xidl_parser/rest_hir/semantics/
cors.rs

1use crate::hir;
2use serde::{Deserialize, Serialize};
3
4use super::annotations::{annotation_name, annotation_params};
5
6#[cfg(test)]
7mod tests;
8
9#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
10pub enum HttpCorsProfile {
11    Any,
12    Origins(Vec<String>),
13}
14
15pub fn effective_cors(
16    interface_annotations: &[hir::Annotation],
17    method_annotations: &[hir::Annotation],
18) -> Result<Option<HttpCorsProfile>, String> {
19    collect_cors(method_annotations)?.map_or_else(
20        || collect_cors(interface_annotations),
21        |profile| Ok(Some(profile)),
22    )
23}
24
25pub(crate) fn collect_cors(
26    annotations: &[hir::Annotation],
27) -> Result<Option<HttpCorsProfile>, String> {
28    let mut matches = annotations.iter().filter(|annotation| {
29        annotation_name(annotation)
30            .map(|name| name.eq_ignore_ascii_case("cors"))
31            .unwrap_or(false)
32    });
33    let Some(annotation) = matches.next() else {
34        return Ok(None);
35    };
36    if matches.next().is_some() {
37        return Err("duplicate @cors annotation".to_string());
38    }
39    parse_cors(annotation).map(Some)
40}
41
42fn parse_cors(annotation: &hir::Annotation) -> Result<HttpCorsProfile, String> {
43    let Some(params) = annotation_params(annotation) else {
44        return Ok(HttpCorsProfile::Any);
45    };
46    match params {
47        hir::AnnotationParams::ConstExpr(expr) => {
48            Ok(HttpCorsProfile::Origins(parse_const_expr_origins(expr)?))
49        }
50        hir::AnnotationParams::Raw(_) | hir::AnnotationParams::Params(_) => {
51            Err("@cors only accepts string literals joined by '|'".to_string())
52        }
53    }
54}
55
56fn parse_const_expr_origins(expr: &hir::ConstExpr) -> Result<Vec<String>, String> {
57    match expr {
58        hir::ConstExpr::Literal(hir::Literal::StringLiteral(value)) => {
59            Ok(vec![parse_origin_literal(value)?])
60        }
61        hir::ConstExpr::BinaryExpr(hir::BinaryOperator::Or, left, right) => {
62            let mut origins = parse_const_expr_origins(left)?;
63            origins.extend(parse_const_expr_origins(right)?);
64            Ok(origins)
65        }
66        _ => Err("@cors only accepts string literals joined by '|'".to_string()),
67    }
68}
69
70fn parse_origin_literal(value: &str) -> Result<String, String> {
71    let Some(value) = trim_string_literal(value) else {
72        return Err("@cors only accepts string literals joined by '|'".to_string());
73    };
74    if value.is_empty() {
75        return Err("@cors origins must not be empty".to_string());
76    }
77    if !is_valid_origin(&value) {
78        return Err(format!("invalid @cors origin '{value}'"));
79    }
80    Ok(value)
81}
82
83fn is_valid_origin(value: &str) -> bool {
84    value == "*"
85        || (value.is_ascii()
86            && !value.bytes().any(|byte| byte.is_ascii_control())
87            && !value.is_empty())
88}
89
90fn trim_string_literal(value: &str) -> Option<String> {
91    let value = value.trim();
92    if value.len() >= 2 && value.starts_with('"') && value.ends_with('"') {
93        Some(value[1..value.len() - 1].to_string())
94    } else {
95        None
96    }
97}
xidl_parser/rest_hir/semantics/cors.rs

xidl_parser/rest_hir/semantics/
cors.rs
