Commit graph

165 commits

Author SHA1 Message Date
Viktor Szakats
1b48c6148a
tidy-up: miscellaneous
- schannel: delete superfluous parenthesis.
- tftp: delete stray space from log output.
- ws: update guard comment.
- docs/examples: constify variables.
- runtests/servers: enclose unknown parameter between quotes.
- scripts/perlcheck.sh: drop redundant grep `-E` option.
- THANKS: move names from comments to THANKS.
- sync `--depth` option style across scripts.
- sync git repo URL ending between some scripts.
- BINDINGS.md: drop protocol from archive.org URL path.
- whitespace, indent, unfold lines.

Closes #19565
2025-11-17 13:32:43 +01:00
Viktor Szakats
f0de14168a
cf-socket: limit use of TCP_KEEP* to Windows 10.0.16299+ at runtime
Before this patch `TCP_KEEP*` socket options were unconditionally used
if the build-time SDK supported them. This caused curl logging errors
(or trace messages since #19527) on Windows versions missing support
for them. After this patch, use them only when the runtime environment
supports it and fall back to the alternate method (`SIO_KEEPALIVE_VALS`)
dynamically.

Also:
- log a trace message when using the Win10 method.
- document which SDK versions offer `TCP_KEEP*` macros.

Ref: https://learn.microsoft.com/windows/win32/winsock/ipproto-tcp-socket-options
Ref: https://learn.microsoft.com/windows/win32/winsock/sio-keepalive-vals

Reported-by: Aleksandr Sergeev
Fixes #19520
Follow-up to dc34498d18 #19527
Closes #19559
2025-11-17 12:16:51 +01:00
Viktor Szakats
554dfa5568
build: drop Windows CE / CeGCC support
Windows CE support was limited to successful builds with ming32ce
(a toolchain that hasn't seen an update since 2009, using an ancient gcc
version and "old mingw"-style SDK headers, that curl deprecated earlier).
Builds with MSVC were broken for a long time. mingw32ce builds were never
actually tested and runtime and unlikely to work due to missing stubs.
Windows CE toolchains also miss to comply with C89. Paired with lack of
demand and support for the platform, curl deprecated it earlier.

This patch removes support from the codebase to ease maintaining Windows
codepaths.

Follow-up to f98c0ba834 #17924
Follow-up to 8491e6574c #17379
Follow-up to 2a292c3984 #15975

Closes #17927
2025-11-15 15:35:23 +01:00
Viktor Szakats
2dc71ba8bf
badwords: check indented lines in source code, fix fallouts
- badwords.pl: add `-a` option to check all lines in source code files.
  Before this patch indented lines were skipped (to avoid Markdown code
  fences.)
- GHA/checksrc: use `-a` when verifying the source code.
- GHA/checksrc: disable `So` and `But` rules for source code.
- GHA/checksrc: add docs/examples to the verified sources.
- badwords.txt: delete 4 duplicates.
- badwords.txt: group and sort contractions.
- badwords.txt: allow ` url = `, `DIR`, `<file name`.

Closes #19536
2025-11-15 13:25:02 +01:00
Stefan Eissing
dc34498d18
cf-socket: trace ignored errors
Instead of blasting the user with infof() statements.

Reported-by: Aleksandr Sergeev
Fixes #19520
Closes #19527
2025-11-14 17:04:15 +01:00
Stefan Eissing
78a610cb83
lib: rename curlx_timediff to curlx_timeleft_ms
Rename `Curl_timeleft()` to `Curl_timeleft_ms()` to make the units in
the returned `timediff_t` clear. (We used to always have ms there, but
with QUIC started to sometimes calc ns as well).

Rename some assigned vars without `_ms` suffix for clarity as well.

Closes #19486
2025-11-13 13:12:58 +01:00
Daniel Stenberg
f1f5cc781c
cf-socket: split out the MTU and GRO setopts into sep functions
It simplifies the #ifdefs and declaring of local variables slightly.

Closes #19467
2025-11-11 17:57:40 +01:00
Stefan Eissing
dbff3eec45
cf-socket: give information when unable to open socket
Give ERRNO explanation in a failf() when unable to open a socket.
Helps in finding out what the issue preventing your curl to work
really is. Just had a wrong ulimit after a sys update.

Closes #19158
2025-10-20 15:21:47 +02:00
Daniel Stenberg
1876ed6296
cf-socket: make set_local_ip void, and remove failf()
No callers of this function checked the return code, meaning failures
are not lethal == using failf was wrong, and it can just as well return
void.

Closes #19137
2025-10-20 10:57:48 +02:00
Daniel Stenberg
c0564ceb3a
cf-socket: if FD_CLOEXEC fails on accepted socket, cleanup
Follow-up to 9d7b532404

Pointed out by ZeroPath

Closes #19098
2025-10-17 16:12:34 +02:00
Stefan Eissing
9d7b532404
cf-socket: set FD_CLOEXEC on all sockets opened
Removed TODO item

Reported-by: Joshua Rogers
Closes #18968
2025-10-10 23:44:43 +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
Stefan Eissing
2f3cf17e33
cf-socket: check params and remove accept procondition
- creating a socket filter with NULL addrinfo fails with
  CURLE_BAD_FUNCTION_ARGUMENT
- remove getsockname use before accept call, serves no purpose
  and did not lead to proper error before

Reported-by: Joshua Rogers
Closes #18882
2025-10-06 14:48:01 +02:00
Viktor Szakats
34ad78da89
curlx: move Curl_strerror, use in src and tests, ban strerror globally
Also:
- tests/server: replace local `sstrerror()` with `curlx_strerror()`.
- tests/server: show the error code next to the string, where missing.
- curlx: use `curl_msnprintf()` when building for src and tests.
  (units was already using it.)
- lib: drop unused includes found along the way.
- curlx_strerror(): avoid compiler warning (and another similar one):
  ```
  In file included from servers.c:14:
  ../../lib/../../lib/curlx/strerr.c: In function ‘curlx_strerror’:
  ../../lib/../../lib/curlx/strerr.c:328:32: error: ‘snprintf’ output may be truncated before the last format character [-Werror=format-truncation=]
    328 |       SNPRINTF(buf, buflen, "%s", msg);
        |                                ^
  ../../lib/../../lib/curlx/strerr.c:47:18: note: ‘snprintf’ output 1 or more bytes (assuming 2) into a destination of size 1
     47 | #define SNPRINTF snprintf
        |                  ^
  ../../lib/../../lib/curlx/strerr.c:328:7: note: in expansion of macro ‘SNPRINTF’
    328 |       SNPRINTF(buf, buflen, "%s", msg);
        |       ^~~~~~~~
  ```

Follow-up to 45438c8d6f #18823

Closes #18840
2025-10-06 09:44:23 +02:00
Daniel Stenberg
ea4ba6d9ef
lib: remove personal names from comments
- it's just too random who got mentioned
- we can't mention all, so better consistently mention none
- make sure they all are mentioned in THANKS
- also remove some unnecessary comment ramblings

Closes #18803
2025-10-02 14:22:57 +02:00
Daniel Stenberg
e891b4195f
cf-socket: tweak a memcpy() to read better
By checking the size of the actual buffer and using that as memcpy
target instead of another union member, this helps readers and static
code analyzers to determine that this is not a buffer overflow.

Ref: #18677
Closes #18787
2025-10-01 15:52:53 +02:00
Stefan Eissing
b022389757
ip-happy: do not set unnecessary timeout
When attempts on all addresses have been started, do no longer set any
EXPIRE_HAPPY_EYEBALLS timeouts.

Fixes #18767
Reported-by: Johannes Schindelin
Closes #18768
2025-10-01 08:01:47 +02:00
Viktor Szakats
f97aa8d7ed
tidy-up: fcntl.h includes
- drop from source files without obvious users.
- include in `curlx/fopen.h` also for Windows.

Follow-up to 9678ff5b1b #18776

Closes #18782
2025-09-30 21:57:17 +02:00
Daniel Stenberg
66c7e92ae4
Revert "cf_socket_recv: don't count reading zero bytes as first byte"
This reverts commit df60e8fe70.

The "first byte" checkpoint is not strictly the first byte received, but
the sign of first traffic from the server, which a closed connection
also is.

Closes #18676
2025-09-24 14:09:05 +02:00
Daniel Stenberg
d27d9c7ef1
cf-socket: use the right byte order for ports in bindlocal
Reported in Joshua's sarif data

Closes #18641
2025-09-20 17:34:18 +02:00
Viktor Szakats
bf7375ecc5
build: avoid overriding system symbols for socket functions
Before this patch `accept4()`, `socket()`, `socketpair()`, `send()` and
`recv()` system symbols were remapped via macros, using the same name,
to local curl debug wrappers. This patch replaces these overrides by
introducing curl-namespaced macros that map either to the system symbols
or to their curl debug wrappers in `CURLDEBUG` (TrackMemory) builds.

This follows a patch that implemented the same for `accept()`.

The old method required tricks to make these redefines work in unity
builds, and avoid them interfering with system headers. These tricks
did not work for system symbols implemented as macros.

The new method allows to setup these mappings once, without interfering
with system headers, upstream macros, or unity builds. It makes builds
more robust.

Also:
- checksrc: ban all mapped functions.
- docs/examples: tidy up checksrc rules.

Follow-up to 9863599d69 #18502
Follow-up to 3bb5e58c10 #17827

Closes #18503
2025-09-20 13:44:59 +02:00
Viktor Szakats
1429858bce
tidy-up: update MS links, allow long URLs via checksrc
- update Microsoft documentation links.
  (also drop language designator where present.)

- checksrc: allow longer than 78 character lines if they
  contain a https URL. To make these links easier to use and parse.

- merge links that were split into two lines.

Closes #18626
2025-09-20 11:49:23 +02:00
Daniel Stenberg
df60e8fe70
cf_socket_recv: don't count reading zero bytes as first byte
Reported in Joshua's sarif data

Closes #18615
2025-09-19 14:39:15 +02:00
Viktor Szakats
9863599d69
lib: introduce CURL_ACCEPT()
To avoid overriding the system symbol `accept`, which is a macro on some
systems (AIX), and thus can't be called via the `(function)` PP trick.

It's also problematic to reset such macro to its original value.

Follow-up to 3bb5e58c10 #17827
Reported-by: Andrew Kirillov
Fixes #18500
Closes #18501
Closes #18502
2025-09-09 15:17:34 +02:00
Viktor Szakats
49145249be
tidy-up: drop stray "unused" comments
Closes #18453
2025-09-03 16:31:16 +02:00
Viktor Szakats
06c12cc08b
build: disable TCP_NODELAY for emscripten
In WebAssembly, using `TCP_NODELAY` fails with:
```
* Could not set TCP_NODELAY: Protocol not available
```

Add a new feature macro in `curl_setup.h` telling whether `TCP_NODELAY`
is known to be supported at runtime, when defined at compile-time.

Keep `TCP_NODELAY` guards at their current positions to ensure the
necessary headers (e.g. `netinet/tcp.h` and `netinet/in.h`) define it.

Reported-by: Jeroen Ooms
Fixes #17974
Closes #18155
2025-08-05 00:34:24 +02:00
Stefan Eissing
5b80b4c012
lib: replace getsock() logic with pollsets
`getsock()` calls operated on a global limit that could
not be configure beyond 16 sockets. This is no longer adequate
with the new happy eyeballing strategy.

Instead, do the following:
- make `struct easy_pollset` dynamic. Starting with
  a minimal room for two sockets, the very common case,
  allow it to grow on demand.
- replace all protocol handler getsock() calls with pollsets
  and a CURLcode to return failures
- add CURLcode return for all connection filter `adjust_pollset()`
  callbacks, since they too can now fail.
- use appropriately in multi.c and multi_ev.c
- fix unit2600 to trigger pollset growth

Closes #18164
2025-08-04 23:43:13 +02:00
Viktor Szakats
3bfcfe82b9
windows: document toolchain support for some macros
The oldest MS SDK I checked is 6.0A (VS2008). Versions are approximate
beyond 7.1A. I only have two Win10 SDKs to verify:
10.0.16299.0 (VS2017-15.4) and 10.0.22621.0 (VS2022).

Ref: https://en.wikipedia.org/wiki/Microsoft_Windows_SDK
Ref: https://developer.microsoft.com/windows/downloads/sdk-archive/index-legacy (recent versions mostly)

Closes #18085
2025-07-31 00:43:57 +02:00
Stefan Eissing
83da4d9d3b
connectdata: remove primary+secondary ip_quadruple
Since the content varies during connection setup and while doing it
(eyeballing), remove these strcut from `connectdata` and replace use
with querying the connection filters. Those keep that information
already.

Change the info logging of established connections to also give the
local address and port.

Closes #17960
2025-07-30 10:56:19 +02:00
Viktor Szakats
89771d19d5
tidy-up: prefer ifdef/ifndef for single checks
Closes #18018
2025-07-27 22:35:17 +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
Daniel Stenberg
91138b014d
vquic: drop msh3
It has never been properly functional in curl while there are several
alternatives that are.

Closes #17729
2025-07-27 17:57:17 +02:00
Stefan Eissing
e9ae1bd404
connection: clarify transport
The `transport` to use for a transfer, e.g. TCP/QUIC/UNIX/UDP, is
initially selected by options and protocol used. This is set at the
`struct connectdata` as `transport` member.

During connection establishment, this transport may change due to
Alt-Svc or Happy-Eyeballing. Most common is the switch from TCP to QUIC.

Rename the connection member to `transport_wanted` and add a way to
query the connection for the transport in use via a new connection
filter query.

The filter query can also be used in the happy eyeballing attempts when
code needs to know which transport is used by the "filter below". This
happens in wolfssl initialization, as one example.

Closes #17923
2025-07-14 14:33:18 +02:00
Viktor Szakats
8eab2b7086
tidy-up: whitespace
Cherry-picked from #17877
Cherry-picked from #17876

Closes #17896
2025-07-11 13:32:54 +02:00
Stefan Eissing
21ecc7e376
cf-socket: make socket data_pending a nop
Eliminating the socket readability check in the socket connection
filters for the 'data_pending' callback. Improves performance of
handling of transfers, up to ~30%, depending on parallelism and response
size.

Whatever `data_pending()` once was, its semantics are now:
"Is there anything buffered in the connection filters that needs
 receive?"
Any checks of the socket's readability are done via `multi_wait()`
and friends.

Fix the one place in HTTP/1 proxy code that checked `data_pending()` and
did an early return if false. Remove that check and actually try to
receive data every time.

Closes #17785
2025-06-30 13:44:24 +02:00
Stefan Eissing
70779199f3
cf: replace the method get_host with query
Connection filters had a method `get_host()` which had not really been
documented. Since then, the cf had the `query()` method added. Replace
the separate get_host with query.

Add `CF_QUERY_HOST_PORT` as query to connection filters to retrieve
which remote hostname and port the filter (or its sub-filter) is talking
to. The query is implemented by HTTP and SOCKS filters, all others pass
it through.

Add `Curl_conn_get_current_host()` to retrieve the remote host and port
for a connection. During connect, this will return the host the
connection is talking to right now. Before/After connect, this will
return `conn->host.name`.

This is used by SASL authentication.

Closes #17419
2025-06-21 17:20:44 +02:00
Stefan Eissing
63381421f5
connection: eliminate member remote_addr
Used to be a pointer set (and cleared) by the socket connection filters
to a struct in their contexts. Instead, add a filter query method to
obtain the pointer when needed.

Closes #17385
2025-06-20 12:54:36 +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
1886260a95
lib: make curlx_inet_ntop()
move function to curlx/, change all callers

Closes #17560
2025-06-09 13:16:01 +02:00
Daniel Stenberg
d4dd43b20d
curlx: move curlx_inet_pton
Used by test server code.

Closes #17300
2025-05-09 13:45:24 +02:00
Daniel Stenberg
16db059a93
curlx: move version_win32.[ch] to curlx/
For curlx_verify_windows_version

Closes #17290
2025-05-08 17:09:32 +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
Andreas Westin
cc884c08a8
cf-socket: fix FTP accept connect
When cf_tcp_accept_connect() is called and it sets up a connection it
never indicates to the caller that the it's done.

Closes #17186
2025-04-25 17:39:27 +02:00
Stefan Eissing
56e40ae6a5
asyn resolver code improvements
"asyn" is the internal name under which both c-ares and threaded
resolver operate. Make the naming more consistent. Implement the c-ares
resolver in `asyn-ares.*` and the threaded resolver in `asyn-thrdd.*`.
The common functions are in `asyn-base.c`.

When `CURLRES_ASYNCH` is defined, either of the two is used and
`data->state.async` exists. Members of that struct vary for the selected
implementation, but have the fields `hostname`, `port` and `ip_version`
always present. This are populated when the async resolving starts and
eliminate the need to pass them again when checking on the status and
processing the results of the resolving.

Add a `Curl_resolv_blocking()` to `hostip.h` that relieves FTP and SOCKS
from having to repeat the same code.

`Curl_resolv_check()` remains the function to check for status of
ongoing resolving. Now it also performs internally the check if the
needed DNS entry exists in the dnscache and if so, aborts the asnyc
operation. (libcurl right now does not check for duplicate resolve
attempts. an area for future improvements).

The number of functions in `asyn.h` has been reduced. There were subtle
difference in "cancel()" and "kill()" calls, both replaced by
`Curl_async_shutdown()` now. This changes behaviour for threaded
resolver insofar as the resolving thread is now always joined unless
`data->set.quick_exit` is set. Before this was only done on some code
paths. A future improvement would be a thread pool that keeps a limit
and also could handle joins more gracefully.

DoH, not previously tagged under "asny", has its struct `doh_probes` now
also in `data->state.async`, moved there from `data->req` because it
makes more sense. Further integration of DoH underneath the "asyn"
umbrella seems like a good idea.

Closes #16963
2025-04-16 09:34:20 +02:00
Andy Pan
3d02872be7
socket: use accept4 when available
Linux, *BSD, and Solaris support accept4 system call that enables the
caller to assign additional flags and save some extra system calls. It
can come in handy when O_NONBLOCK or/and FD_CLOEXEC is/are required on a
socket after being accepted.

Ref:
https://man7.org/linux/man-pages/man2/accept.2.html
https://man.freebsd.org/cgi/man.cgi?query=accept4
https://man.dragonflybsd.org/?command=accept&section=2
https://man.openbsd.org/accept.2
https://man.netbsd.org/accept.2
https://docs.oracle.com/cd/E88353_01/html/E37843/accept4-3c.html
https://www.gnu.org/software/gnulib/manual/html_node/accept4.html

Closes #16979
2025-04-06 13:08:33 +02:00
Viktor Szakats
9465327084
cmake: fix clang-tidy builds to verify tests, fix fallouts
- cmake: disable test bundles for clang-tidy builds.
  clang-tidy ignores #included .c sources, and incompatible with unity
  and bundles. It caused clang-tidy ignoring all test sources. It also
  means this is the first time tests sources are checked with
  clang-tidy. (autotools doesn't run it on tests.)

- cmake: update description for `CURL_TEST_BUNDLES` option.

- fix tests using special `CURLE_*` enums that were missing from
  `curl/curl.h`. Add them as reserved codes.

- fix about ~50 other issues detected by clang-tidy: unchecked results,
  NULL derefs, memory leaks, casts to enums, unused assigments,
  uninitialized `errno` uses, unchecked `open`, indent, and more.

- drop unnecessary casts (lib1533, lib3207).

- suppress a few impossible cases with detailed `NOLINT`s.

- lib/escape.c: drop `NOLINT` no longer necessary.
  Follow-up to 72abf7c13a #13862 (possibly)

- extend two existing `NOLINT` comments with details.

Follow-up to fabfa8e402 #15825

Closes #16756
2025-03-24 10:14:58 +01:00
Viktor Szakats
51d8213579
core: stop redefining E* macros on Windows, map EACCES, related fixes
Before this patch, standard `E*` errno codes were redefined on Windows,
onto matching winsock2 `WSA*` error codes, which have different values.
This broke uses where using the `E*` value in non-socket context, or
other places expecting a POSIX `errno`, e.g. file I/O, threads, IDN or
interfacing with dependencies.

Fix it by introducing a curl-specific `SOCKE*` set of macros that map to
`WSA*` on Windows and standard POSIX codes on other platforms. Then
verify and update the code to use `SOCKE*` or `E*` macro depending on
context.

- Add `SOCKE*` macros that map to either winsock2 or POSIX error codes.
  And use them with `SOCKERRNO` or in contexts requiring
  platform-dependent socket error codes.

  This fixes `E*` uses which were supposed be POSIX values, not `WSA*`
  socket errors, on Windows:
  - lib/curl_multibyte.c
  - lib/curl_threads.c
  - lib/idn.c
  - lib/vtls/gtls.c
  - lib/vtls/rustls.c
  - src/tool_cb_wrt.c
  - src/tool_dirhie.c

- Ban `E*` codes having a `SOCKE*` mapping, via checksrc.
  Authored-by: Daniel Stenberg

- Add exceptions for `E*` codes used in file I/O, or other contexts
  requiring POSIX error codes.

Also:
- ftp: fix missing `SOCKEACCES` mapping for Windows.
- add `SOCKENOMEM` for `Curl_getaddrinfo()` via `asyn-thread.c`.
- tests/server/sockfilt: fix to set `SOCKERRNO` in local `select()`
  override on Windows.
- lib/inet_ntop: fix to return `WSAEINVAL` on Windows, where `ENOSPC` is
  used on other platforms. To simulate Windows' built-in `inet_ntop()`,
  as tested on a Win10 machine.
  Note:
  - WINE returns `STATUS_INVALID_PARAMETER` = `0xC000000D`.
  - Microsoft documentation says it returns `WSA_INVALID_PARAMETER`
    (= `ERROR_INVALID_PARAMETER`) 87:
    https://learn.microsoft.com/windows/win32/api/ws2tcpip/nf-ws2tcpip-inet_ntop#return-value
- lib/inet_ntop: drop redundant `CURL_SETERRNO(ENOSPC)`.
  `inet_ntop4()` already sets it before returning `NULL`.
- replace stray `WSAEWOULDBLOCK` with `USE_WINSOCK` macro to detect
  winsock2.
- move existing `SOCKE*` mappings from `tests/server` to
  `curl_setup_once.h`.
- add missing `EINTR`, `EINVAL` constants for WinCE.

Follow-up to abf80aae38 #16612
Follow-up to d69425ed7d #16615
Bug: https://github.com/curl/curl/pull/16553#issuecomment-2704679377

Closes #16621
2025-03-13 00:03:25 +01:00
Viktor Szakats
ee73d553ed
build: replace Curl_ prefix with curlx_ for functions used in servers
Closes #16689
2025-03-13 00:03:15 +01:00
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
Michał Antoniak
8e07429e43
cf-socket: remove empty switch
Closes #16555
2025-03-04 17:21:27 +01:00