Add wasi:http support to the C API (#12950)

Author: chaynabors

Cargo.lock

@@ -33,6 +33,7 @@ wat = { workspace = true, optional = true }
 cap-std = { workspace = true, optional = true }
 tokio = { workspace = true, optional = true, features = ["fs"] }
 wasmtime-wasi = { workspace = true, optional = true, features = ["p1"] }
+wasmtime-wasi-http = { workspace = true, optional = true, features = ["p2", "default-send-request"] }
 wasmtime-wasi-io = { workspace = true, optional = true, features = ["std"] }
 async-trait = { workspace = true, optional = true }
 bytes = { workspace = true, optional = true }
@@ -47,6 +48,7 @@ profiling = ["wasmtime/profiling"]
 cache = ["wasmtime/cache"]
 parallel-compilation = ['wasmtime/parallel-compilation']
 wasi = ['cap-std', 'wasmtime-wasi', 'wasmtime-wasi-io', 'tokio', 'async-trait', 'bytes']
+wasi-http = ['wasi', 'wasmtime-wasi-http']
 logging = ['dep:env_logger']
 disable-logging = ["log/max_level_off", "tracing/max_level_off"]
 coredump = ["wasmtime/coredump"]

crates/c-api/Cargo.toml

@@ -26,6 +26,7 @@ default = [
   'profiling',
   'wat',
   'wasi',
+  'wasi-http',
   'cache',
   'parallel-compilation',
   'async',
@@ -51,6 +52,7 @@ profiling = ["wasmtime-c-api/profiling"]
 cache = ["wasmtime-c-api/cache"]
 parallel-compilation = ['wasmtime-c-api/parallel-compilation']
 wasi = ['wasmtime-c-api/wasi']
+wasi-http = ['wasmtime-c-api/wasi-http']
 logging = ['wasmtime-c-api/logging']
 disable-logging = ["wasmtime-c-api/disable-logging"]
 coredump = ["wasmtime-c-api/coredump"]

crates/c-api/artifact/Cargo.toml

@@ -8,6 +8,7 @@ const FEATURES: &[&str] = &[
     "CACHE",
     "PARALLEL_COMPILATION",
     "WASI",
+    "WASI_HTTP",
     "LOGGING",
     "DISABLE_LOGGING",
     "COREDUMP",

crates/c-api/build.rs

@@ -31,6 +31,7 @@ feature(wat ON)
 feature(cache ON)
 feature(parallel-compilation ON)
 feature(wasi ON)
+feature(wasi-http ON)
 feature(logging ON)
 feature(disable-logging OFF)
 feature(coredump ON)

crates/c-api/cmake/features.cmake

@@ -165,6 +165,19 @@ wasmtime_component_linker_add_wasip2(wasmtime_component_linker_t *linker);
 
 #endif // WASMTIME_FEATURE_WASI
 
+#ifdef WASMTIME_FEATURE_WASI_HTTP
+
+/**
+ * \brief Add WASI HTTP interfaces into the \p linker provided.
+ *
+ * This adds `wasi:http/types` and `wasi:http/outgoing-handler` to the linker.
+ * Requires WASI to be added first via #wasmtime_component_linker_add_wasip2.
+ */
+WASM_API_EXTERN wasmtime_error_t *
+wasmtime_component_linker_add_wasi_http(wasmtime_component_linker_t *linker);
+
+#endif // WASMTIME_FEATURE_WASI_HTTP
+
 /// Type of the callback used in
 /// #wasmtime_component_linker_instance_add_resource
 typedef wasmtime_error_t *(*wasmtime_component_resource_destructor_t)(

crates/c-api/include/wasmtime/component/linker.h

@@ -215,6 +215,23 @@ class Linker {
     return std::monostate();
   }
 #endif // WASMTIME_FEATURE_WASI
+
+#ifdef WASMTIME_FEATURE_WASI_HTTP
+  /**
+   * \brief Adds WASI HTTP definitions to this linker.
+   *
+   * This adds `wasi:http/types` and `wasi:http/outgoing-handler` to the linker.
+   * Requires WASIp2 to be added first via \ref add_wasip2.
+   */
+  Result<std::monostate> add_wasi_http() {
+    wasmtime_error_t *error =
+        wasmtime_component_linker_add_wasi_http(ptr.get());
+    if (error != nullptr) {
+      return Error(error);
+    }
+    return std::monostate();
+  }
+#endif // WASMTIME_FEATURE_WASI_HTTP
 };
 
 } // namespace component

crates/c-api/include/wasmtime/component/linker.hh

@@ -13,6 +13,7 @@
 #cmakedefine WASMTIME_FEATURE_CACHE
 #cmakedefine WASMTIME_FEATURE_PARALLEL_COMPILATION
 #cmakedefine WASMTIME_FEATURE_WASI
+#cmakedefine WASMTIME_FEATURE_WASI_HTTP
 #cmakedefine WASMTIME_FEATURE_LOGGING
 #cmakedefine WASMTIME_FEATURE_DISABLE_LOGGING
 #cmakedefine WASMTIME_FEATURE_COREDUMP

crates/c-api/include/wasmtime/conf.h.in

@@ -195,6 +195,19 @@ wasmtime_context_set_wasi(wasmtime_context_t *context, wasi_config_t *wasi);
 
 #endif // WASMTIME_FEATURE_WASI
 
+#ifdef WASMTIME_FEATURE_WASI_HTTP
+
+/**
+ * \brief Initializes the WASI HTTP context for this store.
+ *
+ * Must be called before instantiating a component that uses `wasi:http`.
+ * Requires WASI to be configured first via #wasmtime_context_set_wasi.
+ */
+WASM_API_EXTERN void
+wasmtime_context_set_wasi_http(wasmtime_context_t *context);
+
+#endif // WASMTIME_FEATURE_WASI_HTTP
+
 /**
  * \brief Configures the relative deadline at which point WebAssembly code will
  * trap or invoke the callback function.

crates/c-api/include/wasmtime/store.h

@@ -167,6 +167,15 @@ pub unsafe extern "C" fn wasmtime_component_linker_add_wasip2(
     crate::handle_result(result, |_| ())
 }
 
+#[unsafe(no_mangle)]
+#[cfg(feature = "wasi-http")]
+pub unsafe extern "C" fn wasmtime_component_linker_add_wasi_http(
+    linker: &mut wasmtime_component_linker_t,
+) -> Option<Box<wasmtime_error_t>> {
+    let result = wasmtime_wasi_http::p2::add_only_http_to_linker_sync(&mut linker.linker);
+    crate::handle_result(result, |_| ())
+}
+
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn wasmtime_component_linker_define_unknown_imports_as_traps(
     linker: &mut wasmtime_component_linker_t,