1/*
 2 * Helper function for splitting a string into an argv-like array.
 3 */
 4
 5#include <linux/kernel.h>
 6#include <linux/ctype.h>
 7#include <linux/string.h>
 8#include <linux/slab.h>
 9#include <linux/export.h>
 
 
 
 
 
 
 
 
10
11static int count_argc(const char *str)
12{
13	int count = 0;
14	bool was_space;
15
16	for (was_space = true; *str; str++) {
17		if (isspace(*str)) {
18			was_space = true;
19		} else if (was_space) {
20			was_space = false;
21			count++;
 
22		}
23	}
24
25	return count;
26}
27
28/**
29 * argv_free - free an argv
30 * @argv - the argument vector to be freed
31 *
32 * Frees an argv and the strings it points to.
33 */
34void argv_free(char **argv)
35{
36	argv--;
37	kfree(argv[0]);
 
 
38	kfree(argv);
39}
40EXPORT_SYMBOL(argv_free);
41
42/**
43 * argv_split - split a string at whitespace, returning an argv
44 * @gfp: the GFP mask used to allocate memory
45 * @str: the string to be split
46 * @argcp: returned argument count
47 *
48 * Returns an array of pointers to strings which are split out from
49 * @str.  This is performed by strictly splitting on white-space; no
50 * quote processing is performed.  Multiple whitespace characters are
51 * considered to be a single argument separator.  The returned array
52 * is always NULL-terminated.  Returns NULL on memory allocation
53 * failure.
54 *
55 * The source string at `str' may be undergoing concurrent alteration via
56 * userspace sysctl activity (at least).  The argv_split() implementation
57 * attempts to handle this gracefully by taking a local copy to work on.
58 */
59char **argv_split(gfp_t gfp, const char *str, int *argcp)
60{
61	char *argv_str;
62	bool was_space;
63	char **argv, **argv_ret;
64	int argc;
65
66	argv_str = kstrndup(str, KMALLOC_MAX_SIZE - 1, gfp);
67	if (!argv_str)
68		return NULL;
69
70	argc = count_argc(argv_str);
71	argv = kmalloc(sizeof(*argv) * (argc + 2), gfp);
72	if (!argv) {
73		kfree(argv_str);
74		return NULL;
75	}
76
77	*argv = argv_str;
78	argv_ret = ++argv;
79	for (was_space = true; *argv_str; argv_str++) {
80		if (isspace(*argv_str)) {
81			was_space = true;
82			*argv_str = 0;
83		} else if (was_space) {
84			was_space = false;
85			*argv++ = argv_str;
86		}
87	}
88	*argv = NULL;
89
90	if (argcp)
91		*argcp = argc;
92	return argv_ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
93}
94EXPORT_SYMBOL(argv_split);

  1/*
  2 * Helper function for splitting a string into an argv-like array.
  3 */
  4
  5#include <linux/kernel.h>
  6#include <linux/ctype.h>
  7#include <linux/string.h>
  8#include <linux/slab.h>
  9#include <linux/module.h>
 10
 11static const char *skip_arg(const char *cp)
 12{
 13	while (*cp && !isspace(*cp))
 14		cp++;
 15
 16	return cp;
 17}
 18
 19static int count_argc(const char *str)
 20{
 21	int count = 0;
 
 22
 23	while (*str) {
 24		str = skip_spaces(str);
 25		if (*str) {
 
 
 26			count++;
 27			str = skip_arg(str);
 28		}
 29	}
 30
 31	return count;
 32}
 33
 34/**
 35 * argv_free - free an argv
 36 * @argv - the argument vector to be freed
 37 *
 38 * Frees an argv and the strings it points to.
 39 */
 40void argv_free(char **argv)
 41{
 42	char **p;
 43	for (p = argv; *p; p++)
 44		kfree(*p);
 45
 46	kfree(argv);
 47}
 48EXPORT_SYMBOL(argv_free);
 49
 50/**
 51 * argv_split - split a string at whitespace, returning an argv
 52 * @gfp: the GFP mask used to allocate memory
 53 * @str: the string to be split
 54 * @argcp: returned argument count
 55 *
 56 * Returns an array of pointers to strings which are split out from
 57 * @str.  This is performed by strictly splitting on white-space; no
 58 * quote processing is performed.  Multiple whitespace characters are
 59 * considered to be a single argument separator.  The returned array
 60 * is always NULL-terminated.  Returns NULL on memory allocation
 61 * failure.
 
 
 
 
 62 */
 63char **argv_split(gfp_t gfp, const char *str, int *argcp)
 64{
 65	int argc = count_argc(str);
 66	char **argv = kzalloc(sizeof(*argv) * (argc+1), gfp);
 67	char **argvp;
 
 
 
 
 
 
 
 
 
 
 
 
 68
 69	if (argv == NULL)
 70		goto out;
 
 
 
 
 
 
 
 
 
 
 71
 72	if (argcp)
 73		*argcp = argc;
 74
 75	argvp = argv;
 76
 77	while (*str) {
 78		str = skip_spaces(str);
 79
 80		if (*str) {
 81			const char *p = str;
 82			char *t;
 83
 84			str = skip_arg(str);
 85
 86			t = kstrndup(p, str-p, gfp);
 87			if (t == NULL)
 88				goto fail;
 89			*argvp++ = t;
 90		}
 91	}
 92	*argvp = NULL;
 93
 94  out:
 95	return argv;
 96
 97  fail:
 98	argv_free(argv);
 99	return NULL;
100}
101EXPORT_SYMBOL(argv_split);