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