1/*
2 * getopt.c
3 */
4
5#include <linux/kernel.h>
6#include <linux/string.h>
7
8#include <asm/errno.h>
9
10#include "getopt.h"
11
12/**
13 *	ncp_getopt - option parser
14 *	@caller: name of the caller, for error messages
15 *	@options: the options string
16 *	@opts: an array of &struct option entries controlling parser operations
17 *	@optopt: output; will contain the current option
18 *	@optarg: output; will contain the value (if one exists)
19 *	@flag: output; may be NULL; should point to a long for or'ing flags
20 *	@value: output; may be NULL; will be overwritten with the integer value
21 *		of the current argument.
22 *
23 *	Helper to parse options on the format used by mount ("a=b,c=d,e,f").
24 *	Returns opts->val if a matching entry in the 'opts' array is found,
25 *	0 when no more tokens are found, -1 if an error is encountered.
26 */
27int ncp_getopt(const char *caller, char **options, const struct ncp_option *opts,
28	       char **optopt, char **optarg, unsigned long *value)
29{
30	char *token;
31	char *val;
32
33	do {
34		if ((token = strsep(options, ",")) == NULL)
35			return 0;
36	} while (*token == '\0');
37	if (optopt)
38		*optopt = token;
39
40	if ((val = strchr (token, '=')) != NULL) {
41		*val++ = 0;
42	}
43	*optarg = val;
44	for (; opts->name; opts++) {
45		if (!strcmp(opts->name, token)) {
46			if (!val) {
47				if (opts->has_arg & OPT_NOPARAM) {
48					return opts->val;
49				}
50				printk(KERN_INFO "%s: the %s option requires an argument\n",
51				       caller, token);
52				return -EINVAL;
53			}
54			if (opts->has_arg & OPT_INT) {
55				char* v;
56
57				*value = simple_strtoul(val, &v, 0);
58				if (!*v) {
59					return opts->val;
60				}
61				printk(KERN_INFO "%s: invalid numeric value in %s=%s\n",
62					caller, token, val);
63				return -EDOM;
64			}
65			if (opts->has_arg & OPT_STRING) {
66				return opts->val;
67			}
68			printk(KERN_INFO "%s: unexpected argument %s to the %s option\n",
69				caller, val, token);
70			return -EINVAL;
71		}
72	}
73	printk(KERN_INFO "%s: Unrecognized mount option %s\n", caller, token);
74	return -EOPNOTSUPP;
75}
76