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