Re: [ANNOUNCE] hotplug-ng 001 release

[Roman Kagan <rkagan@mail.ru>]

On Mon, Feb 21, 2005 at 09:40:04PM +0100, Erik van Konijnenburg wrote:
> Here are some samples from modules.alias:
> 	alias usb:v097Ap0001dl0000dh0001dc*dsc*dp*ic*isc*ip* usb_storage
> 	alias usb:v05A9p0511dl*dh*dc*dsc*dp*ic*isc*ip* ov511
> 
> And the read_config_file function in modprobe.c simply does a shell
> style wildcard match.
> 
> How can wildcard matching in modprobe against these aliases give the same
> result as a numeric range comparison on DEV_LO and DEV_HI in kernel and
> hotplug agents?
> 
> Since I don't know what modules.aliases was originally intended for,
> I may be missing something obvious.  Any hints appreciated.

That wasn't you who missed something obvious :)  Actually this problem
existed since day 0 and presumably was due to the fact that USB was (and
still is) the only kind which used numeric ranges and thus had two
parameters to match a single value against, which was probably
overlooked when scripts/mod/file2alias.c was written.

The only solution I could come up with was to modify that file to
generate multiple patterns (and thus MODULE_ALIAS strings) out of a
usb_match_id which defined a range of bcdDevice values, e.g. given a
range between 0x0001 and 0xa345 it would create 7 patterns:

000[1-F]*
00[1-F]*
0[1-F]*
[1-9]*
A[0-2]*
A3[0-3]*
A34[0-5]*

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

The attached patch does this.  Please comment and consider applying.

Thanks,
  Roman.


--- linux-2.6.11-rc4/scripts/mod/file2alias.c.orig	2005-02-13 10:06:23.000000000 +0300
+++ linux-2.6.11-rc4/scripts/mod/file2alias.c	2005-02-22 12:58:05.849081056 +0300
@@ -47,32 +47,19 @@
                 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, const char *bcdDevice_pattern,
+			 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");
+	strcat(alias, bcdDevice_pattern);
 	ADD(alias, "dc", id->match_flags&USB_DEVICE_ID_MATCH_DEV_CLASS,
 	    id->bDeviceClass);
 	ADD(alias, "dsc",
@@ -90,7 +77,104 @@
 	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 inline size_t sprint_pattern(char *str, int ndigits, unsigned int initial,
+				  unsigned char clo, unsigned char chi)
+{
+	if (ndigits) {
+		if (clo = chi)
+			return sprintf(str, "%0*X%X*", ndigits, initial, clo);
+		if (clo = 0x0 && chi = 0xf)
+			return sprintf(str, "%0*X*", ndigits, initial);
+		return sprintf(str, "%0*X[%X-%X]*", ndigits, initial, clo, chi);
+	}
+	else {
+		if (clo = chi)
+			return sprintf(str, "%X*", clo);
+		if (clo = 0x0 && chi = 0xf)
+			return sprintf(str, "*");
+		return sprintf(str, "[%X-%X]*", clo, chi);
+	}
+}
+
+static void do_usb_entry_multi(struct usb_device_id *id, struct module *mod)
+{
+	unsigned int devlo, devhi;
+	unsigned char chi, clo;
+	int ndigits;
+	char pattern[32];
+
+	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; 1; ndigits--) {
+		clo = devlo & 0xf;
+		chi = devhi & 0xf;
+		devlo >>= 4;
+		devhi >>= 4;
+
+		if (devlo = devhi || !ndigits) {
+			if (clo <= chi) {
+				sprint_pattern(pattern, ndigits, devlo, clo, chi);
+				do_usb_entry(id, pattern, mod);
+				printf("%s\n", pattern);
+			}
+			break;
+		}
+
+		if (clo != 0x0) {
+			sprint_pattern(pattern, ndigits, devlo, clo, 0xf);
+			do_usb_entry(id, pattern, mod);
+			printf("%s\n", pattern);
+			devlo++;
+		}
+
+		if (chi != 0xf) {
+			sprint_pattern(pattern, ndigits, devhi, 0x0, chi);
+			do_usb_entry(id, pattern, mod);
+			printf("%s\n", pattern);
+			devhi--;
+		}
+	}
+}
+
+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 +346,8 @@
 		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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