From 524b7bc36bf43cac89f27beb009a0bfce8c60a97 Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon>
Date: Sun, 14 Feb 2010 16:00:46 +0000
Subject: [PATCH] Documented the use of netif flags

---
 src/include/lwip/netif.h | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/src/include/lwip/netif.h b/src/include/lwip/netif.h
index 65c1dfc6..d0313715 100644
--- a/src/include/lwip/netif.h
+++ b/src/include/lwip/netif.h
@@ -60,25 +60,35 @@ extern "C" {
     across all types of interfaces in use */
 #define NETIF_MAX_HWADDR_LEN 6U
 
-/** TODO: define the use (where, when, whom) of netif flags */
-
-/** whether the network interface is 'up'. this is
+/** Whether the network interface is 'up'. This is
  * a software flag used to control whether this network
  * interface is enabled and processes traffic.
+ * It is set by the startup code (for static IP configuration) or
+ * by dhcp/autoip when an address has been assigned.
  */
 #define NETIF_FLAG_UP           0x01U
-/** if set, the netif has broadcast capability */
+/** If set, the netif has broadcast capability.
+ * Set by the netif driver in its init function. */
 #define NETIF_FLAG_BROADCAST    0x02U
-/** if set, the netif is one end of a point-to-point connection */
+/** If set, the netif is one end of a point-to-point connection.
+ * Set by the netif driver in its init function. */
 #define NETIF_FLAG_POINTTOPOINT 0x04U
-/** if set, the interface is configured using DHCP */
+/** If set, the interface is configured using DHCP.
+ * Set by the DHCP code when starting or stopping DHCP. */
 #define NETIF_FLAG_DHCP         0x08U
-/** if set, the interface has an active link
- *  (set by the network interface driver) */
+/** If set, the interface has an active link
+ *  (set by the network interface driver).
+ * Either set by the netif driver in its init function (if the link
+ * is up at that time) or at a later point once the link comes up
+ * (if link detection is supported by the hardware).
+ * Only really used with LWIP_NETIF_LINK_CALLBACK. */
 #define NETIF_FLAG_LINK_UP      0x10U
-/** if set, the netif is an device using ARP */
+/** If set, the netif is an ethernet device using ARP.
+ * Set by the netif driver in its init function.
+ * Used to check input packet types and use of DHCP. */
 #define NETIF_FLAG_ETHARP       0x20U
-/** if set, the netif has IGMP capability */
+/** If set, the netif has IGMP capability.
+ * Set by the netif driver in its init function. */
 #define NETIF_FLAG_IGMP         0x40U
 
 /** Function prototype for netif init functions. Set up flags and output/linkoutput