1 /*
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright 2023 Baptiste Daroussin <bapt@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted providing that the following conditions~
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
24 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include <sys/wait.h>
29
30 #include <errno.h>
31 #include <fcntl.h>
32 #include <spawn.h>
33 #include <string.h>
34 #include <stdio.h>
35 #include <unistd.h>
36
37 #include <lua.h>
38 #include "lauxlib.h"
39 #include "lfbsd.h"
40
41 extern char **environ;
42
43 static const char**
luaL_checkarraystrings(lua_State * L,int arg)44 luaL_checkarraystrings(lua_State *L, int arg)
45 {
46 const char **ret;
47 lua_Integer n, i;
48 int t;
49 int abs_arg = lua_absindex(L, arg);
50 luaL_checktype(L, abs_arg, LUA_TTABLE);
51 n = lua_rawlen(L, abs_arg);
52 ret = lua_newuserdata(L, (n+1)*sizeof(char*));
53 for (i=0; i<n; i++) {
54 t = lua_rawgeti(L, abs_arg, i+1);
55 if (t == LUA_TNIL)
56 break;
57 luaL_argcheck(L, t == LUA_TSTRING, arg, "expected array of strings");
58 ret[i] = lua_tostring(L, -1);
59 lua_pop(L, 1);
60 }
61 ret[i] = NULL;
62 return ret;
63 }
64
65 static int
lua_exec(lua_State * L)66 lua_exec(lua_State *L)
67 {
68 int r, pstat;
69 posix_spawn_file_actions_t action;
70 int stdin_pipe[2] = {-1, -1};
71 pid_t pid;
72 const char **argv;
73 int n = lua_gettop(L);
74 luaL_argcheck(L, n == 1, n > 1 ? 2 : n,
75 "fbsd.exec takes exactly one argument");
76
77 if (pipe(stdin_pipe) < 0) {
78 lua_pushnil(L);
79 lua_pushstring(L, strerror(errno));
80 lua_pushinteger(L, errno);
81 return (3);
82 }
83
84 posix_spawn_file_actions_init(&action);
85 posix_spawn_file_actions_adddup2(&action, stdin_pipe[0], STDIN_FILENO);
86 posix_spawn_file_actions_addclose(&action, stdin_pipe[1]);
87
88 argv = luaL_checkarraystrings(L, 1);
89 if (0 != (r = posix_spawnp(&pid, argv[0], &action, NULL,
90 (char*const*)argv, environ))) {
91 lua_pushnil(L);
92 lua_pushstring(L, strerror(r));
93 lua_pushinteger(L, r);
94 return (3);
95 }
96 while (waitpid(pid, &pstat, 0) == -1) {
97 if (errno != EINTR) {
98 lua_pushnil(L);
99 lua_pushstring(L, strerror(r));
100 lua_pushinteger(L, r);
101 return (3);
102 }
103 }
104
105 if (WEXITSTATUS(pstat) != 0) {
106 lua_pushnil(L);
107 lua_pushstring(L, "Abnormal termination");
108 lua_pushinteger(L, r);
109 return (3);
110 }
111
112 posix_spawn_file_actions_destroy(&action);
113
114 if (stdin_pipe[0] != -1)
115 close(stdin_pipe[0]);
116 if (stdin_pipe[1] != -1)
117 close(stdin_pipe[1]);
118 lua_pushinteger(L, pid);
119 return 1;
120 }
121
122 #define REG_SIMPLE(n) { #n, lua_ ## n }
123 static const struct luaL_Reg fbsd_lib[] = {
124 REG_SIMPLE(exec),
125 { NULL, NULL },
126 };
127 #undef REG_SIMPLE
128
129 int
luaopen_fbsd(lua_State * L)130 luaopen_fbsd(lua_State *L)
131 {
132 luaL_newlib(L, fbsd_lib);
133 return (1);
134 }
135