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authorNadrieril2020-03-04 21:54:34 +0000
committerNadrieril2020-03-05 15:58:54 +0000
commit104a8a4a0632ee69e642521ea03239af88366346 (patch)
tree4e5c28561d449eb397ccb1be0754e6cc8bb5f509 /dhall/src/semantics/resolve
parent31cefbdf0364a3d224420365049885051734669b (diff)
Implement conservative sanity checking
Diffstat (limited to 'dhall/src/semantics/resolve')
-rw-r--r--dhall/src/semantics/resolve/env.rs6
-rw-r--r--dhall/src/semantics/resolve/resolve.rs126
2 files changed, 76 insertions, 56 deletions
diff --git a/dhall/src/semantics/resolve/env.rs b/dhall/src/semantics/resolve/env.rs
index 2342dcc..5a7f139 100644
--- a/dhall/src/semantics/resolve/env.rs
+++ b/dhall/src/semantics/resolve/env.rs
@@ -85,16 +85,16 @@ impl ImportEnv {
Ok(match self.cache.get(&location) {
Some(expr) => expr.clone(),
None => {
- // Push the current import on the stack
+ // Push the current location on the stack
self.stack.push(location);
// Resolve the import recursively
let expr = do_resolve(self)?;
- // Remove import from the stack.
+ // Remove location from the stack.
let location = self.stack.pop().unwrap();
- // Add the import to the cache
+ // Add the resolved import to the cache
self.cache.insert(location, expr.clone());
expr
diff --git a/dhall/src/semantics/resolve/resolve.rs b/dhall/src/semantics/resolve/resolve.rs
index d8115f8..d29271d 100644
--- a/dhall/src/semantics/resolve/resolve.rs
+++ b/dhall/src/semantics/resolve/resolve.rs
@@ -37,15 +37,24 @@ pub(crate) enum ImportLocation {
impl ImportLocation {
/// Given an import pointing to `target` found in the current location, compute the next
/// location, or error if not allowed.
+ /// `sanity_check` indicates whether to check if that location is allowed to be referenced,
+ /// for example to prevent a remote file from reading an environment variable.
fn chain(
&self,
target: &ImportTarget<()>,
+ sanity_check: bool,
) -> Result<ImportLocation, Error> {
Ok(match target {
ImportTarget::Local(prefix, path) => {
self.chain_local(prefix, path)?
}
ImportTarget::Remote(remote) => {
+ if sanity_check {
+ if let ImportLocation::Remote(..) = self {
+ // TODO: allow if CORS check passes
+ Err(ImportError::SanityCheck)?
+ }
+ }
let mut url = Url::parse(&format!(
"{}://{}",
remote.scheme, remote.authority
@@ -55,6 +64,11 @@ impl ImportLocation {
ImportLocation::Remote(url)
}
ImportTarget::Env(var_name) => {
+ if sanity_check {
+ if let ImportLocation::Remote(..) = self {
+ Err(ImportError::SanityCheck)?
+ }
+ }
ImportLocation::Env(var_name.clone())
}
ImportTarget::Missing => ImportLocation::Missing,
@@ -124,6 +138,56 @@ impl ImportLocation {
}
})
}
+
+ fn fetch_dhall(self) -> Result<Parsed, Error> {
+ Ok(match self {
+ ImportLocation::Local(path) => Parsed::parse_file(&path)?,
+ ImportLocation::Remote(url) => Parsed::parse_remote(url)?,
+ ImportLocation::Env(var_name) => {
+ let val = match env::var(var_name) {
+ Ok(val) => val,
+ Err(_) => Err(ImportError::MissingEnvVar)?,
+ };
+ Parsed::parse_str(&val)?
+ }
+ ImportLocation::Missing => Err(ImportError::Missing)?,
+ })
+ }
+
+ fn fetch_text(self) -> Result<String, Error> {
+ Ok(match self {
+ ImportLocation::Local(path) => std::fs::read_to_string(&path)?,
+ ImportLocation::Remote(url) => {
+ reqwest::blocking::get(url).unwrap().text().unwrap()
+ }
+ ImportLocation::Env(var_name) => match env::var(var_name) {
+ Ok(val) => val,
+ Err(_) => Err(ImportError::MissingEnvVar)?,
+ },
+ ImportLocation::Missing => Err(ImportError::Missing)?,
+ })
+ }
+
+ fn into_location(self) -> Expr {
+ let (field_name, arg) = match self {
+ ImportLocation::Local(path) => {
+ ("Local", Some(path.to_string_lossy().into_owned()))
+ }
+ ImportLocation::Remote(url) => ("Remote", Some(url.into_string())),
+ ImportLocation::Env(name) => ("Environment", Some(name)),
+ ImportLocation::Missing => ("Missing", None),
+ };
+
+ let asloc_ty = make_aslocation_uniontype();
+ let expr = mkexpr(ExprKind::Field(asloc_ty, field_name.into()));
+ match arg {
+ Some(arg) => mkexpr(ExprKind::App(
+ expr,
+ mkexpr(ExprKind::TextLit(arg.into())),
+ )),
+ None => expr,
+ }
+ }
}
fn mkexpr(kind: UnspannedExpr) -> Expr {
@@ -143,39 +207,18 @@ fn make_aslocation_uniontype() -> Expr {
fn resolve_one_import(
env: &mut ImportEnv,
import: &Import,
- location: ImportLocation,
+ location: &ImportLocation,
) -> Result<TypedHir, Error> {
- match import.mode {
+ let do_sanity_check = import.mode != ImportMode::Location;
+ let location = location.chain(&import.location, do_sanity_check)?;
+ env.handle_import(location.clone(), |env| match import.mode {
ImportMode::Code => {
- let parsed = match location {
- ImportLocation::Local(path) => Parsed::parse_file(&path)?,
- ImportLocation::Remote(url) => Parsed::parse_remote(url)?,
- ImportLocation::Env(var_name) => {
- let val = match env::var(var_name) {
- Ok(val) => val,
- Err(_) => Err(ImportError::MissingEnvVar)?,
- };
- Parsed::parse_str(&val)?
- }
- ImportLocation::Missing => Err(ImportError::Missing)?,
- };
-
+ let parsed = location.fetch_dhall()?;
let typed = resolve_with_env(env, parsed)?.typecheck()?;
Ok((typed.normalize().to_hir(), typed.ty().clone()))
}
ImportMode::RawText => {
- let text = match location {
- ImportLocation::Local(path) => std::fs::read_to_string(&path)?,
- ImportLocation::Remote(url) => {
- reqwest::blocking::get(url).unwrap().text().unwrap()
- }
- ImportLocation::Env(var_name) => match env::var(var_name) {
- Ok(val) => val,
- Err(_) => Err(ImportError::MissingEnvVar)?,
- },
- ImportLocation::Missing => Err(ImportError::Missing)?,
- };
-
+ let text = location.fetch_text()?;
let hir = Hir::new(
HirKind::Expr(ExprKind::TextLit(text.into())),
Span::Artificial,
@@ -183,32 +226,12 @@ fn resolve_one_import(
Ok((hir, Type::from_builtin(Builtin::Text)))
}
ImportMode::Location => {
- let (field_name, arg) = match location {
- ImportLocation::Local(path) => {
- ("Local", Some(path.to_string_lossy().into_owned()))
- }
- ImportLocation::Remote(url) => {
- ("Remote", Some(url.into_string()))
- }
- ImportLocation::Env(name) => ("Environment", Some(name)),
- ImportLocation::Missing => ("Missing", None),
- };
-
- let asloc_ty = make_aslocation_uniontype();
- let expr = mkexpr(ExprKind::Field(asloc_ty, field_name.into()));
- let expr = match arg {
- Some(arg) => mkexpr(ExprKind::App(
- expr,
- mkexpr(ExprKind::TextLit(arg.into())),
- )),
- None => expr,
- };
-
+ let expr = location.into_location();
let hir = skip_resolve(&expr)?;
let ty = hir.typecheck_noenv()?.ty().clone();
Ok((hir, ty))
}
- }
+ })
}
/// Desugar the first level of the expression.
@@ -301,10 +324,7 @@ fn resolve_with_env(
let Parsed(expr, location) = parsed;
let resolved =
traverse_resolve_expr(&mut NameEnv::new(), &expr, &mut |import| {
- let location = location.chain(&import.location)?;
- env.handle_import(location.clone(), |env| {
- resolve_one_import(env, &import, location)
- })
+ resolve_one_import(env, &import, &location)
})?;
Ok(Resolved(resolved))
}