Enhancement/efi shell interface

uefi-test-runner/src/proto/shell.rs

@@ -1,13 +1,169 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
-use uefi::boot;
+use uefi::boot::ScopedProtocol;
 use uefi::proto::shell::Shell;
+use uefi::{boot, cstr16};
+use uefi_raw::Status;
+
+/// Test `get_env()`, `get_envs()`, and `set_env()`
+pub fn test_env(shell: &ScopedProtocol<Shell>) {
+    /* Test retrieving list of environment variable names */
+    let mut cur_env_vec = shell.get_envs();
+    assert_eq!(cur_env_vec.next().unwrap(), cstr16!("path"),);
+    // check pre-defined shell variables; see UEFI Shell spec
+    assert_eq!(cur_env_vec.next().unwrap(), cstr16!("nonesting"),);
+    let cur_env_vec = shell.get_envs();
+    let default_len = cur_env_vec.count();
+
+    /* Test setting and getting a specific environment variable */
+    let cur_env_vec = shell.get_envs();
+    let test_var = cstr16!("test_var");
+    let test_val = cstr16!("test_val");
+    assert!(shell.get_env(test_var).is_none());
+    let status = shell.set_env(test_var, test_val, false);
+    assert_eq!(status, Status::SUCCESS);
+    let cur_env_str = shell
+        .get_env(test_var)
+        .expect("Could not get environment variable");
+    assert_eq!(cur_env_str, test_val);
+
+    let mut found_var = false;
+    for env_var in cur_env_vec {
+        if env_var == test_var {
+            found_var = true;
+        }
+    }
+    assert!(!found_var);
+    let cur_env_vec = shell.get_envs();
+    let mut found_var = false;
+    for env_var in cur_env_vec {
+        if env_var == test_var {
+            found_var = true;
+        }
+    }
+    assert!(found_var);
+
+    let cur_env_vec = shell.get_envs();
+    assert_eq!(cur_env_vec.count(), default_len + 1);
+
+    /* Test deleting environment variable */
+    let test_val = cstr16!("");
+    let status = shell.set_env(test_var, test_val, false);
+    assert_eq!(status, Status::SUCCESS);
+    assert!(shell.get_env(test_var).is_none());
+
+    let cur_env_vec = shell.get_envs();
+    let mut found_var = false;
+    for env_var in cur_env_vec {
+        if env_var == test_var {
+            found_var = true;
+        }
+    }
+    assert!(!found_var);
+    let cur_env_vec = shell.get_envs();
+    assert_eq!(cur_env_vec.count(), default_len);
+}
+
+/// Test `get_cur_dir()` and `set_cur_dir()`
+pub fn test_cur_dir(shell: &ScopedProtocol<Shell>) {
+    /* Test setting and getting current file system and current directory */
+    let fs_var = cstr16!("fs0:");
+    let dir_var = cstr16!("/");
+    let status = shell.set_cur_dir(Some(fs_var), Some(dir_var));
+    assert_eq!(status, Status::SUCCESS);
+
+    let cur_fs_str = shell
+        .get_cur_dir(Some(fs_var))
+        .expect("Could not get the current file system mapping");
+    let expected_fs_str = cstr16!("FS0:\\");
+    assert_eq!(cur_fs_str, expected_fs_str);
+
+    // Changing current file system
+    let fs_var = cstr16!("fs1:");
+    let dir_var = cstr16!("/");
+    let status = shell.set_cur_dir(Some(fs_var), Some(dir_var));
+    assert_eq!(status, Status::SUCCESS);
+
+    let cur_fs_str = shell
+        .get_cur_dir(Some(fs_var))
+        .expect("Could not get the current file system mapping");
+    assert_ne!(cur_fs_str, expected_fs_str);
+    let expected_fs_str = cstr16!("FS1:\\");
+    assert_eq!(cur_fs_str, expected_fs_str);
+
+    // Changing current file system and current directory
+    let fs_var = cstr16!("fs0:");
+    let dir_var = cstr16!("efi/");
+    let status = shell.set_cur_dir(Some(fs_var), Some(dir_var));
+    assert_eq!(status, Status::SUCCESS);
+
+    let cur_fs_str = shell
+        .get_cur_dir(Some(fs_var))
+        .expect("Could not get the current file system mapping");
+    assert_ne!(cur_fs_str, expected_fs_str);
+    let expected_fs_str = cstr16!("FS0:\\efi");
+    assert_eq!(cur_fs_str, expected_fs_str);
+
+    /* Test current working directory cases */
+
+    // At this point, the current working file system has not been set
+    // So we expect a NULL output
+    assert!(shell.get_cur_dir(None).is_none());
+
+    // Setting the current working file system and current working directory
+    let dir_var = cstr16!("fs0:/");
+    let status = shell.set_cur_dir(None, Some(dir_var));
+    assert_eq!(status, Status::SUCCESS);
+    let cur_fs_str = shell
+        .get_cur_dir(Some(fs_var))
+        .expect("Could not get the current file system mapping");
+    let expected_fs_str = cstr16!("FS0:");
+    assert_eq!(cur_fs_str, expected_fs_str);
+
+    let cur_fs_str = shell
+        .get_cur_dir(None)
+        .expect("Could not get the current file system mapping");
+    assert_eq!(cur_fs_str, expected_fs_str);
+
+    // Changing current working directory
+    let dir_var = cstr16!("/efi");
+    let status = shell.set_cur_dir(None, Some(dir_var));
+    assert_eq!(status, Status::SUCCESS);
+    let cur_fs_str = shell
+        .get_cur_dir(Some(fs_var))
+        .expect("Could not get the current file system mapping");
+    let expected_fs_str = cstr16!("FS0:\\efi");
+    assert_eq!(cur_fs_str, expected_fs_str);
+    let cur_fs_str = shell
+        .get_cur_dir(None)
+        .expect("Could not get the current file system mapping");
+    assert_eq!(cur_fs_str, expected_fs_str);
+
+    // Changing current directory in a non-current working file system
+    let fs_var = cstr16!("fs0:");
+    let dir_var = cstr16!("efi/tools");
+    let status = shell.set_cur_dir(Some(fs_var), Some(dir_var));
+    assert_eq!(status, Status::SUCCESS);
+    let cur_fs_str = shell
+        .get_cur_dir(None)
+        .expect("Could not get the current file system mapping");
+    assert_ne!(cur_fs_str, expected_fs_str);
+
+    let expected_fs_str = cstr16!("FS0:\\efi\\tools");
+    let cur_fs_str = shell
+        .get_cur_dir(Some(fs_var))
+        .expect("Could not get the current file system mapping");
+    assert_eq!(cur_fs_str, expected_fs_str);
+}
 
 pub fn test() {
     info!("Running shell protocol tests");
 
     let handle = boot::get_handle_for_protocol::<Shell>().expect("No Shell handles");
 
-    let mut _shell =
+    let shell =
         boot::open_protocol_exclusive::<Shell>(handle).expect("Failed to open Shell protocol");
+
+    test_env(&shell);
+    test_cur_dir(&shell);
 }

uefi/src/proto/shell/mod.rs

@@ -2,12 +2,208 @@
 
 //! EFI Shell Protocol v2.2
 
-use crate::proto::unsafe_protocol;
+use uefi_macros::unsafe_protocol;
+use uefi_raw::Status;
 
-pub use uefi_raw::protocol::shell::ShellProtocol;
+use core::marker::PhantomData;
+use core::ptr;
+
+use uefi_raw::protocol::shell::ShellProtocol;
+
+use crate::{CStr16, Char16};
 
 /// Shell Protocol
 #[derive(Debug)]
 #[repr(transparent)]
-#[unsafe_protocol(uefi_raw::protocol::shell::ShellProtocol::GUID)]
-pub struct Shell(uefi_raw::protocol::shell::ShellProtocol);
+#[unsafe_protocol(ShellProtocol::GUID)]
+pub struct Shell(ShellProtocol);
+
+/// Iterator over the names of environmental variables obtained from the Shell protocol.
+#[derive(Debug)]
+pub struct Vars<'a> {
+    /// Char16 containing names of environment variables
+    inner: *const Char16,
+    /// Placeholder to attach a lifetime to `Vars`
+    placeholder: PhantomData<&'a CStr16>,
+}
+
+impl<'a> Iterator for Vars<'a> {
+    type Item = &'a CStr16;
+    // We iterate a list of NUL terminated CStr16s.
+    // The list is terminated with a double NUL.
+    fn next(&mut self) -> Option<Self::Item> {
+        let cur_start = self.inner;
+        let mut cur_len = 0;
+        unsafe {
+            if *(cur_start) == Char16::from_u16_unchecked(0) {
+                return None;
+            }
+            while *(cur_start.add(cur_len)) != Char16::from_u16_unchecked(0) {
+                cur_len += 1;
+            }
+            self.inner = self.inner.add(cur_len + 1);
+            Some(CStr16::from_ptr(cur_start))
+        }
+    }
+}
+
+impl Shell {
+    /// Gets the value of the specified environment variable
+    ///
+    /// # Arguments
+    ///
+    /// * `name` - The environment variable name of which to retrieve the
+    ///   value.
+    ///
+    /// # Returns
+    ///
+    /// * `Some(<env_value>)` - &CStr16 containing the value of the
+    ///   environment variable
+    /// * `None` - If environment variable does not exist
+    #[must_use]
+    pub fn get_env(&self, name: &CStr16) -> Option<&CStr16> {
+        let name_ptr: *const Char16 = core::ptr::from_ref::<CStr16>(name).cast();
+        let var_val = unsafe { (self.0.get_env)(name_ptr.cast()) };
+        if var_val.is_null() {
+            None
+        } else {
+            unsafe { Some(CStr16::from_ptr(var_val.cast())) }
+        }
+    }
+
+    /// Gets the list of environment variables
+    ///
+    /// # Returns
+    ///
+    /// * `Vec<env_names>` - Vector of environment variable names
+    #[must_use]
+    pub fn get_envs(&self) -> Vars {
+        let env_ptr = unsafe { (self.0.get_env)(ptr::null()) };
+        Vars {
+            inner: env_ptr.cast::<Char16>(),
+            placeholder: PhantomData,
+        }
+    }
+
+    /// Sets the environment variable
+    ///
+    /// # Arguments
+    ///
+    /// * `name` - The environment variable for which to set the value
+    /// * `value` - The new value of the environment variable
+    /// * `volatile` - Indicates whether the variable is volatile or
+    ///   not
+    ///
+    /// # Returns
+    ///
+    /// * `Status::SUCCESS` - The variable was successfully set
+    pub fn set_env(&self, name: &CStr16, value: &CStr16, volatile: bool) -> Status {
+        let name_ptr: *const Char16 = core::ptr::from_ref::<CStr16>(name).cast();
+        let value_ptr: *const Char16 = core::ptr::from_ref::<CStr16>(value).cast();
+        unsafe { (self.0.set_env)(name_ptr.cast(), value_ptr.cast(), volatile) }
+    }
+
+    /// Returns the current directory on the specified device
+    ///
+    /// # Arguments
+    ///
+    /// * `file_system_mapping` - The file system mapping for which to get
+    ///   the current directory
+    ///
+    /// # Returns
+    ///
+    /// * `Some(cwd)` - CStr16 containing the current working directory
+    /// * `None` - Could not retrieve current directory
+    #[must_use]
+    pub fn get_cur_dir(&self, file_system_mapping: Option<&CStr16>) -> Option<&CStr16> {
+        let mapping_ptr: *const Char16 = file_system_mapping.map_or(ptr::null(), |x| (x.as_ptr()));
+        let cur_dir = unsafe { (self.0.get_cur_dir)(mapping_ptr.cast()) };
+        if cur_dir.is_null() {
+            None
+        } else {
+            unsafe { Some(CStr16::from_ptr(cur_dir.cast())) }
+        }
+    }
+
+    /// Changes the current directory on the specified device
+    ///
+    /// # Arguments
+    ///
+    /// * `file_system` - Pointer to the file system's mapped name.
+    /// * `directory` - Points to the directory on the device specified by
+    ///   `file_system`.
+    ///
+    /// # Returns
+    ///
+    /// * `Status::SUCCESS` - The directory was successfully set
+    ///
+    /// # Errors
+    ///
+    /// * `Status::EFI_NOT_FOUND` - The directory does not exist
+    pub fn set_cur_dir(&self, file_system: Option<&CStr16>, directory: Option<&CStr16>) -> Status {
+        let fs_ptr: *const Char16 = file_system.map_or(ptr::null(), |x| (x.as_ptr()));
+        let dir_ptr: *const Char16 = directory.map_or(ptr::null(), |x| (x.as_ptr()));
+        unsafe { (self.0.set_cur_dir)(fs_ptr.cast(), dir_ptr.cast()) }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use alloc::vec::Vec;
+    use uefi::cstr16;
+
+    /// Testing Vars struct
+    #[test]
+    fn test_vars() {
+        // Empty Vars
+        let mut vars_mock = Vec::<u16>::new();
+        vars_mock.push(0);
+        vars_mock.push(0);
+        let mut vars = Vars {
+            inner: vars_mock.as_ptr().cast(),
+            placeholder: PhantomData,
+        };
+        assert!(vars.next().is_none());
+
+        // One environment variable in Vars
+        let mut vars_mock = Vec::<u16>::new();
+        vars_mock.push(b'f' as u16);
+        vars_mock.push(b'o' as u16);
+        vars_mock.push(b'o' as u16);
+        vars_mock.push(0);
+        vars_mock.push(0);
+        let vars = Vars {
+            inner: vars_mock.as_ptr().cast(),
+            placeholder: PhantomData,
+        };
+        assert_eq!(vars.collect::<Vec<_>>(), Vec::from([cstr16!("foo")]));
+
+        // Multiple environment variables in Vars
+        let mut vars_mock = Vec::<u16>::new();
+        vars_mock.push(b'f' as u16);
+        vars_mock.push(b'o' as u16);
+        vars_mock.push(b'o' as u16);
+        vars_mock.push(b'1' as u16);
+        vars_mock.push(0);
+        vars_mock.push(b'b' as u16);
+        vars_mock.push(b'a' as u16);
+        vars_mock.push(b'r' as u16);
+        vars_mock.push(0);
+        vars_mock.push(b'b' as u16);
+        vars_mock.push(b'a' as u16);
+        vars_mock.push(b'z' as u16);
+        vars_mock.push(b'2' as u16);
+        vars_mock.push(0);
+        vars_mock.push(0);
+
+        let vars = Vars {
+            inner: vars_mock.as_ptr().cast(),
+            placeholder: PhantomData,
+        };
+        assert_eq!(
+            vars.collect::<Vec<_>>(),
+            Vec::from([cstr16!("foo1"), cstr16!("bar"), cstr16!("baz2")])
+        );
+    }
+}