1 files changed, 289 insertions, 0 deletions
diff --git a/libexec/flua/lfbsd/lfbsd.c b/libexec/flua/lfbsd/lfbsd.c
new file mode 100644
index 000000000000..541b6c9611df
--- /dev/null
+++ b/libexec/flua/lfbsd/lfbsd.c
@@ -0,0 +1,289 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright 2023 Baptiste Daroussin <bapt@FreeBSD.org>
+ * Copyright (C) 2025 Kyle Evans <kevans@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted providing that the following conditions~
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/wait.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <spawn.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <lua.h>
+#include "lauxlib.h"
+#include "lfbsd.h"
+
+#include "bootstrap.h"
+
+#define	FBSD_PROCESSHANDLE	"fbsd_process_t*"
+
+struct fbsd_process {
+	int	pid;
+	int	stdin_fileno;
+	int	stdout_fileno;
+};
+
+extern char **environ;
+
+static const char**
+luaL_checkarraystrings(lua_State *L, int arg)
+{
+	const char **ret;
+	lua_Integer n, i;
+	int t;
+	int abs_arg = lua_absindex(L, arg);
+	luaL_checktype(L, abs_arg, LUA_TTABLE);
+	n = lua_rawlen(L, abs_arg);
+	ret = lua_newuserdata(L, (n+1)*sizeof(char*));
+	for (i=0; i<n; i++) {
+		t = lua_rawgeti(L, abs_arg, i+1);
+		if (t == LUA_TNIL)
+			break;
+		luaL_argcheck(L, t == LUA_TSTRING, arg, "expected array of strings");
+		ret[i] = lua_tostring(L, -1);
+		lua_pop(L, 1);
+	}
+	ret[i] = NULL;
+	return ret;
+}
+
+static void
+close_pipes(int pipes[2])
+{
+
+	if (pipes[0] != -1)
+		close(pipes[0]);
+	if (pipes[1] != -1)
+		close(pipes[1]);
+}
+
+static int
+lua_exec(lua_State *L)
+{
+	struct fbsd_process *proc;
+	int r;
+	posix_spawn_file_actions_t action;
+	int stdin_pipe[2] = {-1, -1};
+	int stdout_pipe[2] = {-1, -1};
+	pid_t pid;
+	const char **argv;
+	int n = lua_gettop(L);
+	bool capture_stdout;
+	luaL_argcheck(L, n > 0 && n <= 2, n >= 2 ? 2 : n,
+	    "fbsd.exec takes exactly one or two arguments");
+
+	capture_stdout = lua_toboolean(L, 2);
+	if (pipe(stdin_pipe) < 0) {
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(errno));
+		lua_pushinteger(L, errno);
+		return (3);
+	}
+	if (capture_stdout && pipe(stdout_pipe) < 0) {
+		close_pipes(stdin_pipe);
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(errno));
+		lua_pushinteger(L, errno);
+		return (3);
+	}
+
+	proc = lua_newuserdata(L, sizeof(*proc));
+	proc->stdin_fileno = stdin_pipe[1];
+	proc->stdout_fileno = stdout_pipe[1];
+	posix_spawn_file_actions_init(&action);
+	posix_spawn_file_actions_adddup2(&action, stdin_pipe[0], STDIN_FILENO);
+	posix_spawn_file_actions_addclose(&action, stdin_pipe[1]);
+	if (stdin_pipe[0] != STDIN_FILENO)
+		posix_spawn_file_actions_addclose(&action, stdin_pipe[0]);
+
+	/*
+	 * Setup stdout to be captured if requested.  Otherwise, we just let it
+	 * go to our own stdout.
+	 */
+	if (stdout_pipe[0] != -1) {
+		posix_spawn_file_actions_adddup2(&action, stdout_pipe[0],
+		    STDOUT_FILENO);
+		posix_spawn_file_actions_addclose(&action, stdout_pipe[1]);
+		if (stdout_pipe[0] != STDOUT_FILENO) {
+			posix_spawn_file_actions_addclose(&action,
+			    stdout_pipe[0]);
+		}
+	}
+
+	argv = luaL_checkarraystrings(L, 1);
+	if (0 != (r = posix_spawnp(&pid, argv[0], &action, NULL,
+		(char*const*)argv, environ))) {
+		close_pipes(stdin_pipe);
+		close_pipes(stdout_pipe);
+		posix_spawn_file_actions_destroy(&action);
+		lua_pop(L, 2);	/* Pop off the process handle and args. */
+
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(r));
+		lua_pushinteger(L, r);
+		return (3);
+	}
+
+	lua_pop(L, 1);
+
+	close(stdin_pipe[0]);
+	if (stdout_pipe[0] != -1)
+		close(stdout_pipe[0]);
+	posix_spawn_file_actions_destroy(&action);
+
+	proc->pid = pid;
+	luaL_setmetatable(L, FBSD_PROCESSHANDLE);
+
+	return (1);
+}
+
+static int
+lua_process_close(lua_State *L)
+{
+	struct fbsd_process *proc;
+	int pstat, r;
+
+	proc = luaL_checkudata(L, 1, FBSD_PROCESSHANDLE);
+	while (waitpid(proc->pid, &pstat, 0) == -1) {
+		if ((r = errno) != EINTR) {
+			lua_pushnil(L);
+			lua_pushstring(L, strerror(r));
+			lua_pushinteger(L, r);
+			return (3);
+		}
+	}
+
+	if (!WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0) {
+		lua_pushnil(L);
+		lua_pushstring(L, "Abnormal termination");
+		return (2);
+	}
+
+	if (proc->stdin_fileno >= 0) {
+		close(proc->stdin_fileno);
+		proc->stdin_fileno = -1;
+	}
+
+	if (proc->stdout_fileno >= 0) {
+		close(proc->stdout_fileno);
+		proc->stdout_fileno = -1;
+	}
+
+	lua_pushboolean(L, 1);
+	return (1);
+}
+
+static int
+lua_process_makestdio(lua_State *L, int fd, const char *mode)
+{
+	luaL_Stream *p;
+	FILE *fp;
+	int r;
+
+	if (fd == -1) {
+		lua_pushnil(L);
+		lua_pushstring(L, "Stream not captured");
+		return (2);
+	}
+
+	fp = fdopen(fd, mode);
+	if (fp == NULL) {
+		r = errno;
+
+		lua_pushnil(L);
+		lua_pushstring(L, strerror(r));
+		lua_pushinteger(L, r);
+		return (3);
+	}
+
+	p = lua_newuserdata(L, sizeof(*p));
+	p->closef = &lua_process_close;
+	p->f = fp;
+	luaL_setmetatable(L, LUA_FILEHANDLE);
+	return (1);
+}
+
+static int
+lua_process_stdin(lua_State *L)
+{
+	struct fbsd_process *proc;
+
+	proc = luaL_checkudata(L, 1, FBSD_PROCESSHANDLE);
+	return (lua_process_makestdio(L, proc->stdin_fileno, "w"));
+}
+
+static int
+lua_process_stdout(lua_State *L)
+{
+	struct fbsd_process *proc;
+
+	proc = luaL_checkudata(L, 1, FBSD_PROCESSHANDLE);
+	return (lua_process_makestdio(L, proc->stdout_fileno, "r"));
+}
+
+#define PROCESS_SIMPLE(n)	{ #n, lua_process_ ## n }
+static const struct luaL_Reg fbsd_process[] = {
+	PROCESS_SIMPLE(close),
+	PROCESS_SIMPLE(stdin),
+	PROCESS_SIMPLE(stdout),
+	{ NULL, NULL },
+};
+
+static const struct luaL_Reg fbsd_process_meta[] = {
+	{ "__index", NULL },
+	{ "__gc", lua_process_close },
+	{ "__close", lua_process_close },
+	{ NULL, NULL },
+};
+
+#define REG_SIMPLE(n)	{ #n, lua_ ## n }
+static const struct luaL_Reg fbsd_lib[] = {
+	REG_SIMPLE(exec),
+	{ NULL, NULL },
+};
+#undef REG_SIMPLE
+
+int
+luaopen_fbsd(lua_State *L)
+{
+	luaL_newlib(L, fbsd_lib);
+
+	luaL_newmetatable(L, FBSD_PROCESSHANDLE);
+	luaL_setfuncs(L, fbsd_process_meta, 0);
+
+	luaL_newlibtable(L, fbsd_process);
+	luaL_setfuncs(L, fbsd_process, 0);
+	lua_setfield(L, -2, "__index");
+	lua_pop(L, 1);
+
+	return (1);
+}
+
+FLUA_MODULE(fbsd);