vsprintf: add %pMR for Bluetooth MAC address

Bluetooth uses mostly LE byte order which is reversed for visual
interpretation.  Currently in Bluetooth in use unsafe batostr function.

This is a slightly modified version of Joe's patch (sent Sat, Dec 4,
2010).

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 5df176ed59b826e8cbeaca7c96d6ed6d06759fa8..d8d168fa79d654f7c21175b10e6b00d824d762fc 100644 (file)
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -56,6 +56,7 @@ Struct Resources:
 MAC/FDDI addresses:
 
        %pM     00:01:02:03:04:05
+       %pMR    05:04:03:02:01:00
        %pMF    00-01-02-03-04-05
        %pm     000102030405
 
@@ -67,6 +68,10 @@ MAC/FDDI addresses:
        the 'M' specifier to use dash ('-') separators instead of the default
        separator.
 
+       For Bluetooth addresses the 'R' specifier shall be used after the 'M'
+       specifier to use reversed byte order suitable for visual interpretation
+       of Bluetooth addresses which are in the little endian order.
+
 IPv4 addresses:
 
        %pI4    1.2.3.4

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c3f36d415bdf43034415c801b8e3f922f5e5b928..736974576e2d685a2bd68d08b7658bbcee5fd7f8 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -662,15 +662,28 @@ char *mac_address_string(char *buf, char *end, u8 *addr,
        char *p = mac_addr;
        int i;
        char separator;
+       bool reversed = false;
 
-       if (fmt[1] == 'F') {            /* FDDI canonical format */
+       switch (fmt[1]) {
+       case 'F':
                separator = '-';
-       } else {
+               break;
+
+       case 'R':
+               reversed = true;
+               /* fall through */
+
+       default:
                separator = ':';
+               break;
        }
 
        for (i = 0; i < 6; i++) {
-               p = hex_byte_pack(p, addr[i]);
+               if (reversed)
+                       p = hex_byte_pack(p, addr[5 - i]);
+               else
+                       p = hex_byte_pack(p, addr[i]);
+
                if (fmt[0] == 'M' && i != 5)
                        *p++ = separator;
        }
@@ -933,6 +946,7 @@ int kptr_restrict __read_mostly;
  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
  *       with a dash-separated hex notation
+ * - '[mM]R For a 6-byte MAC address, Reverse order (Bluetooth)
  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
@@ -995,7 +1009,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
                return resource_string(buf, end, ptr, spec, fmt);
        case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
        case 'm':                       /* Contiguous: 000102030405 */
-                                       /* [mM]F (FDDI, bit reversed) */
+                                       /* [mM]F (FDDI) */
+                                       /* [mM]R (Reverse order; Bluetooth) */
                return mac_address_string(buf, end, ptr, spec, fmt);
        case 'I':                       /* Formatted IP supported
                                         * 4:   1.2.3.4