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fix: PacketLengthInvalid did not correctly return at any time

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this was due to the value being coerced to usize and then
panicing in debug with integer subtract underflow
This commit is contained in:
Tamipes 2025-12-17 18:44:20 +01:00
parent 822330ef87
commit 39b1a84c55
1 changed files with 8 additions and 4 deletions
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12
src/packets/mod.rs
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@ -74,15 +74,19 @@ impl Packet {
return Err(ParseError::WeirdID.into()); return Err(ParseError::WeirdID.into());
} }
let lenght_value = length.get_int() as usize;
let length_value_length = id.get_data().len();
if lenght_value < length_value_length {
return Err(ParseError::PacketLengthInvalid(length.get_int()).into());
}
let data_size = lenght_value - length_value_length;
// TODO: investigate this, becuase it is just a hunch // TODO: investigate this, becuase it is just a hunch
// but if it is too big, the vec![] macro panics // but if it is too big, the vec![] macro panics
let data_size = length.get_int() as usize - id.get_data().len();
if data_size > u16::MAX.into() { if data_size > u16::MAX.into() {
return Err(ParseError::LengthIsTooBig(length.get_int()).into()); return Err(ParseError::LengthIsTooBig(length.get_int()).into());
} }
if data_size < 0 {
return Err(ParseError::PacketLengthInvalid(length.get_int()).into());
}
// TODO: this is a bandaid fix; the above checks *should* make sure the // TODO: this is a bandaid fix; the above checks *should* make sure the
// next line does not run into "capacity overflow", but it doesn't work // next line does not run into "capacity overflow", but it doesn't work
let mut data: Vec<u8> = match std::panic::catch_unwind(|| vec![0; data_size]) { let mut data: Vec<u8> = match std::panic::catch_unwind(|| vec![0; data_size]) {