wasm: add support for wamr (wasm-micro-runtime)

Makefile.am

@@ -57,6 +57,7 @@ libcrun_SOURCES = src/libcrun/utils.c \
 		src/libcrun/handlers/wasmedge.c \
 		src/libcrun/handlers/wasmer.c \
 		src/libcrun/handlers/wasmtime.c \
+		src/libcrun/handlers/wamr.c \
 		src/libcrun/intelrdt.c \
 		src/libcrun/io_priority.c \
 		src/libcrun/linux.c \

configure.ac

@@ -124,6 +124,10 @@ dnl include support for wasmedge (EXPERIMENTAL)
 AC_ARG_WITH([wasmedge], AS_HELP_STRING([--with-wasmedge], [build with WasmEdge support]))
 AS_IF([test "x$with_wasmedge" = "xyes"], AC_CHECK_HEADERS([wasmedge/wasmedge.h], AC_DEFINE([HAVE_WASMEDGE], 1, [Define if WasmEdge is available]), [AC_MSG_ERROR([*** Missing wasmedge headers])]))
 
+dnl include support for wamr (EXPERIMENTAL)
+AC_ARG_WITH([wamr], AS_HELP_STRING([--with-wamr], [build with WAMR support]))
+AS_IF([test "x$with_wamr" = "xyes"], AC_CHECK_HEADERS([wasm_export.h], AC_DEFINE([HAVE_WAMR], 1, [Define if WAMR is available]), [AC_MSG_ERROR([*** Missing WAMR headers])]))
+
 dnl include support for libkrun (EXPERIMENTAL)
 AC_ARG_WITH([libkrun], AS_HELP_STRING([--with-libkrun], [build with libkrun support]))
 AS_IF([test "x$with_libkrun" = "xyes"], AC_CHECK_HEADERS([libkrun.h], AC_DEFINE([HAVE_LIBKRUN], 1, [Define if libkrun is available]), [AC_MSG_ERROR([*** Missing libkrun headers])]))

docs/wasm-wasi-on-kubernetes.md

@@ -1,8 +1,8 @@
 # Running wasi workload natively on kubernetes using crun
 
-Crun natively supports running wasm/wasi workload on using `wasmedge`, `wasmer` and `wasmtime`.
-Each one of them (`wasmedge`, `wasmer` and `wasmtime`) comes with their own set of unique features.
-For instance `wasmer` can compile your `.wat` on the fly. Similarly `wasmedge` has its own perks.
+Crun natively supports running wasm/wasi workload on using `wasmedge`, `wasmer`, `wasmtime` and `wamr`.
+Each one of them (`wasmedge`, `wasmer`, `wasmtime` and `wamr`) comes with their own set of unique features.
+For instance `wasmer` can compile your `.wat` on the fly. Similarly `wasmedge` has its own perks. `wamr` has a layered JIT architecture which can tier up during runtime.
 Crun can support only one of them at a time. Please build crun with whatever runtime suits you the best.
 
 #### How does crun detects if is a wasm workload ?
@@ -31,6 +31,7 @@ So spec generated by CRI implementation must contain annotation something like.
 
 * Following features works completely out if the box once `cri-o` is using `crun` built with `wasm` support.
 * Configure `cri-o` to use `crun` instead of `runc` by editing config at `/etc/crio/crio.conf` read more about it here https://docs.openshift.com/container-platform/3.11/crio/crio_runtime.html#configure-crio-use-crio-engine
+* As of `cri-o` version `1.31` it defaults to `crun`, but the bundled `crun` may not have been built with `wasm` support.
 * Restart `cri-o` by `sudo systemctl restart crio`
 * `cri-o` automatically propagates pod annotations to container spec. So we don't need to do anything.
 

src/libcrun/custom-handler.c

@@ -45,6 +45,9 @@ extern struct custom_handler_s handler_wasmedge;
 #if HAVE_DLOPEN && HAVE_WASMER
 extern struct custom_handler_s handler_wasmer;
 #endif
+#if HAVE_DLOPEN && HAVE_WAMR
+extern struct custom_handler_s handler_wamr;
+#endif
 #if HAVE_DLOPEN && HAVE_MONO
 extern struct custom_handler_s handler_mono;
 #endif
@@ -65,6 +68,9 @@ static struct custom_handler_s *static_handlers[] = {
 #if HAVE_DLOPEN && HAVE_WASMTIME
   &handler_wasmtime,
 #endif
+#if HAVE_DLOPEN && HAVE_WAMR
+  &handler_wamr,
+#endif
 #if HAVE_DLOPEN && HAVE_MONO
   &handler_mono,
 #endif

src/libcrun/handlers/wamr.c

@@ -0,0 +1,247 @@
+/*
+ * crun - OCI runtime written in C
+ *
+ * Copyright (C) 2017, 2018, 2019, 2020, 2021 Giuseppe Scrivano <giuseppe@scrivano.org>
+ * crun is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * crun is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with crun.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#define _GNU_SOURCE
+
+#include <config.h>
+#include "../custom-handler.h"
+#include "../container.h"
+#include "../utils.h"
+#include "../linux.h"
+#include "handler-utils.h"
+#include <unistd.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef HAVE_DLOPEN
+#  include <dlfcn.h>
+#endif
+
+#ifdef HAVE_WAMR
+#  include <wasm_export.h>
+#endif
+
+#if HAVE_DLOPEN && HAVE_WAMR
+
+static int
+libwamr_load (void **cookie, libcrun_error_t *err)
+{
+  void *handle;
+
+  handle = dlopen ("libiwasm.so", RTLD_NOW);
+  if (handle == NULL)
+    return crun_make_error (err, 0, "could not load `libiwasm.so`: `%s`", dlerror ());
+  *cookie = handle;
+
+  return 0;
+}
+
+static int
+libwamr_unload (void *cookie, libcrun_error_t *err)
+{
+  int r;
+
+  if (cookie)
+    {
+      r = dlclose (cookie);
+      if (UNLIKELY (r < 0))
+        return crun_make_error (err, 0, "could not unload handle: `%s`", dlerror ());
+    }
+  return 0;
+}
+
+static int
+libwamr_exec (void *cookie, __attribute__ ((unused)) libcrun_container_t *container, const char *pathname, char *const argv[])
+{
+  // load symbols from the shared library libiwasm.so
+  bool (*wasm_runtime_init) ();
+  RuntimeInitArgs init_args;
+  bool (*wasm_runtime_full_init) (RuntimeInitArgs *init_args);
+  wasm_module_t module;
+  wasm_module_t (*wasm_runtime_load) (uint8_t *buf, uint32_t size, char *error_buf, uint32_t error_buf_size);
+  wasm_module_inst_t module_inst;
+  wasm_module_inst_t (*wasm_runtime_instantiate) (const wasm_module_t module, uint32_t default_stack_size, uint32_t host_managed_heap_size, char *error_buf, uint32_t error_buf_size);
+  wasm_function_inst_t func;
+  wasm_function_inst_t (*wasm_runtime_lookup_function) (wasm_module_inst_t const module_inst, const char *name);
+  wasm_exec_env_t exec_env;
+  wasm_exec_env_t (*wasm_runtime_create_exec_env) (wasm_module_inst_t module_inst, uint32_t stack_size);
+  bool (*wasm_runtime_call_wasm) (wasm_exec_env_t exec_env, wasm_function_inst_t function, uint32_t argc, uint32_t argv[]);
+  const char *(*wasm_runtime_get_exception) (wasm_module_inst_t module_inst);
+  void (*wasm_runtime_set_exception) (wasm_module_inst_t module_inst, const char *exception);
+  void (*wasm_runtime_clear_exception) (wasm_module_inst_t module_inst);
+  void (*wasm_runtime_destroy_exec_env) (wasm_exec_env_t exec_env);
+  void (*wasm_runtime_deinstantiate) (wasm_module_inst_t module_inst);
+  void (*wasm_runtime_unload) (wasm_module_t module);
+  void (*wasm_runtime_destroy) ();
+  uint32_t (*wasm_runtime_get_wasi_exit_code) (wasm_module_inst_t module_inst);
+  bool (*wasm_application_execute_main) (wasm_module_inst_t module_inst, int32_t argc, char *argv[]);
+  void (*wasm_runtime_set_wasi_args) (wasm_module_t module, const char *dir_list[], uint32_t dir_count, const char *map_dir_list[], uint32_t map_dir_count, const char *env[], uint32_t env_count, char *argv[], int argc);
+
+  wasm_runtime_init = dlsym (cookie, "wasm_runtime_init");
+  wasm_runtime_full_init = dlsym (cookie, "wasm_runtime_full_init");
+  wasm_runtime_load = dlsym (cookie, "wasm_runtime_load");
+  wasm_runtime_instantiate = dlsym (cookie, "wasm_runtime_instantiate");
+  wasm_runtime_lookup_function = dlsym (cookie, "wasm_runtime_lookup_function");
+  wasm_runtime_create_exec_env = dlsym (cookie, "wasm_runtime_create_exec_env");
+  wasm_runtime_call_wasm = dlsym (cookie, "wasm_runtime_call_wasm");
+  wasm_runtime_get_exception = dlsym (cookie, "wasm_runtime_get_exception");
+  wasm_runtime_set_exception = dlsym (cookie, "wasm_runtime_set_exception");
+  wasm_runtime_clear_exception = dlsym (cookie, "wasm_runtime_clear_exception");
+  wasm_runtime_destroy_exec_env = dlsym (cookie, "wasm_runtime_destroy_exec_env");
+  wasm_runtime_deinstantiate = dlsym (cookie, "wasm_runtime_deinstantiate");
+  wasm_runtime_unload = dlsym (cookie, "wasm_runtime_unload");
+  wasm_runtime_destroy = dlsym (cookie, "wasm_runtime_destroy");
+  wasm_runtime_get_wasi_exit_code = dlsym (cookie, "wasm_runtime_get_wasi_exit_code");
+  wasm_application_execute_main = dlsym (cookie, "wasm_application_execute_main");
+  wasm_runtime_set_wasi_args = dlsym (cookie, "wasm_runtime_set_wasi_args");
+
+  if (wasm_runtime_init == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_init symbol in `libiwasm.so`");
+  if (wasm_runtime_full_init == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_full_init symbol in `libiwasm.so`");
+  if (wasm_runtime_load == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_load symbol in `libiwasm.so`");
+  if (wasm_runtime_instantiate == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_instantiate symbol in `libiwasm.so`");
+  if (wasm_runtime_lookup_function == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_lookup_function symbol in `libiwasm.so`");
+  if (wasm_runtime_create_exec_env == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_create_exec_env symbol in `libiwasm.so`");
+  if (wasm_runtime_call_wasm == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_call_wasm symbol in `libiwasm.so`");
+  if (wasm_runtime_get_exception == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_get_exception symbol in `libiwasm.so`");
+  if (wasm_runtime_set_exception == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_set_exception symbol in `libiwasm.so`");
+  if (wasm_runtime_clear_exception == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_clear_exception symbol in `libiwasm.so`");
+  if (wasm_runtime_destroy_exec_env == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_destroy_exec_env symbol in `libiwasm.so`");
+  if (wasm_runtime_deinstantiate == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_deinstantiate symbol in `libiwasm.so`");
+  if (wasm_runtime_unload == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_unload symbol in `libiwasm.so`");
+  if (wasm_runtime_destroy == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_destroy symbol in `libiwasm.so`");
+  if (wasm_runtime_get_wasi_exit_code == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_get_wasi_exit_code symbol in `libiwasm.so`");
+  if (wasm_application_execute_main == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_application_execute_main symbol in `libiwasm.so`");
+  if (wasm_runtime_set_wasi_args == NULL)
+    error (EXIT_FAILURE, 0, "could not find wasm_runtime_set_wasi_args symbol in `libiwasm.so`");
+
+  int ret;
+  const char *exception;
+  cleanup_free char *buffer = NULL;
+  char error_buf[128];
+  size_t buffer_size;
+  uint32_t stack_size = 8096, heap_size = 0;
+  libcrun_error_t tmp_err = NULL;
+  const char *wasi_proc_exit_exception = "wasi proc exit";
+  const char *wasi_addr_pool[2] = { "0.0.0.0/0", "::/0" };
+  const char *wasi_ns_lookup_pool[1] = { "*" };
+
+  const char *dirs[2] = { "/", "." };
+  char **container_env = container->container_def->process->env;
+  size_t env_count = container->container_def->process->env_len;
+
+  int arg_count = 0;
+  char *const *arg;
+  for (arg = argv; *arg != NULL; ++arg)
+    arg_count++;
+
+  // initialize the wasm runtime by default configurations
+  if (! wasm_runtime_init ())
+    error (EXIT_FAILURE, 0, "Failed to initialize the wasm runtime");
+
+  // read WASM file into a memory buffer
+  ret = read_all_file (pathname, &buffer, &buffer_size, &tmp_err);
+  if (UNLIKELY (ret < 0))
+    {
+      crun_error_release (&tmp_err);
+      error (EXIT_FAILURE, 0, "Failed to read file");
+    }
+
+  if (UNLIKELY (buffer_size > UINT32_MAX))
+    error (EXIT_FAILURE, 0, "File size is too large");
+
+  // parse the WASM file from buffer and create a WASM module
+  module = wasm_runtime_load (buffer, buffer_size, error_buf, sizeof (error_buf));
+  if (! module)
+    error (EXIT_FAILURE, 0, "Failed to load WASM file");
+
+  // instantiate the WASI environment
+  wasm_runtime_set_wasi_args (module, dirs, 1, NULL, 0, (const char **) container_env, env_count, (char **) argv, arg_count);
+
+  // enable the WASI socket api
+  wasm_runtime_set_wasi_addr_pool (module, wasi_addr_pool, 2);
+  wasm_runtime_set_wasi_ns_lookup_pool (module, wasi_ns_lookup_pool, 1);
+
+  // create an instance of the WASM module (WASM linear memory is ready)
+  module_inst = wasm_runtime_instantiate (module, stack_size, heap_size, error_buf, sizeof (error_buf));
+  if (! module_inst)
+    error (EXIT_FAILURE, 0, "Failed to instantiate the WASM module");
+
+  // look up a WASM function by its name (The function signature can NULL here)
+  func = wasm_runtime_lookup_function (module_inst, "_start");
+  if (! func)
+    error (EXIT_FAILURE, 0, "Failed to look up the WASM function");
+
+  // create an execution environment to execute the WASM functions
+  exec_env = wasm_runtime_create_exec_env (module_inst, stack_size);
+  if (! exec_env)
+    error (EXIT_FAILURE, 0, "Failed to create the execution environment");
+
+  // call the WASM function
+  ret = wasm_runtime_call_wasm (exec_env, func, 0, NULL);
+  if (ret)
+    wasm_runtime_set_exception (module_inst, wasi_proc_exit_exception);
+  exception = wasm_runtime_get_exception (module_inst);
+  if (! strstr (exception, wasi_proc_exit_exception))
+    error (EXIT_FAILURE, 0, "Failed to call the WASM function");
+  wasm_runtime_clear_exception (module_inst);
+
+  wasm_runtime_destroy_exec_env (exec_env);
+  wasm_runtime_deinstantiate (module_inst);
+  wasm_runtime_unload (module);
+  wasm_runtime_destroy ();
+
+  exit (EXIT_SUCCESS);
+}
+
+static int
+libwamr_can_handle_container (libcrun_container_t *container, libcrun_error_t *err)
+{
+  return wasm_can_handle_container (container, err);
+}
+
+struct custom_handler_s handler_wamr = {
+  .name = "wamr",
+  .alias = "wasm",
+  .feature_string = "WASM:wamr",
+  .load = libwamr_load,
+  .unload = libwamr_unload,
+  .run_func = libwamr_exec,
+  .can_handle_container = libwamr_can_handle_container,
+};
+
+#endif