MEDIUM: lua: Add cli handler for Lua
Now, HAProxy allows to register some keys in the "cli". This patch allows
to handle these keys with Lua code.
diff --git a/src/hlua.c b/src/hlua.c
index 7e56b75..02e9b94 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -32,6 +32,7 @@
#include <proto/applet.h>
#include <proto/channel.h>
#include <proto/connection.h>
+#include <proto/dumpstats.h>
#include <proto/hdr_idx.h>
#include <proto/hlua.h>
#include <proto/hlua_fcn.h>
@@ -6383,6 +6384,239 @@
return 0;
}
+/* This function initialises Lua cli handler. It copies the
+ * arguments in the Lua stack and create channel IO objects.
+ */
+static int hlua_cli_parse_fct(char **args, struct appctx *appctx, void *private)
+{
+ struct hlua *hlua;
+ struct hlua_function *fcn;
+ int i;
+ const char *error;
+
+ hlua = &appctx->ctx.hlua_cli.hlua;
+ fcn = private;
+ appctx->private = private;
+
+ /* Create task used by signal to wakeup applets.
+ * We use the same wakeup fonction than the Lua applet_tcp and
+ * applet_http. It is absolutely compatible.
+ */
+ appctx->ctx.hlua_cli.task = task_new();
+ if (!appctx->ctx.hlua_cli.task) {
+ SEND_ERR(NULL, "Lua applet tcp '%s': out of memory.\n", fcn->name);
+ return 0;
+ }
+ appctx->ctx.hlua_cli.task->nice = 0;
+ appctx->ctx.hlua_cli.task->context = appctx;
+ appctx->ctx.hlua_cli.task->process = hlua_applet_wakeup;
+
+ /* Initialises the Lua context */
+ if (!hlua_ctx_init(hlua, appctx->ctx.hlua_cli.task)) {
+ SEND_ERR(NULL, "Lua cli '%s': can't initialize Lua context.\n", fcn->name);
+ return 1;
+ }
+
+ /* The following Lua calls can fail. */
+ if (!SET_SAFE_LJMP(hlua->T)) {
+ if (lua_type(hlua->T, -1) == LUA_TSTRING)
+ error = lua_tostring(hlua->T, -1);
+ else
+ error = "critical error";
+ SEND_ERR(NULL, "Lua cli '%s': %s.\n", fcn->name, error);
+ goto error;
+ }
+
+ /* Check stack available size. */
+ if (!lua_checkstack(hlua->T, 2)) {
+ SEND_ERR(NULL, "Lua cli '%s': full stack.\n", fcn->name);
+ goto error;
+ }
+
+ /* Restore the function in the stack. */
+ lua_rawgeti(hlua->T, LUA_REGISTRYINDEX, fcn->function_ref);
+
+ /* Once the arguments parsed, the CLI is like an AppletTCP,
+ * so push AppletTCP in the stack.
+ * TODO: get_priv() and set_priv() are useless. Maybe we will
+ * create a new object without these two functions.
+ */
+ if (!hlua_applet_tcp_new(hlua->T, appctx)) {
+ SEND_ERR(NULL, "Lua cli '%s': full stack.\n", fcn->name);
+ goto error;
+ }
+ hlua->nargs = 1;
+
+ /* push keywords in the stack. */
+ for (i = 0; *args[i]; i++) {
+ /* Check stack available size. */
+ if (!lua_checkstack(hlua->T, 1)) {
+ SEND_ERR(NULL, "Lua cli '%s': full stack.\n", fcn->name);
+ goto error;
+ }
+ lua_pushstring(hlua->T, args[i]);
+ hlua->nargs++;
+ }
+
+ /* We must initialize the execution timeouts. */
+ hlua->max_time = hlua_timeout_session;
+
+ /* At this point the execution is safe. */
+ RESET_SAFE_LJMP(hlua->T);
+
+ /* It's ok */
+ return 0;
+
+ /* It's not ok. */
+error:
+ RESET_SAFE_LJMP(hlua->T);
+ hlua_ctx_destroy(hlua);
+ return 1;
+}
+
+static int hlua_cli_io_handler_fct(struct appctx *appctx)
+{
+ struct hlua *hlua;
+ struct stream_interface *si;
+ struct hlua_function *fcn;
+
+ hlua = &appctx->ctx.hlua_cli.hlua;
+ si = appctx->owner;
+ fcn = appctx->private;
+
+ /* If the stream is disconnect or closed, ldo nothing. */
+ if (unlikely(si->state == SI_ST_DIS || si->state == SI_ST_CLO))
+ return 1;
+
+ /* Execute the function. */
+ switch (hlua_ctx_resume(hlua, 1)) {
+
+ /* finished. */
+ case HLUA_E_OK:
+ return 1;
+
+ /* yield. */
+ case HLUA_E_AGAIN:
+ /* We want write. */
+ if (HLUA_IS_WAKERESWR(hlua))
+ si_applet_cant_put(si);
+ /* Set the timeout. */
+ if (hlua->wake_time != TICK_ETERNITY)
+ task_schedule(hlua->task, hlua->wake_time);
+ return 0;
+
+ /* finished with error. */
+ case HLUA_E_ERRMSG:
+ /* Display log. */
+ SEND_ERR(NULL, "Lua cli '%s': %s.\n",
+ fcn->name, lua_tostring(hlua->T, -1));
+ lua_pop(hlua->T, 1);
+ return 1;
+
+ case HLUA_E_ERR:
+ /* Display log. */
+ SEND_ERR(NULL, "Lua cli '%s' return an unknown error.\n",
+ fcn->name);
+ return 1;
+
+ default:
+ return 1;
+ }
+
+ return 1;
+}
+
+static void hlua_cli_io_release_fct(struct appctx *appctx)
+{
+ struct hlua *hlua;
+
+ hlua = &appctx->ctx.hlua_cli.hlua;
+ hlua_ctx_destroy(hlua);
+}
+
+/* This function is an LUA binding used for registering
+ * new keywords in the cli. It expects a list of keywords
+ * which are the "path". It is limited to 5 keywords. A
+ * description of the command, a function to be executed
+ * for the parsing and a function for io handlers.
+ */
+__LJMP static int hlua_register_cli(lua_State *L)
+{
+ struct cli_kw_list *cli_kws;
+ const char *message;
+ int ref_io;
+ int len;
+ struct hlua_function *fcn;
+ int index;
+ int i;
+
+ MAY_LJMP(check_args(L, 3, "register_cli"));
+
+ /* First argument : an array of maximum 5 keywords. */
+ if (!lua_istable(L, 1))
+ WILL_LJMP(luaL_argerror(L, 1, "1st argument must be a table"));
+
+ /* Second argument : string with contextual message. */
+ message = MAY_LJMP(luaL_checkstring(L, 2));
+
+ /* Third and fourth argument : lua function. */
+ ref_io = MAY_LJMP(hlua_checkfunction(L, 3));
+
+ /* Allocate and fill the sample fetch keyword struct. */
+ cli_kws = calloc(1, sizeof(*cli_kws) + sizeof(struct cli_kw) * 2);
+ if (!cli_kws)
+ WILL_LJMP(luaL_error(L, "lua out of memory error."));
+ fcn = calloc(1, sizeof(*fcn));
+ if (!fcn)
+ WILL_LJMP(luaL_error(L, "lua out of memory error."));
+
+ /* Fill path. */
+ index = 0;
+ lua_pushnil(L);
+ while(lua_next(L, 1) != 0) {
+ if (index >= 5)
+ WILL_LJMP(luaL_argerror(L, 1, "1st argument must be a table with a maximum of 5 entries"));
+ if (lua_type(L, -1) != LUA_TSTRING)
+ WILL_LJMP(luaL_argerror(L, 1, "1st argument must be a table filled with strings"));
+ cli_kws->kw[0].str_kw[index] = strdup(lua_tostring(L, -1));
+ if (!cli_kws->kw[0].str_kw[index])
+ WILL_LJMP(luaL_error(L, "lua out of memory error."));
+ index++;
+ lua_pop(L, 1);
+ }
+
+ /* Copy help message. */
+ cli_kws->kw[0].usage = strdup(message);
+ if (!cli_kws->kw[0].usage)
+ WILL_LJMP(luaL_error(L, "lua out of memory error."));
+
+ /* Fill fcn io handler. */
+ len = strlen("<lua.cli>") + 1;
+ for (i = 0; i < index; i++)
+ len += strlen(cli_kws->kw[0].str_kw[i]) + 1;
+ fcn->name = calloc(1, len);
+ if (!fcn->name)
+ WILL_LJMP(luaL_error(L, "lua out of memory error."));
+ strncat((char *)fcn->name, "<lua.cli", len);
+ for (i = 0; i < index; i++) {
+ strncat((char *)fcn->name, ".", len);
+ strncat((char *)fcn->name, cli_kws->kw[0].str_kw[i], len);
+ }
+ strncat((char *)fcn->name, ">", len);
+ fcn->function_ref = ref_io;
+
+ /* Fill last entries. */
+ cli_kws->kw[0].private = fcn;
+ cli_kws->kw[0].parse = hlua_cli_parse_fct;
+ cli_kws->kw[0].io_handler = hlua_cli_io_handler_fct;
+ cli_kws->kw[0].io_release = hlua_cli_io_release_fct;
+
+ /* Register this new converter */
+ cli_register_kw(cli_kws);
+
+ return 0;
+}
+
static int hlua_read_timeout(char **args, int section_type, struct proxy *curpx,
struct proxy *defpx, const char *file, int line,
char **err, unsigned int *timeout)
@@ -6686,6 +6920,7 @@
hlua_class_function(gL.T, "register_converters", hlua_register_converters);
hlua_class_function(gL.T, "register_action", hlua_register_action);
hlua_class_function(gL.T, "register_service", hlua_register_service);
+ hlua_class_function(gL.T, "register_cli", hlua_register_cli);
hlua_class_function(gL.T, "yield", hlua_yield);
hlua_class_function(gL.T, "set_nice", hlua_set_nice);
hlua_class_function(gL.T, "sleep", hlua_sleep);