This macro should be used to declare variables or struct members depending on
the USE_THREAD compile option. It avoids the encapsulation of such declarations
between #ifdef/#endif. It is used to declare all lock variables.
All the references to connections in the data path from streams and
stream_interfaces were changed to use conn_streams. Most functions named
"something_conn" were renamed to "something_cs" for this. Sometimes the
connection still is what matters (eg during a connection establishment)
and were not always renamed. The change is significant and minimal at the
same time, and was quite thoroughly tested now. As of this patch, all
accesses to the connection from upper layers go through the pass-through
mux.
We have two y for nsuring that the data is not concurently manipulated:
- locks
- running task on the same thread.
locks are expensives, it is better to avoid it.
This patch cecks that the Lua task run on the same thread that
the stream associated to the coprocess.
TODO: in a next version, the error should be replaced by a yield
and thread migration request.
The applet manipulates the session and its buffers. We have two methods for
ensuring that the memory of the session will not change during its manipulation
by the task:
1 - adding mutex
2 - running on the same threads than the task.
The second point is smart because it cannot lock the execution of another thread.
Note that the Lua processing is not really thread safe. It provides
heavy system which consists to add our own lock function in the Lua
code and recompile the library. This system will probably not accepted
by maintainers of various distribs.
Our main excution point of the Lua is the function lua_resume(). A
quick looking on the Lua sources displays a lua_lock() a the start
of function and a lua_unlock() at the end of the function. So I
conclude that the Lua thread safe mode just perform a mutex around
all execution. So I prefer to do this in the HAProxy code, it will be
easier for distro maintainers.
Note that the HAProxy lua functions rounded by the macro SET_SAFE_LJMP
and RESET_SAFE_LJMP manipulates the Lua stack, so it will be careful
to set mutex around these functions.
The jmpbuf contains pointer on the stack memory address currently use
when the jmpbuf is set. So the information is local to each thread.
The struct field is too big to put it in the stack, but it is used
as buffer for retriving stats values. So, this buffer si local to each
threads. Each function using this buffer, use it whithout break (yield)
so, the consistency of local buffer is ensured.
A global lock has been added to protect accesses to the list of active
applets. A process mask has also been added on each applet. Like for FDs and
tasks, it is used to know which threads are allowed to process an
applet. Because applets are, most of time, linked to a session, it should be
sticky on the same thread. But in all cases, it is the responsibility of the
applet handler to lock what have to be protected in the applet context.
For now, we have a list of each type per thread. So there is no need to lock
them. This is the easiest solution for now, but not the best one because there
is no sharing between threads. An idle connection on a thread will not be able
be used by a stream on another thread. So it could be a good idea to rework this
patch later.
2 global locks have been added to protect, respectively, the run queue and the
wait queue. And a process mask has been added on each task. Like for FDs, this
mask is used to know which threads are allowed to process a task.
For many tasks, all threads are granted. And this must be your first intension
when you create a new task, else you have a good reason to make a task sticky on
some threads. This is then the responsibility to the process callback to lock
what have to be locked in the task context.
Nevertheless, all tasks linked to a session must be sticky on the thread
creating the session. It is important that I/O handlers processing session FDs
and these tasks run on the same thread to avoid conflicts.
For HTTP/2 we'll need some buffer-only equivalent functions to some of
the ones applying to channels and still squatting the bi_* / bo_*
namespace. Since these names have kept being misleading for quite some
time now and are really getting annoying, it's time to rename them. This
commit will use "ci/co" as the prefix (for "channel in", "channel out")
instead of "bi/bo". The following ones were renamed :
bi_getblk_nc, bi_getline_nc, bi_putblk, bi_putchr,
bo_getblk, bo_getblk_nc, bo_getline, bo_getline_nc, bo_inject,
bi_putchk, bi_putstr, bo_getchr, bo_skip, bi_swpbuf
Since commit 'MAJOR: task: task scheduler rework'
0194897e54. LUA's
scheduling tasks are freezing.
A running task should not handle the scheduling itself
but let the task scheduler to handle it based on the
'expire' field.
[wt: no backport needed]
There are several places where we see feconn++, feconn--, totalconn++ and
an increment on the frontend's number of connections and connection rate.
This is done exactly once per session in each direction, so better take
care of this counter in the session and simplify the callers. At least it
ensures a better symmetry. It also ensures consistency as till now the
lua/spoe/peers frontend didn't have these counters properly set, which can
be useful at least for troubleshooting.
Each user of a session increments/decrements the jobs variable at its
own place, resulting in a real mess and inconsistencies between them.
Let's have session_new() increment jobs and session_free() decrement
it.
These notification management function and structs are generic and
it will be better to move in common parts.
The notification management functions and structs have names
containing some "lua" references because it was written for
the Lua. This patch removes also these references.
When we try to access to other proxy context, we must check
its existence because haproxy can kill it between the creation
and the usage.
This patch should be backported in 1.6 and 1.7
The server state and weight was reworked to handle
"pending" values updated by checks/CLI/LUA/agent.
These values are commited to be propagated to the
LB stack.
In further dev related to multi-thread, the commit
will be handled into a sync point.
Pending values are named using the prefix 'next_'
Current values used by the LB stack are named 'cur_'
Currently a task is allocated in session_new() and serves two purposes :
- either the handshake is complete and it is offered to the stream via
the second arg of stream_new()
- or the handshake is not complete and it's diverted to be used as a
timeout handler for the embryonic session and repurposed once we land
into conn_complete_session()
Furthermore, the task's process() function was taken from the listener's
handler in conn_complete_session() prior to being replaced by a call to
stream_new(). This will become a serious mess with the mux.
Since it's impossible to have a stream without a task, this patch removes
the second arg from stream_new() and make this function allocate its own
task. In session_accept_fd(), we now only allocate the task if needed for
the embryonic session and delete it later.
Till now connections used to rely exclusively on file descriptors. It
was planned in the past that alternative solutions would be implemented,
leading to member "union t" presenting sock.fd only for now.
With QUIC, the connection will need to continue to exist but will not
rely on a file descriptor but a connection ID.
So this patch introduces a "connection handle" which is either a file
descriptor or a connection ID, to replace the existing "union t". We've
now removed the intermediate "struct sock" which was never used. There
is no functional change at all, though the struct connection was inflated
by 32 bits on 64-bit platforms due to alignment.
Haproxy doesn't need this anymore, we're wasting cycles checking for
a Connection header in order to add "Connection: close" only in the
1.1 case so that haproxy sees it and removes it. All tests were run
in 1.0 and 1.1, with/without the request header, and in the various
keep-alive/close modes, with/without compression, and everything works
fine. It's worth noting that this header was inherited from the stats
applet and that the same cleanup probably ought to be done there as
well.
In the HTTP applet, we have to parse the response headers provided by
the application and to produce a response. strcasecmp() is expensive,
and chunk_append() even more as it uses a format string.
Here we check the string length before calling strcasecmp(), which
results in strcasecmp() being called only on the relevant header in
practise due to very few collisions on the name lengths, effectively
dividing the number of calls by 3, and we replace chunk_appendf()
with memcpy() as we already know the string lengths.
Doing just this makes the "hello-world" applet 5% faster, reaching
41400 requests/s on a core i5-3320M.
The header's value was parsed with atoi() then compared against -1,
meaning that all the unparsable stuff returning zero was not considered
and that all multiples of 2^32 + 0xFFFFFFFF would continue to emit a
chunk.
Now instead we parse the value using a long long, only accept positive
values and consider all unparsable values as incorrect and switch to
either close or chunked encoding. This is more in line with what a
client (including haproxy's parser) would expect.
This may be backported as a cleanup to stable versions, though it's
really unlikely that Lua applications are facing side effects of this.
The following Lua code causes emission of a final chunk after the body,
which is wrong :
core.register_service("send204", "http", function(applet)
applet:set_status(204)
applet:start_response()
end)
Indeed, responses with status codes 1xx, 204 and 304 do not contain any
body and the message ends immediately after the empty header (cf RFC7230)
so by emitting a 0<CR><LF> we're disturbing keep-alive responses. There's
a workaround against this for now which consists in always emitting
"Content-length: 0" but it may not be cool with 304 when clients use
the headers to update their cache.
This fix must be backported to stable versions back to 1.6.
Commit d1aa41f ("BUG/MAJOR: lua: properly dequeue hlua_applet_wakeup()
for new scheduler") tried to address the side effects of the scheduler
changes on Lua, but it was not enough. Having some Lua code send data
in chunks separated by one second each clearly shows busy polling being
done.
The issue was tracked down to hlua_applet_wakeup() being woken up on
timer expiration, and returning itself without clearing the timeout,
causing the task to be re-inserted with an expiration date in the past,
thus firing again. In the past it was not a problem, as returning NULL
was enough to clear the timer. Now we can't rely on this anymore so
it's important to clear this timeout.
No backport is needed, this issue is specific to 1.8-dev and results
from an incomplete fix in the commit above.
The recent scheduler change broke the Lua co-sockets due to
hlua_applet_wakeup() returning NULL after waking the applet up. With the
previous scheduler, returning NULL was a way to do nothing on return.
With the new one it keeps TASK_RUNNING set, causing all new notifications
to end up into t->pending_state instead of t->state, and prevents the
task from being added into the run queue again, so and it's never woken
up anymore.
The applet keeps waking up, causing hlua_socket_handler() to do nothing
new, then si_applet_wake_cb() calling stream_int_notify() to try to wake
the task up, which it can't do due to the TASK_RUNNING flag, then decide
that since the associated task is not in the run queue, it needs to call
stream_int_update_applet() to propagate the update. This last one finds
that the applet needs to be woken up to deal with the last reported events
and calling appctx_wakeup() again. Previously, this situation didn't exist
because the task was always added in the run queue despite the TASK_RUNNING
flag.
By returning the task instead in hlua_applet_wakeup(), we can ensure its
flag is properly cleared and the task is requeued if needed or just sits
waiting for new events to happen.
This fix requires the previous ones ("BUG/MINOR: lua: always detach the
tcp/http tasks before freeing them") and MINOR: task: always preinitialize
the task's timeout in task_init().
Thanks to Thierry, Christopher and Emeric for the long head-scratching
session!
No backport is needed as the bug doesn't appear in older versions and
it's unsure whether we'll not break something by backporting it.
In hlua_{http,tcp}_applet_release(), a call to task_free() is performed
to release the task, but no task_delete() is made on these tasks. Till
now it wasn't much of a problem because this was normally not done with
the task in the run queue, and the task was never put into the wait queue
since it doesn't have any timer. But with threading it will become an
issue. And not having this already prevents another bug from being fixed.
Thanks to Christopher for spotting this one. A backport to 1.7 and 1.6 is
preferred for safety.
We cannot perform garbage collection on unreferenced thread.
This memory is now free and another Lua process can use it for
other things.
HAProxy is monothread, so this bug doesn't cause crash.
This patch must be backported in 1.6 and 1.7
In some cases, the socket is misused. The user can open socket and never
close it, or open the socket and close it without sending data. This
causes resources leak on all resources associated to the stream (buffer,
spoe, ...)
This is caused by the stream_shutdown function which is called outside
of the stream execution process. Sometimes, the shtudown is required
while the stream is not started, so the cleanup is ignored.
This patch change the shutdown mode of the session. Now if the session is
no longer used and the Lua want to destroy it, it just set a destroy flag
and the session kill itself.
This patch should be backported in 1.6 and 1.7
When we destroy the Lua session, we manipulates Lua stack,
so errors can raises. It will be better to catch these errors.
This patch should be backported in 1.6 and 1.7
Just forgot of reset the safe mode. This have not consequences
the safe mode just set a pointer on fucntion which is called only
and initialises a longjmp.
Out of lua execution, this longjmp is never executed and the
function is never called.
This patch should be backported in 1.6 and 1.7
The task_wakeup was called on stream_new, but the task/stream
wasn't fully initialized yet. The task_wakeup must be called
explicitly by the caller once the task/stream is initialized.
In the case of a Lua sample-fetch or converter doesn't return any
value, an acces outside the Lua stack can be performed. This patch
check the stack size before converting the top value to a HAProxy
internal sample.
A workaround consist to check that a value value is always returned
with sample fetches and converters.
This patch should be backported in the version 1.6 and 1.7
The priv context is not cleaned when we set a new priv context.
This is caused by a stupid swap between two parameter of the
luaL_unref() function.
workaround: use set_priv only once when we process a stream.
This patch should be backported in version 1.7 and 1.6
luaL_setstate() uses malloc() to initialize the first objects, and only
after this we replace the allocator. This creates trouble when replacing
the standard memory allocators during debugging sessions since the new
allocator is used to realloc() an area previously allocated using the
default malloc().
Lua provides lua_newstate() in addition to luaL_newstate(), which takes
an allocator for the initial malloc. This is exactly what we need, and
this patch does this and fixes the problem. The now useless call to
lua_setallocf() could be removed.
This has no impact outside of debugging sessions and there's no need to
backport this.
Error in the HTTP parser. The function http_get_path() can
return NULL and this case is not catched in the code. So, we
try to dereference NULL pointer, and a segfault occurs.
These two lines are useful to prevent the bug.
acl prevent_bug path_beg /
http-request deny if !prevent_bug
This bug fix should be backported in 1.6 and 1.7
This patch change the names prefixing it by a "_". So "end" becomes "_end".
The backward compatibility with names without the prefix "_" is assured.
In other way, another the keyword "end" can be used like this: Map['end'].
Thanks Robin H. Johnson for the bug repport
This should be backported in version 1.6 and 1.7
The older 'rsprep' directive allows modification of the status reason.
Extend 'http-response set-status' to take an optional string of the new
status reason.
http-response set-status 418 reason "I'm a coffeepot"
Matching updates in Lua code:
- AppletHTTP.set_status
- HTTP.res_set_status
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Now we can simply check the transport layer at run time and decide
whether or not to initialize or destroy these entries. This removes
other ifdefs and includes from cfgparse.c, haproxy.c and hlua.c.
Now we exclusively use xprt_get(XPRT_RAW) instead of &raw_sock or
xprt_get(XPRT_SSL) for &ssl_sock. This removes a bunch of #ifdef and
include spread over a number of location including backend, cfgparse,
checks, cli, hlua, log, server and session.
Most of the SSL functions used to have a proxy argument which was mostly
used to be able to emit clean errors using Alert(). First, many of them
were converted to memprintf() and don't require this pointer anymore.
Second, the rare which still need it also have either a bind_conf argument
or a server argument, both of which carry a pointer to the relevant proxy.
So let's now get rid of it, it needlessly complicates the API and certain
functions already have many arguments.
If the memory allocator fails, it return a bad code, and the execution
continue. If the Lua/cli initializer fails, the allocated struct is not
released.
If the lua/cli fails during initialization, it returns an ok
status, an the execution continue. This will probably occur a
segfault.
Thiw patch should be backported in 1.7
This is a regression from the commit a73e59b690.
When data are sent from a cosocket, the action is done in the context of the
applet running a lua stack and not in the context of the applet owning the
cosocket. So we must take care, explicitly, that this last applet have a buffer
(the req buffer of the cosocket).
This patch must be backported in 1.7
In the case of applet, the Lua context is taken from session
when we get the private values. This patch just update comments
associated to this action because it is not obvious.
The signals system embedded in Lua can be tranformed in general purpose
signals code. To reach this goal, this path removes the Lua part of the
signals.
This is an easy job, because Lua is useles with signal. I change just two
prototypes.
The struct hlua size is 128 bytes. The size is the biggest of all the elements
of the union embedded in the appctx struct. With HTTP2, it is possible that this
appctx struct will be use many times for each connection, so the 128 bytes are
a little bit heavy for the global memory consomation.
This patch replace the embbeded hlua struct by a pointer and an associated memory
pool. Now, the memory for lua is allocated only if it is required.
[wt: the appctx is now down to 160 bytes]
We have very few users of the appctx's private field which was introduced
prior to the split of the CLI. Unfortunately it was not removed after the
end. This commit simply introduces hlua_cli->fcn which is the pointer to
the Lua function that the Lua code used to store in this private pointer.
This problem is already detected here:
8dc7316a6f
Another case raises. Now HAProxy sends a final message (typically
with "http-request deny"). Once the the message is sent, the response
channel flags are not modified.
HAProxy executes a Lua sample-fecthes for building logs, and the
result is ignored because the response flag remains set to the value
HTTP_MSG_RPBEFORE. So the Lua function hlua_check_proto() want to
guarantee the valid state of the buffer and ask for aborting the
request.
The function check_proto() is not the good way to ensure request
consistency. The real question is not "Are the message valid ?", but
"Are the validity of message unchanged ?"
This patch memorize the parser state before entering int the Lua
code, and perform a check when it go out of the Lua code. If the parser
state change for down, the request is aborted because the HTTP message
is degraded.
This patch should be backported in version 1.6 and 1.7
When an entity tries to get a buffer, if it cannot be allocted, for example
because the number of buffers which may be allocated per process is limited,
this entity is added in a list (called <buffer_wq>) and wait for an available
buffer.
Historically, the <buffer_wq> list was logically attached to streams because it
were the only entities likely to be added in it. Now, applets can also be
waiting for a free buffer. And with filters, we could imagine to have more other
entities waiting for a buffer. So it make sense to have a generic list.
Anyway, with the current design there is a bug. When an applet failed to get a
buffer, it will wait. But we add the stream attached to the applet in
<buffer_wq>, instead of the applet itself. So when a buffer is available, we
wake up the stream and not the waiting applet. So, it is possible to have
waiting applets and never awakened.
So, now, <buffer_wq> is independant from streams. And we really add the waiting
entity in <buffer_wq>. To be generic, the entity is responsible to define the
callback used to awaken it.
In addition, applets will still request an input buffer when they become
active. But they will not be sleeped anymore if no buffer are available. So this
is the responsibility to the applet I/O handler to check if this buffer is
allocated or not. This way, an applet can decide if this buffer is required or
not and can do additional processing if not.
[wt: backport to 1.7 and 1.6]
(http|tcp)-(request|response) action cannot take arguments from the
configuration file. Arguments are useful for executing the action with
a special context.
This patch adds the possibility of passing arguments to an action. It
runs exactly like sample fetches and other Lua wrappers.
Note that this patch implements a 'TODO'.
There's no more reason to keep tcp rules processing inside proto_tcp.c
given that there is nothing in common there except these 3 letters : tcp.
The tcp rules are in fact connection, session and content processing rules.
Let's move them to "tcp-rules" and let them live their life there.
proto/dumpstats.h has been split in 4 files:
* proto/cli.h contains protypes for the CLI
* proto/stats.h contains prototypes for the stats
* types/cli.h contains definition for the CLI
* types/stats.h contains definition for the stats
When:
- A Lua action return data and close the channel. The request status
is set to HTTP_MSG_CLOSED for the request and HTTP_MSG_DONE for the
response.
- HAProxy sets the state HTTP_MSG_ERROR. I don't known why, because
there are many line which sets this state.
- A Lua sample-fetch is executed, typically for building the log
line.
- When the Lua sample fetch exits, a control of the data is
executed. If HAProxy is currently parsing the request, the request
is aborted in order to prevent a segfault or sending corrupted
data.
This ast control is executed comparing the state HTTP_MSG_BODY. When
this state is reached, the request is parsed and no error are
possible. When the state is < than HTTP_MSG_BODY, the parser is
running.
Unfortunately, the code HTTP_MSG_ERROR is just < HTTP_MSG_BODY. When
we are in error, we want to terminate the execution of Lua without
error.
This patch changes the comparaison level.
This patch must be backported in 1.6
It does the opposite of 'set-var' action/converter. It is really useful for
per-process variables. But, it can be used for any scope.
The lua function 'unset_var' has also been added.
Somme HTTP manipulation functions are executed without valid and parsed
requests or responses. This causes a segmentation fault when the executed
code tries to change an empty buffer.
This patch must be backported in the 1.6 version
If an action wrapper stops the processing of the transaction
with a txn_done() function, the return code of the action is
"continue". So the continue can implies the processing of other
like adding headers. However, the HTTP content is flushed and
a segfault occurs.
This patchs add a flag indicating that the Lua code want to
stop the processing, ths flags is forwarded to the haproxy core,
and other actions are ignored.
Must be backported in 1.6
The function txn_done() ends a transaction. It does not make
sense to call this function from a lua sample-fetch wrapper,
because the role of a sample-fetch is not to terminate a
transaction.
This patch modify the role of the fucntion txn_done() if it
is called from a sample-fetch wrapper, now it just ends the
execution of the Lua code like the done() function.
Must be backported in 1.6
The number of arguments pushed in the stack are false, so we try to execute a
function out of the stack. This function is always a nil pointer, so the
following message is displayed.
Lua converter 'testconv': runtime error: attempt to call a nil value.
Thanks Michael Ezzell for the repporting.
This patch must be backported in the 1.6 version.
When compiled with GCC 6, the IP address specified for a frontend was
ignored and HAProxy was listening on all addresses instead. This is
caused by an incomplete copy of a "struct sockaddr_storage".
With the GNU Libc, "struct sockaddr_storage" is defined as this:
struct sockaddr_storage
{
sa_family_t ss_family;
unsigned long int __ss_align;
char __ss_padding[(128 - (2 * sizeof (unsigned long int)))];
};
Doing an aggregate copy (ss1 = ss2) is different than using memcpy():
only members of the aggregate have to be copied. Notably, padding can be
or not be copied. In GCC 6, some optimizations use this fact and if a
"struct sockaddr_storage" contains a "struct sockaddr_in", the port and
the address are part of the padding (between sa_family and __ss_align)
and can be not copied over.
Therefore, we replace any aggregate copy by a memcpy(). There is another
place using the same pattern. We also fix a function receiving a "struct
sockaddr_storage" by copy instead of by reference. Since it only needs a
read-only copy, the function is converted to request a reference.
When a converter or sample is called from within a Lua code, there is a risk
of invalid argument string data usage when the upper boundary is reached.
Would be kind to port to 1.6 if possible.
In C89, "void *" is automatically promoted to any pointer type. Casting
the result of malloc/calloc to the type of the LHS variable is therefore
unneeded.
Most of this patch was built using this Coccinelle patch:
@@
type T;
@@
- (T *)
(\(lua_touserdata\|malloc\|calloc\|SSL_get_app_data\|hlua_checkudata\|lua_newuserdata\)(...))
@@
type T;
T *x;
void *data;
@@
x =
- (T *)
data
@@
type T;
T *x;
T *data;
@@
x =
- (T *)
data
Unfortunately, either Coccinelle or I is too limited to detect situation
where a complex RHS expression is of type "void *" and therefore casting
is not needed. Those cases were manually examined and corrected.
This patch adds a Lua post initialisation wrapper. It already exists for
pure Lua function, now it executes also C. It is useful for doing things
when the configuration is ready to use. For example we can can browse and
register all the proxies.
All the HAProxy Lua object are declared with the same pattern:
- Add the function __tosting which dumps the object name
- Register the name in the Lua REGISTRY
- Register the reference ID
These action are refactored in on function. This remove some
lines of code.
The functions
- hlua_class_const_int()
- hlua_class_const_str()
- hlua_class_function()
are use for common class registration actions.
The function 'hlua_dump_object()' is generic dump name function.
These functions can be used by all the HAProxy objects, so I move
it into the safe functions file.
This is the continuation of previous patch called "BUG/MAJOR: samples:
check smp->strm before using it".
It happens that variables may have a session-wide scope, and that their
session is retrieved by dereferencing the stream. But nothing prevents them
from being used from a streamless context such as tcp-request connection,
thus crashing the process. Example :
tcp-request connection accept if { src,set-var(sess.foo) -m found }
In order to fix this, we have to always ensure that variable manipulation
only happens via the sample, which contains the correct owner and context,
and that we never use one from a different source. This results in quite a
large change since a lot of functions are inderctly involved in the call
chain, but the change is easy to follow.
This fix must be backported to 1.6, and requires the last two patches.
Some functions like sample_conv_var2smp(), var_get_byname(), and
var_set_byname() directly or indirectly need to access the current
stream and/or session and must find it in the sample itself and not
as a distinct argument. Thus we first need to call smp_set_owner()
prior to each such calls.
Since commit 6879ad3 ("MEDIUM: sample: fill the struct sample with the
session, proxy and stream pointers") merged in 1.6-dev2, the sample
contains the pointer to the stream and sample fetch functions as well
as converters use it heavily. This requires from a lot of call places
to initialize 4 fields, and it was even forgotten at a few places.
This patch provides a convenient helper to initialize all these fields
at once, making it easy to prepare a new sample from a previous one for
example.
A few call places were cleaned up to make use of it. It will be needed
by further fixes.
At one place in the Lua code, it was moved earlier because we used to
call sample casts with a non completely initialized sample, which is
not clean eventhough at the moment there are no consequences.
Since commit 6879ad3 ("MEDIUM: sample: fill the struct sample with the
session, proxy and stream pointers") merged in 1.6-dev2, the sample
contains the pointer to the stream and sample fetch functions as well
as converters use it heavily.
The problem is that earlier commit 87b0966 ("REORG/MAJOR: session:
rename the "session" entity to "stream"") had split the session and
stream resulting in the possibility for smp->strm to be NULL before
the stream was initialized. This is what happens in tcp-request
connection rulesets, as discovered by Baptiste.
The sample fetch functions must now check that smp->strm is valid
before using it. An alternative could consist in using a dummy stream
with nothing in it to avoid some checks but it would only result in
deferring them to the next step anyway, and making it harder to detect
that a stream is valid or the dummy one.
There is still an issue with variables which requires a complete
independant fix. They use strm->sess to find the session with strm
possibly NULL and passed as an argument. All call places indirectly
use smp->strm to build strm. So the problem is there but the API needs
to be changed to remove this duplicate argument that makes it much
harder to know what pointer to use.
This fix must be backported to 1.6, as well as the next one fixing
variables.
A value is copied two time in teh stack, but only one is usefull. The
second copy leaves unused in the stack and take some room for noting.
This path removes the second copy.
Must be backported in 1.6
This patch must be backported in 1.6
hlua_yield() function returns the required sleep time. The Lua core must
be resume the execution after the required time. The core dedicated to
the http and tcp applet doesn't implement the wake up function. It is a
miss.
This patch fix this.
This patch moves the function hlua_checkudata which check that
an object contains the expected class_reference as metatable.
This function is commonly used by all the lua functions.
The function hlua_metatype is also moved.
When Lua executes functions from its API, these can throws an error.
These function must be executed in a special environment which catch
these error, otherwise a critical error (like segfault) can raise.
This patch add a c file called "hlua_fcn.c" which collect all the
Lua/c function needing safe environment for its execution.
The applet can't have access to the session private data. This patch
fix this problem. Now an applet can use private data stored by actions
and fecthes.
INNER and XFERBODY analyzer were set in order to support HTTP applets
from TCP rulesets, but this does not work (cf previous patch).
Other cases already provides theses analyzers, so their addition is
not needed. Furthermore if INNER was set it could cause some headers
to be rewritten (ex: connection) after headers were already forwarded,
resulting in a crash in buffer_insert_line2().
Special thanks to Bernd Helm for providing very detailed information,
captures and stack traces making it possible to spot the root cause
here.
This fix must be backported to 1.6.
HTTP applets request requires everything initilized by
"http_process_request" (analyzer flag AN_REQ_HTTP_INNER).
The applet will be immediately initilized, but its before
the call of this analyzer.
Due to this problem HTTP applets could be called with uncompletely
initialized http_txn.
This fix must be backported to 1.6.
In certain circumstances (eg: Lua HTTP applet called from a
TCP ruleset before http_process_request()), the HTTP TXN is not
yet fully initialized so some information it contains cannot be
relied on. Such information include the HTTP version, the state
of the expect: 100-continue header, the connection header and
the transfer-encoding header.
Here the bug only turns something which already doesn't work
into something wrong, but better avoid any references to the
http_txn from the Lua code to avoid future mistakes.
This patch should be backported into 1.6 for code consistency.
If a sample fetch needing http_txn is called from an HTTP Lua applet,
the result will be invalid and may even cause a crash because some HTTP
data can be forwarded and the HTTP txn is no longer valid.
Here the solution is to ensure that a fetch called from Lua never
needs http_txn. This is done thanks to a new flag HLUA_F_MAY_USE_HTTP
which indicates whether or not it is safe to call a fetch which needs
HTTP.
This fix needs to be backported to 1.6.
This patch converts a boolean "int" to a bitfiled. The main
reason is to save space in the struct if another flag may will
be require.
Note that this patch is required for next fix and will need to be
backported to 1.6.
When a POST is processed by a Lua service, the HTTP header are
potentially gone. So, we cannot retrieve their content using
the standard "hdr" sample fetchs (which will soon become invalid
anyway) from an applet.
This patch add an entry "headers" to the object applet_http. This
entry is an array containing all the headers. It permits to use the
HTTP headers during the processing of the service.
Many thanks to Jan Bruder for reporting this issue with enough
details to reproduce it.
This patch will have to be backported to 1.6 since it will be the
only way to access headers from Lua applets.
Sander Klein reported an error messages about SSLv3 not
being supported on Debian 8, although he didn't force-sslv3.
Vincent Bernat tracked this down to the LUA initialization, which
actually does force-sslv3.
This patch removes force-sslv3 from the LUA initialization, so
the LUA SSL socket can actually use TLS and doesn't trigger
warnings when SSLv3 is not supported by libssl (such as in
Debian 8).
This should be backported to 1.6.
When the txn.done() fiunction is called, the ouput buffer is cleaned,
but the associated relative pointer on the HTTP requests elements
is not reseted.
This patch remove this cleanup, because the output buffer may contain
data to forward.
The direction (request or response) is not propagated in the
sample fecthes called throught Lua. This patch adds the direction
status in some structs (hlua_txn and hlua_smp) to make sure that
the sample fetches will be called with all the information.
The converters can not access to a TXN object, so there are not
impacted the direction. However, the samples used as input of the
Lua converter wrapper are initiliazed with the direction. Thereby,
the struct smp stay consistent.
[wt: needs to be backported to 1.6]
This patch cleanups the direction names. It replaces numeric values,
by the associated defines. It ensure the compliance with values found
somwhere else in HAProxy.
It is required by the bugfix patch which is following.
[wt: needs to be backported to 1.6]
Lua needs to known the direction of the http data processed (request or
response). It checks the flag SMP_OPT_DIR_REQ, buf this flag is 0. This patch
correctly checks the flags after applying the SMP_OPT_DIR mask.
Thierry reported that keep-alive still didn't cope well with Lua
services. The reason is that for now applets have to be closed at
the end of a transaction so we want to work in server-close mode,
which isn't noticeable by the client since it still sees keep-alive.
Additionally we want to enable the request body transfer analyser
which will be needed to synchronize with the response analyser to
indicate the end of the transfer.
Only the main execution function can set the run flag, because it is
the last function before the execution time.
This patch removes the flag set by another function. It will be used
by the new lua timeout counter.
The garbage collector is a little bit heavy to run, and it was added
only for cosockets. This patch prevent useless executions when no
cosockets are used.
When the channel is down, the applet is waked up. Before this patch,
the applet closes the stream and the unread data are discarded.
After this patch, the stream is not closed except if the buffers are
empty.
It will be closed later by the close function, or by the garbage collector.
The HAProxy Lua socket respects the Lua Socket tcp specs. these specs
are a little bit limited, it not permits to connect to unix socket.
this patch extends a little it the specs. It permit to accept a
syntax that begin with "unix@", "ipv4@", "ipv6@", "fd@" or "abns@".
Actions may yield but must not do it during the final call from a ruleset
because it indicates there will be no more opportunity to complete or
clean up. This is indicated by ACT_FLAG_FINAL in the action's flags,
which must be passed to hlua_resume().
Thanks to this, an action called from a TCP ruleset is properly woken
up and possibly finished when the client disconnects.
Since commit bc4c1ac ("MEDIUM: http/tcp: permit to resume http and tcp
custom actions"), some actions may yield and be called back when new
information are available. Unfortunately some of them may continue to
yield because they simply don't know that it's the last call from the
rule set. For this reason we'll need to pass a flag to the custom
action to pass such information and possibly other at the same time.
When a thread stops this patch forces a garbage collection which
cleanup and free the memory.
The HAProxy Lua Socket class contains an HAProxy session, so it
uses a big amount of memory, in other this Socket class uses a
filedescriptor and maintain a connection open.
If the class Socket is stored in a global variable, the Socket stay
alive along of the life of the process (except if it is closed by the
other size, or if a timeout is reached). If the class Socket is stored
in a local variable, it must die with this variable.
The socket is closed by a call from the garbage collector. And the
portability and use of a variable is known by the same garbage collector.
so, running the GC just after the end of all Lua code ensure that the
heavy resources like the socket class are freed quickly.
Not having the target set on the connection causes it to be released
at the last moment, and the destination address to randomly be valid
depending on the data found in the memory at this moment. In practice
it works as long as memory poisonning is disabled. The deep reason is
that connect_server() doesn't expect to be called with SF_ADDR_SET and
an existing connection with !reuse. This causes the release of the
connection, its reallocation (!reuse), and taking the address from the
newly allocated connection. This should certainly be improved.
Commit d75cb0f ("BUG/MAJOR: lua: segfault after the channel data is
modified by some Lua action.") introduced a regression causing an
action run from a TCP rule in an HTTP proxy to end in HTTP error
if it terminated cleanly, because it didn't parse the HTTP request!
Relax the test so that it takes into account the opportunity for the
analysers to parse the message.
The lua code must the the appropriate wakeup mechanism for cosockets.
It wakes them up from outside the stream and outside the applet, so it
shouldn't use the applet's wakeup callback which is designed only for
use from within the applet itself. For now it didn't cause any trouble
(yet).
When an action or a fetch modify the channel data, the http request parser
pointer become inconsistent. This patch detects the modification and call
again the parser.
The function lua_settable uses the metatable for acessing data,
so in the C part, we want to index value in the real table and
not throught the meta-methods. It's much faster this way.
This function is a callback made only for calls from the applet handler.
Rename it to remove confusion. It's currently called from the Lua code
but that's not correct, we should call the notify and update functions
instead otherwise it will not enable the applet again.
The current Lua action are not registered. The executed function is
selected according with a function name writed in the HAProxy configuration.
This patch add an action registration function. The configuration mode
described above disappear.
This change make some incompatibilities with existing configuration files for
HAProxy 1.6-dev.
This couple of function executes securely some Lua calls outside of
the lua runtime environment. Each Lua call can return a longjmp
if it encounter a memory error.
Lua documentation extract:
If an error happens outside any protected environment, Lua calls
a panic function (see lua_atpanic) and then calls abort, thus
exiting the host application. Your panic function can avoid this
exit by never returning (e.g., doing a long jump to your own
recovery point outside Lua).
The panic function runs as if it were a message handler (see
2.3); in particular, the error message is at the top of the
stack. However, there is no guarantee about stack space. To push
anything on the stack, the panic function must first check the
available space (see 4.2).
We must check all the Lua entry point. This includes:
- The include/proto/hlua.h exported functions
- the task wrapper function
- The action wrapper function
- The converters wrapper function
- The sample-fetch wrapper functions
It is tolerated that the initilisation function returns an abort.
Before each Lua abort, an error message is writed on stderr.
The macro SET_SAFE_LJMP initialise the longjmp. The Macro
RESET_SAFE_LJMP reset the longjmp. These function must be macro
because they must be exists in the program stack when the longjmp
is called
All the code which emits error log have the same pattern. Its:
Send log with syslog system, and if it is allowed, display error
log on screen.
This patch replace this pattern by a macro. This reduces the number
of lines.
The send_log function needs a final \n.
This bug is repported by Michael Ezzell.
Minor bug: when writing to syslog from Lua scripts, the last character from
each log entry is truncated.
core.Alert("this is truncated");
Sep 7 15:07:56 localhost haproxy[7055]: this is truncate
This issue appears to be related to the fact that send_log() (in src/log.c)
is expecting a newline at the end of the message's format string:
/*
* This function adds a header to the message and sends the syslog message
* using a printf format string. It expects an LF-terminated message.
*/
void send_log(struct proxy *p, int level, const char *format, ...)
I believe the fix would be in in src/hlua.c at line 760
<http://git.haproxy.org/?p=haproxy.git;a=blob;f=src/hlua.c;h=1e4d47c31e66c16c837ff2aa5ef577f6cafdc7e7;hb=316e3196285b89a917c7d84794ced59a6a5b4eba#l760>,
where this...
send_log(px, level, "%s", trash.str);
...should be adding a newline into the format string to accommodate what
the code expects.
send_log(px, level, "%s\n", trash.str);
This change provides what seems to be the correct behavior:
Sep 7 15:08:30 localhost haproxy[7150]: this is truncated
All other uses of send_log() in hlua.c have a trailing dot "." in the
message that is masking the truncation issue because the output message
stops on a clean word boundary. I suspect these would also benefit from
"\n" appended to their format strings as well, since this appears to be the
pattern seen throughout the rest of the code base.
Reported-by: Michael Ezzell <michael@ezzell.net>
See commit id bdc97a8795
Michael Ezzell reported that the following Lua code fails in
dev4 when the TCP is not established immediately (due to a little
bit of latency):
function tricky_socket()
local sock = core.tcp();
sock:settimeout(3);
core.log(core.alert,"calling connect()\n");
local connected, con_err = sock:connect("x.x.x.x",80);
core.log(core.alert,"returned from connect()\n");
if con_err ~= nil then
core.log(core.alert,"connect() failed with error: '" .. con_err .. "'\n");
end
The problem is that the flags who want to wake up the applet are
resetted before each applet call, so the applet must set again the
flags if the connection is not established.
Before this patch, two type of custom actions exists: ACT_ACTION_CONT and
ACT_ACTION_STOP. ACT_ACTION_CONT is a non terminal action and ACT_ACTION_STOP is
a terminal action.
Note that ACT_ACTION_STOP is not used in HAProxy.
This patch remove this behavior. Only type type of custom action exists, and it
is called ACT_CUSTOM. Now, the custion action can return a code indicating the
required behavior. ACT_RET_CONT wants that HAProxy continue the current rule
list evaluation, and ACT_RET_STOP wants that HAPRoxy stops the the current rule
list evaluation.
When called from an http ruleset, txn:done() can still crash the process
because it closes the stream without consuming pending data resulting in
the transaction's buffer representation to differ from the real buffer.
This patch also adjusts the transaction's state to indicate that it's
closed to be consistent with what's already done in redirect rules.
When the Lua execution flow endswith the command done (core.done or txn.done())
an error is detourned, and the stack is no longer usable. This patch juste
reinitilize the stack if this case is detected.
The function txn:close() must be terminal because it demands the session
destruction. This patch renames this function to "done()" to be much
clearer about the fact that it is a final operation.
This patch is inspired by Bowen Ni's proposal and it is based on his first
implementation:
With Lua integration in HAProxy 1.6, one can change the request method,
path, uri, header, response header etc except response line.
I'd like to contribute the following methods to allow modification of the
response line.
[...]
There are two new keywords in 'http-response' that allows you to rewrite
them in the native HAProxy config. There are also two new APIs in Lua that
allows you to do the same rewriting in your Lua script.
Example:
Use it in HAProxy config:
*http-response set-code 404*
Or use it in Lua script:
*txn.http:res_set_reason("Redirect")*
I dont take the full patch because the manipulation of the "reason" is useless.
standard reason are associated with each returned code, and unknown code can
take generic reason.
So, this patch can set the status code, and the reason is automatically adapted.
The function dont remove remaineing analysers and dont update response
channel timeout.
The fix is a copy of the behavior of the functions http_apply_redirect_rule()
and stream_int_retnclose().
Tsvetan Tsvetanov reported that the following Lua code fails in
dev2 and dev3 :
function hello(txn)
local request_msg = txn.req:dup()
local tsm_sock = core.tcp()
tsm_sock:connect("127.0.0.1", 7777)
local res = tsm_sock:send(request_msg)
local response = tsm_sock:receive('*l')
txn.res:send(response)
txn:close()
end
Thierry diagnosed that it was caused by commit 563cc37 ("MAJOR: stream:
use a regular ->update for all stream interfaces"). It broke lua's
ability to establish outgoing connections.
The reason is that the applet used to be notified about established
connections just after the stream analyser loop, and that's not the
case anymore. In peers, this issue didn't happen because peers use
a handshake so after sending data, the response is received and wakes
the applet up again. Here we have to indicate that we want to send or
receive data, this will cause the notification to happen as soon as
the connection is ready. This is similar to pretending that we're
working on a full buffer after all. In theory subscribing for reads
is not needed, but it's added here for completeness.
Reported-By: Tsvetan Tsvetanov <cpi.cecko@gmail.com>
Now the prototype for each action from each section are the same, and
a discriminant for determining for each section we are called are added.
So, this patch removes the wrappers for the action functions called from
more than one section.
This patch removes 132 lines of useless code.
This patch normalize the return code of the configuration parsers. Before
these changes, the tcp action parser returned -1 if fail and 0 for the
succes. The http action returned 0 if fail and 1 if succes.
The normalisation does:
- ACT_RET_PRS_OK for succes
- ACT_RET_PRS_ERR for failure
This patch merges the conguration keyword struct. Each declared configuration
keyword struct are similar with the others. This patch simplify the code.
Action function can return 3 status:
- error if the action encounter fatal error (like out of memory)
- yield if the action must terminate his work later
- continue in other cases
For performances considerations, some actions are not processed by remote
function. They are directly processed by the function. Some of these actions
does the same things but for different processing part (request / response).
This patch give the same name for the same actions, and change the normalization
of the other actions names.
This patch is ONLY a rename, it doesn't modify the code.
This patch group the action name in one file. Some action are called
many times and need an action embedded in the action caller. The main
goal is to have only one header file grouping all definitions.
The (http|tcp)-(request|response) action rules use common
opaque type. For the HAProxy embbedded feature, types are know,
it better to add this types in the action union and use it.
This patch is the first of a serie which merge all the action structs. The
function "tcp-request content", "tcp-response-content", "http-request" and
"http-response" have the same values and the same process for some defined
actions, but the struct and the prototype of the declared function are
different.
This patch try to unify all of these entries.
The union name "data" is a little bit heavy while we read the source
code because we can read "data.data.sint". The rename from "data" to "u"
makes the read easiest like "data.u.sint".
This patch remove the struct information stored both in the struct
sample_data and in the striuct sample. Now, only thestruct sample_data
contains data, and the struct sample use the struct sample_data for storing
his own data.
test conf:
global
tune.lua.session-timeout 0
lua-load lol.lua
debug
maxconn 4096
listen test
bind 0.0.0.0:10010
mode tcp
tcp-request content lua act_test
balance roundrobin
server test 127.0.0.1:3304
lua test:
function act_test(txn)
while true do
core.Alert("TEST")
end
end
The function "act_test()" is not executed because a zero timeout is not
considered as TICK_ETERNITY, but is considered as 0.
This path fix this behavior. This is the same problem than the bugfix
685c014e99.
I've been trying out 1.6 dev3 with lua support, and trying to start
lua tasks seems to not be working.
Using this configuration
global
lua-load /lua/lol.lua
debug
maxconn 4096
backend shard_b
server db01 mysql_shard_b:3306
backend shard_a
server db01 mysql_shard_a:3306
listen mysql-cluster
bind 0.0.0.0:8001
mode tcp
balance roundrobin
use_backend shard_b
And this lua function
core.register_task(function()
while true do
core.Alert("LOLOLOLOLOL")
end
end)
I'd always get a timeout error starting the registered function.
The problem lies as far as I can tell in the fact that is possible for
now_ms to not change (is this maybe a problem on my config/system?)
until the expiration check happens, in the resume function that
actually kickstarts the lua task, making HAProxy think that expiration
time for the task is up, if I understand correctly tasks are meant to
never really timeout.
These ones are considered safe as they have already been reused.
They will be useful in "aggressive" and "always" http-reuse modes
in order to place the first request of a connection with the least
risk.
For now it's not populated but we have the list entry. It will carry
all idle connections that sessions don't want to share. They may be
used later to reclaim connections upon socket shortage for example.
Since we now always call this function with the reuse parameter cleared,
let's simplify the function's logic as it cannot return the existing
connection anymore. The savings on this inline function are appreciable
(240 bytes) :
$ size haproxy.old haproxy.new
text data bss dec hex filename
1020383 40816 36928 1098127 10c18f haproxy.old
1020143 40816 36928 1097887 10c09f haproxy.new
This patch removes the 32 bits unsigned integer and the 32 bit signed
integer. It replaces these types by a unique type 64 bit signed.
This makes easy the usage of integer and clarify signed and unsigned use.
With the previous version, signed and unsigned are used ones in place of
others, and sometimes the converter loose the sign. For example, divisions
are processed with "unsigned", if one entry is negative, the result is
wrong.
Note that the integer pattern matching and dotted version pattern matching
are already working with signed 64 bits integer values.
There is one user-visible change : the "uint()" and "sint()" sample fetch
functions which used to return a constant integer have been replaced with
a new more natural, unified "int()" function. These functions were only
introduced in the latest 1.6-dev2 so there's no impact on regular
deployments.
Dmitry Sivachenko reported the following build warning using Clang,
though it's harmless :
src/hlua.c:1911:13: warning: variable '_socket_info_expanded_form' is not needed
and will not be emitted [-Wunneeded-internal-declaration]
static char _socket_info_expanded_form[] = SOCKET_INFO_EXPANDED_FORM;
^
Indeed, the variable is not used except to compute a sizeof which is
taken from the string it is initialized from. It probably is a leftover
after various code refactorings. Let's get rid of it now since it's not
used anymore.
No backport is needed.
Actually, the registered lua actions with "tcp-request lua" and
"tcp-response lua" are final actions. This patch change the action
type type and permit to continue the evaluation of tcp-* processing
after the evaluation of the lua actions.
First, findproxy() was renamed proxy_find_by_name() so that its explicit
that a name is required for the lookup. Second, we give this function
the ability to search for tables if needed. Third we now provide inline
wrappers to pass the appropriate PR_CAP_* flags and to explicitly look
up a frontend, backend or table.
Options are relative to the sample. Each sample fetched is associated with
fetch options or fetch flags.
This patch adds the 'opt' vaue in the sample struct. This permits to reduce
the sample-fetch function prototype. In other way, the converters will have
more detail about the origin of the sample.
This patch removes the structs "session", "stream" and "proxy" from
the sample-fetches and converters function prototypes.
This permits to remove some weight in the prototype call.
Some sample analyzer (sample-fetch or converters) needs to known the proxy,
session and stream attached to the sampel. The sample-fetches and the converters
function pointers cannot be called without these 3 pointers filled.
This patch permits to reduce the sample-fetch and the converters called
prototypes, and provides a new mean to add information for this type of
functions.
It's much easier to centralize this call into the I/O handler than to
do it everywhere with the risk to miss it. Applets are not allowed to
unregister themselves anyway so their SI is still present and it is
possible to update all the context.
The applet I/O handlers now rely on si_applet_done() which itself decides
to wake up or sleep the appctx. Now it becomes critical that applte handlers
properly call this on every exit path so that the appctx is removed from the
active list after I/O have been handled. One such call was added to the Lua
socket handler. It used to work without it probably because the main task is
woken up by the parent task but now it's needed.
Now that applet's functions only take an appctx in argument, not a
stream interface. This slightly simplifies the code and will be needed
to take the appctx out of the stream interface.
We don't pass sess->origin anymore but the pointer to the previous step. Now
it should be much easier to chain elements together once applets are moved out
of streams. Indeed, the session is only used for configuration and not for the
dynamic chaining anymore.
This patch cretes a new Map class that permits to do some lookup in
HAProxy maps. This Map class is integration in the HAProxy update
system, so we can modify the map throught the socket.
the functions (req|res)_get_headers() return only the last entry
for each header with the same name. This patch fix this behavior.
Each header name contain an array of values.
The stick counters in the session will be used for everything not related
to contents, hence the connections / concurrent sessions / etc. They will
be usable by "tcp-request connection" rules even without a stream. For now
they're just allocated and initialized.
Doing so ensures we don't need to use the stream anymore to prepare the
log information to report a failed handshake on an embryonic session.
Thus, prepare_mini_sess_log_prefix() now takes a session in argument.
Many such function need a session, and till now they used to dereference
the stream. Once we remove the stream from the embryonic session, this
will not be possible anymore.
So as of now, sample fetch functions will be called with this :
- sess = NULL, strm = NULL : never
- sess = valid, strm = NULL : tcp-req connection
- sess = valid, strm = valid, strm->txn = NULL : tcp-req content
- sess = valid, strm = valid, strm->txn = valid : http-req / http-res
The registerable http_req_rules / http_res_rules used to require a
struct http_txn at the end. It's redundant with struct stream and
propagates very deep into some parts (ie: it was the reason for lua
requiring l7). Let's remove it now.
All of them can now retrieve the HTTP transaction *if it exists* from
the stream and be sure to get NULL there when called with an embryonic
session.
The patch is a bit large because many locations were touched (all fetch
functions had to have their prototype adjusted). The opportunity was
taken to also uniformize the call names (the stream is now always "strm"
instead of "l4") and to fix indent where it was broken. This way when
we later introduce the session here there will be less confusion.
Now this one is dynamically allocated. It means that 280 bytes of memory
are saved per TCP stream, but more importantly that it will become
possible to remove the l7 pointer from fetches and converters since
it will be deduced from the stream and will support being null.
A lot of care was taken because it's easy to forget a test somewhere,
and the previous code used to always trust s->txn for being valid, but
all places seem to have been visited.
All HTTP fetch functions check the txn first so we shouldn't have any
issue there even when called from TCP. When branching from a TCP frontend
to an HTTP backend, the txn is properly allocated at the same time as the
hdr_idx.
The header captures are now general purpose captures since tcp rules
can use them to capture various contents. That removes a dependency
on http_txn that appeared in some sample fetch functions and in the
order by which captures and http_txn were allocated.
Interestingly the reset of the header captures were done at too many
places as http_init_txn() used to do it while it was done previously
in every call place.
When s->si[0].end was dereferenced as a connection or anything in
order to retrieve information about the originating session, we'll
now use sess->origin instead so that when we have to chain multiple
streams in HTTP/2, we'll keep accessing the same origin.
Just like for the listener, the frontend is session-wide so let's move
it to the session. There are a lot of places which were changed but the
changes are minimal in fact.
There is now a pointer to the session in the stream, which is NULL
for now. The session pool is created as well. Some parts will move
from the stream to the session now.
With HTTP/2, we'll have to support multiplexed streams. A stream is in
fact the largest part of what we currently call a session, it has buffers,
logs, etc.
In order to catch any error, this commit removes any reference to the
struct session and tries to rename most "session" occurrences in function
names to "stream" and "sess" to "strm" when that's related to a session.
The files stream.{c,h} were added and session.{c,h} removed.
The session will be reintroduced later and a few parts of the stream
will progressively be moved overthere. It will more or less contain
only what we need in an embryonic session.
Sample fetch functions and converters will have to change a bit so
that they'll use an L5 (session) instead of what's currently called
"L4" which is in fact L6 for now.
Once all changes are completed, we should see approximately this :
L7 - http_txn
L6 - stream
L5 - session
L4 - connection | applet
There will be at most one http_txn per stream, and a same session will
possibly be referenced by multiple streams. A connection will point to
a session and to a stream. The session will hold all the information
we need to keep even when we don't yet have a stream.
Some more cleanup is needed because some code was already far from
being clean. The server queue management still refers to sessions at
many places while comments talk about connections. This will have to
be cleaned up once we have a server-side connection pool manager.
Stream flags "SN_*" still need to be renamed, it doesn't seem like
any of them will need to move to the session.
These ones were found in the actions to set the query/path/method/uri.
Where it's used, "s" makes one think about session or something like
this, especially when mixed with http_txn.
hlua_run_sample_fetch() uses "struct hlua_smp *s" which starts to become
confusing when "s->s" is used, then hlua_txn_close() uses this for struct
hlua_txn with the same "s->s" everywhere. Let's uniformize everything with
htxn and hsmp as in other places.
Struct hlua_txn is called "htxn" or "ht" everywhere, while here it's
called "hs" which is the name used everywhere for struct "hlua_smp".
Such confusion participate to the dangers of copy-pasting code, so
let's fix the name here.
Last bug was an example of a side effect of abuse of copy-paste, but
there are other places at risk, so better fix all occurrences of sizeof
to really reference the object size in order to limit the risks in the
future.
In hlua_converters_new(), we used to allocate the size of an hlua_txn
instead of hlua_smp, resulting in random crashes with one integer being
randomly overwritten at the end, even when no converter is being used.
Lua supports a memory allocator. This is very important as it's the
only way we can control the amount of memory allocatable by Lua scripts.
That avoids prevents bogus scripts from eating all of the system's memory.
The value can be enforced using tune.lua.maxmem in the global section.
Thispatch adds global log function. Each log message is writed on
the stderr and is sent to the default syslog server. These two
actions are done according the configuration.
This class is accessible via the TXN object. It is created only if
the attached proxy have HTTP mode. It contain all the HTTP
manipulation functions:
- req_get_headers
- req_del_header
- req_rep_header
- req_rep_value
- req_add_header
- req_set_header
- req_set_method
- req_set_path
- req_set_query
- req_set_uri
- res_get_headers
- res_del_header
- res_rep_header
- res_rep_value
- res_add_header
- res_set_header
If the Lua code causes an infinite loop without yield possible, the
clock is not updated. This patch check the clock when the Lua control
code cannot yield.
When we explicitly write si[0] or si[1], we know whether we're working
with s->req or s->res, so better use that instead of si_ic/si_oc(), to
make the code simpler and more readable.
Some fetches uses a proxy name as first parameter. This is used to identify
frontend, backend or table. This first argument is declared as mandatory,
but the documentation says that is optional.
The behavior of the function smp_resolve_args() is to use the current proxy
if it match the required argument.
This patch implements the same behavior in the Lua argument checker for
sample-fetches and sample-converters.
The first argument in the stack is 1 and not 0. So the analyzer
starts at bad argument number, and the error message contains
also bad argument number.
It was inappropriate to put this flag on every failed write into an
input buffer because it depends where it happens. When it's in the
context of an analyser (eg: hlua) it makes sense. When it's in the
context of an applet (eg: dumpstats), it does not make sense, and
it only happens to work because currently applets are scheduled by
the sessions. The proper solution for applets would be to add the
flag SI_FL_WAIT_ROOM on the stream interface.
Thus, we now don't set any flag anymore in bi_put* and it's up to the
caller to either set CF_WAKE_WRITE on the channel or SI_FL_WAIT_ROOM
on the stream interface. Changes were applied to hlua, peers and
dumpstats.
This struct used to carry only a sample fetch function. Thanks to
lua_pushuserdata(), we don't need to have the Lua engine allocate
that struct for us and we can simply push our pointer onto the stack.
This makes the code more readable by removing several occurrences of
"f->f->". Just like the previous patch, it comes with the nice effect
of saving about 1.3% of performance when fetching samples from Lua.
Since last cleanups, this one was only used to carry a struct channel.
Removing it makes the code a bit cleaner (no more chn->chn) and easier
to follow (no more abstraction for a common type). Interestingly it
happens to also make the Lua code slightly faster (about 1.5%) when
using channels, probably thanks to less pointer dereferences and maybe
the use of lua_pushlightuserdata().
Now that we can get the session from the channel, let's simplify the
prototype of session_alloc_recv_buffer() to only require the channel.
Both the caller and the function are now simplified.
These 4 combinations are needlessly complicated since the session already
has direct access to the associated stream interfaces without having to
check an indirect pointer.
The purpose of these two macros will be to pass via the session to
find the relevant stream interfaces so that we don't need to store
the ->cons nor ->prod pointers anymore. Currently they're only defined
so that all references could be removed.
Note that many places need a second pass of clean up so that we don't
have any chn_prod(&s->req) anymore and only &s->si[0] instead, and
conversely for the 3 other cases.
At a few places we need to find one stream interface from the other one.
Instead of passing via the channel, we simply use the session as an
intermediary, which simply results in applying an offset to the pointer.
This new flag "SI_FL_ISBACK" is set only on the back SI and is cleared
on the front SI. That way it's possible only by looking at the SI to
know what side it is.
We'll soon remove direct references to the channels from the stream
interface since everything belongs to the same session, so let's
first not dereference si->ib / si->ob anymore and use macros instead.
The channels were pointers to outside structs and this is not needed
anymore since the buffers have moved, but this complicates operations.
Move them back into the session so that both channels and stream interfaces
are always allocated for a session. Some places (some early sample fetch
functions) used to validate that a channel was NULL prior to dereferencing
it. Now instead we check if chn->buf is NULL and we force it to remain NULL
until the channel is initialized.
In some cases we don't want to known if a fetch or converter
fails. We just want a valid string. After this patch, we
have two sets of fetches and two sets of converters. There are:
txn.f, txn.sf, txn.c, txn.sc. The version prefixed by 's' always
returns strings for any type, and returns an empty string in the
error case or when the data are not available. This is particularly
useful when manipulating headers or cookies.
To add data in channel, it is necessary to process in two times.
First time, get the channel object, and after send data:
local req = txn:req_channel()
req:send("data\n")
Now, the function is converted as a variable containing the req
and res aobject. We can process as following:
txn.req:send("data\n")
This patch implements a wrapper to give access to the converters
in the Lua code. The converters are used with the transaction.
The automatically created function are prefixed by "conv_".
HAProxy proposes many sample fetches. It is possible that the
automatic registration of the sample fetches causes a collision
with an existing Lua function. This patch sets a namespace for
the sample fetches.
Actually an object is just a userdata value with a metatable.
This mode causes some problems like I can't add lua own data.
This new model uses an array as object base, and affect the
userdata at the index 0.
The core entry is just a collection of function, it doesn't depends on
special variable. This patch just converts an object contained in a
metatable in object contained in a normal table.
A few function names in Lua had underscores which did not appear in their
C counterpart. Since almost all of them already had similar names, better
uniformize the naming convention.
For now we don't perform any operation on IP addresses, so at least
we'd like to be able to pass them as strings so that we can log them
or whatever in Lua. Without this patch txn.src(txn) returns "nil" and
now it returns the correct IP address.
Lua 5.3 provides an opaque space associated with each
coroutine stack. This patch uses this lot of memory to
store the "struct hlua *" associated pointer.
This patch makes the retrieval of the "struct hlua *"
associated struct faster because it replace a lookup in
a tree by an immediate access to the data.
This reverts commit cd9084f776.
This commit introduced a regression making it impossible to leave
process_session() during a forced yield because the analyser was always
set on the response even if not needed. The result was a busy loop
making haproxy spin at 100% without even polling anymore in case a
forced yield was performed.
The problem it tried to address (intercept response data from a request
analyser before forwarding) is not a trivial issue to address since
wakeups based on reads will not necessarily happen unless there's write
activity.
Anyway, if functions are attached specifically to a request or to a
response, it's for a reason. So for now let's be clear about the fact
that it's unreliable to try to process data from the opposite channel
until a better solution is found.
This patch fix the Lua library check. Only the version
5.3 or later is allowed.
This bug is added by the patch "MEDIUM: lua: use the
Lua-5.3 version of the library" with commit id
f90838b71a
Specs says that the receive() function with an argument "*l"
must return a line without the final "\n" ( or without "\r\n").
This patch removes these two final bytes.
When we try to write data in a session from another session, the "req"
buffer is not allowed. This patch try to allocate the buffer. The session
wait if the buffer is not yet avalaible.
When a socket is initilized in the body context, a segfaut is generated
because the memory pools are not initilized. This atch check if these
memory pool are initialized.
The function buffer_contig_space() returns the contiguous space avalaible
to add data (at the end of the input side) while the function
hlua_channel_send_yield() needs to insert data starting at p. Here we
introduce a new function bi_space_for_replace() which returns the amount
of space that can be inserted at the head of the input side with one of
the buffer_replace* functions.
This patch proposes a function that returns the space avalaible after buf->p.
The request action can't handle the reponse trafic because its
automatically forwarded. The forard with CHN_INFINITE_FORWARD
is set because any anamizers are registered on the response
channel.
This patch automatically register the request analyzer on the
reponse channel when its yield. This prevent the automatic
tranfer of the response bytes.
The hook function called each nth Lua instructions just
do a yield. Sometimes this yield is not allowed, because
some functions are not compatible.
The Lua-5.3 permits to known if the yield is avalaible with
the function lua_isyieldable().
If the processing is interrupted in non yieldable state,
we try to execute a yield asap. The yield will be may
available at the end of the non-yieldable currently
executed function. So, we require interrupt at the end
of the current function.
But, Lua cannot yield when its returning from a function,
so, we can fix the interrupt hook to 1 instruction,
expecting that the function is finnished.
During this time, the execution timeout is always checked.
The Lua-5.3 version of the library adds a required function to fix
a bug with the forced-yield system.
This patch permits to build with the Lua-5.3 library. Main changes
are:
- "unsigned" type disappear to be replaced by signed type,
- prototype of the yield function callback changes.
First we allow to use the reserved size to write the data that
will be sent. The reserved size remain guaranty because the
writed data will be sent quickly and the reserved room we be
again avalaible.
This permits to guaranty that the function send always have
avalaible space to send data (except if it cannot connect to
the server).
The function buffer_replace2 works only on contiguous buffer.
This patch also detects if the required size is contiguous.
If it not the case we realign the buffer.
If we are writing in the request buffer, we are not waked up
when the data are forwarded because it is useles. The request
analyzers are waked up only when data is incoming. So, if the
request buffer is full, we set the WAKE_ON_WRITE flag.
Before this patch, each yield in a Lua action set a flags to be
waked up when some activity were detected on the response channel.
This behavior causes loop in the analyzer process.
This patch set the wake up on response buffer activity only if we
really want to be waked up on this activity.
This patch reset the flags except th run flag before resuming
the Lua execution. If this initialisation is not done, some
flags can remain at the end of the Lua execution and give bad
informations.
Check if the buffer is avalaible because HAProxy doesn't allocate
the request buffer if its not required. Sometimes, the Lua need to
write some data to the server before that the client send his data.
This patch check the expiration of the execution timeout for each
yield source, and test also the execution timeout before resuming
the execution of the Lua code.
This patch permits to interrupt the Lua execution each n# of
instructions. It is useful for controling the execution time
of an Lua code, and permits at the HAProxy schedule to process
some others tasks waiting execution.
This flag indicate that the current yield is returned by the Lua
execution task control. If this flag is set, the current task may
quit but will be set in the run queue to be re-executed immediatly.
This patch modify the "hlua_yieldk()" function, it adds an argument
that contain a field containing yield options.
This is used to ensure that the task doesn't become a zombie
when the Lua returns a yield. The yield wrapper ensure that an
timer used for waking up the task will be set.
The timer is reseted to TICK_ETERNITY if the Lua execution is
done.
This first patch permits to cofigure the Lua execution exipiration.
This expiration is configured but it is not yet avalaible, it will
be add in a future patch.
In the future, the lua execution must return scheduling informations.
We want more than one flag, so I convert an integer used with an
enum into an interer used as bitfield.
In some cases the Lua "send" function fails. This is caused by the
return of "buffer_replace2()" is not tested. I checked avalaible space
in the buffer and I supposed than "buffer_replace2()" took all the
data. In some cases, "buffer_replace2()" cannot take the incoming
data, it returns the amount of data copied.
This patch check the amount of data really copied by "buffer_replace2()"
and advance the buffer with taking this value in account.
When a Lua script calls an internal haproxy sample fetch, it may segfault in
some conditions :
- when a fetch has no argument,
- when there is no room left to store the special type ARGT_STOP in the argument
list (this one shouldn't happen currently as there isn't any sample fetch with
enough arguments to fill the allocated buffer).
Example of Lua code which reproduces a segfault :
core.register_fetches("segfault", function(txn, ...)
return txn.req_ver(txn)
end)
haproxy Lua support begins with Lua 5.2. In order to ease the diagnostic on
compilation error, a preprocessor error is added when an incompatible version
is used.
The compatibility is determined by the presence of LUA_VERSION_NUM and its
magic value (502 for Lua 5.2.x).
Actually, the Lua context is always initilized in each
session, even if the session doesn't use Lua. This
behavior cause 5% performances loss.
This patch initilize the Lua only if it is use by the
session. The initialization is now on demand.
The code was a bit of a pain to follow because of this, especially
when some of it heavily relies on longjmp... This refreshing makes
it slightly easier to read.
This patch provides a yield function. This function permits to
give back the hand at the HAProxy scheduler. It is used when the
lua processing consumes a lot of time.
The channel class permits manipulation of channels. A channel is
an FIFO buffer between the client and the server. This class provides
function to read, write, forward, destroy and alter data between
the input and the ouput of the buffer.
This patch adds the TCP I/O functionnality. The class implemented
provides the same functions than the "lua socket" project. This
make network compatibility with another LUA project. The documentation
is located here:
http://w3.impa.br/~diego/software/luasocket/tcp.html
This version of sleep is based on a coroutine. A sleeping
task is started and a signal is registered. This sleep version
must disapear to be replaced by a version using the internal
timers.
This patch permits to write LUA converters. Note that
all the converters declared trough LUA are automatically
prefixed by "lua.".
The Lua converters needs the current session to be executed,
but the writed and executed Lua code must be static and
contextless. The TXN object is not created for the converters.
This patch adds the browsing of all the HAProxy fetches and
create associated LUA functions. The HAProxy internal fetches
can be used in LUA trough the class "TXN".
Note that the symbols "-", "+" and "." in the name of current
sample fetch are rewrited as "_" in LUA because ".", "-" and "+"
are operators.
The shared context is a global reference dedicated to one Lua stack.
Even if the TXN is not required, the shared context it is associated
with a TXN object. In fact, the shared has no sense outside a TXN
context
This class of functions permit to access to all the functions
associated with the transaction like http header, HAProxy internal
fetches, etc ...
This patch puts the skeleton of this class. The class will be
enhanced later.
This system permits to execute some lua function after than HAProxy
complete his initialisation. These functions are executed between
the end of the configuration parsing and check and the begin of the
scheduler.
This system permits to send signals between lua tasks. A main lua stack can
register the signal in a coprocess. When the coprocess finish his job, it
send a signal, and the associated task is wakes. If the main lua execution
stack stop (with or without errors), the list or pending signals is purged.
This is the first step of the lua integration. We add the useful
files in the HAProxy project. These files contains the main
includes, the Makefile options and empty initialisation function.
Is is the LUA skeleton.
