batman-adv: create common header for ICMP packets

the icmp and the icmp_rr packets share the same initial
fields since they use the same code to be processed and
forwarded.

Extract the common fields and put them into a separate
struct so that future ICMP packets can be easily added
without bloating the packet definition.

However, keep the seqno field outside of the newly created
common header because future ICMP types may require a
bigger sequence number space.

This change breaks compatibility due to fields reordering
in the ICMP headers.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

1 files changed, 21 insertions, 19 deletions

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index a080f63..3281a50 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -258,7 +258,7 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 	icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 
 	/* add data to device queue */
-	if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
+	if (icmp_packet->icmph.msg_type != BATADV_ECHO_REQUEST) {
 		batadv_socket_receive_packet(icmp_packet, icmp_len);
 		goto out;
 	}
@@ -269,7 +269,7 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 
 	/* answer echo request (ping) */
 	/* get routing information */
-	orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
+	orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->icmph.orig);
 	if (!orig_node)
 		goto out;
 
@@ -279,10 +279,11 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
 
 	icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 
-	memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
-	memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
-	icmp_packet->msg_type = BATADV_ECHO_REPLY;
-	icmp_packet->header.ttl = BATADV_TTL;
+	memcpy(icmp_packet->icmph.dst, icmp_packet->icmph.orig, ETH_ALEN);
+	memcpy(icmp_packet->icmph.orig, primary_if->net_dev->dev_addr,
+	       ETH_ALEN);
+	icmp_packet->icmph.msg_type = BATADV_ECHO_REPLY;
+	icmp_packet->icmph.header.ttl = BATADV_TTL;
 
 	if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
 		ret = NET_RX_SUCCESS;
@@ -306,9 +307,9 @@ static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 	icmp_packet = (struct batadv_icmp_packet *)skb->data;
 
 	/* send TTL exceeded if packet is an echo request (traceroute) */
-	if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
+	if (icmp_packet->icmph.msg_type != BATADV_ECHO_REQUEST) {
 		pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
-			 icmp_packet->orig, icmp_packet->dst);
+			 icmp_packet->icmph.orig, icmp_packet->icmph.dst);
 		goto out;
 	}
 
@@ -317,7 +318,7 @@ static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 		goto out;
 
 	/* get routing information */
-	orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
+	orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->icmph.orig);
 	if (!orig_node)
 		goto out;
 
@@ -327,10 +328,11 @@ static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
 
 	icmp_packet = (struct batadv_icmp_packet *)skb->data;
 
-	memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
-	memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
-	icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
-	icmp_packet->header.ttl = BATADV_TTL;
+	memcpy(icmp_packet->icmph.dst, icmp_packet->icmph.orig, ETH_ALEN);
+	memcpy(icmp_packet->icmph.orig, primary_if->net_dev->dev_addr,
+	       ETH_ALEN);
+	icmp_packet->icmph.msg_type = BATADV_TTL_EXCEEDED;
+	icmp_packet->icmph.header.ttl = BATADV_TTL;
 
 	if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
 		ret = NET_RX_SUCCESS;
@@ -379,8 +381,8 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,
 	icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 
 	/* add record route information if not full */
-	if ((icmp_packet->msg_type == BATADV_ECHO_REPLY ||
-	     icmp_packet->msg_type == BATADV_ECHO_REQUEST) &&
+	if ((icmp_packet->icmph.msg_type == BATADV_ECHO_REPLY ||
+	     icmp_packet->icmph.msg_type == BATADV_ECHO_REQUEST) &&
 	    (hdr_size == sizeof(struct batadv_icmp_packet_rr)) &&
 	    (icmp_packet->rr_cur < BATADV_RR_LEN)) {
 		memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
@@ -389,15 +391,15 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,
 	}
 
 	/* packet for me */
-	if (batadv_is_my_mac(bat_priv, icmp_packet->dst))
+	if (batadv_is_my_mac(bat_priv, icmp_packet->icmph.dst))
 		return batadv_recv_my_icmp_packet(bat_priv, skb, hdr_size);
 
 	/* TTL exceeded */
-	if (icmp_packet->header.ttl < 2)
+	if (icmp_packet->icmph.header.ttl < 2)
 		return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
 
 	/* get routing information */
-	orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst);
+	orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->icmph.dst);
 	if (!orig_node)
 		goto out;
 
@@ -408,7 +410,7 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,
 	icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
 
 	/* decrement ttl */
-	icmp_packet->header.ttl--;
+	icmp_packet->icmph.header.ttl--;
 
 	/* route it */
 	if (batadv_send_skb_to_orig(skb, orig_node, recv_if) != NET_XMIT_DROP)