batman-adv: Reserve extra bytes in skb for better alignment

The ethernet header is 14 bytes long. Therefore, the data after it is not 4
byte aligned and may cause problems on systems without unaligned data access.
Reserving NET_IP_ALIGN more byes can fix the misalignment of the ethernet
header.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 75403a4..9f3925a 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -411,9 +411,11 @@
 
 	if ((atomic_read(&bat_priv->aggregated_ogms)) &&
 	    (packet_len < BATADV_MAX_AGGREGATION_BYTES))
-		skb_size = BATADV_MAX_AGGREGATION_BYTES + ETH_HLEN;
+		skb_size = BATADV_MAX_AGGREGATION_BYTES;
 	else
-		skb_size = packet_len + ETH_HLEN;
+		skb_size = packet_len;
+
+	skb_size += ETH_HLEN + NET_IP_ALIGN;
 
 	forw_packet_aggr->skb = dev_alloc_skb(skb_size);
 	if (!forw_packet_aggr->skb) {
@@ -422,7 +424,7 @@
 		kfree(forw_packet_aggr);
 		goto out;
 	}
-	skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
+	skb_reserve(forw_packet_aggr->skb, ETH_HLEN + NET_IP_ALIGN);
 
 	INIT_HLIST_NODE(&forw_packet_aggr->list);
 
diff --git a/net/batman-adv/icmp_socket.c b/net/batman-adv/icmp_socket.c
index 5874c0e..87ca809 100644
--- a/net/batman-adv/icmp_socket.c
+++ b/net/batman-adv/icmp_socket.c
@@ -177,13 +177,13 @@
 	if (len >= sizeof(struct batadv_icmp_packet_rr))
 		packet_len = sizeof(struct batadv_icmp_packet_rr);
 
-	skb = dev_alloc_skb(packet_len + ETH_HLEN);
+	skb = dev_alloc_skb(packet_len + ETH_HLEN + NET_IP_ALIGN);
 	if (!skb) {
 		len = -ENOMEM;
 		goto out;
 	}
 
-	skb_reserve(skb, ETH_HLEN);
+	skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
 	icmp_packet = (struct batadv_icmp_packet_rr *)skb_put(skb, packet_len);
 
 	if (copy_from_user(icmp_packet, buff, packet_len)) {
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index a570d95..f8b9c32 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1472,11 +1472,11 @@
 	tt_tot = tt_len / sizeof(struct batadv_tt_change);
 
 	len = tt_query_size + tt_len;
-	skb = dev_alloc_skb(len + ETH_HLEN);
+	skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
 	if (!skb)
 		goto out;
 
-	skb_reserve(skb, ETH_HLEN);
+	skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
 	tt_response = (struct batadv_tt_query_packet *)skb_put(skb, len);
 	tt_response->ttvn = ttvn;
 
@@ -1538,11 +1538,11 @@
 	if (!tt_req_node)
 		goto out;
 
-	skb = dev_alloc_skb(sizeof(*tt_request) + ETH_HLEN);
+	skb = dev_alloc_skb(sizeof(*tt_request) + ETH_HLEN + NET_IP_ALIGN);
 	if (!skb)
 		goto out;
 
-	skb_reserve(skb, ETH_HLEN);
+	skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
 
 	tt_req_len = sizeof(*tt_request);
 	tt_request = (struct batadv_tt_query_packet *)skb_put(skb, tt_req_len);
@@ -1653,11 +1653,11 @@
 		tt_tot = tt_len / sizeof(struct batadv_tt_change);
 
 		len = sizeof(*tt_response) + tt_len;
-		skb = dev_alloc_skb(len + ETH_HLEN);
+		skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
 		if (!skb)
 			goto unlock;
 
-		skb_reserve(skb, ETH_HLEN);
+		skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
 		packet_pos = skb_put(skb, len);
 		tt_response = (struct batadv_tt_query_packet *)packet_pos;
 		tt_response->ttvn = req_ttvn;
@@ -1780,11 +1780,11 @@
 		tt_tot = tt_len / sizeof(struct batadv_tt_change);
 
 		len = sizeof(*tt_response) + tt_len;
-		skb = dev_alloc_skb(len + ETH_HLEN);
+		skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
 		if (!skb)
 			goto unlock;
 
-		skb_reserve(skb, ETH_HLEN);
+		skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
 		packet_pos = skb_put(skb, len);
 		tt_response = (struct batadv_tt_query_packet *)packet_pos;
 		tt_response->ttvn = req_ttvn;
@@ -2118,11 +2118,11 @@
 	if (!batadv_tt_check_roam_count(bat_priv, client))
 		goto out;
 
-	skb = dev_alloc_skb(sizeof(*roam_adv_packet) + ETH_HLEN);
+	skb = dev_alloc_skb(sizeof(*roam_adv_packet) + ETH_HLEN + NET_IP_ALIGN);
 	if (!skb)
 		goto out;
 
-	skb_reserve(skb, ETH_HLEN);
+	skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
 
 	roam_adv_packet = (struct batadv_roam_adv_packet *)skb_put(skb, len);
 
diff --git a/net/batman-adv/vis.c b/net/batman-adv/vis.c
index 5abd145..ad14a6c 100644
--- a/net/batman-adv/vis.c
+++ b/net/batman-adv/vis.c
@@ -396,12 +396,12 @@
 		return NULL;
 
 	len = sizeof(*packet) + vis_info_len;
-	info->skb_packet = dev_alloc_skb(len + ETH_HLEN);
+	info->skb_packet = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
 	if (!info->skb_packet) {
 		kfree(info);
 		return NULL;
 	}
-	skb_reserve(info->skb_packet, ETH_HLEN);
+	skb_reserve(info->skb_packet, ETH_HLEN + NET_IP_ALIGN);
 	packet = (struct batadv_vis_packet *)skb_put(info->skb_packet, len);
 
 	kref_init(&info->refcount);
@@ -873,12 +873,13 @@
 	if (!bat_priv->vis.my_info)
 		goto err;
 
-	len = sizeof(*packet) + BATADV_MAX_VIS_PACKET_SIZE + ETH_HLEN;
+	len = sizeof(*packet) + BATADV_MAX_VIS_PACKET_SIZE;
+	len += ETH_HLEN + NET_IP_ALIGN;
 	bat_priv->vis.my_info->skb_packet = dev_alloc_skb(len);
 	if (!bat_priv->vis.my_info->skb_packet)
 		goto free_info;
 
-	skb_reserve(bat_priv->vis.my_info->skb_packet, ETH_HLEN);
+	skb_reserve(bat_priv->vis.my_info->skb_packet, ETH_HLEN + NET_IP_ALIGN);
 	tmp_skb = bat_priv->vis.my_info->skb_packet;
 	packet = (struct batadv_vis_packet *)skb_put(tmp_skb, sizeof(*packet));