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