This function stopped being used before 2.4 because either the task is
dequeued by the scheduler itself and it knows where to find it, or it's
killed by any thread, and task_kill() must be used for this as only this
one is safe.
It's difficult to say whether task_unlink_rq() is still safe, but once
the lock moves to a thread declared in the task itself, it will be even
more difficult to keep it safe.
Let's just remove it now before someone reuses it and causes trouble.
TASK_SHARED_WQ was set upon task creation and never changed afterwards.
Thus if a task was created to run anywhere (e.g. a check or a Lua task),
all its timers would always pass through the shared timers queue with a
lock. Now we know that tid<0 indicates a shared task, so we can use that
to decide whether or not to use the shared queue. The task might be
migrated using task_set_affinity() but it's always dequeued first so
the check will still be valid.
Not only this removes a flag that's difficult to keep synchronized with
the thread ID, but it should significantly lower the load on systems with
many checks. A quick test with 5000 servers and fast checks that were
saturating the CPU shows that the check rate increased by 20% (hence the
CPU usage dropped by 17%). It's worth noting that run_task_lists() almost
no longer appears in perf top now.
As previously advertised in comments, the mask-based task_new() is now
gone. The low-level function now is task_new_on() which takes a thread
number or a negative value for "any thread", which is turned to zero
for thread-less builds since there's no shared WQ in thiscase. The
task_new_here() and task_new_anywhere() functions were adjusted
accordingly.
This removes the mask-based variant so that from now on the low-level
function becomes appctx_new_on() and it takes either a thread number or
a negative value for "any thread". This way we can use task_new_on() and
task_new_anywhere() instead of task_new() which will soon disappear.
At several places we need to figure the ID of the first thread allowed
to run a task. Till now this was performed using my_ffsl(t->thread_mask)
but since we now have the thread ID stored into the task, let's use it
instead. This is tagged major because it starts to assume that tid<0 is
strictly equivalent to atleast2(thread_mask), and that as such, among
the allowed threads are the current one.
The tasks currently rely on a mask but do not have an assigned thread ID,
contrary to tasklets. However, in practice they're either running on a
single thread or on any thread, so that it will be worth simplifying all
this in order to ease the transition to the thread groups.
This patch introduces a "tid" field in the task struct, that's either
the number of the thread the task is attached to, or a negative value
if the task is not bound to a thread, (i.e. its mask is all_threads_mask).
The new ID is only set and updated but not used yet.
For now we still set tid_bit to (1UL << tid) because FDs will not
work with more than one group without this, but once FDs start to
adopt local masks this must change to thr->ltid_bit.
Some FDs might be offered to some external code (external libraries)
which will deal with them until they close them. As such we must not
close them upon fd_delete() but we need to delete them anyway so that
they do not appear anymore in the fdtab. This used to be handled by
fd_remove() before 2.3 but we don't have this anymore.
This patch introduces a new flag FD_DISOWN to let fd_delete() know that
the core doesn't own the fd and it must not be closed upon removal from
the fd_tab. This way it's totally unregistered from the poller but still
open.
This patch must be backported on branches >= 2.3 because it will be
needed to fix a bug affecting SSL async. it should be adapted on 2.3
because state flags were stored in a different way (via bits in the
structure).
Implement a new status function for ncbuf. It allows to quickly report
if a buffer contains data in a fragmented way, i.e. with gaps in between
or at start of the buffer.
To summarize, a buffer is considered as non-fragmented in the following
cases :
- a null or empty buffer
- a full buffer
- a buffer containing exactly one data block at the beginning, following
by a gap until the end.
With ~1500 bytes QUIC datagrams, we can handle less than 200 datagrams
which is less than the default maxpollevents value. This should reduce
the chances of fulfilling the connections RX buffers as reported by
Tristan in GH #1737.
Must be backported to 2.6.
Remove the call to qc_list_all_rx_pkts() which print messages on stderr
during RX buffer overruns and add a new counter for the number of dropped packets
because of such events.
Must be backported to 2.6
We want to be able to schedule a tasklet onto a thread after the current tasklet
is done. What we have to do is to insert this tasklet at the head of the thread
task list. Furthermore, we would like to serialize the tasklets. They must be
run in the same order as the order in which they have been scheduled. This is
implemented passing a list of tasklet as parameter (see <head> parameters) which
must be reused for subsequent calls.
_tasklet_wakeup_after_on() is implemented to accomplish this job.
tasklet_wakeup_after_on() and tasklet_wake_after() are only wrapper macros around
_tasklet_wakeup_after_on(). tasklet_wakeup_after_on() does exactly the same thing
as _tasklet_wakeup_after_on() without having to pass the filename and line in the
filename as parameters (usefull when DEBUG_TASK is enabled).
tasklet_wakeup_after() hides also the usage of the thread parameter which is
<tl> tasklet thread ID.
In GH #1760 (which is marked as being a feature), there were compilation
errors on MacOS which could be reproduced in Linux when building 32-bit code
(-m32 gcc option). Most of them were due to variables types mixing in QUIC_MIN macro
or using size_t type in place of uint64_t type.
Must be backported to 2.6.
Sometimes using "debug dev memstats" can be frustrating because all
pool allocations are reported through pool-os.h and that's all.
But in practice there's nothing wrong with also intercepting pool_alloc,
pool_free and pool_zalloc and report their call counts and locations,
so that's what this patch does. It only uses an alternate set of macroes
for these 3 calls when DEBUG_MEM_STATS is defined. The outputs are
reported as P_ALLOC (for both pool_malloc() and pool_zalloc()) and
P_FREE (for pool_free()).
freq_ctr_overshoot_period() function may be used to retrieve the excess of
events over the current period for a givent frequency counter, ignoring the
history. It is a way compare the "current rate" (the number of events over
the current period) to a given rate and estimate the excess of events.
It may be used to safely add new events, especially at the begining of the
current period for a frequency counter with large period. This way, it is
possible to smoothly add events during the whole period without quickly
consuming all the quota at the beginning of the period and waiting for the
next one to be able to add new events.
Sometimes we need to be able to signal one thread among a mask, without
caring much about which bit will be picked. At the moment we use ffsl()
for this but this sometimes results in imbalance at certain specific
places where the same first thread in a set is always the same one that
is selected.
Another approach would consist in using the rank finding function but it
requires a popcount and a setup phase, and possibly a modulo operation
depending on the popcount, which starts to be very expensive.
Here we take a different approach. The idea is an input bit value is
passed, from 0 to LONGBITS-1, and that as much as possible we try to
pick the bit matching it if it is set. Otherwise we look at a mirror
position based on a decreasing power of two, and jump to the side
that still has bits left. In 6 iterations it ends up spotting one bit
among 64 and the operations are very cheap and optimizable. This method
has the benefit that we don't care where the holes are located in the
mask, thus it shows a good distribution of output bits based on the
input ones. A long-time test shows an average of 16 cycles, or ~4ns
per lookup at 3.8 GHz, which is about twice as fast as using the rank
finding function.
Just like for that one, the code was stored into tools.c since we don't
have a C file for intops.
Implement quic_tp_version_info_dump() to dump such a transport parameter (only remote).
Call it from quic_transport_params_dump() which dump all the transport parameters.
Can be backported to 2.6 as it's useful for debugging.
This counter must be incremented only one time by connection and decremented
as soon as the handshake has failed or succeeded. This is a gauge. Under certain
conditions this counter could be decremented twice. For instance
after having received a TLS alert, then upon SSL_do_handshake() failure.
To stop having to deal to all the current combinations which can lead to such a
situation (and the next to come), add a connection flag to denote if this counter
has been already decremented for a connection. So, this counter must be decremented
only if this flag has not been already set.
Must be backported up to 2.6.
In order to better detect the danger caused by extra shared libraries
which replace some symbols, upon dlopen() we now compare a few critical
symbols such as malloc(), free(), and some OpenSSL symbols, to see if
the loaded library comes with its own version. If this happens, a
warning is emitted and TAINTED_REDEFINITION is set. This is important
because some external libs might be linked against different libraries
than the ones haproxy was linked with, and most often this will end
very badly (e.g. an OpenSSL object is allocated by haproxy and freed
by such libs).
Since the main source of dlopen() calls is the Lua lib, via a "require"
statement, it's worth trying to show a Lua call trace when detecting a
symbol redefinition during dlopen(). As such we emit a Lua backtrace if
Lua is detected as being in use.
Several bug reports were caused by shared libraries being loaded by other
libraries or some Lua code. Such libraries could define alternate symbols
or include dependencies to alternate versions of a library used by haproxy,
making it very hard to understand backtraces and analyze the issue.
Let's intercept dlopen() and set a new TAINTED_SHARED_LIBS flag when it
succeeds, so that "show info" makes it visible that some external libs
were added.
The redefinition is based on the definition of RTLD_DEFAULT or RTLD_NEXT
that were previously used to detect that dlsym() is usable, since we need
it as well. This should be sufficient to catch most situations.
This function may be used to try to show where some Lua code is currently
being executed. It tries hard to detect the initialization phase, both for
the global and the per-thread states, and for runtime states. This intends
to be used by error handlers to provide the users with indications about
what Lua code was being executed when the error triggered.
When the protocol is changed for a client connection at the stream level
(from TCP to H1/H2), there are two cases. The stream may be reused or
not. The first case, when the stream is reused is working. The second one is
buggy since the conn-stream refactoring and leads to a crash.
In this case, the new mux don't reuse the stream. It must be silently
aborted. However, its front stream connector is still referencing the
connection. So it must be detached. But it must be performed in two stages,
to be sure to not loose the context for the upgrade and to be able to
rollback on error. So now, before the upgrade, we prepare to detach the
stconn and it is finally detached if the upgrade succeeds. There is a trick
here. Because we pretend the stconn is detached but its state is preserved.
This patch must be backported to 2.6.
At this time haproxy supported only incompatible version negotiation feature which
consists in sending a Version Negotiation packet after having received a long packet
without compatible value in its version field. This version value is the version
use to build the current packet. This patch does not modify this behavior.
This patch adds the support for compatible version negotiation feature which
allows endpoints to negotiate during the first flight or packets sent by the
client the QUIC version to use for the connection (or after the first flight).
This is done thanks to "version_information" parameter sent by both endpoints.
To be short, the client offers a list of supported versions by preference order.
The server (or haproxy listener) chooses the first version it also supported as
negotiated version.
This implementation has an impact on the tranport parameters handling (in both
direcetions). Indeed, the server must sent its version information, but only
after received and parsed the client transport parameters). So we cannot
encode these parameters at the same time we instantiated a new connection.
Add QUIC_TP_DRAFT_VERSION_INFORMATION(0xff73db) new transport parameter.
Add tp_version_information new C struct to handle this new parameter.
Implement quic_transport_param_enc_version_info() (resp.
quic_transport_param_dec_version_info()) to encode (resp. decode) this
parameter.
Add qc_conn_finalize() which encodes the transport parameters and configure
the TLS stack to send them.
Add ->negotiated_ictx quic_conn C struct new member to store the Initial
QUIC TLS context for the negotiated version. The Initial secrets derivation
is version dependent.
Rename ->version to ->original_version and add ->negotiated_version to
this C struct to reflect the QUIC-VN RFC denomination.
Modify most of the QUIC TLS API functions to pass a version as parameter.
Export the QUIC version definitions to be reused at least from quic_tp.c
(transport parameters.
Move the token check after the QUIC connection lookup. As this is the original
version which is sent into a Retry packet, and because this original version is
stored into the connection, we must check the token after having retreived this
connection.
Add packet version to traces.
See https://datatracker.ietf.org/doc/html/draft-ietf-quic-version-negotiation-08
for more information about this new feature.
This is becoming difficult to handle the QUIC TLS related definitions
which arrive with a QUIC version (draft or not). So, here we add
quic_version C struct which does not define only the QUIC version number,
but also the QUIC TLS definitions which depend on a QUIC version.
Modify consequently all the QUIC TLS API to reuse these definitions
through new quic_version C struct.
Implement quic_pkt_type() function which return a packet type (0 up to 3)
depending on the QUIC version number.
Stop harding the Retry packet first byte in send_retry(): this is not more
possible because the packet type field depends on the QUIC version.
Also modify quic_build_packet_long_header() for the same reason: the packet
type depends on the QUIC version.
Add a quic_version C struct member to quic_conn C struct.
Modify qc_lstnr_pkt_rcv() to set this member asap.
Remove the version member from quic_rx_packet C struct: a packet is attached
asap to a connection (or dropped) which is the unique object which should
store the QUIC version.
Modify qc_pkt_is_supported_version() to return a supported quic_version C
struct from a version number.
Add Initial salt for QUIC v2 draft (initial_salt_v2_draft).
Due to missing brackets around the ternary C operator, quic_pto() could return zero
at the first run, before the QUIC connection was completely initialized. This leaded
the idle timeout task to be executed before this initialization completion. Then
this connection could be immediately released.
This bug was revealed by the multi_packet_client_hello QUIC tracker test.
Must be backported to 2.6.
The nonce and keys used to cipher the Retry tag depend on the QUIC version.
Add these definitions for 0xff00001d (draft-29) and v2 QUIC version. At least
draft-29 is useful for QUIC tracker tests with "quic-force-retry" enabled
on haproxy side.
Validated with -v 0xff00001d ngtcp2 option.
Could not validate the v2 nonce and key at this time because not supported.
ensures that we never insert too many entries in a headers input list.
On the decoding side, a new error QPACK_ERR_TOO_LARGE is reported in
this case.
This prevents crash if headers number on a H3 request or response is
superior to tune.http.maxhdr config value. Previously, a crash would
occur in QPACK decoding function.
Note that the process still crashes later with ABORT_NOW() because error
reporting on frame parsing is not implemented for now. It should be
treated with a RESET_STREAM frame in most cases.
This can be backported up to 2.6.
Clean up QPACK decoder API by removing dependencies on ncbuf and
MUX-QUIC. This reduces includes statements. It will also help to
implement a standalone QPACK decoder.
Add comments on the decoding function to facilitate code analysis.
Also remove the qpack_debug_hexdump() which prints the whole left buffer
on each header parsing. With large HEADERS frame payload, QPACK traces
are complicated to debug with this statement.
This macro was used both for binding and for lookups. When binding tasks
or FDs, using all_threads_mask instead is better as it will later be per
group. For lookups, ~0UL always does the job. Thus in practice the macro
was already almost not used anymore since the rest of the code could run
fine with a constant of all ones there.
Each thread has its own local thread id and its own global thread id,
in addition to the masks corresponding to each. Once the global thread
ID can go beyond 64 it will not be possible to have a global thread Id
bit anymore, so better start to remove it and use only the local one
from the struct thread_info.
Instead of having a global mask of all the profiled threads, let's have
one flag per thread in each thread's flags. They are never accessed more
than one at a time an are better located inside the threads' contexts for
both performance and scalability.
The flow control enforced at connection level is incorrectly calculated.
There is a risk of exceeding the limit. In most cases, this results in a
segfault produced by a BUG_ON which is here to catch this kind of error.
If not compiled with DEBUG_STRICT, this should generate a connection
closed by the client due to the flow control overflow.
The problem is encountered when transfered payload is big enough to fill
the transport congestion window. In this case, some data are rejected by
the transport layer and kept by the MUX to be reemitted later. However,
these preserved data are not counted on the connection flow control when
resubmitted, which gradually amplify the gap between expected and real
consumed flow control.
To fix this, handle the flow-control at the connection level in the same
way as the stream level. A new field qcc.tx.offsets is incremented as
soon as data are transfered between stream TX buffers. The field
qcc.tx.sent_offsets is preserved to count bytes handled by the transport
layer and stop the MUX transfer if limit is reached.
As already stated, this bug can occur during transfers with enough
emitted data, over multiple streams. When using a single stream, the
flow control at the stream level hides it.
The BUG_ON crash is reproduced systematically with quiche client :
$ quiche-client --no-verify --http-version HTTP/3 -n 10000 https://127.0.0.1:20443/10K
This must be backported up to 2.6 when confirmed to work as expected.
This should fix github issue #1738.
Frame type has changed during HTTP/3 specification process. Adjust it to
reflect the latest RFC 9114 status.
Concretly, type for GOAWAY and MAX_PUSH_ID frames has been adjusted.
The impact of this bug is limited as currently these frames are not
handled by haproxy and are ignored.
This can be backported up to 2.6.
Benoit Dolez reported that gcc-4.4 emits several "may be used
uninitialized" warnings around places where there are BUG_ON()
or ABORT_NOW(). The reason is that __builtin_unreachable() was
introduced in gcc-4.5 thus older ones do not know that the code
after such statements is not reachable.
This patch solves the problem by deplacing the statement with
an infinite loop on older versions. The compiler knows that the
code following it cannot be reached, and this is quite cheap
(2 to 4 bytes depending on architectures). It even reduces the
code size a little bit as the compiler doesn't have to optimize
for branches that do not exist.
This may be backported to older versions.
Clean the API used by decode_qcs() and transcoder internal functions.
Parsing functions now returns a ssize_t which represents the number of
consumed bytes or a negative error code. The total consumed bytes is
returned via decode_qcs().
The API is now unified and cleaner. The MUX can thus simply use the
return value of decode_qcs() instead of substracting the data bytes in
the buffer before and after the call. Transcoders functions are not
anymore obliged to remove consumed bytes from the buffer which was not
obvious.
Slightly modify decode_qcs function used by transcoders. The MUX now
gives a buffer instance on which each transcoder is free to work on it.
At the return of the function, the MUX removes consume data from its own
buffer.
This reduces the number of invocation to qcs_consume at the end of a
full demuxing process. The API is also cleaner with the transcoders not
responsible of calling it with the risk of having the input buffer
freed if empty.
As a mirror to qcc/qcs types, add a h3c pointer into h3s struct. This
should help to clean up H3 code and avoid to use qcs.qcc.ctx to retrieve
the h3c instance.
htx_get_head_blk() is used at plenty of places, many of which are known
to be safe, but the function checks for the presence of a first block
and returns NULL if it doesn't exist. While it's properly used, it makes
compilers complain at -Os on stream.c and mux_fcgi.c because they probably
don't propagate variables far enough to see that there's no risk.
Let's add an unchecked version for these use cases.
