root/fs/binfmt_script.c

Revision 1, 2.7 kB (checked in by dkaplan1, 7 years ago)

Initial import

Line 
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/slab.h>
12 #include <linux/binfmts.h>
13 #include <linux/init.h>
14 #include <linux/file.h>
15 #include <linux/smp_lock.h>
16 #include <linux/err.h>
17 #include <linux/fs.h>
18
19 static int load_script(struct linux_binprm *bprm,struct pt_regs *regs)
20 {
21         char *cp, *i_name, *i_arg;
22         struct file *file;
23         char interp[BINPRM_BUF_SIZE];
24         int retval;
25
26         if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!') || (bprm->sh_bang))
27                 return -ENOEXEC;
28         /*
29          * This section does the #! interpretation.
30          * Sorta complicated, but hopefully it will work.  -TYT
31          */
32
33         bprm->sh_bang++;
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 = 0;
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         remove_arg_zero(bprm);
72         retval = copy_strings_kernel(1, &bprm->interp, bprm);
73         if (retval < 0) return retval;
74         bprm->argc++;
75         if (i_arg) {
76                 retval = copy_strings_kernel(1, &i_arg, bprm);
77                 if (retval < 0) return retval;
78                 bprm->argc++;
79         }
80         retval = copy_strings_kernel(1, &i_name, bprm);
81         if (retval) return retval;
82         bprm->argc++;
83         bprm->interp = interp;
84
85         /*
86          * OK, now restart the process with the interpreter's dentry.
87          */
88         file = open_exec(interp);
89         if (IS_ERR(file))
90                 return PTR_ERR(file);
91
92         bprm->file = file;
93         retval = prepare_binprm(bprm);
94         if (retval < 0)
95                 return retval;
96         return search_binary_handler(bprm,regs);
97 }
98
99 struct linux_binfmt script_format = {
100         .module         = THIS_MODULE,
101         .load_binary    = load_script,
102 };
103
104 static int __init init_script_binfmt(void)
105 {
106         return register_binfmt(&script_format);
107 }
108
109 static void __exit exit_script_binfmt(void)
110 {
111         unregister_binfmt(&script_format);
112 }
113
114 core_initcall(init_script_binfmt);
115 module_exit(exit_script_binfmt);
116 MODULE_LICENSE("GPL");
Note: See TracBrowser for help on using the browser.