Add a 1MiB maximum and make sure our message length
is at least the header size - without that we get an underflow, causing
iobuf_pop to remove a huge number of bytes, crashing the other end.
Assisted-by: Claude:claude-opus-4-6
Part-of: <https://gitlab.freedesktop.org/libinput/libei/-/merge_requests/388>
clang-format taken from libinput, except for
ColumnLimit: 100
and some macro definitions (which don't all have an effect anyway...)
It's not perfect but good enough and at least consistent.
Part-of: <https://gitlab.freedesktop.org/libinput/libei/-/merge_requests/383>
With our strings being a 4-byte header followed by the string itself,
they're virtually guaranteed not to be 8-byte aligned. This causes an
issue on some architectures so we need to copy the string out before we
access it.
Since strings are the only protocol type with that extra buffer, let's
hack this in with the minimum effort approach - a null-terminated
char * pointer array that's filled with the strings as they appear in
on the wire. The brei_arg->s points to one of those strings as needed.
This means we can drop the brei_string struct, thanks to pointer alignment
issues this struct doesn't work on s390x, so let's drop it, it no longer
serves any meaningful value.
Fixes#41
src/brei-shared.c:231:16: warning: comparison of integers of different signs: 'int' and 'uint32_t' (aka 'unsigned int') [-Wsign-compare]
if (end - p < len32) {
~~~~~~~ ^ ~~~~~
src/brei-shared.c:233:76: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
"Invalid string length %u, only %li bytes remaining", s->len, (end - p) * 4);
~~~ ^~~~~~~~~~~~~
%i
Co-authored-by: Peter Hutterer <peter.hutterer@who-t.net>
On some architectures (ARM, afaik) addresses needs to be a multiple
of their word size. Since the protocol doesn't enforce alignment on
multiples of 8, let's use a memcpy to copy any 64-bit number instad of
the pointer access.
Now that we have 64 bit integers on the wire and 64 bit object IDs,
we're already different to the Wayland protocol. So we might as well get
the full length and split message length and opcode again to make header
parsing and composing simpler.
This effectively reverts commit bf45a7182cb2f4c13f11e141fc846244d3ac6212.
No real functional changes, this just changes the message header to be
header = [object_id, msglen << 16 | opcode].
The only difference to the wayland protocol is now the fixed vs float
but otherwise tools that can print/debug/mangle the wayland protocol
should be easily adjustable for this protocol too..
Add a new simple object "brei_result" that maps to the protocol-type
reason + explanation. That object is now returned instead of the errno,
giving us better debugging options.
This changes the dispatcher functions from returning an int to returning
a brei_result instead (default NULL for success). A helper function for
converting a neg errno to a result is provided for convenience for now,
eventually all these paths should deal with things correctly.
This event is to notify the client that an object used in a request was
unknown. This allows the client to work around race conditions like
binding to a seat that was removed.
This is currently the server-side only which is probably enough for now.
The only client-side created objects we have are the callbacks.
This protocol is wayland-like though it uses a slightly different
message format. The XML file uses the same structure, except for the
"fixed" type which is "float" here.
The scanner uses a jinja template to generate source and header files
for ei and eis which are now used instead of the protobuf-generated
objects. Note that the scanner is a minimal working version, some
features like enum value checks are not yet implemented.
Unlike wayland we do not need to generate the libwayland-like library,
we only need the wire protocol parser - some shortcuts can thus be taken.
To keep the changes simple, the protocol currently is a flat protocol
with only one interface and all messages copied over from the previous
ei.proto file. In future commits, this will be moved to the respective
interfaces instead.
We need some sort of length field to be able to know how long the next
message is. But for simplicity, we might as well just write that
explicitly on the wire instead of wrapping our messages into yet another
message. This makes the wire format slightly simpler since the first 4
bytes are now always the length, without the previous 0x0d prefix
caused by the protobuf encoding.
0x0d == (field number << 3) | wire_type == 1 << 3 | 5
(see https://protobuf.dev/programming-guides/encoding/#structure)
If we get EPROTO or EINVAL on the connection, all we do is disconnect
(ourselves or the client). So let's drain the fd so there's no other
data to be parsed by accident and then continue with actually
disconnecting.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Re-ordering commands in buildtype=release means recvfd may not be set by the
time _cleanup_ is called (due to the goto outs). Replace those with return
statements, it's more logical here anyway.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
This was intentional here but valgrind doesn't like it, so let's just set it
to something that should look odd.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
This de-duplicates a bunch of things that we don't need to duplicate,
specifically the protocol part that splits the data up into parseable chunks.
That we have Frames in between messages is an implementation detail, this way
neither libei nor libeis have to care about it.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
