batman-adv: Explicitly mark the common header structure

All batman-adv packets have a common 3 byte header. It can be used to share
some code between different code paths, but it was never explicit stated that
this header has to be always the same for all packets. Therefore, new code
changes always have the problem that they may accidently introduce regressions
by moving some elements around.

A new structure is introduced that contains the common header and makes it
easier visible that these 3 bytes have to be the same for all on-wire packets.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

1 files changed, 7 insertions, 7 deletions

diff --git a/net/batman-adv/vis.c b/net/batman-adv/vis.c
index cc3b9f2..ac7e661 100644
--- a/net/batman-adv/vis.c
+++ b/net/batman-adv/vis.c
@@ -617,7 +617,7 @@ static int generate_vis_packet(struct bat_priv *bat_priv)
 	packet->vis_type = atomic_read(&bat_priv->vis_mode);
 
 	memcpy(packet->target_orig, broadcast_addr, ETH_ALEN);
-	packet->ttl = TTL;
+	packet->header.ttl = TTL;
 	packet->seqno = htonl(ntohl(packet->seqno) + 1);
 	packet->entries = 0;
 	skb_trim(info->skb_packet, sizeof(*packet));
@@ -818,19 +818,19 @@ static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 		goto out;
 
 	packet = (struct vis_packet *)info->skb_packet->data;
-	if (packet->ttl < 2) {
+	if (packet->header.ttl < 2) {
 		pr_debug("Error - can't send vis packet: ttl exceeded\n");
 		goto out;
 	}
 
 	memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
-	packet->ttl--;
+	packet->header.ttl--;
 
 	if (is_broadcast_ether_addr(packet->target_orig))
 		broadcast_vis_packet(bat_priv, info);
 	else
 		unicast_vis_packet(bat_priv, info);
-	packet->ttl++; /* restore TTL */
+	packet->header.ttl++; /* restore TTL */
 
 out:
 	if (primary_if)
@@ -910,9 +910,9 @@ int vis_init(struct bat_priv *bat_priv)
 	INIT_LIST_HEAD(&bat_priv->my_vis_info->send_list);
 	kref_init(&bat_priv->my_vis_info->refcount);
 	bat_priv->my_vis_info->bat_priv = bat_priv;
-	packet->version = COMPAT_VERSION;
-	packet->packet_type = BAT_VIS;
-	packet->ttl = TTL;
+	packet->header.version = COMPAT_VERSION;
+	packet->header.packet_type = BAT_VIS;
+	packet->header.ttl = TTL;
 	packet->seqno = 0;
 	packet->entries = 0;