There is a very difficult to reproduce race in the listener's accept
code, which is much easier to reproduce once connection limits are
properly enforced. It's an ABBA lock issue :
- the following functions take l->lock then lq_lock :
disable_listener, pause_listener, listener_full, limit_listener,
do_unbind_listener
- the following ones take lq_lock then l->lock :
resume_listener, dequeue_all_listener
This is because __resume_listener() only takes the listener's lock
and expects to be called with lq_lock held. The problem can easily
happen when listener_full() and limit_listener() are called a lot
while in parallel another thread releases sessions for the same
listener using listener_release() which in turn calls resume_listener().
This scenario is more prevalent in 2.0-dev since the removal of the
accept lock in listener_accept(). However in 1.9 and before, a different
but extremely unlikely scenario can happen :
thread1 thread2
............................ enter listener_accept()
limit_listener()
............................ long pause before taking the lock
session_free()
dequeue_all_listeners()
lock(lq_lock) [1]
............................ try_lock(l->lock) [2]
__resume_listener()
spin_lock(l->lock) =>WAIT[2]
............................ accept()
l->accept()
nbconn==maxconn =>
listener_full()
state==LI_LIMITED =>
lock(lq_lock) =>DEADLOCK[1]!
In practice it is almost impossible to trigger it because it requires
to limit both on the listener's maxconn and the frontend's rate limit,
at the same time, and to release the listener when the connection rate
goes below the limit between poll() returns the FD and the lock is
taken (a few nanoseconds). But maybe with threads competing on the
same core it has more chances to appear.
This patch removes the lq_lock and replaces it with a lockless queue
for the listener's wait queue (well, technically speaking a self-locked
queue) brought by commit a8434ec14 ("MINOR: lists: Implement locked
variations.") and its few subsequent fixes. This relieves us from the
need of the lq_lock and removes the deadlock. It also gets rid of the
distinction between __resume_listener() and resume_listener() since the
only difference was the lq_lock. All listener removals from the list
are now unconditional to avoid races on the state. It's worth noting
that the list used to never be initialized and that it used to work
only thanks to the state tests, so the initialization has now been
added.
This patch must carefully be backported to 1.9 and very likely 1.8.
It is mandatory to be careful about replacing all manipulations of
l->wait_queue, global.listener_queue and p->listener_queue.
Since LIST_DEL_LOCKED() and LIST_POP_LOCKED() now automatically reinitialize
the removed element, there's no need for keeping this LIST_INIT() call in the
idle connection code.
These operations previously used to return a "locked" element, which is
a constraint when multiple threads try to delete the same element, because
the second one will block indefinitely. Instead, let's make sure that both
LIST_DEL_LOCKED() and LIST_POP_LOCKED() always reinitialize the element
after deleting it. This ensures that the second thread will immediately
unblock and succeed with the removal. It also secures the pop vs delete
competition that may happen when trying to remove an element that's about
to be dequeued.
Commit a8434ec14 ("MINOR: lists: Implement locked variations.")
introduced locked lists which use the elements pointers as locks
for concurrent operations. Under heavy stress the lists occasionally
fail. The cause is a missing barrier at some points when updating
the list element and the head : nothing prevents the compiler (or
CPU) from updating the list head first before updating the element,
making another thread jump to a wrong location. This patch simply
adds the missing barriers before these two opeations.
This will have to be backported if the commit above is backported.
There was a typo making the last updated pointer be the pre-last element's
prev instead of the last's prev element. It didn't show up during early
tests because the contention is very rare on this one and it's implicitly
recovered when updating the pointers to go to the next element, but it was
clearly visible in the listener_accept() tests by having all threads block
on LIST_POP_LOCKED() with n==p==LLIST_BUSY.
This will have to be backported if commit a8434ec14 ("MINOR: lists:
Implement locked variations.") is backported.
Commit a8434ec14 ("MINOR: lists: Implement locked variations.")
introduced locked lists which use the elements pointers as locks
for concurrent operations. A copy-paste typo in LIST_ADDQ_LOCKED()
causes corruption in the list in case the next pointer is already
held, as it restores the previous pointer into the next one. It
may impact the server pools.
This will have to be backported if the commit above is backported.
Threads have long matured by now, still for most users their usage is
not trivial. It's about time to enable them by default on platforms
where we know the number of CPUs bound. This patch does this, it counts
the number of CPUs the process is bound to upon startup, and enables as
many threads by default. Of course, "nbthread" still overrides this, but
if it's not set the default behaviour is to start one thread per CPU.
The default number of threads is reported in "haproxy -vv". Simply using
"taskset -c" is now enough to adjust this number of threads so that there
is no more need for playing with cpu-map. And thanks to the previous
patches on the listener, the vast majority of configurations will not
need to duplicate "bind" lines with the "process x/y" statement anymore
either, so a simple config will automatically adapt to the number of
processors available.
tune.listener.multi-queue { on | off }
Enables ('on') or disables ('off') the listener's multi-queue accept which
spreads the incoming traffic to all threads a "bind" line is allowed to run
on instead of taking them for itself. This provides a smoother traffic
distribution and scales much better, especially in environments where threads
may be unevenly loaded due to external activity (network interrupts colliding
with one thread for example). This option is enabled by default, but it may
be forcefully disabled for troubleshooting or for situations where it is
estimated that the operating system already provides a good enough
distribution and connections are extremely short-lived.
It's important to monitor the accept queues to know if some incoming
connections had to be handled by their originating thread due to an
overflow. It's also important to be able to confirm thread fairness.
This patch adds "accq_pushed" to activity reporting, which reports
the number of connections that were successfully pushed into each
thread's queue, and "accq_full", which indicates the number of
connections that couldn't be pushed because the thread's queue was
full.
There is one point where we can migrate a connection to another thread
without taking risk, it's when we accept it : the new FD is not yet in
the fd cache and no task was created yet. It's still possible to assign
it a different thread than the one which accepted the connection. The
only requirement for this is to have one accept queue per thread and
their respective processing tasks that have to be woken up each time
an entry is added to the queue.
This is a multiple-producer, single-consumer model. Entries are added
at the queue's tail and the processing task is woken up. The consumer
picks entries at the head and processes them in order. The accept queue
contains the fd, the source address, and the listener. Each entry of
the accept queue was rounded up to 64 bytes (one cache line) to avoid
cache aliasing because tests have shown that otherwise performance
suffers a lot (5%). A test has shown that it's important to have at
least 256 entries for the rings, as at 128 it's still possible to fill
them often at high loads on small thread counts.
The processing task does almost nothing except calling the listener's
accept() function and updating the global session and SSL rate counters
just like listener_accept() does on synchronous calls.
At this point the accept queue is implemented but not used.
In order to quickly pick a thread ID when accepting a connection, we'll
need to know certain pre-computed values derived from the thread mask,
which are counts of bits per position multiples of 1, 2, 4, 8, 16 and
32. In practice it is sufficient to compute only the 4 first ones and
store them in the bind_conf. We update the count every time the
bind_thread value is adjusted.
The fields in the bind_conf struct have been moved around a little bit
to make it easier to group all thread bit values into the same cache
line.
The function used to return a thread number is bind_map_thread_id(),
and it maps a number between 0 and 31/63 to a thread ID between 0 and
31/63, starting from the left.
Function mask_find_rank_bit() returns the bit position in mask <m> of
the nth bit set of rank <r>, between 0 and LONGBITS-1 included, starting
from the left. For example ranks 0,1,2,3 for mask 0x55 will be 6, 4, 2
and 0 respectively. This algorithm is based on a popcount variant and
is described here : https://graphics.stanford.edu/~seander/bithacks.html.
Now that nbproc and nbthread are exclusive, we can still provide more
detailed explanations about what we've found in the config when a bind
line appears on multiple threads and processes at the same time, then
ignore the setting.
This patch reduces the listener's thread mask to a single mask instead
of an array of masks per process. Now we have only one thread mask and
one process mask per bind-conf. This removes ~504 bytes of RAM per
bind-conf and will simplify handling of thread masks.
If a "bind" line only refers to process numbers not found by its parent
frontend or not covered by the global nbproc directive, or to a thread
not covered by the global nbthread directive, a warning is emitted saying
what will be used instead.
In LIST_DEL_LOCKED(), initialize p2 to NULL, and only attempt to set it back
to its previous value if we had a previous element, and thus p2 is non-NULL.
Instead of having one task per thread and per server that does clean the
idling connections, have only one global task for every servers.
That tasks parses all the servers that currently have idling connections,
and remove half of them, to put them in a per-thread list of connections
to kill. For each thread that does have connections to kill, wake a task
to do so, so that the cleaning will be done in the context of said thread.
Use the locked macros when manipulating idle_orphan_conns, so that other
threads can remove elements from it.
It will be useful later to avoid having a task per server and per thread to
cleanup the orphan list.
Implement LIST_ADD_LOCKED(), LIST_ADDQ_LOCKED(), LIST_DEL_LOCKED() and
LIST_POP_LOCKED().
LIST_ADD_LOCKED, LIST_ADDQ_LOCKED and LIST_DEL_LOCKED work the same as
LIST_ADD, LIST_ADDQ and LIST_DEL, except before any manipulation it locks
the relevant elements of the list, so it's safe to manipulate the list
with multiple threads.
LIST_POP_LOCKED() removes the first element from the list, and returns its
data.
This patch implements "req.ungrpc" sample fetch method to decode and
parse a gRPC request. It takes only one argument: a protocol buffers
field number to identify the protocol buffers message number to be looked up.
This argument is a sort of path in dotted notation to the terminal field number
to be retrieved.
ex:
req.ungrpc(1.2.3.4)
This sample fetch catch the data in raw mode, without interpreting them.
Some protocol buffers specific converters may be used to convert the data
to the correct type.
This function is useful to parse strings made of unsigned integers
and to allocate a C array of unsigned integers from there.
For instance this function allocates this array { 1, 2, 3, 4, } from
this string: "1.2.3.4".
It is the HTX version of co_skip(). Internally, It uses the function htx_drain().
It will be used by other commits to fix bugs, so it must be backported to 1.9.
The function htx_drain() can now be used to drain data from an HTX message.
It will be used by other commits to fix bugs, so it must be backported to 1.9.
in co_skip(), the flag CF_WRITE_PARTIAL is set on the channel. The flag
CF_WROTE_DATA must also be set to notify the channel some data were sent.
This patch must be backported to 1.9.
Calculate if the fd or task should be locked once, before locking, and
reuse the calculation when determing when to unlock.
Fixes a race condition added in 87d54a9a for fds, and b20aa9ee for tasks,
released in 1.9-dev4. When one thread modifies thread_mask to be a single
thread for a task or fd while a second thread has locked or is waiting on a
lock for that task or fd, the second thread will not unlock it. For FDs,
this is observable when a listener is polled by multiple threads, and is
closed while those threads have events pending. For tasks, this seems
possible, where task_set_affinity is called, but I did not observe it.
This must be backported to 1.9.
This is a naive implementation of closefrom() which closes all FDs
starting from the one passed in argument. closefrom() is not provided
on all operating systems, and other versions will follow.
Add a per-thread counter of idling connections, and use it to determine
how many connections we should kill after the timeout, instead of using
the global counter, or we're likely to just kill most of the connections.
This should be backported to 1.9.
Use atomic operations when dealing with srv->curr_idle_conns, as it's shared
between threads, otherwise we could get inconsistencies.
This should be backported to 1.9.
1xx responses does not work in HTTP2 when the HTX is enabled. First of all, when
a response is parsed, only one HEADERS frame is expected. So when an interim
response is received, the flag H2_SF_HEADERS_RCVD is set and the next HEADERS
frame (for another interim repsonse or the final one) is parsed as a trailers
one. Then when the response is sent, because an EOM block is found at the end of
the interim HTX response, the ES flag is added on the frame, closing too early
the stream. Here, it is a design problem of the HTX. Iterim responses are
considered as full messages, leading to some ambiguities when HTX messages are
processed. This will not be fixed now, but we need to keep it in mind for future
improvements.
To fix the parsing bug, the flag H2_MSGF_RSP_1XX is added when the response
headers are decoded. When this flag is set, an EOM block is added into the HTX
message, despite the fact that there is no ES flag on the frame. And we don't
set the flag H2_SF_HEADERS_RCVD on the corresponding H2S. So the next HEADERS
frame will not be parsed as a trailers one.
To fix the sending bug, the ES flag is not set on the frame when an interim
response is processed and the flag H2_SF_HEADERS_SENT is not set on the
corresponding H2S.
This patch must be backported to 1.9.
Initialize ->srv peer field for all the peers, the local peer included.
Indeed, a haproxy process needs to connect to the local peer of a remote
process. Furthermore, when a "peer" or "server" line is parsed by parse_server()
the address must be copied to ->addr field of the peer object only if this address
has been also parsed by parse_server(). This is not the case if this address belongs
to the local peer and is provided on a "server" line.
After having parsed the "peer" or "server" lines of a peer
sections, the ->srv part of all the peer must be initialized for SSL, if
enabled. Same thing for the binding part.
Revert 1417f0b commit which is no more required.
No backport is needed, this is purely 2.0.
The existing threading flag in the 51Degrees API
(FIFTYONEDEGREES_NO_THREADING) has now been mapped to the HAProxy
threading flag (USE_THREAD), and the 51Degrees module code has been made
thread safe.
In Pattern, the cache is now locked with a spin lock from hathreads.h
using a new lable 'OTHER_LOCK'. The workset pool is now created with the
same size as the number of threads to avoid any time waiting on a
worket.
In Hash Trie, the global device offsets structure is only used in single
threaded operation. Multi threaded operation creates a new offsets
structure in each thread.
Commit 1055e687a ("MINOR: peers: Make outgoing connection to SSL/TLS
peers work.") introduced an "srv" field in the peers, which points to
the equivalent server to hold SSL settings. This one is not set when
the peer is local so we must always test it before testing p->srv->use_ssl
otherwise haproxy dies during reloads.
No backport is needed, this is purely 2.0.
For some embedded systems, it's pointless to have 32- or even 64- large
arrays of processes when it's known that much fewer processes will be
used in the worst case. Let's introduce this MAX_PROCS define which
contains the highest number of processes allowed to run at once. It
still defaults to LONGBITS but may be lowered.
This also depends on the nbthread count, so it must only be performed after
parsing the whole config file. As a side effect, this removes some code
duplication between servers and server-templates.
This must be backported to 1.9.
These two functions return either all_{proc,threads}_mask, or the argument.
This is used to default to all_proc_mask or all_threads_mask when not set
on bind_conf or proxies.
We'll call popcount() more often so better use a parallel method
than an iterative one. One optimal design is proposed at the site
below. It requires a fast multiplication though, but even without
it will still be faster than the iterative one, and all relevant
64 bit platforms do have a multiply unit.
https://graphics.stanford.edu/~seander/bithacks.html
Some unused fields were placed early and some important ones were on
the second cache line. Let's move the proto_list and name closer to
the end of the structure to bring accept() and default_target() into
the first cache line.
When compiling with DEBUG_FAIL_ALLOC, add a new option, tune.fail-alloc,
that gives the percentage of chances an allocation fails.
This is useful to check that allocation failures are always handled
gracefully.
With variable connection limits, it's not possible to accurately determine
whether the mux is still in use by comparing usage and max to be equal due
to the fact that one determines the capacity and the other one takes care
of the context. This can cause some connections to be dropped before they
reach their stream ID limit.
It seems it could also cause some connections to be terminated with
streams still alive if the limit was reduced to match the newly computed
avail_streams() value, though this cannot yet happen with existing muxes.
Instead let's switch to usage reports and simply check whether connections
are both unused and available before adding them to the idle list.
This should be backported to 1.9.
The new flag SI_FL_KILL_CONN is now set by the rare actions which
deliberately want the whole connection (and not just the stream) to be
killed. This is only used for "tcp-request content reject",
"tcp-response content reject", "tcp-response content close" and
"http-request reject". The purpose is to desambiguate the close from
a regular shutdown. This will be used by the next patches.
If we're adding a connection to the server orphan idle list, don't forget
to remove the CO_FL_SESS_IDLE flag, or we will assume later it's still
attached to a session.
This should be backported to 1.9.
The previous patch clarifies the fact that the htx pointer is never null
along all the code. This test for a null will never match, didn't catch
the pointer 1 before the fix for b_is_null(), but it confuses the compiler
letting it think that any dereferences made to this pointer after this
test could actually mean we're dereferencing a null. Let's now drop this
test. This saves us from having to add impossible tests everywhere to
avoid the warning.
This should be backported to 1.9 if the b_is_null() patch is backported.
Update the comments above htxbuf() and htx_from_buf() to make it clear
that they always return valid htx pointers so that callers know they do
not have to test them. This is only true after the fix on b_is_null()
which was the only known corner case.
This should be backported to 1.9 if the b_is_null() patch is backported.
In b_is_null(), make sure we return 1 if the buffer is waiting for its
allocation, as users assume there's memory allocated if b_is_null() returns
0.
The indirect impact of not having this was that htxbuf() would not match
b_is_null() for a buffer waiting for an allocation, and would thus return
the value 1 for the htx pointer, causing various crashes under low memory
condition.
Note that this patch makes gcc versions 6 and above report two null-deref
warnings in proto_htx.c since htx_is_empty() continues to check for a null
pointer without knowing that this is protected by the test on b_is_null().
This is addressed by the following patches.
This should be backported to 1.9.
The new function h2_frame_check() checks the protocol limits for the
received frame (length, ID, direction) and returns a verdict made of
a connection error code. The purpose is to be able to validate any
frame regardless of the state and the ability to call the frame handler,
and to emit a GOAWAY early in this case.
There's a very small but existing uncertainty window when waking another
thread up where it is possible for task_wakeup() not to wake the other
task up because it's still running while this once is in the process of
finishing and loses its TASK_RUNNING flag. In this case the wakeup will
be missed.
The problem is that we have a single flag to store 3 states, since the
transition from running to sleeping isn't atomic. Thus we need to have
another flag to cover this part. This patch introduces TASK_QUEUED to
mention that the task is already in the run queue, running or not. This
bit will be removed while TASK_RUNNING is kept once dequeued, and will
be used when removing TASK_RUNNING to check if the task has been requeued.
It might be possible to slightly improve this but the occurrence rate
is quite low and we don't really need to complexify the scheduler to
optimize for a rare case.
The impact with the current code is very low since we have few inter-
thread wakeups. Most of them are caused by checks killing sessions.
This must be backported to 1.9.
There's some value in being able to limit MAX_THREADS, either to save
precious resources in embedded environments, or to protect certain
deployments against accidently incorrect settings.
With this patch, if MAX_THREADS is defined at build time, it will be
used. However, given that LONGBITS is not a macro but is defined
according to sizeof(long), we can't check the value range at build
time and instead we need to perform the check at early boot time.
However, the compiler is able to optimize away the constant comparisons
and doesn't even emit the check code when values are correct.
The output message regarding threading support was improved to report
the number of threads.
The header used to be parsed only in HTX but not in legacy. And even in
HTX mode, the value was dropped. Let's always parse it and report the
parsed value back so that we'll be able to store it in the streams.
Before the first send() attempt, we should be in SI_ST_CON, not
SI_ST_EST, since we have not yet attempted to send and we are
allowed to retry. This is particularly important with complex
outgoing muxes which can fail during the first send attempt (e.g.
failed stream ID allocation).
It only requires that sess_update_st_con_tcp() knows about this
possibility, as we must not forcefully close a reused connection
when facing an error in this case, this will be handled later.
This may be backported to 1.9 with care after some observation period.
Some servers may wish to limit the total number of requests they execute
over a connection because some of their components might leak resources.
In HTTP/1 it was easy, they just had to emit a "connection: close" header
field with the last response. In HTTP/2, it's less easy because the info
is not always shared with the component dealing with the H2 protocol and
it could be harder to advertise a GOAWAY with a stream limit.
This patch provides a solution to this by adding a new "max-reuse" parameter
to the server keyword. This parameter indicates how many times an idle
connection may be reused for new requests. The information is made available
and the underlying muxes will be able to use it at will.
This patch should be backported to 1.9.
RFC7541#6.3 mandates that an error is reported when a dynamic table size
update announces a size larger than the one configured with settings. This
is tested by h2spec using test "hpack/6.3/1".
This must be backported to 1.9 and possibly 1.8 as well.
This patch adds H2_FT_HDR_MASK to group all frame types carrying headers
information, and H2_FT_LATE_MASK to group frame types allowed to arrive
after a stream was closed.
Make "bind" keywork be supported in "peers" sections.
All "bind" settings are supported on this line.
Add "default-bind" option to parse the binding options excepted the bind address.
Do not parse anymore the bind address for local peers on "server" lines.
Do not use anymore list_for_each_entry() to set the "peers" section
listener parameters because there is only one listener by "peers" section.
May be backported to 1.5 and newer.
This patch adds pointer to a struct server to peer structure which
is initialized after having parsed a remote "peer" line.
After having parsed all peers section we run ->prepare_srv to initialize
all SSL/TLS stuff of remote perr (or server).
Remaining thing to do to completely support peer protocol over SSL/TLS:
make "bind" keyword be supported in "peers" sections to make SSL/TLS
incoming connections to local peers work.
May be backported to 1.5 and newer.
When using the peers feature a race condition could prevent
a connection from being properly counted. When this connection
exits it is being "uncounted" nonetheless, leading to a possible
underflow (-1) of the conn_curr stick table entry in the following
scenario :
- Connect to peer A (A=1, B=0)
- Peer A sends 1 to B (A=1, B=1)
- Kill connection to A (A=0, B=1)
- Connect to peer B (A=0, B=2)
- Peer A sends 0 to B (A=0, B=0)
- Peer B sends 0/2 to A (A=?, B=0)
- Kill connection to B (A=?, B=-1)
- Peer B sends -1 to A (A=-1, B=-1)
This fix may be backported to all supported branches.
Since all of them are exclusive, let's move them to an union instead
of eating memory with the sum of all of them. We're using a transparent
union to limit the code changes.
Doing so reduces the struct lbprm from 392 bytes to 372, and thanks
to these changes, the struct proxy is now down to 6480 bytes vs 6624
before the changes (144 bytes saved per proxy).
This one is a proxy option which can be inherited from defaults even
if the LB algo changes. Move it out of the lb_chash struct so that we
don't need to keep anything separate between these structs. This will
allow us to merge them into an union later. It even takes less room
now as it fills a hole and removes another one.
The algo-specific settings move from the proxy to the LB algo this way :
- uri_whole => arg_opt1
- uri_len_limit => arg_opt2
- uri_dirs_depth1 => arg_opt3
Some algorithms require a few extra options (up to 3). Let's provide
some room in lbprm to store them, and make sure they're passed from
defaults to backends.
These ones used to rely on separate variables called hh_name/hh_len
but they are exclusive with the former. Let's use the same variable
which becomes a generic argument name and length for the LB algorithm.
Openssl switched from aes128 to aes256 since may 2016 to compute
tls ticket secrets used by default. But Haproxy still handled only
128 bits keys for both tls key file and CLI.
This patch permit the user to set aes256 keys throught CLI or
the key file (80 bytes encoded in base64) in the same way that
aes128 keys were handled (48 bytes encoded in base64):
- first 16 bytes for the key name
- next 16/32 bytes for aes 128/256 key bits key
- last 16/32 bytes for hmac 128/256 bits
Both sizes are now supported (but keys from same file must be
of the same size and can but updated via CLI only using a key of
the same size).
Note: This feature need the fix "dec func ignores padding for output
size checking."
Instead of assuming we have a server, store the proxy directly in struct
check, and use it instead of s->server.
This should be a no-op for now, but will be useful later when we change
mail checks to avoid having a server.
This should be backported to 1.9.
When mux->init() fails, session_free() will call it again to unregister
it while it was already done, resulting in null derefs or use-after-free.
This typically happens on out-of-memory conditions during H1 or H2 connection
or stream allocation.
This fix must be backported to 1.9.
The function channel_htx_truncate() can now be used on HTX buffer to truncate
all incoming data, keeping outgoing one intact. This function relies on the
function channel_htx_erase() and htx_truncate().
This patch may be backported to 1.9. If so, the patch "MINOR: channel/htx: Add
the HTX version of channel_truncate()" must also be backported.
HTX versions for functions to test the free space in input against the reserve
have been added. Now, on HTX streams, following functions can be used:
* channel_htx_may_recv
* channel_htx_recv_limit
* channel_htx_recv_max
* channel_htx_full
This patch must be backported in 1.9 because it will be used by a futher patch
to fix a bug.
While testing fixes, it's sometimes confusing to rebuild only one C file
(e.g. a mux) and not to have the correct commit ID reported in "haproxy -v"
nor on the stats page.
This patch adds a new "version.c" file which is always rebuilt. It's
very small and contains only 3 variables derived from the various
version strings. These variables are used instead of the macros at the
few places showing the version. This way the output version of the
running code is always correct for the parts that were rebuilt.
Currently the H1 headers parser works for either a request or a response
because it starts from the start line. It is also able to resume its
processing when it was interrupted, but in this case it doesn't update
the list.
Make it support a new flag, H1_MF_HDRS_ONLY so that the caller can
indicate it's only interested in the headers list and not the start
line. This will be convenient to parse H1 trailers.
This function is usable to transform a list of H2 header fields to a
HTX trailers block. It takes care of rejecting forbidden headers and
pseudo-headers when performing the conversion. It also emits the
trailing CRLF that is currently needed in the HTX trailers block.
This function is usable to transform a list of H2 header fields to a
H1 trailers block. It takes care of rejecting forbidden headers and
pseudo-headers when performing the conversion.
This function must be called when new incoming data are pushed in the channel's
buffer. It updates the channel state and take care of the fast forwarding by
consuming right amount of data and decrementing "->to_forward" accordingly when
necessary. In fact, this patch just moves a part of ci_putblk in a dedicated
function.
This patch must be backported to 1.9.
Instead of keeping track of the number of connections we're responsible for,
keep track of the number of connections we're responsible for that we are
currently considering idling (ie that we are not using, they may be in use
by other sessions), that way we can actually reuse connections when we have
more connections than the max configured.
When a session adds a connection to its connection list, we used to remove
connections for an another server if there were not enough room for our
server. This can't work, because those lists are now the list of connections
we're responsible for, not just the idle connections.
To fix this, allow for an unlimited number of servers, instead of using
an array, we're now using a linked list.
This function will be used to move parts of a buffer to another place
in the same buffer, even if the parts overlap. In order to keep things
under reasonable control, it only uses a length and absolute offsets
for the source and destination, and doesn't consider head nor data.
Released version 2.0-dev0 with the following main changes :
- BUG/MAJOR: connections: Close the connection before freeing it.
- REGTEST: Require the option LUA to run lua tests
- REGTEST: script: Process script arguments before everything else
- REGTEST: script: Evaluate the varnishtest command to allow quoted parameters
- REGTEST: script: Add the option --clean to remove previous log direcotries
- REGTEST: script: Add the option --debug to show logs on standard ouput
- REGTEST: script: Add the option --keep-logs to keep all log directories
- REGTEST: script: Add the option --use-htx to enable the HTX in regtests
- REGTEST: script: Print only errors in the results report
- REGTEST: Add option to use HTX prefixed by the macro 'no-htx'
- REGTEST: Make reg-tests target support argument.
- REGTEST: Fix a typo about barrier type.
- REGTEST: Be less Linux specific with a syslog regex.
- REGTEST: Missing enclosing quotes for ${tmpdir} macro.
- REGTEST: Exclude freebsd target for some reg tests.
- BUG/MEDIUM: h2: Don't forget to quit the sending_list if SUB_CALL_UNSUBSCRIBE.
- BUG/MEDIUM: mux-h2: Don't forget to quit the send list on error reports
- BUG/MEDIUM: dns: Don't prevent reading the last byte of the payload in dns_validate_response()
- BUG/MEDIUM: dns: overflowed dns name start position causing invalid dns error
- BUG/MINOR: compression/htx: Don't compress responses with unknown body length
- BUG/MINOR: compression/htx: Don't add the last block of data if it is empty
- MEDIUM: mux_h1: Implement h1_show_fd.
- REGTEST: script: Add support of alternatives in requited options list
- REGTEST: Add a basic test for the compression
- BUG/MEDIUM: mux-h2: don't needlessly wake up the demux on short frames
- REGTEST: A basic test for "http-buffer-request"
- BUG/MEDIUM: server: Also copy "check-sni" for server templates.
- MINOR: ssl: Add ssl_sock_set_alpn().
- MEDIUM: checks: Add check-alpn.
Add a way to configure the ALPN used by check, with a new "check-alpn"
keyword. By default, the checks will use the server ALPN, but it may not
be convenient, for instance because the server may use HTTP/2, while checks
are unable to do HTTP/2 yet.
In si_release_endpoint(), if the end point is a connection, because we don't
know which mux to use it, make sure we close the connection before freeing it,
or else, we'd have a fd left for polling, which would point to a now free'd
connection.
This should be backported to 1.9.
As long-time changes have accumulated over time, the exported functions
of the stream-interface were almost all prefixed "si_<something>" while
most private ones (mostly callbacks) were called "stream_int_<something>".
There were still a few confusing exceptions, which were addressed to
follow this shcme :
- stream_sock_read0(), only used internally, was renamed stream_int_read0()
and made static
- stream_int_notify() is only private and was made static
- stream_int_{check_timeouts,report_error,retnclose,register_handler,update}
were renamed si_<something>.
Now it is clearer when checking one of these if it risks to be used outside
or not.
There was a reference to struct stream in conn_free() for the case
where we're freeing a connection that doesn't have a mux attached.
For now we know it's always a stream, and we only need to do it to
put a NULL in s->si[1].end.
Let's do it better by storing the pointer to si[1].end in the context
and specifying that this pointer is always nulled if the mux is null.
This way it allows a connection to detach itself from wherever it's
being used. Maybe we could even get rid of the condition on the mux.
We most often store the mux context there but it can also be something
else while setting up the connection. Better call it "ctx" and know
that it's the owner's context than misleadingly call it mux_ctx and
get caught doing suspicious tricks.
The SUB_CAN_SEND/SUB_CAN_RECV enum values have been confusing a few
times, especially when checking them on reading. After some discussion,
it appears that calling them SUB_RETRY_SEND/SUB_RETRY_RECV more
accurately reflects their purpose since these events may only appear
after a first attempt to perform the I/O operation has failed or was
not completed.
In addition the wait_reason field in struct wait_event which carries
them makes one think that a single reason may happen at once while
it is in fact a set of events. Since the struct is called wait_event
it makes sense that this field is called "events" to indicate it's the
list of events we're subscribed to.
Last, the values for SUB_RETRY_RECV/SEND were swapped so that value
1 corresponds to recv and 2 to send, as is done almost everywhere else
in the code an in the shutdown() call.
When producing an HTX message, we can't rely on the next-level H1 parser
to check and deduplicate the content-length header, so we have to do it
while parsing a message. The algorithm is the exact same as used for H1
messages.
Types DNS_SRVRQ and CS were not referenced in the type to string
conversions, causing possibly misleading outputs in session dumps.
Now instead of showing "NONE" for unknown invalid types names, we
display "!INVAL!" to clear the confusion that may exist in case of
memory corruption for example.
Add a new flag to conn_streams, CS_FL_ERR_PENDING. This is to be set instead
of CS_FL_ERR in case there's still more data to be read, so that we read all
the data before closing.
When using DEBUG_MEMORY_POOLS, when we want to crash, instead of using
*(int *)0 = 0, use *(volatile int *)0 = 0, or clang will just translate it
to a nop, instead of dereferencing 0.
In session, don't keep an infinite number of connection that can idle.
Add a new frontend parameter, "max-session-srv-conns" to set a max number,
with a default value of 5.
Instead of trying to get the session from the connection, which is not
always there, and of course there could be multiple sessions per connection,
provide it with the init() and attach() methods, so that we know the
session for each outgoing stream.
Instead of the old "idle-timeout" mechanism, add a new option,
"pool-purge-delay", that sets the delay before purging idle connections.
Each time the delay happens, we destroy half of the idle connections.
Add a new command, "pool-max-conn" that sets the maximum number of connections
waiting in the orphan idling connections list (as activated with idle-timeout).
Using "-1" means unlimited. Using pools is now dependant on this.
Sadly we didn't have the cumulated number of connections established to
servers till now, so let's now update it per backend and per-server and
report it in the stats. On the stats page it appears in the tooltip
when hovering over the total sessions count field.
Add a new method to mux, "reset", that is used to let the mux know the
connection attempt failed, and we're about to retry, so it just have to
reinit itself. Currently only the H1 mux needs it.
Handle the CLI level in the master CLI. In order to do this, the master
CLI stores the level in the stream. Each command are prefixed by a
"user" or "operator" command before they are forwarded to the target
CLI.
The level can be configured in the haproxy program arguments with the
level keyword: -S /tmp/sock,level,admin -S /tmp/sock2,level,user.
The maximum number of bytes in a DNS name is indeed 255, but we
need to allocate one more byte for the NULL-terminating byte.
Otherwise dns_read_name() might return 255 for a very long name,
causing dns_validate_dns_response() to write a NULL value one
byte after the end of the buffer:
dns_answer_record->name[len] = 0;
The next fields in the struct being filled from the content of the
query, it might have been possible to fill them with non-0 values,
causing for example a strlen() of the name to read past the end of
the struct and access unintended parts of the memory, possibly
leading to a crash.
To be backported to 1.8, probably also 1.7.
Since the data_len field of the dns_answer_item struct was an int16_t,
record length values larger than 2^15-1 were causing an integer
overflow and thus may have been interpreted as negative, making us
read well before the beginning of the buffer.
This might have led to information disclosure or a crash.
To be backported to 1.8, probably also 1.7.
These flags haven't been used for a while. SF_TUNNEL was reintroduced
by commit d62b98c6e ("MINOR: stream: don't set backend's nor response
analysers on SF_TUNNEL") to handle the two-level streams needed to
deal with the first model for H2, and was not removed after this model
was abandonned. SF_INITIALIZED was only set. SF_CONN_TAR was never
referenced at all.
Now that h1 and legacy HTTP are two distinct things, there's no need
to keep the legacy HTTP parsers in h1.c since they're only used by
the legacy code in proto_http.c, and h1.h doesn't need to include
hdr_idx anymore. This concerns the following functions :
- http_parse_reqline();
- http_parse_stsline();
- http_msg_analyzer();
- http_forward_trailers();
All of these were moved to http_msg.c.
Lots of HTTP code still uses struct http_msg. Not only this code is
still huge, but it's part of the legacy interface. Let's move most
of these functions to a separate file http_msg.c to make it more
visible which file relies on what. It's mostly symmetrical with
what is present in http_htx.c.
The function http_transform_header_str() which used to rely on two
function pointers to look up a header was simplified to rely on
two variants http_legacy_replace_{,full_}header(), making both
sides of the function much simpler.
No code was changed beyond these moves.
All the HTX definition is self-contained and doesn't really depend on
anything external since it's a mostly protocol. In addition, some
external similar files (like h2) also placed in common used to rely
on it, making it a bit awkward.
This patch moves the two htx.h files into a single self-contained one.
The historical dependency on sample.h could be also removed since it
used to be there only for http_meth_t which is now in http.h.
The cache is now able to store and resend HTX messages. When an HTX message is
stored in the cache, the headers are prefixed with their block's info (an
uint32_t), containing its type and its length. Data, on their side, are stored
without any prefix. Only the value is copied in the cache. 2 fields have been
added in the structure cache_entry, hdrs_len and data_len, to known the size, in
the cache, of the headers part and the data part. If the message is chunked, the
trailers are also copied, the same way as data. When the HTX message is
recreated in the cache applet, the trailers size is known removing the headers
length and the data lenght from the total object length.
The CLI proxy was not handling payload. To do that, we needed to keep a
connection active on a server and to transfer each new line over that
connection until we receive a empty line.
The CLI proxy handles the payload in the same way that the CLI do it.
Examples:
$ echo -e "@1;add map #-1 <<\n$(cat data)\n" | socat /tmp/master-socket -
$ socat /tmp/master-socket readline
prompt
master> @1
25130> add map #-1 <<
+ test test
+ test2 test2
+ test3 test3
+
25130>
There were a number of ugly setsockopt() calls spread all over
proto_http.c, proto_htx.c and hlua.c just to manipulate the front
connection's TOS, mark or TCP quick-ack. These ones entirely relied
on the connection, its existence, its control layer's presence, and
its addresses. Worse, inet_set_tos() was placed in proto_http.c,
exported and used from the two other ones, surrounded in #ifdefs.
This patch moves this code to connection.h and makes the other ones
rely on it without ifdefs.
The new function hpack_encode_path() supports encoding a path into
the ":path" header. It knows about "/" and "/index.html" which use
a single byte, and falls back to literal encoding for other ones,
with a fast path for short paths < 127 bytes.
The new function hpack_encode_scheme() supports encoding a scheme
into the ":scheme" header. It knows about "https" and "http" which use
a single byte, and falls back to literal encoding for other ones.
The new function hpack_encode_method() supports encoding a method.
It knows about GET and POST which use a single byte, and falls back
to literal encoding for other ones.
This header exists with 7 different values, it's worth taking them
into account for the encoding, hence these functions. One of them
makes use of an integer only and computes the 3 output bytes in case
of literal. The other one benefits from the knowledge of an existing
string, which for example exists in the case of H1 to H2 encoding.
For long header values whose index is known, hpack_encodde_long_idx()
may now be used. This function emits the short index and follows with
the header's value.
Most direct calls to HPACK functions are made to encode short header
fields like methods, schemes or statuses, whose lengths and indexes
are known. Let's have a small function to do this.
We'll need these functions from other inline functions, let's make them
accessible. len_to_bytes() was renamed to hpack_len_to_bytes() since it's
now exposed.
This macro may be used to block constant propagation that lets the compiler
detect a possible NULL dereference on a variable resulting from an explicit
assignment in an impossible check. Sometimes a function is called which does
safety checks and returns NULL if safe conditions are not met. The place
where it's called cannot hit this condition and dereferencing the pointer
without first checking it will make the compiler emit a warning about a
"potential null pointer dereference" which is hard to work around. This
macro "washes" the pointer and prevents the compiler from emitting tests
branching to undefined instructions. It may only be used when the developer
is absolutely certain that the conditions are guaranteed and that the
pointer passed in argument cannot be NULL by design.
A typical use case is a top-level function doing this :
if (frame->type == HEADERS)
parse_frame(frame);
Then parse_frame() does this :
void parse_frame(struct frame *frame)
{
const char *frame_hdr;
frame_hdr = frame_hdr_start(frame);
if (*frame_hdr == FRAME_HDR_BEGIN)
process_frame(frame);
}
and :
const char *frame_hdr_start(const struct frame *frame)
{
if (frame->type == HEADERS)
return frame->data;
else
return NULL;
}
Above parse_frame() is only called for frame->type == HEADERS so it will
never get a NULL in return from frame_hdr_start(). Thus it's always safe
to dereference *frame_hdr since the check was already performed above.
It's then safe to address it this way instead of inventing dummy error
code paths that may create real bugs :
void parse_frame(struct frame *frame)
{
const char *frame_hdr;
frame_hdr = frame_hdr_start(frame);
ALREADY_CHECKED(frame_hdr);
if (*frame_hdr == FRAME_HDR_BEGIN)
process_frame(frame);
}
Calling tolower/toupper for each character is slow, a lookup into a
256-byte table is cheaper, especially for common characters used in
header field names which all fit into a cache line. Let's create these
two variables marked weak so that they're included only once.
The ist functions were missing functions to copy an IST into a target
buffer, making some code have to resort to memcpy(), which tends to be
overkill for small strings, that the compiler cannot guess. In addition
sometimes there is a need to turn a string to lower or upper case so it
had to be overwritten after the operation.
This patch adds 6 functions to copy an ist to a buffer, as binary or as a
string (i.e. a zero is or is not appended), and optionally to apply a
lower case or upper case transformation on the fly.
A number of tests were performed to optimize the processing for small
strings. The loops are marked unlikely to dissuade the compilers from
over-optimizing them and switching to SIMD instructions. The lower case
or upper case transformations used to rely on external functions for
each character and to crappify the code due to clobbered registers,
which is not acceptable when we know that only a certain class of chars
has to be transformed, so the test was open-coded.
CS_FL_RCV_MORE is used in two cases, to let the conn_stream
know there may be more data available, and to let it know that
it needs more room. We can't easily differentiate between the
two, and that may leads to hangs, so split it into two flags,
CS_FL_RCV_MORE, that means there may be more data, and
CS_FL_WANT_ROOM, that means we need more room.
This should not be backported.
If we try to receive before the connection is established, we lose the
send event and are not woken up anymore once the connection is established.
This was diagnosed by Olivier.
No backport is needed.
There are some situations where we need to wait for the other side to
be connected. None of the current blocking flags support this. It used
to work more or less by accident using the old flags. Let's add a new
flag to mention we're blocking on this, it's removed by si_chk_rcv()
when a connection is established. It should be enough for now.
The master is not supposed to run (at the moment) any task before the
polling loop, the created tasks should be run only in the workers but in
the master they should be disabled or removed.
No backport needed.
To ease the fast forwarding and the infinte forwarding on HTX proxies, 2
functions have been added to let the channel be almost aware of the way data are
stored in its buffer. By calling these functions instead of legacy ones, we are
sure to forward the right amount of data.
Now, the function htx_from_buf() will set the buffer's length to its size
automatically. In return, the caller should call htx_to_buf() at the end to be
sure to leave the buffer hosting the HTX message in the right state. When the
caller can use the function htxbuf() to get the HTX message without any update
on the underlying buffer.
The small HTX overhead is enough to make the system perform multiple
reads and unaligned memory copies. Here we provide a function whose
purpose is to reduce the apparent room in a buffer by the size of the
overhead for DATA blocks, which is the struct htx plus 2 blocks (one
for DATA, one for the end of message so that small blocks can fit at
once). The muxes using HTX will be encouraged to use this one instead
of b_room() to compute the available buffer room and avoid filling
their demux buf with more data than can fit at once into the HTX
buffer.
