Check if process is system on linux (mitmproxy#205)

* check if process is system

* reuse code across macos_list.rs and linux_list.rs

* nits

* modify is_system heuristic

* [autofix.ci] apply automated fixes

* use uid to check if process is system

* [autofix.ci] apply automated fixes

* fix

* [autofix.ci] apply automated fixes

* [autofix.ci] apply automated fixes (attempt 2/3)

* fix

* [autofix.ci] apply automated fixes

* restructure macos_visible_windows

* .deref() uids for comparison

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: errorxyz

src/processes/linux_list.rs

@@ -1,10 +1,10 @@
 pub use image;
 use std::path::PathBuf;
 
-#[cfg(target_os = "macos")]
-mod macos_list;
-#[cfg(target_os = "macos")]
-pub use self::macos_list::active_executables;
+#[cfg(any(target_os = "linux", target_os = "macos"))]
+mod nix_list;
+#[cfg(any(target_os = "linux", target_os = "macos"))]
+pub use self::nix_list::active_executables;
 
 #[cfg(windows)]
 mod windows_list;
@@ -13,11 +13,6 @@ pub use self::windows_list::active_executables;
 #[cfg(windows)]
 pub use self::windows_list::get_process_name;
 
-#[cfg(target_os = "linux")]
-mod linux_list;
-#[cfg(target_os = "linux")]
-pub use self::linux_list::active_executables;
-
 #[cfg(target_os = "macos")]
 mod macos_icons;
 #[cfg(target_os = "macos")]
@@ -44,7 +39,7 @@ pub static ICON_CACHE: once_cell::sync::Lazy<std::sync::Mutex<IconCache>> =
 
 pub mod bench {
     #[cfg(target_os = "macos")]
-    pub use super::macos_list::visible_windows;
+    pub use super::nix_list::visible_windows;
     #[cfg(windows)]
     pub use super::windows_list::visible_windows;
 

src/processes/macos_list.rs

@@ -0,0 +1,161 @@
+use crate::intercept_conf::PID;
+use crate::processes::{ProcessInfo, ProcessList};
+use anyhow::Result;
+use std::collections::hash_map::Entry;
+use std::collections::{HashMap, HashSet};
+use std::path::PathBuf;
+use sysinfo::{Process, ProcessRefreshKind, ProcessesToUpdate, System, UpdateKind};
+
+#[cfg(target_os = "linux")]
+use std::ops::Deref;
+
+#[cfg(target_os = "macos")]
+use macos_visible_windows::macos_visible_windows;
+
+pub fn active_executables() -> Result<ProcessList> {
+    let mut executables: HashMap<PathBuf, ProcessInfo> = HashMap::new();
+    let visible = visible_windows()?;
+    let mut sys = System::new();
+    sys.refresh_processes_specifics(
+        ProcessesToUpdate::All,
+        true,
+        ProcessRefreshKind::nothing()
+            .with_exe(UpdateKind::OnlyIfNotSet)
+            .with_user(UpdateKind::OnlyIfNotSet),
+    );
+    for (pid, process) in sys.processes() {
+        // process.exe() will return empty path if there was an error while trying to read /proc/<pid>/exe.
+        if let Some(path) = process.exe() {
+            let pid = pid.as_u32();
+            let executable = path.to_path_buf();
+            match executables.entry(executable) {
+                Entry::Occupied(mut e) => {
+                    let process_info = e.get();
+                    if !process_info.is_visible && visible.contains(&pid) {
+                        e.get_mut().is_visible = true;
+                    }
+                }
+                Entry::Vacant(e) => {
+                    let executable = e.key().clone();
+                    // .file_name() returns `None` if the path terminates in `..`
+                    // We use the absolute path in such a case.
+                    let display_name = path
+                        .file_name()
+                        .unwrap_or(path.as_os_str())
+                        .to_string_lossy()
+                        .to_string();
+                    let is_system = is_system(process);
+                    let is_visible = visible.contains(&pid);
+                    e.insert(ProcessInfo {
+                        executable,
+                        display_name,
+                        is_visible,
+                        is_system,
+                    });
+                }
+            }
+        }
+    }
+    Ok(executables.into_values().collect())
+}
+
+pub fn visible_windows() -> Result<HashSet<PID>> {
+    #[cfg(target_os = "macos")]
+    return macos_visible_windows();
+
+    #[cfg(target_os = "linux")]
+    // Finding visible windows is less useful on Linux, where more applications tend to be CLI-based.
+    // So we skip all the X11/Wayland complexity.
+    return Ok(HashSet::new());
+}
+
+fn is_system(process: &Process) -> bool {
+    #[cfg(target_os = "macos")]
+    return process
+        .exe()
+        .map(|path| path.starts_with("/System/"))
+        .unwrap_or(false);
+
+    #[cfg(target_os = "linux")]
+    return process
+        .user_id()
+        .map(|uid| *uid.deref() < 1000)
+        .unwrap_or(false);
+}
+
+#[cfg(target_os = "macos")]
+mod macos_visible_windows {
+    use crate::intercept_conf::PID;
+    use anyhow::Result;
+    use cocoa::base::nil;
+    use cocoa::foundation::NSString;
+    use core_foundation::number::{kCFNumberSInt32Type, CFNumberGetValue, CFNumberRef};
+    use core_graphics::display::{
+        kCGNullWindowID, kCGWindowListExcludeDesktopElements, kCGWindowListOptionOnScreenOnly,
+        CFArrayGetCount, CFArrayGetValueAtIndex, CFDictionaryGetValueIfPresent, CFDictionaryRef,
+        CGWindowListCopyWindowInfo,
+    };
+    use std::collections::HashSet;
+    use std::ffi::c_void;
+
+    pub fn macos_visible_windows() -> Result<HashSet<PID>> {
+        let mut pids: HashSet<PID> = HashSet::new();
+        unsafe {
+            let windows_info_list = CGWindowListCopyWindowInfo(
+                kCGWindowListOptionOnScreenOnly + kCGWindowListExcludeDesktopElements,
+                kCGNullWindowID,
+            );
+            let count = CFArrayGetCount(windows_info_list);
+
+            for i in 0..count - 1 {
+                let dic_ref = CFArrayGetValueAtIndex(windows_info_list, i);
+                let key = NSString::alloc(nil).init_str("kCGWindowOwnerPID");
+                let mut pid: *const c_void = std::ptr::null_mut();
+
+                if CFDictionaryGetValueIfPresent(
+                    dic_ref as CFDictionaryRef,
+                    key as *const c_void,
+                    &mut pid,
+                ) != 0
+                {
+                    let pid_cf_ref = pid as CFNumberRef;
+                    let mut pid: i32 = 0;
+                    if CFNumberGetValue(
+                        pid_cf_ref,
+                        kCFNumberSInt32Type,
+                        &mut pid as *mut i32 as *mut c_void,
+                    ) {
+                        pids.insert(pid as u32);
+                    }
+                }
+            }
+            Ok(pids)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn process_list() {
+        let lst = active_executables().unwrap();
+        assert!(!lst.is_empty());
+
+        for proc in &lst {
+            if !proc.is_visible {
+                dbg!(&proc.display_name);
+            }
+        }
+        dbg!(lst.len());
+    }
+
+    #[cfg(target_os = "macos")]
+    #[test]
+    fn visible_windows_list() {
+        let open_windows_pids = visible_windows().unwrap();
+        assert!(!open_windows_pids.is_empty());
+        dbg!(open_windows_pids.len());
+    }
+}