[PATCH] USB: scripts/mod/file2alias.c: handle numeric ranges for USB bcdDevice

Another attempt at that...

The attached patch fixes the longstanding problem with USB bcdDevice
numeric ranges incorrectly converted into patterns for MODULE_ALIAS
generation.  Previously it put both the lower and the upper limits into
the pattern, dlXdhY, making it impossible to fnmatch against except for
a few special cases, like dl*dh* or dlXdhX.

The patch makes it generate multiple MODULE_ALIAS lines covering the
whole range with fnmatch-able patterns.  E.g. for a range between 0x0001
and 0x8345 it gives the following patterns:

000[1-9]
00[1-9]*
0[1-9]*
[1-7]*
8[0-2]*
83[0-3]*
834[0-5]

Since bcdDevice is 2 bytes wide = 4 digits in hex representation, the
max no. of patters is 2 * 4 - 1 = 7.

The values are BCD (binary-coded decimals) and not hex, so patterns
using a dash seem to be safe regardless of locale collation order.

The patch changes bcdDevice part of the alias from dlXdhY to dZ, but
this shouldn't have big compatibility issues because fnmatch()-based
modprobing hasn't yet been widely used.  Besides, the most common (and
almost the only working) case of dl*dh* becomes d* and thus continues to
work.

The patch is against 2.6.12-rc2, applies to -mm3 with an offset.  The
matching patch to fix the MODALIAS environment variable now generated by
the usb hotplug function follows.

Signed-off-by: Roman Kagan <rkagan@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 88 insertions, 23 deletions

diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index d54b52d..32197ef 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -47,32 +47,31 @@ do {                                                            \
                 sprintf(str + strlen(str), "*");                \
 } while(0)
 
-/* Looks like "usb:vNpNdlNdhNdcNdscNdpNicNiscNipN" */
-static int do_usb_entry(const char *filename,
-			struct usb_device_id *id, char *alias)
+/* USB is special because the bcdDevice can be matched against a numeric range */
+/* Looks like "usb:vNpNdNdcNdscNdpNicNiscNipN" */
+static void do_usb_entry(struct usb_device_id *id,
+			 unsigned int bcdDevice_initial, int bcdDevice_initial_digits,
+			 unsigned char range_lo, unsigned char range_hi,
+			 struct module *mod)
 {
-	id->match_flags = TO_NATIVE(id->match_flags);
-	id->idVendor = TO_NATIVE(id->idVendor);
-	id->idProduct = TO_NATIVE(id->idProduct);
-	id->bcdDevice_lo = TO_NATIVE(id->bcdDevice_lo);
-	id->bcdDevice_hi = TO_NATIVE(id->bcdDevice_hi);
-
-	/*
-	 * Some modules (visor) have empty slots as placeholder for
-	 * run-time specification that results in catch-all alias
-	 */
-	if (!(id->idVendor | id->bDeviceClass | id->bInterfaceClass))
-		return 1;
-
+	char alias[500];
 	strcpy(alias, "usb:");
 	ADD(alias, "v", id->match_flags&USB_DEVICE_ID_MATCH_VENDOR,
 	    id->idVendor);
 	ADD(alias, "p", id->match_flags&USB_DEVICE_ID_MATCH_PRODUCT,
 	    id->idProduct);
-	ADD(alias, "dl", id->match_flags&USB_DEVICE_ID_MATCH_DEV_LO,
-	    id->bcdDevice_lo);
-	ADD(alias, "dh", id->match_flags&USB_DEVICE_ID_MATCH_DEV_HI,
-	    id->bcdDevice_hi);
+
+	strcat(alias, "d");
+	if (bcdDevice_initial_digits)
+		sprintf(alias + strlen(alias), "%0*X",
+			bcdDevice_initial_digits, bcdDevice_initial);
+	if (range_lo == range_hi)
+		sprintf(alias + strlen(alias), "%u", range_lo);
+	else if (range_lo > 0 || range_hi < 9)
+		sprintf(alias + strlen(alias), "[%u-%u]", range_lo, range_hi);
+	if (bcdDevice_initial_digits < (sizeof(id->bcdDevice_lo) * 2 - 1))
+		strcat(alias, "*");
+
 	ADD(alias, "dc", id->match_flags&USB_DEVICE_ID_MATCH_DEV_CLASS,
 	    id->bDeviceClass);
 	ADD(alias, "dsc",
@@ -90,7 +89,73 @@ static int do_usb_entry(const char *filename,
 	ADD(alias, "ip",
 	    id->match_flags&USB_DEVICE_ID_MATCH_INT_PROTOCOL,
 	    id->bInterfaceProtocol);
-	return 1;
+
+	/* Always end in a wildcard, for future extension */
+	if (alias[strlen(alias)-1] != '*')
+		strcat(alias, "*");
+	buf_printf(&mod->dev_table_buf,
+		   "MODULE_ALIAS(\"%s\");\n", alias);
+}
+
+static void do_usb_entry_multi(struct usb_device_id *id, struct module *mod)
+{
+	unsigned int devlo, devhi;
+	unsigned char chi, clo;
+	int ndigits;
+
+	id->match_flags = TO_NATIVE(id->match_flags);
+	id->idVendor = TO_NATIVE(id->idVendor);
+	id->idProduct = TO_NATIVE(id->idProduct);
+
+	devlo = id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO ?
+		TO_NATIVE(id->bcdDevice_lo) : 0x0U;
+	devhi = id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI ?
+		TO_NATIVE(id->bcdDevice_hi) : ~0x0U;
+
+	/*
+	 * Some modules (visor) have empty slots as placeholder for
+	 * run-time specification that results in catch-all alias
+	 */
+	if (!(id->idVendor | id->bDeviceClass | id->bInterfaceClass))
+		return;
+
+	/* Convert numeric bcdDevice range into fnmatch-able pattern(s) */
+	for (ndigits = sizeof(id->bcdDevice_lo) * 2 - 1; devlo <= devhi; ndigits--) {
+		clo = devlo & 0xf;
+		chi = devhi & 0xf;
+		if (chi > 9)	/* it's bcd not hex */
+			chi = 9;
+		devlo >>= 4;
+		devhi >>= 4;
+
+		if (devlo == devhi || !ndigits) {
+			do_usb_entry(id, devlo, ndigits, clo, chi, mod);
+			break;
+		}
+
+		if (clo > 0)
+			do_usb_entry(id, devlo++, ndigits, clo, 9, mod);
+
+		if (chi < 9)
+			do_usb_entry(id, devhi--, ndigits, 0, chi, mod);
+	}
+}
+
+static void do_usb_table(void *symval, unsigned long size,
+			 struct module *mod)
+{
+	unsigned int i;
+	const unsigned long id_size = sizeof(struct usb_device_id);
+
+	if (size % id_size || size < id_size) {
+		fprintf(stderr, "*** Warning: %s ids %lu bad size "
+			"(each on %lu)\n", mod->name, size, id_size);
+	}
+	/* Leave last one: it's the terminator. */
+	size -= id_size;
+
+	for (i = 0; i < size; i += id_size)
+		do_usb_entry_multi(symval + i, mod);
 }
 
 /* Looks like: ieee1394:venNmoNspNverN */
@@ -280,8 +345,8 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
 		do_table(symval, sym->st_size, sizeof(struct pci_device_id),
 			 do_pci_entry, mod);
 	else if (sym_is(symname, "__mod_usb_device_table"))
-		do_table(symval, sym->st_size, sizeof(struct usb_device_id),
-			 do_usb_entry, mod);
+		/* special case to handle bcdDevice ranges */
+		do_usb_table(symval, sym->st_size, mod);
 	else if (sym_is(symname, "__mod_ieee1394_device_table"))
 		do_table(symval, sym->st_size, sizeof(struct ieee1394_device_id),
 			 do_ieee1394_entry, mod);