https://best.openssf.org/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.html
as of 2023-11-29 [1].
Enable new recommended warnings (except `-Wsign-conversion`):
- enable `-Wformat=2` for clang (in both cmake and autotools).
- add `CURL_PRINTF()` internal attribute and mark functions accepting
printf arguments with it. This is a copy of existing
`CURL_TEMP_PRINTF()` but using `__printf__` to make it compatible
with redefinting the `printf` symbol:
https://gcc.gnu.org/onlinedocs/gcc-3.0.4/gcc_5.html#SEC94
- fix `CURL_PRINTF()` and existing `CURL_TEMP_PRINTF()` for
mingw-w64 and enable it on this platform.
- enable `-Wimplicit-fallthrough`.
- enable `-Wtrampolines`.
- add `-Wsign-conversion` commented with a FIXME.
- cmake: enable `-pedantic-errors` the way we do it with autotools.
Follow-up to d5c0351055#2747
- lib/curl_trc.h: use `CURL_FORMAT()`, this also fixes it to enable format
checks. Previously it was always disabled due to the internal `printf`
macro.
Fix them:
- fix bug where an `set_ipv6_v6only()` call was missed in builds with
`--disable-verbose` / `CURL_DISABLE_VERBOSE_STRINGS=ON`.
- add internal `FALLTHROUGH()` macro.
- replace obsolete fall-through comments with `FALLTHROUGH()`.
- fix fallthrough markups: Delete redundant ones (showing up as
warnings in most cases). Add missing ones. Fix indentation.
- silence `-Wformat-nonliteral` warnings with llvm/clang.
- fix one `-Wformat-nonliteral` warning.
- fix new `-Wformat` and `-Wformat-security` warnings.
- fix `CURL_FORMAT_SOCKET_T` value for mingw-w64. Also move its
definition to `lib/curl_setup.h` allowing use in `tests/server`.
- lib: fix two wrongly passed string arguments in log outputs.
Co-authored-by: Jay Satiro
- fix new `-Wformat` warnings on mingw-w64.
[1] 56c0fde389/docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C%2B%2B.mdCloses#12489
- use `data->state.dselect_bits` everywhere instead
- remove `bool *comeback` parameter as non-zero
`data->state.dselect_bits` will indicate that IO is
incomplete.
Closes#12512
GCC 14 introduces a new -Walloc-size included in -Wextra which gives:
```
src/tool_operate.c: In function ‘add_per_transfer’:
src/tool_operate.c:213:5: warning: allocation of insufficient size ‘1’ for type ‘struct per_transfer’ with size ‘480’ [-Walloc-size]
213 | p = calloc(sizeof(struct per_transfer), 1);
| ^
src/var.c: In function ‘addvariable’:
src/var.c:361:5: warning: allocation of insufficient size ‘1’ for type ‘struct var’ with size ‘32’ [-Walloc-size]
361 | p = calloc(sizeof(struct var), 1);
| ^
```
The calloc prototype is:
```
void *calloc(size_t nmemb, size_t size);
```
So, just swap the number of members and size arguments to match the
prototype, as we're initialising 1 struct of size `sizeof(struct
...)`. GCC then sees we're not doing anything wrong.
Closes#12292
Connection filter had a `get_select_socks()` method, inspired by the
various `getsocks` functions involved during the lifetime of a
transfer. These, depending on transfer state (CONNECT/DO/DONE/ etc.),
return sockets to monitor and flag if this shall be done for POLLIN
and/or POLLOUT.
Due to this design, sockets and flags could only be added, not
removed. This led to problems in filters like HTTP/2 where flow control
prohibits the sending of data until the peer increases the flow
window. The general transfer loop wants to write, adds POLLOUT, the
socket is writeable but no data can be written.
This leads to cpu busy loops. To prevent that, HTTP/2 did set the
`SEND_HOLD` flag of such a blocked transfer, so the transfer loop cedes
further attempts. This works if only one such filter is involved. If a
HTTP/2 transfer goes through a HTTP/2 proxy, two filters are
setting/clearing this flag and may step on each other's toes.
Connection filters `get_select_socks()` is replaced by
`adjust_pollset()`. They get passed a `struct easy_pollset` that keeps
up to `MAX_SOCKSPEREASYHANDLE` sockets and their `POLLIN|POLLOUT`
flags. This struct is initialized in `multi_getsock()` by calling the
various `getsocks()` implementations based on transfer state, as before.
After protocol handlers/transfer loop have set the sockets and flags
they want, the `easy_pollset` is *always* passed to the filters. Filters
"higher" in the chain are called first, starting at the first
not-yet-connection one. Each filter may add sockets and/or change
flags. When all flags are removed, the socket itself is removed from the
pollset.
Example:
* transfer wants to send, adds POLLOUT
* http/2 filter has a flow control block, removes POLLOUT and adds
POLLIN (it is waiting on a WINDOW_UPDATE from the server)
* TLS filter is connected and changes nothing
* h2-proxy filter also has a flow control block on its tunnel stream,
removes POLLOUT and adds POLLIN also.
* socket filter is connected and changes nothing
* The resulting pollset is then mixed together with all other transfers
and their pollsets, just as before.
Use of `SEND_HOLD` is no longer necessary in the filters.
All filters are adapted for the changed method. The handling in
`multi.c` has been adjusted, but its state handling the the protocol
handlers' `getsocks` method are untouched.
The most affected filters are http/2, ngtcp2, quiche and h2-proxy. TLS
filters needed to be adjusted for the connecting handshake read/write
handling.
No noticeable difference in performance was detected in local scorecard
runs.
Closes#11833
- fold the code to convert dynhds to the nghttp2 structs
into a dynhds internal method
- saves code duplication
- pacifies compiler analyzers
Closes#12097
- If SSL shutdown is not finished then make an additional call to
SSL_read to gather additional tracing.
- Fix http2 and h2-proxy filters to forward do_close() calls to the next
filter.
For example h2 and SSL shutdown before and after this change:
Before:
Curl_conn_close -> cf_hc_close -> Curl_conn_cf_discard_chain ->
ssl_cf_destroy
After:
Curl_conn_close -> cf_hc_close -> cf_h2_close -> cf_setup_close ->
ssl_cf_close
Note that currently the tracing does not show output on the connection
closure handle. Refer to discussion in #11878.
Ref: https://github.com/curl/curl/discussions/11878
Closes https://github.com/curl/curl/pull/11858
- use shared code for setting up the CONNECT request
when tunneling, used in HTTP/1.x and HTTP/2 proxying
- eliminate use of Curl_buffer_send() and other manipulations
of `data->req` or `data->state.ulbuf`
Closes#11808
- added test cases for various code paths
- fixed handling of blocked write when stream had
been closed inbetween attempts
- re-enabled DEBUGASSERT on send with smaller data size
- in debug builds, environment variables can be set to simulate a slow
network when sending data. cf-socket.c and vquic.c support
* CURL_DBG_SOCK_WBLOCK: percentage of send() calls that should be
answered with a EAGAIN. TCP/UNIX sockets.
This is chosen randomly.
* CURL_DBG_SOCK_WPARTIAL: percentage of data that shall be written
to the network. TCP/UNIX sockets.
Example: 80 means a send with 1000 bytes would only send 800
This is applied to every send.
* CURL_DBG_QUIC_WBLOCK: percentage of send() calls that should be
answered with EAGAIN. QUIC only.
This is chosen randomly.
Closes#11756
- depending on what is tunneled, the proxy may never get invoked for
receiving data explicitly. Not progressing ingress may lead to stalls
due to missed WINDOW_UPDATEs.
CI:
- add a chache for building mod_h2
Closes#11527
- fix HTTP/2 check to not declare a connection dead when
the read attempt results in EAGAIN
- add H2-PROXY alive check as for HTTP/2 that was missing
and is needed
- add attach/detach around Curl_conn_is_alive() and remove
these in filter methods
- add checks for number of connections used in some test_10
proxy tunneling tests
Closes#11368
- fixes#11242 where 100% CPU on uploads was reported
- fixes possible stalls on last part of a request body when
that information could not be fully send on the connection
due to an EAGAIN
- applies the same EGAIN handling to HTTP/2 proxying
Reported-by: Sergey Alirzaev
Fixed#11242Closes#11342
- Use CURL_FORMAT_CURL_OFF_T where %zd was erroneously used for some
curl_off_t variables.
- Use %zu where %zd was erroneously used for some size_t variables.
Prior to this change some of the Windows CI tests were failing because
in Windows 32-bit targets have a 32-bit size_t and a 64-bit curl_off_t.
When %zd was used for some curl_off_t variables then only the lower
32-bits was read and the upper 32-bits would be read for part or all of
the next specifier.
Fixes https://github.com/curl/curl/issues/11327
Closes https://github.com/curl/curl/pull/11321
Aka "jumbo" or "amalgamation" builds. It means to compile all sources
per target as a single C source. This is experimental.
You can enable it by passing `-DCMAKE_UNITY_BUILD=ON` to cmake.
It requires CMake 3.16 or newer.
It makes builds (much) faster, allows for better optimizations and tends
to promote less ambiguous code.
Also add a new AppVeyor CI job and convert an existing one to use
"unity" mode (one MSVC, one MinGW), and enable it for one macOS CI job.
Fix related issues:
- add missing include guard to `easy_lock.h`.
- rename static variables and functions (and a macro) with names reused
across sources, or shadowed by local variables.
- add an `#undef` after use.
- add a missing `#undef` before use.
- move internal definitions from `ftp.h` to `ftp.c`.
- `curl_memory.h` fixes to make it work when included repeatedly.
- stop building/linking curlx bits twice for a static-mode curl tool.
These caused doubly defined symbols in unity builds.
- silence missing extern declarations compiler warning for ` _CRT_glob`.
- fix extern declarations for `tool_freq` and `tool_isVistaOrGreater`.
- fix colliding static symbols in debug mode: `debugtime()` and
`statename`.
- rename `ssl_backend_data` structure to unique names for each
TLS-backend, along with the `ssl_connect_data` struct member
referencing them. This required adding casts for each access.
- add workaround for missing `[P]UNICODE_STRING` types in certain Windows
builds when compiling `lib/ldap.c`. To support "unity" builds, we had
to enable `SCHANNEL_USE_BLACKLISTS` for Schannel (a Windows
`schannel.h` option) _globally_. This caused an indirect inclusion of
Windows `schannel.h` from `ldap.c` via `winldap.h` to have it enabled
as well. This requires `[P]UNICODE_STRING` types, which is apperantly
not defined automatically (as seen with both MSVS and mingw-w64).
This patch includes `<subauth.h>` to fix it.
Ref: https://github.com/curl/curl/runs/13987772013
Ref: https://dev.azure.com/daniel0244/curl/_build/results?buildId=15827&view=logs&jobId=2c9f582d-e278-56b6-4354-f38a4d851906&j=2c9f582d-e278-56b6-4354-f38a4d851906&t=90509b00-34fa-5a81-35d7-5ed9569d331c
- tweak unity builds to compile `lib/memdebug.c` separately in memory
trace builds to avoid PP confusion.
- force-disable unity for test programs.
- do not compile and link libcurl sources to libtests _twice_ when libcurl
is built in static mode.
KNOWN ISSUES:
- running tests with unity builds may fail in cases.
- some build configurations/env may not compile in unity mode. E.g.:
https://ci.appveyor.com/project/curlorg/curl/builds/47230972/job/51wfesgnfuauwl8q#L250
Ref: https://github.com/libssh2/libssh2/issues/1034
Ref: https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
Ref: https://en.wikipedia.org/wiki/Unity_buildCloses#11095
- with `--proxy-http2` allow h2 ALPN negotiation to
forward proxies
- applies to http: requests against a https: proxy only,
as https: requests will auto-tunnel
- adding a HTTP/1 request parser in http1.c
- removed h2h3.c
- using new request parser in nghttp2 and all h3 backends
- adding test 2603 for request parser
- adding h2 proxy test cases to test_10_*
scorecard.py: request scoring accidentally always run curl
with '-v'. Removed that, expect double numbers.
labeller: added http1.* and h2-proxy sources to detection
Closes#10967
- progress ingress stopped too early, causing data
from the underlying filters to not be processed and
report that no tunnel data was available
- this lead to "hangers" where no socket activity was
seen but data rested in buffers
Closes#10952
- currently only on debug build and when env variable
CURL_PROXY_TUNNEL_H2 is present.
- will ALPN negotiate with the proxy server and switch
tunnel filter based on the protocol negotiated.
- http/1.1 tunnel code moved into cf-h1-proxy.[ch]
- http/2 tunnel code implemented in cf-h2-proxy.[ch]
- tunnel start and ALPN set remains in http_proxy.c
- moving all haproxy related code into cf-haproxy.[ch]
VTLS changes
- SSL filters rely solely on the "alpn" specification they
are created with and no longer check conn->bits.tls_enable_alpn.
- checks on which ALPN specification to use (or none at all) are
done in vtls.c when creating the filter.
Testing
- added a nghttpx forward proxy to the pytest setup that
speaks HTTP/2 and forwards all requests to the Apache httpd
forward proxy server.
- extending test coverage in test_10 cases
- adding proxy tests for direct/tunnel h1/h2 use of basic auth.
- adding test for http/1.1 and h2 proxy tunneling to pytest
Closes#10780
