1 files changed, 71 insertions, 5 deletions

diff --git a/src/include/ipxe/ip.h b/src/include/ipxe/ip.h
index 285be6dcd..3a5c3e175 100644
--- a/src/include/ipxe/ip.h
+++ b/src/include/ipxe/ip.h
@@ -8,6 +8,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
 
 #include <stdint.h>
 #include <ipxe/in.h>
@@ -54,26 +55,91 @@ struct ipv4_pseudo_header {
 	uint16_t len;
 };
 
-/** An IPv4 address/routing table entry */
+/** An IPv4 address/routing table entry
+ *
+ * Routing table entries are maintained in order of specificity.  For
+ * a given destination address, the first matching table entry will be
+ * used as the egress route.
+ */
 struct ipv4_miniroute {
 	/** List of miniroutes */
 	struct list_head list;
 
-	/** Network device */
+	/** Network device
+	 *
+	 * When this routing table entry is matched, this is the
+	 * egress network device to be used.
+	 */
 	struct net_device *netdev;
 
-	/** IPv4 address */
+	/** IPv4 address
+	 *
+	 * When this routing table entry is matched, this is the
+	 * source address to be used.
+	 *
+	 * The presence of this routing table entry also indicates
+	 * that this address is a valid local destination address for
+	 * the matching network device.
+	 */
 	struct in_addr address;
-	/** Subnet mask */
+	/** Subnet network address
+	 *
+	 * A subnet is a range of addresses defined by a network
+	 * address and subnet mask.  A destination address with all of
+	 * the subnet mask bits in common with the network address is
+	 * within the subnet and therefore matches this routing table
+	 * entry.
+	 */
+	struct in_addr network;
+	/** Subnet mask
+	 *
+	 * An address with all of these bits in common with the
+	 * network address matches this routing table entry.
+	 */
 	struct in_addr netmask;
-	/** Gateway address */
+	/** Gateway address, or zero
+	 *
+	 * When this routing table entry is matched and this address
+	 * is non-zero, it will be used as the next-hop address.
+	 *
+	 * When this routing table entry is matched and this address
+	 * is zero, the subnet is local (on-link) and the next-hop
+	 * address will be the original destination address.
+	 */
 	struct in_addr gateway;
+	/** Host mask
+	 *
+	 * An address in a local subnet with all of these bits set to
+	 * zero represents the network address, and an address in a
+	 * local subnet with all of these bits set to one represents
+	 * the local directed broadcast address.  All other addresses
+	 * in a local subnet are valid host addresses.
+	 *
+	 * For most local subnets, this is the inverse of the subnet
+	 * mask.  In a small subnet (/31 or /32) there is no network
+	 * address or directed broadcast address, and all addresses in
+	 * the subnet are valid host addresses.
+	 *
+	 * When this routing table entry is matched and the subnet is
+	 * local, a next-hop address with all of these bits set to one
+	 * will be treated as a local broadcast address.  All other
+	 * next-hop addresses will be treated as unicast addresses.
+	 *
+	 * When this routing table entry is matched and the subnet is
+	 * non-local, the next-hop address is always a unicast
+	 * address.  The host mask for non-local subnets is therefore
+	 * set to @c INADDR_NONE to allow the same logic to be used as
+	 * for local subnets.
+	 */
+	struct in_addr hostmask;
 };
 
 extern struct list_head ipv4_miniroutes;
 
 extern struct net_protocol ipv4_protocol __net_protocol;
 
+extern struct ipv4_miniroute * ipv4_route ( unsigned int scope_id,
+					    struct in_addr *dest );
 extern int ipv4_has_any_addr ( struct net_device *netdev );
 extern int parse_ipv4_setting ( const struct setting_type *type,
 				const char *value, void *buf, size_t len );