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path: root/drivers/staging/ncpfs/getopt.c
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Diffstat (limited to 'drivers/staging/ncpfs/getopt.c')
-rw-r--r--drivers/staging/ncpfs/getopt.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/drivers/staging/ncpfs/getopt.c b/drivers/staging/ncpfs/getopt.c
new file mode 100644
index 000000000000..5c941bef14c4
--- /dev/null
+++ b/drivers/staging/ncpfs/getopt.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * getopt.c
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+#include <asm/errno.h>
+
+#include "getopt.h"
+
+/**
+ * ncp_getopt - option parser
+ * @caller: name of the caller, for error messages
+ * @options: the options string
+ * @opts: an array of &struct option entries controlling parser operations
+ * @optopt: output; will contain the current option
+ * @optarg: output; will contain the value (if one exists)
+ * @value: output; may be NULL; will be overwritten with the integer value
+ * of the current argument.
+ *
+ * Helper to parse options on the format used by mount ("a=b,c=d,e,f").
+ * Returns opts->val if a matching entry in the 'opts' array is found,
+ * 0 when no more tokens are found, -1 if an error is encountered.
+ */
+int ncp_getopt(const char *caller, char **options, const struct ncp_option *opts,
+ char **optopt, char **optarg, unsigned long *value)
+{
+ char *token;
+ char *val;
+
+ do {
+ if ((token = strsep(options, ",")) == NULL)
+ return 0;
+ } while (*token == '\0');
+ if (optopt)
+ *optopt = token;
+
+ if ((val = strchr (token, '=')) != NULL) {
+ *val++ = 0;
+ }
+ *optarg = val;
+ for (; opts->name; opts++) {
+ if (!strcmp(opts->name, token)) {
+ if (!val) {
+ if (opts->has_arg & OPT_NOPARAM) {
+ return opts->val;
+ }
+ pr_info("%s: the %s option requires an argument\n",
+ caller, token);
+ return -EINVAL;
+ }
+ if (opts->has_arg & OPT_INT) {
+ int rc = kstrtoul(val, 0, value);
+
+ if (rc) {
+ pr_info("%s: invalid numeric value in %s=%s\n",
+ caller, token, val);
+ return rc;
+ }
+ return opts->val;
+ }
+ if (opts->has_arg & OPT_STRING) {
+ return opts->val;
+ }
+ pr_info("%s: unexpected argument %s to the %s option\n",
+ caller, val, token);
+ return -EINVAL;
+ }
+ }
+ pr_info("%s: Unrecognized mount option %s\n", caller, token);
+ return -EOPNOTSUPP;
+}