This change adds all the kernel parts of a network stack. The network stack
is partial but implements many of the important parts.
Add if(4) network interface abstraction. Network interfaces are registered
in a global list that can be iterated and each assigned an unique integer
identifier.
Add reference counted packets with a cache that recycles recent packets.
Add support for lo(4) loopback and ether(4) ethernet network interfaces.
The /dev/lo0 loopback device is created automatically on boot.
Add arp(4) address resolution protocol driver for translation of inet(4)
network layer addresses into ether(4) link layer addresses. arp(4) entries
are cached and evicted from the cache when needed or when the entry has not
been used for a while. The cache is limited to 256 entries for now.
Add ip(4) internet protocol version 4 support. IP fragmentation and options
are not implemented yet.
Add tcp(4) transmission control protocol sockets for a reliable transport
layer protocol that provides a reliable byte stream connection between two
hosts. The implementation is incomplete and does not yet implement out of
band data, options, and high performance extensions.
Add udp(4) user datagram protocol sockets for a connectionless transport
layer that provides best-effort delivery of datagrams.
Add ping(4) sockets for a best-effort delivery of echo datagrams.
Change type of sa_family_t from unsigned short to uint16_t.
Add --disable-network-drivers to the kernel(7) options and expose it with a
bootloader menu. tix-iso-bootconfig can set this option by default.
Import CRC32 code from libz for the Ethernet checksum.
This is a compatible ABI change that adds features to socket(2) (AF_INET,
IPPROTO_TCP, IPPROTO_UDP, IPPROTO_PING), the ioctls for if(4), socket
options, and the lo0 loopback interface.
This commit is based on work by Meisaka Yukara contributed as the commit
bbf7f1e8a5238a2bd1fe8eb1d2cc5c9c2421e2c4. Almost no lines of this work
remains in this final commit as it has been rewritten or refactored away
over the years, see the individual file headers for which files contain
remnants of this work.
Co-authored-by: Meisaka Yukara <Meisaka.Yukara@gmail.com>
The idle thread is now actually run when the system is idle because it
truly goes idle. The idle thread is made power efficient by using the hlt
instruction rather than a busy loop.
The new futex(2) system call is used to implement fast user-space mutexes,
condition variables, and semaphores. The same backend and design is used as
kutexes for truly sleeping kernel mutexes and condition variables.
The new exit_thread(2) flag EXIT_THREAD_FUTEX_WAKE wakes a futex.
Sleeping on clocks in the kernel now uses timers for true sleep.
The interrupt worker thread now truly sleeps when idle.
Kernel threads are now named.
This is a compatible ABI change.
Among other things, redirecting to a directory will now display an error
as it should.
Also fix a bug when opening /dev/pts: O_WRITE on a directory is a POSIX
violation.
The child processes of pid 1 were being reparented to pid 1, causing an
infinite loop. This change fixes the problem by adding a hook that runs in
the last thread about to exit in a process. When pid 1 exits, the hook will
prevent more processes and threads from being created, and then broadcast
kill all processes and threads. The hook is not run in LastPrayer(), as that
function runs in a worker thread and it can't block waiting for another
thread to run LastPrayer() in the same thread.
A new ioctl TIOCGDISPLAYS allow detecting which displays the terminal
has associated. The ability to set a keyboard layout can be detected
with tcgetblob kblayout.
Improve the user-space multi-monitor support while here.
The kernel now sets TERM rather than init(8).
This is a compatible ABI change riding on the previous commit's bump.
This change refactors the process group implementation and adds support
for sessions. The setsid(2) and getsid(2) system calls were added.
psctl(2) now has PSCTL_TTYNAME, which lets you get the name of a process's
terminal, and ps(1) now uses it.
The initial terminal is now called /dev/tty1.
/dev/tty is now a factory for the current terminal.
A global lock now protects the process hierarchy which makes it safe to
access other processes. This refactor removes potential vulnerabilities
and increases system robustness.
A number of terminal ioctls have been added.
This is a compatible ABI change.
The bootloader will now load the /boot/random.seed file if it exists, in
which case the kernel will use it as the initial kernel entropy. The kernel
warns if no random seed was loaded, unless the --no-random-seed option was
given. This option is used for live environments that inherently have no
prior secret state. The kernel initializes its entropy pool from the random
seed as of the first things, so randomness is available very early on.
init(8) will emit a fresh /boot/random.seed file on boot to avoid the same
entropy being used twice. init(8) also writes out /boot/random.seed on
system shutdown where the system has the most entropy. init(8) will warn if
writing the file fails, except if /boot is a real-only filesystem, and
keeping such state is impossible. The system administrator is then
responsible for ensuring the bootloader somehow passes a fresh random seed
on the next boot.
/boot/random.seed must be owned by the root user and root group and must
have file permissions 600 to avoid unprivileged users can read it. The file
is passed to the kernel by the bootloader as a multiboot module with the
command line --random-seed.
If no random seed is loaded, the kernel attempts a poor quality fallback
where it seeds the kernel arc4random(3) continuously with the current time.
The timing variance may provide some effective entropy. There is no real
kernel entropy gathering yet. The read of the CMOS real time clock is moved
to an early point in the kernel boot, so the current time is available as
fallback entropy.
The kernel access of the random seed module is supposed to be infallible
and happens before the kernel log is set up, but there is not yet a failsafe
API for mapping single pages in the early kernel.
sysupgrade(8) creates /boot/random.seed if it's absent as a temporary
compatibility measure for people upgrading from the 1.0 release. The GRUB
port will need to be upgraded with support for /boot/random.seed in the
10_sortix script. Installation with manual bootloader configuration will
need to load the random seed with the --random-seed command line. With GRUB,
this can be done with: module /boot/random.seed --random-seed
This properly avoids problems where the compiler is unaware that this is the
implementation and assumes it can rely on the implementation. For instance,
it might implement calloc using a call to calloc.
Restructure the code that wrongly assumed __STDC_HOSTED__ meant userspace.
I hereby relicense all my work on Sortix under the ISC license as below.
All Sortix contributions by other people are already under this license,
are not substantial enough to be copyrightable, or have been removed.
All imported code from other projects is compatible with this license.
All GPL licensed code from other projects had previously been removed.
Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors.
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
The debugger has fallen behind and has become a maintenance burden. It was
the only user of the old kernel US layout system, which is good to get rid
of. The debugger didn't work with graphical output and was likely to
conflict with the new keyboard system if used, which no longer triggered it.
The kernel symbol code was removed to simplify the kernel.
The kernel debugger was an useful debugging feature, but it needs to be done
in a better way before it can be added back.
Jonas 'Sortie' Termansen
Kartik Agaram