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Merge pull request #37 from h7x4/fix-usbip-parser-error
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usbip_protocol: fix parser bug on cmd_submit and ret_submit
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@jiegec
jiegec authored Dec 26, 2023
2 parents b5e0f7e + f75e1a0 commit 8640fb4
Showing 1 changed file with 104 additions and 10 deletions.
114 changes: 104 additions & 10 deletions src/usbip_protocol.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
//!
//! They are based on the [Linux kernel documentation](https://docs.kernel.org/usb/usbip_protocol.html).

use log::trace;
use std::io::Result;
use tokio::io::{AsyncReadExt, AsyncWriteExt};

Expand Down Expand Up @@ -38,6 +39,17 @@ pub const USBIP_RET_SUBMIT: u16 = 0x0003;
/// Reply code: Reply for URB unlink
pub const USBIP_RET_UNLINK: u16 = 0x0004;

/// USB/IP direction
///
/// NOTE: Must not be confused with rusb::Direction,
/// which has the opposite enum values. This is only for
/// internal use in the USB/IP protocol.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum Direction {
Out = 0,
In = 1,
}

/// Common header for all context sensitive packets
///
/// All commands/responses which rely on a device being attached
Expand Down Expand Up @@ -134,7 +146,6 @@ impl UsbIpCommand {
/// It might fail if the bytes does not follow the USB/IP protocol properly.
pub async fn read_from_socket<T: AsyncReadExt + Unpin>(socket: &mut T) -> Result<UsbIpCommand> {
let version: u16 = socket.read_u16().await?;
let command: u16 = socket.read_u16().await?;

if version != 0 && version != USBIP_VERSION {
return Err(std::io::Error::new(
Expand All @@ -143,6 +154,20 @@ impl UsbIpCommand {
));
}

let command: u16 = socket.read_u16().await?;

trace!(
"Received command: {:#04X} ({}), parsing...",
command,
match command {
OP_REQ_DEVLIST => "OP_REQ_DEVLIST",
OP_REQ_IMPORT => "OP_REQ_IMPORT",
USBIP_CMD_SUBMIT => "USBIP_CMD_SUBMIT",
USBIP_CMD_UNLINK => "USBIP_CMD_UNLINK",
_ => "Unknown",
}
);

match command {
OP_REQ_DEVLIST => {
let status = socket.read_u32().await?;
Expand Down Expand Up @@ -171,8 +196,13 @@ impl UsbIpCommand {
let mut setup = [0; 8];
socket.read_exact(&mut setup).await?;

let mut data = vec![0; transfer_buffer_length as usize];
socket.read_exact(&mut data).await?;
let data = if header.direction == Direction::In as u32 {
vec![]
} else {
let mut data = vec![0; transfer_buffer_length as usize];
socket.read_exact(&mut data).await?;
data
};

// The kernel docs specifies that this should be set to 0xFFFFFFFF for all
// non-ISO packets, however the actual implementation resorts to 0x00000000
Expand Down Expand Up @@ -248,8 +278,12 @@ impl UsbIpCommand {
ref data,
ref iso_packet_descriptor,
} => {
let mut result = Vec::with_capacity(48 + data.len());
debug_assert!(transfer_buffer_length == data.len() as u32);
debug_assert!(
header.direction != Direction::Out as u32
|| transfer_buffer_length == data.len() as u32
);

let mut result = Vec::with_capacity(48 + data.len() + iso_packet_descriptor.len());
result.extend_from_slice(&header.to_bytes());
result.extend_from_slice(&transfer_flags.to_be_bytes());
result.extend_from_slice(&transfer_buffer_length.to_be_bytes());
Expand Down Expand Up @@ -353,6 +387,11 @@ impl UsbIpResponse {
Vec::with_capacity(48 + transfer_buffer.len() + iso_packet_descriptor.len());

debug_assert!(header.command == USBIP_RET_SUBMIT.into());
debug_assert!(if header.direction == Direction::In as u32 {
actual_length == transfer_buffer.len() as u32
} else {
actual_length == 0
});

result.extend_from_slice(&header.to_bytes());
result.extend_from_slice(&status.to_be_bytes());
Expand Down Expand Up @@ -635,11 +674,11 @@ mod tests {
command: USBIP_RET_SUBMIT.into(),
seqnum: 2,
devid: 3,
direction: 0,
direction: Direction::In as u32,
ep: 4,
},
status: 5,
actual_length: 6,
actual_length: 4,
start_frame: 7,
number_of_packets: 8,
error_count: 9,
Expand All @@ -653,10 +692,10 @@ mod tests {
0x00, 0x00, 0x00, 0x03, // command
0x00, 0x00, 0x00, 0x02, // seqnum
0x00, 0x00, 0x00, 0x03, // devid
0x00, 0x00, 0x00, 0x00, // direction
0x00, 0x00, 0x00, 0x01, // direction
0x00, 0x00, 0x00, 0x04, // ep
0x00, 0x00, 0x00, 0x05, // status
0x00, 0x00, 0x00, 0x06, // actual_length
0x00, 0x00, 0x00, 0x04, // actual_length
0x00, 0x00, 0x00, 0x07, // start_frame
0x00, 0x00, 0x00, 0x08, // number_of_packets
0x00, 0x00, 0x00, 0x09, // error_count
Expand All @@ -669,6 +708,30 @@ mod tests {
);
}

#[test]
#[should_panic]
fn byte_serialize_invalid_usbip_ret_submit() {
setup_test_logger();
let res = UsbIpResponse::UsbIpRetSubmit {
header: UsbIpHeaderBasic {
command: USBIP_RET_SUBMIT.into(),
seqnum: 2,
devid: 3,
direction: Direction::Out as u32, // data section should be empty, but is not
ep: 4,
},
status: 5,
actual_length: 4,
start_frame: 7,
number_of_packets: 8,
error_count: 9,
transfer_buffer: vec![0xFF; 4],
iso_packet_descriptor: vec![0xFF; 16],
};

res.to_bytes();
}

#[test]
fn byte_serialize_usbip_ret_unlink() {
setup_test_logger();
Expand Down Expand Up @@ -755,7 +818,7 @@ mod tests {
command: USBIP_CMD_SUBMIT.into(),
seqnum: 1,
devid: 2,
direction: 0,
direction: Direction::Out as u32,
ep: 4,
},
transfer_flags: 5,
Expand All @@ -778,6 +841,37 @@ mod tests {
Ok(())
}

#[tokio::test]
async fn read_usbip_cmd_submit_from_socket_with_no_data() -> Result<()> {
setup_test_logger();
let cmd = UsbIpCommand::UsbIpCmdSubmit {
header: UsbIpHeaderBasic {
command: USBIP_CMD_SUBMIT.into(),
seqnum: 1,
devid: 2,
direction: Direction::In as u32, // data section should be ignored despite transfer_buffer_length
ep: 4,
},
transfer_flags: 5,
transfer_buffer_length: 64,
start_frame: 7,
number_of_packets: 1,
interval: 9,
setup: [0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0xFF],
data: vec![],
iso_packet_descriptor: vec![0xFF; 16],
};

assert_eq!(
cmd.to_bytes(),
UsbIpCommand::read_from_socket(&mut MockSocket::new(cmd.to_bytes()))
.await?
.to_bytes()
);

Ok(())
}

#[tokio::test]
async fn read_usbip_cmd_unlink_from_socket() -> Result<()> {
setup_test_logger();
Expand Down

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