Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/binfmt_script.c | |
3 | * | |
96de0e25 | 4 | * Copyright (C) 1996 Martin von Löwis |
1da177e4 LT |
5 | * original #!-checking implemented by tytso. |
6 | */ | |
7 | ||
8 | #include <linux/module.h> | |
9 | #include <linux/string.h> | |
10 | #include <linux/stat.h> | |
1da177e4 LT |
11 | #include <linux/binfmts.h> |
12 | #include <linux/init.h> | |
13 | #include <linux/file.h> | |
1da177e4 LT |
14 | #include <linux/err.h> |
15 | #include <linux/fs.h> | |
16 | ||
71613c3b | 17 | static int load_script(struct linux_binprm *bprm) |
1da177e4 | 18 | { |
d7627467 DH |
19 | const char *i_arg, *i_name; |
20 | char *cp; | |
1da177e4 | 21 | struct file *file; |
1da177e4 LT |
22 | int retval; |
23 | ||
d7402698 | 24 | if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!')) |
1da177e4 | 25 | return -ENOEXEC; |
51f39a1f DD |
26 | |
27 | /* | |
28 | * If the script filename will be inaccessible after exec, typically | |
29 | * because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give | |
30 | * up now (on the assumption that the interpreter will want to load | |
31 | * this file). | |
32 | */ | |
33 | if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE) | |
34 | return -ENOENT; | |
35 | ||
1da177e4 LT |
36 | /* |
37 | * This section does the #! interpretation. | |
38 | * Sorta complicated, but hopefully it will work. -TYT | |
39 | */ | |
40 | ||
1da177e4 LT |
41 | allow_write_access(bprm->file); |
42 | fput(bprm->file); | |
43 | bprm->file = NULL; | |
44 | ||
8099b047 ON |
45 | for (cp = bprm->buf+2;; cp++) { |
46 | if (cp >= bprm->buf + BINPRM_BUF_SIZE) | |
47 | return -ENOEXEC; | |
48 | if (!*cp || (*cp == '\n')) | |
49 | break; | |
50 | } | |
1da177e4 | 51 | *cp = '\0'; |
8099b047 | 52 | |
1da177e4 LT |
53 | while (cp > bprm->buf) { |
54 | cp--; | |
55 | if ((*cp == ' ') || (*cp == '\t')) | |
56 | *cp = '\0'; | |
57 | else | |
58 | break; | |
59 | } | |
60 | for (cp = bprm->buf+2; (*cp == ' ') || (*cp == '\t'); cp++); | |
c2315c18 | 61 | if (*cp == '\0') |
1da177e4 LT |
62 | return -ENOEXEC; /* No interpreter name found */ |
63 | i_name = cp; | |
64 | i_arg = NULL; | |
65 | for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++) | |
66 | /* nothing */ ; | |
67 | while ((*cp == ' ') || (*cp == '\t')) | |
68 | *cp++ = '\0'; | |
69 | if (*cp) | |
70 | i_arg = cp; | |
1da177e4 LT |
71 | /* |
72 | * OK, we've parsed out the interpreter name and | |
73 | * (optional) argument. | |
74 | * Splice in (1) the interpreter's name for argv[0] | |
75 | * (2) (optional) argument to interpreter | |
76 | * (3) filename of shell script (replace argv[0]) | |
77 | * | |
78 | * This is done in reverse order, because of how the | |
79 | * user environment and arguments are stored. | |
80 | */ | |
b6a2fea3 OW |
81 | retval = remove_arg_zero(bprm); |
82 | if (retval) | |
83 | return retval; | |
1da177e4 | 84 | retval = copy_strings_kernel(1, &bprm->interp, bprm); |
c2315c18 ON |
85 | if (retval < 0) |
86 | return retval; | |
1da177e4 LT |
87 | bprm->argc++; |
88 | if (i_arg) { | |
89 | retval = copy_strings_kernel(1, &i_arg, bprm); | |
c2315c18 ON |
90 | if (retval < 0) |
91 | return retval; | |
1da177e4 LT |
92 | bprm->argc++; |
93 | } | |
94 | retval = copy_strings_kernel(1, &i_name, bprm); | |
c2315c18 ON |
95 | if (retval) |
96 | return retval; | |
1da177e4 | 97 | bprm->argc++; |
c2315c18 | 98 | retval = bprm_change_interp(i_name, bprm); |
b66c5984 KC |
99 | if (retval < 0) |
100 | return retval; | |
1da177e4 LT |
101 | |
102 | /* | |
103 | * OK, now restart the process with the interpreter's dentry. | |
104 | */ | |
c2315c18 | 105 | file = open_exec(i_name); |
1da177e4 LT |
106 | if (IS_ERR(file)) |
107 | return PTR_ERR(file); | |
108 | ||
109 | bprm->file = file; | |
110 | retval = prepare_binprm(bprm); | |
111 | if (retval < 0) | |
112 | return retval; | |
3c456bfc | 113 | return search_binary_handler(bprm); |
1da177e4 LT |
114 | } |
115 | ||
116 | static struct linux_binfmt script_format = { | |
117 | .module = THIS_MODULE, | |
118 | .load_binary = load_script, | |
119 | }; | |
120 | ||
121 | static int __init init_script_binfmt(void) | |
122 | { | |
8fc3dc5a AV |
123 | register_binfmt(&script_format); |
124 | return 0; | |
1da177e4 LT |
125 | } |
126 | ||
127 | static void __exit exit_script_binfmt(void) | |
128 | { | |
129 | unregister_binfmt(&script_format); | |
130 | } | |
131 | ||
132 | core_initcall(init_script_binfmt); | |
133 | module_exit(exit_script_binfmt); | |
134 | MODULE_LICENSE("GPL"); |