With the current way OCSP responses are stored, a single OCSP response
is stored (in a certificate_ocsp structure) when it is loaded during a
certificate parsing, and each ckch_inst that references it increments
its refcount. The reference to the certificate_ocsp is actually kept in
the SSL_CTX linked to each ckch_inst, in an ex_data entry that gets
freed when he context is freed.
One of the downside of this implementation is that is every ckch_inst
referencing a certificate_ocsp gets detroyed, then the OCSP response is
removed from the system. So if we were to remove all crt-list lines
containing a given certificate (that has an OCSP response), the response
would be destroyed even if the certificate remains in the system (as an
unused certificate). In such a case, we would want the OCSP response not
to be "usable", since it is not used by any ckch_inst, but still remain
in the OCSP response tree so that if the certificate gets reused (via an
"add ssl crt-list" command for instance), its OCSP response is still
known as well. But we would also like such an entry not to be updated
automatically anymore once no instance uses it. An easy way to do it
could have been to keep a reference to the certificate_ocsp structure in
the ckch_store as well, on top of all the ones in the ckch_instances,
and to remove the ocsp response from the update tree once the refcount
falls to 1, but it would not work because of the way the ocsp response
tree keys are calculated. They are decorrelated from the ckch_store and
are the actual OCSP_CERTIDs, which is a combination of the issuer's name
hash and key hash, and the certificate's serial number. So two copies of
the same certificate but with different names would still point to the
same ocsp response tree entry.
The solution that answers to all the needs expressed aboved is actually
to have two reference counters in the certificate_ocsp structure, one
for the actual ckch instances and one for the ckch stores. If the
instance refcount becomes 0 then we remove the entry from the auto
update tree, and if the store reference becomes 0 we can then remove the
OCSP response from the tree. This would allow to chain some "del ssl
crt-list" and "add ssl crt-list" CLI commands without losing any
functionality.
Must be backported to 2.8.
The only useful information taken out of the ckch_store in order to copy
an OCSP certid into a buffer (later used as a key for entries in the
OCSP response tree) is the ocsp_certid field of the ckch_data structure.
We then don't need to pass a pointer to the full ckch_store to
ckch_store_build_certid or even any information related to the store
itself.
The ckch_store_build_certid is then converted into a helper function
that simply takes an OCSP_CERTID and converts it into a char buffer.
At the beginning of the 3.0-dev cycle, the zero-copy forwarding support was
added only for the cache applet with an option to disable it. This was a
hack, waiting for a better integration with applets. It is now possible to
implement the zero-copy forwarding for any applets. So the specific option
for the cache applet was renamed to be used for all applets. And this option
is now also checked for the stats applet.
Concretely, 'tune.cache.zero-copy-forwarding' was renamed to
'tune.applet.zero-copy-forwarding'.
Default .rcv_buf and .snd_buf functions that applets can use are now
specialized to manipulate raw buffers or HTX buffers.
Thus a TCP applet should use appctx_raw_rcv_buf() and appctx_raw_snd_buf()
while HTTP applet should use appctx_htx_rcv_buf() and appctx_htx_snd_buf().
Note that the appctx is now directly passed to these functions instead of
the SC.
Just like for the cache applet, it is now possible to send response to the
opposite side using the zero-copy forwarding. Internal functions were
slightly updated but there is nothing special to say. Except the requested
size during the nego stage is not exact.
It is now possible to use a flag during zero-copy forwarding negotiation to
specify the requested size is exact, it means the producer really expect to
receive at least this amount of data.
It can be used by consumer to prepare some processing at this stage, based
on the requested size. For instance, in the H1 mux, it is used to write the
next chunk size.
During zero-copy forwarding negotiation, a pseudo flag was already used to
notify the consummer if the producer is able to use kernel splicing or not. But
this was not extensible. So, now we use a true bitfield to be able to pass flags
during the negotiation. NEGO_FF_FL_* flags may be used now.
Of course, for now, there is only one flags, the kernel splicing support on
producer side (NEGO_FF_FL_MAY_SPLICE).
Thanks to this patch, it is possible to an applet to directly send data to
the opposite endpoint. To do so, it must implement <fastfwd> appctx callback
function and set SE_FL_MAY_FASTFWD flag.
Everything will be handled by appctx_fastfwd() function. The applet is only
responsible to transfer data. If it sets <to_forward> value, it is used to
limit the amount of data to forward.
This patch introduces the support for the callback function responsible to
produce data via the zero-copy forwarding mechanism. There is no
implementation for now. But <to_forward> field was added in the appctx
structure to let an applet inform how much data it want to forward. It is
not mandatory but it will be used during the zero-copy forwarding
negociation.
There is no shutdown for reads and send with applets. Both are performed
when the appctx is released. So instead of 2 flags, like for
muxes/connections, only one flag is used. But the idea is the same:
acknowledge the event at the applet level.
The appctx state was never really used as a state. It is only used to know
when an applet should be freed on the next wakeup. This can be converted to
a flag and the state can be removed. This is what this patch does.
Dedicated appctx flags to report EOI, EOS and errors (pending or terminal) were
added with the functions to set these flags. It is pretty similar to what it
done on most of muxes.
Till now, we've extended the appctx state to add some flags. However, the
field name is misleading. So a bitfield was added to handle real flags. And
helper functions to manipulate this bitfield were added.
A dedicated function to run applets was introduced, in addition to the old
one, to deal with applets that use their own buffers. The main differnce
here is that this handler does not use channels at all. It performs a
synchronous send before calling the applet and performs a synchronous
receive just after.
No applets are plugged on this handler for now.
There is no tasklet to handle I/O subscriptions for applets, but functions
to deal with receives and sends from the SC layer were added. it meanse a
function to retrieve data from an applet with this synchronous version and a
function to push data to an applet wit this synchronous version.
It is pretty similar to the functions used for muxes but there are some
differences. So for now, we keep them separated.
Zero-copy forwarding is not supported for now. In addition, there is no
subscription mechanism.
In this patch, we add default functions to copy data from a channel to the
<inbuf> buffer of an applet (appctx_rcv_buf) and another on to copy data
from <outbuf> buffer of an applet to a channel (appctx_snd_buf).
These functions are not used for now, but they will be used by applets to
define their <rcv_buf> and <snd_buf> callback functions. Of course, it will
be possible for a specific applet to implement its own functions but these
ones should be good enough for most of applets. HTX and RAW buffers are
supported.
For now, it is not usable, but this patch introduce the support of callback
functions, in the applet structure, to exchange data between channels and
applets. It is pretty similar to callback functions defined by muxes.
It is the first patch of a series aimed to align applets on connections.
Here, dedicated buffers are added for applets. For now, buffers are
initialized and helpers function to deal with allocation are added. In
addition, flags to report allocation failures or full buffers are also
introduced. <inbuf> will be used to push data to the applet from the stream
and <outbuf> will be used to push data from the applet to the stream.
IS_HXT_SC() macro is only usable if the stream-connector is attached to a
connection. It is a bit restrictive because this cannot work if the SC is
attached to an applet. So let's fix that be adding the support of applets
too.
wait_event structure was in connection header file because it is only used
by connections and muxes. But, this may change. For instance applets may be
good candidates to use it too. So, the structure is moved to the task header
file instead.
This commit adds support for an optional second argument to BUG_ON(),
WARN_ON(), CHECK_IF(), that can be a constant string. When such an
argument is given, it will be printed on a second line after the
existing first message that contains the condition.
This can be used to provide more human-readable explanations about
what happened, such as "too low on memory" or "memory corruption
detected" that may help a user resolve the incident by themselves.
The ABORT_NOW() macro is not much used since we have BUG_ON(), but
there are situations where it makes sense, typically if the program
must always die regardless od DEBUG_STRICT, or if the condition must
always be evaluated (e.g. decompress something and check it).
It's not convenient not to have any hint about what happened there. But
providing too much info also results in wiping some registers, making
the trace less exploitable, so a compromise must be found.
What this patch does is to provide the support for an optional argument
to ABORT_NOW(). When an argument is passed (a string), then a message
will be emitted with the file name, line number, the message and a
trailing LF, before the stack dump and the crash. It should be used
reasonably, for example in functions that have multiple calls that need
to be more easily distinguished.
As seen in previous commit 59acb27001 ("BUILD: quic: Variable name typo
inside a BUG_ON()."), it can sometimes happen that with DEBUG forced
without DEBUG_STRICT, BUG_ON() statements are ignored. Sadly, it means
that typos there are not even build-tested.
This patch makes these statements reference sizeof(cond) to make sure
the condition is parsed. This doesn't result in any code being emitted,
but makes sure the expression is correct so that an issue such as the one
above will fail to build (which was verified).
This may be backported as it can help spot failed backports as well.
Since d480b7b ("MINOR: debug: make ABORT_NOW() store the caller's line
number when using abort"), building with 'DEBUG_USE_ABORT' fails with:
|In file included from include/haproxy/api.h:35,
| from include/haproxy/activity.h:26,
| from src/ev_poll.c:20:
|include/haproxy/thread.h: In function ‘ha_set_thread’:
|include/haproxy/bug.h:107:47: error: expected ‘;’ before ‘_with_line’
| 107 | #define ABORT_NOW() do { DUMP_TRACE(); abort()_with_line(__LINE__); } while (0)
| | ^~~~~~~~~~
|include/haproxy/bug.h:129:25: note: in expansion of macro ‘ABORT_NOW’
| 129 | ABORT_NOW(); \
| | ^~~~~~~~~
|include/haproxy/bug.h:123:9: note: in expansion of macro ‘__BUG_ON’
| 123 | __BUG_ON(cond, file, line, crash, pfx, sfx)
| | ^~~~~~~~
|include/haproxy/bug.h:174:30: note: in expansion of macro ‘_BUG_ON’
| 174 | # define BUG_ON(cond) _BUG_ON (cond, __FILE__, __LINE__, 3, "FATAL: bug ", "")
| | ^~~~~~~
|include/haproxy/thread.h:201:17: note: in expansion of macro ‘BUG_ON’
| 201 | BUG_ON(!thr->ltid_bit);
| | ^~~~~~
|compilation terminated due to -Wfatal-errors.
|make: *** [Makefile:1006: src/ev_poll.o] Error 1
This is because of a leftover: abort()_with_line(__LINE__);
^^
Fixing it by removing the extra parentheses after 'abort' since the
abort() call is now performed under abort_with_line() helper function.
This was raised by Ilya in GH #2440.
No backport is needed, unless the above commit gets backported.
Placing DO_NOT_FOLD() before abort() only works in -O2 but not in -Os which
continues to place only 5 calls to abort() in h3.o for call places. The
approach taken here is to replace abort() with a new function that wraps
it and stores the line number in the stack. This slightly increases the
code size (+0.1%) but when unwinding a crash, the line number remains
present now. This is a very low cost, especially if we consider that
DEBUG_USE_ABORT is almost only used by code coverage tools and occasional
debugging sessions.
As indicated in previous commit, we don't want calls to ha_crash_now()
to be merged, since it will make gdb return a wrong line number. This
was found to happen with gcc 4.7 and 4.8 in h3.c where 26 calls end up
as only 5 to 18 "ud2" instructions depending on optimizations. By
calling DO_NOT_FOLD() just before provoking the trap, we can reliably
avoid this folding problem. Note that this does not address the case
where abort() is used instead (DEBUG_USE_ABORT).
Modern compilers sometimes perform function tail merging and identical
code folding, which consist in merging identical occurrences of same
code paths, generally final ones (e.g. before a return, a jump or an
unreachable statement). In the case of ABORT_NOW(), it can happen that
the compiler merges all of them into a single one in a function,
defeating the purpose of the check which initially was to figure where
the bug occurred.
Here we're creating a DO_NO_FOLD() macro which makes use of the line
number and passes it as an integer argument to an empty asm() statement.
The effect is a code position dependency which prevents the compiler
from merging the code till that point (though it may still merge the
following code). In practice it's efficient at stopping the compilers
from merging calls to ha_crash_now(), which was the initial purpose.
It may also be used to force certain optimization constructs since it
gives more control to the developer.
It is now possible to selectively retrieve extra counters from stats
modules. H1, H2, QUIC and H3 fill_stats() callback functions are updated to
return a specific counter.
The list of modules registered on the stats to expose extra counters is now
public. It is required to export these counters into the Prometheus
exporter.
set-bc-{mark,tos} actions are pretty similar to set-fc-{mark,tos} to set
mark/tos on packets sent from haproxy to server: set-bc-{mark,tos} actions
act on the whole backend/srv connection: from connect() to connection
teardown, thus they may only be used before the connection to the server
is instantiated, meaning that they are only relevant for request-oriented
rules such as tcp-request or http-request rules. For now their use is
limited to content request rules, because tos and mark informations are
stored directly within the stream, thus it is required that the stream
already exists.
stream flags are used in combination with dedicated stream struct members
variables to pass 'tos' and 'mark' informations so that they are correctly
considered during stream connection assignment logic (prior to connecting
to actually connecting to the server)
'tos' and 'mark' fd sockopts are taken into account in conn hash
parameters for connection reuse mechanism.
The documentation was updated accordingly.
In this patch we add the possibility to use sample expression as argument
for set-fc-{mark,tos} actions. To make it backward compatible with
previous behavior, during parsing we first try to parse the value as
as integer (decimal or hex notation), and then fallback to expr parsing
in case of failure.
The documentation was updated accordingly.
Some CPU time is needlessly wasted in conn_calculate_hash(), because all
params are first copied into a temporary buffer before computing the
hash on the whole buffer. Instead, let's leverage the XXH progressive
hash update functions to avoid expensive memcpys.
0x00000008 bit for CO_FL_* flags is no more unused since 8cc3fc73f1
("MINOR: connection: update rhttp flags usage"). Removing the comment
that says otherwise.
A major reorganization of QUIC MUX sending has been implemented. Now
data transfer occur over a single QCS buffer. This has improve
performance but at the cost of restrictions on snd_buf. Indeed, buffer
instances are now shared from stream callback snd_buf up to quic-conn
layer.
As such, snd_buf cannot manipulate freely already present data buffer.
In particular, realign has been completely removed by the previous
patches.
This commit reintroduces a partial realign support. This is only done if
the buffer contains only unsent data, via a new MUX function
qcc_realign_stream_txbuf() which is called during snd_buf.
This commit is a direct follow-up on the major rearchitecture of send
buffering. This patch implements the proper handling of connection pool
buffer temporary exhaustion.
The first step is to be able to differentiate a fatal allocation error
from a temporary pool exhaustion. This is done via a new output argument
on qcc_get_stream_txbuf(). For a fatal error, application protocol layer
will schedule the immediate connection closing. For a pool exhaustion,
QCC is flagged with QC_CF_CONN_FULL and stream sending process is
interrupted. QCS instance is also registered in a new list
<qcc.buf_wait_list>.
A new connection buffer can become available when all ACKs are received
for an older buffer. This process is taken in charge by quic-conn layer.
It uses qcc_notify_buf() function to clear QC_CF_CONN_FULL and to wake
up every streams registered on buf_wait_list to resume sending process.
This commit is a direct follow-up on the major rearchitecture of send
buffering. It allows application protocol to react if current QCS
sending buffer space is too small. In this case, the buffer can be
released to the quic-conn layer. This allows to allocate a new QCS
buffer and retry HTX parsing, unless connection buffer pool is already
depleted.
A new function qcc_release_stream_txbuf() serves as API for app protocol
to release the QCS sending buffer. This operation fails if there is
unsent data in it. In this case, MUX has to keep it to finalize transfer
of unsent data to quic-conn layer. QCS is thus flagged with
QC_SF_BLK_MROOM to interrupt snd_buf operation.
When all data are sent to the quic-conn layer, QC_SF_BLK_MROOM is
cleared via qcc_streams_sent_done() and stream layer is woken up to
restart snd_buf.
Note that a new function qcc_stream_can_send() has been defined. It
allows app proto to check if sending is currently blocked for the
current QCS. For now, it checks QC_SF_BLK_MROOM flag. However, it will
be extended to other conditions with the following patches.
The previous commit was a major rework for QUIC MUX sending process.
Following this, this patch cleans up a few elements that remains but can
be removed as they are duplicated.
Of notable changes, offset fields from QCS and QCC are removed. They are
both equivalent to flow control soft offsets.
A new function qcs_prep_bytes() is implemented. Its purpose is to return
the count of prepared data bytes not yet sent. It also replaces
qcs_need_sending().
Previously, QUIC MUX sending was implemented with data transfered along
two different buffer instances per stream.
The first QCS buffer was used for HTX blocks conversion into H3 (or
other application protocol) during snd_buf stream callback. QCS instance
is then registered for sending via qcc_io_cb().
For each sending QCS, data memcpy is performed from the first to a
secondary buffer. A STREAM frame is produced for each QCS based on the
content of their secondary buffer.
This model is useful for QUIC MUX which has a major difference with
other muxes : data must be preserved longer, even after sent to the
lower layer. Data references is shared with quic-conn layer which
implements retransmission and data deletion on ACK reception.
This double buffering stages was the first model implemented and remains
active until today. One of its major drawbacks is that it requires
memcpy invocation for every data transferred between the two buffers.
Another important drawback is that the first buffer was is allocated by
each QCS individually without restriction. On the other hand, secondary
buffers are accounted for the connection. A bottleneck can appear if
secondary buffer pool is exhausted, causing unnecessary haproxy
buffering.
The purpose of this commit is to completely break this model. The first
buffer instance is removed. Now, application protocols will directly
allocate buffer from qc_stream_desc layer. This removes completely the
memcpy invocation.
This commit has a lot of code modifications. The most obvious one is the
removal of <qcs.tx.buf> field. Now, qcc_get_stream_txbuf() returns a
buffer instance from qc_stream_desc layer. qcs_xfer_data() which was
responsible for the memcpy between the two buffers is also completely
removed. Offset fields of QCS and QCC are now incremented directly by
qcc_send_stream(). These values are used as boundary with flow control
real offset to delimit the STREAM frames built.
As this change has a big impact on the code, this commit is only the
first part to fully support single buffer emission. For the moment, some
limitations are reintroduced and will be fixed in the next patches :
* on snd_buf if QCS sent buffer in used has room but not enough for the
application protocol to store its content
* on snd_buf if QCS sent buffer is NULL and allocation cannot succeeds
due to connection pool exhaustion
One final important aspect is that extra care is necessary now in
snd_buf callback. The same buffer instance is referenced by both the
stream and quic-conn layer. As such, some operation such as realign
cannot be done anymore freely.
Both QCS and QCC have their owned sent offset field. These fields store
the newest offset sent to the quic-conn layer. It is similar to QCS/QCC
flow control real offset. This patch removes them and replaces them by
the latter for code clarification.
MINOR: mux-quic: remove unneeded qcc.tx.sent_offsets field
This commit as a similar purpose as previous, except that it removes QCC
<sent_offsets> field, now equivalent to connection flow control real
offset.
This commit is a direct follow-up on the previous one. This time, it
deals with connection level flow control. Process is similar to stream
level : soft offset is incremented during snd_buf and real offset during
STREAM frame emission.
On MAX_DATA reception, both stream layer and QMUX is woken up if
necessary. One extra feature for conn level is the introduction of a new
QCC list to reference QCS instances. It will store instances for which
snd_buf callback has been interrupted on QCC soft offset reached. Every
stream instances is woken up on MAX_DATA reception if soft_offset is
unblocked.
This patch is the first of two to reimplement flow control emission
limits check. The objective is to account flow control earlier during
snd_buf stream callback. This should smooth transfers and prevent over
buffering on haproxy side if flow control limit is reached.
The current patch deals with stream level flow control. It reuses the
newly defined flow control type. Soft offset is incremented after HTX to
data conversion. If limit is reached, snd_buf is interrupted and stream
layer will subscribe on QCS.
On qcc_io_cb(), generation of STREAM frames is restricted as previously
to ensure to never surpass peer limits. Finally, flow control real
offset is incremented on lower layer send notification. Thus, it will
serve as a base offset for built STREAM frames. If limit is reached,
STREAM frames generation is suspended.
Each time QCS data flow control limit is reached, soft and real offsets
are reconsidered.
Finally, special care is used when flow control limit is incremented via
MAX_STREAM_DATA reception. If soft value is unblocked, stream layer
snd_buf is woken up. If real value is unblocked, qcc_io_cb() is
rescheduled.
Create a new module dedicated to flow control handling. It will be used
to implement earlier flow control update on snd_buf stream callback.
For the moment, only Tx part is implemented (i.e. limit set by the peer
that haproxy must respect for sending). A type quic_fctl is defined to
count emitted data bytes. Two offsets are used : a real one and a soft
one. The difference is that soft offset can be incremented beyond limit
unless it is already in excess.
Soft offset will be used for HTX to H3 parsing. As size of generated H3
is unknown before parsing, it allows to surpass the limit one time. Real
offset will be used during STREAM frame generation : this time the limit
must not be exceeded to prevent protocol violation.
Add a new argument to qcc_send_stream() to specify the count of sent
bytes.
For the moment this argument is unused. This commit is in fact a step to
implement earlier flow control update during stream layer snd_buf.
Previous patches have reorganize define definitions for SSL 0RTT
support. However a typo was introduced. This caused haproxy to disable
0RTT support announcement and report of an erroneous warning for no
support on the SSL library side when using quictls/openssl compat layer.
This was detected by using ngtcp2-client. No 0RTT packet were emitted by
the client due to haproxy missing support advertisement.
The faulty commit is the following one :
commit 5c45199347
MEDIUM: ssl/quic: always compile the ssl_conf.early_data test
This must be backported wherever the above patch is.
Add the HAVE_SSL_0RTT constant which define if the SSL library supports
0RTT. Which is different from HA_OPENSSL_HAVE_0RTT_SUPPORT which was
used only in the context of QUIC
It is similar to the previous fix but for the chunk size parsing. But this
one is more annoying because a poorly coded application in front of haproxy
may ignore the last digit before the LF thinking it should be a CR. In this
case it may be out of sync with HAProxy and that could be exploited to
perform some sort or request smuggling attack.
While it seems unlikely, it is safer to forbid LF with CR at the end of a
chunk size.
This patch must be backported to 2.9 and probably to all stable versions
because there is no reason to still support LF without CR in this case.
When the message is chunked, all chunks must ends with a CRLF. However, on
old versions, to support bad client or server implementations, the LF only
was also accepted. Nowadays, it seems useless and can even be considered as
an issue. Just forbid LF only at the end of chunks, it seems reasonnable.
This patch must be backported to 2.9 and probably to all stable versions
because there is no reason to still support LF without CR in this case.
