fs/ncpfs/getopt.c

   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  */
  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 }