Commit dd45c9cf authored by Harvey Harrison's avatar Harvey Harrison Committed by David S. Miller
Browse files

printk: add %pM format specifier for MAC addresses 



Add format specifiers for printing out six colon-separated bytes:

MAC addresses (%pM):
xx:xx:xx:xx:xx:xx

%#pM is also supported and omits the colon separators.

Signed-off-by: default avatarHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1080d709

lib/vsprintf.c

+21 −0
Original line number Diff line number Diff line
@@ -581,6 +581,23 @@ static char *resource_string(char *buf, char *end, struct resource *res, int fie 
	return string(buf, end, sym, field_width, precision, flags);

}



static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width,

				int precision, int flags)

{

	char mac_addr[6 * 3]; /* (6 * 2 hex digits), 5 colons and trailing zero */

	char *p = mac_addr;

	int i;



	for (i = 0; i < 6; i++) {

		p = pack_hex_byte(p, addr[i]);

		if (!(flags & SPECIAL) && i != 5)

			*p++ = ':';

	}

	*p = '\0';



	return string(buf, end, mac_addr, field_width, precision, flags & ~SPECIAL);

}



/*

 * Show a '%p' thing.  A kernel extension is that the '%p' is followed

 * by an extra set of alphanumeric characters that are extended format
@@ -592,6 +609,8 @@ static char *resource_string(char *buf, char *end, struct resource *res, int fie 
 * - 'S' For symbolic direct pointers

 * - 'R' For a struct resource pointer, it prints the range of

 *       addresses (not the name nor the flags)

 * - 'M' For a 6-byte MAC address, it prints the address in the

 *       usual colon-separated hex notation

 *

 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64

 * function pointers are really function descriptors, which contain a
@@ -607,6 +626,8 @@ static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field 
		return symbol_string(buf, end, ptr, field_width, precision, flags);

	case 'R':

		return resource_string(buf, end, ptr, field_width, precision, flags);

	case 'M':

		return mac_address_string(buf, end, ptr, field_width, precision, flags);

	}

	flags |= SMALL;

	if (field_width == -1) {