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2016-05-29nbd: Don't trim unrequested bytesEric Blake1-6/+14
Similar to commit df7b97ff, we are mishandling clients that give an unaligned NBD_CMD_TRIM request, and potentially trimming bytes that occur before their request; which in turn can cause potential unintended data loss (unlikely in practice, since most clients are sane and issue aligned trim requests). However, while we fixed read and write by switching to the byte interfaces of blk_, we don't yet have a byte interface for discard. On the other hand, trim is advisory, so rounding the user's request to simply ignore the first and last unaligned sectors (or the entire request, if it is sub-sector in length) is just fine. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1464173965-9694-1-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19qemu-common: stop including qemu/bswap.h from qemu-common.hPaolo Bonzini1-0/+1
Move it to the actual users. There are still a few includes of qemu/bswap.h in headers; removing them is left for future work. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-18Fix some typos found by codespellStefan Weil1-1/+1
Signed-off-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2016-05-12block: Allow BDRV_REQ_FUA through blk_pwrite()Eric Blake1-1/+1
We have several block drivers that understand BDRV_REQ_FUA, and emulate it in the block layer for the rest by a full flush. But without a way to actually request BDRV_REQ_FUA during a pass-through blk_pwrite(), FUA-aware block drivers like NBD are forced to repeat the emulation logic of a full flush regardless of whether the backend they are writing to could do it more efficiently. This patch just wires up a flags argument; followup patches will actually make use of it in the NBD driver and in qemu-io. Signed-off-by: Eric Blake <eblake@redhat.com> Acked-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-04-22nbd: Don't mishandle unaligned client requestsEric Blake1-6/+4
The NBD protocol does not (yet) force any alignment constraints on clients. Even though qemu NBD clients always send requests that are aligned to 512 bytes, we must be prepared for non-qemu clients that don't care about alignment (even if it means they are less efficient). Our use of blk_read() and blk_write() was silently operating on the wrong file offsets when the client made an unaligned request, corrupting the client's data (but as the client already has control over the file we are serving, I don't think it is a security hole, per se, just a data corruption bug). Note that in the case of NBD_CMD_READ, an unaligned length could cause us to return up to 511 bytes of uninitialized trailing garbage from blk_try_blockalign() - hopefully nothing sensitive from the heap's prior usage is ever leaked in that manner. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Tested-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1461249750-31928-1-git-send-email-eblake@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-04-15nbd: Don't kill server on client that doesn't request TLSEric Blake1-2/+13
Upstream NBD documents (as of commit 4feebc95) that servers MAY choose to operate in a conditional mode, where it is up to the client whether to use TLS. For qemu's case, we want to always be in FORCEDTLS mode, because of the risk of man-in-the-middle attacks, and since we never export more than one device; likewise, the qemu client will ALWAYS send NBD_OPT_STARTTLS as its first option. But now that SELECTIVETLS servers exist, it is feasible to encounter a (non-qemu) client that is programmed to talk to such a server, and does not do NBD_OPT_STARTTLS first, but rather wants to probe if it can use a non-encrypted export. The NBD protocol documents that we should let such a client continue trying, on the grounds that maybe the client will get the hint to send NBD_OPT_STARTTLS, rather than immediately dropping the connection. Note that NBD_OPT_EXPORT_NAME is a special case: since it is the only option request that can't have an error return, we have to (continue to) drop the connection on that one; rather, what we are fixing here is that all other replies prior to TLS initiation tell the client NBD_REP_ERR_TLS_REQD, but keep the connection alive. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1460671343-18485-1-git-send-email-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-04-15nbd: Don't fail handshake on NBD_OPT_LIST descriptionsEric Blake1-2/+21
The NBD Protocol states that NBD_REP_SERVER may set 'length > sizeof(namelen) + namelen'; in which case the rest of the packet is a UTF-8 description of the export. While we don't know of any NBD servers that send this description yet, we had better consume the data so we don't choke when we start to talk to such a server. Also, a (buggy/malicious) server that replies with length < sizeof(namelen) would cause us to block waiting for bytes that the server is not sending, and one that replies with super-huge lengths could cause us to temporarily allocate up to 4G memory. Sanity check things before blindly reading incorrectly. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1460077777-31004-1-git-send-email-eblake@redhat.com Reviewed-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-04-08nbd: do not hang nbd_wr_syncv if outside a coroutine and no available dataPaolo Bonzini1-1/+4
Until commit 1c778ef7 ("nbd: convert to using I/O channels for actual socket I/O", 2016-02-16), nbd_wr_sync returned -EAGAIN this scenario. nbd_reply_ready required these semantics because it has two conflicting requirements: 1) if a reply can be received on the socket, nbd_reply_ready needs to read the header outside coroutine context to identify _which_ coroutine to enter to process the rest of the reply 2) on the other hand, nbd_reply_ready can find a false positive if another thread (e.g. a VCPU thread running aio_poll) sneaks in and calls nbd_reply_ready too. In this case nbd_reply_ready does nothing and expects nbd_wr_syncv to return -EAGAIN. Currently, the solution to the first requirement is to wait in the very rare case of a read() that doesn't retrieve the reply header in its entirety; this is what nbd_wr_syncv does by calling qio_channel_wait(). However, the unconditional call to qio_channel_wait() breaks the second requirement. To fix this, the patch makes nbd_wr_syncv return -EAGAIN if done is zero, similar to the code before commit 1c778ef7. This is okay because NBD client-side negotiation is the only other case that calls nbd_wr_syncv outside a coroutine, and it places the socket in blocking mode. On the other hand, it is a bit unpleasant to put this in nbd_wr_syncv(), because the function is used by both client and server. The full fix would be to add a counter to NbdClientSession for how many bytes have been filled in s->reply. Then a reply can be filled by multiple separate invocations of nbd_reply_ready and the qio_channel_wait() call can be removed completely. Something to consider for 2.7... Reported-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-04-08nbd: Don't kill server when client requests unknown optionEric Blake1-1/+4
nbd-server.c currently fails to handle unsupported options properly. If during option haggling the client sends an unknown request, the server kills the connection instead of letting the client try to fall back to something older. This is precisely what advertising NBD_FLAG_FIXED_NEWSTYLE was supposed to fix. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1459982918-32229-1-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-04-08nbd: Fix NBD unsupported optionsAlex Bligh1-10/+45
nbd-client.c currently fails to handle unsupported options properly. If during option haggling the server finds an option that is unsupported, it returns an NBD_REP_ERR_UNSUP reply. According to nbd's proto.md, the format for such a reply should be: S: 64 bits, 0x3e889045565a9 (magic number for replies) S: 32 bits, the option as sent by the client to which this is a reply S: 32 bits, reply type (e.g., NBD_REP_ACK for successful completion, or NBD_REP_ERR_UNSUP to mark use of an option not known by this server S: 32 bits, length of the reply. This may be zero for some replies, in which case the next field is not sent S: any data as required by the reply (e.g., an export name in the case of NBD_REP_SERVER, or optional UTF-8 message for NBD_REP_ERR_*) However, in nbd-client.c, the reply type was being read, and if it contained an error, it was bailing out and issuing the next option request without first reading the length. This meant that the next option / handshake read had an extra 4 or more bytes of data in it. In practice, this makes Qemu incompatible with servers that do not support NBD_OPT_LIST. To verify this isn't an error in the specification or my reading of it, replies are sent by the reference implementation here: https://github.com/yoe/nbd/blob/66dfb35/nbd-server.c#L1232 and as is evident it always sends a 'datasize' (aka length) 32 bit word. Unsupported elements are replied to here: https://github.com/yoe/nbd/blob/66dfb35/nbd-server.c#L1371 Signed-off-by: Alex Bligh <alex@alex.org.uk> Message-Id: <1459882500-24316-1-git-send-email-alex@alex.org.uk> [rework to ALWAYS consume an optional UTF-8 message from the server] Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1459961962-18771-1-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-04-08nbd: Improve debug traces on little-endianEric Blake2-6/+7
Print debug tracing messages while data is still in native ordering, rather than after we've potentially swapped it into network order for transmission. Also, it's nice if the server mentions what it is replying, to correlate it to with what the client says it is receiving. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1459913704-19949-4-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-04-08nbd: Avoid bitrot in TRACE() usageEric Blake1-6/+9
The compiler is smart enough to optimize out 'if (0)', but won't type-check our printfs if they are hidden behind #if. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1459913704-19949-3-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-04-08nbd: Return correct error for write to read-only exportEric Blake1-0/+1
The NBD Protocol requires that servers should send EPERM for attempts to write (or trim) a read-only export. We were correct for TRIM (blk_co_discard() gave EPERM); but were manually setting EROFS which then got mapped to EINVAL over the wire on writes. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1459913704-19949-2-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-04-05nbd: Fix poor debug messageEric Blake1-1/+1
The client sends messages to the server, not itself. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1459459222-8637-3-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster3-0/+3
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-23all: Clean up includesPeter Maydell1-4/+0
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-02-16nbd: implement TLS support in the protocol negotiationDaniel P. Berrange4-8/+275
This extends the NBD protocol handling code so that it is capable of negotiating TLS support during the connection setup. This involves requesting the STARTTLS protocol option before any other NBD options. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-14-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: use "" as a default export name if none providedDaniel P. Berrange2-2/+3
If the user does not provide an export name and the server is running the new style protocol, where export names are mandatory, use "" as the default export name if the user has not specified any. "" is defined in the NBD protocol as the default name to use in such scenarios. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-13-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: always query export list in fixed new style protocolDaniel P. Berrange2-3/+194
With the new style protocol, the NBD client will currenetly send NBD_OPT_EXPORT_NAME as the first (and indeed only) option it wants. The problem is that the NBD protocol spec does not allow for returning an error message with the NBD_OPT_EXPORT_NAME option. So if the server mandates use of TLS, the client will simply see an immediate connection close after issuing NBD_OPT_EXPORT_NAME which is not user friendly. To improve this situation, if we have the fixed new style protocol, we can sent NBD_OPT_LIST as the first option to query the list of server exports. We can check for our named export in this list and raise an error if it is not found, instead of going ahead and sending NBD_OPT_EXPORT_NAME with a name that we know will be rejected. This improves the error reporting both in the case that the server required TLS, and in the case that the client requested export name does not exist on the server. If the server does not support NBD_OPT_LIST, we just ignore that and carry on with NBD_OPT_EXPORT_NAME as before. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-12-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: make client request fixed new style if advertisedDaniel P. Berrange1-10/+17
If the server advertises support for the fixed new style negotiation, the client should in turn enable new style. This will allow the client to negotiate further NBD options besides the export name. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-10-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: make server compliant with fixed newstyle specDaniel P. Berrange1-23/+46
If the client does not request the fixed new style protocol, then we should only accept NBD_OPT_EXPORT_NAME. All other options are only valid when fixed new style has been activated. The qemu-nbd client doesn't currently request fixed new style protocol, but this change won't break qemu-nbd, because it fortunately only ever uses NBD_OPT_EXPORT_NAME, so was never triggering the non-compliant server behaviour. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-9-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: invert client logic for negotiating protocol versionDaniel P. Berrange1-31/+29
The nbd_receive_negotiate() method takes different code paths based on whether 'name == NULL', and then checks the expected protocol version in each branch. This patch inverts the logic, so that it takes different code paths based on what protocol version it receives and then checks if name is NULL or not as needed. This facilitates later code which allows the client to be capable of using the new style protocol regardless of whether an export name is listed or not. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-8-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: convert to using I/O channels for actual socket I/ODaniel P. Berrange4-124/+152
Now that all callers are converted to use I/O channels for initial connection setup, it is possible to switch the core NBD protocol handling core over to use QIOChannel APIs for actual sockets I/O. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-7-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09nbd: avoid unaligned uint64_t storeJohn Snow1-10/+10
cpu_to_be64w can't be used to make unaligned stores, but stq_be_p can. Also, the st?_be_p takes a void* so it is more clearly suited to the case where you're writing into a byte buffer. Use the st?_be_p family of functions everywhere in nbd/server.c. Signed-off-by: John Snow <jsnow@redhat.com> [Changed to use st?_be_p everywhere. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-04all: Clean up includesPeter Maydell3-0/+3
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1454089805-5470-16-git-send-email-peter.maydell@linaro.org
2016-02-02nbd: Switch from close to eject notifierMax Reitz1-0/+13
The NBD code uses the BDS close notifier to determine when a medium is ejected. However, now it should use the BB's BDS removal notifier for that instead of the BDS's close notifier. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-02-02nbd: client_close on error in nbd_co_client_startMax Reitz1-2/+1
Use client_close() if an error in nbd_co_client_start() occurs instead of manually inlining parts of it. This fixes an assertion error on the server side if nbd_negotiate() fails. Signed-off-by: Max Reitz <mreitz@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-01-26Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into stagingPeter Maydell1-0/+2
* chardev support for TLS and leak fix * NBD fix from Denis * condvar fix from Dave * kvm_stat and dump-guest-memory almost rewrite * mem-prealloc fix from Luiz * manpage style improvement # gpg: Signature made Tue 26 Jan 2016 14:58:18 GMT using RSA key ID 78C7AE83 # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" * remotes/bonzini/tags/for-upstream: (49 commits) scripts/dump-guest-memory.py: Fix module docstring scripts/dump-guest-memory.py: Introduce multi-arch support scripts/dump-guest-memory.py: Cleanup functions scripts/dump-guest-memory.py: Improve python 3 compatibility scripts/dump-guest-memory.py: Make methods functions scripts/dump-guest-memory.py: Move constants to the top nbd: add missed aio_context_acquire in nbd_export_new memory: exit when hugepage allocation fails if mem-prealloc cpus: use broadcast on qemu_pause_cond scripts/kvm/kvm_stat: Add optparse description scripts/kvm/kvm_stat: Add interactive filtering scripts/kvm/kvm_stat: Fixup filtering scripts/kvm/kvm_stat: Fix rlimit for unprivileged users scripts/kvm/kvm_stat: Read event values as u64 scripts/kvm/kvm_stat: Cleanup and pre-init perf_event_attr scripts/kvm/kvm_stat: Fix output formatting scripts/kvm/kvm_stat: Make tui function a class scripts/kvm/kvm_stat: Remove unneeded X86_EXIT_REASONS scripts/kvm/kvm_stat: Group arch specific data scripts/kvm/kvm_stat: Cleanup of Event class ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-01-26nbd: add missed aio_context_acquire in nbd_export_newDenis V. Lunev1-0/+2
blk_invalidate_cache() can call qcow2_invalidate_cache which performs IO inside. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Kevin Wolf <kwolf@redhat.com> CC: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1453273940-15382-3-git-send-email-den@openvz.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-20block: Rename BDRV_O_INCOMING to BDRV_O_INACTIVEKevin Wolf1-1/+1
Instead of covering only the state of images on the migration destination before the migration is completed, the flag will also cover the state of images on the migration source after completion. This common state implies that the image is technically still open, but no writes will happen and any cached contents will be reloaded from disk if and when the image leaves this state. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-01-15nbd-server: do not exit on failed memory allocationPaolo Bonzini1-1/+5
The amount of memory allocated in nbd_co_receive_request is driven by the NBD client (possibly a virtual machine). Parallel I/O can cause the server to allocate a large amount of memory; check for failures and return ENOMEM in that case. Cc: qemu-block@nongnu.org Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-15nbd-server: do not check request length except for reads and writesPaolo Bonzini1-7/+7
Only reads and writes need to allocate memory correspondent to the request length. Other requests can be sent to the storage without allocating any memory, and thus any request length is acceptable. Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com> Cc: qemu-block@nongnu.org Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-15nbd-server: Coroutine based negotiationFam Zheng1-47/+103
Create a coroutine in nbd_client_new, so that nbd_send_negotiate doesn't need qemu_set_block(). Handlers need to be set temporarily for csock fd in case the coroutine yields during I/O. With this, if the other end disappears in the middle of the negotiation, we don't block the whole event loop. To make the code clearer, unify all function names that belong to negotiate, so they are less likely to be misused. This is important because we rely on negotiation staying in main loop, as commented in nbd_negotiate_read/write(). Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <1452760863-25350-4-git-send-email-famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-15nbd: Split nbd.cFam Zheng5-0/+1591
We have NBD server code and client code, all mixed in a file. Now split them into separate files under nbd/, and update MAINTAINERS. filter_nbd for iotest 083 is updated to keep the log filtered out. Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <1452760863-25350-3-git-send-email-famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>