From 2e4d54928d2443d7ece3e9750dd126a43772dc27 Mon Sep 17 00:00:00 2001
From: Will Greenberg <willg@eff.org>
Date: Tue, 12 Dec 2023 13:59:03 -0800
Subject: [PATCH] maybe fix read loop?

---
 src/diag.rs        | 12 +++++++++---
 src/diag_device.rs | 23 +++++------------------
 2 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/src/diag.rs b/src/diag.rs
index b35b8a0..4eb19c3 100644
--- a/src/diag.rs
+++ b/src/diag.rs
@@ -46,8 +46,8 @@ pub enum DataType {
 #[derive(Debug, Clone, DekuRead)]
 pub struct MessagesContainer {
     pub data_type: DataType,
-    pub num_responses: u32,
-    #[deku(count = "num_responses")]
+    pub num_messages: u32,
+    #[deku(count = "num_messages")]
     pub messages: Vec<HdlcEncapsulatedMessage>,
 }
 
@@ -362,7 +362,6 @@ mod test {
 
     #[test]
     fn test_logs() {
-        env_logger::init();
         let data = vec![
             16, 0, 38, 0, 38, 0, 192, 176, 26, 165, 245, 135, 118, 35, 2, 1, 20,
             14, 48, 0, 160, 0, 2, 8, 0, 0, 217, 15, 5, 0, 0, 0, 0, 7, 0, 64, 1,
@@ -392,4 +391,11 @@ mod test {
             },
         });
     }
+
+    #[test]
+    fn test_fuck() {
+        env_logger::init();
+        let data = vec![32, 0, 0, 0, 1, 0, 0, 0, 122, 1, 0, 0, 16, 0, 38, 0, 38, 0, 192, 176, 153, 128, 249, 211, 218, 62, 2, 1, 20, 14, 48, 0, 160, 0, 14, 6, 1, 0, 217, 39, 5, 0, 0, 0, 0, 7, 0, 64, 2, 14, 213, 72, 153, 192, 168, 216, 126];
+        dbg!(MessagesContainer::from_bytes((&data, 0)).unwrap());
+    }
 }
diff --git a/src/diag_device.rs b/src/diag_device.rs
index 591f947..e6ad5b2 100644
--- a/src/diag_device.rs
+++ b/src/diag_device.rs
@@ -63,7 +63,7 @@ pub const LOG_CODES_FOR_RAW_PACKET_LOGGING: [u32; 11] = [
     log_codes::LOG_DATA_PROTOCOL_LOGGING_C // 0x11eb
 ];
 
-const BUFFER_LEN: usize = 1024 * 10;
+const BUFFER_LEN: usize = 1024 * 1024 * 10;
 const MEMORY_DEVICE_MODE: i32 = 2;
 const DIAG_IOCTL_REMOTE_DEV: u32 = 32;
 const DIAG_IOCTL_SWITCH_LOGGING: u32 = 7;
@@ -115,26 +115,13 @@ impl<'a> DiagDevice<'a> {
         Ok(result)
     }
 
-    fn next_packet(&mut self) -> DiagResult<Vec<u8>> {
-        let mut read_buf = vec![0; BUFFER_LEN];
-        while !self.accumulator.contains(&0x7e) {
-            let bytes_read = self.file.read(&mut read_buf).unwrap();
-            self.accumulator.extend(&read_buf[0..bytes_read]);
-            // clear out the buffer so we don't accidentally read stale data
-            read_buf.clear();
-            read_buf.resize(BUFFER_LEN, 0);
-        }
-
-        let idx = self.accumulator.iter().position(|&x| x == 0x7e).unwrap();
-        Ok(self.accumulator.drain(0..idx + 1).collect::<Vec<u8>>())
-    }
-
     pub fn read_response(&mut self) -> DiagResult<Vec<Message>> {
+        let mut read_buf = vec![0; BUFFER_LEN];
         loop {
-            let packet = self.next_packet()?;
-            let ((leftover_bytes, _), res_container) = MessagesContainer::from_bytes((&packet, 0))?;
+            let bytes_read = self.file.read(&mut read_buf).unwrap();
+            let ((leftover_bytes, _), res_container) = MessagesContainer::from_bytes((&read_buf[0..bytes_read], 0))?;
             if leftover_bytes.len() > 0 {
-                println!("warning: {} leftover bytes when parsing ResponseContainer", leftover_bytes.len());
+                println!("warning: {} leftover bytes when parsing MessagesContainer", leftover_bytes.len());
             }
             if res_container.data_type == DataType::UserSpace {
                 return self.parse_response_container(res_container);