path: root/scripts/mod/file2alias.c

/* Simple code to turn various tables in an ELF file into alias definitions.
 * This deals with kernel datastructures where they should be
 * dealt with: in the kernel source.
 *
 * Copyright 2002-2003  Rusty Russell, IBM Corporation
 *           2003       Kai Germaschewski
 *
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 */

#include <stdarg.h>
#include <stdio.h>

#include "list.h"
#include "xalloc.h"

#include "modpost.h"
#include "devicetable-offsets.h"

/* We use the ELF typedefs for kernel_ulong_t but bite the bullet and
 * use either stdint.h or inttypes.h for the rest. */
#if KERNEL_ELFCLASS == ELFCLASS32
typedef Elf32_Addr	kernel_ulong_t;
#define BITS_PER_LONG 32
#else
typedef Elf64_Addr	kernel_ulong_t;
#define BITS_PER_LONG 64
#endif
#ifdef __sun__
#include <inttypes.h>
#else
#include <stdint.h>
#endif

#include <ctype.h>
#include <stdbool.h>

/**
 * module_alias_printf - add auto-generated MODULE_ALIAS()
 *
 * @mod: module
 * @append_wildcard: append '*' for future extension if not exist yet
 * @fmt: printf(3)-like format
 */
static void __attribute__((format (printf, 3, 4)))
module_alias_printf(struct module *mod, bool append_wildcard,
		    const char *fmt, ...)
{
	struct module_alias *new, *als;
	size_t len;
	int n;
	va_list ap;

	/* Determine required size. */
	va_start(ap, fmt);
	n = vsnprintf(NULL, 0, fmt, ap);
	va_end(ap);

	if (n < 0) {
		error("vsnprintf failed\n");
		return;
	}

	len = n + 1;	/* extra byte for '\0' */

	if (append_wildcard)
		len++;	/* extra byte for '*' */

	new = xmalloc(sizeof(*new) + len);

	/* Now, really print it to the allocated buffer */
	va_start(ap, fmt);
	n = vsnprintf(new->str, len, fmt, ap);
	va_end(ap);

	if (n < 0) {
		error("vsnprintf failed\n");
		free(new);
		return;
	}

	if (append_wildcard && (n == 0 || new->str[n - 1] != '*')) {
		new->str[n] = '*';
		new->str[n + 1] = '\0';
	}

	/* avoid duplication */
	list_for_each_entry(als, &mod->aliases, node) {
		if (!strcmp(als->str, new->str)) {
			free(new);
			return;
		}
	}

	list_add_tail(&new->node, &mod->aliases);
}

typedef uint32_t	__u32;
typedef uint16_t	__u16;
typedef unsigned char	__u8;

/* UUID types for backward compatibility, don't use in new code */
typedef struct {
	__u8 b[16];
} guid_t;

typedef struct {
	__u8 b[16];
} uuid_t;

#define	UUID_STRING_LEN		36

/* MEI UUID type, don't use anywhere else */
typedef struct {
	__u8 b[16];
} uuid_le;

/* Big exception to the "don't include kernel headers into userspace, which
 * even potentially has different endianness and word sizes, since
 * we handle those differences explicitly below */
#include "../../include/linux/mod_devicetable.h"

struct devtable {
	const char *device_id;
	unsigned long id_size;
	void (*do_entry)(struct module *mod, void *symval);
};

/* Define a variable f that holds the value of field f of struct devid
 * based at address m.
 */
#define DEF_FIELD(m, devid, f) \
	typeof(((struct devid *)0)->f) f = \
		get_unaligned_native((typeof(f) *)((m) + OFF_##devid##_##f))

/* Define a variable f that holds the address of field f of struct devid
 * based at address m.  Due to the way typeof works, for a field of type
 * T[N] the variable has type T(*)[N], _not_ T*.
 */
#define DEF_FIELD_ADDR(m, devid, f) \
	typeof(((struct devid *)0)->f) *f = ((m) + OFF_##devid##_##f)

#define ADD(str, sep, cond, field)                              \
do {                                                            \
        strcat(str, sep);                                       \
        if (cond)                                               \
                sprintf(str + strlen(str),                      \
                        sizeof(field) == 1 ? "%02X" :           \
                        sizeof(field) == 2 ? "%04X" :           \
                        sizeof(field) == 4 ? "%08X" : "",       \
                        field);                                 \
        else                                                    \
                sprintf(str + strlen(str), "*");                \
} while(0)

static inline void add_uuid(char *str, uuid_le uuid)
{
	int len = strlen(str);

	sprintf(str + len, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
		uuid.b[3], uuid.b[2], uuid.b[1], uuid.b[0],
		uuid.b[5], uuid.b[4], uuid.b[7], uuid.b[6],
		uuid.b[8], uuid.b[9], uuid.b[10], uuid.b[11],
		uuid.b[12], uuid.b[13], uuid.b[14], uuid.b[15]);
}

static inline void add_guid(char *str, guid_t guid)
{
	int len = strlen(str);

	sprintf(str + len, "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
		guid.b[3], guid.b[2], guid.b[1], guid.b[0],
		guid.b[5], guid.b[4], guid.b[7], guid.b[6],
		guid.b[8], guid.b[9], guid.b[10], guid.b[11],
		guid.b[12], guid.b[13], guid.b[14], guid.b[15]);
}

/* USB is special because the bcdDevice can be matched against a numeric range */
/* Looks like "usb:vNpNdNdcNdscNdpNicNiscNipNinN" */
static void do_usb_entry(void *symval,
			 unsigned int bcdDevice_initial, int bcdDevice_initial_digits,
			 unsigned char range_lo, unsigned char range_hi,
			 unsigned char max, struct module *mod)
{
	char alias[500];
	DEF_FIELD(symval, usb_device_id, match_flags);
	DEF_FIELD(symval, usb_device_id, idVendor);
	DEF_FIELD(symval, usb_device_id, idProduct);
	DEF_FIELD(symval, usb_device_id, bcdDevice_lo);
	DEF_FIELD(symval, usb_device_id, bDeviceClass);
	DEF_FIELD(symval, usb_device_id, bDeviceSubClass);
	DEF_FIELD(symval, usb_device_id, bDeviceProtocol);
	DEF_FIELD(symval, usb_device_id, bInterfaceClass);
	DEF_FIELD(symval, usb_device_id, bInterfaceSubClass);
	DEF_FIELD(symval, usb_device_id, bInterfaceProtocol);
	DEF_FIELD(symval, usb_device_id, bInterfaceNumber);

	strcpy(alias, "usb:");
	ADD(alias, "v", match_flags&USB_DEVICE_ID_MATCH_VENDOR,
	    idVendor);
	ADD(alias, "p", match_flags&USB_DEVICE_ID_MATCH_PRODUCT,
	    idProduct);

	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), "%X", range_lo);
	else if (range_lo > 0 || range_hi < max) {
		if (range_lo > 0x9 || range_hi < 0xA)
			sprintf(alias + strlen(alias),
				"[%X-%X]",
				range_lo,
				range_hi);
		else {
			sprintf(alias + strlen(alias),
				range_lo < 0x9 ? "[%X-9" : "[%X",
				range_lo);
			sprintf(alias + strlen(alias),
				range_hi > 0xA ? "A-%X]" : "%X]",
				range_hi);
		}
	}
	if (bcdDevice_initial_digits < (sizeof(bcdDevice_lo) * 2 - 1))
		strcat(alias, "*");

	ADD(alias, "dc", match_flags&USB_DEVICE_ID_MATCH_DEV_CLASS,
	    bDeviceClass);
	ADD(alias, "dsc", match_flags&USB_DEVICE_ID_MATCH_DEV_SUBCLASS,
	    bDeviceSubClass);
	ADD(alias, "dp", match_flags&USB_DEVICE_ID_MATCH_DEV_PROTOCOL,
	    bDeviceProtocol);
	ADD(alias, "ic", match_flags&USB_DEVICE_ID_MATCH_INT_CLASS,
	    bInterfaceClass);
	ADD(alias, "isc", match_flags&USB_DEVICE_ID_MATCH_INT_SUBCLASS,
	    bInterfaceSubClass);
	ADD(alias, "ip", match_flags&USB_DEVICE_ID_MATCH_INT_PROTOCOL,
	    bInterfaceProtocol);
	ADD(alias, "in", match_flags&USB_DEVICE_ID_MATCH_INT_NUMBER,
	    bInterfaceNumber);

	module_alias_printf(mod, true, "%s", alias);
}

/* Handles increment/decrement of BCD formatted integers */
/* Returns the previous value, so it works like i++ or i-- */
static unsigned int incbcd(unsigned int *bcd,
			   int inc,
			   unsigned char max,
			   size_t chars)
{
	unsigned int init = *bcd, i, j;
	unsigned long long c, dec = 0;

	/* If bcd is not in BCD format, just increment */
	if (max > 0x9) {
		*bcd += inc;
		return init;
	}

	/* Convert BCD to Decimal */
	for (i=0 ; i < chars ; i++) {
		c = (*bcd >> (i << 2)) & 0xf;
		c = c > 9 ? 9 : c; /* force to bcd just in case */
		for (j=0 ; j < i ; j++)
			c = c * 10;
		dec += c;
	}

	/* Do our increment/decrement */
	dec += inc;
	*bcd  = 0;

	/* Convert back to BCD */
	for (i=0 ; i < chars ; i++) {
		for (c=1,j=0 ; j < i ; j++)
			c = c * 10;
		c = (dec / c) % 10;
		*bcd += c << (i << 2);
	}
	return init;
}

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