Commit graph

100 commits

Author SHA1 Message Date
Viktor Szakats
e0dd6eb4a4
tidy-up: miscellaneous
- examples: sync debug output printf masks.
- INSTALL-CMAKE.md: tidy up section for some options.
- curl_sha512_256: delete comment suggesting an optimization.
- vtls/keylog: scope a variable.
- vtls/openssl: make a source code URL a permalink.
- vtls/schannel: drop redundant parentheses.
- test1119.pl: robustify `$1` -> `$s`.
- sync arg names in comments to match the code.
- tidy up and minor fixes to comments.
- fix formatting/indenting/comment/newline/include nits.
- move `UNITTEST` protos next to definitions, sync their argument names.
- make variables static.
- add parentheses to Perl `open()` calls.
- drop unnecessary double quotes in Perl.
- clang-format.

Closes #21000
2026-04-14 01:08:32 +02:00
Daniel Stenberg
9f5d1a38d1
lib: reserve 'result' for CURLcode
For consistency, whereever we use a local variable named 'result' that
is a CURLcode type. Make other types use other names.

Closes #21244
2026-04-06 23:12:06 +02:00
Viktor Szakats
0df6c01db3
tidy-up: rename Curl_safefree()/tool_safefree() to curlx_safefree()
To sync names for the same macro logic between lib and src, and to move
it to the curlx namespace, to match `curlx_free()` that it's calling.

Closes #21151
2026-04-01 19:53:53 +02:00
Greg Kroah-Hartman
fb6925c243
socks: reject zero-length GSSAPI/SSPI tokens from proxy
A "broken" SOCKS5 proxy can send an invalid length of the encryption
token, which could cause malloc(0) to be called, which is a "platform
can do what it wants" potential problem.

Resolve this by explicitly checking the length and rejecting the invalid
token before ever attempting to allocate any memory.

Closes #21159
2026-03-30 16:07:06 +02:00
Viktor Szakats
578ee6b79b
gcc: guard #pragma diagnostic in core code for <4.6, disable picky warnings
Extend `#pragma diagnostic push`/`pop` guards to the whole codebase
(from tests and examples only) to disable it for GCC <4.6. Rename guard
to `CURL_HAVE_DIAG` and make it include llvm/clang to be interchangeable
with `__GNUC__ || __clang__` in this context.

The above means no longer disabling certain warnings locally, so pair
this with disabling all picky warnings for GCC <4.6.

Also:
- drop global workarounds for misbehaving GCC <4.6 compiler warnings.
  Not needed with picky warnings disabled.

Reported-by: fds242 on github
Reported-by: Sergey Fedorov
Thanks-to: Orgad Shaneh
Follow-up to f07a98ae11 #20366
Fixes #20892
Fixes #20924
Closes #20902
Closes #20907
2026-03-18 11:33:37 +01:00
Viktor Szakats
61df5f466c
tidy-up: miscellaneous
- curl_ntlm_core, smtp, schannel: fix comments.
- curl_setup.h: fix to undef before define.
- tool_doswin, server/sockfilt: reduce variables scopes.
- tool_doswin: drop an interim variable.
- windows: replace `SOCKET_ERROR` with `0` to align with rest of code.
- libssh2: rename variable to align with rest of code.
- gtls, unit1398: use `#if 0`.
- curl_trc.h, curlx/inet_ntop.h: add missing parentheses in macro
  expressions.
- ldap.c: set empty macro to `do {} while(0)`.
- examples/crawler: rename a non-CURLcode `result` variable.
- CURLINFO_TLS_SESSION: drop stray colon.
- add `const` to casts where missing.
- drop unnecessary parentheses.
- fix indent.
- quote style.
- comment style.
- whitespace, newlines, fold/unfold.

Closes #20554
2026-02-12 14:52:16 +01:00
Viktor Szakats
31a4f415af
build: tidy up and dedupe strdup functions
- de-dupe lib/src strdup/memdup functions into curlx.
- introduce `CURLX_STRDUP_LOW()` for mapping `strdup()`, and to do it at
  one place within the code, in `curl_setup.h`.
- tests/server: use `curlx_strdup()`. (Also to fix building without
  a system `strdup()`.)
- curlx/curlx.h: shorten and tidy up.
- adjust Windows build path to not need `HAVE_STRDUP`.
- build: stop detecting `HAVE_STRDUP` on Windows.

Closes #20497
2026-02-03 14:02:30 +01:00
Viktor Szakats
9630593650
build: use more const
Mostly with `char *` types.

Also:
- mime, x509asn1, tool_operate, lib3207: drop redundant casts.
- examples/smooth-gtk-thread: add missing variable declaration.
- reduce variable scopes.
- tests/server: move `data_to_hex()` to its only user: `sws`.

Closes #20489
2026-02-02 12:32:49 +01:00
Viktor Szakats
4651d4c76b
badwords: catch and fix more variants of NN-bit
Closes #20304
2026-01-14 02:35:00 +01:00
Viktor Szakats
c7b25e6e82
lib: drop unused or duplicate curlx/timeval.h includes
Note: This patch doesn't aim to add `timeval.h` includes missing from
local headers using `curltime` type. They remain relying on `urldata.h`
being included first. This patch also doesn't delete existing, used
includes already present in local headers (as internal users may rely
on them).

Ref: #20106
Closes #20126
2025-12-31 15:59:19 +01:00
Viktor Szakats
7032982896
tidy-up: miscellaneous
- asyn-thrdd.c: scope an include.
- apply more clang-format suggestions.
- tidy-up PP guard comments.
- delete empty line from the top of headers.
- add empty line after `curl_setup.h` include where missing.
- fix indent.
- CODE_STYLE.md: add `strcpy`.
  Follow-up to 8636ad55df #20088
- lib1901.c: drop unnecessary line.
  Follow-up to 436e67f65b #20076

Closes #20070
2025-12-26 22:06:09 +01:00
Viktor Szakats
e8415a8296
lib: drop, or replace sendf.h with curl_trc.h where possible
- replace `sendf.h` with `curl_trc.h` where it was included just for it.
- drop unused `curl_trc.h` includes.
- easy: delete obsolete comment about `send.h` include reason.

Also:
- move out `curl_trc.h` include from `sendf.h` and include it directly
  in users, where not done already. To flatten the include tree and
  to less rely on indirect includes.
- stop including `sendf.h` from other headers, replace it with forward
  declaration of `Curl_easy`, as done already elsewhere.

Verified with an all non-unity CI run.

Closes #20061
2025-12-21 12:39:25 +01:00
Viktor Szakats
884b5ea921
lib: include curlx/warnless.h from curl_setup.h
To make it available for all files. Drop includes from individual
sources. This header was already included from most sources and not
specific to any internal subsystem.

Also to ensure that two system symbol redefines on Windows (`read()` and
`write()`) get applied to all sources. Move them to `curl_setup.h`.

Closes #20056
2025-12-21 02:36:33 +01:00
Viktor Szakats
d4298603b5
tidy-up: curlx/nonblock.h includes
Delete where unused, include where to used to avoid relying on
side-effect of other headers.

Also: delete "for curlx_nonblock" comments. That's the only symbol
offered by this header.

Closes #20055
2025-12-21 02:16:34 +01:00
Viktor Szakats
c3b030b860
lib: fix formatting nits (part 3)
From `lib/h` to `lib/w`.

part 1: 47a1ab2ebe #19764
part 2: 86b346443b #19800

Closes #19811
2025-12-03 14:50:16 +01:00
Viktor Szakats
193cb00ce9
build: stop overriding standard memory allocation functions
Before this patch curl used the C preprocessor to override standard
memory allocation symbols: malloc, calloc, strdup, realloc, free.
The goal of these is to replace them with curl's debug wrappers in
`CURLDEBUG` builds, another was to replace them with the wrappers
calling user-defined allocators in libcurl. This solution needed a bunch
of workarounds to avoid breaking external headers: it relied on include
order to do the overriding last. For "unity" builds it needed to reset
overrides before external includes. Also in test apps, which are always
built as single source files. It also needed the `(symbol)` trick
to avoid overrides in some places. This would still not fix cases where
the standard symbols were macros. It was also fragile and difficult
to figure out which was the actual function behind an alloc or free call
in a specific piece of code. This in turn caused bugs where the wrong
allocator was accidentally called.

To avoid these problems, this patch replaces this solution with
`curlx_`-prefixed allocator macros, and mapping them _once_ to either
the libcurl wrappers, the debug wrappers or the standard ones, matching
the rest of the code in libtests.

This concludes the long journey to avoid redefining standard functions
in the curl codebase.

Note: I did not update `packages/OS400/*.c` sources. They did not
`#include` `curl_setup.h`, `curl_memory.h` or `memdebug.h`, meaning
the overrides were never applied to them. This may or may not have been
correct. For now I suppressed the direct use of standard allocators
via a local `.checksrc`. Probably they (except for `curlcl.c`) should be
updated to include `curl_setup.h` and use the `curlx_` macros.

This patch changes mappings in two places:
- `lib/curl_threads.c` in libtests: Before this patch it mapped to
  libcurl allocators. After, it maps to standard allocators, like
  the rest of libtests code.
- `units`: before this patch it mapped to standard allocators. After, it
  maps to libcurl allocators.

Also:
- drop all position-dependent `curl_memory.h` and `memdebug.h` includes,
  and delete the now unnecessary headers.
- rename `Curl_tcsdup` macro to `curlx_tcsdup` and define like the other
  allocators.
- map `curlx_strdup()` to `_strdup()` on Windows (was: `strdup()`).
  To fix warnings silenced via `_CRT_NONSTDC_NO_DEPRECATE`.
- multibyte: map `curlx_convert_*()` to `_strdup()` on Windows
  (was: `strdup()`).
- src: do not reuse the `strdup` name for the local replacement.
- lib509: call `_strdup()` on Windows (was: `strdup()`).
- test1132: delete test obsoleted by this patch.
- CHECKSRC.md: update text for `SNPRINTF`.
- checksrc: ban standard allocator symbols.

Follow-up to b12da22db1 #18866
Follow-up to db98daab05 #18844
Follow-up to 4deea9396b #18814
Follow-up to 9678ff5b1b #18776
Follow-up to 10bac43b87 #18774
Follow-up to 20142f5d06 #18634
Follow-up to bf7375ecc5 #18503
Follow-up to 9863599d69 #18502
Follow-up to 3bb5e58c10 #17827

Closes #19626
2025-11-28 10:44:26 +01:00
Stefan Eissing
56e88e7c14
cfilter: send uint8_t bytes
Change the send parameter from `const void *` to `const uint8_t *` and
adapt calling code. Several had already unsigned chars and were casting.

Closes #19729
2025-11-27 16:03:21 +01:00
x2018
dd71f61ea2
lib: cleanup for some typos about spaces and code style
Closes #19370
2025-11-05 14:07:28 +01:00
Daniel Stenberg
80258309b2
lib: reduce memcpy calls
socks_gssapi: the malloc + memcpy was superflous and can be skipped

cleartext: avoid malloc + three memcpy with aprintf()

digest_sspi: use memdup0 instead of malloc + memcpy

vtls: use memdup0 instead of malloc + memcpy

Closes #19282
2025-10-30 15:40:21 +01:00
Viktor Szakats
4f03e3fcbd
socks_gssapi: also reset buffer length after free
To mimic this behavior of the previously used `gss_release_buffer()`.

Some or all of these zero assignments may be redundant.

Follow-up to e7818999db #19018

Closes #19167
2025-10-26 01:52:41 +02:00
Viktor Szakats
e7818999db
socks_gssapi: replace gss_release_buffer() with curl free for buffers owned by libcurl
Before this patch, this code used to call `gss_release_buffer()` on
objects with buffers allocated via curl's allocator.
`gss_release_buffer()` calls system (or Win32) free on these buffers,
which may mismatch with curl's allocator. To fix it, align these calls
with the pattern used in vauth modules, by replacing
`gss_release_buffer()` with curl free to release the buffers.

Use `Curl_safefree()` to set the freed pointer to NULL, as
`gss_release_buffer()` did.

Also: use object length var when allocating.

Reported-by: Joshua Rogers

Closes #19018
2025-10-20 14:23:46 +02:00
Viktor Szakats
b12da22db1
lib: stop overriding system printf symbols
After this patch, the codebase no longer overrides system printf
functions. Instead it explicitly calls either the curl printf functions
`curl_m*printf()` or the system ones using their original names.

Also:
- drop unused `curl_printf.h` includes.
- checksrc: ban system printf functions, allow where necessary.

Follow-up to db98daab05 #18844
Follow-up to 4deea9396b #18814

Closes #18866
2025-10-06 20:57:59 +02:00
Daniel Stenberg
20d1c6e92e
socks_gssapi: remove superfluous releases of the gss_recv_token
Reported in Joshua's sarif data

Closes #18714
2025-09-25 11:23:04 +02:00
Daniel Stenberg
98dae1d992
socks_gssapi: remove the forced "no protection"
If a protected connection is requested, don't claim to drop down to "no
protection".

Reported in Joshua's sarif data

Closes #18712
2025-09-25 10:11:28 +02:00
Daniel Stenberg
aaa39873ea
socks_gssapi: make the gss_context a local variable
Reported-by: Stanislav Fort
Closes #18711
2025-09-25 09:08:08 +02:00
Daniel Stenberg
7cb5e39f36
socks_gssapi: reject too long tokens
If GSS returns a token to use that is longer than 65535 bytes, it can't
be transmitted since the length field is an unisgned 16 bit field and
thus needs to trigger an error.

Reported in Joshua's sarif data

Closes #18681
2025-09-24 14:07:03 +02:00
Viktor Szakats
b2bccdc257
tidy-up: move literal to the right side of comparisons
Closes #17876
2025-07-27 22:35:17 +02:00
Viktor Szakats
3222eabe18
tidy-up: whitespace/indent
Closes #17925
2025-07-14 18:33:43 +02:00
Viktor Szakats
73840836a5
tests: move GSS-API dynamic stub into debug-mode libcurl
Replace the `libstubgss.so`-based overload solution with one built into
libcurl at compile-time.

The previous, `LD_PRELOAD`-based, solution was non-portable, allowlisted
for Linux, BSD and Solaris. It also required non-debug builds, which
turned out to be an accidental condition:
7d342c723c. It also required a curl tool
built against a shared libcurl. Detecting this condition wasn't always
accurate, e.g. with certain cmake configurations.

The overload solution also didn't work on macOS, though it theoretically
should have:
- #17653
- #2394

Experiments on making the overload solution work in more envs:
- #17759
  That revealed that it also did not work on NetBSD, in CI.

The replacement solution is overloading the necessary GSS-API functions
for test 2056 and 2057 at compile time. It requires a debug-enabled curl
build (due to its insecure nature).

This makes these tests run on all platforms. Including most GSS jobs in
CI, that are running tests. (the exception is old-linux, non-debug jobs,
where it felt overkill to enable debug for this.)

The refactored GSS stub code needs to overload less than before because
it's free to use the official GSS API. (This didn't work with
the overload solution on Alpine for example). It can also use libcurl
functions, allowing to replace `snprintf()` with `msnprintf()`.

OS/400 is also overloading GSS API functions. I haven't tested how this
works after this PR. In theory it should, because this PR doesn't rely
on preprocessor overrides.

Note that for future GSS tests, it may be necessary to stub these GSS
API functions: `gss_inquire_context()`, `gss_unwrap()`, `gss_wrap()`.
They are on codepaths not (yet) touched by tests.

Also:
- stub-gss: check for token buffer overrun.
- stub-gss: replace size macros with `sizeof()`.
- GHA: enable debug for some jobs with GSS.
- GHA/linux: ignore results for 2056 and 2057 in the valgrind job.
  They leak the same way as seen with 2077 and 2078.
  Ref: 7020ba7979 #17462
  Ref: 146759716c #14430
- GHA/linux: fix to ignore `gss_import_name()` leaks in valgrind builds.
  only.
- lib/vauth/krb5_gssapi: reduce variable scope.
- lib/vauth/spnego_gssapi: reduce variable scope.
- tests/libtest: drop code and build logic dealing with `libstubgss`.
- runtests:
  - drop `ld_preload` feature.
  - drop special handling of `LD_PRELOAD` env in tests.
  - drop logic dealing with shared curl tool detection.
  - drop `LD_PRELOAD` envs from tests.

Follow-up to 56d949d31a #1687

Closes #17752
2025-07-01 00:17:15 +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
ef90ee39e1
lib: supress deprecation warnings in apple builds
On apple builds, the gssapi/ldap/securetransport headers deprecate
almost everything which leads to a wall of compiler warnings on use in
code.

Suppress those warning that may hide other warnings/errors.

Closes #15763
2024-12-17 14:54:34 +01:00
Daniel Stenberg
af60bdf4ec
socks_gssapi: switch to dynbuf from buffer with strcpy
Closes #15057
2024-09-26 23:24:14 +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
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
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
Viktor Szakats
72abf7c13a
lib: tidy up types and casts
Cherry-picked from #13489
Closes #13862
2024-06-05 14:02:39 +02:00
RainRat
2cd78f525c misc: Fix typos in docs and lib
This fixes miscellaneous typos and duplicated words in the docs, lib
and test comments and a few user facing errorstrings.

Author: RainRat on Github
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Dan Fandrich <dan@coneharvesters.com>
Closes: #13019
2024-03-01 09:59:48 +01:00
Daniel Stenberg
7309b9cbbf
lib: strndup/memdup instead of malloc, memcpy and null-terminate
- bufref: use strndup
 - cookie: use strndup
 - formdata: use strndup
 - ftp: use strndup
 - gtls: use aprintf instead of malloc + strcpy * 2
 - http: use strndup
 - mbedtls: use strndup
 - md4: use memdup
 - ntlm: use memdup
 - ntlm_sspi: use strndup
 - pingpong: use memdup
 - rtsp: use strndup instead of malloc, memcpy and null-terminate
 - sectransp: use strndup
 - socks_gssapi.c: use memdup
 - vtls: use dynbuf instead of malloc, snprintf and memcpy
 - vtls: use strdup instead of malloc + memcpy
 - wolfssh: use strndup

Closes #12453
2023-12-07 08:47:44 +01:00
Stefan Eissing
5651a36d1a
cf-socket: improvements in socket I/O handling
- Curl_write_plain/Curl_read_plain have been eliminated. Last code use
  now uses Curl_conn_send/recv so that requests use conn->send/revc
  callbacks which defaults to cfilters use.
- Curl_recv_plain/Curl_send_plain have been internalized in cf-socket.c.
- USE_RECV_BEFORE_SEND_WORKAROUND (active on Windows) has been moved
  into cf-socket.c. The pre_recv buffer is held at the socket filter
  context.  `postponed_data` structures have been removed from
  `connectdata`.
- the hanger in HTTP/2 request handling was a result of read buffering
  on all sends and the multi handling is not prepared for this. The
  following happens:

   - multi preforms on a HTTP/2 easy handle
   - h2 reads and processes data
   - this leads to a send of h2 data
   - which receives and buffers before the send
   - h2 returns
   - multi selects on the socket, but no data arrives (its in the buffer already)
   the workaround now receives data in a loop as long as there is something in
   the buffer. The real fix would be for multi to change, so that `data_pending`
   is evaluated before deciding to wait on the socket.

io_buffer, optional, in cf-socket.c, http/2 sets state.drain if lower
filter have pending data.

This io_buffer is only available/used when the
-DUSE_RECV_BEFORE_SEND_WORKAROUND is active, e.g. on Windows
configurations. It also maintains the original checks on protocol
handler being HTTP and conn->send/recv not being replaced.

The HTTP/2 (nghttp2) cfilter now sets data->state.drain when it finds
out that the "lower" filter chain has still pending data at the end of
its IO operation. This prevents the processing from becoming stalled.

Closes #10280
2023-01-31 11:23:59 +01:00
Daniel Stenberg
2bc1d775f5
copyright: update all copyright lines and remove year ranges
- they are mostly pointless in all major jurisdictions
- many big corporations and projects already don't use them
- saves us from pointless churn
- git keeps history for us
- the year range is kept in COPYING

checksrc is updated to allow non-year using copyright statements

Closes #10205
2023-01-03 09:19:21 +01:00
max.mehl
ad9bc5976d
copyright: make repository REUSE compliant
Add licensing and copyright information for all files in this repository. This
either happens in the file itself as a comment header or in the file
`.reuse/dep5`.

This commit also adds a Github workflow to check pull requests and adapts
copyright.pl to the changes.

Closes #8869
2022-06-13 09:13:00 +02:00
Daniel Gustafsson
f1cdeff37a gssapi: initialize gss_buffer_desc strings
Explicitly initialize gss_buffer_desc strings such that a call to
freeing resources will succeed even if no data has been allocated
to it.

Reported-by: Jay Satiro <raysatiro@yahoo.com>
2022-05-12 14:12:41 +02:00
Eddie Lumpkin
8e701cc978
lib: fixing comment spelling typos in lib files
Closes #7894
Signed-off-by: ewlumpkin <ewlumpkin@gmail.com>
2021-10-22 22:53:44 +02:00
Daniel Stenberg
e7416cfd2b
infof: remove newline from format strings, always append it
- the data needs to be "line-based" anyway since it's also passed to the
  debug callback/application

- it makes infof() work like failf() and consistency is good

- there's an assert that triggers on newlines in the format string

- Also removes a few instances of "..."

- Removes the code that would append "..." to the end of the data *iff*
  it was truncated in infof()

Closes #7357
2021-07-07 22:54:01 +02:00
Daniel Stenberg
063d3f3b96
tidy-up: make conditional checks more consistent
... remove '== NULL' and '!= 0'

Closes #6912
2021-04-22 09:10:17 +02:00
Daniel Stenberg
a304051620
lib: more conn->data cleanups
Closes #6479
2021-01-19 09:14:51 +01:00
Daniel Stenberg
215db086e0
lib: pass in 'struct Curl_easy *' to most functions
... in most cases instead of 'struct connectdata *' but in some cases in
addition to.

- We mostly operate on transfers and not connections.

- We need the transfer handle to log, store data and more. Everything in
  libcurl is driven by a transfer (the CURL * in the public API).

- This work clarifies and separates the transfers from the connections
  better.

- We should avoid "conn->data". Since individual connections can be used
  by many transfers when multiplexing, making sure that conn->data
  points to the current and correct transfer at all times is difficult
  and has been notoriously error-prone over the years. The goal is to
  ultimately remove the conn->data pointer for this reason.

Closes #6425
2021-01-17 23:56:09 +01:00