ucode-mod-bpf: add new package for a ucode libbpf binding

The bpf plugin provides functionality for loading and interacting with
eBPF modules.

It allows loading full modules and pinned maps/programs and supports
interacting with maps and attaching programs as tc classifiers.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

2 files changed, 854 insertions, 0 deletions

diff --git a/package/utils/ucode-mod-bpf/Makefile b/package/utils/ucode-mod-bpf/Makefile
new file mode 100644
index 0000000000..a748b9dbbd
--- /dev/null
+++ b/package/utils/ucode-mod-bpf/Makefile
@@ -0,0 +1,40 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=ucode-mod-bpf
+PKG_RELEASE:=1
+PKG_LICENSE:=ISC
+PKG_MAINTAINER:=Felix Fietkau <nbd@nbd.name>
+
+include $(INCLUDE_DIR)/package.mk
+include $(INCLUDE_DIR)/nls.mk
+
+define Package/ucode-mod-bpf
+  SECTION:=utils
+  CATEGORY:=Utilities
+  TITLE:=ucode eBPF module
+  DEPENDS:=+libucode +libbpf
+endef
+
+define Package/ucode-mod-bpf/description
+The bpf plugin provides functionality for loading and interacting with
+eBPF modules.
+
+It allows loading full modules and pinned maps/programs and supports
+interacting with maps and attaching programs as tc classifiers.
+endef
+
+define Package/ucode-mod-bpf/install
+	$(INSTALL_DIR) $(1)/usr/lib/ucode
+	$(CP) $(PKG_BUILD_DIR)/bpf.so $(1)/usr/lib/ucode/
+endef
+
+define Build/Configure
+endef
+
+define Build/Compile
+	$(TARGET_CC) $(TARGET_CFLAGS) $(TARGET_LDFLAGS) $(FPIC) \
+		-Wall -ffunction-sections -Wl,--gc-sections -shared -Wl,--no-as-needed -lbpf \
+		-o $(PKG_BUILD_DIR)/bpf.so $(PKG_BUILD_DIR)/bpf.c
+endef
+
+$(eval $(call BuildPackage,ucode-mod-bpf))
diff --git a/package/utils/ucode-mod-bpf/src/bpf.c b/package/utils/ucode-mod-bpf/src/bpf.c
new file mode 100644
index 0000000000..415215e54e
--- /dev/null
+++ b/package/utils/ucode-mod-bpf/src/bpf.c
@@ -0,0 +1,814 @@
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "ucode/module.h"
+
+#define err_return_int(err, ...) do { set_error(err, __VA_ARGS__); return -1; } while(0)
+#define err_return(err, ...) do { set_error(err, __VA_ARGS__); return NULL; } while(0)
+#define TRUE ucv_boolean_new(true)
+
+static uc_resource_type_t *module_type, *map_type, *map_iter_type, *program_type;
+static uc_value_t *registry;
+static uc_vm_t *debug_vm;
+
+static struct {
+	int code;
+	char *msg;
+} last_error;
+
+struct uc_bpf_fd {
+	int fd;
+	bool close;
+};
+
+struct uc_bpf_map {
+	struct uc_bpf_fd fd; /* must be first */
+	unsigned int key_size, val_size;
+};
+
+struct uc_bpf_map_iter {
+	int fd;
+	unsigned int key_size;
+	bool has_next;
+	uint8_t key[];
+};
+
+__attribute__((format(printf, 2, 3))) static void
+set_error(int errcode, const char *fmt, ...)
+{
+	va_list ap;
+
+	free(last_error.msg);
+
+	last_error.code = errcode;
+	last_error.msg = NULL;
+
+	if (fmt) {
+		va_start(ap, fmt);
+		xvasprintf(&last_error.msg, fmt, ap);
+		va_end(ap);
+	}
+}
+
+static void init_env(void)
+{
+	static bool init_done = false;
+	struct rlimit limit = {
+		.rlim_cur = RLIM_INFINITY,
+		.rlim_max = RLIM_INFINITY,
+	};
+
+	if (init_done)
+		return;
+
+	setrlimit(RLIMIT_MEMLOCK, &limit);
+	init_done = true;
+}
+
+static uc_value_t *
+uc_bpf_error(uc_vm_t *vm, size_t nargs)
+{
+	uc_value_t *numeric = uc_fn_arg(0);
+	const char *msg = last_error.msg;
+	int code = last_error.code;
+	uc_stringbuf_t *buf;
+	const char *s;
+
+	if (last_error.code == 0)
+		return NULL;
+
+	set_error(0, NULL);
+
+	if (ucv_is_truish(numeric))
+		return ucv_int64_new(code);
+
+	buf = ucv_stringbuf_new();
+	if (code < 0 && msg) {
+		ucv_stringbuf_addstr(buf, msg, strlen(msg));
+	} else {
+		s = strerror(code);
+		ucv_stringbuf_addstr(buf, s, strlen(s));
+		if (msg)
+			ucv_stringbuf_printf(buf, ": %s", msg);
+	}
+
+	return ucv_stringbuf_finish(buf);
+}
+
+static int
+uc_bpf_module_set_opts(struct bpf_object *obj, uc_value_t *opts)
+{
+	uc_value_t *val;
+
+	if (!opts)
+		return 0;
+
+	if (ucv_type(opts) != UC_OBJECT)
+		err_return_int(EINVAL, "options argument");
+
+	if ((val = ucv_object_get(opts, "rodata", NULL)) != NULL) {
+		struct bpf_map *map = NULL;
+
+		if (ucv_type(val) != UC_STRING)
+			err_return_int(EINVAL, "rodata type");
+
+		while ((map = bpf_object__next_map(obj, map)) != NULL) {
+			if (!strstr(bpf_map__name(map), ".rodata"))
+				continue;
+
+			break;
+		}
+
+		if (!map)
+			err_return_int(errno, "rodata map");
+
+		if (bpf_map__set_initial_value(map, ucv_string_get(val),
+					       ucv_string_length(val)))
+			err_return_int(errno, "rodata");
+	}
+
+	if ((val = ucv_object_get(opts, "program-type", NULL)) != NULL) {
+		if (ucv_type(val) != UC_OBJECT)
+			err_return_int(EINVAL, "prog_types argument");
+
+		ucv_object_foreach(val, name, type) {
+			struct bpf_program *prog;
+
+			if (ucv_type(type) != UC_INTEGER)
+				err_return_int(EINVAL, "program %s type", name);
+
+			prog = bpf_object__find_program_by_name(obj, name);
+			if (!prog)
+				err_return_int(-1, "program %s not found", name);
+
+			bpf_program__set_type(prog, ucv_int64_get(type));
+		}
+	}
+
+	return 0;
+}
+
+static uc_value_t *
+uc_bpf_open_module(uc_vm_t *vm, size_t nargs)
+{
+	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, bpf_opts);
+	uc_value_t *path = uc_fn_arg(0);
+	uc_value_t *opts = uc_fn_arg(1);
+	struct bpf_object *obj;
+
+	if (ucv_type(path) != UC_STRING)
+		err_return(EINVAL, "module path");
+
+	init_env();
+	obj = bpf_object__open_file(ucv_string_get(path), &bpf_opts);
+	if (libbpf_get_error(obj))
+		err_return(errno, NULL);
+
+	if (uc_bpf_module_set_opts(obj, opts)) {
+		bpf_object__close(obj);
+		return NULL;
+	}
+
+	if (bpf_object__load(obj)) {
+		bpf_object__close(obj);
+		err_return(errno, NULL);
+	}
+
+	return uc_resource_new(module_type, obj);
+}
+
+static uc_value_t *
+uc_bpf_map_create(int fd, unsigned int key_size, unsigned int val_size, bool close)
+{
+	struct uc_bpf_map *uc_map;
+
+	uc_map = xalloc(sizeof(*uc_map));
+	uc_map->fd.fd = fd;
+	uc_map->key_size = key_size;
+	uc_map->val_size = val_size;
+	uc_map->fd.close = close;
+
+	return uc_resource_new(map_type, uc_map);
+}
+
+static uc_value_t *
+uc_bpf_open_map(uc_vm_t *vm, size_t nargs)
+{
+	struct bpf_map_info info;
+	uc_value_t *path = uc_fn_arg(0);
+	__u32 len = sizeof(info);
+	int err;
+	int fd;
+
+	if (ucv_type(path) != UC_STRING)
+		err_return(EINVAL, "module path");
+
+	fd = bpf_obj_get(ucv_string_get(path));
+	if (fd < 0)
+		err_return(errno, NULL);
+
+	err = bpf_obj_get_info_by_fd(fd, &info, &len);
+	if (err) {
+		close(fd);
+		err_return(errno, NULL);
+	}
+
+	return uc_bpf_map_create(fd, info.key_size, info.value_size, true);
+}
+
+static uc_value_t *
+uc_bpf_open_program(uc_vm_t *vm, size_t nargs)
+{
+	uc_value_t *path = uc_fn_arg(0);
+	struct uc_bpf_fd *f;
+	int fd;
+
+	if (ucv_type(path) != UC_STRING)
+		err_return(EINVAL, "module path");
+
+	fd = bpf_obj_get(ucv_string_get(path));
+	if (fd < 0)
+		err_return(errno, NULL);
+
+	f = xalloc(sizeof(*f));
+	f->fd = fd;
+	f->close = true;
+
+	return uc_resource_new(program_type, f);
+}
+
+static uc_value_t *
+uc_bpf_module_get_maps(uc_vm_t *vm, size_t nargs)
+{
+	struct bpf_object *obj = uc_fn_thisval("bpf.module");
+	struct bpf_map *map = NULL;
+	uc_value_t *rv;
+	int i = 0;
+
+	if (!obj)
+		err_return(EINVAL, NULL);
+
+	rv = ucv_array_new(vm);
+	bpf_object__for_each_map(map, obj)
+		ucv_array_set(rv, i++, ucv_string_new(bpf_map__name(map)));
+
+	return rv;
+}
+
+static uc_value_t *
+uc_bpf_module_get_map(uc_vm_t *vm, size_t nargs)
+{
+	struct bpf_object *obj = uc_fn_thisval("bpf.module");
+	struct bpf_map *map;
+	uc_value_t *name = uc_fn_arg(0);
+	int fd;
+
+	if (!obj || ucv_type(name) != UC_STRING)
+		err_return(EINVAL, NULL);
+
+	map = bpf_object__find_map_by_name(obj, ucv_string_get(name));
+	if (!map)
+		err_return(errno, NULL);
+
+	fd = bpf_map__fd(map);
+	if (fd < 0)
+		err_return(EINVAL, NULL);
+
+	return uc_bpf_map_create(fd, bpf_map__key_size(map), bpf_map__value_size(map), false);
+}
+
+static uc_value_t *
+uc_bpf_module_get_programs(uc_vm_t *vm, size_t nargs)
+{
+	struct bpf_object *obj = uc_fn_thisval("bpf.module");
+	struct bpf_program *prog = NULL;
+	uc_value_t *rv;
+	int i = 0;
+
+	if (!obj)
+		err_return(EINVAL, NULL);
+
+	rv = ucv_array_new(vm);
+	bpf_object__for_each_program(prog, obj)
+		ucv_array_set(rv, i++, ucv_string_new(bpf_program__name(prog)));
+
+	return rv;
+}
+
+static uc_value_t *
+uc_bpf_module_get_program(uc_vm_t *vm, size_t nargs)
+{
+	struct bpf_object *obj = uc_fn_thisval("bpf.module");
+	struct bpf_program *prog;
+	uc_value_t *name = uc_fn_arg(0);
+	struct uc_bpf_fd *f;
+	int fd;
+
+	if (!obj || !name || ucv_type(name) != UC_STRING)
+		err_return(EINVAL, NULL);
+
+	prog = bpf_object__find_program_by_name(obj, ucv_string_get(name));
+	if (!prog)
+		err_return(errno, NULL);
+
+	fd = bpf_program__fd(prog);
+	if (fd < 0)
+		err_return(EINVAL, NULL);
+
+	f = xalloc(sizeof(*f));
+	f->fd = fd;
+
+	return uc_resource_new(program_type, f);
+}
+
+static void *
+uc_bpf_map_arg(uc_value_t *val, const char *kind, unsigned int size)
+{
+	static union {
+		uint32_t u32;
+		uint64_t u64;
+	} val_int;
+
+	switch (ucv_type(val)) {
+	case UC_INTEGER:
+		if (size == 4)
+			val_int.u32 = ucv_int64_get(val);
+		else if (size == 8)
+			val_int.u64 = ucv_int64_get(val);
+		else
+			break;
+
+		return &val_int;
+	case UC_STRING:
+		if (size != ucv_string_length(val))
+			break;
+
+		return ucv_string_get(val);
+	default:
+		err_return(EINVAL, "%s type", kind);
+	}
+
+	err_return(EINVAL, "%s size mismatch (expected: %d)", kind, size);
+}
+
+static uc_value_t *
+uc_bpf_map_get(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_map *map = uc_fn_thisval("bpf.map");
+	uc_value_t *a_key = uc_fn_arg(0);
+	void *key, *val;
+
+	if (!map)
+		err_return(EINVAL, NULL);
+
+	key = uc_bpf_map_arg(a_key, "key", map->key_size);
+	if (!key)
+		return NULL;
+
+	val = alloca(map->val_size);
+	if (bpf_map_lookup_elem(map->fd.fd, key, val))
+		return NULL;
+
+	return ucv_string_new_length(val, map->val_size);
+}
+
+static uc_value_t *
+uc_bpf_map_set(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_map *map = uc_fn_thisval("bpf.map");
+	uc_value_t *a_key = uc_fn_arg(0);
+	uc_value_t *a_val = uc_fn_arg(1);
+	uc_value_t *a_flags = uc_fn_arg(2);
+	uint64_t flags;
+	void *key, *val;
+
+	if (!map)
+		err_return(EINVAL, NULL);
+
+	key = uc_bpf_map_arg(a_key, "key", map->key_size);
+	if (!key)
+		return NULL;
+
+	val = uc_bpf_map_arg(a_val, "value", map->val_size);
+	if (!val)
+		return NULL;
+
+	if (!a_flags)
+		flags = BPF_ANY;
+	else if (ucv_type(a_flags) != UC_INTEGER)
+		err_return(EINVAL, "flags");
+	else
+		flags = ucv_int64_get(a_flags);
+
+	if (bpf_map_update_elem(map->fd.fd, key, val, flags))
+		return NULL;
+
+	return ucv_string_new_length(val, map->val_size);
+}
+
+static uc_value_t *
+uc_bpf_map_delete(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_map *map = uc_fn_thisval("bpf.map");
+	uc_value_t *a_key = uc_fn_arg(0);
+	uc_value_t *a_return = uc_fn_arg(1);
+	void *key, *val = NULL;
+	int ret;
+
+	if (!map)
+		err_return(EINVAL, NULL);
+
+	key = uc_bpf_map_arg(a_key, "key", map->key_size);
+	if (!key)
+		return NULL;
+
+	if (!ucv_is_truish(a_return)) {
+		ret = bpf_map_delete_elem(map->fd.fd, key);
+
+		return ucv_boolean_new(ret == 0);
+	}
+
+	val = alloca(map->val_size);
+	if (bpf_map_lookup_and_delete_elem(map->fd.fd, key, val))
+		return NULL;
+
+	return ucv_string_new_length(val, map->val_size);
+}
+
+static uc_value_t *
+uc_bpf_map_delete_all(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_map *map = uc_fn_thisval("bpf.map");
+	uc_value_t *filter = uc_fn_arg(0);
+	bool has_next;
+	void *key, *next;
+
+	if (!map)
+		err_return(EINVAL, NULL);
+
+	key = alloca(map->key_size);
+	next = alloca(map->key_size);
+	has_next = !bpf_map_get_next_key(map->fd.fd, NULL, next);
+	while (has_next) {
+		bool skip = false;
+
+		memcpy(key, next, map->key_size);
+		has_next = !bpf_map_get_next_key(map->fd.fd, next, next);
+
+		if (ucv_is_callable(filter)) {
+			uc_value_t *rv;
+
+			uc_value_push(ucv_get(filter));
+			uc_value_push(ucv_string_new_length((const char *)key, map->key_size));
+			if (uc_call(1) != EXCEPTION_NONE)
+				break;
+
+			rv = uc_vm_stack_pop(vm);
+			if (!rv)
+				break;
+
+			skip = !ucv_is_truish(rv);
+			ucv_put(rv);
+		}
+
+		if (!skip)
+			bpf_map_delete_elem(map->fd.fd, key);
+	}
+
+	return TRUE;
+}
+
+static uc_value_t *
+uc_bpf_map_iterator(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_map *map = uc_fn_thisval("bpf.map");
+	struct uc_bpf_map_iter *iter;
+
+	if (!map)
+		err_return(EINVAL, NULL);
+
+	iter = xalloc(sizeof(*iter) + map->key_size);
+	iter->fd = map->fd.fd;
+	iter->key_size = map->key_size;
+	iter->has_next = !bpf_map_get_next_key(iter->fd, NULL, &iter->key);
+
+	return uc_resource_new(map_iter_type, iter);
+}
+
+static uc_value_t *
+uc_bpf_map_iter_next(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_map_iter *iter = uc_fn_thisval("bpf.map_iter");
+	uc_value_t *rv;
+
+	if (!iter->has_next)
+		return NULL;
+
+	rv = ucv_string_new_length((const char *)iter->key, iter->key_size);
+	iter->has_next = !bpf_map_get_next_key(iter->fd, &iter->key, &iter->key);
+
+	return rv;
+}
+
+static uc_value_t *
+uc_bpf_map_iter_next_int(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_map_iter *iter = uc_fn_thisval("bpf.map_iter");
+	uint64_t intval;
+	uc_value_t *rv;
+
+	if (!iter->has_next)
+		return NULL;
+
+	if (iter->key_size == 4)
+		intval = *(uint32_t *)iter->key;
+	else if (iter->key_size == 8)
+		intval = *(uint64_t *)iter->key;
+	else
+		return NULL;
+
+	rv = ucv_int64_new(intval);
+	iter->has_next = !bpf_map_get_next_key(iter->fd, &iter->key, &iter->key);
+
+	return rv;
+}
+
+static uc_value_t *
+uc_bpf_map_foreach(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_map *map = uc_fn_thisval("bpf.map");
+	uc_value_t *func = uc_fn_arg(0);
+	bool has_next;
+	void *key, *next;
+	bool ret = false;
+
+	key = alloca(map->key_size);
+	next = alloca(map->key_size);
+	has_next = !bpf_map_get_next_key(map->fd.fd, NULL, next);
+
+	while (has_next) {
+		uc_value_t *rv;
+		bool stop;
+
+		memcpy(key, next, map->key_size);
+		has_next = !bpf_map_get_next_key(map->fd.fd, next, next);
+
+		uc_value_push(ucv_get(func));
+		uc_value_push(ucv_string_new_length((const char *)key, map->key_size));
+
+		if (uc_call(1) != EXCEPTION_NONE)
+			break;
+
+		rv = uc_vm_stack_pop(vm);
+		stop = (ucv_type(rv) == UC_BOOLEAN && !ucv_boolean_get(rv));
+		ucv_put(rv);
+
+		if (stop)
+			break;
+
+		ret = true;
+	}
+
+	return ucv_boolean_new(ret);
+}
+
+static uc_value_t *
+uc_bpf_obj_pin(uc_vm_t *vm, size_t nargs, const char *type)
+{
+	struct uc_bpf_fd *f = uc_fn_thisval(type);
+	uc_value_t *path = uc_fn_arg(0);
+
+	if (ucv_type(path) != UC_STRING)
+		err_return(EINVAL, NULL);
+
+	if (bpf_obj_pin(f->fd, ucv_string_get(path)))
+		err_return(errno, NULL);
+
+	return TRUE;
+}
+
+static uc_value_t *
+uc_bpf_program_pin(uc_vm_t *vm, size_t nargs)
+{
+	return uc_bpf_obj_pin(vm, nargs, "bpf.program");
+}
+
+static uc_value_t *
+uc_bpf_map_pin(uc_vm_t *vm, size_t nargs)
+{
+	return uc_bpf_obj_pin(vm, nargs, "bpf.map");
+}
+
+static uc_value_t *
+uc_bpf_set_tc_hook(uc_value_t *ifname, uc_value_t *type, uc_value_t *prio,
+		   int fd)
+{
+	DECLARE_LIBBPF_OPTS(bpf_tc_hook, hook);
+	DECLARE_LIBBPF_OPTS(bpf_tc_opts, attach_tc,
+			    .handle = 1);
+	const char *type_str;
+	uint64_t prio_val;
+
+	if (ucv_type(ifname) != UC_STRING || ucv_type(type) != UC_STRING ||
+	    ucv_type(prio) != UC_INTEGER)
+		err_return(EINVAL, NULL);
+
+	prio_val = ucv_int64_get(prio);
+	if (prio_val > 0xffff)
+		err_return(EINVAL, NULL);
+
+	type_str = ucv_string_get(type);
+	if (!strcmp(type_str, "ingress"))
+		hook.attach_point = BPF_TC_INGRESS;
+	else if (!strcmp(type_str, "egress"))
+		hook.attach_point = BPF_TC_EGRESS;
+	else
+		err_return(EINVAL, NULL);
+
+	hook.ifindex = if_nametoindex(ucv_string_get(ifname));
+	if (!hook.ifindex)
+		goto error;
+
+	bpf_tc_hook_create(&hook);
+	attach_tc.priority = prio_val;
+	if (bpf_tc_detach(&hook, &attach_tc) < 0 && fd < 0)
+		goto error;
+
+	if (fd < 0)
+		goto out;
+
+	attach_tc.prog_fd = fd;
+	if (bpf_tc_attach(&hook, &attach_tc) < 0)
+		goto error;
+
+out:
+	return TRUE;
+
+error:
+	if (fd >= 0)
+		err_return(ENOENT, NULL);
+	return NULL;
+}
+
+static uc_value_t *
+uc_bpf_program_tc_attach(uc_vm_t *vm, size_t nargs)
+{
+	struct uc_bpf_fd *f = uc_fn_thisval("bpf.program");
+	uc_value_t *ifname = uc_fn_arg(0);
+	uc_value_t *type = uc_fn_arg(1);
+	uc_value_t *prio = uc_fn_arg(2);
+
+	if (!f)
+		err_return(EINVAL, NULL);
+
+	return uc_bpf_set_tc_hook(ifname, type, prio, f->fd);
+}
+
+static uc_value_t *
+uc_bpf_tc_detach(uc_vm_t *vm, size_t nargs)
+{
+	uc_value_t *ifname = uc_fn_arg(0);
+	uc_value_t *type = uc_fn_arg(1);
+	uc_value_t *prio = uc_fn_arg(2);
+
+	return uc_bpf_set_tc_hook(ifname, type, prio, -1);
+}
+
+static int
+uc_bpf_debug_print(enum libbpf_print_level level, const char *format,
+		   va_list args)
+{
+	char buf[256], *str = NULL;
+	uc_value_t *val;
+	va_list ap;
+	int size;
+
+	va_copy(ap, args);
+	size = vsnprintf(buf, sizeof(buf), format, ap);
+	va_end(ap);
+
+	if (size > 0 && (unsigned long)size < ARRAY_SIZE(buf) - 1) {
+		val = ucv_string_new(buf);
+		goto out;
+	}
+
+	if (vasprintf(&str, format, args) < 0)
+		return 0;
+
+	val = ucv_string_new(str);
+	free(str);
+
+out:
+	uc_vm_stack_push(debug_vm, ucv_get(ucv_array_get(registry, 0)));
+	uc_vm_stack_push(debug_vm, ucv_int64_new(level));
+	uc_vm_stack_push(debug_vm, val);
+	if (uc_vm_call(debug_vm, false, 2) == EXCEPTION_NONE)
+		ucv_put(uc_vm_stack_pop(debug_vm));
+
+	return 0;
+}
+
+static uc_value_t *
+uc_bpf_set_debug_handler(uc_vm_t *vm, size_t nargs)
+{
+	uc_value_t *handler = uc_fn_arg(0);
+
+	if (handler && !ucv_is_callable(handler))
+		err_return(EINVAL, NULL);
+
+	debug_vm = vm;
+	libbpf_set_print(handler ? uc_bpf_debug_print : NULL);
+
+	ucv_array_set(registry, 0, ucv_get(handler));
+
+	return NULL;
+}
+
+static void
+register_constants(uc_vm_t *vm, uc_value_t *scope)
+{
+#define ADD_CONST(x) ucv_object_add(scope, #x, ucv_int64_new(x))
+	ADD_CONST(BPF_PROG_TYPE_SCHED_CLS);
+	ADD_CONST(BPF_PROG_TYPE_SCHED_ACT);
+
+	ADD_CONST(BPF_ANY);
+	ADD_CONST(BPF_NOEXIST);
+	ADD_CONST(BPF_EXIST);
+	ADD_CONST(BPF_F_LOCK);
+}
+
+static const uc_function_list_t module_fns[] = {
+	{ "get_map",			uc_bpf_module_get_map },
+	{ "get_maps",			uc_bpf_module_get_maps },
+	{ "get_programs",		uc_bpf_module_get_programs },
+	{ "get_program",		uc_bpf_module_get_program },
+};
+
+static void module_free(void *ptr)
+{
+	struct bpf_object *obj = ptr;
+
+	bpf_object__close(obj);
+}
+
+static const uc_function_list_t map_fns[] = {
+	{ "pin",			uc_bpf_map_pin },
+	{ "get",			uc_bpf_map_get },
+	{ "set",			uc_bpf_map_set },
+	{ "delete",			uc_bpf_map_delete },
+	{ "delete_all",			uc_bpf_map_delete_all },
+	{ "foreach",			uc_bpf_map_foreach },
+	{ "iterator",			uc_bpf_map_iterator },
+};
+
+static void uc_bpf_fd_free(void *ptr)
+{
+	struct uc_bpf_fd *f = ptr;
+
+	if (f->close)
+		close(f->fd);
+	free(f);
+}
+
+static const uc_function_list_t map_iter_fns[] = {
+	{ "next",			uc_bpf_map_iter_next },
+	{ "next_int",			uc_bpf_map_iter_next_int },
+};
+
+static const uc_function_list_t prog_fns[] = {
+	{ "pin",			uc_bpf_program_pin },
+	{ "tc_attach",			uc_bpf_program_tc_attach },
+};
+
+static const uc_function_list_t global_fns[] = {
+	{ "error",			uc_bpf_error },
+	{ "set_debug_handler",		uc_bpf_set_debug_handler },
+	{ "open_module",		uc_bpf_open_module },
+	{ "open_map",			uc_bpf_open_map },
+	{ "open_program",		uc_bpf_open_program },
+	{ "tc_detach",			uc_bpf_tc_detach },
+};
+
+void uc_module_init(uc_vm_t *vm, uc_value_t *scope)
+{
+	uc_function_list_register(scope, global_fns);
+	register_constants(vm, scope);
+
+	registry = ucv_array_new(vm);
+	uc_vm_registry_set(vm, "bpf.registry", registry);
+
+	module_type = uc_type_declare(vm, "bpf.module", module_fns, module_free);
+	map_type = uc_type_declare(vm, "bpf.map", map_fns, uc_bpf_fd_free);
+	map_iter_type = uc_type_declare(vm, "bpf.map_iter", map_iter_fns, free);
+	program_type = uc_type_declare(vm, "bpf.program", prog_fns, uc_bpf_fd_free);
+}