[B.A.T.M.A.N.] [PATCHv2 1/2] batman-adv: Add wrapper for ARP reply creation

Linus Lüssing
2016-07-05T18:01:36Z

Removing duplicate code.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---

Changes in v2:
* Rebase to master
* Moved skb_reset_mac_header to earlier position (to avoid calling it on NULL)

Changes in RFC -> non-RFC:
* Added kerneldoc
* Added Signed-off-by

net/batman-adv/distributed-arp-table.c | 67 ++++++++++++++++++++--------------
1 file changed, 40 insertions(+), 27 deletions(-)

diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index b1cc8bf..081b1dc 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -948,6 +948,41 @@ static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
}

/**
+ * batadv_dat_arp_create_reply - create an ARP Reply
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ip_src: ARP sender IP
+ * @ip_dst: ARP target IP
+ * @hw_src: Ethernet source and ARP sender MAC
+ * @hw_dst: Ethernet destination and ARP target MAC
+ * @vid: VLAN identifier (optional, set to zero otherwise)
+ *
+ * Creates an ARP Reply from the given values, optionally encapsulated in a
+ * VLAN header.
+ *
+ * Return: An skb containing an ARP Reply.
+ */
+static struct sk_buff *
+batadv_dat_arp_create_reply(struct batadv_priv *bat_priv, __be32 ip_src,
+ __be32 ip_dst, u8 *hw_src, u8 *hw_dst,
+ unsigned short vid)
+{
+ struct sk_buff *skb;
+
+ skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->soft_iface,
+ ip_src, hw_dst, hw_src, hw_dst);
+ if (!skb)
+ return NULL;
+
+ skb_reset_mac_header(skb);
+
+ if (vid & BATADV_VLAN_HAS_TAG)
+ skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
+ vid & VLAN_VID_MASK);
+
+ return skb;
+}
+
+/**
* batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to
* answer using DAT
* @bat_priv: the bat priv with all the soft interface information
@@ -1005,20 +1040,12 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
goto out;
}

- skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
- bat_priv->soft_iface, ip_dst, hw_src,
- dat_entry->mac_addr, hw_src);
+ skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src,
+ dat_entry->mac_addr,
+ hw_src, vid);
if (!skb_new)
goto out;

- if (vid & BATADV_VLAN_HAS_TAG) {
- skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
- vid & VLAN_VID_MASK);
- if (!skb_new)
- goto out;
- }
-
- skb_reset_mac_header(skb_new);
skb_new->protocol = eth_type_trans(skb_new,
bat_priv->soft_iface);
bat_priv->stats.rx_packets++;
@@ -1082,25 +1109,11 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
if (!dat_entry)
goto out;

- skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src,
- bat_priv->soft_iface, ip_dst, hw_src,
- dat_entry->mac_addr, hw_src);
-
+ skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src,
+ dat_entry->mac_addr, hw_src, vid);
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);
- if (!skb_new)
- goto out;
- }
-
/* To preserve backwards compatibility, the node has choose the outgoing
* format based on the incoming request packet type. The assumption is
* that a node not using the 4addr packet format doesn't support it.
--
2.1.4