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.
The earlier iterations did too much guesswork when it came to things
like stderr logging and syscall origin verification. This change will
make things more conformant to existing practices. The __pledge_mode
extension now can be configured in a better way.
There's also a new `-q` flag added to pledge.com, e.g.
o//tool/build/pledge.com -qv. ls
Is a good way to disable warnings about `tty` access attempts.
This change also removes the futimens() call on the Landlock Make output
file workaround, since it caused problems with commands like fixupobj
which modify-in-place. It turns out if a file is opened for writing and
then no writes actually occur, then the modified time doesn't change.
- 10.5% reduction of o//depend dependency graph
- 8.8% reduction in latency of make command
- Fix issue with temporary file cleanup
There's a new -w option in compile.com that turns off the recent
Landlock output path workaround for "good commands" which do not
unlink() the output file like GNU tooling does.
Our new GNU Make unveil sandboxing appears to have zero overhead
in the grand scheme of things. Full builds are pretty fast since
the only thing that's actually slowed us down is probably libcxx
make -j16 MODE=rel
RL: took 85,732,063µs wall time
RL: ballooned to 323,612kb in size
RL: needed 828,560,521µs cpu (11% kernel)
RL: caused 39,080,670 page faults (99% memcpy)
RL: 350,073 context switches (72% consensual)
RL: performed 0 reads and 11,494,960 write i/o operations
pledge() and unveil() no longer consider ENOSYS to be an error.
These functions have also been added to Python's cosmo module.
This change also removes some WIN32 APIs and System Five magnums
which we're not using and it's doubtful anyone else would be too
We're now able to drop both `exec` and `prot_exec` privileges
automatically when launching glibc dynamic executables. We also have
really outstanding standard error logging now, that explains which
promises are needed, even in cases where `exec` is used.
- We now kill the program on violations like OpenBSD
- We now print a message explaining which promise is needed
- This change also fixes a linkage bug with thread local storage
- Your sigaction() handlers should now be more thread safe
A new `__pledge_mode` global has been introduced to make pledge() more
customizable on Linux. For example:
__attribute__((__constructor__)) static void init(void) {
__pledge_mode = SECCOMP_RET_ERRNO | EPERM;
}
Can be used to restore our old permissive pledge() behavior.
- Make memmem() faster
- Make readdir() thread safe
- Remove 64kb limit from mkdeps.com
- Add old crypt() function from Musl
- Improve new fix-third-party.py tool
- Improve libc/isystem/ headers and fix bugs
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.
This change also fixes a bug with gettid() being incorrect after fork().
We now implement the ENOENT behavior for getauxval(). The getuid() etc.
system calls are now faster too. Plus issetugid() will work on BSDs.
This change addresses review comments from Günther Noack on GitHub.
We're now blacklisting truncate() and setxattr() since Landlock lets
them operate on veiled files. The restriction has been lifted on using
unveil() multiple times, since Landlock does that well.
- Fix getpriority()
- Add AT_MINSIGSTKSZ
- Fix bugs in BPF code
- Show more stuff in printargs.com
- Write manual test for pledge.com
- pledge() now generates tinier BPF code
- Have pledge("exec") only enable execve()
- Fix pledge.com chroot setuid functionality
- Improve pledge.com unveiling of ape loader
This change fixes bugs, adds more system calls, and improves
compatibility with OpenBSD. Going forward, versions on the web will be
pinned to a permanent version. There were many other changes over the
last week which also improved this new release.
Redbean Lua and JSON serialization now goes faster because we're now
inserting object entries into tree data structure rather than making
an array and sorting it at the end. For example, when serializing an
object with 10,000 entries this goes twice as fast. However it still
goes slower than saying EncodeJson(x, {sorted=false}).
- Introduce path module to redbean
- Fix glitch with linenoise printing extra line on eof
- Introduce closefrom() and close_range() system calls
- Make file descriptor closing more secure in pledge.com
This change reconciles our pledge() implementation with the OpenBSD
kernel source code. We now a polyfill that's much closer to OpenBSD's
behavior. For example, it was discovered that "stdio" permits threads.
There were a bunch of Linux system calls that needed to be added, like
sched_yield(). The exec / execnative category division is now dropped.
We're instead using OpenBSD's "prot_exec" promise for launching APE
binaries and dynamic shared objects. We also now filter clone() flags.
The pledge.com command has been greatly improved. It now does unveiling
by default when Landlock is available. It's now smart enough to unveil a
superset of paths that OpenBSD automatically unveils with pledge(), such
as /etc/localtime. pledge.com also now checks if the executable being
launched is a dynamic shared object, in which case it unveils libraries.
These changes now make it possible to pledge curl on ubuntu 20.04 glibc:
pledge.com -p 'stdio rpath prot_exec inet dns tty sendfd recvfd' \
curl -s https://justine.lol/hello.txt
Here's what pledging curl on Alpine 3.16 with Musl Libc looks like:
pledge.com -p 'stdio rpath prot_exec dns inet' \
curl -s https://justine.lol/hello.txt
Here's what pledging curl.com w/ ape loader looks like:
pledge.com -p 'stdio rpath prot_exec dns inet' \
o//examples/curl.com https://justine.lol/hello.txt
The most secure sandbox, is curl.com converted to static ELF:
o//tool/build/assimilate.com o//examples/curl.com
pledge.com -p 'stdio rpath dns inet' \
o//examples/curl.com https://justine.lol/hello.txt
A weird corner case needed to be handled when resolving symbolic links
during the unveiling process, that's arguably a Landlock bug. It's not
surprising since Musl and Glibc are also inconsistent here too.
We had previously not enabled TLS in MODE=tiny in order to keep the
smallest example programs (e.g. life.com) just 16kb in size. But it
was error prone doing that, so now we just always enable it because
this change uses hacks to ensure it won't increase life.com's size.
This change also fixes a bug on NetBSD, where signal handlers would
break thread local storage if SA_SIGINFO was being used. This looks
like it might be a bug in NetBSD, but it's got a simple workaround.
This is an unusual failure that seems to happen intermittently across
the various build modes. It should not be possible for life.elf to be
exiting with status zero.
The pledge.com command now supports the new [WIP] unveil() support. For
example, to strongly sandbox our command for listing directories.
o//tool/build/assimilate.com o//examples/ls.com
pledge.com -v /etc -p 'stdio rpath' o//examples/ls.com /etc
This file system sandboxing is going to be perfect for us, because APE
binaries are self-contained static executables that really don't use the
filesystem that much. On the other hand, with non-static executables,
sandboxing is going to be more difficult. For example, here's how to
sandbox the `ls` command on the latest Alpine:
pledge.com -v rx:/lib -v /usr/lib -v /etc -p 'stdio rpath exec' ls /etc
This change fixes the `execpromises` API with pledge().
This change also adds unix.unveil() to redbean.
Fixes#494
This change simplifies the thread-local storage support code. On Windows
and Mac OS X the startup latency of __enable_tls() has been reduced from
30ms to 1ms. On Windows, TLS memory accesses will now go much faster due
to better self-modifying code that prevents a function call and acquires
our thread information block pointer in a single instruction.
We now rewrite the binary image at runtime on Windows and XNU to change
mov %fs:0,%reg instructions to use %gs instead. There's also simpler
threading API introduced by this change and it's called _spawn() and
_join(), which has replaced most clone() usage.
Our build was flaking due to ETXTBSY errors running multiple redbean
instances in parallel. This is due to the StoreAsset() support which
seems to cause enough problems it's worth making a *breaking change*
turning it off by default for now. There's a new -* flag, to restore
redbean's old self-modifying behavior.
- Fix DescribeSigset()
- Introduce new unix.rmrf() API
- Fix redbean sigaction() doc example code
- Fix unix.sigaction() w/ more than two args
- Improve redbean re module API (non-breaking)
- Enhance Lua with Python string multiplication
- Make third parameter of unix.socket() default to 0
This change fixes a regression from 281a0f27 which resulted in the
integer literal `0` being interpreted as a floating point number. This
should also fix a reported issue with Fennel integration.
The Compress() and Uncompress() APIs were a mistake. The functions
themselves work fine, but it's a design blemish and does superfluous
work. Since they were only introduced in the last few weeks, they're now
deprecated and references to them have been scrubbed from the website
and other documentation. Please use the new APIs since the old APIs will
be removed at some point in the future.
This change introduces automated Lua unit tests for the Redbean APIs.
There's a few functions that were broken which have now been fixed, e.g.
Underlong() and Decimate().
- Wrap clock_getres()
- Wrap sched_setscheduler()
- Make sleep() api conformant
- Polyfill sleep() using select()
- Improve clock_gettime() polyfill
- Make nanosleep() POSIX conformant
- Slightly improve some DNS functions
- Further strengthen pledge() sandboxing
- Improve rounding of timeval / timespec
- Allow layering of pledge() calls on Linux
- Polyfill sched_yield() using select() on XNU
- Delete more system constants we probably don't need
When a format string like %2x is provided, the width parameter was read
correctly as 2, but it was not used when decoding the number from the
input string (ie instead of reading 2 characters from the input string,
vcscanf read all the characters).
This change uses the value of width within the number decoding loop to
read fixed number of digits correctly. if width is zero (not provided),
the default of width is set as bits.
Fixes#423
- Introduce __assert_disable global
- Improve strsignal() thread safety
- Make system call tracing thread safe
- Fix SO_RCVTIMEO / SO_SNDTIMEO on Windows
- Refactor DescribeFoo() functions into one place
- Fix fork() on Windows when TLS and MAP_STACK exist
- Round upwards in setsockopt(SO_RCVTIMEO) on Windows
- Disable futexes on OpenBSD which seem extremely broken
- Implement a better kludge for monotonic time on Windows
On all operating systems tested so far, PROT_EXEC without PROT_READ
always makes memory readable. This turned out to not be the case on
Chromebooks, which likely means they have the capability of running
programs which aren't able to read their own code.
