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2018-01-26qapi: add nbd-server-removeVladimir Sementsov-Ogievskiy
Add command for removing an export. It is needed for cases when we don't want to keep the export after the operation on it was completed. The other example is a temporary node, created with blockdev-add. If we want to delete it we should firstly remove any corresponding NBD export. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180119135719.24745-3-vsementsov@virtuozzo.com> [eblake: drop dead nb_clients code] Signed-off-by: Eric Blake <eblake@redhat.com>
2018-01-17nbd/server: structurize option reply sendingVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20171122101958.17065-6-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2018-01-17nbd/server: Add helper functions for parsing option payloadEric Blake
Rather than making every callsite perform length sanity checks and error reporting, add the helper functions nbd_opt_read() and nbd_opt_drop() that use the length stored in the client struct; also add an assertion that optlen is 0 before any option (ie. any previous option was fully handled), complementing the assertion added in an earlier patch that optlen is 0 after all negotiation completes. Note that the call in nbd_negotiate_handle_export_name() does not use the new helper (in part because the server cannot reply to NBD_OPT_EXPORT_NAME - it either succeeds or the connection drops). Based on patches by Vladimir Sementsov-Ogievskiy. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180110230825.18321-6-eblake@redhat.com>
2018-01-17nbd/server: Add va_list form of nbd_negotiate_send_rep_err()Eric Blake
This will be useful for the next patch. Based on a patch by Vladimir Sementsov-Ogievskiy Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180110230825.18321-5-eblake@redhat.com>
2018-01-17nbd/server: Better error for NBD_OPT_EXPORT_NAME failureEric Blake
When a client abruptly disconnects before we've finished reading the name sent with NBD_OPT_EXPORT_NAME, we are better off logging the failure as EIO (we can't communicate with the client), rather than EINVAL (the client sent bogus data). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180110230825.18321-4-eblake@redhat.com>
2018-01-17nbd/server: refactor negotiation functions parametersVladimir Sementsov-Ogievskiy
Instead of passing currently negotiating option and its length to many of negotiation functions let's just store them on NBDClient struct to be state-variables of negotiation phase. This unifies semantics of negotiation functions and allows tracking changes of remaining option length in future patches. Asssert that optlen is back to 0 after negotiation (including old-style connections which don't negotiate), although we need more patches before we can assert optlen is 0 between options during negotiation. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20171122101958.17065-2-vsementsov@virtuozzo.com> [eblake: rebase, commit message tweak, assert !optlen after negotiation completes] Signed-off-by: Eric Blake <eblake@redhat.com>
2018-01-17nbd/server: Hoist nbd_reject_length() earlierEric Blake
No semantic change, but will make it easier for an upcoming patch to refactor code without having to add forward declarations. Fix a poor comment while at it. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180110230825.18321-2-eblake@redhat.com>
2018-01-09nbd/server: add additional assert to nbd_export_putVladimir Sementsov-Ogievskiy
This place is not obvious, nbd_export_close may theoretically reduce refcount to 0. It may happen if someone calls nbd_export_put on named export not through nbd_export_set_name when refcount is 1. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20171207155102.66622-2-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2018-01-08nbd/server: Optimize final chunk of sparse readEric Blake
If we are careful to handle 0-length read requests correctly, we can optimize our sparse read to send the NBD_REPLY_FLAG_DONE bit on our last OFFSET_DATA or OFFSET_HOLE chunk rather than needing a separate chunk. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20171107030912.23930-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2018-01-08nbd/server: Implement sparse reads atop structured replyEric Blake
The reason that NBD added structured reply in the first place was to allow for efficient reads of sparse files, by allowing the reply to include chunks to quickly communicate holes to the client without sending lots of zeroes over the wire. Time to implement this in the server; our client can already read such data. We can only skip holes insofar as the block layer can query them; and only if the client is okay with a fragmented request (if a client requests NBD_CMD_FLAG_DF and the entire read is a hole, we could technically return a single NBD_REPLY_TYPE_OFFSET_HOLE, but that's a fringe case not worth catering to here). Sadly, the control flow is a bit wonkier than I would have preferred, but it was minimally invasive to have a split in the action between a fragmented read (handled directly where we recognize NBD_CMD_READ with the right conditions, and sending multiple chunks) vs. a single read (handled at the end of nbd_trip, for both simple and structured replies, when we know there is only one thing being read). Likewise, I didn't make any effort to optimize the final chunk of a fragmented read to set the NBD_REPLY_FLAG_DONE, but unconditionally send that as a separate NBD_REPLY_TYPE_NONE. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20171107030912.23930-2-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2017-11-28nbd/server: CVE-2017-15118 Stack smash on large export nameEric Blake
Introduced in commit f37708f6b8 (2.10). The NBD spec says a client can request export names up to 4096 bytes in length, even though they should not expect success on names longer than 256. However, qemu hard-codes the limit of 256, and fails to filter out a client that probes for a longer name; the result is a stack smash that can potentially give an attacker arbitrary control over the qemu process. The smash can be easily demonstrated with this client: $ qemu-io f raw nbd://localhost:10809/$(printf %3000d 1 | tr ' ' a) If the qemu NBD server binary (whether the standalone qemu-nbd, or the builtin server of QMP nbd-server-start) was compiled with -fstack-protector-strong, the ability to exploit the stack smash into arbitrary execution is a lot more difficult (but still theoretically possible to a determined attacker, perhaps in combination with other CVEs). Still, crashing a running qemu (and losing the VM) is bad enough, even if the attacker did not obtain full execution control. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com>
2017-11-28nbd/server: CVE-2017-15119 Reject options larger than 32MEric Blake
The NBD spec gives us permission to abruptly disconnect on clients that send outrageously large option requests, rather than having to spend the time reading to the end of the option. No real option request requires that much data anyways; and meanwhile, we already have the practice of abruptly dropping the connection on any client that sends NBD_CMD_WRITE with a payload larger than 32M. For comparison, nbdkit drops the connection on any request with more than 4096 bytes; however, that limit is probably too low (as the NBD spec states an export name can theoretically be up to 4096 bytes, which means a valid NBD_OPT_INFO could be even longer) - even if qemu doesn't permit exports longer than 256 bytes. It could be argued that a malicious client trying to get us to read nearly 4G of data on a bad request is a form of denial of service. In particular, if the server requires TLS, but a client that does not know the TLS credentials sends any option (other than NBD_OPT_STARTTLS or NBD_OPT_EXPORT_NAME) with a stated payload of nearly 4G, then the server was keeping the connection alive trying to read all the payload, tying up resources that it would rather be spending on a client that can get past the TLS handshake. Hence, this warranted a CVE. Present since at least 2.5 when handling known options, and made worse in 2.6 when fixing support for NBD_FLAG_C_FIXED_NEWSTYLE to handle unknown options. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com>
2017-11-17nbd/server: Fix error reporting for bad requestsEric Blake
The NBD spec says an attempt to NBD_CMD_TRIM on a read-only export should fail with EPERM, as a trim has the potential to change disk contents, but we were relying on the block layer to catch that for us, which might not always give the right error (and even if it does, it does not let us pass back a sane message for structured replies). The NBD spec says an attempt to NBD_CMD_WRITE_ZEROES out of bounds should fail with ENOSPC, not EINVAL. Our check for u64 offset + u32 length wraparound up front is pointless; nothing uses offset until after the second round of sanity checks, and we can just as easily ensure there is no wraparound by checking whether offset is in bounds (since a disk size cannot exceed off_t which is 63 bits, adding a 32-bit number for a valid offset can't overflow). Bonus: dropping the up-front check lets us keep the connection alive after NBD_CMD_WRITE, whereas before we would drop the connection (of course, any client sending a packet that would trigger the failure is already buggy, so it's also okay to drop the connection, but better quality-of-implementation never hurts). Solve all of these issues by some code motion and improved request validation. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20171115213557.3548-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2017-11-09nbd/server: Fix structured read of length 0Eric Blake
The NBD spec was recently clarified to state that a read of length 0 should not be attempted by a compliant client; but that a server must still handle it correctly in an unspecified manner (that is, either a successful no-op or an error reply, but not a crash) [1]. However, it also implies that NBD_REPLY_TYPE_OFFSET_DATA must have a non-zero payload length, but our existing code was replying with a chunk that a picky client could reject as invalid because it was missing a payload (our own client implementation was recently patched to be that picky, after first fixing it to not send 0-length requests). We are already doing successful no-ops for 0-length writes and for non-structured reads; so for consistency, we want structured reply reads to also be a no-op. The easiest way to do this is to return a NBD_REPLY_TYPE_NONE chunk; this is best done via a new helper function (especially since future patches for other structured replies may benefit from using the same helper). [1] https://github.com/NetworkBlockDevice/nbd/commit/ee926037 Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20171108215703.9295-8-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2017-11-09nbd: Fix struct name for structured readsEric Blake
A closer read of the NBD spec shows that a structured reply chunk for a hole is not quite identical to the prefix of a data chunk, because the hole has to also send a 32-bit size field. Although we do not yet send holes, we should fix the misleading information in our header and make it easier for a future patch to support sparse reads. Messed up in commit bae245d1. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20171108215703.9295-5-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2017-11-08nbd/server: fix nbd_negotiate_handle_infoVladimir Sementsov-Ogievskiy
namelen should be here, length is unrelated, and always 0 at this point. Broken in introduction in commit f37708f6, but mostly harmless (replying with '' as the name does not violate protocol, and does not confuse qemu as the nbd client since our implementation does not ask for the name; but might confuse some other client that does ask for the name especially if the default export is different than the export name being queried). Adding an assert makes it obvious that we are not skipping any bytes in the client's message, as well as making it obvious that we were using the wrong variable. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> CC: qemu-stable@nongnu.org Message-Id: <20171101154204.27146-1-vsementsov@virtuozzo.com> [eblake: improve commit message, squash in assert addition] Signed-off-by: Eric Blake <eblake@redhat.com>
2017-10-30nbd/server: Include human-readable message in structured errorsEric Blake
The NBD spec permits including a human-readable error string if structured replies are in force, so we might as well send the client the message that we logged on any error. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171027104037.8319-9-eblake@redhat.com>
2017-10-30nbd: Minimal structured read for serverVladimir Sementsov-Ogievskiy
Minimal implementation of structured read: one structured reply chunk, no segmentation. Minimal structured error implementation: no text message. Support DF flag, but just ignore it, as there is no segmentation any way. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20171027104037.8319-8-eblake@redhat.com>
2017-10-30nbd/server: Refactor zero-length option checkEric Blake
Consolidate the response for a non-zero-length option payload into a new function, nbd_reject_length(). This check will also be used when introducing support for structured replies. Note that STARTTLS response differs based on time: if the connection is still unencrypted, we set fatal to true (a client that can't request TLS correctly may still think that we are ready to start the TLS handshake, so we must disconnect); while if the connection is already encrypted, the client is sending a bogus request but is no longer at risk of being confused by continuing the connection. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20171027104037.8319-7-eblake@redhat.com> [eblake: correct return value on STARTTLS] Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2017-10-30nbd/server: Simplify nbd_negotiate_options loopEric Blake
Instead of making each caller check whether a transmission error occurred, we can sink a common error check to the end of the loop. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20171027104037.8319-6-eblake@redhat.com> [eblake: squash in compiler warning fix] Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2017-10-30nbd/server: Report error for write to read-only exportEric Blake
When the server is read-only, we were already reporting an error message for NBD_CMD_WRITE_ZEROES, but failed to set errp for a similar NBD_CMD_WRITE. This will matter more once structured replies allow the server to propagate the errp information back to the client. While at it, use an error message that makes a bit more sense if viewed on the client side. Note that when using qemu-io to test qemu-nbd behavior, it is rather difficult to convince qemu-io to send protocol violations (such as a read beyond bounds), because we have a lot of active checking on the client side that a qemu-io request makes sense before it ever goes over the wire to the server. The case of a client attempting a write when the server is started as 'qemu-nbd -r' is one of the few places where we can easily test error path handling, without having to resort to hacking in known temporary bugs to either the server or client. [Maybe we want a future patch to the client to do up-front checking on writes to a read-only export, the way it does up-front bounds checking; but I don't see anything in the NBD spec that points to a protocol violation in our current behavior.] Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171027104037.8319-5-eblake@redhat.com>
2017-10-30nbd: Expose constants and structs for structured readEric Blake
Upcoming patches will implement the NBD structured reply extension [1] for both client and server roles. Declare the constants, structs, and lookup routines that will be valuable whether the server or client code is backported in isolation. This includes moving one constant from an internal header to the public header, as part of the structured read processing will be done in block/nbd-client.c rather than nbd/client.c. [1]https://github.com/NetworkBlockDevice/nbd/blob/extension-structured-reply/doc/proto.md Based on patches from Vladimir Sementsov-Ogievskiy. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171027104037.8319-4-eblake@redhat.com>
2017-10-30nbd: Include error names in trace messagesEric Blake
NBD errors were originally sent over the wire based on Linux errno values; but not all the world is Linux, and not all platforms share the same values. Since a number isn't very easy to decipher on all platforms, update the trace messages to include the name of NBD errors being sent/received over the wire. Tweak the trace messages to be at the point where we are using the NBD error, not the translation to the host errno values. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171027104037.8319-2-eblake@redhat.com>
2017-10-13nbd/server: simplify reply transmissionVladimir Sementsov-Ogievskiy
Send qiov via qio_channel_writev_all instead of calling nbd_write twice with a cork. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171012095319.136610-8-vsementsov@virtuozzo.com> [eblake: rebase to tweaks earlier in series] Signed-off-by: Eric Blake <eblake@redhat.com>
2017-10-13nbd/server: refactor nbd_co_send_simple_reply parametersVladimir Sementsov-Ogievskiy
Pass client and buffer (*data) parameters directly, to make the function consistent with further structured reply sending functions. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171012095319.136610-7-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-10-13nbd/server: do not use NBDReply structureVladimir Sementsov-Ogievskiy
NBDReply structure will be upgraded in future patches to handle both simple and structured replies and will be used only in the client Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171012095319.136610-6-vsementsov@virtuozzo.com> [eblake: rebase to tweaks earlier in series] Signed-off-by: Eric Blake <eblake@redhat.com>
2017-10-12nbd/server: structurize simple reply header sendingVladimir Sementsov-Ogievskiy
Use packed structure instead of pointer arithmetics. Also, merge two redundant traces into one. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171012095319.136610-5-vsementsov@virtuozzo.com> [eblake: tweak and mention impact on traces, fix errp usage] Signed-off-by: Eric Blake <eblake@redhat.com>
2017-10-12nbd: rename some simple-request related objects to be _simple_Vladimir Sementsov-Ogievskiy
To be consistent when their _structured_ analogs will be introduced. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20171012095319.136610-4-vsementsov@virtuozzo.com> [eblake: also tweak trace message contents] Signed-off-by: Eric Blake <eblake@redhat.com>
2017-10-12NBD: use g_new() family of functionsMarc-André Lureau
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20171006235023.11952-22-f4bug@amsat.org> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-08-15nbd: Fix order of bdrv_set_perm and bdrv_invalidate_cacheKevin Wolf
The "inactive" state of BDS affects whether the permissions can be granted, we must call bdrv_invalidate_cache before bdrv_set_perm to support "-incoming defer" case. Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com> Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170815130740.31229-3-famz@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-17nbd: Fix server reply to NBD_OPT_EXPORT_NAME of older clientsEric Blake
A typo in commit 23e099c set the size of buf[] used in response to NBD_OPT_EXPORT_NAME according to the length needed for old-style negotiation (4 bytes of flag information) instead of the intended 2 bytes used in new style. If the client doesn't enable NBD_FLAG_C_NO_ZEROES, then the server sends two bytes too many, and is then out of sync in response to the client's next command (the bug is masked when modern qemu is the client, since we enable the no zeroes flag). While touching this code, add some more defines to nbd_internal.h rather than having quite so many magic numbers in the .c; also, use "" initialization rather than memset(), and tweak the oldstyle negotiation to better match the spec description of the layout (since the spec is big-endian, skipping two bytes as 0 followed by writing a 2-byte flag is the same as writing a zero-extended 4-byte flag), to make it a bit easier to follow compared to the spec. [checkpatch.pl has some false positives in the comments] Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170717192635.17880-3-eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com>
2017-07-14nbd: Implement NBD_INFO_BLOCK_SIZE on serverEric Blake
The upstream NBD Protocol has defined a new extension to allow the server to advertise block sizes to the client, as well as a way for the client to inform the server that it intends to obey block sizes. Thanks to a recent fix (commit df7b97ff), our real minimum transfer size is always 1 (the block layer takes care of read-modify-write on our behalf), but we're still more efficient if we advertise 512 when the client supports it, as follows: - OPT_INFO, but no NBD_INFO_BLOCK_SIZE: advertise 512, then fail with NBD_REP_ERR_BLOCK_SIZE_REQD; client is free to try something else since we don't disconnect - OPT_INFO with NBD_INFO_BLOCK_SIZE: advertise 512 - OPT_GO, but no NBD_INFO_BLOCK_SIZE: advertise 1 - OPT_GO with NBD_INFO_BLOCK_SIZE: advertise 512 We can also advertise the optimum block size (presumably the cluster size, when exporting a qcow2 file), and our absolute maximum transfer size of 32M, to help newer clients avoid EINVAL failures or abrupt disconnects on oversize requests. We do not reject clients for using the older NBD_OPT_EXPORT_NAME; we are no worse off for those clients than we used to be. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707203049.534-9-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14nbd: Implement NBD_OPT_GO on serverEric Blake
NBD_OPT_EXPORT_NAME is lousy: per the NBD protocol, any failure requires us to close the connection rather than report an error. Therefore, upstream NBD recently added NBD_OPT_GO as the improved version of the option that does what we want [1], along with NBD_OPT_INFO that returns the same information but does not transition to transmission phase. [1] https://github.com/NetworkBlockDevice/nbd/blob/extension-info/doc/proto.md This is a first cut at the information types, and only passes the same information already available through NBD_OPT_LIST and NBD_OPT_EXPORT_NAME; items like NBD_INFO_BLOCK_SIZE (and thus any use of NBD_REP_ERR_BLOCK_SIZE_REQD) are intentionally left for later patches. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707203049.534-7-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14nbd: Refactor reply to NBD_OPT_EXPORT_NAMEEric Blake
Reply directly in nbd_negotiate_handle_export_name(), rather than waiting until nbd_negotiate_options() completes. This will make it easier to implement NBD_OPT_GO. Pass additional parameters around, rather than stashing things inside NBDClient. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707203049.534-6-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14nbd: Simplify trace of client flags in negotiationEric Blake
Simplify the tracing of client flags in the server, and return -EINVAL instead of -EIO if we successfully read but don't like those flags. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707203049.534-5-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14nbd: Expose and debug more NBD constantsEric Blake
The NBD protocol has several constants defined in various extensions that we are about to implement. Expose them to the code, along with an easy way to map various constants to strings during diagnostic messages. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707203049.534-4-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14nbd: Don't bother tracing an NBD_OPT_ABORT response failureEric Blake
We really don't care if our spec-compliant reply to NBD_OPT_ABORT was received, so shave off some lines of code by not even tracing it. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707203049.534-3-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-10nbd: use generic trace subsystem instead of TRACE macroVladimir Sementsov-Ogievskiy
Let NBD use the trace mechanisms already present in qemu. Now you can use the -trace optino of qemu, or the -T/--trace option of qemu-img, qemu-io, and qemu-nbd, to select nbd traces. For qemu, the QMP commands trace-event-{get,set}-state can also toggle tracing on the fly. Example: qemu-nbd --trace 'nbd_*' <image file> # enables all nbd traces Recompilation with CFLAGS=-DDEBUG_NBD is no more needed, furthermore, DEBUG_NBD macro is removed from the code. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20170707152918.23086-11-vsementsov@virtuozzo.com> [eblake: minor tweaks to a couple of traces] Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-10nbd: refactor tracingVladimir Sementsov-Ogievskiy
Reorganize traces: move, reword, add information, drop extra ones. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20170707152918.23086-10-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-10nbd/server: rename clientflags var in nbd_negotiate_optionsVladimir Sementsov-Ogievskiy
Rename 'clientflags' to just 'option'. This variable has nothing to do with flags, but is a single integer representing the option requested by the client. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20170707152918.23086-9-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-10nbd/server: fix TRACE in nbd_negotiate_send_rep_lenVladimir Sementsov-Ogievskiy
Fix wrong order of TRACE arguments. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20170707152918.23086-8-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-10nbd/server: add errp to nbd_send_reply()Vladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707152918.23086-5-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-10nbd/server: use errp instead of LOGVladimir Sementsov-Ogievskiy
Move to modern errp scheme from just LOGging errors. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20170707152918.23086-4-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-10nbd/server: refactor nbd_negotiateVladimir Sementsov-Ogievskiy
Combine two successive "if (oldStyle) {...} else {...}" into one. Block "if (client->tlscreds)" under "if (oldStyle)" is unreachable, as we have "oldStyle = client->exp != NULL && !client->tlscreds;". So, delete this block. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20170707152918.23086-3-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-10nbd/server: nbd_negotiate: return 1 on NBD_OPT_ABORTVladimir Sementsov-Ogievskiy
Separate the case when a client sends NBD_OPT_ABORT from all other errors. It will be needed for the following patch, where errors will be reported. This particular case is not actually an error - it honestly follows the NBD protocol. Therefore it should not be reported like an error. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707152918.23086-2-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-06-15nbd/server: refactor nbd_tripVladimir Sementsov-Ogievskiy
- do not use 'goto error_reply' outside a switch to jump into the middle of the switch's default case label - reduce code duplication Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20170602150150.258222-13-vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15nbd/server: rename rc to retVladimir Sementsov-Ogievskiy
For consistency use 'ret' name for saving return code everywhere in the file. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20170602150150.258222-12-vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15nbd/server: get rid of fail: return rcVladimir Sementsov-Ogievskiy
"goto fail" error handling scheme is not needed for just returning error code. Better is return it immediately. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20170602150150.258222-11-vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15nbd/server: nbd_negotiate: fix error pathVladimir Sementsov-Ogievskiy
Current code will return 0 on this nbd_write fail, as rc is 0 after successful nbd_negotiate_options. Fix this. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20170602150150.258222-10-vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15nbd/server: remove NBDClientNewDataVladimir Sementsov-Ogievskiy
"co" field of NBDClientNewData has never been used, all the way back to its declaration in commit 1a6245a5. So let's just use client pointer instead of extra structure. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20170602150150.258222-9-vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>