Adding upstream version 9.1.upstream/9.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 420 insertions, 0 deletions

diff --git a/lib/frrscript.c b/lib/frrscript.c
new file mode 100644
index 0000000..50410fb
--- /dev/null
+++ b/lib/frrscript.c
@@ -0,0 +1,420 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Scripting foo
+ * Copyright (C) 2020  NVIDIA Corporation
+ * Quentin Young
+ */
+#include <zebra.h>
+
+#ifdef HAVE_SCRIPTING
+
+#include <stdarg.h>
+#include <lua.h>
+
+#include "frrscript.h"
+#include "frrlua.h"
+#include "memory.h"
+#include "hash.h"
+#include "log.h"
+
+
+DEFINE_MTYPE_STATIC(LIB, SCRIPT, "Scripting");
+
+/*
+ * Script name hash utilities
+ */
+
+struct frrscript_names_head frrscript_names_hash;
+
+/*
+ * Wrapper for frrscript_names_add
+ * Use this to register hook calls when a daemon starts up
+ */
+int frrscript_names_add_function_name(const char *function_name)
+{
+	struct frrscript_names_entry *insert =
+		XCALLOC(MTYPE_SCRIPT, sizeof(*insert));
+	strlcpy(insert->function_name, function_name,
+		sizeof(insert->function_name));
+
+	if (frrscript_names_add(&frrscript_names_hash, insert)) {
+		zlog_warn(
+			"Failed to add hook call function name to script_names");
+		return 1;
+	}
+	return 0;
+}
+
+void frrscript_names_destroy(void)
+{
+	struct frrscript_names_entry *ne;
+
+	while ((ne = frrscript_names_pop(&frrscript_names_hash)))
+		XFREE(MTYPE_SCRIPT, ne);
+}
+
+/*
+ * Given a function_name, set its script_name. function_names and script_names
+ * are one-to-one. Each set will wipe the previous script_name.
+ * Return 0 if set was successful, else 1.
+ *
+ * script_name is the base name of the file, without .lua.
+ */
+int frrscript_names_set_script_name(const char *function_name,
+				    const char *script_name)
+{
+	struct frrscript_names_entry lookup;
+
+	strlcpy(lookup.function_name, function_name,
+		sizeof(lookup.function_name));
+	struct frrscript_names_entry *snhe =
+		frrscript_names_find(&frrscript_names_hash, &lookup);
+	if (!snhe)
+		return 1;
+	strlcpy(snhe->script_name, script_name, sizeof(snhe->script_name));
+	return 0;
+}
+
+/*
+ * Given a function_name, get its script_name.
+ * Return NULL if function_name not found.
+ *
+ * script_name is the base name of the file, without .lua.
+ */
+char *frrscript_names_get_script_name(const char *function_name)
+{
+	struct frrscript_names_entry lookup;
+
+	strlcpy(lookup.function_name, function_name,
+		sizeof(lookup.function_name));
+	struct frrscript_names_entry *snhe =
+		frrscript_names_find(&frrscript_names_hash, &lookup);
+	if (!snhe)
+		return NULL;
+
+	if (snhe->script_name[0] == '\0')
+		return NULL;
+
+	return snhe->script_name;
+}
+
+uint32_t frrscript_names_hash_key(const struct frrscript_names_entry *snhe)
+{
+	return string_hash_make(snhe->function_name);
+}
+
+int frrscript_names_hash_cmp(const struct frrscript_names_entry *snhe1,
+			     const struct frrscript_names_entry *snhe2)
+{
+	return strncmp(snhe1->function_name, snhe2->function_name,
+		       sizeof(snhe1->function_name));
+}
+
+/* Codecs */
+
+struct frrscript_codec frrscript_codecs_lib[] = {
+	{.typename = "integer",
+	 .encoder = (encoder_func)lua_pushintegerp,
+	 .decoder = lua_tointegerp},
+	{.typename = "string",
+	 .encoder = (encoder_func)lua_pushstring_wrapper,
+	 .decoder = lua_tostringp},
+	{.typename = "prefix",
+	 .encoder = (encoder_func)lua_pushprefix,
+	 .decoder = lua_toprefix},
+	{.typename = "interface",
+	 .encoder = (encoder_func)lua_pushinterface,
+	 .decoder = lua_tointerface},
+	{.typename = "in_addr",
+	 .encoder = (encoder_func)lua_pushinaddr,
+	 .decoder = lua_toinaddr},
+	{.typename = "in6_addr",
+	 .encoder = (encoder_func)lua_pushin6addr,
+	 .decoder = lua_toin6addr},
+	{.typename = "sockunion",
+	 .encoder = (encoder_func)lua_pushsockunion,
+	 .decoder = lua_tosockunion},
+	{}};
+
+/* Type codecs */
+
+struct hash *codec_hash;
+char scriptdir[MAXPATHLEN];
+
+static unsigned int codec_hash_key(const void *data)
+{
+	const struct frrscript_codec *c = data;
+
+	return string_hash_make(c->typename);
+}
+
+static bool codec_hash_cmp(const void *d1, const void *d2)
+{
+	const struct frrscript_codec *e1 = d1;
+	const struct frrscript_codec *e2 = d2;
+
+	return strmatch(e1->typename, e2->typename);
+}
+
+static void *codec_alloc(void *arg)
+{
+	struct frrscript_codec *tmp = arg;
+
+	struct frrscript_codec *e =
+		XCALLOC(MTYPE_SCRIPT, sizeof(struct frrscript_codec));
+	e->typename = XSTRDUP(MTYPE_SCRIPT, tmp->typename);
+	e->encoder = tmp->encoder;
+	e->decoder = tmp->decoder;
+
+	return e;
+}
+
+static void codec_free(void *data)
+{
+	struct frrscript_codec *c = data;
+	char *constworkaroundandihateit = (char *)c->typename;
+
+	XFREE(MTYPE_SCRIPT, constworkaroundandihateit);
+	XFREE(MTYPE_SCRIPT, c);
+}
+
+/* Lua function hash utils */
+
+unsigned int lua_function_hash_key(const void *data)
+{
+	const struct lua_function_state *lfs = data;
+
+	return string_hash_make(lfs->name);
+}
+
+bool lua_function_hash_cmp(const void *d1, const void *d2)
+{
+	const struct lua_function_state *lfs1 = d1;
+	const struct lua_function_state *lfs2 = d2;
+
+	return strmatch(lfs1->name, lfs2->name);
+}
+
+void *lua_function_alloc(void *arg)
+{
+	struct lua_function_state *tmp = arg;
+	struct lua_function_state *lfs =
+		XCALLOC(MTYPE_SCRIPT, sizeof(struct lua_function_state));
+
+	lfs->name = tmp->name;
+	lfs->L = tmp->L;
+	return lfs;
+}
+
+static void lua_function_free(void *data)
+{
+	struct lua_function_state *lfs = data;
+
+	lua_close(lfs->L);
+	XFREE(MTYPE_SCRIPT, lfs);
+}
+
+/* internal frrscript APIs */
+
+int _frrscript_call_lua(struct lua_function_state *lfs, int nargs)
+{
+
+	int ret;
+	ret = lua_pcall(lfs->L, nargs, 1, 0);
+
+	switch (ret) {
+	case LUA_OK:
+		break;
+	case LUA_ERRRUN:
+		zlog_err("Lua hook call '%s' : runtime error: %s", lfs->name,
+			 lua_tostring(lfs->L, -1));
+		break;
+	case LUA_ERRMEM:
+		zlog_err("Lua hook call '%s' : memory error: %s", lfs->name,
+			 lua_tostring(lfs->L, -1));
+		break;
+	case LUA_ERRERR:
+		zlog_err("Lua hook call '%s' : error handler error: %s",
+			 lfs->name, lua_tostring(lfs->L, -1));
+		break;
+	case LUA_ERRGCMM:
+		zlog_err("Lua hook call '%s' : garbage collector error: %s",
+			 lfs->name, lua_tostring(lfs->L, -1));
+		break;
+	default:
+		zlog_err("Lua hook call '%s' : unknown error: %s", lfs->name,
+			 lua_tostring(lfs->L, -1));
+		break;
+	}
+
+	if (ret != LUA_OK) {
+		lua_pop(lfs->L, 1);
+		goto done;
+	}
+
+	if (lua_gettop(lfs->L) != 1) {
+		zlog_err(
+			"Lua hook call '%s': Lua function should return only 1 result",
+			lfs->name);
+		ret = 1;
+		goto done;
+	}
+
+	if (lua_istable(lfs->L, 1) != 1) {
+		zlog_err(
+			"Lua hook call '%s': Lua function should return a Lua table",
+			lfs->name);
+		ret = 1;
+	}
+
+done:
+	/* LUA_OK is 0, so we can just return lua_pcall's result directly */
+	return ret;
+}
+
+void *frrscript_get_result(struct frrscript *fs, const char *function_name,
+			   const char *name,
+			   void *(*lua_to)(lua_State *L, int idx))
+{
+	void *p;
+	struct lua_function_state *lfs;
+	struct lua_function_state lookup = {.name = function_name};
+
+	lfs = hash_lookup(fs->lua_function_hash, &lookup);
+
+	if (lfs == NULL)
+		return NULL;
+
+	/* At this point, the Lua state should have only the returned table.
+	 * We will then search the table for the key/value we're interested in.
+	 * Then if the value is present (i.e. non-nil), call the lua_to*
+	 * decoder.
+	 */
+	assert(lua_gettop(lfs->L) == 1);
+	assert(lua_istable(lfs->L, -1) == 1);
+	lua_getfield(lfs->L, -1, name);
+	if (lua_isnil(lfs->L, -1)) {
+		lua_pop(lfs->L, 1);
+		zlog_warn(
+			"frrscript: '%s.lua': '%s': tried to decode '%s' as result but failed",
+			fs->name, function_name, name);
+		return NULL;
+	}
+	p = lua_to(lfs->L, 2);
+
+	/* At the end, the Lua state should be same as it was at the start
+	 * i.e. containing solely the returned table.
+	 */
+	assert(lua_gettop(lfs->L) == 1);
+	assert(lua_istable(lfs->L, -1) == 1);
+
+	return p;
+}
+
+void frrscript_register_type_codec(struct frrscript_codec *codec)
+{
+	struct frrscript_codec c = *codec;
+
+	if (hash_lookup(codec_hash, &c)) {
+		zlog_backtrace(LOG_ERR);
+		assert(!"Type codec double-registered.");
+	}
+
+	(void)hash_get(codec_hash, &c, codec_alloc);
+}
+
+void frrscript_register_type_codecs(struct frrscript_codec *codecs)
+{
+	for (int i = 0; codecs[i].typename != NULL; i++)
+		frrscript_register_type_codec(&codecs[i]);
+}
+
+struct frrscript *frrscript_new(const char *name)
+{
+	struct frrscript *fs = XCALLOC(MTYPE_SCRIPT, sizeof(struct frrscript));
+
+	fs->name = XSTRDUP(MTYPE_SCRIPT, name);
+	fs->lua_function_hash =
+		hash_create(lua_function_hash_key, lua_function_hash_cmp,
+			    "Lua function state hash");
+	return fs;
+}
+
+int frrscript_load(struct frrscript *fs, const char *function_name,
+		   int (*load_cb)(struct frrscript *))
+{
+
+	/* Set up the Lua script */
+	lua_State *L = luaL_newstate();
+
+	frrlua_export_logging(L);
+
+	char script_name[MAXPATHLEN];
+
+	if (snprintf(script_name, sizeof(script_name), "%s/%s.lua", scriptdir,
+		     fs->name)
+	    >= (int)sizeof(script_name)) {
+		zlog_err("frrscript: path to script %s/%s.lua is too long",
+			 scriptdir, fs->name);
+		goto fail;
+	}
+
+	if (luaL_dofile(L, script_name) != 0) {
+		zlog_err("frrscript: failed loading script '%s': error: %s",
+			 script_name, lua_tostring(L, -1));
+		goto fail;
+	}
+
+	/* To check the Lua function, we get it from the global table */
+	lua_getglobal(L, function_name);
+	if (lua_isfunction(L, lua_gettop(L)) == 0) {
+		zlog_err("frrscript: loaded script '%s' but %s not found",
+			 script_name, function_name);
+		goto fail;
+	}
+	/* Then pop the function (frrscript_call will push it when it needs it)
+	 */
+	lua_pop(L, 1);
+
+	if (load_cb && (*load_cb)(fs) != 0) {
+		zlog_err(
+			"frrscript: '%s': %s: loaded but callback returned non-zero exit code",
+			script_name, function_name);
+		goto fail;
+	}
+
+	/* Add the Lua function state to frrscript */
+	struct lua_function_state key = {.name = function_name, .L = L};
+
+	(void)hash_get(fs->lua_function_hash, &key, lua_function_alloc);
+
+	return 0;
+fail:
+	lua_close(L);
+	return 1;
+}
+
+void frrscript_delete(struct frrscript *fs)
+{
+	hash_clean_and_free(&fs->lua_function_hash, lua_function_free);
+	XFREE(MTYPE_SCRIPT, fs->name);
+	XFREE(MTYPE_SCRIPT, fs);
+}
+
+void frrscript_init(const char *sd)
+{
+	codec_hash = hash_create(codec_hash_key, codec_hash_cmp,
+				 "Lua type encoders");
+
+	strlcpy(scriptdir, sd, sizeof(scriptdir));
+
+	/* Register core library types */
+	frrscript_register_type_codecs(frrscript_codecs_lib);
+}
+
+void frrscript_fini(void)
+{
+	hash_clean_and_free(&codec_hash, codec_free);
+
+	frrscript_names_destroy();
+}
+#endif /* HAVE_SCRIPTING */