[PATCH] Module Parameter Core Patch

This patch is a rewrite of the insmod and boot parameter handling,
to unify them.

The new format is fairly simple: built on top of __module_param_call there
are several helpers, eg "module_param(foo, int, 000)".  The final argument
is the permissions bits, for exposing parameters in sysfs (if
non-zero) at a later stage.

1 files changed, 338 insertions, 0 deletions

diff --git a/kernel/params.c b/kernel/params.c
new file mode 100644
index 000000000000..ffc65eb38748
--- /dev/null
+++ b/kernel/params.c
@@ -0,0 +1,338 @@
+/* Helpers for initial module or kernel cmdline parsing
+   Copyright (C) 2001 Rusty Russell.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt , ...)
+#endif
+
+static int parse_one(char *param,
+		     char *val,
+		     struct kernel_param *params, 
+		     unsigned num_params,
+		     int (*handle_unknown)(char *param, char *val))
+{
+	unsigned int i;
+
+	/* Find parameter */
+	for (i = 0; i < num_params; i++) {
+		if (strcmp(param, params[i].name) == 0) {
+			DEBUGP("They are equal!  Calling %p\n",
+			       params[i].set);
+			return params[i].set(val, &params[i]);
+		}
+	}
+
+	if (handle_unknown) {
+		DEBUGP("Unknown argument: calling %p\n", handle_unknown);
+		return handle_unknown(param, val);
+	}
+
+	DEBUGP("Unknown argument `%s'\n", param);
+	return -ENOENT;
+}
+
+/* You can use " around spaces, but can't escape ". */
+/* Hyphens and underscores equivalent in parameter names. */
+static char *next_arg(char *args, char **param, char **val)
+{
+	unsigned int i, equals = 0;
+	int in_quote = 0;
+
+	/* Chew any extra spaces */
+	while (*args == ' ') args++;
+
+	for (i = 0; args[i]; i++) {
+		if (args[i] == ' ' && !in_quote)
+			break;
+		if (equals == 0) {
+			if (args[i] == '=')
+				equals = i;
+			else if (args[i] == '-')
+				args[i] = '_';
+		}
+		if (args[i] == '"')
+			in_quote = !in_quote;
+	}
+
+	*param = args;
+	if (!equals)
+		*val = NULL;
+	else {
+		args[equals] = '\0';
+		*val = args + equals + 1;
+	}
+
+	if (args[i]) {
+		args[i] = '\0';
+		return args + i + 1;
+	} else
+		return args + i;
+}
+
+/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
+int parse_args(const char *name,
+	       char *args,
+	       struct kernel_param *params,
+	       unsigned num,
+	       int (*unknown)(char *param, char *val))
+{
+	char *param, *val;
+
+	DEBUGP("Parsing ARGS: %s\n", args);
+
+	while (*args) {
+		int ret;
+
+		args = next_arg(args, &param, &val);
+		ret = parse_one(param, val, params, num, unknown);
+		switch (ret) {
+		case -ENOENT:
+			printk(KERN_ERR "%s: Unknown parameter `%s'\n",
+			       name, param);
+			return ret;
+		case -ENOSPC:
+			printk(KERN_ERR
+			       "%s: `%s' too large for parameter `%s'\n",
+			       name, val ?: "", param);
+			return ret;
+		case 0:
+			break;
+		default:
+			printk(KERN_ERR
+			       "%s: `%s' invalid for parameter `%s'\n",
+			       name, val ?: "", param);
+			return ret;
+		}
+	}
+
+	/* All parsed OK. */
+	return 0;
+}
+
+/* Lazy bastard, eh? */
+#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn)      	\
+	int param_set_##name(const char *val, struct kernel_param *kp)	\
+	{								\
+		char *endp;						\
+		tmptype l;						\
+									\
+		if (!val) return -EINVAL;				\
+		l = strtolfn(val, &endp, 0);				\
+		if (endp == val || *endp || ((type)l != l))		\
+			return -EINVAL;					\
+		*((type *)kp->arg) = l;					\
+		return 0;						\
+	}								\
+	int param_get_##name(char *buffer, struct kernel_param *kp)	\
+	{								\
+		return sprintf(buffer, format, *((type *)kp->arg));	\
+	}
+
+STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol);
+STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", long, simple_strtol);
+STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol);
+STANDARD_PARAM_DEF(uint, unsigned int, "%u", long, simple_strtol);
+STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol);
+STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_strtoul);
+
+int param_set_charp(const char *val, struct kernel_param *kp)
+{
+	if (!val) {
+		printk(KERN_ERR "%s: string parameter expected\n",
+		       kp->name);
+		return -EINVAL;
+	}
+
+	if (strlen(val) > 1024) {
+		printk(KERN_ERR "%s: string parameter too long\n",
+		       kp->name);
+		return -ENOSPC;
+	}
+
+	*(char **)kp->arg = (char *)val;
+	return 0;
+}
+
+int param_get_charp(char *buffer, struct kernel_param *kp)
+{
+	return sprintf(buffer, "%s", *((char **)kp->arg));
+}
+
+int param_set_bool(const char *val, struct kernel_param *kp)
+{
+	/* No equals means "set"... */
+	if (!val) val = "1";
+
+	/* One of =[yYnN01] */
+	switch (val[0]) {
+	case 'y': case 'Y': case '1':
+		*(int *)kp->arg = 1;
+		return 0;
+	case 'n': case 'N': case '0':
+		*(int *)kp->arg = 0;
+		return 0;
+	}
+	return -EINVAL;
+}
+
+int param_get_bool(char *buffer, struct kernel_param *kp)
+{
+	/* Y and N chosen as being relatively non-coder friendly */
+	return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
+}
+
+int param_set_invbool(const char *val, struct kernel_param *kp)
+{
+	int boolval, ret;
+	struct kernel_param dummy = { .arg = &boolval };
+
+	ret = param_set_bool(val, &dummy);
+	if (ret == 0)
+		*(int *)kp->arg = !boolval;
+	return ret;
+}
+
+int param_get_invbool(char *buffer, struct kernel_param *kp)
+{
+	int val;
+	struct kernel_param dummy = { .arg = &val };
+
+	val = !*(int *)kp->arg;
+	return param_get_bool(buffer, &dummy);
+}
+
+/* We cheat here and temporarily mangle the string. */
+int param_array(const char *name,
+		const char *val,
+		unsigned int min, unsigned int max,
+		void *elem, int elemsize,
+		int (*set)(const char *, struct kernel_param *kp))
+{
+	int ret;
+	unsigned int count = 0;
+	struct kernel_param kp;
+
+	/* Get the name right for errors. */
+	kp.name = name;
+	kp.arg = elem;
+
+	/* No equals sign? */
+	if (!val) {
+		printk(KERN_ERR "%s: expects arguments\n", name);
+		return -EINVAL;
+	}
+
+	/* We expect a comma-separated list of values. */
+	do {
+		int len;
+		char save;
+
+		if (count > max) {
+			printk(KERN_ERR "%s: can only take %i arguments\n",
+			       name, max);
+			return -EINVAL;
+		}
+		len = strcspn(val, ",");
+
+		/* Temporarily nul-terminate and parse */
+		save = val[len];
+		((char *)val)[len] = '\0';
+		ret = set(val, &kp);
+		((char *)val)[len] = save;
+
+		if (ret != 0)
+			return ret;
+		kp.arg += elemsize;
+		val += len+1;
+		count++;
+	} while (val[-1] == ',');
+
+	if (count < min) {
+		printk(KERN_ERR "%s: needs at least %i arguments\n",
+		       name, min);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/* First two elements are the max and min array length (which don't change) */
+int param_set_intarray(const char *val, struct kernel_param *kp)
+{
+	int *array;
+
+	/* Grab min and max as first two elements */
+	array = kp->arg;
+	return param_array(kp->name, val, array[0], array[1], &array[2],
+			   sizeof(int), param_set_int);
+}
+
+int param_get_intarray(char *buffer, struct kernel_param *kp)
+{
+	int max;
+	int *array;
+	unsigned int i;
+
+	array = kp->arg;
+	max = array[1];
+
+	for (i = 2; i < max + 2; i++)
+		sprintf(buffer, "%s%i", i > 2 ? "," : "", array[i]);
+	return strlen(buffer);
+}
+
+int param_set_copystring(const char *val, struct kernel_param *kp)
+{
+	struct kparam_string *kps = kp->arg;
+
+	if (strlen(val)+1 > kps->maxlen) {
+		printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
+		       kp->name, kps->maxlen-1);
+		return -ENOSPC;
+	}
+	strcpy(kps->string, val);
+	return 0;
+}
+
+EXPORT_SYMBOL(param_set_short);
+EXPORT_SYMBOL(param_get_short);
+EXPORT_SYMBOL(param_set_ushort);
+EXPORT_SYMBOL(param_get_ushort);
+EXPORT_SYMBOL(param_set_int);
+EXPORT_SYMBOL(param_get_int);
+EXPORT_SYMBOL(param_set_uint);
+EXPORT_SYMBOL(param_get_uint);
+EXPORT_SYMBOL(param_set_long);
+EXPORT_SYMBOL(param_get_long);
+EXPORT_SYMBOL(param_set_ulong);
+EXPORT_SYMBOL(param_get_ulong);
+EXPORT_SYMBOL(param_set_charp);
+EXPORT_SYMBOL(param_get_charp);
+EXPORT_SYMBOL(param_set_bool);
+EXPORT_SYMBOL(param_get_bool);
+EXPORT_SYMBOL(param_set_invbool);
+EXPORT_SYMBOL(param_get_invbool);
+EXPORT_SYMBOL(param_set_intarray);
+EXPORT_SYMBOL(param_get_intarray);
+EXPORT_SYMBOL(param_set_copystring);