These changes are compatible with clang-format 16 and will be mandatory
when we eventually bump clang-format version. So, since there are no
real downsides, let's commit them now.
RFC9293 states that a closed socket should reply to all non-RST
packets with an RST. This change implements this behaviour as
specified in section 3.5.2 in bullet point 1.
According to RFC 9293 Section 3.6.1. Half-Closed Connections, we should
still accept incoming packets in the FinWait2 state. Additionally, we
didn't handle the FIN+ACK case. We should handle this the same we
handle the FIN flag. The ACK is only added to signify successful
reception of the last packet.
This should allow us to eventually properly saturate high-bandwidth
network links when using TCP, once other nonoptimal parts of our
network stack are improved.
Instead, use the FixedCharBuffer class to ensure we always use a static
buffer storage for these names. This ensures that if a Process or a
Thread were created, there's a guarantee that setting a new name will
never fail, as only copying of strings should be done to that static
storage.
The limits which are set are 32 characters for processes' names and 64
characters for thread names - this is because threads' names could be
more verbose than processes' names.
Since we never check a kernel process's state like a userland process,
it's possible for a kernel process to ignore the fact that someone is
trying to kill it, and continue running. This is not desireable if we
want to properly shutdown all processes, including Kernel ones.
"Wherever applicable" = most places, actually :^), especially for
networking and filesystem timestamps.
This includes changes to unzip, which uses DOSPackedTime, since that is
changed for the FAT file systems.
That's what this class really is; in fact that's what the first line of
the comment says it is.
This commit does not rename the main files, since those will contain
other time-related classes in a little bit.
There is a big mix of LockRefPtrs all over the Networking subsystem, as
well as lots of room for improvements with our locking patterns, which
this commit will not pursue, but will give a good start for such work.
To deal with this situation, we change the following things:
- Creating instances of NetworkAdapter should always yield a non-locking
NonnullRefPtr. Acquiring an instance from the NetworkingManagement
should give a simple RefPtr,as giving LockRefPtr does not really
protect from concurrency problems in such case.
- Since NetworkingManagement works with normal RefPtrs we should
protect all instances of RefPtr<NetworkAdapter> with SpinlockProtected
to ensure references are gone unexpectedly.
- Protect the so_error class member with a proper spinlock. This happens
to be important because the clear_so_error() method lacked any proper
locking measures. It also helps preventing a possible TOCTOU when we
might do a more fine-grained locking in the Socket code, so this could
be definitely a start for this.
- Change unnecessary LockRefPtr<PacketWithTimestamp> in the structure
of OutgoingPacket to a simple RefPtr<PacketWithTimestamp> as the whole
list should be MutexProtected.
- Instead of taking the first new thread as an out-parameter, we now
bundle the process and its first thread in a struct and use that
as the return value.
- Make all Process factory functions return ErrorOr. Use this to convert
some places to more TRY().
- Drop the "try_" prefix on Process factory functions.
This was mostly straightforward, as all the storage locations are
guarded by some related mutex.
The use of old-school associated mutexes instead of MutexProtected
is unfortunate, but the process to modernize such code is ongoing.
Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:
- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable
This patch renames the Kernel classes so that they can coexist with
the original AK classes:
- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable
The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
This change unifies the naming convention for kernel tasks.
The goal of this change is to:
- Make the task names more descriptive, so users can more
easily understand their purpose in System Monitor.
- Unify the naming convention so they are consistent.
For the same reason we ignore interfaces without an IP address when
choosing where to send a route, we should also ignore interfaces without
IP addresses when updating the ARP table on incoming packets from
local addresses.
On an interface with a null address, the mask checking would always
result in zero, which resulted in the system updating the ARP table on
almost every incoming packet from any address (private or public).
This patch fixes this behavior by only applying this check to interfaces
with valid addresses and now the ARP table won't get constantly
hammered.
Closes#13713
It doesn't make sense after introduction of routing table which allows
having multiple gateways for every interface, and isn't used by any of
the userspace programs now.
1. When receiving FIN while in FinWait1, we now reply with ACK
in addition to the FinWait1->Closing transition.
2. When receiving FIN|ACK while in FinWait1, we now reply with
ACK and transition from FinWait1->TimeWait.
3. When receiving FIN while in FinWait2, we now reply with ACK.
We don't really have anywhere to propagate the error in NetworkTask at
the moment, since it runs in its own kernel thread and has no direct
userspace caller.
This expands the reach of error propagation greatly throughout the
kernel. Sadly, it also exposes the fact that we're allocating (and
doing other fallible things) in constructors all over the place.
This patch doesn't attempt to address that of course. That's work for
our future selves.
This patch removes KResult::operator int() and deals with the fallout.
This forces a lot of code to be more explicit in its handling of errors,
greatly improving readability.
Note: TCPSocket::create_client() has a dubious locking process where
the sockets by tuple table is first shared lock to check if the socket
exists and bail out if it does, then unlocks, then exclusively locks to
add the tuple. There could be a race condition where two client
creation requests for the same tuple happen at the same time and both
cleared the shared lock check. When in doubt, lock exclusively the
whole time.
Previously there was no way for Serenity to send a packet without an
established socket connection, and there was no way to appropriately
respond to a SYN packet on a non-listening port. This patch will respond
to any non-established socket attempts with the appropraite RST/ACK,
letting the client know to close the connection.
