This patch adds support for Microsoft Windows in the Process subsystem.
Libevent does not support mixing different types of handles (sockets,
named pipes, etc.) on Windows in its core event loop code. This have
historically meant that Tor have avoided attaching any non-networking
handles to the event loop. This patch uses a slightly different approach
to roughly support the same features for the Process subsystem as we do
with the Unix backend.
In this patch we use Windows Extended I/O functions (ReadFileEx() and
WriteFileEx()) which executes asynchronously in the background and
executes a completion routine when the scheduled read or write operation
have completed. This is much different from the Unix backend where the
operating system signals to us whenever a file descriptor is "ready" to
either being read from or written to.
To make the Windows operating system execute the completion routines of
ReadFileEx() and WriteFileEx() we must get the Tor process into what
Microsoft calls an "alertable" state. To do this we execute SleepEx()
with a zero millisecond sleep time from a main loop timer that ticks
once a second. This moves the process into the "alertable" state and
when we return from the zero millisecond timeout all the outstanding I/O
completion routines will be called and we can schedule the next reads
and writes.
The timer loop is also responsible for detecting whether our child
processes have terminated since the last timer tick.
See: https://bugs.torproject.org/28179
This patch adds the Unix backend for the Process subsystem. The Unix
backend attaches file descriptors from the child process's standard in,
out and error to Tor's libevent based main loop using traditional Unix
pipes. We use the already available `waitpid` module to get events
whenever the child process terminates.
See: https://bugs.torproject.org/28179
This patch adds a new Process subsystem for running external programs in
the background of Tor. The design is focused around a new type named
`process_t` which have an API that allows the developer to easily write
code that interacts with the given child process. These interactions
includes:
- Easy API for writing output to the child process's standard input
handle.
- Receive callbacks whenever the child has output on either its standard
output or standard error handles.
- Receive callback when the child process terminates.
We also support two different "protocols" for handling output from the
child process. The default protocol is the "line" protocol where the
process output callbacks will be invoked only when there is complete
lines (either "\r\n" or "\n" terminated). We also support the "raw"
protocol where the read callbacks will get whatever the operating system
delivered to us in a single read operation.
This patch does not include any operating system backends, but the Unix
and Windows backends will be included in separate commits.
See: https://bugs.torproject.org/28179
This patch adds two new functions: buf_flush_to_pipe() and
buf_read_from_pipe(), which makes use of our new buf_flush_to_fd() and
buf_read_from_fd() functions.
See: https://bugs.torproject.org/28179
This patch refactors buf_read_from_socket() into buf_read_from_fd(), and
creates a specialized function for buf_read_from_socket(), which uses
buf_read_from_fd().
See: https://bugs.torproject.org/28179
This patch refactors buf_flush_to_socket() into buf_flush_to_fd() and
creates a specialization function for buf_flush_to_socket() that makes
use of buf_flush_to_fd().
See: https://bugs.torproject.org/28179
This patch explicitly specifies the path to our OpenSSL dependency and
disables the installation of an external OpenSSL version and instead
uses the OpenSSL version available from the MinGW environments.
See: https://bugs.torproject.org/28574
The DormantClientTimeout option controls how long Tor will wait before
going dormant. It also provides a way to disable the feature by setting
DormantClientTimeout to e.g. "50 years".
The DormantTimeoutDisabledByIdleStreams option controls whether open but
inactive streams count as "client activity". To implement it, I had to
make it so that reading or writing on a client stream *always* counts as
activity.
Closes ticket 28429.
After we clear the protover map for getting full, we need to
re-create it, since we are about to use it.
This is a bugfix for bug 28558. It is a bugfix for the code from
ticket 27225, which is not in any released Tor. Found by Google
OSS-Fuzz, as issue 11475.
To succesful compile tor-print-ed-signing-cert.exe on Windows we
sometimes need to include the @TOR_LIB_GDI@ library.
See: https://bugs.torproject.org/28485
This representation is meant to save memory in microdescriptors --
we can't use it in routerinfo_t yet, since those families need to be
encoded losslessly for directory voting to work.
This representation saves memory in three ways:
1. It uses only one allocation per family. (The old way used a
smartlist (2 allocs) plus one strdup per entry.)
2. It stores identity digests in binary, not hex.
3. It keeps families in a canonical format, memoizes, and
reference-counts them.
Part of #27359.
