Re-implement the QUIC mux. It will reuse the mechanics from the previous
mux without all untested/unsupported features. This should ease the
maintenance.
Note that a lot of features are broken for the moment. They will be
re-implemented on the following commits to have a clean commit history.
Commit 3d2093af9 ("MINOR: connection: Add a connection error code sample
fetch") added these convenient sample-fetch functions but it appears that
due to a misunderstanding the redundant "conn" part was kept in their
name, causing confusion, since "fc" already stands for "front connection".
Let's simply call them "fc_err" and "bc_err" to match all other related
ones before they appear in a final release. The VTC they appeared in were
also updated, and the alpha sort in the keywords table updated.
Cc: William Lallemand <wlallemand@haproxy.org>
Define a new stream flag SF_WEBSOCKET and a new cs flag CS_FL_WEBSOCKET.
The conn-stream flag is first set by h1/h2 muxes if the request is a
valid websocket upgrade. The flag is then converted to SF_WEBSOCKET on
the stream creation.
This will be useful to properly manage websocket streams in
connect_server().
Sometimes we'd like to do our best to drain pending data before closing
in order to save the peer from risking to receive an RST on close.
This adds a new connection flag CO_FL_WANT_DRAIN that is used to
trigger a call to conn_ctrl_drain() from conn_ctrl_close(), and the
sock_drain() function ignores fd_recv_ready() if this flag is set,
in order to catch latest data. It's not used for now.
No need to include the full tree management code, type files only
need the definitions. Doing so reduces the whole code size by around
3.6% and the build time is down to just 6s.
The hash type stored everywhere is XXH64_hash_t, which annoyingly forces
everyone to include the huge xxhash file. We know it's an uint64_t because
that's its purpose and the type is only made to abstract it on machines
where uint64_t is not availble. Let's switch the type to uint64_t
everywhere and avoid including xxhash from the type file.
In case of a connection error happening after the SSL handshake is
completed, the error code stored in the connection structure would not
always be set, hence having some connection failures being described as
successful in the fc_conn_err or bc_conn_err sample fetches.
The most common case in which it could happen is when the SSL server
rejects the client's certificate. The SSL_do_handshake call on the
client side would be sucessful because the client effectively sent its
client hello and certificate information to the server, but the next
call to SSL_read on the client side would raise an SSL_ERROR_SSL code
(through the SSL_get_error function) which is decribed in OpenSSL
documentation as a non-recoverable and fatal SSL error.
This patch ensures that in such a case, the connection's error code is
set to a special CO_ERR_SSL_FATAL value.
The transient flag CO_RFL_BUF_NOT_STUCK should now be set when the mux's
rcv_buf() function is called, in si_cs_recv(), to be sure the mux is able to
perform some optimisation during data copy. This flag is set when we are
sure the channel buffer is not stuck. Concretely, it happens when there are
data scheduled to be sent.
It is not a fix and this flag is not used for now. But it makes sense to have
this info to be sure to be able to do some optimisations if necessary.
This patch is related to the issue #1362. It may be backported to 2.4 to
ease future backports.
The flow control at stream level is organized by types (client bidi, server bidi,
client uni, server uni). Adds at least callback to retrieve the number
of available streams by direction.
The fc_conn_err and fc_conn_err_str sample fetches give information
about the problem that made the connection fail. This information would
previously only have been given by the error log messages meaning that
thanks to these fetches, the error log can now be included in a custom
log format. The log strings were all found in the conn_err_code_str
function.
listener-t comes with openssl just due to the SSL_CTX type that is
declred as a typedef in openssl hence cannot be abstracted at this
level. However connection-t.h doen't need all that just to know that
bind_conf is a struct. Let's declare it with other external types
instead..
When the abortonclose option is enabled, to be sure to be immediately
notified when a shutdown is received from the client, the frontend
conn-stream must be sure the mux will wait for read events. To do so, the
CO_RFL_KEEP_RECV flag is set when mux->rcv_buf() is called. This new flag
instructs the mux to wait for read events, regardless its internal state.
This patch is required to fix abortonclose option for H1 client connections.
Implement a safe mechanism to close front idling connection which
prevents the soft-stop to complete. Every h1/h2 front connection is
added in a new per-thread list instance. On shutdown, a new task is
waking up which calls wake mux operation on every connection still
present in the new list.
A new stopping_list attach point has been added in the connection
structure. As this member is only used for frontend connections, it
shared the same union as the session_list reserved for backend
connections.
Move the session_list attach point in an anonymous union. This member is
only used for backend connections. This commit is in preparation for the
support of stopping frontend idling connections which will add another
member to the union.
This change means that a special care must be taken to be sure that only
backend connections manipulate the session_list. A few BUG_ON has been
added as special guard to prevent from misuse.
MX_FL_NO_UPG flag may now be set on a multiplexer to explicitly disable
upgrades from this mux. For now, it is set on the FCGI multiplexer because
it is not supported and there is no upgrade on backend-only multiplexers. It
is also set on the H2 multiplexer because it is clearly not supported.
Now that connections aren't being reused when they failed, remove the
reset() method. It was unimplemented anywhere, except for H1 where it did
nothing, anyway.
Introduce a new XPRT method, start(). The init() method will now only
initialize whatever is needed for the XPRT to run, but any action the XPRT
has to do before being ready, such as handshakes, will be done in the new
start() method. That way, we will be sure the full stack of xprt will be
initialized before attempting to do anything.
The init() call is also moved to conn_prepare(). There's no longer any reason
to wait for the ctrl to be ready, any action will be deferred until start(),
anyway. This means conn_xprt_init() is no longer needed.
It was brought by commit c44b8de99 ("CLEANUP: connection: Use `VAR_ARRAY`
in `struct tlv` definition") but breaks the build with clang. Actually it
had already been done 6 months ago by commit 4987a4744 ("CLEANUP: tree-wide:
use VAR_ARRAY instead of [0] in various definitions") then reverted by
commit 441b6c31e ("BUILD: connection: fix build on clang after the VAR_ARRAY
cleanup") which explained the same thing but didn't place a comment in the
code to justify this (in short it's just an end of struct marker).
These functions are used on the mux layer to indicate that the connection
is becoming idle and that the xprt ought to be careful before checking the
context or that it's not idle anymore and that the context is safe. The
purpose is to allow a mux which is going to release a connection to tell
the xprt to be careful when touching it. At the moment, the xprt are
always careful and that's costly so we want to have the ability to relax
this a bit.
No xprt layer uses this yet.
If dispatch mode or transparent backend is used, the backend connection
target is a proxy instead of a server. In these cases, the reuse of
backend connections is not consistent.
With the default behavior, no reuse is done and every new request uses a
new connection. However, if http-reuse is set to never, the connection
are stored by the mux in the session and can be reused for future
requests in the same session.
As no server is used for these connections, no reuse can be made outside
of the session, similarly to http-reuse never mode. A different
http-reuse config value should not have an impact. To achieve this, mark
these connections as private to have a defined behavior.
For this feature to properly work, the connection hash has been slightly
adjusted. The server pointer as an input as been replaced by a generic
target pointer to refer to the server or proxy instance. The hash is
always calculated on connect_server even if the connection target is not
a server. This also requires to allocate the connection hash node for
every backend connections, not just the one with a server target.
Remove ebmb_node entry from struct connection and create a dedicated
struct conn_hash_node. struct connection contains now only a pointer to
a conn_hash_node, allocated only for connections where target is of type
OBJ_TYPE_SERVER. This will reduce memory footprints for every
connections that does not need http-reuse such as frontend connections.
Use the proxy protocol frame if proxy protocol is activated on the
server line. Do not add anymore these connections in the private list.
If some requests are made with the same proxy fields, they can reuse
the idle connection.
The reg-tests proxy_protocol_send_unique_id must be adapted has it
relied on the side effect behavior that every requests from a same
connection reused a private server connection. Now, a new connection is
created as expected if the proxy protocol fields differ.
The source address is used as an input to the the server connection hash. The
address and port are used as separate hash inputs. Do not add anymore these
connections in the private list.
This parameter is set only if used in the transparent-proxy mode.
The destination address is used as an input to the server connection hash. The
address and port are used as separated hash inputs. Note that they are not used
when statically specified on the server line. This is only useful for dynamic
destination address.
This is typically used when the server address is dynamically set via the
set-dst action. The address and port are separated hash parameters.
Most notably, it should fixed set-dst use case (cf github issue #947).
The sni parameter is an input to the server connection hash. Do not add
anymore connections with dynamic sni in the private list. Thus, it is
now possible to reuse a server connection if they use the same sni.
The pointer of the target server is used as a first parameter for the
server connection hash calcul. This prevents the hash to be null when no
specific parameters are present, and can serve as a simple defense
against an attacker trying to reuse a non-conform connection.
This is a preliminary work for the calcul of the backend connection
hash. A structure conn_hash_params is the input for the operation,
containing the various specific parameters of a connection.
The high bits of the hash will reflect the parameters present as input.
A set of macros is written to manipulate the connection hash and extract
the parameters/payload.
The server idle/safe/available connection lists are replaced with ebmb-
trees. This is used to store backend connections, with the new field
connection hash as the key. The hash is a 8-bytes size field, used to
reflect specific connection parameters.
This is a preliminary work to be able to reuse connection with SNI,
explicit src/dst address or PROXY protocol.
This is a preparation work for connection reuse with sni/proxy
protocol/specific src-dst addresses.
Protect every access to idle conn lists with a lock. This is currently
strictly not needed because the access to the list are made with atomic
operations. However, to be able to reuse connection with specific
parameters, the list storage will be converted to eb-trees. As this
structure does not have atomic operation, it is mandatory to protect it
with a lock.
For this, the takeover lock is reused. Its role was to protect during
connection takeover. As it is now extended to general idle conns usage,
it is renamed to idle_conns_lock. A new lock section is also
instantiated named IDLE_CONNS_LOCK to isolate its impact on performance.
The MUX_ES_NOTIMPL_ERR exit status is added to allow the multiplexers to
report errors about not implemented features. This will be used by the H1
mux to return 501-not-implemented errors.
Now the show_fd helpers at the transport and mux levels return an integer
which indicates whether or not the inspected entry looks suspicious. When
an entry is reported as suspicious, "show fd" will suffix it with an
exclamation mark ('!') in the dump, that is supposed to help detecting
them.
For now, helpers were adjusted to adapt to the new API but none of them
reports any suspicious entry yet.
Just like we did for the muxes, now the transport layers will have the
ability to provide helpers to report more detailed information about their
internal context. When the helper is not known, the pointer continues to
be dumped as-is if it's not NULL. This way a transport with no context nor
dump function will not add a useless "xprt_ctx=(nil)" but the pointer will
be emitted if valid or if a helper is defined.
This is from the output of codespell. It's done at once over a bunch
of files and only affects comments, so there is nothing user-visible.
No backport needed.
This is a simple patch to prepare the integration of QUIC support to come.
quic_conn struct is supposed to embed any QUIC specific information for a QUIC
connection.
The ctl param MUX_EXIT_STATUS can be request to get the exit status of a
multiplexer. For instance, it may be an HTTP status code or an H2 error. For
now, 0 is always returned. When the mux h1 will be able to return HTTP
errors itself, this ctl param will be used to get the HTTP status code from
the logs.
the mux_exit_status enum has been created to map internal mux exist status
to generic one. Thus there is 5 possible status for now: success, invalid
error, timeout error, internal error and unknown.
This callback function was only defined by the mux-h1. But it has been
removed in the previous commit because it is unused now. So, we can do a
step forward removing the callback function from the mux definition and the
cs_info structure.
A few structures were slightly rearranged in order to plug some holes
left around the locks. Sizes ranging from 8 to 32 bytes could be saved
depending on the structures. No performance difference was noticed (none
was expected there), though memory usage might be slightly reduced in
some rare cases.
accept_conn() will be used to accept an incoming connection and return it.
It will have to deal with various error codes. The currently identified
ones were created as CO_AC_*.
Commit 4987a4744 ("CLEANUP: tree-wide: use VAR_ARRAY instead of [0] in
various definitions") broke the build on clang due to the tlv field used
to receive/send the proxy protocol. The problem is that struct tlv is
included at the beginning of struct tlv_ssl, which doesn't make much
sense. In fact the value[] array isn't really a var array but just an
end of struct marker, and must really be an array of size zero.
Surprisingly there were still a number of [0] definitions for variable
sized arrays in certain structures all over the code. We need to use
VAR_ARRAY instead of zero to accommodate various compilers' preferences,
as zero was used only on old ones and tends to report errors on new ones.
When we takeover a connection, let the xprt layer know. If it has its own
tasklet, and it is already scheduled, then it has to be destroyed, otherwise
it may run the new mux tasklet on the old thread.
Note that we only do this for the ssl xprt for now, because the only other
one that might wake the mux up is the handshake one, which is supposed to
disappear before idle connections exist.
No backport is needed, this is for 2.2.
