Sandbox the file device

Unless the --trust-files switch is used, the file device will be
sandboxed to a program-specific config folder placed according to the
conventions of the operating system.

7 files changed, 125 insertions, 14 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 288668e..4050f85 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9,7 +9,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5a15f179cd60c4584b8a8c596927aadc462e27f2ca70c04e0071964a73ba7a75"
 dependencies = [
  "cfg-if",
- "getrandom",
+ "getrandom 0.3.3",
  "once_cell",
  "version_check",
  "zerocopy",
@@ -108,12 +108,14 @@ dependencies = [
  "bedrock-asm",
  "bedrock-core",
  "chrono",
+ "dirs-next",
  "geometry",
  "gilrs",
  "inked",
  "log 2.0.0",
  "phosphor",
  "switchboard",
+ "vagabond",
  "windows 0.58.0",
 ]
 
@@ -368,6 +370,27 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f27ae1dd37df86211c42e150270f82743308803d90a6f6e6651cd730d5e1732f"
 
 [[package]]
+name = "dirs-next"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf36e65a80337bea855cd4ef9b8401ffce06a7baedf2e85ec467b1ac3f6e82b6"
+dependencies = [
+ "cfg-if",
+ "dirs-sys-next",
+]
+
+[[package]]
+name = "dirs-sys-next"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ebda144c4fe02d1f7ea1a7d9641b6fc6b580adcfa024ae48797ecdeb6825b4d"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
+]
+
+[[package]]
 name = "dispatch"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -510,6 +533,17 @@ dependencies = [
 
 [[package]]
 name = "getrandom"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.11.1+wasi-snapshot-preview1",
+]
+
+[[package]]
+name = "getrandom"
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "26145e563e54f2cadc477553f1ec5ee650b00862f0a58bcd12cbdc5f0ea2d2f4"
@@ -517,7 +551,7 @@ dependencies = [
  "cfg-if",
  "libc",
  "r-efi",
- "wasi",
+ "wasi 0.14.2+wasi-0.2.4",
 ]
 
 [[package]]
@@ -666,7 +700,7 @@ version = "0.1.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "38f262f097c174adebe41eb73d66ae9c06b2844fb0da69969647bbddd9b0538a"
 dependencies = [
- "getrandom",
+ "getrandom 0.3.3",
  "libc",
 ]
 
@@ -1212,6 +1246,17 @@ dependencies = [
 ]
 
 [[package]]
+name = "redox_users"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba009ff324d1fc1b900bd1fdb31564febe58a8ccc8a6fdbb93b543d33b13ca43"
+dependencies = [
+ "getrandom 0.2.16",
+ "libredox",
+ "thiserror",
+]
+
+[[package]]
 name = "rustix"
 version = "0.38.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1508,6 +1553,12 @@ dependencies = [
 
 [[package]]
 name = "wasi"
+version = "0.11.1+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+
+[[package]]
+name = "wasi"
 version = "0.14.2+wasi-0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9683f9a5a998d873c0d21fcbe3c083009670149a8fab228644b8bd36b2c48cb3"
@@ -1716,6 +1767,22 @@ dependencies = [
 ]
 
 [[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
 name = "winapi-util"
 version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1725,6 +1792,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
+[[package]]
 name = "windows"
 version = "0.58.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
index 8309a1f..bfec877 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,9 +13,11 @@ geometry = { git = "git://benbridle.com/geometry", tag = "v1.0.0" }
 inked = { git = "git://benbridle.com/inked", tag = "v1.0.0" }
 log = { git = "git://benbridle.com/log", tag = "v2.0.0" }
 switchboard = { git = "git://benbridle.com/switchboard", tag = "v2.1.0" }
+vagabond = { git = "git://benbridle.com/vagabond", tag = "v1.1.1" }
 
 chrono = { version = "0.4.38" }
 gilrs = "0.11.0"
+dirs-next = "1.0.2"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 windows = { version = "0.58.0", features = ["Win32_Storage_FileSystem"] }
diff --git a/src/bin/br/main.rs b/src/bin/br/main.rs
index 81c5ec9..f4d79fa 100644
--- a/src/bin/br/main.rs
+++ b/src/bin/br/main.rs
@@ -55,6 +55,7 @@ fn main() {
     args.named("size").short('s');
     args.named("decode-stdin").short('i');
     args.named("encode-stdout").short('o');
+    args.named("trust-files");
     args.raise_errors();
 
     let source             = args.get("source").as_path_opt();
@@ -71,6 +72,7 @@ fn main() {
     };
     let decode_stdin       = args.get("decode-stdin").as_bool();
     let encode_stdout      = args.get("encode-stdout").as_bool();
+    let trust_files        = args.get("trust-files").as_bool();
 
     // -----------------------------------------------------------------------
 
@@ -78,7 +80,9 @@ fn main() {
     let mut title = String::from("Bedrock program");
     let mut icon = None;
 
-    if let Some(metadata) = Metadata::from(&bytecode) {
+    let metadata = Metadata::from(&bytecode);
+
+    if let Some(ref metadata) = metadata {
         let name = metadata.name().unwrap_or("unnamed".to_string());
         let authors = metadata.authors().unwrap_or_else(Vec::new);
         let mut metadata_string = format!("Program is '{name}'");
@@ -110,10 +114,20 @@ fn main() {
         path.add_extension("sym"); path
     });
 
+    let name = metadata.and_then(|m| m.name()).and_then(|n| match n.split_once('/') {
+        Some((name, _)) => Some(name.to_string()),
+        None => Some(n),
+    });
+    let identifier = name.as_ref().and_then(
+        |n| Some(n.to_lowercase().chars().filter_map(
+            |c| c.is_alphanumeric().then_some(c)
+        ).collect())
+    );
+
     let config = EmulatorConfig {
         dimensions, fullscreen, zoom, palette, show_cursor,
-        decode_stdin, encode_stdout,
-        symbols_path, title, icon,
+        decode_stdin, encode_stdout, trust_files,
+        symbols_path, name, identifier, title, icon,
     };
 
     if let Ok(phosphor) = Phosphor::new() {
diff --git a/src/devices/file_device.rs b/src/devices/file_device.rs
index ff5629b..43bb239 100644
--- a/src/devices/file_device.rs
+++ b/src/devices/file_device.rs
@@ -16,6 +16,7 @@ pub struct FileDevice {
     pub pointer_write: u32,
     pub length_write: u32,
 
+    pub enable: bool,
     pub enable_read: bool,
     pub enable_write: bool,
     pub enable_create: bool,
@@ -26,6 +27,7 @@ pub struct FileDevice {
 
 impl Device for FileDevice {
     fn read(&mut self, port: u8) -> u8 {
+        if !self.enable { return 0x00; }
         match port {
             0x0 => read_b!(self.entry.is_some()),
             0x1 => read_b!(self.success),
@@ -48,6 +50,7 @@ impl Device for FileDevice {
     }
 
     fn write(&mut self, port: u8, value: u8) -> Option<Signal> {
+        if !self.enable { return None; }
         match port {
             0x0 => self.write_to_entry_port(value),
             0x1 => self.write_to_action_port(value),
@@ -81,20 +84,35 @@ impl Device for FileDevice {
 
 
 impl FileDevice {
-    pub fn new() -> Self {
+    pub fn new(config: &EmulatorConfig) -> Self {
         #[cfg(target_family = "unix")]
         let default_base: PathBuf = PathBuf::from("/");
         #[cfg(target_family = "windows")]
         let default_base: PathBuf = PathBuf::from("");
 
+        let current_dir = match std::env::current_dir() {
+            Ok(dir) => PathBuf::from(dir),
+            Err(_) => PathBuf::from(""),
+        };
+
+        let (enable, base_path, default_path) = if config.trust_files {
+            (true, default_base, current_dir)
+        } else if let Some(config_dir) = dirs_next::config_dir() {
+            let bedrock_dir = config_dir.join("bedrock");
+            let identifier = config.identifier.clone().unwrap_or("default".to_string());
+            let sandbox_dir = bedrock_dir.join(identifier);
+            vagabond::make_directory(&sandbox_dir).unwrap();
+            (true, sandbox_dir.clone(), sandbox_dir)
+        } else {
+            error!("Could not determine sandbox path for file device");
+            (false, default_base, current_dir)
+        };
+
         // TODO: I'm not at all confident that the default path is correct
         //       when not being set as the current directory.
         Self {
-            base_path: default_base,
-            default_path: match std::env::current_dir() {
-                Ok(dir) => PathBuf::from(dir),
-                Err(_) => PathBuf::from(""),
-            },
+            base_path,
+            default_path,
 
             entry_buffer:  BedrockPathBuffer::new(),
             action_buffer: BedrockPathBuffer::new(),
@@ -107,6 +125,7 @@ impl FileDevice {
             pointer_write: 0,
             length_write: 0,
 
+            enable,
             enable_read: true,
             enable_write: true,
             enable_create: true,
diff --git a/src/emulators/graphical_emulator.rs b/src/emulators/graphical_emulator.rs
index 2680d3f..03e3057 100644
--- a/src/emulators/graphical_emulator.rs
+++ b/src/emulators/graphical_emulator.rs
@@ -112,7 +112,7 @@ impl GraphicalDeviceBus {
             input:  InputDevice::new(),
             screen: ScreenDevice::new(&config),
             stream: StreamDevice::new(&config),
-            file:   FileDevice::new(),
+            file:   FileDevice::new(&config),
             wake_queue: WakeQueue::new(),
         }
     }
diff --git a/src/emulators/headless_emulator.rs b/src/emulators/headless_emulator.rs
index cac58cf..770bae3 100644
--- a/src/emulators/headless_emulator.rs
+++ b/src/emulators/headless_emulator.rs
@@ -70,7 +70,7 @@ impl HeadlessDeviceBus {
             math:   MathDevice::new(),
             clock:  ClockDevice::new(),
             stream: StreamDevice::new(&config),
-            file:   FileDevice::new(),
+            file:   FileDevice::new(&config),
             wake_queue: WakeQueue::new(),
         }
     }
diff --git a/src/emulators/mod.rs b/src/emulators/mod.rs
index 8f04e4d..d4a58f9 100644
--- a/src/emulators/mod.rs
+++ b/src/emulators/mod.rs
@@ -15,7 +15,10 @@ pub struct EmulatorConfig {
     pub show_cursor: bool,
     pub decode_stdin: bool,
     pub encode_stdout: bool,
+    pub trust_files: bool,
     pub symbols_path: Option<PathBuf>,
+    pub name: Option<String>,
+    pub identifier: Option<String>,
     pub title: String,
     pub icon: Option<Icon>,
 }