Commit Graph

498 Commits

Author SHA1 Message Date
Stefan Eissing
1454aa17d6
http2: do not delay RST send on aborted transfer
When a transfer is done prematurely, a RST is generated to the server,
but was not send right away due to send buffering.

Flush the send buffer in a best effort when transfer is done.

Reported-by: Michael Kaufmann
Fixes #17611
Closes #17638
2025-06-17 11:57:56 +02:00
Stefan Eissing
20c90ba298
lib: unify recv/send function signatures
cfilter/conn: change send/recv function signatures. Unify the
calling/return conventions in our send/receive handling.

Curl_conn_recv(), adjust pnread type

Parameter `pnread` was a `ssize_t *`, but `size_t *` is better since the
function returns any error in its `CURLcode` return value.

Closes #17546
2025-06-11 11:21:10 +02:00
Daniel Stenberg
255aac56f9
curlx: move into to curlx/
Move curlx_ functions into its own subdir.

The idea is to use the curlx_ prefix proper on these functions, and use
these same function names both in tool, lib and test suite source code.
Stop the previous special #define setup for curlx_ names.

The printf defines are now done for the library alone. Tests no longer
use the printf defines. The tool code sets its own defines. The printf
functions are not curlx, they are publicly available.

The strcase defines are not curlx_ functions and should not be used by
tool or server code.

dynbuf, warnless, base64, strparse, timeval, timediff are now proper
curlx functions.

When libcurl is built statically, the functions from the library can be
used as-is. The key is then that the functions must work as-is, without
having to be recompiled for use in tool/tests. This avoids symbol
collisions - when libcurl is built statically, we use those functions
directly when building the tool/tests. When libcurl is shared, we
build/link them separately for the tool/tests.

Assisted-by: Jay Satiro

Closes #17253
2025-05-07 11:01:15 +02:00
Stefan Eissing
657aae79c0
lib: add meta_hash to connection, eliminate hash_offt
With a meta_hash at each connection (similar to easy handle, let
multi_ev.c store its pollsets as meta data, no longer needing its own
hashes.

This eliminates the last use of Curl_hash_offt. Remove it.

Closes #17095
2025-04-22 15:57:18 +02:00
Stefan Eissing
909af1a43b
multi: do transfer book keeping using mid
Change multi's book keeping of transfers to no longer use lists, but a
special table and bitsets for unsigned int values.

`multi-xfers` is the `uint_tbl` where `multi_add_handle()` inserts a new
transfer which assigns it a unique identifier `mid`. Use bitsets to keep
track of transfers that are in state "process" or "pending" or
"msgsent".

Use sparse bitsets to replace `conn->easyq` and event handlings tracking
of transfers per socket. Instead of pointers, keep the mids involved.

Provide base data structures and document them in docs/internal:
* `uint_tbl`: a table of transfers with `mid` as lookup key,
   handing out a mid for adds between 0 - capacity.
* `uint_bset`: a bitset keeping unsigned ints from 0 - capacity.
* `uint_spbset`: a sparse bitset for keeping a small number of
  unsigned int values
* `uint_hash`: for associating `mid`s with a pointer.

This makes the `mid` the recommended way to refer to transfers inside
the same multi without risk of running into a UAF.

Modifying table and bitsets is safe while iterating over them. Overall
memory requirements are lower as with the double linked list apprach.

Closes #16761
2025-04-17 17:28:38 +02:00
Stefan Eissing
5fbd78eb2d
http2: fix stream window size after unpausing
When pausing a HTTP/2 transfer, the stream's local window size
is reduced to 0 to prevent the server from sending further data
which curl cannot write out to the application.

When unpausing again, the stream's window size was not correctly
increased again. The attempt to trigger a window update was
ignored by nghttp2, the server never received it and the transfer
stalled.

Add a debug feature to allow use of small window sizes which
reproduces this bug in test_02_21.

Fixes #16955
Closes #16960
2025-04-05 14:54:40 +02:00
Stefan Eissing
1f844dd3f0
http2: fix stream assignemnt for pushes
When a PUSH_PROMISE was received, the h2_stream object was assigned
to the wrong `newhandle->mid` and was thereafter not found. This led
to internal confusion, because the nghttp2 stream user_data was not
cleared and an invalid easy handle was use for trace messages,
resulting in a crash.

Reported-by: Viktor Szakats
Fixes #16881
Closes #16905
2025-04-01 14:19:27 +02:00
Viktor Szakats
f4e23950c7
build: enable -Wcast-qual, fix or silence compiler warnings
The issues found fell into these categories, with the applied fixes:

- const was accidentally stripped.
  Adjust code to not cast or cast with const.

- const/volatile missing from arguments, local variables.
  Constify arguments or variables, adjust/delete casts. Small code
  changes in a few places.

- const must be stripped because an API dependency requires it.
  Strip `const` with `CURL_UNCONST()` macro to silence the warning out
  of our control. These happen at API boundaries. Sometimes they depend
  on dependency version, which this patch handles as necessary. Also
  enable const support for the zlib API, using `ZLIB_CONST`. Supported
  by zlib 1.2.5.2 and newer.

- const must be stripped because a curl API requires it.
  Strip `const` with `CURL_UNCONST()` macro to silence the warning out
  of our immediate control. For example we promise to send a non-const
  argument to a callback, though the data is const internally.

- other cases where we may avoid const stripping by code changes.
  Also silenced with `CURL_UNCONST()`.

- there are 3 places where `CURL_UNCONST()` is cast again to const.
  To silence this type of warning:
  ```
  lib/vquic/curl_osslq.c:1015:29: error: to be safe all intermediate
    pointers in cast from 'unsigned char **' to 'const unsigned char **'
    must be 'const' qualified [-Werror=cast-qual]
  lib/cf-socket.c:734:32: error: to be safe all intermediate pointers in
    cast from 'char **' to 'const char **' must be 'const' qualified
    [-Werror=cast-qual]
  ```
  There may be a better solution, but I couldn't find it.

These cases are handled in separate subcommits, but without further
markup.

If you see a `-Wcast-qual` warning in curl, we appreciate your report
about it.

Closes #16142
2025-03-10 22:30:15 +01:00
Stefan Eissing
e542fd9da1
http2: detect session being closed on ingress handling
nghttp2 will on its own send GOAWAY frames, closing the connection, when
internal processing of frames runs into errors. This may not become
visible in a direct error code from a call to nghttp2.

Check for session being closed on ingress processing (on sending, we
already did that) and report an error if so. In addition, monitor
outgoing GOAWAY not initiated by us so that the user will get a fail
message when that happens.

Add some more long response header tests.

Closes #16544
2025-03-05 10:59:27 +01:00
Stefan Eissing
aa042210d9
http2: add on_invalid_frame callback for error detection
When the server sends HEADER/CONTINUATION frames that exceed nghttp2's
size, this error is being reported via the on_invalid_frame_recv
callback. Without registering there, it will go unnoticed.

RST the stream when such a frame is encountered.

Closes #16544
2025-03-05 10:59:19 +01:00
Stefan Eissing
e7de83aa29
http2: reset stream on response header error
We send a GOAWAY, but some servers ignore that and happily continue
sending the stream response. RST the stream when response header errors
are encountered.

Fixes #16535
Reported-by: Peng-Yu Chen
Closes #16544
2025-03-05 10:58:52 +01:00
Peng-Yu Chen
f61b218e7d
http2: enhance error messages on Curl_dyn* upon receiving headers
This is a partial fix of #16535. The error message format is borrowed
from the existing code[1].

Sample message before:
    curl: (56) process_pending_input: nghttp2_session_mem_recv() returned -902:The user callback function failed

Sample message after:
    curl: (56) Error receiving HTTP2 header: 100(A value or data field grew larger than allowed)

[1]: df672695e5/lib/http2.c (L1999-L2000)

Closes #16536
2025-03-03 10:30:54 +01:00
Stefan Eissing
1aa69221be
hash_offt: standalone hash for curl_off_t
Add a standalong hash table for curl_offt_t as key. This allows a
smaller memory footprint and faster lookups as we do not need to deal
with variable key lengths.

Use in all places we had the standard hash for this purpose.

Closes #16442
2025-03-01 18:42:10 +01:00
Stefan Eissing
f78700814d
client writer: handle pause before deocding
Adds a "cw-pause" client writer in the PROTOCOL phase that buffers
output when the client paused the transfer. This prevents content
decoding from blowing the buffer in the "cw-out" writer.

Added test_02_35 that downloads 2 100MB gzip bombs in parallel and
pauses after 1MB of decoded 0's.

This is a solution to issue #16280, with some limitations:
- cw-out still needs buffering of its own, since it can be paused
  "in the middle" of a write that started with some KB of gzipped
  zeros and exploded into several MB of calls to cw-out.
- cw-pause will then start buffering on its own *after* the write
  that caused the pause. cw-pause has no buffer limits, but the
  data it buffers is still content-encoded.
  Protocols like http/1.1 stop receiving, h2/h3 have window sizes,
  so the cw-pause buffer should not grow out of control, at least
  for these protocols.
- the current limit on cw-out's buffer is ~75MB (for whatever
  historical reason). A potential content-encoding that blows 16KB
  (the common h2 chunk size) into > 75MB would still blow the buffer,
  making the transfer fail. A gzip of 0's makes 16KB into ~16MB, so
  that still works.

A better solution would be to allow CURLE_AGAIN handling in the client
writer chain and make all content encoders handle that. This would stop
explosion of encoding on a pause right away. But this is a large change
of the deocoder operations.

Reported-by: lf- on github
Fixes #16280
Closes #16296
2025-02-20 15:53:18 +01:00
Stefan Eissing
279a4772ae
http: negotiation and room for alt-svc/https rr to navigate
Add a 'wanted' major HTTP version bitmask next to the 'allowed' bitmask
in HTTP version negotiation. This will try connections as specified in
'wanted', but enabled Alt-Svc and HTTPS-RR to redirect to other major
HTTP versions, if those are 'allowed'.

Changes libcurl internal default to `CURL_HTTP_VERSION_NONE` and removes
the code in curl that sets `CURL_HTTP_VERSION_2TLS` if the command line
does not say anything else.

Closes #16117
2025-02-20 15:45:46 +01:00
Stefan Eissing
a1850ad7de
cfilter: remove 'blocking' connect handling
Remove `blocking` argument from cfilter's connect method.

Implement blocking behaviour in Curl_conn_connect() instead for all
filter chains.

Update filters implementations. Several of which did never use the
paramter (QUIC for example). Simplifies connect handling in TLS filters
that no longer need to loop

Fixed a blocking connect call in FTP when waiting on a socket accept()
which only worked because the filter did not implement it.

Closes #16397
2025-02-20 11:13:51 +01:00
Viktor Szakats
3fd1dfc829
tidy-up: use CURL_ARRAYSIZE()
Follow-up to 13b2ea68f0 #16111

Closes #16381
2025-02-19 00:59:45 +01:00
Stefan Eissing
db72b8d4d0
http: version negotiation
Translate the `data->set.httpwant` which is one of the consts from the
public API (CURL_HTTP_VERSION_*) into a major version mask plus
additional flags for internal handling.

`Curl_http_neg_init()` does the translation and flags setting in http.c,
using new internal consts CURL_HTTP_V1x, CURL_HTTP_V2x and CURL_HTTP_V3x
for the major versions. The flags are

- only_10: when the application explicity asked fro HTTP/1.0
- h2_upgrade: when the application asks for upgrading 1.1 to 2.
- h2_prior_knowledge: when directly talking h2 without ALPN
- accept_09: when a HTTP/0.9 response is acceptable.

The Alt-Svc and HTTPS RR redirections from one ALPN to another obey the
allowed major versions. If a transfer has only h3 enabled, Alt-Svc
redirection to h2 is ignored.

This is the current implementation. It can be debated if Alt-Svc should
be able to override the allowed major versions. Added test_12_06 to
verify the current restriction.

Closes #16100
2025-02-18 16:10:12 +01:00
Daniel Stenberg
edd013326d
lib: strtoofft.h header cleanup
Drop the include from five C files, add it to one.

Closes #16331
2025-02-14 10:30:39 +01:00
Stefan Eissing
5b73a7b637
http2: fix data_pending check
The h2 filter mistakenly also checked `sendbuf` when asked
about pending data. The call is only meant to account for
buffered data that still needs to be received.

Also, remove obsolete recvbuf in stream as we write received
headers and data directly.

Fixes #16084
Closes #16098
Reported-by: Deniz Sökmen
2025-01-27 15:46:33 +01:00
Stefan Eissing
e83818cae1
lib: clarify 'conn->httpversion'
The variable `conn->httpversion` was used for several purposes and it
was unclear at which time the value represents what.

- rename `conn->httpversion` to `conn->httpversion_seen`
  This makes clear that the variable only records the last
  HTTP version seen on the connection - if any. And that it
  no longer is an indication of what version to use.
- Change Alt-Svc handling to no longer modify `conn->httpversion`
  but set `data->state.httpwant` for influencing the HTTP version
  to use on a transfer.
- Add `data->req.httpversion_sent` to have a record of what
  HTTP version was sent in a request
- Add connection filter type CF_TYPE_HTTP
- Add filter query `CF_QUERY_HTTP_VERSION` to ask what HTTP
  filter version is in place
- Lookup filters HTTP version instead of using `conn->httpversion`

Test test_12_05 now switches to HTTP/1.1 correctly and the
expectations have been fixed.

Removed the connection fitler "is_httpN()" checks and using
the version query instead.

Closes #16073
2025-01-24 10:59:02 +01:00
Stefan Eissing
cd9107e012
cfilters: kill connection filter events attach+detach
Make transfer attach/detach to/from connections chepaer.

- the "attach" event was no longer implemented by any filter
- the "detach" did the same as the "done" event for the filters
  who still implemented it. It should be superfluous as the "done"
  must always happen.

Closes #16067
2025-01-22 08:28:38 +01:00
Viktor Szakats
5474d70c3e
tidy-up: drop parenthesis around return expression
Closes #15990
2025-01-14 12:11:42 +01:00
Viktor Szakats
fabfa8e402
clang-tidy: add to CI, add cmake support, fix fallouts
build:
- autotools: fix to build generated sources for the `tidy` target.
- autotools: allow passing custom clang-tidy options via
  `CURL_CLANG_TIDYFLAGS` env.
- cmake: add `CURL_CLANG_TIDY` option to configure for `clang-tidy`.
  Also add:
  - `CLANG_TIDY` variable to customize the `clang-tidy` tool.
  - `CURL_CLANG_TIDYFLAGS` to pass custom options to `clang-tidy`.
- apply `--enable-werror` and `-DCURL_WERROR=ON` to `clang-tidy`.

CI/GHA:
- add clang-tidy job for Linux, using autotools and clang-tidy v18.
  This one needs to disable `clang-analyzer-valist.Uninitialized`
  to avoid false positives:
  https://github.com/llvm/llvm-project/issues/40656
  Duration: 5.5 minutes
- add clang-tidy job for macOS, using cmake and clang-tidy v19.
  This one also covers tests and examples, and doesn't hit the false
  positives seen with llvm v18 and earlier.
  Duration: 4.5 minutes
- Linux/macOS: skip installing test dependencies when not building or
  running tests.

fix fallouts reported by `clang-tidy`:
- lib:
  - cf-h2-proxy: unused assignment in non-debug builds.
  - cf-socket: silence warning.
    FIXME: https://github.com/curl/curl/pull/15825#issuecomment-2561867769
  - ftp: NULL passed to `strncmp()`.
  - http2: NULL-ptr deref.
  - mprintf: silence warning.
- src/tool_writeout: NULL passed to `fputs()`.
- examples:
  - invalid file pointers.
  - missing `fclose()`.
- tests:
  - http/clients/hx-download: memory leaks on error.
  - http/clients/hx-download: memory leak on repeat `-r` option.
  - server: double `fclose()`.
    https://www.man7.org/linux/man-pages/man3/fclose.3.html
  - server: invalid file pointer/handle.
  - server/getpart: unused assignments.
  - server/mqttd: leak on failed `realloc()`.
  - server/tftpd: NULL passed to `strcmp()`.

Closes #15825
2024-12-27 13:42:32 +01:00
Daniel Stenberg
ebcf3d20d7
http2: fix value stored to 'result' is never read
Detected by clang-tidy

Closes #15806
2024-12-23 08:27:28 +01:00
Ethan Everett
9089ef1f4f
nghttp2: use custom memory functions
Provide libcurl's memory functions as callbacks to replace nghttp2's own memory
functions. This allows custom memory callbacks provided by users of libcurl to
be used by nghttp2 as well.

Closes #15527
2024-11-08 23:20:32 +01:00
Daniel Stenberg
522c89a134
lib: remove Curl_ prefix from static functions
'Curl_' is a prefix used for library global functions (cross-files).
Static functions should thus not use it.

Closes #15419
2024-10-27 10:57:21 +01:00
Stefan Eissing
fe2a72029e
http2: auto reset stream on server eos
When a server signals EOS from its side and the curl upload is
unfinished and the server has not given a positive HTTP status response,
auto RST the stream to signal that the upload is incomplete and that the
whole transfer can be stopped.

Fixes the case where the server responds with 413 on an upload but does
not RST the stream from its side, as httpd and others do.

Reported-by: jkamp-aws on github
Fixes #15316
Closes #15325
2024-10-17 23:03:41 +02:00
Stefan Eissing
962097b8dd
TLS: TLSv1.3 earlydata support for curl
Based on #14135, implement TLSv1.3 earlydata support for the curl
command line, libcurl and its implementation in GnuTLS.

If a known TLS session announces early data support, and the feature is
enabled *and* it is not a "connect-only" transfer, delay the TLS
handshake until the first request is being sent.

- Add --tls-earldata as new boolean command line option for curl.
- Add CURLSSLOPT_EARLYDATA to libcurl to enable use of the feature.
- Add CURLINFO_EARLYDATA_SENT_T to libcurl, reporting the amount of
  bytes sent and accepted/rejected by the server.

Implementation details:
- store the ALPN protocol selected at the SSL session.
- When reusing the session and enabling earlydata, use exactly
  that ALPN protocol for negoptiation with the server. When the
  sessions ALPN does not match the connections ALPN, earlydata
  will not be enabled.
- Check that the server selected the correct ALPN protocol for
  an earlydata connect. If the server does not confirm or reports
  something different, the connect fails.
- HTTP/2: delay sending the initial SETTINGS frames during connect,
  if not connect-only.

Verification:
- add test_02_32 to verify earlydata GET with nghttpx.
- add test_07_70 to verify earlydata PUT with nghttpx.
- add support in 'hx-download', 'hx-upload' clients for the feature

Assisted-by: ad-chaos on github
Closes #15211
2024-10-11 12:28:22 +02:00
Daniel Stenberg
bcec0840b0
lib: use bool/TRUE/FALSE properly
booleans should use the type 'bool' and set the value to TRUE/FALSE

non-booleans should not be 'bool' and should not set the value to
TRUE/FALSE

Closes #15123
2024-10-03 09:31:56 +02:00
Daniel Stenberg
aca28abac7
lib: fix disabled-verbose-strings + enable-debug build warnings 2024-09-27 13:20:25 +02:00
Daniel Stenberg
fbf5d507ce
lib/src: white space edits to comply better with code style
... as checksrc now finds and complains about these.

Closes #14921
2024-09-19 14:59:12 +02:00
Gabriel Marin
5a263710f6
lib, src, tests: added space around ternary expressions
Closes #14912
2024-09-18 15:27:26 +02:00
Stefan Eissing
70d3a9b6aa
http2: when uploading data from stdin, fix eos forwarding
When uploading data from stdin ('-T -'), and the EOS was only detected
on a 0-length read, the EOS was not forwarded to the filters. This led
HTTP/2 to hang on not forwarding this to the server.

Added test_07_14 to reproduce and verify.

Fixes #14870
Reported-by: nekopsykose on github
Closes #14877
2024-09-12 13:46:38 +02:00
Daniel Stenberg
4ff04615a0
lib: use FMT_ as prefix instead of CURL_FORMAT_
For printf format defines used internally. Makes the code slighly
easier to read.

Closes #14764
2024-09-03 08:45:45 +02:00
Stefan Eissing
00ef607326
url: fix connection reuse for HTTP/2 upgrades
Normally, when a connection's filters have all connected, the
multiplex status is determined. However, HTTP/2 Upgrade:
requests will only do this when the first server response
has been received.

The current connection reuse mechanism does not accomodate
that and when the time between connect and response is large
enough, connection reuse may not happen as desired.

See test case 2405 failures, such as in
https://github.com/curl/curl/actions/runs/10629497461/job/29467166451

Add 'conn->bits.asks_multiplex' as indicator that a connection is
still being evaluated for mulitplexing, so that new transfers
may wait on this to be cleared.

Closes #14739
2024-09-02 12:39:03 +02:00
Stefan Eissing
1be704e17e
cpool: rename "connection cache/conncache" to "Connection Pools/cpool"
This is a better match for what they do and the general "cpool"
var/function prefix works well.

The pool now handles very long hostnames correctly.

The following changes have been made:

* 'struct connectdata', e.g. connections, keep new members
  named `destination` and ' destination_len' that fully specifies
  interface+port+hostname of where the connection is going to.
  This is used in the pool for "bundling" of connections with
  the same destination. There is no limit on the length any more.
* Locking: all locks are done inside conncache.c when calling
  into the pool and released on return. This eliminates hazards
  of the callers keeping track.
* 'struct connectbundle' is now internal to the pool. It is no
  longer referenced by a connection.
* 'bundle->multiuse' no longer exists. HTTP/2 and 3 and TLS filters
  no longer need to set it. Instead, the multi checks on leaving
  MSTATE_CONNECT or MSTATE_CONNECTING if the connection is now
  multiplexed and new, e.g. not conn->bits.reuse. In that case
  the processing of pending handles is triggered.
* The pool's init is provided with a callback to invoke on all
  connections being discarded. This allows the cleanups in
  `Curl_disconnect` to run, wherever it is decided to retire
  a connection.
* Several pool operations can now be fully done with one call.
  Pruning dead connections, upkeep and checks on pool limits
  can now directly discard connections and need no longer return
  those to the caller for doing that (as we have now the callback
  described above).
* Finding a connection for reuse is now done via `Curl_cpool_find()`
  and the caller provides callbacks to evaluate the connection
  candidates.
* The 'Curl_cpool_check_limits()' now directly uses the max values
  that may be set in the transfer's multi. No need to pass them
  around. Curl_multi_max_host_connections() and
  Curl_multi_max_total_connections() are gone.
* Add method 'Curl_node_llist()' to get the llist a node is in.
  Used in cpool to verify connection are indeed in the list (or
  not in any list) as they need to.

I left the conncache.[ch] as is for now and also did not touch the
documentation. If we update that outside the feature window, we can
do this in a separate PR.

Multi-thread safety is not achieved by this PR, but since more details
on how pools operate are now "internal" it is a better starting
point to go for this in the future.

Closes #14662
2024-08-28 13:52:49 +02:00
Jay Satiro
c8d71e598d http2: fix GOAWAY message sent to server
- fix typo in GOAWAY debug message "shutown" -> "shutdown"

Closes https://github.com/curl/curl/pull/14623
2024-08-21 03:36:50 -04:00
Stefan Eissing
22d292b3ec
urldata: introduce data->mid, a unique identifier inside a multi
`data->id` is unique in *most* situations, but not in all. If a libcurl
application uses more than one connection cache, they will overlap. This
is a rare situations, but libcurl apps do crazy things. However, for
informative things, like tracing, `data->id` is superior, since it
assigns new ids in curl's serial curl_easy_perform() use.

Introduce `data->mid` which is a unique identifer inside one multi
instance, assigned on multi_add_handle() and cleared on
multi_remove_handle().

Use the `mid` in DoH operations and also in h2/h3 stream hashes.

Reported-by: 罗朝辉
Fixes #14414
Closes #14499
2024-08-14 11:21:34 +02:00
Stefan Eissing
cb17c069a8
http2+h3 filters: fix ctx init
Members of the filter context, like stream hash and buffers, need to be
initialized early and protected by a flag to also avoid double cleanup.

This allow the context to be used safely before a connect() is started
and the other parts of the context are set up.

Closes #14505
2024-08-12 22:48:08 +02:00
Stefan Eissing
0bc5b2e37c
http/2: simplify eos/blocked handling
- rely on the new flush to handle blocked sends. No longer
  do simulated EAGAIN on (partially) blocked sends with their
  need to handle repeats.
- fix some debug handling CURL_SMALLREQSEND env var
- add some assertings in request.c for affirming we do it right
- enhance assertion output in test_16 for easier analysis

Closes #14435
2024-08-07 18:28:49 +02:00
Stefan Eissing
35bf766280
http2: improved upload eos handling
- replace the counting of upload lengths with the new eos send flag
- improve frequency of stream draining to happen less on events where it
  is not needed
- this PR is based on #14220

http2, cf-h2-proxy: fix EAGAINed out buffer
- in adjust pollset and shutdown handling, a non-empty `ctx->outbufq`
  must trigger send polling, irregardless of http/2 flow control
- in http2, fix retry handling of blocked GOAWAY frame

test case improvement:
- let client 'upload-pausing' handle http versions

Closes #14253
2024-08-05 08:53:55 +02:00
Stefan Eissing
709a6a3965
cfilters: send flush
Since data can be held in connection filter buffers when sending gives
EAGAIN, add methods to query this and perform flushing of those buffers.

The transfer loop will continue sending until all upload data is
processed and the connection is flushed.

- add `CF_QUERY_SEND_PENDING` to query filters
- add `CF_CTRL_DATA_SEND_FLUSH` to flush filters
- change `Curl_req_want_send()` to query the connection
  if it needs flushing
- use `Curl_req_want_send()` to determine the POLLOUT
  in the PERFORMING multi state
- implement flush handling in the HTTP/2 connection filter

Closes #14271
2024-08-03 19:55:45 +02:00
Stefan Eissing
911c3166b6
lib: add eos flag to send methods
Adds a `bool eos` flag to send methods to indicate that the data
is the last chunk the invovled transfer wants to send to the server.

This will help protocol filters like HTTP/2 and 3 to forward the
stream's EOF flag and also allow to EAGAIN such calls when buffers
are not yet fully flushed.

Closes #14220
2024-08-03 19:53:54 +02:00
Stefan Eissing
eb0a366b70
http2: improve rate limiting of downloads
Set the initial stream window size to 64KB and increase that to the 10MB
we used to start with on the first server reply, unless a rate limit is
in effect.

Continously monitory changes to the transfers rate limit and adjust the
stream window size accordingly. `max_recv_speed` is a transfer propert
that can be changed during processing by a callback.

Closes #14326
2024-08-02 08:45:01 +02:00
Stefan Eissing
02e0151a3a
lib: convert some debugf()s into traces
Use CURL_TRC_CF() for some useful tracing information instead of
DEBUGF().

Closes #14322
2024-07-31 23:14:24 +02:00
Daniel Stenberg
25321de30e
Revert "lib: send eos flag"
This reverts commit be93299f10.
2024-07-19 01:38:05 +02:00
Stefan Eissing
be93299f10
lib: send eos flag
Adds a `bool eos` flag to send methods to indicate that the data is the
last chunk the invovled transfer wants to send to the server.

This will help protocol filters like HTTP/2 and 3 to forward the
stream's EOF flag and also allow to EAGAIN such calls when buffers are
not yet fully flushed.

Closes #14220
2024-07-18 23:27:35 +02:00
Daniel Stenberg
c074ba64a8
code: language cleanup in comments
Based on the standards and guidelines we use for our documentation.

 - expand contractions (they're => they are etc)
 - host name = > hostname
 - file name => filename
 - user name = username
 - man page => manpage
 - run-time => runtime
 - set-up => setup
 - back-end => backend
 - a HTTP => an HTTP
 - Two spaces after a period => one space after period

Closes #14073
2024-07-01 22:58:55 +02:00
Stefan Eissing
c9b95c0bb3
lib: graceful connection shutdown
When libcurl discards a connection there are two phases this may go
through: "shutdown" and "closing". If a connection is aborted, the
shutdown phase is skipped and it is closed right away.

The connection filters attached to the connection implement the phases
in their `do_shutdown()` and `do_close()` callbacks. Filters carry now a
`shutdown` flags next to `connected` to keep track of the shutdown
operation.

Filters are shut down from top to bottom. If a filter is not connected,
its shutdown is skipped. Notable filters that *do* something during
shutdown are HTTP/2 and TLS. HTTP/2 sends the GOAWAY frame. TLS sends
its close notify and expects to receive a close notify from the server.

As sends and receives may EAGAIN on the network, a shutdown is often not
successful right away and needs to poll the connection's socket(s). To
facilitate this, such connections are placed on a new shutdown list
inside the connection cache.

Since managing this list requires the cooperation of a multi handle,
only the connection cache belonging to a multi handle is used. If a
connection was in another cache when being discarded, it is removed
there and added to the multi's cache. If no multi handle is available at
that time, the connection is shutdown and closed in a one-time,
best-effort attempt.

When a multi handle is destroyed, all connection still on the shutdown
list are discarded with a final shutdown attempt and close. In curl
debug builds, the environment variable `CURL_GRACEFUL_SHUTDOWN` can be
set to make this graceful with a timeout in milliseconds given by the
variable.

The shutdown list is limited to the max number of connections configured
for a multi cache. Set via CURLMOPT_MAX_TOTAL_CONNECTIONS. When the
limit is reached, the oldest connection on the shutdown list is
discarded.

- In multi_wait() and multi_waitfds(), collect all connection caches
  involved (each transfer might carry its own) into a temporary list.
  Let each connection cache on the list contribute sockets and
  POLLIN/OUT events it's connections are waiting for.

- in multi_perform() collect the connection caches the same way and let
  them peform their maintenance. This will make another non-blocking
  attempt to shutdown all connections on its shutdown list.

- for event based multis (multi->socket_cb set), add the sockets and
  their poll events via the callback. When `multi_socket()` is invoked
  for a socket not known by an active transfer, forward this to the
  multi's cache for processing. On closing a connection, remove its
  socket(s) via the callback.

TLS connection filters MUST NOT send close nofity messages in their
`do_close()` implementation. The reason is that a TLS close notify
signals a success. When a connection is aborted and skips its shutdown
phase, the server needs to see a missing close notify to detect
something has gone wrong.

A graceful shutdown of FTP's data connection is performed implicitly
before regarding the upload/download as complete and continuing on the
control connection. For FTP without TLS, there is just the socket close
happening. But with TLS, the sent/received close notify signals that the
transfer is complete and healthy. Servers like `vsftpd` verify that and
reject uploads without a TLS close notify.

- added test_19_* for shutdown related tests
- test_19_01 and test_19_02 test for TCP RST packets
  which happen without a graceful shutdown and should
  no longer appear otherwise.
- add test_19_03 for handling shutdowns by the server
- add test_19_04 for handling shutdowns by curl
- add test_19_05 for event based shutdowny by server
- add test_30_06/07 and test_31_06/07 for shutdown checks
  on FTP up- and downloads.

Closes #13976
2024-06-26 08:33:17 +02:00