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

[Roman Kagan <rkagan@mail.ru>]

On Fri, Mar 25, 2005 at 09:40:48AM -0800, Greg KH wrote:
> On Fri, Mar 25, 2005 at 10:43:01AM +0300, Roman Kagan wrote:
> > > > The patch expects a matching change in scripts/mod/file2alias.c I sent
> > > > to linux-hotplug-devel list a few days ago (i.e. puts
> > > > bcdDevice in MODNAME as dXXXX, rather that dlXXXXdhXXXX).
> > > 
> > > I changed this back, as this change doesn't seem to have gone anywhere.
> > 
> > It was sent to linux-hotplug-devel and cc to you on Feb. 26, as I
> > thought it was up to you to include it.  Has it got lost and should I
> > resend it, or should I better send it to another list?  I think it's
> > worth merging as the current scheme bites everybody with nontrivial
> > bcdDevice range.
> 
> Ok, care to resend it?  I saw a lot of different patches floating
> around, and didn't know which one was the decided apon best fix.

Sure, here you are.  This is the latest version of the patch I sent on
Feb 26.  Erik van Konijnenburg reviewed it and was OK with it
(Erik mind adding your Signed-off-by?), so it's "decided upon best" by
the two of us :)

  Roman.

================
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 0xa345 it gives the following patterns:

000[123456789ABCDEF]*
00[123456789ABCDEF]*
0[123456789ABCDEF]*
[123456789]*
A[012]*
A3[0123]*
A34[012345]*

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

Explicit lists of allowed characters inside brackets are used to avoid
dependencies on locale collation order with patterns using a dash, like
[3-B].

The patch uses "d" prefix for bcdDevice; the most common (and almost the
only working) case of dl*dh* becomes d* and thus continues to work.

Please consider applying.
  Roman.

Signed-off-by: Roman Kagan <rkagan@mail.ru>

 scripts/mod/file2alias.c |  112 +++++++++++++++++++++++++++++++++++++----------
 1 files changed, 89 insertions(+), 23 deletions(-)

--- linux-2.6.11-rc4/scripts/mod/file2alias.c.orig	2005-02-13 06:06:23.000000000 +0300
+++ linux-2.6.11-rc4/scripts/mod/file2alias.c	2005-02-26 19:15:49.769160544 +0300
@@ -47,32 +47,34 @@ 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;
-
+	static const char hexdigits[] = "0123456789ABCDEF";
+	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)
+		strncat(alias, hexdigits + range_lo, 1);
+	else if (range_lo > 0x0 || range_hi < 0xf) {
+		strcat(alias, "[");
+		strncat(alias, hexdigits + range_lo, range_hi - range_lo + 1);
+		strcat(alias, "]");
+	}
+	strcat(alias, "*");
+
 	ADD(alias, "dc", id->match_flags&USB_DEVICE_ID_MATCH_DEV_CLASS,
 	    id->bDeviceClass);
 	ADD(alias, "dsc",
@@ -90,7 +92,71 @@ static int do_usb_entry(const char *file
 	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;
+		devlo >>= 4;
+		devhi >>= 4;
+
+		if (devlo = devhi || !ndigits) {
+			do_usb_entry(id, devlo, ndigits, clo, chi, mod);
+			break;
+		}
+
+		if (clo != 0x0)
+			do_usb_entry(id, devlo++, ndigits, clo, 0xf, mod);
+
+		if (chi != 0xf)
+			do_usb_entry(id, devhi--, ndigits, 0x0, 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 */
@@ -262,8 +328,8 @@ void handle_moddevtable(struct module *m
 		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);


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