0 bug: the server forgot to send
+ * "qemu:" replies to 0 queries. If we saw at least one
+ * reply (probably base:allocation), but none of them were
+ * qemu:, then run a more specific query to make sure.
+ */
+seen_qemu = true;
+if (nbd_send_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
+ info->name, "qemu:", errp) < 0) {
+return -1;
+}
+continue;
+}
if (ret <= 0) {
return ret;
}
+seen_any = true;
+seen_qemu |= strstart(context, "qemu:", NULL);
info->contexts = g_renew(char *, info->contexts, ++info->n_contexts);
info->contexts[info->n_contexts - 1] = context;
}
--
2.20.1
[Qemu-block] [PATCH v3 03/19] qemu-nbd: Sanity check partition bounds
When the user requests a partition, we were using data read
from the disk as disk offsets without a bounds check. We got
lucky that even when computed offsets are out-of-bounds,
blk_pread() will gracefully catch the error later (so I don't
think a malicious image can crash or exploit qemu-nbd, and am
not treating this as a security flaw), but it's better to
flag the problem up front than to risk permanent EIO death of
the block device down the road. Also, note that the
partition code blindly overwrites any offset passed in by the
user; so make the -o/-P combo an error for less confusion.
This can be tested with nbdkit:
$ echo hi > file
$ nbdkit -fv --filter=truncate partitioning file truncate=64k
Pre-patch:
$ qemu-nbd -p 10810 -P 1 -f raw nbd://localhost:10809 &
$ qemu-io -f raw nbd://localhost:10810
qemu-io> r -v 0 1
Disconnect client, due to: Failed to send reply: reading from file failed:
Input/output error
Connection closed
read failed: Input/output error
qemu-io> q
[1]+ Doneqemu-nbd -p 10810 -P 1 -f raw
nbd://localhost:10809
Post-patch:
$ qemu-nbd -p 10810 -P 1 -f raw nbd://localhost:10809
qemu-nbd: Discovered partition 1 at offset 1048576 size 512, but size exceeds
file length 65536
Signed-off-by: Eric Blake
---
v3: new patch
---
qemu-nbd.c | 18 +-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 51b55f2e066..ff4adb9b3eb 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -1013,12 +1013,28 @@ int main(int argc, char **argv)
fd_size -= dev_offset;
if (partition != -1) {
-ret = find_partition(blk, partition, _offset, _size);
+off_t limit;
+
+if (dev_offset) {
+error_report("Cannot request partition and offset together");
+exit(EXIT_FAILURE);
+}
+ret = find_partition(blk, partition, _offset, );
if (ret < 0) {
error_report("Could not find partition %d: %s", partition,
strerror(-ret));
exit(EXIT_FAILURE);
}
+/* partition limits are (32-bit << 9); can't overflow 64 bits */
+assert(dev_offset >= 0 && dev_offset + limit >= dev_offset);
+if (dev_offset + limit > fd_size) {
+error_report("Discovered partition %d at offset %lld size %lld, "
+ "but size exceeds file length %lld", partition,
+ (long long int) dev_offset, (long long int) limit,
+ (long long int) fd_size);
+exit(EXIT_FAILURE);
+}
+fd_size = limit;
}
export = nbd_export_new(bs, dev_offset, fd_size, export_name,
--
2.20.1
[Qemu-block] [PATCH v3 02/19] qemu-nbd: Enhance man page
Document some useful qemu-nbd command lines. Mention some restrictions
on particular options, like -p being only for MBR images, or -c/-d
being Linux-only. Update some text given the recent change to no
longer serve oldstyle protocol (missed in commit 7f7dfe2a). Also,
consistently use trailing '.' in describing options.
Signed-off-by: Eric Blake
---
v3: wording improvements, use -t in more examples [Rich]
---
qemu-nbd.texi | 91 ---
1 file changed, 72 insertions(+), 19 deletions(-)
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 96b1546006a..3f22559beb4 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -10,11 +10,17 @@
Export a QEMU disk image using the NBD protocol.
+Other uses:
+@itemize
+@item
+Bind a /dev/nbdX block device to a QEMU server (on Linux).
+@end itemize
+
@c man end
@c man begin OPTIONS
@var{filename} is a disk image filename, or a set of block
-driver options if @var{--image-opts} is specified.
+driver options if @option{--image-opts} is specified.
@var{dev} is an NBD device.
@@ -27,24 +33,25 @@ supported. The common object types that it makes sense to
define are the
keys, and the @code{tls-creds} object, which is used to supply TLS
credentials for the qemu-nbd server.
@item -p, --port=@var{port}
-The TCP port to listen on (default @samp{10809})
+The TCP port to listen on (default @samp{10809}).
@item -o, --offset=@var{offset}
-The offset into the image
+The offset into the image.
@item -b, --bind=@var{iface}
-The interface to bind to (default @samp{0.0.0.0})
+The interface to bind to (default @samp{0.0.0.0}).
@item -k, --socket=@var{path}
-Use a unix socket with path @var{path}
+Use a unix socket with path @var{path}.
@item --image-opts
Treat @var{filename} as a set of image options, instead of a plain
filename. If this flag is specified, the @var{-f} flag should
not be used, instead the '@code{format=}' option should be set.
@item -f, --format=@var{fmt}
Force the use of the block driver for format @var{fmt} instead of
-auto-detecting
+auto-detecting.
@item -r, --read-only
-Export the disk as read-only
+Export the disk as read-only.
@item -P, --partition=@var{num}
-Only expose partition @var{num}
+Only expose MBR partition @var{num}. Understands physical partitions
+1-4 and logical partitions 5-8.
@item -B, --bitmap=@var{name}
If @var{filename} has a qcow2 persistent bitmap @var{name}, expose
that bitmap via the ``qemu:dirty-bitmap:@var{name}'' context
@@ -52,7 +59,7 @@ accessible through NBD_OPT_SET_META_CONTEXT.
@item -s, --snapshot
Use @var{filename} as an external snapshot, create a temporary
file with backing_file=@var{filename}, redirect the write to
-the temporary one
+the temporary one.
@item -l, --load-snapshot=@var{snapshot_param}
Load an internal snapshot inside @var{filename} and export it
as an read-only device, @var{snapshot_param} format is
@@ -76,19 +83,20 @@ driver-specific optimized zero write commands.
@var{detect-zeroes} is one of
converts a zero write to an unmap operation and can only be used if
@var{discard} is set to @samp{unmap}. The default is @samp{off}.
@item -c, --connect=@var{dev}
-Connect @var{filename} to NBD device @var{dev}
+Connect @var{filename} to NBD device @var{dev} (Linux only).
@item -d, --disconnect
-Disconnect the device @var{dev}
+Disconnect the device @var{dev} (Linux only).
@item -e, --shared=@var{num}
-Allow up to @var{num} clients to share the device (default @samp{1})
+Allow up to @var{num} clients to share the device (default
+@samp{1}). Safe for readers, but for now, consistency is not
+guaranteed between multiple writers.
@item -t, --persistent
-Don't exit on the last connection
+Don't exit on the last connection.
@item -x, --export-name=@var{name}
-Set the NBD volume export name. This switches the server to use
-the new style NBD protocol negotiation
+Set the NBD volume export name (default of a zero-length string).
@item -D, --description=@var{description}
Set the NBD volume export description, as a human-readable
-string. Requires the use of @option{-x}
+string.
@item --tls-creds=ID
Enable mandatory TLS encryption for the server by setting the ID
of the TLS credentials object previously created with the --object
@@ -96,11 +104,11 @@ option.
@item --fork
Fork off the server process and exit the parent once the server is running.
@item -v, --verbose
-Display extra debugging information
+Display extra debugging information.
@item -h, --help
-Display this help and exit
+Display this help and exit.
@item -V, --version
-Display version information and exit
+Display version information and exit.
@item -T, --trace
[[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
@findex --trace
@include qemu-option-trace.texi
@@ -108,6 +116,51 @@ Display version information and exit
@c man end
+@c man begin EXAMPLES
+Start a server listening on port 10809 that exposes only the
+guest-visible contents of a qcow2 file, with no TLS
[Qemu-block] [PATCH v3 17/19] qemu-nbd: Add --list option
We want to be able to detect whether a given qemu NBD server is
exposing the right export(s) and dirty bitmaps, at least for
regression testing. We could use 'nbd-client -l' from the upstream
NBD project to list exports, but it's annoying to rely on
out-of-tree binaries; furthermore, nbd-client doesn't necessarily
know about all of the qemu NBD extensions. Thus, it is time to add
a new mode to qemu-nbd that merely sniffs all possible information
from the server during handshake phase, then disconnects and dumps
the information.
This patch actually implements --list/-L, while reusing other
options such as --tls-creds for now designating how to connect
as the client (rather than their non-list usage of how to operate
as the server).
I debated about adding this functionality to something akin to
'qemu-img info' - but that tool does not readily lend itself
to connecting to an arbitrary NBD server without also tying to
a specific export (I may, however, still add ImageInfoSpecificNBD
for reporting the bitmaps available when connecting to a single
export). And, while it may feel a bit odd that normally
qemu-nbd is a server but 'qemu-nbd -L' is a client, we are not
really making the qemu-nbd binary that much larger, because
'qemu-nbd -c' has to operate as both server and client
simultaneously across two threads when feeding the kernel module
for /dev/nbdN access.
Sample output:
$ qemu-nbd -L
exports available: 1
export: ''
size: 65536
flags: 0x4ed ( flush fua trim zeroes df cache )
min block: 512
opt block: 4096
max block: 33554432
available meta contexts: 1
base:allocation
Note that the output only lists sizes if the server sent
NBD_FLAG_HAS_FLAGS, because a newstyle server does not give
the size otherwise. It has the side effect that for really
old servers that did not send any flags, the size is not
output even though it was available. However, I'm not too
concerned about that - oldstyle servers are (rightfully)
getting less common to encounter (qemu 3.0 was the last
version where we even serve it), and most existing servers
that still even offer oldstyle negotiation (such as nbdkit)
still send flags (since that was added to the NBD protocol
in 2007 to permit read-only connections).
Not done here, but maybe worth future experiments: capture
the meat of NBDExportInfo into a QAPI struct, and use the
generated QAPI pretty-printers instead of hand-rolling our
output loop. It would also permit us to add a JSON output
mode for machine parsing.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-21-ebl...@redhat.com>
Reviewed-by: Richard W.M. Jones
---
v3: comment tweak [Rich], rebase to earlier changes
---
qemu-nbd.texi | 27 +++--
qemu-nbd.c| 155 +-
2 files changed, 165 insertions(+), 17 deletions(-)
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 3f22559beb4..65caeb7874a 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -2,6 +2,8 @@
@c man begin SYNOPSIS
@command{qemu-nbd} [OPTION]... @var{filename}
+@command{qemu-nbd} @option{-L} [OPTION]...
+
@command{qemu-nbd} @option{-d} @var{dev}
@c man end
@end example
@@ -14,6 +16,8 @@ Other uses:
@itemize
@item
Bind a /dev/nbdX block device to a QEMU server (on Linux).
+@item
+As a client to query exports of a remote NBD server.
@end itemize
@c man end
@@ -31,13 +35,15 @@ See the @code{qemu(1)} manual page for full details of the
properties
supported. The common object types that it makes sense to define are the
@code{secret} object, which is used to supply passwords and/or encryption
keys, and the @code{tls-creds} object, which is used to supply TLS
-credentials for the qemu-nbd server.
+credentials for the qemu-nbd server or client.
@item -p, --port=@var{port}
-The TCP port to listen on (default @samp{10809}).
+The TCP port to listen on as a server, or connect to as a client
+(default @samp{10809}).
@item -o, --offset=@var{offset}
The offset into the image.
@item -b, --bind=@var{iface}
-The interface to bind to (default @samp{0.0.0.0}).
+The interface to bind to as a server, or connect to as a client
+(default @samp{0.0.0.0}).
@item -k, --socket=@var{path}
Use a unix socket with path @var{path}.
@item --image-opts
@@ -97,10 +103,14 @@ Set the NBD volume export name (default of a zero-length
string).
@item -D, --description=@var{description}
Set the NBD volume export description, as a human-readable
string.
+@item -L, --list
+Connect as a client and list all details about the exports exposed by
+a remote NBD server.
@item --tls-creds=ID
Enable mandatory TLS encryption for the server by setting the ID
of the TLS credentials object previously created with the --object
-option.
+option; or provide the credentials needed for connecting as a client
+in list mode.
@item --fork
Fork off the server process and exit the parent once the server is running.
@item -v, --verbose
@@ -159,6 +169,15 @@ qemu-nbd -c /dev/nbd0 -f qcow2 file.qcow2
qemu-nbd
[Qemu-block] [PATCH v3 10/19] nbd/client: Split out nbd_send_one_meta_context()
Refactor nbd_negotiate_simple_meta_context() to pull out the
code that can be reused to send a LIST request for 0 or 1 query.
No semantic change. The old comment about 'sizeof(uint32_t)'
being equivalent to '/* number of queries */' is no longer
needed, now that we are computing 'sizeof(queries)' instead.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-14-ebl...@redhat.com>
Reviewed-by: Richard W.M. Jones
---
v3: Improve commit message [Rich], formatting tweak [checkpatch],
rebase to dropped patch
---
nbd/client.c | 67 +---
nbd/trace-events | 2 +-
2 files changed, 48 insertions(+), 21 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 77993890f04..3c716be2719 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -629,6 +629,49 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc,
return QIO_CHANNEL(tioc);
}
+/*
+ * nbd_send_one_meta_context:
+ * Send 0 or 1 set/list meta context queries.
+ * Return 0 on success, -1 with errp set for any error
+ */
+static int nbd_send_one_meta_context(QIOChannel *ioc,
+ uint32_t opt,
+ const char *export,
+ const char *query,
+ Error **errp)
+{
+int ret;
+uint32_t export_len = strlen(export);
+uint32_t queries = !!query;
+uint32_t context_len = 0;
+uint32_t data_len;
+char *data;
+char *p;
+
+data_len = sizeof(export_len) + export_len + sizeof(queries);
+if (query) {
+context_len = strlen(query);
+data_len += sizeof(context_len) + context_len;
+} else {
+assert(opt == NBD_OPT_LIST_META_CONTEXT);
+}
+data = g_malloc(data_len);
+p = data;
+
+trace_nbd_opt_meta_request(nbd_opt_lookup(opt), query ?: "(all)", export);
+stl_be_p(p, export_len);
+memcpy(p += sizeof(export_len), export, export_len);
+stl_be_p(p += export_len, queries);
+if (query) {
+stl_be_p(p += sizeof(uint32_t), context_len);
+memcpy(p += sizeof(context_len), query, context_len);
+}
+
+ret = nbd_send_option_request(ioc, opt, data_len, data, errp);
+g_free(data);
+return ret;
+}
+
/* nbd_negotiate_simple_meta_context:
* Request the server to set the meta context for export @info->name
* using @info->x_dirty_bitmap with a fallback to "base:allocation",
@@ -653,26 +696,10 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
NBDOptionReply reply;
const char *context = info->x_dirty_bitmap ?: "base:allocation";
bool received = false;
-uint32_t export_len = strlen(info->name);
-uint32_t context_len = strlen(context);
-uint32_t data_len = sizeof(export_len) + export_len +
-sizeof(uint32_t) + /* number of queries */
-sizeof(context_len) + context_len;
-char *data = g_malloc(data_len);
-char *p = data;
-trace_nbd_opt_meta_request(context, info->name);
-stl_be_p(p, export_len);
-memcpy(p += sizeof(export_len), info->name, export_len);
-stl_be_p(p += export_len, 1);
-stl_be_p(p += sizeof(uint32_t), context_len);
-memcpy(p += sizeof(context_len), context, context_len);
-
-ret = nbd_send_option_request(ioc, NBD_OPT_SET_META_CONTEXT, data_len,
data,
- errp);
-g_free(data);
-if (ret < 0) {
-return ret;
+if (nbd_send_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
+ info->name, context, errp) < 0) {
+return -1;
}
if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, ,
@@ -689,7 +716,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
if (reply.type == NBD_REP_META_CONTEXT) {
char *name;
-if (reply.length != sizeof(info->context_id) + context_len) {
+if (reply.length != sizeof(info->context_id) + strlen(context)) {
error_setg(errp, "Failed to negotiate meta context '%s', server "
"answered with unexpected length %" PRIu32, context,
reply.length);
diff --git a/nbd/trace-events b/nbd/trace-events
index c3966d2b653..59521e47a3d 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -12,7 +12,7 @@ nbd_receive_query_exports_start(const char *wantname)
"Querying export list for
nbd_receive_query_exports_success(const char *wantname) "Found desired export
name '%s'"
nbd_receive_starttls_new_client(void) "Setting up TLS"
nbd_receive_starttls_tls_handshake(void) "Starting TLS handshake"
-nbd_opt_meta_request(const char *context, const char *export) "Requesting to
set meta context %s for export %s"
+nbd_opt_meta_request(const char *optname, const char *context, const char
*export) "Requesting %s %s for export %s"
nbd_opt_meta_reply(const char *context, uint32_t id) "Received mapping of
context %s to id %" PRIu32
[Qemu-block] [PATCH v3 05/19] nbd/server: Favor [u]int64_t over off_t
Although our compile-time environment is set up so that we always
support long files with 64-bit off_t, we have no guarantee whether
off_t is the same type as int64_t. This requires casts when
printing values, and prevents us from directly using qemu_strtoi64().
Let's just flip to [u]int64_t (signed for length, because we have to
detect failure of blk_getlength() and because off_t was signed;
unsigned for offset because it lets us simplify some math without
having to worry about signed overflow).
Suggested-by: Vladimir Sementsov-Ogievskiy
Signed-off-by: Eric Blake
---
v3: new patch
---
include/block/nbd.h | 4 ++--
nbd/server.c| 14 +++---
qemu-nbd.c | 26 ++
3 files changed, 19 insertions(+), 25 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 1971b557896..0f252829376 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -294,8 +294,8 @@ int nbd_errno_to_system_errno(int err);
typedef struct NBDExport NBDExport;
typedef struct NBDClient NBDClient;
-NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
- const char *name, const char *description,
+NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
+ int64_t size, const char *name, const char *desc,
const char *bitmap, uint16_t nbdflags,
void (*close)(NBDExport *), bool writethrough,
BlockBackend *on_eject_blk, Error **errp);
diff --git a/nbd/server.c b/nbd/server.c
index c9937ccdc2a..15357d40fd7 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -77,8 +77,8 @@ struct NBDExport {
BlockBackend *blk;
char *name;
char *description;
-off_t dev_offset;
-off_t size;
+uint64_t dev_offset;
+int64_t size;
uint16_t nbdflags;
QTAILQ_HEAD(, NBDClient) clients;
QTAILQ_ENTRY(NBDExport) next;
@@ -1455,8 +1455,8 @@ static void nbd_eject_notifier(Notifier *n, void *data)
nbd_export_close(exp);
}
-NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
- const char *name, const char *description,
+NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
+ int64_t size, const char *name, const char *desc,
const char *bitmap, uint16_t nbdflags,
void (*close)(NBDExport *), bool writethrough,
BlockBackend *on_eject_blk, Error **errp)
@@ -1497,7 +1497,7 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t
dev_offset, off_t size,
exp->blk = blk;
exp->dev_offset = dev_offset;
exp->name = g_strdup(name);
-exp->description = g_strdup(description);
+exp->description = g_strdup(desc);
exp->nbdflags = nbdflags;
assert(dev_offset <= size);
exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE);
@@ -2131,8 +2131,8 @@ static int nbd_co_receive_request(NBDRequestData *req,
NBDRequest *request,
if (request->from > client->exp->size ||
request->from + request->len > client->exp->size) {
error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32
- ", Size: %" PRIu64, request->from, request->len,
- (uint64_t)client->exp->size);
+ ", Size: %" PRId64, request->from, request->len,
+ client->exp->size);
return (request->type == NBD_CMD_WRITE ||
request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL;
}
diff --git a/qemu-nbd.c b/qemu-nbd.c
index ff4adb9b3eb..96c0829970c 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -176,7 +176,7 @@ static void read_partition(uint8_t *p, struct
partition_record *r)
}
static int find_partition(BlockBackend *blk, int partition,
- off_t *offset, off_t *size)
+ uint64_t *offset, int64_t *size)
{
struct partition_record mbr[4];
uint8_t data[MBR_SIZE];
@@ -500,14 +500,14 @@ int main(int argc, char **argv)
{
BlockBackend *blk;
BlockDriverState *bs;
-off_t dev_offset = 0;
+uint64_t dev_offset = 0;
uint16_t nbdflags = 0;
bool disconnect = false;
const char *bindto = NULL;
const char *port = NULL;
char *sockpath = NULL;
char *device = NULL;
-off_t fd_size;
+int64_t fd_size;
QemuOpts *sn_opts = NULL;
const char *sn_id_or_name = NULL;
const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:";
@@ -665,10 +665,6 @@ int main(int argc, char **argv)
error_report("Invalid offset `%s'", optarg);
exit(EXIT_FAILURE);
}
-if (dev_offset < 0) {
-error_report("Offset must be positive `%s'", optarg);
-exit(EXIT_FAILURE);
-}
break;
case 'l':
if (strstart(optarg,
[Qemu-block] [PATCH v3 14/19] nbd/client: Pull out oldstyle size determination
Another refactoring creating nbd_negotiate_finish_oldstyle()
for further reuse during 'qemu-nbd --list'.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-18-ebl...@redhat.com>
Reviewed-by: Richard W.M. Jones
---
nbd/client.c | 49 -
1 file changed, 32 insertions(+), 17 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 5053433ea5e..620fbb5ef01 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -818,7 +818,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
* Start the handshake to the server. After a positive return, the server
* is ready to accept additional NBD_OPT requests.
* Returns: negative errno: failure talking to server
- * 0: server is oldstyle, client must still parse export size
+ * 0: server is oldstyle, must call nbd_negotiate_finish_oldstyle
* 1: server is newstyle, but can only accept EXPORT_NAME
* 2: server is newstyle, but lacks structured replies
* 3: server is newstyle and set up for structured replies
@@ -923,6 +923,36 @@ static int nbd_start_negotiate(QIOChannel *ioc,
QCryptoTLSCreds *tlscreds,
}
}
+/*
+ * nbd_negotiate_finish_oldstyle:
+ * Populate @info with the size and export flags from an oldstyle server,
+ * but does not consume 124 bytes of reserved zero padding.
+ * Returns 0 on success, -1 with @errp set on failure
+ */
+static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo *info,
+ Error **errp)
+{
+uint32_t oldflags;
+
+if (nbd_read(ioc, >size, sizeof(info->size), errp) < 0) {
+error_prepend(errp, "Failed to read export length: ");
+return -EINVAL;
+}
+info->size = be64_to_cpu(info->size);
+
+if (nbd_read(ioc, , sizeof(oldflags), errp) < 0) {
+error_prepend(errp, "Failed to read export flags: ");
+return -EINVAL;
+}
+oldflags = be32_to_cpu(oldflags);
+if (oldflags & ~0x) {
+error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
+return -EINVAL;
+}
+info->flags = oldflags;
+return 0;
+}
+
/*
* nbd_receive_negotiate:
* Connect to server, complete negotiation, and move into transmission phase.
@@ -936,7 +966,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds
*tlscreds,
int result;
bool zeroes = true;
bool base_allocation = info->base_allocation;
-uint32_t oldflags;
assert(info->name);
trace_nbd_receive_negotiate_name(info->name);
@@ -1009,23 +1038,9 @@ int nbd_receive_negotiate(QIOChannel *ioc,
QCryptoTLSCreds *tlscreds,
error_setg(errp, "Server does not support non-empty export names");
return -EINVAL;
}
-
-if (nbd_read(ioc, >size, sizeof(info->size), errp) < 0) {
-error_prepend(errp, "Failed to read export length: ");
+if (nbd_negotiate_finish_oldstyle(ioc, info, errp) < 0) {
return -EINVAL;
}
-info->size = be64_to_cpu(info->size);
-
-if (nbd_read(ioc, , sizeof(oldflags), errp) < 0) {
-error_prepend(errp, "Failed to read export flags: ");
-return -EINVAL;
-}
-oldflags = be32_to_cpu(oldflags);
-if (oldflags & ~0x) {
-error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
-return -EINVAL;
-}
-info->flags = oldflags;
break;
default:
return result;
--
2.20.1
[Qemu-block] [PATCH v3 12/19] nbd/client: Refactor return of nbd_receive_negotiate()
The function could only ever return 0 or -EINVAL; make this
clearer by dropping a useless 'fail:' label.
Signed-off-by: Eric Blake
Reviewed-by: Richard W.M. Jones
Reviewed-by: Vladimir Sementsov-Ogievskiy
Message-Id: <20181215135324.152629-16-ebl...@redhat.com>
---
nbd/client.c | 51 +++
1 file changed, 23 insertions(+), 28 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 22505199d3b..fa931fd8e5d 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -818,7 +818,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds
*tlscreds,
NBDExportInfo *info, Error **errp)
{
uint64_t magic;
-int rc;
bool zeroes = true;
bool structured_reply = info->structured_reply;
bool base_allocation = info->base_allocation;
@@ -829,31 +828,30 @@ int nbd_receive_negotiate(QIOChannel *ioc,
QCryptoTLSCreds *tlscreds,
trace_nbd_receive_negotiate_name(info->name);
info->structured_reply = false;
info->base_allocation = false;
-rc = -EINVAL;
if (outioc) {
*outioc = NULL;
}
if (tlscreds && !outioc) {
error_setg(errp, "Output I/O channel required for TLS");
-goto fail;
+return -EINVAL;
}
if (nbd_read(ioc, , sizeof(magic), errp) < 0) {
error_prepend(errp, "Failed to read initial magic: ");
-goto fail;
+return -EINVAL;
}
magic = be64_to_cpu(magic);
trace_nbd_receive_negotiate_magic(magic);
if (magic != NBD_INIT_MAGIC) {
error_setg(errp, "Bad initial magic received: 0x%" PRIx64, magic);
-goto fail;
+return -EINVAL;
}
if (nbd_read(ioc, , sizeof(magic), errp) < 0) {
error_prepend(errp, "Failed to read server magic: ");
-goto fail;
+return -EINVAL;
}
magic = be64_to_cpu(magic);
trace_nbd_receive_negotiate_magic(magic);
@@ -865,7 +863,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds
*tlscreds,
if (nbd_read(ioc, , sizeof(globalflags), errp) < 0) {
error_prepend(errp, "Failed to read server flags: ");
-goto fail;
+return -EINVAL;
}
globalflags = be16_to_cpu(globalflags);
trace_nbd_receive_negotiate_server_flags(globalflags);
@@ -881,18 +879,18 @@ int nbd_receive_negotiate(QIOChannel *ioc,
QCryptoTLSCreds *tlscreds,
clientflags = cpu_to_be32(clientflags);
if (nbd_write(ioc, , sizeof(clientflags), errp) < 0) {
error_prepend(errp, "Failed to send clientflags field: ");
-goto fail;
+return -EINVAL;
}
if (tlscreds) {
if (fixedNewStyle) {
*outioc = nbd_receive_starttls(ioc, tlscreds, hostname, errp);
if (!*outioc) {
-goto fail;
+return -EINVAL;
}
ioc = *outioc;
} else {
error_setg(errp, "Server does not support STARTTLS");
-goto fail;
+return -EINVAL;
}
}
if (fixedNewStyle) {
@@ -903,7 +901,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds
*tlscreds,
NBD_OPT_STRUCTURED_REPLY,
errp);
if (result < 0) {
-goto fail;
+return -EINVAL;
}
info->structured_reply = result == 1;
}
@@ -911,7 +909,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds
*tlscreds,
if (info->structured_reply && base_allocation) {
result = nbd_negotiate_simple_meta_context(ioc, info, errp);
if (result < 0) {
-goto fail;
+return -EINVAL;
}
info->base_allocation = result == 1;
}
@@ -923,7 +921,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds
*tlscreds,
* export, then use NBD_OPT_EXPORT_NAME. */
result = nbd_opt_go(ioc, info, errp);
if (result < 0) {
-goto fail;
+return -EINVAL;
}
if (result > 0) {
return 0;
@@ -935,25 +933,25 @@ int nbd_receive_negotiate(QIOChannel *ioc,
QCryptoTLSCreds *tlscreds,
* export name is not available.
*/
if (nbd_receive_query_exports(ioc, info->name, errp) < 0) {
-goto fail;
+return -EINVAL;
}
}
/* write the export name request */
if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name,
errp) < 0) {
-goto fail;
+return -EINVAL;
}
/* Read the response */
if (nbd_read(ioc,
[Qemu-block] [PATCH v3 08/19] nbd/client: Move export name into NBDExportInfo
Refactor the 'name' parameter of nbd_receive_negotiate() from
being a separate parameter into being part of the in-out 'info'.
This also spills over to a simplification of nbd_opt_go().
The main driver for this refactoring is that an upcoming patch
would like to add support to qemu-nbd to list information about
all exports available on a server, where the name(s) will be
provided by the server instead of the client. But another benefit
is that we can now allow the client to explicitly specify the
empty export name "" even when connecting to an oldstyle server
(even if qemu is no longer such a server after commit 7f7dfe2a).
Signed-off-by: Eric Blake
Reviewed-by: Richard W.M. Jones
Reviewed-by: Vladimir Sementsov-Ogievskiy
Message-Id: <20181215135324.152629-11-ebl...@redhat.com>
---
include/block/nbd.h | 8
block/nbd-client.c | 5 +++--
nbd/client.c| 39 ++-
qemu-nbd.c | 6 --
nbd/trace-events| 2 +-
5 files changed, 30 insertions(+), 30 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 0f252829376..6d76d3dc221 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -262,6 +262,7 @@ struct NBDExportInfo {
/* Set by client before nbd_receive_negotiate() */
bool request_sizes;
char *x_dirty_bitmap;
+char *name; /* must be non-NULL */
/* In-out fields, set by client before nbd_receive_negotiate() and
* updated by server results during nbd_receive_negotiate() */
@@ -279,10 +280,9 @@ struct NBDExportInfo {
};
typedef struct NBDExportInfo NBDExportInfo;
-int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
- QCryptoTLSCreds *tlscreds, const char *hostname,
- QIOChannel **outioc, NBDExportInfo *info,
- Error **errp);
+int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, QIOChannel **outioc,
+ NBDExportInfo *info, Error **errp);
int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
Error **errp);
int nbd_send_request(QIOChannel *ioc, NBDRequest *request);
diff --git a/block/nbd-client.c b/block/nbd-client.c
index ef320759716..3309376bc16 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -999,10 +999,11 @@ int nbd_client_init(BlockDriverState *bs,
client->info.structured_reply = true;
client->info.base_allocation = true;
client->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap);
-ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,
-tlscreds, hostname,
+client->info.name = g_strdup(export ?: "");
+ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), tlscreds, hostname,
>ioc, >info, errp);
g_free(client->info.x_dirty_bitmap);
+g_free(client->info.name);
if (ret < 0) {
logout("Failed to negotiate with the NBD server\n");
return ret;
diff --git a/nbd/client.c b/nbd/client.c
index fd4ba8dec37..8227e69478a 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -330,15 +330,14 @@ static int nbd_receive_list(QIOChannel *ioc, char **name,
char **description,
}
-/* Returns -1 if NBD_OPT_GO proves the export @wantname cannot be
+/* Returns -1 if NBD_OPT_GO proves the export @info->name cannot be
* used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and
* NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to
- * go (with @info populated). */
-static int nbd_opt_go(QIOChannel *ioc, const char *wantname,
- NBDExportInfo *info, Error **errp)
+ * go (with the rest of @info populated). */
+static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
{
NBDOptionReply reply;
-uint32_t len = strlen(wantname);
+uint32_t len = strlen(info->name);
uint16_t type;
int error;
char *buf;
@@ -348,10 +347,10 @@ static int nbd_opt_go(QIOChannel *ioc, const char
*wantname,
* flags still 0 is a witness of a broken server. */
info->flags = 0;
-trace_nbd_opt_go_start(wantname);
+trace_nbd_opt_go_start(info->name);
buf = g_malloc(4 + len + 2 + 2 * info->request_sizes + 1);
stl_be_p(buf, len);
-memcpy(buf + 4, wantname, len);
+memcpy(buf + 4, info->name, len);
/* At most one request, everything else up to server */
stw_be_p(buf + 4 + len, info->request_sizes);
if (info->request_sizes) {
@@ -753,10 +752,9 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
return 0;
}
-int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
- QCryptoTLSCreds *tlscreds, const char *hostname,
- QIOChannel **outioc, NBDExportInfo *info,
- Error **errp)
+int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char
[Qemu-block] [PATCH v3 09/19] nbd/client: Change signature of nbd_negotiate_simple_meta_context()
Pass 'info' instead of three separate parameters related to info,
when requesting the server to set the meta context. Update the
NBDExportInfo struct to rename the received id field to match the
fact that we are currently overloading the field to match whatever
context the user supplied through the x-dirty-bitmap hack, as well
as adding a TODO comment to remind future patches about a desire
to request two contexts at once.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-12-ebl...@redhat.com>
Reviewed-by: Richard W.M. Jones
Reviewed-by: Vladimir Sementsov-Ogievskiy
---
include/block/nbd.h | 2 +-
block/nbd-client.c | 4 ++--
nbd/client.c| 53 +
3 files changed, 28 insertions(+), 31 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 6d76d3dc221..bdc7ec7195a 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -276,7 +276,7 @@ struct NBDExportInfo {
uint32_t opt_block;
uint32_t max_block;
-uint32_t meta_base_allocation_id;
+uint32_t context_id;
};
typedef struct NBDExportInfo NBDExportInfo;
diff --git a/block/nbd-client.c b/block/nbd-client.c
index 3309376bc16..813539676d2 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -249,11 +249,11 @@ static int nbd_parse_blockstatus_payload(NBDClientSession
*client,
}
context_id = payload_advance32();
-if (client->info.meta_base_allocation_id != context_id) {
+if (client->info.context_id != context_id) {
error_setg(errp, "Protocol error: unexpected context id %d for "
"NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context
"
"id is %d", context_id,
- client->info.meta_base_allocation_id);
+ client->info.context_id);
return -EINVAL;
}
diff --git a/nbd/client.c b/nbd/client.c
index 8227e69478a..77993890f04 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -630,26 +630,30 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc,
}
/* nbd_negotiate_simple_meta_context:
- * Set one meta context. Simple means that reply must contain zero (not
- * negotiated) or one (negotiated) contexts. More contexts would be considered
- * as a protocol error. It's also implied that meta-data query equals queried
- * context name, so, if server replies with something different than @context,
- * it is considered an error too.
- * return 1 for successful negotiation, context_id is set
+ * Request the server to set the meta context for export @info->name
+ * using @info->x_dirty_bitmap with a fallback to "base:allocation",
+ * setting @info->context_id to the resulting id. Fail if the server
+ * responds with more than one context or with a context different
+ * than the query.
+ * return 1 for successful negotiation,
*0 if operation is unsupported,
*-1 with errp set for any other error
*/
static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
- const char *export,
- const char *context,
- uint32_t *context_id,
+ NBDExportInfo *info,
Error **errp)
{
+/*
+ * TODO: Removing the x_dirty_bitmap hack will mean refactoring
+ * this function to request and store ids for multiple contexts
+ * (both base:allocation and a dirty bitmap), at which point this
+ * function should lose the term _simple.
+ */
int ret;
NBDOptionReply reply;
-uint32_t received_id = 0;
+const char *context = info->x_dirty_bitmap ?: "base:allocation";
bool received = false;
-uint32_t export_len = strlen(export);
+uint32_t export_len = strlen(info->name);
uint32_t context_len = strlen(context);
uint32_t data_len = sizeof(export_len) + export_len +
sizeof(uint32_t) + /* number of queries */
@@ -657,9 +661,9 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
char *data = g_malloc(data_len);
char *p = data;
-trace_nbd_opt_meta_request(context, export);
+trace_nbd_opt_meta_request(context, info->name);
stl_be_p(p, export_len);
-memcpy(p += sizeof(export_len), export, export_len);
+memcpy(p += sizeof(export_len), info->name, export_len);
stl_be_p(p += export_len, 1);
stl_be_p(p += sizeof(uint32_t), context_len);
memcpy(p += sizeof(context_len), context, context_len);
@@ -685,7 +689,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
if (reply.type == NBD_REP_META_CONTEXT) {
char *name;
-if (reply.length != sizeof(received_id) + context_len) {
+if (reply.length != sizeof(info->context_id) + context_len) {
error_setg(errp, "Failed to negotiate meta context '%s', server "
[Qemu-block] [PATCH v3 04/19] nbd/server: Hoist length check to qemp_nbd_server_add
We only had two callers to nbd_export_new; qemu-nbd.c always
passed a valid offset/length pair (because it already checked
the file length, to ensure that offset was in bounds), while
blockdev-nbd always passed 0/-1. Then nbd_export_new reduces
the size to a multiple of BDRV_SECTOR_SIZE (can only happen
when offset is not sector-aligned, since bdrv_getlength()
currently rounds up), which can result in offset being greater
than the enforced length, but that's not fatal (the server
rejects client requests that exceed the advertised length).
However, I'm finding it easier to work with the code if we are
consistent on having both callers pass in a valid length, and
just assert that things are sane in nbd_export_new.
Signed-off-by: Eric Blake
---
v3: new patch
---
blockdev-nbd.c | 10 +-
nbd/server.c | 9 ++---
2 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index c76d5416b90..d73ac1b026a 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -146,6 +146,7 @@ void qmp_nbd_server_add(const char *device, bool has_name,
const char *name,
BlockDriverState *bs = NULL;
BlockBackend *on_eject_blk;
NBDExport *exp;
+int64_t len;
if (!nbd_server) {
error_setg(errp, "NBD server not running");
@@ -168,6 +169,13 @@ void qmp_nbd_server_add(const char *device, bool has_name,
const char *name,
return;
}
+len = bdrv_getlength(bs);
+if (len < 0) {
+error_setg_errno(errp, -len,
+ "Failed to determine the NBD export's length");
+return;
+}
+
if (!has_writable) {
writable = false;
}
@@ -175,7 +183,7 @@ void qmp_nbd_server_add(const char *device, bool has_name,
const char *name,
writable = false;
}
-exp = nbd_export_new(bs, 0, -1, name, NULL, bitmap,
+exp = nbd_export_new(bs, 0, len, name, NULL, bitmap,
writable ? 0 : NBD_FLAG_READ_ONLY,
NULL, false, on_eject_blk, errp);
if (!exp) {
diff --git a/nbd/server.c b/nbd/server.c
index e8c56607eff..c9937ccdc2a 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1499,13 +1499,8 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t
dev_offset, off_t size,
exp->name = g_strdup(name);
exp->description = g_strdup(description);
exp->nbdflags = nbdflags;
-exp->size = size < 0 ? blk_getlength(blk) : size;
-if (exp->size < 0) {
-error_setg_errno(errp, -exp->size,
- "Failed to determine the NBD export's length");
-goto fail;
-}
-exp->size -= exp->size % BDRV_SECTOR_SIZE;
+assert(dev_offset <= size);
+exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE);
if (bitmap) {
BdrvDirtyBitmap *bm = NULL;
--
2.20.1
[Qemu-block] [PATCH v3 19/19] iotests: Enhance 223, 233 to cover 'qemu-nbd --list'
Any good new feature deserves some regression testing :)
Coverage includes:
- 223: what happens when there are 0 or more than 1 export,
proof that we can see multiple contexts including qemu:dirty-bitmap
- 233: proof that we can list over TLS, and that mix-and-match of
plain/TLS listings will behave sanely
Signed-off-by: Eric Blake
Reviewed-by: Richard W.M. Jones
Tested-by: Richard W.M. Jones
Reviewed-by: Vladimir Sementsov-Ogievskiy
---
v3: Rebase to earlier changes
---
tests/qemu-iotests/223 | 2 ++
tests/qemu-iotests/223.out | 20
tests/qemu-iotests/233 | 19 +--
tests/qemu-iotests/233.out | 15 +++
4 files changed, 50 insertions(+), 6 deletions(-)
diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index 773892dbe60..f120a016460 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -127,6 +127,7 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
"arguments":{"addr":{"type":"unix",
"data":{"path":"'"$TEST_DIR/nbd"1'"' "error" # Attempt second server
+$QEMU_NBD_PROG -L -k "$TEST_DIR/nbd"
_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
"arguments":{"device":"n", "bitmap":"b"}}' "return"
_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
@@ -142,6 +143,7 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
"arguments":{"device":"n", "name":"n2", "writable":true,
"bitmap":"b2"}}' "return"
+$QEMU_NBD_PROG -L -k "$TEST_DIR/nbd"
echo
echo "=== Contrast normal status to large granularity dirty-bitmap ==="
diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out
index 0de5240a75e..6476b77ba20 100644
--- a/tests/qemu-iotests/223.out
+++ b/tests/qemu-iotests/223.out
@@ -30,12 +30,32 @@ wrote 2097152/2097152 bytes at offset 2097152
{"error": {"class": "GenericError", "desc": "NBD server not running"}}
{"return": {}}
{"error": {"class": "GenericError", "desc": "NBD server already running"}}
+exports available: 0
{"return": {}}
{"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor
node_name=nosuch"}}
{"error": {"class": "GenericError", "desc": "NBD server already has export
named 'n'"}}
{"error": {"class": "GenericError", "desc": "Enabled bitmap 'b2' incompatible
with readonly export"}}
{"error": {"class": "GenericError", "desc": "Bitmap 'b3' is not found"}}
{"return": {}}
+exports available: 2
+ export: 'n'
+ size: 4194304
+ flags: 0x4ef ( readonly flush fua trim zeroes df cache )
+ min block: 512
+ opt block: 4096
+ max block: 33554432
+ available meta contexts: 2
+ base:allocation
+ qemu:dirty-bitmap:b
+ export: 'n2'
+ size: 4194304
+ flags: 0x4ed ( flush fua trim zeroes df cache )
+ min block: 512
+ opt block: 4096
+ max block: 33554432
+ available meta contexts: 2
+ base:allocation
+ qemu:dirty-bitmap:b2
=== Contrast normal status to large granularity dirty-bitmap ===
diff --git a/tests/qemu-iotests/233 b/tests/qemu-iotests/233
index 1814efe..a6ef7b20fb4 100755
--- a/tests/qemu-iotests/233
+++ b/tests/qemu-iotests/233
@@ -68,10 +68,12 @@ echo
echo "== check TLS client to plain server fails =="
nbd_server_start_tcp_socket -f $IMGFMT "$TEST_IMG"
-$QEMU_IMG info --image-opts \
---object tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0 \
+obj=tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0
+$QEMU_IMG info --image-opts --object $obj \
driver=nbd,host=$nbd_tcp_addr,port=$nbd_tcp_port,tls-creds=tls0 \
2>&1 | sed "s/$nbd_tcp_port/PORT/g"
+$QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port --object $obj \
+--tls-creds=tls0
nbd_server_stop
@@ -84,20 +86,25 @@ nbd_server_start_tcp_socket \
-f $IMGFMT "$TEST_IMG"
$QEMU_IMG info nbd://localhost:$nbd_tcp_port 2>&1 | sed
"s/$nbd_tcp_port/PORT/g"
+$QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port
echo
echo "== check TLS works =="
-$QEMU_IMG info --image-opts \
---object tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0 \
+obj=tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0
+$QEMU_IMG info --image-opts --object $obj \
driver=nbd,host=$nbd_tcp_addr,port=$nbd_tcp_port,tls-creds=tls0 \
2>&1 | sed "s/$nbd_tcp_port/PORT/g"
+$QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port --object $obj \
+--tls-creds=tls0
echo
echo "== check TLS with different CA fails =="
-$QEMU_IMG info --image-opts \
---object tls-creds-x509,dir=${tls_dir}/client2,endpoint=client,id=tls0 \
+obj=tls-creds-x509,dir=${tls_dir}/client2,endpoint=client,id=tls0
+$QEMU_IMG info --image-opts --object $obj \
driver=nbd,host=$nbd_tcp_addr,port=$nbd_tcp_port,tls-creds=tls0 \
2>&1 | sed "s/$nbd_tcp_port/PORT/g"
+$QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port --object $obj \
+--tls-creds=tls0
echo
echo "== perform I/O over TLS =="
diff --git
[Qemu-block] [PATCH v3 01/19] maint: Allow for EXAMPLES in texi2pod
The next commit will add an EXAMPLES section to qemu-nbd.8;
for that to work, we need to recognize EXAMPLES in texi2pod.
We also need to add a dependency from all man pages against
the generator script, since a change to the generator may
cause the resulting man page to differ.
Signed-off-by: Eric Blake
---
v3: add generic dependency for all man pages in $(DOCS) instead of
per-line editing [Vladimir]
---
Makefile| 2 ++
scripts/texi2pod.pl | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
index a9ac16d94e8..e2d3ace190a 100644
--- a/Makefile
+++ b/Makefile
@@ -857,6 +857,8 @@ docs/interop/qemu-qmp-ref.dvi
docs/interop/qemu-qmp-ref.html \
docs/interop/qemu-qmp-ref.txt docs/interop/qemu-qmp-ref.7: \
docs/interop/qemu-qmp-ref.texi docs/interop/qemu-qmp-qapi.texi
+$(filter %.1 %.7 %.8,$(DOCS)): scripts/texi2pod.pl
+
# Reports/Analysis
%/coverage-report.html:
diff --git a/scripts/texi2pod.pl b/scripts/texi2pod.pl
index 39ce584a322..839b7917cf7 100755
--- a/scripts/texi2pod.pl
+++ b/scripts/texi2pod.pl
@@ -398,7 +398,7 @@ $sects{NAME} = "$fn \- $tl\n";
$sects{FOOTNOTES} .= "=back\n" if exists $sects{FOOTNOTES};
for $sect (qw(NAME SYNOPSIS DESCRIPTION OPTIONS ENVIRONMENT FILES
- BUGS NOTES FOOTNOTES SEEALSO AUTHOR COPYRIGHT)) {
+ BUGS NOTES FOOTNOTES EXAMPLES SEEALSO AUTHOR COPYRIGHT)) {
if(exists $sects{$sect}) {
$head = $sect;
$head =~ s/SEEALSO/SEE ALSO/;
--
2.20.1
[Qemu-block] [PATCH v3 00/19] nbd: add qemu-nbd --list
I got tired of debugging whether a server was advertising the correct things during negotiation by inspecting the trace logs of qemu-io as client - not to mention that without SOME sort of client tracing particular commands, we can't easily regression test the server for correct behavior. The final straw was at KVM Forum, when Nir asked me to make sure there was a way to easily determine if an NBD server is exposing what we really want (and fixing x-dirty-bitmap to behave saner fell out as a result of answering that question). I note that upstream NBD has 'nbd-client -l $host' for querying just export names (with no quoting, so you have to know that a blank line means the default export), but it wasn't powerful enough, so I implemented 'qemu-nbd -L' to document everything. Upstream NBD has separate 'nbd-client' and 'nbd-server' binaries, while we only have 'qemu-nbd' (which is normally just a server, but 'qemu-nbd -c' also operates a second thread as a client). Our other uses of qemu as NBD client are for consuming a block device (as in qemu-io, qemu-img, or a drive to qemu) - but those binaries are less suited to something so specific to the NBD protocol. Bonus: As a result of my work on this series, nbdkit now supports NBD_OPT_INFO (my interoperability testing between server implementations has been paying off, both at fixing server bugs, and at making this code more reliable across difference in valid servers). Also available at: https://repo.or.cz/qemu/ericb.git qemu-nbd-list-v2 Based-on: <20181221093529.23855-1-js...@redhat.com> [jsnow: 0/11 bitmaps: remove x- prefix from QMP api] Based-on: <2019063519.11457-1-phi...@redhat.com> [philmd: qemu-nbd: Rename 'exp' variable clashing with math::exp() symbol] Based-on: <2019094720.15671-1-ebl...@redhat.com> [eblake: 0/8 Promote x-nbd-server-add-bitmap to stable] Since v2: - Several patches merged already - 3 new patches based on audit of off_t vs. strtol - rebase patches on top of other changes, such as qemu-nbd --bitmap - address various review comments [Vladimir, Rich] - drop patch 12/22 001/19:[0020] [FC] 'maint: Allow for EXAMPLES in texi2pod' 002/19:[0030] [FC] 'qemu-nbd: Enhance man page' 003/19:[down] 'qemu-nbd: Sanity check partition bounds' 004/19:[down] 'nbd/server: Hoist length check to qemp_nbd_server_add' 005/19:[down] 'nbd/server: Favor [u]int64_t over off_t' 006/19:[0007] [FC] 'qemu-nbd: Avoid strtol open-coding' 007/19:[0016] [FC] 'nbd/client: Refactor nbd_receive_list()' 008/19:[] [--] 'nbd/client: Move export name into NBDExportInfo' 009/19:[] [--] 'nbd/client: Change signature of nbd_negotiate_simple_meta_context()' 010/19:[0007] [FC] 'nbd/client: Split out nbd_send_one_meta_context()' 011/19:[0048] [FC] 'nbd/client: Split out nbd_receive_one_meta_context()' 012/19:[] [--] 'nbd/client: Refactor return of nbd_receive_negotiate()' 013/19:[] [-C] 'nbd/client: Split handshake into two functions' 014/19:[] [--] 'nbd/client: Pull out oldstyle size determination' 015/19:[0008] [FC] 'nbd/client: Add nbd_receive_export_list()' 016/19:[] [-C] 'nbd/client: Add meta contexts to nbd_receive_export_list()' 017/19:[0015] [FC] 'qemu-nbd: Add --list option' 018/19:[] [--] 'nbd/client: Work around 3.0 bug for listing meta contexts' 019/19:[0002] [FC] 'iotests: Enhance 223, 233 to cover 'qemu-nbd --list'' Eric Blake (19): maint: Allow for EXAMPLES in texi2pod qemu-nbd: Enhance man page qemu-nbd: Sanity check partition bounds nbd/server: Hoist length check to qemp_nbd_server_add nbd/server: Favor [u]int64_t over off_t qemu-nbd: Avoid strtol open-coding nbd/client: Refactor nbd_receive_list() nbd/client: Move export name into NBDExportInfo nbd/client: Change signature of nbd_negotiate_simple_meta_context() nbd/client: Split out nbd_send_one_meta_context() nbd/client: Split out nbd_receive_one_meta_context() nbd/client: Refactor return of nbd_receive_negotiate() nbd/client: Split handshake into two functions nbd/client: Pull out oldstyle size determination nbd/client: Add nbd_receive_export_list() nbd/client: Add meta contexts to nbd_receive_export_list() qemu-nbd: Add --list option nbd/client: Work around 3.0 bug for listing meta contexts iotests: Enhance 223, 233 to cover 'qemu-nbd --list' qemu-nbd.texi | 114 -- Makefile | 2 + include/block/nbd.h| 31 +- block/nbd-client.c | 9 +- blockdev-nbd.c | 10 +- nbd/client.c | 756 ++--- nbd/server.c | 23 +- qemu-nbd.c | 221 --- nbd/trace-events | 11 +- scripts/texi2pod.pl| 2 +- tests/qemu-iotests/223 | 2 + tests/qemu-iotests/223.out | 20 + tests/qemu-iotests/233 | 19 +- tests/qemu-iotests/233.out | 15 + 14 files changed, 910 insertions(+), 325 deletions(-) -- 2.20.1
[Qemu-block] [PATCH v3 07/19] nbd/client: Refactor nbd_receive_list()
Right now, nbd_receive_list() is only called by
nbd_receive_query_exports(), which in turn is only called if the
server lacks NBD_OPT_GO but has working option negotiation, and is
merely used as a quality-of-implementation trick since servers
can't give decent errors for NBD_OPT_EXPORT_NAME. However, servers
that lack NBD_OPT_GO are becoming increasingly rare (nbdkit was a
latecomer, in Aug 2018, but qemu has been such a server since commit
f37708f6 in July 2017 and released in 2.10), so it no longer makes
sense to micro-optimize that function for performance.
Furthermore, when debugging a server's implementation, tracing the
full reply (both names and descriptions) is useful, not to mention
that upcoming patches adding 'qemu-nbd --list' will want to collect
that data. And when you consider that a server can send an export
name up to the NBD protocol length limit of 4k; but our current
NBD_MAX_NAME_SIZE is only 256, we can't trace all valid server
names without more storage, but 4k is large enough that the heap
is better than the stack for long names.
Thus, I'm changing the division of labor, with nbd_receive_list()
now always malloc'ing a result on success (the malloc is bounded
by the fact that we reject servers with a reply length larger
than 32M), and moving the comparison to 'wantname' to the caller.
There is a minor change in behavior where a server with 0 exports
(an immediate NBD_REP_ACK reply) is now no longer distinguished
from a server without LIST support (NBD_REP_ERR_UNSUP); this
information could be preserved with a complication to the calling
contract to provide a bit more information, but I didn't see the
point. After all, the worst that can happen if our guess at a
match is wrong is that the caller will get a cryptic disconnect
when NBD_OPT_EXPORT_NAME fails (which is no different from what
would happen if we had not tried LIST), while treating an empty
list as immediate failure would prevent connecting to really old
servers that really did lack LIST. Besides, NBD servers with 0
exports are rare (qemu can do it when using QMP nbd-server-start
without nbd-server-add - but qemu understands NBD_OPT_GO and
thus won't tickle this change in behavior).
Fix the spelling of foundExport to match coding standards while
in the area.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-10-ebl...@redhat.com>
Reviewed-by: Richard W.M. Jones
Reviewed-by: Vladimir Sementsov-Ogievskiy
---
v3: comment tweak, s/listEmpty/list_empty/,
s/foundExport/found_export/ [Vladimir]
---
nbd/client.c | 91 ++--
nbd/trace-events | 1 +
2 files changed, 59 insertions(+), 33 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index f625c207c54..fd4ba8dec37 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -234,18 +234,24 @@ static int nbd_handle_reply_err(QIOChannel *ioc,
NBDOptionReply *reply,
return result;
}
-/* Process another portion of the NBD_OPT_LIST reply. Set *@match if
- * the current reply matches @want or if the server does not support
- * NBD_OPT_LIST, otherwise leave @match alone. Return 0 if iteration
- * is complete, positive if more replies are expected, or negative
- * with @errp set if an unrecoverable error occurred. */
-static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
+/* nbd_receive_list:
+ * Process another portion of the NBD_OPT_LIST reply, populating any
+ * name received into *@name. If @description is non-NULL, and the
+ * server provided a description, that is also populated. The caller
+ * must eventually call g_free() on success.
+ * Returns 1 if name and description were set and iteration must continue,
+ * 0 if iteration is complete (including if OPT_LIST unsupported),
+ * -1 with @errp set if an unrecoverable error occurred.
+ */
+static int nbd_receive_list(QIOChannel *ioc, char **name, char **description,
Error **errp)
{
+int ret = -1;
NBDOptionReply reply;
uint32_t len;
uint32_t namelen;
-char name[NBD_MAX_NAME_SIZE + 1];
+char *local_name = NULL;
+char *local_desc = NULL;
int error;
if (nbd_receive_option_reply(ioc, NBD_OPT_LIST, , errp) < 0) {
@@ -253,9 +259,6 @@ static int nbd_receive_list(QIOChannel *ioc, const char
*want, bool *match,
}
error = nbd_handle_reply_err(ioc, , errp);
if (error <= 0) {
-/* The server did not support NBD_OPT_LIST, so set *match on
- * the assumption that any name will be accepted. */
-*match = true;
return error;
}
len = reply.length;
@@ -292,33 +295,38 @@ static int nbd_receive_list(QIOChannel *ioc, const char
*want, bool *match,
nbd_send_opt_abort(ioc);
return -1;
}
-if (namelen != strlen(want)) {
-if (nbd_drop(ioc, len, errp) < 0) {
-error_prepend(errp,
- "failed to skip export name with wrong length: ");
-
[Qemu-block] [PATCH v3 06/19] qemu-nbd: Avoid strtol open-coding
Our copy-and-pasted open-coding of strtol handling forgot to
handle overflow conditions. Use qemu_strto*() instead.
In the case of --partition, since we insist on a user-supplied
partition to be non-zero, we can use 0 rather than -1 for our
initial value to distinguish when a partition is not being
served, for slightly more optimal code.
The error messages for out-of-bounds values are less specific,
but should not be a terrible loss in quality.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-8-ebl...@redhat.com>
---
v3: rebase to use int64_t rather than off_t [Vladimir]
---
qemu-nbd.c | 28 +---
1 file changed, 9 insertions(+), 19 deletions(-)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 96c0829970c..4670b659167 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -546,9 +546,8 @@ int main(int argc, char **argv)
};
int ch;
int opt_ind = 0;
-char *end;
int flags = BDRV_O_RDWR;
-int partition = -1;
+int partition = 0;
int ret = 0;
bool seen_cache = false;
bool seen_discard = false;
@@ -660,9 +659,8 @@ int main(int argc, char **argv)
port = optarg;
break;
case 'o':
-dev_offset = strtoll (optarg, , 0);
-if (*end) {
-error_report("Invalid offset `%s'", optarg);
+if (qemu_strtou64(optarg, NULL, 0, _offset) < 0) {
+error_report("Invalid offset '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
@@ -684,13 +682,9 @@ int main(int argc, char **argv)
flags &= ~BDRV_O_RDWR;
break;
case 'P':
-partition = strtol(optarg, , 0);
-if (*end) {
-error_report("Invalid partition `%s'", optarg);
-exit(EXIT_FAILURE);
-}
-if (partition < 1 || partition > 8) {
-error_report("Invalid partition %d", partition);
+if (qemu_strtoi(optarg, NULL, 0, ) < 0 ||
+partition < 1 || partition > 8) {
+error_report("Invalid partition '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
@@ -711,15 +705,11 @@ int main(int argc, char **argv)
device = optarg;
break;
case 'e':
-shared = strtol(optarg, , 0);
-if (*end) {
+if (qemu_strtoi(optarg, NULL, 0, ) < 0 ||
+shared < 1) {
error_report("Invalid shared device number '%s'", optarg);
exit(EXIT_FAILURE);
}
-if (shared < 1) {
-error_report("Shared device number must be greater than 0");
-exit(EXIT_FAILURE);
-}
break;
case 'f':
fmt = optarg;
@@ -1007,7 +997,7 @@ int main(int argc, char **argv)
}
fd_size -= dev_offset;
-if (partition != -1) {
+if (partition) {
int64_t limit;
if (dev_offset) {
--
2.20.1
[Qemu-block] [PATCH v3 13/19] nbd/client: Split handshake into two functions
An upcoming patch will add the ability for qemu-nbd to list
the services provided by an NBD server. Share the common
code of the TLS handshake by splitting the initial exchange
into a separate function, leaving only the export handling
in the original function. Functionally, there should be no
change in behavior in this patch, although some of the code
motion may be difficult to follow due to indentation changes
(view with 'git diff -w' for a smaller changeset).
I considered an enum for the return code coordinating state
between the two functions, but in the end just settled with
ample comments.
Signed-off-by: Eric Blake
Reviewed-by: Richard W.M. Jones
Reviewed-by: Vladimir Sementsov-Ogievskiy
Message-Id: <20181215135324.152629-17-ebl...@redhat.com>
---
nbd/client.c | 144 +++
nbd/trace-events | 2 +-
2 files changed, 95 insertions(+), 51 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index fa931fd8e5d..5053433ea5e 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -813,21 +813,24 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
return received;
}
-int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
- const char *hostname, QIOChannel **outioc,
- NBDExportInfo *info, Error **errp)
+/*
+ * nbd_start_negotiate:
+ * Start the handshake to the server. After a positive return, the server
+ * is ready to accept additional NBD_OPT requests.
+ * Returns: negative errno: failure talking to server
+ * 0: server is oldstyle, client must still parse export size
+ * 1: server is newstyle, but can only accept EXPORT_NAME
+ * 2: server is newstyle, but lacks structured replies
+ * 3: server is newstyle and set up for structured replies
+ */
+static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, QIOChannel **outioc,
+ bool structured_reply, bool *zeroes,
+ Error **errp)
{
uint64_t magic;
-bool zeroes = true;
-bool structured_reply = info->structured_reply;
-bool base_allocation = info->base_allocation;
-trace_nbd_receive_negotiate(tlscreds, hostname ? hostname : "");
-
-assert(info->name);
-trace_nbd_receive_negotiate_name(info->name);
-info->structured_reply = false;
-info->base_allocation = false;
+trace_nbd_start_negotiate(tlscreds, hostname ? hostname : "");
if (outioc) {
*outioc = NULL;
@@ -872,7 +875,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds
*tlscreds,
clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
}
if (globalflags & NBD_FLAG_NO_ZEROES) {
-zeroes = false;
+*zeroes = false;
clientflags |= NBD_FLAG_C_NO_ZEROES;
}
/* client requested flags */
@@ -894,7 +897,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds
*tlscreds,
}
}
if (fixedNewStyle) {
-int result;
+int result = 0;
if (structured_reply) {
result = nbd_request_simple_option(ioc,
@@ -903,39 +906,85 @@ int nbd_receive_negotiate(QIOChannel *ioc,
QCryptoTLSCreds *tlscreds,
if (result < 0) {
return -EINVAL;
}
-info->structured_reply = result == 1;
}
+return 2 + result;
+} else {
+return 1;
+}
+} else if (magic == NBD_CLIENT_MAGIC) {
+if (tlscreds) {
+error_setg(errp, "Server does not support STARTTLS");
+return -EINVAL;
+}
+return 0;
+} else {
+error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic);
+return -EINVAL;
+}
+}
-if (info->structured_reply && base_allocation) {
-result = nbd_negotiate_simple_meta_context(ioc, info, errp);
-if (result < 0) {
-return -EINVAL;
-}
-info->base_allocation = result == 1;
-}
+/*
+ * nbd_receive_negotiate:
+ * Connect to server, complete negotiation, and move into transmission phase.
+ * Returns: negative errno: failure talking to server
+ * 0: server is connected
+ */
+int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, QIOChannel **outioc,
+ NBDExportInfo *info, Error **errp)
+{
+int result;
+bool zeroes = true;
+bool base_allocation = info->base_allocation;
+uint32_t oldflags;
+
+assert(info->name);
+trace_nbd_receive_negotiate_name(info->name);
+
+result = nbd_start_negotiate(ioc, tlscreds, hostname, outioc,
+ info->structured_reply, , errp);
+
+info->structured_reply =
[Qemu-block] [PATCH v3 16/19] nbd/client: Add meta contexts to nbd_receive_export_list()
We want to be able to detect whether a given qemu NBD server is
exposing the right export(s) and dirty bitmaps, at least for
regression testing. We could use 'nbd-client -l' from the upstream
NBD project to list exports, but it's annoying to rely on
out-of-tree binaries; furthermore, nbd-client doesn't necessarily
know about all of the qemu NBD extensions. Thus, we plan on adding
a new mode to qemu-nbd that merely sniffs all possible information
from the server during handshake phase, then disconnects and dumps
the information.
This patch continues the work of the previous patch, by adding the
ability to track the list of available meta contexts into
NBDExportInfo. It benefits from the recent refactoring patches
with a new nbd_list_meta_contexts() that reuses much of the same
framework as setting a meta context.
Note: a malicious server could exhaust memory of a client by feeding
an unending loop of contexts; perhaps we could place a limit on how
many we are willing to receive. But this is no different from our
earlier analysis on a server sending an unending list of exports,
and the death of a client due to memory exhaustion when the client
was going to exit soon anyways is not really a denial of service
attack.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-20-ebl...@redhat.com>
Reviewed-by: Richard W.M. Jones
---
v3: mention security (non-)issue in commit message [Rich]
---
include/block/nbd.h | 2 ++
nbd/client.c| 41 +++--
2 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index e9a442ce7e9..80ee3cc997e 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -284,6 +284,8 @@ struct NBDExportInfo {
/* Set by server results during nbd_receive_export_list() */
char *description;
+int n_contexts;
+char **contexts;
};
typedef struct NBDExportInfo NBDExportInfo;
diff --git a/nbd/client.c b/nbd/client.c
index a5a705a67f7..2001e6e8160 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -817,6 +817,36 @@ static int nbd_negotiate_simple_meta_context(QIOChannel
*ioc,
return received;
}
+/*
+ * nbd_list_meta_contexts:
+ * Request the server to list all meta contexts for export @info->name.
+ * return 0 if list is complete (even if empty),
+ *-1 with errp set for any other error
+ */
+static int nbd_list_meta_contexts(QIOChannel *ioc,
+ NBDExportInfo *info,
+ Error **errp)
+{
+int ret;
+
+if (nbd_send_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
+ info->name, NULL, errp) < 0) {
+return -1;
+}
+
+while (1) {
+char *context;
+
+ret = nbd_receive_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
+ , NULL, errp);
+if (ret <= 0) {
+return ret;
+}
+info->contexts = g_renew(char *, info->contexts, ++info->n_contexts);
+info->contexts[info->n_contexts - 1] = context;
+}
+}
+
/*
* nbd_start_negotiate:
* Start the handshake to the server. After a positive return, the server
@@ -1063,7 +1093,7 @@ int nbd_receive_negotiate(QIOChannel *ioc,
QCryptoTLSCreds *tlscreds,
/* Clean up result of nbd_receive_export_list */
void nbd_free_export_list(NBDExportInfo *info, int count)
{
-int i;
+int i, j;
if (!info) {
return;
@@ -1072,6 +1102,10 @@ void nbd_free_export_list(NBDExportInfo *info, int count)
for (i = 0; i < count; i++) {
g_free(info[i].name);
g_free(info[i].description);
+for (j = 0; j < info[i].n_contexts; j++) {
+g_free(info[i].contexts[j]);
+}
+g_free(info[i].contexts);
}
g_free(info);
}
@@ -1139,7 +1173,10 @@ int nbd_receive_export_list(QIOChannel *ioc,
QCryptoTLSCreds *tlscreds,
break;
}
-/* TODO: Grab meta contexts */
+if (result == 3 &&
+nbd_list_meta_contexts(ioc, [i], errp) < 0) {
+goto out;
+}
}
/* Send NBD_OPT_ABORT as a courtesy before hanging up */
--
2.20.1
[Qemu-block] [PATCH v3 15/19] nbd/client: Add nbd_receive_export_list()
We want to be able to detect whether a given qemu NBD server is
exposing the right export(s) and dirty bitmaps, at least for
regression testing. We could use 'nbd-client -l' from the upstream
NBD project to list exports, but it's annoying to rely on
out-of-tree binaries; furthermore, nbd-client doesn't necessarily
know about all of the qemu NBD extensions. Thus, we plan on adding
a new mode to qemu-nbd that merely sniffs all possible information
from the server during handshake phase, then disconnects and dumps
the information.
This patch adds the low-level client code for grabbing the list
of exports. It benefits from the recent refactoring patches, as
well as a minor tweak of changing nbd_opt_go() to nbd_opt_info_or_go(),
in order to share as much code as possible when it comes to doing
validation of server replies. The resulting information is stored
in an array of NBDExportInfo which has been expanded to any
description string, along with a convenience function for freeing
the list.
Note: a malicious server could exhaust memory of a client by feeding
an unending loop of exports; perhaps we should place a limit on how
many we are willing to receive. But note that a server could
reasonably be serving an export for every file in a large directory,
where an arbitrary limit in the client means we can't list anything
from such a server; the same happens if we just run until the client
fails to malloc() and thus dies by an abort(), where the limit is
no longer arbitrary but determined by available memory. Since the
client is already planning on being short-lived, it's hard to call
this a denial of service attack that would starve off other uses,
so it does not appear to be a security issue.
Signed-off-by: Eric Blake
Message-Id: <20181215135324.152629-19-ebl...@redhat.com>
Reviewed-by: Richard W.M. Jones
---
v3: mention security (non-)issue in commit message [Rich], formatting
tweaks
---
include/block/nbd.h | 15 -
nbd/client.c| 144 +---
nbd/trace-events| 2 +-
3 files changed, 150 insertions(+), 11 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index bdc7ec7195a..e9a442ce7e9 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2016-2017 Red Hat, Inc.
+ * Copyright (C) 2016-2019 Red Hat, Inc.
* Copyright (C) 2005 Anthony Liguori
*
* Network Block Device
@@ -262,6 +262,9 @@ struct NBDExportInfo {
/* Set by client before nbd_receive_negotiate() */
bool request_sizes;
char *x_dirty_bitmap;
+
+/* Set by client before nbd_receive_negotiate(), or by server results
+ * during nbd_receive_export_list() */
char *name; /* must be non-NULL */
/* In-out fields, set by client before nbd_receive_negotiate() and
@@ -269,7 +272,8 @@ struct NBDExportInfo {
bool structured_reply;
bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS
*/
-/* Set by server results during nbd_receive_negotiate() */
+/* Set by server results during nbd_receive_negotiate() and
+ * nbd_receive_export_list() */
uint64_t size;
uint16_t flags;
uint32_t min_block;
@@ -277,12 +281,19 @@ struct NBDExportInfo {
uint32_t max_block;
uint32_t context_id;
+
+/* Set by server results during nbd_receive_export_list() */
+char *description;
};
typedef struct NBDExportInfo NBDExportInfo;
int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
const char *hostname, QIOChannel **outioc,
NBDExportInfo *info, Error **errp);
+void nbd_free_export_list(NBDExportInfo *info, int count);
+int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+const char *hostname, NBDExportInfo **info,
+Error **errp);
int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
Error **errp);
int nbd_send_request(QIOChannel *ioc, NBDRequest *request);
diff --git a/nbd/client.c b/nbd/client.c
index 620fbb5ef01..a5a705a67f7 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -330,11 +330,14 @@ static int nbd_receive_list(QIOChannel *ioc, char **name,
char **description,
}
-/* Returns -1 if NBD_OPT_GO proves the export @info->name cannot be
+/*
+ * Returns -1 if NBD_OPT_GO proves the export @info->name cannot be
* used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and
* NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to
- * go (with the rest of @info populated). */
-static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
+ * go (with the rest of @info populated).
+ */
+static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt,
+ NBDExportInfo *info, Error **errp)
{
NBDOptionReply reply;
uint32_t len = strlen(info->name);
@@ -347,7 +350,8 @@ static int nbd_opt_go(QIOChannel *ioc,
