networking: Update some comments to correct the naming used for the link layer.

include/nuttx/net/net.h

@@ -112,7 +112,7 @@
  * Public Types
  ****************************************************************************/
 
-/* Data link layer type.  This type is used with netdev_register in order to
+/* Link layer type.  This type is used with netdev_register in order to
  * identify the type of the network driver.
  */
 

include/nuttx/net/netconfig.h

@@ -83,7 +83,7 @@
 
 /* Layer 2 Configuration Options ********************************************/
 
-/* The default data link laye is Ethernet.  If CONFIG_NET_SLIP is defined in
+/* The default link layer is Ethernet.  If CONFIG_NET_SLIP is defined in
  * the NuttX header file, then SLIP will be supported.  The basic
  * differences between the SLIP and Ethernet configurations is that when SLIP
  * is selected:

include/nuttx/net/netdev.h

@@ -237,7 +237,7 @@ struct net_driver_s
 
   uint8_t d_flags;
 
-  /* Multi network devices using multiple data links protocols are selected */
+  /* Multi network devices using multiple link layer protocols are supported */
 
   uint8_t d_lltype;             /* See enum net_lltype_e */
   uint8_t d_llhdrlen;           /* Link layer header size */

net/Kconfig

@@ -124,9 +124,9 @@ menuconfig NET_SLIP
 		at least one IP protocol selected.
 
 		SLIP supports point-to-point IP communications over a serial port.
-		The default data link layer for network layer is Ethernet. If
-		NET_SLIP is defined in the NuttX configuration file, then SLIP will
-		be supported.  The basic differences between the SLIP and Ethernet
+		The default link layer for network layer is Ethernet. If NET_SLIP
+		is defined in the NuttX configuration file, then SLIP will be
+		supported.  The basic differences between the SLIP and Ethernet
 		configurations is that when SLIP is selected:
 
 			* The link level header (that comes before the IP header) is omitted.
@@ -227,7 +227,7 @@ config NET_USRSOCK
 		can access standard socket API, with socket descriptors that
 		can be used with NuttX system calls.
 
-endmenu # Data link support
+endmenu # Link layer support
 
 source "net/netdev/Kconfig"
 

net/arp/arp_send.c

@@ -231,9 +231,9 @@ int arp_send(in_addr_t ipaddr)
       goto errout;
     }
 
-  /* ARP support is only built if the Ethernet data link is supported.
+  /* ARP support is only built if the Ethernet link layer is supported.
    * Continue and send the ARP request only if this device uses the
-   * Ethernet data link protocol.
+   * Ethernet link layer protocol.
    */
 
   if (dev->d_lltype != NET_LL_ETHERNET)

net/devif/devif_loopback.c

@@ -147,7 +147,7 @@ int devif_loopback(FAR struct net_driver_s *dev)
 
       NETDEV_TXDONE(dev);
 
-      /* Add the data link header length for the next loop */
+      /* Add the link layer header length for the next loop */
 
       if (dev->d_len != 0)
         {

net/icmpv6/icmpv6_autoconfig.c

@@ -320,8 +320,8 @@ static int icmpv6_wait_radvertise(FAR struct net_driver_s *dev,
  *   Stateless auto-configuration exploits several other features in IPv6,
  *   including link-local addresses, multi-casting, the Neighbor Discovery
  *   protocol, and the ability to generate the interface identifier of an
- *   address from the underlying data link layer address. The general idea
- *   is to have a device generate a temporary address until it can determine
+ *   address from the underlying link layer address. The general idea is
+ *   to have a device generate a temporary address until it can determine
  *   the characteristics of the network it is on, and then create a permanent
  *   address it can use based on that information.
  *
@@ -378,7 +378,7 @@ int icmpv6_autoconfig(FAR struct net_driver_s *dev)
    *    addresses. Link-local addresses have "1111 1110 10" for the first
    *    ten bits. The generated address uses those ten bits followed by 54
    *    zeroes and then the 64 bit interface identifier. Typically this
-   *    will be derived from the data link layer (MAC) address.
+   *    will be derived from the link layer (MAC) address.
    *
    *    IEEE 802 MAC addresses, used by Ethernet and other IEEE 802 Project
    *    networking technologies, have 48 bits.  The IEEE has also defined a

net/icmpv6/icmpv6_neighbor.c

@@ -231,7 +231,7 @@ int icmpv6_neighbor(const net_ipv6addr_t ipaddr)
     }
 
   /* Send the Neighbor Solicitation request only if this device uses the
-   * Ethernet data link protocol.
+   * Ethernet link layer protocol.
    *
    * REVISIT:  Other link layer protocols may require Neighbor Discovery
    * as well.

net/inet/inet_globals.c

@@ -88,7 +88,7 @@ const net_ipv6addr_t g_ipv6_allrouters =  /* All link local routers */
 #ifdef CONFIG_NET_ICMPv6_AUTOCONF
 /* Link-Local Address: Link-local addresses have "1111 1110 10" for the
  * first ten bits followed by 54 zeroes and then the 64 bit interface
- * identifier (typically derived from the data link layer address).
+ * identifier (typically derived from the link layer MAC address).
  */
 
 const net_ipv6addr_t g_ipv6_llnetmask =   /* Netmask for local link address */