openwrt/package/kernel/broadcom-wl/patches/120-fixup-mac-addresses.patch

--- a/driver/nvram_stub.c
+++ b/driver/nvram_stub.c
@@ -5,6 +5,7 @@
 #include <siutils.h>
 #include <bcmendian.h>
 #include <bcmnvram.h>
+#include <proto/ethernet.h>
 
 #ifdef BCMDBG_ERR
 #define NVR_MSG(x) printf x
@@ -24,6 +25,7 @@ typedef struct _vars {
 static vars_t *vars = NULL;
 static int nvram_init_done = 0;
 extern char *nvram_buf[];
+static void fixup_mac_addr(vars_t *new);
 
 int
 BCMATTACHFN(nvram_init)(void *si)
@@ -55,6 +57,7 @@ BCMATTACHFN(nvram_init)(void *si)
 	vars = new;
 
 	bcopy((char *)(&nvh[1]), new->vars, nvs);
+	fixup_mac_addr(new);
 	return 0;
 }
 
@@ -164,3 +167,65 @@ nvram_getall(char *buf, int count)
 	*buf = '\0';
 	return 0;
 }
+
+static bool nvram_is_valid_mac(struct ether_addr *mac)
+{
+	return mac && !(mac->octet[0] == 0x00 && mac->octet[1] == 0x90 && mac->octet[2] == 0x4c);
+}
+
+static int nvram_increase_mac_addr(struct ether_addr *mac, u8 num)
+{
+	u8 *oui = mac->octet + ETHER_ADDR_LEN/2 - 1;
+	u8 *p = mac->octet + ETHER_ADDR_LEN - 1;
+
+	do {
+		(*p) += num;
+		if (*p > num)
+			break;
+		p--;
+		num = 1;
+	} while (p != oui);
+
+	if (p == oui) {
+		pr_err("unable to fetch mac address\n");
+		return -ENOENT;
+	}
+	return 0;
+}
+
+static void nvram_change_mac_addr(vars_t *new, struct ether_addr *valid, const char *name)
+{
+	char *macaddr_c;
+	struct ether_addr macaddr;
+
+	macaddr_c = findvar(new->vars, new->vars + new->size, name);
+	if (!macaddr_c)
+		return;
+
+	bcm_ether_atoe(macaddr_c, &macaddr);
+	if (nvram_is_valid_mac(&macaddr))
+		return;
+	nvram_increase_mac_addr(valid, 1);
+	bcm_ether_ntoa(valid, macaddr_c);
+}
+
+static void fixup_mac_addr(vars_t *new)
+{
+	char *macaddr_base_c;
+	struct ether_addr macaddr_base;
+
+	macaddr_base_c = findvar(new->vars, new->vars + new->size, "et0macaddr");
+	if (!macaddr_base_c)
+		return;
+
+	bcm_ether_atoe(macaddr_base_c, &macaddr_base);
+	if (!nvram_is_valid_mac(&macaddr_base))
+		return;
+
+	/* jump over the first free address so it can be used for wan */
+	nvram_increase_mac_addr(&macaddr_base, 1);
+	nvram_change_mac_addr(new, &macaddr_base, "sb/1/macaddr");
+	nvram_change_mac_addr(new, &macaddr_base, "pci/1/1/macaddr");
+	nvram_change_mac_addr(new, &macaddr_base, "pci/1/2/macaddr");
+	nvram_change_mac_addr(new, &macaddr_base, "pci/2/1/macaddr");
+}