batman-adv: use vlan_/eth_hdr() instead of skb->data in interface_tx path

Our .ndo_start_xmit handler (batadv_interface_tx()) can rely on having
the skb mac header pointer set correctly since the following commit
present in kernels >= 3.9:

"net: reset mac header in dev_start_xmit()" (6d1ccff627)

Therefore we can safely use eth_hdr() and vlan_eth_hdr() instead of
skb->data now, which spares us some ugly type casts.

At the same time set the mac_header in batadv_dat_snoop_incoming_arp_request()
before sending the skb along the TX path.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c
index 05f0712..73d8372 100644 (file)
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/net/batman-adv/bridge_loop_avoidance.c
@@ -882,7 +882,7 @@ static int batadv_bla_process_claim(struct batadv_priv *bat_priv,
        proto = ethhdr->h_proto;
        headlen = ETH_HLEN;
        if (vid & BATADV_VLAN_HAS_TAG) {
-               vhdr = (struct vlan_ethhdr *)ethhdr;
+               vhdr = vlan_eth_hdr(skb);
                proto = vhdr->h_vlan_encapsulated_proto;
                headlen += VLAN_HLEN;
        }

diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index edee504..5bb37a8 100644 (file)
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -1027,6 +1027,11 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
        if (!skb_new)
                goto out;
 
+       /* the rest of the TX path assumes that the mac_header offset pointing
+        * to the inner Ethernet header has been set, therefore reset it now.
+        */
+       skb_reset_mac_header(skb_new);
+
        if (vid & BATADV_VLAN_HAS_TAG)
                skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
                                          vid & VLAN_VID_MASK);

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index d7fafc1..07c7f21 100644 (file)
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -678,7 +678,7 @@ batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
        if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
                return BATADV_DHCP_NO;
 
-       ethhdr = (struct ethhdr *)skb->data;
+       ethhdr = eth_hdr(skb);
        proto = ethhdr->h_proto;
        *header_len += ETH_HLEN;
 
@@ -687,7 +687,7 @@ batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
                if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
                        return BATADV_DHCP_NO;
 
-               vhdr = (struct vlan_ethhdr *)skb->data;
+               vhdr = vlan_eth_hdr(skb);
                proto = vhdr->h_vlan_encapsulated_proto;
                *header_len += VLAN_HLEN;
        }
@@ -726,7 +726,7 @@ batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
                return BATADV_DHCP_NO;
 
        /* skb->data might have been reallocated by pskb_may_pull() */
-       ethhdr = (struct ethhdr *)skb->data;
+       ethhdr = eth_hdr(skb);
        if (ntohs(ethhdr->h_proto) == ETH_P_8021Q)
                ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
 

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index 843febd..1703a2e 100644 (file)
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -256,7 +256,7 @@ static int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
 {
        struct ethhdr *ethhdr;
        struct batadv_unicast_packet *unicast_packet;
-       int ret = NET_XMIT_DROP, hdr_size;
+       int ret = NET_XMIT_DROP;
 
        if (!orig_node)
                goto out;
@@ -265,16 +265,12 @@ static int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
        case BATADV_UNICAST:
                if (!batadv_send_skb_prepare_unicast(skb, orig_node))
                        goto out;
-
-               hdr_size = sizeof(*unicast_packet);
                break;
        case BATADV_UNICAST_4ADDR:
                if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
                                                           orig_node,
                                                           packet_subtype))
                        goto out;
-
-               hdr_size = sizeof(struct batadv_unicast_4addr_packet);
                break;
        default:
                /* this function supports UNICAST and UNICAST_4ADDR only. It
@@ -283,7 +279,10 @@ static int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
                goto out;
        }
 
-       ethhdr = (struct ethhdr *)(skb->data + hdr_size);
+       /* skb->data might have been reallocated by
+        * batadv_send_skb_prepare_unicast{,_4addr}()
+        */
+       ethhdr = eth_hdr(skb);
        unicast_packet = (struct batadv_unicast_packet *)skb->data;
 
        /* inform the destination node that we are still missing a correct route

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index f82c267..c4392fc 100644 (file)
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -176,11 +176,11 @@ static int batadv_interface_tx(struct sk_buff *skb,
 
        soft_iface->trans_start = jiffies;
        vid = batadv_get_vid(skb, 0);
-       ethhdr = (struct ethhdr *)skb->data;
+       ethhdr = eth_hdr(skb);
 
        switch (ntohs(ethhdr->h_proto)) {
        case ETH_P_8021Q:
-               vhdr = (struct vlan_ethhdr *)skb->data;
+               vhdr = vlan_eth_hdr(skb);
 
                if (vhdr->h_vlan_encapsulated_proto != ethertype)
                        break;
@@ -194,7 +194,7 @@ static int batadv_interface_tx(struct sk_buff *skb,
                goto dropped;
 
        /* skb->data might have been reallocated by batadv_bla_tx() */
-       ethhdr = (struct ethhdr *)skb->data;
+       ethhdr = eth_hdr(skb);
 
        /* Register the client MAC in the transtable */
        if (!is_multicast_ether_addr(ethhdr->h_source)) {
@@ -230,7 +230,7 @@ static int batadv_interface_tx(struct sk_buff *skb,
                /* skb->data may have been modified by
                 * batadv_gw_dhcp_recipient_get()
                 */
-               ethhdr = (struct ethhdr *)skb->data;
+               ethhdr = eth_hdr(skb);
                /* if gw_mode is on, broadcast any non-DHCP message.
                 * All the DHCP packets are going to be sent as unicast
                 */