We really don't want to do this, but in the case that the AF_UNIX path
is longer than the 108-byte limit that sun_path provides we don't really
have a choice. The alternative choice would be to switch /entirely/ away
from AF_UNIX and instead use pipes. We need a bandage fix for now, so
throw the socket in to a temp folder if the path is too long.
building with clang/musl causes these warnings:
```
FEX/Source/Tools/FEXServer/ProcessPipe.cpp:100:96: warning: format specifies type 'ssize_t' (aka 'long') but the argument has type 'rlim_t' (aka 'unsigned long long') [-Wformat]
```
- cast platform specific MaxFDs members to uintmax_t and print as PRIuMAX
- use %zu for GetNumFilesOpen (size_t)
fix: #5471
Signed-off-by: Pepper Gray <hello@peppergray.xyz>
In portable mode, FEXOfflineCompiler may not be in PATH (and if it is, it's
most likely not a compatible version). Instead, use the executable next to
the FEXServer binary.
This was a requested feature. To make sure that FEXServer is running and
managed by a parent process, we need to have a way to tell FEXServer to
keep alive without any FEX clients. The best way to do this is to pass
FEXServer a Pipe (like FEX does when a client starts it), but instead of
FEXServer signaling to FEXInterpreter that it's ready. FEXServer listens
to the pipe to see if the management process is still alive.
The expectation here is that the management process passes FEXServer the
read end of a pipe, and when the management software is done (or gets
killed by the kernel!) then the write end of the pipe is closed, and
FEXServer naturally closes (As long as there's no FEX processes
remaining).
Managing code maps in FEXServer rather than in FEXInterpreter makes it
easier to handle multiple concurrent processes sharing code caches for
the main executable and libraries.
Still creates a copy of FEXInterpreter from FEX for downstream projects
to have some time to get off the old name. Creating a symlink is kind of
a pain in cmake so just doing an install copy is easy.
The character counting logic isn't actually needed, since bind() doesn't
need the exact byte length of the input data. Dropping the manual bookkeeping
cleans up this code considerably.
Abstract sockets have one limitation: they are bound to a network
namespace. Chromium/CEF sandboxes using a new netns, which breaks
connecting to the FEXServer.
To work around this, use and try *both* abstract and named sockets. As
long as either the filesystem or the network is unsandboxed, things will
work. If both are sandboxed, there isn't much we can do... but at that
point we shouldn't be reinitializing the FEXServer connection anyway
since the FS should be available on FEXInterpreter startup.
Fixes this file compiling on musl at least.
POLLREMOVE usage here is technically incorrect as it shouldn't be OR'd
with other flags.
But it is also additionally wrong here because the Linux kernel doesn't
even support this flag anymore, so it doesn't change behaviour.
Two changes here.
- Make the mount path follow server temp folder requirements.
- Will be mounted in `/tmp/` or `$XDG_RUNTIME_DIR/` now
- Switch the FEXServer socket to an "abstract" AF_UNIX socket.
- If the socket is in `/tmp/` then systemd will put the service in a
private `/tmp` folder that only exists for the service.
- If the socket is in `$XDG_RUNTIME_DIR` then pressure-vessel can't
chroot anymore since they make their own runtime directory.
- If it is in `$HOME/.fex-emu/` then it breaks usage where the
filesystem is a mount that doesn't support AF_UNIX like sshfs.
The only reasonable thing to do is to switch over to `abstract` sockets
which will work in all cases.
Tested with pressure-vessel and systemd and now it works in all
situations.
Chrome seems to like sending us invalid packets of data sometimes. With
an invalid packet type just skip parsing the data entirely.
Fixes an infinite loop in Vampire Survivors.
pidfd_open was added in kernel 5.3 so older kernel devices weren't able
to use `FEXServer -w`. If the syscall doesn't give us an FD to the
process, then use a pipe instead.
Since we are only polling for the FD to hangup this works for us.
Depending on the operation we will do a vector insert or removal while
iterating over the vector.
Fixes a use after free that asan found when insert caused the vector to
resize.
It can be useful to know in tooling when the current active FEXServer
has exited.
Two things can happen when this command is run.
No FEXServer is active, returns immediately.
A FEXServer is active, we query for a pidfd from the active server, then
we wait until it exits.
Both instances of this is valid to use.
This is a relatively invasive change since multiple things needed to
happen at once.
* Socket based logging is removed
* Logging has been replaced to only support stdout, stderr, and server
* Server is now default and replaces what FEXLogServer did
* Server logging now uses a pipe instead of a socket
* Can be faster than stderr and stdout since the application doesn't
need to wait on terminal output
* FEXMountDaemon has been removed
* Functionality has been merged in to FEXServer
* FEXServer is always executed on FEX initialization time
* Similar in behaviour to Wine's wineserver
* Can explicitly start this before using FEX for logging purposes
* Stays around until all instances of FEX exit
* Will stick around for a short amount of time in case of spurious
execution
* FEXServer will soon be extended to do more than logging and squashfs
mounting
* FEX rootfs scripts will need to be updated to support this path
* Just means rbinding the /tmp folder and forcing a FEXServer instance
to be alive
* Pressure-vessel works fine in this case since FEXServer will already
be running
* It already rbinds the host /tmp folder which is why this works
Ryan Houdek