[ARP]: Introduce the arp_hdr_len helper.
There are some place, that calculate the ARP header length. These
calculations are correct, but
a) some operate with "magic" constants,
b) enlarge the code length (sometimes at the cost of coding style),
c) are not informative from the first glance.
The proposal is to introduce a helper, that includes all the good
sides of these calculations.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 9666434..5fc9d8d58 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2646,10 +2646,7 @@
if (!slave || !slave_do_arp_validate(bond, slave))
goto out_unlock;
- /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
- if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
- (2 * dev->addr_len) +
- (2 * sizeof(u32)))))
+ if (!pskb_may_pull(skb, arp_hdr_len(dev)))
goto out_unlock;
arp = arp_hdr(skb);
diff --git a/include/linux/if_arp.h b/include/linux/if_arp.h
index 296e8e8..4d34018 100644
--- a/include/linux/if_arp.h
+++ b/include/linux/if_arp.h
@@ -156,6 +156,12 @@
{
return (struct arphdr *)skb_network_header(skb);
}
+
+static inline int arp_hdr_len(struct net_device *dev)
+{
+ /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
+ return sizeof(struct arphdr) + (dev->addr_len + sizeof(u32)) * 2;
+}
#endif
#endif /* _LINUX_IF_ARP_H */
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 6faa128..7ae9865 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -384,9 +384,7 @@
if (skb->dev->flags & IFF_NOARP)
return;
- if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
- (2 * skb->dev->addr_len) +
- (2 * sizeof(u32)))))
+ if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
return;
skb_reset_network_header(skb);
@@ -414,7 +412,7 @@
ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
return;
- size = sizeof(struct arphdr) + 2 * (skb->dev->addr_len + 4);
+ size = arp_hdr_len(skb->dev);
send_skb = find_skb(np, size + LL_RESERVED_SPACE(np->dev),
LL_RESERVED_SPACE(np->dev));
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 8e17f65..69e80bd 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -570,14 +570,13 @@
* Allocate a buffer
*/
- skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4)
- + LL_RESERVED_SPACE(dev), GFP_ATOMIC);
+ skb = alloc_skb(arp_hdr_len(dev) + LL_RESERVED_SPACE(dev), GFP_ATOMIC);
if (skb == NULL)
return NULL;
skb_reserve(skb, LL_RESERVED_SPACE(dev));
skb_reset_network_header(skb);
- arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4));
+ arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev));
skb->dev = dev;
skb->protocol = htons(ETH_P_ARP);
if (src_hw == NULL)
@@ -916,9 +915,7 @@
goto freeskb;
/* ARP header, plus 2 device addresses, plus 2 IP addresses. */
- if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
- (2 * dev->addr_len) +
- (2 * sizeof(u32)))))
+ if (!pskb_may_pull(skb, arp_hdr_len(dev)))
goto freeskb;
arp = arp_hdr(skb);
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index c90e75a..f84041d 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -459,10 +459,7 @@
if (rarp->ar_pro != htons(ETH_P_IP))
goto drop;
- if (!pskb_may_pull(skb,
- sizeof(struct arphdr) +
- (2 * dev->addr_len) +
- (2 * 4)))
+ if (!pskb_may_pull(skb, arp_hdr_len(dev)))
goto drop;
/* OK, it is all there and looks valid, process... */
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index a7591ce..9b59044 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -233,10 +233,7 @@
void *table_base;
struct xt_table_info *private;
- /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
- if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
- (2 * skb->dev->addr_len) +
- (2 * sizeof(u32)))))
+ if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
return NF_DROP;
indev = in ? in->name : nulldevname;