[ETH]: Combine format_addr() with print_mac().

print_mac() used many most net drivers and format_addr() used by
net-sysfs.c are very similar and they can be intergrated.

format_addr() is also identically redefined in the qla4xxx iscsi
driver.

Export a new function sysfs_format_mac() to be used by net-sysfs,
qla4xxx and others in the future.  Both print_mac() and
sysfs_format_mac() call _format_mac_addr() to do the formatting.

Changed print_mac() to use unsigned char * to be consistent with
net_device struct's dev_addr.  Added buffer length overrun checking
as suggested by Joe Perches.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 35 insertions, 32 deletions

diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index f55b9f7d9396..d3f86646cb08 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -173,18 +173,6 @@ static void qla4xxx_conn_stop(struct iscsi_cls_conn *conn, int flag)
                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
 }
 
-static ssize_t format_addr(char *buf, const unsigned char *addr, int len)
-{
-        int i;
-        char *cp = buf;
-
-        for (i = 0; i < len; i++)
-                cp += sprintf(cp, "%02x%c", addr[i],
-                              i == (len - 1) ? '\n' : ':');
-        return cp - buf;
-}
-
-
 static int qla4xxx_host_get_param(struct Scsi_Host *shost,
                                   enum iscsi_host_param param, char *buf)
 {
@@ -193,7 +181,7 @@ static int qla4xxx_host_get_param(struct Scsi_Host *shost,
 
         switch (param) {
         case ISCSI_HOST_PARAM_HWADDRESS:
-                len = format_addr(buf, ha->my_mac, MAC_ADDR_LEN);
+                len = sysfs_format_mac(buf, ha->my_mac, MAC_ADDR_LEN);
                 break;
         case ISCSI_HOST_PARAM_IPADDRESS:
                 len = sprintf(buf, "%d.%d.%d.%d\n", ha->ip_address[0],
diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index cc002cbbdc26..7a1e011b8a2c 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -124,12 +124,14 @@ int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
 extern struct ctl_table ether_table[];
 #endif
 
+extern ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len);
+
 /*
  *      Display a 6 byte device address (MAC) in a readable format.
  */
-#define MAC_FMT "%02x:%02x:%02x:%02x:%02x:%02x"
-extern char *print_mac(char *buf, const u8 *addr);
-#define DECLARE_MAC_BUF(var) char var[18] __maybe_unused
+extern char *print_mac(char *buf, const unsigned char *addr);
+#define MAC_BUF_SIZE    18
+#define DECLARE_MAC_BUF(var) char var[MAC_BUF_SIZE] __maybe_unused
 
 #endif
 
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index e41f4b9d2e7e..7635d3f72723 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -95,17 +95,6 @@ NETDEVICE_SHOW(type, fmt_dec);
 NETDEVICE_SHOW(link_mode, fmt_dec);
 
 /* use same locking rules as GIFHWADDR ioctl's */
-static ssize_t format_addr(char *buf, const unsigned char *addr, int len)
-{
-        int i;
-        char *cp = buf;
-
-        for (i = 0; i < len; i++)
-                cp += sprintf(cp, "%02x%c", addr[i],
-                              i == (len - 1) ? '\n' : ':');
-        return cp - buf;
-}
-
 static ssize_t show_address(struct device *dev, struct device_attribute *attr,
                             char *buf)
 {
@@ -114,7 +103,7 @@ static ssize_t show_address(struct device *dev, struct device_attribute *attr,
 
         read_lock(&dev_base_lock);
         if (dev_isalive(net))
-            ret = format_addr(buf, net->dev_addr, net->addr_len);
+                ret = sysfs_format_mac(buf, net->dev_addr, net->addr_len);
         read_unlock(&dev_base_lock);
         return ret;
 }
@@ -124,7 +113,7 @@ static ssize_t show_broadcast(struct device *dev,
 {
         struct net_device *net = to_net_dev(dev);
         if (dev_isalive(net))
-                return format_addr(buf, net->broadcast, net->addr_len);
+                return sysfs_format_mac(buf, net->broadcast, net->addr_len);
         return -EINVAL;
 }
 
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 6b2e454ae313..a7b417523e9b 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -359,10 +359,34 @@ struct net_device *alloc_etherdev_mq(int sizeof_priv, unsigned int queue_count)
 }
 EXPORT_SYMBOL(alloc_etherdev_mq);
 
-char *print_mac(char *buf, const u8 *addr)
+static size_t _format_mac_addr(char *buf, int buflen,
+                                const unsigned char *addr, int len)
 {
-        sprintf(buf, MAC_FMT,
-                addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+        int i;
+        char *cp = buf;
+
+        for (i = 0; i < len; i++) {
+                cp += scnprintf(cp, buflen - (cp - buf), "%02x", addr[i]);
+                if (i == len - 1)
+                        break;
+                cp += strlcpy(cp, ":", buflen - (cp - buf));
+        }
+        return cp - buf;
+}
+
+ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
+{
+        size_t l;
+
+        l = _format_mac_addr(buf, PAGE_SIZE, addr, len);
+        l += strlcpy(buf + l, "\n", PAGE_SIZE - l);
+        return ((ssize_t) l);
+}
+EXPORT_SYMBOL(sysfs_format_mac);
+
+char *print_mac(char *buf, const unsigned char *addr)
+{
+        _format_mac_addr(buf, MAC_BUF_SIZE, addr, ETH_ALEN);
         return buf;
 }
 EXPORT_SYMBOL(print_mac);