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authorHarvey Harrison <harvey.harrison@gmail.com>2008-10-27 23:47:12 +0100
committerDavid S. Miller <davem@davemloft.net>2008-10-28 01:06:15 +0100
commitdd45c9cf687682c9ce256ab14bd8914db77410bb (patch)
tree0769c1655b55f2528e9aaf8f96ba8d856f72f0ca /lib/vsprintf.c
parentnet: implement emergency route cache rebulds when gc_elasticity is exceeded (diff)
downloadlinux-dd45c9cf687682c9ce256ab14bd8914db77410bb.tar.xz
linux-dd45c9cf687682c9ce256ab14bd8914db77410bb.zip
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: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
-rw-r--r--lib/vsprintf.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index a013bbc23717..0deaaaf2b14e 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -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) {