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>

4 files changed, 22 insertions, 19 deletions

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 75403a491892..9f3925a85aab 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -411,9 +411,11 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
 
         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 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
                 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 5874c0e84846..87ca8095b011 100644
--- a/net/batman-adv/icmp_socket.c
+++ b/net/batman-adv/icmp_socket.c
@@ -177,13 +177,13 @@ static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
         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 a570d957a5a0..f8b9c32c29a5 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1472,11 +1472,11 @@ batadv_tt_response_fill_table(uint16_t tt_len, uint8_t ttvn,
         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 @@ static int batadv_send_tt_request(struct batadv_priv *bat_priv,
         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 @@ batadv_send_other_tt_response(struct batadv_priv *bat_priv,
                 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 @@ batadv_send_my_tt_response(struct batadv_priv *bat_priv,
                 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 @@ static void batadv_send_roam_adv(struct batadv_priv *bat_priv, uint8_t *client,
         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 5abd1454fb07..ad14a6c91d6a 100644
--- a/net/batman-adv/vis.c
+++ b/net/batman-adv/vis.c
@@ -396,12 +396,12 @@ batadv_add_packet(struct batadv_priv *bat_priv,
                 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 @@ int batadv_vis_init(struct batadv_priv *bat_priv)
         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));