Some PT applications support more than one transport. For example,
obfs4proxy supports obfs4, obfs3, and meek. If one or more transports
specified in the torrc file are supported, we shouldn't kill the managed
proxy on a {C,S}METHOD-ERROR. Instead, we should log a warning.

We were already logging warnings on method errors. This change just
makes sure that the managed proxy isn't killed, and then if no
transports are configured for the managed proxy, bumps the log level up
from a notice to a warning.

Closes #7362

From LibreSSL versions 3.2.1 through 3.4.0, our configure script
would conclude that TLSv1.3 as supported, but it actually wasn't.
This led to annoying breakage like #40128 and #40445.

Now we give an error message if we try to build with one of those
versions.

Closes #40511.

Previously the logic was reversed, and always gave the wrong answer.
This has no other effect than to change whether we suppress
deprecated API warnings.

Fixes #40429; bugfix on 0.3.5.13.

Mingw headers sometimes like to define alternative scanf/printf
format attributes depending on whether they're using clang, UCRT,
MINGW_ANSI_STDIO, or the microsoft version of printf/scanf.  This
change attempts to use the right one on the given platform.

This is an attempt to fix part of #40355.

Signed-off-by: David Goulet <dgoulet@torproject.org>

glibc versions 2.33 and newer use the modern "statx" system call in their
implementations of stat() and opendir() for Linux on i386.  Prevent failures in
the sandbox unit tests by modifying the sandbox to allow this system call
without restriction on i386 when it is available, and update the test suite to
skip the "sandbox/stat_filename" test in this case as it is certain to fail.

On 32-bit architectures where Linux provides the "stat64" system call,
including i386, the sandbox is unable to filter calls to stat() as glibc uses
this system call itself internally and the sandbox must allow it without
restriction.

Update the sandbox unit tests to skip the "sandbox/stat_filename" test on
systems where the "stat64" system call is defined and the test is certain to
fail.  Also reorder the "#if" statement's clauses to correspond with the
comment preceding it, for clarity.

On 32-bit architectures where Linux provides the "clock_gettime64" system call,
including i386, glibc uses it in place of "clock_gettime".  Modify the sandbox
implementation to match, to prevent Tor's monotonic-time functions (in
src/lib/time/compat_time.c) failing when the sandbox is active.

On i386 glibc uses the "chown32" system call instead of "chown".  Prevent
attempts to filter calls to chown() on this architecture from failing by
modifying the sandbox implementation to match.

Signed-off-by: David Goulet <dgoulet@torproject.org>

This also moves the warnings and add some theatrical effect around the
code so anyone modifying those list should notice the warnings signs and
read the comment accordingly.

Signed-off-by: David Goulet <dgoulet@torproject.org>

Doing this in the wrong way has potential to cause serious havoc on
the network, so let's make it harder for future programmers to mess
it up.

Signed-off-by: David Goulet <dgoulet@torproject.org>

Signed-off-by: David Goulet <dgoulet@torproject.org>

Our code doesn't allow it and so this prevents an assert() crash if the
DirPort is for instance IPv6 only.

Fixes #40494

Signed-off-by: David Goulet <dgoulet@torproject.org>

Signed-off-by: David Goulet <dgoulet@torproject.org>

Signed-off-by: David Goulet <dgoulet@torproject.org>