1 files changed, 96 insertions, 0 deletions
diff --git a/server/lua-privsep.c b/server/lua-privsep.c
new file mode 100644
index 0000000..65dc39e
--- /dev/null
+++ b/server/lua-privsep.c
@@ -0,0 +1,96 @@
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+
+#include "conn.h"
+#include "lua-privsep.h"
+
+#ifndef PRIVSEP_PATH
+#define PRIVSEP_PATH "./"
+#endif
+
+static int traceback (lua_State *L) {
+	if (!lua_isstring(L, 1))  /* 'message' not a string? */
+		return 1;  /* keep it intact */
+	fprintf(stderr, "traceback\n");
+	lua_getfield(L, LUA_GLOBALSINDEX, "debug");
+	if (!lua_istable(L, -1)) {
+		fprintf(stderr, "traceback: debug\n");
+		lua_pop(L, 1);
+		return 1;
+	}
+
+	lua_getfield(L, -1, "traceback");
+	if (!lua_isfunction(L, -1)) {
+		fprintf(stderr, "traceback: traceback\n");
+		lua_pop(L, 2);
+		return 1;
+	}
+
+	lua_pushvalue(L, 1);  /* pass error message */
+	lua_pushinteger(L, 2);  /* skip this function and traceback */
+	lua_call(L, 2, 1);  /* call debug.traceback */
+	return 1;
+}
+
+static void lerror(lua_State *L, const char *fmt, ...)
+{
+	va_list argp;
+	va_start(argp, fmt);
+	vfprintf(stderr, fmt, argp);
+	va_end(argp);
+	lua_close(L);
+	exit(EXIT_FAILURE);
+}
+
+int call_lua(struct conn *c, const char *msg, size_t msglen)
+{
+	const char *retbuf;
+	size_t retsize;
+	lua_State *L = c->L;
+
+	lua_getglobal(L, "handler");
+	lua_pushlstring(L, msg, msglen);
+
+
+	if (lua_pcall(L, 1, 1, 0))
+		return luaL_error(L, lua_tostring(L, -1));
+
+	if (!lua_isstring(L, -1))
+		lerror(L, "handler function must return string\n");
+
+	retbuf = lua_tolstring(L, -1, &retsize);
+	return write(c->io.fd, retbuf, retsize);
+}
+
+int init_lua(struct conn *c)
+{
+	const char *luamain = PRIVSEP_PATH "handler.lua";
+	int traceback_index;
+	const char *retbuf;
+	size_t retsize;
+
+	c->L = luaL_newstate();
+	if (c == NULL)
+		return -1;
+	luaL_openlibs(c->L);
+
+	if (luaL_loadfile(c->L, luamain) || lua_pcall(c->L, 0, 0, 0)) {
+		lerror(c->L, "%s: %s", luamain, lua_tostring(c->L, -1));
+		lua_close(c->L);
+		c->L = NULL;
+		return -1;
+	}
+	return 0;
+}
+
+void close_lua(struct conn *c)
+{
+	lua_close(c->L);
+	c->L = NULL;
+}