aboutsummaryrefslogtreecommitdiffstats
path: root/src/include/ipxe/ip.h
diff options
context:
space:
mode:
Diffstat (limited to 'src/include/ipxe/ip.h')
-rw-r--r--src/include/ipxe/ip.h22
1 files changed, 20 insertions, 2 deletions
diff --git a/src/include/ipxe/ip.h b/src/include/ipxe/ip.h
index 285be6dcd..b1b5cb2e7 100644
--- a/src/include/ipxe/ip.h
+++ b/src/include/ipxe/ip.h
@@ -64,9 +64,27 @@ struct ipv4_miniroute {
/** IPv4 address */
struct in_addr address;
- /** Subnet mask */
+ /** Subnet mask
+ *
+ * An address with all of these bits in common with our IPv4
+ * address is in the local subnet.
+ */
struct in_addr netmask;
- /** Gateway address */
+ /** Host mask
+ *
+ * An address in the local subnet with all of these bits set
+ * to zero represents the network address, and an address in
+ * the local subnet with all of these bits set to one
+ * represents the directed broadcast address. All other
+ * addresses in the local subnet are valid host addresses.
+ *
+ * For most 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.
+ */
+ struct in_addr hostmask;
+ /** Gateway address, or zero for no gateway */
struct in_addr gateway;
};