Commit graph

7 commits

Author SHA1 Message Date
Justine Tunney
7cf66bc161 Prevent Make from talking to public Internet
This change introduces the nointernet() function which may be called to
prevent a process and its descendants from communicating with publicly
routable Internet addresses. GNU Make has been modified to always call
this function. In the future Landlock Make will have a way to whitelist
subnets to override this behavior, or disable it entirely. Support is
available for Linux only. Our firewall does not require root access.

Calling nointernet() will return control to the caller inside a new
process that has a SECCOMP BPF filter installed, which traps network
related system calls. Your original process then becomes a permanent
ptrace() supervisor that monitors all processes and threads descending
from the returned child. Whenever a networking system call happens the
kernel will stop the process and wakes up the monitor, which then peeks
into the child memory to read the sockaddr_in to determine if it's ok.

The downside to doing this is that there can be only one supervisor at a
time using ptrace() on a process. So this firewall won't be enabled if
you run make under strace or inside gdb. It also makes testing tricky.
2022-08-12 21:51:39 -07:00
Justine Tunney
cf93ecbbb2 Prove that Makefile is fully defined
The whole repository is now buildable with GNU Make Landlock sandboxing.
This proves that no Makefile targets exist which touch files other than
their declared prerequisites. In order to do this, we had to:

  1. Stop code morphing GCC output in package.com and instead run a
     newly introduced FIXUPOBJ.COM command after GCC invocations.

  2. Disable all the crumby Python unit tests that do things like create
     files in the current directory, or rename() files between folders.
     This ended up being a lot of tests, but most of them are still ok.

  3. Introduce an .UNSANDBOXED variable to GNU Make to disable Landlock.
     We currently only do this for things like `make tags`.

  4. This change deletes some GNU Make code that was preventing the
     execve() optimization from working. This means it should no longer
     be necessary in most cases for command invocations to be indirected
     through the cocmd interpreter.

  5. Missing dependencies had to be declared in certain places, in cases
     where they couldn't be automatically determined by MKDEPS.COM

  6. The libcxx header situation has finally been tamed. One of the
     things that makes this difficult is MKDEPS.COM only wants to
     consider the first 64kb of a file, in order to go fast. But libcxx
     likes to have #include lines buried after huge documentation.

  7. An .UNVEIL variable has been introduced to GNU Make just in case
     we ever wish to explicitly specify additional things that need to
     be whitelisted which aren't strictly prerequisites. This works in
     a manner similar to the recently introduced .EXTRA_PREREQS feature.

There's now a new build/bootstrap/make.com prebuilt binary available. It
should no longer be possible to write invalid Makefile code.
2022-08-06 04:05:08 -07:00
Justine Tunney
b45d50b690 Make improvements
- Fix build flakes
- Polyfill SIGWINCH on Windows
- Fix an execve issue on Windows
- Make strerror show more information
- Improve cmd.exe setup/teardown on Windows
- Support bracketed paste mode in Blinkenlights
- Show keyboard shortcuts in Blinkenlights status bar
- Fixed copy_file_range() and copyfile() w/ zip filesystem
- Size optimize GetDosArgv() to keep life.com 12kb in size
- Improve Blinkenlights ability to load weird ELF executables
- Fix program_executable_name and add GetInterpreterExecutableName
- Make Python in tiny mode fail better if docstrings are requested
- Update Python test exclusions in tiny* modes such as tinylinux
- Add bulletproof unbreakable kprintf() troubleshooting function
- Remove "oldskool" keyword from ape.S for virus scanners
- Fix issue that caused backtraces to not print sometimes
- Improve Blinkenlights serial uart character i/o
- Make clock_gettime() not clobber errno on xnu
- Improve sha256 cpuid check for old computers
- Integrate some bestline linenoise fixes
- Show runit process names better in htop
- Remove SIGPIPE from ShowCrashReports()
- Make realpath() not clobber errno
- Avoid attaching GDB on non-Linux
- Improve img.com example
2022-03-16 13:40:10 -07:00
Alexander Nicholi
ec9bfd8c56
finish intellisense support and sync with upstream 2021-02-03 13:50:08 -05:00
Justine Tunney
9e3e985ae5 Make terminal ui binaries work well everywhere
Here's some screenshots of an emulator tui program that was compiled on
Linux, then scp'd it to Windows, Mac, and FreeBSD.

https://justine.storage.googleapis.com/blinkenlights-cmdexe.png
https://justine.storage.googleapis.com/blinkenlights-imac.png
https://justine.storage.googleapis.com/blinkenlights-freebsd.png
https://justine.storage.googleapis.com/blinkenlights-lisp.png

How is this even possible that we have a nontrivial ui binary that just
works on Mac, Windows, Linux, and BSD? Surely a first ever achievement.

Fixed many bugs. Bootstrapped John McCarthy's metacircular evaluator on
bare metal in half the size of Altair BASIC (about 2.5kb) and ran it in
emulator for fun and profit.
2020-10-19 06:38:31 -07:00
Justine Tunney
416fd86676 Make improvements
- Emulator can now test the αcτµαlly pδrταblε εxεcµταblε bootloader

- Whipped up a webserver named redbean. It services 150k requests per
  second on a single core. Bundling assets inside zip enables extremely
  fast serving for two reasons. The first is that zip central directory
  lookups go faster than stat() system calls. The second is that both
  zip and gzip content-encoding use DEFLATE, therefore, compressed
  responses can be served via the sendfile() system call which does an
  in-kernel copy directly from the zip executable structure. Also note
  that red bean zip executables can be deployed easily to all platforms,
  since these native executables work on Linux, Mac, BSD, and Windows.

- Address sanitizer now works very well
2020-09-14 00:02:34 -07:00
Justine Tunney
5aabacb361 Add pseudoteletypewriter to emulator
https://justine.storage.googleapis.com/emulator628.mp4
2020-08-29 23:51:09 -07:00