refactor into a struct to prepare for tcp server

2026-05-04 19:19:09 -07:00 · 2023-11-09 15:05:20 -08:00
parent 2b776815eb
commit 5da9aad0a8
3 changed files with 115 additions and 50 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,24 +2,12 @@
 # It is not intended for manual editing.
 version = 3

-[[package]]
-name = "bitflags"
-version = "2.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "327762f6e5a765692301e5bb513e0d9fef63be86bbc14528052b1cd3e6f03e07"
-
-[[package]]
-name = "cfg-if"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
-
 [[package]]
 name = "diag"
 version = "0.1.0"
 dependencies = [
 "libc",
- "nix",
+ "thiserror",
 ]

 [[package]]
@@ -29,12 +17,56 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "89d92a4743f9a61002fae18374ed11e7973f530cb3a3255fb354818118b2203c"

 [[package]]
-name = "nix"
-version = "0.27.1"
+name = "proc-macro2"
+version = "1.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2eb04e9c688eff1c89d72b407f168cf79bb9e867a9d3323ed6c01519eb9cc053"
+checksum = "134c189feb4956b20f6f547d2cf727d4c0fe06722b20a0eec87ed445a97f92da"
 dependencies = [
- "bitflags",
- "cfg-if",
- "libc",
+ "unicode-ident",
 ]
+
+[[package]]
+name = "quote"
+version = "1.0.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.39"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23e78b90f2fcf45d3e842032ce32e3f2d1545ba6636271dcbf24fa306d87be7a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "thiserror"
+version = "1.0.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f9a7210f5c9a7156bb50aa36aed4c95afb51df0df00713949448cf9e97d382d2"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "266b2e40bc00e5a6c09c3584011e08b06f123c00362c92b975ba9843aaaa14b8"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,5 +7,5 @@ edition = "2021"

 [dependencies]
 libc = "0.2.150"
-nix = { version = "0.27.1", features = ["ioctl"]}
+thiserror = "1.0.50"

--- a/src/main.rs
+++ b/src/main.rs
@@ -1,45 +1,78 @@
 use std::fs::File;
 use std::mem;
 use std::os::unix::io::AsRawFd;
+use thiserror::Error;

-fn main() -> std::io::Result<()> {
-    const DIAG_IOCTL_SWITCH_LOGGING: u32 = 7;
-    const MEMORY_DEVICE_MODE: i32 = 2;
-    const DIAG_IOCTL_REMOTE_DEV: u32 = 32;
+type DiagResult<T> = Result<T, DiagDeviceError>;

-    let mut mode_param: [i32; 3] = [MEMORY_DEVICE_MODE, -1, 0]; // diag_logging_mode_param_t
-    let use_mdm: i32 = 0;
+const DIAG_IOCTL_REMOTE_DEV: u32 = 32;
+const MEMORY_DEVICE_MODE: i32 = 2;
+const DIAG_IOCTL_SWITCH_LOGGING: u32 = 7;

-    println!("Initializing DIAG");
+#[derive(Error, Debug)]
+enum DiagDeviceError {
+    #[error("IO error: {0}")]
+    IO(#[from] std::io::Error),
+    #[error("Failed to initialize /dev/diag: {0}")]
+    InitializationFailed(String),
+}

-    let diag_file = File::options()
-         .read(true)
-         .write(true)
-         .open("/dev/diag")?;
-    let diag_fd = diag_file.as_raw_fd();
+struct DiagDevice {
+    file: File,
+    fd: i32,
+    use_mdm: i32,
+}

+fn enable_frame_readwrite(fd: i32, mode: i32) -> DiagResult<()> {
    unsafe {
-        if libc::ioctl(diag_fd, DIAG_IOCTL_SWITCH_LOGGING, MEMORY_DEVICE_MODE, 0, 0, 0) < 0
-            && libc::ioctl(
-                diag_fd,
+        if libc::ioctl(fd, DIAG_IOCTL_SWITCH_LOGGING, mode, 0, 0, 0) < 0 {
+            let ret = libc::ioctl(
+                fd,
                DIAG_IOCTL_SWITCH_LOGGING,
-                &mut mode_param as *mut _,
+                &mut [mode, -1, 0] as *mut _, // diag_logging_mode_param_t
                mem::size_of::<[i32; 3]>(), 0, 0, 0, 0
-            ) < 0
-        {
-            println!("ioctl failed 1");
-            //std::process::exit(1);
+            );
+            if ret < 0 {
+                let msg = format!("DIAG_IOCTL_SWITCH_LOGGING ioctl failed with error code {}", ret);
+                return Err(DiagDeviceError::InitializationFailed(msg))
+            }
        }
    }
-
-    unsafe {
-        if libc::ioctl(diag_fd, DIAG_IOCTL_REMOTE_DEV, &use_mdm as *const i32) < 0 {
-            println!("ioctl failed 2");
-            std::process::exit(1);
-        }
-    }
-
-    println!("successfully opened diag device");
-
+    Ok(())
+}
+
+fn determine_use_mdm(fd: i32) -> DiagResult<i32> {
+    let use_mdm: i32 = 0;
+    unsafe {
+        if libc::ioctl(fd, DIAG_IOCTL_REMOTE_DEV, &use_mdm as *const i32) < 0 {
+            let msg = format!("DIAG_IOCTL_REMOTE_DEV ioctl failed with error code {}", 0);
+            return Err(DiagDeviceError::InitializationFailed(msg))
+        }
+    }
+    Ok(use_mdm)
+}
+
+impl DiagDevice {
+    pub fn new() -> DiagResult<Self> {
+        let file = File::options()
+            .read(true)
+            .write(true)
+            .open("/dev/diag")?;
+        let fd = file.as_raw_fd();
+
+        enable_frame_readwrite(fd, MEMORY_DEVICE_MODE)?;
+        let use_mdm = determine_use_mdm(fd)?;
+
+        Ok(DiagDevice {
+            file,
+            fd,
+            use_mdm,
+        })
+    }
+}
+
+fn main() -> DiagResult<()> {
+    println!("Initializing DIAG");
+    let dev = DiagDevice::new()?;
    Ok(())
 }