xref: /freebsd/libexec/flua/modules/lposix.c (revision f126890ac5386406dadf7c4cfa9566cbb56537c5)
1 /*-
2  * Copyright (c) 2019 Kyle Evans <kevans@FreeBSD.org>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 #include <sys/stat.h>
29 
30 #include <errno.h>
31 #include <grp.h>
32 #include <pwd.h>
33 #include <string.h>
34 #include <unistd.h>
35 
36 #include <lua.h>
37 #include "lauxlib.h"
38 #include "lposix.h"
39 
40 /*
41  * Minimal implementation of luaposix needed for internal FreeBSD bits.
42  */
43 
44 static int
45 lua_chmod(lua_State *L)
46 {
47 	int n;
48 	const char *path;
49 	mode_t mode;
50 
51 	n = lua_gettop(L);
52 	luaL_argcheck(L, n == 2, n > 2 ? 3 : n,
53 	    "chmod takes exactly two arguments");
54 	path = luaL_checkstring(L, 1);
55 	mode = (mode_t)luaL_checkinteger(L, 2);
56 	if (chmod(path, mode) == -1) {
57 		lua_pushnil(L);
58 		lua_pushstring(L, strerror(errno));
59 		lua_pushinteger(L, errno);
60 		return 3;
61 	}
62 	lua_pushinteger(L, 0);
63 	return 1;
64 }
65 
66 static int
67 lua_chown(lua_State *L)
68 {
69 	int n;
70 	const char *path;
71 	uid_t owner = (uid_t) -1;
72 	gid_t group = (gid_t) -1;
73 
74 	n = lua_gettop(L);
75 	luaL_argcheck(L, n > 1, n,
76 	   "chown takes at least two arguments");
77 	path = luaL_checkstring(L, 1);
78 	if (lua_isinteger(L, 2))
79 		owner = (uid_t) lua_tointeger(L, 2);
80 	else if (lua_isstring(L, 2)) {
81 		struct passwd *p = getpwnam(lua_tostring(L, 2));
82 		if (p != NULL)
83 			owner = p->pw_uid;
84 		else
85 			return (luaL_argerror(L, 2,
86 			    lua_pushfstring(L, "unknown user %s",
87 			    lua_tostring(L, 2))));
88 	} else if (!lua_isnoneornil(L, 2)) {
89 		const char *type = luaL_typename(L, 2);
90 		return (luaL_argerror(L, 2,
91 		    lua_pushfstring(L, "integer or string expected, got %s",
92 		    type)));
93 	}
94 
95 	if (lua_isinteger(L, 3))
96 		group = (gid_t) lua_tointeger(L, 3);
97 	else if (lua_isstring(L, 3)) {
98 		struct group *g = getgrnam(lua_tostring(L, 3));
99 		if (g != NULL)
100 			group = g->gr_gid;
101 		else
102 			return (luaL_argerror(L, 3,
103 			    lua_pushfstring(L, "unknown group %s",
104 			    lua_tostring(L, 3))));
105 	} else if (!lua_isnoneornil(L, 3)) {
106 		const char *type = luaL_typename(L, 3);
107 		return (luaL_argerror(L, 3,
108 		    lua_pushfstring(L, "integer or string expected, got %s",
109 		    type)));
110 	}
111 
112 	if (chown(path, owner, group) == -1) {
113 		lua_pushnil(L);
114 		lua_pushstring(L, strerror(errno));
115 		lua_pushinteger(L, errno);
116 		return (3);
117 	}
118 	lua_pushinteger(L, 0);
119 	return (1);
120 }
121 
122 static int
123 lua_getpid(lua_State *L)
124 {
125 	int n;
126 
127 	n = lua_gettop(L);
128 	luaL_argcheck(L, n == 0, 1, "too many arguments");
129 	lua_pushinteger(L, getpid());
130 	return 1;
131 }
132 
133 #define REG_SIMPLE(n)	{ #n, lua_ ## n }
134 static const struct luaL_Reg sys_statlib[] = {
135 	REG_SIMPLE(chmod),
136 	{ NULL, NULL },
137 };
138 
139 static const struct luaL_Reg unistdlib[] = {
140 	REG_SIMPLE(getpid),
141 	REG_SIMPLE(chown),
142 	{ NULL, NULL },
143 };
144 #undef REG_SIMPLE
145 
146 int
147 luaopen_posix_sys_stat(lua_State *L)
148 {
149 	luaL_newlib(L, sys_statlib);
150 	return 1;
151 }
152 
153 int
154 luaopen_posix_unistd(lua_State *L)
155 {
156 	luaL_newlib(L, unistdlib);
157 	return 1;
158 }
159