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authorAntonio Quartulli <ordex@autistici.org>2013-05-12 21:51:15 +0200
committerAntonio Quartulli <antonio@meshcoding.com>2013-10-12 11:58:30 +0200
commitf7f8ed5695ef441495cfab5287951927d9d5f12e (patch)
treebce239bcd43bdb8e61c7162d1f314adb32b1e7d2 /net/batman-adv
parent210260594782ba9bc52732d84880573466c13441 (diff)
downloadlinux-next-f7f8ed5695ef441495cfab5287951927d9d5f12e.tar.gz
batman-adv: h_vlan_encapsulated_proto access refactoring
In case of a VLAN tagged frame the ethhdr pointer is moved forward by 4 bytes so that the offset of h_proto in struct ethhdr matches the real h_vlan_encapsulated_proto address in the skb. While this trickery is correct it makes the code harder to understand and may lead to bugs in case of re-use of ethhdr for other purposes. This patch introduces a proto variable to make things cleaner and easier to understand. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Diffstat (limited to 'net/batman-adv')
-rw-r--r--net/batman-adv/gateway_client.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 1bce63aa5f5f..ac97ca7f4ad0 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -655,24 +655,29 @@ bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
struct iphdr *iphdr;
struct ipv6hdr *ipv6hdr;
struct udphdr *udphdr;
+ struct vlan_ethhdr *vhdr;
+ __be16 proto;
/* check for ethernet header */
if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
return false;
ethhdr = (struct ethhdr *)skb->data;
+ proto = ethhdr->h_proto;
*header_len += ETH_HLEN;
/* check for initial vlan header */
- if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
+ if (proto == htons(ETH_P_8021Q)) {
if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
return false;
- ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
+
+ vhdr = (struct vlan_ethhdr *)skb->data;
+ proto = vhdr->h_vlan_encapsulated_proto;
*header_len += VLAN_HLEN;
}
/* check for ip header */
- switch (ntohs(ethhdr->h_proto)) {
- case ETH_P_IP:
+ switch (proto) {
+ case htons(ETH_P_IP):
if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
return false;
iphdr = (struct iphdr *)(skb->data + *header_len);
@@ -683,7 +688,7 @@ bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
return false;
break;
- case ETH_P_IPV6:
+ case htons(ETH_P_IPV6):
if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
return false;
ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
@@ -710,11 +715,11 @@ bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
*header_len += sizeof(*udphdr);
/* check for bootp port */
- if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
+ if ((proto == htons(ETH_P_IP)) &&
(ntohs(udphdr->dest) != 67))
return false;
- if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
+ if ((proto == htons(ETH_P_IPV6)) &&
(ntohs(udphdr->dest) != 547))
return false;