[PATCH 01/12] ethernet: Add generic ether__addr addresses

[Joe Perches]

Treewide there are ~60 declarations of Ethernet broadcast or zero address
use as a 6 byte array that are later used as either an output for vsprintf
extension %pM or as a source array to copy or compare.

Create const globals for these uses with EXPORT_SYMBOL for modules.

Miscellanea:

o Rename and move static const eth_reservd_addr_base from etherdevice.h
  to this new ether_addrs.c file so it is no longer oddly declared
  as static const in a .h file

Signed-off-by: Joe Perches <j...@perches.com>
---
 include/linux/etherdevice.h | 12 ++++++++----
 net/ethernet/Makefile       |  2 +-
 net/ethernet/ether_addrs.c  | 19 +++++++++++++++++++
 3 files changed, 28 insertions(+), 5 deletions(-)
 create mode 100644 net/ethernet/ether_addrs.c

diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index 79563840c295..85d2486b2959 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -63,10 +63,14 @@ struct sk_buff **eth_gro_receive(struct sk_buff **head,
                                 struct sk_buff *skb);
 int eth_gro_complete(struct sk_buff *skb, int nhoff);
 
+/* Generic Ethernet addresses */
+extern const u8 ether_broadcast_addr[ETH_ALEN];        /* all 0xff */
+extern const u8 ether_zero_addr[ETH_ALEN];     /* all zeros */
+
 /* Reserved Ethernet Addresses per IEEE 802.1Q */
-static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
-{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
-#define eth_stp_addr eth_reserved_addr_base
+extern const u8 ether_reserved_addr_base[ETH_ALEN];
+
+#define eth_stp_addr ether_reserved_addr_base
 
 /**
  * is_link_local_ether_addr - Determine if given Ethernet address is link-local
@@ -80,7 +84,7 @@ static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) 
=
 static inline bool is_link_local_ether_addr(const u8 *addr)
 {
        __be16 *a = (__be16 *)addr;
-       static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
+       static const __be16 *b = (const __be16 *)ether_reserved_addr_base;
        static const __be16 m = cpu_to_be16(0xfff0);
 
 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
diff --git a/net/ethernet/Makefile b/net/ethernet/Makefile
index 323177505404..fbbcfec2ba10 100644
--- a/net/ethernet/Makefile
+++ b/net/ethernet/Makefile
@@ -2,4 +2,4 @@
 # Makefile for the Linux Ethernet layer.
 #
 
-obj-y                                  += eth.o
+obj-y                                  += eth.o ether_addrs.o
diff --git a/net/ethernet/ether_addrs.c b/net/ethernet/ether_addrs.c
new file mode 100644
index 000000000000..e0b7a57628e8
--- /dev/null
+++ b/net/ethernet/ether_addrs.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Various const global Ethernet addresses */
+
+#include <linux/etherdevice.h>
+
+const u8 ether_broadcast_addr[ETH_ALEN] __aligned(2) = {
+       0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+};
+EXPORT_SYMBOL(ether_broadcast_addr);
+
+const u8 ether_zero_addr[ETH_ALEN] __aligned(2) = {
+       0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+EXPORT_SYMBOL(ether_zero_addr);
+
+const u8 ether_reserved_addr_base[ETH_ALEN] __aligned(2) = {
+       0x01, 0x80, 0xc2, 0x00, 0x00, 0x00
+};
+EXPORT_SYMBOL(ether_reserved_addr_base);
-- 
2.15.0