From: Antonio Quartulli <antonio@meshcoding.com>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org,
Antonio Quartulli <ordex@autistici.org>,
Marek Lindner <lindner_marek@yahoo.de>
Subject: [PATCH 05/16] batman-adv: h_vlan_encapsulated_proto access refactoring
Date: Sun, 13 Oct 2013 13:22:50 +0200 [thread overview]
Message-ID: <1381663381-626-6-git-send-email-antonio@meshcoding.com> (raw)
In-Reply-To: <1381663381-626-1-git-send-email-antonio@meshcoding.com>
From: Antonio Quartulli <ordex@autistici.org>
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>
---
net/batman-adv/gateway_client.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 1bce63a..ac97ca7 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;
--
1.8.3.2
next prev parent reply other threads:[~2013-10-13 11:24 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-13 11:22 pull request: batman-adv 2013-10-13 Antonio Quartulli
[not found] ` <1381663381-626-1-git-send-email-antonio-x4xJYDvStAgysxA8WJXlww@public.gmane.org>
2013-10-13 11:22 ` [PATCH 01/16] batman-adv: only add recordroute information to icmp request/reply Antonio Quartulli
2013-10-13 11:22 ` [PATCH 02/16] batman-adv: make tt_global_add static and return bool Antonio Quartulli
2013-10-13 11:22 ` [PATCH 03/16] batman-adv: remove batadv_tt_global_add_orig declaration Antonio Quartulli
2013-10-13 11:22 ` [PATCH 04/16] batman-adv: don't use call_rcu if not needed Antonio Quartulli
2013-10-13 11:22 ` Antonio Quartulli [this message]
2013-10-13 11:22 ` [PATCH 06/16] batman-adv: use VLAN_ETH_HLEN instead of sizeof(struct vlan_eth_hdr) Antonio Quartulli
2013-10-13 11:22 ` [PATCH 07/16] batman-adv: Remove old fragmentation code Antonio Quartulli
2013-10-13 11:22 ` [PATCH 08/16] batman-adv: Receive fragmented packets and merge Antonio Quartulli
2013-10-13 11:22 ` [PATCH 09/16] batman-adv: Fragment and send skbs larger than mtu Antonio Quartulli
2013-10-13 11:22 ` [PATCH 10/16] batman-adv: use htons when possible Antonio Quartulli
2013-10-13 11:22 ` [PATCH 11/16] batman-adv: create common header for ICMP packets Antonio Quartulli
2013-10-13 11:22 ` [PATCH 12/16] batman-adv: consider network coding overhead when calculating required mtu Antonio Quartulli
2013-10-13 11:22 ` [PATCH 13/16] batman-adv: remove useless find_router look up Antonio Quartulli
2013-10-13 11:22 ` [PATCH 14/16] batman-adv: implement batadv_tt_entries Antonio Quartulli
2013-10-13 11:23 ` [PATCH 15/16] batman-adv: make batadv_tt_save_orig_buffer() generic Antonio Quartulli
2013-10-13 11:23 ` [PATCH 16/16] batman-adv: Add dummy soft-interface rx mode handler Antonio Quartulli
2013-10-17 18:27 ` pull request: batman-adv 2013-10-13 David Miller
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