Initial commit

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 345 insertions, 0 deletions

diff --git a/wasmtime-wasi-http.c b/wasmtime-wasi-http.c
new file mode 100644
index 0000000..8b8ddff
--- /dev/null
+++ b/wasmtime-wasi-http.c
@@ -0,0 +1,345 @@
+/*
+ * Copyright (C) Andrew Clayton
+ * Copyright (C) F5, Inc.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <wasm.h>
+#include <wasi.h>
+#include <wasmtime.h>
+
+static void exit_with_error(const char *message, wasmtime_error_t *error,
+			    wasm_trap_t *trap)
+{
+	wasm_byte_vec_t error_message;
+
+	fprintf(stderr, "error: %s\n", message);
+	if (error != NULL) {
+		wasmtime_error_message(error, &error_message);
+		wasmtime_error_delete(error);
+	} else {
+		wasm_trap_message(trap, &error_message);
+		wasm_trap_delete(trap);
+	}
+	fprintf(stderr, "%.*s\n", (int) error_message.size, error_message.data);
+	wasm_byte_vec_delete(&error_message);
+
+	exit(EXIT_FAILURE);
+}
+
+static wasm_trap_t *dummy_func(void *env, wasmtime_caller_t *caller,
+			       const wasmtime_val_t *args, size_t nargs,
+			       wasmtime_val_t *results, size_t nresults)
+{
+	(void)env;
+	(void)caller;
+	(void)args;
+	(void)nargs;
+	(void)results;
+	(void)nresults;
+
+	return NULL;
+}
+
+static wasm_functype_t *create_wasm_func(const wasm_valkind_t *pk,
+					 size_t nr_params,
+					 const wasm_valkind_t *rk,
+					 size_t nr_results)
+{
+	wasm_valtype_t *pt[14];
+	wasm_valtype_t *rt[1];
+	wasm_valtype_vec_t params;
+	wasm_valtype_vec_t results;
+
+	if (nr_params > 0) {
+		for (size_t i = 0; i < nr_params; i++)
+			pt[i] = wasm_valtype_new(pk[i]);
+		wasm_valtype_vec_new(&params, nr_params, pt);
+	} else {
+		wasm_valtype_vec_new_empty(&params);
+	}
+
+	if (nr_results > 0) {
+		for (size_t i = 0; i < nr_results; i++)
+			rt[i] = wasm_valtype_new(rk[i]);
+		wasm_valtype_vec_new(&results, nr_results, rt);
+	} else {
+		wasm_valtype_vec_new_empty(&results);
+	}
+
+	return wasm_functype_new(&params, &results);
+}
+
+static inline size_t rg(const char *s)
+{
+	return strlen(s);
+}
+
+/*
+ * Argument counting macros gleamed from
+ * https://gist.github.com/christophercrouzet/db9bbb07d427381253a91210e7ddc68d
+ */
+#define ARG( \
+	_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, ...) \
+	_14
+#define COUNT_ARGS(...) \
+	ARG(__VA_ARGS__, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,)
+
+#define SET_VALS(type, ...) \
+	.type	   = { __VA_ARGS__ }, \
+	.nr_##type = COUNT_ARGS(__VA_ARGS__)
+
+#define SET_FUNC(function, function_name, module) \
+	.func_name    = function_name, \
+	.func_namelen = strlen(function_name), \
+	.mod_name     = module, \
+	.mod_namelen  = strlen(module), \
+	.func	      = dummy_func
+
+static void set_function_imports(wasmtime_linker_t *linker)
+{
+	static const struct {
+		const char                *func_name;
+		int			  func_namelen;
+		const char		  *mod_name;
+		int			  mod_namelen;
+
+		wasmtime_func_callback_t  func;
+
+		wasm_valkind_t            params[14];
+		size_t			  nr_params;
+		wasm_valkind_t            results[1];
+		size_t			  nr_results;
+	} import_functions[] = {
+		{
+			SET_FUNC(poll_oneoff, "poll-oneoff", "poll2"),
+			SET_VALS(params, WASM_I32, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(read, "read", "streams2"),
+			SET_VALS(params, WASM_I32, WASM_I64, WASM_I32),
+		}, {
+			SET_FUNC(blocking_read, "blocking-read", "streams2"),
+			SET_VALS(params, WASM_I32, WASM_I64, WASM_I32),
+		}, {
+			SET_FUNC(subscribe_to_input_stream,
+				"subscribe-to-input-stream", "streams2"),
+			SET_VALS(params, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(write, "write", "streams2"),
+			SET_VALS(params,
+				 WASM_I32, WASM_I32, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(blocking_write, "blocking-write", "streams2"),
+			SET_VALS(params,
+				 WASM_I32, WASM_I32, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(subscribe_to_output_stream,
+				"subscribe-to-output-stream", "streams2"),
+			SET_VALS(params, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(handle, "handle", "default-outgoing-HTTP2"),
+			SET_VALS(params,
+				 WASM_I32, WASM_I32, WASM_I32, WASM_I32,
+				 WASM_I32, WASM_I32, WASM_I32, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(new_fields, "new-fields", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(fields_entries, "fields-entries", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(finish_incoming_stream,
+				"finish-incoming-stream", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(finish_outgoing_stream,
+				"finish-outgoing-stream", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(incoming_request_method,
+				"incoming-request-method", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(incoming_request_path_with_query,
+				"incoming-request-path-with-query", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(incoming_request_headers,
+				"incoming-request-headers", "types2"),
+			SET_VALS(params, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(incoming_request_consume,
+				"incoming-request-consume", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(new_outgoing_request, "new-outgoing-request",
+				"types2"),
+			SET_VALS(params,
+				 WASM_I32, WASM_I32, WASM_I32, WASM_I32,
+				 WASM_I32, WASM_I32, WASM_I32, WASM_I32,
+				 WASM_I32, WASM_I32, WASM_I32, WASM_I32,
+				 WASM_I32, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(outgoing_request_write,
+				"outgoing-request-write", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(set_response_outparam,
+				 "set-response-outparam", "types2"),
+			SET_VALS(params,
+				 WASM_I32, WASM_I32, WASM_I32, WASM_I32,
+				 WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(incoming_response_status,
+				"incoming-response-status", "types2"),
+			SET_VALS(params, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(incoming_response_headers,
+				"incoming-response-headers", "types2"),
+			SET_VALS(params, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(incoming_response_consume,
+				"incoming-response-consume", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(new_outgoing_response,
+				"new-outgoing-response", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		}, {
+			SET_FUNC(outgoing_response_write,
+				"outgoing-response-write", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(future_incoming_response-get,
+				"future-incoming-response-get", "types2"),
+			SET_VALS(params, WASM_I32, WASM_I32),
+		}, {
+			SET_FUNC(listen_to_fauture_incoming_response,
+				"listen-to-future-incoming-response",
+				"types2"),
+			SET_VALS(params, WASM_I32),
+			SET_VALS(results, WASM_I32),
+		},
+
+		{ }
+	}, *imf;
+
+	for (imf = import_functions; imf->func_name != NULL; imf++) {
+		wasm_functype_t  *func_ty;
+
+		printf("    [%s::%s]\n", imf->mod_name, imf->func_name);
+
+		func_ty = create_wasm_func(imf->params, imf->nr_params,
+					   imf->results, imf->nr_results);
+		wasmtime_linker_define_func(linker,
+					    imf->mod_name, imf->mod_namelen,
+					    imf->func_name, imf->func_namelen,
+					    func_ty,  imf->func, NULL, NULL);
+		wasm_functype_delete(func_ty);
+	}
+}
+
+int main(void)
+{
+	wasm_engine_t *engine;
+	wasmtime_store_t *store;
+	wasmtime_context_t *context;
+	wasmtime_module_t *module = NULL;
+	wasmtime_linker_t *linker;
+	wasmtime_error_t *error;
+	wasm_byte_vec_t wasm;
+	wasmtime_extern_t item;
+	wasi_config_t *wasi_config;
+	FILE *file;
+	size_t file_size;
+	bool ok;
+
+	printf("Initializing...\n");
+	engine = wasm_engine_new();
+	store = wasmtime_store_new(engine, NULL, NULL);
+	context = wasmtime_store_context(store);
+
+	linker = wasmtime_linker_new(engine);
+	error = wasmtime_linker_define_wasi(linker);
+	if (error != NULL)
+		exit_with_error("failed to link wasi", error, NULL);
+
+	printf("Loading binary...\n");
+	file = fopen(WASM_MODULE, "r");
+	if (!file) {
+		printf("> Error loading file!\n");
+		exit(EXIT_FAILURE);
+	}
+	fseek(file, 0L, SEEK_END);
+	file_size = ftell(file);
+	wasm_byte_vec_new_uninitialized(&wasm, file_size);
+	fseek(file, 0L, SEEK_SET);
+	if (fread(wasm.data, file_size, 1, file) != 1) {
+		printf("> Error loading module!\n");
+		exit(EXIT_FAILURE);
+	}
+	fclose(file);
+
+	printf("Compiling module...\n");
+	error = wasmtime_module_new(engine, (uint8_t*)wasm.data, wasm.size,
+				    &module);
+	if (!module)
+		exit_with_error("failed to compile module", error, NULL);
+	wasm_byte_vec_delete(&wasm);
+
+	printf("Setting function imports...\n");
+	set_function_imports(linker);
+
+	printf("Initialising WASI...\n");
+	wasi_config = wasi_config_new();
+	wasi_config_inherit_env(wasi_config);
+	wasi_config_inherit_stdin(wasi_config);
+	wasi_config_inherit_stdout(wasi_config);
+	wasi_config_inherit_stderr(wasi_config);
+	error = wasmtime_context_set_wasi(context, wasi_config);
+	if (error)
+		exit_with_error("failed to initialise WASI", error, NULL);
+
+	printf("Instantiating module...\n");
+	error = wasmtime_linker_module(linker, context, "", 0, module);
+	if (error != NULL)
+		exit_with_error("failed to instantiate module", error, NULL);
+
+	printf("Getting function exports...\n");
+	ok = wasmtime_linker_get(linker, context, "", 0, "HTTP#handle", 11,
+				 &item);
+	if (!ok) {
+		printf("> Error getting function export [HTTP#handle]\n");
+		exit(EXIT_FAILURE);
+	}
+	printf("    [HTTP#handle]\n");
+
+	ok = wasmtime_linker_get(linker, context, "", 0, "cabi_realloc", 12,
+				 &item);
+	if (!ok) {
+		printf("> Error getting function export [cabi_realloc]\n");
+		exit(EXIT_FAILURE);
+	}
+	printf("    [cabi_realloc]\n");
+
+	printf("Shutting down...\n");
+	wasmtime_module_delete(module);
+	wasmtime_store_delete(store);
+	wasm_engine_delete(engine);
+
+	printf("Done.\n");
+
+	exit(EXIT_SUCCESS);;
+}