'httpclient' command does not properly handle full buffer cases. When the
response buffer is full, we exit to retry later. However, the context flags
are updated. It means when this happens, we may loose a part of the
response.
So now, flags are preserved when we fail to push data into the response
buffer. In addition, instead of dumping one part per call, we now try to
dump as much data as possible.
Finally, when there is no more data, because everything was dumped or
because we are waiting for more data from the HTTP client, the applet is
updated accordingly by calling applet_have_no_more_data(). Otherwise, when
some data are blocked, applet_putchk() already takes care to update the SE
flags. So, it is useless to call sc_need_room().
This patch should fix the issue #1723. It must be backported as far as
2.5. But a massive refactoring was performed in 2.6. So, for the 2.5 and
below, the patch will have to be adapted.
Commit 534645d6 ("BUG/MEDIUM: httpclient: Fix loop consuming HTX blocks from
the response channel") introduced a regression. When the response is
consumed, The HTX header blocks are removed before duplicating them. Thus,
the first header block is always lost.
This patch must be backported as far as 2.5.
There's no more reason for keepin the code and definitions in conn_stream,
let's move all that to stconn. The alphabetical ordering of include files
was adjusted.
This file contains all the stream-connector functions that are specific
to application layers of type stream. So let's name it accordingly so
that it's easier to figure what's located there.
The alphabetical ordering of include files was preserved.
An equivalent applet_need_more_data() was added as well since that function
is mostly used from applet code. It makes it much clearer that the applet
is waiting for data from the stream layer.
These functions were used by the channel to inform the lower layer
whether reading was acceptable or not. Usually this directly mimmicks
the CF_DONT_READ flag from the channel, which may be set when it's
desired not to buffer incoming data that will not be processed, or
that the buffer wants to be flushed before starting to read again,
or that bandwidth limiting might be enforced, etc. It's always a
policy reason, not a purely resource-based one.
The new name mor eclearly indicates that a stream connector cannot make
any more progress because it needs room in the channel buffer, or that
it may be unblocked because the buffer now has more room available. The
testing function is sc_waiting_room(). This is mostly used by applets.
Note that the flags will change soon.
These functions return the app-layer associated with an stconn, which
is a check, a stream or a stream's task. They're used a lot to access
channels, flags and for waking up tasks. Let's just name them
appropriately for the stream connector.
We're starting to propagate the stream connector's new name through the
API. Most call places of these functions that retrieve the channel or its
buffer are in applets. The local variable names are not changed in order
to keep the changes small and reviewable. There were ~92 uses of cs_ic(),
~96 of cs_oc() (due to co_get*() being less factorizable than ci_put*),
and ~5 accesses to the buffer itself.
This applies the change so that the applet code stops using ci_putchk()
and friends everywhere possible, for the much saferapplet_put*() instead.
The change is mechanical but large. Two or three functions used to have no
appctx and a cs derived from the appctx instead, which was a reminiscence
of old times' stream_interface. These were simply changed to directly take
the appctx. No sensitive change was performed, and the old (more complex)
API is still usable when needed (e.g. the channel is already known).
The change touched roughly a hundred of locations, with no less than 124
lines removed.
It's worth noting that the stats applet, the oldest of the series, could
get a serious lifting, as it's still very channel-centric instead of
propagating the appctx along the chain. Given that this code doesn't
change often, there's no emergency to clean it up but it would look
better.
This renames the "struct conn_stream" to "struct stconn" and updates
the descriptions in all comments (and the rare help descriptions) to
"stream connector" or "connector". This touches a lot of files but
the change is minimal. The local variables were not even renamed, so
there's still a lot of "cs" everywhere.
Now at least it makes it obvious that it's the stream endpoint descriptor
and not an endpoint. There were few changes thanks to the previous refactor
of the flags.
This changes all main uses of endp->flags to the se_fl_*() equivalent
by applying coccinelle script endp_flags.cocci. The se_fl_*() functions
themselves were manually excluded from the change, of course.
Note: 144 locations were touched, manually reviewed and found to be OK.
The script was applied with all includes:
spatch --in-place --recursive-includes -I include --sp-file $script $files
In httpclient_applet_init() function, ss_dst variable is always defined
before the call to sockaddr_alloc(). There is no reason to test it.
This patch should fix the issue #1706.
In the same way than for the tasks, the applets api was changed to be able
to start a new appctx on a thread subset. For now the feature is
disabled. Only appctx_new_here() is working. But it will be possible to
start an appctx on a specific thread or a subset via a mask.
A .init callback function is defined for the httpclient_applet applet. This
function finishes the appctx startup by calling appctx_finalize_startup()
and its handles the stream customization.
The session created for frontend applets is now totally owns by the
corresponding appctx. It means the appctx is now responsible to release
it. This removes the hack in stream_free() about frontend applets to be sure
to release the session.
The two functions became exact copies since there's no more special case
for the appctx owner. Let's merge them into a single one, that simplifies
the code.
This one is the pointer to the conn_stream which is always in the
endpoint that is always present in the appctx, thus it's not needed.
This patch removes it and replaces it with appctx_cs() instead. A
few occurences that were using __cs_strm(appctx->owner) were moved
directly to appctx_strm() which does the equivalent.
The few applets that set CS_EP_EOI or CS_EP_ERROR used to set it on the
endpoint retrieved from the conn_stream while it's already available on
the appctx itself. Better use the appctx one to limit the unneeded
interactions between the two sides.
The httpclient already uses its own pointer and only used to store this
single pointer into the appctx.ctx field. Let's just move it to the
svcctx and remove this entry from the appctx union.
The httpclient's CLI uses ctx.cli.i0 for its flags and .p0 for the client
instance. Let's have a locally defined structure for this so that we don't
need the generic cli variables anymore.
Try to create a "default" resolvers section at startup, but does not
display any error nor warning. This section is initialized using the
/etc/resolv.conf of the system.
This is opportunistic and with no guarantee that it will work (but it should
on most systems).
This is useful for the httpclient as it allows to use the DNS resolver
without any configuration in most of the cases.
The function is called from the httpclient_pre_check() function to
ensure than we tried to create the section before trying to initiate the
httpclient. But it is also called from the resolvers.c to ensure the
section is created when the httpclient init was disabled.
The httpclient.resolvers.prefer global keyword allows to configure an
ipv4 or ipv6 preference when resolving. This could be useful in
environment where the ipv6 is not supported.
By default the httpclient uses the resolvers section whose ID is
"default", the httpclient.resolvers.id global option allows to configure
another section to use.
The hard_error_ssl flag is set when the configuration is explicitely
done for the ssl in the httpclient.
If no configuration was made, the features are simply disabled and no
alert is emitted.
Cleanup the error handling in the initialization so we rely on the
ERR_CODE and use memprintf() to set the errmsg before printing it at the
end of the functions.
httpclient_set_dst() allows one to set the destination address instead
of using the one in the URL or resolving one from the host.
This function also support other types of socket like sockpair@, unix@,
anything that could be used on a server line.
In order to still support this behavior, the address must be set on the
backend in this particular case because the frontend connection does not
support anything other than ipv4 or ipv6.
To allow the http-request set-dst to work for the httpclient DNS
resolving, some changes need to be done:
- The destination address need to be set in the frontend (s->csf->dst)
instead of the backend (s->csb->dst) to be able to use
tcp_action_req_set_dst()
- SRV_F_MAPPORTS need to be set on the proxy in order to allow the port
change in alloc_dst_address()
The httpclient_resolve_init() adds http-request actions which does the
resolving using the Host header of the HTTP request.
The parse_http_req_cond function is directly used over an array of http
rules.
The do-resolve rule uses the "default" resolvers section. If this
section does not exist in the configuration, the resolving is disabling.
The httpclient DNS resolver will need a more efficient URL parser which
splits the URL into parts and does not try to resolve.
httpclient_spliturl uses the http_uri_parser in order to split the URL
into several ist.
The result of the function host part is then processed into str2ip2(),
and fails if it it not an IP, allowing us to resolve the domain later.
This flag is no longer needed now that it must always match the presence
of a destination address on the backend conn_stream. Worse, before previous
patch, if it were to be accidently removed while the address is present, it
could result in a leak of that address since alloc_dst_address() would first
be called to flush it.
Its usage has a long history where addresses were stored in an area shared
with the connection, but as this is no longer the case, there's no reason
for putting this burden onto application-level code that should not focus
on setting obscure flags.
The only place where that made a small difference is in the dequeuing code
in case of queue redistribution, because previously the code would first
clear the flag, and only later when trying to deal with the queue, would
release the address. It's not even certain whether there would exist a
code path going to connect_server() without calling pendconn_dequeue()
first (e.g. retries on queue timeout maybe?).
Now the pendconn_dequeue() code will rely on SF_ASSIGNED to decide to
clear and release the address, since that flag is always set while in
a server's queue, and its clearance implies that we don't want to keep
the address. At least it remains consistent and there's no more risk of
leaking it.
The use of co_set_data() should be strictly limited to setting the amount of
existing data to be transmitted. It ought not be used to decrement the
output after the data have left the buffer, because doing so involves
performing incorrect calculations using co_data() that still comprises data
that are not in the buffer anymore. Let's use c_rew() for this, which is
made exactly for this purpose, i.e. decrement c->output by as much as
requested.
When HTX blocks are transfer from the HTTP client context to the request
channel, via htx_xfer_blks() function, the metadata must also be counted, in
addition to the data size. Otherwise, expected payload size will not be
copied because the metadata of an HTX block (8 bytes) will be reserved. And
if the payload size is lower than 8 bytes, nothing will be copied. Thus only
a zero-copy will be able to copy the payload.
This issue is 2.6-specific, no backport is needed.
When the HTTP client consumes the response, it loops on the HTX message to
copy blocks content and it removes blocks by calling htx_remove_blk(). But
this function removes a block and returns the next one in the HTX
message. The result must be used instead of using htx_get_next(). It is
especially important because the block used in htx_get_next() loop was
removed. It only works because the message is not defragmented during the
loop.
In addition, the loop on the response was simplified to iter on blocks
instead of positions.
This patch must be backported to 2.5.
The SSL_SERVER_VERIFY_* constants were incorrectly set on the httpclient
server verify. The right constants are SSL_SOCK_VERIFY_* .
This could cause issues when using "httpclient-ssl-verify" or when the
SSL certificates can't be loaded.
No backport needed
Since the httpclient verify now has a fallback which disable the SSL in
the httpclient without exiting haproxy at startup, we can safely
re-enable it by default.
It could still be disabled with "httpclient-ssl-verify none".
Emit a warning when the ca-file couldn't be loaded for the httpclient,
and disable the SSL of the httpclient.
We must never be in a case where the verify is disabled without any
configuration, so better disable the SSL completely.
Move the check on the scheme above the initialization of the applet so
we could abort before initializing the appctx.
Disable temporary the SSL verify by default in the httpclient. The
initialization of the @system-ca during the init of the httpclient is a
problem in some cases.
The verify can be reactivated with "httpclient-ssl-verify required" in
the global section.
