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| author | Antonio Quartulli <ordex@autistici.org> | 2013-05-12 21:51:15 +0200 |
|---|---|---|
| committer | Antonio Quartulli <antonio@meshcoding.com> | 2013-10-12 11:58:30 +0200 |
| commit | f7f8ed5695ef441495cfab5287951927d9d5f12e (patch) | |
| tree | bce239bcd43bdb8e61c7162d1f314adb32b1e7d2 /net/batman-adv | |
| parent | batman-adv: don't use call_rcu if not needed (diff) | |
| download | linux-f7f8ed5695ef441495cfab5287951927d9d5f12e.tar.xz linux-f7f8ed5695ef441495cfab5287951927d9d5f12e.zip | |
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.c | 19 |
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; |